Abnormal voltage alarming circuit for electrophotographic printing device

Abstract

Abstract PURPOSE:To shorten a printing interruption period by providing circuits comparing 1st and 2nd reference voltages with a discharge voltage, displaying the cleaning alarm when the discharge voltage exceeds the 1st reference one, and instructing printing stoppage when the discharge voltage exceeds the 2nd reference one. CONSTITUTION:Comparators 12a to 12d compare the voltage of an electrifier 1 and the discharge voltage Vin of a transfer unit 5 with the two-staged reference voltages such as prealarm and alarm, and prealarm display and printing stoppage are carried out. When the discharge voltage Vin exceeds the 1st reference voltage, the comparator 12b or 12c outputs a signal due to a change in the impedances of the electrifier 1 and the transfer unit 5, and displays the prealarm to prompt the cleaning of the electrifier 1 and the transfer unit 5. When the discharge voltage Vin changes greatly to exceed the 2nd reference voltage, the comparators 12a and 12d output signals to instruct printing stoppage. In such a way a printing interruption period can be shortened.

Inventors

• 👤 Shigeo Nemoto
• 👤 茂雄 根本
• 👤 Shigeru Wakamatsu
• 👤 茂 若松

Bibliographic Details