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:
Sep. 22, 1987
Filed:
May. 22, 1985
Makoto Itonaga, Yokohama, JP;
Kanji Kayanuma, Hatano, JP;
Abstract
A film thickness measuring apparatus comprises a light source for impinging light on a measuring plate with a predetermined incident angle .theta..sub.0, where the measuring plate comprises a transparent film on top of a transparent substrate and the transparent film has a film thickness which is to be measured by the film thickness measuring apparatus, a light receiving system for receiving and detecting light which is impinged on the measuring plate and is reflected thereby, and an analyzer system responsive to an output of the light receiving system for measuring an angle .DELTA. of the phase difference between two polarized light components of the reflected light from the measuring plate and for calculating the film thickness of the transparent film from the angle .DELTA. of the phase difference. The incident angle .theta..sub.0 of the light from the light source with respect to the measuring plate is selected equal to or approximately equal to a polarizing angle .theta..sub.b of the transparent film of the measuring plate.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile