Process Cartridge and Remanufacturing Method

The present invention relates to a process cartridge and remanufacturing method therefor.

Here, the electrophotographic image forming apparatus means an apparatus which forms images on a recording medium, using an electrophotographic image forming process. It includes an electrophotographic copying machine, an electrophotographic printer (for example, an LED printer, a laser beam printer, etc.), an electrophotographic facsimile machine, an electrophotographic word processor, and the like.

The process cartridge means a cartridge having as a unit an electrophotographic photosensitive member, and charging means, developing means and cleaning means, which is detachably mountable to a main assembly of an image forming apparatus. It may include as a unit an electrophotographic photosensitive member and at least one of charging means, developing means and cleaning means. It may include as a unit developing means and an electrophotographic photosensitive member.

An image forming apparatus using an electrophotographic process is known which is used with the process cartridge. This is advantageous in that the maintenance operation can be, in effect, carried out by the users thereof without expert service persons, and therefore, the operativity can be remarkably improved. Therefore, this type is now widely used.

Accordingly, it is a principal object of the present invention to provide a recycling method, remanufacturing method and a recycled or remanufactured process cartridge, and a process cartridge which can be easily recycled or remanufactured.

It is another object of the present invention to provide a recycling method, remanufacturing method and a recycled or remanufactured process cartridge, and a process cartridge wherein a seal is mounted to seal a developer supply opening to prevent leakage of the toner.

According to an aspect of the present invention, there is provided a recycling method for a process cartridge detachably mountable to an electrophotographic Image forming apparatus, the process cartridge including a first unit supporting an electrophotographic photosensitive member, and a second unit supporting developing means for developing a latent image formed on the electrophotographic photosensitive member and having a developer accommodation portion for accommodating a developer to be used by the developing means, wherein the first and second units are rotatable relative to each other. The method comprises: (a) a disassembling step for dismounting a coupling member for coupling the first unit and the second unit to separate the units, wherein the second unit has a developing device frame for supporting the developing means and a developer frame having the developer accommodation portion, which frames are coupled by a connecting portion; then (b) a separation step for machining the connecting portion between the developing device frame and developer frame to separate the developing device frame and the developer frame from each other without damage to dowels of the developer frame; then (c) seal mounting step for mounting a seal which seals a developer supply opening provided in the developer accommodation portion to supply, to the developing means, the developer accommodated in the developer accommodation portion, wherein the seal is mounted on a seal mounting plate, and the seal mounting plate is positioned by engagement between a hole thereof and the dowel provided in the developer frame; (d) a refilling step for refilling a developer into the developer accommodation portion before or after the seal mounting step; and (e) a recoupling step for recoupling the first unit and second unit using a coupling member for coupling the first unit and second unit.

These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.

FIG. 1 side sectional view of an electrophotographic image forming apparatus according to a first embodiment of the present invention.

FIG. 2 show an outer appearance of the apparatus of FIG. 1.

FIG. 3 is a side sectional view of a process cartridge according to an embodiment of the present invention.

FIG. 4 shows a schematic outer appearance of the process cartridge of FIG. 3.

FIG. 5 is a right side view of the process cartridge of FIG. 3.

FIG. 6 is a left side view of the process cartridge of FIG. 3.

FIG. 7 shows an outer appearance of the process cartridge of FIG. 3.

FIG. 8 shows an outer appearance of the process cartridge of FIG. 3, as seen from the bottom.

FIG. 9(a) shows an outer appearance of a cleaning unit of the process cartridge of FIG. 3.

FIG. 9(b) shows an outer appearance of a developing unit of the process cartridge of FIG. 3.

FIG. 10 is a side view illustrating a mounting and demounting operation of the process cartridge of FIG. 3 relative to the main assembly of the image forming apparatus.

FIG. 11 is a side view illustrating a mounting and demounting operation of the process cartridge of FIG. 3 relative to the main assembly of the image forming apparatus.

FIG. 12 is a side view illustrating a mounting and demounting operation of the process cartridge of FIG. 3 relative to the main assembly of the image forming apparatus.

FIG. 13 is a side view illustrating a mounting and demounting operation of the process cartridge of FIG. 3 relative to the main assembly of the image forming apparatus.

FIG. 14 is a side view illustrating a mounting and demounting operation of the process cartridge of FIG. 3 relative to the main assembly of the image forming apparatus.

FIG. 15 is a side view illustrating a mounting and demounting operation of the process cartridge of FIG. 3 relative to the main assembly of the image forming apparatus.

FIG. 16 is a side view illustrating a mounting and demounting operation of the process cartridge of FIG. 3 relative to the main assembly of the image forming aparatus.

FIG. 17 is a side view illustrating a mounting and demounting operation of the process cartridge of FIG. 3 relative to the main assembly of the image forming apparatus.

FIG. 18 is a perspective view of an inside of the main assembly of the apparatus

FIG. 19(a) is a perspective view of an inside of the main assembly of the apparatus.

FIG. 19(b) is a side view of an inside of the main assembly of the apparatus.

FIG. 20 shows contact between a contact member and a contact point.

FIGS. 21(a), (b) and (c) show contact between a contact member and a contact point.

FIG. 22 is a side view of a process cartridge according to an embodiment of the present invention.

FIG. 23(a) shows an outer appearance of a developing holder.

FIG. 23(b) is a perspective view of an inside of a developing device holder.

FIG. 24 is a sectional view taken along a line I--I in FIG. 23(a).

FIG. 25 is an enlarged view of a toner detection point in FIG. 23.

FIG. 26 is an exploded perspective view of a developing unit.

FIG. 27 is a perspective view of a developing device frame or developing frame.

FIG. 28 is a perspective view of a developing unit without the developing holder.

FIG. 29 is a perspective view of a toner frame.

FIG. 30 is a perspective view of the toner frame after a toner seal is mounted.

FIG. 31 is a longitudinal sectional view of the toner seal of FIG. 30.

FIG. 32 is a sectional view taken along a line RO--RO of FIG. 3.

FIG. 33 is an exploded perspective view of a toner frame.

FIG. 34 is a bottom view of a process cartridge.

FIG. 35 is a side view illustrating a gear train of FIG. 28.

FIG. 36 is a side view of a toner frame.

FIG. 37 is a side view of a coupling member.

FIG. 38 is a bottom view of the member of FIG. 37.

FIG. 39(a) is a longitudinal sectional view of a connecting portion of a process cartridge, and 39(b) shows a configuration of a locking claw of the coupling member.

FIG. 40 is a perspective view illustrating a recycling operation of a process cartridge.

FIG. 41 is an exploded perspective view of a cleaning frame.

FIG. 42 is a perspective view of a cleaning operation for a cleaning frame.

FIG. 43 is a partly broken perspective view of a developing unit.

FIG. 44 is a longitudinal sectional view showing a separating method of a toner developing device frame.

FIG. 45 is a longitudinal sectional view showing another separation method for the toner developing device frame.

FIG. 46 is an exploded perspective view showing a connecting portion between a toner frame and the developing device frame.

FIG. 47 is a longitudinal sectional view of a toner filling machine.

FIG. 48 is a longitudinal sectional view showing a coupling method between the the developing device frame and the toner frame.

Hereinafter, the preferable embodiments of the present invention will be described. In the following descriptions, the widthwise direction of a process cartridge B means the direction in which the process cartridge B is inserted or removed from the main assembly 14 of an image forming apparatus (hereinafter, apparatus main assembly). This direction coincides with the direction in which the recording medium is conveyed. The longitudinal direction of the process cartridge B means the direction perpendicular (substantially) to the direction in which the process cartridge B is inserted or removed from the apparatus main assembly 14. This direction intersects with (is substantially perpendicular to) the direction in which the recording medium is conveyed. FIG. 1 is a schematic view of an embodiment of the electrophotographic image forming apparatus (laser beam printer) in accordance with the present invention, and FIG. 2 is an external perspective view thereof. FIGS. 3-8 are drawings depicting an embodiment of the process cartridge in accordance with the present invention. FIG. 3 is a sectional side view of the process cartridge; FIG. 4, an external perspective view thereof; FIG. 5, a right side view thereof; FIG. 6, a left side view thereof; FIG. 7, a perspective view as seen from above; and FIG. 8 is a perspective view as seen from below. Also in the following description, the top surface of the process cartridge B means the surface which faces upward when the process cartridge B is in the apparatus main assembly 14, and the bottom surface means the surface which faces downward when the process cartridge B is in the main assembly means 14. Electrophotographic Image Forming Apparatus A and Process Cartridge.

To begin with, referring to FIGS. 1 and 2, a laser beam printer as an electrophotographic image forming apparatus, to which the embodiment of the present invention has been applied, will be described. FIG. 3 is a side view of a process cartridge B.

Referring to FIG. 1, this laser beam printer A is of a type which forms an image on a recording medium, for example, recording paper, OHP sheet, or fabric, through the electrophotographic image forming process. First, a toner image is formed on a drum shaped electrophotographically sensitive member (hereinafter, photosensitive drum) as an image bearing member. More specifically, the photosensitive drum is charged by charging means, and then, a laser beam is projected onto the charged photosensitive member from optical means in response to imaging data, to form a latent image on the photosensitive member in response to the imaging data. Next, this latent image is developed into a toner image by developing means. Meanwhile, a sheet of recording medium 2 placed in a cassette 3a is conveyed, being thereby fed out, by a conveying means 3 comprising a pair of pickup rollers 3b and 3c, and a pair of registration rollers 3d and 3e, and the like, in synchronism with the toner image formation. Next, a voltage is applied to a transfer roller 4 as transferring means, whereby the toner image formed on the photosensitive drum, which a process cartridge B comprises, is transferred onto the recording medium 2. Then, the recording medium having received the toner image is delivered to a fixing means 5. This fixing means 5 comprises a driving roller 5c and a fixing roller 5b containing a heater 5a, and applies heat and pressure to the recording medium 2, which is passed through the fixing means 5, whereby the transferred toner image is fixed. Next, the recording medium 2 now bearing the fixed toner image is conveyed and discharged into a discharge tray 6, through a sheet-reversing path 3j, by a group of discharging roller pairs 3g, 3h and 3i. This discharge tray 6 is provided on the top surface of the apparatus main assembly 14 of the image forming apparatus A. The apparatus A comprises also a pivotable flapper 3k and a discharge roller pair 3m, and when this flapper 3k is operated, the recording medium 2 can be discharged without being flipped over through the discharge roller pair 3m, without going through the sheet-reversing path 3j. In this embodiment, the aforementioned pickup roller 3b, conveyer roller pairs 3c and 3d, register roller 3e, conveyer guide 3f, discharge roller pairs 3g, 3h and 3i, and discharge roller pair 3m constitute conveying means.

Referring to FIGS. 3-8, in the process cartridge B, the surface of a photosensitive drum 7 as the image bearing member with a photosensitive layer 7e (FIG. 20) is uniformly charged by applying a voltage to a charging roller 8, which is a charging means, while the photosensitive drum 7 is rotated. Next, a laser beam carrying the image data is projected by an optical system 1 onto the photosensitive drum 7 through an exposure opening 9, whereby a latent image is formed on the photosensitive drum 7. This latent image is developed with toner by a developing means 9.

The charging roller 8 is placed in contact with the photosensitive drum 7 to charge the photosensitive drum 7, wherein this charging roller 8 is rotated by the rotation on the photosensitive drum 7. The developing means 9 develops the latent image formed on the photosensitive drum 7, by supplying the toner to the photosensitive drum 7, on the regions to be developed. The optical system 1 comprises a laser diode 1a, a polygon mirror 1b, a lens 1c, and a full reflection mirror 1d.

As the toner stirring member 9b of the aforementioned developing means 9 is rotated, the developing means 9 stirs the toner within the toner container 11A, and sends it toward the developing roller 9c, and as a developing roller 9c, in which a magnet is fixed, is rotated, a layer of toner triboelectrically charged by a developing blade 9d is formed on the surface of the developing roller 9c. The toner is supplied from this toner layer to the photosensitive drum 7, on the region to be developed. As the toner Is transferred onto the photosensitive drum 7 in correspondence with the latent image, the latent image is visualized. This developing blade 9d regulates the amount of the toner coated on the peripheral surface of the developing roller 9c. Also, stirring members 9e and 9f for stirring and circulating the toner are rotatively mounted adjacent to the developing roller 9c.

Next, a voltage with a polarity opposite to that of the toner image is applied to the transfer roller 4, whereby the toner image on the photosensitive drum 7 is transferred onto the recording medium 2. Then, the residual toner on the photosensitive drum 7 is removed by a cleaning means 10. The cleaning means 10 comprises an elastic cleaning blade 10a, which is disposed in contact with the photosensitive drum 7. The toner remaining on the photosensitive drum 7 is scraped off by the elastic cleaning blade 10a to be collected in a waste toner collector 10b.

The process cartridge B is formed by combining: a toner chamber portion 11 of the cartridge frame (hereinafter toner chamber frame), which constitutes a portion of the toner container 11A (toner containing portion) for storing the toner; a. developing chamber portion 12 of the frame (hereinafter, developing chamber frame), which contains the developing means such as the developing roller 9c; and a cleaning means portion 13 of the frame (hereinafter, cleaning means frame), which comprises the photosensitive drum 7, cleaning means such as the cleaning blade 10a, charging roller 8, and the like. This process cartridge B is removably installed in the apparatus main assembly 14 by an operator.

The process cartridge B is provided with an exposure opening 1e, which allows the light beam carrying the image data to be irradiated onto the photosensitive drum 7, and a transfer opening 13n, which allows the photosensitive drum 7 to face directly the recording medium 2. More specifically, the exposure opening 1e is provided in the cleaning means portion 13, and the transfer opening 13n is formed between the developing chamber portion 12 and cleaning means portion 13.

Next, the structure of the housing of an embodiment of the process cartridge B according to the present invention will be described.

This process cartridge B in accordance with the present invention is assembled in the following manner. First, the toner chamber frame 11 and developing chamber frame 12 are joined. Then, the cleaning means frame 13 is rotatively attached to the structure formed by joining the preceding two frame portions, completing thereby a cartridge housing. Next, the aforementioned photosensitive drum 7, charging roller 8, developing means 9, cleaning means 10 and the like are disposed within the housing to complete the process cartridge B. The process cartridge B is removably installed in a cartridge installing means provided within the apparatus main assembly 14.

Structure of Housing of Process Cartridge B

The housing of the process cartridge B according to the present invention is constructed by joining the toner chamber frame 11, developing chamber frame 12, and cleaning means frame 13, and its structure will be described below.

Referring to FIGS. 3 and 9, the toner chamber frame 11 comprises a toner storing container portion 11A, in which the toner stirring member 9b for stirring and sending out the contained toner is mounted. The developing roller 9c and developing blade 9d are mounted on the developing chamber frame 12, and the stirring members 9e and 9f, which circulate the toner within the developing chamber, are rotatively mounted adjacent to the developing roller 9c. Further, an antenna rod 9h is disposed adjacent to the developing roller 9c, substantially in parallel thereto. The aforementioned toner chamber frame 11 and developing chamber frame 12 are melt-welded (by the ultrasonic welding in this embodiment) to form a developing unit D as an integral second frame member (refer to FIG. 9(b)).

The photosensitive drum 7, charging roller 8, and cleaning means 10 are mounted on the cleaning means frame 13. Further, a drum shutter member 18, which covers and protects the photosensitive drum 7 when the process cartridge B is out of the apparatus main assembly 14, is attached to the cleaning means portion 13 of the frame to form a cleaning unit C as the first frame member (refer to FIG. 9(a)).

