JPH11295958A - Color image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize the actuation of a photoreceptor drum in rotation and to facilitate the attachment/detachment of it to/from the main body of the device by reducing its weight. SOLUTION: In the middle of a flange member 120A of the support member 20 of an exposing optical system 12, on the side of the back of the device, a fixing member 121 having a shaft 121A and an engagement pin 121P is provided, and on the peripheral part of the flange member 10A of the photoreceptor drum 10, a plurality of clutch pins 10P are disposed. On the other hand, on the substrate of the device, on the side of the back, a support shaft 130 having an engagement hole 130A and a V-shaped groove, and a clutch member 131 bearing-received by a support shaft 130 are provided. By the engagement of the engagement hole 130A and the shaft 121A and the engagement of the angle restriction pin 121P and the V-shaped groove, the angle of the exposing optical system 12 is set. By the engagement of the clutch pin 10P and the clutch hole 131A of the clutch member 131, the rotating power of the driving gear G1 on the device side is transmitted to the photoreceptor drum 10 via a gear G2 integrated with the clutch member 131.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drum-shaped image forming body, on which a plurality of charging, image exposing, and developing means are arranged so that toner is applied to the image forming body during one rotation of the image forming body. The present invention relates to an electrophotographic color image forming apparatus which is formed by superimposing and transferring to a transfer material via an intermediate transfer member.

[0002]

2. Description of the Related Art As a method of forming a multicolor image, a photoconductor, a charger, a developing device and the like are provided in the same number as required for the image. Apparatus for superimposing a color image on a body (A)
Or an apparatus (B) for forming a color image by repeating charging, image exposure and development for each color by rotating one photoconductor a plurality of times, or charging and image exposure for each color within one rotation of one photoconductor An apparatus (C) for forming a color image by sequentially performing development is known.

However, the above-mentioned apparatus (A) has a disadvantage that the capacity of the apparatus is increased because a plurality of photoconductors and intermediate transfer bodies are required, while the apparatus (B) has only one charging means, image exposure means and photoconductor. Although only one is used, the volume is reduced, but there is a restriction that the size of the formed image is limited to the surface area of the photoconductor or less.

On the other hand, the apparatus (C) is excellent in that the image size is not restricted and high-speed image formation can be realized.

[0005]

For this reason, a small-diameter photosensitive drum is used in the above-mentioned apparatus (C).
On the other hand, since the space on the peripheral surface is insufficient, the photosensitive drum has a transparent body and the image exposure means is disposed inside the photosensitive drum, and the photosensitive drum is attached to and detached from the apparatus as an integrated unit together with the image exposure means. JP-A-9-258518
And so on.

Further, the rotating photosensitive drum is integrally provided with a gear for receiving rotational power from the apparatus main body.
Since a gear having a large inertia and thus a heavy gear is used to stabilize the rotation speed, the photosensitive drum itself has a considerable weight and is not easy to handle. Furthermore, since the engagement and disengagement of the photoreceptor drum with the drive gear on the apparatus main body side are repeated each time the photoreceptor drum is attached and detached, the engagement depth is not constant, so that rotation unevenness may occur or the tooth tip may be damaged. is there.

The present invention has been made to solve the above problems, and as a result, the photosensitive drum has been reduced in weight to facilitate the handling, and has a constant speed of rotation while keeping the meshing state of the gears constant. The purpose of the present invention is to provide a color image forming apparatus capable of performing the following.

[0008]

An object of the present invention is to provide a plurality of sets of charging means, image exposing means and developing means for an image forming body, and to charge, image expose and develop during one rotation of the image forming body. Is repeated to form a plurality of toner images superimposed on the peripheral surface of the image forming body, in a color image forming apparatus that transfers the superimposed color toner image to a transfer material, the image forming body is an image exposure unit Incorporated and integrally rotatable gears are provided so as to be separable, and the gears include a holding unit for a fixed member that supports the image exposure unit at a central portion, and an engagement unit that couples the image forming body to an outer peripheral portion. This is achieved by a color image forming apparatus comprising:

[0009]

Embodiments of the present invention will be described below. Note that the description in this column does not limit the technical scope of the claims and the meaning of terms. Also, the following assertive description in the embodiment of the present invention indicates the best mode, and does not limit the meaning of the terms of the present invention or the technical scope.

