JPH1069206A - Color image foring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To load an image forming unit without damaging an image forming body by constituting the integral image forming unit by housing an image exposure means inside the image forming body, forming a process unit by providing the circumference of the image forming unit with a casing and enabling the process unit to be assembled and disassembled. SOLUTION: The process unit 400 is formed by concentrically integrating the image forming body (photoreceptor drum) 10 and respective exposure units 12 as a drum unit 300 with a supporting shaft 30 as a center and including the unit 300 in the casing 410. The unit 400 is formed so that it can be assembled or disassembled. By such constitution, when the drum 10 is exchanged or the units 12 are maintained, a drum supporting substrate 80 holding the unit 400 is separated from a front side plate 70. Thus, the unit 300 can be loaded without damaging the drum 10 and the drum 10 is easily exchanged in order to use the units 12 again.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copier, a printer, a facsimile, etc., which is provided with a plurality of sets of image exposure means inside an image forming body and a plurality of sets of charging means on the outer periphery of the image forming body. The present invention relates to an image forming unit having a built-in image exposing means used in an electrophotographic color image forming apparatus which forms a color image by superposing a toner image during one rotation of the image forming body by arranging means.

[0002]

2. Description of the Related Art Conventionally, as a method of forming a multi-color image, a single color image formed on each image forming body is provided with the same number of image forming bodies, charging means, developing means and the like as the number of colors required for image formation. Color image forming apparatus that forms a color image by superimposing the toner image on a transfer material, or a color image forming apparatus that rotates the image forming body a plurality of times and repeats charging, image exposure, and development for each color to form a color image Alternatively, there is known a color image forming apparatus which forms a color image by sequentially performing charging, image exposure, and development for each color within one rotation of the image forming body.

However, each of the above image forming apparatuses is provided with the same number of image forming bodies, charging means, developing means, etc. as the number of colors required for image formation, and superposes a single color toner image formed on each image forming body on a transfer material. A color image forming apparatus that forms a color image together has a drawback that the volume of the apparatus is increased due to the necessity of transporting a plurality of image forming bodies and a transfer material. A color image forming apparatus that forms a color image by repeating charging, image exposure, and development has a limitation that although the volume is reduced, the size of the formed image is limited to the surface area of the image forming body or less. .

In this regard, a color image forming apparatus which forms a color image by sequentially performing charging, image exposure and development for each color within one rotation of the image forming body has no restriction on the size of the image and has a high speed image. There are advantages such as enabling formation. Further, an apparatus in which a light-transmitting substrate is used as a substrate of an image forming body and an image exposing means is arranged inside the image forming body to reduce the size of the apparatus has been proposed, for example, in Japanese Patent Application Laid-Open No. 5-307307. .

[0005]

However, the apparatus according to the above proposal has a complicated structure because a number of image exposure means fixed inside are arranged for the image forming body. The image exposing means has a long life and maintenance and replacement at 500 to 1,000,000 copies, whereas the image forming body has a short life and needs to be replaced every 50 to 100,000 copies. Further, although the image forming body is supported by flange members which are press-fitted at both ends, if the press-fitting portion of the flange member is once removed and disassembled at the time of replacement, the image forming body cannot be reused due to accuracy.

Accordingly, the image exposing means is reused when the image forming body is exchanged. However, the image forming means for reusing the image exposing means between the image forming means once assembled and the image exposing means is used. Disassembly and assembly of replacements are difficult. Further, there is also a problem that the image forming body is damaged when the reassembled image forming body is mounted on the apparatus.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and an image forming unit can be mounted without damaging the image forming body. An object of the present invention is to provide a color image forming apparatus that can be easily assembled.

[0008]

An object of the present invention is to provide a cylindrical image forming body for forming a latent image, a plurality of sets of charging means and developing means outside the image forming body, and a plurality of image exposing means inside the same. Disposed, the image forming body is charged by the charging means, is subjected to image exposure by the image exposure means, and sequentially repeats the formation of a toner image thereon by development by the development means, In a color image forming apparatus for forming an image by superimposing the toner image on an image forming body, the image exposing means is an integrated image forming unit housed inside the image forming body; A process unit is formed by providing a casing around the image forming unit, and the process unit can be assembled or disassembled so that the image forming unit can be stored or taken out. It is accomplished by a color image forming apparatus, wherein (first invention).

