CA-3108746-C - DRUM UNIT, CARTRIDGE AND COUPLING MEMBER

CA3108746CCA 3108746 CCA3108746 CCA 3108746CCA-3108746-C

Abstract

A drum unit, cartridge and coupling member are provided. In one embodiment, the process cartridge comprises a casing, toner contained in the casing, a photosensitive drum rotatably supported by the casing, a developing roller configured to develop a latent image formed on the photosensitive drum with the toner, a coupling member operatively connected to the photosensitive drum, the coupling member including an arm portion and a projection projecting from the arm portion, a cleaning blade configured to remove the toner from a surface of the photosensitive drum, and a charging roller configured to charge the photosensitive drum.

Inventors

Tetsuo Uesugi
Makoto Hayashida
Koji Yamaguchi
Takashi Yano

Assignees

CANON KABUSHIKI KAISHA

Dates

Publication Date: 20260505
Application Date: 20160226
Priority Date: 20150227

Claims (1)

303 CLAIMS 1. A process cartridge comprising: a casing; toner contained in the casing; a photosensitive drum rotatably 5 supported by the casing; a developing roller configured to develop a latent image formed on the photosensitive drum with the toner; a coupling member operatively connected to the photosensitive drum, the coupling member including an arm portion and a projection projecting from the arm portion; and 10 a cleaning blade configured to remove the toner from a surface of the photosensitive drum; a charging roller configured to charge the photosensitive drum, wherein the photosensitive drum is rotatable such that a part of the surface of the photosensitive drum moves from an upstream position where the part of the surface of the 15 photosensitive drum is adjacent to the cleaning blade to a downstream position where the part of the surface of the photosensitive drum is adjacent to the developing roller via an intermediate position where the part of the surface of the photosensitive drum is adjacent to the charging roller, and wherein the arm portion of the coupling member extends from a point that is upstream 20 in a rotational direction of the photosensitive drum towards a point that is downstream in the rotation direction of the photosensitive drum and such that an end of the arm portion that is downstream in the rotational direction of the photosensitive drum is closer to a rotational axis of the photosensitive drum than an end of the arm portion that is upstream in the rotational direction of the photosensitive drum. 25 2. A process cartridge according to claim 1, wherein the projection projects from the arm portion to an end of the projection such that the end of the projection is closer to a rotational axis of the coupling member than the arm portion is to the rotational axis of the coupling 304 member. 3. A process cartridge according to claim 1, wherein the arm portion is movable between a first position and a second position, and wherein the projection is closer to the rotational axis of the photosensitive drum when the arm portion is in the first position than when the arm portion 5 is in the second position. 4. A process cartridge according to claim 3, wherein the arm portion is biased towards the first position. 5. A process cartridge according to claim 1, wherein the coupling member includes a plurality of arm portions, with a projection projecting from each of the arm portions such that 10 an end of each of the projections is closer to a rotational axis of the coupling member than each of the arm portions is to the rotational axis of the coupling member. 6. A process cartridge according to claim 1, wherein at least a part of the arm portion is positioned inside of the photosensitive drum. 7. A process cartridge according to claim 1, wherein at least a part of the projection is 15 positioned inside of the photosensitive drum. 8. A process cartridge according to claim 1, wherein the projection is projected from the arm portion such that an end of the projected portion is closer to a rotational axis of the coupling member than the arm portion is to the rotational axis of the coupling member. 9. A process cartridge according to claim 1, wherein an open space is formed in the 20 coupling member between the arm portion and a rotational axis of the coupling member. 10. A process cartridge according to claim 1, wherein the arm portion has a fixed end that is fixed to the coupling member, at least a part of the fixed end of the arm portion being positioned inside of the photosensitive drum. 11. A process cartridge according to claim 1, wherein the photosensitive drum has a first 25 end and a second end, and the coupling member is positioned adjacent to the first end of the photosensitive drum, and wherein the coupling member includes a recess, with the recess extending about a rotational axis of the coupling member, being positioned closer to the second end of the photosensitive drum than the projection is to the second end of the 305 photosensitive drum, and being positioned such that a surface adjacent to the recess faces the projection. 12. A process cartridge according to claim 1, wherein the arm portion extends from an inner surface of the coupling member. 