Optical scanning device and image forming apparatus including the same

摘要

An optical scanning device is disclosed. The optical scanning device comprises an overfilled optical system in which an incoming light beam, formed wider than a width in a rotation direction of a rotating multifaceted mirror's reflective surface, is caused to be incident on the reflective surface and a scanning object's scanning surface is scanned by an outgoing beam reflected by the reflective surface. The incoming beam is incident on the rotating multifaceted mirror's reflective surface, having an angle with respect to a virtual vertical surface that is vertical to the scanning surface and the outgoing beam's scanning direction. A light amount distribution for positions on the scanning surface in the scanning direction is corrected based on a slope of a straight line that expresses a ratio of light amount changes for positions on the scanning surface in the scanning direction when scanning the scanning surface using the outgoing beam.

主权项

1. An optical scanning device comprising an overfilled optical system in which an incoming beam of a light beam incident on a reflective surface of a rotating multifaceted mirror from a light source is incident such that the width of the incident light beam is wider on the reflective surface than a width in a rotation direction of the reflective surface of the rotating multifaceted mirror, and is reflected on the reflective surface; and a scanning surface of a scanning object is scanned by an outgoing beam reflected by the reflective surface,
wherein the incoming beam is caused to be incident on the reflective surface of the rotating multifaceted mirror in a state having an angle with respect to a virtual vertical surface that is vertical to the scanning surface and vertical to a scanning direction of the outgoing beam so that a light amount distribution is approximated by a straight line having a one-sided gradient, the light amount distribution for positions on the scanning surface in the scanning direction when scanning the scanning surface using the outgoing beam, wherein the light amount distribution for positions on the scanning surface in the scanning direction is corrected based on a slope of the straight line; wherein a light emission amount of the light source is controlled to perform the correction based on the slope of the straight line, and wherein a first light amount detection portion that detects a light amount of the outgoing beam at a scan start side of the scanning surface, and a second light amount detection portion that detects the light amount of the outgoing beam at a scan finish side of the scanning surface are provided so that the slope of the straight line can be obtained based on the light amount detected by the first light amount detection portion and the second light amount detection portion.