Patent ID: 7385733
Filing Date: 2008-06-10
Classification: G02B,H04N

Abstract:
1. An imaging optical system for imaging information on an object surface in a region having a length (A) in a long side direction and a length (B) in a short side direction which satisfy a relation of A/B>10, on an image plane, comprising: a diaphragm; a first set of a plurality of off-axial reflection surfaces arranged on the object surface side from the diaphragm; and a second set of a plurality of off-axial reflection surfaces arranged on the image plane side from the diaphragm, wherein an optical path of a light beam passing through a center of the diaphragm and a center of the image plane is deflected by the off-axial reflection surfaces within a surface perpendicular to the long side direction of the region to undergo crossing at least once, wherein all of the off-axial reflection surfaces satisfy a conditional expression: where P (mm