Patent ID: 6885465
Filing Date: 2005-04-26
Classification: G01M,G02B,H04N

Abstract:
1. An optical element inspection device to inspect the relative positions of each reflective surface of an optical element having four reflective surfaces disposed in an X-shape so as to form an angle of incidence of 45° when viewed from a direction orthogonal to an optical axis of an incident light beam so that one set of reflective surfaces along one extending direction of the X-shape reflect a light beam of a wavelength range different from that of another set of reflective surfaces, the optical element inspection device comprising: a pedestal on which the optical element to be inspected is installed; a measurement light introduction unit to introduce measurement light at the angle of incidence of 45° with respect to any of said four reflective surfaces; a return light detection unit to detect return light of the measurement light introduced in said optical element from the measurement light introduction unit; and a measurement light switching unit to introduce said measurement light in only either area of two areas demarcated by the intersection of one set of the reflective surfaces with the other set of the reflective surfaces when viewed from the introducing direction of said measurement light.