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:
Nov. 09, 2010
Filed:
Sep. 16, 2005
Masahiko Nishimoto, Osaka, JP;
Yasuyuki Kochi, Osaka, JP;
Shinichi Ijima, Osaka, JP;
Takuya Okuda, Kyoto, JP;
Masayuki Ono, Osaka, JP;
Masahiko Nishimoto, Osaka, JP;
Yasuyuki Kochi, Osaka, JP;
Shinichi Ijima, Osaka, JP;
Takuya Okuda, Kyoto, JP;
Masayuki Ono, Osaka, JP;
Panasonic Corporation, Osaka, JP;
Abstract
An optical pickup device in which a hologram element has a plurality of different diffraction directions. In the tracking standard state, the hologram element is divided into six areas by a straight line connecting two strength center points of two light beams, and by two straight lines that are perpendicular to the straight line. By adding the amount of light received by an area demarcated by two straight lines that pass the two strength center points, to the amount of light received by one of two outer areas sandwiching the area depending on the type of the light beam, it is possible to obtain a well-balanced tracking error signal for each of the two light beams.