An image forming process and configuration of an embodiment of the color image forming apparatus of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional configuration diagram of a color image forming apparatus,
FIG. 2 is a front sectional view showing a support structure of the photosensitive drum.

A photosensitive drum 1 which is a drum-shaped image forming body
Reference numeral 0 denotes, for example, a cylindrical transparent resin substrate formed by a transparent member of a transparent acrylic resin provided inside, and a transparent conductive layer and an organic photoconductor layer (OPC) formed on the outer periphery of the substrate. It is rotated in the direction shown by the arrow in FIG.

In the present embodiment, it is sufficient that the photoconductive layer of the photosensitive drum has an exposure light amount capable of giving an appropriate contrast. Therefore, the light transmittance of the transparent resin substrate of the photosensitive drum in the present embodiment does not need to be 100%, and may have a characteristic such that a certain amount of light is absorbed when the exposure beam is transmitted. As a material of the light-transmitting substrate, an acrylic resin, particularly one polymerized using a methyl methacrylate monomer, is preferably used because it is excellent in transparency, strength, precision, surface properties, and the like, but is used for other general optical members and the like. Various translucent resins such as fluorine, polyester, polycarbonate, polyethylene terephthalate, and the like can be used. Also,
It may be colored as long as it has a property of transmitting the exposure light. The refractive index of these resins is approximately 1.5. As a method of forming the light-transmitting conductive layer, indium tin oxide (ITO), alumina, tin oxide, lead oxide, and the like can be used by vacuum evaporation, active reaction evaporation, various sputtering methods, and various CVD methods. Indium oxide, copper iodide, Au, A
A light-transmissive thin film made of g, Ni, Al, or the like is used, or a conductive resin made of the above-described metal fine particles and a binder resin by a dip coating method, a spray coating method, or the like is used. Various organic photoconductor layers (OPC) can be used as the photoconductor layer.

Examples of preferred image forming members are shown below.

After adding a catalyst for synthesizing and polymerizing the plastic material monomer, pouring it into a cylindrical mold, sealing and fixing with a side plate, rotating this at a high speed and heating it appropriately Promotes uniform polymerization. After completion of the polymerization, the mixture is cooled, the obtained transparent resin substrate is taken out of the mold, cut and, if necessary, subjected to a finishing step to produce a transparent resin substrate for a photosensitive drum of an image forming apparatus (centrifugal polymerization method). .

As a material of a transparent resin substrate of a transparent plastic molded by centrifugal polymerization, a material obtained by polymerizing a methacrylic acid methyl ester monomer as described above is the best in terms of transparency, strength, precision, surface properties and the like. And other polyethyl methacrylate, polybutyl methacrylate, polyethyl acrylate, polybutyl acrylate, polystyrene, polyimide, polyester, polyvinyl chloride, and the like, or a copolymer thereof, and the like. In the centrifugal polymerization method, since the roundness is determined by the mold used for molding, a highly accurate substrate can be obtained. In addition, uneven thickness varies depending on rotation unevenness and viscosity during polymerization and heating conditions during polymerization.

As the conductive layer, conductive fine particles made of indium tin oxide (ITO), tin oxide, lead oxide, indium oxide, alumina, copper iodide, Au, Ag, Ni, Al, etc., and resin are used. Is used, and as a film forming method, a dip coating method, a spray coating method, or the like is preferably used.

The organic photoreceptor layer comprises a charge generating material (CGM)
And a charge transport layer (CTL) containing a charge transport material (CTM) as a main component. The organic photoreceptor layer having a two-layer structure has a low CGL, and thus has good transparency of image exposure light and is suitable for the present invention. The organic photoreceptor layer may have a single-layer structure containing a charge generation material (CGM) and a charge transport material (CTM) in one layer, and may have the single-layer structure or the two-layer structure. Usually contains a binder resin.

