JP2000019800A - Process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the surface of a photoreceptor drum from being flawed by impact in a packed state by holding a sheet-like protective member between the photoreceptor drum and spacer rollers. SOLUTION: A photoreceptor drum 7 and a developing roller are opposed with a constant space by pressing spacer rollers 9i larger in diameter than the developing roller, to the photoreceptor drum 7 at both longitudinal ends of the developing roller. One rectangular cushioning protective sheet 40 is inserted from a contact part between one spacer roller 9i and the photoreceptor drum 7 to a contact part between the other spacer roller 9i and the photoreceptor drum 7. The cushioning protective sheet 40 is provided to cover the photoreceptor drum 7 part between the spacer rollers 9i on the cleaning unit C side from above a drum shutter member 18 so as to prevent the photoreceptor drum 7 and the center part of the developing roller from coming in flexural contact at the time of vibration or falling to flaw the photoreceptor drum 7 and to prevent the spacer rollers 9i from applying impact to the photoreceptor drum 7 to flaw the surface of the photoreceptor drum 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process cartridge detachable from a main body of an electrophotographic image forming apparatus for forming an image on a recording medium by using an electrophotographic method.

Here, an electrophotographic image forming apparatus forms an image on a recording medium by using an electrophotographic image forming process. For example, an electrophotographic copying machine, an electrophotographic printer (for example, an LED printer, a laser, etc.) -Beam printer-
Etc.), an electrophotographic facsimile machine, and an electrophotographic word processor.
Processor and the like.

As a process cartridge, a charging means, a developing means or a cleaning means and an electrophotographic photosensitive member are integrally made into a cartridge, and this cartridge is attached to and detached from an electrophotographic image forming apparatus main body. It is possible. In addition, at least one of the charging means, the developing means, and the cleaning means and the electrophotographic photosensitive member are integrally made into a cartridge so as to be detachable from the main body of the electrophotographic image forming apparatus. Further, it means that at least the developing means and the electrophotographic photosensitive member are integrally formed into a cartridge so as to be detachable from the electrophotographic image forming apparatus main body.

[0004]

2. Description of the Related Art In an image forming apparatus using an electrophotographic image forming process, an electrophotographic photosensitive member and process means acting on the electrophotographic photosensitive member are integrally formed into a cartridge, and this cartridge is used as an image forming apparatus. A process cartridge that can be attached to and detached from the 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 usability is remarkably improved. A typical configuration of such a process cartridge is one in which two frames are connected. For example, a fulcrum around a cleaning frame supporting a photosensitive drum, a charger and a cleaning device, and a frame formed by joining a developing frame supporting a developing means and a toner frame having a toner chamber. Rotatably coupled to Then, the relative positions of the photosensitive drum and the developing means are determined by urging the two frame members around the fulcrum by an elastic member such as a spring. A spacer is rotatably provided on the developing roller in order to keep a minute interval between the surface of the photosensitive drum and the surface of the developing roller constant. Process car having such a configuration
In the cartridge, a polyethylene sheet of about 100 μm is provided at the center at a very small interval between the photosensitive drum and the developing roller in order to prevent the photosensitive drum and the developing roller from coming into contact with each other due to an impact in a packed state. I was

As another means, a spacer member made of a material such as polypropylene is sandwiched between both ends of the cleaning frame and the developing frame.

[0006]

SUMMARY OF THE INVENTION The present invention is a further development of the prior art, and the present invention relates to an increase in toner capacity between a photosensitive drum surface and a space die due to an impact in a packed state due to an increase in toner capacity. The surface of the photosensitive drum is not scratched and does not appear as a defective image.
It is an object of the present invention to provide a packaged process cartridge in which when a spacer member or the like is sandwiched between both ends of a roller, the member is not inserted into the image forming apparatus without removing the member.

[0007]

Means for Solving the Problems The following is a description of typical inventions of the present invention by attaching the numbers corresponding to the claims.

According to a first aspect of the present invention, there is provided an electrophotographic photosensitive drum, and a space roller which is in pressure contact with the electrophotographic photosensitive drum in a process cartridge which is detachable from a main body of an image forming apparatus and is transported or stored. And a seal having a length substantially covering the entire length of the electrophotographic photosensitive drum and the developing roller, and being sandwiched between the space roll and the electrophotographic photosensitive drum. And a protection member in a shape of a circle.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below. In the following description, the short direction of the process cartridge B is
This is the direction in which the process cartridge B is attached to and detached from the apparatus main body 14, and coincides with the transport direction of the recording medium. The longitudinal direction of the process cartridge B is a direction (substantially orthogonal) that intersects (substantially orthogonal) the direction in which the process cartridge B is attached to and detached from the apparatus main body 14, and intersects (substantially orthogonal) the recording medium conveyance direction. ing.

