Invention Grant
- Patent Title: Optical head and optical disc device
- Patent Title (中): 光头和光盘装置
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Application No.: US12089984Application Date: 2006-10-10
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Publication No.: US08493824B2Publication Date: 2013-07-23
- Inventor: Fumitomo Yamasaki , Akihiro Arai , Hideki Aikoh
- Applicant: Fumitomo Yamasaki , Akihiro Arai , Hideki Aikoh
- Applicant Address: JP Osaka
- Assignee: Panasonic Corporation
- Current Assignee: Panasonic Corporation
- Current Assignee Address: JP Osaka
- Agency: Renner, Otto, Boisselle & Sklar, LLP
- Priority: JP2005-297461 20051012
- International Application: PCT/JP2006/320206 WO 20061010
- International Announcement: WO2007/043522 WO 20070419
- Main IPC: G11B7/00
- IPC: G11B7/00

Abstract:
A tilt can be detected highly accurately by minimizing the tilt detection error. An optical head includes: an objective lens for converging a light beam from a light source onto an optical disc; a photodetector section receiving the beam, reflected from the disc, at divided areas on its photodetection plane and outputting light detection signals from those areas; and a tilt detecting section for detecting a relative tilt between the lens and disc based on the detection signals. The tilt detecting section generates a first push-pull signal PP1 based on the detection signals supplied from a first group of areas, which are arranged symmetrically to a virtual reference line drawn parallel to a disc radial direction and crossing an optical axis, also generates a second push-pull signal PP2 based on the detection signals supplied from a second group of areas, different from the first group and also arranged symmetrically to the reference line, changes coefficients k according to the location of the lens in a disc radial direction, and generates a tilt detection signal TLT by TLT=PP1−k×PP2.
Public/Granted literature
- US20090279399A1 OPTICAL HEAD AND OPTICAL DISC DEVICE Public/Granted day:2009-11-12
Information query
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