Then, the developing unit D and cleaning unit C are joined with a joining member 22, in such a manner as to be pivotable relative to each other, to complete the process cartridge B. More specifically, referring to FIG. 9, an axis 20 is provided at the end of an arm portion 19 formed at each of the longitudinal ends (in the axial direction of the developing roller 2c) of the-developing chamber portion 12 of the frame (refer to FIG. 9(b)). On the other hand, a recessed portion 21, in which the axis 20 is fitted to fix the positional relationship between the developing unit D and cleaning unit C, is provided at each of the longitudinal ends of the cleaning means portion 13 of the frame (refer to FIG. 9(a)). The joining member 22 is mounted on the cleaning means portion 13 of the frame by inserting the axis 20 into the recessed portion 21, whereby the developing unit D and cleaning unit C are joined in a manner so as to pivot relative to each other about the axis 20. The joining member 22 is provided with a compression spring 22a, so that the developing chamber frame 12 is pressed downward to reliably press the developing roller 9 toward the photosensitive drum 7. Further, a spacer ring 9i having a larger diameter than the developing roller 9 is provided at each of the longitudinal end portions of the developing roller 9, wherein this ring 9i is pressed on the photosensitive drum 7 to keep a predetermined distance (approximately 300 .mu.m) between the photosensitive drum 7 and developing roller 9c. Thus, the positional relationship between the peripheral surface of the photosensitive drum 7 and the peripheral surface of the developing roller 9c can be precisely maintained by the elastic force of the compression spring 22a.

Structure of Guiding Means of Process Cartridge B

Next, guiding means, which guides the cartridge B when the cartridge B is installed into the apparatus main assembly 14 or removed therefrom, will be described referring to FIGS. 4-9, wherein FIG. 5 is a right-hand side view of the cartridge B relative to the direction of an arrow mark X, in which the cartridge B is inserted into the apparatus main assembly 14 (i.e., right-hand side as seen from the developing unit D side), and FIG. 6 is a left-hand side view of the same.

As is evident from the drawings, the guiding means, which serves as a guide when the process cartridge B is inserted into the apparatus main assembly 14 or removed therefrom, is provided on each of the longitudinal end surfaces of the housing 100. This guiding means comprises a cylindrical guide 13a as a first guiding member, a long guide 12a as a second guiding member, and a short guide 13b as a third guiding member.

The cylindrical guide 13a, that is, a cylindrical member, projects outward from the lateral surface of the cleaning means frame 13, in line with the axis of the photosensitive drum 7. It supports the drum shaft 7a, which supports the photosensitive drum 7, in such a manner as not to rotate it. The long guide 12a is provided on each of the longitudinal end surfaces of the developing chamber frame 12, and bridges the surfaces of the developing chamber frame 12 and cleaning means frame 13. The short guide 13b is provided on each of the longitudinal end surfaces of the cleaning means frame 13, above the cylindrical guide 13m. More specifically, the long guide 12a is integrally formed on developing roller holders 40 and 41 (refer to FIG. 23), which will be described later. Further, the cylindrical guide 13a and short guide 13b are integrally formed on the cleaning means frame 13.

The long guide 12a extends in the direction (arrow X direction) in which the cartridge B is inserted, and its angle is set to be substantially equal to an angle at which the process cartridge B is inserted. The cylindrical guide 13a is disposed so as to fall in the path of the imaginary extension of the long guide 12a in the cartridge inserting direction, and the short guide 13b is substantially parallel to the long guide 13a. Referring to FIG. 6, the cylindrical guide 13a, and second guide member 12a, third guide member 13b are also provided on the longitudinal side surface opposite to the one illustrated in FIG. 10, and their configuration and positions are the same as those shown in FIG. 5. These three guiding members project substantially the same distance from the external surface of the cleaning means frame 13 and developing chamber frame 12, which are in the same plane.

Hereinafter, a more detailed description will be given.

The cylindrical guide 13 as the first guiding member is provided on each of the lateral surfaces C1 (right-hand side 13c) and C2 (left-hand side 13d) of the cleaning unit C, wherein the side C1 is the right-hand side portion 13c of the cleaning means frame 13, relative to the axial direction of the photosensitive drum 7, as the cartridge B is seen from the developing unit D side (as the cartridge B is seen from the downstream side of the cartridge B inserting direction). The other side C2 is the left-hand side portion of the cleaning means frame 13, relative to the axial direction of the photosensitive drum 7. This cylindrical guide 13a is a cylindrical member, which projects from each of both longitudinal end surfaces 13c and 13d of the cleaning means frame 13 in the axial direction of the photosensitive drum 7. The drum shaft 7a is supported by this cylindrical member 13a, which fits around the drum shaft 7a. In other words, the drum shaft 7a is guided by the guiding member 16a, which will be described later, with the cylindrical member 13a being interposed, and then, the position of the drum shaft 7a is fixed by a groove 16a15 (refer to FIGS. 10-17).

The long guide 12a as the second guide member is provided on each of the longitudinal end surfaces D1 (right-hand portion 12c) and D2 (left-hand side 12d) of the developing unit D, wherein one surface, D1, of the lateral portion is the right-hand portion 12c, relative to the axial direction of the photosensitive drum 7, of the developing chamber frame portion 12, and the other surface, D2, is the left-hand side portion 12d, relative to the axial direction of the photosensitive drum 7, of the developing chamber frame portion 12. The long guide 12a is disposed away from the cylindrical guide 13a, being on the upstream side of the cylindrical guide 13a, relative to the cartridge inserting direction (arrow X direction). More precisely, the long guide 12a is disposed within a region L formed between the top and bottom imaginary lines 111 and 112 (FIG. 5) extended parallel in the inserting direction and tangentially from the peripheral surface of the cylindrical guide 13a, and this long guide 12a bridges between the developing chamber frame portion 12 and cleaning means frame portion 13, with its inserting end portion 12a1 extending over the lateral surface area of the cleaning frame portion 13 (by an approximate distance of 1 mm to 3 mm).

The short guide 13b as the third guiding member is provided on the lateral surfaces 13c and 13d of the cleaning unit C, above the cylindrical guide 13a. More specifically, the short guide 13b is substantially directly above the cylindrical guide 13a as seen from the cartridge inserting direction. In other words, the short guide 13b is disposed within the region 15 formed between two parallel lines 113 and 114, which are drawn in such a manner as to be tangent to the peripheral surface of the cylindrical guide 13a and substantially perpendicular to the cartridge inserting direction (arrow X direction). In addition, the short guide 13b is substantially parallel to the long guide 13a.

Here, typical measurements of the guiding members will be listed Hereinafter, a tolerable range means the measurement range adopted in this embodiment of the process cartridge.

The cylindrical guide 13a is approximately 10.0 mm in diameter (tolerable range of 7.5 mm to 10.0 mm); the long guide 12a, approximately 36.0 mm in length (tolerable range of 15.0 mm to 41.0 mm) and approximately 8.0 mm in width (tolerable range of 1.5 mm to 10.0 mm); and short guide 13b is approximately 10.0 mm in length (tolerable range of 3.0 mm to 17.0 mm) and approximately 4.0 mm (tolerable range of 1.5 mm to 7.0 mm) in width. Further, the distance between the peripheral surface of the cylindrical guide 13a and the inserting end portion 12a1 of the long guide 12a is approximately 9.0 mm.

The distance between the peripheral surface of the cylindrical guide 13a and the bottom end tip 13b1 of the short guide 13b is approximately 7.5 mm (tolerable range of 5.5 mm to 9.5 mm).

Next, a regulatory contact portion 13e and a disengagement contact portion 13f, which are provided on the top surface 13d of the cleaning unit C, will be described. Here, the top surface means such a portion of the cleaning unit C surface that is going to face upward when the process cartridge B is installed into the apparatus main assembly 14. In this embodiment, it is the top surface 13i of the cleaning unit C.

The regulatory contact portion 13e and disengagement contact portion 13f are provided on each Of the right lateral end portion 13c and left lateral and portion 13d of this surface 13i. This regulatory contact 13e fixes the position of the process cartridge B in the apparatus main assembly 14. More specifically, when the process cartridge B is inserted into the apparatus main assembly 14, the contact 13e comes in contact with a fixing member 25 provided on the apparatus main assembly 14 (FIGS. 10-17), whereby the position of the process cartridge B is regulated. The disengagement contact portion 13f displays its function when the process cartridge B is removed from the apparatus main assembly 14. More specifically, when the process cartridge B is taken out of the apparatus main assembly 14, it comes in contact with the fixing member 25 to permit a moment to function to smoothly remove the cartridge B. The steps for installing or removing the process cartridge B will be described later with reference to FIGS. 10-17.

Describing in more detail, a recessed portion 13g is provided on the cleaning unit C, on the top surface 13i of the cleaning unit C, at each of the lateral edges relative to the cartridge inserting direction. This recess portion 13g is provided with: the first slanted surface 13g1, which extends upward toward the rear from the leading end of the cartridge B relative to the inserting direction (arrow X direction); the second slanted surface 13g3, which extends downward toward the rear from the top end 13g2 of the slanted surface 13g3; and the fourth slanted surface 13g5, which extends further downward toward the rear from the bottom end 13g4 of the slanted surface 13g3. At the bottom end 13g6 of the slanted surface 13g5, a wall (slanted or inclined surface) 13g7 is provided. The second slanted surface 13g3 corresponds to the regulatory contact portion 13e, and the wall 13g7 corresponds to the disengagement contact portion 13f.

Here, the typical measurements of the portions described above will be listed.

The regulatory contact portion 13e is angled by 0 degree relative to the horizontal direction X (FIG. 5) of the cartridge B in the apparatus main assembly 14, and is approximately 6.0 mm in length (tolerable range of 4.5 mm to 8.0 mm)). The disengagement contact portion 13f is slanted by .theta.1 (approximately 45 degrees) relative to the horizontal direction 1, and is approximately 10.0 mm in length (tolerable range of 8.5 mm to 15.0 mm).

Steps for Installing or Removing Process Cartridge

Next, the steps for installing the process cartridge B into the apparatus main assembly 14, or removing it therefrom, will be described with reference to FIGS. 10-19.

Let it be assumed that the process cartridge B structured as described above can be installed into the cartridge accommodating means provided within the apparatus main assembly 14, and can be removed therefrom.

Referring to FIGS. 18 and 19, as an operator opens a pivotal cover 35 by pivoting it about a supporting point 35a, a cartridge accommodating space S, and left and right cartridge installation guides 16, which are mounted on the corresponding sides of the apparatus main assembly 14, are exposed. Each of the cartridge installation guides 16 comprises a pair of guide portions of its own, that is, a first guide portion 16a and a second guide portion 16b, which correspond to the same on the opposite side. The installation of the process cartridge B into the apparatus main assembly 14 is accomplished by inserting the process cartridge B along the guide portions 16a and 16b and closing the cover 15. As for the inserting direction of the cartridge B, it is a direction which intersects with the axial line of the photosensitive drum 7; more specifically, such a direction that is substantially perpendicular to the axial line of the photosensitive drum 7 as illustrated in FIGS. 10-17. In this case, the cleaning unit C side is the leading side and the developing unit D side is the trailing side.

A recessed portion 17 is provided on the cartridge B, at each of the longitudinal ends, which makes it easier for an operator to hold it during its installation or removal (see FIG. 3); the operator uses both hands to hang onto the recessed portions, as handholds, of the process cartridge when installing or removing it.

Further, the process cartridge B comprises a drum shutter 18 (see FIG. 3), the movement of which is linked to the movement of the cartridge B during its installation or removal. When the cartridge B is removed from the laser beam printer assembly, the shutter 18 is closed to protect the portion of the photosensitive drum 7 which faces the transfer opening. This shutter member 18 is connected to each of the tips of an arm 18a and a link member 18b, being thereby supported, both of which are rotatively supported on the cleaning means frame 13 as illustrated in FIG. 6. Also referring to FIG. 6, as the process cartridge B is inserted in the apparatus main assembly 14 in the arrow X direction, the leading end of the lever 23, which is fixed to the arm 18a by its base portion, strikes a stopper (unillustrated) fixed on the apparatus main assembly 14, whereby the lever 23 is rotated about a supporting point 18c where the shutter arm 18a is supported, opening thereby the shutter member 18. As the process cartridge B is taken out of the apparatus main assembly 14, the shutter member 18 is closed due to the elastic force of a torsion spring 23a.

The first guide portion 16a is the bottom; portion of the guide member 16, and guides the long guide 12a and cylindrical guide 13a provided on the process cartridge B side. This first guide portion 16a comprises a main guide portion 16a1, a stepped portion 16a2, a recessed portion 16a3, an auxiliary guide portion 16a4, and a positioning groove 16a5, which are disposed in this order from the upstream side toward the downstream side relative to the inserting direction. The main guide portion 16a1 guides the long guide 12a and cylindrical guide 13a. The auxiliary guide portion 16a4 guides the cylindrical guide 13a into the positioning groove 16a5. The positioning groove 16a5 is where the cylindrical guide 13a is fitted to regulate the position of the cartridge B in the apparatus main assembly 14. The second guide portion 16b is the upper portion of the guide member 16, and comprises a slanted surface 16b1 and a recess 16b2, which are disposed in this order from the upstream side toward the downstream side relative to the inserting direction.

Further, in the cartridge accommodating space S of the apparatus main assembly 14, a fixed member 25 (member for regulating the rotation) Is provided on the left and right sides. It is fixed to a stay 27. This fixed member 25 comes in contact with the aforementioned regulatory contact portion 13e to regulate the clockwise rotation of the cartridge B (FIG. 15). More specifically, the cartridge B is accurately positioned in the apparatus main assembly 14 as the cylindrical guide 13a fits into the groove 16a5 and the regulatory contact 13e comes in contact with the fixed member 25. Further, when the cartridge B is taken out, the fixed member 25 comes in contact with the disengagement contact portion 13f to facilitate the smooth removal of the cartridge B.

Further, in the cartridge accommodating space S, a pressing member 26 is disposed on the left and right sides (refer to FIGS. 10-19). This pressing member 26 pressed in the clockwise direction (FIGS. 10-17) by the elastic force of a coil spring 26a is rotatable about a fulcrum 26b, and elastically presses the top surface of the cartridge S, whereby the cartridge B is prevented from being vibrated when the apparatus A is subjected to vibration or the like.

Next, the relationship between the installation guide 16 provided on the apparatus main assembly 14 and the guide members 12a, 13a and 13b provided on the cartridge B, during the installation or removal of the cartridge B, will be described with reference to the drawings. FIGS. 10-15 are schematic drawings, which depict the steps for installing the process cartridge B from the beginning of the cartridge installation to the moment when the process cartridge B is finally positioned in a predetermined location. In FIGS. 10 and 15, the full side view of the process cartridge B is depicted with a solid line, and the installation guide member of the apparatus main assembly 14 is depicted with a double dot chain line (imaginary line). In FIGS. 11-14, which depict intermediary steps of the cartridge installation, only the guide members of the process cartridge B are depicted with the solid line, and the other portions are depicted with the double dot chain lines.

First, referring to FIG. 10, at the beginning of the cartridge B installation into the apparatus main assembly 14 by an operator, the cylindrical guide 13a and long guide 12a of the cartridge B are guided by the guide portion 16a in such a manner as to slide thereon. At this moment, the short guide 13b is not guided by the guide portion 16b, being away from it by a predetermined distance E (in this embodiment, approximately 2.0 mm to 4.0 mm).

