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:
Apr. 16, 1985
Filed:
Jan. 24, 1983
Chiaki Nonaka, Yokohama, JP;
Sony Corporation, Tokyo, JP;
Abstract
An optical reproducing apparatus includes an optical pickup device which projects a laser beam onto a record disc having an information signal recorded in a plurality of record tracks thereon and which reproduces the information signal from the modulated laser beam reflected from the record disc, the optical pickup device including an objective lens movable in directions toward and away from the record disc to focus the projected laser beam onto the record disc; a focus servo control arrangement which moves the objective lens in the directions toward and away from the record disc in response to a focusing error signal which, in turn, is produced in response to the modulated laser beam, so as to focus the projected laser beam onto the record disc; a laser beam tracking device which rapidly moves the laser beam projected onto the record disc, during a search mode of operation, in a direction transverse to the record tracks to a desired position with respect to the record disc; a track jump signal generating circuit which produces a track jump signal in response to a track jump command signal to control the laser beam tracking device to rapidly move the projected laser beam to the desired position; and a current divider circuit which reduces the level of the focusing error signal, at least during the duration of the track jump signal, in response to the track jump command signal.