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
  • G11B7/12—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
• • 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
  • G11B7/1372—Lenses
  • G11B7/1378—Separate aberration correction lenses; Cylindrical lenses to generate astigmatism; Beam expanders

Landscapes

• Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Optical Head (AREA)
• Optical Recording Or Reproduction (AREA)
• Vehicle Body Suspensions (AREA)
• Investigating Or Analysing Materials By Optical Means (AREA)
• Optical Communication System (AREA)
• Electrochromic Elements, Electrophoresis, Or Variable Reflection Or Absorption Elements (AREA)
• Microscoopes, Condenser (AREA)
• Holo Graphy (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=6400308

Family Applications (1)

Country Status (11)

Families Citing this family (5)

Family Cites Families (3)

• 1990
  • 1990-02-16 DE DE4004858A patent/DE4004858A1/en not_active Withdrawn
• 1991
  • 1991-02-06 AT AT91903373T patent/ATE110875T1/en active
  • 1991-02-06 JP JP3503714A patent/JP2930137B2/en not_active Expired - Fee Related
  • 1991-02-06 EP EP91903373A patent/EP0515422B1/en not_active Expired - Lifetime
  • 1991-02-06 ES ES91903373T patent/ES2063491T3/en not_active Expired - Lifetime
  • 1991-02-06 HU HU922455A patent/HUT62419A/en unknown
  • 1991-02-06 AU AU72157/91A patent/AU7215791A/en not_active Abandoned
  • 1991-02-06 WO PCT/EP1991/000226 patent/WO1991012609A1/en not_active Ceased
  • 1991-02-06 DE DE59102748T patent/DE59102748D1/en not_active Expired - Fee Related
  • 1991-02-15 CN CN91101248A patent/CN1023920C/en not_active Expired - Fee Related
• 1992
  • 1992-08-14 FI FI923636A patent/FI923636A0/en not_active Application Discontinuation
• 1995
  • 1995-07-13 HK HK113395A patent/HK113395A/en not_active IP Right Cessation

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