Also at this moment, the pressing member 26 rotates upward following the slanted surface 13i provided on the top surface of the cartridge B, so that it does not interfere with the cartridge installation. As the cartridge B is being further inserted, the pressing member 26 keeps on sliding on the top surface of the cartridge B, checking thereby the upward movement of the cartridge B. Even after the cartridge B has been installed in the apparatus A, the pressing member 26 keeps on pressing on the top surface of the cartridge B as long as the cartridge B is in the apparatus A.

Next, when the process cartridge B has been further inserted and is in the state depicted in FIG. 11, the cylindrical guide 13a is ready to pass the stepped portion 16a2 provided on the first installation guide portion 16a and to move onto the recess portion 16a3 provided also on the first installation guide portion 16a. This recessed portion 16a3 of the guide portion 16a is to let go the long guide 12a when the process cartridge B is inserted to a predetermined point (FIG. 15), and its depth m (in this embodiment, approximately 4.0 mm to 8.0 mm) is set to be larger than the aforementioned distance E (E<M). It should be noted that at this moment, the short guide 13b is not in contact with the second guide portion 16b (upwardly slanted surface 16b1).

Next, as the process cartridge B is further inserted till the state depicted in FIG. 12 is realized, the short guide 13b makes contact with the guide portion 16b before the cylindrical guide 13a of the cartridge B reaches the bottom of the recessed portion 16a3. In other words, at this time, both the long and short guides 12a and 13b serve as the insertion guide, whereby the shock, which might be imparted on the cartridge B by the stepped portion or the like, is reduced.

As the process cartridge B is further inserted, the state Illustrated in FIG. 13 is realized. In this state, the trailing end of the long guide 12a of the process cartridge B is at the edge of the recessed portion 16a3 of the first guide portion 16a, and the cylindrical guide 13a of the process cartridge B is in contact with the auxiliary guide portion 16a4, being ready to follow the guide portion 16a4. Next, the cylindrical guide 13a and short guide 13b of the process cartridge B are guided by the first guide portion 16a and second guide portion 16b, respectively (FIG. 14).

Next, as the cartridge B is further inserted and the state illustrated in FIG. 14 is realized, the short guide 13b comes to the recessed portion 16b2 of the second guide portion 16b. For a short period in which this short guide 13b drops into the recessed portion 16b2, only the cylindrical guide 13a is in contact with the apparatus main assembly 14, at the auxiliary guide portion 16a4; therefore, the process cartridge B slightly rotates in the counterclockwise direction, and lastly, the cylindrical guide 13a drops into the groove 16a5 of the guide portion 16a (FIG. 15). At substantially the same time, the regulatory contact portion 13c provided on the cleaning means frame portion 13 comes in contact with the rotation regulating portion 25a (FIG. 15) of the fixed member 25 fixed to the apparatus main assembly 14. As a result, the overall position and orientation of the process cartridge B within the apparatus A is fixed. In this state, the position of the process cartridge B is fixed by the cylindrical guide 13a alone, and the other guides (long and short guides 12a and 13b) are not in contact with any portion of the installation guide member 16 of the apparatus main assembly 14; therefore, the position of the cartridge B is accurately fixed.

The positional relationship between the regulatory contact portion 13e and rotation regulating portion 25a, which will be described later in detail, is such that the moment, which is generated on the process cartridge B as the process cartridge B is driven, is received by the contact between regulatory contact portion 13e and rotation regulating portion 25a. The distance from the contact point between the regulatory contact portion 13e and rotation regulating portion 25 to the center of the cylindrical guide 13a is longer than the distance between the long guide 12a and the center of the cylindrical guide 13a, and the distance between the short guide 13b and center of the cylindrical guide 13a. Therefore, the orientation of the process cartridge B remains more stable when the process cartridge B is driven.

In a state shown in FIG. 15, a helical drum gear 7b provided on the photosensitive drum 7, at one of the axial ends, engages with a driving helical gear 28 provided on the apparatus main assembly 14. Thus, the driving force is transmitted from the apparatus main assembly 14 to the photosensitive drum by way of the gears 28 and 7b, wherein as the driving force is transmitted from the helical gear 28 to helical gear 7b, the cartridge B is subjected to a force that works in the clockwise direction (FIG. 17). However, the movement generated on the cartridge B is regulated by the contact portion 13e.

The pressing member 26 presses down the process cartridge B from above. Therefore, even if the cylindrical guide 13a fails to drop into the groove 16a5 of the apparatus main assembly 14, a moment is generated about the contact point between the rotation regulating portion 25a and contact portion 13e, whereby the cylindrical guide 13a is caused to drop into the groove 16a5.

Next, referring to FIGS. 16 and 17, the steps for taking the process cartridge B out of the apparatus main assembly 14 will be described. In the drawing, the direction indicated by an arrow Y is the direction in which the process cartridge B is removed.

Referring to FIG. 16, when the process cartridge B is to be removed from the apparatus main assembly 14, the operator grabs a handle portion 17 (to provide the handle, recessed portions, are formed on the cartridge B) and lifts the cartridge B by the handle portion 17 (direction of an arrow a), whereby the process cartridge B is rotated counterclockwise about the cylindrical guide 13a. As a result, the disengagement contact portion 13f of the process cartridge B makes contact with the disengagement contact portion 25b of the fixed member 25 provided on the apparatus main assembly 14. As the process cartridge B is further lifted. It is rotated about the contact point F between the disengagement contact portion 13f and disengagement contact portion 25b of the fixed member 25. As a result, the cylindrical guide 13a is lifted out of the groove 16a5 At this moment, the engagement between the drum gear 7b and driving gear 28 is smoothly broken. In this state, the process cartridge B can be pulled straight out of the apparatus A, following the steps depicted in FIGS. 14, 13, 12, 11 and 10 in that order.

As described above, according to this embodiment, the long guide as the second guide member is extended in the cartridge inserting direction in such a manner as to bridge the lateral surfaces of the developing unit D and cleaning unit C; therefore, the process cartridge is prevented from wobbling during the installation or removal. As a result, the cartridge installation becomes more reliable., which improves the operational efficiency.

The guiding means, which serves as the guide when the process cartridge is inserted into the apparatus main assembly 14 or removed therefrom, is constituted of three guide members: cylindrical guide 13a, long guide 12a, and short guide 13b, and the process cartridge B is guided by at least two guides during its installation or removal; therefore, even if there is a stepped portion or the like on the installation guide members of the apparatus main assembly 14, the shock, to which the process cartridge B might be subjected, is cushioned.

The position of the process cartridge B is fixed by the rotation regulating portion 25a oriented to control the moment, which is generated on the cartridge B as the cartridge is driven, and the cylindrical guide 13a, whereas the other guides (long and short guides 12a and 13b) remain in non-contact with the guide members of the apparatus main assembly 14; therefore, the orientation of the process cartridge B remains more stable while the image forming apparatus is driven (during the image formation).

As for the guiding means for installing or removing the cartridge B, the embodiment described above exemplifies a guiding means comprising three guide members positioned at different locations. However, the embodiment described above is not limited to this example, but instead, it may be a guiding means comprising at least a cylindrical guide as the first guide member, and a long guide as the second guide member, or a guiding means comprising an additional guide member or guide members besides the three mentioned above. Such an arrangement can also stabilize the cartridge B during the installation or removal, and improves the operational efficiency.

Referring to FIGS. 9(a) and 9(b), a spur gear 7n is disposed on the photosensitive drum 7, at the end opposite, relative to the axial direction, to the end where the drum gear 7b is disposed. When the process cartridge B is mounted in the apparatus main assembly 14, this spur gear 7n engages with a gear (unillustrated), which is disposed in the apparatus main assembly 14 on the same axis as the transfer roller 4. As it engages with the unillustrated gear, the driving force is transmitted from the process cartridge to rotate the transfer roller 4.

A reference numeral 9u designates a helical gear, which is disposed at one of the axial ends of the developing roller 9c. It engages with the aforementioned spur gear 7b, whereby the driving force for rotating the developing roller 9c is transmitted by way of the helical drum gear 7b.

Toner Container Frame (toner container)

Referring to FIGS. 3, 29, 30, 32 and 33, a toner container frame (toner container) will be described in detail. FIG. 29 is a perspective view before a toner seal is welded; FIG. 30, a perspective view after the toner is filled; FIG. 32, a plan view a top frame 11a; and FIG. 33 is a perspective view of the disassembled toner container frame.

A toner container frame 11 is constituted of two components: a top frame 11a (first frame) and a bottom frame 11a (second frame). On each of the longitudinal end surfaces of the top frame 11a, a recessed portion 17 is provided. It is disposed close to the top surface of the top frame, and serves as the handhold described above. The bottom frame 11b is provided with a number of ribs 11c. They are disposed in parallel to the longitudinal direction of the process cartridge B, with intervals of approximately 5 mm, on the exterior surface, which becomes the bottom portion when the process cartridge B is assembled. When grasping the process cartridge B, the operator uses both hands, holding onto the recessed portion 17 and ribs 11c. In this case, the ribs 11c prevent the hands from slipping when grasping the process cartridge B. The top and bottom frames 11a and 11b are joined at a welding surface U, and the welding rib is melted by forced vibration, welding the frames 11a and 11b together. The methods for joining two frames are not limited to the forced vibration method. For example, they may be welded using heat welding, ultrasonic welding, or the like, or may be simply glued. Before joining two frames 11a and 11b, the stirring member 9b is assembled into the top frame 11a, and then a coupling member 11e is put through a hole 11e1, and engaged to the end portion of the stirring member 9b (state illustrated in FIG. 29). The hole 11e is located at one of the longitudinal ends of the top frame 11a. On the same side as this hole 11e, a toner filling opening 11d for filling the toner is located. The diameter of this toner filling opening 11d is approximately 30 mm. In other words, the hole 11e1 and toner filling opening lid are located next to each other. The toner frame 11 is provided with an opening 11i for feeding the toner from the toner frame 11 to the developing frame 12, and a seal, which will be described later, is welded to cover this opening 11i. After the seal is welded, the toner is filled through the toner filling opening lid, and then the toner filling opening lid is covered with a toner cap 11f, completing a toner unit J. The toner cap 11f is formed of soft material such as polyethylene or polypropylene, and is pressed into the toner filling opening 11d of the toner frame 11 so that it does not come off. Next, the toner unit J is joined with the developing frame 12, which will be described later, using ultrasonic welding, constituting a part of a completed developing unit D. The joining methods are not limited to ultrasonic welding. They may be glued together, or may be snap-fitted using the elasticity of their materials.

Referring to FIG. 3, the angle .theta. of a slanted surface K, constituting a part of the bottom frame 11b of the toner frame 11, must be such an angle that the toner located in the deeper end of the toner chamber slides down, naturally and continuously, in response to toner consumption. More specifically, the angle .theta. is the angle formed between the slanted surface K of the process cartridge B and the horizontal surface Z, with the apparatus main assembly 14 being leveled. The preferable value for the angle .theta. is approximately 60 degrees. When rotating, the stirring member 9b reaches beyond the plane of the slanted surface K. Therefore, the bottom frame 11a is provided with a recessed portion 11g to afford a clearance for the rotating stirring member 9b; it bulges outward The rotational diameter of the stirring member 9b is approximately 30 mm. (According to this embodiment, the bottom surface of the bottom frame 11b dips approximately 3.6 mm. The depth of this recessed portion has only to be approximately 2.0 mm to 10 mm.) The reason for this arrangement is as follows. If the sweeping area of the stirring member 9b is above the slanted surface K, it is possible that the toner settling between the tip of the toner feeding (stirring) member 9b and the slanted surface K is not fed into the developing frame 12, being left unused. However, in this embodiment, the toner is reliably fed from the toner frame 11 into the developing frame 12.

Referring to FIG. 29, the stirring member 9b is formed of a rod of steel or the like material, having a diameter of approximately 3 mm and being in the form of a rectangular frame to improve toner stirring/feeding performance. Each of the opposing longitudinal ends of the stirring member 9b is provided with a supporting axis 9b1. The supporting axis 9b1 on one end is fitted in a hole 11r, which is located on the internal surface of the top frame 11a, adjacent to the opening 11i of the top frame 11a, and the supporting member 9b1 on the other end is fixed to the coupling member 11e.

As described above, the toner frame 11 is constituted of two members, that is, the top and bottom frames 11a and 11b, and the bottom wall of the bottom frame 11b is provided with the recessed portion 11g to afford a clearance for the toner feeding member 9b; therefore, it is possible to provide even a large capacity process cartridge with reliable toner feeding performance, without increasing cost.

The foregoing can be summarized as follows.

The toner frame (toner container) 11 constitutes a part of a replaceable process cartridge for an electrophotographic image forming apparatus, which comprises an electrophotographic photosensitive member (7, 7e), and developing means 9 for developing the latent image formed on the electrophotographic photosensitive member. It stores the toner used in the developing means 9 for developing the latent image, and comprises the top frame 11a, and the bottom frame 11b which is joined with the top frame 11a. The top frame 11a comprises the opening 11i for supplying the stored toner to the developing means 9, and a stirring member mount 9b1 (FIG. 29) where the stirring member 9b for stirring the stored toner is rotatively mounted. The bottom frame 11b is provided with the recessed portion 11g (as seen from within), that is, a bulge (as seen from outside), to afford the clearance for the sweeping area of the stirring member 9b. Further, the top frame 11a is provided with the welding surface U (joining surface) where the bottom frame 11b is welded (FIGS. 29, 33 and 36). The angle of this welding surface, that is, the angle which is formed between this welding surface and the horizontal line 12 when the shorter edge of the rectangular opening 11i (FIG. 29) is vertically oriented, is approximately 20 to 40 degrees. Further, the top frame 11a is provided with the hole 11e1 (transmission opening), through which the coupling member 11e (tansmission member) for transmitting the driving force from the apparatus main assembly to the stirring member 9b, when the process cartridge is in the image forming apparatus, is put. One end of the coupling member 11e is engaged with the stirring member 9b, and the other end is engaged with the toner feeding gear 9s to receive the driving force. The stirring member 9b is formed of a metallic rod, and is in the form of a rectangular frames Further, the top frame 11a is provided with the toner filling opening 11d (filling opening), which is disposed next to the hole 11e (FIG. 29). It is to this toner filling opening 11d that the toner cap 11f for sealing the toner filling opening 11d is attached. Further, the top frame 11a is provided with a grove 11n which extends in parallel to the plane of the opening 11i. This groove 11n is where the developing frame 12, in which the developing roller 9c of the developing means 9 is mounted, is joined. Further, the top frame 11a is provided with a cover film plate 53 (seal mount) where a cover film 51 for sealing the opening 11i and a tear tape 52 (toner seal) for unsealing the opening 11i are attached. The cover film plate 53 is also in parallel to the plane of the opening 11i. Further, the top frame 11a is provided with the handhold (recessed portion) 17, which is where the longitudinal end surfaces of the process cartridge are indented to offer the handhold. The recessed portion 11g (bulge) of the bottom frame 11b is in the form of a longitudinally sliced cylinder, having an arc shaped cross section. It is disposed close to the opening 11i, relative to the widthwise direction of the bottom frame 11b, and extends in the longitudinal direction of the opening 11i, along substantially the entire length the opening 11i. Further, the top frame 11a is provided with a slanted surface L. The angle of the slanted surface L, that is, the angle which is formed between this slanted surface L and the vertical line when the shorter edge of the opening 11i is vertically oriented, is approximately 10 to 40 degrees (FIG. 36). This slanted surface L is located above the opening 11i, sloping down toward the opening 11i and extending in parallel to the longitudinal direction of the opening 11i, along substantially the entire length of the opening 11i.

