Cartridge having movable spacer for restricting movement of a first frame relative to a second frame

[0001] The disclosure relates to an image forming apparatus such as a copying machine or a printer which uses an electrophotographic process, and a cartridge which can be mounted to or dismounted from the image forming apparatus.

[0002] Here, the electrophotographic image forming apparatus (hereinafter, also referred to as “image forming apparatus”) is an apparatus which forms an image on a sheet-like recording material such as paper using an electrophotographic image forming process. Examples of the image forming apparatus include a copying machine, a facsimile machine, a printer (laser beam printer, LED printer, and so on, a multifunction printer thereof, and the like).

[0003] The cartridge is a unit which can be mounted to and dismounted from the image forming apparatus described above, and is a unit including a photosensitive member and/or a process means (a charging member, a developing member, a cleaning member, and so on, for example) which is actable on the photosensitive member.

[0004] An image forming apparatus which uses an electrophotographic image forming process includes an image forming apparatus which forms an image by a contact developing method which forms an image by performing a developing process in a state in which a developing member (developing roller) is in contact with a photosensitive drum. In such an image forming apparatus, the developing roller is urged toward the photosensitive drum at a predetermined pressure, and is in contact with the surface of the photosensitive drum at a predetermined pressure, during the development process.

[0005] In the case that a developing roller including an elastic layer on the surface is used, the following can be considered, for example. That is, if the period during which the image is not formed (the developing roller is not rotating) with the elastic layer kept in contact with the surface of the photosensitive drum is long, the elastic layer of the developing roller may be deformed by the contact with the surface of the photosensitive drum. By this, image defects such as unintended unevenness of the developer image may occur when the developing process is performed.

[0006] Further, as another example, when the developing roller is in contact with the photosensitive drum during the period when the developing process is not performed, the developer carried on the developing roller is unnecessarily deposited to the photosensitive drum, and such developer is deposited on the recording material with the result of contamination of the recording material. This problem may occur irrespective of the provision of an elastic layer on the surface of the developing roller.

[0007] Further, as another example, when the photosensitive drum and the developing roller are in contact with each other for a long period of time other than the period during which the developing process is performed, the photosensitive drum and the developing roller are rubbed against each other for a long period of time. Deterioration of the developing roller or the developer may be accelerated. This may occur with or without an elastic layer on the surface of the developing roller.

[0008] In order to avoid the above-mentioned problem, JP-A-2007-213024 and JP-A-2014-67005 disclose an image forming apparatus and a cartridge having a structure for spacing a developing roller from a surface of a photosensitive drum during a period in which developing process is not performed.

[0009] However, there is still room for further improvement in the conventional techniques described in Patent Documents. Therefore, it is an object of the present disclosure to further develop the conventional technique.

[0010] A representative structure of the present invention to achieve the above described object is a cartridge comprising a photosensitive member; a charging member for charging the photosensitive member; a first unit including the photosensitive member and the charging member; a developing member for depositing toner onto the photosensitive member; a second unit including the developing member and movable between a developing position in which the toner is capable of being deposited onto the photosensitive member from the developing member and a spaced position in which at least a part of the developing member is spaced from the photosensitive member; a holding portion movably supported by the first unit or the second unit and configured to restrict a relative position between the first unit and the second unit, the holding portion being movable between a first position for holding the second unit in the spaced position by the first unit and a second position for holding the second unit in the developing position by the first unit; and an urging portion including a force receiving portion capable of receiving an external force, the urging portion being capable of applying, to the second unit, an urging force for urging the second unit toward the developing position, while receiving the external force at the force receiving portion.

[0011] A representative structure of the present invention to achieve the above described object is a cartridge mountable to a main assembly of an image forming apparatus, wherein the main assembly includes an abutting force applying portion, a spacing force applying portion and a force imparting portion for an urging portion, the cartridge comprising a photosensitive member; a charging member for charging the photosensitive member; a first unit including the photosensitive member and the charging member; a developing member for depositing toner onto the photosensitive member; a second unit including the developing member and movable between a developing position in which the toner is capable of being deposited onto the photosensitive member from the developing member and a spaced position in which at least a part of the developing member is spaced from the photosensitive member; a holding portion movably supported by the first unit or the second unit and configured to restrict a relative position between the first unit and the second unit, the holding portion being movable between a first position for holding the second unit in the spaced position by the first unit and a second position for holding the second unit in the developing position by the first unit; and an abutting force receiving portion capable of receiving, from the abutting force applying portion, a force for moving the holding portion from the first position to the second position; a spacing force receiving portion capable of receiving, from the spacing force applying portion, a force for moving the holding portion from the second position to the first position; and the urging portion provided with a force receiving portion capable of receiving a force from the force imparting portion and capable of applying an urging force for urging the second unit toward the developing position while receiving the force at the force receiving portion.

[0012] A representative structure of the present invention to achieve the above described object is an image forming apparatus comprising: a main assembly including an abutting force applying portion, a spacing force applying portion and a force imparting portion for an urging portion; a cartridge capable of forming a toner image in a state in which the cartridge is mounted to a mounting position of the main assembly, the cartridge including, a photosensitive member, a charging member for charging the photosensitive member, a first unit including the photosensitive member and the charging member, a developing member for depositing toner onto the photosensitive member, a second unit including the developing member and movable between a developing position in which the toner is capable of being deposited onto the photosensitive member from the developing member and a spaced position in which at least a part of the developing member is spaced from the photosensitive member, a holding portion movably supported by the first unit or the second unit and configured to restrict a relative position between the first unit and the second unit, the holding portion being movable between a first position for holding the second unit in the spaced position by the first unit and a second position for holding the second unit in the developing position by the first unit, an abutting force receiving portion capable of receiving, from the abutting force applying portion, a force for moving the holding portion from the first position to the second position, a spacing force receiving portion capable of receiving, from the spacing force applying portion, a force for moving the holding portion from the second position to the first position, and the urging portion provided with a force receiving portion capable of receiving a force from the force imparting portion in a state in which the cartridge is mounted to the mount position, the urging portion being capable of applying, to the second unit, an urging force for urging the second unit toward the developing position while receiving the force at the force receiving portion.

[0013] According to the present disclosure, the prior art cartridge and so on can be further developed.

[0310] In the following, examples in this disclosure will be described. The structures disclosed in the following examples, namely the functions, materials, shapes of parts, and their relative arrangements are examples of the structures related to the scope of claims, and it is not intended to limit the present invention to the structure disclosed in the examples. In addition, the problem solved by the structure disclosed in the following examples or the function or effect provided by the disclosed structure is not intended to limit the scope of claims.

[0311] In the following, Embodiment 1 will be described in conjunction with the accompanying drawings. In the following embodiment, a laser beam printer which four process cartridges (cartridges) can be mounted to and dismounted from is illustrated as an image forming apparatus. The number of process cartridges mounted in the image forming apparatus is not limited to this example. The number of process cartridges may be selected as appropriate if necessary.

[Outline of Structure of Image Forming Apparatus]

[0312] FIG. 2 is a schematic sectional view of the image forming apparatus M. FIG. 3 is a sectional view of the process cartridge 100. The image forming apparatus M is a four-color full-color laser printer using an electrophotographic process, and forms a color image on a recording material S. The image forming apparatus M is a process cartridge type, in which the process cartridge is dismountably mounted to the image forming apparatus main assembly (apparatus main assembly) 170 to form a color image on the recording material S.

[0313] Here, regarding the image forming apparatus M, a side where a front door 11 is provided is a front surface (front surface), and a side opposite to the front surface is a back surface (rear side). Further, a right side of the image forming apparatus M as viewed from the front is referred to as a drive-side, and a left side is referred to as a non-drive-side. In addition, as the image forming apparatus M is viewed from the front, an upper side is an upper surface part, and a lower side is a lower surface part. FIG. 2 is a sectional view of the image forming apparatus M as viewed from the non-drive-side; the front side of the sheet of the drawing is the non-drive-side of the image forming apparatus M; the right side of the sheet of the drawing is the front side; and the rear side of the sheet of the drawing is the drive-side of the image forming apparatus.

[0314] The drive-side of the process cartridge 100 is the side on which the drum coupling member (photosensitive member coupling member), which will be described hereinafter, is provided with respect to an axial direction of the photosensitive drum (the axial direction of the rotation axis of the photosensitive drum). In addition, the drive-side of the process cartridge 100 is the side on which a development coupling portion 132a, which will be described hereinafter, is provided with respect to the axis direction of the developing roller (development member) (the axial direction of the rotation axis of the developing roller). The axial direction of the photosensitive drum and the axial direction of the developing roller are parallel to each other, and the longitudinal direction of the process cartridge 100 is also parallel to these directions.

[0315] The image forming apparatus main assembly 170 is provided with four process cartridges 100 (100Y, 100M, 100C, 100K), i.e. a first process cartridge 100Y, a second process cartridge 100M, a third process cartridge 100C, and a fourth process cartridge 100K. It is arranged substantially horizontally.

[0316] Each of the first to fourth process cartridges 100 (100Y, 100M, 100C, 100K) have the same electrophotographic process mechanisms, but the colors of the developers (hereinafter referred to as toner) are different from each other. Rotational driving forces are transmitted to the first to fourth process cartridges 100 (100Y, 100M, 100C, 100K) from the drive output portion (details will be described hereinafter) of the image forming apparatus main assembly 170. Further, bias voltages (charging bias, development bias, and so on) are supplied from the image forming apparatus main assembly 170 to the first to fourth process cartridges 100 (100Y, 100M, 100C, 100K).

[0317] As shown in FIG. 3, each of the first to fourth process cartridges 100 (100Y, 100M, 100C, 100K) of this embodiment includes a drum unit 108 having a photosensitive drum 104 and a charging means as a process means acting on the photosensitive drum 104. Here, the drum unit may have a cleaning means as well as the charging means as the process means. Further, each of the first to fourth process cartridges 100 (100Y, 100M, 100C, 100K) includes a developing unit 109 having developing means for developing an electrostatic latent image on the photosensitive drum 104. The layout of the electrophotographic image forming apparatus in which a plurality of photosensitive drums are arranged substantially in line in this manner is sometimes called an in-line layout or a tandem layout.

[0318] In each of the first to fourth process cartridges 100, the drum unit 108 and the developing unit 109 are coupled with each other. A more specific structure of the process cartridge will be described hereinafter.

[0319] The first process cartridge 100Y contains yellow (Y) toner in a developing container 125, and forms a yellow toner image on the surface of the photosensitive drum 104. The second process cartridge 100M contains magenta (M) toner in a developing container 125, and forms a magenta toner image on the surface of the photosensitive drum 104. The third process cartridge 100C contains cyan (C) toner in a developing container 125, and forms a cyan toner image on the surface of the photosensitive drum 104. The fourth process cartridge 100K contains black (K) toner in a developing container 125, and forms a black toner image on the surface of the photosensitive drum 104.

[0320] As shown in FIG. 1, a laser scanner unit 14 as an exposure means is provided above the first to fourth process cartridges 100 (100Y, 100M, 100C, 100K). The laser scanner unit 14 outputs the laser beam U in accordance with image information. Then, the laser beam U passes through an exposure window 110 of the process cartridge 100 to scan and expose the surface of the photosensitive drum 104.

[0321] An intermediary transfer unit 12 as a transfer member is provided below the first to fourth process cartridges 100 (100Y, 100M, 100C, 100K). The intermediary transfer unit 12 includes a drive roller 12e, a turn roller 12c, a tension roller 12b, and a flexible transfer belt 12a extended around them. The lower surface of the photosensitive drum of each of the first to fourth process cartridges 100 (100Y, 100M, 100C, 100K) is in contact with the upper surface of the transfer belt 12a. The contact portion between them is a primary transfer portion. Inside the transfer belt 12a, a primary transfer roller 12d is provided so as to oppose the photosensitive drum 104. A secondary transfer roller 6 is contacted with the turn roller 12c by way of the transfer belt 12a. The contact portion between the transfer belt 12a and the secondary transfer roller 6 is a secondary transfer portion.

[0322] A feeding unit 4 is provided below the intermediary transfer unit 12. The feeding unit 4 includes a sheet feed tray 4a on which the recording material S is loaded and accommodated, and a sheet feed roller 4b.

[0323] A fixing device 7 and a sheet discharging device 8 are provided on the upper left side of the image forming apparatus main assembly 170 in FIG. 2. The upper surface of the image forming apparatus main assembly 170 is a sheet discharge tray 13. The recording material S is heated and pressed by fixing means provided in the fixing device 7, so that the toner image is fixed and discharged to the sheet discharge tray 13.

[Image Forming Operation]

[0324] The operation for forming a full-color image is as follows. The photosensitive drum 104 of each of the first to fourth process cartridges 100 (100Y, 100M, 100C, 100K) is rotationally driven at a predetermined speed (in the direction of arrow A in FIG. 3). The transfer belt 12a is also rotationally driven in a forward direction (direction of an arrow C in FIG. 2) codirectionally, at the peripheries, with the rotation of the photosensitive drum at a speed corresponding to the speed of the photosensitive drum 104.

[0325] The laser scanner unit 14 is also driven. Synchronized with the drive of the laser scanner unit 14, the charging roller 105 uniformly charges the surface of the photosensitive drum 104 to a predetermined polarity and potential in each process cartridge. The laser scanner unit 14 scans and exposes the surface of each photosensitive drum 104 with laser beam U in accordance with the image signals of each color. By this, an electrostatic latent image corresponding to the image signal of the corresponding color is formed on the surface of each photosensitive drum 104. The formed electrostatic latent image is developed by a developing roller 106 that is rotationally driven at a predetermined speed. By the electrophotographic image forming process operation described above, a yellow toner image corresponding to a yellow component of the full-color image is formed on the photosensitive drum 104 of the first process cartridge 100Y. Then, the toner image is primary-transferred onto the transfer belt 12a.

[0326] Similarly, a magenta color toner image corresponding to a magenta component of the full color image is formed on the photosensitive drum 104 of the second process cartridge 100M. Then, the toner image is primary-transferred and superimposed on the yellow toner image already transferred on the transfer belt 12a. Similarly, a cyan toner image corresponding to a cyan component of the full-color image is formed on the photosensitive drum 104 of the third process cartridge 100C. Then, the toner image is primary-transferred and superimposed on the yellow-colored and magenta-colored toner images already transferred on the transfer belt 12a. Similarly, a black toner image corresponding to a black component of the full-color image is formed on the photosensitive drum 104 of the fourth process cartridge 100K. Then, the toner image is primary-transferred and superimposed on the yellow, magenta, and cyan toner images already transferred on the transfer belt 12a. In this manner, an unfixed four-color full-color toner image of yellow, magenta, cyan, and black is formed on the transfer belt 12a.

[0327] On the other hand, the recording material S is separated and fed one by one at a predetermined control timing. The recording material S is introduced into the secondary transfer portion, which is a contact portion between the secondary transfer roller 6 and the transfer belt 12a, at a predetermined control timing. By this, in the process of transporting the recording material S toward the secondary transfer unit, the four-color superimposed toner image on the transfer belt 12a is sequentially and collectively transferred onto the surface of the recording material S. Thereafter, the recording material S is fed to the fixing device 7 to fix the toner image on the recording material S, and then is discharged onto the sheet discharge tray 13.

[Outline of Process Cartridge Mounting/Dismounting Structure]

[0328] Referring to FIGS. 1 and 4 to 7, the tray (hereinafter referred to as a tray) 171 which supports the process cartridge will be described in more detail. FIG. 4 is a sectional view of the image forming apparatus M in which the tray 171 is inside the image forming apparatus main assembly 170 with the front door 11 open. FIG. 5 is a sectional view of the image forming apparatus M in a state where the tray 171 is outside the image forming apparatus main assembly 170 with the front door 11 open and the process cartridge 100 mounted on the tray. FIG. 6 is a sectional view of the image forming apparatus M in a state where the tray 171 is outside the image forming apparatus main assembly 170 with the front door 11 open and the process cartridge 100 is not mounted on the tray. Part (a) of FIG. 7 is a partial detailed view of the tray 171 as viewed from the drive-side in the state of FIG. 4. Part (b) of FIG. 7 is a partial detailed view of the tray 171 as viewed from the non-drive-side in the state of FIG. 4.

[0329] As shown in FIGS. 4 and 5, the tray 171 is movable in a direction indicated by an arrow X1 (pushing direction) and the direction indicated by an arrow X2 (pulling direction) with respect to the image forming apparatus main assembly 170. That is, the tray 171 is provided so as to be retractable and insertable relative to the image forming apparatus main assembly 170, and the tray 171 is structured to be movable in a substantially horizontal direction in a state where the image forming apparatus main assembly 170 is installed on a horizontal surface. Here, the state in which the tray 171 is outside the image forming apparatus main assembly 170 (the state shown in FIG. 5) is referred to as an outside position. Further, a state in which the tray is inside the image forming apparatus main assembly 170 with the front door 11 open and the photosensitive drum 104 and the transfer belt 12a being separated from each other (state in FIG. 4) is referred to as an inner position.

[0330] Further, the tray 171 includes a mounting portion 171a in which the process cartridge 100 can be dismountably mounted as shown in FIG. 6 in the outer position. Then, each process cartridge 100 mounted on the mounting portion 171a in the outer position of the tray 171 is supported on the tray 171 by a drive-side cartridge cover member 116 and a non-drive-side cartridge cover member 117 as shown in FIG. 7. The process cartridge moves into the image forming apparatus main assembly 170 by the movement of the tray 171 in a state of being mounted in the mounting portion 171a. At this time, during this movement, the transfer belt 12a and the photosensitive drum 104 are spaced with a gap. Therefore, the tray 171 can move the process cartridge 100 into the image forming apparatus main assembly 170 without the photosensitive drum 04 contacting the transfer belt 12a (details will be described hereinafter).

[0331] As described above, the tray 171 is capable of moving the plurality of process cartridges 100 collectively to a position where image formation is possible inside the image forming apparatus main assembly 170, and is collectively moved to the outside of the image forming apparatus main assembly 170.

[Positioning of Process Cartridge]

[0332] More specifically, referring to FIG. 7, the positioning of the process cartridge 100 with respect to the image forming apparatus main assembly 170 will be described. As shown in FIG. 7, the tray 171 is provided with positioning portions 171VR and 171VL for holding the cartridge 100. The positioning portion 171VR has straight portions 171VR1 and 171VR2. The center of the photosensitive drum is determined by arc portions 116VR1 and 116VR2 of the cartridge cover member 116 shown in FIG. 7 contacting to the straight portions 171VR1 and 171VR2. Further, the tray 171 shown in FIG. 7 is provided with a rotational direction position setting projection 171KR. The attitude of the process cartridge 100 is determined with respect to the apparatus main assembly 170 by the rotational positioning projection 171KR fitting in the rotational direction position setting recess 116KR of the cartridge cover member 116 shown in FIG. 7.

[0333] The positioning portion 171VL and the rotational direction position setting projection 171KL are arranged at positions (non-drive-side) opposing each other across the intermediary transfer belt 12a in the longitudinal direction of the process cartridge 100 from the positioning portion 171VR. That is, on the non-drive-side as well, the position of the process cartridge is determined by engaging the arc portions 117VL1 and 117VL2 of the cartridge cover member 117 with the positioning portion 171VL and the rotational direction position setting recess 117KL with the rotational direction position setting projection 171KL. By doing so, the position of the process cartridge 100 with respect to the tray 171 is correctly determined.

