JP2003043776A - Color image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize the improvement of maintainability and the reduction of running cost and color position deviation by integrating a plurality of photoreceptors and an exposure device as a cartridge and making a developing device attachable to/detachable from the cartridge. SOLUTION: In the tandem type color image forming device, a color image is formed by providing two or more image forming stations where an electrifying device 42, an exposure device 43, a developing device 44 and a transfer device 45 are arranged around the photoreceptor and making a transfer medium pass through the individual stations. In the device, a plurality of photoreceptors 41 are attached to a photoreceptor cartridge 40 which can be attached to/ detached from a device main body, and the developing means 44 is constituted to be attachable to/detachable from each photoreceptor 41 attached to the cartridge 40, and the exposure device 43 is attached to a position corresponding to each of a plurality of photoreceptors 41.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image forming apparatus, and more particularly to a color image forming apparatus in a tandem type color image forming apparatus in which a plurality of photoconductors are made into a cartridge and can be attached / detached and replaced to improve maintainability. It relates to the device.

[0002]

2. Description of the Related Art Generally, an electrophotographic toner image forming means includes a photosensitive member as an image carrier having a photosensitive layer on its outer peripheral surface, a charging means for uniformly charging the outer peripheral surface of the photosensitive member, and An exposing unit that selectively exposes the outer peripheral surface uniformly charged by the charging unit to form an electrostatic latent image, and a toner that is a developer is applied to the electrostatic latent image formed by the exposing unit. And a developing unit for forming a visible image (toner image).

Further, as a tandem type image forming apparatus for forming a color image, the toner image forming means as described above is used for an intermediate transfer belt (an example of a transfer belt).
A plurality (for example, four) are arranged, and the toner images on the photoconductor by these monochromatic toner image forming means are sequentially transferred to the intermediate transfer belt, and a plurality of colors (for example, yellow, cyan, magenta, black ( (Black)) an intermediate transfer belt type in which a toner image of (1) is superimposed to obtain a color image on the intermediate transfer belt, and a recording medium (for example, a paper) is held and conveyed by a recording medium holding belt (an example of the transfer belt),
Known as a conveyor belt type in which toner images formed by a plurality of single-color toner image forming means are sequentially transferred to a recording medium, and toner images of a plurality of colors are superposed on the recording medium to obtain a color image on the recording medium. There is.

As a conventional example of such a tandem type image forming apparatus, for example, in Japanese Unexamined Patent Publication No. 62-141574, an image carrier and process means such as charging and developing disposed around the image carrier are unitized to form each unit. An image forming apparatus has been proposed in which the connected units can be connected to and detached from the main body.By making each unit individually attachable and detachable, only an unusable cartridge can be replaced. It is economical.

Further, in Japanese Patent Laid-Open No. 3-238467, there is proposed an image forming apparatus in which each process unit having a developing means and an image bearing member is supported by one supporting plate and can be attached and detached. Since the unit can be taken out all at once, maintainability is improved.

Further, in Japanese Patent Application Laid-Open No. 9-160471, the process units except for black are integrated so that they can be replaced, and the replacement frequency of the process section is reduced to facilitate the management of consumables. is there.

Further, in Japanese Patent Laid-Open No. 9-304994, a plurality of image bearing members are integrally supported, and in this embodiment, the image bearing members are integrated together with the developing means. The position accuracy of the body is improved, color misregistration is eliminated, maintainability is improved, and there is no risk of erroneous insertion.

Further, in Japanese Patent Application Laid-Open No. 11-174772, a support member for positioning both ends of each image forming member at a predetermined position is provided to minimize misalignment of each image forming member. It is a thing.

[0009]

Generally, in an image forming apparatus that visualizes an electrostatic latent image on an image bearing member by applying toner from the developing unit, the lifespan of the image bearing member and the developing unit are greatly different. . Particularly, in the case of an image forming apparatus using a one-component developer, it is necessary to press the regulating blade against the developing roller with a high load in order to regulate the thin layer of the developer on the developing roller. Then, the developing roller and the regulating blade are worn by friction between them, and the life of the developing roller and the regulating blade is inevitably shortened as compared with the image carrier. Therefore, in the above-mentioned conventional method in which the image bearing member and the developing unit are replaced at the same time, the life is dominated by the developing unit, and the image bearing member is replaced even though it is still usable, which increases the running cost. There is a problem. In particular, in recent years, the image bearing member has been made cleaner-less, and in this method, since there is no member that wears the image bearing member, the image bearing member has a long life, and the life difference between the image bearing member and the developing unit is In particular, there is an increasing demand to replace only the developing means.

Further, in the case of the tandem system, since a plurality of image carriers are provided, the accuracy of color matching of each color largely depends on the position and shape of the image carrier. When the image bearing member is replaced, it is difficult to completely match the position and shape of the image bearing member before and after the replacement, and therefore a work for color matching is required after the replacement. In the above-mentioned conventional example, since the image carrier is exchanged together with the developing means, there is a problem that the color matching work is frequently required and the work efficiency is lowered.

In the tandem type image forming apparatus,
The accuracy of color matching largely depends on the accuracy of the latent image writing position on the image carrier. In the above-mentioned conventional example, the writing means is attached to the main body, and when the image carrier is exchanged, the latent image writing position on the image carrier is misaligned, causing color misregistration and degrading image quality. There was a problem.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to integrate a plurality of image carriers and writing means of a tandem type color image forming apparatus into an integrated cartridge, and to provide individual cartridges. The developing means for the image carrier can be attached to and detached from the cartridge to improve maintainability, reduce running cost, and reduce color misregistration.

[0013]

A color image forming apparatus of the present invention that achieves the above object has at least two image forming stations in which a charging unit, a writing unit, a developing unit and a transfer unit are arranged around an image carrier. In the tandem type color image forming apparatus that performs the color image formation by providing the transfer medium through each station as described above, a plurality of image carriers are mutually attached to an image carrier cartridge that is detachable from the apparatus main body. The image carrier is positioned and attached to the image carrier cartridge, and the developing means is configured to be attachable to and detachable from each image carrier attached to the image carrier cartridge, and the plurality of image carrier members of the image carrier cartridge are attached. The writing means is attached to each of the positions corresponding to the writing means.

The color image forming apparatus of the present invention is suitable when the developer of the developing means is a one-component developer.

Further, a plurality of image carriers are positioned relative to each other and integrally attached to the image carrier cartridge, and the image carrier cartridge constitutes a developing means for each of the plurality of image carriers. Even if a plurality of developing cartridges are individually removably arranged, or if a developing cartridge in which all the developing means for each of the plurality of image carriers are integrated is removably arranged, The developing means for a specific one image carrier among the plurality of image carriers is configured as one developing cartridge, and the developing means for each of the remaining image bearing bodies are integrally configured as another developing cartridge, The two developing cartridges may be individually detachably arranged.

