| 摘要 |
PURPOSE:To inexpensively provide a copying device in which the effective voltage of impressed voltage on an exposing lamp and a ceramic heater is made constant regardless of the fluctuation of a commercial AC power source. CONSTITUTION:The AC power source is inputted in a phase control circuit 27, and the effective voltage of the exposing lamp 2 is made constant according to output from the circuit 27. Then, the time from the rising of an output signal from a zerocross generation circuit 28 till the rising of an output signal from the circuit 27 is measured by a microprocessor Q7, and the peak voltage value of the AC power source is obtained based on the measured value, and the microprocessor Q7 controls so that the effective voltage of the impressed voltage on the ceramic heater 24 may be constant. |
