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. 12, 1985
Filed:
Apr. 30, 1982
Applicant:
Inventor:
Tsuneshi Yokota, Kawasaki, JP;
Assignee:
Tokyo Shibaura Denki Kabushiki, Kawasaki, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369 54 ; 369 58 ; 369243 ;
Abstract
An optical disk apparatus has a detector for detecting absence of an optical disk in a prescribed position, a detection circuit for detecting non-rotation of the disk and an AND circuit for producing a logical product of the outputs from the detector and detection circuit. The detector comprises a light-emitting diode and a light-receiving element. An output signal from the AND circuit is supplied to a beam source driver/control circuit, thereby turning off a beam source.