| 摘要 |
PURPOSE:To make a lamp lighting circuit independent of a high-voltage power supply device by addtion of only a resistor, switch and capacitor by lighting a lamp by the charging energy from a power supply for Corotrons to a capacitor and charging the capacitor prior to electrostatic charging after transferring. CONSTITUTION:A DC high voltage is kept impressed at all times to 'Corotrons 5-7. A switch 3 is changed over to a high voltage DC power supply circuit 1. C4 starts charging and after charging, the switch 3 is set neutral. Since the charging current changes in this charging, the charging is carried out after transferring and before electrostatic charging. When the part of a photosensitive material 8 used for exposure arrives at the front surface of an optical system including a high-voltage discharge lamp 9, the switch 3 is changed over to the lamp 9 side. Then the DC high voltage of the C4 is impressed on the lamp 9 by which the lamp is lighted. The lighting of the lamp 9 continues until the energy of the C4 is consumed and the voltage of C drops to the voltage for maintaining the discharge or below. It is equally well to light the lamp only during the time when the illuminance is nearly constant in terms of the uniformity of the copied image. |
