Control method for development bias

Abstract

Abstract PURPOSE:To obtain copies without background, by grasping the characteristics of a photoreceptor from the amount of exposure by a reference pattern and a crrepage potential, and controlling the development bias voltage according to the light amount of background and creepage potential at original copying. CONSTITUTION:The amount of exposure of a reference pattern formed with specified dark and light regions 2A, 2B and the creepage potential of a photo sensing drum formed with this exposure are detected with sensors 17, 19 and a development bias operation controller 18 can operate and grasp the characteristic of a photoreceptor 10. Then, the amount of exposure and creepage potential of the background of an original 3 are detected with the sensors 17, 19 and applied to the device 18 to control the bias voltage of a developper 13. With this constitution, the copying without background and dirt can be made independently of time eging characteristic variance of the photoreceptor, and types of originals with different reflection factors of background.

Inventors

• 👤 Makoto Kozu

Bibliographic Details