Patent ID: 8582190

Claim:
A two-dimensional scanning device for scanning a test surface in a first direction and a second direction orthogonal to the first direction, the two-dimensional scanning device comprising: a light source; a scanning optical system to scan the test surface in the first direction and the second direction with light emitting from the light source; a first lens having different powers in relation to the first direction and the second direction; and a second lens having different powers in relation to the first direction and the second direction, wherein the scanning optical system is placed between the light source and a lens group including the first lens and the second lens, the lens group has an image-side telecentricity, and following Expressions (1) and (2) are satisfied in the two-dimensional scanning device: | f 1 x/f 1 y|< 1 (1) | f 2 x/f 2 y|> 1 (2) where f1x is a focal length of the first lens when the scanning direction is the first direction, f1y is a focal length of the first lens when the scanning direction is the second direction, f2x is a focal length of the second lens when the scanning direction is the first direction, and f1y is a focal length of the second lens when the scanning direction is the second direction.