The toner frame (toner container) 11 is assembled in the following manner. First, the top frame 11a, which is provided with the opening 11i for supplying the stored toner into the developing means 9, and the stirring member mount 9b1 where the stirring member 9b is mounted, is prepared. Next, the bottom frame 11, which is provided with the recessed portion 11g bulging outward to afford the clearance to the sweeping area of the stirring member 9b, is prepared. Finally, the two frames, 11a and 11b, are joined to complete the toner frame (toner container) 11.

It is predictable that the toner within the toner frame 11 will move suddenly due to vibration, impact, or the like, during the shipment of the process cartridge B from factory to user.

Therefore, according to the present invention, plural partitioning plates 11p are-provided within the top frame 11a of the toner frame 11.

They are arranged in the longitudinal direction of the top frame 11a (FIGS. 3, 32 and 33). In this embodiment, three partitioning plates 11p are disposed at three different locations. As for the configuration of the partitioning plates 11p, the edge 11p1 facing the toner feeding member 9b forms a substantial quadrant in such a manner as to surround the toner feeding member 9b, and the edge 11p2 facing the bottom frame 11a holds a slight gap therefrom. Further, as seen from the longitudinal direction of the top frame 11a, the edge 11p1 is positioned so that the partitioning plates 11p partially blocks the toner filling opening 11d.

In order to prevent the toner from shifting within the toner container 11A, the partitioning plate 11p should be as large as possible. However, when the toner filling opening 11d is faced upward to fill the toner, the partitioning plates 11p is situated directly below the toner filling opening 11d, and if the partitioning plate lip blocks the toner filling opening 11d entirely, it is difficult to fill the toner into the deepest corner of the toner container 11A. Therefore, the partitioning plate 11p should be formed as it is in this embodiment, so that the toner can be filled all the way into the deepest corner through the space which is not blocked by the partitioning plate 11d. Further, according to the present invention, the partitioning plates 11p occupies a substantial part of the cross-sectional area perpendicular to the longitudinal direction of the toner frame 11; therefore, even when the process cartridge B is subjected to vibration, impact, or the like, the partitioning plate 11p can prevent the toner from shifting and becoming compacted.

Toner Frame Structure Facing Developing Frame

Referring to FIGS. 3, 29 and 31, at the joint between the toner frame 11 and developing frame 12, the opening 11i for feeding the toner from the toner frame 11 into the developing frame 12 is provided. The opening 11i is surrounded by a recessed surface 11k, on which the cover film plate 53 is thermally welded. The depth of this recessed surface 11k is such that after the cover film plate 53 is welded to the recessed surface 11, the outward facing surface of the cover film plate 53 becomes substantially level with the surface 11j of the toner frame 11 (top frame 11a). On the recessed surface 11k, plural dowels 11m are disposed in a straight line along one of the longitudinal edges of the opening 11i (in this embodiment, five dowels 11m are disposed at five different locations). Also, two dowels 11o are disposed on the surface 11j along one of the widthwise edges of opening 11i; these two dowels 11o are not on the recessed surface 11k. Further, along each of the longitudinal external edges of the surface 11j, a grove 11n is disposed in parallel to the one on the opposing side. The bottom surface 11n2 of this groove 11n is above the level of the surface 11j (closer to the developing frame 11 than the surface 11i) (FIG. 31).

The surface of the developing frame 12, which comes directly in contact with the surface of the toner frame 11, is a surface 12u. Along each of the longitudinal edges of this surface 12u, a tongue 12v, which fits into the grove 11n of the toner frame 11, is provided. At the end surface of this tongue 12v, an angular ridge 12v1, used for ultrasonic welding, is provided (FIG. 31); the angular ridge 12 is melted by ultrasonic welding to weld the toner frame 11 and developing frame 12, along their longitudinal external edges.

Referring to FIG. 30, the cover film plate 53, which is loosely fitted onto the recessed surface Ilk of the toner frame 11, is provided with holes 53c, which correspond to the plural dowels 11m. The holes 53c1, which exactly fit to the corresponding end dowels 11m1, are round, and the holes 53c other than the round holes 53c1 are elongated so as to be loosely fitted to the corresponding dowels 11m other than the end dowels 11m1. More specifically, the positional relationship between the dowels 11m and hole 53c is such that when the dowels 11m1 and 11m are fitted in the corresponding holes 53c1 and 53c, the dowels 11m is positioned at the middle of the elongated holes 53c in the longitudinal direction of the elongated holes 53c. Further, the cover film plate 53 is provided with an opening 53b (having approximately the same size as the opening 11i), which corresponds to the opening 11i. In order to seal this opening 53b, a cover film 51, which can be easily torn in the longitudinal direction, is pasted on the cover film plate 53; the four peripheral areas of the cover film 51 are pasted on corresponding four peripheral areas of the opening 53b. On the cover film 51, the tear tape 52 for tearing the cover film 51 to unseal the opening 53b is welded. The tear tape 52 is extended from one of the longitudinal ends of the opening 53b to the other end, where it is doubled back and put through the starting end, between the toner frame 11 and an elastic seal member 54 (FIG. 27), such as a piece of felt, which is pasted on the flat developing frame surface 12u, directly facing the toner frame 11, at the starting end. The doubled back end of the tear tape 52 is exposed from between the toner frame 11 and developing frame 12 (FIGS. 6 and 30). On the inward side surface of the seal member 54, a synthetic resin film tape 55 with a small friction coefficient is pasted. Also on the flat surface 12u, an elastic seal member 56 is pasted at the longitudinal end opposite from where the seal member 54 is pasted (FIG. 27).

In order to make it easier to align the toner frame 11 and developing frame 12 when joining the two frames 11 and 12, the surface 11j of the toner frame 11 is provided with a round hole 11r and a square hole 11q, which engage with a cylindrical dowel 12w1 and square column dowel 12w2, respectively, provided on the developing frame 12; the round hole 11r engages with the dowel 12w1, and the square hole 11q loosely engages with the dowel 12w2. The seal member 56 is fitted around the cylindrical dowel 12w1, and also is glued to the flat surface 12u. Further, in the flat surface 12u of the developing frame 12, which directly comes in contact with the toner frame 11, recessed portions 12y are provided, in which the dowels 11m and 11o of the toner frame 11 loosely fit.

Before the toner frame 11 and developing frame 12 are joined, each frame is independently assembled as a subcomponent Thereafter, the cylindrical positioning dowel 12w1 and square column positioning dowel 12w2 of the developing frame 12 are fitted into the round positioning hole 11r and square positioning hole 11q of the toner frame 11, respectively. Also, the tongue 12v of the developing frame 12 is fitted into the groove 11n of the toner frame 11. Then, as the toner frame and developing frame 12 are pressed together, the seal members 54 and 56 are compressed, and ridges 12z, which are integrally formed as spacers with the developing frame, at each of the longitudinal ends, approach the surface of the toner frame 11. The ridges 12z are aligned in the widthwise direction of the developing frame 12, with an interval substantially equal to the width of the tear tape 52, to allow the tear tape 52 to be put through. With the toner frame 11 and developing frame 12 being pressed together as described above, ultrasonic vibration is applied between the tongue 12v and groove 11n, whereby the angular ridge 12v1 is melted and welded to the bottom of the grove 11n by the frictional heat. As a result, the edges 11n1 of the grooves 11n of the toner frame 11, and the ridges 12z, as the spacers, of the developing frame 12, firmly contact their counterparts, sealing the entire joint between the toner frame 11 and developing frame 12, except for the gap left between the surface 11j of the toner frame 11 and the flat surface 12u of the developing frame 12. The cover film 51 and tear tape 52 are confined in this gap.

In order to feed the toner stored in the toner frame 11 into the developing frame 12, the operator has only to pull the end portion 52a (FIG. 6) of the tear tape 52, which is exposed from the process cartridge B, by hand. As the tear tape 52 is pulled, the cover film 51 is torn open to unseal the opening 53b (11i), allowing the toner to be fed from the toner frame 11 into the developing frame 12.

Since the joining portions of the toner frame 11 and developing frame 12 are structured as described in the foregoing, that is since the surface of the cover film plate 53 and the surface 11j of the toner frame 11 are substantially at the same level, the tear tape 52 can be smoothly pulled out from between the two frames 11 and 12 by applying to the tear tape 52 a sufficient amount of force for tearing the cover film 51 as described above. The cover film plate 53 is located by the dowel 11m1 at one of its longitudinal ends, that is, the end opposite to where the tear tape 52 is pulled out, and in addition, it is disposed on the recessed surface 11k of the toner frame 11; therefore, it is not liable to be dislocated. Further, the dowels 11m are aligned in a straight line in the longitudinal direction, and the cover film plate 53 is fitted to these dowels 11m; therefore, even the easily deformable cover film 51 can be precisely located to allow it to remain flat. Further, even if the assembly process moves on to the subsequent steps before the welded joint between the cover film plate 53 and toner frame 11 is solidified and stabilized, the cover film plate 53 is not dislocated

When the toner frame 11 and developing frame 12 are joined using an ultrasonic welding method, frictional heat is generated to melt the angular ridge 12v1. This frictional heat is liable to cause thermal stress in the toner frame 11 and developing frame 12, which might result in the thermal deformation of the toner frame 11 and developing frame 12. However, according to this embodiment, the grove 11n of the toner frame 11 and the tongue 12v of the developing frame 12 are engaged across substantially the full length in the longitudinal direction. In other words, the joint portions between the toner frame 11 and developing frame 12 are reinforced as to frames 11 and 12 are joined; therefore, the thermal deformation due to the thermal stress is not likely to occur.

As described above, the grooves 11n, handholds (recessed portions) 17, partitioning plates 11p, toner filling opening 11d, hole 11e1, round hole 11r, square hole 11q, and cover film plate mount (recessed surface 11k, dowels 11m and opening 11i), of 1i the top frame 11a are integrally formed with the top frame 11a. Also, the ribs 11c and recessed portion 11g, of the bottom frame 11b are integrally formed with the bottom frame 11b. The material for the top and bottom frames 11a and 11b is a plastic material, for example, polyethylene, ABS resin (acrylonitrile-butadiene-styrene copolymer), polycarbonate, polyethylene, and polypropylene.

FIG. 36 is a side view of the toner frame 11 used in this embodiment; the surface 11j of the toner frame 11, which is joined with the developing frame 12, is vertically oriented.

The toner frame 11 employed in this embodiment is provided with two slanted surfaces K and L, which allow the toner (single component toner) stored in the storage portion 11A to efficiently descend toward the opening 11i. Both slanted surfaces K and L extend across the entire longitudinal length of the toner frame 11. The slanted surface L is located above the opening 11i, and the slanted surface K is located immediately behind the opening 11i (being slanted in the widthwise direction of the toner frame 11). The slanted surface L belongs to the top frame 11a, and the slanted surface K is formed as a part of the structure of the bottom frame 11b. The angle .theta.2 of the slanted surface L relative to a vertical line 11 (joining surface 11j) is approximately 10 degrees to 40 degrees (in this embodiment, .theta.2 is set at 24 degrees). The angle .theta.3 of the slanted surface K, relative to the horizontal plane 12, perpendicular to the vertical line 11, is approximately 20 to 40 degrees (in this embodiment, .theta.3 is set at approximately 27 degrees). In other words, the configuration of the top frame 11a in this embodiment is regulated so that when the bottom frame 11b is joined with the top frame 11a, the joined bottom frame 11b holds the aforementioned angle. Therefore, even if the toner storage portion 11A is such a toner storage portion that contains a large amount (for example, no less than 800 g), the toner can be efficiently fed toward the opening 11i.

Next, the developing frame will be further described in detail.

Developing Frame

The developing frame will be described with reference to FIGS. 3, 26, 27 and 28. FIG. 26 is an exploded perspective view of the developing frame 12, illustrating how the components are assembled; FIG. 27, a perspective view of the developing frame 12 and toner stirring member 9e and 9f, as seen from the direction of the surface to be welded, illustrating how the stirring members 9e and 9f are assembled into the frame 12; and FIG. 28 is a perspective view of the developing unit without the developing frame holder.

As described above, the developing roller 9c, developing blade 9d, toner stirring members 9e and 9f, and antenna rod 9h for detecting the amount of the remaining toner, are assembled into the developing frame 12.

The developing blade 9d comprises a 1-2 mm thick metallic plate 9d1, and a urethane rubber blade 9d2 fixed to the metallic plate 9d2 by means of hot melting, double-side adhesive tape, or the like. It regulates the amount of toner coated on the peripheral surface of the developing roller 9c. The flatness of a blade accommodating flat surface 12i, as a blade mount, provided on the developing frame 12 is regulated; it is approximately 0.05 mm. This flat surface 12i is provided with dowels 12i1 and screw holes 12i2. The dowels 12i1 are fitted into the holes 9d3 provided on the metallic plate 9d1. Thereafter, the metallic plate 9d1 is screwed onto the flat surface 12i, using the screw holes 9dr provided on the metallic plate 9d1, and the screw holes 12i2. Also on the developing frame 12, an elastic seal member 12s formed of MOLTPLANE or the like is pasted to prevent toner invasion. It is disposed above the metallic plate 9d1, extending in the longitudinal direction thereof. In addition, an elastic seal member 12s1 is pasted on the developing member, at each of the longitudinal ends, covering from both ends of the elastic seal member 12s to a round surface 12j, which follows the contour developing roller 9c. Further, on the mandible-like portion 12h, a thin elastic seal member 12s2 is pasted. This elastic seal member 12s2 contracts the generatrix of the developing roller 9c.

One of the longitudinal ends 9d1a of the developing blade 9d is bent by approximately 90 degrees. This bent portion 9d1a equalizes the voltages of the metallic plate 9d1 and developing roller 9c by contacting a development bias contact point 121 (FIGS. 23(a) and 23(b)), supported on a developing frame holder 40 which will be described later. This arrangement is made because the amount of the toner is detected on the basis of the change in the capacitance between the antenna rod 9h for detecting the amount of the remaining toner, and the developing roller 9c, and this capacitance must be prevented from irregularly changing due to the influence of the metallic plate 9d1.

Next, a developing roller unit G will be described. The developing roller unit G comprises: (1) developing roller 9c; (2) spacer roller 9i for keeping constant the distance between the peripheral surface of the developing roller 9c and the peripheral surface of the photosensitive drum 7; (3) developing roller bearing 9j for locating the developing roller 9c on the developing frame 12; (4) sleeve cap 9o which is placed on both ends of the developing roller 9c so that leakage does not occur between the aluminum cylindrical portion of the photosensitive drum 7 and the aluminum cylindrical portion of the developing roller 9c; (5) developing roller gear 9k (helical gear) which rotates the developing roller 9c as it receives the driving force from the helical gear 7b mounted on the photosensitive drum 7; (6) coil spring contact point 91, one end of which is in engagement with the developing roller gear 9k mounted at one end of the developing roller gear 9k; and (7) magnet 9g which is contained in the developing roller 9c to adhere the toner to the peripheral surface of the developing roller 9c. This developing unit G is attached to the developing roller mount 12X of the developing frame 12 in the following manner. First, a hole 9j1 provided on each of the developing roller bearings 9j is aligned with the hole 12p provided at each of the longitudinal ends of the developing frame 12, and a pin provided on the development holder 40, which will be described later, is inserted through the holes 9j1 and 12d. Then, the developing frame holder 40 is fixed to the developing frame 12 using screws.

