| 摘要 |
PURPOSE:To securely perform APC(Auto Power Control) control over laser light for a fast printing machine by holding a developing bias voltage at such a potential that an electrostatic latent image formed on a photosensitive body is not developed as the driving current of a semiconductor laser is controlled. CONSTITUTION:The electrophotographic printer has a means 1 which controls the driving current of the semiconductor laser at specific timing between images and a bias voltage control part 10 which holds the bias voltage at such a potential that the electrostatic latent image formed on the photosensitive body 8 is not developed while the latent image passes opposite the developing device as the driving current of the semiconductor laser is controlled. Therefore, the laser beam is projected on an image formation area on the photosensitive body 8 during the APC control, so the time for the APC control is secured sufficiently even for the fast printing machine. Then, the developing bias is controlled to the potential at which the electrostatic latent image formed on the photosensitive body 8 is not developed into a toner image, so no toner sticks on the photosensitive body. Consequently, the APC control is securely performed for the fast printer. |