In the photosensitive drum having the two-layered organic photosensitive layer, the CGM contained in the CGL may be an azo pigment, an azulenium pigment, a phthalocyanine pigment which is sensitive to light from a light source such as an LED or an LD. , A perylene pigment is used, and red to infrared light (600 nm
Copper phthalocyanine pigments, titanyl phthalocyanine pigments, and the like are preferably used as the CGM of the OPC photoreceptor that is sensitive to light of about 850 nm.

As the binder resin used for CGL, a polyvinyl butyral resin or a polycarbonate resin is used, which is excellent in sensitivity, potential change upon repeated use, and the like. These binder resins can be used alone or as a mixture of two or more.

As a solvent or a dispersion medium used for forming CGL, a ketone-based or halogen-based solvent is preferably used, and the sensitivity and the potential change upon repeated use are further improved. In addition, these solvents can be used alone or as a mixed solvent of two or more kinds.

The weight ratio of CGM to the binder resin in the CGL is 100: 1 to 1000, the thickness of the CGL is 0.01 to 10 μm, and the coating method for forming the CGL is a blade. There are various coating methods such as coating, wire bar coating, spray coating, dip coating and slide hopper coating.

Next, as the CTM contained in the CTL, hydrazone compounds, styryl compounds, benzidine compounds, stilbene compounds and the like are used.

As the binder resin used in the CTL, a wide range of insulating resins can be appropriately selected and used, and preferred binder resins are silicon-alkyd resin, phenol-formaldehyde resin, poly-N- Insulating resins such as vinyl carbazole and polysilane can be mentioned, and these binder resins can be used alone or in combination of two or more.

The mixing ratio of the binder resin and CTM is 1:
It is set to 10 to 500, and more preferably 1:20 to 150. The thickness of the CTL is set to 1: 100 μm.
~ 50 μm is preferred.

As a coating method, a method similar to CGL can be used.

If necessary, an intermediate layer is provided between the organic photoreceptor layer and the conductive layer. Examples of the intermediate layer include polyvinyl chloride vinyl acetate copolymer, vinyl acetate vinyl acetate maleate copolymer, ethyl cellulose and carboxymethyl cellulose. And a resin layer having a thickness of 0.01 to 2 μm, such as a copolymer type or modified type alcohol-soluble polyamide resin.

By using the plastic cylindrical transparent resin substrate produced by the above-described manufacturing method, the thickness is uniform, the cylindrical substrate has excellent cylindricity and roundness, and the image exposure light is defocused. The present invention provides a photoreceptor drum free of defects.

Numeral 11 denotes a scorotron charger (hereinafter simply referred to as a charger) which performs a charging action on the above-mentioned organic photoreceptor layer of the photoreceptor drum 10 by a grid maintained at a predetermined potential and corona discharge by a discharge wire. A uniform potential is applied to the photosensitive drum 10.

Reference numeral 12 denotes an exposure optical system comprising image exposure means, that is, LEDs arranged in the axial direction of the photosensitive drum 10 and a selfoc lens which is a unity-magnification imaging system, which is read by a separate image reading device. The image signals of the respective colors are sequentially taken out of the memory and input to the respective exposure optical systems 12 as electric signals.

Each of the exposure optical systems 12 is attached to a support member 20 provided as an optical system support means, and is housed inside the substrate of the photosensitive drum 10.

Reference numerals 13Y to 13K denote developing units for accommodating yellow (Y), magenta (M), cyan (C) and black (K) developers, each having a predetermined gap with respect to the peripheral surface of the photosensitive drum 10. And a developing sleeve 130 that rotates in the same direction while maintaining the same.

Each of the developing units is in a non-contact state by applying a developing bias voltage to the electrostatic latent image on the photosensitive drum 10 formed by the charging by the charger 11 and the image exposure by the exposure optical system 12. To reverse development.

