Image forming cartridge set-up and control

[0002] 1. Field of the Invention

[0003] The present invention relates to an image forming apparatus of, for example, electrophotographic type such as a copying machine or a laser printer, and more particularly, it relates to an image forming apparatus capable of forming a color image on a recording material, and a cartridge detachably attachable to such an image forming apparatus.

[0004] 2. Related Background Art

[0005] For example, as one of color image forming apparatuses, there is an image forming apparatus of four-drum multi transfer type (referred to as “in-line color printer” hereinafter) in which a plurality of photosensitive drums as a plurality of electrophotographic photosensitive members are disposed side by side along a conveying direction of a transfer material, developing means such as developing devices containing different color toner are opposed to the respective photosensitive drums, and a full-color image constituted by four color toners is formed on the transfer material conveyed by means of a transfer belt and the like by successively transferring different color toner images formed on the photosensitive drums and developed by the developing means onto the transfer material.

[0006] This system can obtain a print image at a higher speed in comparison with an image forming apparatus of type in which different color toner images are successively transferred onto an intermediate transfer member in a superimposed fashion by using a single photosensitive drum and then the toner images are collectively transferred onto a transfer material.

[0007] FIG. 6 shows an example of such an in-line color printer. In FIG. 6, an endless transfer belt 6 is mounted on drive rollers 7 and is rotated in a direction shown by the arrow. Along a transfer material conveying direction of the transfer belt 6, there are provided image forming portions Y, M, C and Bk for yellow Y, magenta M, cyan C and Black Bk disposed side by side.

[0008] The image forming portions Y, M, C and Bk have similar constructions and include photosensitive drums 1a, 1b, 1c, 1darranged in series along the transfer material conveying direction of the transfer belt 6, charging rollers 2a, 2b, 2c, 2das contact type charging means, developing means 4a, 4b, 4c, 4dand cleaning means 5a, 5b, 5c, 5d, which means are located around the respective photosensitive drums.

[0009] Now, an image forming operation will be described. Laser beams 3a, 3b, 3c, 3dmodulated in accordance with image data from a host computer such as a personal computer are illuminated onto surfaces of the photosensitive drums 1a, 1b, 1c, 1duniformly charged by the charging rollers 2a, 2b, 2c, 2d, thereby obtaining desired electrostatic latent images. These latent images are visualized as toner images by reversal developing at respective developing areas effected by the developing means 4a, 4b, 4c, 4das the developing devices containing the different color toners. The toner images are electrostatically transferred onto a transfer material P fed by sheet feeding means (not shown) and conveyed by the transfer belt 6 under the action of transfer means 8a, 8b, 8c, 8dat respective transfer nip portions. Further, after the transferring, non-transferred residual toners remaining on the photosensitive drums 1a, 1b, 1c, 1dare removed by the cleaning means 5a, 5b, 5c, 5dsuch as cleaning blade, respectively, for preparation for next image formation.

[0010] In the image forming apparatus according to this example, the photosensitive drums 1a, 1b, 1c, 1d, charging rollers 2a, 2b, 2c, 2d, developing means 4a, 4b, 4c, 4dand cleaning means 5a, 5b, 5c, 5dare integrally incorporated in cartridge units, respectively, to obtain process cartridges (CRG) 9a, 9b, 9c, 9das shown in FIG. 7. Incidentally, FIG. 7 shows a process cartridge 9afor yellow color including toner supplying means 20afor supplying toner into the developing means or developing device 4a. The toner supplying means 20acomprise a toner container 21acontaining toner to be supplied, and a toner supplying mechanism 22afor feeding the toner to the developing device 4a.

[0011] In FIG. 7, the toner container 21acontaining the yellow toner is connected to the developing device 4athrough the toner supplying mechanism 22aso that, when the fact that an amount of toner in the developing device 4ais decreased below a predetermined amount is detected by appropriate detecting means, a predetermined amount of the yellow toner in the toner container 21ais supplied into the developing device 4aby the toner supplying mechanism 22a. Regarding the other colors, the similar arrangements are adopted. Namely, for magenta color toner, cyan color toner and black color toner, there are provided process cartridges 9b, 9c, 9dand toner supplying means 20b, 20c, 20dcontaining respective toners.

