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:
Jun. 29, 1999
Filed:
Aug. 21, 1997
Hideyoshi Horimai, Kanagawa, JP;
Kimihiro Saito, Saitama, JP;
Sony Corporation, Tokyo, JP;
Abstract
An optical information recording/playback apparatus having a compact construction of a recording/playback optical system. A light beam emitted from a laser coupler is modulated by a spatial modulator according to difference in the polarizing direction. The modulated light enters an S-polarized light hologram which separates an information light and a recording reference light of different polarizing directions and having different focal positions. An optical rotation is effected by a split optical rotation plate such that the polarizing directions of the information light and the recording reference light coincide with each other in a region of a holographic layer of a recording medium where the information light and the recording reference light are superposed on each other. The light beam having undergone the optical rotation is applied to the holographic layer through an objective lens, whereby the information carried by the information light is recorded in the holographic layer in terms of an interference pattern produced as a result of an interference between the information light and the recording reference light.