JPH09281800A - Color image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attach and detach an image forming body without receiving the interference of the driving gear of the image forming body and the driving transmission means thereof and the like by setting the abutting position of the gap holding means of a developing unit inside by a specified distance from the end part of a flange member when the gap holding means is made to abut on the inside end part of the image forming body. SOLUTION: A photoreceptor drum 10 is freely turnably supported by a supporting member 20 held by a fixed supporting shaft 30 constituted so that the flange member 10B and the like are fixed to a side plate 40 through a bearing B. A stopper part is arranged as a stop means when the flange member 10B and the like of both ends of the drum 10 are press fitted so that the flange member 10B and the like are press fitted and the drum 10 is held by the flange member 10B and the like. Besides, an abutting roller 131 is made to abut on the drum 10 inside the flange member 10B and the like by a gap L2 from the end part of the stopper part of the flange member 10B and the like with respect to the drum 10. Then, 5-30mm is respectively required for a press-fitting margin L1 and the gap L2 in order to surly hold the drum 10 and to evade the deformation of the press fitting part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly arranges a plurality of charging means, image exposing means and developing means on the peripheral surface of a drum-shaped image forming body to form a toner image during one rotation of the image forming body. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic color image forming apparatus that is formed by superimposing on a body.

[0002]

2. Description of the Related Art As a method of forming a multi-color image, image exposure and development of an image corresponding to each color are sequentially repeated during one rotation of an image forming body to superimpose toner images of each color on the image forming body. There is known a color image forming apparatus for forming a color image.

However, in such an apparatus, a plurality of charging means, image exposing means, and developing means are arranged on the peripheral surface of the image forming body, and furthermore, a space is also required in a transfer material conveying area and a cleaning means. Insufficient peripheral space,
Therefore, there are drawbacks that layout is difficult, a large-sized image forming body having a long peripheral surface is required, and the balance is poor.

As one method of solving this shortage of space, the base of the image forming body is made transparent, and each image exposing means is housed inside the image forming body so that image exposure is performed from the inside of the image forming body. In addition, an apparatus or the like in which an intermediate transfer member is used to set the transfer surface of the transfer material that is transferred in the tangential direction to the transfer area at a position apart from the peripheral surface of the image forming body. Proposed.

[0005]

In such an apparatus, in order to maintain the exposure accuracy of the photosensitive surface and to simplify the handling, the image exposing means is generally provided in the apparatus as a unit integrated with the image forming body. In many cases, when attaching and detaching the image forming body, a plurality of charging means and developing means arranged on the outer periphery of the unit-shaped image forming body having a large weight, particularly the drive gear of the image forming body It is required to be able to perform an operation of moving without being interfered with the drive transmission means or the drive gear of the developing device.

Conventionally, flange members are press-fitted to both ends of the image forming body to form a support portion of the image forming body. However, when the flange members are press-fitted to the image forming body, the press-fitted portions of the image forming body are formed. Is deformed, and the accurate developing gaps of the plurality of developing devices held with a predetermined gap by the gap holding means abutting on the end of the image forming body cannot be maintained, and a good image cannot be obtained. Problem has occurred.

The present invention solves the above problems and provides a method of disposing gap holding means for holding an accurate developing gap, a drive gear of an image forming body and its drive transmission means, a drive gear of a developing device, and the like. It is an object of the present invention to provide a color image forming apparatus in which an image forming body can be attached and detached without being interfered with.

[0008]

The above-mentioned object is to have a plurality of image exposing means mounted on an optical system supporting means inside a drum-shaped image forming body, and to arrange a plurality of developing devices around the image forming body. In the color image forming apparatus, the image forming body is
The optical system support means is integrally supported together by side plates, and has flange members press-fitted at both ends of the image forming body, and the gap holding means of the developing device is brought into contact with the inner end portion of the image forming body. At this time, the contact position of the gap maintaining means is set to be 5 to 30 mm inside from the end of the flange member (first invention).

A further object of the present invention is to provide a color image forming apparatus having a plurality of image exposing means attached to an optical system supporting means inside a drum-shaped image forming body and a plurality of developing devices arranged around the image forming body. In the image forming body, the optical system supporting means is integrally supported together by side plates, and has flange members press-fitted at both ends of the image forming body. When the gap holding means of the developing device is brought into contact with the outer peripheral surface, the contact position of the gap holding means is 5 to 30 mm from the end of the flange member.
This is achieved by a color image forming apparatus characterized by being inside (second invention).

