ELECTROPHOTOGRAPHIC IMAGE FORMING APPARATUS, DEVELOPING APPARATUS, AND COUPLING MEMBER

• US 20080240796A1
• Filed: 03/24/2008
• Published: 10/02/2008
• Est. Priority Date: 03/23/2007
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Ueno, Takahito, Morioka, Masanari, Miyabe, Shigeo
• Granted Patent: US 8,437,669 B2
• Time in Patent Office: Days
• US Class Current: 399/279
• CPC Class Codes: F16D 1/10 Quick-acting couplings in which the parts are connected by simply bringing them together axially
• CPC Class Codes: F16D 1/101 without axial retaining means rotating with the coupling
• CPC Class Codes: F16D 3/04 specially adapted to allow radial displacement, e.g. Oldham couplings
• CPC Class Codes: G03G 15/0121 for developing
• CPC Class Codes: G03G 15/0173 plural rotations of recording member to produce multicoloured copy, e.g. rotating set of developing units G03G15/0163 takes precedence
• CPC Class Codes: G03G 15/08 using a solid developer, e.g. powder developer
• CPC Class Codes: G03G 15/081 characterised by the developer handling means after the supply and before the regulating, e.g. means for preventing developer blocking
• CPC Class Codes: G03G 15/0815 characterised by the developer handling means after the developing zone and before the supply, e.g. developer recovering roller
• CPC Class Codes: G03G 15/0865 Arrangements for supplying new developer
• CPC Class Codes: G03G 15/0896 Arrangements or disposition of the complete developer unit or parts thereof not provided for by groups G03G15/08 - G03G15/0894
• CPC Class Codes: G03G 21/1647 Mechanical connection means
• CPC Class Codes: G03G 21/1676 for the developer unit
• CPC Class Codes: G03G 21/186 Axial couplings
• CPC Class Codes: G03G 2215/0177 Rotating set of developing units
• CPC Class Codes: G03G 2221/1657 transmitting mechanical drive power

Abstract

A developing device usable with an electrophotographic image forming apparatus includes a driving shaft having a rotating force applying portion, and a movable member. The developing device is mounted to the moving member and includes a developing roller, and a coupling member that includes a rotating force receiving portion and a rotating force applying portion. The coupling member is capable of taking (i) a rotational force transmitting angular position for transmitting the rotational force to the developing roller, (ii) a pre-engagement angular position taken before the coupling member is engaged with the rotating force applying portion, in which the coupling member is inclined away from the rotational force transmitting angular position, and (iii) a disengaging angular position, which enables the coupling member to disengage from the driving shaft, and inclines the coupling member away from the rotational force transmitting angular position, in a direction opposite to the pre-engagement angular position.

Claims

1. A developing device usable with an electrophotographic image forming apparatus, said apparatus including a driving shaft rotatable by a motor and having a rotating force applying portion, and a movable member, said developing device being mountable to the movable member, and said developing device being movable in a direction substantially perpendicular to an axial direction of the driving shaft in response to movement of the movable member in one direction with said developing device mounted to the movable member, said developing device comprising:

i) a developing roller for developing an electrostatic latent image formed on an electrophotographic photosensitive drum, said developing roller being rotatable about an axis; and

ii) a coupling member for transmitting a rotating force to said developing roller, said coupling member including,

a rotating force receiving portion engageable with the rotating force applying portion to receive a rotating force from the driving shaft, and

a rotating force transmitting portion for transmitting the rotating force received through said rotating force receiving portion to said developing roller,

said coupling member being capable of taking a rotational force transmitting angular position for transmitting the rotational force for rotating said developing roller to said developing roller, a pre-engagement angular position which is taken before said coupling member is engaged with the rotating force applying portion and in which said coupling member is inclined away from said rotational force transmitting angular position, and a disengaging angular position which is taken for said coupling member to disengage from the driving shaft and in which said coupling member is inclined away from the rotational force transmitting angular position in a direction opposite to said pre-engagement angular position;

wherein in response to a movement of said developing device when the movable member moves in said one direction, said coupling member moves from the pre-engagement angular position to the rotational force transmitting angular position to be opposed to the driving shaft, and wherein when the movable member makes a further movement in said one direction from a position where said coupling member is opposed to the driving shaft, in response to the further movement, said coupling member is disengaged from the driving shaft by moving from the rotational force transmitting angular position to the disengaging angular position.

