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. 17, 1998
Filed:
Mar. 13, 1996
Applicant:
Inventor:
Sou Ishika, Kanagawa-ken, JP;
Assignee:
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369 4426 ; 369 4442 ;
Abstract
A light detecting device includes an object leans for leading a light beam from a light source to a recording medium. The recording medium has a groove and a header portion formed by interrupting the groove. The light detecting device further includes a photo-detector for detecting the light beam reflected on the recording medium and led by the object lens to output a signal corresponding to intensity of the reflected light beam, the photo-detector including a light beam detecting surface in a specified shape to which a component of the reflected light beam diffracted by the header portion is not incident.