JPH10307444A - Color image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily connect lead wires from light emission elements arranged at plural image exposure means and to prevent unnecessary stress from being imposed on the image exposure means when an image forming body unit is exchanged by forming an image forming body and the exposure means as the image forming body unit which can be integrally exchanged. SOLUTION: All of respective exposure optical systems 12 are fitted to a supporting member 20 using a pipe-like hollow member and housed on the inside of the substrate of a photoreceptor drum 10 so as to constitute the image forming body unit. Besides, the lead wire WA of an LED is arranged through a connector C fitted to one end of the lower part of a metallic easing 12d drawn out from the substrate of the optical system 12. The wires WA of the respective optical systems 12 of respective colors are connected to a fixed electrode PA. Then, respective inserting holes 20h are closed together with the wires WA from the inside circumference side of the supporting member 20 by a seal member S after the connector C and the wire WA are connected. Thus, splashed toner, dust and the like is prevented from entering the optical system 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile or the like, and forms a color image by arranging a charging means, a plurality of image exposing means and a developing means around an image forming body. The present invention relates to an electrophotographic color image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, as one method of forming a multi-color image, a color image is formed by sequentially performing charging, image exposure and development for each color within one rotation of one image forming body. Image forming apparatuses are known.

[0003] However, the above-mentioned color image forming apparatus is capable of forming a high-speed image in a method of forming a multi-color image, but the charging means, image exposing means and developing means within one rotation of the photosensitive member. It is necessary to arrange multiple sets of
The image exposure means may be contaminated by toner leaking from the adjacent developing means and impair image quality, and in order to avoid this, it is necessary to increase the distance between the image exposure means and the developing device. There is a drawback that the apparatus becomes large in size. For the purpose of avoiding this drawback, the base of the photoconductor is formed of a transparent material, a plurality of image exposing means is housed therein, and an image is exposed through the base to the photoconductor layer formed on the outer periphery thereof. A device is proposed, for example, by Japanese Patent Laid-Open No. 5-307307.

[0004]

The image forming apparatus according to the above proposal requires a small image exposing means for accommodating a plurality of image exposing means therein, and a small exposing element is provided in the image exposing means. Used. For this reason, an image exposure unit in which a plurality of LEDs (light emitting diodes) are linearly arranged on a substrate as a light emitting element and the exposure element is held by a holding member of the exposure element is often used. Further, the image forming body and the image exposing means are integrated into an image forming body unit,
A system in which the image forming unit is provided in a color image forming apparatus in a replaceable manner is often used.

However, when the image forming unit is replaced, since there are many lead wires from the light emitting elements provided in the plurality of image exposure means, it takes a lot of time and labor to connect these lead wires, and at the same time, the individual lead wires. Is difficult to connect to a corresponding lead wire outside the image forming unit. Further, when connecting or disconnecting the wires, if the wires are pulled or the image exposing means is left in a stressed state, the image exposing means may be displaced.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and facilitates connection of lead wires from light emitting elements provided in a plurality of image exposure means when exchanging an image forming unit. An object of the present invention is to provide a color image forming apparatus in which reliability of connection is improved without giving any stress.

[0007]

The object of the present invention is to provide a rotating image forming apparatus and a plurality of image exposing means for arranging a plurality of light emitting elements arranged in a line on a substrate. In a color image forming apparatus provided inside, a common support for supporting the plurality of image exposing means is provided, and the image forming body and the image exposing means are integrally replaceable as an image forming body unit, This is achieved by a color image forming apparatus characterized in that a fixed electrode exposed from the image forming unit connected to a lead wire from the light emitting element provided in a plurality of image exposing units is provided in the image forming unit. .

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. The description of the present application does not limit the technical scope of the claims or 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 an embodiment of a color image forming apparatus, FIG. 2 is a diagram illustrating an image exposure unit, and FIG.
2 is a perspective view of FIG. 2, FIG. 4 is a cross-sectional configuration diagram showing a first example of an image forming body unit, FIG. 5 is a diagram showing a flange member of FIG. 4, and FIG. It is an enlarged view of the electrode connection part of FIG.

Referring to FIGS. 1 to 4, a photosensitive drum 10 as a drum-shaped image forming member is provided with, for example, a cylindrical transparent resin base formed of a transparent member made of a transparent acrylic resin on the inner side. Conductive layer and organic photoreceptor layer (O
PC) is formed on the outer periphery of the base body, and is rotated in the direction shown by the arrow in FIG.

