| 摘要 |
PURPOSE:To stabilize the level of picture density by forming the electrostatic latent images of reference light patterns on a picture forming body, detecting the potential thereof, comparing the same with reference potential, calibrating and controlling a latent image forming process and further detecting the picture density of the final copy by the reference light pattern and comparing the same with a reference value. CONSTITUTION:A latent image forming process by a reference light pattern is executed upon a photoreceptor 1 by outputting signals at preset integrated copying times. The potential of the bright and dark parts of latent images is detected with a sensor 12, and is inputted to an operational amplifier 14 via an amplifier 13, where it is compared with reference potential. In accordance with the result thereof, the high vaoltage power sources 15, 16 of electrostatic chargers 4, 5 are corrected and controlled. Thereafter, the reference light pattern is again obtained as the final copy by the copying process and the picture density thereof is detected with a sensor 19 and is inputted to an arithmetic control circuit 20, where it is compared with the reference value, and the control for the developer concn. is calibrated to an adequate level. |