FIG. 1 is an explanatory view of the configuration of an electrophotographic image forming apparatus (laser beam printer) to which an embodiment of the present invention is applied, and FIG. 2 is an external perspective view thereof. 3 to 5 are drawings related to a process cartridge to which the embodiment of the present invention is applied. FIG. 3 is a side sectional view of the process cartridge, FIG. 4 is an external perspective view schematically showing the external appearance, and FIG. 5 is an external perspective view in which the cleaning unit and the developing unit are separated.

(Electrophotographic Image Forming Apparatus A and Process Cartridge B) First, referring to FIGS. 1 and 2, a laser beam as an electrophotographic image forming apparatus to which an embodiment of the present invention is applied will be described. The printer A will be described. FIG. 3 is a side sectional view of the process cartridge B.

As shown in FIG. 1, the laser beam printer A forms an image on a recording medium (for example, recording paper, OHP sheet, cloth, etc.) by an electrophotographic image forming process. It is. Then, a toner image is formed on a drum-shaped electrophotographic photosensitive member (hereinafter, referred to as a photosensitive drum).
Specifically, the photosensitive drum is charged by the charging means, and then the photosensitive drum is irradiated with laser light from the optical means in accordance with the image information to form a latent image on the photosensitive drum according to the image information. I do. The latent image is developed by a developing means to form a toner image.

In synchronization with the formation of the toner image, the recording medium 2 set in the sheet feeding cassette 3a is picked up by a pickup roller 3b, transport roller pairs 3c and 3d and a registration roller.
It is reversed and transported by the pair 3e. Next, the toner image formed on the photosensitive drum of the process cartridge B is transferred to the recording medium 2 by applying a voltage to a transfer roller 4 as a transfer unit. Thereafter, the recording medium 2 to which the toner image has been transferred is conveyed to the fixing unit 5 by the conveyance guide 3f. The fixing means 5 includes a driving roller 5c and a heater 5a.
Is provided in the fixing roller 5b. Then, the transferred toner image is fixed by applying heat and pressure to the recording medium 2 passing therethrough. Then, the recording medium 2 is discharged with a discharge roller pair 3g,
The sheet is conveyed by 3h and 3i and discharged to the discharge tray 6 through the reversing path 3j.

The discharge tray 6 is provided on the upper surface of the apparatus main body 14 of the image forming apparatus A. It is also possible to operate the swingable flapper 3k and discharge the recording medium 2 by the discharge roller pair 3m without passing through the reversing path 3j.

In the present embodiment, the pickup roller 3b, the transport roller pair 3c, 3d, the registration roller
Roller pair 3e, transport guide 3f, discharge roller pair 3g, 3h,
The conveying means 3 is constituted by 3i and a discharge roller pair 3m.

On the other hand, as shown in FIG. 3, the process cartridge B rotates a photosensitive drum 7 having a photosensitive layer and changes its surface by applying a voltage to a charging roller 8 as charging means. Charge. Next, laser beam light corresponding to the image information from the optical system 1 is applied to the photosensitive drum 7 through the exposure opening 1e to form a latent image. The latent image is developed by developing means 9 using toner.
That is, the charging roller 8 is provided in contact with the photosensitive drum 7 and charges the photosensitive drum 7. The charging roller 8 is driven and rotated by the photosensitive drum 7. The developing means 9 transfers toner to a developing area of the photosensitive drum 7.
To develop the latent image formed on the photosensitive drum 7. The optical system 1 has a laser diode 1a, a polygon mirror-1b, a lens 1c, and a reflection mirror-1d.

Here, the developing means 9 includes the toner container 1
The toner in 1A is turned by the rotation of the toner feeding member 9b.
It is sent to the developing roller 9c. Then, the developing roller 9c containing the fixed magnet 9g is rotated, and the developing blade 9c is rotated.
The toner layer provided with the triboelectric charge by the contact 9d is formed on the surface of the developing roller 9c, and the toner is supplied to the developing area of the photosensitive drum 7. Then, the toner is transferred to the photosensitive drum 7 in accordance with the latent image, thereby forming a toner image and visualizing the toner image. Here, the development blade 9
d specifies the toner amount on the peripheral surface of the developing roller 9c. In the vicinity of the developing roller 9c, toner stirring members 9e and 9f for circulating toner in the developing chamber are rotatably mounted.

