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:
Oct. 20, 1992
Filed:
Apr. 04, 1990
Applicant:
Inventors:
Assignee:
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369 4428 ; 369 4434 ; 369 32 ; 369 43 ; 369 59 ;
Abstract
An optical disk unit is incidence a light spot upon an optical disk. The light spot is radially moved to cross tracks formed on the optical disk. The tracks are provided with specific access marks. The number of access marks passed by the light spot as well as the number of tracks crossed by the light spot until a change is found in a detected access mark are counted. The latter number is divided by the former number and multiplied by a coefficient to provide a speed signal indicative of a speed of the light spot relative to the optical disk.