[0012] Although various developing systems have been proposed in the past, in the apparatus shown in FIG. 6, any developing system of contact type or non-contact type may be used and one-component toner or two-component toner may be used as toner or developer. As an example, there is a jumping developing method of non-contact type using non-magnetic one-component toner.

[0013] The process cartridges 9a, 9b, 9cand 9dcan be detachably mounted on a main body of the image forming apparatus. Further, the image forming apparatus has means for detecting service lives of the respective cartridges so that, even if the service life of any cartridge is expired, the image forming apparatus can be used continuously by exchanging such a cartridge with a new one by the operator.

[0014] In the recent laser printers, in many cases, a process cartridge which does not require maintenance which is exchange of worn part such as photosensitive member or developer difficult to be replaced by the user, waste toner treatment and the like, and which is detachably attachable to the image forming apparatus has been used. For example, various process cartridges such as a developing cartridge obtained by integrally incorporating a container containing toner and developing means, a drum cartridge obtained by integrally incorporating a photosensitive member, charging means and cleaning means and a cartridge obtained by integrally incorporating such a developing cartridge and such a drum cartridge have been proposed.

[0015] In these process cartridges, a service life is alarmed in accordance with a worn extent of each part, and each process cartridge can be exchanged by the user himself. Further, since each cartridge is designed to optimize its service life, a good image having no inconvenience can always be obtained until the service life of the cartridge is expired, and the operator can easily exchange the expired cartridge to a new one.

[0016] However, in the image forming apparatus as shown in FIG. 6, when the user firstly mounts the process cartridge to the image forming apparatus after he bought it, it is required that four process cartridges for respective colors Y, M, C, Bk be mounted to predetermined positions. Further, when the service life of any process cartridge is approached, if a corresponding new process cartridge is not prepared, upon expiration of the process cartridge, the image forming apparatus cannot be further used.

[0017] As mentioned above, although the advantage that any expert is not required by using the cartridge in the electrophotographic apparatus can be obtained, in the color image forming apparatus, at least four additional process cartridges for respective colors must be previously prepared. Normally, the service lives of the four color process cartridges are rarely expired simultaneously, and, thus, continual preparation of four kinds of process cartridges burdens the user with high expense. Particularly, for the user who operates and controls a plurality of apparatuses, since the storing condition of the respective color cartridges must be ascertained in accordance with the operating condition, inconvenience is increased.

[0018] On the other hand, makers for manufacturing the process cartridges perform manufacturing control such as sorting the cartridges for respective colors and production adjustment, and, thus, the makers are burdened with great load in the process cartridges for the color image forming apparatus. In general, the developing devices for respective colors are designed to have no difference in construction in order to reduce the cost by using the identical parts.

[0019] However, even when designed in this way, nowadays, in order to prevent user from erroneous mounting, specifications of process cartridges are made to be different from each other. For example, configurations of the cartridge containers for respective colors have been partly changed, seals identifying particular colors have been adhered to the cartridges for respective colors or colors of packages for the respective color cartridges have been changed. Thus, the number of parts are increased to increase the cost in comparison with the case where the identical process cartridges are manufactured.

[0020] The present invention aims to eliminate the above-mentioned conventional drawbacks, and an object of the present invention is to provide an image forming apparatus which can reduce the burden of the users and/or makers, and a cartridge detachably attachable to such an image forming apparatus.

[0021] Another object of the present invention is to provide an image forming apparatus having low cost, and a cartridge detachably attachable to such an image forming apparatus.

[0022] A further object of the present invention is to provide an image forming apparatus comprising a plurality of cartridges each having a toner container and a memory and detachably attachable to a main body of the image forming apparatus, a plurality of supplying means for supplying toners to the respective toner containers, and a plurality of writing means for writing information in the respective memories, and wherein, when a new cartridge is mounted, the writing means write color information corresponding to a mounting position in the memory.

