JPH1020610A - Color image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent image quality from being deteriorated because an image forming body is deformed by load for driving in the case of directly driving plural developing means by the turning power of the image forming body. SOLUTION: Developing devices 13M and 13C are arranged at positions whose angle θ1 to a perpendicular MM passing the center of a photoreceptor drum 10 is 40 deg.±20 deg., and developing devices 13Y and 13K are arranged at positions whose angle thereto θ2 is 120 deg.+20 deg.. The integrated gear 10G of the drum 10 is meshed with the integrated gear 130G of the developing sleeve 130 of each developing device, and meshed with a gear for driving G nearly just under the drum 10, so that the load for driving imposed not only on the gear 10G but also on the surface of the drum 10 is equally dispersed so as not to be locally concentrated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art As a method of forming a multi-color image, a plurality of charging means, image exposing means and developing means are arranged in the vicinity of the peripheral surface of an image forming body so as to correspond to each color during one rotation of the image forming body. 2. Description of the Related Art A color image forming apparatus is known which forms a color image by superimposing toner images of respective colors on an image forming body by sequentially repeating image exposure and development of an image to be formed.

[0003]

However, in such an apparatus, since a plurality of developing means are dispersedly arranged on the peripheral surface of the image forming member, a gear train for transmitting power to each developing means becomes long and the apparatus becomes complicated. In addition to this, there is a problem that the driving efficiency is deteriorated and a stable driving speed cannot be obtained.

As a solution to this problem, means for directly transmitting the rotation of the image forming body to the developing sleeves of the respective developing means through meshing of gears can be considered. If it is not good, the photoconductor may be deformed such as twisting, and if there is uneven rotation on the image forming body side, the resist of each toner image formed by developing after image exposure does not match so that the color shift may occur. In addition, there is a possibility that the position of the image forming body in the axial direction becomes unstable due to the load of the driving of the developing unit, causing adverse effects such as color shift also occurring in the main scanning direction.

SUMMARY OF THE INVENTION The present invention has been made to solve these problems, and as a result, a plurality of developing means are rotated at a constant speed by a simple driving mechanism to form a high quality image with a guaranteed resist without distortion. It is an object of the present invention to provide a color image forming apparatus capable of performing the above.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to dispose a plurality of charging means, image exposing means and developing means in the vicinity of a peripheral surface of an image forming body, and charge and image exposing during one rotation of the image forming body. And a developing process, wherein a color toner image is formed by superimposing a plurality of toner images on a peripheral surface of the image forming body, wherein the image forming body is a drum-shaped image forming body, The gear integrated with the forming body is driven and rotated while meshing with a gear provided on a developing sleeve shaft of the developing means, and the developing means is divided by a vertical line and a horizontal line passing through the center of the image forming body. A color image forming apparatus which is arranged on the peripheral surface of the image forming body, and a plurality of charging means, image exposing means and developing means near the peripheral surface of the image forming body. Means for disposing the image In a color image forming apparatus in which charging, image exposure and development are repeated during one rotation of the body to form a color toner image by superimposing a plurality of toner images on the peripheral surface of the image forming body, the image forming body has a drum shape. Wherein a gear integrated with the image forming member is driven to rotate by meshing with a gear provided on a developing sleeve shaft of the developing means, and a gear tooth provided on the developing sleeve shaft. A color image forming apparatus (invention according to claim 5), wherein the number is an integer multiple of the number of teeth corresponding to each of the image exposing means of the gears of the image forming body; A plurality of charging means, an image exposing means, and a developing means are disposed in the vicinity of the peripheral surface of the image forming body, and charging, image exposing and developing are repeated during one rotation of the image forming body, and a plurality of toners are provided on the peripheral surface of the image forming body. Superimpose images to form a color toner image In the color image forming apparatus, the image forming body is a drum-shaped image forming body, and a gear integrated with the image forming body is driven by meshing with a gear provided on a developing sleeve shaft of the developing unit. This is achieved by a color image forming apparatus (the invention according to claim 9), wherein each of the gears is a helical gear while being rotated, and applies a thrust in a certain direction to the image forming body with the driving rotation. Is done.

