Color image forming apparatus

摘要

An image forming apparatus includes a process unit arranged in the vicinity of the circumference of each photosensitive member and the process unit is configured to act on the photosensitive member in forming a toner image thereon. The image forming apparatus detects a time period since a laser beam emission unit emits a laser beam to the photosensitive member to form an electrostatic latent image for detection until the formed electrostatic latent image for detection or a toner image based on the electrostatic latent image for detection reaches the process unit, and performs color misregistration correction control based on the result of detection. In this case, a control unit at least decreases the light amount of a pre-exposure LED when the electrostatic latent image for detection passes through a position facing the pre-exposure LED.

主权项

1. A color image forming apparatus including an image forming unit, wherein the image forming unit includes a rotating photosensitive member, a charging unit configured to charge the photosensitive member, a light irradiation unit configured to perform light irradiation to form an electrostatic latent image on the photosensitive member, a development unit configured to apply toner to the electrostatic latent image to form a toner image on the photosensitive member, and a transfer unit configured to transfer the toner image adhering to the photosensitive member onto a belt, the color image forming apparatus comprising:
a pre-exposure unit configured to be arranged on the downstream side of the transfer unit in a rotational direction of the photosensitive member and to irradiate the photosensitive member surface with light before the photosensitive member surface is charged by the charging unit; a power supply unit configured to supply power to the charging unit associated with the photosensitive member; a detection unit configured to detect an output of the power supply unit when an electrostatic latent image for color misregistration correction that is formed on the photosensitive member by the light irradiation performed by the light irradiation unit passes through a position facing the charging unit; a color misregistration correction control unit configured to control a color misregistration correction based on the result of detection by the detection unit so that a detected color misregistration state at least comes closer to a reference state; and a light amount control unit configured to control a light emission amount of the pre-exposure unit, wherein the light amount control unit performs control such that the pre-exposure unit has a decreased light emission amount when the formed electrostatic latent image for color misregistration correction passes through a position facing the pre-exposure unit before passing through the position facing the charging unit.