| 摘要 |
<p>PURPOSE:To prevent generation of an optical memory by image exposure on the surface of an image forming body by shutting off the image exposure to the surface of the image forming body according to the detection signal of a detecting means when the abnormal state of a device such as jam of a sheet material for printing arises. CONSTITUTION:A jam detecting means 20 such as microswitch to detect the jam of the sheet material 17 is provided and an optical scanning unit 11 is returned to a home position 11H according to the detection signal thereof so that the image is not exposed on the surface of a photosensitive drum. More specifically, a drum driving motor of a printer mechanism part C is instantaneously stopped and an optical mirror driving motor of an optical scanning mechanism part B is driven in succession until the unit 11 returns to the home position 11H when the jam arises. Generation of the optical memory on the surface 10 of the image forming body is thereby prevented and, therefore, the printed image having high image quality is always obtd. without generating fogging, white voids, etc., on the image.</p> |
