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:
Aug. 11, 2009
Filed:
Aug. 28, 2006
Yukio Watanabe, Uji, JP;
Tetsuo Ueyama, Nara, JP;
Osamu Miyazaki, Kyoto, JP;
Kazunori Matsubara, Nara, JP;
Shinzoh Murakami, Nara, JP;
Kazuhiro Tsuchida, Higashihiroshima, JP;
Yukio Watanabe, Uji, JP;
Tetsuo Ueyama, Nara, JP;
Osamu Miyazaki, Kyoto, JP;
Kazunori Matsubara, Nara, JP;
Shinzoh Murakami, Nara, JP;
Kazuhiro Tsuchida, Higashihiroshima, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
An optical pickup includes a hologram element. The hologram element is provided with a hologram pattern including a splitting section for focus which splits light used for the detection of an FES and a splitting section for tracking which splits light used for the detection of a TES. The splitting section for tracking is formed in a region excluding a region interposed between a first virtual straight line and a second virtual straight line. The first virtual straight line is drawn on the hologram element in parallel to an X direction and passes through an optical axis of reflected light entering the hologram element in a state where the objective lens is in a neutral position, and the second virtual straight line is drawn in parallel to the first virtual straight line, while being spaced at a distance d from the first virtual straight line.