JP2003195729A - Process cartridge and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To integrally and relatively movably structure a photoreceptor unit and an intermediate transfer body, to enhance the rigidity of a photoreceptor unit and the rigidity of connection between the photoreceptor unit and the intermediate transfer unit, and to simplify fitting them together. <P>SOLUTION: The photoreceptor drum unit 21, having a photoreceptor frame 129 freely rotatably supporting a photoreceptor drum via a bearing 102, and the intermediate transfer body unit 22, having an intermediate transfer belt 5a, are integrally fitted together with long holes 129b and metal pins 140 so as to be relatively movable. Also, both side-plates 129a of the photoreceptor frame 129 are integrally connected with connecting portions 130. The connecting portions 130 are provided with drop prevention shafts 130a, 130b. When the photoreceptor unit 2 and the intermediate transfer body unit 22 are fitted together, the drop prevention shafts 130a and 130b are fitted into the drop prevention holes 223a and 223b of the intermediate transfer body unit 22. Thus, the rigidity of connection between both the units is enhanced. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process cartridge and an image forming apparatus to which the process cartridge can be attached and detached.

Here, the image forming apparatus includes, for example, an electrophotographic copying machine, an electrophotographic printer (for example, an LED printer, a laser beam printer, etc.), an electrophotographic facsimile machine, and an electrophotographic word processor.

Further, the process cartridge is a cartridge in which an electrophotographic photosensitive member and at least one of process means acting on the electrophotographic photosensitive member are integrally made into a cartridge which can be attached to and detached from the main body of the image forming apparatus. .

[0004]

2. Description of the Related Art In an image forming apparatus using an electrophotographic image forming process, a developer image formed on a photosensitive drum, which is an image carrier, is transferred to a recording medium to form an image.
Further, a color image forming apparatus is used which has a configuration in which developer images of respective colors sequentially formed on a photoconductor drum are superposed and transferred onto an intermediate transfer member, and the color images are collectively transferred onto a recording medium. Came. In this case, in order to facilitate the handling of the parts that are deteriorated or consumed such as the photosensitive drum,
A unit in which these are unitized and detachable from the main body of the image forming apparatus is widely used.

As a conventional example of a color image forming apparatus using an intermediate transfer member, a photosensitive member unit 350 and an intermediate transfer member unit 351 are provided as in a device shown in FIG. 8 (hereinafter referred to as "conventional device A"). Each of them is configured as an independent cartridge, and is configured such that the large movable frame 352 is rotated toward the front surface of the apparatus and opened, and the photoconductor unit 350 and the intermediate transfer body unit 351 are respectively inserted from above and attached to the apparatus main body. There is.

Then, the photosensitive drum 35 is provided on the upper surface of the intermediate transfer belt 355 of the intermediate transfer body unit 351 in the projection direction.
3 and a removed developer containing box 35 containing the removed developer
4 is provided as an integrated photoconductor unit 350, and the residual developer on the photoconductor drum 353 is scraped off by the cleaning blade and stored in the removed developer storage box 354 on the back surface. The residual developer on the intermediate transfer belt 355 is also scraped off by another cleaning blade,
It is transported to the lower part of the first transport pipe by the transport screw, and further, by the screw in the first transport pipe,
The removed developer is contained in the removed developer containing box 354 by being conveyed to an upper position where the removed developer containing box 354 is located, and then conveyed by a conveying screw in the second conveying pipe.

Further, since the connecting portion between the second pipe and the removed developer accommodating box 354 is configured to be attached and detached in a separate unit, the shutter is opened and closed at the time of attaching and detaching so that the removed developer does not spill. ing.

In the conventional apparatus A as described above, the photoconductor unit 350 and the intermediate transfer body unit 351 are independently positioned in the main body of the image forming apparatus, and the photoconductor drum 353 and the intermediate transfer belt 355 are respectively arranged. The drive transmission couplings are also independently connected to the couplings on the image forming apparatus main body side.

Further, as another conventional example of a color image forming apparatus using an intermediate transfer member, as described in JP-A-11-30944 and JP-A-10-177329, a photoreceptor belt is disclosed. A device in which the intermediate transfer belt and the removed developer storage box are integrated (hereinafter,
"Conventional device B") has been proposed.

In the conventional apparatus B, the photosensitive belt and the removed developer accommodating box are arranged on the projection lower surface of the intermediate transfer belt. Also, like the conventional device A, a large movable frame is pivoted to the front of the device to open it,
The process cartridge in which the intermediate transfer member, the photosensitive member, and the removed developer accommodating box are integrated is inserted from above.