After applying a voltage having a polarity opposite to that of the toner image to the transfer roller 4 to transfer the toner image formed on the photosensitive drum 7 to the recording medium 2, the cleaning means 1 is used.
By 0, the residual toner on the photosensitive drum 7 is removed.
Here, the cleaning means 10 scrapes off the toner remaining on the photosensitive drum 7 by means of an elastic cleaning blade 10a provided in contact with the photosensitive drum 7, and collects it in a waste toner reservoir 10b.

The process cartridge B includes a toner frame 11 having a container (toner storage section) 11A for storing toner and a developing frame 12 for holding developing means 9 such as a developing roller 9c. And And the photosensitive drum 7,
Cleaning means 10 such as a cleaning blade 10a
In addition, the cleaning frame 13 to which the charging roller 8 is attached is connected. The process cartridge B is detachable from the apparatus main body 14 by an operator.

The process cartridge B has an exposure opening 1e for irradiating the photosensitive drum 7 with light corresponding to image information and a transfer opening 13n for facing the photosensitive drum 7 to the recording medium 2. It is provided. More specifically, the exposure opening 1e is provided in the cleaning frame 13, and the transfer opening 13n is formed between the developing frame 12 and the cleaning frame 13.

Next, the configuration of the housing of the process cartridge B according to this embodiment will be described.

The process cartridge B shown in this embodiment has a housing in which a toner frame 11 and a developing frame 12 are connected, and a cleaning frame 13 is rotatably connected thereto. The photosensitive drum 7, the charging roller 8, the developing means 9 and the cleaning means 10 are housed therein to form a cartridge. Then, the process cartridge B is detachably attached to a cartridge attaching means provided on the apparatus main body 14.

In the process cartridge B according to the present embodiment, the toner frame 11, the developing frame 12, and the cleaning frame 13 are combined to form a housing as described above. The configuration will be described below.

As shown in FIG. 3, a toner feeding member 9b is rotatably mounted on the toner frame 11. Further, a developing roller 9c and a developing blade 9d are attached to the developing frame 12, and stirring members 9e and 9f for circulating toner in the developing chamber are rotatable near the developing roller 9c. Attached. Further, an antenna rod 9h is attached substantially in parallel with the developing roller 9c so as to face the longitudinal direction of the developing roller 9c. The toner frame 11 and the developing frame 12 are welded (in this embodiment, ultrasonic welding) to form a developing unit D (see FIG. 5B) as an integrated second frame. I have.

Each member of the photosensitive drum 7, the charging roller 8, and the cleaning means 10 is attached to the cleaning frame 13. Further, when the process cartridge B is detached from the apparatus main body 14, the photosensitive drum 7 is covered, and a drum shutter member 18 for protecting the photosensitive drum 7 from exposure to light for a long time or contact with foreign matter is attached to the first frame. Cleaning unit (drum unit)
C (see FIG. 5A).

Then, the developing unit D and the clear
The process cartridge B is constituted by connecting the rotating units C to each other by a connecting member 22 so as to be rotatable. That is, as shown in FIG. 5, the arc formed on both sides in the longitudinal direction of the developing frame 12 (the axial direction of the developing roller 9c).
A rotation shaft 20 is provided at the tip of the memory portion 19.
(B)). On the other hand, concave portions 21 for positioning and locking the rotation shaft 20 are provided at two places on both sides in the longitudinal direction of the cleaning frame 13 (see FIG. 5A). The arm 19 is inserted into the recess 21, and the connecting member 22 is cleared.
By attaching the developing unit D and the cleaning unit C to the cleaning frame 13, the developing unit D and the cleaning unit C are rotatably coupled about the pivot shaft 20 restricted by the coupling member 22. At this time, the developing roller 9c is reliably pressed against the photosensitive drum 7 by urging the developing frame 12 downward by a compression coil spring 22a contracted between the developing frame 12 and the cleaning frame 13. Therefore, by attaching a space roller 9i having a diameter larger than that of the development roller 9c to both ends in the longitudinal direction of the development roller 9c, the space roller 9i is moved to the photosensitive drum 7
, The photosensitive drum 7 and the developing roller 9c face each other at a constant interval (about 300 μm). Therefore, the developing unit D and the cleaning unit C are rotatable about the rotary shaft 20. Therefore,
The positional relationship between the peripheral surface of the photosensitive drum 7 and the peripheral surface of the developing roller 9c can be maintained by the elastic force of the compression coil spring 22a.