[0007]

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

Photosensitive drum 1 as 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 providing 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 bodies are shown below.

After adding a catalyst for synthesizing and polymerizing the plastic material monomer, pour it into a cylindrical mold, seal and fix it with side plates, rotate it at high speed, and heat 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 the material of the transparent resin substrate of a transparent plastic molded by centrifugal polymerization, those obtained by polymerization using a methyl methacrylate monomer as described above are the best in terms of transparency, strength, precision, surface properties, etc. 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 changes due to uneven rotation 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 is composed of a charge generation 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 a 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 sensitivity and potential change upon repeated use are further improved. These solvents can be used alone or as a mixture of two or more solvents.

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, a hydrazone compound, a styryl compound, a benzidine compound, a stilbene compound or the like is used.

The binder resin used in the CTL can be selected from a wide range of insulating resins as appropriate, and preferred binder resins include silicon-alkyd resin, phenol-formaldehyde resin, and 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, more 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 may be 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 maleic acid 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-mentioned 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.

Reference 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 image exposure means, that is, the photosensitive drum 1
An exposure optical system including an LED arrayed in the 0 axis direction and a selfoc lens which is an equal-magnification image forming system. Image signals of respective colors read by a separate image reading device are sequentially taken out from a memory. Each of the exposure optical systems 12 is input as an electric signal.

Each of the exposure optical systems 12 is attached to a support member 20 provided as an optical system support means, and is accommodated in the base 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.

An original image is temporarily stored in an image reading device separate from the present device as an image 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 driving 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 the photosensitive drum 10 is applied with a potential, 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 color signal of the exposure optical system 12 (M), ie, Exposure is performed with an electric signal corresponding to the magenta (M) image signal, and the magenta (M) toner image is formed on the yellow (Y) toner image by non-contact reversal development by the developing device 13 (M). Are sequentially superimposed and formed.

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.

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 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 inside the photosensitive drum 10 and prevent the temperature from rising due to the heat generation of 2, the support member 20 is made of a material having good thermal conductivity, 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 that does not cause any trouble.
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.

FIG. 7 shows each of the developing units 13 and the exposure optical system 1.
FIG. 8 is an explanatory diagram of a developing function of the main part showing the position of No. 2. As shown in FIG.

In the figure, reference numeral 130 denotes a developing sleeve which is a developer conveying member, which is made of a non-magnetic material such as aluminum and can be rotated in the direction indicated by the arrow. The developer moves in the same direction by the rotation of the developing sleeve 130 and is transported to the developing area. A regulating blade 136 is provided upstream of the rotating developing sleeve 130 in the developing area, and regulates an amount of the developer conveyed to the developing area. A scraper 133 scrapes the developer D adhering to the developing sleeve 130 after the development. Taking member,
134 is a supply member for supplying the agitated developer, 13
Reference numeral 5 denotes a stirring screw for stirring the developer D to uniformly charge the toner, 138 denotes a developing casing, and 139 denotes a base of the support member 181 of the control electrode plate 180 by the developing casing 13.
8, supporting portions 188 and 189 provided on the developing casing 138 are provided on the supporting member 1 of the control electrode plate 180.
A holding plate and a set screw for fixing 81 to the support portion 139 are shown.

Numeral 180 denotes an insulating member made of an electrically insulating material provided on the upstream side of the developing area so as to contact the layer of the developer D.
A control electrode plate including an electrode portion 182 on which a voltage can be applied and a support member 181 connected to support an insulating member 183 on the upstream side of the electrode portion 182.
Reference numeral 82 is made of a conductive material such as metal, and is provided linearly and integrally on the tip of the insulating member 183.

A developing bias voltage in which DC and AC are superimposed is applied to the developing sleeve 130, and the photosensitive drum 10
The reversal development is performed in a non-contact state in the development region closest to the above. In the embodiment shown here, the developing sleeve 130 rotates in the same direction and at substantially the same linear velocity at the portion facing the rotation of the photosensitive drum 10.