Further, the residual developer on the intermediate transfer belt and the photoconductor belt is similarly scraped off by the respective cleaning blades and stored in the removed developer storage box. The developer removed from the intermediate transfer belt is configured to drop from the upper side to the lower side by the conveying pipe.

When the unit in which the photosensitive member unit and the intermediate transfer member unit are integrally formed as described above is positioned in the main body of the image forming apparatus, the positional relationship between the drive transmission couplings of the photosensitive member belt and the intermediate transfer belt is changed. A slight misalignment occurs between the unit side and the device body side. Therefore, in order to absorb this misalignment, a so-called Oldham coupling is adopted in which the intermediate member of the coupling slides the claw portion to absorb the misalignment.

[0013]

However, the conventional color image forming apparatus described above has the following problems.

In the conventional apparatus A, since the intermediate transfer member and the photosensitive member are separate units, the respective drive transmission couplings are positioned independently of each other, so that misalignment does not occur, but there are two types. Since a large opening for attaching and detaching the cartridge is required, and two cartridge insertion guides, a cartridge fixing member, etc. are required, the entire apparatus becomes large, the number of parts increases, and the cost increases. In addition, the presence of the two types of cartridges may cause the usability to deteriorate because the user may need to insert and remove the unit when attaching or detaching the unit.

Further, in the conventional apparatus B, the photosensitive member unit and the intermediate transfer member unit are integrated, but a so-called Oldham coupling is adopted in order to absorb the positional deviation of each drive transmission coupling. There is. Furthermore, the drive transmission coupling of the main body of the device is configured to slide in the axial direction and retreat in conjunction with the opening / closing operation of the door for attaching / detaching the unit, making the configuration of the coupling extremely complicated. ing. Further, in order to sufficiently bring out the performance as the Oldham's joint, accurate coupling is required. For these reasons, the above-mentioned coupling is very expensive in terms of cost and requires space.

In view of the above-mentioned problems in the prior art, the present invention provides a photosensitive member unit and an intermediate transfer member unit, which are relatively movable and integrally formed, and the rigidity and rigidity of the photosensitive member unit. An object of the present invention is to provide a process cartridge and an image forming apparatus in which a coupling rigidity between a photoconductor unit and an intermediate transfer body unit is enhanced, assembly is easy, and a drive transmission unit that is simple and does not cause misalignment is provided. To do.

[0017]

In order to achieve the above object, the process cartridge of the present invention is a process cartridge detachable from the main body of an image forming apparatus, and a photosensitive drum carrying an electrostatic latent image and the photosensitive drum. A photoconductor unit having a photoconductor frame for rotatably supporting the photoconductor frame and an intermediate transfer body unit having an intermediary transfer body to which a developer image formed on the photoconductor drum is transferred. The photoconductor frame is integrally formed, and the photoconductor drum is supported by both side plates via a bearing member. The both side plates of the photoconductor frame are the intermediate transfer in the circumferential direction of the photoconductor drum. The contact portion with the body and the contact portion with the developing unit are integrally connected.

In the process cartridge of the present invention,
It is preferable that both ends of the photoconductor unit are supported by metal pins so as to be swingable with respect to the intermediate transfer body unit. It is preferable to provide a retaining function when the photoconductor unit and the intermediate transfer body unit are integrally assembled.

Further, in the image forming apparatus of the present invention, the process cartridge is attachable / detachable, and in the image forming apparatus for forming an image on a recording medium, a mounting means for detachably mounting the process cartridge described above,
And a conveying unit for conveying the recording medium.

[0020]

According to the present invention, by integrally connecting both side plates of the photoconductor frame of the photoconductor unit, the supporting rigidity of the photoconductor drum can be increased, and at the same time, the connection of the photoconductor unit to the connecting portion can be improved. Since the retaining function is provided and the photoconductor unit is supported by the metal pin so as to be movable and swingable relative to the intermediary transfer unit, the photoconductor unit and the intermediary transfer unit are configured. Therefore, it is possible to provide a process cartridge and an image forming apparatus that have a high coupling rigidity with, and are therefore easy to assemble and that can obtain a stable and stable image.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

In the following description, the front surface of the apparatus refers to the surface on the upstream side of conveyance of the recording medium from the transfer process to the fixing process (right side in FIG. 1), and the left and right sides of the apparatus main body and the process cartridge are the front surface of the apparatus. Seen from the left or right. The longitudinal direction is a direction parallel to the surface of the recording medium and intersecting (substantially orthogonal) with the conveying direction of the recording medium. In addition, the code in the description is
It is intended to refer to the drawings and not to limit the configuration.