[0334] As shown in FIG. 5, the process cartridge 100 integral with the tray 171 is moved in the direction of the arrow X1 and inserted to the position shown in FIG. 4. Then, by closing the front door 11 in the direction of the arrow R, the process carriage 100 is pressed by a cartridge pressing mechanism (not shown) described hereinafter, and is fixed to the image forming apparatus main assembly 170 together with the tray 171. Further, the transfer belt 12a comes into contact with the photosensitive member 4 in interrelation with the operation of the cartridge pressing mechanism. In this state, an image can be formed (FIG. 2).

[0335] In this embodiment, the positioning portion 171VR and the positioning portion 171VL also function as reinforcements for maintaining stiffness in a pull-out operation of the tray 171, and for this reason, a sheet metal is used, but the present invention is not limited to this example.

[Cartridge Pressing Mechanism]

[0336] Next, the details of the cartridge pressing mechanism will be described with reference to part (a) of FIG. 8. Part (a) of FIG. 8 shows only the process cartridge 100, the tray 171 and cartridge pressing mechanisms 190 and 191 and the intermediary transfer unit 12 in the state of FIG. 4. Part (b) of FIG. 8 shows only the process cartridge 100, the tray 171 and the cartridge pressing mechanisms and 191 and the intermediary transfer unit 12 in the state of FIG. 2.

[0337] Here, the process cartridge 100 receives a driving force during image formation, and further receives a reaction force from the primary transfer roller 12d (FIG. 2) in the direction of arrow Z1. Therefore, it is necessary to press the process cartridge in the Z2 direction in order to maintain a stable attitude during the image forming operation to prevent the process cartridge from separating from the positioning portions 171VR and 171VL.

[0338] In order to achieve this, in this embodiment, the image forming apparatus main assembly 170 is provided with cartridge pressing mechanisms (190, 191). In the cartridge pressing mechanism (190, 191), a storing element pressing unit 190 works for the non-drive-side, and a cartridge pressing unit 191 works for the drive-side. This will be described in more detail below.

[0339] By closing the front door 11 shown in FIG. 4, the storing element pressing unit 190 and the cartridge pressing unit 191 shown in FIG. 8 lowers in the direction of arrow Z2. The storing element pressing unit 190 mainly comprises a main assembly side electric contact (not shown) contactable to the electric contact of the storing element (not shown) provided in the process cartridge 100. By interrelating with the front door 11 by a link mechanism (not shown), the storing element 140 and the electric contact on the main assembly side can be brought into and out of contact with each other. That is, the contacts are brought into contact with each other by closing the front door 11, and the contacts are disconnected by opening the front door 11.

[0340] By doing so, when the process cartridge 100 moves inside the image forming apparatus main assembly together with the tray 171, the electric contacts are not rubbed, and the contacts are retracted from the insertion/removal locus of the process cartridge 100, by which the tray 171 can be inserted/removed without hindering by them. The storing element pressing unit 190 also functions to press the process cartridge 100 against the positioning portion 171VR described above. Further, similar to the storing element pressing unit 190, the cartridge pressing unit 191 also lowers in the direction of arrow Z2 in interrelation with the operation of closing the front door 11 and functions to press the process cartridge 100 against the positioning portion 171VL described above. Further, although the details will be described hereinafter, the cartridge pressing mechanism (190, 191) also functions to push down movable members 152L and 152R of the process cartridge 100 which will be described hereinafter.

[Drive Transmission Mechanism]

[0341] Next, referring to FIGS. 9 and 10 (for convenience, the tray 171 is omitted), the drive transmission mechanism of the main assembly in this embodiment will be described. Part (a) of FIG. 9 is a perspective view in which the process cartridge 100 and the tray 171 are omitted in the state of FIG. 4 or FIG. 5. Part (b) of FIG. 9 is a perspective view in which the process cartridge 100, the front door 11, and the tray 171 are omitted in the state of FIG. 1. FIG. 10 is a side view of the process cartridge 100 as viewed from the drive-side.

[0342] As shown in FIG. 10, the process cartridge in this embodiment has a development coupling portion (rotational driving force receiving portion) 132a and a drum coupling member (photosensitive member coupling member) 143. By closing the front door 11 (state of part (b) of FIG. 9, the main assembly side drum drive coupling 180 and the main assembly side development drive coupling 185 for transmitting the driving forces to the process cartridge 100 project in the arrow Y1 direction by a link mechanism (not shown). Further, by opening the front door 11 (state of part (a) of FIG. 9), the drum drive coupling 180 and a development drive coupling 185 are retracted in the direction of arrow Y2. By retracting each coupling from the insertion/removal locus of the process cartridge (X1 direction, X2 direction), the insertion/removal of the tray 171 is not hindered.

[0343] By closing the front door 11 and starting to drive the image forming apparatus main assembly 170, the drum drive coupling 180 described above engages with the drum coupling member 143. Further, the development drive coupling 185 on the main assembly side engages with the development coupling portion 132a to transmit the drive to the process cartridge 100. The drive transmission to the process cartridge 100 is not limitedly effected at two places as described above, and a mechanism for inputting the drive only to the drum coupling to transmit the drive to the developing roller may be provided.

[Intermediary Transfer Unit Structure]

[0344] Next, referring to FIG. 9, the intermediary transfer unit 12 of the image forming apparatus main assembly in this embodiment will be described. In this embodiment, the intermediary transfer unit 12 is raised in the direction of arrow R2 by a link mechanism (not shown) by closing the front door 11 to the position at the time of image formation (the position where the photosensitive drum 104 and the intermediary transfer belt 12a are in contact with each other). Further, by opening the front door 11, the intermediary transfer unit 12 lowers in the direction of arrow R1, and the photosensitive drum 2 and the intermediary transfer belt 12a are spaced from each other. That is, in the state where the process cartridge 100 is set on the tray 171, the photosensitive drum 104 and the intermediary transfer belt 12a are brought into and out of contact with each other by the opening and closing operations of the front door 11.

[0345] The contact/separation operation uses rising and lowering of the intermediary transfer unit with a rotational locus around the center point PV1 shown in FIG. 4. The intermediary transfer belt 12a is driven by receiving a force from a gear (not shown) arranged coaxially with the center PV1. Therefore, by setting the above-mentioned position PV1 as the rotation center, the intermediary transfer unit 12 can be raised and lowered without moving the gear center. By doing so, it is unnecessary to move the center of the gear, and the position of the gear can be maintained with high accuracy.

[0346] With the above-described structure, when the process cartridge 100 is set in the tray 171 and the tray 11 is inserted or removed, the photosensitive drum 104 does not slide on the intermediary transfer belt 12a, and therefore, image deterioration which may otherwise be caused by the damaged photosensitive drum 104 is prevented.

[Development Separation Control Unit]

[0347] Next, referring to FIGS. 8, 11, and 12, a spacing mechanism of the image forming apparatus main assembly in this embodiment will be described. FIG. 11 is a sectional view of the image forming apparatus M taken at a drive-side end portion of the process cartridge 100. FIG. 12 is a perspective view of the development separation control unit as viewed obliquely from the top. In this embodiment, a development separation control unit 195 controls spacing and contact operations of the developing unit 109 with respect to the photosensitive drum 104 by engaging with a portion of the developing unit 109. The development separation control unit 195 is disposed below the image forming apparatus main assembly 170 as shown in FIG. 8.

[0348] Specifically, the development separation control unit 195 is arranged below the development coupling portion 132a and the drum coupling member 143 in the vertical direction (downward in the arrow Z2 direction).

[0349] Further, the development separation control unit 195 is arranged adjacent each of opposite ends, in the longitudinal direction (Y1, Y2 direction) of the photosensitive drum, of the intermediary transfer belt 12. That is, the development separation control unit 195 includes a development separation control unit 195R on the drive-side and a development separation control unit 195L on the non-drive-side. By arranging the development separation control unit 195 in dead space of the image forming apparatus main assembly as described above, the main assembly can be downsized.

[0350] The development separation control unit 195R includes four separation control members (force applying members) 196R corresponding to the process cartridge 100 (100Y, 100M, 100C, 100K). The four separation control members have substantially the same shape. The development separation control unit 195R is always fixed to the image forming apparatus main assembly. However, the separation control member 196R is structured to be movable in the W41 and W42 directions by a control mechanism (not shown). The directions W41 and W42 are substantially parallel to an arrangement direction of the process cartridges set in the image forming apparatus main assembly 170. The detailed structure will be described hereinafter.

[0351] The development separation control unit 195L has four separation control members (force applying members) 196L corresponding to the process cartridge 100 (100Y, 100M, 100C, 100K). The four separation control members have substantially the same shape. The development separation control unit 195L is always fixed to the image forming apparatus main assembly. However, the separation control member 196L is structured to be movable in the W41 and W42 directions by a control mechanism (not shown). The detailed structure will be described hereinafter.

[0352] Further, in order for the development separation control unit 195 to engage with a portion of the developing unit 109 and control the separation/contact operation of the developing unit 109, it is necessary that a portion of a development control unit 196 and a portion of the developing unit overlap in the vertical direction (Z1, Z2 direction). Therefore, after the process cartridge 100 is inserted in the X1 direction, a portion of the developing unit (movable member 152 in the case of this embodiment) is required to project in the vertical direction (Z1, Z2 direction) as described above (details will be described hereinafter). When a development separation control unit 195 itself is raised in the same manner as the above-mentioned intermediary transfer unit 12 for the purpose of such engagement, there are problems such as an increase in the operating force of the interrelated front door 11 and complication of the drive train.

[0353] In consideration of these problems, this embodiment employs a method in which the development separation control unit 195 is fixed to the image forming apparatus main assembly 170, and a portion (movable member 152) of the developing unit 109 is projected downward (Z2) in the image forming apparatus main assembly 170. Further, as for the mechanism for projecting the movable member 152, the mechanisms of the storing element pressing unit 190 and the cartridge pressing unit 191 described above are used as they are, and therefore, there is no problem as described above and no problem of increase in the cost of the apparatus main assembly.

[0354] The unit of the development separation control unit 195 as a whole is fixed to the image forming apparatus main assembly 170. However, in order to engage with the movable member 152 to operate so that the developing unit 109 is spaced (spaced position, retracted position) and contacted (contact position) relative to the photosensitive drum 104, a portion of the development separation control unit 195 has a movable structure. Details will be described hereinafter.

[Overall Structure of Process Cartridge]

[0355] Referring to FIGS. 3, 13 and 14, the structure of the process cartridge will be described. FIG. 13 is an assembly perspective view of the process cartridge 100 as viewed from the drive-side, which is one end side in the axial direction of the photosensitive drum 104. FIG. 14 is a perspective view of the process cartridge 100 as viewed from the drive-side.

[0356] In this embodiment, the first to fourth process cartridges 100 (100Y, 100M, 100C, 100K) may differ in the color of the contained toner, the toner filling amount, and the control by the image forming apparatus main assembly 170. However, although these four process cartridges may be different in dimensions and the like, they have the same basic structures and functions, and can perform the same functions. Therefore, one process cartridge 100 will be described as a representative in the following.

[0357] The process cartridge 100 includes the photosensitive drum (photosensitive member) 104 and the process means for acting on the photosensitive drum 104. Here, the process means includes the charging roller 105 as the charging means (charging member) for charging the photosensitive drum 104, and a developing means (development member) as the developing roller 106 for developing the latent image formed on the photosensitive drum 104 by depositing toner onto the photosensitive drum 104. The developing roller 106 carries the toner on the surface thereof. The process cartridge 100 may be provided further with a cleaning blade, a brush, or the like which contacts with the photosensitive drum 104, as the cleaning means (cleaning member) for removing residual toner remaining on the surface of the photosensitive drum 104. As a further process means, as the discharging means for removing electric charge from the surface of the photosensitive drum 104, the light guide member such as a light guide or a lens for irradiating the photosensitive drum 104 with light, a light source, or the like may be provided. The process cartridge 100 is divided into a drum unit (first unit) 108 (108Y, 108M, 108C, 108K) and the developing unit (second unit) 109 (109Y, 109M, 109C, 109K).

[Drum Unit Structure]

[0358] As shown in FIGS. 3 and 13, the drum unit 108 includes the photosensitive drum 104, the charging roller 105, a first drum frame portion 115, a drive-side cartridge cover member 116, and a non-drive-side cartridge cover member 117 as the second drum frame mounted to the first drum frame portion 115. The photosensitive drum 104 is rotatably supported about the rotation axis (rotation center) M1 by the drive-side cartridge cover member 116 and the non-drive-side cartridge cover member 117 provided at both ends in the longitudinal direction of the process cartridge 100. The drum frame (first frame) in which the first drum frame portion 115, the drive-side cartridge cover member 116, and the non-drive-side cartridge cover member as the second drum frame portion 117 constitutes the drum frame (first frame or second frame) rotatably supporting the photosensitive drum 104.

[0359] The drive-side cartridge cover member 116 and the non-drive-side cartridge cover member 117 will be described hereinafter. As shown in FIGS. 13 and 14, a coupling member 143 for transmitting a driving force to the photosensitive drum 104 is provided on one end side of the photosensitive drum 104 in the longitudinal direction. As described above, the coupling member 143 engages with the main assembly side drum drive coupling (see FIG. 9) as a drum drive output portion of the image forming apparatus main assembly 170. Then, the driving force of the driving motor (not shown) of the image forming apparatus main assembly 170 is transmitted to the photosensitive drum 104 to rotate it in a direction of arrow A. Further, the photosensitive drum 104 is provided with a drum flange 142 on the other end side in the longitudinal direction. The charging roller 105 is supported by the drum frame 115 in contact with the photosensitive drum 104 and is driven thereby to rotate. The rotation axis M1 is parallel to the longitudinal direction of the process cartridge 100 and the longitudinal direction of the drum unit 108.

[Structure of Developing Unit]

[0360] As shown in FIGS. 3 and 13, the developing unit 109 includes the developing roller 106, a toner feeding roller (developer agent supply member) 107, a developing blade 130, the developing container 125, and so on. The developing container 125 includes a lower frame 125a and a lid member 125b. The lower frame 125a and a lid member 125b are connected by ultrasonic welding or the like. The developing container 125, which is the second frame, has a toner accommodating portion 129 for accommodating toner to be supplied to the developing roller 106. A drive-side bearing 126 and a non-drive-side bearing are mounted and fixed to respective ends of the developing container 125 in the longitudinal direction. The developing container 125 rotatably supports the developing roller 106, a toner feeding roller 107, and a stirring member 129a by way of the drive-side bearing and the non-drive-side bearing 127, and holds the developing blade 130. In this manner, the developing container 125, the drive-side bearing 126, and the non-drive-side bearing 127 constitute the developing frame (second frame) that rotatably supports the developing roller 106 about the rotation axis (rotation center) M2.

[0361] The stirring member 129a rotates to stir the toner in the toner accommodating portion 129. The toner feeding roller (developer material supply member) 107 contacts the developing roller 106, supplies toner to the surface of the developing roller 106, and also strips the toner off the surface of the developing roller 106. The developing blade 130 is formed by mounting an elastic member 130b, which is a sheet-like metal including a thickness of about 0.1 mm, to a supporting member 130a, which is a metal material including an L-shaped cross-section, by welding or the like. The developing blade 130 regulates the toner layer thickness (thickness of the toner layer) on the peripheral surface of the developing roller 106 to form a toner layer having a predetermined thickness between the elastic member 130b and the developing roller 106. The developing blade 130 is mounted to the developing container 125 with fixing screws 130c at two positions in one end side and the other end side in the longitudinal direction. The developing roller 106 comprises a metal core metal 106c and a rubber portion 106d.

[0362] Further, as shown in FIGS. 13 and 14, the development coupling portion 132a for transmitting the driving force to the developing unit 109 is provided on one end side of the developing unit in the longitudinal direction. The development coupling portion 132a engages with the development drive coupling 185 (see FIG. 9) on the main assembly side as a development drive output portion of the image forming apparatus main assembly 170 to receive the driving force, thereby to rotate the drive motor (not shown) of the image forming apparatus main assembly 170. The driving force received by the development coupling portion 132a is transmitted by a driving train (not shown) provided in the developing unit 109, so that the developing roller 106 can be rotated in the direction of arrow D in FIG. 3. A development cover member 128 which supports and covers a development coupling portion 132a and a driving train (not shown) is provided on one end side of the developing unit 109 in the longitudinal direction. An outer diameter of the developing roller 106 is selected to be smaller than the outer diameter of the photosensitive drum 104. The outer diameter of the photosensitive drum 104 in this embodiment is in the range of Φ18 to Φ22 (mm), and the outer diameter of the developing roller 106 is in the range of Φ8 to Φ14 (mm). By selecting the outer diameters in this way, efficient arrangement is accomplished. The rotation axis M2 is parallel to the longitudinal direction of the process cartridge 100 and to the longitudinal direction of the developing unit 109.

[Assembly of Drum Unit and Developing Unit]

[0363] Referring to FIG. 13, the assembly of the drum unit 108 and the developing unit 109 will be described. The drum unit 108 and the developing unit 109 are connected by a drive-side cartridge cover member 116 and a non-drive-side cartridge cover member 117 provided at opposite ends in the longitudinal direction of the process cartridge 100. The drive-side cartridge cover member 116 provided on one end side of the process cartridge 100 in the longitudinal direction is provided with a developing unit supporting hole 116a for swinging (moving) of the developing unit 109. Similarly, the non-drive-side cartridge cover member 117 provided on the other end side of the process cartridge 100 in the longitudinal direction is provided with a developing unit supporting hole 117a for swingably supporting the developing unit 109. Further, the drive-side cartridge cover member 116 and the non-drive-side cartridge cover member 117 are provided with drum supporting holes 116b and 117b for rotatably supporting the photosensitive drum 104. Here, on one end side, the outer diameter portion of a cylindrical portion 128b of the development cover member 128 is fitted into the developing unit supporting hole 116a of the drive-side cartridge cover member 116. On the other end side, the outer diameter portion of the cylindrical portion (not shown) of the non-drive-side bearing 127 is fitted into the developing unit supporting hole 117a of the non-drive-side cartridge cover member 117. Further, the opposite ends of the photosensitive drum 104 in the longitudinal direction are fitted into the drum supporting holes 116b of the drive-side cartridge cover member 116 and drum supporting holes 117b of the non-drive-side cartridge cover member 117. The drive-side cartridge cover member 116 and the non-drive-side cartridge cover member are fixed to the drum unit 108 with screws or adhesives (not shown). By this, the developing unit 109 is rotatably supported by the drive-side cartridge cover member 116 and the non-drive-side cartridge cover member 117 with respect to the drum unit 108 (photosensitive drum 104). In such a structure, the developing roller 106 can be positioned at a place for acting on the photosensitive drum 104 during image formation.

[0364] FIG. 14 shows a state in which the drum unit 108 and the developing unit 109 are assembled by the above-described steps and integrated into the process cartridge 100.