[0023] The other object of the present invention is to provide a cartridge comprising a toner container and a memory, and wherein, in a condition that the cartridge is never mounted to an apparatus, the toner container is empty.

[0024] The other objects and features of the present invention will be apparent from the following detailed explanation of the invention referring to the accompanying drawings.

[0025] FIG. 1 is a constructural view showing a process cartridge according to a first embodiment of the present invention;

[0026] FIG. 2 is a flow chart showing a control flow according to the first embodiment;

[0027] FIG. 3 is a constructural view showing a process cartridge and a toner cartridge according to a second embodiment of the present invention;

[0028] FIG. 4 is a flow chart according to the second embodiment and showing a control flow in a case where arranging order of the process cartridge and the toner cartridge is previously determined;

[0029] FIG. 5 is a flow chart according to the second embodiment and showing a control flow in a case where arranging order of the process cartridge and the toner cartridge is not previously determined;

[0030] FIG. 6 is a constructural view showing a color image forming apparatus associated with an embodiment of the present invention and a prior art; and

[0031] FIG. 7 is a constructural view showing a conventional process cartridge.

[0032] Now, an image forming apparatus according to the present invention will be fully explained with reference to the accompanying drawings. Incidentally, since a construction of a main body of the image forming apparatus and an imaging process thereof are the same as those of the image forming apparatus shown in FIG. 6, explanation of the entire construction and function of the image forming apparatus will be omitted, and only characteristic portions of the present invention will be described.

[0033] First Embodiment

[0034] A first embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a constructural view showing process cartridges 10a, 10b, 10c, 10daccording to the first embodiment, and the process cartridges 10ato 10dare detachably attachable to the in-line color printer as the conventional image forming apparatus shown in FIG. 6.

[0035] Different from the process cartridges 9ato 9dshown in FIG. 7, the process cartridges 10ato 10dfor yellow (Y), magenta (M), cyan (C) and black (Bk) colors are provided with non-volatile read/write memory means Ra, Rb, Rc, Rd such as EEPROMs which are electrically connected to a main body of the image forming apparatus through connectors (not shown) to permit communication of information between the memories and a control portion of the main body. Further, in a condition that the process cartridge is never mounted to the main body of the apparatus, there is no toner in a container 4a. Regarding the memory means Ra to Rd, information can be read and written by the control portion. As the memory means, read/write non-contact memories of electromagnetic coupling type capable of sending and receiving a signal in a non-contact condition may be used.

[0036] Now, preparation in which the process cartridges 10ato 10dare firstly mounted to the main body of the apparatus will be firstly explained.

[0037] Although the process cartridges 10ato 10dare mounted to four positions corresponding to toner supplying means 20ato 20dfor Y, M, C, Bk color toners within the main body of the apparatus, since the process cartridges 10ato 10dfor respective colors according to the illustrated embodiment are common, the process cartridges are not mounted to the particular positions corresponding to the particular colors, but may be merely mounted without consideration of color.

[0038] When the control portion of the main body of the image forming apparatus detects the fact that the process cartridges 10ato 10dare mounted to the main body, the control portion writes information regarding the color of the toner which has been supplied in the initiation of usage, into the memory means Ra to Rd of the process cartridges 10ato 10d, thereby preparing for an image forming operation (“Ready” condition).

[0039] Incidentally, as means for storing the information regarding the color of the toner which has been supplied, other than the aforementioned memories, electrical or mechanical storing means may be provided. For example, four fuses or resistance elements may be provided on the process cartridge and the fuse or the resistance element corresponding to the position where the toner was firstly supplied may be broken, which fact may be detected by the control portion. Alternatively, several protruded portions may be provided on the process cartridge and the protruded portion corresponding to the position where the toner was firstly supplied may be bent from the main body side, which fact may be detected by the control portion by using an optical sensor and the like. Namely, means for continuously storing the color of toner firstly supplied in the initiation of usage of the process cartridge may be provided, and, thereafter, such color may be discriminated by the control portion.

[0040] Next, control for preventing operator's erroneous mounting of the process cartridge in the normal usage will be described.

