Process cartridge remanufacturing method Number:6,763,209 from the United States Patent and Trademark Office (PTO) owispatent A remanufacturing method for a process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, includes (a) a frame separating step of separating the first frame and the second frame from each other; (b) a developing blade dismounting step of dismounting, from the second frame, a developing blade which is mounted on the second frame to regulate an amount of the developer deposited on the developing roller; (c) a thin plate sheet material mounting step of mounting a thin sheet material on such a side of a longitudinal seal for providing a seal extended between the first frame and the second frame in a longitudinal direction of the second frame as is opposite from a side mounted to the second frame; (d) a developer filling step of filling the developer into the developer accommodating portion; (e) a developing blade mounting step of mounting the developing blade in a facing orientation which is opposite from a facing orientation in which the developing blade has been mounted on the second frame; and (f) a frame coupling step of coupling the separated first frame and second frame.<H remanufacturing, cartridge, Process, cartrid, 6763209.html, Patent, pto, 6763209

Title: Process cartridge remanufacturing method

Abstract: A remanufacturing method for a process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, includes (a) a frame separating step of separating the first frame and the second frame from each other; (b) a developing blade dismounting step of dismounting, from the second frame, a developing blade which is mounted on the second frame to regulate an amount of the developer deposited on the developing roller; (c) a thin plate sheet material mounting step of mounting a thin sheet material on such a side of a longitudinal seal for providing a seal extended between the first frame and the second frame in a longitudinal direction of the second frame as is opposite from a side mounted to the second frame; (d) a developer filling step of filling the developer into the developer accommodating portion; (e) a developing blade mounting step of mounting the developing blade in a facing orientation which is opposite from a facing orientation in which the developing blade has been mounted on the second frame; and (f) a frame coupling step of coupling the separated first frame and second frame.

Patent Number: 6,763,209 Issued on 07/13/2004 to Higeta, et al.

Inventors: Higeta; Akira (Shizuoka-ken, JP), Yasuda; Satoshi (Toride, JP), Hoshi; Takayoshi (Toride, JP)
Assignee: Canon Kabushiki Kaisha (Tokyo, JP)

Appl. No.: 10/283,287

Filed: October 30, 2002

Foreign Application Priority Data


Oct 31, 2001 [JP]			2001-334405

Current U.S. Class: 399/109 ; 399/111; 399/113

Current International Class: G03G 21/18 (20060101)

Field of Search: 399/109,111,113,103,105,106,114,119,274,284

References Cited [Referenced By]

U.S. Patent Documents


5485249	January 1996	Higeta et al.
5740499	April 1998	Higeta et al.
5809374	September 1998	Tsuda et al.
6029031	February 2000	Yokomori et al.
6101348	August 2000	Nonaka et al.
6397025	May 2002	Higeta et al.
6400914	June 2002	Noda et al.
6473577	October 2002	Higeta et al.
6519430	February 2003	Higeta et al.

Primary Examiner: Ngo; Hoang
Attorney, Agent or Firm: Fitzpatrick, Cella, Harper & Scinto

Claims

What is claimed is:

1. A remanufacturing method for a process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, the process cartridge including a first frame supporting an electrophotographic photosensitive drum and a second frame supporting a developing roller for developing an electrostatic latent image formed on the electrophotographic photosensitive drum and accommodating developer to be used by the developing roller to develop the electrostatic latent image, the first frame and the second frame being rotatably coupled, the method comprising: (a) a frame separating step of separating the first frame and the second frame, from each other; (b) a developing blade dismounting step of dismounting, from the second frame, a developing blade which is mounted on the second frame to regulate an amount of the developer deposited on the developing roller; (c) a thin plate sheet material mounting step of mounting a thin sheet material on such a side of a longitudinal seal, for providing a seal extending between the first frame and the second frame in a longitudinal direction of the second frame, that is opposite from a side mounted to the second frame; (d) a developer filling step of filling the developer into a developer accommodating portion of the process cartridge; (e) a developing blade mounting step of mounting the developing blade in a facing orientation which is opposite from a facing orientation in which the developing blade has been mounted on the second frame; and (f) a frame coupling step of coupling the separated first frame and second frame.

2. A method according to claim 1, further comprising a developing roller dismounting step of dismounting the developing roller from the second frame prior to said developing blade dismounting step, and a developing roller mounting step of mounting the developing roller to the second frame prior to said frame coupling step and after said developing blade mounting step.

3. A remanufacturing method for a process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, the process cartridge including a first frame supporting an electrophotographic photosensitive drum and a second frame supporting a developing roller for developing an electrostatic latent image formed on the electrophotographic photosensitive drum and accommodating developer to be used by the developing roller to develop the electrostatic latent image, the first frame and second frame being rotatably coupled, said method comprising: (a) a frame separating step of separating the first frame and the second frame from each other; (b) a developing roller dismounting step of dismounting the developing roller mounted on the second frame; (c) an elastic sealing member dismounting step of dismounting a thin elastic sealing member providing a seal extending between the second frame and the developing roller in a longitudinal direction of the second frame; (d) a reinforcing member mounting step of mounting a reinforcing member adjacent a portion of the second frame on which the elastic sealing member is mounted so as to extend in a longitudinal direction of the second frame, the reinforcing member being effective to reinforce the portion; (e) an end assistance seal mounting step of mounting a second auxiliary end seal for the developing roller so as to enclose a part of a first auxiliary end seal for the developing roller which is mounted to be covered by the thin elastic sealing member inside a developing roller end seal provided at each of the end portions of the developing roller mounted to the second frame; (f) an elastic sealing member mounting step of mounting the thin elastic sealing member; (g) a developer filling step of filling the developer into a developer accommodating portion of the process cartridge; (h) a developing roller mounting step of mounting the developing roller to the second frame; and (I) a frame coupling step of coupling the separated first frame and second frame.

4. A method according to claim 3, further comprising: a developing blade dismounting step of dismounting a developing blade from the second frame immediately after said developing roller dismounting step; and a developing blade mounting step of mounting the developing blade on the second frame prior to said developing roller mounting step.