The developer layer formed on the developing sleeve 130 does not come into contact with the surface of the photoreceptor drum 10 so as to maintain a gap between the developing sleeve 130 and the regulating blade 136 and the developing sleeve 130 and the photoreceptor. The closest distance g ₀ of the drum 10 is adjusted.

The developing sleeve 130 has a DC power supply E
₁ and AC bias voltage obtained by superposing an AC component on a DC component by the AC power source E ₂ is applied. Further, the electrode portions 182 bias voltage of only a DC component from the DC power source E ₃ is applied. It is preferable to apply a DC voltage having the same polarity as the toner of the developer to the electrode portion 182 from the viewpoint of preventing toner adhesion.

In the developing unit 13 described above, the photosensitive drum 10 and the developing sleeve 1 are applied by applying the AC bias voltage.
30 together with an alternating electric field (hereinafter referred to as a second oscillating electric field) generated between the electrode portion 182 of the control electrode plate 180 and the developing sleeve 130. It is.

In this case, the electrode portion 182 is connected to the photosensitive drum 1
Since it is provided closer to the developing sleeve 130 than 0, the intensity of the first oscillating electric field is greater than the intensity of the second oscillating electric field.

Since the toner particles of the developer reaching the vicinity of the electrode portion 182 are vibrated in the direction perpendicular to the line of electric force by the first oscillating electric field, the toner becomes cloudy and the so-called toner cloud is sufficiently reduced. Can be generated. This toner cloud is assisted by the second oscillating electric field to fly toward the latent image on the photoreceptor drum 10, and highly efficient and uniform development is performed.

At this time, since the AC bias voltage is applied only to the developing sleeve 130, the first oscillating electric field and the second oscillating electric field have the same phase, and the toner particles are moved from the first oscillating electric field to the second oscillating electric field. Smooth transition to oscillating electric field.

In this color image forming apparatus, an exposure optical system 12 using an LED or the like is disposed inside the photosensitive drum 10, and an image exposure position by the exposure optical system 12 is located upstream of the developing sleeve 130 in the developing casing 138. In the
Assuming that a center line connecting the center of the photosensitive drum 10 and the center of the developing sleeve 130 is a center line p, the distance between the photosensitive drum 10 and the developing sleeve 130 on the center line p is the shortest, and the development is performed on the center line p. There is a center P. The photosensitive drum 1 from the development center P to the end surface of the upstream development casing 138
0, L ₁ , the distance of the photosensitive drum 10 from the developing center P to the image exposure position is L ₂ , and the width of the developing area where the developing is performed from the developing center P (in the circumferential direction of the photosensitive drum 10). length) w _1, T the reduction time potential of the organic photosensitive material coated on the photosensitive drum 10, when the peripheral speed of the process speed i.e. the photosensitive drum 10 was set to v, of _{L 1> L 2> vT +} w 1 Set in a relationship.

Here, in this embodiment, L ₁ and L ₂ are set between 3 and 30 mm. Also the process speed v
Is between 30 and 300 mm / sec. The potential reduction time T of the organic photoreceptor used in this embodiment can be easily obtained experimentally, but is 0.1 sec or less. The width w1 of the development area is usually between _{1 and} 2 mm.

Therefore, the process speed v is 30 to 300.
mm / sec and the potential drop time T is 0.1 sec, vT + w ₁ = 4 to 32 mm, and the process speed v is 30 to 300 mm / sec and the potential drop time T is 0.
When the 05Sec, by configuring to perform the image exposure at satisfying position of vT + w ₁ = 2.5~17mm next, L _2> 3~32mm or L _2> 2.5~17mm,
With the photoconductor potential sufficiently lowered and the previously developed toner image stably adhered to the image forming body, the next development is performed thereon.

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 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 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 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 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 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 nipped 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.

