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:
Feb. 06, 1979
Filed:
Jun. 27, 1978
Jean-Claude Lehureau, Paris, FR;
Pierre Oprandi, Paris, FR;
Thomson-Brandt, Paris, FR;
Abstract
The optical reader, for information discs of which the items of information are locatable by addresses previously recorded on each of the grooves forming the track, comprises a device for counting the number of grooves traversed during search phases which simultaneously uses the envelope of the reading signal and the signal representing the radial error in the position of the head relative to the nearest track, for algebraically counting the number of tracks traversed. After comparison with the number of grooves to be traversed, the counting device controls the deceleration of the radial advance when the spot is at a predetermined distance from the groove to be reached and also its total stoppage and the closure of the radial servocontrol loop when the groove is reached.