Invention Grant
US07936658B2 Photodetector, diffraction grating, optical pickup and optical disc apparatus
有权
光电检测器，衍射光栅，光学拾取器和光盘装置
- Patent Title: Photodetector, diffraction grating, optical pickup and optical disc apparatus
- Patent Title (中): 光电检测器，衍射光栅，光学拾取器和光盘装置
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Application No.: US12709613Application Date: 2010-02-22
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Publication No.: US07936658B2Publication Date: 2011-05-03
- Inventor: Tomoto Kawamura , Kunikazu Ohnishi , Masayuki Inoue , Katsuhiko Izumi
- Applicant: Tomoto Kawamura , Kunikazu Ohnishi , Masayuki Inoue , Katsuhiko Izumi
- Applicant Address: JP Iwate
- Assignee: Hitachi Media Electronics Co., Ltd.
- Current Assignee: Hitachi Media Electronics Co., Ltd.
- Current Assignee Address: JP Iwate
- Agency: Antonelli, Terry, Stout & Kraus, LLP.
- Priority: JP2005-213606 20050725; JP2006-044644 20060222
- Main IPC: G11B7/00
- IPC: G11B7/00
Abstract:
The present invention provides a photodetector capable of generating highly accurate tracking and focusing error signals free of variations in light quantity caused by interference, in an optical pickup with a two-wavelength multilaser. The photodetector comprises first three light receiving areas arranged linearly to receive three light beams respectively resulting from splitting of a light beam emitted from a laser light source of a first wavelength and second three light receiving areas arranged linearly to receive three light beams respectively resulting from splitting of a light beam emitted from a laser light source of a second wavelength longer than the first wavelength. The distance between both-end light receiving areas out of the first three light receiving areas is longer than the distance between both-end light receiving areas out of the second three light receiving areas.
Public/Granted literature
- US20100148045A1 PHOTODETECTOR, DIFFRACTION GRATING, OPTICAL PICKUP AND OPTICAL DISC APPARATUS Public/Granted day:2010-06-17
Information query
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