Further, the driving force for the plurality of image carriers and the developing means for each of the plurality of image carriers is received at one place from the main body of the apparatus, and the drive for the plurality of image carriers is performed in the image carrier cartridge. It is desirable that the force be branched and transmitted to the developing means.

In that case, it is desirable that the mutual transmission of the driving force among the plurality of image bearing members be performed via a gear train, a belt or a chain.

Further, the driving force of the plurality of image bearing members is received from one driving source of the apparatus main body, and the driving force of the developing unit for each of the plurality of image bearing members is received from another driving source of the apparatus main body. May be.

Further, it is desirable that a mechanism for adjusting the position of at least one writing means attached to the image carrier cartridge to adjust the color misregistration is provided.

Further, it is desirable that the writing means is constructed as a line head for performing linear writing on each image carrier.

Further, the cleaning means for independently collecting the residual developer may not be arranged around the image carrier of the image carrier cartridge.

In the present invention, as described above, a plurality of image carriers are attached to the image carrier cartridge which is detachable from the apparatus main body while being positioned relative to each other. The developing means is configured to be attachable / detachable to / from each of the image bearing members, and
Since the writing unit is attached to each of the positions corresponding to each of the plurality of image carriers of the image carrier cartridge, the relative positional accuracy between the image carriers and the writing unit is improved, and the image carrier and the writing unit are improved. It is possible to prevent a color shift due to a position shift of the means and a parallelism shift. Further, since a plurality of image carriers can be replaced at the same time, maintainability is improved. Further, the developing means and the image carrier cartridge can be independently replaced, and even when the developing means reaches the end of its life, there is no need to replace the image carrier, and the running cost can be reduced.
Further, even if the developing means reaches the end of its life and is replaced, only the developing means is replaced, so there is no need for color matching work depending on the position and shape of the image carrier, and a color image forming apparatus with good work efficiency is provided. Become. Further, when the developing means is replaced, the image carrier cartridge may be taken out of the apparatus main body and then attached / detached to / from the image carrier cartridge, which facilitates the replacement work of the developing means and improves the maintainability.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION The color image forming apparatus of the present invention will be described below based on embodiments.

FIG. 1 is a front view showing the overall schematic structure of an example of a color image forming apparatus to which the present invention is applied. Figure 1
As shown in FIG. 1, this image forming apparatus is tensioned by a driving roller 10, a driven roller 20, and a tension roller 21, and is stretched, and is circulated and driven in the direction of the arrow (counterclockwise direction) in the drawing. And four photoconductors (photosensitive drums) 41K, 41C, 41M and 41Y having a photosensitive layer on the outer peripheral surface as the image bearing members arranged at a predetermined interval with respect to the intermediate transfer belt 30. K, C, M, and Y added after the symbols mean black, cyan, magenta, and yellow, respectively, and indicate that they are photoconductors for black, cyan, magenta, and yellow, respectively.
The same applies to other members. Photoconductor 41K, 41
C, 41M, and 41Y are rotationally driven in the direction of the arrow (clockwise) in the figure in synchronism with the driving of the intermediate transfer belt 30, but the photosensitive members 41 (K, C, M, and Y) are exposed to light around them. A corona charger 42 (K, C, M, Y) composed of a scorotron as a charging means for uniformly charging the outer peripheral surface of the body 41 (K, C, M, Y), and the corona charger 42.
An exposure device 43 (K, C, M, Y) that selectively exposes the outer peripheral surface uniformly charged by (K, C, M, Y) for each color to form an electrostatic latent image; This exposure device 43 (K,
A developing device 44 that applies toner, which is a developer, to the electrostatic latent image formed by C, M, and Y) to form a visible image (toner image).
(K, C, M, Y) and the developing device 44 (K, C,
(M, Y) primary transfer roller 45 (K, C, M, Y) as a transfer unit that sequentially transfers the toner image developed by M, Y) to the intermediate transfer belt 30 that is the primary transfer target, and the photoreceptor 41 after the transfer. It has a cleaning device 46 (K, C, M, Y) as a cleaning means for removing the toner remaining on the surface of (K, C, M, Y).

The developing device 44 (K, C, M, Y) uses, for example, a non-magnetic one-component toner as a developer and is constructed as a developing cartridge 47 (K, C, M, Y) (FIG. 4). ), Such one-component developer stored therein is conveyed to the developing roller 49 (K, C, M, Y) by the supply roller 48 (K, C, M, Y), and the developing roller 49
The film thickness of the developer attached to the (K, C, M, Y) surface is regulated by the regulation blade 50 (K, C, M, Y), and the developing roller 49 (K, C, M, Y) is exposed. Body 41 (K, C,
When the photoconductor 41 (K,
The toner is developed as a toner image by adhering a developer according to the potential level of (C, M, Y).

The black, cyan, magenta, and yellow toner images formed by the four-color monochromatic toner image forming stations are transferred to the primary transfer rollers 45 (K, C, M, and
The toner images that have been transferred to the intermediate transfer belt 30 sequentially by the primary transfer bias applied to Y), and are sequentially superimposed on the intermediate transfer belt 30 to become a full-color toner image on the secondary transfer roller 66 such as paper. The image is secondarily transferred onto the recording medium P, is fixed on the recording medium P by passing through the fixing roller pair 61 which is a fixing portion, and is discharged onto the paper discharge tray 68 formed on the upper part of the apparatus by the paper discharge roller pair 62.

In FIG. 1, 63 is a large number of recording media P.
Are stacked and held, 64 is a pickup roller for feeding the recording media P one by one from the paper feed cassette 63, and 65 is a timing of supplying the recording media P to the secondary transfer portion of the secondary transfer roller 66. Gate roller pair that defines
Reference numeral 66 denotes a secondary transfer roller as a secondary transfer unit that forms a secondary transfer portion with the intermediate transfer belt 30, and 67 denotes cleaning for removing toner remaining on the surface of the intermediate transfer belt 30 after the secondary transfer. It is a cleaning blade as a means.