Cleaning devices 100 and 140 are installed on the photosensitive drum 10 and the intermediate transfer belt 14, respectively, and the blades of the cleaning devices 100 and 140 are always pressed against each other, so that the remaining adhered toner is removed, and the peripheral surface is always kept. It is kept clean.

The support member 20 is composed of a pair of front and rear members fixed to a rotation support shaft 30 of the photosensitive drum 10 as shown in FIGS.
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 in the flange member 10B. It is rotated about the rotation support shaft 30 in a fixed state as a rotation center.

The rotation support shaft 30 is connected to 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 hanging means at the front and rear connecting portions, and the rail members 50 are inserted into and engaged with the guide members 60 provided in the apparatus main body to be in a suspended state. By doing so, the rotation support shaft 30, and thus the photosensitive drum 10 and each of the exposure optical systems 12 are placed at substantially predetermined positions.

Further, when the rotation support shaft 30 is inserted to a proper position, the shaft end 30B protruding from the rear side plate 40 from the above-mentioned suspended state is fitted into the receiving seat 71 provided on the apparatus board, Shaft end 30 protruding from 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 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.

Accordingly, the support substrate 80 is provided with 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 the start of the attaching / detaching operation of the photosensitive drum 10 supported by the side plate 40 to the apparatus main body, each developing unit 13, the intermediate transfer belt 14, and the cleaning device 100 with respect to the peripheral surface of the photosensitive drum 10 are started. Each pressing action of the blade is released in advance, and the blade is in a retracted state of about 1 to 10 mm, and is returned to the pressed state again after mounting.

After the side plate 40 is detached from the apparatus main body, the rail member 50 can be placed on the lower side as shown in FIG. Function as a table,
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 where the intermediate transfer belt 14 is stretched by the urging force of the tension roller T, and the front and rear side plates 45 are integrally connected. Bearings are supported between them.

The above-mentioned side plates 45 are further formed in a U-shape and connected to the asymmetrical front and rear support substrates 85 which are integrally connected.
Between the cleaning device 140 and the cleaning device 140.

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 on the rear surface. 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 with the transfer roller 15. A second transfer area for transferring the toner image to the image 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-mentioned reference pins and each of the reference holes by slightly pulling out the entire surface of the apparatus main body after releasing the screw, and slightly descends downward. 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. 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 an extremely simple attachment / detachment operation of the support substrate 85, and further, 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 press-contact operation of the transfer roller against the roller 14C for stretching the intermediate transfer belt 14 is released in advance, and after returning to a predetermined set position, the support substrate 85 is pressed again. Placed in state.

(Embodiment 1) An embodiment of the invention according to claims 1 to 4 will be described with reference to FIG.

The photosensitive drum 10 is engaged with a gear 10G integrally formed with a flange member 10B with a gear G of a drive system on the apparatus main body side, and is driven and rotated counterclockwise in the drawing by the power thereof.

Further, the developing sleeves 130 of the respective developing units 13 have gears 130G of the same shape integrally formed on respective rotating shafts protruding from the developing casing 138, and these gears 130G are meshed with the gears 10G. The photosensitive drum 10 is driven and rotated integrally clockwise following the rotation of the photosensitive drum 10.

Each of the developing units 13 is disposed approximately isotropically with respect to the peripheral surface of each of the drums divided by a vertical line MM passing through the center of the photosensitive drum 10 and a horizontal line NN. Since the load applied by the developing unit 13 is dispersed and equalized, the drum is prevented from being deformed and twisted. Therefore, the power transmission efficiency is extremely high.
Is driven and rotated in the same direction in the developing area.

In consideration of the layout of the intermediate transfer belt 14 and the cleaning device 100, each of the developing sleeves 130 is positioned below the vertical line MM above the horizontal line NN.
Each of the developing sleeves 1 of the developing devices 13 (M) and 13 (C)
30 is 40 °, while the angle θ2 between the developing sleeves 130 of the developing units 13 (Y) and 13 (K) is 1 °.
It is desirable to arrange each of the positions at 20 ° with ± 20 ° as a permissible range. If the above range is deviated, the balance will be lost and adverse effects such as distortion will occur. By arranging the driving gear G for driving and rotating the photosensitive drum 10 in the vicinity of the vertical line MM below the horizontal line NN by arranging it within the above range, the space on the drum peripheral surface can be efficiently used. Also.

