JPH11295959A - Color image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and safely attach/detach a photoreceptor drum to/from a main body of a device in its axial direction while protecting its photoreceptive face. SOLUTION: Movable shafts 133, each sandwiching a cushioning medium 132, are disposed in at least three areas on the peripheral face of the photoreceptor drum 10 in the axial direction. When a front lid F is attached, the actuation pin 135 of each actuation lever 134 integrated with the movable shaft 133, is pressed by the square hale H of the front lid F to separate the cushioning medium 132 from the peripheral face of the drum, and it is held in the position by the elastic force of a restriction plate 136. When the photoreceptor drum 10 is detached, the movable shaft 133 is turned counterclockwise by the operation of turning the front lid F counterclockwise to disengage a lock pin PL and a key-shaped hole HK from each other, and the cushioning medium 132 is brought into contact with the peripheral face of the drum and held in the state by the restriction plate 136.

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, the space on the peripheral surface is insufficient, so that the photosensitive drum has a transparent body, the image exposing means is disposed inside the photosensitive drum, and the photosensitive drum is attached to and detached from the apparatus as an integral unit together with the image exposing means. JP-A-9-258518
No. has been proposed.

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. Therefore, considerable skill and attention is required to attach and detach the image forming body to and from the apparatus main body without interfering with various means such as charging, developing and cleaning provided on the peripheral surface of the image forming body.

The present invention has solved and improved the above points,
The photoreceptor drum, which is the image forming body, is accurately moved in the direction of its rotation axis by easy operation so that it can be attached and detached without touching the equipment provided near the peripheral surface and without damaging the photoreceptor surface and surrounding members. It is an object of the present invention to provide a color image forming apparatus capable of performing such operations.

[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 The image forming body is provided so as to be detachably provided in the rotation axis direction, and a plurality of support members disposed on the peripheral surface of the image forming body abut at the time of attachment / detachment, and are moved in the rotation axis direction by the guide of the support member. And a color image forming apparatus.

[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 130a that rotates in the same direction while maintaining the image quality.

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 a low temperature, and a heat pipe is used at a high temperature. 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 130a, and a jumping development is performed by a one-component or two-component developer contained in the developing device, and the developing sleeve 130a 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 preventing 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 photoreceptor drum 10 is sequentially intermediate-transferred by applying a bias voltage having a polarity opposite to that of the toner to the roller 14B at the contact point with the intermediate transfer belt 14. 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 of press-fitting or screws, etc., so that 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.

The photosensitive drum 10 has a movable shaft 133 sandwiching the cushion member 132 as a drum support member in the axial direction between the apparatus substrates 70 at least at three positions facing the outer peripheral surface. An operating lever 134 is integrally fixed to an end of the movable shaft 133 protruding from the device substrate 70.

Although the cushion member 132 regulates the lateral displacement of the photosensitive drum 10, the cushioning member 132 is made of a web or fluorine-coated soft rubber so as not to damage the photosensitive surface of the photosensitive drum 10 even if it comes into sliding contact. A soft and slippery material having such a surface is used.

As shown in FIG. 5 or FIG. 6, the operating lever 134 has two flat portions 13 substantially perpendicular to the shaft portion.
4A, and an operating pin 135 is provided at the tip of the lever portion 134B. Each of the cushion members 132 is connected to the photosensitive drum 10 at an angle at which the square hole H of the front cover F engages the operating pin 135. At a position separated from the peripheral surface of the flat portion 134A, and this state is maintained by the elasticity of the regulating plate 136 pressing the flat portion 134A.

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 is provided with reference holes H2 as suspending means at upper and lower rising portions 85A, while the rear support substrate 85 is provided with a pair of reference pins P4 as suspenders 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 (product 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 screw holes and slightly pulling out the entire surface of the apparatus main body, and is slightly lowered. Therefore, when the respective abutment plates 87 are mounted on the movable portions 200A, the guide rails 200 are extended to the front of the apparatus main body from the openings 70A of the apparatus 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 mounting is performed again, the guide rail 200 is returned from the extended state and slightly upwardly guided by 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 attaching / detaching operation of the support substrate 85. Further, the jammed paper staying in the conveyance path by pulling out the support substrate 85 can be 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 press contact is performed again. Placed in state.

The photosensitive drum 10 can be 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 from the opening 70A of the apparatus substrate 70 and removed. 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.

As shown in FIG. 5, the front lid F has a pair of key holes HK on the left and right mounting surfaces, and engages with the necks of the lock pins PL projecting from the device board 70, respectively. It is mounted and fixed with a plurality of set screws T.