Here, the black developing device 44K is arranged on the most upstream side in the circulating direction of the intermediate transfer belt 30, and the yellow developing device 44Y is arranged on the most downstream side when the recording medium P is transferred. The most noticeable color is black, and the least noticeable color is yellow. That is,
In reversal development and the like, fog is caused by toner charged to the opposite polarity in the developing device, but black toner with the most noticeable fog is first transferred as the lowermost layer on the intermediate transfer belt 30. The toner that causes the fog continues to adhere firmly to the intermediate transfer belt 30 by a mirror image force or the like, and thus is difficult to be transferred onto the recording medium P at the secondary transfer portion. On the other hand, the toner that causes the least noticeable yellow fog is attached as the uppermost layer on the intermediate transfer belt 30 and easily transfers onto the recording medium P, but is not very noticeable. That is, by adopting the above arrangement, the black toner of the color with the most noticeable fogging becomes relatively hard to be transferred onto the recording medium P, and the yellow toner with the least noticeable fogging is moved relatively to the recording medium P. As a result, fog is less noticeable as a whole.

Further, since a one-component developer such as a non-magnetic one-component toner is used as the developer, it is not necessary to use a carrier such as a two-component developer, so that each developing device 44 (K, C,
The volume of M, Y) becomes small, and a small color image forming apparatus can be constructed.

In the present invention, in the color image forming apparatus as described above, as shown in FIGS.
Four photoconductors 41K, 41C, 41M, 41Y and corona charger 42 (K, C, M, Y) arranged around them
And the exposure device 43 (K, C, M, Y) and the cleaning device 46 (K, C, M, Y) as an integrated photoconductor cartridge 40, which is pulled out from the device main body and removed. Can be installed and attached. In this case, the developing devices 44K, 44C, 44M, and 44Y attached to the photoconductors 41K, 41C, 41M, and 41Y are detachable from the photoconductor cartridge 40.

That is, referring to FIG. 2, four photoconductors 41 are provided in the frame 70 of the photoconductor cartridge 40.
K, 41C, 41M, 41Y, corona charger 42 (K, C, M, Y) attached to them, and exposure device 43
(K, C, M, Y) and the cleaning device 46 (K,
C, M, and Y) are relatively positioned and attached, and can be pulled out from the apparatus main body by lifting upward as indicated by a double arrow in the figure. For this reason, the paper discharge tray 68 is attached to the apparatus main body so as to be pivotable upward at one end, and by retracting the paper discharge tray 68 from the upper portion of the apparatus main body, an opening through which the photoconductor cartridge 40 can be drawn out of the apparatus is provided. To be formed. In this way, when the photoconductor cartridge 40 is pulled out from the apparatus main body, the photoconductor 41 (K, C, M,
Y) is separated from the intermediate transfer belt 30, the photoconductor cartridge 40 can be removed from the apparatus, and can be replaced with a new photoconductor cartridge 40.

FIG. 3 shows developing devices 44K, 44C and 44.
Photoconductor cartridge 4 with M and 44Y removed
0 is a perspective view of a single unit, and FIG. 4 is a perspective view showing a state in which the developing devices 44K, 44C, and 44M are attached to the photoconductor cartridge 40, and the developing device removes or attaches 44Y, and the frame 70 has a rectangular shape. It has a side plate shape, and four photoconductors 41 are provided between both side plates of the rectangular frame 70.
K, 41C, 41M, and 41Y are rotatably attached to each other in parallel at a predetermined interval by shafts 71K, 71C, 71M, and 71Y. Each photoconductor 41 (K, C, M,
Gears 72K, 72C, 72M, and 72Y are attached to one ends of shafts 71 (K, C, M, and Y) of Y), and the photoconductors 41 (K, C, M, and Y) through gear trains described later. )
Are configured to be rotatable in the arrow direction (clockwise direction) in FIG. 1 synchronously at the same speed.

Also, between the same both side plates of the frame 70, the corona charger 4 belonging to each photoconductor 41 (K, C, M, Y).
2 (K, C, M, Y) and the exposure device 43 (K, C, M,
Y) and the cleaning device 46 (K, C, M, Y) (FIG. 3)
Then, it cannot be seen because it is hidden by the photoconductor 41 (K, C, M, Y) and the frame 70. ) Is attached at a predetermined position, and an electrode 75 (K, C, M,) for applying a high voltage to the discharge wire of the scorotron of each corona charger 42 (K, C, M, Y).
Y) and an electrode 76 (K, C, M, Y) for applying a high voltage to the grit of the scorotron are provided on one side surface of the side plate of the frame 70, and the exposure device 43 (K, C,
Electrodes 69 (K, C, M, Y) for applying a light emission control signal to the LED line head of (M, Y) are provided on the same side surface of the frame 70, and further, the developing devices 44 (K, C, M, Y), the developing roller 49 of each developing device 44 (K, C, M, Y) is mounted.
An electrode 77 (K, C, M, Y) that applies a developing bias voltage to (K, C, M, Y) and a supply roller 48 (K, C,
Electrode 78 for applying a developing supply bias voltage to (M, Y)
Similarly, (K, C, M, Y) is 1 of the side plate of the frame 70.
It is provided on one side. Further, on the same side plate, an IC as a storage means for storing manufacturing information, usage state information, color misregistration information, etc. of the photoconductor cartridge 40.
110 is also attached to the photoconductor cartridge 40.
When the device is attached to the device main body, these electrodes 75 (K,
C, M, Y), electrode 76 (K, C, M, Y), electrode 69
(K, C, M, Y), the electrode 77 (K, C, M, Y), the electrode 78 (K, C, M, Y), and the IC 110 are automatically connected to the power supply circuit and the control circuit of the apparatus body. It is supposed to be connected. Further, the shaft 71 (K, C, M, Y) of each photoconductor 41 (K, C, M, Y) is also grounded, so that it is automatically connected to the ground in that state. .

Further, the developing devices 44 (K, C, M, Y) are received at fixed positions corresponding to the respective photoconductors 41 (K, C, M, Y) on the inner upper portions of the same both side plates of the frame 70. Guide grooves 73 (K, C, M, Y) for arranging the developing devices 44 (K, C, M, Y) received along the guide grooves 73 (K, C, M, Y). Y) fixed lever 74 pivotally mounted for fixing
(K, C, M, Y) are provided. Further, the developing cartridge 47 of each developing device 44 (K, C, M, Y)
Each guide groove 73 is provided on both sides of (K, C, M, Y).
From the upper open end of (K, C, M, Y) to the guide groove 73
(K, C, M, Y) guide projection 79 (K,
C, M, Y) are attached (only the guide protrusion 79Y on one side of the developing cartridge 47Y is visible in FIG. 4), and each photoconductor 41 (K, C, M, Y) is supported. To attach the developing device 44 (K, C, M, Y), insert the guide protrusion 79 (K, C, M, Y) into the corresponding guide groove 73 (K, C, M, Y) from above, After that, the fixing lever 74 (K, C, M, Y) may be rotated and fixed. Each developing cartridge 47 (K, C, M,
To remove (Y) for replacement or the like, the fixed lever 74 (K, C, M, Y) at the position to be removed is pivoted in the opposite direction to remove it, and the developing cartridge 47 (K, C, M, Y) is guided. It may be extracted upward along the groove 73 (K, C, M, Y).