In the present embodiment, it suffices 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 film formation method of the light-transmitting conductive layer, indium tin oxide (ITO), alumina, tin oxide, lead oxide, indium oxide is used by a vacuum evaporation method, an active reaction evaporation method, various sputtering methods, and various CVD methods. , Copper iodide, Au, Ag, Ni,
A thin film made of Al or the like that maintains the translucency is used,
A conductive resin composed of the above-mentioned metal fine particles and a binder resin is used by a dip coating method, a spray coating method or the like. Further, as the photoconductor layer, various organic photoreceptor layers (O
PC) can be used.

The following are examples of preferred image forming members.

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

As the conductive layer, indium tin oxide (I
TO), tin oxide, lead oxide, indium oxide, alumina,
A conductive resin obtained by mixing a resin and conductive fine particles made of copper iodide, Au, Ag, Ni, Al, or the like is used. 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 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. , Perylene pigments are used, especially 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 850 nm.

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

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, potential change during repeated use and the like are further improved. Further, these solvents can be used alone or as a mixed solvent of two or more kinds.

The weight ratio of CGM and binder resin in CGL is 100: 1 to 100: 1000.
The film thickness is 0.01 to 10 μm. As the coating method for forming the CGL, there are various coating methods such as blade 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 in the CTL can be selected from a wide range of insulating resins as appropriate, and preferred binder resins include 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 mixing ratio of the binder resin and CTM is 1:
It is set to 10 to 500, and more preferably 1:20 to 150. The thickness of the CTL is set to 1: 100 μm.
~ 50 μm is preferred.

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

An intermediate layer is optionally 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. 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.

The use of the plastic cylindrical transparent resin substrate produced by the above-described manufacturing method allows the thickness of the cylindrical substrate to be uniform, the cylindrical substrate to have excellent cylindricity and roundness, and the image exposure light to be out of focus. There is provided a photoconductor drum without.

Reference numeral 11 denotes a scorotron charger as a charging means, which performs a charging action on the above-described organic photoreceptor layer of the photoreceptor drum 10 by a grid held at a predetermined potential and corona discharge by a discharge wire, and the photoreceptor drum. 10 is given a uniform potential.

An exposure optical system 12 as an image exposure means for each color of Y, M, C and K has a plurality of exposure systems arranged on a substrate 122 in a main scanning direction parallel to the axis of the photosensitive drum 10. LED (light emitting diode) 12 as a light emitting element
1 are arranged in an array, and a light converging light transmitter (trade name, Selfoc lens) 12b as an imaging element. The Selfoc lens 12b is mounted on a lens holder 12c, for example. 2 and FIG. 3, the exposure element 12a is fixed to a metal casing 12d as a holding member of the exposure element having good thermal conductivity by, for example, an adhesive indicated by a black circle. With the 12a and the SELFOC lens 12b positioned, the lens holder 12c is fixed to the metal casing 12d with, for example, an adhesive indicated by a black circle to form the exposure optical system 12. By using the metal casing 12d, the heat generated in the exposure element 12a portion is quickly transmitted and diffused, which affects the displacement between the exposure elements 12a due to thermal expansion and the fluctuation in the amount of light.
A non-uniform temperature distribution and temperature rise of the are prevented.

Although the holding member of the exposure element is preferably a metal casing, it is not always limited to a metal member, and a casing made of resin or the like may be used.

In addition, FL (phosphor emission), EL (electroluminescence), PL (plasma discharge) and the like are used as the light emitting element.

The exposure optical system 12 for each color uses a spacer block 12e as a wedge-shaped block member, and a main scanning direction with the photosensitive drum 10 and a sub-scanning direction with respect to the rotation direction of the photosensitive drum 10 by a tool or the like in advance. Are adjusted to be positioned, and are positioned on a support member 20 using a pipe-shaped hollow member such as a cylindrical pipe or a square pipe, which is a common support of the image exposure unit for each color, and is positioned in the metal casing. 12d and the spacer block 12e, and the spacer block 12e and the support member 20 are fixed to each other with an adhesive indicated by black circles in FIGS. 2 and 3, for example. With the exposure optical system 12 for each color held, the center axis of the support member 20 is aligned with the center axis of the
Placed inside. Therefore, image exposure by the exposure optical system 12 is performed on the photoconductor drum 10 perpendicularly to the central axis of the photoconductor drum 10.

