Invention Grant
- Patent Title: Object lens, optical pickup, and optical disc device
- Patent Title (中): 物镜,光拾取器和光盘装置
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Application No.: US12142351Application Date: 2008-06-19
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Publication No.: US07924684B2Publication Date: 2011-04-12
- Inventor: Kazumasa Kaneda , Yoshito Asoma , Toshifumi Yasui , Kazuyuki Takahashi
- Applicant: Kazumasa Kaneda , Yoshito Asoma , Toshifumi Yasui , Kazuyuki Takahashi
- Applicant Address: JP Tokyo
- Assignee: Sony Corporation
- Current Assignee: Sony Corporation
- Current Assignee Address: JP Tokyo
- Agency: Oblon, Spivak, McClelland, Maier & Neustadt, L.L.P.
- Priority: JP2007-197961 20070730; JP2007-303610 20071122; JP2008-063383 20080312
- Main IPC: G11B7/00
- IPC: G11B7/00

Abstract:
An optical pickup includes: a first emitting unit to emit an optical beam of a first wavelength; a second emitting unit to emit an optical beam of a second wavelength; a third emitting unit to emit an optical beam of a third wavelength; an object lens to condense optical beams emitted from the first through third emitting units onto a signal recording face of an optical disc; and a diffraction unit provided on one face of an optical element or the object lens positioned on the optical path of the optical beams of the first through third wavelengths; wherein the diffraction unit includes a generally circular first diffraction region provided on the innermost perimeter, a ring zone shaped second diffraction region provided on the outer side of the first diffraction region, and a ring zone shaped third diffraction region provided on the outer side of the second diffraction region.
Public/Granted literature
- US20090034398A1 OBJECT LENS, OPTICAL PICKUP, AND OPTICAL DISC DEVICE Public/Granted day:2009-02-05
Information query
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