Patent ID: 7450146
Filing Date: 2008-11-11
Classification: G02B,H04N

Abstract:
1. An optical scanning device comprising: a plurality of light sources that are arranged separately in a height direction; a deflector that includes a polygon mirror, reflects light beams from the light sources on the polygon mirror while rotating, and separates the light beams in two substantially symmetrical directions to obtain deflected light beams; an optical system corresponding to each of the light source that guides each of the deflected light beams of a corresponding light source onto a surface of a corresponding photoconductor to form a latent image on the photoconductor; a plurality of light shielding units that are located outside a deflection scanning area of the deflected light beams and near the deflector, and shield flare light from an opposite optical system, wherein the light shielding units include first and second light shielding units, which are arranged not to satisfy the following condition where θ is an angle formed by a line from a portion of the first light shielding unit nearest the deflector to a rotation axis of the deflector and a line from a portion of the second light shielding unit nearest the deflector to the rotation axis of the deflector with the rotation axis of the deflector being an apex angle, x is number of mirror faces of the polygon mirror, and n is an integer not more than x, and wherein the first light shielding unit and the second light shielding unit are provided at different relative heights in a rotation axis direction of the deflector; and an upper light shielding member and a lower light shielding member that are provided at a different height in the rotation axis direction, wherein the upper light shielding member and the lower light shielding member each have a hollow triangular shape seen in the deflector rotating axis direction, and wherein the two hollow triangular shapes are symmetrically formed and symmetrically placed in line symmetry about a symmetrical line, wherein