Optical beam scanning device and diaphragm device capable of adjusting light quantity distribution

Abstract

An optical beam scanning device of the present invention has a light source, a deflection reflecting surface for deflecting to scan light from the light source on a recording medium, and a diaphragm device which is provided between the light source and the deflection reflecting surface, and the diaphragm has an opening section formed by a nonplanar light shielding section. The light shielding section makes light shielding quantity of the light from the light source in a vertical scanning direction different in positions in a horizontal scanning direction and in a light advancing direction.

1 . An optical beam scanning device, comprising:
 a light source;   a deflection reflecting surface for deflecting to scan light from the light source on a recording medium; and   a diaphragm device provided between the light source and the deflection reflecting surface, the diaphragm device having an aperture formed by a nonplanar light shielding section, the light shielding section making a light shielding quantity of the light from the light source in a vertical scanning direction different in positions of a horizontal scanning direction and a light advancing direction,   wherein the light shielding section is composed of at least two or more nonplanar light shielding plates which have a certain angle to the horizontal scanning direction and are provided so as to shield the light from the light source.