| 摘要 |
PURPOSE:To quickly converge the surface potential of a photosensitive body to a target potential by adding a manipulated variable obtained by multiplying a potential difference between a measured potential and the target potential by a control constant to an electrostatic charging voltage or a laser diode current quantity so that it may be set as a proportional constant which differs every control time. CONSTITUTION:A process control part 6 performs the transfer of each control signal C between a controller and the part 6, detection processing by VL (the surface potential of a photosensitive body at an exposed part) and VO (the surface potential of the photosensitive body at a non-exposed part) from an electrometer 50, the control of driving an LD driving part 41 and the control of the high voltage power source 7 of each charger 30. Then, it measure the surface potential of the electrostatically charged part and the exposed part of the photosensitive body and adds the manipulated variable obtained by multiplying the potential difference between the measured potential and the target potential by the control constant which is set at a different value every control time by a proportional controlled variable setting part 60 to a manipulated object. Thus, the surface potential of the photosensitive body is converged to the target potential in a short time. |