In the embodiment of FIG. 4, each photosensitive member 4
1 (K, C, M, Y) individual developing device 44
(K, C, M, Y) developing cartridge 47
Since (K, C, M, Y) can be separately attached and detached, only the developing device 44 (K, C, M, Y) that has reached the end of its life can be replaced, and the remaining developing devices 44 (K, C, M, Y) is not exchanged unnecessarily, and therefore the running cost can be reduced.

In FIG. 5, four developing devices 44 (K, C, M, and Y) for black, cyan, magenta, and yellow are configured as an integral developing cartridge 47 with respect to the photosensitive cartridge 40 as described above. It is a perspective view for explaining an attachment / detachment mechanism in the case. In this case, the photoconductor cartridge 4
The upper part of both side plates of the frame 70 of No. 0 is provided with only a pair of guide grooves 73 between the both side plates, and is also provided with a pair of rotatable fixed levers 74 corresponding thereto. On the other hand, four developing devices 44 (K, C, M,
Y) is integrated into one developing cartridge 47, and guide protrusions 79 that are inserted into the guide groove 73 from the upper open end of the guide groove 73 are attached to both side surfaces of the developing cartridge 47. (In FIG. 5, only the guide protrusion 79 on one side is visible.) To attach the developing cartridge 47 to the photoconductor cartridge 40, the guide protrusion 79 is inserted into the guide groove 73 from above, and then the fixing lever 74 is attached. It can be rotated and fixed. To remove the developing cartridge 47 for replacement or the like, the fixed lever 74 may be pivoted in the opposite direction to be removed, and the developing cartridge 47 may be extracted upward along the guide groove 73.

In the embodiment of FIG. 5, K, C,
To improve the maintainability and avoid the risk of erroneous mounting by reducing the number of consumables by using the developing device 44 (K, C, M, Y) of four colors M and Y as an integral developing cartridge 47. There is an advantage.

FIG. 6 shows a black developing device 44K as one developing cartridge 47K for the above-described photoconductor cartridge 40, and for the black photoconductor 41K as in the case of FIG. 3 and FIG. 3 developing devices 44 (C, M, Y) for cyan, magenta, and yellow.
FIG. 6 is a perspective view for explaining an attaching / detaching mechanism when the developing cartridge is configured as an integrated developing cartridge 47YMC and is configured to be detachable / exchangeable. In this case, a guide groove 73K for receiving the developing cartridge 47K between the both side plates is provided at the upper inside of both side plates of the frame 70 of the photoconductor cartridge 40.
And a guide groove 73YMC for receiving the developing cartridge 47YMC, and corresponding fixed rotatable levers 74K and 74YMC. On the other hand, the guide protrusions 79K are attached to both side surfaces of the black photoconductor cartridge 40, and the guide protrusions 79YMC are attached to both side surfaces of the developing cartridge 47YMC integrated with three colors (in FIG. 6, the guide protrusions on one side of the developing cartridge 47YMC are attached. Only 79YMC can be seen.), This developing cartridge 47K or 47YMC
To attach to 0, guide protrusion 79K or 79YMC
May be inserted into the guide groove 73K or 73YMC from above, and then the fixing lever 74K or 74YMC may be pivoted and fixed. To remove the developing cartridge 47K or 47YMC for replacement, etc., the fixing lever 74K or 7
Turn the 4YMC in the opposite direction to remove it, and
K or 47YMC may be extracted upward along the guide groove 73K or 73YMC.

In the embodiment of FIG. 6, C, M, Y
By using the three-color developing device 44 (C, M, Y) as an integrated developing cartridge 47YMC to reduce the number of consumables, the maintainability can be improved and the risk of incorrect installation can be avoided. is there. In addition, since the black developing device 44K, which is generally frequently used, can be replaced as an independent developing cartridge 47K, C,
There is an advantage that the developing devices 44 (C, M, Y) for three colors of M and Y are not wasted.

In the above embodiment, the frame 70 of the photoconductor cartridge 40 has four photoconductors 41K, 41C, 41M and 41Y, as shown in FIG.
Corona charger 42 (K, C, M, Y) attached to them
The exposure device 43 (K, C, M, Y) and the cleaning device 46 (K, C, M, Y) are relatively positioned and attached. K,
C, M, Y) is the frame 70 of the photoconductor cartridge 40.
An example of a configuration to be attached to is shown. FIG. 7 is a partially enlarged perspective view showing only one end portions of the photoconductors 41Y and 41M of the photoconductor cartridge 40. The exposure device 43 (K, C,
M, Y) respectively corresponding photoconductors 41 (K, C, M,
Y), mounting protrusions 111 (K, C, M, Y) are integrally provided so as to face each other from the inner surfaces of both side plates of the frame 70 in order to be mounted in parallel to the accurately positioned positions around Y). And the mounting projections 111 (K, C,
M and Y) are each provided with a positioning hole into which a positioning pin is fitted and a screw hole (both not shown). Then, the positioning pins 115 provided at both ends of the long substrate 113 (FIG. 8) of the exposure device 43 (K, C, M, Y) are inserted into the positioning holes of the mounting projections 111 (K, C, M, Y) facing each other. The fixing screws 112 (K, C, M, Y) are fitted and passed through the screw insertion holes 114 provided at both ends of the long board 113 (FIG. 8).
Are fixed to the exposure protrusions 43 (K, C, M) by screwing them into the screw holes of the attachment protrusions 111 (K, C, M, Y).
M, Y) are fixed in place.

In FIG. 8, each exposure device 43 (K, C, M,
FIG. 11 is a perspective view showing a case where Y) is configured as an LED line head including the LED array 116. As described above, the exposure device 43 (K, C, M, Y) is mounted on the long substrate 113 having a length extending between both side plates of the frame 70, and the photoconductor 41 (K, C). , M, Y), an LED array 116 that forms a line image parallel to its axis is attached to a long substrate 113, and each LED is connected to a driver IC 117 that controls light emission. Positioning pins 115 for determining the mounting position and screw insertion holes 114 for mounting are provided at both ends of the long substrate 113. As described above, each photosensitive member 41 (K, C) of the photosensitive member cartridge 40 is provided. , M, Y) is fixed in the correct position. A gradient index rod lens array 118 is integrally fixed in front of the LED array 116. Due to the image forming action of the gradient index rod lens array 118, a photoconductor corresponding to a light emitting point array of the LED array 116. An image is formed on the photosensitive surface of 41 (K, C, M, Y).

