| 摘要 |
PURPOSE:To hold a photosensitive body and an optical scanning mechanism in constant synchronism relation of start timing by generating a reference signal for the formation start position of an electrostatic latent image in synchronization with the rotation of a photosensitive body, and starting the optical scanning mechanism based on the signal when the photosensitive body reaches a prescribed angle of rotation. CONSTITUTION:When a motor 21 is started first and the photosensitive drum 1 begins to rotate, a pulse generator 27 generates a signal PRZ and then a motor 18 is started a prescribed time later, so that a pulse generator 26 generates rotary pulse signals CRB and CRA. The measuring means of a servocontroller 23 counts the signal CRB or CRA to generate a reference signal CRZ, based on said signal CRZ and optical systems 10 and 11 are started when the photosensitive drum 1 reaches the prescribed angle of rotation. When the moving optical systems 10 and 11 reach the position of a sensor 29, a latent image begins to be formed on a photosensitive rod 1 with a signal SNSR. The speed of the motor 22 which is started at the same time is controlled based on the signal SNSR to make the transfer start point of a transfer drum 6 coincident with the latent image start point of the photosensitive drum 1. |