The distance between the inner peripheral surface of the supporting member 20 and the outer peripheral surface of the base of the photosensitive drum 10 is determined by the exposure optical system 1.
2, the bottom surface of the exposure optical system 12 has a circumferential surface which is always located outside the inner circumferential surface of the support member 20. The support member 20 does not need to break the cylindrical surface, the strength is maintained, and the exposure optical system 12 can be reliably held at a predetermined imaging position.

A storage unit (not shown), for example, RA, which is read by an image scanner or input by an external signal or the like.
The image signal of each color stored in M is sequentially read from the storage unit through the control unit of the apparatus main body, and input as an electric signal to the exposure optical system 12 for each color, and the LED 121
Are emitted by, for example, a pulse width modulation method (PWM method). The emission wavelength of the light emitting element used in this embodiment is in the range of 600 to 900 nm.

As described above, each of the exposure optical systems 12 is attached to the supporting member 20 using a pipe-shaped hollow member and is housed inside the base of the photosensitive drum 10 to form an image forming unit described later. However, the lead wire WA of the LED 121 is provided through the connector C that is pulled out from the substrate 122 of each exposure optical system 12 and attached to one end of the lower portion of the metal casing 12d. Lead wires WA of the exposure optical system 12 for each color are respectively connected to fixed electrodes PA described later.

Each insertion hole 20H is connected to the connector C and the lead wire W.
A, after the connection with the sealing member S
With this, the lead wire WA is closed together with the lead wire WA, thereby preventing the scattered toner and dust from entering the exposure optical system 12. Further, an adhesive or an elastic member such as urethane foam or a rubber material is filled in the insertion hole 20H to prevent intrusion of toner or dust. As the sealing material S, for example, a hardening type silicone rubber sheet is used, and each insertion hole 20H is closed by an adhesive or the like, thereby maintaining airtightness. As a result, the lead wire WA is easily connected to the fixed electrode PA along the inner peripheral surface of the support member 20 without being strongly bent. Further, the holding member of the exposure element does not receive the stress due to the lead wire WA and does not come off due to bending of the lead wire WA.

A thin hollow member made of a light metal material such as aluminum or stainless steel, preferably a cylindrical pipe or a square pipe, is used as the support member 20 which is a common support for each exposure optical system 12. Accordingly, the weight and the heat capacity of the supporting member 20 using the metallic hollow member are reduced, and the weight of the image forming unit is reduced, the heat capacity is small, the heat conductivity is good, and the temperature control is achieved. Efficiency is increased. In addition, cylindrical and prismatic pipes are also resistant to mechanical deformation.

Reference numerals 13Y to 13K denote developing devices as developing means for accommodating yellow (Y), magenta (M), cyan (C) and black (K) developers, respectively, on the peripheral surface of the photosensitive drum 10. On the other hand, a developing sleeve 130 is provided which rotates in the same direction while maintaining a predetermined gap.

Each of the above-mentioned developing units makes the electrostatic latent image on the photosensitive drum 10 formed by the charging by the scorotron charger 11 and the image exposure by the exposure optical system 12 non-contact by applying a developing bias voltage. Develop reversely in the state of.

The original image is temporarily stored in an image reading device separate from the present device as an image signal read by an image pickup device or an image edited by a computer as image signals for respective colors of Y, M, C and K. And stored.

When the image recording starts, the photosensitive drum driving motor starts to rotate the photosensitive drum 10 in a counterclockwise direction, and at the same time, the charging action of the scorotron charger 11 (Y) starts applying a potential to the photosensitive drum 10. Is done.

After a potential is applied to the photosensitive drum 10, the exposure optical system 12 (Y) starts exposure by an electric signal corresponding to the first color signal, that is, the image signal of yellow (Y), 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 further applies a scorotron charger 11 on the yellow (Y) toner image.
An electric potential is applied by the charging action of (M), and the exposure optical system 1
2 (M) second color signal, that is, exposure with an electric signal corresponding to a magenta (M) image signal is performed, and the developing device 13
By the non-contact reversal development by (M), a magenta (M) toner image is sequentially superposed and formed on the yellow (Y) toner image.