The object is to provide a cylindrical image forming body for forming a latent image, a plurality of sets of charging means and developing means outside the image forming body, and a plurality of image exposing means inside the same. The image forming body is charged by the charging unit, is subjected to image exposure by the image exposing unit, and sequentially forms a toner image thereon by development by the developing unit. A color image forming apparatus that forms an image by superimposing the toner image on the image forming unit, wherein the image exposing unit is an integrated image forming unit housed inside the image forming unit, and a casing is provided around the image forming unit. And a process unit is formed, and the image forming unit can be assembled or disassembled so that the image exposure means can be stored or taken out. It is achieved by an image forming apparatus (second invention).

[0010]

Embodiments of the present invention will be described below. The description of the present application 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 image forming apparatus of the present invention will be described with reference to FIGS. 1 is a cross-sectional configuration diagram of a color image forming apparatus according to an embodiment of the image forming apparatus, FIG. 2 is an enlarged cross-sectional view of a main part of the image exposure unit of FIG. 1, and FIG. FIG. 4
FIG. 5 is a front view showing a support structure of the image forming body, and FIG.
FIG. 6 is a sectional view showing a support structure of the process unit, and FIG.
FIG. 7 is a sectional view of the image forming unit, FIG. 7 is a view showing a method of assembling the process unit, FIG. 8 is a front view showing a support structure of the intermediate transfer belt, and FIG. It is a side view which shows the support structure of a belt.

Referring to FIGS. 1 to 3 and 5, the photosensitive drum 10 which is a cylindrical image forming member is made of, for example, a cylindrical member formed of a light-transmitting member made of a glass material or a light-transmitting acrylic resin. A light-transmitting conductive layer and an organic photoconductor layer (OPC) are formed on the outer periphery of a transparent light-transmitting substrate, and the conductive layer is grounded, and the conductive layer is grounded. Rotated clockwise.

In this embodiment, it is sufficient that the photoconductor layer of the photosensitive drum has an exposure sensitivity capable of generating an appropriate contrast with respect to image exposure light. Accordingly, the light transmittance of the substrate made of glass or light-transmitting resin of the photosensitive drum in the present embodiment does not need to be 100%, and has such characteristics that a certain amount of light is absorbed when the exposure beam is transmitted. It does not matter. As the material of the light-transmitting substrate, an acrylic resin other than a glass material, in particular, a polymer obtained by polymerization using a methyl methacrylate monomer is preferably used because of its excellent transparency, strength, accuracy, surface properties, and the like. Various light-transmitting resins such as fluorine, polyester, polycarbonate, and polyethylene terephthalate used for general optical members and the like can be used. The light-transmitting substrate may be colored as long as it has a light-transmitting property with respect to exposure light. The refractive index of these resins is approximately 1.5.

As a method of manufacturing a substrate using a light-transmitting resin, a high-precision element cylinder can be manufactured by a centrifugal polymerization method. This production method is to synthesize a plastic material monomer, add a catalyst for polymerization, pour it into a cylindrical mold, seal and fix it with side plates, rotate it, and heat it moderately Promotes uniform polymerization. After completion of the polymerization, the substrate is cooled, the obtained translucent resin substrate is taken out of the mold, cut and, if necessary, subjected to a finishing step to produce a substrate for a photosensitive drum of an image forming apparatus (centrifugal polymerization method).

As the material of the transparent plastic substrate molded by centrifugal polymerization, the material obtained by polymerization using a methyl methacrylate monomer as described above is the best in terms of transparency, strength, accuracy, surface properties, etc. , Other 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. In addition, uneven thickness varies depending on rotation unevenness and viscosity during polymerization and heating conditions during polymerization.

By using a plastic cylindrical light-transmitting resin substrate produced by the above-described manufacturing method, the thickness of the cylindrical substrate is uniform, the cylindrical substrate has excellent cylindricity and roundness, and is superior to a glass material. A photosensitive drum that is easy to manufacture and that is easy to provide is provided.