The original image is temporarily stored in an image reading apparatus separate from the present apparatus as an image signal read by an image sensor or an image edited by a computer as an image signal for each color of Y, M, C and K. And stored.

At the start of image recording, the photosensitive drum 10 is rotated counterclockwise by the start of the photosensitive member drive motor, and at the same time, the application of a potential to the photosensitive drum 10 is started by the charging action of the charger 11 (Y). You.

After a potential is applied to the photosensitive drum 10, the exposure optical system 12 (Y) starts exposure with an electric signal corresponding to a first color signal, that is, an image signal of yellow (Y). An electrostatic latent image corresponding to the yellow (Y) image of the original image is formed on the photosensitive layer on the surface by rotational scanning.

The latent image is reversal-developed by the developing device 13 (Y) in a state where the developer on the developing sleeve is not in contact, and a yellow (Y) toner image is formed according to the rotation of the photosensitive drum 10.

Next, the photosensitive drum 10 is further provided with a potential on the yellow (Y) toner image by the charging action of the charger 11 (M), and the second potential of the exposure optical system 12 (M) is changed.
Exposure is performed using an electric signal corresponding to the color signal of magenta (M), that is, the image signal of magenta (M), and the magenta (M) ) Are sequentially formed to be superimposed.

By the same process, the charger 11 (C),
The exposure optical system 12 (C) and the developing device 13 (C) further form a cyan (C) toner image corresponding to the third color signal.
Further, a black (K) toner image corresponding to the fourth color signal is sequentially superimposed and formed by the charger 11 (K), the exposure optical system 12 (K), and the developing device 13 (K). Within one rotation, a color toner image is formed on the peripheral surface.

The photosensitive drum 1 by each of these exposure optical systems
The exposure of the organic photosensitive layer of No. 0 is performed from the inside of the drum through a substrate transparent to the above-mentioned exposure wavelength. Therefore, the exposure of the images corresponding to the second, third, and fourth color signals is performed without any influence from the previously formed toner image, and is equivalent to the image corresponding to the first color signal. It is possible to form an electrostatic latent image. Each exposure optical system 12
In order to stabilize the temperature in the photoconductor drum 10 and prevent the temperature from rising due to the heat generated by the above, a material having good thermal conductivity is used for the support member 20, a heater is used at low temperatures, and a heat pipe is used at high temperatures. By taking measures such as dissipating heat to the outside through the device, it can be suppressed to a level where there is no problem. In the developing operation of each developing device, a developing bias to which a direct current or a further alternating current is applied is applied to the developing sleeve 130, and a jumping development is performed by a one-component or two-component developer contained in the developing device, and the developing sleeve 130 is transparent. Non-contact reversal development is performed on the photosensitive drum 10 that grounds the conductive layer.

Thus, the color toner image formed on the peripheral surface of the photosensitive drum 10 is temporarily transferred to the peripheral surface of the intermediate transfer belt 14 provided as an intermediate transfer means.

The intermediate transfer belt 14 has a thickness of 0.5 to 2.0.
mm, a semiconductive substrate of silicon rubber or urethane rubber having a resistance of 10 ⁸ to 10 ¹² Ω · cm, and a thickness of 5 to 50 μm as a toner filming prevention layer on the outside of the rubber substrate. And a two-layer structure with fluorine coating. This layer also preferably has a similar semiconductivity. 0.1-0.5m thickness instead of rubber belt base
m, a semiconductive polyester, polystyrene, polyethylene, polyethylene terephthalate, or the like can also be used. The intermediate transfer belt 14 has rollers 14A, 14B,
The photosensitive drum 10 is stretched between the rollers 14C and 14D, and is circulated clockwise in synchronization with the peripheral speed of the photosensitive drum 10 by the power transmitted to the roller 14D.

The intermediate transfer belt 14 has a roller 14A.
The belt surface between the roller 14B and the roller 14B is in contact with the peripheral surface of the photosensitive drum 10, while the belt surface on the outer periphery of the roller 14C is in contact with the transfer roller 15, which is a transfer member, to form a toner image transfer area at each contact point. ing.