As shown in FIG. 9B, if the gear 10B provided on the photosensitive drum 10 is set as a gear having a diameter slightly larger than the diameter of the drum, the gear 130G of the developing sleeve 130 meshes with the gear 10B. The operation of pulling out the container 13 to the front side of the device becomes possible, and this operation also releases the meshing relationship at the same time.

(Embodiment 2) An embodiment of the invention according to claims 5 to 8 will be described with reference to FIG.

The photosensitive drum 10 is engaged with a gear 10G integrally formed with a flange member 10B with a gear G of a drive system on the apparatus main body side, and is driven to rotate counterclockwise in FIG.

Further, the developing sleeves 130 of the respective developing units 13 have gears 130G of the same shape integrally formed on respective rotating shafts protruding from the developing casing 138, and these gears 130G mesh with the gears 10G. The photosensitive drum 10 is driven and rotated integrally clockwise following the rotation of the photosensitive drum 10.

Each gear 130G has a number of teeth N1, N2, and N3 corresponding to the angle between the gear No. and each exposure optical system 12 of the gear 10G provided on the photosensitive drum 10.
Are equal or an integer multiple,
That is, in the case of the present embodiment, the gears 13 provided on the developing sleeve 130 such that the numbers of teeth N1, N2, and N3 have the same number or the integer ratio of the number of teeth No.
0G number of teeth No. and photosensitive drum 10 of each exposure optical system 12
The positional relationship on the peripheral surface is set.

The gear 10G provided on the photosensitive drum 10 has a total number of teeth that is an integral multiple of each of the numbers N1, N2 and N3 indicating the positional relationship of the exposure optical system 12. Therefore, the gears 130G provided on each of the developing sleeves 130 are set to have an integer ratio of the number of teeth No.

Further, by setting the number of teeth of the gear G of the drive system provided on the apparatus body side to be the same as the number of teeth No. of the gear 130G, the total number of teeth of the gear 10G is an integer of the number of teeth of the drive side gear G. As a result, when there is a tooth pitch error or an eccentricity in the gear G on the driving side, the rotation unevenness of the gear 10G transmitted by the rotation is as shown in FIG. The exposure is performed in a constant phase relationship between the rotation periods of the body drum 10. Therefore, the exposure of each image by each exposure optical system 12 is performed by superimposing the image under the condition of the same peripheral speed of the photosensitive drum 10. Is performed, so that the accuracy of the so-called image registration can be improved, and no deviation (color deviation) occurs between the superimposed toner images.

Rotational unevenness is transmitted to each developing sleeve 130 via a gear 10G provided on the photosensitive drum 10, but each distance from the exposure position of the exposure optical system 12 to the developing sleeve 130 is made equal. As a result, each developing sleeve 130 is rotated in accordance with the moving speed of the image on the drum surface. As a result, the peripheral speed of the photosensitive drum 10 and the peripheral speed of each developing sleeve 130 are made substantially equal using one-component developer. Even in the set image forming apparatus of this embodiment, it is possible to develop a high-quality toner image without development unevenness.

The gear 10G has a rotation support shaft 3 for stabilizing and maintaining the rotation speed of the photosensitive drum 10.
It is preferable to provide a flywheel on the flywheel to increase the inertia rate. In this case, the gear 10G may be formed on the flywheel peripheral surface and directly driven and rotated by the gear G.

(Embodiment 3) An embodiment of the invention according to claims 9 to 11 will be described with reference to FIG.