First, the overall structure of the color image forming apparatus and the image forming operation will be briefly described with reference to FIG. FIG. 1 is a longitudinal sectional view showing a schematic configuration of a four-color full-color electrophotographic laser beam printer, which is an embodiment of an image forming apparatus embodying the present invention.

As shown in FIG. 1, the image forming apparatus A according to the present embodiment has a photosensitive drum 1 which is an image carrier and an exposing means 3 which irradiates the photosensitive drum 1 with an optical image based on image information. A developing device 4 including a developing device of each color configured to develop an electrostatic latent image of each color formed on the photosensitive drum 1, and a developing device 4 of each color formed on the photosensitive drum 1. An intermediate transfer member (hereinafter, also referred to as an intermediate transfer belt) 5a for temporarily transferring the developer image, and the developer image on the intermediate transfer member 5a is a recording medium (transfer material) such as a recording paper, an OHP sheet, or a cloth.
Intermediate transfer device 5 including a secondary transfer roller 11 that is a transfer unit for transferring to a sheet, a fixing device 8 including a pressure roller and a heating roller, and a recording medium that is sequentially conveyed to the intermediate transfer device 5 and the fixing device 8 and discharged. It is provided with a transporting means and the like.

Details of the image forming process by the image forming apparatus A will be described. In synchronization with the rotation of the intermediate transfer belt 5a, the photosensitive drum 1, which is an image carrier, is rotated in the direction of the arrow (counterclockwise) in FIG. 1, and the surface of the photosensitive drum 1 is uniformly charged by the charging device 2. Together with the exposure means 3
The light irradiation of each color image based on the image information, for example, the light irradiation of the yellow image is performed to form a yellow electrostatic latent image on the photosensitive drum 1.

The exposing means 3 irradiates a light image on the photosensitive drum 1 by irradiating light on the basis of image information read from an external device or the like.
It contains a polygon mirror, a scanner motor, an imaging lens and a reflection mirror. When an image signal is given from an external device or the like, the laser diode emits light according to the image signal and irradiates the polygon mirror as the image light. This polygon mirror is rotated at a high speed by a scanner motor, and the image light reflected by the polygon mirror selectively exposes the surface of the photosensitive drum 1 through the imaging lens and the reflecting mirror, and as a result, the image is reflected on the photosensitive drum 1. Form a latent image.

Simultaneously with the electrostatic latent image formation, the developing device 4 is driven to rotationally move the yellow developing device 4Y to the developing position,
A voltage having the same polarity as the charging polarity of the photosensitive drum 1 and substantially the same potential is applied to the developing roller 4a to attach the yellow developer to the electrostatic latent image for development.

After that, a voltage having a polarity opposite to that of the developer is applied to the pressing roller (primary transfer roller) 5j of the intermediate transfer belt 5a so that the yellow developer image on the photosensitive drum 1 is transferred to the intermediate transfer belt 5a by one. Next transfer.

When the primary transfer of the yellow developer image is completed as described above, the next developing device (4M) of the developing device 4 is rotationally moved and positioned at a position facing the photosensitive drum. The steps of forming, developing and primary transfer of the electrostatic latent image as described above are sequentially repeated for each color of magenta (M), cyan (C) and black (BK) to thereby obtain the intermediate transfer belt 5a. Overlay the four color developer images on top.

During this time, the secondary transfer roller 11 is not in contact with the intermediate transfer belt 5a, and the cleaning charging roller 5f as a cleaning unit is also in non-contact with the intermediate transfer belt 5a.

After the formation of the four color developer images on the intermediate transfer belt 5a is completed, the secondary transfer roller 11 is pressed against the intermediate transfer belt 5a as shown in FIG. Further, in synchronism with the pressure contact of the secondary transfer roller 11, the recording medium which has been waiting at a predetermined position near the registration roller pair 7 as a feeding means is a nip portion between the intermediate transfer belt 5a and the secondary transfer roller 11. Sent to. Immediately before the registration roller pair 7, the registration roller pair 7 is detected by detecting the leading edge of the recording medium.
There is provided a pre-registration sensor that shuts off the rotational driving force of the recording medium and makes the recording medium stand by at a predetermined position.