The color toner image adhered to the peripheral surface of the photosensitive drum 10 is first subjected to intermediate transfer by applying a bias voltage having a polarity opposite to that of the toner to the roller 14B at the contact point between the intermediate transfer belt 14 and the roller. The image is transferred to the peripheral surface of the belt 14. That is, the color toner image on the drum is conveyed to the transfer area without scattering the toner by the guidance of the grounded roller 14A,
The intermediate transfer belt 14 is applied by applying a bias voltage of kV.
It is efficiently transferred to the side.

On the other hand, the transfer paper P is carried out by the operation of the paper feed roller 17 of the paper feed cassette (not shown) and fed to the timing roller 18, and synchronized with the transport of the color toner image on the intermediate transfer belt 14. The paper is fed to the transfer area of the transfer roller 15.

The transfer roller 15 is connected to the intermediate transfer belt 14.
The transfer paper P fed in the counterclockwise direction is synchronized with the peripheral speed of the intermediate transfer in the transfer area formed by the nip portion between the transfer roller 15 and the roller 14C in the ground state. The color toner images are successively transferred onto the transfer paper P by applying a bias voltage of the opposite polarity to the toner of 1 to 2 kV to the transfer roller 15 in close contact with the color toner image on the belt 14.

The transfer paper P to which the color toner image has been transferred is neutralized, conveyed to the fixing device 91 via the conveyance plate 19, and sandwiched and conveyed between the heat roller 91A and the pressure roller 91B to be heated. After the toner is fused and fixed, the toner is discharged to the outside of the apparatus via a discharge roller 92.

The photosensitive drum 10 and the intermediate transfer belt 14 have cleaning devices 100 and 14 respectively.
No. 0 is provided, and the blades provided are always in pressure contact with each other, the remaining adhered toner is removed, and the peripheral surface is always kept in a clean state.

As shown in the sectional view of FIG. 2, the photosensitive drum 10 and the support member 20 have flange members 10A and 120A and a flange member 1 at the rear and front ends of the apparatus, respectively.
0B and 120B are integrated by means such as press-fitting or screws, and the photosensitive drum 10 has a fixing member 121 and a flange member 120 in which the flange members 10A and 10B are integrated with the flange member 120A of the support member 20.
B is rotatably supported by bearings B1 and B2, respectively.

The fixing member 121 is used for the photosensitive drum 10
Is provided with a shaft portion 121A as a holding means, and a support shaft 130 having an engaging hole 130A is provided on the rear device substrate 70 as the engaging means. The support shaft 130 rotatably supports a clutch member 131 integrally formed with a gear G2 meshing with a drive gear G1 via a bearing B3.
A similar opening 70A into which 0 can be inserted and removed is opened.

For the supporting member 20, the shaft 121A of the fixing member 121 is inserted into the engaging hole 130A of the support shaft 130 with respect to the device board 70 on the rear side, and the engaging pin inserted through the shaft 121A is inserted. 121P is engaged with the engaging portion 130B of the support shaft 130.
The exposure optical system 12 is attached by regulating the angular position of the exposure optical system 12 by engaging with the V-shaped groove formed on the front surface side. By fixing the front cover F while pressing the material K in the axial direction, the front cover F is mounted at a predetermined position.

In the photosensitive drum 10, the clutch pin 10P provided on the side surface of the flange member 10A is inserted into the clutch hole 131A formed on the side surface of the clutch member 131 at the mounting position of the support member 20. The rotational power of the gear G1 is transmitted to the photosensitive drum 10 via the clutch member 131.

As shown in the front view of FIG. 3, the clutch member 131 has a plurality of the above-described clutch holes 131A formed in a plurality of slots in the circumferential direction concentric with the outer peripheral portion. An elastic plate S having one end fixed near the upstream end in the rotational direction is provided, and the rotational power of the clutch member 131 is transmitted to the photosensitive drum 10 after absorbing the impact by the elastic force of the elastic plate S. It has become.

The fixing member 121 and the clutch pin 10P are provided on the clutch member 131 side, and the engaging hole 1
30A and the clutch hole 131A may be formed in the flange member 10A, and the engagement means and the holding means described above may be replaced and installed.

Next, the intermediate transfer belt 14 will be described. As shown in FIG. 4, each of the rollers 14A to 14D is placed in a state where the intermediate transfer belt 14 is stretched by the urging force of a tension roller T. It is bearing-supported between the front and rear side plates 45 formed in a letter shape and connected integrally.

The side plate 45 is formed in a U-shape and sandwiched together with the cleaning device 140A between the asymmetrical front and rear support substrates 85 which are integrally connected to each other so as to be integrated.

The front support substrate 85 has a reference hole H2 as a suspending means at the upper and lower rising portions 85A, while the rear support substrate 85 has a pair of reference pins P4 as the suspending means at the back. The reference hole H
2 has a reference pin P3 provided on the front device board 70, and a reference hole H having the reference pin P4 provided on the rear device board.
The intermediate transfer belt 14 is set at a predetermined position by screwing and fixing the upper screw engaged with the photosensitive drum 1 and the photosensitive drum 1.
0 to form a first transfer area for transferring a toner image from the photosensitive drum 10 to the intermediate transfer belt 14 by pressing the transfer material from the intermediate transfer belt 14 by pressing the transfer roller 15. For transferring the toner image to the second
Is formed.

The support substrate 85 is provided between the front and rear device substrates 70.
On the other hand, it is supported so as to be able to be pulled out to the front side of the apparatus main body via a pair of guide rails 200 which can be extended and contracted in two steps called an accuride rail (trade name).

The support substrate 85 is formed by a pair of front and rear guide plates 86 provided on the left and right sides, respectively.
The movable part 200A is slidably held in the vertical direction, and the movable part 200A is integrated in the pulling-out direction.
It is configured to be able to descend until it hits 00A.

The above-mentioned support substrate 85 is released from engagement with the above-described reference pins and the respective reference holes by slightly pulling out the entire surface of the apparatus main body after releasing the screwing means, and is slightly lowered. Accordingly, when the respective abutment plates 87 are mounted on the movable portions 200A, the guide rails 200 are extended to the front of the device main body from the opening portions 70A of the device substrate 70 by the extension operation of the guide rails 200. As a result, the intermediate transfer belt 14
The guide rail 200 is retracted from the peripheral surface of the photosensitive drum 10 and is pulled out in a state where the pressure contact is released. Even when the guide rail 200 is mounted again, the guide rail 200 is returned from the extended state and is slightly moved upward by the guide of the tapered portion of each reference pin. Move to the photosensitive drum 10
The operation of returning to the pressure-contact state is automatically and reliably performed.

Accordingly, the photosensitive drum 10 can be taken out without interfering with the intermediate transfer belt 14 by a very simple operation of attaching / detaching the support substrate 85, and furthermore, the jammed paper staying in the conveyance path by pulling out the support substrate 85 is removed. Maintenance such as removal processing, replacement of the intermediate transfer belt 14, and inspection can be easily performed.

Prior to the operation of pulling out the support substrate 85 from the apparatus main body, the pressing action of the transfer roller against the roller 14C for stretching the intermediate transfer belt 14 is released in advance, and after returning to the predetermined set position, the pressing action is again performed. Placed in state.

The photosensitive drum 10 is easily and safely attached to and detached from the apparatus main body by the following operation procedure.

When the photosensitive drum 10 is attached or detached, first, the front cover C of the apparatus shown in the perspective view of FIG. 7 is opened, and then each charger 11 is pulled out and removed from the opening 70A of the apparatus substrate 70. The contact of each developing device 13, the cleaning device 100, and the intermediate transfer belt 14 with the peripheral surface of the drum 10 is released.