Next, as a method for forming the light-transmitting conductive layer, a vacuum evaporation method, an active reaction evaporation method, various sputtering methods and various CVD methods are used to form indium tin oxide (IT).
O), alumina, tin oxide, lead oxide, indium oxide, copper iodide, or a thin film of a light-transmitting material such as Au, Ag, Ni, or Al is used. Preferably, a conductive resin layer or the like made of the above-mentioned transparent conductive (for example, ITO) fine particles and a binder resin is used by a dip coating method, a spray coating method, or the like. In this case, in order to enhance the translucency, the fine particles constituting the layer are controlled to be about 500 Å or less in the Rayleigh scattering (scattering by fine particles having a size of 1/10 or less of the exposure wavelength) region where there is almost no light scattering. Is preferred. In particular, as a main constituent material,
It is preferable to use conductive fine particles having a primary particle diameter of 400 angstroms or less and a particle radius distribution controlled to ± 100 angstroms or less.

The organic photoreceptor layer comprises 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.

Reference numeral 11 denotes a scorotron charger serving as a charger for corona discharge. The scorotron charger 11 functions to charge the organic photosensitive layer of the photosensitive drum 10 by a grid maintained at a predetermined potential and corona discharge by a discharge electrode. To apply a uniform potential to the photosensitive drum 10.

An exposure unit 12 as an image exposure means for each color includes a photosensitive drum 10 on a substrate 122 as an exposure system.
A linear exposure element 12a in which a plurality of LEDs (light emitting diodes) 121 as light emitting elements arranged in a main scanning direction parallel to the axis of the light emitting element 12a, and a light converging light transmitter (image forming element) The selfoc lens 12b is fixed to the holding member 12c by, for example, an adhesive shown by a black circle in FIGS. 2 and 3, and the exposure element 12a is formed by an adhesive shown by a black circle, for example. The holding member 12c is fixed to the metal casing 12d by, for example, an adhesive indicated by a black circle while the exposure element 12a and the selfoc lens 12b are positioned and fixed to a metal casing 12d as a metal member having good heat conductivity. The exposure unit 12 is fixed and configured.

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

The exposure unit 12 for each color uses a wedge-shaped sticking member 21 in advance by using a jig or the like.
The main scanning direction of the photosensitive drum 10 and the sub-scanning direction of the rotation of the photosensitive drum 10 are adjusted so as to be positioned. The exposure unit is a support member and serves as a common support. It is attached to the members 20a and 20b with an adhesive. The left and right support members 20a and 20b are positioned relative to each other, and the center of the left and right support members 20a and 20b is aligned with the center axis of the photoconductor drum 10 while holding the exposure unit 12 for each color. It is arranged inside the drum 10. Therefore, image exposure of the photosensitive drum 10 by the exposure unit 12 is performed perpendicular to the central axis of the photosensitive drum 10.

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

A storage unit (not shown), such as an 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 unit 12 for each color, and the LED 12
1 is 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 units 12 is provided with the left and right support members 20 provided as exposure unit support means.
a, 20b attached to the inside of the substrate of the photosensitive drum 10 and provided in each of the exposure units 12.
The lead wire 12A of the ED 121 is drawn out through the hole 20B of the support member 20a on the front side (left side in FIG. 5) and the windows 20A.

13 (Y), 13 (M), 13 (C) and 13 (K) are developing units containing yellow (Y), magenta (M), cyan (C) and black (K) developers, respectively. The developing device includes a developing sleeve 130 that rotates in the same direction as the photosensitive drum 10 in a developing region while maintaining a predetermined gap with respect to the peripheral surface of the photosensitive drum 10.

Reference numeral 410 denotes a cylindrical photosensitive drum 10 to which a scorotron charger 11 and a photosensitive drum cleaning device 100 are attached, and each of the exposure units 12 is included.
And a cylindrical casing disposed coaxially with the central axis of the photosensitive drum 10.

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

The original image is temporarily stored in an image reading apparatus separate from the present apparatus, using 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 driving motor is started to rotate the photosensitive drum 10 in a counterclockwise direction, and at the same time, the application of a potential to the photosensitive drum 10 is started by the charging action of the scorotron charger 11 (Y). Is done.

After the potential is applied to the photosensitive drum 10, the exposure unit 12 (Y) starts exposure with an electric signal corresponding to a first color signal, ie, a yellow (Y) image signal, and rotates the drum. By scanning, an electrostatic latent image corresponding to the yellow (Y) image of the original image is formed on the photosensitive layer on the surface.

