Patent ID: 8134760
Filing Date: 2012-03-13
Classification: G01N

Abstract:
1. An imaging device for inspecting semiconductors, the imaging device comprising: an imaging lens for imaging light reflected from an object; a first planar element comprising at least a first light source and a second light source; and a second planar element comprising at least a first Fresnel prism and a second Fresnel prism, wherein the first planar element is positioned substantially parallel to the second planar element such that the first Fresnel prism redirects light from the first light source toward the object from a first direction and the second Fresnel prism redirects light from the second light source toward the object from a second direction, wherein the redirected light from the first light source diverges from the first Fresnel prism so as to illuminate a desired portion of the object from the first direction, and wherein the redirected light from the second light source diverges from the second Fresnel prism so as to illuminate the desired portion of the object from the second direction.