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:
Dec. 29, 2009
Filed:
Jul. 15, 2005
Kazushi Uno, Kawasaki, JP;
Kouichi Tezuka, Kawasaki, JP;
Hiroyasu Yoshikawa, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A disk-type hologram recording medium and a hologram recording and reproduction device utilizing such a recording medium are provided. The hologram recording and reproduction device includes a spatial optical modulator provided with a plurality of optical elements arranged in a grid-like form. These optical elements are divided into groups each associated with 1 bit of data for performing required light modulation. Thus, a special pattern exhibiting a greater S/N margin for 1 bit can be recorded in the recoding medium. During data recording or data reproduction, the special pattern is read from the recording medium, and based on the retrieved special pattern, fine adjustment by servo control is conducted for adjustment of tilting or focusing of the recording medium and for adjustment of the wavelength of the light emitted from the light source.