Patent ID: 7330295
Filing Date: 2008-02-12
Classification: G02B

Abstract:
1. An optical scanning device comprising a light deflective optical system in which two stationary plane mirrors are disposed to face a deflective reflecting facet which s parallel to a rotational axis and can be rotated or swivelled about the rotational axis such that a light beam being incident on and reflected from said deflective reflecting facet is reflected by said two stationary plane mirrors sequentially and is incident on and reflected by the deflective reflecting facet again, wherein assuming that a plane being parallel to said rotational axis and including the light beam to be first incident on said deflective reflecting facet is an incident plane, said two stationary plane mirrors are disposed perpendicular to said incident plane, and the central ray of an emergent light beam when the emergent light beam after the second reflection by said deflective reflecting facet is on said incident plane and a straight line as the central ray of an emergent light beam being projected on the incident plane when the deflective reflecting facet is revolved by the maximum rotational angle are set substantially parallel to each other, wherein said optical scanning device is structured such that the light beam to be first incident on said deflective reflecting facet passes through a space between said two stationary plane mirrors and the deflected light beam after the second reflection by said deflective reflecting facet passes through the space between said two stationary plane mirrors.