Next, the photoconductor 4 in the photoconductor cartridge 40 when the photoconductor cartridge 40 is mounted on the main body of the apparatus.
A mechanism for synchronously rotating 1K, 41C, 41M, and 41Y so as not to cause color misregistration will be described. FIG. 9 is a diagram showing one configuration for that purpose, and as described above, the shafts 71 (K, C, M, etc.) of the photoconductors 41 (K, C, M, Y) are used.
The gear 7 formed by the same mold at one end of Y)
2K, 72C, 72M, 72Y are attached,
Three idle gears 81, 82, 83 for transmitting rotational force are interposed between the gears 72K, 72C, 72M, 72Y to form a gear train. A drive gear 91 that meshes with one gear of the gear train, in the example shown in the drawing, a gear 72Y is arranged in the drive source 90 of the apparatus main body, and when the photoconductor cartridge 40 is mounted at a predetermined position of the apparatus main body, the drive gear 91 91 engages with the gear 72Y.

On the other hand, each developing device 44 (K, C, M, Y)
Developing roller 49 (K, C, M, Y) has a developing roller gear 84 (K, C, M, Y) at one end of its axis, and supply roller 48 (K, C, M, Y) has Supply roller gears 85 (K, C, M, Y) are fixed to one end of the shaft, and developing roller gears 84 (K, C, M, Y) and supply roller gears 85 (K, C, M, Y). Idle gear 86 between
(K, C, M, Y) are interposed, and the developing roller gears 84 (K, C, M, Y) of the developing roller gears 84 (K, C, M, Y) are provided.
(M, Y) gear 72 (K, C, M, Y) meshes with each other, so that in synchronization with the rotation of each photoconductor 41 (K, C, M, Y), the developing device 44 (K, C) belonging to it. , M, Y) developing roller 49 (K, C, M, Y) and supply roller 48.
(K, C, M, Y) is also rotationally driven.

With such a structure, by rotating the drive gear 91 of the drive source 90 at one place on the apparatus main body side, the four photoconductors 41 (K, C, M, Y) Developing roller 49 of the developing device 44 (K, C, M, Y) to which it belongs
(K, C, M, Y) and supply roller 48 (K, C, M,
All Y) can be rotationally driven in synchronization.

In the case of such a structure, since the gear has one meshing point to which the driving force is transmitted when the photoconductor cartridge 40 is attached or detached, the work efficiency when the photoconductor cartridge 40 is attached or detached is improved. Further, by using the driving force transmission gear 91 as the positioning reference of the photoconductor cartridge 40, it is possible to improve the meshing accuracy, and image quality without color misregistration and banding (unevenness such as density perpendicular to the feeding direction). An image forming apparatus can be provided.

The photoconductors 41K, 41C, 41M, 4
It is needless to say that the synchronized rotational force transmission mechanism between 1Y is not limited to the gear train shown in the figure, and a belt or a chain may be used.

FIG. 10 is a diagram showing a configuration of a modification of FIG. 9, and FIG. 11 is a gear 91, a gear 92, and a clutch 9 of FIG.
FIG. 3 is a view of the rotation transmitting unit including the gears 94 to 96 as viewed from above. In this case, the device main body side drive source 90 (FIG. 9)
The drive gear 91 is engaged with the gear 72K via the gear 92, and the idle gear 81 between the gear 72K and the gear 72C is omitted. Instead,
As shown in FIG. 11, the gear 92, the clutch 93, and the gear 9
A rotation transmission mechanism composed of 4 to gears 96 is provided between the gears 72K and 72C, and when the clutch 93 is turned on, the rotational force of the gears 92 is transmitted to the gears 94 and the gears 95 meshing with the gears 94 receive the rotation force. The rotational force is transmitted, the rotation in the same direction as the gear 72K is transmitted to the gear 72C via the gear 96 interposed between the gear 95 and the gear 72C, and the rotation of the gear 72M and the gear 72Y is the same as in the case of FIG. Transmitted. Here, since the gears 92, 94 and 96 are molded by the same molding die, the four photoconductors are synchronously driven to rotate at the same speed.

In this structure, when the clutch 93 is turned off, the rotation of the drive gear 91 is transmitted only to the black developing device 44K, and the other developing devices 44 (C, M, Y) do not operate. Therefore, when performing an image forming operation for only one black color, the photoconductor 41K and the developing device 44K for that color are used.
Only the photosensitive member 41 (C, M, Y) and the developing device 44 (C, M, Y) which do not need to be operated are effectively inoperative, and unnecessary consumption of them is prevented. Therefore, there is an advantage that the life of the developing device 44 (C, M, Y) can be extended.

12 and 13 show the photoconductor cartridge 4
When 0 is attached to the main body of the apparatus, the photoconductor cartridge 4
0 photoconductor 41 (K, C, M, Y) and developing device 44
FIG. 12 is a diagram for explaining an embodiment in which (K, C, M, Y) are driven by different drive sources, and FIG. 12 is a diagram similar to FIG. 9. In this embodiment, as is clear from FIG.
Developing roller gear 8 of each developing device 44 (K, C, M, Y)
4 (K, C, M, Y) are the photoconductors 41 (K, C, M,
The gear 72 (K, C, M, Y) of (Y) does not mesh, but is separated. This is the only difference regarding the gear train of the photoconductor cartridge 40. Therefore, as shown in FIG. 12, by rotating the drive gear 91 of the drive source 90 on the apparatus main body side, the four photoconductors 41 (K, C, M, Y) are rotated.
Can be rotationally driven in synchronization. However, depending on the driving force of the driving source 90, each developing device 44 (K, C,
The developing roller 49 (K, C, M, Y) of M, Y) and the supply roller 48 (K, C, M, Y) do not rotate. In the case of this example, as shown in FIG. 13, another drive source 100 is provided at another position on the apparatus main body side, and the photoconductor cartridge 40 is provided.
When the drive is mounted at a predetermined position on the device body, another drive source 1
Four gears 101 that rotate in the same direction in synchronization with 00
(K, C, M, Y) is fixed to one end of the shaft of the developing roller 49 (K, C, M, Y) of the developing device 44 (K, C, M, Y) attached to the photoconductor cartridge 40. The developing roller gear 84 (K, C, M, Y) is arranged so as to mesh with it. Therefore, the developing device 44 (K, C,
M, Y) is rotationally driven by a driving source 100 of a different system from the photoconductor 41 (K, C, M, Y).

