Patent ID: 7864300

Claim:
A door opening and closing unit for an image forming apparatus, the image forming apparatus comprising a main body, and a door rotatably mounted on the main body, the door opening and closing unit comprising: a door speed control unit coupling the door to the main body, the door speed control unit comprising: a coupling boss; a guide groove that engages the coupling boss and along which the coupling boss moves as the door rotates relative to the main body; and a speed control groove provided on one side of the guide groove inclined at a predetermined angle with respect to a lengthwise direction of the guide groove, wherein the door speed control unit controls a frictional force between the coupling boss and the guide groove according to a rotating angle of the door relative to the main body to control a rotating speed of the door as the door rotates relative to the main body, wherein the door speed control unit gradually reduces a rotating speed of the door as the door rotates from a closed position in which the door is rotated against the main body to a fully open position in which the door is maximally rotated away from the main body.