[0365] The axis connecting the center of the developing unit supporting hole 116a of the drive-side cartridge cover member 116 and the center of the developing unit supporting hole 117a of the non-drive-side cartridge cover member 117 is called a swing axis (rotation axis, rotation center) K. Here, the cylindrical portion 128b of the development cover member on one end side is coaxial with the development coupling portion 132a. That is, the rotation axis of the development coupling portion 132a is coaxial with the swing axis K. In other words, the swing axis K is also the rotation axis K of the development coupling portion 132a. Further, the developing unit 109 is supported rotatably about the swing shaft K. In a state where the drum unit 108 and the developing unit 109 are assembled and integrated as the process cartridge 100, the rotation axis M1, the rotation axis M2, and the swing axis K are substantially parallel to each other. Further, in this state, the rotation axis M1, the rotation axis M2, and the swing axis K are substantially parallel to the longitudinal direction of the process cartridge 100.

[Structure of Separation/Contact Mechanism 150]

[0366] The structure in which the photosensitive drum 104 of the process cartridge 100 and the developing roller 106 of the developing unit 109 are spaced (separated) and contacted with each other in this embodiment will be described in detail. The process cartridge is provided with a separation/contact mechanism 150R on the drive-side and a separation/contact mechanism 150L on the non-drive-side. FIG. 15 shows an assembly perspective view of the drive-side of the developing unit 109 including the separation/contact mechanism 150R. FIG. 16 shows an assembly perspective view of the developing unit including the separation/contact mechanism 150L on the non-drive-side. Regarding the separation/contact mechanism, the details of the separation/contact mechanism 150R on the drive-side will first be described, and then the separation/contact mechanism 150L on the non-drive-side will be described. The separation/contact mechanism has almost the same functions on the drive-side and the non-drive-side, and therefore, R is added to the reference numeral of each member on the drive-side. For the non-drive-side, the reference numeral of each member is the same as that of the drive-side, and L is added.

[0367] The separation/contact mechanism 150R includes a spacer 151R which is a restriction member (holding member), a movable member 152R which is a pressing member (force applying member), and a tension spring 153. The separation/contact mechanism 150L includes a spacer 151L which is a restricting member, a movable member 152L which is a pressing member (force applying member), and a tension spring 153.

[Detailed Description of Spacer 151R]

[0368] Here, the spacer (holding member) 151R will be described in detail with reference to FIG. 17. Part (a) of FIG. 17 is a front view of the process cartridge 100 of the spacer 151R per se as viewed from the drive-side longitudinal direction. Part (b) of FIG. 17 and part (c) of FIG. 17 are perspective views of the spacer 151R, and part (d) of FIG. 17 is a view of the spacer 151R as viewed in the direction of arrow Z2 in part (a) of FIG. 17 (vertically upward in the image forming state). The spacer 151R includes an annular supported portion 151Ra, and includes a separation holding portion (holding portion) 151Rb projecting from the supported portion 151Ra in the radial direction of the supported portion 151Ra. The free end of the separation holding portion 151Rb includes a contact surface (contact portion) 151Rc having an arc shape centered on the swing axis H of the spacer 151R and having an inclination of an angle θ1 with respect to the line HA substantially parallel to the swing axis H. The angle θ1 is selected so as to satisfy the following inequality (1):
0°≤θ1≤45°  (1)

[0369] The separation holding portion (holding portion) 151Rb is a portion which connects the supported portion 151Ra and the contact surface 151Rc, is sandwiched between the drum unit 108 and the developing unit 109, and has sufficient rigidity to maintain the spaced position.

[0370] Further, the spacer 151R has a restricted surface (restricted portion) 151Rk adjacent to the contact surface 151Rc. Further, the spacer 151R has a restricted surface (restricted portion) 151Rd projecting in the Z2 direction beyond the supported portion 151Ra, and has an arc shape pressed surface (at-contact pressed portion) 151Re projecting from the restricted surface 151Rd in the swing axis H direction of the supported portion 151Ra.

[0371] Further, the spacer 151R includes a main body portion 151Rf connected to the supported portion 151Ra, and the main body portion 151Rf includes a spring-hooked portion 151Rg projecting in the swing axis H direction of the supported portion 151Ra. Further, the main body portion 151Rf has a rotation prevention portion 151Rm projecting in the Z2 direction, and the rotation prevention surface 151Rn is provided in a direction of opposing the pressed surface 151Re.

[Detailed Description of Movable Member 152R]

[0372] Here, the movable member 152R will be described in detail with reference to FIG. 18. Part (a) of FIG. 18 is a front view of the movable member 152R as viewed in the longitudinal direction of the process cartridge 100, and FIGS. 18B and 18C are perspective views of the movable member 152R per se.

[0373] The movable member 152R has an oblong-shaped oblong supported portion 152Ra. Here, the longitudinal direction of the oblong shape of the oblong supported portion 152Ra is indicated by an arrow LH, the upper portion is indicated by an arrow LH1, and the lower portion is referred to as an arrow LH2. Further, the direction in which the oblong round supported portion 152Ra is formed is indicated by HB. The movable member 152R is provided with a projecting portion including a receiving portion 152Rh formed on the downstream side in the arrow LH2 direction of the oblong supported portion 152Ra. The oblong supported portion 152Ra and the projecting portion 152Rh are connected by a main body portion 152Rb. On the other hand, the movable member 152R includes a pressed portion 152Re projecting in the direction of the arrow LH1 direction and the direction substantially perpendicular to the direction of arrow LH1, an arc-shaped pressed surface 152Rf (moving force receiving portion, operating force receiving portion) on the downstream side in the arrow LH1 direction, and a pressing-restricting surface 152Rg on the upstream side. Further, the movable member 152R has a first restricted surface (first restricted portion) 152Rv extending from the main body portion 152Rb toward the upstream side in the arrow LH2 direction with respect to the projecting portion 152Rh. Further, the movable member 152R has a second restricted surface 152Rw adjacent to the first restricted surface 152Rv and substantially parallel to the developing frame pressing surface (developing frame pressing portion, second frame pressing portion) 152Rq.

[0374] The projecting portion 152Rh includes a first force receiving portion (retracting force receiving portion, separating force receiving portion) 152Rk and a second force receiving portion (contact force receiving portion) 152Rn arranged at the end in the arrow LH2 direction and in a direction substantially perpendicular to the arrow LH2 direction. The first force receiving portion 152Rk and the second force receiving portion 152Rn include an arc shape first force receiving surface (retracting force receiving surface and the separating force receiving surface) 152Rm and a second force receiving surface (contact force receiving surface 152Rp) extending in the HB direction. Further, the projecting portion 152Rh has a spring-hooked portion 152Rs projecting in the H direction and a locking portion 152Rt, and the locking portion 152Rt has a locking surface 152Ru opposing in the same direction as the second force receiving surface 152Rp.

[0375] Further, the movable member 152R is a part of the main body portion 152Rb, is arranged on the upstream side in the arrow LH2 direction with respect to the second force receiving portion 152Rn, and has a developing frame pressing surface 152Rq facing the same direction as the second force receiving surface 152Rp. Further, the movable member 152R has a spacer pressing surface (pressing portion) 152Rr which is perpendicular to the first restricted surface 152Rv and is arranged to oppose the developing frame pressing surface 152Rq.

[0376] When the process cartridge 100 is mounted on the image forming apparatus main assembly 170, the LH1 direction is substantially the same as the Z1 direction, and the LH2 direction is substantially the same as the Z2 direction. Further, the HB direction is substantially the same as the longitudinal direction of the process cartridge 100.

[Assembly of Separation/Contact Mechanism 150R]

[0377] Referring to FIGS. 10 and 15 to 19, the assembly of the separation/contact mechanism 150R will be described. FIG. 19 is a perspective view of the process cartridge 100 after assembling the spacer 151R as viewed from the drive-side.

[0378] As described above, as shown in FIG. 15, in the developing unit 109, the outer diameter portion of the cylindrical portion 128b of the development cover member 128 is fitted into a developing unit supporting hole portion 116a of the drive-side cartridge cover member 116. By this, the developing unit 109 is supported rotatably about the swing axis K relative to the photosensitive drum 104. Further, the development cover member is provided with a cylindrical first supporting portion 128c and a second supporting portion 128k projecting in the direction of the swing axis K.

[0379] The outer diameter of the first supporting portion 128c fits with an inner diameter of the supported portion 151Ra of the spacer 151R, and rotatably supports the spacer 151R. Here, a swing center of the spacer 151R assembled to the development cover member 128 is defined as the swing axis H. The development cover member 128 is provided with a first retaining portion 128d which projects in the direction of the swing axis H. As shown in FIG. 15, the movement of the spacer 151R assembled to the development cover member 128 in the swing axis H direction is restricted by the contact of the first retaining portion 128d to the spacer 151R.

[0380] Further, the outer diameter of the second supporting portion 128k fits with an inner wall of the oblong supported portion 152Ra of the movable member 152R, and supports the movable member 152R so as to be rotatable and movable in the length direction of the oblong direction. Here, the swing center of the movable member 152R assembled to the development cover member 128 is referred to as a movable member swing axis HC. As shown in FIG. 15, the movement of the movable member 152R assembled to the development cover member 128 in the movable member swing axis HC direction is restricted by the contact of a second retaining portion 128m to the spacer 151R.

[0381] FIG. 10 is a sectional view in which a portion of the drive-side cartridge cover member 116 and a portion of the development cover member 128 are omitted in a sectional line CS so that the fitting portion between the oblong supported portion 151Ra of the movable member 152R and the cylindrical portion 128b of the development cover member 128 can be seen. The separation/contact mechanism 150R includes the tension spring 153 provided with a spacer portion urging portion (holding portion urging portion) which urges the spacer 151R to rotate in the direction of arrow B1 in the drawing about the swing shaft H, and provided with a force receiving portion urging portion (projecting portion urging portion) for urging the movable member 152R is in the B3 direction indicated by an arrow. The tension spring 153 is a coil spring, which is an elastic member. The arrow B3 direction is a direction substantially parallel to the long circle extending longitudinal direction LH2 (see FIG. 18) of the oblong round supported portion 152Ra of the movable member 152R. The tension spring 153 is engaged with and connected with the spring-hooked portion 151Rg provided on the spacer 151R and the spring-hooked portion 152Rs provided on the movable member 152R, and is assembled between them. The tension spring 153 applies a force to the spring-hooked portion 151Rg of the spacer 151R in the direction of arrow F2 in FIG. 10 to apply an urging force to rotate the spacer 151R in the direction of arrow B1. Further, the tension spring 153 applies a force to the spring-hooked portion 152Rs of the movable member 152R in the direction of the arrow F1 to move the movable member 152R in the direction of the arrow B3 (direction toward the accommodating position (reference position, stand-by position)).

[0382] The line GS is a line connecting the spring-hooked portion 151Rg of the spacer 151R and a spring-hooked portion 152Rs of the force holding member 152R, and the line HS is a line connecting the spring-hooked portion 152Rs of the movable member 152R and the movable member swinging axis HC. An angle θ2 formed by the line GS and the line HS is selected so as to satisfy the following inequality (2) with the clockwise direction centered on the spring-hooked portion 152Rs of the movable member 152R as positive. By this, the movable member 152R is urged to rotate in the direction of arrow BA with the movable member swing axis HC as the center of rotation.
0°≤θ2≤90°  (2)

[0383] As shown in FIG. 15, in the development drive input gear (development coupling member) 132 provided with the development coupling portion 132a, an inner diameter portion of the cylindrical portion 128b of the development cover member 128 and an outer circumference of a cylindrical portion 32b of the development drive input gear 132 are fitted, and in addition, a support portion 126a of the drive-side bearing 126 and the cylindrical portion (not shown) of the development drive input gear 132 are fitted. By this, the development drive input gear 132 is rotatably supported around the rotation axis K. The developing roller gear 131 is fixed to the drive-side end of the developing roller 106, and a toner feeding roller gear 133 is fixed to the drive-side end of the toner feeding roller (developer supply member) 107. The development drive input gear (development coupling member) 132 is provided with a gear portion on an outer peripheral surface of the cylinder, and this gear portion meshes with the developing roller gear 131, the toner feeding roller gear 133, and other gears to transmit the received rotational driving force to these gears.

[0384] In this embodiment, the arrangement of the spacer 151R and the movable member 152R in the direction of the swing axis K will be described. As shown in FIG. 15, in the direction of the swing axis K, the spacer 151R is provided on the side where the drive-side cartridge cover member 116 is disposed (outside in the longitudinal direction) with respect to with the development cover member 128, and the movable member 152R is provided on the side (inside in the longitudinal direction) where the development drive input gear 132 is disposed. However, the positional arrangement is not limited to this example, and the positions of the spacer 151R and the movable member 152R may be interchanged, or the spacer 151R and the movable member 152R may be arranged on one side with respect to the development cover member 128 in the swing axis K direction. Further, the arrangement order of the spacer 151R and the movable member 152R may be exchanged.

[0385] The development cover member 128 is fixed to the developing container 125 by way of the drive-side bearing 126 to form the developing unit 109. As shown in FIG. 15, the fixing method in this embodiment uses a fixing screw 145 and an adhesive (not shown), but the fixing method is not limited to this example, and welding such as welding by heating or pouring and hardening of resin may be used.

[0386] Here, FIG. 20 is a sectional view in which a periphery of the separation holding portion 151R in FIG. 10 is enlarged, and a part of the tension spring 153 and the spacer 151R is partially omitted on the partial sectional line CS4 for the sake of better illustration. In the movable member 152R, the first restricted surface 152Rv of the movable member 152R comes into contact with a first restricted surface 128h of the development cover member 128 by the urging force of the tension spring 153 in the F1 direction in the drawing. Further, the second restricted surface 152Rw of the movable member 152R comes into contact with a second restricted surface 128q of the development cover member 128 and is positioned. This position is referred to as an accommodated position for the movable member 152R and the projecting portion 152Rh. The accommodated position can also be referred to as a reference position or a stand-by position. Further, the spacer 151R is rotated in the B1 direction about the swing axis H by the urging force of the tension spring 153 in the F2 direction, and the restricted surface 151Rd of the spacer 151R is brought into contact with the spacer pressing surface 152Rr of the movable member 152R to stop the rotation. This position is referred to as a separation holding position (restriction position, first position) of the spacer 151R.

[0387] Further, FIG. 21 is an illustration in which the periphery of the separation holding portion 151R in FIG. 10 is enlarged, and the tension spring 153 is omitted for better illustration. Here, the case will be considered in which the process cartridge 100 including the separation/contact mechanism 150R of this embodiment is dropped in the JA direction in FIG. 21 when the process cartridge 100 is transported. At this time, the spacer 151R receives a force tending to rotate in the direction of arrow B2 due to its weight around the separation holding swing shaft H. When the spacer 151R starts to rotate in the B2 direction for this reason, the rotation prevention surface 151Rn of the spacer 151R comes into contact with the locking surface 152Ru of the movable member 152R, and the spacer 151R receives a force in the F3 direction in the drawing so as to suppress the rotation in the B2 direction. By this, it is possible to prevent the spacer 151R from rotating in the B2 direction during transportation, and it is possible to prevent the separation state between the photosensitive drum 104 and the developing unit 109 from being broken.

[0388] In this embodiment, the tension spring 153 is used as the urging means for urging the spacer 151R to the separation holding position and the movable member 152R to the accommodated position, but the urging means is not limited to this example. For example, a torsion coil spring, a leaf spring, or the like may be used as an urging means to urge the movable member 152R to the accommodated position and the spacer 151R to the separation holding position. Further, the material of the urging means may be metal, a mold, or the like, if it has elasticity and can urge the spacer 151R and the movable member 152R.

[0389] As described above, the developing unit 109 provided with the separation/contact mechanism 150R is integrally coupled with the drum unit 108 by the drive-side cartridge cover member 116 as described above (state in FIG. 19).

[0390] FIG. 22 is a view as seen in the direction of arrow J in FIG. 19. As shown in FIG. 15, the drive-side cartridge cover 116 of this embodiment has a contacted surface (contact portion) 116c. As shown in FIG. 22, the contacted surface 116c is formed with an inclination of an angle θ3 with respect to the swing axis K. The angle θ3 is preferably the same as the angle θ1 forming the contact surface 151Rc of the spacer 151R, but is not limited to such. Further, as shown in FIGS. 15 and 19, the contacted surface 116c is opposed to the contact surface 151Rc of the spacer 151R placed at the separation holding position when the drive-side cartridge cover member 116 is assembled to the developing unit 109 and the drum unit 108. Further, the contacted surface 116c contacts the contact surface 151Rc by the urging force of the development pressure spring 134 which will be described hereinafter. When the contacted surface 116Rc and the contact surface 151Rc are brought into contact with each other, the attitude of the developing unit 109 is determined so that the developing roller 106 of the developing unit 109 and the photosensitive drum 104 are separated by a gap P1. The state in which the developing roller 106 (developing member) is spaced from the photosensitive drum 104 by the gap P1 by the spacer 151R is referred to as a spaced position (retracted position) of the developing unit 109 (see part (a) of FIG. 1).

[Separation State and Contact State of Process Cartridge 100 (Drive-Side)]

[0391] Referring to FIG. 1, the spaced state and the contact state of the process cartridge 100 will be described in detail. FIG. 1 is a side view of the process cartridge 100 as viewed from the drive-side with the process cartridge 100 mounted inside the image forming apparatus main assembly 170. Part (a) of FIG. 1 shows a state in which the developing unit 109 is separated from the photosensitive drum 104. Part (b) of FIG. 1 shows a state in which the developing unit 109 is in contact with the photosensitive drum 104.

[0392] First, a state in which the spacer 151R is in the separation holding position (first position) and the developing unit 109 is in the separation position (retracted position) will be described. In this state, the supported portion 151Ra which is one end of the separation holding portion 151Rb contacts the first supporting portion 128c of the development cover member 128, and the contact portion 151Rc which is the other end contacts the contacted surface 116c of the drive-side cartridge cover member 116. Further, the first supporting portion 128c is pressed toward the supported portion 151Ra by the action of the development pressure spring 134, and the contact portion 151Rc is pressed toward the contacted surface 116c. Therefore, it can be said that this state is a state in which the drive-side cartridge cover member 116 positions the development cover member 128 by way of (sandwiching) the separation holding portion 151Rb of the spacer 151R and stably holds the development cover member 128. That is, it can be said that the drum unit 108 is positioned and stably hold it by the developing unit 109 by way of the spacer 151R.

[0393] From this state, the pressed portion 152Re of the movable member 152R is pushed in the ZA direction. By this, the movable member 152R and the projecting portion 152Rh move linearly from the stand-by position in the ZA direction (operating direction, predetermined direction) to reach the projecting position. The ZA direction is parallel to the rotation axis M2 of the developing roller 106 or the rotation axis M1 of the photosensitive drum 108. Therefore, the projecting portion 152Rh when in the projecting position is arranged downstream in the ZA direction from the projecting portion 152Rh when in the stand-by position. Therefore, the projecting portion 152Rh placed in the projecting position is located more remote from the swing axis K than the projecting portion 152Rh placed in the stand-by position. Further, the projecting portion 152Rh placed at the projecting position projects in the ZA direction from the drum frame and the developing frame (arranged downstream in the ZA direction). In this embodiment, as described above, the drum frame includes the first drum frame portion 115, the drive-side cartridge cover member 116, and the non-drive-side cartridge cover member 117, and the developing frame includes the developing container 125 and the drive-side bearing 126 and the non-drive-side bearing 127. The ZA direction is the direction crossing with the direction in which the four process cartridges 100 are arranged, the W41 direction, and the W42 direction.

