Imaging unit and image forming apparatus including connecting development device and drum cartridge

1. An imaging unit comprising:

a drum cartridge having an image carrier composed of a photosensitive drum, a butting member and a fixation release member that rotates about a fulcrum, and

a development device having a development roller facing the image carrier, the development device developing an electrostatic latent image formed on the image carrier to form a toner image,

wherein the drum cartridge and the development device are provided so as to be allowed to be connected to and separated from each other and the drum cartridge and the development device, when connected to each other, can be made to pivot relative to each other on a shaft of the development roller that is engaged between the butting and fixation release members.

2. The imaging unit as claimed in claim 1 , wherein

a roller or a D-cut shaft is provided on the shaft of the development roller of the development device to butt with the butting member and the fixation release member,

which is capable of pressing the roller or the D-cut shaft of the development roller against the butting member and which is capable of releasing the pressure against the butting member.

3. The imaging unit as claimed in claim 1 , wherein the drum cartridge and the development device in a situation connected to each other can be attached to an image forming apparatus body in an axial direction along rails provided on the image forming apparatus body and can be drawn out of the image forming apparatus body.

4. The imaging unit as claimed in claim 1 , further comprising a plurality of positioning members for positioning of the drum cartridge with respect to the image forming apparatus body when the drum cartridge and the development device in a situation connected to each other are attached to the image forming apparatus body, and a turn prevention member for preventing the development device from turning relative to the drum cartridge.

5. The imaging unit as claimed in claim 4 , wherein the development device is prevented by the turn prevention member from turning after the positioning of the drum cartridge is achieved by the positioning members.

6. An image forming apparatus comprising:

the imaging unit as claimed in claim 1 ,

rails for attaching and drawing of the imaging unit, and

receiving members for positioning of the imaging unit.

7. The image forming apparatus as claimed in claim 6 , wherein

a roller or a D-cut shaft is provided on the shaft of the development roller of the development device to butt with the butting member and the fixation release member,

which is capable of pressing the roller or the D-cut shaft of the development roller against the butting member and which is capable of releasing the pressure against the butting member.

8. The image forming apparatus as claimed in claim 6 , wherein the drum cartridge and the development device in a situation connected to each other can be attached to an image forming apparatus body in an axial direction along rails provided on the image forming apparatus body and can be drawn out of the image forming apparatus body.

9. The image forming apparatus as claimed in claim 6 , further comprising a plurality of positioning members for positioning of the drum cartridge with respect to the image forming apparatus body when the drum cartridge and the development device in a situation connected to each other are attached to the image forming apparatus body, and a turn prevention member for preventing the development device from turning relative to the drum cartridge.

10. The image forming apparatus as claimed in claim 9 , wherein the development device is prevented by the turn prevention member from turning after the positioning of the drum cartridge is achieved by the positioning members.