| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming device with a piezoelectric transformer type high-voltage power supply unit capable of a stable high-voltage output at start-up time with practically no problems in a simple method, by suppressing control of a voltage control oscillator (VCO) and oscillation of an output voltage. <P>SOLUTION: The piezoelectric transformer type high-voltage power supply unit used for the image forming device includes a latent image forming portion for forming an electrostatic latent image on an image supporter, a development portion for forming a toner image in the electrostatic latent image, and a transfer portion for transferring the toner image in a transfer material. The power supply unit includes a piezoelectric transformer, a piezoelectric transformer drive circuit, an output voltage set signal output circuit for outputting the output voltage set signal, output voltage detection circuit, and a drive control circuit for outputting a control signal for controlling a piezoelectric transformer drive circuit based on the signal from the output voltage detection circuit and the output voltage set signal. The output voltage set signal output circuit outputs the output voltage set signal corresponding to a voltage less than a target voltage, and then attains to output the output voltage set signal corresponding to the target voltage. <P>COPYRIGHT: (C)2007,JPO&INPIT |
