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:
Nov. 16, 1976
Filed:
Nov. 26, 1974
Applicant:
Inventors:
Christiaan Hendrik Velzel, Eindhoven, NL;
Peter Ferdinand Greve, Eindhoven, NL;
Assignee:
U.S. Philips Corporation, New York, NY (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04N / ; G11B / ;
U.S. Cl.
CPC ...
178 / ; 178 / ; 1791 / ; 250201 ;
Abstract
An apparatus is described for reading a record carrier on which information is stored in an optically readable reflecting structure. By projecting two radiation spots one before and one behind the plane of the information structure, it is possible to ascertain whether a read beam is properly focussed on the information structure.
Velzel, Christiaan. (1976). Apparatus for optically reading a record carrier by means of an (U.S. Patent No. 3992575). U.S. Patent and Trademark Office. https://idiyas.com/patent/badge/3992575
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile