Protection cover, and process cartridge and image forming apparatus using the same

1. A protection cover, which is detachably disposed in a process cartridge that is detachably inserted and mounted to an image forming apparatus housing body and that comprises a photosensitive member; protects an external exposure portion of the photosensitive member before the process cartridge is inserted and mounted to the image forming apparatus housing body; and which detaches from the process cartridge with the process cartridge being inserted and mounted to the image forming apparatus housing body,

the protection cover comprising:

a cover base that covers and protects the external exposure portion of the photosensitive member and that comes into contact with the image forming apparatus housing body to movably guide the process cartridge at the time the process cartridge is inserted to the image forming apparatus housing body;

an extrusion member that is disposed in the cover base on a side opposite to an insertion direction of the process cartridge to the image forming apparatus housing body and that moves in the insertion direction of the process cartridge to extrude the process cartridge from the cover base; and

a restriction portion that is disposed in the extrusion member to restrict the process cartridge in the cover base in a state where the process cartridge is located in the cover base and to release the process cartridge from the cover base in a state where the process cartridge is inserted and mounted to the image forming apparatus housing body.

2. The protection cover according to claim 1 , wherein

the cover base comprises a guide surface that guides the extrusion member, and

at least a part of the guide surface has an ascending slope portion in the insertion direction of the process cartridge to the image forming apparatus housing body so as to change a relative position between the restriction portion and the process cartridge.

3. The protection cover according to claim 1 , wherein

the extrusion member moves to release the restriction state between the process cartridge and the restriction portion at a position where the process cartridge is inserted and mounted to the image forming apparatus housing body.

4. The protection cover according to claim 1 , further comprising:

a positioning/holding portion that is disposed in the cover base on a side in the insertion direction of the process cartridge to the image forming apparatus housing body, positions and holds the cover base so as to prevent the process cartridge from being drawn at the time of inserting and mounting the process cartridge, and that is capable of releasing the positioning/holding state after the process cartridge is inserted and mounted,

wherein the extrusion member releases the holding state of the positioning/holding portion at an extrusion end position at the time the extrusion member ends the inserting/mounting operation of the process cartridge.

5. The protection cover according to claim 4 , wherein

the positioning/holding portion comprises an elastic hold piece, which is elastically deformable, and is hooked in a positioning hole formed in the image forming apparatus housing body to be fixed and held therein, and

the protection cover has a position regulation mechanism which regulates the extrusion member in the extrusion end position at the time the inserting/mounting operation of the process cartridge ends.

6. The protection cover according to claim 1 , wherein

the restriction portion comprises a pair of elastic restriction pieces that are elastically deformable,

the elastic restriction piece comprises a flange portion that comes into contact with a blocking portion of the cover base and that elastically deforms the pair of elastic restriction pieces to enable the pair of elastic restriction pieces to fall inward, and

the flange portion comprises, at a portion which comes into contact with the blocking portion of the cover base, at least two steps of slope guide surfaces so that an angle between a first slope guide surface, with respect to the extrusion direction of the extrusion member, and the blocking portion is set to be bigger than that between a subsequent slope guide surface and the blocking portion.

7. A process cartridge, which is detachably inserted and mounted to an image forming apparatus housing body,

the process cartridge comprising:

a photosensitive member; and

a cartridge frame in which the photosensitive member is disposed,

wherein

the cartridge frame is held by a protection cover which protects an external exposure portion of the photosensitive member before the cartridge frame is inserted and mounted to the image forming apparatus housing body and which is detached with the cartridge frame being inserted and mounted to the image forming apparatus housing body, and

the protection cover comprises:

a cover base that is detachably disposed in the cartridge frame to protect the external exposure portion of the photosensitive member and that comes into contact with the image forming apparatus housing body to movably guide the cartridge frame at the time the cartridge frame is inserted to the image forming apparatus housing body;

an extrusion member that is disposed in the cover base on a side opposite to an insertion direction of the cartridge frame to the image forming apparatus housing body and that moves in the insertion direction of the cartridge frame to extrude the cartridge frame from the cover base; and

a restriction portion that is disposed in the extrusion member to restrict the cartridge frame in the cover base in a state where the cartridge frame is located in the cover base and to release the cartridge frame from the cover base in a state where the cartridge frame is inserted and mounted to the image forming apparatus housing body.

8. An image forming apparatus comprising:

an image forming apparatus housing body to which a process cartridge comprising a photosensitive member is detachably inserted and mounted; and

a protection cover that protects an external exposure portion of the photosensitive member before the process cartridge is inserted and mounted to the image forming apparatus housing body and that is detached from the process cartridge with the process cartridge being inserted and mounted to the image forming apparatus housing body,

wherein

the protection cover comprises:

a cover base that covers and protects the external exposure portion of the photosensitive member and that comes into contact with the image forming apparatus housing body to movably guide the process cartridge at the time the process cartridge is inserted to the image forming apparatus housing body;

an extrusion member that is disposed in the cover base on a side opposite to an insertion direction of the process cartridge to the image forming apparatus housing body and that moves in the insertion direction of the process cartridge to extrude the process cartridge from the cover base; and

a restriction portion that is disposed in the extrusion member to restrict the process cartridge in the cover base in a state where the process cartridge is located in the cover base and to release the process cartridge from the cover base in a state where the process cartridge is inserted and mounted to the image forming apparatus housing body.