A further object of the present invention is to provide a color image forming apparatus having a plurality of image exposing means attached to an optical system supporting means inside a drum-shaped image forming body and a plurality of developing devices arranged around the image forming body. In the image forming body, the optical system supporting means is integrally supported together by a side plate, a gear is provided at an end of the image forming body, and the image forming body is formed on a side plate supporting the optical system supporting means. A drive motor for driving the image forming body in combination with a gear provided at the end of the image forming body, and a transmission means for the drive motor, and the outer diameter of the gear provided at the end of the image forming body is equal to that of the image forming body. This is achieved by a color image forming apparatus characterized by being provided smaller than the outer diameter (third invention).

[0011]

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 a 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 view showing the support structure of the photosensitive drum,
FIG. 3 is a cross-sectional view showing the support structure of the photosensitive drum,
4 is an external view of the drum unit, FIG. 5 is a front view showing a supporting structure of the intermediate transfer belt, and FIG. 6 is a sectional view showing a supporting structure of the intermediate transfer belt.

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 imparting 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. Further, various organic photoconductor layers (OPC) can be used as the photoconductor layer.

Examples of preferable image forming bodies are shown below.

After adding a catalyst for synthesizing and polymerizing the plastic material monomer, it is poured into a cylindrical mold, fixed by sealing with a side plate, rotated at a high speed, and appropriately heated. 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 for a transparent resin substrate of a transparent plastic molded by centrifugal polymerization, a polymer obtained by using a methyl methacrylate monomer as described above is the best in terms of transparency, strength, precision and surface property. In addition, polyethyl methacrylate, polybutyl methacrylate, polyethyl acrylate, polybutyl acrylate, polystyrene, polyimide, polyester, polyvinyl chloride, or the like, or a copolymer thereof or the like can be used. In the centrifugal polymerization method, since the roundness is determined by the mold used for molding, a highly accurate substrate can be obtained. Also,
The uneven thickness varies depending on the rotation unevenness and viscosity during polymerization and the heating conditions during polymerization.

As the conductive layer, indium tin oxide (ITO), tin oxide, lead oxide, indium oxide, alumina, copper iodide, conductive fine particles of Au, Ag, Ni, Al, etc., and resin. A conductive resin mixed with 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 is 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 photoconductor drum having the two-layer organic photoconductor layer, the CGM contained in the CGL is an azo pigment, an azurenium pigment, or a phthalocyanine pigment having photosensitivity to light from a light source such as an LED or LD. , Perylene pigments are used, among which infrared light (600 nm to 8 nm) is used.
The CGM of the OPC photoreceptor sensitive to 50 nm) is as follows.
Copper phthalocyanine pigments and titanyl phthalocyanine pigments are preferably used.

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

As the solvent or dispersion medium used for the formation of CGL, a ketone-based or halogen-based solvent is preferably used, and the sensitivity, the potential change during repeated use and the like are further improved. These solvents can be used alone or as a mixture of two or more solvents.

The weight ratio of CGM in the CGL to the binder resin is 100: 1 to 1000, and the film thickness of the CGL is 0.01 to 10 μm. As a coating method for forming the CGL, a blade is used. 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.

The binder resin used for the CTL can be appropriately selected from a wide range of insulating resins and used. Preferred binder resins are silicon-alkyd resins, phenol-formaldehyde resins and poly-N- resins. Insulating resins such as vinylcarbazole and polysilane can be mentioned, and these binder resins can be used alone or in combination of two or more kinds.

The compounding ratio of the binder resin and CTM is 1:
It is set to 10 to 500, and preferably 1:20 to 150. The thickness of the CTL is set to 1: 100 μm, preferably 5 to 50 μm.

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 vinyl chloride vinyl acetate copolymer, vinyl chloride vinyl acetate maleic acid copolymer, ethyl cellulose and carboxymethyl cellulose. The resin layer has 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-mentioned manufacturing method, the thickness is uniform, the cylindrical substrate has excellent cylindricity and roundness, and the defocus of the image exposure light is deviated. There is provided a photoconductor drum without.

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

Reference numeral 12 is an image exposing means, that is, the photosensitive drum 1.
An exposure optical system composed of LEDs arranged in the axial direction of 0 and a SELFOC lens which is an equal-magnification imaging system, in which image signals of respective colors read by a separate image reading device are sequentially taken out from a memory. An electric signal is input to each of the exposure optical systems 12 described above.

