TECHNICAL FIELD

The present invention relates to an electrophotographic image forming apparatus, a cartridge, a process cartridge, and a drum unit, for electrophotographic image formation.

BACKGROUND OF THE INVENTION

In a electrophotographic image forming apparatus, the structure is known in which elements such as a photosensitive drum and a developing roller as a rotatable member related to image formation are integrated as a cartridge, which can be dismountably mounted to a image forming apparatus main assembly (hereinafter, apparatus main assembly). Here, in order to rotate the photosensitive drum in the cartridge, it is preferable to transmit the driving force from the apparatus main assembly. In this connection, the structure is known in which the coupling member on the cartridge side is engaged with the drive force transmission portion such as the drive pin on the apparatus main assembly side to transmit the drive force.

Here, in some image forming apparatus, the structure of is known in which the cartridge can be removed in a predetermined direction substantially perpendicular to the rotation axis of the photosensitive drum. In Japanese Laid-open Patent Application No. 2008-233867 discloses a structure in which a coupling member provided at the end of the photosensitive drum is advanced and retracted in the rotation axis direction of the photosensitive drum. By this, a coupling member provided on the cartridge engages with and disengages from the drive pin provided in the apparatus main assembly. As a result, the rotational driving force of the apparatus main assembly is transmitted to the cartridge. The structure as described above is known.

SUMMARY OF THE INVENTION

Problem to be Solved by the Invention

An object of the present invention is to develop the above-mentioned prior art.

Means for Solving the Problem

A representative structure disclosed in the present application is a process cartridge comprising:

(1) a photosensitive drum;

(2) a frame rotatably supporting said photosensitive drum;

(3) a flange provided at an end portion of said photosensitive drum to transmit a driving force to said photosensitive drum; and

(4) a coupling member provided on said flange including (4-1) a movable member provided with a driving force receiving portion configured to receive the driving force, said movable member being movable relative to said flange between (a) an advanced position advanced away from said photosensitive member and (b) a retracted position retracted toward said photosensitive drum, and (4-2) a connecting member connected with said flange so as to transmit the driving force from said movable member to said flange;

wherein said connecting member includes, (4-2-1) a shaft portion extending along a moving direction of said movable member, and

(4-2-2) a restricting portion configured to restrict said movable member so as to suppress disengagement, from said flange, of said movable member placed in the position,

wherein said restricting portion receives the driving force from said movable member by engagement with said movable member.

Another representative structure disclosed in the present application is a process cartridge comprising:

(1) a photosensitive drum;

(2) a frame rotatably supporting said photosensitive drum;

(3) a flange provided at an end portion of said photosensitive drum; and

(4) a coupling member provided on said flange to receive a driving force for rotating said photosensitive drum, said coupling member including (4-1) a movable member provided with a driving force receiving portion configured to receive the driving force, said movable member being movable relative to said flange between (a) an advanced position advanced away from said photosensitive member and (b) a retracted position retracted toward said photosensitive drum, and (4-2) a connecting member connected with said flange so as to transmit the driving force from said movable member to said flange;

wherein said connecting member includes,

(4-2-1) a shaft portion extending along a moving direction of said movable member, and

(4-2-2) an enlarged portion provided at the free end side of said shaft portion, said enlarged portion having a maximum rotation radius larger than a maximum rotation radius of said shaft portion, said enlarged portion being capable of receiving the driving force from said movable member by engagement with said movable member.

In addition, further representative structure disclosed in the present application is a cartridge comprising:

(1) a rotatable member rotatable while carrying toner on a surface thereof;

(2) a frame configured to rotatably support said rotatable member;

(3) a transmission member configured to transmit a driving force to said rotatable member; and

(4) a coupling member provided on said transmission member, said coupling member including (4-1) a movable member provided with a driving force receiving portion configured to receive the driving force, said movable member being movable relative to said transmission member between (a) an advanced position advanced toward outside of said cartridge and (b) a retracted position retracted toward an inside of said cartridge, and (4-2) a connecting member connected with said transmission member so as to transmit the driving force from said movable member to said transmission member;

wherein said connecting member includes,

(4-2-1) a shaft portion extending along a moving direction of said movable member, and

(4-2-2) an enlarged portion provided at the free end side of said shaft portion, said enlarged portion having a maximum rotation radius larger than a maximum rotation radius of said shaft portion, said enlarged portion being capable of receiving the driving force from said movable member by engagement with said movable member.