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

The photosensitive drum 1 by each of these exposure optical systems
The exposure of the organic photosensitive layer of No. 0 is performed from the inside of the drum through a substrate transparent to the above-mentioned exposure wavelength. Therefore, the exposure of the images corresponding to the second, third, and fourth color signals is performed without any influence from the previously formed toner image, and is equivalent to the image corresponding to the first color signal. It is possible to form an electrostatic latent image. During the developing operation by each developing device, a developing bias in which direct current or further alternating current is applied to the developing sleeve 130 is applied,
Jumping development using a one-component or two-component developer contained in the developing device is performed, and non-contact reversal development is performed on the photosensitive drum 10 that grounds the transparent conductive layer.

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

The intermediate transfer belt 14 as an intermediate transfer member is an endless rubber belt having a thickness of 0.5 to 2.0 mm and is made of silicon rubber or urethane rubber of 10 ⁸ to 10 ¹² Ω · cm.
And a resistance value of 10 ¹⁰ to 10 ¹⁶ Ω as a toner filming preventing layer on the outside of the rubber substrate.
-It has a two-layer structure in which a fluorine coating having a thickness of 5 to 50 µm is performed in cm. This layer also preferably has a similar semiconductivity. 0.1-0.5m thickness instead of rubber belt base
m, a semiconductive polyester, polystyrene, polyethylene, polyethylene terephthalate, or the like can also be used. The intermediate transfer belt 14 has rollers 14A, 14B,
The photosensitive drum 10 is stretched between the rollers 14C and 14D, and is circulated clockwise in synchronization with the peripheral speed of the photosensitive drum 10 by the power transmitted to the roller 14D.

The intermediate transfer belt 14 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 point. ing.

The color toner image adhered to the peripheral surface of the photosensitive drum 10 is first subjected to intermediate transfer in sequence 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 roller 14A that is grounded,
The intermediate transfer belt 14 is applied by applying a bias voltage of kV.
It is efficiently transferred to the side.

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

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 to be 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 as cleaning means are installed on the photoconductor drum 10 and the intermediate transfer belt 14, respectively, and blades of the cleaning devices 100 and 140 are constantly in pressure contact with each other to remove residual adhered toner. The circumference is always kept clean.

Generally, the photosensitive drum 10 has an outer diameter depending on the size of the apparatus and the restrictions of the plurality of scorotron chargers 11, the plurality of developing devices 13, the cleaning device 100, etc. installed on the outer peripheral surface of the photosensitive drum 10. A drum having a diameter of 50 mm to 200 mm is preferably used, but in that case, the photosensitive drum 10 is used for the purpose of maintaining rigidity.
The thickness of the substrate is 2mm to 10m, which corresponds to the drum diameter.
On the other hand, the supporting member 20 for supporting these photosensitive drums 10 has a smaller diameter by the exposure optical system 12 and its image forming distance, and has an outer diameter of 20 mm in the case of a cylindrical pipe.
By setting the thickness of the support member 20 to 0.5 mm to 5 mm corresponding to the outer diameter, the strength is sufficient and the respective exposure optical diameters 12 are set on the support member 20 with a margin. Becomes possible.

According to FIGS. 4 to 6 and 2, the support member 20 as the common support is a bearing B1 held directly on the outer periphery and a bearing B2 held by the disk member 22 integrated with the support member 20. The image forming apparatus includes a support member 20 to which the exposure optical system 12 is attached, which supports the flanges 10A and 10B at both left and right ends of FIG. A drum unit 300 as a body unit is configured.

A disk member 21 is fitted into the outer peripheral surface on the left side of FIG. 4 of the support member 20 provided in the drum unit 300, and a pin 20P is driven into a hole provided in each of the support members 20 so that the disk member 21 is supported. Further, the disk member 22 is fitted into the outer peripheral surface on the right side of FIG. 4 of the support member 20, the interior ring 20B is fitted into the inner peripheral surface, and the pins 20P are driven into the holes provided respectively. The disc member 22 and the interior ring 20B are fixed to the support member 20. A plurality of fixed electrodes PA are provided along the inner peripheral surface of the convex ring of the inner ring 20B corresponding to the external electrodes PB shown in the figure. The tip of the lead wire WA from the LED 121 provided on the plurality of exposure elements 12a and arranged through the pipe-shaped inside of the support member 20 is connected to each fixed electrode PA by, for example, soldering. The interior ring 20 </ b> B is fixed to the support member 20 with the fixed electrode PA positioned above.

