JP2000132057A - Process cartridge and electrophotographic image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process cartridge making an electrophotographic photoreceptor possible to be effectively protected by plurally dividing the cartridge shutter, and an electrophotographic device making the above processing cartridge possible to be attached detached. SOLUTION: This process cartridge B is, provided with the cartridge shutter 18 capable of preferring a closing position for covering an exposure section of the electrophotographic photoreceptor 1, and the releasing position for letting one section of the electrophotographic photoreceptor 1 exposed by retreated from the above closing position. Then, cartridge shutter 18 is, allowed to cover the exposure section on the electrophotographic photoreceptor 1 by a first section 18f, a second section 18d and a sheet member 30.

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 electrophotographic image forming apparatus.

Here, an electrophotographic image forming apparatus forms an image on a recording medium using an electrophotographic image forming process. Examples of the electrophotographic image forming apparatus include, for example, an electrophotographic copying machine, an electrophotographic printer (for example, a laser printer, an LED printer, and the like), a facsimile machine, a word processor, and the like.

A process cartridge is a cartridge in which charging means or cleaning means and an electrophotographic photosensitive member are integrally formed into a cartridge, and this cartridge is made detachable from an image forming apparatus main body. In addition, at least one of the charging unit and the cleaning unit and the electrophotographic photosensitive member are integrally formed into a cartridge so as to be detachable from the image forming apparatus main body.

[0004]

2. Description of the Related Art Conventionally, in an electrophotographic image forming apparatus using an electrophotographic image forming process, a cartridge is integrally formed with an electrophotographic photosensitive member and process means acting on the electrophotographic photosensitive member, and the cartridge is used for image forming. A cartridge system that can be attached to and detached from the forming apparatus main body is employed. According to this process cartridge system, the maintenance of the apparatus can be performed by the user himself without relying on a serviceman, so that the operability can be remarkably improved. Therefore, this process cartridge system is widely used in image forming apparatuses.

In such a process cartridge, the exposed portion of the electrophotographic photosensitive member is made large in the cartridge frame so as to be opposed to the exposing means, the color developing means and the transferring means of the main body of the electrophotographic image forming apparatus. The cartridge frame is rotatably mounted with a cartridge shutter for covering the exposed portion of the electrophotographic photoreceptor and protecting the electrophotographic photoreceptor from being touched by external light and humans.

[0006]

SUMMARY OF THE INVENTION The present invention is a further development of the above-mentioned prior art, and its main object is to divide a cartridge shutter into a plurality of parts to effectively protect an electrophotographic photosensitive member. Another object of the present invention is to provide a process cartridge having the above configuration.

Another main object is to provide an electrophotographic image forming apparatus in which a process cartridge in which a cartridge shutter is divided into a plurality of parts to effectively protect an electrophotographic photosensitive member is detachable.

[0008]

A typical configuration for achieving the above object is as follows: (1) A process cartridge detachable from the main body of an electrophotographic image forming apparatus, comprising: an electrophotographic photosensitive member; A process means acting on a body, a cartridge frame for supporting the electrophotographic photosensitive member and the process means, and a cover for covering an exposed portion of the electrophotographic photosensitive member exposed from an opening of the cartridge frame; A cartridge shutter that can take a position and an open position for retreating from the closed position and exposing a part of the electrophotographic photosensitive member from the opening, wherein the cartridge shutter moves from the closed position to the open position. In the moving opening direction, at least a first portion located on the downstream side and a second portion located on the upstream side And a connecting member for connecting the first portion and the second portion so as to be swingable with each other, and a sheet member provided at an upstream end of the second portion, One part,
A process cartridge, wherein the second portion and the sheet member cover an exposed portion of the electrophotographic photosensitive member.

(2) In an electrophotographic image forming apparatus for detachably attaching a process cartridge and forming an image on a recording medium, a) an electrophotographic photosensitive member, and a process means acting on the electrophotographic photosensitive member; A cartridge frame for supporting the electrophotographic photosensitive member and the process means; a closed position covering an exposed portion of the electrophotographic photosensitive member exposed from an opening of the cartridge frame; and a retracted position from the closed position. And a cartridge shutter that can take an open position that exposes a part of the electrophotographic photoreceptor from the opening, wherein the cartridge shutter is at least downstream in an opening direction moving from the closed position to the open position. The first portion located on the side, and the second portion located on the upstream side, the first portion and the A connecting member that swingably connects the two portions to each other, and a sheet member provided at an upstream end of the second portion, the first portion, the second portion, Mounting means for removably mounting a process cartridge covering the exposed portion of the electrophotographic photosensitive member with the sheet member; and b) developing an electrostatic latent image formed on the electrophotographic photosensitive member. An electrophotographic image forming apparatus, comprising: a developing unit for performing the recording; and c) a conveying unit for conveying the recording medium.

(Operation) In the process cartridge and the electrophotographic image forming apparatus, the cartridge shutter is in the closed position covering the exposed portion of the electrophotographic photosensitive member exposed from the opening of the cartridge frame. , The second portion, and the sheet member cover the exposed portion of the electrophotographic photosensitive member.

