| 摘要 |
PURPOSE:To provide a method for carrying out concentration adjustment without varying a development bias, in an electrophotography. CONSTITUTION:The light source 3a of a light exposure means 3 is driven by the drive pulse supplied from a driving means 15. As for the printing signal, the signal having a set pulse width is inputted into the driving circuit 15 by a pulse width setting means 16, the light exposure time per dot forms the set pulse width. The radiation energy applied to a photosensitive drum varies substantially according to the light exposure time, and the light exposure electric potential can be varied. Since, if the development bias is constant, the development electric potential varies according to the light exposure electric potential, concentration adjustment is enabled. |