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

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

Each of the developing devices is in a non-contact state by applying a developing bias voltage to the electrostatic latent image formed on the photosensitive drum 10 formed by the charging by the charging device 11 and the image exposure by the exposure optical system 12 described above. Reverse development with.

The original image is temporarily stored in an image reading apparatus separate from this apparatus, in which the image read by the image pickup device or the image edited by the computer is temporarily stored as an image signal for each color of Y, M, C and K. Are stored and stored in.

When the image recording is started, the photoconductor drive motor is started to rotate the photoconductor drum 10 counterclockwise, and at the same time, the charging action of the charger 11 (Y) starts to apply the potential to the photoconductor drum 10. It

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

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

Next, the photosensitive drum 10 is further given a potential on the yellow (Y) toner image by the charging action of the charger 11 (M), and the second color signal of the exposure optical system 12 (M), that is, Exposure is performed by an electric signal corresponding to the magenta (M) image signal, and non-contact reversal development by the developing device 13 (M) causes a magenta (M) toner image on the yellow (Y) toner image. Will be sequentially stacked.

By the same process, the charger 11 (C),
The exposure optical system 12 (C) and the developing unit 13 (C) further form a cyan (C) toner image corresponding to the third color signal, and the charging unit 11 (K), the exposure optical system 12 (K) and the developing unit 13 (C). A black (K) toner image corresponding to the fourth color signal is sequentially superimposed and formed by the unit 13 (K), and a color toner image is formed on the peripheral surface within one rotation of the photosensitive drum 10. You.

Photoreceptor drum 1 by 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 the same exposure as the image corresponding to the first color signal is performed. It is possible to form an electrostatic latent image. Each exposure optical system 1
In order to stabilize the temperature in the photosensitive drum 10 and prevent the temperature from rising due to the heat generated by 2, heat is used for the supporting member 20, a heater is used for low temperature, and a heat pipe is used for high temperature. By taking measures such as radiating heat to the outside via the, it can be suppressed to the extent that there is no problem.
Further, at the time of the developing action by 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, so that the developing sleeve 130 is transparent. Non-contact reversal development is performed on the photosensitive drum 10 that grounds the conductive layer.

The color toner image thus formed on the peripheral surface of the photosensitive drum 10 is once 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 includes rollers 14A, 14B,
The photosensitive drum 10 is stretched between the rollers 14C and 14D and 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 is 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. ing.

The color toner image adhered to the peripheral surface of the photosensitive drum 10 is first 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 guide of the roller 14A which is grounded, and is transferred to the roller 14B by 1
The transfer is efficiently performed on the intermediate transfer belt 14 side by applying a bias voltage of about 2 kV.

On the other hand, the transfer paper P is unloaded by the operation of the paper feed roller 17 of the paper feed cassette (not shown) and is fed to the timing roller 18 in synchronization with the conveyance of the color toner image on the intermediate transfer belt 14. And is fed to the transfer area of the transfer roller 15.

The transfer roller 15 is 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 having the color toner image transferred thereto is destaticized, conveyed to the fixing device 91 via the conveying plate 19, and conveyed by being sandwiched between the heat roller 91A and the pressure roller 91B and heated. After the toner is fused and fixed, the toner is ejected to the outside of the apparatus via the paper ejection roller 92.

Cleaning devices 100 and 140 are installed on the photoconductor drum 10 and the intermediate transfer belt 14, respectively, and the blades of the cleaning devices 100 and 140 are constantly in pressure contact with each other to remove the remaining adhered toner, and the peripheral surfaces are always kept. It is kept clean.

As shown in FIGS. 2 and 3, the support member 20 is composed of a pair of front and rear members fixed to the rotary support shaft 30 of the photosensitive drum 10, and each exposure optical system 1
2 has both ends adjusted so that the distance to the photosensitive surface via the attaching member 21 is in a predetermined positional relationship, and is fixed to the adjustment position by bonding.

On the other hand, the photosensitive drum 10 has flange members 10A and 10B provided at both ends thereof rotatably supported by the support member 20 via bearings B, respectively, and is driven by a gear 10G provided on the flange member 10B. The rotation support shaft 30 in the fixed state is rotated about the rotation center.

The rotary support shaft 30 is the photosensitive drum 10.
Each of the symmetrical front and rear side plates 40 formed in a U-shape and integrally connected while supporting each of the exposure optical systems 12.
The bearing is supported between.