5. A remanufacturing method for a process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, the process cartridge including a first frame supporting an electrophotographic photosensitive drum and a second frame supporting a developing roller for developing an electrostatic latent image formed on the electrophotographic photosensitive drum and accommodating developer to be used by the developing roller to develop the electrostatic latent image, the first frame and the second frame being rotatably coupled, said method comprising: (a) a frame separating step of separating the first frame and the second frame from each other; (b) a developing roller dismounting step of dismounting the developing roller mounted on the second frame; (c) a developing blade dismounting step of dismounting, from the second frame, a developing blade which is mounted on the second frame to regulate an amount of the developer deposited on the developing roller; (d) an elastic sealing member dismounting step of dismounting a thin elastic sealing member providing a seal extending between the second frame and the developing roller in a longitudinal direction of the second frame; (e) a thin plate sheet material mounting step of mounting a thin sheet material on such a side of a longitudinal seal, for providing a seal extending between the first frame and the second frame in a longitudinal direction of the second frame, that is opposite from a side mounted to the second frame; (f) a reinforcing member mounting step of mounting a reinforcing member adjacent a portion of the second frame on which the elastic sealing member is mounted so as to extend in a longitudinal direction of the second frame, the reinforcing member being effective to reinforce the portion; (g) an end assistance seal mounting step of mounting a second auxiliary end seal for the developing roller so as to enclose a part of a first auxiliary end seal for the developing roller which is mounted to be covered by the thin elastic sealing member inside a developing roller end seal provided at each of the end portions of the developing roller mounted to the second frame; (h) an elastic sealing member mounting step of mounting the thin elastic sealing member; (i) a developer filling step of filling a developer into a developer accommodating portion of the process cartridge; (j) a developing blade mounting step of mounting the developing blade in a facing orientation which is opposite from a facing orientation in which the developing blade has been mounted on the second frame; (k) a developing roller mounting step of mounting the developing roller on the second frame; and (l) a frame coupling step of coupling the separated first frame and second frame.

6. A method according to claim 1, 2 or 5, wherein a width of the thin sheet material is larger than a width of the longitudinal seal of the developing blade and protrudes toward the developing roller.

7. A method according to any one of claims 3-5, wherein the reinforcing member has an L-shaped cross-section.

8. A method according to any one of claims 3-5, wherein the second auxiliary end seal is made of an elastic material and has an L-shaped cross-section.

9. A method according to any one of claims 3-5, wherein the elastic sealing member mounted in said elastic sealing member mounting step has a width larger than a width of the elastic sealing member that was mounted to the process cartridge.

10. A method according to any one of claims 3-5, wherein the second auxiliary end seal extends between the second frame and the reinforcing member.

11. A method according to claim 1, 2, or 5, wherein the thin sheet material is mounted by means of a double coated adhesive tape.

12. A method according to any one of claims 3-5, wherein at least one of the reinforcing member, the second auxiliary end seal, and the thin elastic sealing member is mounted by means of a double coated adhesive tape.

13. A method according to claim 1, 2, 4 or 5, wherein the developing blade mounted on the second frame in said developing blade mounting step is that removed from the second frame of the process cartridge or a developing blade dismounted from another process cartridge.

14. A method according to any one of claims 2-5, wherein the developing roller mounted to the second frame in said developing roller mounting step is that dismounted from the second frame of the process cartridge or a developing roller dismounted from another process cartridge.

15. A method according to claim 1, 2, 4, or 5, wherein the developing blade includes a silicone rubber plate and a metal plate member integral therewith and extends in the longitudinal direction thereof at one lateral end thereof, and the developing blade is mounted on the second frame by screws.

16. A method according to claim 1, 2, 4, or 5, wherein a positioning reference in a longitudinal direction of the developing blade relative to the second frame before said developing blade dismounting step is provided at one longitudinal end portion of the process cartridge and a positioning reference in the longitudinal direction of the developing blade relative to the second frame in said developing blade dismounting step is provided at the other longitudinal end portion of the process cartridge.

17. A method according to any one of claims 1-5, wherein a combination of the first frame and the second frame coupled in said frame coupling step is a combination of the first frame and the second frame of the process cartridge or one of random combinations of first frames and second frames separated out of a plurality of process cartridges.

18. A method according to any one of claims 1-5, further comprising a step of dismounting, prior to said frame coupling step, the electrophotographic photosensitive drum and a cleaning blade for removing the developer remaining on the electrophotographic photosensitive drum, from the first frame, and a step of removing from the first frame a developer removed by the cleaning blade from the electrophotographic photosensitive drum.

19. A method according to any one of claims 1-5, wherein the electrophotographic photosensitive drum is replaced with a new electrophotographic photosensitive drum, or the electrophotographic photosensitive drum is reused, wherein the developing roller is replaced with a new developing roller, or the developing roller is reused, wherein a cleaning blade for removing the developer remaining on the electrophotographic photosensitive drum is replaced with a new cleaning blade, or the cleaning blade is reused.

20. A method according to claim 19, wherein the reused electrophotographic photosensitive drum is that dismounted from the first frame of the process cartridge, or an electrophotographic photosensitive drum dismounted from a first frame of another process cartridge.

21. A method according to claim 19, wherein the reused developing roller is that dismounted from the second frame of the process cartridge, or a developing roller dismounted from a second frame of another process cartridge.

22. A method according to claim 19, wherein the reused cleaning blade is that dismounted from the first frame of the process cartridge, or a cleaning blade dismounted from a first frame of another process cartridge.

23. A method according to any one of claims 1-5, wherein in said developer filling step, the developer is filled through a developer supply opening for supplying the developer to the developing roller from the developer accommodating portion.

24. A method according to any one of claims 1-5, wherein said method is carried out with a sealing member for sealing a developer supply opening being in a pulled out position to supply the developer from the developer accommodating portion to the developing roller.

