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WO2007000681A3 - Astigmatic multi-spot systems - Google Patents

Astigmatic multi-spot systems Download PDF

Info

Publication number
WO2007000681A3
WO2007000681A3 PCT/IB2006/051961 IB2006051961W WO2007000681A3 WO 2007000681 A3 WO2007000681 A3 WO 2007000681A3 IB 2006051961 W IB2006051961 W IB 2006051961W WO 2007000681 A3 WO2007000681 A3 WO 2007000681A3
Authority
WO
WIPO (PCT)
Prior art keywords
focus
astigmatic
photo detector
segment
detection
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/IB2006/051961
Other languages
French (fr)
Other versions
WO2007000681A2 (en
Inventor
Dominique M Bruls
Der Lee Alexander M Van
Albert H J Immink
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Koninklijke Philips NV
Original Assignee
Koninklijke Philips Electronics NV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Koninklijke Philips Electronics NV filed Critical Koninklijke Philips Electronics NV
Publication of WO2007000681A2 publication Critical patent/WO2007000681A2/en
Publication of WO2007000681A3 publication Critical patent/WO2007000681A3/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
    • G11B7/13—Optical detectors therefor
    • G11B7/131—Arrangement of detectors in a multiple array
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
    • G11B7/09—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
    • G11B7/0943—Methods and circuits for performing mathematical operations on individual detector segment outputs
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
    • G11B7/13—Optical detectors therefor
    • G11B7/133—Shape of individual detector elements
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
    • G11B7/09—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
    • G11B7/0908—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following for focusing only
    • G11B7/0909—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following for focusing only by astigmatic methods

Landscapes

  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Mathematical Physics (AREA)
  • Optical Recording Or Reproduction (AREA)
  • Optical Head (AREA)

Abstract

The invention relates to photo detection, and in particular to an apparatus and a method for focus detection in a multi-spot astigmatic focus system for optical storages in order to improve the focus detection. According to an aspect of the invention there is provided a photo detector system (312) comprising at least one photo detector comprising at least eight segments (402, 404, 406, 408, 410, 412, 414, 416), each segment providing a segment signal in response to an amount of radiation received by the segment so that at least eight signals are provided. The photo detector system (312) is adapted to determine a focus condition of the system (301) from at least one of the signals and to generate a focus error signal based on the determined focus condition in order to achieve an improved S-curve generation and operating displacement of an objective lens accordingly.
PCT/IB2006/051961 2005-06-28 2006-06-19 Astigmatic multi-spot systems Ceased WO2007000681A2 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
EP05105743.8 2005-06-28
EP05105743 2005-06-28

Publications (2)

Publication Number Publication Date
WO2007000681A2 WO2007000681A2 (en) 2007-01-04
WO2007000681A3 true WO2007000681A3 (en) 2007-03-22

Family

ID=37460030

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IB2006/051961 Ceased WO2007000681A2 (en) 2005-06-28 2006-06-19 Astigmatic multi-spot systems

Country Status (2)

Country Link
TW (1) TW200709201A (en)
WO (1) WO2007000681A2 (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0777217A2 (en) * 1995-12-04 1997-06-04 Sharp Kabushiki Kaisha Optical pickup device, optical disk recording/reproducing apparatus, and method of generating focus error signal
US5907530A (en) * 1995-08-30 1999-05-25 Samsung Electronics Co., Ltd. Optical pickup device
JP2002056550A (en) * 2000-08-04 2002-02-22 Sharp Corp Optical pickup, information recording / reproducing apparatus and information recording / reproducing method using the pickup
JP2003022562A (en) * 2001-07-04 2003-01-24 Sharp Corp Optical pickup device

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5907530A (en) * 1995-08-30 1999-05-25 Samsung Electronics Co., Ltd. Optical pickup device
EP0777217A2 (en) * 1995-12-04 1997-06-04 Sharp Kabushiki Kaisha Optical pickup device, optical disk recording/reproducing apparatus, and method of generating focus error signal
JP2002056550A (en) * 2000-08-04 2002-02-22 Sharp Corp Optical pickup, information recording / reproducing apparatus and information recording / reproducing method using the pickup
JP2003022562A (en) * 2001-07-04 2003-01-24 Sharp Corp Optical pickup device

Also Published As

Publication number Publication date
WO2007000681A2 (en) 2007-01-04
TW200709201A (en) 2007-03-01

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