The photosensitive drum 10 has a rotating support shaft 3
0, the gear 10 integrated with the flange member 10B.
A gear 30G is fixed separately from the gear G, and a gear G of a drive system on the apparatus main body side is meshed with the gear 30G, and the power (drive rotation in the direction of the arrow A) causes the photosensitive drum 10 to rotate counterclockwise. (Driven rotation in the direction of arrow B).

Further, the developing sleeves 130 of the respective developing units 13 are formed by integrally forming gears 130G of the same shape on respective rotating shafts protruding from the developing casing 138, and connecting these gears 130G to the flange member 10B. The gear 10G meshes with the provided gear 10G, and is driven to rotate clockwise (following rotation in the direction of arrow C) by the power of the gear G of the drive system via the gear 10G.

Each of the above-mentioned gears is constituted by a helical gear, and the gear G and the gear 10G are helical gears having a helical angle of a left direction.
G is a helical gear with a helical angle to the right, whereby the driving power of the gear G is transmitted through the gear 30G to the gear 10G.
G, that is, the photosensitive drum 10 and the gear 130G, that is, the developing sleeve 130 are smoothly transmitted without vibration due to meshing between the teeth.

Further, the power of the gear G is indicated by an arrow F together with the rotational force on the gear 30G due to the helical angle of the helical gear.
The thrust in one direction acts to urge the photosensitive drum 10 toward the back of the apparatus main body, while the rotational force of the gear 10G is caused by the helical angle of the helical gear with respect to the gear 130G together with the rotational force. The gear 10G is also urged in the direction indicated by the arrow F1 by the reaction force of the thrust in the direction indicated by F2, thereby promoting the urging of the photosensitive drum 10 in the rear direction.

As a result, at the time of forming an image,
Is more strongly pressed against the V-shaped groove of the receiving seat 71, and the position of each exposure optical system 12 in the angular direction is determined, and at the same time, the asobi of the bearing B and the like is absorbed in the F1 direction and the photosensitive drum is absorbed. 10 also regulates the position in the axial direction to stabilize the image forming area, eliminates asobi of the image exposure position in the scanning direction by each image exposure optical system 12, and eliminates the deviation in the scanning direction between the superimposed images. As a result, a color image without color shift is obtained.

The gear 10G, that is, the photosensitive drum 10
It is preferable to provide a flywheel on the rotation support shaft 30 in order to stabilize and maintain the rotation speed of the flywheel, in which case the gear 30G is formed on the peripheral surface of the flywheel and the gear The drive rotation may be performed by G.

In each of the embodiments described above, the color image forming apparatus in which the image exposing means is arranged inside the image forming body has been described. However, in any of the present invention, the image exposing means is arranged on the outer periphery of the image forming body. The same effect can be obtained even when the present invention is applied to a color image forming apparatus in which image exposure is performed from the outside.

[0098]

According to the present invention, a plurality of developing means provided in a color image forming apparatus can be efficiently driven at a constant speed by a power of an image forming body through a very simple gear device. According to (4), the space around the image forming body is effectively utilized, and the driving load applied to the image forming body is dispersed. As a result, deformation of the image forming body is prevented, and image formation between the superposed toner images is performed. Color shift due to body deformation is eliminated. In addition, even if rotation unevenness of the image forming body occurs, registration of image exposure and development timing of each toner image is guaranteed, and color shift between toner images is eliminated. Claims 9 to 11
Accordingly, the image forming body and the image exposing unit are secured at the regulated positions at which the respective images can be formed at the time of image formation, and the color shift in the main scanning direction is eliminated.

As a result, a highly practical color image forming apparatus capable of forming a high-quality color image with a simple mechanism is provided.

[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 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 main part configuration diagram showing positions of a developing device and an exposure optical system.

FIG. 8 is an explanatory diagram illustrating a developing function of the developing device.

FIG. 9 is an explanatory diagram showing an arrangement position of a developing device.

FIG. 10 is an explanatory diagram illustrating a driving mechanism of the developing device.

FIG. 11 is an explanatory view showing a gear mechanism of the developing device.