The new process car constructed as described above
In the cartridge B, a toner container 11A is filled with toner, and an opening 11i of the toner container 11A facing the developing frame 12 can be removed from the outside of the process cartridge B by a toner seal 11j ( (See FIG. 7). Further, a sheet 40 is interposed between the photosensitive drum 7 and the developing roller 12 as described later.

The drum shutter member 18 has a four-bar linkage mechanism in which the drum shutter member 18 is used as one of the links, the process cartridge B is used as another link, and these are connected by two links. When the opening / closing member 35 is opened centering on the hinge 35a in FIG. 1, the cartridge mounting portion (the process cartridge B is already mounted in FIG. 1) in the apparatus main body 14 can be seen. Then, when the operator inserts the process cartridge B in the direction of arrow X while holding the periphery of the concave portion 17 of the process cartridge B by hand, the process cartridge is inserted into the guide members provided on the left and right walls of the cartridge mounting portion. The guides at both ends in the longitudinal direction of the cartridge B are engaged and mounted as shown in FIG. When the process cartridge B is mounted on the cartridge mounting portion, the link supporting the drum shutter member 18 is prevented from entering the cartridge mounting portion, and the drum shutter member 18 is moved to the toner frame 11. It moves downward to open the transfer opening 13n. Here, when the opening / closing member 35 is closed, an image can be formed. Removal of the process cartridge B from the apparatus main body 14 is the reverse of the above.

(Package state of process cartridge) FIG. 6
As shown in the figure, the process cartridge B is sealed in a polyethylene bag (not shown) in a sealed state.
The process cartridge is packaged by covering the longitudinal ends of the process cartridge with a cushioning material 41 such as a mold.

In the packing state before using the process cartridge B, as shown in FIGS. 7 and 8, the developing unit D and the cleaning unit C are provided at both ends in the longitudinal direction of the developing roller 9c. By pressing a space roll 9i having a diameter larger than that of the drum 9c against the photosensitive drum 7, the photosensitive drum 7 and the developing roller 9c are opposed to each other at a constant interval (about 300 μm). After the process cartridge B is manufactured and used until it is used, the space between the one space roller 9i and the photosensitive drum 7 is removed from the other space.
A rectangular cushioning prevention sheet 40 is sandwiched between the contact portion between the sash 9i and the photosensitive drum 7. Buffer prevention sheath
As shown in FIG. 8, the photosensitive drum 7 between the space rollers 9i on the cleaning unit C side is provided to cover the drum shutter member 18 from above. This prevents the photosensitive drum 7 from being damaged due to flexing contact between the photosensitive drum 7 and the central portion of the developing roller 9c when vibrating or falling, and also causes the space drum 9i to impact the photosensitive drum 7 To prevent the surface of the photosensitive drum 7 from being damaged. The material of the buffer prevention sheet 40 in this embodiment is a polyethylene sheet having a thickness of about 200 μm.
When using the process cartridge B, the packing material 41 is removed and taken out of the polyethylene bag. By pulling out the central portion of the buffer prevention sheet 40 in the direction of arrow Y in FIG. 8, the photosensitive drum 7 and the developing roller 9c can be kept at a constant distance via the space roller 9i.

As shown in FIG. 9, the shape of the cushioning prevention sheet is as shown in FIG. 9 where the space rollers at both ends are in contact with the photosensitive drum, and the developing roller and the vicinity of the longitudinal center of the photosensitive drum are vibrated or dropped. A comb may be used to protect the surface of the photoreceptor drum 7 that may be damaged during impact.

[0032]

As described above, according to the present invention, 1
By inserting a sheet of anti-buffer sheets between the electrophotographic photosensitive drum and the space where the electrophotographic photosensitive drum contacts, and between the electrophotographic photosensitive drum and the development roller, the electrophotographic photosensitive member can be used in the event of an impact in a packed state. Scratches at the space contact portion on the drum and bending of the electrophotographic photosensitive drum and the central portion of the developing roller can be prevented from contacting and damaging. In addition, since one sheet-like protective member protects the entire length of the electrophotographic photosensitive drum, the sheet can be pulled out only by holding the central portion once. Is also possible. Since the protective member is exposed to the outside even in the central portion of the developing roller, there is no danger that the protective member will not be removed in spite of the existence of the protective member.

[Brief description of the drawings]

FIG. 1 is a side sectional view of an electrophotographic image forming apparatus to which an embodiment of the present invention is applied.

FIG. 2 is an external perspective view of the apparatus shown in FIG.