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 further includes a scorotron charger 11 on the yellow (Y) toner image.
A potential is applied by the charging action of (M), exposure is performed by an electrical signal corresponding to the second color signal of the exposure unit 12 (M), that is, an image signal of magenta (M), and the developing unit 13 (M) performs exposure. A magenta (M) toner image is sequentially superimposed on the yellow (Y) toner image by non-contact reversal development.

The scorotron charger 11 (C), the exposure unit 12 (C), and the developing device 13
(C) further produces a cyan (C) toner image corresponding to the third color signal, and the scorotron charger 11
(K), exposure unit 12 (K) and developing unit 13
(K), a black (K) toner image corresponding to the fourth color signal is sequentially superimposed and formed.
Within one rotation, a color toner image is formed on the peripheral surface.

The exposure of the organic photosensitive layer of the photosensitive drum 10 by each of the exposure units 12 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. At the time of the developing operation by each developing device, the developing sleeve 13
A developing bias in which a direct current or further alternating current is applied to 0 is applied, jumping development is performed by a one-component or two-component developer contained in the developing device, and the photosensitive drum 10 that grounds the translucent conductive layer is applied. Thus, non-contact reversal development is performed.

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

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

The intermediate transfer belt 14 has a roller 14A.
The belt surface between the roller 14B and the roller 14B is in contact with the peripheral surface of the photosensitive drum 10, while the belt surface on the outer periphery of the roller 14C is in contact with the transfer roller 15, which is a transfer member. Has formed.

The color toner image adhered to the peripheral surface of the photosensitive drum 10 is first transferred to the intermediate transfer belt 14.
At a contact point between the intermediate transfer belt 14 and the intermediate transfer belt 14 by applying a bias voltage having a polarity opposite to that of the toner to the roller 14B.
Is transferred to the peripheral surface side of. 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, and is efficiently transferred to the intermediate transfer belt 14 side by applying a bias voltage of 1 to 3 kV to the roller 14B. .

On the other hand, the transfer paper P as the transfer material 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 the color toner image on the intermediate transfer belt 14 is formed. The sheet is fed to the transfer area of the transfer roller 15 in synchronization with the conveyance.

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 that of the toner of 1 to 3 kV to the transfer roller 15 in close contact with the color toner image on the belt 14.

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

A cleaning device 100 and an intermediate transfer belt cleaning device 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 constantly pressed to remove residual toner adhered. The surrounding surface is always kept clean.

Referring to FIG. 6, reference numeral 300 denotes a drum unit serving as an image forming unit;
Is assembled and configured as follows.

The support members 20a and 20b are composed of a pair of left and right members for supporting both ends of each exposure unit 12, and both are inserted and supported on a support shaft 30 which is a central axis. Both ends of each exposure unit 12 are attached and fixed to the outer peripheral surfaces of the support members 20a and 20b. On the support shaft 30, a right pin 31 is implanted at a predetermined position. After the exposure unit 12 is inserted into the support shaft 30, the right pin 31 is attached to the V-shaped right side of the right support member 20b in the drawing. The groove is brought into contact, and then the pin 32 is implanted at a predetermined position on the support shaft 30, and the left side pin 32 is brought into contact with the right side surface of the support member 20a on the left side in the figure, thereby performing axial positioning. .

If the support members 20a and 20b and the support shaft 30 are integrally formed from the beginning, this operation is not necessary.

The support portions of the support members 20a and 20b which support and attach both ends of the exposure unit 12 form regular octagonal prism-shaped side surfaces, and the regular octagonal prism-like side surfaces of the support members 20a and 20b are previously set on the surface plate. So that they are on the same plane.

Each exposing unit 12 is adjusted in position by a jig (not shown) such that the distance between the photoreceptor drum 10 and the photoreceptor layer surface is in a predetermined positional relationship by a wedge-shaped attaching member 21 at both ends thereof, and is bonded. Thus, the support members 20a and 20b are fixed to the regular octagonal column-shaped support portions.

The photosensitive drum 10 is inserted from the side along the central axis of the exposure unit 12 while including the respective exposure units 12 fixed to the support shaft 30 via support members 20a and 20b. Both ends of a support shaft 30 that supports the exposure unit 12 and both ends of the photosensitive drum 10 outside the image area are held by a jig (not shown) with the center axes of the exposure unit 12 and the photosensitive drum 10 aligned. You.

