| 摘要 |
PURPOSE:To provide the titled apparatus enabled in the simplification of constitution and the achievement of cost reduction, constituted so as to remove the directly induced noise of a charging electrode by a gate pulse synchronous to a charging pulse. CONSTITUTION:A sensor 5 is connected to a comparator 12 through an amplifier 10 and the comparator 12 is connected to an AND circuit 15 for limiting the passage of a comparison signal. The AND circuit 15 checks the reversal output of a gate pulse generating circuit 14 for generating a gate pulse synchronous to the charging pulse of a charging electrode 4 and the AND condition of the output of a comparator 12 and the comparison signal is passed only when the gate pulse is not outputted. The comparison signal passed through the AND circuit 15 is subjected to signal treatment in a control part 13. |
