When a sheet is determined to arrive at a registration roller, a motor is temporarily stopped and then, is rotated so as to return a cam to an initial position. When the motor is rotated, in a case where a relation between a rotation angle θ of the cam at the time of stopping the motor and a rotation angle γ of the cam according to the rotation of the motor in a time required for the motor until acceleration up to constant-speed rotation from a stopped state of the motor and until deceleration from the constant-speed rotation and stop after the deceleration is “θ 360−γ”, the motor is rotated at a constant second speed lower than the first speed.