2. A device according to claim 1, wherein said coupling member has a recess in which a rotational axis of said coupling member extends, and said recess is over a free end of said driving shaft in the state in which said coupling member is positioned at said rotational force transmitting angular position, wherein said coupling member is rotated by a rotational force through engagement, in a rotational direction of said coupling member, to the rotational force applying portion which is projected in a direction substantially perpendicular to an axis of the driving shaft adjacent to the free end of the driving shaft, wherein said coupling member moves from said rotational force transmitting angular position to said disengaging angular position by the further movement of the movable member in said one direction so that part of said coupling member circumvents the driving shaft in response to movement of said developing device in the direction substantially perpendicular to the axis of said developing roller.

3. A device according to claim 2, wherein a plurality of such rotational force receiving portions are provided on a phantom circle having a center on the rotational axis of said coupling member at positions substantially diametrically opposite to each other.

4. A device according to claim 2, wherein said coupling member has a circular flat portion at a free end thereof, and said recess is disposed at a central portion of said circular flat portion, said recess includes an expanding portion expanding toward a free end thereof, and wherein said rotational force receiving portion is provided projected at each of two positions of an edge portion of said flat portion interposing the central portion, wherein the rotational force applying portion is provided projected in a direction perpendicular to the axis of the driving shaft at each of two positions opposite to each other, and wherein said coupling member receives a rotational force from the driving shaft to rotate by one of said rotational force receiving portions engaging to one of the rotational force applying portion and by the other of rotational force receiving portions engaging to the other of the rotational force applying portions, said one of said rotational force receiving portions being opposed to the other of said rotational force receiving portions, and said one of said rotational force applying portions being opposed to the other of said rotational force applying portions.

5. A device according to any one of claims 1-4, further comprising an elastic member for elastically urging said coupling member with such an elastic force as to permit said coupling member to move from said pre-engagement angular position to said rotational force transmitting angular position to maintain said coupling member at said pre-engagement angular position and as to permit said coupling member to moves from said rotational force transmitting angular position to said disengaging angular position.

6. A device according to claim 5, wherein said coupling member is provided in a position away from said axis of said developing roller with respect to a direction perpendicular to said axis of said developing roller, and said rotating force transmitting portion is disposed in a side opposite from said rotating force receiving portion, and wherein the rotating force received by said rotating force transmitting portion is transmitted to said developing roller through said rotating force receiving portion and said driving force transmission member.

7. A device according to claim 6, wherein said developing device contains a yellow color developer, a magenta color developer, a cyan color developer or a black color developer, and is a developing cartridge detachably mountable to said movable member in the form of a developing rotary.

8. A developing cartridge usable with an electrophotographic image forming apparatus, said apparatus including a driving shaft rotatable by a motor and having a rotating force applying portion, and a developing rotary, said developing cartridge being mountable to the developing rotary, and said developing cartridge being movable in a direction substantially perpendicular to an axial direction of the driving shaft in response to rotation of the developing rotary in one direction with said developing cartridge mounted to the developing rotary, said developing cartridge comprising:

i) a developing roller for developing an electrostatic latent image formed on an electrophotographic photosensitive drum, said developing roller being rotatable about an axis;

ii) a coupling member for transmitting a rotating force to said developing roller, said coupling member including,

a recess provided coaxially with a rotational axis of said coupling member at a free end of said coupling member, wherein said recess is over a free end of the driving shaft in a state in which said coupling member receives the rotating force from the driving shaft,

a rotating force receiving portions engageable with the rotating force applying portion to receive a rotating force from the driving shaft, wherein rotating force receiving portions are disposed projected in said rotational axis direction along a rotational direction of said coupling member, and

a rotating force transmitting portion for transmitting the rotating force received through said rotating force receiving portion to said developing roller,

said coupling member being capable of taking a rotational force transmitting angular position for transmitting the rotational force for rotating said developing roller to said developing roller, a pre-engagement angular position which is taken before said coupling member is engaged with the rotating force applying portion and in which said coupling member is inclined away from said rotational force transmitting angular position, and a disengaging angular position which is taken for said coupling member to disengage from the driving shaft and in which said coupling member is inclined away from the rotational force transmitting angular position in a direction opposite to said pre-engagement angular position;

iii) a rotating force receiving portion for receiving the rotating force from said rotating force transmitting portion to rotate said developing roller;

iv) a developer accommodating portion accommodating a developer to be used to develop the electrostatic latent image; and

v) an elastic member for elastically urging said coupling member with such an elastic force as to permit said coupling member to move from said pre-engagement angular position to said rotational force transmitting angular position to maintain said coupling member at said pre-engagement angular position and as to permit said coupling member to moves from said rotational force transmitting angular position to said disengaging angular position;

wherein in response to a movement of said developing device when the developing rotary rotates in said one direction, said coupling member moves from the pre-engagement angular position to the rotational force transmitting angular position to be opposed to the driving shaft, and wherein when the movable member makes a further movement in said one direction from a position where said coupling member is opposed to the driving shaft, in response to the further movement, said coupling member is disengaged from the driving shaft by moving from the rotational force transmitting angular position to the disengaging angular position.

9. A developing cartridge according to claim 8, wherein a plurality of such rotational force receiving portions are provided on a phantom circle having a center on the rotational axis of said coupling member at positions substantially diametrically opposite to each other.

10. A developing cartridge according to claim 8, wherein said coupling member has a circular flat portion at a free end thereof, and said recess is disposed at a central portion of said circular flat portion, said recess includes an expanding portion expanding toward a free end thereof, and wherein said rotational force receiving portion is provided projected at each of two positions of an edge portion of said flat portion interposing the central portion, wherein the rotational force applying portion is provided projected in a direction perpendicular to the axis of the driving shaft at each of two positions opposite to each other, and wherein said coupling member receives a rotational force from the driving shaft to rotate by one of said rotational force receiving portions engaging to one of the rotational force applying portion and by the other of rotational force receiving portions engaging to the other of the rotational force applying portions, said one of said rotational force receiving portions being opposed to the other of said rotational force receiving portions, and said one of said rotational force applying portions being opposed to the other of said rotational force applying portions.

11. A developing cartridge according to claim 8, 9 or 10, wherein said coupling member is provided in a position away from said axis of said developing roller with respect to a direction perpendicular to said axis of said developing roller, and said rotating force transmitting portion is disposed in a side opposite from said rotating force receiving portion, and wherein the rotating force received by said rotating force transmitting portion is transmitted to said developing roller through said rotating force receiving portion and said driving force transmission member.

12. A developing cartridge usable with an electrophotographic image forming apparatus, said apparatus including a driving shaft rotatable by a motor and having a rotating force applying portion, and a developing rotary, said developing cartridge being mountable to the developing rotary, and said developing cartridge being movable in a direction substantially perpendicular to an axial direction of the driving shaft in response to rotation of the developing rotary in one direction with said developing cartridge mounted to the developing rotary, said developing cartridge comprising:

i) a developing roller for developing an electrostatic latent image formed on an electrophotographic photosensitive drum, said developing roller being rotatable about an axis;

ii) a coupling member for transmitting the rotating force to said developing roller, said coupling member being disposed in a position away from said axis of said developing roller with respect to a direction perpendicular to said axis of said developing roller, said coupling member including,

a recess coaxial with a rotational axis of said coupling member in a central portion of a circular flat portion provided at a free end of said coupling member, said recess extends over a free end of the driving shaft in a state in which coupling member receives the rotating force from the driving shaft,

a rotating force receiving portions engageable with the rotating force applying portion to receive a rotating force from the driving shaft, wherein rotating force receiving portions are disposed projected in said rotational axis direction along a rotational direction of said coupling member, and wherein said rotational force receiving portions are provided on a phantom circle having a center on the rotational axis of said coupling member at positions substantially diametrically opposite to each other, and