The cartridge shutter has a first part, a second part, and a sheet member, and is divided into a plurality of parts. This makes it possible to reduce the rotation trajectory when moving the cartridge shutter from the closed position to the open position or from the open position to the closed position, and to compactly store the cartridge shutter in the open position. Becomes as a result,
The size of the electrophotographic image forming apparatus can be reduced.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment An embodiment according to the present invention will be described below in detail with reference to the drawings.

In the following description, the short direction of the process cartridge B is the direction in which the process cartridge B is attached to and detached from the electrophotographic image forming apparatus main body A1, and coincides with the transport direction of the recording medium S. The longitudinal direction of the process cartridge B is a direction that intersects (substantially orthogonal) the direction in which the process cartridge B is attached to and detached from the electrophotographic image forming apparatus main body A1, is parallel to the surface of the recording medium S, and Intersects (substantially orthogonal) with the transport direction of the recording medium S
Direction. Further, left and right with respect to the process cartridge B are right or left when the recording medium is viewed from above according to the transport direction of the recording medium S.

(Overall Configuration of Electrophotographic Image Forming Apparatus) FIG.
1 is a longitudinal sectional view illustrating a schematic configuration of an entire electrophotographic image forming apparatus (hereinafter, referred to as an image forming apparatus) according to the present embodiment.

First, an outline of the entire image forming apparatus A will be described with reference to FIG. The image forming apparatus A shown in FIG. 1 is a four-color full-color laser beam printer.

The image forming apparatus A shown in FIG. 1 includes a drum-shaped electrophotographic photosensitive member (hereinafter, referred to as “photosensitive drum”) 1. The photosensitive drum 1 is driven to rotate in a counterclockwise direction in FIG. Around the photosensitive drum 1, a charging device (charging means) 2, an exposure device 3, and a developing device (developing means) are arranged in this order in the rotation direction.
4, a transfer device 5, a cleaning device (cleaning means) 6, and the like. The charging device 2 uniformly charges the surface of the photosensitive drum 1. Exposure device 3
Is for forming an electrostatic latent image on the photosensitive drum 1 by irradiating a laser beam based on image information. The developing device 4 attaches toner (developer) to the electrostatic latent image formed on the photosensitive drum 1 and develops the latent image as a toner image. The transfer device 5 is a device to which the toner image on the photosensitive drum 1 is primarily transferred. Cleaning device 6
Is to remove the transfer residual toner remaining on the surface of the photosensitive drum 1 after the primary transfer.

Here, the photosensitive drum 1, the charging device 2, and the cleaning device 6 for removing the toner are integrated into a cartridge to constitute a process cartridge B. The process cartridge B includes the image forming apparatus A
Of the electrophotographic image forming apparatus main body A1 (hereinafter referred to as the apparatus main body).

In addition, a recording medium S such as a recording paper, an OHP sheet, and a cloth is fed toward the transfer device 5, and
A feeding / conveying device (conveying means) 7 for conveying the recording medium S is provided. Further, a fixing device 8 for fixing the toner image after the secondary transfer to the recording medium S by the transfer device 5 to the recording medium S
It also has.

Next, the configuration of each part of the laser beam printer will be described.

(Photosensitive Drum) The photosensitive drum 1 is an aluminum cylinder 1c having a diameter of 47 mm (FIG. 17A).
(See FIG. 3), an organic photoconductor layer (OPC photoreceptor) is applied to the outer peripheral surface. The photosensitive drum 1 is rotatably supported at both ends by a frame 100 (described later) of the process cartridge B (see FIG. 3). Then, a driving force is transmitted to a first end from a driving motor (not shown) in the apparatus main body A1, whereby the apparatus is rotated in the direction of the arrow.

(Charging Device) As the charging device 2, for example, a so-called contact charging system as disclosed in JP-A-63-149669 can be used. The charging member is a conductive roller (C roller) formed in a roller shape. The roller is brought into contact with the surface of the photosensitive drum 1, and a charging bias voltage is applied to the roller by a power source (not shown) to uniformly charge the surface of the photosensitive drum 1.

(Exposure Apparatus) The exposure apparatus 3 has a polygon mirror 3a, and the polygon mirror 3a is irradiated with image light corresponding to an image signal by a laser diode (not shown). The polygon mirror 3a is rotated at a high speed by a scanner motor (not shown), and selectively exposes the surface of the charged photosensitive drum 1 to the reflected image light via the imaging lens 3b, the reflection mirror 3c, and the like. It is configured to form an electrostatic latent image.

(Developing Apparatus) The developing apparatus 4 includes an apparatus main body A1.
A rotating body 4A rotatable around an axis 4d of
The four developing devices mounted on this, namely, yellow,
Developing units 4Y, 4M, 4C, and 4Bk that store toners of respective colors of magenta, cyan, and black are provided. When the electrostatic latent image on the photosensitive drum 1 is developed, a predetermined developing device of a color to be attached to the electrostatic latent image is arranged at a developing position. That is, the predetermined developing device is stopped at the developing position facing the photosensitive drum 1 by the index rotation of the rotating body 4A, and the developing sleeve 4b of the developing device has a minute gap (about 300 μm) with respect to the photosensitive drum 1. It is positioned so as to face. Thus, the developing sleeve 4b
Is positioned, the electrostatic latent image on the photosensitive drum 1 is developed. This development is performed as follows. The toner in the container of the developing device corresponding to the color to be developed is sent to the application roller 4a by a feeding mechanism (not shown). Then, a thin layer of toner is applied to the outer periphery of the rotating developing sleeve 4b by the rotating application roller 4a and the toner regulating blade 4c, and a charge is applied to the toner (frictional charging). By applying a developing bias between the developing sleeve 4b and the photosensitive drum 1 on which the electrostatic latent image is formed, a toner image is attached to the electrostatic latent image and developed as a toner image. The developing sleeve 4b of each of the developing units 4Y, 4M, 4C, and 4Bk is connected to a high-voltage power supply for each color (not shown) provided in the apparatus main body A1 when each developing unit is disposed at the developing position. The voltage is selectively applied for each color development. Each developing unit 4
Y, 4M, 4C, and 4Bk are configured to be individually detachable from the rotating body 4A, and the rotating body 4A is configured to be detachable from the apparatus main body A1.