13. A process cartridge according to claim 1, wherein the 5 coupling member includes a cylindrical portion, a part of the cylindrical portion being positioned inside of the photosensitive drum, and a part of the cylindrical portion being positioned outside of the photosensitive drum. 14. A process cartridge according to claim 1, wherein the arm portion is capable of 10 transmitting a driving force from the projection to the photosensitive drum, and the arm portion is elastically deformable. 15. A process cartridge according to claim 1, wherein the photosensitive drum has a first end and a second end opposite to the first end, and the coupling member is provided adjacent to the first end of the photosensitive drum, and wherein a part of the projection is inclined 15 relative to a rotational axis of the coupling member, and, as measured in a direction perpendicular to the rotational axis of the coupling member, a distance between the inclined part of the projection and the rotational axis of the coupling member increases as the distance in the direction of the rotational axis of the coupling member to the second end of the photosensitive drum decreases. 20 16. A developing cartridge comprising: a casing; toner contained in the casing; a developing roller rotatably supported by the casing; a coupling member operatively connected to the developing roller, the coupling 25 member being rotatable about a rotational axis thereof, and the coupling member including an arm portion and a projection projecting from the arm portion, with the coupling member being configured to rotate the developing roller by rotating in a direction opposite to the direction that the developing roller rotates; and 306 a developing blade configured to regulate an amount of the toner on a surface of the developing roller, wherein the developing roller is rotatable such that a part of the surface of the developing roller moves from a position exposed to outside of the casing to a position inside of the casing, then moves to a position adjacent to the developing 5 blade, and then returns to the position exposed to outside of the casing, and wherein the arm portion of the coupling member extends from a point that is upstream in a rotational direction of the coupling member towards a point that is downstream in the rotation direction of the coupling member and such that an end of the arm portion that 10 is downstream in the rotational direction of the coupling member is closer to the rotational axis of the coupling member than an end of the arm portion that is upstream in the rotational direction of the coupling member. 17. A developing cartridge according to claim 16, wherein the projection projects from the arm portion to an end of the projection such that the end of the projection is closer to the 15 rotational axis of the coupling member than the arm portion is to the rotational axis of the coupling member. 18. A developing cartridge according to claim 16, wherein the arm portion is movable between a first position and a second position, and wherein the projection is closer to the rotational axis of the coupling member when the arm portion is in the first position than when 20 the arm portion is in the second position. 19. A developing cartridge according to claim 18, wherein the arm portion is biased towards the first position. 20. A developing cartridge according to claim 16, wherein the coupling member includes a plurality of arm portions, with a projection projecting from each of the arm portions. 25 21. A developing cartridge according to claim 16, further comprising a supplying roller configured to supply toner to the developing roller. 22. A developing cartridge according to claim 16, wherein the coupling member is operatively connected to the developing roller through a supplying roller. 307 23. A developing cartridge according to claim 16, wherein a supplying roller includes a shaft, and the coupling member is fixed to the shaft of the supplying roller. 24. A developing cartridge according to claim 22, further comprising gears configured to transmit a driving force from the supplying roller to the developing roller. 25. A developing cartridge according to claim 16, wherein 5 the projection is projected from the arm portion such that an end of the projected portion is closer to the rotational axis of the coupling member than the arm portion is to the rotational axis of the coupling member. 26. A developing cartridge according to claim 16, wherein an open space is formed in the coupling member between the arm portion and the rotational axis of the coupling member. 10 27. A developing cartridge according to claim 16, wherein the casing has a first end and a second end opposite to the first end, and the coupling member is positioned adjacent to the first end of the casing, wherein the coupling member includes a recess, with the recess extending about the rotational axis of the coupling member, being positioned closer to the second end of the casing than the projection is to the second end of the casing, and being 15 positioned such that a surface adjacent to the recess faces the projection. 28. A developing cartridge according to claim 16, wherein the arm portion is capable of transmitting a driving force from the projection to the developing roller. 29. A developing cartridge according to claim 16, wherein the coupling member includes a cylindrical portion, and the arm portion extends from an inner surface of the cylindrical 20 portion. 30. A developing cartridge according to claim 16, wherein the coupling member includes: a driving force receiving member including the arm portion and the projection; and a force transmitting member configured to transmit a driving force from the driving force receiving member to the developing roller. 