In addition, further representative arrangement disclosed in the present application is a cartridge comprising:

(1) a rotatable member rotatable while carrying toner on a surface thereof;

(2) a frame rotatably supporting said rotatable member;

(3) a transmission member configured to transmit a driving force to said rotatable member; and

(4) a coupling member provided on said transmission member, said coupling member including (4-1) a movable member provided with a driving force receiving portion configured to receive the driving force, said movable member being movable relative to said transmission member between (a) an advanced position advanced toward outside of said cartridge and (b) a retracted position retracted toward an inside of said cartridge, and (4-2) a connecting member connected with said transmission member so as to transmit the driving force from said movable member to said transmission member;

wherein said connecting member includes,

(4-2-1) a shaft portion extending along a moving direction of said movable member, and

(4-2-2) an enlarged portion provided at the free end side of said shaft portion, said enlarged portion having a maximum rotation radius larger than a maximum rotation radius of said shaft portion, said enlarged portion being capable of receiving the driving force from said movable member by engagement with said movable member.

In addition, further representative arrangement disclosed in the present application is a drum unit comprising:

(1) a photosensitive drum;

(2) the flange provided at an end portion of said photosensitive drum to transmit a driving force to said photosensitive drum; and

(3) a coupling member provided on said flange including (3-1) a movable member provided with a driving force receiving portion configured to receive the driving force, said movable member being movable relative to said flange between (a) an advanced position advanced away from said photosensitive member and (b) a retracted position retracted toward an inside of said photosensitive drum, and (3-2) a connecting member connected with said flange so as to transmit the driving force from said movable member to said flange;

wherein said connecting member includes,

(3-2-1) a shaft portion extending along a moving direction of said movable member, and

(3-2-2) a restricting portion configured to restrict said movable member so as to suppress disengagement, from said flange, of said movable member placed in the position,

wherein said restricting portion receives said driving force from said movable member by engagement with said movable member.

In addition, the representative structure disclosed in the present application is a drum unit comprising:

(1) a photosensitive drum;

(2) the flange provided at an end portion of said photosensitive drum to transmit a driving force to said photosensitive drum; and

(3) a coupling member provided on said flange including (3-1) a movable member provided with a driving force receiving portion configured to receive the driving force, said movable member being movable relative to said flange between (a) an advanced position advanced away from said photosensitive member and (b) a retracted position retracted toward an inside of said photosensitive drum, and (3-2) a connecting member connected with said flange so as to transmit the driving force from said movable member to said flange,

wherein said connecting member includes,

(3-2-1) a shaft portion extending along a moving direction of said movable member, and

(3-2-2) a enlarged portion provided at the free end side of said shaft portion, said enlarged portion having a maximum rotation radius larger than a maximum rotation radius of said shaft portion, said enlarged portion being capable of receiving the driving force from said movable member by engagement with said movable member,

wherein said enlarged portion receives the driving force from said movable member by engagement with said movable member.

In addition, another representative arrangement disclosed in the present application is a drum unit detachably mountable to a main assembly of an electrophotographic image forming apparatus, said drum unit comprising:

a photosensitive drum;

a flange provided at an end portion of said photosensitive drum to transmit a driving force to said photosensitive drum;

a movable member having a free end portion provided with a driving force receiving portion configured to receive the driving force from the main assembly, and a small diameter portion at a position closer to said flange than the free end portion, the small diameter portion having a maximum rotation radius smaller than a maximum rotation radius of the free end portion, the movable member being movable relative to said flange between a transmitting position in which the driving force is capable of being transmitted to said flange and a non-transmitting position in which the driving force is not transmitted to said flange, and

a regulated portion which is restricted to restrict movement of said movable member in a direction away from said flange is provided and at least a part of said free end portion and said small diameter portion of said movable member.

In addition, further representative arrangement disclosed in the present application is a drum unit detachably mountable to a main assembly of an electrophotographic image forming apparatus, said drum unit comprising:

a photosensitive drum;

a shaft provided at an end of said photosensitive drum and configured to transmit a driving force to said photosensitive drum;

a movable member configured to receive a driving force and transmit the driving force to said shaft, said movable member being movable relative to said shaft between a transmitting position in which the driving force is capable of being transmitted to said shaft and a non-transmitting position in which the driving force is not transmitted to said shaft;

a first urging member to urge said movable member in a direction from the non-transmitting position toward the transmitting position; and

a second urging member configured to urge said movable member in a direction from the transmitting position toward the non-transmitting position.

Effect of the Invention

The prior art described above can be developed.