In the arrangement shown in FIG. 1, the color misregistration of each color and the banding of the image largely depend on the rotation accuracy of the image carrier, but do not depend so much on the rotation accuracy of the developing roller. Therefore, as shown in FIGS. 12 and 13, the drive source 90 of the photoconductor 41 (K, C, M, Y) of the photoconductor cartridge 40 and the drive source 100 of the developing device 44 (K, C, M, Y).
By separating the and from, it is possible to prevent the influence of the rotation unevenness caused by the torque fluctuation of the developing device from affecting the rotation of the image carrier, and to provide a high quality image forming apparatus without color misregistration or image banding. Can be provided.

Next, the photoconductor cartridge 4 as described above
0, the exposure devices 43K, 43C, 43 positioned and attached to the respective photoconductors 41 (K, C, M, Y)
Due to the relative positional deviation of M and 43Y, especially the parallelism deviation (skew), four color monochromatic toner images are transferred to the intermediate transfer belt 30.
FIG. 14 shows an embodiment of a mechanism that adjusts the color shift that occurs when the images are superimposed and transferred on top of each other. As shown, each exposure device 43 (K,
C, M, Y) mounting protrusions 111 (K, C, M, or the long board 113 are respectively sandwiched between the adjusting screw 105 and the tip of the expandable spring 106, and the other end of the expandable spring 106 is attached. The position of one end of each exposure device 43 (K, C, M, Y) is adjusted by fixing it to the side plate 70 and adjusting the tip of the adjusting screw 105 in the direction opposite to the expanding direction of the expandable spring 106. Exposure device 43K, 43C, 4
It becomes possible to adjust the deviation of the parallelism between 3M and 43Y. Such a color misregistration adjustment mechanism does not necessarily have to be provided in all the four exposure devices 43K, 43C, 43M, and 43Y. Each exposure device 43 (K,
A similar adjusting mechanism may be provided at the end portion on the opposite side of (C, M, Y), but the positional deviation while maintaining the parallelism between the exposure devices 43 (K, C, M, Y) is Each exposure device 43
It is not necessary because it can be solved electrically by adjusting the writing timing of the latent image of each color formed by (K, C, M, Y).

By thus providing the photosensitive cartridge 40 with the position adjusting mechanism of the exposure device 43 (K, C, M, Y), the latent image writing position on the photosensitive body 41 (K, C, M, Y). The transfer position can be finely adjusted, and the color misregistration can be further reduced. This color shift (position)
The color registration adjustment by the adjustment mechanism is performed by the photoconductor cartridge 40.
This can be done at the time of shipment of the product or at any time after attachment to the device body.

By the way, in an electrophotographic system in which a latent image is formed on an image carrier, toner development is performed, and the toner image is transferred to a transfer medium, in order to recover the untransferred residual toner on the image carrier, FIG. There is a so-called cleanerless system in which a cleaning device is used without providing such a cleaning device (for example, Japanese Patent Publication No. 6-77166). When such a cleanerless system is adopted, the cleaning device 46 (K, C, M, Y) of FIG.
The structure is as shown in FIG. In the case of FIG. 15, the configuration is the same as that of the case of FIG. 1 except that the cleaning device 46 (K, C, M, Y) is not provided as shown in the figure, and the description of the configuration and operation is omitted. The configuration of the photoconductor cartridge 40 in this case is also different from the case of FIGS. 1 and 2 in that only the cleaning device 46 (K, C, M, Y) does not exist, and four photoconductors 41K, 41C, 41M, 41Y and corona chargers 42 (K, C, M,
Y) and the exposure device 43 (K, C, M, Y) are integrally configured.

By adopting the method of eliminating the cleaning device as described above, not only can the photoconductor cartridge 40 and the main body of the device be downsized, but also the photoconductor 41 (K, C, M,
The reaction force applied to Y) can be reduced, which reduces the deformation of the frame 70, and the color shift caused by the deformation of the frame 70 and the displacement of the photoconductor 41 (K, C, M, Y) position. Can be prevented.

By the way, in the above embodiment, the intermediate transfer belt 3 is used.
In the tandem type color image forming apparatus using 0 (FIG. 1), four photoconductors 41 (K,
C, M, Y) is an example in which the photoconductor cartridge 40 is integrated, but in any of the above cases, the recording medium holding belt is used instead of the intermediate transfer belt,
A method in which a recording medium such as paper is held and conveyed by the recording medium holding belt, a plurality of single-color toner images are sequentially transferred directly onto the recording medium, and the superimposed toner images of a plurality of colors are fixed on the recording medium. The same can be applied to the case. An example thereof is shown in FIG. The difference from the case of FIG. 1 is that
A recording medium holding belt 30 ′ is used instead of the intermediate transfer belt 30 of FIG. 1, and the recording medium holding belt 30 ′ is picked up one by one from a paper feed cassette 63 by a pickup roller 64 and exposed on each photoconductor 41 (K, C, M, Y). The recording medium (paper) P whose supply timing is regulated by the gate roller pair 65 so as to be synchronized with the electrostatic latent image formed by the recording medium holding belt 30 ′ is conveyed by the recording medium holding belt 30 ′. On the recording medium P being conveyed by the photoconductor 4
The toner images formed on 1 (K, C, M, Y) are sequentially transferred by the action of the primary transfer roller 45 (K, C, M, Y), and the toner images in full color are sequentially superposed. The loaded recording medium P is peeled from the recording medium holding belt 30 ′ by the peeling roller 107, and the full-color toner image is fixed on the recording medium P by passing through the fixing roller pair 61 which is a fixing unit. Paper discharge roller pair 62
However, the configuration of the photoconductor cartridge 40 is the same as that shown in FIG. 1 and the like, and any of the above-described embodiments has such a configuration. It is obvious that the present invention can be applied to a tandem type color image forming apparatus in which a recording medium is held and conveyed by a recording medium holding belt without using an intermediate transfer belt and a toner image is transferred onto the recording medium.

In the above embodiment, the exposure device 43 (K, C, M, Y) integrally attached to the photoconductor cartridge 40 together with the photoconductor 41 (K, C, M, Y) is as shown in FIG. The LED line head including the LED array 116 is used, but
The organic EL line head including the organic EL array proposed in 1-208076 or the like may be used, or the liquid crystal line head including the liquid crystal shutter array may be used.