25 31. A process cartridge according to any one of claims 1-15, wherein the arm portion is capable of transmitting driving force from the projection towards the photosensitive drum. 308 32. A process cartridge according to any one of claims 1-15 and 31, wherein: the projection has a non-circular shape. 33. A cartridge comprising: a casing; a photosensitive drum rotatably 5 supported by the casing; a coupling member operatively connected to the photosensitive drum, the coupling member including an arm portion and a projection projecting from the arm portion; a cleaning blade configured to remove toner from a surface of the photosensitive drum; and 10 a charging roller configured to charge the photosensitive drum; wherein the photosensitive drum is rotatable such that a part of the surface of the photosensitive drum moves from an upstream position where the part of the photosensitive drum is exposed to outside of the casing to a downstream position where the part of the surface of the photosensitive drum is adjacent to the charging roller via an intermediate 15 position where the part of the surface of the photosensitive drum is adjacent to the cleaning blade, and wherein the arm portion of the coupling member extends from a point that is upstream in a rotational direction of the photosensitive drum towards a point that is downstream in the rotation direction of the photosensitive drum and such that an end of the 20 arm portion that is downstream in the rotational direction of the photosensitive drum is closer to a rotational axis of the photosensitive drum than an end of the arm portion that is upstream in the rotational direction of the photosensitive drum. 34. A cartridge according to claim 33, wherein the projection projects from the arm portion to an end of the projection such that the end of the projection is closer to a rotational 25 axis of the coupling member than the arm portion is to the rotational axis of the coupling member. 35. A cartridge according to claim 33, wherein the arm portion is movable between a first 309 position and a second position, and wherein the projection is closer to the rotational axis of the photosensitive drum when the arm portion is in the first position than when the arm portion is in the second position. 36. A cartridge according to claim 35, wherein the arm portion is biased towards the first 5 position. 37. A cartridge according to claim 33, wherein the coupling member includes a plurality of arm portions, with a projection projecting from each of the arm portions. 38. A cartridge according to claim 33, wherein at least a part of the arm portion is positioned inside of the photosensitive drum. 10 39. A cartridge according to claim 33, wherein at least a part of the projection is positioned inside of the photosensitive drum. 40. A cartridge according to claim 33, wherein the projection is projected from the arm portion such that an end of the projected portion is closer to a rotational axis of the coupling member than the arm portion is to the rotational axis of the coupling member. 15 41. A cartridge according to claim 33, wherein an open space is formed in the coupling member between the arm portion and a rotational axis of the coupling member. 42. A cartridge according to claim 33, wherein the coupling member includes a cylindrical portion, a part of the cylindrical portion being positioned inside of the photosensitive drum, and a part of the cylindrical portion being positioned outside of the 20 photosensitive drum. 43. A cartridge according to claim 33, wherein the photosensitive drum includes a first end and a second end opposite to the first end, and the coupling member is positioned adjacent to the first end of the photosensitive drum, and wherein the coupling member includes a recess, with the recess extending about a rotational axis of the coupling member, 25 being positioned closer to the second end of the photosensitive drum than the projection is to the second end of the photosensitive drum, and being positioned such that a surface adjacent to the recess faces the projection. 44. A cartridge according to claim 33, wherein the arm portion extends from an inner 310 surface of the coupling member. 45. A cartridge according to claim 33, wherein the arm portion is capable of transmitting a driving force from the projection to the photosensitive drum. 46. A cartridge according to claim 33, wherein the photosensitive drum has a first end and a second end opposite to the first end, and the coupling member 5 is provided adjacent to the first end of the photosensitive drum, and wherein a part of the projection is inclined relative to a rotational axis of the coupling member, and, as measured in a direction perpendicular to the rotational axis of the coupling member, a distance between the inclined part of the projection and the rotational axis of the coupling member increases as the distance in the 10 direction of the rotational axis of the coupling member to the second end of the photosensitive drum decreases. 47. A cartridge according to claim 33, wherein the coupling member includes a cylindrical portion, and wherein a part of the cylindrical portion is positioned outside of the photosensitive drum, and a part of the cylindrical portion is positioned inside of the 15 photosensitive drum.