(Transfer Apparatus) The transfer apparatus 5 transfers a plurality of toner images, which are sequentially primary-transferred from the photosensitive drum 1 and are superimposed, on the recording medium S collectively. The transfer device 5 includes an intermediate transfer belt 5 running in the direction of arrow R5.
a. Intermediate transfer belt 5a of the present embodiment
Is a belt having a circumference of about 440 mm,
b, a secondary transfer facing roller 5c and a driven roller 5d. The driven roller 5d
, And a pressing roller 5j is provided in the vicinity of. Presser roller 5
j moves backward so as to take a position where the intermediate transfer belt 5a is pressed against the photosensitive drum 1 and a position where the intermediate transfer belt 5a is separated from the photosensitive drum 1. The intermediate transfer belt 5a travels in the direction of arrow R5 by the rotation of the drive roller 5b. Further, at a predetermined position outside the intermediate transfer belt 5a, there is provided a cleaning unit 5e that can come in contact with and separate from the surface of the intermediate transfer belt 5a. This cleaning unit 5e
Is to remove the transfer residual toner on the intermediate transfer belt 5a remaining after the secondary transfer of the toner image to the recording medium S at once. That is, the cleaning unit 5e
Makes the charging roller 5f abut on the intermediate transfer belt 5a to apply a charge to the toner that is opposite to that at the time of transfer. The toner to which the opposite charge has been applied is electrostatically attached to the photosensitive drum 1 and then collected by a cleaning device 6 for the photosensitive drum 1 described later. The intermediate transfer belt 5a
The cleaning method is not limited to the electrostatic cleaning described above, but may be a mechanical method such as a blade or a fur brush, or a method using both of them.

(Cleaning device) Cleaning device 6
After the toner on the photosensitive drum 1 is primarily transferred onto the intermediate transfer belt 5a by the developing device 4, the so-called untransferred toner remaining on the surface of the photosensitive drum 1 without being primary-transferred is cleaned by a cleaning blade 6a (FIG. 3). See). The removed toner removed from the surface of the photosensitive drum 1 by the cleaning blade 6a is
The cleaning cartridge 11 is stored in the cleaning container 11 having a volume sufficient to accommodate the life of the photosensitive drum 1 and is removed when the process cartridge B is replaced. Cleaning container 1
As shown in FIG. 3, 1 includes a plurality of removed toner transport containers 17, and these removed toner transport containers 17 are provided with rotatable removed toner transport members 25, respectively. Then, the removed toner stored in the removed toner transport container 17 on the photosensitive drum 1 side is removed by the removed toner transport member 2.
By the rotation of 5, the toner is sequentially conveyed to the next removed toner conveying container 17. The removed toner transport member 25 is connected to a later-described removed toner transport coupling 20 and is driven to rotate.

(Supply / Conveyance Apparatus) The supply / conveyance apparatus 7 feeds the recording medium S to the image forming section, and stores a plurality of recording mediums S and supplies the recording medium S to the lower portion of the apparatus main body A1. A paper cassette 7a is provided. At the time of image formation, the pickup member 7e and the transport roller 7b are driven and rotated in accordance with the image forming operation, and separate and feed the recording medium S in the sheet cassette 7a one by one. Then, the recording medium S is transferred to the guide plate 7.
c, and is fed to the intermediate transfer belt 5a through the registration roller 7d.

(Fixing Device) The fixing device 8 fixes a plurality of toner images secondary-transferred onto the recording medium S. As shown in FIG. 1, the driving roller 8a is driven and rotated.
And a fixing roller 8b which presses the recording medium S to apply heat and pressure thereto. That is, the recording medium S that has passed through the secondary transfer roller 5n that collectively transfers the toner on the intermediate transfer belt 5a is conveyed by the driving roller 8a when passing through the fixing device 8, and the heat and pressure are reduced by the fixing roller 8b. Applied. As a result, the toner images of a plurality of colors are fixed on the surface of the recording medium S. Further, the recording medium S includes a belt 9a moving in the direction indicated by an arrow in FIG.
The paper is discharged onto a paper discharge tray 10 at the upper part of the apparatus main body A1 by a paper discharge device 9 comprising a discharge roller 9b wound around and driven by a.

(Mounting and Demounting of Process Cartridge from Apparatus Body) Next, mounting and demounting of the process cartridge will be described with reference to FIGS. 2, 13 and 14. FIG.