Description

FIELD OF THE INVENTION

The present invention relates to a process cartridge remanufacturing method. Here, a process cartridge is a cartridge in which a charging means, a developing or cleaning means, and an electrophotographic photoconductive member are integrally disposed, and which is removably mountable in the main assembly of an image forming apparatus. A process cartridge also is a cartridge in which at least one means among a charging means, a developing, or a cleaning means, and an image bearing member are integrally disposed, and which is removably mountable in the main assembly of an image forming apparatus, as well as a cartridge in which at least a developing means and an electrophotographic photoconductive member are integrally disposed, and which is removably mountable in the main assembly of an image forming apparatus.

An image forming apparatus means is an apparatus such as an electrophotographic copying machine, an electrophotographic printer (LED printer, laser beam printer, etc.), an electrophotographic facsimile machine, an electrophotographic word processor, etc.

In the field of an image forming apparatus employing an electrophotographic image formation process, a process cartridge system has been widely in use. According to a process cartridge system, a single or plurality of processing means, which act on the aforementioned electrophotographic photoconductive member, are integrally disposed in a cartridge which is removably mountable in the image assembly of an image forming apparatus, making it possible for an ordinary user to maintain an image forming apparatus without calling on a service person. Thus, the employment of a process cartridge system dramatically improves the operational efficiency of an image forming apparatus. Therefore, a process cartridge system is widely used in the field of an image forming apparatus.

A process cartridge uses developer in order to form an image on recording medium; it consumes the developer therein as it forms images. Eventually, the amount of the developer in a process cartridge will be reduced by the consumption to a level, below which the process cartridge fails to form an image satisfactory in quality to the user who bought the process cartridge. At this point, this process cartridge loses its value as a merchandise.

SUMMARY OF THE INVENTION

There has long been a desire for a simple process cartridge remanufacturing method capable of restoring the commercial value of a used process cartridge, more specifically, a process cartridge which has lost its commercial value due to the consumption of the developer therein.

The primary object of the present invention is to provide a simple process cartridge remanufacturing method.

Another object of the present invention is to provide a process cartridge remanufacturing method capable of restoring the market value of a used process cartridge, that is, a process cartridge which has lost its commercial value due to the consumption of the developer therein to a level, below which the process cartridge fails to form an image satisfactory in quality to the user of the cartridge.

According to one of the characteristic aspects of the present invention, the present invention relates to a method for remanufacturing a process cartridge which is removably mountable in the main assembly of an electrophotographic image forming apparatus, and which comprises: a first frame for supporting an electrophotographic photoconductive drum; and a second frame which is for supporting a development roller for developing an electrostatic latent image formed on the electrophotographic photoconductive drum and has a developer storage portion for holding the developer used for the development of the electrostatic latent image, and which is connected to the first frame in such a manner that the two frames are pivotally movable about their joint. The method comprises: (a) a frame separating process for separating the first frame from the second frame; (b) a development blade removing process for removing from the second frame, a development blade attached to the second frame to regulate the amount of developer allowed to remain adhered to the development roller; (c) a thin plate attaching process for attaching a piece of a thin plate to a lengthwise seal attached in advance to the second frame to seal between the development blade and second frame, across the surface opposite to the surface by which the lengthwise seal is attached to the second frame; (d) a developer filling process for refilling the developer storage portion with developer; (e) a development blade attaching process for inversely reattaching the removed blade to the second frame in such a manner that the surface of the blade, which was facing the front, will face the rear; and (f) a frame reconnecting process for reconnecting the separated first and second frames to each other.

According to another characteristic aspect of the present invention, the invention relates to a method for remanufacturing a process cartridge which is removably mountable in the main assembly of an electrophotographic image forming apparatus, and which comprises: a first frame for supporting an electrophotographic photoconductive drum; and a second frame which is for supporting a development roller for developing an electrostatic latent image formed on the electrophotographic photoconductive drum and has a developer storage portion for holding the developer used for the development of the electrostatic latent image, and which is connected to the first frame in such a manner that the two frames are pivotally movable about their joint. The method comprises: (a) a frame separating process for separating the first frame from the second frame; (b) a development roller removing process for removing the development roller attached to the second frame; (c) a thin elastic sealing member removing process for removing a thin elastic sealing member attached in advance to the second frame, along one of the lengthwise edges thereof, to seal between the development roller and second frame; (d) a reinforcing member attaching process for attaching a reinforcing member to the second frame, next to the area to which the thin elastic sealing member was attached, along one of the lengthwise edges of the second frame, in order to reinforce the area to which the thin elastic sealing member was attached; (e) a second auxiliary development roller end seal attaching process for attaching second auxiliary development roller end seals to the second frame, inward of development roller end seals attached to the lengthwise ends of the second frame to seal between the development roller and second frame, in a manner to partially surround first auxiliary development roller end seals attached in advance to the second frame, across the areas covered by the thin elastic sealing member; (f) a thin elastic sealing member attaching process for attaching the thin elastic sealing member; (g) a developer filling process for refilling the developer storage portion with developer; (h) a development roller attaching process for reattaching the removed development roller to the second frame; and (i) a frame reconnecting process for reconnecting the separated first and second frames.

According to one of the characteristic aspects of the present invention, the invention relates to a method for remanufacturing a process cartridge which is removably mountable in the main assembly of an electrophotographic image forming apparatus, and which comprises: a first frame for supporting an electrophotographic photoconductive drum; and a second frame which is for supporting a development roller for developing an electrostatic latent image formed on the electrophotographic photoconductive drum and has a developer storage portion for holding the developer used for the development of the electrostatic latent image, and which is connected to the first frame in such a manner that the two frames are pivotally movable about their joint. The method comprises: (a) a frame separating process for separating the first frame from the second frame; (b) a development roller removing process for removing the development roller attached to the second frame; (c) a development blade removing process for removing from the second frame, a development blade attached to the second frame to regulate the amount of developer allowed to remain adhered to the development roller; (d) a thin elastic sealing member removing process for removing a thin elastic sealing member attached in advance to second frame, along one of the lengthwise edges thereof, to seal between the development roller and second frame; (e) a thin plate attaching process for attaching a piece of a thin plate to a lengthwise seal attached in advance to the second frame to seal between the development blade and second frame, across the surface opposite to the surface by which the lengthwise seal is attached to the second frame; (f) a reinforcing member attaching process for attaching a reinforcing member to the second frame, next to the area to which the thin elastic sealing member was attached, along one of the lengthwise edges of the second frame, in order to reinforce the area to which the thin elastic sealing member was attached; (g) a second auxiliary development roller end seal attaching process for attaching second auxiliary development roller end seals to the second frame, inward of development roller end seals attached to the lengthwise ends of the second frame to seal between the development roller and second frame, in a manner to partially surround first auxiliary development roller end seals attached in advance to the second frame, across the areas covered by the thin elastic sealing member; (h) a thin elastic sealing member attaching process for attaching the thin elastic sealing member; (i) a developer filling process for refilling the developer storage portion with developer; (j) a development blade attaching process for inversely reattaching the removed blade to the second frame in such a manner that the surface of the blade, which was facing the front, will face the rear; (k) a development roller attaching process for reattaching the removed development roller to the second frame; and (l) a frame reconnecting process for reconnecting the separated first and second frames.