As described above, in this embodiment, when the developing roller 9c is mounted on the developing frame 12, the developing roller unit G is assembled first. Then, the assembled developing roller unit G is mounted on the developing frame 12 with the use of developing frame holder 40. By going through these steps, assembly efficiency is improved compared to the case in which the developing roller 9c along is directly mounted on the developing frame 12.

The developing roller unit G is assembled through the following steps. To begin with, each end of the developing roller 9c is covered with the sleeve cap 9o. Next, the spacer roller 9i is mounted at each end of the developing roller 9c; the spacer roller 9i is placed on the outward side of the sleeve cap 9o. Then, the developing roller bearing 9j is mounted on the outward side of the spacer roller 9i. Next, the developing roller gear 9k is mounted at one of the longitudinal ends of the developing roller 9c, on the outward side of the bearing 9j, and the coil spring contact point 91 is mounted on the further outward side. At this point in the assembly, one end 9g1 of magnet 9g, which has a D-shaped cross section, protects from one end of the developing roller 9c, that is, the end where the developing roller gear 9k is mounted, and the other end of the magnet 9g, which is cylindrical, projects from the other end of the developing roller 9c. This is the way developing roller unit G is assembled.

Next, the antenna rod 9h for detecting the amount of the remaining toner will be described. One end of the antenna rod 9h is U-shaped. This U-shaped portion 9h1 is placed in contact with, being thereby electrically connected to, the toner detection contact point 122 mounted on the developing frame holder 40 which will be described later. This antenna rod 9h is attached to the developing frame 12 in the following manner. First, the end portion 9h3 of the antenna rod 9h is inserted into the developing frame 12 through a through hole 12b, provided on the side plate 12A of the developing frame 12. Then, the inserted end portion 9h3 is put through a through hole 12k provided on the other side plate of the developing frame 12, being supported thereby. In other words, the antenna rod 9h is located and supported by the through holes 12b and 12k. In the through hole 12b, a seal member (unillustrated) formed of felt, sponge, or the like, is inserted to prevent toner invasion.

Further, the tip portion 9h2 of the U-shaped portion 9h1 is inserted into an approximately 5 mm deep hole 12o of the developing frame 12 to locate the antenna rod 9h in the axial direction. Also, this arrangement improves the rigidity of the U-shaped portion 9h1 as the contact point which contacts the toner detection contact point 122 which will be described later. The through hole 12k, into which the end portion 9h3 of the antenna rod 9h has been inserted, is plugged from outside using thermal welding or a like method, so that toner invasion can be prevented. Next, the toner stirring members 9e and 9f will be described. The toner stirring members 9e and 9f are shaped like a crank, and stir the toner as they rotate. They are disposed near the developing roller 9c and antenna rod 9h, across the toner path which the toner having been stored in the toner container 11A passes as it is fed toward the developing roller 9c. The toner stirring members 9e and 9f are fixed perpendicular to each other.

In assembling the toner stirring members 9e and 9f onto the developing frame 12, to begin with, the end portions 9e3 and 9f3 of the toner stirring members 9e and 9f, respectively, are inserted through corresponding through holes 12t and 12r provided on the side plate 12A of the developing frame 12, which is on the same side as the one through which the antenna rod 9h is inserted. Then, the end portions 9e3 and 9f3 are inserted into corresponding through holes 12m and 12n, provided on the side plate 12B, which is the opposite side plate of the side plate 12A. Thereafter, each of the through holes 12m and 12n are plugged from outside by the thermal welding method, as are the through holes 12k for the antenna rod 9h. After the stirring members 9e and 9f are inserted into the developing frame 12 as described above, stirring gears 9m and 9n are fitted into the through holes 12t and 12r. At this time, notches 9m1 and 9n1, which are cut in the axial direction at the end portions of the gears 9m and 9n, respectively, are engaged with the crank arms 9e2 and 9f2 of the toner stirring members 9e and 9f, respectively. Further, the journals 9e1 and 9f1 of the stirring members 9e and 9f are fitted into center holes (unillustrated) provided at the deeper ends of the notches 9m1 and 9n1 of the gear 9m and in, respectively, supporting thereby the toner stirring members 9e and 9f on the developing frame 12.

When the toner frame 11 and developing frame 12 are joined, the side plate 12A of the developing frame 12, which is located on the side from which the antenna rod 9h and toner stirring members 9e and 9f are inserted, overlaps the side plate of the toner frame 11, covering the toner cap 11f provided on the top frame 11a of the toner frame 11. Also, on the side plate 12A, a hole 12x is provided, in which a toner feeding gear 9s (FIG. 28) for transmitting the driving force to the toner feeding member 9b is rotatively fitted- The toner feeding gear 9s is linked with the coupling member 11e (FIGS. 29 and 30), which is rotatively supported by the toner frame 11a and is engaged with the end portion of the toner feeding member 9b, whereby the driving force is transmitted to the toner feeding member 9b.

Next, how the driving force is transmitted will be described.

Referring to FIGS. 28 and 35, the stirring gears 9m and 9n, and the toner feeding gear 9s, receive the driving force from the developing roller gear 9k. More specifically, to begin with the stirring gear 9m receives the driving force through a small gear 9g1 of an idler gear 9q as a stepped gear. Receiving this driving force, the stirring member 9e rotates. The idler gear 9g receives the driving force from the developing roller gear 9k since the large gear 9g3 of the idler gear 9g meshes with the developing roller gear 9k. The received driving force is transmitted from the middle gear 9g2 of the idler gear 9g to an idler gear 9r as a stepped gear. Then, the driving force is further transmitted from the small gear 9r1 of the idler gear 9r to the toner feeding gear 9s, rotating thereby the stirring member 9b (through the coupling member 11e). Further, the driving force is transmitted from the toner feeding gear 9s to the stirring gear 9n by way of an idler gear 9t to rotate the stirring member 9f. It should be noted here that all the idler gears, 9q, 9r and 9t, are rotatively mounted on corresponding dowels, 12e 12f and 12g, which are integrally formed with the developing frame 12. These dowels 12e, 12f and 12g are approximately 2 mm to 3 mm in diameter, and their end portions are supported by the developing frame holder 40 which will be described later; therefore, the dowels 12e, 12f and 12g do not deform due to load. Further, the rigidity of dowels 12e, 12f or 12g is increased by padding or stepping their base portions, or the like means.

The gear train described above is disposed on the same side surface as the previously described U-shaped portion 9h1 of the antenna 9h.

With the adoption of the above structure, a single member (in this embodiment, the developing frame holder 40) can support the gears constituting the gear train, and establish electrical connection for the toner remaining detecting contact point. In addition, all of the toner stirring members 9e and 9f, antenna rod 9h, gears 9o, 9r, 9s and 9t constituting the gear train, and stirring gears 9m and 9n, can be assembled into the developing frame 12 from the same side relative to the longitudinal direction of the developing frame 12. Therefore, assembly efficiency can be greatly improved.

The mandible-like portion 12h of the developing frame 12 doubles as a conveying guide for the recording medium 2, such as recording paper. In order to increase the rigidity, the developing frame 12 may be formed using the blow molding method.

Referring to FIG. 27, a reference numeral 12P designates an opening which extends in the longitudinal direction of the developing frame 12. As the toner frame 11 and developing frame 12 are joined, this opening 12P aligns with the opening 11i of the toner frame 11, allowing the toner stored in the toner frame 11 to be supplied to the developing roller 9c The aforementioned stirring members 9e and 9f, and antenna rod 9h, are mounted across the entire longitudinal length of this opening 12P.

Further, according to this embodiment, the developing frame 12 comprising the developing roller mount 12X, side plate 12A, developing blade mount (blade accommodating flat surface 12i), antenna rod 9h mount (through holes 12b, 12k and 12o), stirring member mount (through holes 12t, 12r, 12m and 12n), gear mount (dowels 12e, 12f and 12g), and the like, is integrally formed with these portions. The material for the developing frame 12 is the same as the aforementioned material for the toner frame 11.

Developing Frame Holder

Next, the developing frame holder 40 will be described.

Referring to FIGS. 4-9 and FIGS. 23-25, description will be given as to the developing frame holder 40. FIG. 23(a) is a perspective view of the developing frame holder, which is mounted on the driving side, as seen from the outside of the developing frame 12; FIG. 23(a) a perspective view of the same as seen from inside; FIG. 24, an enlarged sectional view of the FIG. 3(b) at the (I)--(I) line; and FIG. 25 is an enlarged perspective view of the toner detecting contact point.

The developing unit D is completed by attaching the development holders 40 and 41 at the corresponding lateral ends of the developing frame assembly, having been finished up to the stage illustrated in FIG. 28. In this case, the developing roller unit G is mounted in the following manner. First, one of two pins 40d provided at different locations of the developing frame holder is engaged with the hole 9j1 of the aforementioned developing roller bearing, and the other pin 40d is engaged with the hole 12p of the developing frame 12. Next, the developing frame holders 40 and 41 are fixed to the developing frame 12 with screws, in such a manner that the developing roller bearings 9j are sandwiched between the corresponding developing frame holders 40 and 41, and the developing frame 12. At this time, the screws are put through the corresponding holes 401 of the holders 40 and 41. Next, one end 9g1 of the magnet 9g (FIGS. 3 and 28) contained in the developing roller 9c is engaged with a D-shaped hole 40e provided on the developing frame holder 40, and the other end 9g2 is engaged with a hole (unillustrated) provided on the developing frame holder 41, whereby the position of the magnet 9g in the longitudinal direction is fixed. The angles of the magnetic poles of the magnet 9g are determined as the end portion 9g1, having the aforementioned D-shaped section, is engaged with the D-shaped hole 40e of the developing frame holder 40.

Next, rotational shafts 20, which are integrally formed with the developing frame holders 40 and 41 and project therefrom, are placed into recessed portions 21 (FIG. 9(b)) of the cleaning frame, and covered with connector members 22 (FIG. 7), whereby the developing unit D is rotatively supported on the cleaning frame 13 which supports the photosensitive drum 7, and in addition, the compression spring 22a attached to the connector members 22 is compressed against the spring seats 40h of the developing frame holders 40 and 41, stabilizing the distance between the photosensitive drum 7 and developing roller 9c (preventing the distance from widening).

As already described, the long guide 12a is disposed on the external surfaces of the developing frame holders 40 and 41. In addition, the metallic plate toner detecting contact point 122 for detecting the amount of the remaining toner, and the developing bias contact point 121, are fitted on the developing frame holder 40; these contact points 121 and 122 are fixed to the developing frame holder 40 as the dowels provided on the internal surface of the developing frame holder 40 are forced into the locking hole of the contact points.

To begin with, how the toner detection contact point 122 is attached will be described with reference to the drawings.

FIG. 24 is a sectional view of FIG. 23(b), at the (I)--(I) line, and FIG. 25 is an enlarged view of the toner detection contact point illustrated in FIG. 23(b) and the adjacent areas thereof. The toner detection contact point 122 has an external contact point portion 122a and an internal contact portion 122b. The external contact point portion 122a is disposed on the external surface of the holder 40, and when the process cartridge B is in the apparatus main assembly 14, it contacts a toner detection contact point member 126 provided on the apparatus main assembly 14. The internal contact point portion 122b presses on the U-shaped portion 9h1 of the antenna rod 9h. Referring to FIG. 24, the external contact point portion 122a is at substantially the same level as the side plate 40a of developing frame holder 40. The internal contact point portion 122b is disposed within the developing frame holder 40, opposing the antenna rod 9h.

Referring to FIG. 25, the toner detection contact point 122 is mounted on the developing frame holder 40, with its locking flap 122c1 cut out of the mounting base 122c being fitted around the dowel 40h which projects inwardly from the side plate 40a, and the mounting base 122c being in contact with the side plate 40a. Further, from the mounting base 122c, an angled portion 122d is extended at an angle, and from the angled portion 122d, the internal contact point 122b is extended at an angle, so that the internal contact point 122b becomes parallel to the side plate 40a. Further, a connective portion 122e, which is bent outward at 90 degrees from the mounting base 122c, projects outward along one of the edges of the first rectangular hole 40c formed in the side plate 40a. Then, the connective portion 122e is bent at 90 degrees in the direction opposite to the direction in which the connective portion 122e is already bent, constituting the external contact point portion 122a. The external contact point portion 122a is in contact with the bottom surface of a recessed portion 40i formed in the side plate 40a. The depth of this recessed portion 40i is substantially the same as the thickness of the external contact point portion 122a (FIG. 24). Therefore, the outward facing surface of the external contact point portion 122a, and the outward facing surface 40a1 of the side plate 40, are 10 at substantially the same level. Further, the end portion of the external contact point portion 122a is put through the second rectangular hole 40j formed in the side plate 40a, reaching the interior of the side wall 40a, with an end fixing portion 122f being engaged with a dowel 40k projecting from one of the walls of the second rectangular hole 40j. This is the way that toner detection contact point is mounted on the developing frame holder 40.

Referring to FIG. 24, a width L2 of the 20 first hole 40c, of the side plate 40a, is greater than a distance L1 between the side wall facing surface of the mounting base 122c of the toner detection contact point 122 and the outwardly facing surface of the external contact point portion 122a, and is also greater than the height of the end fixing portion 122f. Further, a gap large enough to allow the end fixing portion 122f of the toner detection contact point 122 to be passed through is provided between the end surface of the dowel 40k within the second hole 40j and the opposing surface of the second hole.

The toner detection contact point 122 is mounted in the following manner. First, the end fixing portion 122f is inserted into the first hole 40c, from the inside of the developing frame holder 40. Then, the end fixing portion 122f is inserted into the second hole 40j by rotating the toner detection contact point 122 in the clockwise direction of FIG. 24. Subsequently, the hole 122c of the mounting base 122cis engaged with the dowel 40k. On the other hand, the end fixing portion 122f rides over the dowel 40k due to its own elasticity, and the hole of the end fixing portion 122f engages with the dowel 40k.

The developing bias contact point 121 will be described.

The developing bias contact point 121 comprises a plate spring portion 121a located within the developing frame holder 40; an internal contact point portion 121b; and an external contact point portion 121c located on the outwardly facing surface 40a1. As the developing frame holder 40 is attached to the developing fram 12, the plate spring portion 121a elastically contacts the bent portion 9d1a of the metal plate substantially equal to the potential of the developing roller 9c. The internal contact point portion 121b is fitted around a boss 40f provided with the aforementioned hole 40e being elastically in contact with the coil spring contact point 91 which is fitted around the 40f (contact pressure is approx 100 g to 300 g). The frictional area of the internal contact point portion 121b may be coated with electrically conductive grease if desired. The external contact point portion 121c is disposed in the recessed portion of the side plate 40a, and on the external outwardly facing surface 40a1 of the developing frame holder 40. When the process cartridge B is in the apparatus main assembly 14 external contact point portion 121c is in contact with a developing frame contact point member 125 provided in the apparatus main assembly 14, and receives the developing bias to be applied from the apparatus main assembly 14 to the developing roller 9c. The developing bias received from the apparatus main assembly 14 is applied to the developing roller 9c through the developing bias contact point 121 and coil spring contact point 91.

