Optical scanning device and image forming apparatus

摘要

An optical scanning device includes a vertical-cavity surface-emitting laser light source that emits laser beams perpendicular to a top surface thereof; a first optical system that couples the beams from the light source; a deflecting unit that deflects the beams; a second optical system that guides the beams from the first optical system to the deflecting unit; a third optical system that focuses the beams deflected by the deflecting unit into an optical spot on a scanned surface; and a light-quantity adjusting element disposed between the light source and the deflecting unit and having a substrate formed of a first and second surfaces. The first surface of the light-quantity adjusting element is coated with neutral density coating and the second surface is coated with antireflection coating so that reflectance of the second surface is made smaller than reflectance of the first surface.

主权项

1. An optical scanning device comprising:
a vertical-cavity surface-emitting laser light source that emits laser beams perpendicular to a top surface thereof; a first optical system that couples the laser beams from the light source; a beam limiting element that limits a thickness of the laser beams; a deflecting unit deflects the laser beams; a second optical system that guides the laser beams from the first optical system to the deflecting unit; and a third optical system that focuses the laser beams deflected by the deflecting unit into an optical spot on a scanned surface, wherein the second optical system includes a cylindrical lens having a curved surface coated with neutral density coating, wherein the curved surface coated with the neutral density coating reflects a part of the laser beams emitted from the light source, to thereby generate reflected beams in a direction toward the light source, and wherein the cylindrical lens having the curved surface is configured to converge and then diverge the reflected beams between the second optical system and the light source, such that the reflected beams do not enter into the light source.