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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.:

US 4541716 B1

PDFFull Text
Date of Patent:
Sep. 17, 1985

Filed:

Apr. 15, 1983

Detection of defects in a circular or spiral diffraction grating

Applicant:
Inventors:

Horatio N Crooks, Indianapolis, IN (US);

Martin J Kelly, Jr, Indianapolis, IN (US);

Assignee:

RCA Corporation, Princeton, NJ (US);

Attorneys:

Morris; Birgit E.

Cohen; Donald S.

Lazar; Joseph D.

Primary Examiner:

Davis L Willis

Assistant Examiner:

Matthew W Koren

Int. Cl.
CPC ...
G01N / ;
U.S. Cl.
CPC ...
356237 ; 356354 ;
Abstract

Topographical defect detecting apparatus and process for optically inspecting a circular or spiral track surface defining a diffraction grating such as exists on a video disc or optical disc record. Light from a substantially point source illuminates the track surface. Diffracted reflections from the surface are viewed by the human eye with or without the aid of a TV camera and monitor. Non-uniformities in track spacing and deviation from average surface flatness are readily observable.

Find Patent Forward Citations

Crooks, Horatio. (1985). Detection of defects in a circular or spiral diffraction grating (U.S. Patent No. 4541716). U.S. Patent and Trademark Office. https://idiyas.com/patent/badge/4541716

Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile

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