a rotating force transmitting portion for transmitting the rotating force received through said rotating force receiving portion to said developing roller,

said coupling member being capable of taking a rotational force transmitting angular position for transmitting the rotational force for rotating said developing roller to said developing roller, a pre-engagement angular position which is taken before said coupling member is engaged with the rotating force applying portion and in which said coupling member is inclined away from said rotational force transmitting angular position, and a disengaging angular position which is taken for said coupling member to disengage from the driving shaft and in which said coupling member is inclined away from the rotational force transmitting angular position in a direction opposite to said pre-engagement angular position;

iii) a rotating force receiving portion for receiving the rotating force from said rotating force transmitting portion to rotate said developing roller;

iv) a developer accommodating portion accommodating a developer to be used to develop the electrostatic latent image;

v) an elastic member for elastically urging said coupling member with such an elastic force as to permit said coupling member to move from said pre-engagement angular position to said rotational force transmitting angular position to maintain said coupling member at said pre-engagement angular position and as to permit said coupling member to moves from said rotational force transmitting angular position to said disengaging angular position; and

vi) a driving force transmission member for transmitting the rotating force received by said rotating force receiving portion to said developing roller;

wherein when said developing rotary rotates in said one direction, said coupling member moves from said pre-engagement angular position to said rotational force transmitting angular position against said elastic force so as to permit a downstream part of said coupling member with respect to the rotational direction of said developing rotary in response to movement of said developing cartridge so that coupling member is opposed to the driving shaft, and wherein when the developing rotary makes the further movement in said one direction from a position where said coupling member is opposed to the driving shaft, said coupling member moves from said rotational force transmitting angular position to said disengaging angular position against said elastic force so as to permit an upstream part of said coupling member with respect to the rotational direction to circumvent the driving shaft, by which said coupling member disengages from the driving shaft.

13. A developing cartridge according to claim 12, wherein said recess has the conical shape expanding to the free end of said coupling member, and said rotating force receiving portion projects in the rotational axis direction of said coupling member and is disposed at each of two positions interposing the rotational axis, and wherein said rotating force applying portion projects in a direction perpendicular to the axis of the driving shaft and is disposed at each of two positions opposed to each other, wherein said coupling member receives a rotational force from the driving shaft to rotate by one of said rotational force receiving portions engaging to one of the rotational force applying portion and by the other of rotational force receiving portions engaging to the other of the rotational force applying portions, said one of said rotational force receiving portions being opposed to the other of said rotational force receiving portions, and said one of said rotational force applying portions being opposed to the other of said rotational force applying portions.

14. A developing cartridge according to claim 12 or 13, further comprising a developer supplying roller for supplying the developer in said developing roller, wherein said driving force transmission member transmits the rotating force to said developing roller and to said developer supplying roller.

15. An electrophotographic image forming apparatus for forming an image on a recording material, said electrophotographic image forming apparatus comprising:

i) driving shaft rotatable by a motor and having a rotating force applying portion;

ii) a movable member;

iii) a developing device movable in a direction substantially perpendicular to an axial direction of the driving shaft in response to movement of the movable member in one direction with said developing device mounted to the movable member, said developing device including,

a developing roller for developing an electrostatic latent image formed on an electrophotographic photosensitive drum, said developing roller being rotatable about an axis;

a coupling member for transmitting a rotating force to said developing roller, said coupling member including,

a rotating force receiving portion engageable with the rotating force applying portion to receive a rotating force from the driving shaft, and

a rotating force transmitting portion for transmitting the rotating force received through said rotating force receiving portion to said developing roller,

said coupling member being capable of taking a rotational force transmitting angular position for transmitting the rotational force for rotating said developing roller to said developing roller, a pre-engagement angular position which is taken before said coupling member is engaged with the rotating force applying portion and in which said coupling member is inclined away from said rotational force transmitting angular position, and a disengaging angular position which is taken for said coupling member to disengage from the driving shaft and in which said coupling member is inclined away from the rotational force transmitting angular position in a direction opposite to said pre-engagement angular position;

wherein in response to a movement of said developing device when the movable member moves in said one direction, said coupling member moves from the pre-engagement angular position to the rotational force transmitting angular position to be opposed to the driving shaft, and wherein when the movable member makes a further movement in said one direction from a position where said coupling member is opposed to the driving shaft, in response to the further movement, said coupling member is disengaged from the driving shaft by moving from the rotational force transmitting angular position to the disengaging angular position.

