Color image forming apparatus

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:na 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; anda 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.

A method for 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:na 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;na detection unit;a color misregistration correction control unit; anda light amount control unit;nthe method comprising:causing the pre-exposure unit to irradiate the photosensitive member surface with light before the photosensitive member surface is charged by the charging unit;causing the detection unit to detect an output of a 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;causing the light amount control unit to control a light emission amount of the pre-exposure unit; andcausing the light amount control unit to perform 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.