JP2003015378A - Color image forming equipment - Google Patents

Abstract

(57) [Problem] To improve the maintainability and reduce the running cost by integrating a plurality of image carriers into a cartridge and making the developing means detachable therefrom. SOLUTION: Charging means 42 (K, K) are provided around an image carrier.
C, M, Y), developing means, transfer means 45 (K, C, M,
In a tandem-type color image forming apparatus in which at least two or more image forming stations provided with Y) are provided and a transfer medium passes through each station to form a color image, an image carrier detachable from the apparatus main body is provided. A plurality of image carriers 41 (K,
C, M, Y) are positioned and attached to each other, and a developing unit 44 is provided for each image carrier 41 (K, C, M, Y) attached to the image carrier cartridge 40.
(K, C, M, Y) are detachable.

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.

The present invention has been made in view of such problems of the prior art, and an object of the present invention is to make a plurality of image carriers of a tandem type color image forming apparatus into an integrated cartridge so that individual image carriers can be formed. The developing means for the cartridge can be attached to and detached from the cartridge to improve the maintainability and reduce the running cost.

[0012]

A color image forming apparatus of the present invention which achieves the above object, is provided with at least two or more image forming stations having a charging means, a developing means and a transfer means arranged around an image carrier. In a tandem-type color image forming apparatus that forms a color image by passing a transfer medium through each station, a plurality of image bearing members are positioned relative to each other with respect to an image bearing member cartridge that is attachable to and detachable from the apparatus body. The developing means is detachably attached to each image carrier mounted on the image carrier cartridge.

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 between the plurality of image bearing members is 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 means 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 color shift by adjusting the position of at least one image carrier attached to the image carrier cartridge with respect to the other image carrier is provided.

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 attachable to and detachable from the apparatus main body while being positioned relative to each other. Since the developing means is configured to be attachable / detachable to / from each of the attached image carriers, the relative positional accuracy between the image carriers is improved, and the color misregistration caused by the displacement of the image carriers and the deviation of the parallelism. Can be prevented. 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.

[0021]

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.
Exposure position 43 (K, C, M, Y) that forms an electrostatic latent image by selectively exposing the outer peripheral surface uniformly charged by (K, C, M, Y) for each color with the exposure light from the exposure unit 43. C, M,
Y) and a developing device 44 (K, which develops a visible image (toner image) by applying toner as a developer to the electrostatic latent image formed at the exposure position 43 (K, C, M, Y). C, M, Y)
And a primary transfer roller 45 (K, as a transfer means for sequentially transferring the toner image developed by the developing device 44 (K, C, M, Y) onto the intermediate transfer belt 30 which is a primary transfer target.
C, M, Y) and the photoconductor 41 (K, C, Y) after being transferred.
M, Y) cleaning device 46 (K, C, as a cleaning means for removing the toner remaining on the surface).
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,
M or Y) so that 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 circulation 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, with the above arrangement, the color with the most noticeable fog is relatively hard to transfer the black toner onto the recording medium P, and the yellow toner with the least noticeable fog is relatively transferred onto 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 cleaning device 46 (K, C, M, Y) as an integrated photoconductor cartridge 40 can be pulled out from the main body of the apparatus and removed, and can be attached to the main body of the apparatus to be attached. In this case, the photoconductors 41K, 41C, 41
Developing devices 44K, 44C, 44 attached to M, 41Y
M and 44Y are attachable to and 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 and 41Y, corona charger 42 (K, C, M and Y) attached to them, and cleaning device 46 (K, C, M and Y) are relatively positioned and attached. As shown by the double arrow in the figure, it can be pulled out from the apparatus main body by temporarily lifting and then sliding. For this reason, the fixing roller pair 61 and the paper discharging roller pair 62 are attached to a side plate 69 which can be swiveled concentrically with the rotation center of the driven roller 20, and retract the fixing roller pair 61 and the paper discharging roller pair 62. Thus, an opening is formed so that the photoconductor cartridge 40 can be pulled out of the apparatus. In this way, in the state where the photoconductor cartridge 40 is pulled out from the apparatus main body,
The photoconductors 41 (K, C, M, Y) are separated from the intermediate transfer belt 30, and 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.