The side plate 40 is provided with rail members 50 as suspending means at front and rear connecting portions, and the rail members 50 are inserted into and engaged with a guide member 60 provided in the main body of the apparatus to bring them into a suspended state. As a result, the rotary support shaft 30, and thus the photoconductor drum 10 and each exposure optical system 12, are placed at substantially predetermined set positions.

Further, when the rotary support shaft 30 is inserted to the proper position, the shaft end portion 30B protruding from the rear side plate 40 from the above-mentioned suspended state is fitted into the seat 71 provided on the device substrate, Shaft end 30 protruding from the front side plate 40
A is supported by a screw member 82 which is tapered into a receiving seat 81 provided on a support substrate 80, thereby accurately regulating the photosensitive drum 10 to a regular set position and meshing the gear 10G with the driving gear. On the other hand, each exposure optical system 12 is further engaged with the through-pin P1 provided on the shaft end 30B in the V-shaped groove formed in the receiving seat 71 by the cross section.
It is accurately regulated at a predetermined angular position with respect to the apparatus main body, and becomes a fixed state. Thereafter, the lead wires of the respective optical systems are connected from the respective windows 20A of the support member 20 on the front side to the power supply unit through the cutouts 40A of the side plate 40.

The support substrate 80 has the upper and lower reference holes H.
1 is engaged with a pair of reference pins P2 provided on the front device board 70, the attachment position thereof is determined, and is fixed to the front device board 70 by a plurality of screwing screws. Each of the rod-shaped chargers 11 having the window 80A opened and having the above-described rod shape is inserted from the outside of the support substrate 80 to be set at a predetermined interval position with respect to the photoconductor drum 10, and a screwing screw is set in a state where the electrodes are connected. It is fixed and supported by.

Therefore, the support substrate 80 is used for each charger 1.
When the screw member 82 is removed in a state where 1 is removed through the window 80A, the screw member 82 is only released from a plurality of screw holes, and is separated from the device substrate 70. From this state, the side plate 40 is removed. The rail member 50 is slid under the guidance of the guide member 60 so that the photosensitive drum 10 and each of the exposure optical systems 12 are integrally moved in the horizontal direction, and can be taken out of the apparatus main body through the opening 70A of the apparatus substrate 70. Becomes

Prior to starting the attachment / detachment operation of the photosensitive drum 10 supported by the side plate 40 to / from the apparatus main body, each developing device 13, the intermediate transfer belt 14, and the cleaning device 100 with respect to the peripheral surface of the photosensitive drum 10 are started. The pressure contact action of the blade is released in advance and the blade is retracted by about 1 to 10 mm, and after the mounting, the blade is returned to the pressure contact state again.

After the side plate 40 is removed from the apparatus main body, the rail member 50 may be placed on the lower side as shown in FIG. 4 so that the side plate 40 can be placed in a well-balanced manner so that the photosensitive drum or the like does not contact the floor surface. Function as a stand for
It is also used to protect the photoreceptor surface.

Each of the rollers 14A to 14D is formed in a U-shape in a state in which the intermediate transfer belt 14 is stretched by the bias of the tension roller T, and the front and rear side plates 45 are integrally connected. Bearings are supported between them.

The side plate 45 is further formed in a U shape and is integrally connected to each other.
Between the cleaning device 140 and the cleaning device 140.

The front supporting substrate 85 is provided with a reference hole H2 as a suspending means in the upper and lower rising portions 85A, while the rear supporting substrate 85 is provided with a pair of reference pins P4 as a suspending means on the rear surface. The reference hole H
2 is a reference pin P3 provided on the front device board 70, and the reference pin P4 is a reference hole H 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 with the transfer roller 15. A second transfer area for transferring the toner image to the image is formed.

The supporting substrate 85 is the front and rear device substrate 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 board 85 includes 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 so that it can descend until it hits 00A.

The above-mentioned support substrate 85 is released slightly from the front surface of the main body of the apparatus after releasing the screws, and the above-mentioned reference pins and reference holes are disengaged from each other, so that the support substrate 85 is slightly lowered. Therefore, when each of the abutting plates 87 is on the movable portion 200A, the guide rail 200 is extended to the front side of the apparatus main body from the opening 70A of the apparatus substrate 70 by the extending operation of the guide rail 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. Move to the photosensitive drum 10
The operation of returning to the pressure-contact state is automatically and reliably performed.

