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:
Dec. 10, 1991
Filed:
Jan. 31, 1989
Applicant:
Inventors:
Gohji Uchikoshi, Higashimurayama, JP;
Tosihiko Otomo, Tokyo, JP;
Assignee:
Nakamichi Corporation, Kodaira, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369 4428 ; 369 4434 ; 369 54 ;
Abstract
A moving velocity detection circuit to detect the moving velocity and direction of motion for an optical spot. Detectors provide sine wave signals having periods inversely proportional to the moving velocity and having phases advanced or delayed opposite the direction of rotation. Deformed and differential signals derived from the detection signals are used to provide half wave signals which are added and subtracted in a predetermined combination, the polarity of which indicate direction of movement and the absolute value of which indicate velocity.