主权项 |
1. An optical scanning device for forming an image on a scanning target by scanning the scanning target with light in a main scanning direction, the optical scanning device comprising:
a housing; a polygon mirror disposed in the housing and configured to reflect light incident thereon while being rotated; a motor disposed in the housing and configured to rotate the polygon mirror,a first optical system configure to emit light onto the polygon mirror; and
a second optical system configured to emit light onto the polygon mirror, wherein the housing has a first cooling passage configured to cool an interior of the housing, the first cooling passage is asymmetrically located relative to a rotation shaft of the motor in a cross section perpendicular to the main scanning direction, the first optical system and the second optical system are located symmetrically to each other relative to the rotation shaft of the motor, the polygon mirror has a plurality of reflecting surfaces, and the motor rotates the polygon mirror such that one of the reflecting surfaces facing the first optical system is moved, over a shortest distance, to a position facing the second optical system, and the first cooling passage is located closer to the second optical system than to the first optical system. |