[0394] It can be said that the attitude shown in FIG. 1 is also the attitude in which the rotation axis M1 of the photosensitive drum 104 is horizontal and the photosensitive drum 104 is arranged at the lower portion in the process cartridge 100 when the vertical direction in the Figure is the vertical direction. In this attitude, it can be said that the projecting portion 152Rh projects downward by projecting in the ZA direction.

[0395] Further, FIGS. 26 and 38 show the attitude of the process cartridge 100 in a state of being mounted in the image forming apparatus main assembly 170, and the vertical direction in the drawing is the vertical direction (Z1 direction, Z2 direction) when the image forming apparatus main assembly 170 is installed on a horizontal surface. The ZA direction vector in this attitude is a vector including at least a vertical component. Therefore, even in this attitude, it can be said that the projecting portion 152Rh projects downward by projecting in the ZA direction.

[0396] The movable member 152R can move in the ZA direction and the direction opposite thereto while maintaining the state that the spacer 151R is in the separation holding position (first position). Therefore, even when the movable member 152R and the projecting portion 152Rh are in the operating position, the spacer 151R is located in the separation holding position (first position). At this time, the pressed surface 151Re of the spacer 151R is in contact with the spacer pressing surface 152Rr of the movable member 152R by the tension spring 153 as described above. Therefore, when the second force receiving portion 152Rn is pressed in the direction of the arrow W42, the movable member 152R rotates in the direction of the arrow BB about the movable member swing axis HC, and the spacer pressing surface 152Rr presses the restricted portion 151Rd, by which the spacer 151R is rotated in the direction of arrow B2. When the spacer 151R rotates in the direction of arrow B2, the contact surface 151Rc separates from the contacted surface 116c, and the developing unit 109 can rotate in the direction of arrow V2 about the swing axis K from the separated position. That is, the developing unit 109 rotates in the V2 direction from the separated position, and the developing roller 106 of the developing unit 109 is brought into contact with the photosensitive drum 104. More specifically, the developing roller 106 includes a metal shaft (core metal), a rubber layer covering the metal shaft, and a roller mounted to the metal shaft at an axial end more than the rubber layer, and the surface of the rubber layer and the roller is contacted with the photosensitive drum 104. Since the rubber layer is deformed, the distance between the rotating axis M2 of the developing roller 106 and the rotating axis M1 of the photosensitive drum 104 can be accurately maintained by determining the distance between the rotating axis M2 of the developing roller 109 and the rotating axis M1 of the photosensitive drum 104.

[0397] Here, the position of the developing unit 109 in which the developing roller 106 and the photosensitive drum 104 are in contact with each other is referred to as a contact position (development position) (state of part (b) of FIG. 1). The contact position (development position) in which the developing roller 106 is in contact with the photosensitive drum 104 is not only the position where the surface of the developing roller 106 is in contact with the surface of the photosensitive drum 104, but the position where the toner carried on the surface of the photosensitive drum 104 can contact the surface of the photosensitive drum 104 when the developing roller 106 rotates is also included. That is, it can be said that the contact position is a developing position where the toner carried on the surface of the developing roller 106 can be transferred (deposited) to the surface of the photosensitive drum 104 when the developing roller 106 rotates. The position where the contact surface 151Rc of the spacer 151R is spaced from the contacted surface 116c is referred to as a separation release position (permitted position, second position). When the developing unit 109 is in contact position, the restriction surface 151Rk of the spacer 151R is in contact with the spacer restriction surface (spacer portion restriction portion) 116d of the drive-side cartridge cover 116. By this, the spacer 151R is constrained from moving to the separation holding position and is maintained at the separation release position.

[0398] Further, the drive-side bearing 126 has a first pressed surface (at-separation pressed portion) 126c which is a surface perpendicular to the swing axis K. The drive-side bearing 126 is fixed to the developing unit 109. Therefore, when the developing unit 109 presses the first force receiving portion 152Rk of the movable member 152R in the direction of an arrow 41 when the developing unit 109 is in the contact position, the developing frame pressing surface 152Rq comes into contact with the first pressed surface 126c. By this, the developing unit 109 rotates about the swing axis K in the direction of the arrow V1 to move to the separated position (retracted position) (state of part (a) of FIG. 1). Here, when the developing unit 109 moves from the contact position to the separated position, the direction in which the first force receiving surface 126c moves is shown by arrows W41 in part (a) of FIG. 1 and part (b) of FIG. 1. Further, the direction opposite to the arrow W41 is the arrow W42, and the arrow W41 and the arrow W42 are substantially horizontal directions (X1, X2 directions). The second force receiving surface 152Rp of the movable member 152R assembled to the developing unit 109 as described above is placed on the upstream side of the first force receiving surface 126c of the drive-side bearing 126 in the direction of the arrow W41. Further, the first force receiving surface 126c and the pressed surface 151Re of the spacer 151R are arranged at positions where at least a portion of them overlap in the W1 and W2 directions. The detailed operation of the separation/contact mechanism 150R in the image forming apparatus main assembly 170 will be described below.

[Mounting of Process Cartridge 100 to Image Forming Apparatus Main Assembly 170 (Drive-Side)]

[0399] Next, referring to FIGS. 12, 23, and 24, engaging operation of 195 will be described between the separation/contact mechanism 150R of the process cartridge 100 and the development separation control unit 195 of the image forming apparatus main assembly 170 at the time when the process cartridge 100 is mounted on the image forming apparatus main assembly 170. For better illustration, these figures are cross-sectional views in which a portion of the development cover member 128 and a portion of the drive-side cartridge cover member 116 are partially omitted along the partial cross-sectional lines CS1 and CS2, respectively.

[0400] FIG. 23 is a view as seen from the drive-side of the process cartridge 100 when the process cartridge 100 is mounted on the cartridge tray 171 (not shown) of the image forming apparatus M, and the cartridge tray 171 is inserted into the first mounting position. In this Figure, portions other than the process cartridge 100, the cartridge pressing unit 191, and the separation control member 196R are omitted.

[0401] As described above, the image forming apparatus main assembly 170 of this embodiment has separation control members 196R corresponding to respective process cartridge 100 as described above. The separation control member 196R is disposed on the lower surface side of the image forming apparatus main assembly 170 with respect to the spacer 151R when the process cartridge 100 is placed at a first inner position and a second inner position. The separation control member 196R includes a first force application surface (force applying portion, contact force applying portion) 196Ra and a second force application surface (retracting force applying portion, separating force applying portion) 196Rb which project toward the process cartridge 100 and face each other through the space 196Rd. The first force application surface 196Ra and the second force application surface 196Rb are connected with each other by a connecting portion 196Rc on the lower surface side of the image forming apparatus main assembly 170. Further, the separation control member 196R is rotatably supported by the control sheet metal 197 with the rotation center 196Re as the center of rotation. The separating member 196R is normally urged in the E1 direction by an urging member 196R. Further, by the control sheet metal 197 being structured to be movable in the W41 and W42 directions by a control mechanism (not shown), the separation control member 196R is structured to be movable in the W41 and W42 directions.

[0402] As described above, the cartridge pressing unit 191 lowers in the direction of arrow ZA in interrelation with the transition of the front door 11 of the image forming apparatus main assembly 170 from the open state to the closed state, and a first force applying portion 191a comes into contact with the pressed surface 152Rf of the movable member 152R. Thereafter, when the cartridge pressing unit 191 is lowered to a predetermined position which is the second mounting position, the projecting portion 152Rh of the movable member 152R moves in the ZA direction (operating direction, predetermined direction) and projects downward in the Z2 direction of the process cartridge 100 (state of FIG. 24). The ZA direction is a direction intersecting (orthogonally in this embodiment) the rotation axis M2 of the developing roller 106, the rotation axis M1 of the photosensitive drum 108 and the swing axis HC. This position is referred to as projecting positions of the movable member 152R and the projecting portion 152Rh. The projecting position can also be referred to as a force receiving position or an operating position. The projecting portion 152Rh projects more from the developing frame when it is in the projecting position than when it is in the stand-by position. When this operation is completed, as shown in FIG. 24, a gap T4 is formed between the first force application surface 196Ra of the separation control member 196R and the second force receiving surface 152Rp of the movable member 152R, and a gap T3 is formed between the second force application surface 196Rb and the first force receiving surface 152 Rm. Then, it is located at the second mounting position where the separation control member 196R does not act on the movable member 152R. It can be said that this position of the separation control member 196R is a home position. At this time, the second force receiving surface 152Rp of the movable member 152R and the first force application surface 196Ra of the separation control member 196R are arranged so as to partially overlap with each other in the W41 and W42 directions. Similarly, the first force receiving surface 152Rm of the movable member 152R and the second force application surface 196Rb of the separation control member 196R are arranged so as to partially overlap in the W41 and W42 directions.

[Contact Operation of Developing Unit (Drive-Side)]

[0403] Next, the contacting operation between the photosensitive drum 104 and the developing roller 106 by the separation/contact mechanism 150R will be described in detail referring to FIGS. 24 to 26. For better illustration, in these Figures, a portion of the development cover member 128, a portion of the drive-side cartridge cover member 116, and a portion of the drive-side bearing 126 are partly omitted along partial cross-sectional lines CS1, CS2, and CS3, respectively.

[0404] In the structure of this embodiment, the development coupling 32 receives a driving force from the image forming apparatus main assembly 170 in the direction of arrow V2 in FIG. 24, so that the developing roller 106 rotates. That is, the developing unit 109 including the development coupling 32 receives torque (driving torque) in the arrow V2 direction about the swing axis K from the image forming apparatus main assembly 170. The case where the developing unit 109 shown in FIG. 24 is in the separated position and the spacer 151R is in the separation holding position will be described. In such a case, even if the developing unit receives this driving torque and the urging force of the development pressure spring which will be described hereinafter, the attitude of the developing unit 109 is maintained at the separated position because the contact surface 151Rc of the spacer 151R contacts the contacted surface 116c of the drive-side cartridge cover member 116.

[0405] The separation control member 196R of this embodiment is structured to be movable in the direction of arrow W42 in FIG. 24 from the home position. When the separation control member 196R moves in the W42 direction, the second force application surface 196Ra of the separation control member 196R and the second force receiving surface 152Rp of the second force receiving portion 152Rn of the movable member 152R come into contact with each other, so that the movable member 152R rotates in the BB direction with the swing axis HC as the center of rotation. The contact between the first force application surface 196Ra and the second force receiving surface 152Rp is not necessarily surface contact, and may be line contact or point contact. In this manner, the first force application surface 196Ra applies a contact force to the second force receiving surface 152Rp. The moving direction of the projecting portion 152Rh when the movable member 152R is rotated in the BB direction is referred to as a first direction. Further, as the movable member 152R rotates in the BB direction, the spacer 151R is rotated in the B2 direction while the spacer pressing surface 152Rr of the movable member 152R is in contact with the pressed surface 151Re of the spacer 151R. The spacer 151R is rotated by the movable member 152R to the separation release position (second position) where the contact surface 151Rc and the contacted surface 116c are separated from each other. Here, the position of the separation control member 196R for moving the spacer 151R to the separation release position (second position) shown in FIG. 25 is referred to as a first position.

[0406] When the spacer 151R is moved to the separation release position (second position) by the separation control member 196R in this manner, the developing unit 109 rotates in the V2 direction by the drive torque received from the image forming apparatus main assembly 170 and the development pressure spring (biased portion) 134 which will be described hereinafter. Then, the developing unit 109 moves to the contact position where the developing roller 106 and the photosensitive drum 104 contact each other (state in FIG. 25). At this time, the spacer 151R urged in the direction of arrow B1 by the tension spring 153 is maintained at the separation release position (second position) by the restricted surface 151Rk contacting to the spacer restriction surface 116d of the drive-side cartridge cover member 116. After that, the separation control member 196R moves in the direction of W41 and returns to the home position. At this time, the movable member 152R is rotated in the BA direction by the tension spring 153, and the state is shifted such that the developing frame pressing surface 152Rq of the movable member 152R and the first pressing surface 126c of the drive-side bearing 126 are in contact with each other is reached (state shown in FIG. 26). At this time, it can be said that the movable member 152R and the projecting portion 152Rh are in the operating position.

[0407] By this, the above-mentioned gaps T3 and T4 are formed again, and are located at positions where the separation control member 196R does not act on the movable member 152R. The change from the state of FIG. 25 to the state of FIG. 26 is performed without delay.

[0408] As described above, in the structure of this embodiment, by the movement of the separation control member 196R from the home position to the first position, the force is applied to the movable member 152R, so as to rotate the movable member 152R and move the spacer 151R to the separation release position (second position) from the separation holding position (first position). This makes it possible for the developing unit to move from the separated position to the contacting position where the developing roller 9 and the photosensitive drum 104 are in contact with each other. That is, the contact force applied from the separation control member 196R is transmitted to the spacer 151R by way of the movable member 152R to move the spacer 151R from the separation holding position (first position) to the separation release position (second position), by which the developing unit 109 is moved from the spaced position (retracted position) to the contact position (developed position).

[0409] When the developing unit 109 is in the contact position (development position), it is urged in the V2 direction by the driving torque received from the image forming apparatus main assembly 170 and the development pressure spring 134, and the position of the developing unit relative to the drum unit 108 is determined by the roller 106 contacting to the photosensitive drum 104. Therefore, the photosensitive drum can be said to be a positioning portion (second positioning portion) which determines the position of the developing unit 109 at the developing position relative to the drum unit 108. Further, at this time, it can be said that the developing unit 109 is stably held by the drum unit 108. At this time, the spacer 151R in the separation release position is not directly contributable to the positioning of the developing unit 109. However, the spacer 151R does not prevent (permits) the developing roller 106 from contacting the photosensitive drum 104 and determining the position of the developing unit 109 relative to the drum unit 108 by moving from the separation holding position to the separation release position. That is, it can be said that the spacer 151R at the separation release position (second position) creates a situation in which the drum unit 108 can stably hold the developing unit 109 at the contact position (development position).

[0410] When the spacer 151R is in the separation release position (second position), the position of the developing unit 109 with respect to the drum unit 108 may be determined by way of the spacer 151R as long as the developing roller 106 is in contact with the photosensitive drum 104. In such a case, a surface different from the contact portion 151Rc of the spacer 151R may be brought into contact with the drive-side cartridge cover member 116, and the development cover member 128 may be positioned by the drive-side cartridge cover member 116 by way of the spacer 151R (sandwiched), for example.

[0411] The position of the separation control member 196R in FIG. 26 is the same as that in FIG. 24.

[0412] Further, when the front door 11 of the image forming apparatus main assembly 170 shifts from the closed state to the open state in this state, the first force applying portion 191a rises in the direction opposite to the arrow ZA direction. Along with this operation, the movable member 152R moves in the direction opposite to the arrow ZA direction by the action of the urging member 153. However, the spacer 151R still maintains the separation release position, and the developing unit 109 also maintains the developing position.

[Separation Operation of Developing Unit (Drive-Side)]

[0413] Next, referring to FIGS. 26 and 27, the description will be made as to the operation of moving the developing unit 109 from the contact position to the spaced position by the separation/contact mechanism 150R. For better illustration, these Figures are cross-sectional views in which a portion of the development cover member 128, a portion of the drive-side cartridge cover member 116, and a portion of the drive-side bearing 126 are partially omitted in the partial cross-sectional line CS.

[0414] As described above, in the state shown in FIG. 26, it can be said that the movable member 152R and the projecting portion 152Rh are in the operating position. The separation control member 196R in this embodiment is structured to be movable from the home position in the direction of arrow W41 in FIG. 26. When the separation control member 196R moves in the W41 direction, the second force application surface 196Rb and the first force receiving surface 152Rm of the first force receiving portion 152Rk of the movable member 152R come into contact with each other, and the movable member 152R rotates in the direction of arrow BA about the swing axis HC for the movable member. The contact between the second force application surface 196Rb and the first force receiving surface 152Rm is not necessarily surface contact, but may be line contact or point contact. In this manner, the second force application surface 196Rb applies a separating force (retracting force) to the first force receiving surface 152Rm. The moving direction of the projecting portion 152Rh at the time when the movable member 152R is rotated in the BA direction is referred to as a second direction. Then, by the developing frame pressing surface 152Rq of the movable member 152R being brought into contact with the first pressed surface 126c of the drive-side bearing 126, the developing unit 109 rotates from the contact position in the direction of the arrow V1 about the swing axis K (State of FIG. 27). Here, the pressed surface 152Rf of the movable member 152R forms an arc shape, and the center of the arc is disposed so as to be aligned with the swing axis K. By doing so, when the developing unit 109 moves from the contact position to the spaced position, the force received by the pressed surface 152Rf of the movable member 152R from the cartridge pressing unit 191 is directed in the direction of the swing axis K. Therefore, the rotation of the developing unit 109 in the arrow V1 direction is not hindered. In the spacer 151R, the restricted surface 151Rk of the spacer 151R and the spacer restriction surface 116d of the drive-side cartridge cover member 116 are separated, and the spacer 151R rotates in the direction of arrow B1 (direction from the separation release position to the separation holding position) by the urging force of the tension spring 153. By this, the spacer 151R rotates until the pressed surface 151Re contacts spacer pressing surface 152Rr of the movable member 152R, and by this contacting, it shifts to the separation holding position (first position). When the developing unit 109 is moved from the contact position to the separation position by the separation control member 196R and the spacer 151R is at the separation holding position (first position), a gap T5 is formed between the contact surface 151Rc and the contacted surface 116Rc as shown in FIG. 27. Here, the position shown in FIG. 27 in which the developing unit 109 is rotated from the contact position toward the separation position, and the spacer 151R can move to the separation holding position is referred to as a second position of the separation control member 196R.

[0415] Thereafter, the separation control member 196R moves in the direction of the arrow W42 and returns from the second position to the home position. Then, while the spacer 151R is maintained in the separation holding position, the developing unit 109 is rotated in the arrow V2 direction by the driving torque received from the image forming apparatus main assembly 170 and the development pressure spring 134 described hereinafter, and the contact surface 151Rc contacts the contacted surface 116c. That is, the developing unit 109 is in a state where the separated position is maintained by the spacer 151R, and the developing roller 106 and the photosensitive drum 104 are spaced by the gap P1 (states in FIG. 24 and part (a) of FIG. 1). That is, the developing unit 109 is constrained by the spacer 151R from moving to the contact position against the driving torque received from the image forming apparatus main assembly 170 and the urging force in the arrow V2 direction due to the urging of the development pressure spring 134, and the developing unit 109 is maintained in a separated position. At this time, it can be said that the developing unit 109 is stably held in a separated position (retracted position) by the drum unit 108. By this, the above-mentioned gaps T3 and T4 are formed again, and are located at positions where the separation control member 196R does not act on the movable member 152R (state shown in FIG. 24). The transition from the state of FIG. 27 to the state of FIG. 24 is executed without a delay.

[0416] As described above, in this embodiment, the spacer 151R moves from the separation release position to the separation holding position by moving the separation control member 196R from the home position to the second position. Then, by the separation control member 196R returning from the second position to the home position, the developing unit 109 becomes in a state of maintaining the separation position by the spacer 151R. In this manner, the separation force applied from the separation control member 196R is transmitted to the first pressed surface 126c of the drive-side bearing (portion of the development frame) 126 by way of the movable member 152R, so that the developing unit is moved from the contact position to the separation position (retracted position), and the spacer 151R is moved from the separation release position to the separation holding position.

