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:
Dec. 18, 1979
Filed:
Feb. 27, 1978
Applicant:
Inventors:
Ping Sheng, Princeton, NJ (US);
Arthur H Firester, Skillman, NJ (US);
Assignee:
RCA Corporation, New York, NY (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
358128 ; 358127 ; 365120 ;
Abstract
Recovery from a record of information recorded in an elongated information track comprising depressed areas alternating along the length of the track with relatively non-depressed areas, is effected by an optical playback system. The playback system employs means for illuminating a focusing lens with a light beam having a cross-section forming a closed band of light, such as an annulus, to thereby increase the depth-of-field of the resulting focused spot formed on the information track. Light detection means, responsive to light diffracted by the track provides an output signal representative of the recorded data.