Patent ID: 8152686

Claim:
A drive transmission device comprising, a drive source capable of producing a rotational drive force; a drive transmission unit configured to transmit the rotational drive force of the drive source; a drive transmission switching mechanism having a sun gear, a planetary gear, and a planetary arm capable of supporting the planetary gear so as to be freely revolvable around the sun gear, the drive transmission switching mechanism being capable of selectively switching the rotational drive force from the drive transmission unit to a plurality of drive transmission destinations; a plurality of drive input gears capable of transmitting the rotational drive force transmitted from the drive transmission switching mechanism to the drive transmission destinations; a clutch mechanism capable of switching a revolving state of the planetary gear between a freely revolvable state where the rotational drive force of the sun gear is transmitted to the planetary arm so that the planetary arm is able to rotate and a revolving restricted state where the rotational drive force of the sun gear is not transmitted to the planetary arm so that the planetary arm is unable to rotate; and a revolving state switching unit capable of operating the clutch mechanism by moving the planetary gear in an axial direction of the center of revolution, thereby switching between the revolving restricted state and the freely revolvable state, wherein: in the revolving restricted state, the planetary gear meshes with the drive input gear, and the clutch mechanism is unable to transmit the rotational drive force; in the freely revolvable state, the planetary gear is separated apart from the drive input gear, and the clutch mechanism is able to transmit the rotational drive force; the drive transmission switching mechanism is provided with first and second abutting portions which are configured to come into contact with the planetary arm rotated in the freely revolvable state so as to initialize the revolving position of the planetary gear; and the drive transmission switching mechanism is capable of selecting which one of the first and second abutting portions will come into contact with the planetary arm in accordance with the position of the drive input gear transmitting the rotational drive force among the plurality of drive input gears.