When the set screw T is removed and the front cover F is rotated counterclockwise by a predetermined angle as shown in FIG. 6, the key hole HK is disengaged from the lock pin PL and the front cover F is released. In the axial direction, that is, in the front of the apparatus.

At the same time, as the front lid F rotates in the counterclockwise direction, the square hole H presses the operating pin 135 to rotate the operating lever 134 in the counterclockwise direction. As a result, the actuating lever 134 has the other flat portion 134A
Instead of the angle pressed by 6, the cushion member 132 is brought into contact with the peripheral surface of the photosensitive drum 10 to maintain the peripheral surface of the drum in a state of supporting the drum from at least three directions.

Therefore, even if the front cover F is removed, the photosensitive drum 10 is held substantially coaxially without touching the surrounding equipment, so that the photosensitive drum 10 can be safely moved in the axial direction and the clutch pin 10 can be moved.
P and clutch hole 131A and shaft portion 121A and engagement hole 1
The clutch members 131 are disengaged, the clutch member 131 is separated, and the clutch member 131 is taken out through an opening 70A similar to the photosensitive drum 10 opened to the apparatus substrate 70.

After the removed photosensitive drum 10 is inserted into the apparatus by using the cushion member 132 as a guide, the shaft portion 121A and the engaging hole 130A, the clutch pin 10P and the clutch hole 131A, and the angle regulation are performed. The front lid F is inserted into the device through the respective engagements of the pin 121P and the engagement portion 130B in sequence, and the key-shaped hole HK is locked with the lock pin PL and the square hole H from the angle shown in FIG. By engaging with the operating pins 135 and rotating clockwise and returning to the angle shown in FIG.
Is also rotated clockwise to hold the cushion member 132 at a position separated from the peripheral surface of the photosensitive drum 10 by pressing the regulating plate 136 again, and set the photosensitive drum 10 to an operable position.

As described above, the photosensitive drum 10 can separate the gear group of the drive system which occupies a relatively large weight and leave it in the apparatus and take it out of the apparatus while supporting the peripheral surface. It is very easy, and scratches on the drum surface and damage to the tooth surfaces of the gears due to peripheral charging devices, developing devices, intermediate transfer belts and other process members are prevented.

[0073]

According to the first aspect of the present invention, the photosensitive member can be easily operated at the time of attachment and detachment, and the photosensitive surface can be safely protected.
As a result, a practically useful color image forming apparatus capable of always forming a high-quality image and having excellent maintainability is provided.

Further, according to the present invention, the safety of the photosensitive surface is further enhanced by claim 2, the reduction in the strength of the device substrate is minimized by claim 3, and the operation for attachment and detachment is easier and more reliable than by claims 4 and 5. It was decided to be done.

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional configuration diagram 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 an explanatory diagram showing a positional relationship when a cushion material is separated.

FIG. 6 is an explanatory diagram showing a positional relationship at the time of contact of a cushion material.

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

[Explanation of symbols]

 Reference Signs List 10 photoconductor drum 10P clutch pin 11 scorotron charger 12 exposure optical system 13 developing device 14 intermediate transfer belt 15 transfer roller 20 support member 70 device substrate 70A opening 121 fixing member 121A shaft portion 130 support shaft 130A engagement hole 131 clutch member 131A Clutch hole 132 Cushion material 134 Operating lever 135 Operating pin 136 Restriction plate F Front cover H Square hole

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor ▲ Hama ▼ Shuta 2970-2, Ishikawacho, Hachioji-shi, Tokyo Konica Corporation (72) Inventor Toshihide Miura 5--14-14 Midoricho, Koganei-shi, Tokyo

Claims (5)

[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 for forming a plurality of toner images by superimposing on a peripheral surface and transferring the superposed color toner image to a transfer material, the image forming body includes an image exposing means, and is detachable in a rotation axis direction. A color image forming apparatus, wherein a plurality of supporting members provided on a peripheral surface of the image forming body are in contact with each other at the time of attachment and detachment, and are moved in a rotation axis direction by the guidance of the supporting members. 2. The color image forming apparatus according to claim 1, wherein the image forming body is moved after a transfer unit or a cleaning unit is retracted from a peripheral surface. 3. The color image forming apparatus according to claim 1, wherein the apparatus main body is provided with an opening having a shape similar to the side surface of the image forming body so as to be openable and closable on the side surface. 4. The color image forming apparatus according to claim 1, wherein the contacting and releasing of the supporting member are performed in conjunction with an attaching / detaching operation of the image forming body. apparatus. 5. The color image forming apparatus according to claim 1, wherein the image forming body is moved while leaving a gear that rotates as a unit in the apparatus.