Image forming apparatus and control method of image forming apparatus

摘要

An image forming apparatus has a charging unit (2a, 2b, 2c, 2d) which charges an image carrier by applying a voltage to a charging member arranged to be in contact with the image carrier. The image forming apparatus includes an alternating voltage applying unit (608) which generates an alternating voltage, a first voltage detection unit (609) which detects a positive peak voltage of the alternating voltage, a second voltage detection unit (610) which detects a negative peak voltage of the alternating voltage, a voltage amplitude determination unit (601) which determines an amplitude value of the alternating voltage based on the positive peak voltage detected, and an alternating voltage control unit (603, 604) which outputs a signal which changes an output from the alternating voltage applying unit.