A voltage having a polarity opposite to that of the developer is applied to the secondary transfer roller 11, so that the developer image on the intermediate transfer belt 5a is secondarily transferred onto the surface of the conveyed recording medium all together. It

The recording medium on which the developer image is secondarily transferred in this manner is conveyed to the fixing means 8 via the conveying belt unit 12, and here, by the pressure roller and the heating roller of the fixing means 8, The developer images of a plurality of colors are fixed, conveyed by a pair of discharge rollers 13 along a discharge guide 15, and discharged by a pair of discharge rollers 9 to a discharge tray 10 above the color image forming apparatus A to form an image. To complete.

On the other hand, after the secondary transfer, the cleaning charging roller 5f is brought into pressure contact with the intermediate transfer belt 5a, and the residual developer remaining on the intermediate transfer belt 5a after the secondary transfer is given an electric charge opposite to that at the time of transfer. The residual developer to which the opposite charge is applied is electrostatically attached to the photosensitive drum 1 from the intermediate transfer belt 5a at the primary transfer nip portion,
The surface of a is cleaned. The residual developer remaining after the secondary transfer attached to the photosensitive drum 1 is removed and collected by the cleaning blade 6 for the photosensitive drum 1.
The recovered residual developer traces the transport path for transporting the removed developer, and is recovered and accumulated in the removed developer storage box 216.

The developing device 4 is a black (BK),
A developing cartridge containing developer of each color of magenta (M), yellow (Y), and cyan (C) is detachably fixed to a predetermined position in the developing rotary. Each developing cartridge is roughly divided into a developer storage portion and a developing portion. The developer storage portion is filled with a developer of a predetermined color, and the stirring means rotates to convey the required amount of developer to the developing portion. . The conveyed developer is supplied to the surface of the developing roller by the rotation of the sponge-like developer supplying roller in the developing section, and is further given a charge by the friction between the thin plate-like developing blade and the developing roller to form a thin layer. The developer on the thinned developing roller is conveyed to the developing section by rotation,
By applying a predetermined developing bias, the electrostatic latent image on the photosensitive drum is visualized as a developer image. Then, the residual developer which has not contributed to the visualization of the latent image on the photosensitive drum by the developer on the surface of the developing roller is stripped off again by the developer supplying roller section, and at the same time, a new developer is deposited on the developing roller. It is supplied and new developing operation is continuously performed.

Next, the structure of the process cartridge in which the photosensitive member unit and the intermediate transfer member unit are integrated will be described in detail.

FIG. 2 is a vertical cross-sectional view of the process cartridge according to the present invention as seen from the front side of the apparatus from the left side, FIG. 3 is a perspective view as seen from the left side of the process cartridge according to the present invention, and FIG. FIG. 3 is a perspective view of the process cartridge according to the present invention as viewed from the right side. 5 and 6 are exploded perspective views seen from the left side surface and the right side surface, respectively, for explaining the configuration of the process cartridge according to the present invention. 7 is a schematic view of the process cartridge according to the present invention as viewed from the left side surface direction.

As shown in FIG. 2, the process cartridge 20 includes a photoconductor unit 21 including a photoconductor drum 1 and a photoconductor frame 129 that rotatably supports the photoconductor drum 1, an intermediate transfer belt 5a, and a removal and development unit. It is composed of two units, an intermediate transfer body unit 22 including an agent storage box 216 and an intermediate transfer body frame 245. The photoconductor unit 21 is arranged in the upward projection direction of the intermediate transfer body unit 22, and the left and right side covers 260, 26 are provided.
1 (FIGS. 3 to 6) is fixed to both side surfaces of the intermediate transfer body unit 22 and extends to both side surfaces of the photoconductor unit 21 to hold the photoconductor unit 21 from the side surface.

The photoconductor unit 21 includes a photoconductor drum 1
Is a left side bearing 102 (FIG. 5) and a right side bearing 106 at both ends.
It is rotatably held by the photoconductor frame 129 via (FIG. 6), and a predetermined rotational driving force is transmitted from the apparatus main body via the coupling 124 (FIG. 6, FIG. 4) at the right end portion thereof. It is like this.

Further, as shown in FIG. 2, the charging roller 2 is pressed against the photosensitive drum 1 with a predetermined force by the compression spring 126 via the bearings 125 at both ends and is driven to rotate. At least one of the bearings 125 is made of a conductive material, and the surface of the photosensitive drum 1 is uniformly charged by applying a predetermined charging bias voltage to the charging roller 2. Incidentally, regarding such a contact charging type charging device, Japanese Patent Laid-Open No. 63-14
It is disclosed in Japanese Patent No. 9669.

