Title:
光学ヘッド、記録及び/又は再生装置
Document Type and Number:
Japanese Patent JP4329364
Kind Code:
B2
Abstract:
An optical head and a recording and/or reproducing apparatus employing the optical head, are disclosed in which variations in the amplitude and phase of the push-pull detected preformat signals, such as MSK modulated wobble signals which encode address information, are reduced. Such variations occur because of variations in the phase relationship with the neighbouring tracks, since the interference from in-phase and out-of-phase reletionships is different. The beam from the in-phase relationship between neighbouring tracks contains a reflected beam and diffracted beams with a shift »/(Tp·NA) and the beam from the out-of-phase relationship a reflected beam and diffracted beams with shifts »/(Tp·NA) and »/(2·Tp·NA). The photodetector unit includes a first light receiving section (230b) and a second light receiving section (230c). Each of the first and second light receiving section receives the light of one of two light spot areas lying on both sides of a centre area, and the signal components from the diffracted light with a shift »/(2·Tp·NA) generated in the centre area of the light spot may be removed and variation in the amplitude or phase of the push-pull signal reduced.
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Inventors:
Noriaki Nishi
Ken Tezuka
Ken Tezuka
Application Number:
JP2003062574A
Publication Date:
September 09, 2009
Filing Date:
March 07, 2003
Export Citation:
Assignee:
ソニー株式会社
International Classes:
G11B7/13; G11B7/24; G11B7/005; G11B7/007; G11B7/09; G11B7/125; G11B7/1263; G11B7/131; G11B7/1356; G11B7/1369; G11B7/1392; G11B7/135
Domestic Patent References:
| JP11120608A | ||||
| JP5047004A | ||||
| JP2002298364A | ||||
| JP7262583A | ||||
| JP2003016672A | ||||
| JP2001357545A | ||||
| JP10097753A | ||||
| JP2001110074A | ||||
| JP2001297462A | ||||
| JP2002312966A | ||||
| JP7296397A | ||||
| JP5047016A | ||||
| JP2004071010A |
Foreign References:
| WO2002021518A1 | ||||
| WO2004042714A1 |
Attorney, Agent or Firm:
Akira Koike
Seiji Iga
Toshiya Fujii
Nobuhiro Noguchi
Yusei Atsuya
Seiji Iga
Toshiya Fujii
Nobuhiro Noguchi
Yusei Atsuya