Patent ID: 7355712

Claim:
An apparatus for measuring a goniometric reflection property of a sample comprising: one or more illuminators; a toroidal mirror which is rotationally symmetrical around a center axis effectively contacting with a surface of a sample; a light receiver having an incident aperture on said center axis; a rotating optics which rotates around a rotation axis which effectively coincides with said center axis; and a controller for controlling operations of said illuminators, said light receiver, and said rotating optics, wherein said toroidal mirror reflects light fluxes emitted from the surface of the sample illuminated by said one or more illuminators in emitting directions perpendicular to said center axis and directs each of said light fluxes to said center axis, and wherein said rotating optics specifies one of said light fluxes reflected by said toroidal mirror and directs said specified light flux to said incident aperture of said light receiver.