16. An apparatus according to claim 15, wherein said coupling member has a recess in which a rotational axis of said coupling member extends, and said recess is over a free end of said driving shaft in the state in which said coupling member is positioned at said rotational force transmitting angular position, wherein said coupling member is rotated by a rotational force through engagement, in a rotational direction of said coupling member, to the rotational force applying portion which is projected in a direction substantially perpendicular to an axis of the driving shaft adjacent to the free end of the driving shaft, wherein said coupling member moves from said rotational force transmitting angular position to said disengaging angular position by the further movement of the movable member in said one direction so that part of said coupling member circumvents the driving shaft in response to movement of said developing device in the direction substantially perpendicular to the axis of said developing roller.

17. An apparatus according to claim 16, wherein a plurality of such rotational force receiving portions are provided on a phantom circle having a center on the rotational axis of said coupling member at positions substantially diametrically opposite to each other.

18. An apparatus according to claim 16, wherein said coupling member has a circular flat portion at a free end thereof, and said recess is disposed at a central portion of said circular flat portion, said recess includes an expanding portion expanding toward a free end thereof, and wherein said rotational force receiving portion is provided projected at each of two positions of an edge portion of said flat portion interposing the central portion, wherein the rotational force applying portion is provided projected in a direction perpendicular to the axis of the driving shaft at each of two positions opposite to each other, and wherein said coupling member receives a rotational force from the driving shaft to rotate by one of said rotational force receiving portions engaging to one of the rotational force applying portion and by the other of rotational force receiving portions engaging to the other of the rotational force applying portions, said one of said rotational force receiving portions being opposed to the other of said rotational force receiving portions, and said one of said rotational force applying portions being opposed to the other of said rotational force applying portions.

19. An apparatus according to claim 18, further comprising an elastic member for elastically urging said coupling member with such an elastic force as to permit said coupling member to move from said pre-engagement angular position to said rotational force transmitting angular position to maintain said coupling member at said pre-engagement angular position and as to permit said coupling member to moves from said rotational force transmitting angular position to said disengaging angular position.

20. An apparatus according to claim 19, wherein said coupling member is provided in a position away from said axis of said developing roller with respect to a direction perpendicular to said axis of said developing roller, and said rotating force transmitting portion is disposed in a side opposite from said rotating force receiving portion, and wherein the rotating force received by said rotating force transmitting portion is transmitted to said developing roller through said rotating force receiving portion and said driving force transmission member.

21. An apparatus according to claim 19 or 20, wherein said developing device contains a yellow color developer, a magenta color developer, a cyan color developer or a black color developer, and is a developing cartridge detachably mountable to said movable member in the form of a developing rotary.

22. An electrophotographic image forming apparatus for forming an image on a recording material, said electrophotographic image forming apparatus comprising:

i) driving shaft rotatable by a motor and having a rotating force applying portion;

ii) a developing rotary;

iii) a developing cartridge movable in a direction substantially perpendicular to an axial direction of the driving shaft in response to movement of the developing rotary in one direction with said developing cartridge mounted to the developing rotary, said developing cartridge including,

a developing roller for developing an electrostatic latent image formed on an electrophotographic photosensitive drum, said developing roller being rotatable about an axis;

a coupling member for transmitting a rotating force to said developing roller, said coupling member including,

a recess provided coaxially with a rotational axis of said coupling member at a free end of said coupling member, wherein said recess is over a free end of the driving shaft in a state in which said coupling member receives the rotating force from the driving shaft,

a rotating force receiving portions engageable with the rotating force applying portion to receive a rotating force from the driving shaft, wherein rotating force receiving portions are disposed projected in said rotational axis direction along a rotational direction of said coupling member,

