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
  • G11B7/08—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
• • 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
• • 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
  • G11B7/0901—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 track following only
  • G11B7/0903—Multi-beam tracking systems
• • 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
  • G11B7/135—Means for guiding the beam from the source to the record carrier or from the record carrier to the detector
  • G11B7/1365—Separate or integrated refractive elements, e.g. wave plates

Landscapes

• Optics & Photonics (AREA)
• Physics & Mathematics (AREA)
• Investigating Or Analysing Materials By Optical Means (AREA)
• Optical Communication System (AREA)
• Optical Recording Or Reproduction (AREA)
• Vehicle Body Suspensions (AREA)
• Laser Beam Printer (AREA)
• Mechanical Optical Scanning Systems (AREA)
• Optical Head (AREA)
• Microscoopes, Condenser (AREA)
• Eye Examination Apparatus (AREA)
• Photometry And Measurement Of Optical Pulse Characteristics (AREA)
• Length Measuring Devices By Optical Means (AREA)
• Measuring Pulse, Heart Rate, Blood Pressure Or Blood Flow (AREA)
• Geophysics And Detection Of Objects (AREA)
• Holo Graphy (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=6396430

Family Applications (1)

Country Status (15)

Families Citing this family (1)

Family Cites Families (2)

• 1989
  • 1989-12-23 DE DE3942943A patent/DE3942943A1/en not_active Withdrawn
• 1990
  • 1990-12-07 AT AT91900230T patent/ATE102382T1/en active
  • 1990-12-07 AU AU80043/91A patent/AU8004391A/en not_active Abandoned
  • 1990-12-07 ES ES91900230T patent/ES2050527T3/en not_active Expired - Lifetime
  • 1990-12-07 EP EP91900230A patent/EP0506699B1/en not_active Expired - Lifetime
  • 1990-12-07 JP JP3500648A patent/JPH05502538A/en active Pending
  • 1990-12-07 KR KR1019920701503A patent/KR920704284A/en not_active Ceased
  • 1990-12-07 DK DK91900230.3T patent/DK0506699T3/en active
  • 1990-12-07 DE DE91900230T patent/DE59004837D1/en not_active Expired - Fee Related
  • 1990-12-07 HU HU922043A patent/HUT62722A/en active IP Right Revival
  • 1990-12-07 SG SG1995904520A patent/SG30574G/en unknown
  • 1990-12-07 WO PCT/EP1990/002117 patent/WO1991010232A1/en not_active Ceased
  • 1990-12-20 MY MYPI90002237A patent/MY105281A/en unknown
  • 1990-12-22 CN CN90110150A patent/CN1020011C/en not_active Expired - Fee Related
• 1992
  • 1992-06-22 FI FI922900A patent/FI922900A7/en not_active Application Discontinuation
• 1995
  • 1995-05-04 HK HK69095A patent/HK69095A/en not_active IP Right Cessation

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