Process cartridge B to apparatus body A1
Is mounted on the process cartridge B as shown in FIG.
Is carried out by a movable body 50 for guiding the inside of the apparatus main body A1. The movable body 50 is configured to be movable in the apparatus main body A1 substantially in parallel with the transport direction of the recording medium 2. Then, the process cartridge B is detachably mounted on the movable body 50 pulled out from the apparatus main body A1.

More specifically, when the process cartridge B is mounted on the movable body 50, as shown in FIGS. 13 and 14, the drum of the process cartridge B faces the first guide surface 50a provided on the movable body 50. Coupling 1
9 (the opposite side is the cylindrical portion 14b of the side cover 14). At the same time, the second
The rotation determining dowel 11a (the rotation determining dowel 11b on the opposite side) of the process cartridge B is guided with respect to the guide surface 50b. A cylindrical positioning boss 13a (cylindrical positioning boss 14a on the opposite side) that is arranged in the axial direction with a later-described drum coupling 19 (on the opposite side, the cylindrical portion 14b) of the process cartridge B is provided at the tip of the first guide surface 50a. It enters the provided temporary receiving portion 50f (see FIG. 2). Then, the process cartridge B swings clockwise around the temporary receiving portion 50f. Thereby, the rotation determining dowel 11a of the process cartridge B (the rotation determining dowel 11a on the opposite side).
b) abuts against a rotation determining portion 50e provided at the bottom of the second guide surface 50b of the movable body 50. The dowel 11a (11b) is provided on the CR provided on the movable body 50.
By being pressed by the G pressing member (cartridge pressing member) 54, the movable body 50 of the process cartridge B is
Installation to the is completed.

At this time, the ROM connector 23 of the process cartridge B shown in FIG. 12 is connected to a connector (not shown) arranged on the movable body 50. The drum shutter 18 is provided with a cam receiving portion 50 provided on the movable body 50.
Opened halfway by g.

After the process cartridge B is mounted on the movable body 50, the movable body 50 is further moved to the apparatus main assembly A1.
Side (see FIG. 2). As the movable body 50 moves, the cylindrical positioning boss 13a of the process cartridge B (the cylindrical positioning boss 14a on the opposite side) becomes a cartridge receiving member (positioning member) in the apparatus main assembly A1.
(Hereinafter, referred to as CRG receiving member) 55. At this time, the hook portion 51b of the pressing portion 51 disposed on the back surface of the movable body 50 is hooked on the side surface of the apparatus main body A1, and the movable body 50 is pressed against the back plate 51a of the pressing portion 51.
As a result, the abutting portion 50d provided at the lower end of the front part of the movable body 50 is used for the cylindrical positioning dowel 13a of the process cartridge B.
a) is positioned under pressure with respect to the CRG receiving member 55.
As a result, the mounting position of the process cartridge B is determined with respect to the apparatus main assembly A1, and an image can be formed as shown in FIG.

At this time, the drum drive coupling 52 and the removed toner transport drive coupling 53 of the apparatus main assembly A1 shown in FIG. 2 move toward the gear cover 13 of the process cartridge B. The drum drive coupling (drive transmission member) 52 is connected to the drum coupling (driven transmission member) 19 of the process cartridge B. And
The removed toner transport drive coupling 53 is connected to the removed toner transport coupling 20 through a notch 50 c provided in the movable body 50. As a result, the drum coupling 19 and the removed toner transport coupling 20 of the process cartridge B are driven.

The laser shutter opening / closing rib 11c of the process cartridge B is connected to the exposure device 3 shown in FIGS.
The laser shutter 3d is opened. 5 and a primary bias contact 22 shown in FIG. 6 provided on the charging device cover 15 of the process cartridge B. The drum ground contact 21 shown in FIG. It is electrically connected to a high-voltage contact (not shown) of the apparatus main body A1. Further, the drum shutter 18 is completely opened by a shutter opening / closing rib (not shown) of the apparatus main body A1.

(Image Forming Operation) Next, an image forming operation of the image forming apparatus A according to the present embodiment will be described with reference to FIG.

The photosensitive drum 1 is rotated in the direction of the arrow in FIG. 1 (counterclockwise) in synchronization with the rotation of the intermediate transfer belt 5a, and the surface of the photosensitive drum 1 is uniformly charged by the charging device 2 and exposed. The device 3 irradiates a yellow image with light to form a yellow electrostatic latent image on the photosensitive drum 1. Simultaneously with the formation of the electrostatic latent image, the developing device 4 is driven to dispose the yellow developing unit 4Y at the developing position, and the photosensitive drum 1 is moved so that the yellow toner adheres to the electrostatic latent image on the photosensitive drum 1. A voltage having the same polarity as the charging polarity and substantially the same potential is applied to cause the yellow toner to adhere to the electrostatic latent image for development. A voltage having a polarity opposite to that of the toner is applied to the primary transfer roller (driven roller) 5d, and the yellow toner image on the photosensitive drum 1 is primarily transferred onto the intermediate transfer belt 5a.

When the primary transfer of the yellow toner image is completed as described above, the next developing unit is rotated and positioned at the developing position facing the photosensitive drum 1, and the magenta and the magenta are transferred in the same manner as in the case of yellow. The formation, development, and primary transfer of the electrostatic latent image are sequentially performed for each of the cyan and black colors, and four color toner images are superimposed on the intermediate transfer belt 5a. These toner images are collectively and secondarily transferred onto the recording medium S supplied from the feeding / conveying device 7.