The left end (the left end in the figure) of the support member 20a forms a cylindrical surface concentric with the support shaft 30.
The inner ring portion of the ball bearing member (position regulating member) B1 is press-fitted into the cylindrical surface portion. The outer ring portion of the ball bearing member B1 has a flange 10
A is press-fitted into the inner diameter portion. The flange 10A is pressed into the inner diameter of the photosensitive drum 10 and fixed.

Similarly, the right end (the right end in the figure) of the support member 20b forms a cylindrical surface concentric with the support shaft 30, and the inner race of the ball bearing member (position regulating member) B2 is formed on the cylindrical surface. Press-fit. The outer ring portion of the ball bearing member B2 is pressed into the inner diameter portion of the flange 10B. The flange 10B is press-fitted into the inner diameter portion of the photosensitive drum 10 and fixed, and a drum unit 300 as an image forming unit is assembled.

LED 1 provided in each exposure unit 12
The 21 lead wires 12A are drawn out of the drum unit 300 through a window 20A provided in the support member 20a. The windows 20A through which the lead wires 12A pass are sealed so that toner and the like do not enter inside.

Further, as shown in FIGS. 7 and 5, Y,
Each of the scorotron chargers 11 is attached to each of the M, C, and K scorotron charger attachment portions 411, and the cylindrical casing 410 in which the cleaning device 100 for the photosensitive drum is attached to the cleaning device attachment portion 419 is the above-described case. 5 is inserted along the center axis of the drum unit 300 from the side in FIG. 5 (the lower side in FIG. 7), and the side cover 421 shown in the upper side in FIG. 7 (the left side in FIG. 5) and the lower side in FIG. 7 (the right side in FIG. 5). Are provided with holes 421a, 421a provided respectively.
422 a is fitted and inserted into the support shaft 30 of the drum unit 300, and is pressed into the casing 410. The casing 410 has holes 4 for inserting Y, M, C and K developing units.
13 and a hole 414 for inserting the intermediate transfer belt.

A pin 33 for retaining the casing 410 is implanted on the support shaft 30, and the scorotron charger 11, the holes 413 for inserting the developing devices of the cleaning devices 100, Y, M, C and K, and the intermediate transfer belt are inserted. Holes 414 are aligned with the exposure unit 12 of the drum unit 300 and the center axes of the casing 410 and the photosensitive drum 10 are aligned, and the side lids 421, 42 at both ends are aligned.
2 is screwed and fixed to the support members 20a and 20b (not shown), and the process unit 400 is assembled.

The LED 121 pulled out from the window 20A provided on the support member 20a of the drum unit 300
The lead wire 12A is provided with a hole 421 provided in the side lid 421.
b, it is drawn out of the process unit 400. The windows 20A through which the lead wires 12A pass are sealed so that toner and the like do not enter inside.

According to FIGS. 4 and 5, a process unit 400 including the above-described drum unit 300 is included.
Is attached to the apparatus main body, the gear 10G of the flange 10B is connected to the gear G1, and the flange 1 is driven by the driving of the gear G1 rotated by a drive motor (not shown).
The gear 10G provided at 0B is rotated, and the photosensitive drum 10 is rotated about the support shaft 30 in a fixed state as a rotation center.

As described above, the photosensitive drum 10 and the respective exposure units 12 are coaxially integrated as the drum unit 300 with the support shaft 30 at the center, and the drum unit 300 is enclosed in the casing 410 to form the process unit. In the state where the support shaft 30 supports the process unit 400, the process unit 400 is formed in a U-shape and connected between the symmetrical front and rear drum support plates 40 integrally connected. Supported.

The drum support plate 40 has a rail member 50 as a suspending means using a metal member such as iron or aluminum at the front and rear connection portions. The rail member 50 is provided in the main body of the apparatus. The support shaft 3 is inserted into and engaged with the guide member 60 to be in a suspended state.
0 indicates that the photosensitive drum 10 and each of the exposure units 12, the scorotron charger 11, the cleaning device 10
0, etc. are placed at approximately predetermined setting positions.