Therefore, the photosensitive drum 10 can be taken out without interfering with the intermediate transfer belt 14 by an extremely simple attachment / detachment operation of the supporting substrate 85, and the jammed paper staying in the conveying path can be removed by pulling out the supporting substrate 85. Maintenance such as take-out processing, replacement of the intermediate transfer belt 14, and inspection can be easily performed.

The supporting substrate 85 is previously released from the pressure contact action of the transfer roller with the roller 14C for stretching the intermediate transfer belt 14 prior to the operation of pulling out from the main body of the apparatus, and is pressure-contacted again after returning to a predetermined set position. Put in a state.

The arrangement of the image forming body of the present invention and the gap holding means provided in the developing device and its drive system will be described with reference to FIGS. 7 and 8. FIG. 7 is a diagram showing a first example of how the gap holding means is brought into contact with the image forming body, and FIG.
It is a figure which shows the 2nd example of the method of abutting | contacting an image forming body of a space | gap holding means, and the driving method of an image forming body.

As described in the above-mentioned image forming process, the developing device 13 serves as the gap maintaining means, for example, the thickness 3
mm, a disc-shaped abutting roller 131 having an outer diameter of 20 mm, and a gap of a predetermined value from the photosensitive drum 10, for example, 100 μm.
The developing sleeve 130 is maintained in a non-contact state with a gap of up to 1000 μm, and the developing sleeve 130
A developing bias with a DC voltage or an AC voltage AC applied thereto is applied to the photosensitive drum, and a one-component or two-component developer contained in the developing device is used for jumping development to ground the transparent conductive layer. A non-contact reversal development is performed in which a DC bias having the same polarity as that of the toner is applied to the drum 10 to attach the toner to the exposed portion. At this time, the precision of the development interval needs to be about 20 μm or less in order to prevent image unevenness.

The developing device 13 for each color is the above-mentioned charging device 1.
The electrostatic latent image formed on the photosensitive drum 10 by the charging by 1 and the image exposure by the exposure optical system 12 has the same polarity as the charging polarity in the non-contact state by the non-contact developing method by applying the voltage of the developing bias voltage. Reverse development with toner.

As shown in FIG. 7, the photosensitive drum 10 has flange members 10B and 10A (not shown) at both ends which are held by a rotary support shaft 30 which is fixed to a rear side plate 40 via bearings B. Is rotatably supported by the supporting member 20 of each of the flange members 10B and 1B at both ends of the photosensitive drum 10.
The flange member 1 is provided with stopper portions 101B and 101A (not shown) as stop means at the time of press-fitting 0A (not shown).
0B and 10A (not shown) are press-fitted, and the flange member 10
The photosensitive drum 10 is held by B and 10A (not shown). The press-fitting margin L1 is preferably 5 to 30 mm so that the photosensitive drum 10 can be securely held. Further, the press-fitting of the flange members 10B and 10A (not shown) causes the photosensitive drum 10 to expand at the press-fitting margin. In particular, this phenomenon is remarkable because the transparent resin substrate used for the photosensitive drum 10 is soft.

As described above, the developing sleeve 1 of the developing device 13
30 is developed by the abutting roller 131 with a predetermined gap from the photosensitive drum 10, but the abutting roller 131 of the developing device 13 is provided on the photosensitive drum 10 with flange members 10B and 10A (not shown). Stopper parts 101B, 10
1A (not shown) is abutted on the photosensitive drum 10 at a position inside the flange members 10B and 10A with a gap L2 from the end. The distance L2 needs to be 5 to 30 mm in order to avoid deformation of the press-fitted portion of the photosensitive drum 10. If the distance from the ends of the flange members 10B and 10A (not shown) is 5 mm or less, the development gap cannot be obtained because of the influence of deformation. Also, the flange members 10B, 1
If the distance from the end of 0A (not shown) is 30 mm or more, an unnecessary space is provided. Further, the developing sleeve 130
The developing area is provided inside the abutting portion of the abutting roller 131.

The developing sleeve 130 is connected to a gear 10G provided on a flange member 10B on the rear side of the photosensitive drum 10, and is rotationally driven by a gear 13G for driving the developing device held by a developing casing 132 of the developing device 13. It The abutting roller 131 is driven to rotate by the rotation of the photosensitive drum 10.