As the developing frame holder 40 is attached to the developing frame 12, the internal contact point portion 122b in the form of a plate spring comes in contact with the U-shaped portion 9h1 of the antenna rod 9h illustrated in FIG. 28; therefore, the toner detection contact point 122 is electrically connected to the antenna rod 9h. The contact pressure between the antenna rod 9h and internal contact point portion 122b is approx. 100 g. When the process cartridge B is in the apparatus main assembly 14, the external contact point portion 122a provided on the outwardly facing surface 40a1 of the developing frame holder 40 is electrically connected to the contact point member 126 provided in the apparatus main assembly 14. Therefore, an electrical signal, corresponding to the capacitance which changes in response to the change in the amount of toner between the developing roller 9c and antenna rod 9h, is transmitted to the developing frame 12 through the antenna rod 9h, and toner detection contact point 122. As the control section (not shown) detects that the electric signal transmitted to the contact point member 126 has reached a predetermined value, it signals a need for process cartridge exchange. Three engagement holes 40g provided in the internal surface of the developing frame holder 40 are engaged with the corresponding end portions of the dowels 12e, 12f and 12g which serve as the gear shafts for the gears 9q, 9r and 9t illustrated in FIG. 35. In other words, the dowels 12e, 12f and 12g are supported by the developing frame holder 40 and the developing frame 12, coming between the two. The engagement hole 40m provided in the internal surface of the developing frame holder 40, rotatably supports the stirring gear 9m.

As is evident from the foregoing description, the fact that various functions are assigned to a single component (developing frame holder) leads to improvement in assembling efficiency, and also, cost reduction.

Further, according to this embodiment, developing frame holder 40 comprises the rotatable shaft 20, spring seat 40b, long guide 12a, engagement hole (hole 40a) for magnet 9g, mount (boss 40f and the like) for the developing bias contact point 121, mount (dowel 40h, first hole 40c), developing frame holder 40 (dowel 40k and the like) for the toner detection contact point 122, engagement hole 40m, pin 40d, screw hole 401, and the like, and these portions are integrally formed with the developing frame holder 40. The developing frame holder 41 comprises the rotatable shaft 20, spring seat 40b, long guide 12a, and the like, and these portions are integrally formed with the developing frame holder 41. Each of the developing frame holders 40 and 41 is formed, as a single piece component of acrylonitrile-styrene copolymer resin (containing glass filler by 20%).

The positions of the developing frame holders 40 and 41 are fixed as the pins 40d of the developing frame holders 40 and 40 are inserted into the corresponding holes 12p of the developing frame 12. Then, the developing frame holders 40 and 41 are fixed to the developing frame 12 with the use of screws put through the screw holes 401 (developing frame holders 40 and 41), and screw holders 12r1 (developing frame 12).

Structure of Bottom Surface of Cleaning Frame

The developing frame 12 and cleaning frame 13 are provided with guide ribs 121 and 13m, which project from the bottom surfaces thereof, respectively, extending in parallel in the moving direction of the recording medium or material 2. Both guide ribs 121 and 13m are arranged in such a manner that the outermost ribs 121 and 13m fall within the path of the widest piece of recording medium 2 by a small margin. In this embodiment, the outermost ribs are located approx. 5 mm inwardly from the edges of the path of the widest piece of recording medium 2. The remainder of the ribs are spread between the outermost ribs to facilitate conveyance of the recording medium 2. The image forming apparatus in this embodiment is of a type that can accommodate recording medium 2 of different sizes, and the recording medium 2 is centered regardless of size (center line CL coincides with the center line of the recording medium 2). Therefore, the arrangement of the ribs provided on the bottom surface of the developing frame 12 and cleaning frame 13 is symmetrical relative to the (center line CL). The rib height is set at predetermined values for the developing frame 12 and cleaning frame 13, respectively, to facilitate conveyance of the recording medium 2. By adopting the above structure, the image disturbance due to the contact between the pre-fixation toner image and the bottom surface of the cleaning frame 13 can be prevented, while improving conveyance efficiency. FIG. 34 shows an example of measurement in millimeters between the center line CL and various ribs, along with the symbols corresponding to the standard sizes (Japan Industrial Standard) for the recording medium 2. For example, a symbol A3L stands for an A3 size recording medium fed in the longitudinal direction; a symbol A4s stands for an A4 size recording medium fed in the widthwise direction. A symbol ENV stands for a recording medium of envelope size, and EXE corresponds to a recording medium of an EXE size. The guide ribs 121 and/or 13m, located 5.0 mm, 13.0 mm and 28 mm away from the center line CL, are the ribs which make contact with the center line of the recording medium 2.

FIG. 34 is a schematic view of the bottom portion of the cleaning frame 13 as seen from the sheet conveyance direction. This embodiment is different in that the height of guide ribs 13m is symmetrically increased in relation to the distance from the center line; both ribs of each rib pair corresponding to one of the various sheet sizes of the recording medium 2 have the same height. This rib arrangement can reliably prevent the ribs located toward the center line CL from coming in contact with the image bearing surface of the recording medium 2, reliably preventing image disturbance The horizontal rib arrangement in this embodiment is the same as the embodiment in which the rib height is the same for all ribs.

Structure of Electrical Contact Points

Hereinafter referring to FIGS. 5, 8, 9 and 19, the connection and placement of the contact points, which establish electrical connections between the process cartridge B and the laser beam printer main assembly 14 when the former is installed into the latter, will be described.

The process cartridge B is provided with a plurality of electrical contact points: (1) Electrically conductive grounding contact point 119 electrically connected to the photosensitive drum 7 to ground the drum 7 through the apparatus main assembly 14; (2) Electrically Conductive charging bias contact point 120 electrically connected to the charging roller shaft 8a in order to apply a charge bias from the apparatus main assembly 14 to the charging roller 8; (3) Electrically conductive developing bias contact point 121 electrically connected to the developing roller 9c in order to apply a developing bias from the apparatus main assembly 14, and (4) Electrically conductive toner remaining detecting contact point 122 electrically connected to an antenna rod 9h in order to detect the amount of the remaining toner. All of these four contact points 119-122 are exposed on the lateral surface (right-hand side) of the cartridge frame, with intervals large enough to prevent electrical leakage among them. As described before, the ground contact point 119 and charge bias contact point 120 are disposed on the cleaning means frame 13, and development bias contact 121 and toner remainder detecting contact point 122 are disposed on the development chamber frame 12 (developer holder 40). It should be noted here that the toner remaining detecting contact point 122 doubles as a cartridge detecting contact point for detecting the presence (or absence) of the process cartridge within the apparatus main assembly 14.

The grounding contact point 119 is constituted of the electrically conductive axial shaft 7a of the photosensitive drum 7, or an electrically conductive insert molded in the shaft 7 of resin material. In this embodiment, it is constituted of a metallic shaft 7a of iron or the like. The other contact points 120, 121 and 122 are approximately 0.1 mm to 0.3 mm thick electrically conductive metallic pieces, for example, stainless steel piece, phosphor bronze piece, or the like, which are planted on the surface so as for their leg portions to reach into the process cartridge interior. The charging bias contact point 120 is exposed on the driving side surface (lateral side C1) of the cleaning unit C, and the developing bias contact point 121 and toner remaining detecting contact point 122 are exposed on the driving side surface (lateral side D1) of the developing unit D.

More specifically, referring to FIG. 20, in this embodiment, the helical drum gear 7b is provided at one end of the photosensitive drum 7 in the axial direction of the drum 7 as described before. This helical drum gear 7b engages with the helical driver gear 28 provided on the apparatus main assembly 14 to rotate the drum 7. As this helical gear 7b rotates, it generates a thrust (in the direction of an arrow d in FIG. 20), pressing thereby the drum 7, which is mounted on the cleaning means frame portion 13 with the allowance of some play in its longitudinal direction, toward the direction of the helical gear 7b. As a result, one of the lateral surfaces 7 b1 of the helical gear 7b remains in contact with the internal surface 13k1 of one 13k of the lateral surfaces 13k of the cleaning means frame portion 13 of the cartridge frame, whereby the position of the drum 7 within the cartridge B in the axial direction is regulated. The grounding contact point 119 and charging bias contact point 120 are exposed on the one of the lateral surfaces 13k of the cleaning means portion 13 of the frame, wherein the grounding contact point 119 is at the end of the drum shaft 7a, and projects outward slightly (approximately 0.8 mm) beyond the end of the aforementioned cylindrical guide 13a. This drum shaft 7a is put through the drum cylinder 7d (aluminum cylinder in this embodiment) covered with a photosensitive layer 7e, and is supported at each end by the cylindrical guide 13a, which in turn is supported on the lateral walls 13c and 13d. The drum cylinder 7d and shaft 7a are connected with a grounding plate 7f, which is in contact with both the internal surface 7d1 of the drum cylinder 7d and peripheral surface 7a1 of the shaft 7a.

The charging bias contact point 120 is located almost directly above the long guide 12, that is, adjacent to the cleaning means portion 13 of the frame, which supports the charging roller 8 (FIG. 9(a)). Also, the charging bias contact point 120 is electrically connected to the charging roller shaft 8a through an electrically conductive member 120a, which is in contact with the charging roller shaft 8a.

Next, the developing bias contact point 121 and toner remaining detecting contact point 122 will be described These two contact points 121 and 122 are located on one surface, D1, of the lateral surface of the developing unit D, that is, the same side as the lateral surface 13k of the cleaning means portion 13 of the frame. The developing bias contact point 121 is located directly below the long guide 12a and adjacent to the right-hand end of the frame portion 12cwhere the magnet 9g contained in the developing roller 9c is supported (FIG. 5), and is electrically connected to the developing roller 9c through the coil. spring contact point 91, which is in contact with the lateral end of the developing roller 9c (FIG. 9(b)). Referring to FIG. 5, the toner remaining detecting contact point 122 is disposed on the upstream side of the long guide 12a relative to the cartridge inserting direction (arrow X direction in FIG. 8), and is connected to an antenna rod 9h, which is disposed on the side of the toner container 11A and extends in the longitudinal direction of the developing roller 9c in parallel with the developing roller 9c as shown in FIG. 9(b), through the electrically conductive member 9f, which is in contact with an antenna rod 9h. The antenna rod 9h is disposed so as to hold a predetermined distance from the developing roller 9c. The capacitance between this antenna rod 9h and developing roller 9c varies in response to the amount of the toner present between two components; therefore, the amount of the remaining toner is detected by measuring this capacitance change as a potential difference change, through a control section (unillustrated) in the apparatus main assembly 14.

Here, the terminology "amount of the remaining toner" means an amount of the toner that creates a predetermined amount of capacitance by being present between the developing roller 9c and antenna rod 9h. In other words, the detection of the predetermined amount of capacitance means that the amount of the toner remaining in the toner chamber 11A has reached the predetermined amount.

Thus, it is detected by the control section, which is provided in the apparatus main assembly 14 and is connected to the cartridge B through the toner remaining detecting contact point 122, that the capacitance has reached a predetermined first value; whereby it is determined that the amount of the toner remaining in the toner chamber 11a has reached the predetermined amount. When it is detected that the capacitance has reached the aforementioned first determined value, the apparatus main assembly 14 signals the need for process cartridge B exchange (for example, by a flashing light, a buzzing sound, etc.). When the capacitance detected by the control section matches a predetermined second value, which is smaller than the first value, the detecting circuit determines that the cartridge B has been installed in the apparatus main assembly 14. The control section circuit does not allow the apparatus main assembly 14 to be driven unless it detects that the cartridge B has been installed in the apparatus main assembly. In other words, the control section does not allow the apparatus main assembly 14 to start forming images.

It may be arranged so that a warning signal (for example, a blinking light or the like) may be provided to inform the operator of the absence of the cartridge B in the apparatus.

Next, a description will be given as to the connection between the contact point provided on the cartridge B and the contact point member provided on the apparatus main assembly 14.

Referring to FIG. 19, four contact point members, which make contact with corresponding contact points 119-122 when the process cartridge is installed in the apparatus A, are provided on one of the lateral walls of the cartridge accommodating space S of the image forming apparatus A (grounding contact point member 123 which electrically contacts the grounding contact point 119, charging bias contact point member 124 which electrically contacts the charging bias contact point 120, developing contact point member 125 which electrically contacts the developing bias contact point 121, and toner detection contact point member 126 which electrically contacts the toner remaining detecting contact point 122).

As shown in FIGS. 19(a) and 19(b), the grounding contact point member 123 is disposed in correspondence to the groove 16a5. The developing bias contact point member 125 and toner remaining detecting contact point member 126 are disposed below the first guide portion 16a. The charging bias contact point member 124 is disposed above the second guide portion 16b.

Here, the positional relationship between the contact points and guides will be described.

First, referring to FIG. 5, as for the positional relationship in the vertical direction (as seen from the horizontal direction), the developing bias contact point 121 is the bottommost one; the toner remaining detecting contact point 122, long guide 12a and cylindrical guide 13a (grounding contact point 119) are disposed above the bias contact point 121, being at about the same level; above them is the short guide 13b, and the topmost one is the charging bias contact point 120. As for the positional relationship in the cartridge inserting direction (arrow X direction), the toner remaining detecting contact point 122 is the most upstream one; next is the long guide 12a; at a further downstream location is the charging bias contact point 120 and developing bias contact point 121; and at the most downstream locations are short guide 13b and cylindrical guide 13a (grounding contact point 119). Arranging the contact points as described above allows the charging bias contact point 120 to be positioned near the charging roller 8; the developing bias contact point 121, near the developing roller 9c; the toner remaining detecting contact point 122, near the antenna rod 9h; and the grounding contact point 119 to be positioned near the photosensitive drum 7. Therefore, the wiring for the contact points can be shortened.

The measurements of the contact points are as follows: the charging bias contact point 120 is approximately 10.0 mm in height and width (tolerable range of 8.0 mm to 2.0 mm); developing bias contact point 121, approximately 9.0 mm in height (tolerable range of 6.0 mm to 12.0 mm) and approximately 8.0 mm (tolerable range of 5.0 mm to 11.0 mm); toner remaining detecting contact point 122, approximately 8.0 mm (tolerable range of 6.0 mm to 10.0 mm) in height and approximately 9.0 mm (tolerable range of 7.0 mm to 11.0 mm) in width; and grounding contact point 119 is circular and its diameter is approximately 7.0 mm. The charging bias contact point 120, developing bias contact point 121, and toner remaining detecting contact point 122 are rectangular.

The grounding contact point member 123 is an electrically conductive plate spring member, and is mounted in the groove 16a5, in which the cylindrical guide 13a (in which the drum shaft 7a of the photosensitive drum 7 is fitted), on which the grounding contact point 119 of the cartridge B is mounted, is disposed to fix the position of the cartridge B, whereby the grounding contact point member 123 is grounded through the chassis of the apparatus main assembly (FIGS. 19 and 26). The other contact point members 124, 125 and 126 are mounted in the corresponding holder covers 127 in such a manner as to be projected therefrom by the corresponding compression springs 129. This arrangement will be described referring to the charging bias contact point member 124. Referring to FIG. 20, the charging bias contact point member 124 is placed under a holder cover so that it projects but does not come off, and then, this holder cover 127 is fixed to a circuit board 128 mounted on one of the lateral walls of the apparatus main assembly, whereby the contact point members are electrically connected to the wiring patterns by the electrically conductive compression springs 129, correspondingly.

Next, referring to FIG. 21, it will be described with reference to the charging bias contact point member 120 how the contact points on the cartridge side come in contact with the corresponding contact point members on the image forming apparatus side when the process cartridge B is installed into the image forming apparatus A. FIG. 21 is an explanatory drawing, which depicts the state of the process cartridge B in the image forming apparatus A, wherein an arrow mark H designates the movement of the charging bias contact point 124 on the apparatus main assembly, relative to the process cartridge B, when the cartridge B is installed into the image forming apparatus A. It should be noted here that FIG. 21 is a cross-section of FIG. 5 at a line O.