Further, when the support shaft 30 is inserted to the proper position, the shaft end 30B protruding from the rear drum support plate 40 from the suspended state described above is used as a rear plate (right side in FIG. 5) as an apparatus substrate. Seat 72 provided on the side plate 71
, And the shaft end 30A protruding from the front drum support plate 40 is supported by a screw member 82 taperedly fitted to a receiving seat 81 provided on the drum support substrate 80, so that the photosensitive drum 10 can be properly formed. , The gear 10G meshes with the gear on the driving side, and each exposure unit 12 further includes a through pin P1 provided on the shaft end 30B.
By being engaged with the V-shaped groove formed in the receiving seat 72, it is accurately regulated at a predetermined angular position with respect to the apparatus main body to be in a fixed state.

LED 1 provided in each exposure unit 12
21 of the support member 20a on the front side (the left side in FIG. 5) provided in the process unit 300.
B, window 20A and side cover 421 of drum unit 400
Notch 40A of drum support plate 40 through hole 421b of
To the power supply. As described above, lead wire 1
Each window 20A through which 2A passes is sealed so that toner and the like do not enter inside.

The upper and lower reference holes H1 of the drum support substrate 80 are engaged with a pair of reference pins P2 of a front side plate (left side plate in FIG. 5) 70 as a front device substrate, and the mounting position of the pair of reference pins P2 is set. Is fixed to the front side plate 70 by a plurality of screwing bolts. Further, the developing devices 13 for each color are inserted through the holes 413 for inserting the developing devices. The intermediate transfer belt 14 is inserted through the insertion hole 414, and the developing device 13 and the intermediate transfer belt 14 are fixed at predetermined positions with respect to the photosensitive drum 10 by screwing.

Accordingly, the photosensitive drum 1 as an image forming body
In the case of replacement of the image forming unit 0 and maintenance of the exposure unit 12 as an image exposing means, the developing unit 13 and the intermediate transfer belt 14 for each color are separated from the photosensitive drum 10 and then the screw member 82 and a plurality of screws are fixed. The drum support substrate 80 holding the process unit 400 including the drum unit 300 is separated from the front plate 70 by releasing the hook.

From the state, the drum support plate 40
Is pulled out by sliding the rail member 50 under the guidance of the guide member 60, and includes the drum unit 300 in which the photosensitive drum 10 and each of the exposure units 12 are integrated.
The process unit 400 to which the scorotron charger 11 and the cleaning device 100 are attached moves in the horizontal direction, and is taken out of the apparatus main body through an opening 70A as an image forming body opening of the front plate 70 as an apparatus substrate. .

A process unit 400 is formed by the front and rear drum support plates 40 formed in a U-shape and integrally connected.
Is removed. The left and right side lids 421 and 422 are unscrewed from the support members 20a and 20b, respectively, are removed from the casing 410, and the casing 410 is moved along the center axis of the drum unit 300.
Separated laterally from 00.

Next, the flange 10B press-fitted to the right side of the photosensitive drum 10 of the drum unit 300 is detached from the flange 10b of the flange 10B by a tool, for example, a gear puller, and pulled out to be removed. Further, with the exposure unit 12 attached to the support shaft 30 held by a jig or tool (not shown) so as not to contact the photosensitive drum 10, the flange 10 </ b> A pressed into the left side of the photosensitive drum 10 is A removal tool, for example, a gear puller is hung on the flange 10a of the 10A and pulled out to be removed. The photoconductor drum 10 is removed laterally along the central axis of the exposure unit 12 and separated from the exposure unit 12.

After the above disassembly, the photosensitive drum 10 is replaced,
Assembly is performed as described above with reference to FIGS.

Further, a protective cover (not shown) can be provided in the hole 413 for inserting the developing device and the hole 414 for inserting the intermediate transfer belt in the casing 410 of the process unit 400, so that the photosensitive unit during the carrying of the process unit 400 can be provided. The body drum 10 is prevented from being damaged. Process unit 40
When the protective cover is attached to the apparatus main body of No. 0, the protective cover is opened and attached.

The image forming unit can be mounted without damaging the image forming unit by the disassembling and assembling methods of the process unit 400 and the drum unit 300 as the image forming unit described with reference to FIGS. Also,
Disassembling and assembling replacement of the image forming body for reuse of the image exposing means becomes easy.

According to FIG. 8 and FIG.
Reference numerals 4A to 14D denote each of the front and rear belt support plates 4 formed integrally in a U-shape while the intermediate transfer belt 14 is stretched by the bias of the tension roller T.
5 between the bearings.

