Patent ID: 8099021
Filing Date: 2012-01-17
Classification: G03G

Abstract:
1. An image forming apparatus comprising: four image carriers; four image carrier gears corresponding to the respective image carriers; four transmission gears corresponding to and meshed with the respective image carrier gears; and two driving sources, each corresponding to a pair of the transmission gears being adjacent to each other, for driving each pair of transmission gears, two phase detection units corresponding to the respective pairs of transmission gears for detecting a phase of at least one of the pair of transmission gears; and a control unit for controlling the respective driving sources on the basis of detection results of the respective phase detection units, wherein in each pair of transmission gears, with a phase of one transmission gear being set as a reference phase, a phase of the other transmission gear is provided so as to shift with respect to the reference phase by a rotation angle α° as expressed by the following formula (2): where P1 is a distance between centers of the image carriers being adjacent to each other; and D is a diameter of the image carrier.