Then, the recording medium S after the secondary transfer is conveyed to the fixing device 8, where the toner image is fixed. Thereafter, the belt 9 that moves the recording medium S in the direction of the arrow shown in the figure.
a and a discharge roller 9b wound around and driven by the belt 9a to discharge the image onto the paper discharge tray 10 and complete the image formation.

(Frame Structure of Process Cartridge) Next, the structure of the frame of the process cartridge will be described with reference to FIG.
This will be described with reference to FIGS.

As shown in FIG. 3, the process cartridge B includes a charging device (C roller) 2 around the photosensitive drum 1.
And a cleaning device 6. These are integrated by a frame (cartridge frame) 100, and the above-mentioned movable body (mounting means) included in the apparatus main body A1.
It is configured to be detachable from 50. The frame 100 of the process cartridge B includes a cleaning container 11 and a rear container 12 joined to the rear end of the cleaning container 11 by ultrasonic waves. Further cleaning container 11
Supports the charging device 2, a drum supporting portion 11 e extending to both ends in the longitudinal direction of the photosensitive drum 1 and the charging device 2, a cleaning blade supporting portion 11 d for supporting the cleaning blade 6 a of the cleaning device 6. And a roller support portion 11f. The frame 100 has an opening 100a that exposes a part of the photosensitive drum 1 by the cleaning container 11 and the roller support 11f. The rear container 12 is provided with a handle 1 for the operator to grip the process cartridge B when attaching or detaching the process cartridge B to / from the apparatus main body A1.
6. As shown in FIGS. 4 to 12, a gear cover (one side cover) 13 is fixed over the cleaning container 11 and the rear container 12 on the longitudinal drive side of the process cartridge B. On the other side of the process cartridge B in the longitudinal direction, the other side cover 14 is fixed over the cleaning container 11 and the rear container 12. The gear cover 13 and the side cover 14 have cylindrical positioning bosses (positioning portions) 13a and 14a serving as guides when the process cartridge B is mounted on the apparatus main assembly A1, and the rotation determining dowel 11
a and 11b are provided. A charging device cover 15 that covers the longitudinal direction of the charging device 2 and both ends thereof is attached to an upper portion of the cleaning container 11.

Further, a drum shutter (not shown) is provided below the cleaning container 11 to protect the photosensitive drum 1 from being exposed to outside light and people when the photosensitive drum 1 is taken out of the apparatus main body A1. A cartridge shutter 18 is rotatably provided.

The photosensitive drum 1 has a first shutter cover (second portion) 1 to be described later, which constitutes a drum shutter 18.
8d, the second shutter cover (first portion) 18f, and the sheet member 30 protect the light from light and the like.

(Configuration of Drum Shutter) The configuration of the drum shutter 18 will be described in detail with reference to FIGS.

When the process cartridge B is removed from the apparatus main assembly A and handled outside the apparatus main assembly A1, the drum shutter 18 damages the photosensitive layer, particularly the photosensitive layer of the photosensitive drum 1, or is exposed and exposed to external light. The peripheral surface of the photosensitive drum 1 is covered so as to prevent the layer from deteriorating (see FIG. 3).
When the process cartridge B is mounted on the apparatus main assembly A1, the photosensitive drum 1 is moved to the developing device 4 and the transfer device 5
The surface of the photosensitive drum 1 is partially opened from the opening 100a of the frame 100 (FIG. 1).
5).

That is, the drum shutter 18 is
A closed position (the position shown in FIG. 3) covering the exposed portion of the photosensitive drum 1 exposed from the opening 100a of the frame 100, and a part of the surface of the photosensitive drum 1 retracted from the closed position to open the frame 100 with the opening. An open position (position shown in FIG. 15) to be exposed from the portion 100a is taken.

The drum shutter 18 has a second shutter cover 18f on the downstream side and a first shutter cover 18d on the upstream side in the opening direction moving from the closed position to the open position. Then, as shown in FIGS. 4 and 5, a shutter support member (shutter support means) 18A is rotatable so that the gear cover 13 on the driving side and the side cover 14 on the non-driving side move from the closed position to the open position. Supported. More specifically, a root shaft 18b of an arm 18a constituting a shutter support member 18A is provided in an engagement hole 13c provided in the drive-side gear cover 13 and an engagement hole 14c provided in the counter-drive side cover 14, respectively. Are bent into an L shape and are rotatably engaged.
The distal end of the arm 18a is an engagement shaft 18c that is connected to the process cartridge B in the longitudinal direction. A concave portion 18d1 provided on the root side, which is the upstream end portion of the first shutter cover 18d, is engaged with the engaging shaft 18c.

As shown in FIG. 3, a plate-like sheet member 30 is attached to the root side of the first shutter cover 18d. The sheet member 30 has a role to cover the photosensitive drum 1 exposed at substantially the entire length of the photosensitive drum 1 at that position, that is, the photosensitive drum 1 exposed between the root side of the first shutter cover 18 d and the charging device cover 15. I have.