[0417] In the state that the developing unit 109 is in the separated position (retracted position), the position of the developing unit 109 with respect to the drum unit 108 is determined by being urged in the V2 direction by the driving torque received from the image forming apparatus main assembly 170 and the development pressure spring 134 in the state that the supported portion 151Ra is in contact with the first supported portion 128c, and the contact portion 151Rc is in contact with the contacted surface 116c, as described above. Therefore, the contacted surface 116c can be said to be a positioning portion (first positioning portion) for positioning the developing unit 109 at the separated position (retracted position). At this time, it can be said that the developing unit 109 is stably held by the drum unit 108. Further, it can be said that the spacer 151R at the separation holding position (first position) establishes a situation in which the drum unit 108 can stably hold the developing unit at the separation position (retracted position).

[0418] Further, when the front door 11 of the image forming apparatus main assembly 170 shifts from the closed state to the open state in this state, the first force applying portion 191a rises in the direction opposite to the arrow ZA direction. Along with this, the movable member 152R moves in the direction opposite to the arrow ZA direction by the action of the urging member 153. However, the spacer 151R still maintains the separation holding position, and the developing unit 109 also maintains the separation position.

[Detailed Description of Spacer L]

[0419] Here, the spacer 151L will be described in detail referring to FIG. 28. Part (a) of FIG. 28 is a front view of the spacer 151L of as viewed in the longitudinal direction of the drive-side of the process cartridge 100, and part (b) of FIG. 28 and part (c) of FIG. 28 are perspective views of the spacer 151L per se. The spacer 151L is provided with the annular supported portion 151La, and is provided with a separation holding portion (holding portion) 151Lb projecting from the supported portion 151La in the radial direction of the supported portion 151La. The free end of the separation holding portion 151Lb has an arc-shaped contact surface (contact portion) 151Lc centered on the swing shaft H of the spacer 151L. The swing shaft H of the spacer 151L is the same as the swing shaft H of the spacer 151R.

[0420] The separation holding portion (holding portion) 151Lb is a portion which connects the supported portion 151La and the contact surface 151Lc with each other, and is sandwiched between the drum unit 108 and the developing unit 109 and has sufficient rigidity to maintain the separating position.

[0421] Further, the spacer 151L has a restricted surface (restricted portion) 151Lk adjacent to the contact surface 151Lc. Further, the spacer 151L has a restricted portion 151Ld projecting in the Z2 direction from the supported portion 151La, and has an arc-shaped pressed portion 151Le (at-contact pressed portion) projecting from the restricted portion 151Ld in the direction of the swing axis H of the supported portion 151La.

[0422] Further, the spacer 151L has a main body portion 151Lf connected to the supported portion 151La, and the main body portion 151Lf is provided with a spring-hooked portion 151Lg projecting in the swing axis H direction of the supported portion 151La. Further, the main body portion 151Lf has a rotation prevention portion 151m projecting in the Z2 direction, and a rotation prevention surface 151Ln is provided in a direction opposing the pressed portion 151Le.

[Detailed Description of Movable Member L]

[0423] Here, referring to FIG. 29, the movable member 152L will be described in detail. Part (a) of FIG. 29 is a front view of the movable member 152L per se as viewed from the longitudinal direction of the process cartridge 100, and part (b) of FIG. 29 and part (c) of FIG. 29 are perspective views of the movable member 152L.

[0424] The movable member 152L is provided with the oblong supported portion 152La. Here, the longitudinal direction of the oblong shape of the oblong supported portion 152La is referred to as an arrow LH, the upward direction is referred to as an arrow LH1, and the downward direction is referred to as an arrow LH2. Further, the direction in which the oblong supported portion 152La is formed is defined as HD. The movable member 152L is provided with the projecting portion (force receiving portion) 152Lh formed on the downstream side, in the arrow LH2 direction, of the oblong supported portion 152La. The oblong supported portion 152La and the projecting portion 152Lh are connected with each other by the main body portion 152Lb. On the other hand, the movable member 152L is provided with a pressed portion 152Le projecting in the direction substantially perpendicular to the direction of arrow LH1, and an arc-shaped pressed surface (moving force receiving portion, operating force receiving portion) 152Lf at a position downstream in the arrow LH1 direction, a push-restricting surface 152Lg on the upstream side. Further, the movable member 152L has a first restricted surface (first restricted portion) 152Lv which is a portion of the oblong supported portion 152La and which is located on the downstream side in the arrow LH2 direction.

[0425] The projecting portion 152Lh is a first force receiving portion (retracting force receiving portion, separating force receiving portion) 152Lk and a second force receiving portion (contact force receiving portion) 152Ln which are provided opposed to each other in a direction substantially perpendicular to the arrow LH2 direction, at the end in the arrow LH2 direction. The first force receiving portion 152Lk and the second force receiving portion 152Ln are provided with a first force receiving surface (retracting force receiving surface, a separating force receiving surface) 152Lm and a second force receiving surface (contact force receiving surface) 152Lp which extend in the HD direction and which have arc shapes. Further, the projecting portion 152Lh is provided with a spring-hooked portion 152Ls projecting in the HB direction and a locking portion 152Lt, and the locking portion 152Lt is provided with a locking surface 152Lu facing in the same direction as the second force receiving surface 152Lp.

[0426] Further, the movable member 152L is a part of the main body portion 152Lb, is disposed on the upstream side in the arrow LH2 direction from the second force receiving portion 152Ln, and has a developing frame pressing surface (developing frame pressing portion, at-separation pressing portion) 152Lq facing in the same direction as the second force receiving surface 152Lp. Further, the movable member 152L is a part of the main body portion 152Lb and is disposed on the upstream side in the arrow LH2 direction from the first force receiving portion 152Lk, and has a spacer pressing surface (spacer portion pressing portion, at-contact pressing portion) 152Lr facing in the same direction as the first force receiving surface 152Lm.

[0427] When the process cartridge 100 is mounted on the image forming apparatus main assembly 170, the LH1 direction is substantially the same as the Z1 direction, and the LH2 direction is substantially the same as the Z2 direction. Further, the HB direction is substantially the same as the longitudinal direction of the process cartridge 100.

[Assembly of Separation/Contact Mechanism 150L]

[0428] Next, referring to FIGS. 16 and 29 to 35 assembling of the separation mechanism will be described. FIG. 30 is a perspective view of the process cartridge 100 after the spacer 151L is assembled thereto as viewed from the drive-side. As described above, as shown in FIG. 16, the developing unit 109 is supported so as to rotatable relative to the photosensitive drum 104 about the swing axis K by fitting the outer diameter portion of the cylindrical portion 127a into the developing unit supporting hole portion 117a. Further, the non-drive-side bearing 127 is provided with a first cylindrical support portion 127b and a second cylindrical support portion 127e projecting in the direction of the swing axis K.

[0429] The outer diameter of the first supporting portion 127b fits with the inner diameter of the supported portion 151La of the spacer 151L, and the spacer 151L is rotatably supported. Here, the swing axis of the spacer 151L assembled to the non-drive-side bearing 127 is the swing axis H. The non-drive-side bearing 127 is provided with a first retaining portion 127c projecting in the direction of the swing axis H. As shown in FIG. 16, the movement of the spacer 151L assembled to the non-drive-side bearing 127 in the swing axis H direction is restricted by the contact of the first retaining portion 127c with the spacer 151L.

[0430] Further, the outer diameter of the second supporting portion 127e fits with the inner wall of the oblong supported portion 152La of the movable member 152L, and supports the movable member 152L so as to be rotatable and movable in the oblong direction. Here, the swing axis of the movable member 152L assembled to the non-drive-side bearing 127 is referred to as the movable member swing axis HC. As shown in FIG. 16, the movement of the movable member 152L assembled to the non-drive-side bearing 127 in the movable member swing axis HE direction is restricted by the contact of the second retaining portion 127f with the spacer 151L.

[0431] FIG. 31 is a view of the process cartridge 100 after assembling the spacer 151L as viewed in the developing unit swing axis H direction. It is a cross-sectional view in which a portion of the non-drive-side cartridge cover member 117 is partially omitted by the partial cross-sectional line CS so that the fitting portion between the oblong supported portion 151La of the movable member 152L and the cylindrical portion 127e of the non-drive-side bearing 127 can be seen. Here, the separation/contact mechanism 150L is provided with a tension spring 153 as an urging member (holding portion urging member) a spacer portion urging portion (holding portion urging portion) which urges the spacer 151L to rotate in the direction of the arrow B1 about the swing axis H, and provided with a force receiving portion urging portion (projecting portion urging portion) urging the movable member 152L in the B3 direction indicated by the arrow. The tension spring 153 is a coil spring and an elastic member. The arrow B3 direction is a direction substantially parallel to the longitudinal direction LH2 (FIG. 29) of the oblong supported portion 152La of the movable member 152L. The tension spring 153 is engaged and connected to the spring-hooked portion 151Lg provided on the spacer 151L and the spring-hooked portion 152Ls provided on the movable member 152 L, and is assembled between them. The tension spring 153 applies a force to the spring-hooked portion 151Lg of the spacer 151L in the direction of arrow F2 in FIG. 31 to impart an urging force to rotate the spacer 151L in the direction of arrow B1. Further, the tension spring applies a force to the spring-hooked portion 152Ls of the movable member 152L in the direction of the arrow F1 to move the movable member 152L in the direction of the arrow B3 (direction toward the accommodating position (reference position, stand-by position).

[0432] A line GS connects the spring-hooked portion 151Lg of the spacer 151L and the spring-hooked portion 152Ls of the force holding member 152L, and a line HS connects the spring-hooked portion 152Ls of the movable member 152L and the movable member swinging axis HE. Then, an angle θ3 formed by the line GS and the line HS is set so as to satisfy the following equation (3) with the counterclockwise direction being positive about the spring-hooked portion 152Ls of the movable member 152L. By this, the movable member 152L is urged to rotate in the BA direction in the drawing with the movable member swinging axis HE as the center of rotation.
0°≤θ3≤90°  (3)

[0433] As shown in FIG. 29, the spacer 151L and the movable member 152L are mounted to the spacer on the side (longitudinal outside) of the non-drive side bearing 127 on which the non-driving cartridge cover member 117 is arranged in the direction of the swing axis K. However, the positions to be arranged are not limited to this example, and they may be arranged on the developing container 125 side (inside in the longitudinal direction) of the non-drive-side bearing 127, respectively, and the spacer 151L and the movable member 152L may be arranged with the non-drive-side bearing interposed therebetween. Further, the order of the arrangement of the spacer 151L and the movable member 152L may be exchanged.

[0434] The non-drive-side bearing 127 is fixed to the developing container 125 to form the developing unit 109. As shown in FIG. 16, the fixing method in this embodiment is fixed by a fixing screw 145 and an adhesive (not shown), but the fixing method is not limited to this, and welding such as welding by heating or pouring and hardening of resin may be used.

[0435] Here, part (a) of FIG. 32 and part (b) of FIG. 32 are enlarged cross-sectional views of the movable member rocking axis HE and the distance holding portion 151L of the movable member 152L in FIG. 31 for better illustration. Further, part (a) of FIG. 32 and part (b) of FIG. 32 are cross-sectional views in which the non-drive-side cartridge cover member 117, the tension spring 153, and the spacer 151L are partially omitted by the partial cross-sectional line CS. In the movable member 152L, the first restricted surface 152Lv of the movable member 152L is brought into contact with the second supporting portion 127e of the non-drive-side bearing 127 by the urging force of the tension spring 153 in the arrow F1 direction. Further, as shown in part (b) of FIG. 32, the developing frame pressing surface 152Lq of the movable member 152L is brought into contact with the pressed surface 127h of the non-drive-side bearing 127 and is thereby positioned. This position is referred to as an accommodated position of the movable member 152L. The accommodated position can also be referred to as a reference position or a stand-by position. Further, the spacer 151L is rotated in the direction of the arrow B4 about the swing axis H by the urging force of the tension spring 153 in the arrow F2 direction, and the contact surface 151Lp of the spacer 151L is positioned by contacting to the spacer pressing surface 152Lr of the movable member 152L. This position is referred to as a separation holding position (restriction position) of the spacer 151L. When the movable member 152L moves to the projecting position which will be described hereinafter, the pressed portion 151Le of the spacer 151L contacts the spacer pressing surface 152Lr of the movable member 152L, so that the movable member 152L can be positioned at the separation holding position.

[0436] Further, FIG. 33 is an illustration in which the periphery of the separation holding portion 151L in FIG. 31 is enlarged, and the tension spring 153 is omitted, for better illustration. Here, a case is considered in which the process cartridge 100 including the separation/contact mechanism 150L drops in the direction of an arrow JA in FIG. 33 when the process cartridge 100 is transported. At this time, the spacer 151L receives a force of rotating in the direction of arrow B2 due to its own weight about the separation holding swing axis H. When the spacer 151L starts to rotate in the arrow B2 direction for this reason, the rotation prevention surface 151Ln of the spacer 151L comes into contact with the locking surface 152Lu of the movable member 152L, and the spacer 151L receives a force in the arrow F4 direction so as to suppress the rotation in the arrow B2 direction. By this, it is possible to constrain the spacer 151L from rotating in the arrow B2 direction during transportation, and it is possible to prevent impairment of the spaced state between the photosensitive drum 104 and the developing unit 109.

[0437] In this embodiment, the tension spring 153 is mentioned as an urging means for urging the spacer 151L to the separation holding position and the movable member 152L to the accommodated position, but the urging means is not limited to this example. For example, a torsion coil spring, a leaf spring, or the like may be used as an urging means to urge the movable member 152L to the accommodated position and the spacer 151L to the separation holding position. Further, the material of the urging means may be metal, a mold, or the like, which has elasticity and can urge the spacer 151L and the movable member 152L.

[0438] As described above, the developing unit 109 provided with the separation/contact mechanism 150L is integrally coupled with the drum unit 108 by the non-drive-side cartridge cover member 117 as described above (state of FIG. 30). As shown in FIG. 16, the non-drive-side cartridge cover 117 of this embodiment has the contact surface (contact portion) 117c. The contacted surface 117c is substantially parallel to the swing axis K. Further, as shown in FIGS. 16 and 30, the contacted surface 117c opposes the surface 151Lc of the spacer 151L located at the separation holding position when the non-drive-side cartridge cover member 117 is assembled to the developing unit 109 and the drum unit 108. Here, the process cartridge 100 has a development pressure spring 134 as a developing unit urging member (a second unit urging member) for urging the developing unit 109 from the spaced position toward the contact position to bring the developing roller 106 into contact with the photosensitive drum 104. The development pressure spring 134 is a coil spring assembled between the spring-hooked portion 117e of the non-drive-side cartridge cover member 117 and the spring-hooked portion 127k of the non-drive-side bearing 127, and is an elastic member. The urging force of the development pressing spring 134 brings the contact surface 151Lc of the spacer 151L into contact with the contacted surface 117c of the non-drive-side cartridge cover member 117. Then, when the contacted surface 117c and the contact surface 151Lc come into contact with each other, the attitude of the developing unit 109 is determined with a gap P1 between the developing roller 106 of the developing unit 109 and the photosensitive drum 104. The state in which the developing roller 106 is spaced from the photosensitive drum 104 by the gap P1 by the spacer 151L in this manner is referred to as a separating position (retracted position) of the developing unit 109 (part (a) of FIG. 35).

[Separation State and Contact State of Process Cartridge 100 (Non-Drive-Side)]

[0439] Here, referring to FIG. 34, the separated state and the contact state of the process cartridge 100 will be described in detail. FIG. 34 is a side view of the process cartridge 100 as viewed from the non-drive-side with the process cartridge 100 mounted inside the image forming apparatus main assembly 170. Part (a) of FIG. 34 shows a state in which the developing unit is separated from the photosensitive drum 104. Part (b) of FIG. 34 shows a state in which the developing unit 109 is in contact with the photosensitive drum 104.

[0440] First, the description will be made as to the state in which the spacer 151L is located at the separation holding position (first position) and the developing unit 109 is placed at the separation position (retracted position). In this state, the supported portion 151La, which is one end of the separation holding portion 151Lb, is in contact with the first supporting portion 127b of the non-drive-side bearing 127, and the contact portion 151Lc, which is the other end, is in contact with the contacted surface 117c of the non-drive-side cartridge cover member 117. Further, the first supporting portion 127b is pressed toward the supported portion 151La by the action of the development pressure spring 134, and the contact portion 151Lc is pressed toward the contacted surface 117c. Therefore, in this state, the non-drive-side cartridge cover member 117 (which constitutes a portion of the drum unit 108) determines the position of the non-drive-side bearing 127 (which constitutes a portion of the developing unit 109) by way of the separation holding portion 151Lb of the spacer 151L.

[0441] From this state, the pressed portion 152Le of the movable member 152L is pushed in the direction of arrow ZA. By this, the movable member 152L and the projecting portion 152Lh move linearly from the stand-by position in the ZA direction (operating direction) to reach the projecting position. The ZA direction is a direction which intersects (orthogonally in this embodiment) the rotation axis M2 of the developing roller 106, the rotation axis M1 of the photosensitive drum 108, and the swing axis HE. Therefore, the projecting portion 152Lh at the time when it is in the projecting position is placed downstream in the ZA direction from the projecting portion 152Lh when it is in the stand-by position. Therefore, the projecting portion 152Lh when it is in the projecting position is placed more remote from the swing axis K than the projecting portion 152Lh when it is in the stand-by position. Further, the projecting portion 152Lh when it is at the projecting position projects in the ZA direction beyond the drum frame and the developing frame (placed downstream in the ZA direction). In this embodiment, the drum frame includes the first drum frame portion 115, the drive-side cartridge cover member 116, the non-drive-side cartridge cover member 117, and the developing frame includes the developing container 125, the drive-side bearing 126, and the non-drive-side bearing 127. The projecting position can also be referred to as a force receiving position or an operating position.

[0442] The movable member 152L is movable in the ZA direction and the opposite direction while maintaining the state in which the spacer 151L is in the separation holding position (first position). Therefore, also when the movable member 152L and the projecting portion 152Lh are in the operating positions, the spacer 151L is in the separation holding position (first position). The pressed portion 151Le of the spacer 151L is in contact with the spacer pressing surface 152Lr of the movable member 152L by the tension spring 153 as described above. Therefore, when the second force receiving portion 152Ln (second force receiving surface 152Lp) is pressed in the direction of the arrow W42, the movable member 152L rotates in the direction of the arrow BD about the movable member swing axis HE, so that the spacer pressing surface 152Lr urges the pressed portion 151Le, and the spacer 151L is rotated in the direction of arrow B5. When the spacer 151L rotates in the direction of arrow B5, the contact surface 151Lc separates from the contacted surface 117c, and the developing unit 109 becomes rotatable in the direction of arrow V2 about the swing axis K from the spaced position. That is, the developing unit 109 rotates in the V2 direction from the spaced position, and the developing roller 106 of the developing unit comes into contact with the photosensitive drum 104. Here, the position of the developing unit 109 in which the developing roller 106 and the photosensitive drum 104 contact with each other is referred to as a contact position (development position) (state in part (b) of FIG. 34). The position where the contact surface 151Lc of the spacer 151L is separated from the contacted surface 117c is referred to as a separation release position (permission position, second position). When the developing unit 109 is placed at the contact position, the restriction surface 151Lk of the spacer 151L contacts the spacer restriction surface (spacer portion restriction portion) 117d of the drive-side cartridge cover 116, so that the spacer 151L is maintained at the separation release position.

