Patent ID: 7681798

Claim:
An optical scanner device comprising: a scanning optical system to deflect and scan a light beam emitted from a light source by a rotational polygonal mirror and focusing it on a photosensitive member; and a housing to store the scanning optical system; wherein the housing includes: a bottom portion on which the scanning optical system is provided and fixed; a first wall installed on a part of the periphery of the bottom portion orthogonally to the bottom portion; a second wall installed outside the first wall at a predetermined interval with the first wall; a parallel rib installed in parallel with the bottom portion at a central part in the height direction of the first wall between the first wall and the second wall for connecting the first wall and the second wall; a plurality of first orthogonal ribs installed orthogonally to the bottom portion under the parallel rib between the first wall and the second wall for connecting the first wall and the second wall; and a plurality of second orthogonal ribs installed orthogonally to the bottom portion above the parallel rib between the first wall and the second wall for connecting the first wall and the second wall, wherein each of the second orthogonal ribs is disposed at a central portion between two adjacent ones of the first orthogonal ribs.