FIG. 4, FIG.
As shown in FIGS. 8 and 11, the pin shaft (connection member) 18
The second shutter cover 18f is swingably connected by e. As shown in FIGS. 5, 8 and 12, an operating arm 18h is engaged with a fixed shaft 14d integrally formed with the side cover 4. A screw 14g is screwed into the fixed shaft 14d to prevent the operation arm 18h from coming off. The operating arm 18h is engaged with the root side of the second shutter cover 18f by a shaft 18i concentric with the pin shaft 18e.

A torsion coil spring 18j which is in contact with the outer surfaces of the first and second shutter covers 18d and 18f is inserted into the pin shaft 18e. As shown in FIG. 11, the first and second shutter covers 18d and 18f
Each of the inner surfaces is urged by a torsion coil spring 18j so as to be in contact with each other.

As shown in FIG. 5, a torsion coil spring 18m is attached to the fixed shaft 14d with which the operating arm 18h is engaged.
Is fitted. One end of the torsion coil spring 18m is stopped by a spring receiver 14h formed integrally with the side cover 14, and the other end is stopped by an operating arm 18h. Thereby, the operating arm 18h is biased counterclockwise about the fixed shaft 14d in FIG.
When the process cartridge B is mounted on the apparatus main body A1, the operation arm 18h is provided with a cam portion 18n that comes into contact with a fixing member such as a cam receiving member 50g (see FIG. 13) and a shutter opening / closing rib (not shown) on the apparatus main body A1 side. Have.

The opening operation of the drum shutter 18 is performed as follows.

When the process cartridge B advances for mounting on the apparatus main assembly A1, the cam portion 18 of the operating arm 18h is moved.
n comes into contact with the fixing member of the apparatus main body A1 and stops moving forward.

At this time, the operating arm 18h rotates upward (clockwise) around the fixed shaft 14d in FIG. 5 against the spring force of the torsion coil spring 18m. As a result, the pin shaft 18e and the shaft 18i are lifted upward. Therefore, the first and second shutter covers 18d, 1
8f is moved upward. At this time, the root side of the first shutter cover 18d rises with the sheet member 30 along the same locus as the circular locus of the engaging shaft 18c that rotates upward about the root shaft 18b of the arm 18a. Accordingly, the leading end side of the first shutter cover 18d and the root side of the second shutter cover 18f draw the same locus as the circular arc locus about the fixed shaft 14d of the shaft 18i due to the upward rotation of the operation arm 18h. To rise. At this time, the tip 18g of the second shutter cover 18f is connected to the first shutter cover 18d and the second shutter cover 18f.
Torsion coil spring 1 that tries to fold the inwards into each other
Due to the spring force of 8j, the photosensitive drum 1 rises while being in contact with the outer periphery of both ends. The drum shutter 18 is shown in FIG.
1 and as shown in FIG. 15, the charging device is stored behind the charging device cover 15. At this time, the first shutter cover 18d
The sheet member 30 provided on the root side of the cleaning container 11 is stored in a shape following the upper surface of the cleaning container 11.

As described above, in the process cartridge B according to the present embodiment, the drum shutter 18 is
The second shutter cover 18f, the first shutter cover 18d, and the closed position covering the exposed portion of the photosensitive drum 1 exposed from the opening 100a
The exposed portion of the photosensitive drum 1 is covered by the sheet member 30.

The drum shutter 18 has a second shutter cover 18f, a first shutter cover 18d, and a sheet member 30, and is divided into a plurality of parts.
For this reason, the rotation locus when moving the drum shutter 18 from the closed position to the open position or from the open position to the closed position can be reduced. Further, the storage state of the drum shutter 18 can be made compact in the open position. For this reason, the space occupied by the drum shutter 18 and the process cartridge B in the apparatus main assembly A1 can be reduced, and as a result, the size of the image forming apparatus A can be reduced.

[Second Embodiment] FIGS. 16 and 17 show a process cartridge according to this embodiment.

The process cartridge B according to this embodiment is the same as the drum shutter 18 of the first embodiment described above.
Of the first shutter cover 18 instead of the sheet member 30 of FIG.
The end of a flexible sheet member 31 is fixed to d and the charging device cover 15.

As shown in FIG. 16, one end 31a of the flexible sheet member 31 is attached to the root side of the first shutter cover 18d, and the other end 31b is attached to the rear side of the charging device cover 15. . Thereby, the sheet member 31 is
It serves to cover the photosensitive drum 1 exposed between the root side of the first shutter cover 18d and the charging device cover 15.

As described above, the drum shutter 18 of the process cartridge B according to the present embodiment moves the first shutter cover 18 with the rotation of the operation arm 18h.
d and the second shutter cover 18f move from the closed position shown in FIG. 16 to the open position shown in FIG. 17, and are stored behind the charging device cover 15. At this time, the sheet member 31
Are stored on the lower surface side of the drum shutter 18.

As described above, in the process cartridge B according to the present embodiment, the drum shutter 18 is
The second shutter cover 18f, the first shutter cover 18d, and the closed position covering the exposed portion of the photosensitive drum 1 exposed from the opening 100a
The exposed portion of the photosensitive drum 1 is covered by the sheet member 31.