The drum unit 300 is inserted through the insertion hole 30b of the right side plate (the right side plate in FIG. 4) 30B and protrudes inside the left side plate (the left side plate in FIG. 4) 30A. 31. The support member 20
At the time of holding, the engagement pin 32 provided on the outer peripheral surface of the engagement portion 31 of the one side substrate 30 is engaged with the notch 20A on the end face of the support member 20, and the fixing angle of the support member 20 is regulated.
Each exposure optical system 12 is set at a predetermined position with respect to the apparatus main body, and the correct positional relationship is maintained with respect to the scorotron charger 11 and the developing device 13 arranged along the peripheral surface of the photosensitive drum 10. . An insertion hole 30H for cooling the heat generated by the LED 121 is provided in the left side plate 30A so as to be continuous with the cylindrical hole of the engaging portion 31 and concentric with the cylindrical hole.

Reference numeral 40 denotes a disk-shaped flange member as a side member, which has a cylindrical engaging portion 41 provided at the center of the disk and a cylindrical protruding portion 42 provided at the tip thereof in continuation therewith. A cylindrical hole is provided inside through the engaging portion 41 and the protruding portion 42, and an insertion hole 40 </ b> H is provided at the center of the disc-shaped flange member 40 so as to be continuous with the cylindrical hole and concentric with the cylindrical hole.

The cylindrical projection 4 of the flange member 40
A plurality of external electrodes PB are provided on the outer peripheral surface of the device 2 corresponding to the fixed electrode PA. The external electrode PB is a projection 42
Through the wall of the to the inside of the cylindrical protrusion 42,
It is connected to the end of the external lead wire WB inserted through the insertion hole 40H, for example, by soldering. An external signal is input to the exposure optical system 12 through the external lead wire WB.
In addition, a wind flow path is formed through the insertion hole 40H, the insertion hole 30H, and the hollow hole of the pipe-shaped support member 20,
Heat generated by the LED 121 is cooled.

The flange member 40 is inserted from the right side of FIG. 4 into the drum unit 300 locked by the engaging portion 31 of the left side plate 30A, the flange member 40 is positioned by the hole 40B, and the right side plate is screwed by the screw 51. It is fixed to 30B. At this time, the engaging portion 41 of the flange member 40 is fitted into the inner peripheral surface of the interior ring 20B, the flange member 40 holds the drum unit 300, and the interior ring 20
The fixed electrode PA provided on B and the external electrode PB provided on the protrusion 42 of the flange member 40 are positioned and connected. The drum unit 300 can be replaced by removing the flange member 40.

With the drum unit 300 mounted on the left and right side plates 30A, 30B, the photosensitive drum 10 can be rotated by the power of a driving gear G that meshes with the gear 10G of the flange 10A. The developing device 13 is inserted, and the outer peripheral surfaces of the disk members 21 and 22 are used as a reference for abutting rollers 13
The developing device 13 is positioned with respect to the photoconductor drum 10 by being abutted with 0A, and is fixed to the apparatus main body by a screw or the like (not shown). Therefore, since the photosensitive drum 10 does not receive a load due to the pressure contact of the developing unit 13, the photosensitive drum 10 having no cylindrical shape does not cause distortion or deformation, and even between toner images formed on the drum surface. There is no deviation due to deformation or the like. Further, since the vibration of the developing device 13 is not directly transmitted to the photoconductor drum 10, no blurring occurs during image exposure. In this way, the photoconductor drum 10 is always driven and rotated with high precision roundness, and as a result, high-quality color image formation is realized.

With the drum unit 300 mounted on the left and right side plates 30A and 30B, the developing means, the charging means, the cleaning means, the intermediate transfer body and the like described in FIG. 1 are attached at predetermined positions.

Second Example of Image Forming Unit FIG. 7
~ It demonstrates by FIG. 11 and FIG. 1 mentioned above. FIG. 7 is a view showing an image exposing means according to a second example of the image forming unit, FIG. 8 is a perspective view of FIG. 7, and FIG. 9 is a view showing a second example of the image forming unit. FIG.
[Fig. 11] is a view showing the flange member of Fig. 9, and Fig. 11 is an enlarged view of the electrode connecting portion of Fig. 9.