Further, the photoconductor 4 is attached to the photoconductor cartridge 40.
The writing means integrally attached with 1 (K, C, M, Y) is not limited to the writing means by light, and for example, the applicant of the present invention can file Japanese Patent Application Nos. 2000-298925 and 20.
The writing means by charge transfer such as charge injection and charge removal proposed in 00-298927 may be used.
FIG. 17 is a front view showing the overall schematic configuration of the color image forming apparatus when the charge injection electrode line head 3 (K, C, M, Y) is used as the writing means, and FIG. 18 is the charge injection electrode line thereof. FIG. 3 is a perspective view showing an arrangement and a configuration of a head 3 (K, C, M, Y) with respect to a photoconductor 41 (K, C, M, Y). When writing is performed by this charge injection, the charger 42 (K, C, M, Y) in FIG. 1 is not necessarily required, so the charger cartridge is omitted in the configuration of FIG. 17 to configure the photoconductor cartridge 40. Also, the exposure device 43
Instead of (K, C, M, Y), the charge injection electrode line head 3 (K, C, M, Y) as shown in FIG. 18 is arranged. Charge injection electrode line head 3 (K, C, M,
Y) corresponds to the photoconductor 41 (K, C, M, Y), and the array of the electrodes 3b contacts the photoconductor 41 (K, C, M, Y).
A latent image is formed by creating a potential distribution in Y). The charge injected into each electrode 3b by the driver IC 119 is controlled. The other configuration of FIG. 17 is the same as that of FIG.
It is similar to the case of and the description is omitted.

As described above, in the color image forming apparatus of the present invention, the plurality of photoconductors 41 (K, C, M, Y) and the writing means 43 are attached to the photoconductor cartridge 40 which can be attached to and detached from the apparatus main body. (K, C, M, Y) or 3 (K, C,
M, Y) are positioned and attached to each other,
For each photoconductor 41 (K, C, M, Y) attached to the photoconductor cartridge 40, a developing device 44 (K,
(C, M, Y) are configured to be detachable, the relative positional accuracy between the photoconductors and the writing unit is improved, and color misregistration due to misalignment between the photoconductor and the writing unit and skew is prevented. You can

Further, the photoconductor gear is mounted on the photoconductor in such a phase relation that the speed fluctuation due to the gear driving the photoconductor (photoconductor gear) is reduced, and the integrated cartridge 40 is provided.
And the color shift due to the photoconductor gear can be significantly reduced (FIG. 9).
etc). When the photoconductors are individually assembled to the apparatus main body, the photoconductors rotate independently, and thus the phase of the photoconductor gear cannot be adjusted.

Further, the photoconductor cartridge 40 can be assembled by selecting photoconductors having uniform characteristics at the time of shipment, and color change due to variations in photoconductor properties of respective colors can be prevented. Moreover, since a plurality of photoconductors can be replaced at the same time, the maintainability is improved.

Further, the developing device 44 (K, C, M, Y)
The developing device 44 (K, C, M, Y) and the photosensitive member cartridge 40 can be independently replaced because the developing device 44 can be detached from the photosensitive member cartridge 40.
Even when (K, C, M, Y) has reached the end of life, it is not necessary to replace the photoconductor 41 (K, C, M, Y), and running costs can be reduced.

Even when the developing device 44 (K, C, M, Y) has reached the end of its life and is replaced, the developing device 44 (K, C, M,
Since only Y) is replaced, the photoconductor 41 (K, C, M,
Y) and writing means 43 (K, C, M, Y) or 3
It is possible to provide an image forming apparatus with good work efficiency, which does not require color matching work depending on the position and shape of (K, C, M, Y).

Further, since the developing device 44 (K, C, M, Y) can be replaced by removing the photoconductor cartridge 40 from the main body of the device and then attaching and detaching it to the photoconductor cartridge 40, the development device 44 ( (K, C, M, Y) replacement work becomes easier and maintainability is improved.

A plurality of photoconductors 41 (K, C, M,
Y) as one replacement part, and the developing device 44 (K, C,
M and Y) can also be replaced by one replacement part 47 (FIG. 5), and the maintainability can be greatly improved.

The color image forming apparatus of the present invention has been described above based on the embodiments, but the present invention is not limited to these embodiments and various modifications can be made.

[0066]

As is apparent from the above description, according to the color image forming apparatus of the present invention, a plurality of image bearing members are positioned relative to each other with respect to the image bearing member cartridge which is detachable from the apparatus main body. The developing means is attached to each of the image carriers mounted on the image carrier cartridge, and the developing means is configured to be attachable to and detachable from each of the plurality of image carriers of the image carrier cartridge. Since the writing means is attached so as to be positioned, the relative positional accuracy between the image carriers and the writing means is improved, and the color shift due to the positional shift or the parallelism shift of the image carrier and the writing means is prevented. be able to. Further, since a plurality of image carriers can be replaced at the same time, maintainability is improved. Further, the developing means and the image carrier cartridge can be independently replaced, and even when the developing means reaches the end of its life, there is no need to replace the image carrier, and the running cost can be reduced. Further, even if the developing means reaches the end of its life and is replaced, only the developing means is replaced, so there is no need for color matching work depending on the position and shape of the image carrier, and a color image forming apparatus with good work efficiency is provided. Become. Further, when the developing means is replaced, the image carrier cartridge may be taken out of the apparatus main body and then attached / detached to / from the image carrier cartridge, which facilitates the replacement work of the developing means and improves the maintainability.

[Brief description of drawings]

FIG. 1 is a front view showing the overall schematic configuration of an example of a color image forming apparatus to which the present invention is applied.

FIG. 2 is a diagram showing a state in which the photosensitive cartridge is pulled out from the apparatus main body in the configuration of FIG.

FIG. 3 is a perspective view of a single photosensitive body cartridge with a developing device removed.

FIG. 4 is a perspective view showing a state in which some of a plurality of developing cartridges are mounted on the photosensitive cartridge and some of the developing cartridges are mounted.

FIG. 5 is a perspective view for explaining an attaching / detaching mechanism in the case where all the developing devices are configured as an integral developing cartridge.

FIG. 6 is a perspective view for explaining an attaching / detaching mechanism when the black developing device is configured as one developing cartridge and the remaining developing devices are configured as an integral developing cartridge.

FIG. 7 is a partially enlarged perspective view showing an example of a configuration in which the exposure device is attached to the frame of the photoconductor cartridge.

FIG. 8 is a perspective view when the exposure device is configured as an LED line head including an LED array.

FIG. 9 is a diagram showing a configuration of an example of a mechanism for synchronously rotating a photoconductor in a photoconductor cartridge.

10 is a diagram showing a configuration of a modified example of FIG.

11 is a view of the rotation transmission unit of FIG. 10 as seen from above.

FIG. 12 is a diagram showing a configuration of a mechanism for synchronously rotating the photoconductor of the embodiment in which the photoconductor and the developing device are driven by different drive sources when the photoconductor cartridge is mounted.

13 is a diagram showing the configuration of a mechanism for rotating the developing device of the embodiment of FIG.

FIG. 14 is a diagram showing an embodiment of a mechanism for adjusting the color misregistration of the photoconductor cartridge.

