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. 28, 2009
Filed:
Jul. 13, 2004
Takuya Tsukagoshi, Tokyo, JP;
Yuichi Sato, Tokyo, JP;
Jiro Yoshinari, Tokyo, JP;
TDK Corporation, Tokyo, JP;
Abstract
In recording of information, an information beam as S-polarization is incident on an optical information recording medium. After passing through the optical information recording medium, the information beam is reflected by reflection apparatus and passes through a polarization controller. In this process, the information beam undergoes S-polarization control and the polarization direction changes to P-polarization direction. The information beam interferes with a recording reference beam as P-polarization incident on a surface of the optical information recording medium inside the optical information recording medium to form an interference pattern. In reproduction of information, a reproduction reference beam is incident on the surface of the optical information recording medium. The reproduction reference beam is then diffracted by a refractive index grating caused by an interference pattern formed in the optical information recording medium to form a reproduction beam. The reproduction beam is emitted from the surface of the optical information recording medium and is incident on a light receiving element. The original data is then reproduced.