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:
Aug. 08, 1989
Filed:
Jun. 29, 1988
Applicant:
Inventor:
Claude Tinet, Paris, FR;
Assignee:
Thomson-CSF, Paris, FR;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ; G11B / ; G11B / ;
U.S. Cl.
CPC ...
369 46 ; 369 44 ; 369109 ; 369111 ; 358342 ;
Abstract
The present invention relates to systems for reproducing signals, from a record whose engraved surface contains a recorded track in the form of an embossed print made of diffractive elements, representing the time variation of a pulse time modulated waveform. In accordance with the invention, there is provided a record and an optical read-out device wherein the relief elements carried by the record have a width in the order of the wavelength of the concentrated read-out radiation for determining a spatial variation in the diffracted energy emerging from the illuminated portion of the record, this variation being detected with photo-electric means.