FIG. 3 is a process card to which an embodiment of the present invention is applied;
FIG. 4 is a side sectional view of the cartridge.

FIG. 4 is a schematic external perspective view of the process cartridge shown in FIG.

FIG. 5A is an external perspective view of a cleaning unit of the process cartridge shown in FIG. FIG. 4B is an external perspective view of the developing unit of the process cartridge shown in FIG.

FIG. 6 is an external perspective view of the process cartridge in a packaged state.

FIG. 7 is a longitudinal sectional view of a process cartridge.

FIG. 8 is an external front view of the cleaning unit of the process cartridge as viewed from the developing unit side.

FIG. 9 is an external front view of a cleaning unit of a process cartridge according to a second embodiment of the present invention as viewed from a developing unit side.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Optical system 1a ... Laser diode 1b ... Polygon mirror 1c ... Lens 1d ... Reflection mirror 1e ... Exposure opening 2 ... Recording medium 3 ... Conveying means 3a ... Cassette 3b ... Pickup roller 3c ... Transfer Roller Pair 3d ... Transport Roller Pair 3e
… Registration roller pair 3f… Transport guide 3g, 3h,
3i: discharge roller pair 3j: reversing path 3k: flapper 3m: discharge roller pair 4: transfer roller 5: fixing means 5a: heater 5b: fixing roller 5c
... Driving roller 6 ... Discharge tray 7 ... Photoreceptor drum 8 ... Charging roller 9 ... Developing means 9b ... Toner feeding member 9c ... Developing roller
La 9d: Development blade 9e, 9f: Toner stirring member 9g: Fixed magnet 9h: Antenna rod 9i: Spacing device 10: Cleaning means 10a: Elastic cleaning blade 10b: Toner reservoir 11: Toner -Frame 11A-Toner container 11i-Opening 11j-Toner seal 12-Developing frame 13-Cleaning frame 14-Image forming apparatus main body 18-Drum shutter member 20-Rotating shaft 22-Coupling Member 22a: Compression coil spring 35: Opening / closing member 35a: Hinge 40: Buffer prevention sheet 41: Packing member A: Laser beam printer B: Process cartridge C: Cleaning unit D: Development unit

Continuation of the front page (72) Inventor Yo Suzuki 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 2H071 BA04 BA13 BA22 DA06 DA08 DA13 DA15 EA02

Claims (10)

[Claims] 1. A process cartridge which is detachable from a main body of an image forming apparatus and which is transported or stored, comprising: an electrophotographic photosensitive drum; and a developing roller having at both ends a space roll which is in pressure contact with said electrophotographic photosensitive drum. A sheet-like protection member having a length substantially corresponding to the entire length of the electrophotographic photosensitive drum and the developing roller, and being sandwiched between the space roll and the electrophotographic photosensitive drum. A process cartridge comprising: 2. The protection member according to claim 1, wherein the protection member is a sheet member of polyethylene resin having a thickness of about 200 μm.
4. The process cartridge described in 1. above. 3. The process cartridge according to claim 1, wherein an intermediate portion of the protective member is exposed outside the process cartridge in a longitudinal direction of the developing roller. 4. The process cartridge according to claim 1, wherein the protection sheet is rectangular. 5. The process cartridge according to claim 1, wherein the protection sheet is comb-shaped. 6. The process cartridge includes a charging unit or a cleaning unit, a developing unit, and an electrophotographic photosensitive drum which are integrally formed into a cartridge, and the cartridge is attached to an image forming apparatus main body. 6. The process cartridge according to claim 1, wherein the process cartridge is detachable from the process cartridge. 7. The process cartridge is configured such that at least one of a charging unit and a cleaning unit, a developing unit and an electrophotographic photosensitive drum are integrally formed as a cartridge and can be attached to and detached from an image forming apparatus main body. The process cartridge according to any one of claims 1 to 5, wherein 8. The process cartridge according to any one of claims 1 to 5, wherein the developing means and the electrophotographic photosensitive drum are integrally formed into a cartridge so as to be detachable from an image forming apparatus main body. The described process cartridge. 9. The developing means includes: a developing frame having a developing roller and a developing blade; and a toner forming a toner container.
9. The process cartridge according to claim 6, wherein the frames are integrally connected. 10. The process cartridge comprises a drum unit having a charging means or a cleaning means, an electrophotographic photosensitive drum, and a developing unit having a developing member and a toner rotatably connected thereto. 10. The process car according to claim 1, further comprising an elastic member for pressing the body drum and the developing member into contact with each other.
Tridge.