These and other objects, features, and advantages of the present invention will become more apparent upon consideration of the following description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

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

FIG. 2 is a vertical sectional view of a process cartridge.

FIG. 3 is an external perspective view of the process cartridge in FIG. 2, as seen from diagonally above the lengthwise right end thereof.

FIG. 4 is an external perspective view of the process cartridge in FIG. 2, as seen from diagonally above the lengthwise left end thereof.

FIG. 5 is an external perspective view of the process cartridge in FIG. 2, as seen from diagonally below the lengthwise left end thereof.

FIG. 6 is an external perspective view of the process cartridge mounting portion of the main assembly of the image forming apparatus in FIG. 1.

FIG. 7 is another external perspective view of the process cartridge mounting portion of the main assembly of the image forming apparatus in FIG. 1.

FIG. 8 is a vertical sectional view of the combination of the photoconductive drum and a driving apparatus therefor.

FIG. 9 is a perspective view of the cleaning unit.

FIG. 10 is a perspective view of the development unit.

FIG. 11 is a partially broken perspective view of the development unit.

FIG. 12 is a perspective view of the developing means holder, as seen from the rear side thereof.

FIG. 13 is a side view of the combination of the side walls of the developing means frame and the toner storage frame.

FIG. 14 is a perspective view of the development roller bearing box.

FIG. 15 is a perspective view of the developing means frame.

FIG. 16 is a perspective view of the toner storage frame.

FIG. 17 is another perspective view of the toner storage frame.

FIG. 18 is a vertical section of the toner seal portion shown in FIG. 17 and its adjacencies.

FIG. 19 is a perspective view of the portion of the cleaning means holding frame, to which the photoconductive drum is attached.

FIG. 20 is a vertical sectional view of the drum shaft bearing and its adjacencies.

FIG. 21 is an external side view of the drum shaft bearing, for showing the external shape thereof.

FIG. 22 is a sectional view of the partially disassembled process cartridge, for describing the process for attaching the components which must be attached in this process cartridge remanufacturing method in accordance with the present invention.

FIG. 23 is a top plan view of the partially disassembled process cartridge, for describing the process for attaching the components which must be attached in this process cartridge remanufacturing method in accordance with the present invention.

FIG. 24 is an enlarged top view of a reinforcement member which is not present in a brand-new process cartridge and is attached during this process cartridge remanufacturing method in accordance with the present invention, and its adjacencies, for describing the process for attaching the reinforcement member.

FIG. 25 is an enlarged top view of a second auxiliary development roller end seal which is not present in a brand-new process cartridge and is attached during this process cartridge remanufacturing method in accordance with the present invention, and its adjacencies, for describing the process for attaching the second auxiliary development roller end seal.

FIG. 26 is an enlarged top view of one of the end portions of the thin elastic sealing member, and its adjacencies, for describing the process for reattaching the thin elastic sealing member.

FIG. 27 is a vertical sectional view of the process cartridge for showing the process for refilling the cartridge with toner.

FIG. 28 is a perspective view of the cleaning means holding frame for describing the process for cleaning the cleaning means holding frame.

FIG. 29 is a vertical sectional view of the process cartridge remanufactured using one of the process cartridge remanufacturing methods in accordance with the present invention.

FIG. 30 is an external perspective view of the development blade employed by a process cartridge which can be remanufactured with the use of one of the process cartridge remanufacturing methods in accordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, preferable embodiments of the present invention will be described. In the following descriptions of the embodiments, the widthwise direction of a process cartridge B is the direction in which the process cartridge B is mounted into, or removed from, the main assembly 14 of the image forming apparatus, and coincides with the direction in which recording medium is conveyed. The lengthwise direction of the process cartridge B is the direction perpendicular (approximately perpendicular) to the direction in which the process cartridge B is mounted into, or removed from, the apparatus main assembly 14, being parallel to the top surface of the recording medium and perpendicular (approximately perpendicular) to the direction in which recording medium is conveyed. The left or right of the process cartridge B is the left or right of the process cartridge B as seen from diagonally above the downstream end thereof in terms of the direction in which recording medium is conveyed.

FIG. 1 is a drawing for describing the structure of the electrophotographic image forming apparatus (laser beam printer) in this embodiment of the present invention. FIGS. 2-5 are drawings related to the process cartridge in this embodiment of the present invention. FIG. 2 is a sectional view of the process cartridge, at a plane perpendicular to the lengthwise direction of the process cartridge FIG. 3 is an external perspective view of the process cartridge in FIG. 2, for showing the general appearance thereof. FIG. 4 is a perspective view of the process cartridge in FIG. 2, as seen from diagonally above. FIG. 5 is a perspective view of the inverted process cartridge, as seen from diagonally above. In the following descriptions of the preferred embodiments of the present invention, the top surface of the process cartridge B is the surface which will be positioned at the top of the process cartridge B as the process cartridge B is properly mounted in the apparatus main assembly 14, whereas the bottom surface of the process cartridge B is the surface which will be positioned at the bottom as the process cartridge B is properly mounted in the apparatus main assembly 14.

