| 摘要 |
PURPOSE:To perform a compensation in accordance with the deterioration of a photosensitive body by estimating the deterioration of the photosensitive body based on the counted value of a counter corresponding to the quantity of prints and changing the potential difference between the photosensitive body and an electrostatic charger in accordance with this estimated deterioration. CONSTITUTION:The counted value of a counter 1 is counted up by one for every one print, and a signal control circuit 2 reads in the counted value from a terminal 22 and outputs a voltage corresponding to the counted value. A high-voltage constant current generating circuit 3 outputs a voltage proportional to the charging voltage from a terminal 34, and this voltage is inputted again from a terminal 33 through a resistance 6 to output the charging current while performing the feedback control. Since the output of the control circuit 2 is inputted to the high voltage constant current generating circuit 3 from the terminal 33 through a resistance 7, the current inputted to the terminal 33 is changed in accordance with the counted value of the counter 1 to change the charging voltage. Thus, the surface potential of the photosensitive body is kept constant with an inexpensive constitution. |