FIG. 8 shows a second example of how the gap holding means abuts on the image forming body and how to drive the image forming body. The photosensitive drum is the same as that described with reference to FIG. Reference numeral 10 denotes a flange member 10B, 10A (not shown) at both ends, which is rotatably supported by a support member 20 at both ends held by a rotary support shaft 30 fixed to a rear side plate 40 via a bearing B. ,
Flange members 10B and 10A are provided at both ends of the photosensitive drum 10.
Stopper portion 10 as stop means at the time of press-fitting (not shown)
1B and 101A (not shown) are provided to form the flange member 10.
B and 10A (not shown) are press-fitted, and the flange member 10
The photosensitive drum 10 is held by B and 10A (not shown). The press-fitting margin L1 is preferably 5 to 30 mm so that the photosensitive drum 10 can be securely held.

The developing sleeve 130 of the developing unit 13 is developed by the abutting roller 131 with a predetermined gap from the photosensitive drum 10, and the abutting roller 131 of the developing unit 13 is used for the photosensitive drum 10. Flange members 10B, 10
The flange members 10B and 10A (not shown) are brought into contact with the outer peripheral surfaces of the flange members 10B and 10A (not shown) at a distance L3 from the outer end of A (not shown). It is necessary to set the distance L3 to 5 to 30 mm so that the flange member comes into contact with the position where the roundness is best maintained. If it is less than 5 mm, the development gap cannot be obtained accurately due to the influence of side sag. Further, if the distance is 30 mm or more, an unnecessary interval is set. Also, the developing sleeve 1
The developing region 30 is provided on the inner side of the press-fitting margin L1, and preferably on the inner side at the interval L2 described with reference to FIG.

A drive motor M1 for driving the gear 10G and a power transmission means thereof, that is, a drive system G (T) for the gear 10G are mounted and supported on the rear side plate 40 on the rear side thereof. ), The photosensitive drum 10 is rotated. The gear 10G provided on the photoconductor drum 10 and at least the final gear G1 of the drive system G (T) that is coupled to the gear 10G are formed by helical gears, and the photoconductor drum 10 is pressed in the direction of the arrow during rotation to form a flange member. The play in the thrust direction of the bearing B fitted in 10B and 10A (not shown) and the support members 20 at both ends is absorbed, and the bearing B is rotated while being pressed in one direction. This prevents displacement of the exposure light between the exposure optical systems on the image forming body, which is caused by the play of the bearings B at both ends, and provides a good superimposed color toner image with highly accurate registration. It is formed.

As described with reference to FIG. 7, the developing sleeve 1
Reference numeral 30 is rotationally driven by a gear (not shown) connected to a gear 10G provided on the flange member 10B on the rear side of the photosensitive drum 10. The abutting roller 131 is driven to rotate by the rotation of the photosensitive drum 10.

Further, as shown in FIGS. 7 and 8, the outer diameter of the gear 10G provided on the photoconductor drum 10 is set smaller than the outer diameter of the photoconductor drum 10, and the photoconductor as the image forming body is exposed. When pulling out the body drum 10, the gear 10G
It is possible to easily pull out without interfering with the developing device driving gear 13G that meshes with the developing device driving gear G or the final gear G1 of the driving system G (T). When the photoconductor drum 10 is pulled out, the developing device 13 is in the retracted state.

FIG. 9 is a sectional view showing the drive system for the photosensitive drum and the intermediate transfer belt.
Is the roller 1 that drives the intermediate transfer belt 14 on its back surface.
It is also possible to install 4D driving motor M2 and driving What gear G _N meshes provided at the end of the drive system consisting of the power transmission means G _N (T), further driving system of the photoreceptor drum 10 It is also possible to install it together to automatically engage and disengage the power transmission means with respect to the photoconductor drum 10 in accordance with the slide of the support substrate 85, and integrate the respective drive systems thereof to form the side plate as a unit. It is also possible to support 45.

[0079]

According to the first aspect of the present invention, the gap holding member is brought into contact with a portion which is not affected by the deformation of the image forming body due to the press-fitting of the flange member, and the accurate developing gap is held.

According to the second aspect, a more accurate developing gap is maintained.

According to the third aspect of the present invention, the flange member is surely pressed into the image forming body and the gap holding member is accurately brought into contact with the image forming body, so that the more accurate developing gap is held.

According to the fourth aspect, good development is carried out while maintaining an accurate development gap.

According to the fifth aspect, the gap holding member is brought into contact with the flange member, so that the accurate developing gap is held without being affected by the deformation of the image forming body due to the press-fitting of the flange member.