First, referring to FIG. 1, the laser beam printer A as an electrophotographic image forming apparatus which is compatible with the present invention will be described. This laser beam printer is an apparatus for forming an image on recording medium (for example, recording paper, OHP sheet, fabric, etc.) with the use of an electrophotographic process. An image is formed as follows: First, a toner image, that is, a visible image, is formed on the electrophotographic photoconductive member (which hereinafter will be referred to as a photoconductive drum) in the form of a drum, with the use of developer (which hereinafter will be referred to as toner). More specifically, the photoconductive drum is charged with the use of the charging means. Then, a beam of laser light is projected from an optical means, while being modulated with image formation information, onto the peripheral surface of the charged photoconductive drum. As a result, a latent image in accordance with the image formation information is formed on the peripheral surface of the photoconductive drum. This latent image is developed into a toner image by a developing means. Meanwhile, in synchronism with the formation of this toner image, a recording medium 2 in a sheet feeder cassette 3a is conveyed by a pickup roller 3b, a pair of conveyer rollers 3c and 3d, and a pair of registration rollers 3e, while being turned over. Then, the toner image formed on the photoconductive drum 7 of the process cartridge B is transferred onto the recording medium 2 by applying electrical voltage to the transfer roller 4 as a transferring means. Then, the recording medium 2, which is bearing the toner image, is guided to the fixing means 5 by the conveyer guide 3f. The fixing means 5 comprises a driver roller 5c, and a fixing roller 5b containing a heater 5a. As the recording medium 2 is conveyed through the fixing means 5, the toner image on the recording medium 2 is fixed to the recording medium 2 with the application of heat and pressure. Thereafter, the recording medium 2 is further conveyed through the turnover path 3j, and discharged into the delivery tray 6, by a pair of discharge rollers 3g, a pair of discharge rollers 3h, and a pair of discharge rollers 3i. The delivery tray 6 constitutes a part of the top surface of the main assembly 14 of the image forming apparatus A. The pivotable flapper 3k may be switched in position in order to discharge the recording medium 2 with the use of a pair of discharge rollers 3m, without allowing the recording medium 2 to go through the turnover path 3j. In this embodiment, the pair of pickup rollers 3b, two pairs of conveyer rollers 3c and 3d, a pair of registration rollers 3e, conveyer guide 3f, three pairs of discharge rollers 3g, 3h, and 3i, and a pair of discharge rollers 3m, make up the conveying means 3.

Referring to FIGS. 2-5, on the other hand, in the process cartridge B, while the photoconductive drum 7, the peripheral layer 7e (FIG. 8) of which is a photoconductive layer, is rotated, the peripheral surface of the photoconductive drum 7 is uniformly charged by the application of electrical voltage to the charge roller 8 as a charging means. Then, a beam of laser light modulated with the image formation information is projected from the optical system 1 onto the photoconductive drum 7 through the exposure opening 1e. As a result, a latent image is formed. This latent image is developed by the developing means 9 which uses toner. More specifically, the charge roller 8 is placed in contact with the photoconductive drum 7, and charges the photoconductive drum 7. It is rotated by the rotation of the photoconductive drum 7. The developing means 9 supplies developer to the area of the peripheral surface of the photoconductive drum 7 in the development station, to develop a latent image on the peripheral surface of the photoconductive drum 7. The optical system 1 comprises a laser diode 1a, a polygonal mirror 1b, a lens 1c, and a deflection mirror 1d.

In the developing means 9, the toner in the toner container 11A is sent to the rotating development roller 9c, by the rotation of the toner sending member 9b. The development roller 9c contains a stationary magnet. As the development roller 9c rotates, the toner is borne on the peripheral surface of the development roller 9c, and is made to form a toner layer on the peripheral surface of the development roller 9c, by the development blade 9d, while being given triboelectric charge by the development blade 9d. Then, the toner particles in the toner layer are supplied to the area of the peripheral surface of the photoconductive drum 7 in the development station. In the development station, the toner particles are transferred onto the peripheral surface of the photoconductive drum 7, in a pattern which corresponds to the pattern of the latent image. As a result, a toner image, that is, a visible image, is formed on the peripheral surface of the photoconductive drum 7. The development blade 9d is a blade for regulating the amount of the toner on the peripheral surface of the development roller 9c while triboelectrically charging the toner. In the adjacencies of the development roller 9c, a toner stirring member 9e for circulating the toner in the development chamber is rotatably disposed. After the transfer of the toner image on the photoconductive drum 7 onto the recording medium 2 by the application of voltage opposite in polarity to the transfer roller 4, the toner particles remaining of the photoconductive drum 7 are removed by the cleaning means 10. More specifically, the toner particles remaining on the photoconductive drum 7 are scraped down and collected into the removed toner bin 10b, by the elastic cleaning blade 10a placed in contact with the photoconductive drum 7. The process cartridge B comprises: a toner storage frame 11 having the toner container (toner storage portion) 11A; a developing means holding frame 12 for holding developing means such as the development roller 9c; and the cleaning means holding frame 13 to which the photoconductive drum 7, the cleaning means 10 comprising the cleaning blade 10a, etc., and the charge roller 8 are attached. Structurally, the toner storage frame 11 and the developing means holding frame 12 are first joined with each other, and then, the cleaning means holding frame 13 is joined with the combination of the toner storage frame 11 and developing means holding frame 12. The process cartridge B is removably mountable in the image forming apparatus main assembly 14 by an operator. The process cartridge B is provided with the exposure opening 1e for projecting the beam of light modulated with the image formation information, onto the peripheral surface of the photoconductive drum 7, and a transfer opening 13n for enabling the recording medium 2 to be placed in contact with the photoconductive drum 7. Precisely speaking, the exposure opening 1e belongs to the cleaning means holding frame 13, and the transfer opening 13n is a gap purposely left between the developing means holding frame 12 and cleaning means holding frame 13.

{Structure of Housing of Process Cartridge B}

Next, the structure of the housing of the process cartridge B in this embodiment will be described.

