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:
May. 10, 1988
Filed:
Jan. 20, 1987
Junichi Kitabayashi, Machida, JP;
Toshio Kanoh, Tokyo, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A device for optically measuring an aspheric surface includes a fringe-scanning shearing interferometer for applying a wavefront of illuminating light to the aspheric surface and optically measuring the aspheric surface based on light reflected by the aspheric surface along a measurement optical path. A plurality of ring filters having respective different light-transmitting areas are successively positionable, one at a time, in the illuminating light and outside of the measurement optical path for applying divided portions of the wavefront of illuminating light successively to the aspheric surface. The radius of curvature of the wavefront of illuminating light applied to the aspheric surface is measured.