Image formation apparatus

1. An image formation apparatus, comprising:

an image formation unit including an image carrier configured to carry a developer image;

a drive unit configured to drive the image carrier;

a holder provided with the drive unit and configured to move together with the image formation unit;

a transfer unit located opposed to the image carrier and configured to transfer the developer image from the image carrier onto a transfer medium; and

a switching unit configured to switch a position of the holder, between an image formation position, at which the transfer unit is operational to transfer the developer image from the image carrier onto the transfer medium, and a non-image formation position.

2. The image formation apparatus according to claim 1 , wherein

the holder is configured to move together with the image formation unit in a state where the holder holds the image formation unit and maintains a connection between the image carrier and the drive unit.

3. The image formation apparatus according to claim 1 , wherein

the switching unit is configured to move the holder together with the image formation unit.

4. The image formation apparatus according to claim 1 , wherein

the holder includes a first support unit configured to engage with an apparatus main body and support the holder and the image formation unit, and

the switching unit includes:

a slider configured to engage with the first support unit and move the holder and the image formation unit to the image formation position or the non-image formation position; and

a slider drive unit configured to drive the slider.

5. The image formation apparatus according to claim 4 , wherein

the transfer medium is an intermediate transfer belt,

the apparatus main body includes a first engagement hole configured to engage with the first support unit or a second support unit, and

the first engagement hole extends in a direction in which the image carrier is brought into contact with and is separated from the intermediate transfer belt.

6. The image formation apparatus according to claim 1 , wherein

the image formation unit includes a second support unit configured to engage with the apparatus main body and support the holder and the image formation unit,

the switching unit includes:

a slider configured to engage with the second support unit and to move the holder and the image formation unit to the image formation position or the non-image formation position; and

a slider drive unit configured to drive the slider.

7. The image formation apparatus according to claim 6 , wherein

the transfer medium is an intermediate transfer belt,

the apparatus main body includes a second engagement hole configured to engage with one of the first support unit and the second support unit, and

the second engagement hole extends in a direction in which the image carrier is brought into contact with and separated from the intermediate transfer belt.

8. The image formation apparatus according to claim 1 , wherein

the transfer medium is a belt member.

9. The image formation apparatus according to claim 1 , wherein

the transfer medium is a printing paper sheet.

10. The image formation apparatus according to claim 1 , wherein

the image formation unit is configured to slide to and removably mount to the holder.

11. The image formation apparatus according to claim 1 , wherein

the image formation unit is movable in a direction to be brought into contact with and separate from the transfer medium.

12. The image formation apparatus according to claim 1 , wherein

the image carrier and the drive unit are connected by a joint unit capable of being connected or released along an axis direction.

13. The image formation apparatus according to claim 1 , wherein

the image carrier comprises a gear wheel configured to mesh with a drive gear on the drive unit for rotatably driving the image carrier.

14. The image formation apparatus according to claim 1 , wherein

the transfer unit includes the transfer medium.

15. The image formation apparatus according to claim 14 , wherein

the transfer unit is an intermediate transfer belt unit configured to transfer the developer image from the image carrier onto the transfer medium.

16. The image formation apparatus according to claim 1 , wherein

the transfer medium comprises a recording medium.

17. The image formation apparatus according to claim 16 , wherein

the transfer unit is a direct transfer unit configured to directly transfer the developer image from the image carrier onto the recording medium as the transfer medium.

18. The image formation apparatus according to claim 15 , wherein

the intermediate transfer belt unit includes:

an intermediate transfer belt as the transfer medium;

a drive roller configured to drive the intermediate transfer belt;

a primary transfer roller facing the image carrier with intermediate transfer belt between the primary transfer roller and the image carrier at a primary transfer position and configured to transfer the developer image from the image carrier to the intermediate transfer belt; and

a secondary transfer backup roller facing a secondary transfer roller with the intermediate transfer belt between the secondary transfer backup roller and the secondary transfer roller at a secondary transfer position, wherein the secondary transfer roller is configured to transfer the developer image from the intermediate transfer belt to a recording medium at the secondary transfer position.

19. The image formation apparatus according to claim 17 , wherein

the direct transfer unit includes:

a conveyance belt;

a drive roller configured to drive the conveyance belt; and

a transfer roller facing the image carrier with intermediate transfer belt between the transfer roller and the image carrier and configured to transfer the developer image from the image carrier to the recording medium being conveyed on the conveyance belt.