Further, the photoconductor unit 21 is provided with a drum shutter 119 which opens and closes in association with the operation of attaching to and detaching from the main body of the image forming apparatus.

Further, the photosensitive drum 1 is provided with a cleaning blade 6 at a predetermined position, and the residual developer on the intermediate transfer belt 5a to which the above-mentioned reverse charge is applied is collected on the photosensitive drum 1 and exposed. It is configured to be scraped off together with the residual developer on the body drum 1. The developer scraped off by the cleaning blade 6 is the squi sheet 127.
The falling developer is prevented from falling onto the intermediate transfer belt 5a, and the removed developer accumulated on the squeeze sheet 127 in the section formed by the photoconductor frame 129 is formed by the photoconductor frame 129 as the feed blade 151 rotates. Is swept out to the inner side of the section, that is, in the direction away from the photosensitive drum 1. Then, as the first screw 128 provided further inside than the feed blade 151 rotates, the removed developer is left side when viewed from the front side of the apparatus (see FIG.
In the front direction). A downward opening 1 is formed at the left end of the groove in which the first screw 128 is arranged.
52 is provided and the removed developer is the first screw 1
The removed developer conveyed to the left end by the opening 28
Impeller cover 253 that falls from the bottom and communicates with the removed developer accommodating box 216 of the intermediate transfer body unit 22 described later.
Is sent to the receiving port 253a. A seal member 254 is provided on the lower surface of the opening 152, and has a receiving port 253.
The developer is prevented from leaking at the joint with a.

Next, the intermediate transfer device 5 constituting the intermediate transfer body unit 22 and the removed developer storage box 216 for collecting and storing the removed developer will be described below.

Intermediate transfer belt 5 in the intermediate transfer device 5
The a is suspended and stretched between two rollers, a driving roller 240 and a driven roller 241, which are held by an intermediate transfer member frame 245 including a grip portion 280. The drive roller 240 includes a left bearing 240a (FIG. 5) and a right bearing 240b at both ends.
It is rotatably held by the intermediate transfer member frame 245 via (FIG. 6), and a predetermined rotational driving force is transmitted from the apparatus main body via the coupling 242 (FIG. 6, FIG. 4) at the right end portion. Has become. A compression spring 244 is provided on the bearings 243 (FIG. 2) at both ends of the driven roller 241.
A predetermined tension is applied to the intermediate transfer belt 5a.

A primary transfer roller 5j is provided at a position facing the photoconductor drum 1 with the intermediate transfer belt 5a interposed therebetween. The primary transfer roller 5j is provided with a compression spring 247 via bearings 246 at both ends. With a predetermined force, the photosensitive drum 1 is pressed against the photosensitive drum 1 via the intermediate transfer belt 5a and is driven to rotate. At least one of the bearings 246 is made of a conductive material, and by applying a predetermined transfer bias voltage to the primary transfer roller 5j, the developer on the surface of the photosensitive drum 1 is primarily transferred onto the intermediate transfer belt 5a. Transfer.

The drive roller 2 for the intermediate transfer belt 5a
At a position facing 40, a cleaning charging roller unit 223 is provided to apply a reverse charge to the residual developer on the intermediate transfer belt 5a as compared with the transfer. The cleaning charging roller 5f of the cleaning charging roller unit 223 drives the driving roller 240 via the bearings 211 on both ends and the intermediate transfer belt 5a with a predetermined force by the compression spring 212.
It is pressed against and is driven to rotate. Further, at least one of the bearings 211 is made of a conductive material, and by applying a voltage opposite to that at the time of transfer to the cleaning charging roller 5f, a charge opposite to that at the time of transfer is applied to the residual developer on the intermediate transfer belt 5a. The residual developer is electrostatically adsorbed and collected on the surface of the photosensitive drum 1 at the primary transfer nip portion.

The intermediate transfer body unit 22 is provided with a removed developer accommodating box 216 on the opposite side of the photosensitive body unit 21 with the intermediate transfer belt 5a as the center. The removed developer storage box 216 is provided in the intermediate transfer member frame 2
The partition plate 250 is formed by welding to a part of 45, and finally contains the residual developer on the photosensitive drum 1.