During the installation of the process cartridge B into the image forming apparatus A using the guide members 16a and 16b as the guide, the charging bias contact point member 124 is in the state (a) depicted in FIG. 21 before it reaches the predetermined position where it is to be fixedly disposed. At this time, the charging bias contact point member 124 is not in contact with the flat surface 20 of the cleaning means portion 13 of the frame. As the cartridge B is further inserted, the charging bias contact point member 124 is advanced to a position (b) in FIG. 21. In this state, it remains in contact with the slanted surface 31 (FIG. 5) formed on the right lateral wall 13c of the cleaning means portion 13 of the frame; slides on this slanted surface 31, whereby it is gradually pressed, compressing thereby gradually the compression spring 129; and smoothly moves onto the flat surface 32 where the charging bias contact point 120 is exposed. When the inserted cartridge B arrives at the predetermined location, the contact member 124 arrives at a position (c) in FIG. 21, where it makes contact with the charging bias contact point 120. The other contact point members 125 and 126 come in contact with the contact points 121 and 122, respectively, in the same manner.

With such an arrangement as described above being in place, when the cartridge B is guided by the guide member 16 into the predetermined cartridge accommodating location, the contact points and the corresponding contact point members are reliably placed in contact with each other.

Further, when the process cartridge B is positioned at the predetermined location in the apparatus main assembly 14, the grounding contact point member 123 in the form of a plate spring makes contact with the grounding contact point 119 projecting from the cylindrical guide 13a (FIG. 20). As the process cartridge B is inserted into the apparatus main assembly 14, the grounding contact point 119 and grounding contact member 123 electrically contact with each other, grounding thereby the photosensitive drum 7. The charging bias contact point 120 and charging bias contact member 124 electrically contact with each other, allowing thereby a high voltage (superposed voltage of AC and DC voltages) to be applied to the charging roller 8. The developing bias contact point 121 and developing contact member 125 make electrical contact with each other, allowing thereby a high voltage to be applied to the developing roller 9c. The toner remaining detecting contact point 122 and toner remaining detecting contact member 126 make electrical contact with each other, allowing thereby information reflecting the capacitance to be transmitted to the apparatus main assembly 14.

Next, a case in which the photosensitive 7 is rotated by driving the image forming apparatus A, will be described. The photosensitive drum 7 is given an approximately 2 mm to 3 mm thrust play in the axial direction so that it is easier to install the process cartridge B into the image forming apparatus A. Therefore, it is necessary for the charging bias contact point member 124 or the like to be capable of protecting by a distance larger than the thrust play. Further, in this embodiment, a plate spring 45 is provided, which presses the process cartridge B toward one side (side where the contact point members 123-126 are located) of the apparatus main assembly when the cartridge B is in the apparatus main assembly. This plate spring 45 is on the side opposite to the side where the contact point members are located, above the first installation guide 16a.

Further, when the contact points 119-122 of the process cartridge B are disposed, as they are in this embodiment, on the side where the helical drum gear 7b is disposed (lateral wall on the driving side), the connection for mechanically driving the cartridge B by the apparatus main assembly through the helical drum gear 7b, and the electrical connection between the cartridge B and apparatus main assembly through the contact points 119-122, can be made on the same side of the cartridge B. Therefore, when the aforementioned side of the cartridge B is used as the reference side, the integrated error in the component sizes can be reduced, which makes it possible to mount more accurately the contact points and helical gear. Further, when a helical drum gear with teeth cut in such a direction as to generate a thrust directed toward the side where the helical drum gear is positioned is used, the position of the photosensitive drum 7 in the axial direction is fixed on the side where the contact points are located. Therefore, in this case, the accuracy in the positional relationship between the photosensitive drum 7 and the contact points is also improved, in addition to the aforementioned effects. Further, when a lever 23 (FIG. 6) for opening or closing the drum shutter 18 is located, as it is in the aforementioned embodiment, on the side opposite to the one where the contact points 119-122 are located, the frictional resistance generated on one side of the cartridge by the contact points 119-122 as the cartridge B is inserted into the image forming apparatus A, and the resistance (or pressure), which is made by the lever 23 (FIG. 6) for opening or closing the drum shutter member 18, are distributed toward the longitudinal ends of the cartridge B when the process cartridge B is inserted into the image forming apparatus A. In other words, the resistance generated when the cartridge B is inserted is evenly distributed in the longitudinal direction of the cartridge B. Therefore, the cartridge B can be smoothly inserted.

Further, as described in the preceding embodiment, when all the contact points of the process cartridge B are positioned on one and the same lateral wall of the cartridge frame, and the process cartridge B is placed under the elastic pressure generated by the plate spring, it is possible to provide stable electrical connections between the contact points and the corresponding contact point members on the apparatus main assembly side.

FIG. 22 illustrates an arrangement in which the contact points are located on the side where the aforementioned lever 23 is located. This arrangement can also sufficiently provide the aforementioned effects.

Structure of Housing

The process cartridge B of this example is such that the housing is constituted by coupling the toner frame 11, developing device frame 12 and cleaning frame 13, as has been described hereinbefore, and the structure thereof will be described.

As shown in FIG. 3, the toner frame 11 forms a toner container 11A, and is provided with a toner feeding member 9b. To the developing device frame 12, a developing roller 9c and a development blade 9d are mounted, and adjacent to the developing roller 9c, stirring members 9e and 9f are rotatably mounted to circulate the toner in the developer chamber. The toner frame 11 and the developing device frame 12 are welded with each other to provide an integral developing unit D (FIG. 9, (b)).

The cleaning frame 13 has a photosensitive drum 7, charging roller 8 and cleaning means 10, and is further provided with a drum shutter member 18 for protecting the photosensitive drum 7 by covering it when the process cartridge B is dismounted from the main assembly 14, by which the cleaning unit C is constituted (FIG. 9(a)). The process cartridge B is constituted by coupling the developing unit D and the cleaning unit C by coupling members 22. The description will be made as to the coupling member 22, referring to the drawings. As shown in FIGS. 37 and 38, the coupling member 22 integrally has a positioning projection 22b for positioning the developing unit D at a predetermined position relative to the cleaning unit C, a compression spring 22a for urging a developing roller 9c of a developing unit D to the photosensitive drum 7 of the cleaning unit C, and a plurality of locking claws 22c1 and 22c2 for engagement with the cleaning frame 13 by snap fit to couple the cleaning unit C and the developing unit D. More particularly, the coupling member 22 is formed by integral molding with the positioning projection 22b and the plurality of locking claws 22c1 and 22c2, and further integrated with the compression spring 22a.

To a lateral side of the developing device frame 12 of the developing unit D, a development holder 41 and a development holder 40 are mounted. Each of the development holders 40 and 41 has an arm portion 19 with an end connecting projection functioning as a rotational shaft 20, and the connecting projections are coaxial (FIG. 9, (b)). On the other hand, connecting recess 21 for positioning and fixing said connecting projection is provided at each of two positions of the cleaning frame 13. As shown in FIG. 39, the upper surface of the cleaning frame 13 is provided, adjacent the connecting recess 21, with a non-circular hole 13o for engaging with the positioning projection 22b of the coupling member 22, non-circular holes 13p1 13p2 for engagement with the snap fit locking claws 22c1 and 22c2, and a circular hole 13q through which the compression spring 22a is penetrated.

Then, the rotational shaft 20 of the connecting projection is engaged with the connecting recess 21 of the cleaning frame 13, and thereafter, the coupling member 22 is inserted through the cleaning frame 13, and they are coupled by snap fit, by which the developing unit D is rotatably coupled with the cleaning unit C.

After the coupling, the compression spring 22a mounted to the coupling member 22 is engaged with the spring receptor portion 19a formed at the base portion of the arm portion 19 of the developing unit D, so that a moment is produced about the rotational shaft 20 of the connecting projection in the developing unit D. Therefore, the developing roller 9c is press-contacted toward the photosensitive drum 7 and, more particularly, to slightly large diameter spacer rollers 9i coaxial with the developing roller 9c.

The ends of the photosensitive drum 7 and developing roller 9c are provided with drum gear 7b and developing roller in the form of helical gears 9u FIGS. 9(a) and 9(b)), which are meshed with each other, so that the developing roller 9c is rotated by the photosensitive drum 7. The rotational shaft 20 of the connecting projection is disposed at such a position that the gears of the photosensitive drum 7 and developing roller 9c interfere more than the meshing pressure angle by approx. 0-6 degrees. Therefore, a rotation moment is also produced to the developing unit D by r rotation of the developing roller 9c so that the developing roller 9c is press-contacted toward the photosensitive drum 7 through the spacer rollers 9i.

So, the developing roller 9c is press-contacted toward the photosensitive drum 7 through the spacer rollers 9i by the weight of the developing unit D, the urging force of the compression spring 22a and the rotation of the gears of the developing roller 9c and the photosensitive drum 7. Thus, the clearance between the photosensitive drum 7 and the developing roller 9c is maintained constant at all times (approx. 300 .mu.m), and satisfactory image quality is provided stably.

The detailed description will be made as to the coupling member 22. The coupling member 22 has integrally molded positioning projection 22b and a plurality of locking claws 22c1, 22c2 by injection molding from resin material, and a compression spring 22a is mounted thereinto. Examples of the resin material include polyethylene (PS), acrylonitrile-butadienestyrol (ABS) polyphenyleneoxide (PPO) or the like.

The coupling member 22 has an integrally molded positioning projection 22b in the form of a square pole configuration having a reference surface 22a1 in contact with the rotational shaft 20 of the connecting projection to position the rotational shaft 20 of the connecting projection relative to the connecting recess 21 of the cleaning frame 13. If the positioning projection 22b were in the form of a circular column configuration, the connecting projection would make point contact with the rotational shaft 20 with the result that the positional variation would be large due to the elastic deformation thereof. In other words, by using the square pole configuration having the reference surface 22a1 as the positioning projection 22b, the variation of the above-described positioning portion is minimized. The tolerance setting of the positioning projection 22b is such that it is press-fittingly engaged into the non-circular hole 13o in the upper surface of the cleaning frame 13. By doing so, the coupling member 22 can be fixed without play relative to the cleaning frame 13. If there were play therebetween, the positioning accuracy of the rotational shaft 20 of the connecting projection i degraded corresponding to the degree of the play. The coupling mender 22 is further provided with an integrally molded boss 22d for press-fitting the inner diameter side of the compression spring 22a in the form of a compression coil spring. By this, the compression spring 22a can be press-fitted into the boss 22d of the coupling member 22 beforehand to facilitate the assembling of the process cartridge B.

The plurality of locking claws 22c1 and 22c2 of the coupling member 22 is provided adjacent to the compression spring 22a and adjacent the positioning projection 22b, with a pair at each side, as shown in FIG. 37. The locking claw 22c1 positioned adjacent to the positioning projection 22b has the leading edge directed toward the positioning projection 22b. Similarly, the leading edge of the locking claw 22c2 positioned adjacent to the compression spring 22a is directed toward the compression spring 22a. With this structure, the coupling is firm, and therefore, the coupling member 22 is prevented from becoming removed from the cleaning frame 13.

Thus, the coupling member 22 always receives force in the direction away from the cleaning frame 13 by the restoring force of the compression spring 22a. Here, the locking claw 22c2 has the leading edge directed toward the compression spring 22a, and therefore, the locking claw 22c2 tends to interfere with the hook portion of the cleaning frame 13. By this, the coupling member 22 is always prevented form being removed from the cleaning frame 13 by the restoring force of the compression spring 22a.

On the other hand, the rotational shaft 20 of the connecting projection normally rotates during driving by fine vibration of the developing unit D due to the deflection of the photosensitive drum 7, developing roller 9c spacer roller 9i or the like. The movement of the rotational shaft 20 of the connecting projection tends to urge upwardly the positioning projection 22b of the coupling member 22 through frictional force. Here, since the leading edge of the locking claw 22c1 is directed toward the positioning projection 22b, it tends to interfere with the engaging portion of the frame 13. By this, the coupling member 22 is prevented from leaving from the cleaning frame 13 by the upward urging force of the rotational shaft 20 of the connecting projection.

The degree of interference between the locking claws 22c1 and 22c2 and the cleaning frame 13 is approx 0.4-1.2 mm, as shown in FIGS. 39(a) and 39(b). If it is less than 0.1 mm, the binding power is too weak, and if it exceeds 1.2 mm, the stress in the bottom trunk of the locking claw upon the snap fit coupling is too large, as have been confirmed by experiments. In this example, the dimensions of each portion of the locking claws 22c1 and 22c2, as shown in FIG. 39(b), are h2=1.5 mm, h3=7.0 mm, and h4=4.0 mm.

In this embodiment, two pairs of locking claws (four in total) are used, but this is not limiting, and two locking claws having end portions oriented toward the compression spring 22a and the positioning projection 22b, respectively, are usable. With this structure, sufficient binding power can also be provided.

The positioning hole of the rotational shaft 20 of the connecting projection constituted by the positioning projection 22b of the coupling member 22 and the connecting recess 21 of the cleaning frame 13, are provided at two longitudinal positions, and one of the positioning holes has a play of approx. 0.5-0.8 relative to the shaft diameter of the rotational shaft 20 of the positioning projection. Therefore, the process cartridge can be properly assembled even it the rotational shafts 20 of the connecting projections are deviated from the axis due to manufacturing error of the parts or the like.

Recycling of the Process Cartridge.

The description will be made as to the recycling of the process cartridge according to this example. Here, the general process of the recycling for the process cartridge will be described. The process includes (1) collection, (2) classification. (3) disassembling, (4) selection, (5) cleaning, (6) inspection, and (7) reassembling. The description will be made as to each step.

(1) Collection

The used process cartridges are collected to collection centers by cooperation of the users and servicemen and so on.

(2). Classification

The used process cartridges are then transported from the collection centers to a cartridge recycling plant. The used process cartridges are classified or grouped on the basis of types.

(3) Disassembling

The process cartridges are then disassembled, and parts are taken out.

(4) Selection

The parts are inspected, and are grouped into the ones reusable and the others which are not reusable due to damages or service lives.

(5) Cleaning

Only the reusable parts are cleaned to reuse them.

(6) Inspection

The cleaned parts are inspected to confirm that they are reusable.

(7) Reassembling

Using the parts which were satisfactory as a result of the inspection, the process cartridge is assembled.

Recycling Method as Recycling

The description will be made as to a recycling method.

The following is an example of recycling methods.

In this example, the recycling is carried out through the recycling process described above. Here, the description will be made as to the (1) disassembling of a process cartridge B, (2) mounting of a sealing film 91 for plugging the toner container, (3) supply of the toner into the toner container 11A, and (4) the re-assembling of the process cartridge B.

Before each step is described, the schematic structure of the developing unit D before the disassembling will be described, referring to FIGS. 26 and 43. A sleeve flange at each of the opposite ends is rotatably supported by developing device bearing 9j, and a development blade 9d is mounted to the developing device frame 12 adjacent an opening thereof. Partly circular shafts 9g1 and 9g2 are projected from the opposite ends of a magnet 9g inside the developing roller 9c. The ends of the shafts are engaged in holes 40e of partly circular cylindrical shape provided in development holders 40 and 41 (the hole in the development holder 40 is not seen in the Figure), and the development holders 40 and 41 are fixed to the opposite ends of the developing device frame 12 by screws. Namely, the developing roller 9c is supported rotatably by the developing device bearings 9j, and the end portions of the partly circular shafts 9g1 and 9g2 of the magnet 9g are positioned by the development holders 41 and 40.