According to the sixth aspect, a more accurate developing gap is maintained.

According to the seventh aspect, the flange member is securely press-fitted into the image forming body, and the accurate developing gap is maintained.

According to the eighth aspect, good development can be performed while maintaining an accurate development gap.

According to the ninth aspect, the image forming body can be pulled out without interfering with the driving gear of the image forming body and the drive transmission means thereof or the driving gear of the developing device.

According to the tenth aspect, the play of the thrust of the bearing member of the image forming body is suppressed to one side, and the positional deviation of the image exposure light between the image exposing means is prevented.

According to the eleventh aspect, safe wiring is secured.

[Brief description of drawings]

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 a photosensitive drum.

FIG. 3 is a cross-sectional view illustrating a support structure of a photosensitive drum.

FIG. 4 is an external view of a drum unit.

FIG. 5 is a front sectional view showing a support structure of the intermediate transfer belt.

FIG. 6 is a cross-sectional view illustrating a support structure of the intermediate transfer belt.

FIG. 7 is a diagram showing a first example of a manner of abutting a gap holding unit on an image forming body.

FIG. 8 is a diagram showing a second example of a manner of abutting the gap holding means on the image forming body and a manner of driving the image forming body.

FIG. 9 is a cross-sectional view showing a drive system for a photosensitive drum and an intermediate transfer belt.

[Explanation of symbols]

 10 Photoreceptor Drums 10A, 10B Flange Member 11 Charger 12 Exposure Optical System 13 Developing Device 14 Intermediate Transfer Belt 15 Transfer Roller 20 Supporting Member 30 Rotation Support Shaft 101B Stopper 130 Developing Sleeve 131 Abutting Roll

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

Claims (11)

[Claims] 1. A color image forming apparatus having a plurality of image exposing means attached to an optical system supporting means inside a drum-shaped image forming body, and a plurality of developing devices arranged around the image forming body, The forming body is configured to integrally support the optical system supporting means together with side plates, has flange members press-fitted to both ends of the image forming body, and holds a gap of a developing device at an inner end portion of the image forming body. A color image forming apparatus, characterized in that, when the means are brought into contact with each other, the contact position of the gap holding means is located within 5 to 30 mm from the end of the flange member. 2. The press-fitting margin of the flange member is 5 to 3
The color image forming apparatus according to claim 1, wherein the color image forming apparatus is 0 mm. 3. The color image forming apparatus according to claim 1, further comprising stop means for press-fitting the flange member at both ends inside the image forming body. 4. The color image forming apparatus according to claim 1, wherein the developing area of the developing unit is set inside the press-fitting margin. 5. A color image forming apparatus having a plurality of image exposing means attached to an optical system supporting means inside a drum-shaped image forming body, and a plurality of developing devices arranged around the image forming body, The forming body is configured to integrally support the optical system supporting means together by side plates, has flange members press-fitted at both ends of the image forming body, and develops on the outer peripheral surface of the flange member outside the image forming body. The color image forming apparatus is characterized in that, when the gap holding means of the container is brought into contact, the abutting position of the gap holding means is 5 to 30 mm inside the end of the flange member. 6. The press-fitting margin of the flange member is 5 to 3
The color image forming apparatus according to claim 5, wherein the color image forming apparatus is 0 mm. 7. The color image forming apparatus according to claim 5, wherein press-fitting stop means for the flange member is provided at both ends inside the image forming body. 8. The color image forming apparatus according to claim 5, wherein a developing area of the developing device is set inside the press-fitting margin. 9. A color image forming apparatus having a plurality of image exposing means attached to an optical system supporting means inside a drum-shaped image forming body, and a plurality of developing devices arranged around the image forming body, The forming body is configured to integrally support the optical system supporting means together by side plates, and a gear is provided at an end portion of the image forming body, and a side plate supporting the optical system supporting means is provided at an end portion of the image forming body. A drive motor for driving the image forming body in combination with a provided gear and a transmission means thereof, and an outer diameter of a gear provided at an end portion of the image forming body is larger than an outer diameter of the image forming body. A color image forming apparatus characterized by being provided in a small size. 10. The driving force of a gear provided at an end portion of the image forming body is directed in a direction in which the image forming body is moved in a rotation supporting axis direction of the image forming body.
3. The color image forming apparatus according to 1. 11. The color image forming apparatus according to claim 9, wherein the wiring provided inside the image forming body is drawn in from an end portion of the image forming body opposite to a driving unit. .