Photoreceptor drum and image forming apparatus

An image forming apparatus, comprising:

• a photoreceptor drum and a process unit which acts on said photoreceptor drum which are detachably provided;
• said photoreceptor drum including a barrel-shaped drum whose peripheral surface is coated with a photosensitive layer and which is provided with a flange;
• a coupling section at which said photoreceptor drum is attached to or detached from said image forming apparatus includes an input section and an apparatus output section;
• and
• said input section is composed of an internal gear formed on the inner surface, and receives rotation driving force from said image forming apparatus main body;
• and
• said apparatus output section includes an external gear having teeth shaped in an involute curve, and is provided in an image forming apparatus main body for outputting rotation driving force from said image forming apparatus main body to said input section.

An image forming apparatus comprising:

• a photoreceptor drum unit provided with a photoreceptor drum including a barrel-shaped drum whose peripheral surface is coated with a photosensitive layer, said photoreceptor drum unit being detachably provided from an image forming apparatus main body, wherein:
• said barrel-shaped drum includes a first flange at one end, a second flange at the other end and a rotation axis which passes through a center of said barrel-shaped drum and which supports said first flange and said second flange;
• said first flange includes an input section for receving rotation driving force from said image forming apparatus main body and an output section for transmitting rotation driving force to said process unit which acts on said photoreceptor drum;
• one end of said rotation axis is projected out of said second flange and is supported by the flame member of said photoreceptor drum unit so as to be freely rotatable;
• the other end of said rotation axis extends to a position where said input section and said output section are overlapped with each other;
• and
• at said position where said input section and said output section are overlapped, the other end of said rotation axis is fit in a fitting section provided in an axis of said image forming apparatus main body for transmitting rotation driving force to said barrel-shaped drum.