(1) Disassembling

The description will be made as to disassembling of the process cartridge B.

The process cartridge B is disassembled into the cleaning unit C and the developing unit D.

As shown in FIG. 40, a pair of coupling members 22 coupling the developing unit D and the cleaning unit C on a top part of the process cartridge B, are cut by a cutter 37 or the like to remove the coupling member 22. The coupling members 22 are made of resin material, and function to position the developing unit D relative to the cleaning unit C for rotation, and urge the developing unit D to the cleaning unit C by a pressing compression spring 22a mounted to the coupling member 22. The coupling member 22, as has been described, is non-removably mounted to the process cartridge B by snap fit or the like.

By using it, the cleaning unit C and the developing unit D can be easily and accurately coupled. In order to dismount the coupling member 22, a "-" screw driver is wedged into between the coupling member 22 and the developing device frame 12 or the cleaning frame 13. In some cases, the locking claws 22c1, 22c2 may be damaged at this time. In such a case, the coupling member 22 is exchanged with a new one in the reassembly. When it is reusable after inspection, the coupling member 22 is reused. The pressing compression spring 22a is reused if it is reusable after the inspection.

By removing this, the process cartridge is divided into the cleaning unit C and the developing unit D.

Recycling of the Cleaning Unit

The photosensitive drum 7 in the form of a unit mounted to the cleaning unit C is removed. In FIG. 41, the photosensitive drum 7 unit is disposed between the lateral walls 10p of the cleaning frame 13 of the cleaning unit C, and is rotatably mounted on a drum shaft 7a fixed into the bearing holes 10p1 of the side walls 10p.

When the drum shaft 7a is pulled out of the cleaning frame 13, one end of the drum shaft 7a is beaten by a hammer or the like. The operation will be easier if a shaft material thinner than the drum shaft 7a is placed between the drum shaft 7a and the hammer. Thus, the photosensitive drum 7 is dismounted from the cleaning unit C. The inside of the cleaning frame 13 is separated by partition ribs 10Q, between which reinforcing ribs 10r are provided.

The description will be made as to cleaning of the cleaning unit C. As shown in FIG. 42, the cleaning unit C from which the photosensitive drum 7 has been removed is placed on a proper table and fixed to it. The operator uses by hand a suction nozzle R of a suction device (unshown), and presses a suction opening thereof into the portion where a gap 10d is formed between the cleaning blade 10a of the cleaning unit C and the receptor sheet 10c. While beating the portion indicated by an arrow P on the top of the cleaning unit C, the suction port of the suction nozzle R is moved along the gap to suck the residual toner from the inside.

The cleaning blade 10a and the receptor sheet 10c are dismounted from the cleaning unit C from which the residual toner is thus removed, and the inside of the cleaning frame 13 and the residual toner container 10b is cleaned by air or the like.

The cleaning blade 10a is cleaned, and inspected, and may be reused if no abnormality is recognized.

Subsequently, both longitudinal end portions of the developing unit D, are removed. The development holder 40 is provided over the same of the toner frame 11 and developing device frame 12 unified with each other, and as shown in FIG. 43, and covers a driving transmission gear train 24 for transmitting driving force to the toner feeding member 9b and the toner stirring members 9e and 9f of the developing means 9, and it also functions as an outer frame.

The development holder 41 also covers the side portion of the other side of the developing device frame 12, and also functions as an outer frame.

The development holder 40 and the development holder 41 support the magnet 9g contained in the developing roller 9c.

A positioning pin 40d is set in the positioning hole portion 12p (FIG. 26) of the developing device frame 12, and the screw 33 at the different position is removed, by which the development holder 40 is removed from the side surface of the toner developing unit D.

At an end of the arm portion 19 of the development holder 40, a rotational shaft 20 of the connecting projection for engaging the developing device frame 12 into the rearmost portion of the connecting recess 21 of the cleaning frame 13, is integrally formed by molding.

The driving transmission gear train 24 has 7 gears having different diameters, which are meshed. The gears function to transmit rotating force to the developing roller 9c, the toner feeding member 9b and the toner stirring members 9e, 9f. The gears can be easily dismounted by pulling them from the shaft and engaging portion in the developing device frame 12.

When the development holder 41 is dismounted, a positioning pin 41d is set in the positioning hole of the developing device frame 12, and two screws 34 at different positions are removed, by which it is removed through a side of the developing unit D. At an end of the arm portion 19 of the development holder 41, a rotational shaft 20 of the connecting projection for engaging the developing device frame 12 into the rearmost portion of the cleaning frame 13, is integrally molded.

As shown in FIG. 26, the developing roller 9c, of which the partly cylindrical shape shafts 9g1 and 9g2 at the opposite ends are released, is dismounted in a direction perpendicular to the axial direction. The screw in the screw bore 9d4 of the development blade 9d corresponding to the screw bore 12i2 in the blade abutting surface 12i of the developing device frame 12, is removed. The engaging of the engaging hole 9d3 with the left and right positioning dowels 12i1 in the flat surface 12i is released to dismount the development blade 9d from the developing device frame 12.

Subsequently, the developing device frame 12 and the toner frame 11 are separated from each other.

The developing device frame 12 and the toner frame 11 are coupled by ultrasonic welding or the like, and therefore, are not easily separated.

As shown in FIG. 44, the welded portions are cut by a cutter 38, an ultrasonic cutting process, laser machining or the like to separate the developing device frame 12 and the toner frame 11

When a cutter 38 is used, it cuts the joining surface 36, as shown in FIG. 44. As another example, as shown in FIG. 45, it may cut along the joining surface 36 away from the welded portion. The same is applied to the case of the ultrasonic cutting process since ultrasonic vibration is imparted to the cutter 38, and in the case of laser machining, the reaching distance of the laser beam is limited to the portion to be cut.

As will be understand in FIG. 31, dowel 11m is paralleled below the portion of the joining surface 36 between the developing device frame 12 and the toner frame 11 where the cutter acts Therefore, the operation is carried out so as not to damage the dowel 11m by the cutter 38 entering deeply when the welded portion is separated. In order to prevent the cutter 38 from reaching the dowels 11m, a stopper 38b is provided at a side surface of the cutter 38 at a position away from the blade edge 38a of the cutter 38, for example.

Thus, the disassembling operation is completed.

(2) Mounting of the toner seal

As shown in FIGS. 46 and 30, a concave portion in the form of an outer frame is formed along the entire circumference of the rectangular opening 11i of the toner frame 11. On the other hand, the cover film 51 is mounted to a cover film plate 53 of plastic resin material plate in the form of an outer frame having the same shape as the concave surface 11k. Namely, the cover film 51 and the cover film plate 53 are made integral by heat seal or the like, although separable from each other. The cover film 51 is removable from the cover film plate 53, in order to permit the supply, to the developing roller of the toner existing in the toner frame 11 by removing the cover film 51 by the operator prior to the start of the use of the process cartridge B.

Here, for the seal by the cover film 51, the cover film 51 is mounted to the cover film plate 53 having the opening 53b by heat seal. As for a manufacturing method of the cover film plate 53, a plastic resin material plate of polyester plate, polystyrene plate, Nylon plate, A plate or the like having a thickness of approx. 0.3-2 mm is provided by sheet molding, and then the opening 53b is formed by stamping. Or, the cover film plate 53 is molded into the outer frame shape.

The cover film 51 is mounted to the cover film plate 53 by heat cramping

Subsequently, the cover film plate 53 having the cover film 51, is welded to the concave surface 11k of the toner frame 11.

By this, the opening 11i of the toner frame 11 is completely sealed by mounting the cover film plate 53 to which the cover film 51 is mounted.

(3) Supply of toner

As described hereinbefore, the toner is filled into a toner frame 11 which is sealed by the cover film 51 at the opening. The toner T is filled through a toner filling opening 11d of the toner frame 11 which appears when the development holder 40 and gear train 24 are removed as shown in FIG. 47, using a development hopper 97 or the like. A supply port 97b for supplying the toner T is formed at the upper side of the main assembly 97a in the form of a funnel, and an adapter 97c is mounted at the lower end to meet the toner filling opening 11d of the toner frame 11. In the main assembly 97a, a rotatable auger 97d is disposed, and the filling speed is controlled by controlling the rotation of the auger 97d. When the fluorine treatment is made to the inner surface of the main assembly 97a to reduce the friction coefficient, the toner supplying efficiency from the development hopper 97 is improved.

The toner frame 11 now filled with the toner, is plugged by a toner cap 11f at the toner filling opening 11d (FIG. 46). Normally, the toner cap 11f is a new fresh one rather than reused one. This is done in order to prevent the toner cap 11f from inadvertently becoming removed.

Then, the toner frame 11 and the developing device frame 12 are coupled by a connecting metal 80 of spring material and in the form of a "U" as shown in FIG. 48. At this time, the cover film 51 is folded back at a rear side 51b. To the folding returning end, a pulling tear tape 52 is coupled. The tear tape 52 has a length not less than the longitudinal length of the opening 53b in the cover film plate 53, and when it is folded back, the leading end 52a extends beyond one longitudinal end of the toner frame 11.

The developing device frame 12 is overlaid on the toner frame 11. At this time, the leading end 52a of said tear tape 52 is exposed outwardly of the developing device frame 12 end.

As shown in FIG. 27, the developing device frame 12 is provided with cylindrical shape and non-circular shape dowels 12w1 and 12w2, for positioning, at predetermined positions on the joining surface relative to the toner frame 11, and as shown in FIG. 30, the toner frame 11 is provided with corresponding non-circular and circular holes 11q and 11r. When the frames 11 and 12 are overlaid, the dowels 12w1 and 12w2 are inserted in the holes 11q, 11r, thus providing correct alignment therebetween, by which the deviation and deformation therebetween can be avoided upon the coupling.

By using the cover film plate 53, the cover film 51 can be mounted between the frames 11 and 12 with proper strength corresponding to the pulling of the operator. By properly selecting the area of the opening of the cover film plate 53, the toner amount to be supplied to the developing device frame 12 from the toner frame 11 can be adjusted. The toner frame 11 and the developing device frame 12 may be coupled by bonding.

(4) Assembling of the process cartridge B

After the opening 11i is hermetically sealed by the cover film 51 through the process described above, the toner is refilled into the toner frame 11, and the process cartridge B is reassembled. The reassembling of the process cartridge B is carried out through the reverse process of the above-described process. As shown in FIG. 26, the development blade 9d is mounted by threading the plate 9d1 of the blade mounting portion to the blade abutting surface 12i of the developing device frame 12. Thereafter, the developing roller 9c is set so that it plugs the opening and so that the ends thereof abut the toner leakage preventing member 12S1.

As shown in FIGS. 26 and 28, the developing device hearing 9j is engaged in the developing roller 9c to fix it to the developing device frame 12, and the developing roller gear 9k is set to the developing roller 9c. To the dowels 12e,12f and 12g projected from the developing device frame 12, idler gears 9q, 9r, 9t or the like are set. Then, the positioning pin 40d of the development holder 40 is inserted into the hole portion 12p of the developing device frame 12, and they are fixed by screws 33, and the developing unit D is assembled as shown in the Figure.

As shown in and FIG. 26, the developing device bearing 19j is engaged with the developing roller 9c, and is fixed to the developing device frame 12, and then, the positioning pin 41d of the development holder 41 is inserted to a pin hole not shown (in an end surface opposite from the end having the pin hole 12p), and they are fixed by screw 34 stops.

Subsequently, the rotational shaft 20 of the connecting projections projected from the development holders 40 and 41, are engaged into the connecting recess 21 of the cleaning frame 13 to mount the developing unit D to the cleaning unit C. A fresh or the reused coupling member 22 is inserted into the connecting portion to fix them to each other, thus completing the assembling of the process cartridge B .

In the foregoing, the mounting operation is such that the development holder 41 is removed after the development holder 40 is mounted. But, the order may be different, and if the operation is automated, they may be carried out simultaneously.

In the above-described embodiment, the process cartridge B is recycled, but this is not limiting, and the method is usable when a fresh cartridge is assembled.

The figures given in the foregoing are examples and not limiting. All of parts and steps of the process described above may be automated using a robot or the like.

The foregoing process includes exchange of the parts, but it is a possible alternative to effect only the cleaning and the filling of the toner.

As described in the foregoing, according to the present invention, an easy method for recycling the process cartridge is provided.

Further, in each of the preceding embodiments, the process cartridge B is of a type which is used to form a monochrome image, but the present invention is also applicable to a multicolor process cartridge, which comprises two or more developing means and is used to form a multicolor image (image of two colors, three colors, or full-color).

As for the electrophotographic photosensitive member, it is not limited to the aforementioned photosensitive drum 7. The present invention is also applicable to the following. To begin with, the photoconductive material is usable as the photosensitive material. As for the photoconductive material, amorphous silicon, amorphous selenium, zinc oxide, titanium oxide, organic photoconductor (OPC), or the like, is usable. Further, as for the configuration of a base member on which the photosensitive material is placed, a base member in the form of a drum or a belt is used. For example, in the case of the base member of the drum type, the photoconductive material is coated, deposited, or placed by the like means on a cylinder of aluminum alloy or the like.

As for the developing method, the present invention is compatible with various well-known methods such as the double component magnetic brush developing method, cascade developing method, touch down developing method, cloud developing method, and the like.

Further, as to the structure of the charging means, the so-called contact charging method is employed in the first embodiment, but it is needless to say that the present invention is also applicable to other conventional charging methods such as the one in which a metallic shield of aluminum or the like is placed on three sides of a tungsten wire, and positive or negative ions generated by applying a high voltage to the tungsten wire are transferred onto the surface of the photosensitive drum to charge it uniformly.

Further, the aforementioned charging means may be of the blade type, (charging blade), pad type, block type, rod type, wire type, or the like, in addition to the roller typo described previously.

As for the method for cleaning the residual toner on the photosensitive drum, the cleaning means may be constituted of a blade, fur brush, magnetic brush, or the like.

As described above, all of the plural electrical contact points of the process cartridge are disposed on only one of the lateral surfaces of the cartridge frame; therefore, the electrical connection between the process cartridge and image forming apparatus can be reliably established by positioning the process cartridge in such a manner as to be pressed by elastic means toward its lateral surface where the electrical contact points are disposed.

Further, the electrical connection, as well as the driving mechanism connection, between the process cartridge and image forming apparatus can be more reliably established by means of disposing the helical gear and electrical contact points on the side toward which the electrophotographic photosensitive member is pressed by the rotation of the helical gear for transmitting the driving force to the photosensitive member.

Further, the distance the wiring must be routed within the process cartridge can be shortened by means of disposing each of the contact points in the same mariner as described in the preceding embodiments.

Further, according to this embodiment, the electrical circuit board of the apparatus main assembly, to which the aforementioned electrical contact points are to be connected, can be vertically arranged on the lateral surface of the apparatus main assembly; therefore, the apparatus size can be reduced.

As described in the foregoing, according to this embodiment, the toner supply performance is high even if the amount of toner is large.

As described in the foregoing, according to the present invention, there is provided a recycling method, remanufacturing method and a recycled or remanufactured process cartridge, and a process cartridge which can be easily recycled or remanufactured.

While the invention has been described with reference to the structures disclosed herein, it is not confined to the details set forth and this application is intended to cover such modifications or changes as may come within the purposes of the improvements or the scope of the following claims.