a rotating force transmitting portion for transmitting the rotating force received through said rotating force receiving portion to said developing roller,

said coupling member being capable of taking a rotational force transmitting angular position for transmitting the rotational force for rotating said developing roller to said developing roller, a pre-engagement angular position which is taken before said coupling member is engaged with the rotating force applying portion and in which said coupling member is inclined away from said rotational force transmitting angular position, and a disengaging angular position which is taken for said coupling member to disengage from the driving shaft and in which said coupling member is inclined away from the rotational force transmitting angular position in a direction opposite to said pre-engagement angular position,

a rotating force receiving portion for receiving the rotating force from said rotating force transmitting portion to rotate said developing roller;

a developer accommodating portion accommodating a developer to be used to develop the electrostatic latent image, and

an elastic member for elastically urging said coupling member with such an elastic force as to permit said coupling member to move from said pre-engagement angular position to said rotational force transmitting angular position to maintain said coupling member at said pre-engagement angular position and as to permit said coupling member to moves from said rotational force transmitting angular position to said disengaging angular position;

wherein in response to a movement of said developing device when the developing rotary rotates in said one direction, said coupling member moves from the pre-engagement angular position to the rotational force transmitting angular position to be opposed to the driving shaft, and wherein when the movable member makes a further movement in said one direction from a position where said coupling member is opposed to the driving shaft, in response to the further movement, said coupling member is disengaged from the driving shaft by moving from the rotational force transmitting angular position to the disengaging angular position.

23. An apparatus according to claim 22, wherein a plurality of such rotational force receiving portions are provided on a phantom circle having a center on the rotational axis of said coupling member at positions substantially diametrically opposite to each other.

24. An apparatus according to claim 22, wherein said coupling member has a circular flat portion at a free end thereof, and said recess is disposed at a central portion of said circular flat portion, said recess includes an expanding portion expanding toward a free end thereof, and wherein said rotational force receiving portion is provided projected at each of two positions of an edge portion of said flat portion interposing the central portion, wherein the rotational force applying portion is provided projected in a direction perpendicular to the axis of the driving shaft at each of two positions opposite to each other, and wherein said coupling member receives a rotational force from the driving shaft to rotate by one of said rotational force receiving portions engaging to one of the rotational force applying portion and by the other of rotational force receiving portions engaging to the other of the rotational force applying portions, said one of said rotational force receiving portions being opposed to the other of said rotational force receiving portions, and said one of said rotational force applying portions being opposed to the other of said rotational force applying portions.

25. An apparatus according to claim 22 or 24, wherein said coupling member is provided in a position away from said axis of said developing roller with respect to a direction perpendicular to said axis of said developing roller, and said rotating force transmitting portion is disposed in a side opposite from said rotating force receiving portion, and wherein the rotating force received by said rotating force transmitting portion is transmitted to said developing roller through said rotating force receiving portion and said driving force transmission member.

26. An electrophotographic image forming apparatus for forming an image on a recording material, said electrophotographic image forming apparatus comprising:

i) driving shaft rotatable by a motor and having a rotating force applying portion;

ii) a developing rotary;

iii) a developing cartridge movable in a direction substantially perpendicular to an axial direction of the driving shaft in response to movement of the developing rotary in one direction with said developing cartridge mounted to the developing rotary, said developing cartridge including,

a developing roller for developing an electrostatic latent image formed on an electrophotographic photosensitive drum, said developing roller being rotatable about an axis,

a coupling member for transmitting the rotating force to said developing roller, said coupling member being disposed in a position away from said axis of said developing roller with respect to a direction perpendicular to said axis of said developing roller, said coupling member including,

a recess coaxial with a rotational axis of said coupling member in a central portion of a circular flat portion provided at a free end of said coupling member, said recess extends over a free end of the driving shaft in a state in which coupling member receives the rotating force from the driving shaft,