Further, 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 cleaning device 46 (K,
C, M, Y) (photoreceptor 41 (K, C, M, Y) in FIG. 3)
And it is hidden in the frame 70 and cannot be seen. ) Is attached at a predetermined position, and each corona charger 42 (K, C, M,
The electrode 75 (K, C, M, Y) for applying a high voltage to the discharge wire of the scorotron in (Y) and the electrode 76 (K, C, M, Y) for applying a high voltage to the grit of the scorotron are included in the frame 70. Is provided on one side surface of the side plate of each of the developing devices 44 (K, C, M,
Y) is mounted, each developing device 44 (K, C,
An electrode 77 (K, C, M, Y) for applying a developing bias voltage to the developing roller 49 (K, C, M, Y) of (M, Y);
An electrode 78 (K, C, M, Y) for applying a developing supply bias voltage to the supply roller 48 (K, C, M, Y) is also provided on one side surface of the side plate of the frame 70. Further, on the same side plate, the photoconductor cartridge 40
The IC 110 as a storage means for storing manufacturing information, usage state information, color misregistration information, and the like is also attached, and in the state where the photoconductor cartridge 40 is attached to the apparatus main body,
These electrodes 75 (K, C, M, Y), electrodes 76 (K,
C, M, Y), electrode 77 (K, C, M, Y), electrode 78
(K, C, M, Y) and the IC 110 are automatically connected to the power supply circuit and control circuit of the apparatus body. In addition, the shaft 71 of each photoconductor 41 (K, C, M, Y)
Since (K, C, M, Y) is also grounded, 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 inside upper part 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 constructed 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 photoconductor cartridge 40 as described above, and for the black photoconductor 41K as in the case of FIGS. 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.

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. 7 is a diagram showing one configuration for that purpose, and as described above, the shafts 71 (K, C, M, etc.) of the respective photoconductors 41 (K, C, M, Y).
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 mesh point to which the driving force is transmitted when the photoconductor cartridge 40 is attached or detached is only one point, 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. 8 is a diagram showing the configuration of the modification of FIG. 7, and FIG. 9 is a diagram showing the gear 91, gear 92, clutch 93, and FIG.
It is the figure which looked at the rotation transmission part which consists of gears 94-96 from above. In this case, the drive gear 91 of the apparatus main body side drive source 90 (FIG. 7) meshes with the gear 72K via the gear 92, and the idle gear 81 between the gear 72K and the gear 72C is omitted. There is. Instead, FIG.
As shown in FIG. 7, the rotation transmission mechanism including the gear 92, the clutch 93, and the gears 94 to 96 has a gear 72K and a gear 72C.
It is provided between the two, and when the clutch 93 is turned on,
The rotational force of the gear 92 is transmitted to the gear 94, and the rotational force is transmitted to the gear 95 that meshes with the gear 94.
Via the gear 96 interposed between the gear 72 and the gear 72C.
Rotation in the same direction as K is transmitted to the gear 72C,
The rotations of M and the gear 72Y are transmitted as in the case of FIG. 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.

10 and 11 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. 10 is a diagram for explaining an embodiment in which (K, C, M, Y) are driven by different drive sources, and FIG. 10 is a diagram similar to FIG. 7. 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. 10, 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. 11, 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. 10 and 11, 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 photosensitive cartridge 4 as described above
At 0, the color misregistration that occurs when the four-color monochromatic toner images are superimposed and transferred onto the intermediate transfer belt 30 due to the mutual positional deviation of the photoconductors 41K, 41C, 41M, and 41Y, in particular, the parallelism deviation (skew). An embodiment of the adjusting mechanism is shown in FIG. As illustrated, the shaft 71 (K, C, M, Y) of each photoconductor 41 (K, C, M, Y) protruding from one side plate of the frame 70 is attached to the adjustment screw 105 and the expandable spring 106. Expandable spring 10 sandwiched between the tip and
One end of the shaft 71 (K, C, M, Y) by fixing the other end of 6 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. By adjusting the position of the photoconductors 41K, 41C, 4
It becomes possible to adjust the deviation of the parallelism between 1M and 41Y. It is not always necessary to provide such a color misregistration adjustment mechanism on all four photoconductors 41K, 41C, 41M, and 41Y. Each axis 71 (K, C, M,
Although a similar adjustment mechanism may be provided at the end opposite to Y), the positional deviations of the photoconductors 41 (K, C, M, Y) while maintaining the parallelism with each other may be different. (K, C, M,
It is not always necessary because it can be solved electrically by adjusting the writing timing of the latent image of each color formed on Y).

By thus providing the photosensitive body cartridge 40 with the position adjusting mechanism of the photosensitive body 41 (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. Note that the color misregistration (position) adjustment mechanism can adjust the color misregistration at the time of shipment of the photoconductor cartridge 40 or at any time after the photoconductor cartridge 40 is attached to the apparatus main 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 configuration shown in FIG. In the case of FIG. 13, the configuration is the same as that 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,
And Y) are integrated with each other.

By adopting the method of eliminating the cleaning device as described above, not only can the size of the photoconductor cartridge 40 and the main body of the device be reduced, 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.

