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:
Apr. 13, 1993
Filed:
Feb. 19, 1991
Applicant:
Inventor:
Masahiko Tanaka, Yokohama, JP;
Assignee:
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B / ; G02B / ; G11B / ;
U.S. Cl.
CPC ...
359281 ; 359283 ; 359639 ; 360114 ; 365122 ;
Abstract
First and second beam splitters are arranged on the optical path of a light beam emerging from a recording surface, and such that the phases and amplitudes of the respective polarized light components of a light beam incident thereon are changed to equal extends. As a result of this arrangement, the state of polarization beam of the light beam emerging from the recording surface is maintained when a light beam is outputted through the two beam splitters. Stable reproduction signals and servo control signals for focusing, tracking, and the like can be reliably supplied by utilizing an apparatus of this invention.