DESCRIPTION OF SYMBOLS 10 Photoconductor drum 10A, 10B flange member 11 Charger 12 Exposure optical system 13 Developing device 14 Intermediate transfer belt 15 Transfer roller 20 Support member 30 Rotation support shaft 40 (Drum) side plate 70 (Device) substrate 71 ( Rotation support shaft) receiver 130 developing sleeve 138 developing casing G (drive) gear 10G (drum) gear 130G (developing sleeve) gear

Continued 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) Invention Person Toshihide Miura 5-14-14 Midoricho, Koganei-shi, Tokyo

Claims (11)

[Claims] A plurality of charging means near a peripheral surface of the image forming body;
An image exposure unit and a development unit are provided, and charging, image exposure and development are repeated during one rotation of the image forming body, and a plurality of toner images are superimposed on the peripheral surface of the image forming body to form a color toner image. In the color image forming apparatus, the image forming body is a drum-shaped image forming body, and a gear integrated with the image forming body is driven to rotate by meshing with a gear provided on a developing sleeve shaft of the developing unit. A color image forming apparatus, wherein the developing means is arranged on a peripheral surface of the image forming body which is divided by a vertical line and a horizontal line passing through the center of the image forming body. 2. A color image forming apparatus according to claim 1, wherein a driving gear meshing with a gear provided on said image forming body for driving is installed near said vertical line below said horizontal line. apparatus. 3. The color image forming apparatus according to claim 1, wherein a developing sleeve of said developing means is disposed at an angle of 40 ° ± 20 ° with respect to said vertical line above said horizontal line. 4. A color image forming apparatus according to claim 1, wherein a developing sleeve of said developing means is arranged at an angle of 120 ° ± 20 ° with respect to said vertical line above said horizontal line. . 5. A plurality of charging means near the peripheral surface of the image forming body,
An image exposure unit and a development unit are provided, and charging, image exposure and development are repeated during one rotation of the image forming body, and a plurality of toner images are superimposed on the peripheral surface of the image forming body to form a color toner image. In the color image forming apparatus, the image forming body is a drum-shaped image forming body, and a gear integrated with the image forming body is driven and rotated by meshing with a gear provided on a developing sleeve shaft of the developing unit. Wherein the number of teeth of gears provided on the developing sleeve shaft is an integer multiple of the number of teeth corresponding to each of the gears of the image forming body between the respective image exposing means. apparatus. 6. The color image forming apparatus according to claim 5, wherein the number of gear teeth provided on the image forming body is an integral multiple of the number of gear teeth provided on the developing sleeve shaft. 7. The image forming apparatus according to claim 5, wherein the number of teeth of the gear provided on the image forming body is an integral multiple of the number of gears corresponding to each of the gears provided on the image forming body between image exposure units. Color image forming apparatus. 8. The image forming apparatus according to claim 1, wherein the number of teeth of a driving gear for driving the image forming body meshing with the gear provided on the image forming body is the same as the number of teeth of a gear provided on the developing sleeve shaft. The color image forming apparatus according to claim 5. 9. A plurality of charging means near the peripheral surface of the image forming body,
An image exposure unit and a development unit are provided, and charging, image exposure and development are repeated during one rotation of the image forming body, and a plurality of toner images are superimposed on the peripheral surface of the image forming body to form a color toner image. In the color image forming apparatus, the image forming body is a drum-shaped image forming body, and a gear integrated with the image forming body is driven and rotated by meshing with a gear provided on a developing sleeve shaft of the developing unit. The color image forming apparatus is characterized in that each of the gears is a helical gear, and applies a thrust in a fixed direction to the image forming body as the drive rotates. 10. A drive gear meshing with a gear provided on the image forming body for driving is a helical gear, and causes a thrust in the same direction as the fixed direction to act on the image forming body with driving rotation. 10. The color image forming apparatus according to claim 9, wherein: 11. A gear provided on the image forming body is provided at an end of the image forming body on the back side of the apparatus, and meshes with a gear provided on a developing sleeve shaft of each of the developing units. The color image forming apparatus according to claim 9.