Description

DRUM UNIT, CARTRIDGE AND COUPLING MEMBER Technical Field [0001] The present invention relates to a process cartridge usable with an image forming apparatus using an electrophotographic process, or the like. s Background Art [0002] In an electrophotographic image forming apparatus, there is known a structure in which elements such as a photosensitive drum and a developing roller, which are rotatable members related to image formation, are integrated into a cartridge which is detachably mountable relative to a main assembly of an image forming apparatus (hereinafter, the 1 o apparatus main assembly). In such a structure, a structure for receiving a driving force from the apparatus main assembly to rotate the photosensitive drum in the cartridge is employed in many apparatuses. At this time, a structure is known in which a driving force is transmitted through engagement between a coupling member on a cartridge side and a driving force transmitting portion such as a drive pin on the apparatus main assembly side. 15 [0003] For example, Japanese Patent Laid-Open No. 2008-233867 discloses a cartridge having a coupling member provided at a end portion of a photosensitive drum so as to be tiltable with respect to a rotation axis of the photosensitive drum. Problem to be Solved by the Invention [0004] It is another object of the present invention to develop the above-mentioned 2 o conventional technique. Means for Solving the Problem [0005] Typical structures are as follows. [0006] A drum unit detachably mountable to a main assembly of an electrophotographic image forming apparatus, the apparatus including a driving shaft provided with a recess, the 2 s drum unit comprising: (I) a photosensitive drum; and 1 Date Reyue/Date Received 2021-02-09 (II) a coupling member provided on the photosensitive drum, the coupling member including, (II-I) a driving force receiving portion configured to enter the recess and receive a driving force for rotating the photosensitive drum, and (11-11) a supporting portion movably supporting the driving force receiving portion, wherein at least a part of the supporting portion and/or at least a part of the driving force receiving portion is disposed inside the photosensitive drum. Effects of the Invention 1 o [0007] The above-mentioned conventional technique is further developed. Brief Description of the Drawings [0008] Figure 1 is a schematic sectional view of an image forming apparatus 100. [0009] Figure 2 is a perspective view of an outer appearance of a process cartridge 7. [0010] Figure 3 is a sectional view of the process cartridge 7 taken along a plane 1 s perpendicular to a rotation axis of a photosensitive drum 1. [0011] Figure 4 is a cross-sectional view of the process cartridge taken along a plane including the rotation axis center (rotation axis) of the photosensitive drum 1. [0012] Figure 5 is an external view of the main assembly driving shaft. [0013] Figure 6 is a cross-sectional view taken along a plane including the rotation axis 20 center (rotation axis) of the main assembly driving shaft 101 mounted to the image forming apparatus main assembly. [0014] Figure 7 is a cross-sectional view of the coupling 28 and the main assembly driving shaft 101 taken along a plane including the rotation center line (rotation axis). [0015] Figure 8 is a cross-sectional view of the coupling member 28 and the main assembly 2 s driving shaft 101, taken along a plane perpendicular to the rotation axis. 2 Date Reyue/Date Received 2021-02-09 [0016] Figure 9 is a cross-sectional view of the coupling 28 and the main assembly driving shaft 101 taken along a plane including the rotation center line (rotation axis). [0017] Figure 10 is a perspective view of the coupling member 28. [0018] Figure 11 is a sectional view of the coupling member 28 taken along a plane s perpendicular to the axis of rotation of the coupling member 28 and passing through the base portion 74. [0019] Figure 12 is a cross-sectional perspective view of the coupling member 28. [0020] Figure 13 is a cross-sectional view of the coupling member 28 taken along a plane including rotation center line (rotation axis). 1 o [0021] Figure 14 is a cross-sectional view of the coupling member 28 and the main assembly driving shaft 101 taken along a plane perpendicular to the rotation axis and passing through the base portion 74. [0022] Figure 15 is a cross-sectional view of the coupling member 28 and the main assembly drive shaft 101 taken along a plane including the rotation center line (rotation axis). 15 [0023] Figure 16 is a perspective view illustrating mounting of the cartridge 7 to the image forming apparatus main assembly 1 00A. [0024] Figure 17 is cross-sectional views illustrating the mounting operation of the cartridge 7 to the image forming apparatus main assembly 1 00A. [0025] Figure 18 is a sectional view illustrating the operation of mounting the coupling 20 member 28 on the main assembly driving shaft 101. [0026] Figure 19 show