An impeller cover 253 is joined to the left side surface of the intermediate transfer member frame 245 with a seal member interposed therebetween. The impeller cover 253 has an opening 253a on the upper side, and is joined to the opening 152 provided at the lower left end of the photoconductor frame 129 with the seal member 254 sandwiched therebetween, and the removed developer dropped from the opening 152 has impeller cover 253. Fall inside. Inside the impeller cover 253, the impeller 255 rotates counterclockwise when viewed from the left side surface and conveys the removed developer inside to the removed developer storage box 216. The impeller cover 253 is provided on the left side surface of the removed developer storage box 216.
Overlap each other, and a hole communicating with the inside of the impeller cover 253 is provided in the overlapped portion. Further, the second screw 258 is provided at a position extending in the longitudinal direction from the hole, and the removed developer conveyed by the impeller 255 is supplied to the second screw 258.
Is rotated to transport the removed developer storage box 216 from the left side to the right side. Removed developer storage box 21
In FIG. 6, several small chambers are partitioned by a plurality of partition walls perpendicular to the second screw 258, and the removed developer is sequentially filled from the leftmost small chamber to the right adjacent small chamber. A detection unit (not shown) that detects fullness of the removed developer storage box 216 is provided in the rightmost small chamber.

Next, the frame structure of the process cartridge 20 according to the present invention will be described in more detail with reference to FIGS. 3 to 7.

Also in the frame structure of the process cartridge 20 according to the present invention, it is roughly divided into two units. First, the first unit is composed of the photoconductor drum 1, left and right bearings 102 and 106, the charging roller 2, the cleaning blade 6, the screw 128, the drum shutter 119, and the like, and a photoconductor frame 129 that holds these main parts. The photoconductor unit 21.

The photoconductor frame 129 constituting the photoconductor unit 21 has a plurality of engaging portions on both side plates 129a, 129a for engaging the left and right side covers 260, 261. Slotted holes 129b and 129b for swingably supported by metal pins 140 and 141, which will be described later, are provided at front portions of the side plates 129a and 129a (end portions on the side opposite to the photosensitive drum 1). . As shown in FIG. 7, the long holes 129b and 129b have a long hole shape along the direction toward the substantial center of the photosensitive drum 1. Further, both side plates 129 of the photoconductor frame 129 are
a and a hole 129 for positioning and fixing the flanges of the left bearing 102 and the right bearing 106, which hold the photosensitive drum 1 rotatably, at the rear of a and 129a, respectively.
9c and 129d are provided (FIGS. 5 and 6).

Both side plates 12 of the photoconductor frame 129
9a and 129a are at the rear lower end portion of the photosensitive drum 1 in FIGS. 5 and 6, that is, the photosensitive drum 1
A contact portion X (FIG. 7) with the intermediate transfer belt 5a in the circumferential direction and a contact portion Y (FIG. 7) with the developing roller 4a are integrally connected by a connecting portion 130. Further, at both ends of the connecting portion 130, retaining shafts 130a and 130b functioning as retaining stoppers when incorporated in an intermediate transfer body unit 22 described later are integrally formed.

The second unit is an intermediate transfer belt 5 suspended between a driving roller 240 and a driven roller 241.
a, a cleaning charging roller unit 223 including a primary transfer roller 5j disposed at a position facing the photosensitive drum 1 with the intermediate transfer belt 5a interposed therebetween and a cleaning charging roller 5f disposed at a position facing the drive roller 240.
And the intermediate transfer body frame 2 that holds these main parts
The intermediate transfer body unit 22 includes a 45 and a removed developer storage box 216.

A left side cover 260 and a right side cover 261 are fixed to both sides of the intermediate transfer body frame 245 of the intermediate transfer body unit 22 by means such as screws (FIGS. 5 and 6). As shown in FIGS. 4 and 6, from the outer surface of the right side cover 261, the flange portion of the right bearing 240b of the drive roller 240 of the intermediate transfer belt 5a projects through the hole 261c, and further, the right side cover 261 An integrally provided protrusion 204 is protruding. Also, from the outer surface of the left side cover 260, as shown in FIGS.
As in No. 1, the flange portion of the left bearing 240a of the drive roller 240 projects through the hole 260c, and the projection 203 integrally provided with the left side cover 260 projects.

Next, the first unit (photoreceptor unit 2)
Assembly of the process cartridge 20 configured by integrating 1) and the second unit (intermediate transfer member unit 22) will be described.

