A rotation-body controlling apparatus including: a first motor configured to rotate a first rotation body; a second motor configured to rotate a second rotation body; a first rotation amount detecting portion configured to detect a rotation amount of the first rotation body rotated in synchronization with the first motor; a second rotation amount detecting portion configured to detect a rotation amount of a second rotation shaft rotated in synchronization with the second rotation body; a transmitting mechanism configured such that a rotation of the first rotation body is transmittable to the second rotation shaft; and an origin-position detecting portion configured to detect an origin position of a rotation phase of the first rotation body on the basis of a phase of the first rotation body at a time when the second rotation amount detecting portion has detected a rotation of the second rotation shaft, where the rotation of the first rotation body operated by the first motor is transmitted to the second rotation shaft via the transmitting mechanism.