Image carrier unit and image forming apparatus

1. An image carrier unit insertable into and removable from an apparatus housing, comprising:

an image carrier;

a protection cover removable from and attachable to the image carrier and including a covering portion and a block, the covering portion covering an exposed portion of the image carrier, the block being disposed on a near side in an insertion-removal direction and protruding in a direction crossing the insertion-removal direction; and

a surface opposing a far side of the block in the insertion-removal direction,

wherein the block is pressed by a protrusion movable toward the apparatus housing.

2. The image carrier unit according to claim 1 , wherein the protection cover includes a tab that is disposed on a bottom surface of the block to extend to the near side in the insertion-removal direction, and that is grippable from a front side of the apparatus housing.

3. The image carrier unit according to claim 2 , wherein the block has the bottom surface wider than an upper surface.

4. The image carrier unit according to claim 3 ,

wherein the image carrier unit includes a handle on the near side in the insertion-removal direction to be grippable together with the tab for insertion and removal of the image carrier unit, and

wherein the upper surface of the block and a lower surface of the handle define a gap that is narrowed when the block and the handle are gripped to bring the upper surface and the lower surface into contact with each other.

5. The image carrier unit according to claim 4 , wherein the block includes a rib on an upper surface of the block and, when the handle and the tab are gripped, the rib is engaged with a rib of the handle on the lower surface of the handle at a position different from a position of the rib of the handle to overlap with the rib of the handle in the insertion-removal direction.

6. The image carrier unit according to claim 2 ,

wherein the image carrier unit includes a handle on the near side in the insertion-removal direction to be grippable together with the tab for insertion and removal of the image carrier unit, and

wherein the upper surface of the block and a lower surface of the handle define a gap that is narrowed when the block and the handle are gripped to bring the upper surface and the lower surface into contact with each other.

7. The image carrier unit according to claim 6 , wherein the block includes a rib on an upper surface of the block and, when the handle and the tab are gripped, the rib is engaged with a rib of the handle on the lower surface of the handle at a position different from a position of the rib of the handle to overlap with the rib of the handle in the insertion-removal direction.

8. The image carrier unit according to claim 2 , wherein the tab includes a nonslip portion on a gripped surface to prevent slipping when being pulled out to the near side.

9. The image carrier unit according to claim 8 , wherein the block has the bottom surface wider than an upper surface.

10. The image carrier unit according to claim 9 ,

wherein the image carrier unit includes a handle on the near side in the insertion-removal direction to be grippable together with the tab for insertion and removal of the image carrier unit, and

wherein the upper surface of the block and a lower surface of the handle define a gap that is narrowed when the block and the handle are gripped to bring the upper surface and the lower surface into contact with each other.

11. The image carrier unit according to claim 10 , wherein the block includes a rib on an upper surface of the block and, when the handle and the tab are gripped, the rib is engaged with a rib of the handle on the lower surface of the handle at a position different from a position of the rib of the handle to overlap with the rib of the handle in the insertion-removal direction.

12. The image carrier unit according to claim 8 ,

wherein the image carrier unit includes a handle on the near side in the insertion-removal direction to be grippable together with the tab for insertion and removal of the image carrier unit, and

wherein the upper surface of the block and a lower surface of the handle define a gap that is narrowed when the block and the handle are gripped to bring the upper surface and the lower surface into contact with each other.

13. The image carrier unit according to claim 12 , wherein the block includes a rib on an upper surface of the block and, when the handle and the tab are gripped, the rib is engaged with a rib of the handle on the lower surface of the handle at a position different from a position of the rib of the handle to overlap with the rib of the handle in the insertion-removal direction.

14. An image forming apparatus, comprising:

an image carrier unit removable from and attachable to an apparatus housing and including an image carrier;

a protection cover removable from and attachable to the image carrier unit and including a covering portion and a block, the covering portion covering an exposed portion of the image carrier, the block being disposed on a near side in an insertion-removal direction of the image carrier unit and protruding to cross the insertion-removal direction, the block opposing a surface of the image carrier; and

a protrusion being movable with respect to the apparatus housing and pressing the block of the protection cover attached to the image carrier unit inserted into the apparatus housing.

15. The image forming apparatus according to claim 14 , wherein the protrusion is attached to a body member that allows the image forming apparatus to operate by moving, moves horizontally toward the block in response to movement of the body member, and substantially perpendicularly comes into contact with a surface of the block.

16. The image forming apparatus according to claim 14 , wherein the protrusion has an amount by which the protrusion is to overlap the block, and comes into contact with the block to fail to move to a predetermined position when the protection cover is attached to the image carrier.

17. The image forming apparatus according to claim 15 , wherein the protrusion has an amount by which the protrusion is to overlap the block, and comes into contact with the block to fail to move to a predetermined position when the protection cover is attached to the image carrier.

18. The image forming apparatus according to claim 16 , wherein the amount by which the protrusion is to overlap the block exceeds a range within which a sensor determines a unit position as being normal.

19. The image forming apparatus according to claim 17 , wherein the amount by which the protrusion is to overlap the block exceeds a range within which a sensor determines a unit position as being normal.