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:
Jan. 29, 1991
Filed:
Jun. 22, 1988
Applicant:
Inventor:
Noriyuki Kondo, Kyoto, JP;
Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01B / ;
U.S. Cl.
CPC ...
356357 ; 356359 ;
Abstract
An apparatus for measuring a very small difference comprises a stage for receiving a sample to be measured, a light source illuminating the sample, an optical system for condensing light reflected from the sample, structure for intercepting a portion of the reflected light, a spectroscope for analyzing the condensed reflected light and a detector for detecting spectrum of the analyzed light. Light reflected only from a main surface of the sample is intercepted by the intercepting structure. Thus, the signal to noise ratio of the reflected light is reduced to enhance measurement capability.