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:
Jul. 13, 1993
Filed:
Nov. 18, 1991
Applicant:
Inventor:
David Cheng, Santa Clara, CA (US);
Assignee:
Frontier Semiconductor Measurements, Inc., San Jose, CA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01V / ;
U.S. Cl.
CPC ...
250561 ; 356376 ;
Abstract
A system for measuring the curvature of a surface includes a laser for emitting a beam of light to be incident upon the surface; a photodetector for detecting light reflected by the surface; a first stage for selectively moving the surface in a direction normal to the direction of the incident beam; a second stage for selectively moving the photodetector in a direction normal to the reflected beam; a sensor connected to the photodetector for detecting the displacement of the reflected beam relative to the photodetector.