[0443] Further, the non-drive-side bearing 127 of this embodiment is provided with a pressed surface (pressed portion at the time of separation) 127h which is a surface perpendicular to the swing axis K. The non-drive-side bearing 127 is fixed to the developing unit 109. Therefore, when the first force receiving portion 152Lk (first force receiving surface 152Lm) of the movable member 152L is urged in the direction of the arrow 41 while the developing unit 109 is in the contact position, the developing frame pressing surface 152Lq comes into contact with the pressed surface 127h. By this, the developing unit 109 rotates about the swing axis K in the direction of the arrow V1 to move to the separated position (state of part (a) of FIG. 34). Here, when the developing unit 109 moves from the contact position to the separated position, the direction in which the pressed surface 127h moves is indicated by an arrow W41 in part (a) of FIG. 34 and part (b) of FIG. 34. Further, the direction opposite to the arrow W41 is the arrow W42, and the arrow W41 and the arrow W42 are substantially horizontal directions (X1, X2 directions). The second force receiving surface 152Lp of the movable member 152L assembled to the developing unit 109 as described above is placed on the upstream side of the pressed surface 127h of the non-drive-side bearing 127 in the direction of the arrow W41. Further, the pressed surface 127h and the pressed portion 151Le of the spacer 151L are placed at positions where at least parts of them overlap in the W1 and W2 directions. The operation of the separation/contact mechanism 150L in the image forming apparatus main assembly 170 will be described hereinafter.

[Mounting of Process Cartridge 100 to Image Forming Apparatus Main Assembly 170 (Non-Drive-Side)]

[0444] Next, referring to FIGS. 35 and 36, the description will be made as to the engaging operation between the separation/contact mechanism 150L of the process cartridge 100 and the development separation control unit 196L of the image forming apparatus main assembly 170 when the process cartridge 100 is mounted in the image forming apparatus main assembly 170. These Figures are cross-sectional views in which a part of the development cover member 128 and a part of the non-drive-side cartridge cover member are omitted by the partial cross-sectional line CS, respectively, for better illustration. FIG. 35 is a view as seen from the drive-side of the process cartridge 100 when the process cartridge 100 is mounted on the cartridge tray 171 (not shown) of the image forming apparatus M and the cartridge tray 171 is inserted to the first mounting position. In FIG. 35, portions other than the process cartridge 100, the cartridge pressing unit 190, and the separation control member 196L are omitted.

[0445] As described above, the image forming apparatus main assembly 170 of this embodiment is provided with a separation control member 196L corresponding to each process cartridge 100 as described above. The separation control member 196L is disposed on the lower surface side of the image forming apparatus main assembly 170 with respect to the spacer 151L when the process cartridge 100 is placed at the first inner position and the second inner position. The separation control member 196L has the first force application surface (force applying portion) 196La and the second force application surface (retracting force applying portion) 196Lb which project toward the process cartridge 100 and face each other across the space 196Rd. The first force application surface 196Ra and the second force application surface 196Rb are connected by a connecting portion 196Rc on the lower surface side of the image forming apparatus main assembly 170. Further, the separation control member 196R is supported by the control sheet metal 197 so as to be rotatable about the rotation center 196Re. The separating member 196R is normally urged in the E1 direction by the urging spring. Further, the control sheet metal 197 is structured to be movable in the W41 and W42 directions by a control mechanism (not shown), so that the separation control member 196R is movable in the W41 and W42 directions.

[0446] The cartridge pressing unit 190 lowers in the direction of arrow ZA in interrelation with the transition of the front door 11 of the image forming apparatus main assembly 170 from the open state to the closed state, as described above, and the first force applying portion 190a is brought into contact with the pressed surface 152Lf of the movable member 152L. Thereafter, when the cartridge pressing unit 190 is lowered to a predetermined position which is the second mounting position, the projecting portion 152Lh of the movable member 152L moves to a projecting position where it projects downward of the process cartridge 100 in the Z2 direction (state in FIG. 36). When this operation is completed, the gap T4 is formed between the first force application surface 196La of the separation control member 196L and the second force receiving surface 152Lp of the movable member 152L, and the gap T3 is formed between the second force application surface 196Lb and the first force receiving surface 152Lm, as shown in FIG. 36. Then, it is placed at the second mounting position where the separation control member 196L does not act on the movable member 152L. This position of the separation control member 196L is referred to as a home position. At this time, the second force receiving surface 152Lp of the movable member 152L and the first force application surface 196La of the separation control member 196L are arranged so as to partially overlap in the W1 and W2 directions. Similarly, the first force receiving surface 152Lm of the movable member 152L and the second force application surface 196Lb of the separation control member 196L are arranged so as to partially overlap in the W1 and W2 directions.

[Contact Operation of Developing Unit (Non-Drive-Side)]

[0447] Next, referring to FIGS. 36 to 38, a description will be made as to the operation in which the photosensitive drum 104 and the developing roller 106 are brought into contact with each other by the separation/contact mechanism 150L. For better illustration, a part of the development cover member 128, a part of the non-drive-side cartridge cover member 117, and a part of the non-drive-side bearing 127 are omitted by the partial cross-sectional line CS in the sectional view.

[0448] As described above, the development coupling 32 receives a driving force from the image forming apparatus main assembly 170 in the direction of arrow V2 in FIG. 24, and the developing roller 106 rotates. That is, the developing unit 109 including the development coupling 32 receives the driving torque in the arrow V2 direction about the swing axis K from the image forming apparatus main assembly 170. Further, the developing unit 109 also receives an urging force in the arrow V2 direction due to the urging force of the development pressure spring 134 described above. As shown in FIG. 36, a state in which the developing unit 109 is in the separated position and the spacer 151L is in the separation holding position (first position) will be described. In this state, even if the developing unit 109 receives this driving torque and the urging force of the development pressure spring 134, the contact surface 151Lc of the spacer 151L contacts the contacted surface 117c of the non-drive-side cartridge cover member 117. Therefore, the attitude of the developing unit 109 is maintained in the separated position.

[0449] The separation control member 196L of this embodiment is structured to be movable from the home position in the direction of arrow W41 in FIG. 36. When the separation control member 196L moves in the W41 direction, the first force application surface 196La of the separation control member 196L and the second force receiving surface 152Lp of the second force receiving portion 152Ln of the movable member 152L come into contact with each other, and the movable member 152L rotates in the BD direction about the swing axis HD. The contact between the first force application surface 196La and the second force receiving surface 152Lp is not necessarily surface contact, and may be line contact or point contact. In this manner, the first force application surface 196La applies a contact force to the second force receiving surface 152Lp by moving in the W41 direction. The moving direction of the projecting portion 152Lh when the movable member 152L is rotated in the BD direction is referred to as the first direction. Further, as the movable member 152L rotates, while the spacer pressing surface 152Lr of the movable member 152L is in contact with the pressed portion 151Le of the spacer 151L, the spacer 151L is rotated in the B5 direction. Then, the spacer 151L is rotated by the movable member 152L to the separation release position (second position) where the contact surface 151Lc and the contacted surface 117c are spaced from each other. Here, the position of the separation control member 196L for moving the spacer 151L to the separation release position (second position) shown in FIG. 37 is referred to as a first position.

[0450] When the spacer 151L is moved to the separation release position by the separation control member 196L in this manner, the developing unit 109 rotates in the V2 direction by the driving torque received from the image forming apparatus main assembly 170 and the urging force of the development pressure spring 134. By this, the developing unit 109 moves to the contact position where the developing roller 106 and the photosensitive drum 104 contact each other (state in FIG. 37). At this time, the spacer 151L urged in the direction of arrow B4 by the tension spring 153 is maintained at the separation release position (second position) by the contact of the restricted surface 151Lk with the spacer restriction surface 117d of the non-drive-side cartridge cover member 117. Thereafter, the separation control member 196L moves in the direction of W42 and returns to the home position. At this time, the movable member 152L is rotated in the BC direction by the tension spring 153, to establish the state in which the developing frame pressing surface 152Lq of the movable member 152L and the pressed surface 127h of the non-drive-side bearing 127 are in contact with each other (state of FIG. 38). At this time, it can be said that the movable member 152L and the projecting portion 152Lh are in the operating positions.

[0451] By this, the above-mentioned gaps T3 and T4 are formed again, and the separation control member 196L is placed at the position where it does not act on the movable member 152L. The transition from the state of FIG. 37 to the state of FIG. 38 is performed without a delay. The position of the separation control member 196L in FIG. 38 is the same as that in FIG. 36.

[0452] Further, in the above description, it is assumed that the second force receiving surface 152Lp is subjected to the contact force from the first force application surface 196La. In this regard, the contact force is a force applied from the first force application surface 196La moving in the W41 direction, and this is a force applied to the process cartridge 100 to move it in a direction (contact direction, approaching direction, or V2 direction) in which the developing roller 106 comes closer and contacts to the photosensitive drum 104. Therefore, it is sufficient if the developing unit 109 moves from the retracted position to the developing position triggered by receiving the contact force, and it is not necessary that the process cartridge continues to receive the contact force until the developing unit 109 reaches the developing position. As described above, it is unnecessary that when the developing unit shifts from the retracted position to the developing position by the contact force, the developing roller 106 and the photosensitive drum 104 are in contact with each other at the developing position.

[0453] As described above, in the structure of this embodiment, the separation control member 196L moves from the home position to the first position to apply a contact force to the movable member 152L, rotate the movable member 152L, and hold the spacer 151L in the separation holding position. It can be moved from the (first position) to the separation release position (second position). By doing so, it is possible for the developing unit 109 to move from the separated position to the contacting position where the developing roller 9 and the photosensitive drum 104 come into contact with each other. That is, it can be said that the contact force applied from the separation control member 196L is transmitted to the spacer 151L by way of the movable member 152L, so that the developing unit 109 moves from the separated position (retract position) to the contact position (development position).

[0454] In the state that the developing unit 109 is in the contact position (development position), the position of the developing unit 109 relative to the drum unit 108 is determined by the developing unit 109 being urged in the V2 direction by the driving torque received from the image forming apparatus main assembly 170 and the development pressure spring 134 by which the developing roller 106 is in contact with the photosensitive drum 104. Therefore, the photosensitive drum 104 can be said to be a positioning portion (second positioning portion) for positioning the developing roller 6 of the developing unit 109 at the developing position. At this time, it can be said that the developing unit 109 is stably held by the drum unit 108. At this time, the spacer 151L in the separation release position is not directly contributable to the positioning of the developing unit 109. However, it can be said that the spacer 151L creates the situation in which the drum unit 108 can stably hold the developing unit 109 at the contact position (development position) by moving from the separation holding position to the separation release position.

[0455] Further, when the front door 11 of the image forming apparatus main assembly 170 shifts from the closed state to the open state in this state, the first force applying portion 190a rises in the direction opposite to the arrow ZA direction. Along with this, the movable member 152R moves in the direction opposite to the arrow ZA direction by the action of the urging member 153. However, the spacer 151R still maintains the separation release position, and the developing unit 109 also maintains the developing position.

[Separation Operation of Developing Unit (Non-Drive-Side)]

[0456] Referring to FIGS. 38 and 39, the operation of moving the developing unit 109 from the contact position to the separation position will be described in detail. FIG. 39 is a cross-section in which a part of the development cover member 128, a part of the non-drive-side cartridge cover member 117, and a part of the non-drive-side bearing are partially omitted by the partial cross-section line CS, respectively.

[0457] As described above, in the state shown in FIG. 38, it can be said that the movable member 152L and the projecting portion 152Lh are in the operating position. The separation control member 196L in this embodiment is structured to be movable from the home position in the direction of arrow W42 in FIG. 38. When the separation control member 196L moves in the W42 direction, the second force application surface 196Lb and the first force receiving surface 152Lm of the first force receiving portion 152Lk of the movable member 152L are brought into contact with each other, and the movable member swings 152L about the swing axis HD in the direction of arrow BC. The contact between the second force application surface 196Lb and the first force receiving surface 152Lm is not necessarily surface contact, and may be line contact or point contact. In this manner, the second force application surface 196Lb applies a separating force (retracting force) to the first force receiving surface 152Lm. The moving direction of the projecting portion 152Lh when the movable member 152L is rotated in the BC direction is referred to as a second direction. Since the developing frame pressing surface 152Lq of the movable member 152L is in contact with the pressed surface 127h of the non-drive-side bearing 127, the developing unit 109 rotates from the contact position in the arrow V1 direction about the swing axis K (state in FIG. 39). At this time, the pressed surface 152Lf of the movable member 152L has an arc shape, and the center of the arc is positioned so as to be the same as the swing axis K.

[0458] By this, when the developing unit 109 moves from the contact position to the separating position, the force received by the pressed surface 152Lf of the movable member 152L from the cartridge pressing unit 190 is directed in the swing axis K direction. Therefore, the developing unit 109 can be operated so as not to hinder the rotation in the arrow V1 direction. In the spacer 151L, the restricted surface 151Lk of the spacer 151L and the spacer restriction surface 117d of the non-drive-side cartridge cover member 117 are separated from each other, and the spacer 151L rotates in the arrow B4 direction (the direction from the separation release position to the separation holding position) by the urging force of the tension spring 153. By this, the spacer 151L rotates until the pressed portion 151Le contacts to the spacer pressing surface 152LR of the movable member 152L, and by the contact, it shifts to the separation holding position (first position).

[0459] When the developing unit 109 is moved from the contact position to the separation position by the separation control member 196L, and the spacer 151L is located at the separation holding position, a gap T5 is formed between the contact surface 151Lc and the contacted surface 117c as shown in FIG. 39. Here, the position where the developing unit 109 is rotated from the contact position toward the separation position, and the spacer 151L can move to the separation holding position is referred to as a second position of the separation control member 196L.

[0460] Thereafter, the separation control member 196L moves in the direction of the arrow W41 and returns from the second position to the home position. Then, while the spacer 151L is maintained in the separation holding position, the developing unit 109 rotates in the arrow V2 direction by the driving torque received from the image forming apparatus main assembly and the urging force of the development pressure spring 134, so that the contact surface 151Lc is brought into contact with the contacted surface 117c. That is, the developing unit 109 becomes in the state that the separated position is maintained by the spacer 151L, and the developing roller 106 and the photosensitive drum 104 are spaced from each other by the gap P1 (states in FIG. 36 and part (a) of FIG. 34). By this, the above-mentioned gaps T3 and T4 are formed again, and the state is reached in which the separation control member 196L does not act on the movable member 152L (state in FIG. 36). The transition from the state of FIG. 39 to the state of FIG. 36 is executed without a delay.

[0461] Further, in the above-described example, the first force receiving surface 152Lm receives a separation force (retracting force) from the second force application surface 196Lb. In this regard, the separation force is a force applied from the second force application surface 196Lb which moves in the W42 direction, and is for moving the developing roller 106 in the direction away from the photosensitive drum 104 (separation direction, retracting direction, or V1 direction). This is the force applied to the process cartridge 100. Therefore, it suffices if the developing unit 109 moves from the developing position to the retracted position triggered by receiving the separating force as a trigger, and the process cartridge 100 does not necessarily continue to receive the separating force until the developing unit 109 reaches the retracted position.

[0462] As described above, in the structure of this embodiment, by the separation control member 196L moving from the home position to the second position, the spacer 151L moves from the separation release position to the separation holding position. Then, the separation control member 196L returning from the second position to the home position, the developing unit 109 becomes a state of maintaining the separation position by the spacer 151L. That is, the developing unit 109 is constrained by the spacer 151L from moving to the contact position against the driving torque received from the image forming apparatus main assembly 170 and the urging force in the arrow V2 direction by the urging of the development pressure spring 134, and therefore is maintained in a separated position.

[0463] In this manner, the separation force applied from the separation control member 196L is transmitted to the pressed surface 127h of the non-drive-side bearing (a part of the developing frame) 127 by way of the movable member 152L, so that the developing unit 109 is moved from the contact position to the separation position (retracted position), and the spacer 151R is moved from the separation release position to the separation holding position.

[0464] With the developing unit 109 in the separated position (retracted position), the position of the developing unit 109 with respect to the drum unit 108 is determined by the urging in the V2 direction by the driving torque received from the image forming apparatus main assembly 170 and the development pressure spring 134, the contacting of the supported portion 151La to the first supporting portion 127b as described above, and the contacting of the contact portion 151Lc to the contacted surface 117c. Therefore, the contacted surface 117c can be said to be a positioning portion (first positioning portion) for positioning the developing unit 109 at the separated position (retracted position) of the photosensitive drum 104. At this time, it can be said that the developing unit 109 is stably held by the drum unit 108. Further, it can be said that the spacer 151L at the separation holding position (first position) creates a state in which the drum unit 108 can stably hold the developing unit at the separation position (retracted position).

[0465] Further, when the front door 11 of the image forming apparatus main assembly 170 shifts from the closed state to the open state in this state, the first force applying portion 190a rises in the direction opposite to the arrow ZA direction. Along with this, the movable member 152L moves in the direction opposite to the arrow ZA direction by the action of the urging member 153. However, the spacer 151L still maintains the separation holding position, and the developing unit 109 also maintains the separation position.

[0466] So far, the operation of the separation mechanism located on the drive-side of the process cartridge 100 and the operation of the separation mechanism located on the non-drive-side have been described separately, but in this embodiment, they operate in interrelation with each other. That is, when the developing unit 109 is positioned at the separated position by the spacer 151R, the developing unit 109 is positioned at the separated position by the spacer 151L at substantially the same time, and the same is true at the contact position. Specifically, the movements of the separation control member 196R and the separation control member 196L described in FIGS. 23 to 27 and FIGS. 35 to 39 are integrally moved by a connecting mechanism (not shown). By this, the timing at which the spacer 151R located on the drive-side is placed at the separation holding position and the timing at which the spacer 151L located on the non-drive-side is placed at the separation holding position are substantially simultaneous. Further, the timing at which the spacer 151R is placed at the separation release position and the timing at which the spacer 151L is placed at the separation release position are substantially the same. Note that these timings may be different between the drive-side and the non-drive-side, but in order to shorten the time from the start of the print job by the user until the printed matter is discharged, it is desirable that at least the timing at which it is positioned at the separation release position is the same. In this embodiment, the swing axis H of the spacer 151R and the spacer 151L are coaxial, but the present invention is not limited to this example, and it will suffice if the timings of the spacers 151R and the spacers 151L may be substantially the same as those at the separation release position as described above. Similarly, the movable member swing axis HC of the movable member 152R and the movable member swinging axis HE of the movable member 152L are not coaxial, but the present invention is not limited to such an example, and it is sufficient that the timings of being located at the separation release positions are substantially the same as described above.

[0467] In order to perform the above-mentioned contact operation and separation operation, the width of the projecting portion 152Rh of the movable member 152R or the distance between the first force receiving surface 152Rm and the first force receiving surface 152Rp measured in the W41 direction or the W42 direction is preferably 10 mm or less, and more preferably 6 mm or less. With such a dimensional relationship, it is possible to perform an appropriate contact operation and separation operation. The same applies to the movable member 152L on the non-drive-side.

[0468] As described above, in this embodiment, the drive-side and the non-drive-side have similar separation/contact mechanisms 150R and 150L, and they operate substantially at the same time. By this, even when the process cartridge 100 is twisted or deformed in the longitudinal direction, the amount of separation between the photosensitive drum 104 and the developing roller 9 can be controlled at both ends in the longitudinal direction. Therefore, it is possible to suppress variations in the amount of separation along the longitudinal direction.

[0469] Further, according to this embodiment, by moving the separation control member 196R (196L) between the home position, the first position, and the second position in one direction (arrows W41 and W42 directions), it is possible to control the contact state and the separation state between the developing roller 106 and the photosensitive the drum 104. Therefore, the developing roller 106 can be contacted with the photosensitive drum 104 only when the image is formed, and the developing roller 4 can be maintained in the spaced state from the photosensitive drum 104 when the image is not formed. Therefore, even if the apparatus is unoperated left for a long time without forming an image, the developing roller 106 and the photosensitive drum 104 are prevented from being deformed, and a stable image formation can be formed.

[0470] Further, according to this embodiment, the movable member 152R (152L) which acts on the spacer 151R (151L) to rotationally move can be positioned at the accommodated position by the urging force of the tension spring 153 or the like. Therefore, when the process cartridge 100 is outside of the image forming apparatus main assembly 170, the process cartridge 100 can be downsized as a single unit without projecting from the outermost shape of the process cartridge 100.

[0471] Similarly, the movable member 152R (152L) can be positioned at the accommodated position by the urging force of the tension spring 153 or the like. Therefore, when the process cartridge is mounted on the image forming apparatus main assembly 170, the process cartridge 100 can be mounted by moving only in one direction. Therefore, it is not necessary to move the process cartridge 100 (tray 171) both in the upward and downward directions. For this reason, the image forming apparatus main assembly 170 does not require an extra space, and the main assembly can be downsized.

[0472] In addition, according to this embodiment, when the separation control member 196R (196L) is located at the home position, the separation control member 196R (196L) is free of load thereto from the process cartridge 100. Therefore, the rigidity required for the mechanism for operating the separation control member 196R (196L) and the separation control member 196R (196L) can be reduced, and the size thereof can be reduced. Further, the load on the sliding portion of the mechanism for operating the separation control member 196R (196L) is also reduced, and therefore, wearing of the sliding portion and generation of abnormal noise can be suppressed.

[0473] Further, according to this embodiment, the developing unit 109 can maintain the separated position only by the spacer 151R (151L) of the process cartridge 100. Therefore, the total component tolerance can be eased and the spacing amount can be minimized by reducing the number of portions which may cause variations in the spacing amount between the developing roller 106 and the photosensitive drum 104. Since the amount of separation can be reduced, when the process cartridge 100 is placed in the image forming apparatus main assembly 170, the occupying space of the developing unit 109 at the time when the developing unit 109 is moved between the contact position and the separated position becomes smaller, and therefore, the image forming apparatus can be downsized. In addition, since the space of the developer accommodating portion 29 of the developing unit 109 in which the movement between the contact position and the separation position occurs can be increased, a downsized and large-capacity process cartridge 100 can be placed in the image forming apparatus main assembly 170.

[0474] Further, according to this embodiment, the movable member 152R (152L) is located at the accommodated position when the process cartridge 100 is mounted, and the developing unit can maintain the spaced position by the spacer 151R (151L) of the process cartridge 100. Therefore, when the process cartridge 100 is mounted in the image forming apparatus main assembly 170, the mounting of the process cartridge 100 can be completed by moving only in one direction. Therefore, it is not necessary to move the process cartridge (tray 171) both in the upward and downward directions. In addition, the image forming apparatus main assembly does not require an extra space, and the main assembly can be downsized. Further, since the spacing amount can be reduced, when the process cartridge 100 is arranged in the image forming apparatus main assembly 170, the occupying zone of the developing unit 109 at the time when the developing unit 109 moves between the contact position and the separated position can be reduced, so that the image forming apparatus can be downsized. In addition, since the space of the developer accommodating portion 29 of the developing unit 109 which moves between the contact position and the separated position can be increased, the downsized and large-capacity process cartridge 100 can be placed in the image forming apparatus main assembly 170.

[0475] In this embodiment, the structure is such that the developing unit 109 is moved in the arrow V2 direction (direction of movement from the separated position to the development position) by the driving torque of the development coupling portion 132a received from the image forming apparatus main assembly 170 and the urging force of the development pressure spring 134. However, as a structure for urging the developing unit in the V2 direction, it is also possible to utilize the gravity applied to the developing unit 109. That is, the structure may be such that the gravity applied to the developing unit 109 is produce a moment which rotates the developing unit 109 in the V2 direction. In the case of employing such an urging structure in the V2 direction by its own weight, the urging structure using the development pressure spring 134 may not be provided, or may be used in combination with the urging structure using the development pressure spring 134.

[Details of Arrangement of Separation/Contact Mechanisms 150R and 150L]

[0476] Subsequently, referring to FIGS. 40 and 41, the arrangement of the separation/contact mechanisms 150R and 150L in this embodiment will be described in detail. FIG. 40 is an enlarged view of the periphery of the spacer 151R as the process cartridge 100 as viewed from the drive-side along the swing axis K (photosensitive drum axis direction) of the developing unit 109. In addition, for better illustration, it is a sectional view in which a portion of the development cover member 128 and a portion of the drive-side cartridge cover member 116 are partially omitted by the partial cross-sectional line CS. FIG. 41 is an enlarged view of the periphery of the spacer 151R as the process cartridge 100 is viewed from the non-drive-side along the swing axis K (photosensitive drum axis direction) of the developing unit 109. In addition, for better illustration, it is a sectional view in which a portion of the development cover member 128 and a portion of the drive-side cartridge cover member 116 are partially omitted by the partial cross-sectional line CS. Regarding the arrangement of the spacer and the movable member, which will be described below, there is no distinction between the drive-side and the non-drive-side except for the part which will be described in detail hereinafter, and the description of the non-drive-side (FIG. 41) is omitted, because the non-drive-side has a similar structure.

[0477] As shown in FIG. 40, a straight line passing through the rotation axis M1 of the photosensitive drum 104 (point M1 in FIG. 40) and the rotation axis M2 of the developing roller 106 (point M2 in FIG. 40) is line N. In addition, the contact region between the contact surface 151Rc of the spacer 151R and the contacted surface 116c of the drive-side cartridge cover member 116 is M3, and the contact region between the pressed surface 151Re of the spacer 151R and the spacer pressing surface 152Rr of the movable member 152R is M4. Further, the distance between the swing axis K and the point M2 of the developing unit 109 is distance e1, the distance between the swing axis K and the region M3 is distance e2, and the distance between the swing axis K and the point M4 is distance e3.

[0478] In the structure of this embodiment, when the developing unit 109 is in the separated position and the movable member 152R (152L) is in the projecting position, the positional relationship is as follows, as the developing unit 109 is viewed along the swing axis K (or the rotation axis M1 or the rotation axis M2). That is, as viewed along the swing axis K as shown in FIG. 40, at least a part of the contact region M3 is disposed in a region AD1, which is opposite to an region AU1 in which the center (swing axis K) of the development coupling portion 132a exists, when the region is divided with the line N as a boundary. In other words, the contact surface 151Rc of the spacer 151R is placed such that the distance e2 is longer than the distance e1. Further, as shown in FIG. 40, when the region is divided with the line N as a boundary, at least a portion of the projecting portion 152Rh is placed in the region AD1 opposite to the region AU1 in which the center of the development coupling portion 132a (swing axis K) exist, as viewed along the swing axis K. The vertical direction in the attitude shown in FIG. 40 (FIG. 41), is the vertical direction in the actual attitude at the time when it is mounted to the image forming apparatus main assembly 170. This attitude can be said to be an attitude in which the rotation axis M1 of the photosensitive drum 104 is horizontal and the photosensitive drum 104 is placed at the lower portion in the process cartridge 100. In such an attitude, the region AD1 corresponds to the lower portion of the process cartridge 100, and is also the region including the lower portion of the process cartridge 100.

[0479] By arranging the spacer 151R and the contact surface 151Rc in this manner, it is possible to suppress variations in the attitudes of the separation positions of the developing unit 109, even when the positions of the contact surface 151Rc vary due to component tolerances and the like. That is, the influence of the variation of the contact surface 151Rc on the spacing amount (gap) P1 (see part (a) of FIG. 1) between the developing roller 106 and the photosensitive drum 104 can be minimized, and the developing roller 106 and the photosensitive drum 104 can be spaced from each other with high precision. Further, it is not necessary to provide an extra space for retraction when the developing unit 109 is moved for the spacing, which leads to the downsizing of image forming apparatus main assembly 170.

[0480] Further, the first force receiving portion 152Rk (152Lk) and the second force receiving portion 152Rn (152Ln), which are the force receiving portions of the movable member 152R (152L), are disposed on the opposite side of the side including the rotation center (rotation axis) of the development coupling portion 132a with respect to line N. That is, at least a portion of each of the force receiving portions 152Rk (152Lk) and 152Rn (152Ln) is arranged in the region AD1 opposite to the region AU1 in which the rotation center (rotation axis) K of the development coupling 132a is placed.

[0481] As described above, the projecting portion (force receiving portion) 152Rh (152Lh) is disposed at the end portion in the longitudinal direction. Further, as shown in FIG. 15 (FIG. 16), a cylindrical portion 128b (127a), which is a support portion of the developing unit 109, is disposed at the end portion in the longitudinal direction. Therefore, the force receiving portion 152Rh (152Lh) including the first force receiving portion 152Rk (152Lk) and the second force receiving portion 152Rn (152Ln) is disposed on the opposite side of the side including the cylindrical portion 128b (127a) (that is, the swing axis K) of the developing unit 109 with respect to the line N, so that the functional portions can be arranged efficiently. That is, it leads to downsizing of the process cartridge 100 and the image forming apparatus M. More specifically, when the region is divided by the straight line N as viewed in the direction along the rotation axis M2, the structure such as the cylindrical portion 128b (127a) for movably (relative to the developing unit 109) supporting the drum unit 108 is placed in the region AU1 where the swing axis K is placed. Therefore, at least a portion of each of the force receiving portions 152Rk (152Lk) and 152Rn (152Ln) is arranged in the region AD1 in which the development coupling portion 132a is not arranged in the region AU in which the swing axis K is arranged. It is possible to obtain an efficient layout that avoids interference between the members. This is contributable to downsizing of the process cartridge 100 and the image forming apparatus M.

[0482] In addition, the force receiving portion 152Rh (152Lh) is disposed at the end portion on the drive-side in the longitudinal direction. Further, as shown in FIG. 15, a development drive input gear 132 (or a development coupling portion 132a) which receives a drive from the image forming apparatus main assembly 170 and drives the developing roller 106 is provided at the end (with respect to the longitudinal direction) portion on the drive-side. As shown in FIG. 40, the first force receiving portion 152Rk and the second force receiving portion 152Rn of the movable member is placed on the side opposite from the side in which the rotation center K of the development drive input gear 132 (development coupling portion 132a) shown by the broken line, with respect to extension line of the line N. With this arrangement, the functional portions can be efficiently arranged. That is, it leads to downsizing of the process cartridge and the image forming apparatus M. More specifically, when the region is divided by a straight line N as viewed in the direction along the rotation axis M2, in the region AU1 where the development coupling portion 132a exist, the driving member for driving a member included in the developing unit 109, such as the developing roller 106 such as a development drive input gear 132 is provided. Therefore, at least a portion of the force receiving portion 152Rh is better disposed in the region AD1 in which the development coupling portion 132a is not placed than in the region AU1 in which the development coupling portion 132a is placed, from the standpoint of an efficient layout to avoid interference between the members. This is contributable to downsizing of the process cartridge and the image forming apparatus M.

[0483] In the above description, the region AU1 and the region AD1 are defined as regions where the swing axis K or the development coupling portion 132a is placed and the region where it is not placed, when the region is divided by the straight line N, as viewed in the direction along the rotation axis M2. However, it is possible to use another definition. For example, the regions AU1 and AD1 may be the region where the charging roller 105 or rotation axis (center of rotation) M5 thereof is provided and the region where it is not provided, when the region is divided by the straight line N, as viewed in the direction along the rotation axis M2.

[0484] Further, FIG. 236 is a schematic cross-sectional view of the process cartridge 100 in the separated state as viewed in the direction along the rotation axis M2. Referring to FIGS. 3 and 236, as a further definition, when the region is divided by a straight line N as viewed in the direction along the rotation axis M2, the regions AU1 and AD1 may be defined as the region in which the developing blade 130, the proximity point 130d, or the stirring member 129a and the rotation axis M7 of the stirring member 129a, or the pressed surface 152Rf are provided, and the reason in which it is not provided. The proximity point 130d is the position closest to the surface of the developing roller 106 of the developing blade 130.

[0485] In a general electrophotographic cartridge, particularly a cartridge usable with an in-line layout image forming apparatus, it is relatively difficult to arrange other members of the cartridge in the region AD1. Further, if at least a portion of each of the force receiving portions 152Rk (152Lk) and 152Rn (152Ln) is placed in the region AD1, the apparatus main assembly 170 also has the following advantage. That is, the separation control member 196R (196L) of the apparatus main assembly 170 is placed on the lower side of the cartridge and moves in the substantially horizontal direction (W41 and W42 directions, and the arrangement direction of the photosensitive drum 104 or the cartridge 100, in this embodiment) to urge the force receiving portion 152Rh (152Lh). With such a structure, the separation control member 196R (196L) and driving mechanism therefor can be formed in a relatively simple structure or a compact structure. This is particularly remarkable in the in-line layout image forming devices. As described above, arranging at least a portion of each of the force receiving portions 152Rk (152Lk) and 152Rn (152Ln) in the region AD1 can be expected to contribute to the downsizing and cost reduction of the apparatus main assembly 170.

[0486] Further, the contact portion between the spacer 151R and the movable member 152R is placed such that the distance e3 is longer than the distance e1. By this, the spacer 151R and the drive-side cartridge cover member 116 can be contacted with each other with a lighter force. That is, the developing roller 106 and the photosensitive drum 104 can be stably spaced from each other.

[0487] The arrangement of the separation/contact mechanisms 150R and L described above has been described referring to FIGS. 40 and 41 showing the process cartridge 100 in the separation state, but as is apparent in the other Figures, the same relationship applies in the process cartridge 100 in the contact state. FIG. 235 is a side view (partial cross-sectional view) of the process cartridge 100 in the contact state as viewed in the direction along the rotation axis M2. The arrangement of the force receiving portions 152Rk (152Lk) and 152Rn (152Ln) is the same as that described above.

[0488] Further, the direction perpendicular to the straight line N is VD1. On the drive-side, the movable member 152R and the force receiving portions 152Rk and 152Rn move between the stand-by position and the operating position by moving in the ZA direction and the opposite direction thereto relative to the drum frame and the developing frame. By the movement in the ZA direction and the opposite direction, the movable member 152R and the force receiving portions 152Rk and 152Rn are moved at least in the VD1 direction. That is, the movable member 152R and the force receiving portions 152Rk and 152Rn are moved at least in the VD1 direction between the stand-by position and the operating position. According to this structure, when the movable member 152R is in the operating position, the developing unit 109 can be moved between the developing position and the retracted position by receiving a force from the separation control member 196R at each of the force receiving portions 152Rk and 152Rn. When the movable member 152R is in the stand-by position, the movable member 152R and the force receiving portions 152Rk and 152Rn interfere with the separation control member 196R so that it can be avoided that the process cartridge 100 cannot be inserted or removed from the apparatus main assembly 170. The same applies to the structure on the non-drive-side.

[0489] Further, when the movable member 152R is in the operating position, the projecting portion 152Rh provided with the respective force receiving portions 152Rk and 152Rn is disposed at a position such that they are projected from the developing unit 109 in at least the VD1 direction. Therefore, it is possible to arrange the projecting portion 152Rh in the space 196Rd between the first force application surface 196Ra and the second force application surface 196Rb of the separation control member 196R. The same applies to the structure on the non-drive-side.

[Details of Arrangement of Separation Contact Mechanisms 150R and 150L (Part 2)]

[0490] Referring to FIGS. 236 and 237, a concept similar to the concept of placing at least a portion of each of the force receiving portions 152Rk (152Lk) and 152Rn (152Ln) in the region AD1 as described above will be described.

[0491] FIGS. 236 and 237 are schematic cross-sectional views of the process cartridge 100 as viewed from the drive-side along the rotation axis M1, the rotation axis K, or the rotation axis M2 of the developing unit 109, FIG. 236 shows a separated state, and FIG. 237 shows a contact state. Regarding the arrangement of the spacer 151 and the movable member 152 described below, there is no difference between the drive-side and the non-drive-side, that is, both are common, and the contact state and the separation state are almost common, and therefore, only the separated state on the drive-side will be described referring to FIG. 236, and the description on the non-drive-side and the description on the contact state will be omitted.

[0492] The rotation axis of the toner feeding roller (developer supply member) 107 is the rotation axis (rotation center) M6. Further, the process cartridge 100 is provided with a stirring member 108 for rotating and stirring the developer contained in the developing unit 109, and the rotation axis thereof is the rotation axis (rotation center) M7.

[0493] In FIG. 236, the one, which is farther from the rotation axis M5, of the intersections of the straight line N10 connecting the rotation axis M1 and the rotation axis M5 and the surface of the photosensitive drum 104 is the intersection MX1. The tangent line to the surface of the photosensitive drum 104 passing through the intersection MX1 is a tangent line (predetermined tangent line) N11. The region is divided by the tangent line N11 as a boundary, and a region containing the rotation axis M1, the charging roller 105, the rotation axis M5, the developing roller 106, the rotation axis M2, the development coupling portion 132a, the rotation axis K, the developing blade 130, the proximity point 130d, and the toner feeding roller 107, the rotating axis M6, the stirring member 129a, the rotating axis M7, or the pressed surface 152Rf is an region AU2, and the region not containing it is an region (predetermined region) AD2. Further, the regions AU2 and AD2 may be defined in another way as follows. That is, assuming that the direction parallel to the direction from the rotation axis M5 to the rotation axis M1 and orientating the same is a VD10 direction, the most downstream portion of the photosensitive drum 104 in the VD10 direction is the intersection MX1. Then, with respect to the direction VD10, the region on the upstream side of the most downstream portion MX1 is the region AU2, and the region on the downstream side is the region (predetermined region) AD2. Regardless of the expression, the defined regions AU2 are the same, and the regions AD2 are the same.

[0494] Then, at least parts of each force receiving portion 152Rk and 152Rn are arranged in the region AD2. As described above, arranging at least parts of each of the force receiving portions 152Rk and 152Rn in the region AD2 can be expected to contribute to the downsizing and cost reduction of the process cartridge 100 and the apparatus main assembly 170. This is for the same reason as in the case that at least a part of each of the force receiving portions 152Rk and 152Rn is arranged in the region AD1. The same applies to the structure on the non-drive-side.

[0495] Further, the movable member 152R and the force receiving portions 152Rk and 152Rn are displaced at least in the VD10 direction by moving in the ZA direction and the opposite direction. That is, the movable member 152R and the force receiving portions 152Rk and 152Rn are displaced at least in the VD10 direction between the stand-by position and the operating position. According to this structure, when the movable member 152R is in the operating position, the developing unit 109 can be moved between the developing position and the retracting position by receiving a force from the separation control member 196R at each of the force receiving portions 152Rk and 152Rn. When the movable member 152R is in the stand-by position, it can be avoided that the movable member 152R and the force receiving portions 152Rk and 152Rn interfere with the separation control member 196R so that the process cartridge 100 cannot be inserted or removed from the apparatus main assembly 170. The same applies to the structure on the non-drive-side.

[0496] Further, the projecting portion 152Rh provided with the respective force receiving portions 152Rk and 152Rn is disposed at a position such that it is projected from the developing unit 109 in at least the VD10 direction, when the movable member 152R is in the operating position. Therefore, it is possible to dispose the projecting portion 152Rh in the space 196Rd between the first force application surface 196Ra and the second force application surface 196Rb of the separation control member 196R. The same applies to the structure on the non-drive-side.

[Details of Arrangement of Separation/Contact Mechanisms 150R and 150L (Part 3)]

[0497] A concept similar to the concept of arranging at least a portion of each of the force receiving portions 152Rk (152Lk) and 152Rn (152Ln) in the region AD1 as described above will be described referring to FIG. 238.

[0498] FIG. 238 is a schematic sectional view of the process cartridge 100 in the separated state as viewed from the drive-side along the rotation axis M1, the rotation axis K, or the rotation axis M2 of the developing unit 109. Regarding the arrangement of the spacer 151 and the movable member 152 described below, there is no difference between the drive-side and the non-drive-side, and both are common, and the contact state and the separated state are substantially the common. Therefore, only the separated state on the drive-side will be described referring to FIG. 238, and the description on the non-drive-side and the description in the contact state will be omitted.

[0499] In FIG. 238, of the intersection of the straight line N12 connecting the rotation axis K and the rotation axis M2 and the surface of the developing roller 106, the one farther from the rotation axis K, is defined as the intersection MX2. The tangent line to the surface of the developing roller 106 passing through the intersection MX2 is a tangent line (predetermined tangent line) N13. The region is divided with the tangent line N13 as a boundary, and the part in which the development coupling portion 132a, the rotation axis K, the rotation axis M2, the charging roller 105, the rotation axis M5, the developing blade 130, the proximity point 130d, the toner feeding roller 107, the rotation axis M6, the stirring member 129a, the rotation axis M7, or the pressed surface 152Rf exists is a region AU3, and the region it does not exist is a region (predetermined region) AD3. Further, the regions AU3 and AD3 may be defined in another way as follows. That is, the direction parallel to the direction from the rotation axis K to the rotation axis M2 and orientating the same is a VD12 direction, the most downstream portion of the developing roller 106 in the VD12 direction is the intersection MX2. Then, in the VD12 direction, the region on the upstream side of the most downstream portion MX2 is the region AU3, and the region on the downstream side is the region (predetermined region) AD3. The regions AU3 and AD3 defined in any of the above expressions are the same, respectively.

[0500] Then, at least a part of each force receiving portion 152Rk and 152Rn is arranged in the region AD3. As described above, arranging at least a part of each of the force receiving portions 152Rk and 152Rn in the region AD3 can be expected to contribute to the downsizing and cost reduction of the process cartridge 100 and the apparatus main assembly 170. This is for the same reason as when at least a part of each of the force receiving portions 152Rk and 152Rn is arranged in the region AD1. The same applies to the structure on the non-drive-side.

[0501] Further, the movable member 152R and the force receiving portions 152Rk and 152Rn are displaced at least in the VD12 direction by moving in the ZA direction and the opposite direction thereto. That is, the movable member 152R and the force receiving portions 152Rk and 152Rn are displaced at least in the VD12 direction to move between the stand-by position and the operating position. According to this structure, when the movable member 152R is in the operating position, the developing unit 109 can be moved between the developing position and the retracting position by receiving a force from the separation control member 196R at each of the force receiving portions 152Rk and 152Rn. When the movable member 152R is in the stand-by position, it can be avoided that the movable member 152R and the force receiving portions 152Rk and 152Rn interfere with the separation control member 196R with the result that the process cartridge 100 cannot be inserted or removed from the apparatus main assembly 170. The same applies to the structure on the non-drive-side.

[0502] Further, the projecting portion 152Rh provided with the respective force receiving portions 152Rk and 152Rn is disposed at a position such that it is projected from the developing unit 109 in at least the VD12 direction, when the movable member 152R is in the operating position. Therefore, it is possible to place the projecting portion 152Rh in the space 196Rd between the first force application surface 196Ra and the second force application surface 196Rb of the separation control member 196R. The same applies to the structure on the non-drive-side.

[Details of Arrangement of Separation/Contact Mechanisms 150R and 150L (Part 4)]

[0503] A concept similar to the concept of placing at least a part of each of the force receiving portions 152Rk (152Lk) and 152Rn (152Ln) in the region AD1 as described above will be described referring to FIG. 239.

[0504] FIG. 239 is a schematic cross-sectional view of the process cartridge 100 in the separated state as viewed from the drive-side along the rotation axis M1, the rotation axis K, or the rotation axis M2 of the developing unit 109. Regarding the arrangement of the spacer 151 and the movable member 152 described below, there is no distinction between the drive-side and the non-drive-side, and both are common, and the contact state and the separated state are substantially common, and therefore, in the following description, only the separated state on the drive-side will be described referring to FIG. 239, and the description on the non-drive-side and the description in the contact state will be omitted.

[0505] In FIG. 239, of the intersection of the straight line N14 connecting the rotation axis M2 and the rotation axis M6 and the surface of the developing roller 106, the one which is more remote from the rotation axis K, is the intersection MX2. The tangent line to the surface of the developing roller 106 passing through the intersection MX2 is a tangent line (predetermined tangent line) N14. When the region is divided by the tangent line N14 as the boundary, the region in which the development coupling portion 132a, the rotation axis K, the charging roller 105, the rotation axis M5, the developing blade 130, the proximity point 130d, the stirring member 129a, the rotation axis M7, or the pressed surface exists is the region AU4, and the region in which it does not exist is the region (predetermined region) AD4.

[0506] At least a portion of each force receiving portion 152Rk and 152Rn is arranged in the region AD4. As described above, arranging at least a part of each of the force receiving portions 152Rk and 152Rn in the region AD4 can be expected to contribute to the downsizing and cost reduction of the process cartridge 100 and the apparatus main assembly 170. This is for the same reason as when at least a part of each of the force receiving portions 152Rk and 152Rn is arranged in the region AD1. The same applies to the structure on the non-drive-side.

[0507] Further, the movable member 152R and the force receiving portions 152Rk and 152Rn are displaced at least in the VD14 direction perpendicular to the straight line N14 by the movement in the ZA direction and the opposite direction. That is, the movable member 152R and the force receiving portions 152Rk and 152Rn are displaced at least in the VD14 direction to move between the stand-by position and the operating position. According to this structure, when the movable member 152R is in the operating position, the developing unit 109 can be moved between the developing position and the retracted position by receiving a force from the separation control member 196R at each of the force receiving portions 152Rk and 152Rn. When the movable member 152R is in the stand-by position, it can be avoided the movable member 152R and the force receiving portions 152Rk and 152Rn interfere with the separation control member 196R with the result that the process cartridge cannot be inserted or removed from the apparatus main assembly 170. The same applies to the structure on the non-drive-side.

[0508] Further, when the movable member 152R is in the operating position, the projecting portions 152Rh provided on the respective force receiving portions 152Rk and 152Rn are disposed at positions such that they are projected from the developing unit 109 in at least the VD14 direction. Therefore, it is possible to arrange the projecting portion 152Rh in the space 196Rd between the first force application surface 196Ra and the second force application surface 196Rb of the separation control member 196R. The same applies to the structure on the non-drive-side.

[0509] The arrangement relationship of each force receiving portion described above has the same relationship in all the examples described below.

[Holding Mechanism]

[0510] In the above-described embodiment, the structure for the drum unit 108 to stably hold the developing unit 109 at the retracted position and the developing position is a holding member holding the spacer 151R capable of taking the first position and the second position or a holding portion holding the separation holding portion 151Rb which is a part thereof. However, it is also possible to deem the structure of this embodiment as follows. That is, as a holding mechanism in which the drum unit 108 stably holds the developing unit 109 at the retracted position and the developing position, at least the spacer 151R, it is possible to raise the first supporting portion 128c of the development cover member 128, and the contacted surface 116c of the drive-side cartridge cover member 116 and the development pressure spring 134. In such a case, it can be said that the holding mechanism is in the first state when the spacer 151R is in the first position and the developing unit 109 is in the retracted position, and the holding mechanism is in the second position when the spacer 151R is in the second position and the developing unit 109 is in the developing position.

[0511] Next, referring to FIGS. 42 to 46, the Embodiment 2 will be described. In this embodiment, structures and operations different from those in the above-described embodiment will be described, and members including the same structures and functions will be assigned the same reference numbers, and the description thereof will be omitted. In an Embodiment 1, the separation/contact mechanism 150R and the separation/contact mechanism 150L are provided as the separation/contact mechanism on the drive-side and the non-drive-side, respectively. On the other hand, in the embodiment, a structure in which the separation/contact mechanism is provided only on one side of the process cartridge will be described.

[0512] FIGS. 42 to 46 are illustrations showing a state when the developing unit 109 is in the separated position and the movable member of the separation/contact mechanism is in the projecting position. Part (a) of FIG. 42 is a perspective view of the process cartridge 100 of the Embodiment 1 as viewed from below on the drive-side. Part (b) of FIG. 42 is a schematic view illustrating the amount of spacing of the developing roller 106 from the photosensitive drum 104 of the process cartridge 100 of Embodiment 1.

[0513] As shown in FIG. 42, the spacing amount P1 of the Embodiment 1 is set to be the same amount on the drive-side and the non-drive-side. The spacing amount P1 can be changed by changing the distance n1 from the swing axis H of the spacer 151 to the contact surface 151Rc. In this embodiment shown below, the spacing amount is changed with the same structure.

[0514] In the embodiment shown in FIG. 43 of this embodiment, the separation/contact mechanism 250-1 of the process cartridge 200-1 is arranged only on the drive-side, and the separation/contact mechanism is not provided on the non-drive-side. Part (a) of FIG. 43 is a perspective view of the process cartridge 200-1 as viewed from below on the drive-side. Part (b) of FIG. 43 is a schematic view illustrating the amount of spacing of the developing roller 106 from the photosensitive drum 104 of the process cartridge 200-1.

[0515] As shown in FIG. 43, since the separation/contact mechanism 250-1 is arranged only on the drive-side, the spacing amount P2-1L on the non-drive-side is smaller than the amount P2-1R on the drive-side because of the influence of the development pressure spring (not shown in FIG. 43, see 134 in FIG. 34). Here, the spacing amount P2-1R on the drive-side is selected so as to be larger than the spacing amount P1 (see part (b) of FIG. 42) in Embodiment 1 so that the spacing amount P2-1L on the non-drive-side does not become 0, that is, the developing roller 106 and the photosensitive drum 104 do not contact each other on the non-drive-side.

[0516] By doing so, the same effect as in Example 1 can be provided. In addition, since there is no separation/contact mechanism on the non-drive-side, the process cartridge and the image forming apparatus main assembly can be downsized and the cost can be reduced accordingly.

[0517] FIG. 44 shows another example 1 of this embodiment. In this example, the separation/contact mechanism 250-2 of the process cartridge 200-2 is provided only on the drive-side, and there is not provided separation/contact mechanism on the non-drive-side. In this example, when the developing unit 109 is in a separated position, the end of the developing roller 106 on the non-drive-side is in contact with the photosensitive drum 104. Part (a) of FIG. 44 is a perspective view of the process cartridge 200-2 as viewed from below on the drive-side. Part (b) of FIG. 44 is a schematic view illustrating the amount of spacing of the developing roller 106 from the photosensitive drum 104 of the process cartridge 200-2.

[0518] As contrasted to the example shown in FIG. 43, in the example of FIG. 44, the spacing amount P2-2R on the drive-side is selected so as to be equal to or smaller than the spacing amount P1 of Embodiment 1. In this case, the developing roller 106 and the photosensitive drum are in contact with each other on the non-drive-side due to the urging force of the development pressure spring (not shown in FIG. 43, see 134 in FIG. 34). However, if the contact range m2 on the non-drive-side is set out of the range of the image forming region m4, the image is not affected adversely. Nevertheless, if the effect on the image is so small that it can be ignored, or in the case of the usage in which the affect, if any, on the image can be ignored, the contact range m2 is not necessarily set out of the image forming range m4. That is, in such a case, the contact range m2 may be set within the image forming range m4.

[0519] As described above, in this example, by reducing the spacing amount as compared with the embodiment shown in FIG. 43, it is possible to the downsizing of the image forming apparatus as described in the Embodiment 1. In addition, since there is no separation/contact mechanism on the non-drive-side, the process cartridge and the image forming apparatus main assembly can be downsized and the cost can be reduced.

[0520] FIG. 45 shows another example 2 of this embodiment. In this embodiment, the separation/contact mechanism 250-1 of the process cartridge 200-3 is provided only on the non-drive-side, and there is no separation/contact mechanism on the drive-side. Part (a) of FIG. 45 is a perspective view of the process cartridge 200-3 as viewed from below on the non-drive-side. Part (b) of FIG. 45 is a schematic view illustrating the amount of spacing of the developing roller 106 from the photosensitive drum 104 of the process cartridge 200-3.

[0521] As shown in FIG. 45, since the separation/contact mechanism 250-3 is provided only on the non-drive-side, the spacing amount P2-3R on the drive-side is smaller than the spacing amount P2-3L on the non-drive-side by the influence of the drive input gear (not shown in FIG. 45, see 132a in FIG. 1). Here, the spacing amount P2-3L on the non-drive-side is selected so as to be large than the spacing amount P1 in Embodiment 1 so that the spacing amount P2-3R on the drive-side does not become 0, that is, the developing roller 106 and the photosensitive drum 104 do not contact each other on the drive-side.

[0522] By doing so, the same effect as in Example 1 can be provided. In addition, since there is no separation/contact mechanism on the drive-side, the process cartridge and the image forming apparatus main assembly can be downsized and the cost can be reduced.

[0523] FIG. 46 shows further example 3 of this embodiment. In this embodiment, the separation/contact mechanism 250-4 of the process cartridge 200-4 is provided only on the non-drive-side, and no separation/contact mechanism is provided the drive-side. Further, when the developing unit 109 is in a separated position, the end portion of the developing roller 106 on the drive-side and the photosensitive drum 104 are provided. Part (a) of FIG. 46 is a perspective view of the process cartridge 200-4 as viewed from below on the drive-side. Part (b) of FIG. 46 is a schematic view illustrating the amount of spacing of the developing roller 106 from the photosensitive drum 104 of the process cartridge 200-4.

[0524] Unlike the example of FIG. 45, in the example of FIG. 46, the spacing amount P2-4L on the non-drive-side is selected so as to be equal to or smaller than the spacing amount P1 of the Embodiment 1. In this case, due to the influence of the drive input gear (not shown in FIG. 46, 132a in FIG. 1), the developing roller 106 and the photosensitive drum 104 contact each other on the drive-side. However, if the contact range m5 on the drive-side is set within a range which does not fall within the image forming region m4, the image is not affected. The amount of separation at the drive-side and the non-drive-side can be arbitrarily set within a range that does not affect the image.

[0525] As described above, by reducing the spacing amount as compared with the example of FIG. 45, it is possible to downsize the image forming apparatus as described in the Embodiment 1, and also to reduce the cost of the process cartridge.

[0526] In the four examples described above in this embodiment, the amount of spacing at the drive-side and the non-drive-side can be arbitrarily set within a range which does not affect the image.

[0527] Next, referring to FIGS. 47 to 55, Embodiment 3 of the present invention will be described.

[0528] In this embodiment, structures and operations different from those of the above-described embodiment will be mainly described, and description of similar structures and operations will be omitted. For the structure corresponding to that in the above-described embodiments, the same reference numerals and characters are assigned, or the reference numerals in the first part is changed while the reference numerals and characters in the second part are the same. In this embodiment, the structure and operation of the movable member are mainly different from those in the Embodiment 1. The spacer 351L has the similar structure as the spacer 151L.

[Structure of Movable Member]

[0529] First, the structure of the movable member will be described by taking the non-drive-side as an example. FIG. 47 is an illustration of disassembly and assembly of the movable member 352L on the non-drive-side. In Embodiment 3, the movable member corresponding to the movable member 152L in the Embodiment 1 is divided into two parts and they are connected together. Specifically, as shown in FIG. 47, the movable member 352L is divided into two parts, namely, an upper movable member 352L1 and a lower movable member 352L2. A shaft 352L2a is provided on the lower movable member 352L2. Further, as shown in part (a) of FIG. 48, the lower movable member 352L2 is provided with a projecting portion 352Lh capable of projecting from the developing unit in the ZA direction, and the projecting portion 352Lh includes a first force receiving portion (retracting force receiving portion, separating force receiving portion) 352Lk and a second force receiving portion (contact force receiving portion) 352Ln. The upper movable member 352L1 has an opening portion 352L1d in a surface opposing the lower movable member 352L2. In addition, the upper movable member 352L1 has an at-separation pressing portion 352L1q for pressing the non-drive-side bearing 327.

[0530] Further, the upper movable member 352L1 is provided with a pair of oblong round holes 352L1h with an open portion 352L1d interposed therebetween. The lower movable member 352L2 is provided with a spring holding portion 352L2b. One end of the compression spring 352Lsp is fitted to the spring holding portion 352L2b, the other end is inserted from the opening portion 352L1d to be supported by the holding portion (not shown) at the back thereof, and then shafts 352L2a are inserted into the respective oblong round holes 352L1h. At that time, the free end portion 352L1a is assembled while being expanded, and therefore, a plastic material is preferable for the element 352L. In the case that the 352L is made of a hard material, the shafts 352L2a and 352L2 may be formed separately. For example, the shaft 352L2a may be finally press-fitted into the shaft 352L2 for the assembling.

[0531] By doing so, the upper movable member 352L1 and the lower movable member 352L2 are connected with each other by the oblong round hole 352L1h and the pair of shafts 352L2a, and the upper movable member 352L1 is urged away from the lower movable member 352L2 by the compression spring 352Lsp. Further, the lower movable member 352L2 is rotatably structured about the shaft 352L2a relative to the upper movable member 352L1. In addition, it is structured to be relatively movable in the direction along the oblong round hole 352L1h2 relative to the upper movable member 352L1.

[Description of Operation of Movable Member]

[0532] Next, referring to part (a) of FIG. 48 to part (d) of FIG. 48, the operation of the movable member 352L will be described. As described in the Embodiment 1, after the process cartridge 300 is completely inserted into the image forming apparatus main assembly 170, the movable member 352L is pressed by the cartridge pressing unit 190 in interrelation with the operation of closing the front door 11. The operation of the movable member 352L at that time will be described.