The process cartridge B in this embodiment is the combination of the housing, that is, the shell portion, of the process cartridge B, and the set of components, such as the photoconductive drum 7, the charge roller 8, the developing means 9, the cleaning means 10, etc., integrally disposed in the housing. The housing is assembled in the following manner: First, the toner storage frame 11 and developing means holding frame 12 are joined, and then, the cleaning means holding frame 13 is pivotally attached to the combination of the toner storage frame 11 and developing means holding frame 12. The thus assembled process cartridge B is removably mounted in the cartridge mounting means of the image forming apparatus main assembly 14. To describe in detail each of the frames, referring to FIGS. 2 and 16, to the toner storage frame 11, the toner sending member 9b is rotationally attached. To the developing means holding frame 12, the development roller 9c and development blade 9d are attached. Further, the stirring member 9e for circulating the toner in the development chamber is attached to the developing means holding frame 12, being disposed close to the development roller 9c. Next, referring to FIGS. 2 and 15, to the developing means holding frame 12, a rod antenna 9h is attached, being disposed next to the development roller 9c, and parallel to the development roller 9c. The toner storage frame 11 and developing means holding frame 12 are welded (in this embodiment, ultrasonic welding is used) into a second frame, that is, the frame of the development unit D (FIG. 10). The development unit D is provided with a drum shutter assembly 18 for covering the photoconductive drum 7 to protect the photoconductive drum 7 from such accidents as being exposed to the ambient light for an extended period of time, coming into contact with foreign objects, etc., when the process cartridge B is out of the image forming apparatus main assembly 14. Referring to FIGS. 2 and 4, the drum shutter assembly 18 comprises a shutter, and a pair of linkage members 18b and 18c for supporting the shutter. Referring to FIG. 3, the linkage member 18c is a piece of metallic rod put through the downstream end of the developing means holder 40, in terms of the direction in which the recording medium 2 is conveyed. The right end of the linkage member 18c extends from a hole 40g of the developing means holder 40 and is fitted in the hole of the shutter located in the upstream end portion, in terms of the direction in which the process cartridge B is mounted, as shown in FIG. 3, whereas the left end of the linkage member 18c is extended from a hole 11h of the bottom portion 11b of the toner storage frame 11, and is fitted in the hole of the shutter located in the upstream end portion, as shown in FIG. 4. The linkage member 18b is located at the left end of the shutter. One end of the linkage member 18b is fitted in a hole located in the downstream end portion of the shutter, in terms of the recording medium 2 conveyance direction, whereas the other end is fitted around the joggle 12d of the developing means holding frame 12. The material of which the linkage member 18b is composed is synthetic resin. The linkage members 18b and 18c are different in length. The shutter, two linking members 18b and 18c, and the integrated combination of the toner storage frame 11 and developing means holding frame 12 together make up a four-joint linkage. Each of the two end portions of the linking member 18c extending from the lengthwise ends of the development unit D, one for one, is provided with a U-shaped portion 18c1, which projects outward in the lengthwise direction of the development unit D. Thus, as the process cartridge B is inserted into the cartridge mounting space S of the image forming apparatus main assembly 14, the U-shaped portion 18c1 comes into contact with a solid projection (unshown) located in the adjacencies of the cartridge mounting space S, and puts the drum shutter assembly 18 into motion, opening therefore the shutter. The shutter assembly 18 is kept under the pressure generated in the direction to cause the shutter to cover the transfer opening 13n, by an unshown torsion coil spring, which is fitted around the joggle 12d. One end of the torsion coil spring is anchored to the linking member 18b and the other is anchored to the developing means holding frame 12.

Referring to FIGS. 2 and 9, to the cleaning means holding frame 13, the photoconductive drum 7, the charge roller 8, and the cleaning means 10 are attached. The cleaning means holding frame 13, the photoconductive drum 7, the charge roller 8, and the cleaning means 10 together make up the cleaning unit C or the first unit (FIG. 9).

The development unit D and cleaning unit C are joined with the use of a pair of round connective pins 22, being enabled to pivot about the pins 22; and the process cartridge B is completed thereby. More specifically, referring to FIG. 10, the developing means holding frame 12 is provided with a pair of arm portions 19, which are located at the lengthwise (axial direction of development roller 9c) ends of the developing means holding frame 12, one for one. The end portion of each arm portion 19 is provided with a round hole, the axial line of which is parallel to the axial line of the development roller 9c. On the other hand, the cleaning means holding frame 13 is provided with a pair of recesses 21, which are located in the lengthwise end portions, and in which the arm portions 19 are fitted, one for one, (FIG. 9). Thus, the development unit D and cleaning unit C are connected in the following manner: First, the arm portions 19 are inserted into the recesses 21. Then, the connective members 22 are pressed through the holes 13e of the outward wall of the cleaning means holding frame 13, put through the holes 20 of the arm portions 19, and pressed into the hole 13e of the inward wall of the cleaning means holding frame 13, one for one. As a result, the development unit D and cleaning unit C are connected, being enabled to pivot about the connective members 22. During the joining of the development unit D and cleaning unit C, a pair of compression coil springs 22a fitted around a pair of unshown joggles projecting from the base portions of the arm portions 19, are compressed as they come into contact with the top wall of the recesses 21 of the cleaning means holding frame 13. As a result, the developing means holding frame 12 is kept pressed downward by the resiliency of the compression coil springs 22a, assuring that the development roller 9c is kept pressed upon the peripheral surface of the photoconductive drum 7. More specifically, referring to FIG. 10, the lengthwise end portions of the development roller 9c are fitted with a pair of spacer rings 9i, one for one, the diameters of which are greater than that of the development roller 9c. Therefore, the spacer rings 9i are pressed upon the photoconductive drum 7, assuring that a predetermined distance (approximately 300 .mu.m) is maintained between the peripheral surfaces of the photoconductive drum 7 and development roller 9c. In other words, the development unit D and cleaning unit C are enabled to pivot about the connective members 22, and the resiliency of the compression coil springs 22a keeps constant the positional relationship between the peripheral surfaces of the photoconductive drum 7 and development roller 9c.