A plurality of setscrews T for fixing the front lid F as shown in the sectional view of FIG.
Is moved in the axial direction, the flange member 12 of the support member 20 is moved.
0C is disengaged, so that the photosensitive drum 10 is free at the end on the front side of the apparatus, and the flange member 10B
Cushion 1 made of a web or a soft rubber whose outer periphery is adhered to a key point around the opening 70A of the device substrate 70
32 temporarily supported.

In this state, when the photosensitive drum 10 is moved in the axial direction as shown in the sectional view of FIG. 6, first, the clutch pin 10P is disengaged from the clutch hole 131A of the clutch member 131, and then the fixing member is fixed. Shaft 121 of 121
A is disengaged from the engagement hole 130A of the support shaft 130, the clutch member 131 is separated into the device and removed from the front of the device.

After the removed photosensitive drum 10 is inserted into the apparatus by using the cushion member 132 as a guide, the shaft 121A, the engaging hole 130A, the clutch pin 1
0P, the clutch hole 131A, and the engagement pin 121P and the engagement portion 130B are sequentially inserted into the device through the engagement,
The front cover F is set to a predetermined operating position by the mounting support.

As described above, the photosensitive drum 10 is taken out of the apparatus in a state where the gear group of the drive system occupying a relatively large weight is separated and left inside the apparatus. At the same time, the gear system always maintains a constant meshing state to transmit a stable rotational speed and prevent tooth surface damage.

[0068]

According to the first aspect of the present invention, the color of the photoreceptor is improved in the accuracy of image superposition due to the stable rotation speed, and the weight is reduced so that the photoreceptor can be easily attached and detached. An image forming apparatus has been provided.

Further, according to the second and third aspects of the present invention, the degree of freedom of the configuration is expanded, and as a result, the present invention is widely applied to many color image forming apparatuses.

[Brief description of the drawings]

FIG. 1 is a cross-sectional configuration diagram of a color image forming apparatus.

FIG. 2 is a front sectional view showing a supporting and driving structure of a photosensitive drum.

FIG. 3 is a front view of a main part showing a drive connection mechanism of the photosensitive drum.

FIG. 4 is a front view showing a support structure of the intermediate transfer belt.

FIG. 5 is a sectional view of a main part (front side) showing a photosensitive drum attaching / detaching means.

FIG. 6 is a sectional view of a main part (rear side) showing a photosensitive drum attaching / detaching means.

FIG. 7 is a perspective view showing a front part of the apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Photoconductor drum 10A, 10B, 120A, 120B, 120C Flange member 10P Clutch pin 11 Scorotron charger 12 Exposure optical system 13 Developing device 14 Intermediate transfer belt 15 Transfer roller 20 Supporting member 70 Device substrate 70A Opening 100, 140A Cleaning device 121 Fixing member 121A Shaft part 130 Support shaft 130A Engagement hole 131 Clutch member 131A Clutch hole K Buffer material C Front cover F Front cover

Continued on the front page (72) Inventor Tetsu Haneda 2970 Ishikawacho, Hachioji-shi, Tokyo Konica Corporation (72) Inventor Toshihide Miura 5-14-14 Midoricho, Koganei-shi, Tokyo

Claims (3)

[Claims] 1. A plurality of sets of charging means, image exposing means and developing means are provided for an image forming body, and charging, image exposing and developing are repeated during one rotation of the image forming body, and In a color image forming apparatus in which a plurality of toner images are superimposed on a peripheral surface and a superposed color toner image is transferred to a transfer material, the image forming body includes an image exposing unit and rotates integrally. A collar provided detachably with the gear, wherein the gear has a fixing member holding means for supporting the image exposing means at a central portion, and an engaging means for coupling the image forming member to an outer peripheral portion. Image forming device. 2. A color image forming apparatus according to claim 1, wherein said holding means provided in said gear is a convex portion or a concave portion. 3. The color image forming apparatus according to claim 1, wherein the engaging means of the gear is a convex portion or a concave portion.