| 摘要 |
PURPOSE:To compensate various fluctuations of charging properties of a drum and to obtain an optimum picture, by compensating the picture conditions using a control coefficient which is coincident with the drum characteristics with the variation properties at the early stage of charging and the charging career. CONSTITUTION:In the case of the charging control, both the bright and dark part potentials VSL and VD on the surface of a drum are measured by a sensor 8. Thus the primary and secondary currents I1 and I2 of the primary and secondary chargers 5 and 6 are obtained first from the control coefficient that is previously stored. Then the potentials VSL and VD are measured when the currents I1 and I2 are changed three times to calculate a new control coefficient. Thus the I1 and I2 are obtained to perform the charging control. In the same way, both the exposure value and the development bias are controlled. Then the charging stop time is integrated with the charging time, and a prescribed operation is carried out to give a correction to the voltage VHL. In such a way, the picture conditions coincident with the drum characteristics is compensated by the leading characteristics and the charging career to obtain an optimum picture. |
