Patent ID: 8903278

Claim:
An image forming apparatus comprising: a drum-shaped image bearer; a rotary member disposed around the image bearer; and a drive unit to drive the image bearer and the rotary member, the drive unit comprising: a drive source; an output gear driven by the drive source; a first gear to engage the output gear, the first gear greater in diameter than the output gear; a first joint member projecting from a rotation center of the first gear coaxially with the first gear and coupled to a rotation center of the first rotary member; a second gear disposed between the first gear and the first joint member and connected to the first gear and the first joint member coaxially therewith, the second gear smaller in diameter than the first gear; a driven gear to engage the second gear to be driven thereby, the driven gear smaller in diameter than the first gear and disposed entirely within an area of the first gear in a radial direction thereof; and a second joint member projecting coaxially from a rotation center of the driven gear in a direction in which the first joint member projects and connected to a rotation center of the rotary member.