The belt support plate 45 is further formed in a U-shape and sandwiched together with the intermediate transfer belt cleaning device 140 between the asymmetrical front and rear belt support substrates 85 which are integrally connected. It is one.

The front belt support substrate 85 is provided with a reference hole H2 as a suspending means on the upper and lower rising portions 85A, while the rear belt support substrate 85 is provided on the rear surface with a pair of reference pins P4 also serving as the suspending means. And a reference pin P provided with the reference hole H2 of the front plate 70 on the front side.
On the other hand, the intermediate transfer belt 14 is set at a predetermined position by fixing the above-mentioned reference pin P4 with an upper screw engaged with a reference hole H3 provided in a rear side plate 71 as a rear device board. A first transfer area for transferring a toner image from the photosensitive drum 10 to the intermediate transfer belt 14 by pressing against the peripheral surface of the photosensitive drum 10, and further pressing the intermediate transfer belt by pressing the transfer roller 15. A second transfer area for transferring the toner image to the transfer material is formed from 14.

The belt support substrate 85 is provided on the front and rear side plates 7.
0 and 71 are supported on a 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 belt support substrate 85 has a pair of front and rear guide plates 86 provided on the left and right sides, respectively, sandwiching the movable portion 200A of the guide rail 200 so as to be slidable in the vertical direction. The movable part 200A
However, in the vertical direction, the abutting plate 87 can be lowered until it abuts against the movable portion 200A.

The above-mentioned belt support substrate 85 is released from engagement with the above-described reference pins and the respective reference holes by slightly pulling out the entire surface of the apparatus main body after releasing the screw fixing member, and is slightly lowered. Therefore, in a state where each of the abutting plates 87 is mounted on the movable portion 200A, the guide rail 200 is extended to a large extent from the opening 70A serving as the image forming body opening of the front side plate 70 to the front surface of the apparatus main body. .
As a result, the intermediate transfer belt 14 is retracted from the peripheral surface of the photosensitive drum 10 and is pulled out in a state where the pressure contact is released. Even when the belt is re-mounted, the guide rail 200 returns from the extended state and guides the tapered portion of each reference pin. As a result, the photosensitive drum 10 is slightly moved upward, and the operation of returning to the state of being pressed against the photosensitive drum 10 is automatically and reliably performed.

Accordingly, the photosensitive drum 10 is attached to the intermediate transfer belt 14 by an extremely simple attachment / detachment operation of the belt support substrate 85.
Can be taken out without interfering with the process unit 400. Further, by pulling out the belt support substrate 85, the process unit 400 described above can be pulled out, the jammed paper staying in the conveyance path can be taken out, and the intermediate transfer belt 14 can be replaced. Maintenance such as inspection can be easily performed.

Before the belt support substrate 85 is pulled out from the apparatus main body, the pressing 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 belt support substrate 85 is returned again. Placed in pressure contact.

FIG. 10 shows another method of separating the process units.

As shown in FIG. 10, the cylindrical integral casing 510 is composed of an upper casing 511, which is substantially horizontally divided into upper and lower parts with the cylindrical integral casing 510 having the side lids as a center axis. A scorotron charger 11 (not shown) and a cleaning device 100 (not shown) are attached to the lower casing 512, and M, C, and K scorotron chargers (not shown) are attached to the upper casing 511. 11 is attached.

Similarly to the above example, the exposure unit 12 for each color provided with the center axis aligned with the support shaft 30 and the exposure unit 12 for each color are included, and the exposure unit 12 for each color and the center axis are aligned. A drum unit 300 as an image forming unit in which the photosensitive drum 10 provided together is integrated with a drum unit 300 on a half-moon-shaped hole 512b provided on the left and right sides of a lower casing 512 at the center of a half cylinder. After the support shaft 30 is mounted on the exposure unit 12 in a direction orthogonal to the center axis of the exposure unit 12, the upper casing 511 is placed on the lower casing 512 in a direction orthogonal to the center axis of the drum unit 300.

The pin 511a of the upper casing 511 is fitted in the hole 512a of the lower casing 512, and the half-moon-shaped holes 511b provided on the left and right of the upper casing 511 at the center of the semi-cylinder sandwich the support shaft 30. . With the exposure unit 12, the scorotron charger 11, and the cleaning device 100 positioned, the left and right stop rings 513 are fitted into the support shaft 30, and the drum unit 300
Is fixed to the upper casing 511 and the lower casing 512 by screws, and the process unit 50 is fixed.
0 is assembled.