Also in the second example, the same image forming process and mechanism as described in FIG. 1 are used. The same members as those described in the first example are designated by the same reference numerals.

According to FIG. 7 to FIG. 9, the exposure optical system 12 as an image exposure means for each color of Y, M, C and K is provided on the substrate 122 as an exposure system in parallel with the axis of the photosensitive drum 10. LE as a plurality of light emitting elements arranged in the main scanning direction
It is composed of a linear exposure element 12a in which D (light emitting diodes) 121 are arranged in an array, and a light converging light transmission body (product name, SELFOC lens) 12b as an imaging element, and the SELFOC lens 12b is a lens. The holder 12c is fixed to the holder 12c with an adhesive shown by black circles in FIGS. 7 and 8, and the exposure element 12a is fixed to a metal casing 12d as a holding member of the exposure element with good thermal conductivity by an adhesive shown with black circles. Then, in a state where the exposure element 12a and the SELFOC lens 12b are positioned, the lens holder 12c is fixed to the metal casing 12d with, for example, an adhesive indicated by a black circle, thereby forming the exposure optical system 12.
By using the metal casing 12d, the exposure element 1
The heat generated in the portion 2a is quickly transmitted and diffused, thereby preventing the non-uniform temperature distribution and the temperature rise of the exposure elements 12a, which affect the displacement and the light quantity fluctuation between the exposure elements 12a due to the thermal expansion. .

Although the holding member of the exposure element is preferably a metal casing, it is not necessarily limited to a metal member, but a casing made of resin or the like may be used.

Besides, as the light emitting element, FL (fluorescent substance light emission), EL (electroluminescence), PL (plasma discharge) and the like are used.

The exposure optical system 12 for each color uses a wedge-shaped spacer block 12e to determine the main scanning direction with respect to the photosensitive drum 10 and the sub-scanning direction with respect to the rotation direction of the photosensitive drum 10 in advance by using a jig or the like. Is adjusted to
For example, the right and left support members 220a, 220 of a regular octagonal prism are attached.
It is attached to 20b with an adhesive. Left and right support members 22
The left and right support members 220a and 220b are positioned relative to each other and hold the exposure optical system 12 for each color.
The central axes of a and 220b are aligned with the central axis of the photoconductor drum 10 and are arranged inside the photoconductor drum 10. Therefore,
Image exposure of the photoconductor drum 10 by the exposure optical system 12 is performed perpendicular to the central axis of the photoconductor drum 10.

The outer diameter of the photosensitive drum 10 is 60-18.
The ones of 0 mm are used, and the left and right support members 220a, 220
As 20b, one having a delivery diameter of 40 to 160 mm is used.

A storage unit (not shown), for example, RA, which is read by an image scanner or input by an external signal or the like.
The image signal of each color stored in M is sequentially read from the storage unit through the control unit of the apparatus main body, and input as an electric signal to the exposure optical system 12 for each color, and the LED 121
Are emitted by, for example, a pulse width modulation method (PWM method). The emission wavelength of the light emitting element used in this embodiment is in the range of 600 to 900 nm.

As described above, each of the exposure optical systems 12 is attached to the left and right support members 220a and 220b and is housed inside the base body of the photosensitive drum 10 to form an image forming body unit which will be described later. A lead wire WA of the LED 121 is provided through a connector C that is drawn from the substrate 122 of each exposure optical system 12 and is attached to one end of the lower portion of the metal casing 12d. The lead wire WA of the LED 121 provided in the exposure optical system 12 for each color is connected to a fixed electrode P provided in each window 220A of a support member 220a to be described later.
Connected to A.

Referring to FIG. 9, reference numeral 300a denotes a drum unit as an image forming unit;
0a is assembled and configured as follows.

The support members 220a and 220b are composed of a pair of left and right members for supporting both ends of each exposure optical system 12, each having a central axis and a shaft-like support shaft as a common support for the image exposure means. It is inserted into 230 and supported. Both ends of each exposure optical system 12 are supported
a, 220b are fixed to the outer peripheral surface. A right pin 231 is implanted at a predetermined position on the support shaft 230, and after the exposure optical system 12 is inserted into the support shaft 230,
The V-shaped groove on the right side surface of the right side support member 220b is brought into contact with the right side pin 231. Next, the left side pin 232 is planted at a predetermined position on the support shaft 230, and the left side pin 232.
To contact the right side surface of the support member 220a on the left side in the figure,
Axial positioning is performed.

