Patent ID: 7721859

Claim:
A rotary force controlling apparatus of an image forming apparatus, comprising: a clutch device including a shaft and a rotary body mounted on one end of the shaft; a housing into which the shaft is inserted and that rotates together with the shaft; a power transferring member rotatably mounted in the housing and selectively rotates the housing by a clutch inserted between the housing and the power transferring member; and a positioning unit protruding from the periphery of the housing that positions a stop location of the rotary body; a solenoid unit spaced apart from the clutch device and that is selectively turned on and off; the positioning unit including a first positioning unit that positions an initial location of the rotary body when the solenoid unit is turned on, and a plurality of second positioning units that are separated from the first positioning unit and that stop the rotary body at other locations when the solenoid unit is turned off; and a connecting member integrally assembling both sides of the clutch device and the solenoid unit together; wherein the second positioning units form a pair and are symmetrical around the center of the housing, and the first positioning unit is positioned at approximately 90° degrees from each of the second positioning units around the center of the housing, wherein the first positioning unit and the plurality of second positioning units are located on the same even periphery of the housing and the first positioning unit having a different shape from the plurality of second positioning units, and wherein the plurality of second positioning units have substantially the same height different than the height of the first positioning unit, such that the first positioning unit interferes with the interfering unit only when the solenoid is turned on.