| 摘要 |
PROBLEM TO BE SOLVED: To reduce the loss of power consumption and to improve efficiency by connecting a pump up circuit and a voltage generation part in a flyback period and preventing the pump up circuit and the voltage generation part from connecting in a scanning period. SOLUTION: The voltage generation part 13 supplying power voltage to a signal amplification part 11 and a capacity element for charge/discharge Cp are provided. In the scanning period, the capacity element Cp is charged and capacity element Cp is discharged in the flyback period. The pump up circuit 12 boosting prescribed voltage and obtaining the power voltage of the signal amplifier 11 and a switch circuit 15 which is connected between the voltage generation part 13 and the pump up circuit 12, connects the pump up circuit 12 and the voltage generation part 13 in the flyback period and prevents the connection of the pump up circuit 12 and the voltage generation part 13 in the scanning period are provided. Thus, a problem that follow-up to the output voltage of the signal amplification part 11 is impossible, the loss of power becomes large and efficiency deteriorates can be suppressed. |