If the support members 220a and 220b and the support shaft 230 are integrally formed from the beginning,
This work will be unnecessary.

The support portions of the support members 220a and 220b which support and attach both ends of the exposure optical system 12 form regular octagonal prism-shaped side surfaces, and the regular octagonal prism-like lateral surfaces of the support members 220a and 220b are It is installed so that it is on the same plane as above.

Each of the exposure optical systems 12 is positioned by a jig (not shown) so that the distance between the exposure optical system 12 and the photoconductor layer surface of the photoconductor drum 10 has a predetermined positional relationship by means of spacer blocks 12e as wedge-shaped block members. After being adjusted, the support members 220a and 220b are fixed to the regular octagonal pillar-shaped support portions by bonding.

A shaft-shaped support shaft 2 as a common support
The photosensitive drum 10 is inserted from the side along the central axis of the exposure optical system 12 while including the respective exposure optical systems 12 fixed to the exposure optical system 30 via support members 220a and 220b. Both ends of the support shaft 230 that supports the exposure optical system 12 and both ends of the photoconductor drum 10 outside the image area are aligned by a jig (not shown) with the center axes of the exposure optical system 12 and the photoconductor drum 10 aligned. Will be retained.

The left end portion (end portion on the left side in the drawing) of the support member 220a forms a cylindrical surface portion concentric with the support shaft 230, and the inner ring portion of the bearing B3 is press-fitted into the cylindrical surface portion. The outer ring portion of the bearing B3 is pressed into the inner diameter portion of the flange 210A. The flange 210A is pressed into the inner diameter of the photosensitive drum 10 and fixed.

Similarly, the right end portion (the end portion on the right side in the figure) of the support member 220b forms a cylindrical surface portion concentric with the support shaft 230, and the inner ring portion of the bearing B4 is press-fitted into the cylindrical surface portion.
The outer ring portion of the bearing B4 is press-fitted into the inner diameter portion of the flange 210B. The flange 210B is press-fitted and fixed to the inner diameter portion of the photosensitive drum 10, and the drum unit 300a as the image forming unit is assembled.

According to FIGS. 7 to 11, the lead wire WA of the LED 121 pulled out from the exposure optical system 12 through the connector C to the outside of the support shaft 230 is fitted on the inner peripheral surface of the bearing B3 on the left side in FIG. The support member 220a is provided on the outer peripheral surface of four fan-shaped windows 220A (same shape as the window 240a shown in FIG. 10) provided corresponding to the positions of the exposure optical system 12 for each color. It is connected to the fixed electrode PA.

Numeral 240 is a disk-shaped flange member as a side member. A seat 241 is caulked at the center of the disk, and the exposure for each color is carried out on the outside thereof in the same manner as the fan-shaped windows 220A. 4 fan-shaped windows 2 corresponding to 12 positions of the optical system
40a is provided. A plurality of external electrodes PB are provided on the outer peripheral surface of each fan-shaped window 240a, and are connected to the external lead wires WB by, for example, soldering. As shown in FIG. 11, the external electrode PB and the external lead wire WB may be fixed to the flange member 240 by screws.

A shaft-like support shaft 230 as a common support for the image exposure means provided on the drum unit 300a is fitted into the receiving seat 241 of the flange member 240,
The drum unit 300a is attached to the flange member 240 by the screw member 282. At this time, the support member 220
The fixed electrode PA provided in the window 220A of a and the external electrode PB provided in the window 240a of the flange member 240 are fitted into each other, but in this state, their phases are not matched.

The flange member 240 and the drum unit 30
0a is integrated with the side plate 270 on the left side of FIG.
The shaft end 230B on the right side of the support shaft 230 of the drum unit 300a is inserted through the insertion hole 270a of the drum unit 300a.
Is fitted into the receiving seat 272 provided on the right side plate 271 in FIG. The pin P1 provided on the shaft end portion 230B is fitted into the V groove of the seat 272, and the exposure optical system 12 is positioned with respect to the apparatus main body. Further, the flange member 240
Is fixed to the left side plate 270 and fixed with a screw, the fixed electrode PA and the external electrode PB are coupled in phase with each other. An external signal is input to the exposure optical system 12 through the external lead wire WB.