The drum shutter 18 has a second shutter cover 18f, a first shutter cover 18d, and a sheet member 31, and is divided into a plurality of parts.
For this reason, the rotation locus when moving the drum shutter 18 from the closed position to the open position or from the open position to the closed position can be reduced. Further, the storage state of the drum shutter 18 can be made compact in the open position. For this reason, the space occupied by the drum shutter 18 and the process cartridge B in the apparatus main assembly A1 can be reduced, and as a result, the size of the image forming apparatus A can be reduced.

As described above, according to the embodiment of the present invention, the plurality of shutter members 18d and 18f that cover the photosensitive drum 1 exposed from the opening 100a of the frame 100 of the process cartridge B are provided. It is rotatable (swingable). Then, the shutter member 18d is supported by the shutter support member 11A, and the respective shutter members 18d and 18f are supported so as to be openable and closable. Further, all covers of the photosensitive drum 1 are replaced with shutter members 18d, 18d.
By using the sheet members 30 and 31 together instead of f, the area of the rotation locus of the drum shutter 18 is reduced, and the shutter storage space after the opening is reduced. Thereby, the electrophotographic image forming apparatus A can be designed compact.

In the process cartridge B shown in the above-described embodiment, the drum shutter 18 includes the second shutter cover 18f, the first shutter cover 18d, and the three shutter members 30 and 31. However, the process cartridge according to the present invention is not limited to this, and the drum shutter 18 may be configured by four or more shutter members.

[0064]

[Embodiments] These are described together with the embodiments.

(Other Embodiments) The case where the process cartridge B shown in the above-described embodiment is applied to a color image forming apparatus has been exemplified, but the process cartridge of the present invention is a single color image, a two color image, or a three color image. The present invention can be suitably applied to a process cartridge used in an image forming apparatus for forming a color image.

The electrophotographic photosensitive member is not limited to the photosensitive drum, and includes, for example, the following. First, a photoconductor is used as a photoconductor. Examples of the photoconductor include amorphous silicon, amorphous selenium, zinc oxide, titanium oxide, and an organic photoconductor (OP).
C) and the like. As the shape on which the photoconductor is mounted, for example, a drum-shaped or belt-shaped one is used. For example, in the case of a drum-type photoconductor, a photoconductor is deposited or coated on a cylinder such as an aluminum alloy. It has been worked.

In the above-described embodiment, a so-called contact charging method is used for the structure of the charging device. However, as another structure, a metal shield such as aluminum is provided around three sides of a conventionally used tungsten wire. It is a matter of course that a configuration may be used in which positive or negative ions generated by applying a high voltage to the tungsten wire are moved to the surface of the photosensitive drum, and the surface of the drum is uniformly charged.

The charging device may be a blade (charging blade), a pad type, a block type, a rod type, a wire type, or the like, in addition to the roller type.

Further, as a method of cleaning the toner remaining on the photosensitive drum 1, a blade, a fur brush,
The cleaning means may be configured using a magnetic brush or the like.

The process cartridge described above is provided with, for example, an electrophotographic photosensitive member and at least one of processing means. Therefore, as an aspect of the process cartridge, in addition to the above-described embodiment, for example, an electrophotographic photosensitive member and a charging unit are integrally formed into a cartridge and can be attached to and detached from the apparatus main body. In some cases, the electrophotographic photosensitive member and the cleaning unit are integrally formed into a cartridge, and the cartridge is detachable from the apparatus main body.

That is, the above-described process cartridge includes at least one of the charging unit and the cleaning unit.
And an electrophotographic photoreceptor are integrally formed into a cartridge, and this cartridge is made detachable from the image forming apparatus main body. The process cartridge can be attached to and detached from the apparatus main body by the user himself. Therefore, the maintenance of the apparatus main body can be performed by the user himself.

Further, in the above-described embodiment, a laser beam printer is exemplified as the electrophotographic image forming apparatus. However, the present invention is not limited to this. For example, an electrophotographic copying machine, a facsimile machine, a word processor, etc. Of course, it is also possible to use it for the electrophotographic image forming apparatus.

[0073]

As described above, according to the process cartridge and the electrophotographic image forming apparatus of the present invention,
The electrophotographic photosensitive member can be effectively protected by the plurality of divided cartridge shutters.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an electrophotographic image forming apparatus.

FIG. 2 is an explanatory diagram when a process cartridge is attached to and detached from an electrophotographic image forming apparatus main body.

FIG. 3 is a longitudinal sectional view of the process cartridge shown in FIG.

FIG. 4 is a right side view of the process cartridge shown in FIG.

FIG. 5 is a left side view of the process cartridge shown in FIG. 3;

FIG. 6 is a plan view of the process cartridge shown in FIG.

FIG. 7 is a bottom view of the process cartridge shown in FIG.

FIG. 8 is a front view of the process cartridge shown in FIG.

FIG. 9 is a rear view of the process cartridge shown in FIG. 3;

FIG. 10 is an external perspective view of the process cartridge shown in FIG.

11 is an external perspective view of the process cartridge shown in FIG.

FIG. 12 is a perspective view of the process cartridge shown in FIG.

FIG. 13 is a perspective view of a movable body for mounting the process cartridge to the main body of the electrophotographic image forming apparatus.

FIG. 14 is an explanatory diagram when the process cartridge is mounted on the main body of the electrophotographic image forming apparatus.