As described above, the process cartridge 20 includes the photoconductor unit 21 in which the photoconductor drum 1 is rotatably supported and the intermediate transfer to which the developer image formed on the surface of the photoconductor drum 1 is transferred. They are separately attached to the intermediate transfer body unit 22 that holds the belt 5a.
Here, the left and right side covers 2 of the intermediate transfer body unit 22
As shown in FIGS. 5 and 6, holes 260 a, 261 a and 245 for press-fitting and supporting the metal pins 140 and 141 are formed in the frames 60 and 261 and the intermediate transfer member frame 245.
a and 245b are provided coaxially with each other, and holes 223a are provided at both ends of the standing frame 224 that is connected to the cleaning charging roller unit 223 to prevent the photoconductor unit 21 from coming off when assembled. 223b are provided respectively.

When assembling the photoconductor unit 21 to the intermediate transfer body unit 22, first, the photoconductor frame 129 is inserted into the holes 223a and 223b for preventing the intermediate transfer body unit 22 from coming off.
Retaining shafts 130a and 130b provided on the connecting portion 130 of the
, And then the side plates 12 of the photoconductor frame 129.
9a and 129a, holes 129b and 129b, left and right side covers 260 and 261, holes 260a and 261a, and holes 245a and 245b of the intermediate transfer body frame 245 are aligned, and the metal pins 140 and 141 are press-fitted. At this time, the retaining hole 223 of the intermediate transfer body unit 22
a and 223b and the retaining shafts 130a and 130b of the connecting portion 130 of the photoconductor frame 129 are fitted with a predetermined gap. Further, the flange portions of the right side bearing 106 and the left side bearing 102 of the photoconductor drum 1 which are positioned and fixed to the photoconductor frame 129 have the right and left side covers 2 respectively.
U-shaped grooves 261b respectively provided in 61 and 260,
It projects outward through 260b. The flange portions of the right side bearing 106 and the left side bearing 102 and the U-shaped grooves 261b and 260b are also configured to have a predetermined gap. Therefore, the photoconductor unit 21
Is a metal pin 140 with respect to the intermediate transfer body unit 22,
Since the elongated holes 129b of the both side plates 129a of the photoconductor frame 129 are swingably supported by 141, and have a long hole shape along the direction toward the substantial center of the photoconductor drum 1, The relative positions of the unit 21 and the intermediate transfer body unit 22 are movable.

When the process cartridge 20 assembled as described above is mounted in the main body of the image forming apparatus, in the photoconductor unit 21, the right side of the photoconductor drum 1 protruding from the right side cover 261 and the left side cover 260. The flange portion of the bearing 106 and the flange portion of the left bearing 102 are positioned directly on the apparatus main body, and the photosensitive drum 1
Is fixed. Further, in the intermediate transfer body unit 22, the flange portion of the right side bearing 240 b of the drive roller 240 and the protrusion portion 204 of the right side cover 260, and the flange portion of the left side bearing 240 a of the drive roller 240 and the protrusion portion 203 of the left side cover 260. Is positioned directly on the device body. Here, since the photoconductor unit 21 and the intermediate transfer body unit 22 are in the state of an integrated cartridge, the drive transmission couplings (124, 242) of the photoconductor unit 21 and the intermediate transfer body unit 22 have a component tolerance. However, since the photoconductor unit 21 is swingably supported and relatively movable with respect to the intermediate transfer body unit 22, the photoconductor unit 21 is relatively movable. And the drive transmission coupling (12
4, 242) are independently positioned in the apparatus main body, the relative positional deviation due to the component tolerance or the like is absorbed.

In the process cartridge of the present invention, the photosensitive member unit 21 and the intermediate transfer member unit 2
2 has a structure in which they can be independently positioned in the image forming apparatus main body A, and at the same time, both side plates 129a of the photoconductor frame 129 of the photoconductor unit 21 are integrally connected and the photoconductor is connected to the connecting portion 130. A function to prevent the unit 21 from coming off is provided, and further the photoconductor unit 20 is attached to the metal pin 1.
The intermediate transfer body unit 22 is configured to be swingably supported by 40 and 141. In the above structure, the photoconductor unit 21 includes the photoconductor frame both side plates 12
By integrally connecting 9a, the supporting rigidity of the photoconductor drum 1 can be increased. In addition, the photoconductor unit 2
1 is swingably supported with respect to the intermediate transfer body unit 22 by metal pins 140 and 141 press-fitted so that both ends are supported by the side covers 260 and 261 and the intermediate transfer body frame 245, and at the same time, Metal pin 1
The intermediate transfer body unit 22 has a structure in which the support portions 40 and 141 and the connection portion 130 of the photoconductor frame 129 on the opposite side with the photoconductor drum 1 interposed therebetween have a retaining function.
It is possible to provide a process cartridge and an image forming apparatus that have high coupling rigidity with and that are easy to assemble.

