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:
Aug. 30, 1988
Filed:
Jun. 30, 1987
Applicant:
Inventors:
Ryoichi Kawasaki, Sawa, JP;
Noriyoshi Ooyama, Nitta, JP;
Masami Shimizu, Oota, JP;
Kouzou Suzuki, Ohra, JP;
Assignee:
Sanyo Electric Co., Ltd., , JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01J / ;
U.S. Cl.
CPC ...
250201 ; 369 45 ;
Abstract
An optical pickup device in which a laser light source is so disposed that one of two dividing lines of a photo-detector having at least four sensing portions symmetrically divided by the dividing lines so as to detect focusing deviation of a light beam onto a signal surface of a record disc, is aligned with the tangential direction of the signal track at the portion where the light beam is projected onto the signal surface, whereby the optical pickup is free from a wrong focusing control due to erroneous detection even during track jumping.