Patent ID: 6128093
Filing Date: 2000-10-03
Classification: G01N

Abstract:
A unit for measuring optical properties comprising:a first through sixth reflecting surfaces for reflecting light of incidence by the first through fourth reflecting surfaces in first measurement, and for reflecting light of incidence by the first, the fifth, the sixth and the fourth reflecting surface in second measurement;a reflecting surface rotating device for rotating the first and fourth reflecting surfaces; andan object moving device for inserting and extracting the object at a place between the second and third reflecting surfaces, or between the fifth and sixth reflecting surfaces,wherein the first through fourth reflecting surfaces are arranged so that light traveling from the first through fourth reflecting surfaces draws an ""N""-like light path, and so that the light of incidence on the first reflecting surface has the same optical axis as the light exiting from the fourth reflecting surface,each of the first and fourth reflecting surfaces is arranged so that each of the first and fourth reflecting surfaces is perpendicular to a plane containing the ""N""-like light path,the second reflecting surface is defined as a first ellipsoid of revolution having foci of an optical center O and a point of incidence A, wherein the point of incidence A is a point at which the light of incidence impinges on the first reflecting surface, and the optical center O is a point that a line segment AD, which connects the point of incidence A with a point D that is an exit point on the fourth reflecting surface, intersects a light path between the second reflecting surface and the third reflecting surface,the third reflecting surface is defined as a second ellipsoid of revolution having foci of the optical center O and the exit point D,the fifth reflecting surface makes the reflected light from the first reflecting surface parallel,the sixth reflecting surface converges the reflected light from the fifth reflecting surface onto the fourth reflecting surface,the reflecting surface rotating device rotates the first and fourth reflecting surfaces at each of their positions about each axis perpendicular to the plane containing the N-like light path, the fourth reflecting surface operating with the first reflecting surface,the object moving device selectively sets either an insertion state or a non-insertion state, the insertion state being a state that the object is inserted to a position between the second and third reflecting surfaces, or between the fifth and sixth reflecting surfaces, so that a measuring surface of the object contains the optical center, and the non-insertion state being a state that the object is extracted from the position.