[0041] The color toner information stored in the memory means Ra to Rd is read out by the control portion at a timing in which there is the possibility of mounting or dismounting of the process cartridges 10ato 10d, i.e., at a timing when the fact that the process cartridges 10ato 10dare mounted or dismounted is detected or when a power supply switch of the main body is turned ON/OFF, and, after the fact that the color toner contained in the toner supplying means 20ato 20dcorresponding to the presently mounted position is coincided with the color toner information stored in the memory means is ascertained, the image forming operation is started. On the other hand, if not coincided, the image forming apparatus is not operated to prevent the different color toner from entering into the developing device, and the fact that the mounting positions of the process cartridges 10ato 10dare wrong is alarmed on a display portion of the image forming apparatus.

[0042] Further explanation will be made with reference to the flow chart shown in FIG. 2.

[0043] First of all, when the fact that the process cartridges 10ato 10dare mounted to the main body of the in-line color printer in the waiting condition is detected (step S1), the control portion ascertains whether the supplied color toner information has already been written in the memory means Ra to Rd or not (step S2). If not written, i.e., if the process cartridges are new, predetermined amount of toners having colors corresponding to the mounted positions are supplied into the developing devices of such process cartridges by toner supplying means. At the same time when the supplying operation is started, the control portion writes the data regarding the supplied toner colors in the memory means of the process cartridges (step S3), thereby establishing a ready state in which the image forming operation can be started in response to print request from a host computer (step S6).

[0044] On the other hand, in the step S2, if the supplied color toner information has already been written in the memory means Ra to Rd, the control portion reads out the color toner information written in the memory means R (step S4) and ascertains whether the color toner contained in the toner supplying means 20ato 20dcorresponding to the presently mounted position is coincided with the color toner information stored in the memory means (step S5). If coincided, the ready state is established (step S6). On the other hand, if not coincided, the control portion does not establish the ready state, and the fact that the mounting positions of the process cartridges 10ato 10dare wrong is alarmed on the display portion of the image forming apparatus or on the connected host computer via a printer driver or the like (step S7).

[0045] When the process cartridges are re-mounted in accordance with the alarming, the processing from the step S1 is performed. Incidentally, when one of the process cartridges is exchanged to a new one due to expiration of the service life thereof, the same processing is performed.

[0046] With the arrangement as mentioned above, even if the user erroneously mounts the process cartridges, the correct re-mounting is demanded to the user, and various image troubles due to color mixing can be prevented. By providing a new cartridge having the empty container and the memory, the process cartridges for various colors can be made common.

[0047] Accordingly, as mentioned above, the user does not require to prepare and control the process cartridges for respective colors and merely exchanges the expired cartridge to a new one without consideration of color, thereby reducing the user's burden.

[0048] On the other hand, since the maker may merely manufacture identical process cartridges for various colors, the manufacturing and controlling costs can be reduced.

[0049] Second Embodiment

[0050] Next, a second embodiment of the present invention will be explained with reference to FIGS. 3 to 5.

[0051] FIG. 3, is an explanatory view showing process cartridges 30a, 30b, 30c, 30dand toner cartridges 40a, 40b, 40c, 40daccording to a second embodiment of the present invention. Both cartridges can detachably be mounted on an in-line color printer as an image forming apparatus shown in FIG. 6. Incidentally, for the purpose for simplifying the explanation, FIG. 3 shows a case of yellow toner, but, the other color toners are the same.

[0052] As a point that the process cartridge 30aaccording to the illustrated embodiment differs from the first embodiment, a magnet brush charging device 12autilizing conductive magnetic particles is used as charging means, so that an injection charging system for directly injecting charges to the photosensitive member is adopted. Further, a developing device 14aof a two-component contact type is used as developing means so that a thin layer of developer comprised of a magnetic carrier and non-magnetic toner is formed on a developing sleeve 14a2 including therein a magnet roller 14a1 by means of a blade 14a3. By applying a predetermined bias at a developing station, an electrostatic latent image is formed.