[0060]

As described above, according to the present invention,
The support rigidity of the photoconductor drum is increased by integrally connecting both side plates of the photoconductor frame of the photoconductor unit, and at the same time, a function of preventing the photoconductor unit from coming off is provided at the connecting portion. Since the pin is configured to support the intermediate transfer body unit so as to be movable and swingable relative to the intermediate transfer body unit, the coupling rigidity between the photosensitive body unit and the intermediate transfer body unit is high, and therefore,
It is possible to provide a process cartridge and an image forming apparatus that are easy to assemble, have high rigidity, and can obtain a stable image.

[Brief description of drawings]

FIG. 1 shows one form of an image forming apparatus embodying the present invention.
It is a longitudinal cross-sectional view showing a schematic configuration of a full-color laser beam printer.

FIG. 2 is a vertical cross-sectional view of a process cartridge according to the present invention as viewed from the front side of the apparatus and as viewed from the left side.

FIG. 3 is a perspective view of the process cartridge according to the present invention as viewed from the left side.

FIG. 4 is a perspective view of the process cartridge according to the present invention as viewed from the right side.

FIG. 5 is an exploded perspective view seen from the left side for explaining the configuration of the process cartridge according to the present invention.

FIG. 6 is an exploded perspective view seen from the right side for explaining the configuration of the process cartridge according to the present invention.

FIG. 7 is a schematic view of the process cartridge according to the present invention as viewed from the left side surface direction.

FIG. 8 is a vertical cross-sectional view of a conventional electrophotographic image forming apparatus.

[Explanation of symbols]

1 photoconductor drum 2 charging roller 3 exposure means 4 Developing device 4a Developing roller 5 Intermediate transfer device 5a Intermediate transfer belt 5f Cleaning charging roller 5j Primary transfer roller 8 fixing means 20 process cartridges 21 Photoconductor unit 22 Intermediate transfer unit 102 (photosensitive drum) bearing 106 (photosensitive drum) bearing 129 Photoconductor frame 129a Side plate 129b long hole 130 connection 130a, 130b retaining shaft 140, 141 Metal pin 203 Projection 204 protrusion 216 Removed developer storage box 223 Cleaning charging roller unit 223a, 223b retaining holes 224 standing frame 240 (Intermediate transfer belt) drive roller 240a (driving roller) left bearing 240b (driving roller) right bearing 245 Intermediate transfer body frame 245a, 245b Support holes 260 left side cover 260a support hole 260b U-shaped groove 261 Right side cover 261a Support hole 261b U-shaped groove

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Koji Yamaguchi             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation F-term (reference) 2H035 CA07 CB04 CD05 CD07 CD11                       CD14                 2H071 BA05 BA13 BA22 BA27 BA29                       DA06 DA09 EA18                 2H200 FA12 GA23 GA34 GA47 GB12                       GB25 GB44 HA02 HB12 JA02                       JB10 JC04 JC07 JC09 JC12                       LB15 LB18

Claims (4)

[Claims] 1. A process cartridge detachably mountable to a main body of an image forming apparatus, comprising: a photoconductor unit having a photoconductor drum carrying an electrostatic latent image and a photoconductor frame rotatably supporting the photoconductor drum; An intermediate transfer body unit having an intermediate transfer body on which a developer image formed on the photosensitive drum is transferred is integrally configured to be relatively movable, and the photosensitive body frame supports the photosensitive drum. Both side plates are supported via a member, and the both side plates of the photoconductor frame have a space between a contact portion with the intermediate transfer member and a contact portion with the developing unit in the circumferential direction of the photosensitive drum. A process cartridge characterized by being integrally connected. 2. The process cartridge according to claim 1, wherein both ends of the photoconductor unit are swingably supported with respect to the intermediate transfer body unit by metal pins. 3. A portion for connecting both side plates of the photosensitive body frame is provided with a retaining function when the photosensitive body unit and the intermediate transfer body unit are integrally assembled. The process cartridge according to claim 1, wherein the process cartridge comprises: 4. An image forming apparatus for forming an image on a recording medium, wherein a process cartridge is attachable / detachable,
Mounting means for detachably mounting the process cartridge according to any one of claims 1 to 3,
An image forming apparatus comprising: a conveying unit configured to convey a recording medium.