{Structure of Means for Guiding Process Cartridge B}

Next, the means for guiding the process cartridge B when mounting the process cartridge B into the apparatus main assembly 14 or dismounting the process cartridge B from the apparatus main assembly 14 will be described. The guiding means are shown in FIGS. 6 and 7. FIGS. 6 and 7 are perspective views of the left and right walls, respectively, of the process cartridge mounting space S, as seen from the direction (arrow mark X) in which the process cartridge B is mounted (as seen from the development unit D side).

Referring to FIGS. 3 and 4, the internal surface of each of the end walls of the cleaning means holding frame 13, in terms of the lengthwise direction of the process cartridge B, is provided with a guiding means for guiding the process cartridge B when the process cartridge B is mounted into, or removed from, the apparatus main assembly 14. The right and left guiding means respectively comprise: cylindrical guides 13aR and 13aL as guiding means for positioning the process cartridge B; and rotation control guides 13bR and 13bL for controlling the attitude of the process cartridge B during the mounting or dismounting of the process cartridge B. The cylindrical guide 13aR is a hollow member, and the rotation control 13bR is an integral part of the cylindrical guide 13aR, and extends from the circumference of the cylindrical guide 13aR approximately in the radius direction of the cylindrical guide 13aR. The cylindrical guide 13aR, and the rotation control guide 13bR integral with the cylindrical guide 13aR, are securely fixed to the cleaning means holding frame 13 with the use of screws. The axial line of the cylindrical guide 13aL coincides with that of the unshown drum shaft for rotationally supporting the photoconductive drum 7, and the cylindrical guide 13aL and unshown drum shaft are formed of a metallic substance such as steel. They are integrally formed, or integrated after their formation. The cleaning means holding frame 13 is also provided with a rotational control guide 13bL, which is located a short distance apart from the cylindrical guide 13aL. The rotational control guide 13bL is an elongated member, which extends approximately in the radius direction of the cylindrical guide 13aL and is perpendicular to the end wall of cleaning means holding frame 13. It is an integrally formed part of the cleaning means holding frame 13. In other words, the left guide member comprises two discrete components: the cylindrical guide 13aL formed of a metallic substance, and the rotation control guide 13bL formed of a synthetic resin.

Next, an attitude regulating contact area 13j, which is a part of the top surface 13i of the cleaning unit C, will be described. Here, the top surface of the process cartridge B is the surface which will be at the top of the process cartridge B after the proper mounting of the process cartridge B in the image forming apparatus main assembly 14. Referring to FIGS. 3 and 4, in this embodiment, the top surface of the process cartridge B is provided with a pair of attitude regulating contact areas 13j, which are parts of the top surface 13i of the cleaning unit C, and are at the right and left ends 13p and 13q, one for one, of the cleaning unit C in terms of the direction perpendicular to the process cartridge mounting direction. The attitude regulating contact area 13j is an area which regulates the attitude of the process cartridge B by coming into contact with the process cartridge B when the process cartridge B is mounted into the image forming apparatus main assembly 14. In other words, as the process cartridge B is inserted into the image forming apparatus main assembly 14, the attitude regulating contact area 13j comes into contact with the solid projection 25 (FIGS. 6 and 7) of the image forming apparatus main assembly 14, fixing the attitude of the process cartridge B with respect to the rotational range of the process cartridge B about the cylindrical guides 13aR and 13aL.

Next, the process cartridge guiding means of the image forming apparatus main assembly 14 will be described. As a lid 35 of the image forming apparatus main assembly 14 is rotated about a hinge 35a in the counterclockwise direction in FIG. 1, the interior of the top portion, that is, the process cartridge mounting space S, of the image forming apparatus main assembly 14 is exposed as shown in FIGS. 6 and 7. The internal surfaces of the left and right walls of the process cartridge mounting space, as seen from the trailing end in terms of the process cartridge mounting direction, are provided with guiding members 16L and 16R, respectively, as shown in FIGS. 6 and 7. As is evident from the drawings, the guiding members 16L and 16R respectively comprise: guiding portions 16a and 16c which are tilted downward as seen from the trailing side in terms of the process cartridge insertion direction indicated by an arrow mark X; semicylindrical positioning grooves 16b and 16d which are directly connected to the guiding portions 16a and 16c, and into which the cylindrical guides 13aL and 13aR of the process cartridge B exactly fit. After the proper mounting of the process cartridge B into the image forming apparatus main assembly 14, the axial lines of the positioning grooves 16b and 16d coincide with those of the cylindrical guides 13aL and 13aR of the process cartridge B, and hence, the axial line of the photoconductive drum 7. The widths of the guiding portions 16a and 16c are sufficient for the cylindrical guides 13aL and 13aR to loosely fit into the guiding portions 16a and 16c. Therefore, naturally, the rotation control guides 13bL and 13bR, the widths of which are less than the diameters of the cylindrical guides 13aL and 13aR loosely fit into the guiding portions 16a and 16c, respectively. However, the rotation of the cylindrical guides 13aL and 13aR, and the rotation of the rotation control guides 13bL and 13bR, are regulated by the guiding portions 16a and 16c. Therefore, while the process cartridge B is mounted into the image forming apparatus main assembly 14, the attitude of the process cartridge B is kept within a predetermined range. After the mounting of the process cartridge B into the image forming apparatus main assembly 14, the cylindrical guides 13aL and 13aR of the process cartridge B remain exactly fitted in the positioning grooves 16b and 16d, and the left and right attitude regulating contact areas 13j located at the forward end of the cleaning means holding frame 13 of the process cartridge B remain in contact with the solid projection 25 of the apparatus main assembly 14. The weight of the process cartridge B is distributed so that as the process cartridge B is horizontally and rotationally supported by the cylindrical guides 13aL and 13aR, the primary moment of the development unit D side becomes greater about the line connecting the centers of the cylindrical guides 13aL and 13aR than the primary moment of the cleaning unit C side.

