DEVELOPING DEVICE, PROCESS CARTRIDGE, AND IMAGE FORMING APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a developing device that can suppress density variation while optimizing a development bias responding to variation in a development gap due to an assembling error.SOLUTION: A developing device 5 includes: a developing roller 50, which comprises a magnet roller 55 having a plurality of magnetic poles and a developing sleeve 51 that has a cylindrical form including a magnet roller 55 inside, carries a developer on the cylindrical outer circumferential surface by the magnetic force of the magnet roller 55, and moves on the surface thereof by rotating with respect to the device main body; and a developing sleeve power supply 151 that applies a development voltage to the developing sleeve 51. The developing device further includes: development gap information acquiring means 603 that acquires information about a development gap in a gap between the developing roller 50 and a photoreceptor 1; and a control unit 600 that controls the development voltage containing an AC component based on the development gap acquired by the development gap information acquiring means 603.