Further, a wind flow path along the support shaft 230 is formed through the fan-shaped insertion hole 220B having the same shape as the insertion hole 220A provided in the insertion holes 240a, 220A and the support member 220b, and the heat generated by the LED 121 is generated. Is cooled. In addition, as shown in FIG. 11, it is also possible to make the distal end of the external electrode PB convex with respect to the fixed electrode PA, and to couple with the fixed electrode PA.

The drum unit 300a has the flange member 240 removed from the side plate 270 and is pulled out from the apparatus main body.
The drum unit 300a is removed from the flange member 240 by removing the screw member 282, and the drum unit 300a can be replaced.

With the left and right side plates 270, 271 mounted, the drum unit 300a can be rotated by the power of a drive gear (not shown) that meshes the photosensitive drum 10 with the gear 10G of the flange 210B. Also, the left and right side plates 2
In a state where the drum unit 300a is mounted on the drums 70 and 271, the developing unit, the charging unit, the cleaning unit, the intermediate transfer member, and the like described in FIG.

As described above, the image forming unit is provided with the fixed electrode connected to the lead wire from the light emitting element, and furthermore, by connecting the fixed electrode and the external electrode, it is possible to replace the image forming unit when replacing the image forming unit. Connection of the lead wires from the light emitting element provided in the image exposure means becomes easy, and the fixed electrode and the external electrode are aligned in phase with each other without giving stress to the image exposure means due to pulling or deformation of the connection. Are connected, the connection reliability is improved without causing a connection error. Also, the displacement of the image exposure means does not occur,
High positioning accuracy can be maintained.

[0088]

According to the first to fourth aspects, it is easy to connect the lead wires from the light emitting elements provided in the plurality of image exposure means when replacing the image forming unit, and unnecessary stress on the image exposure means is obtained. Without increasing the reliability of the connection.

[Brief description of the drawings]

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

FIG. 2 is a diagram showing an image exposure unit.

FIG. 3 is a perspective view of FIG. 2;

FIG. 4 is a cross-sectional configuration diagram illustrating a first example of an image forming unit.

FIG. 5 is a view showing the flange member of FIG. 4;

FIG. 6 is an enlarged view of an electrode connecting portion of FIG.

FIG. 7 is a diagram illustrating an image exposure unit according to a second example of the image forming unit.

FIG. 8 is a perspective view of FIG. 7.

FIG. 9 is a cross-sectional configuration diagram showing a second example of the image forming unit.

FIG. 10 is a view showing the flange member of FIG. 9.

FIG. 11 is an enlarged view of the electrode connection part of FIG. 9;

[Explanation of symbols]

 10 Photoconductor drum 11 Scorotron charger 12 Exposure optical system 12a Exposure element 12d Metal casing 12e Spacer block 40,240 Flange member 20,220a, 220b Support member 121 LED 230 Support shaft PA Fixed electrode PB External electrode WA Lead wire WB External lead line

Claims (4)

[Claims] 1. A color image forming apparatus having a rotating image forming body and a plurality of image exposing means for arranging an exposing element having a plurality of light emitting elements arranged in a line on a substrate inside the image forming body. In which a common support for supporting the plurality of image exposing means is provided, and the image forming body and the image exposing means are integrally replaceable as an image forming body unit, and the plurality of image exposing means are provided. A color image forming apparatus comprising: a fixed electrode which is connected to a lead wire from the light emitting element and which is exposed from the image forming body unit, in the image forming body unit. 2. The common support has a shaft shape, the lead wire is provided outside the common support, and the lead wire is provided outside the common support and inside a bearing member that supports the image forming body. 2. A fixed electrode is provided.
The color image forming apparatus described in 1. 3. The method according to claim 1, wherein the common support is formed in a pipe shape, the lead wire is provided inside the common support, and the fixed electrode is provided inside the common support. The color image forming apparatus as described in the above. 4. The image forming apparatus according to claim 1, wherein the fixed electrode is connectable to an external electrode provided on a side member of the image forming unit that is connected to the common support. Item 10. A color image forming apparatus according to item 9.