FIG. 15 is a front view showing the overall schematic configuration of the embodiment of the color image forming apparatus adopting the cleanerless system.

FIG. 16 is a front view showing an overall schematic configuration of an embodiment of a color image forming apparatus using a recording medium holding belt instead of an intermediate transfer belt.

FIG. 17 is a front view showing an overall schematic configuration of an embodiment of a color image forming apparatus using a charge injection electrode line head as a writing unit.

FIG. 18 is a perspective view showing the arrangement and configuration of the charge injection electrode line head with respect to the photoconductor in the case of FIG. 17;

[Explanation of symbols]

P ... Recording medium (paper) 3 (K, C, M, Y) ... Charge injection electrode line head 3b ... Charge injection electrode 10 ... Driving roller 20 ... Followed roller 21 ... Tension roller 30 ... Intermediate transfer belt 30 '... Recording medium Holding belt 40 ... Photoconductor cartridge 41 (K, C, M, Y) ... Photoconductor (photosensitive drum) 42 (K, C, M, Y) ... Corona charger 43 (K, C, M, Y) ... Exposure Device 44 (K, C, M, Y) ... Developing device 45 (K, C, M, Y) ... Primary transfer roller 46 (K, C, M, Y) ... Cleaning device 47, 47 (K, C, M) , Y), 47YMC ... Developing cartridge 48 (K, C, M, Y) ... Supply roller 49 (K, C, M, Y) ... Developing roller 50 (K, C, M, Y) ... Regulation blade 61 ... Fixing Roller pair 62 ... Ejection roller pair 63 ... Paper feed cassette 64 ... Pickup roll La 65 ... Gate roller pair 66 ... Secondary transfer roller 67 ... Cleaning blade 68 ... Paper discharge tray 69 (K, C, M, Y) ... Electrode 70 for applying light emission control signal to LED line head ... Frame 71 (K, C, M, Y) ... Shaft 72 (K, C, M, Y) of photoconductor ... Gears 73, 73 (K, C, M, Y), 73YMC ... Guide grooves 74, 74 (K, C, M, Y), 74YMC ... Fixed lever 75 (K, C, M, Y) ... Electrode 76 (K, C, M, Y) for applying a high voltage to the discharge wire ... Electrode 77 (for applying a high voltage to the grit of the scorotron) K, C, M, Y) ... Electrodes 78 (K, C, M, Y) for applying developing bias voltage to the developing roller ... Electrodes 79, 79 (K, C, M) for applying developing supply bias voltage to the supplying roller , Y), 79YMC ... Guide protrusions 81, 82, 83 ... Dollar gear 84 (K, C, M, Y) ... Development roller gear 85 (K, C, M, Y) ... Supply roller gear 86 (K, C, M, Y) ... Idle gear 90 ... Device main body side drive source 91 ... Drive gears 92, 94, 95, 96 ... Gear 93 ... Clutch 100 ... Another drive source 101 (K, C, M, Y) ... Drive gear 105 ... Adjusting screw 106 ... Expandable spring 107 ... Separation roller 110 ... IC 111 (K, C, M, Y) ... Mounting protrusion 112 (K, C, M, Y) ... Fixing screw 113 ... Long board 114 ... Screw insertion hole 115 ... Positioning pin 116 ... LED array 117 ... Driver IC 118 ... Refractive index distribution type rod lens array 119 ... Driver IC

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 15/08 507 G03G 15/00 554 21/16 15/08 507H F term (reference) 2H030 AA01 AA06 AA07 AB02 AD01 AD03 BB02 BB22 2H071 BA03 BA13 BA16 BA29 CA05 DA03 DA08 DA13 DA15 EA06 EA18 2H077 BA09 BA10 EA11 GA00 GA13 GA14

Claims (11)

[Claims] 1. At least two image forming stations each having a charging unit, a writing unit, a developing unit, and a transfer unit are provided around an image carrier, and a transfer medium passes through each station to form a color image. In a tandem type color image forming apparatus, a plurality of image carriers are attached to an image carrier cartridge which is attachable to and detachable from the main body of the apparatus, and the image carrier cartridge is attached to the image carrier cartridge. A developing unit is configured to be attachable to and detachable from each image carrier, and a writing unit is attached to each of the image carrier cartridges at a position corresponding to each of the plurality of image carriers. And a color image forming apparatus. 2. The color image forming apparatus according to claim 1, wherein the developer of the developing means is a one-component developer. 3. A plurality of image bearing members are positioned relative to each other and are integrally attached to the image bearing member cartridge, and for the image bearing member cartridge, developing means for each of the plurality of image bearing members. 3. The color image forming apparatus according to claim 1, wherein a plurality of developing cartridges constituting the above are individually detachably arranged. 4. A plurality of image bearing members are positioned relative to each other and are integrally attached to the image bearing member cartridge. With respect to the image bearing member cartridge, a developing means for each of the plurality of image bearing members is provided. 3. The color image forming apparatus according to claim 1, wherein a developing cartridge in which all of the above are integrated is detachably arranged. 5. A plurality of image carriers are positioned relative to each other and integrally attached to the image carrier cartridge, and a specific one of the plurality of image carriers is attached to the image carrier cartridge. The developing means for one image bearing member is configured as one developing cartridge, and the developing means for each of the remaining image bearing members are integrated to form another developing cartridge, and the two developing cartridges are individually The color image forming apparatus according to claim 1, wherein the color image forming apparatus is detachably arranged. 6. The plurality of image carriers are received in the image carrier cartridge by receiving a driving force of the plurality of image carriers and a developing unit for each of the plurality of image carriers at one place from an apparatus main body. 2. A drive force for a body is branched and is transmitted to the developing means for driving.
6. The color image forming apparatus according to any one of 1 to 5. 7. The color image forming apparatus according to claim 6, wherein the driving force is mutually transmitted between the plurality of image carriers via a gear train, a belt or a chain. 8. The driving force of the plurality of image carriers is received from one driving source of the apparatus main body, and the driving force of the developing unit for each of the plurality of image carriers is received from another driving source of the apparatus main body. It is comprised, It is characterized by the above-mentioned.
5. The color image forming apparatus according to any one of 1. 9. A mechanism for adjusting a color shift by adjusting a position of at least one writing unit attached to the image carrier cartridge, according to any one of claims 1 to 8. A color image forming apparatus as described in the item. 10. The color image forming apparatus according to claim 1, wherein the writing unit is configured as a line head that performs linear writing on each of the image carriers. apparatus. 11. The cleaning device for independently recovering the residual developer is not arranged around the image carrier of the image carrier cartridge, according to any one of claims 1 to 10. Color image forming apparatus.