DISCHARGE DETECTION CIRCUIT, DEVELOPING DEVICE, CHARGING DEVICE, AND IMAGE FORMING APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a discharge detection circuit capable of achieving a reduction in power consumption, and contributing to energy saving of an image forming apparatus.SOLUTION: A discharge detection circuit 20A includes: a high-voltage insulating cable 24 that connects a high-voltage output terminal 22a of a high-output transformer 22 as a high-voltage power source, with a developing roller 42 of a developing device; a pulse transformer 26 that is provided with a core 32 in a closed loop shape; a rectification circuit 28 that rectifies a secondary voltage obtained from electromagnetic induction between primary winding and secondary winding of the pulse transformer 26; and a smoothing circuit 30 that smooths output from the rectification circuit 28. The primary winding of the pulse transformer 26 is formed by penetrating the high-voltage insulating cable 24 into the core 32, and the secondary winding is formed by winding low-voltage insulating enameled electric wire 25 as low-voltage insulating electric wire around the core 32 by a predetermined number of times. A development gap g as a minute gap is set between a photoreceptor 2 and the developing roller 42.