[0053] The developing device 14ais provided with an inductance sensor 14a5 as toner density detecting means so that a ratio (toner density) between the toner and the carrier is detected by measuring permeability of the developer. If the toner density is decreased below a predetermined value, a predetermined amount of toner in a toner container 16ais supplied to the developing device 14aby a supplying mechanism 17a.

[0054] The process cartridge 30a(30bto 30d) does not have the cleaning means shown in FIG. 1, but, a so-called cleaner-less system in which the residual toner on the photosensitive member is collected into the developing device 14aby difference in potential between the surface of the photosensitive member and bias applied to the developing sleeve 14a2 for re-use is adopted. By adopting such a system, the apparatus can be made more compact.

[0055] In the illustrated embodiment, the toner container containing the toner is designed as a toner cartridge detachably mountable on the main body of the apparatus, and the toner cartridge is provided with memory means.

[0056] Data regarding the color toner contained is written in the memory means Re of the yellow (Y) toner cartridge 40ashown in FIG. 3 and the memory means is electrically connected to the main body so that the color of the toner contained in the toner cartridge 40amounted at. that position can be discriminated by the control portion.

[0057] The toner cartridges 40a, 40b, 40c, 40dfor Y, M, C and Bk colors are provided with memory means Re, Rf, Rg, Rh, respectively so that the color of the toner contained in the toner cartridge mounted to the main body of the image forming apparatus can be discriminated by the control portion. ROMs for only reading may be used as the memory means Re to Rh.

[0058] In the first embodiment, while an example that the images are formed in the order Y, M, C, Bk in the apparatus of FIG. 6 was explained, in the second embodiment, upon image formation, there is a case-where the order of color image formation is predetermined and a case where the forming order of the color images is voluntary. These cases will now be described.

[0059] First of all, as in the first embodiment, in the case where the images are formed in the order Y, M, C and Bk, when the toner cartridges 40ato 40dare mounted to the main body, the control portion ascertains whether the color information read out from the memory means Re to Rh of the cartridges 40ato 40dcoincide with the positions where the toner cartridges 40ato 40dare mounted, i.e., ascertains whether the cartridges are located at the corresponding color positions.

[0060] Further explanation will be made with reference to the flow chart shown in FIG. 4.

[0061] First of all, when the fact that the toner cartridges 40ato 40dare mounted to the main body of the in-line color printer in the waiting condition is detected (step S1), the control portion reads out the color toner information written in the memory means Re to Rh (step S2). It is ascertained whether the read-out toner colors coincide with the presently mounted positions or not (step S3). If the colors coincide, a ready state can be established in response to a print request from a host computer (step S4). On the other hand, if the colors do not coincide, the control portion does not establish the ready state, and the fact that the mounting positions of the toner cartridges 40ato 40dare wrong is alarmed on the display portion of the image forming apparatus or on the connected host computer (step S5).

[0062] As is in the process cartridges according to the first embodiment, the above-mentioned series of operations are performed at a predetermined timing in which there is the possibility of mounting or dismounting of the toner cartridges 40ato 40d, and, after the fact that the presently mounted positions are coincided with the colors of toners contained in the toner cartridges 40ato 40dis ascertained, the image forming operation is started.

[0063] Incidentally, in a new condition, each of the process cartridges 30ato 30dcontains the carrier (used in development by mixing it with toner) but does not contain the toner.

[0064] Next, the case where the image forming order of the Y, M, C and Bk color images is voluntary will be explained.

[0065] Now, a case where the toner cartridges 40ato 40dand the process cartridges 30ato 30dare mounted to the main body of the image forming apparatus in the initiation of usage will firstly be described.

[0066] Although eight cartridges, i.e., toner cartridges 40ato 40dand process cartridges 30ato 30dfor Y, M, C and Bk colors are mounted to the main body, in the illustrated embodiment, since the color mounting positions are voluntary and the process cartridges 30ato 30dare common for various colors, the cartridges are not required to be mounted to the predetermined corresponding color positions, but may merely be mounted without consideration of colors.