FIG. 15 is an explanatory diagram showing a storage state of the process cartridge shown in FIG. 3 at an open position of a drum shutter.

FIG. 16 is a longitudinal sectional view of a process cartridge according to another embodiment.

17 is an explanatory diagram showing a storage state of the process cartridge shown in FIG. 16 at an open position of a drum shutter.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Electrophotographic photoreceptor 2 Charging device (charging means) 4Y, 4M, 4C, 4Bk Developing device (developing device) 6 Cleaning device (cleaning device) 7 Feeding / conveying device (conveying device) 18 Drum shutter (cartridge shutter) 18d First Shutter cover (second portion) 18e Pin shaft (connection member) 18f Second shutter cover (first portion) 30, 31 Sheet member 50 Movable body (mounting means) 100 Frame (cartridge frame) 100a Opening A1 Electronics Photographic image forming apparatus main body B Process cartridge S Recording medium

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Jun Miyamoto 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 2H071 BA13 BA23 BA35 DA06 DA08 DA13 DA15 DA23

Claims (7)

[Claims] 1. A process cartridge detachably mountable to a main body of an electrophotographic image forming apparatus, comprising: an electrophotographic photosensitive member; a process means acting on the electrophotographic photosensitive member; and a support for supporting the electrophotographic photosensitive member and the process means. A closed position for covering an exposed portion of the electrophotographic photosensitive member exposed from an opening of the cartridge frame; A cartridge shutter that can take an open position to be exposed from, and wherein the cartridge shutter is at least a first portion located on the downstream side in the opening direction moving from the closed position to the open position, and on the upstream side. A second portion located, and the first portion and the second portion swingably connected to each other. A connecting member, and a sheet member provided at an upstream end of the second portion, the first portion,
A process cartridge, wherein the second portion and the sheet member cover an exposed portion of the electrophotographic photosensitive member. 2. The cartridge shutter according to claim 1, wherein the cartridge shutter is located above the cartridge frame when the process cartridge is mounted at a mounting position of the main body of the electrophotographic image forming apparatus and is at the open position. Item 2. The process cartridge according to item 1. 3. A process cartridge detachable from a main body of an electrophotographic image forming apparatus, comprising: an electrophotographic photoreceptor; processing means acting on the electrophotographic photoreceptor; and supporting the electrophotographic photoreceptor and the process means. A closed position for covering an exposed portion of the electrophotographic photosensitive member exposed from an opening of the cartridge frame; and a part of the electrophotographic photosensitive member retracted from the closed position to remove a portion of the electrophotographic photosensitive member from the opening. A cartridge shutter that can take an open position to be exposed from, and wherein the cartridge shutter is at least a first portion located on the downstream side in the opening direction moving from the closed position to the open position, and on the upstream side. A second portion located, and the first portion and the second portion swingably connected to each other. A connecting member, a sheet member having one end attached to an upstream end of the second portion and the other end attached to the cartridge frame, wherein the first portion, the second portion And a cover that covers the exposed portion of the electrophotographic photosensitive member with the sheet member. 4. The cartridge shutter according to claim 1, wherein the cartridge shutter is located above the cartridge frame when the process cartridge is mounted at the mounting position of the electrophotographic image forming apparatus main body and is located at the open position. Item 4. The process cartridge according to Item 3. 5. The processing means is at least one of a charging means for charging the electrophotographic photosensitive member and a cleaning means for removing a developer remaining on the electrophotographic photosensitive member. The process cartridge according to claim 1, wherein: 6. An electrophotographic image forming apparatus for detachably attaching a process cartridge to form an image on a recording medium, comprising: a) an electrophotographic photosensitive member; a process means acting on the electrophotographic photosensitive member; A cartridge frame for supporting the photoreceptor and the process means; a closed position covering an exposed portion of the electrophotographic photoreceptor exposed from an opening of the cartridge frame; A cartridge shutter that can take an open position that exposes a part of the electrophotographic photoreceptor from the opening, and A first portion located, a second portion located upstream, the first portion and the second And a sheet member provided at an upstream end of the second portion, the first portion,
Mounting means for removably mounting a process cartridge covering the exposed portion of the electrophotographic photosensitive member with the second portion and the sheet member; and b) formed on the electrophotographic photosensitive member. An electrophotographic image forming apparatus, comprising: developing means for developing an electrostatic latent image; and c) conveying means for conveying the recording medium. 7. An electrophotographic image forming apparatus for detachably attaching a process cartridge and forming an image on a recording medium, comprising: a) an electrophotographic photosensitive member; a process means acting on the electrophotographic photosensitive member; A cartridge frame for supporting the photoreceptor and the process means; a closed position covering an exposed portion of the electrophotographic photoreceptor exposed from an opening of the cartridge frame; A cartridge shutter that can take an open position that exposes a part of the electrophotographic photoreceptor from the opening, and A first portion located, a second portion located upstream, the first portion and the second And a sheet member having one end attached to the upstream end of the second portion and the other end attached to the cartridge frame, Mounting means for removably mounting a process cartridge covering the exposed portion of the electrophotographic photosensitive member with the first portion, the second portion, and the sheet member; b) the electrophotographic photosensitive member An electrophotographic image forming apparatus, comprising: developing means for developing an electrostatic latent image formed on a body; and c) conveying means for conveying the recording medium.