a rotating force receiving portions engageable with the rotating force applying portion to receive a rotating force from the driving shaft, wherein rotating force receiving portions are disposed projected in said rotational axis direction along a rotational direction of said coupling member, and wherein said rotational force receiving portions are provided on a phantom circle having a center on the rotational axis of said coupling member at positions substantially diametrically opposite to each other,

a rotating force transmitting portion for transmitting the rotating force received through said rotating force receiving portion to said developing roller,

said coupling member being capable of taking a rotational force transmitting angular position for transmitting the rotational force for rotating said developing roller to said developing roller, a pre-engagement angular position which is taken before said coupling member is engaged with the rotating force applying portion and in which said coupling member is inclined away from said rotational force transmitting angular position, and a disengaging angular position which is taken for said coupling member to disengage from the driving shaft and in which said coupling member is inclined away from the rotational force transmitting angular position in a direction opposite to said pre-engagement angular position,

a rotating force receiving portion for receiving the rotating force from said rotating force transmitting portion to rotate said developing roller,

a developer accommodating portion accommodating a developer to be used to develop the electrostatic latent image,

an elastic member for elastically urging said coupling member with such an elastic force as to permit said coupling member to move from said pre-engagement angular position to said rotational force transmitting angular position to maintain said coupling member at said pre-engagement angular position and as to permit said coupling member to moves from said rotational force transmitting angular position to said disengaging angular position, and

a driving force transmission member for transmitting the rotating force received by said rotating force receiving portion to said developing roller;

wherein when said developing rotary rotates in said one direction, said coupling member moves from said pre-engagement angular position to said rotational force transmitting angular position against said elastic force so as to permit a downstream part of said coupling member with respect to the rotational direction of said developing rotary in response to movement of said developing cartridge so that coupling member is opposed to the driving shaft, and wherein when the developing rotary makes the further movement in said one direction from a position where said coupling member is opposed to the driving shaft, said coupling member moves from said rotational force transmitting angular position to said disengaging angular position against said elastic force so as to permit an upstream part of said coupling member with respect to the rotational direction to circumvent the driving shaft, by which said coupling member disengages from the driving shaft.

27. An apparatus according to claim 26, wherein said recess has the conical shape expanding to the free end of said coupling member, and said rotating force receiving portion projects in the rotational axis direction of said coupling member, and is disposed at each of two positions interposing the rotational axis, and wherein said rotating force applying portion projects in a direction perpendicular to the axis of the driving shaft and is disposed at each of two positions opposed to each other, wherein said coupling member receives a rotational force from the driving shaft to rotate by one of said rotational force receiving portions engaging to one of the rotational force applying portion and by the other of rotational force receiving portions engaging to the other of the rotational force applying portions, said one of said rotational force receiving portions being opposed to the other of said rotational force receiving portions, and said one of said rotational force applying portions being opposed to the other of said rotational force applying portions.

28. An apparatus according to claim 26 or 27, wherein said driving force transmission member transmits the rotating force to said developing roller and to said developer supplying roller.

29. A coupling member usable with an electrophotographic image forming apparatus, said apparatus including a driving shaft rotatable by a motor and having a rotating force applying portion, and a movable member, said coupling member being effective to transmit a rotating force from the driving shaft in a developing roller which is movable in a direction substantial perpendicular to an axial direction of the driving shaft, said coupling member comprising:

a rotating force receiving portion engageable with the rotating force applying portion to receive the rotating force from the driving shaft; and

a rotating force transmitting portion for transmitting the rotating force received through said rotating force receiving portion to said developing roller,

said coupling member being capable of taking a rotational force transmitting angular position for transmitting the rotational force for rotating said developing roller to said developing roller through the rotating force transmitting portion, a pre-engagement angular position in which said coupling member is inclined away from said rotational force transmitting angular position, and a disengaging angular position which said coupling member is inclined away from the rotational force transmitting angular position in a direction opposite to said pre-engagement angular position.

