Patent ID: 7526231

Claim:
An image forming apparatus, comprising: a driver unit integrated to the image forming apparatus; a drive gear, having a first contact portion and connected to the driver unit, configured to be driven with a driving force of the driver unit; a drive-force output gear, having a second contact portion and connected to the drive gear with a common shaft, configured to be driven with the drive gear, the drive-force output gear being relatively rotatable with respect to the drive gear; a driven unit, detachably provided in the image forming apparatus, comprising: a rotating member; and a drive-force input gear configured to be connected to the rotating member to rotate the rotating member, the drive-force input gear being contactable with the drive-force output gear when the driven unit is installed into the image forming apparatus, and engageable with the drive-force output gear with a rotation of at least one of the drive-force input gear and drive-force output gear in one direction; wherein the drive gear is rotated by the driving force of the driver unit to contact the first contact portion of the drive gear to the second contact portion of the drive-force output gear after installing the driven unit in the image forming apparatus so that the drive gear and drive-force output gear are integrally rotatable, and wherein the driver unit is driven at a first driving speed to rotate the drive gear, by which the first contact portion of the drive gear is contacted to the second contact portion of the drive-force output gear, and the driver unit is driven at a second driving speed, by which the image forming apparatus conducts an image forming operation after the first contact portion of the drive gear is contacted to the second contact portion of the drive-force output gear, and the first driving speed is set to a slower speed as compared to the second driving speed wherein the driver unit is driven at the first driving speed after installing the driven unit in the image forming apparatus, the driver unit is deactivated when the first contact portion of the drive gear and the second contact portion of the drive-force output gear contact each other, and the driver unit is then driven at the second driving speed to conduct an image forming operation; and wherein the driver unit is driven at the first driving speed to contact the first contact portion of the drive gear to the second contact portion of the drive-force output gear while operation of another driven unit provided in the image forming apparatus is stopped.