Photosensitive conductor unit and image forming apparatus

1. A photosensitive conductor unit comprising:

a casing rotatably retaining a photosensitive conductor drum including

an engaging portion on an end in axial direction of the photosensitive conductor drum, and a guide portion disposed in proximity to the end opposite to the engaging portion in axial direction of the photosensitive conductor drum; and

a protective cover for protecting at least a portion of the surface of the photosensitive conductor drum that is exposed from the casing and detachably attached to the casing including

a hook portion that engages with the engaging portion, a positioning portion formed in proximity of the engaging portion to determine the position of the protective cover, a side wall covering an exposed portion of the surface by extending along an axial direction of the photosensitive conductor drum, and a rail portion extending along an axial direction of the photosensitive conductor drum in proximity to both ends of the side wall in a direction orthogonal to the axial direction of the photosensitive conductor drum, and engaging with the guide portion such that the guide portion slidably guides the protective cover,

wherein the photosensitive conductor unit is detachably attached and slides along an axial direction of the photosensitive conductor drum with respect to an image forming apparatus main body,

the image forming apparatus main body includes a positioning indentation, and

when attaching the photosensitive conductor unit to the image forming apparatus main body in a configuration in the protective cover has been attached to the photosensitive conductor unit, the position of the positioning portion is determined by engagement with the positioning indentation.

2. The photosensitive conductor unit according to claim 1 , wherein

the image forming apparatus main body includes a hook guide portion, and

when attaching the photosensitive conductor unit to the image forming apparatus main body in a configuration in the protective cover has been attached to the photosensitive conductor unit, the engagement between the hook portion and the engaging portion is released by abutment of the side wall with the hook guide portion.

3. The photosensitive conductor unit according to claim 1 , wherein the protective cover has respective leg portions on an outer surface in proximity to both ends of the side wall along the axial direction of the photosensitive conductor drum, and

wherein the leg portions enable the photosensitive conductor unit with the protective cover attached thereto to be disposed on a flat surface.

4. An image forming apparatus comprising:

a image forming apparatus main body including a positioning indentation; and

a photosensitive conductor unit having a photosensitive conductor drum, and detachably attached and sliding along an axial direction of the photosensitive conductor drum with respect to the image forming apparatus main body; wherein

the photosensitive conductor unit comprises:

a casing rotatably retaining the photosensitive conductor drum in the photosensitive conductor unit including an engaging portion on an end in the insertion side when attaching the photosensitive conductor unit to the image forming apparatus main body, and a guide portion disposed in proximity to the end opposite to the insertion-side end of the photosensitive conductor unit; and

a protective cover for protecting at least a portion of the surface of the photosensitive conductor drum that is exposed from the casing, and detachably attached to the casing including a hook portion that engages with the engaging portion, a positioning portion formed to determine the position of the protective cover immediately after starting of attachment when attaching to the image forming apparatus main body, a side wall covering an exposed portion of the surface by extending along an axial direction of the photosensitive conductor drum, and a rail portion extending in the insertion direction of the photosensitive conductor unit in proximity to both ends of the side wall in a direction orthogonal to the axial direction of the photosensitive conductor drum, and engaging with the guide portion such that the guide portion slidably guides the protective cover,

wherein when attaching the photosensitive conductor unit to the image forming apparatus main body in a configuration in the protective cover has been attached to the photosensitive conductor unit, the position of the positioning portion is determined by engagement with the positioning indentation.

5. The image forming apparatus according to claim 4 , wherein the image forming apparatus main body includes a hook guide portion, and

when attaching the photosensitive conductor unit to the image forming apparatus main body in a configuration in the protective cover has been attached to the photosensitive conductor unit, the engagement between the hook portion and the engaging portion is released by abutment of the side wall with the hook guide portion.

6. The image forming apparatus according to claim 4 , wherein the protective cover has respective leg portions on an outer surface in proximity to both ends of the side wall along the axial direction of the photosensitive conductor drum, and

wherein the leg portions enable the photosensitive conductor unit with the protective cover attached thereto to be disposed on a flat surface in a configuration approximating attachment of the photosensitive conductor unit to the image forming apparatus main body.