The window 20 provided in the drum unit 300
A and the LED 121 provided in each exposure unit 12 through the hole 512 c provided in the lower casing 512.
12A is drawn out of the process unit 500. The windows 20A through which the lead wires 12A pass are sealed so that toner and the like do not enter inside.

The process unit 500 is attached to the apparatus main body in the same manner as described above.

When replacing the photosensitive drum 10 as an image forming body or performing maintenance on the exposure unit 12 as an image exposing means, the process unit 500 including the drum unit 300 is taken out of the apparatus main body.

After the left and right retaining rings 513 have been removed,
The upper and lower casings 511 and 512 are
The drum unit 3 is separated in a direction orthogonal to the central axis of
00 is taken out. Further, the drum unit 300 is disassembled in the same manner as described above, and the photosensitive drum 10 is separated.
Be exchanged.

Further, it is possible to provide a protective cover (not shown) in the holes 513 for inserting the developing device and the holes 514 for inserting the intermediate transfer belt provided in the upper and lower casings 511 and 512 of the process unit 500. The photoconductor drum 10 is prevented from being damaged while the unit 500 is being carried. When the process unit 500 is mounted on the apparatus main body, the protective cover is opened and mounted.

The drum unit 300 as the image forming unit can be mounted without damaging the photosensitive drum 10 as the image forming unit, and image forming for reusing the exposure unit 12 as the image exposing means. Disassembly and assembly of body exchange become easy.

[0087]

According to the first to fourth aspects of the present invention, the image forming unit can be mounted without damaging the image forming body, and replacement of the image forming body for reuse of the image exposing means is achieved. Disassembly and assembly are facilitated.

[Brief description of the drawings]

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

FIG. 2 is an enlarged sectional view of a main part of the image exposure means of FIG.

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

FIG. 4 is a front view showing a support structure of the image forming body.

FIG. 5 is a sectional view showing a support structure of the process unit.

FIG. 6 is a sectional view of the image forming unit.

FIG. 7 is a view showing a method of assembling a process unit.

FIG. 8 is a front view showing a support structure of the intermediate transfer belt.

FIG. 9 is a side view showing a support structure of the intermediate transfer belt.

FIG. 10 is a diagram illustrating another method of separating a process unit.

[Explanation of symbols]

 Reference Signs List 10 photoconductor drum 11 scorotron charger 12 exposure unit 13 developing device 14 intermediate transfer belt 20a, 20b support member 30 support shaft 100 cleaning device 300 drum unit 400, 500 process unit 410, 511, 512 casing

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

Claims (4)

[Claims] 1. An image forming apparatus comprising: a cylindrical image forming body for forming a latent image; a plurality of sets of charging means and developing means outside the image forming body; Is charged by the charging unit, is subjected to image exposure by the image exposing unit, and is successively repeated to form a toner image thereon by development by the developing unit, whereby the toner image is formed on the image forming body. A color image forming apparatus that forms an image by superimposing image forming units, wherein the image exposing unit is an integrated image forming unit housed inside the image forming unit, and a casing is provided around the image forming unit. A color image forming unit, wherein the process unit is assembled or disassembled so that the image forming unit can be housed or taken out. Location. 2. An image forming apparatus comprising: a cylindrical image forming body for forming a latent image; a plurality of sets of a charging unit and a developing unit outside the image forming unit; Is charged by the charging unit, is subjected to image exposure by the image exposing unit, and is successively repeated to form a toner image thereon by development by the developing unit, whereby the toner image is formed on the image forming body. A color image forming apparatus that forms an image by superimposing image forming units, wherein the image exposing unit is an integrated image forming unit housed inside the image forming unit, and a casing is provided around the image forming unit. A color image forming apparatus, wherein a unit is formed, and the image forming unit can be assembled or disassembled so that the image exposure means can be stored or taken out. 3. The color image forming apparatus according to claim 1, wherein the casing can be assembled or separated in a direction lateral to the image forming unit or in a direction perpendicular to a central axis. 4. The image forming apparatus according to claim 1, wherein said image forming body can be assembled or separated on a side of said image exposing means.
3. The color image forming apparatus according to claim 3.