| 摘要 |
PURPOSE:To shorten a fast copying time by inhibiting control from being performed once a controlled electrostatic charging value are settled within variation width in less than an expected frequency. CONSTITUTION:A blank exposure lamp 16 is turned on and off before image exposure 15 is started through the operation of a copy start key to generate light and dark potentials V1 and V2, which are measured by a sensor 17, whose outputs are sent to control part 18 and compared with a standard potential; and the results are sent to primary and secondary transformers 19 and 20 to conrol current values of primary and secondary charging operations so that they approach the standard value. This is repeated at the expected frequency, or until the difference from the standard potential decreases to within the range of an expected control value. Then, this control value is compared with control values of five times before - last time, and when the variation width of the comparison value is within some range, the control is not performed thereafter until a main switch is turned off to perform image formation with the control value of development. |
