Patent ID: 7466941

Claim:
A drive device comprising: a planetary roller type power transmission unit having a motor having and being configured to rotate a motor rotation shaft, a plurality of planetary rollers having at least a part thereof made from an elastic material, said plurality of planetary rollers being pressed against the periphery of said motor rotation shaft, a ring being configured to contact said plurality of planetary rollers on an internal surface of said ring, a carrier roller being configured to rotate in conjunction with the rotation of said plurality of planetary rollers, and an output shaft being configured to output the rotation of said carrier roller to a driven device; a measurement unit being configured to measure a temperature of said planetary rollers or a temperature near the planetary rollers; a delay time determination unit being configured to determine a delay time from a starting time of said motor until a start of an image forming process based on the temperature measured by said measurement unit; and an image processing control unit being configured to start said image forming process after said delay time has passed from the starting time of said motor.