HIGH-VOLTAGE POWER SUPPLY DEVICE AND IMAGE FORMING DEVICE

摘要

PROBLEM TO BE SOLVED: To make compatible the reduction of the number of control lines (common between clock signals) for connecting a high-voltage control part of a high-voltage power supply which outputs a high voltage so as to correspond to each of a plurality of loads and a high-voltage power supply part, and the elimination of wasteful power consumption in a system which is not necessary to be operated. SOLUTION: CLK signals to high-voltage generation parts 302to 304corresponding to the loads which are not operated (only a black-colored part is a load at monochrome printing) are blocked without increasing the number of control lines for connecting the high-voltage control part 10 and the composite high-voltage power supply part 20a, and the wasteful power consumption is eliminated. For this purpose, an OR circuit 43 for controlling a clock signal gate circuit 42 and a PWM signal detection circuit 41 are arranged in the composite high-voltage power supply part 20a. When the clock signal gate circuit 42 is in a gate-opened state (conductive state) usually, it is detected that the loads are in operation states at monochrome printing by making PWM signals to the loads which are not operated pass through the OR circuit 43 and the PWM signal detection circuit 41, a gate is closed by the signals, and inputs of the CLK signals to the high-voltage generation parts 302to 304having colors other than black are blocked. COPYRIGHT: (C)2011,JPO&INPIT