Invention Grant
- Patent Title: Optical pickup apparatus and drive apparatus having the same
- Patent Title (中): 光拾取装置及其驱动装置
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Application No.: US12188906Application Date: 2008-08-08
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Publication No.: US07808878B2Publication Date: 2010-10-05
- Inventor: Osamu Miyazaki
- Applicant: Osamu Miyazaki
- Applicant Address: JP Osaka-shi
- Assignee: Sharp Kabushiki Kaisha
- Current Assignee: Sharp Kabushiki Kaisha
- Current Assignee Address: JP Osaka-shi
- Agency: Morrison & Foerster LLP
- Priority: JP2007-252291 20070927
- Main IPC: G11B7/00
- IPC: G11B7/00

Abstract:
An optical pickup apparatus and a drive apparatus having the same are provided. Second light-receiving elements or third light-receiving elements for receiving ±first-order diffraction light beams from a polarization hologram are arranged outwardly of a circular region having the optical axis of a zero-order diffraction light beam on a light detector as its center, a radius of which is expressed by (2×t/n)×(f2/f1), where f1 denotes a focal length of an objective lens, f2 denotes a focal length of a coupling lens, t denotes a maximum value of a light transmitting layer thickness, n denotes a refractive index of a light transmitting layer.
Public/Granted literature
- US20090086609A1 OPTICAL PICKUP APPARATUS AND DRIVE APPARATUS HAVING THE SAME Public/Granted day:2009-04-02
Information query
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