发明名称 Image forming apparatus with beam splitter and aperture positioned for compactness
摘要 An image forming apparatus is provided that reduces main scanning jitter with a simple configuration and performs light amount control with high accuracy. The image forming apparatus includes: a laser emitting luminous flux; a main-scanning aperture portion shaping the luminous flux; a beam splitter splitting the luminous flux passed through the main-scanning aperture portion into a reflected beam and a transmitted beam; a rotary polygon mirror deflecting the transmitted beam so that the transmitted beam scans the surface of a photosensitive drum; and an optical box in which the laser, the main-scanning aperture portion, the beam splitter and the rotary polygon mirror are disposed. The main-scanning aperture portion is disposed so as not to block a deflected and transmitted beam. The beam splitter abuts against the main-scanning aperture portion so as not to block a deflected and transmitted beam deflected, and is positioned by abutting against the main-scanning aperture portion.
申请公布号 US8970650(B2) 申请公布日期 2015.03.03
申请号 US201313856878 申请日期 2013.04.04
申请人 Canon Kabushiki Kaisha 发明人 Iwamoto Kazuyuki
分类号 B41J15/14;B41J27/00;G03G15/043 主分类号 B41J15/14
代理机构 Fitzpatrick, Cella, Harper & Scinto 代理人 Fitzpatrick, Cella, Harper & Scinto
主权项 1. An image forming apparatus, comprising: a light source configured to emit a laser beam; an aperture configured to shape the laser beam that is emitted from the light source; a beam splitter configured to split the laser beam, which is shaped by the aperture, into a first laser beam that is a reflected beam and a second laser beam that is a transmitted beam, wherein the beam splitter is positioned by contacting to the aperture, and wherein the first laser beam is reflected for incidence on a light-receiving unit; a deflection unit configured to deflect the second laser beam so that the deflected second laser beam scans a photosensitive member; a lens configured to guide the second laser beam deflected by the deflection unit to the photosensitive member, wherein the lens is disposed at a closest position to the deflection unit in a plurality of optical elements, which includes the lens, on an optical path of the second laser beam deflected by the deflection unit; an optical box in which the light source, the aperture, the beam splitter, the light-receiving unit, the deflection unit, and the lens are disposed; and a control unit configured to control a light amount of the laser beam that the light source emits based on a light amount of the first laser beam received by the light-receiving unit; wherein the aperture and the beam splitter are disposed between an optical axis of the lens and an end of the lens on a side where the light source is disposed, in a longitudinal direction of the lens, and wherein the aperture defines a position of the beam splitter relative to the optical box so that the beam splitter is prevented from blocking the second laser beam deflected by the deflection unit for incidence on the lens and so that an extension line, which overlaps an optical path of the first laser beam reflected by the beam splitter and which extends toward a side of the beam splitter, intersects with the lens.
地址 Tokyo JP