The process cartridge B is to be mounted into the image forming apparatus main assembly 14 in the following manner: First, the process cartridge B is to be grasped by one hand, by the recess 17 and ribs 11c located on the top and bottom sides, respectively, of the toner storage frame 11. Then, the process cartridge B is to be inserted so that cylindrical guides 13aL and 13aR are fitted into guiding portions 16a and 16c, respectively, of the cartridge mounting portion of the image forming apparatus main assembly 14. Then, the process cartridge B is to be tilted, with the forward end of the process cartridge B, in terms of the process cartridge B inserting direction, positioned lower than the rearward end, so that the rotation control guides 13bL and 13bR enter the guiding portions 16a and 16c of the image forming apparatus main assembly 14. Then, the process cartridge B is further inserted, with the cylindrical guides 13aL and 13aR, and the rotational control guides 13bL and 13bR, being guided by the guiding portions 16a and 16c of the image forming apparatus main assembly 14, until the cylindrical guides 13aL and 13aR reach the positioning grooves 16b and 16d of the image forming apparatus main assembly 14. As the cylindrical guides 13aL and 13aR reach the positioning grooves 16b and 16d, they settle into the positioning grooves 16b and 16d due to the weight of the process cartridge B. As a result, the positions of the cylindrical guides 13aL and 13aR of the process cartridge B are accurately fixed relative to the positioning grooves 16b and 16d. Therefore, the position of the photoconductive drum 7 relative to the image forming apparatus main assembly 14 becomes approximately fixed, because the line connecting the centers of the cylindrical guides 13aL and 13aR coincides with the axial line of the photoconductive drum 7. However, the ultimate positional relationship between the photoconductive drum 7 and apparatus main assembly 14 is not realized until the driving force receiving portion of the process cartridge B couples with the driving force transmitting portion of the image forming apparatus main assembly 14. In other words, immediately after the settling of the cylindrical portions 13aL and 13aR into the positioning grooves 16b and 16d, there still remains a small gap between the solid projections 25 of the image forming apparatus main assembly 14 and the attitude regulating contact areas 13j of the process cartridge B. At this point, the operator is to release the process cartridge B from his/her hand. As the process cartridge B is released, the process cartridge B rotates about the cylindrical guides 13aL and 13aR so that the development unit D side goes down (cleaning unit C side goes up). As a result, the attitude regulating contact areas 13j come into contact with the solid projections 25 of the image forming apparatus main assembly 14, accurately positioning the process cartridge B relative to the image forming apparatus main assembly 14. Thereafter, the lid 35 is to be closed by rotating it about the hinge 35a in the clockwise direction of FIG. 1.

The process for removing the process cartridge B from the apparatus main assembly 14 is opposite to the above described process for mounting the process cartridge B into the apparatus main assembly 14, and is as follows: First, the lid 35 of the apparatus main assembly 14 is to be opened, and the process cartridge B is to be pulled upward by the operator, by the rearward end of the process cartridge B, in terms of the process cartridge B inserting direction, with the hand of the operator placed on the aforementioned ribs 11c located on the top and bottom sides, respectively, of the toner storage frame 11. As the process cartridge B is pulled upward by the rearward end of the process cartridge B, the process cartridge B rotates about the axial lines of the cylindrical guides 13aL and 13aR in the positioning grooves 16b and 16c of the apparatus main assembly 14. As a result, the attitude regulating contact areas 13j of the process cartridge B is moved away from the solid projections 25 of the apparatus main assembly 14. Then, the process cartridge B is to be pulled outward. As the process cartridge B is pulled, the cylindrical guides 13aL and 13aR come out of the positioning grooves 16b and 16d, moving onto the guiding portions 16a and 16c of the guiding members 16L and 16R, respectively, of the apparatus main assembly 14. Then, the process cartridge B is to be pulled further. As the process cartridge B is pulled further, the process cartridge B moves outward, with the cylindrical guides 13aL and 13aR, and rotation control guides 13bL and 13bR, of the process cartridge B remaining fitted in the guiding portions 16a and 16c. As a result, the process cartridge B comes out of the apparatus main assembly 14 while being controlled in attitude, and therefore, being prevented from colliding with the portions of the apparatus main assembly 14 other than the guiding portions.

{Toner Storage Frame}

Referring to FIGS. 2, 4, 13, 16, and 17, the toner storage frame will be described in detail. FIG. 16 is a perspective view of the toner storage frame 11 before the welding of the toner seal, and FIG. 17 is a perspective view of the toner storage frame 11 after the welding of the toner seal. Referring to FIG. 2, the toner storage frame 11 comprises two essential components: the top frame 11a and bottom frame 11b. The two frames 11a and 11b are integrated by ultrasonic welding. More specifically, the bottom surface (welding surface U) of the flange 11a1 of the top frame 11a is placed in contact with the top surface (welding surface U) of the rimmed flange 11b1 of the bottom frame 11b, and the welding ribs are melted by ultrasonic waves. In order to securely hold the frames 11a and 11b when ultrasonically welding two frames 11a and 11b to each other, the toner storage frame 11 is provided with a stepped portion 11m, in addition to the aforementioned rimmed flange 11b1. The stepped portion is above the opening 11i, and the top surface of the "riser-portion" of the stepped portion 11m is rendered virtually level with the top surface of the flange 11b1. Prior to the joining of the two frames 11a and 11b, the toner sending member 9b is disposed in the bottom frame 11b. Further, referring to FIG. 13, a coupling member 11e is partially put through the hole 11e1 of the side wall (one of lengthwise end walls) of the toner storage frame 11 from outside so that the coupling member 11e engages with the end portion of the toner sending member 9b. The side wall with the hole 11e1 is also provided with a toner filling hole 11d, which is approximately in the form of an equilateral triangle and is used for filling toner into the toner storage frame 11. Referring to FIG. 16, the toner storage frame 11 is provided with the rectangular opening 11i through which toner is sent from the toner storage frame 11 to the developing means holding frame 12. The lengthwise direction of the rectangular opening 11i coincides with the lengthwise direction of the toner storage frame 11. A seal (which will be described later) is welded to the toner storage frame 11 to close the opening 11i. Then, toner is filled into the toner storage fram