Image forming apparatus and exposure position adjusting method

摘要

In one aspect of the present invention, exposure timings for a plurality of light beams are adjusted on the basis of a toner concentration of a boundary part between line images formed by one light beam and line images formed by another light beam neighboring the one light beam and a toner concentration of a part except the boundary part in a pattern image. Here, in the pattern image, line images extending in the main-scan direction of a photoreceptor are formed while having a predetermined pitch in the sub-scan direction of the photoreceptor and also the boundary part is arranged so as to be shifted from the sub-scan direction of the photoreceptor, by an image forming section.

主权项

1. An image forming apparatus comprising:
an image forming section configured to form a pattern image in which line images extending in a main-scan direction of a photoreceptor are formed periodically while having a predetermined pitch in a sub-scan direction of the photoreceptor by scanning of the photoreceptor with a plurality of light beams emitted from an exposing portion, and also a boundary part between line images formed by one light beam and line images formed by another light beam neighboring the one light beam is arranged so as to be shifted from the sub-scan direction of the photoreceptor; a toner concentration detecting section configured to detect a toner concentration of the pattern image on the photoreceptor or the transferred pattern image which has been transferred from the photoreceptor to a transfer material; and a control section configured to calculate exposure timings for the plurality of light beams in the image forming section on the basis of a toner concentration of the boundary part and a toner concentration of a part except the boundary part, the toner concentrations being detected by the toner concentration detecting section.