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. 07, 1987
Filed:
May. 06, 1985
Takashi Nakatsuyama, Chiba, JP;
Akashi Ito, Tokyo, JP;
Sony Corporation, Tokyo, JP;
Abstract
Start-control method and circuit for an optical disc play-back system according to this invention can allow the starting current of the system to be reduced considerably. The method includes the steps of loading the disc onto a disc drive motor, then finding the focal position of the lens, then powerfully energizing the disc drive motor for a certain period of time so as to start the disc spinning and then energizing the focus- and the tracking-servo circuits during inertial rotation of the disc drive motor. The circuit includes a disc-drive-motor servo switch capable of switching the power supply for the disc drive motor from the kick circuit to the disc-drive-motor servo circuit, a focus servo switch capable of switching the power supply for the focus servomotor from the focus search circuit to the focus servo circuit, and a tracking servo switch capable of initiating power supply to the tracking servomotor.