As described above, in the color image forming apparatus of the present invention, the plurality of photoconductors 41 (K, C, M, Y) are positioned relative to each other with respect to the photoconductor cartridge 40 which is attachable to and detachable from the apparatus main body. Attached to each of the photoconductor cartridges 40 (K,
Developing device 44 (K, C, M, Y) for C, M, Y)
Since it is configured to be detachable, the relative positional accuracy between the photoconductors is improved, and color misregistration due to misalignment or skew of the photoconductors can be prevented.

Further, the photoconductor gear is mounted on the photoconductor in such a phase relationship that the speed fluctuation due to the gear driving the photoconductor (photoconductor gear) is reduced, and the cartridge 40 is integrated.
And the color shift due to the photoconductor gear can be significantly reduced (see FIG. 7).
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 if the developing device 44 (K, C, M, Y) reaches 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,
It is possible to provide an image forming apparatus with good work efficiency, which does not require the work of color matching depending on the position and shape of Y).

To replace the developing device 44 (K, C, M, Y), the developing device 44 (K, C, M, Y) can be replaced by removing the photosensitive cartridge 40 from the main body of the apparatus and then attaching and detaching the photosensitive cartridge 40. (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.

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

[0060]

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. Since the developing means is configured to be attached to and detached from each image carrier attached to the image carrier cartridge, the relative positional accuracy between the image carriers is improved, and the position of the image carrier is improved. It is possible to prevent a color shift due to a shift or a shift in parallelism. 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 diagram showing a configuration of an example of a mechanism for synchronously rotating a photoconductor in a photoconductor cartridge.

FIG. 8 is a diagram showing a configuration of a modified example of FIG. 7.

9 is a view of the rotation transmission unit of FIG. 8 as viewed from above.

FIG. 10 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.

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

FIG. 12 is a diagram showing an embodiment of a mechanism for adjusting the color misregistration of the photoconductor cartridge.

FIG. 13 is a front view showing the overall schematic configuration of the embodiment of the color image forming apparatus adopting the cleanerless system.

FIG. 14 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.

[Explanation of symbols]

P ... Recording medium (paper) 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 ... Exposure unit 43 (K, C, M, Y) ... Exposure position 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 ... Paper discharge roller pair 63 ... Paper feed cassette 64 ... Pickup roller 65 ... Gate roller pair 66 ... Secondary transfer roller 6 ... cleaning blade 68 ... paper discharge tray 69 ... side plate 70 ... frame 71 (K, C, M, Y) ... photoconductor shaft 72 (K, C, M, Y) ... gears 73, 73 (K, C, M) , Y), 73YMC ... Guide grooves 74, 74 (K, C, M, Y), 74YMC ... Fixed lever 75 (K, C, M, Y) ... Electrodes 76 (K, C) for applying a high voltage to the discharge wire. , M, Y) ... Electrodes 77 (K, C, M, Y) for applying high voltage to the scorotron grit ... Electrodes 78 (K, C, M, Y) for applying developing bias voltage to the developing roller ... Supplying roller Electrodes 79, 79 (K, C, M, Y), 79YMC ... guide protrusions 81, 82, 83 ... idle gear 84 (K, C, M, Y) ... developing roller gear 85 ( K, C, M, Y) ... Supply roller gear 86 (K, C, M, Y) ... idle gear 90 ... drive source 91 on the apparatus body side ... drive gears 92, 94, 95, 96 ... gear 93 ... clutch 100 ... another drive source 101 (K, C, M, Y) ... drive gear 105 ... adjusting screw 106 ... Expansion spring 107 ... Peeling roller 110 ... IC

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 15/08 506 G03G 15/08 506A (72) Inventor Kaneo Yoda 3-3-5 Yamato, Suwa City, Nagano Prefecture No. Seiko Epson Corporation F term (reference) 2H030 AA01 AA07 AB02 BB23 BB42 BB46 BB63 2H071 BA03 BA05 BA13 BA14 BA16 BA27 BA29 BA41 CA05 DA06 DA08 DA13 DA15 EA18 2H077 AC04 AD02 AD13 BA08 BA09 EA14 EA15 GA12 GA17

Claims (10)

[Claims] 1. A charging means, a developing means, and
At least two image forming stations equipped with transfer means
In a tandem type color image forming apparatus that forms a color image by providing one or more transfer media through each station, a plurality of image carriers can be attached to and detached from the image carrier cartridge that is detachable from the apparatus main body. A color image forming apparatus, wherein the color image forming apparatus is positioned and attached to each other, and a developing unit is configured to be attachable to and detachable from each image carrier attached to the image carrier cartridge. 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 color misregistration by adjusting a position of at least one image carrier attached to the image carrier cartridge with respect to another image carrier is provided. 9. The color image forming apparatus according to any one of 1 to 8. 10. The cleaning means for independently collecting the residual developer is not provided around the image carrier of the image carrier cartridge, according to any one of claims 1 to 9. Color image forming apparatus.