[0067] After all of the cartridges are mounted and this fact is detected, under the control of the control portion, predetermined amounts of respective color toners are supplied into the developing devices 14ato 14dof the process cartridges 30ato 30dby the toner supplying means 15ato 15d. At the same time, when the supplying operation is started, the control portion reads out the color toner information written in the memory means Re to Rh of the toner cartridges 40ato 40dand writes the supplied colors in the memory means Re to Rh of the process cartridges 30ato 30d, thereby establishing the ready state in which the image forming operation can be started.

[0068] Next, control for preventing erroneous insertion of the toner cartridges 40ato 40dand the process cartridges 30ato 30din the normal usage will be explained.

[0069] The color toner informations written in the memory means Re to Rh of the toner cartridges 40ato 40dand the process cartridges 30ato 30dare read out by the control portion at the predetermined timing in which there is the possibility of mounting or dismounting of the cartridges. In the control portion, the fact that the color data written in the memory means Re to Rh of the toner cartridges 40ato 40dcorresponding to the presently mounted positions coincide with the color data written in the memory means Re to Rh of the process cartridges 30ato 30dis ascertained, and, thereafter, the image forming operation is started. If not coincided, the image forming apparatus is not operated, and the fact that the mounting positions of the process cartridges 30ato 30dor the toner cartridges 40ato 40dare wrong is alarmed on the display portion of the image forming apparatus.

[0070] Further explanation will be made with reference to the flow chart shown in FIG. 5.

[0071] First of all, when the fact that the toner cartridges 40ato 40dare mounted to the main body of the in-line color printer in the waiting condition is detected (step S1), the control portion of the main body reads out the color toner information written in the memory means Re to Rh (step S2).

[0072] Then, when the fact that the process cartridges 30ato 30dare mounted is detected (step S3), the control portion successively ascertains whether the supplied color toner information has already been written in the memory means Re to Rh (step S4). If there is any process cartridge in which the color toner information is not yet written, i.e., regarding a new process cartridge, a predetermined amount of toner having color corresponding to the mounted position is supplied to the developing device of such process cartridge by the toner supplying means. At the same time when the supplying operation is started, the control portion writes the supplied toner color in the memory means of the process cartridge (step S5), thereby establishing the ready state in which the image forming operation can be started in response to the printer request from a host computer (step S8).

[0073] On the other hand, if the supplied color toner information has already been written in the memory means Ra to Rd of the process cartridges 30ato 30d, the control portion reads out the color toner information written in the memory means Ra to Rd of the process cartridges 30ato 30d(step S6) and ascertains whether the color toner information written in the memory means Ra to Rd of the toner cartridges 40ato 40dopposed to the presently mounted positions coincide with the color toner information written in the memory means Ra to Rd (step S7). If coincided, the ready condition is established (step S8). On the other hand, if not coincided, the control portion does not establish the ready state, and the fact that the mounting positions of the process cartridges 30ato 30dare wrong is alarmed on the display portion of the image forming apparatus or on the connected host computer (step S9).

[0074] When the process cartridges or the toner cartridges are re-mounted in accordance with the alarming, similar processing from step S1 is performed. Incidentally, when one of the process cartridges or the toner cartridges is exchanged for a new one due to expiration of the service life thereof, the same processing is performed.

[0075] As mentioned above, by providing the memory means on the process cartridges, any troubles due to the erroneous mounting can be prevented and the process cartridges for various colors can be made common. Further, also by providing the memory means on the toner cartridges, in the case where the image forming order of the in-line color printer is voluntary, particularly, troublesome of mounting of the cartridges in the installing operation can be reduced.

[0076] Incidentally, in the illustrated embodiment, while the image forming apparatus having four-drum multi transfer system was explained, the present invention is not limited to such a system but can be applied to other color image forming apparatuses of type having toner supplying developing devices.

[0077] Further, the process cartridge is not limited to the illustrated process cartridge integrally including the photosensitive member, developing means and charging means, but, various kinds of cartridges such as a cartridge including only developing means can be used. That is to say, the same effect can be achieved by providing the memory means on the cartridges of type having the toner supplying developing devices and by applying the present invention explained in connection with the second embodiment.

[0078] The present invention is not limited to the above-mentioned embodiments, but various alterations and modifications can be made within the scope of the invention.