30. A coupling member usable with an electrophotographic image forming apparatus, said apparatus including a driving shaft rotatable by a motor and having a rotating force applying portion, and a movable member, said coupling member being effective to transmit a rotating force from the driving shaft in a developing roller which is movable in a direction substantial perpendicular to an axial direction of the driving shaft, said coupling member comprising:

a recess provided coaxially with a rotational axis of said coupling member at a free end of said coupling member, wherein said recess is over a free end of the driving shaft in a state in which said coupling member receives the rotating force from the driving shaft;

a rotating force receiving portions engageable with the rotating force applying portion to receive a rotating force from the driving shaft, wherein rotating force receiving portions are disposed projected in said rotational axis direction along a rotational direction of said coupling member; and

a rotating force transmitting portion for transmitting the rotating force received through said rotating force receiving portion to said developing roller,

said coupling member being capable of taking a rotational force transmitting angular position for transmitting the rotational force for rotating said developing roller to said developing roller, a pre-engagement angular position which is taken before said coupling member is engaged with the rotating force applying portion and in which said coupling member is inclined away from said rotational force transmitting angular position, and a disengaging angular position which is taken for said coupling member to disengage from the driving shaft and in which said coupling member is inclined away from the rotational force transmitting angular position in a direction opposite to said pre-engagement angular position.

32. An apparatus according to claim 30 or 31, wherein said developing roller is mounted to the developing cartridge, and wherein said recess extends over the free end of the driving shaft by movement of said coupling member from said pre-engagement angular position to rotational force transmitting angular position in response to movement of said developing cartridge when said developing rotary rotates in said one direction with said developing cartridge mounted to said developing rotary rotating in said one direction, wherein said coupling member rotates by the rotating force received from the driving shaft by engagement of said rotating force receiving portion with the rotating force applying portion in the rotational direction of said coupling, and wherein when said developing rotary further moves in said one direction from a position where said recess extends over the free end of the driving shaft, said coupling member moves from said rotational force transmitting angular position to said disengaging angular position in response to the rotation of said developing rotary to disengage from the driving shaft.

31. A coupling member usable with an electrophotographic image forming apparatus, said apparatus including a driving shaft rotatable by a motor and having a rotating force applying portion, and a movable member, said coupling member being effective to transmit a rotating force from the driving shaft in a developing roller which is movable in a direction substantial perpendicular to an axial direction of the driving shaft, said coupling member comprising:

a recess coaxial with a rotational axis of said coupling member in a central portion of a circular flat portion provided at a free end of said coupling member, said recess extends over a free end of the driving shaft in a state in which coupling member receives the rotating force from the driving shaft, said recess has a conical shape expanding toward the free end of said coupling;

a rotational force receiving portion provided projected at each of two positions of an edge portion of said flat portion interposing the central portion, wherein the rotational force applying portion is provided projected in the rotational axis direction at each of two positions opposite to each other; and

a rotating force transmitting portion for transmitting the rotating force received through said rotating force receiving portion to said developing roller,

wherein said coupling member receives a rotational force from the driving shaft to rotate by one of said rotational force receiving portions engaging to one of the rotational force applying portion and by the other of rotational force receiving portions engaging to the other of the rotational force applying portions, said one of said rotational force receiving portions being opposed to the other of said rotational force receiving portions, and said one of said rotational force applying portions being opposed to the other of said rotational force applying portions, and wherein said coupling member being capable of taking a rotational force transmitting angular position for transmitting the rotational force for rotating said developing roller to said developing roller through the rotating force transmitting portion, a pre-engagement angular position in which said coupling member is inclined away from said rotational force transmitting angular position, and a disengaging angular position which said coupling member is inclined away from the rotational force transmitting angular position in a direction opposite to said pre-engagement angular position.

33. An apparatus according to claim 31, further comprising an elastic member for elastically urging said coupling member with such an elastic force as to permit said coupling member to move from said pre-engagement angular position to said rotational force transmitting angular position to maintain said coupling member at said pre-engagement angular position and as to permit said coupling member to moves from said rotational force transmitting angular position to said disengaging angular position.

34. An apparatus according to claim 31, wherein when said coupling member is used in said electrophotographic image forming apparatus, said coupling member is disposed in a position away from said axis of said developing roller with respect to a direction perpendicular to said axis of said developing roller.