The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 03, 2000
Filed:
Oct. 07, 1999
Hiroshi Niikura, Chigasaki, JP;
Nikon Corporation, Tokyo, JP;
Abstract
A unit for measuring optical properties. The unit includes the first through sixth reflecting surfaces, a reflecting surface rotating device and an object moving device. In order to accurately measure transmittance, reflectance and phase change in transmittance or reflection of optical elements, especially transmittance of a thick object, the first through the fourth reflecting surfaces M1-M4 are arranged so that an optical path formed by the reflecting surfaces M1-M4 has a shape like an 'N' letter and so that light of incidence L1 has the same optical axis as exit light L2. An optical center O is a point that a line segment that connects a point of incidence A with an exit point D intersects an optical path that connects the reflecting surface M2 with the reflecting surface M3. The reflecting surface M2 is an ellipsoid of revolution having foci of the optical center O and the point of incidence A. The reflecting surface M3 is an ellipsoid of revolution having foci of the optical center and the exit point D. A reflecting surface rotating device rotates M4 at the exit point D in conjunction with the reflecting surface M1 that is rotated at the point of incidence A. The reflecting surface M5 is a parabolic mirror that makes light reflected from the reflecting surface M1 parallel. M6 is a parabolic mirror that converges light reflected from the reflecting surface M5 onto the reflecting mirror M4.