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
• • 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
• • 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
  • G11B7/0917—Focus-error methods other than those covered by G11B7/0909 - G11B7/0916
• • 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
  • G11B7/0917—Focus-error methods other than those covered by G11B7/0909 - G11B7/0916
  • G11B2007/0924—Skewed beams methods (using an angled beam, i.e. a beam which is reflected from the disc at an angle different from 90°)

Landscapes

• Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Optical Recording Or Reproduction (AREA)
• Optical Head (AREA)
• Automatic Focus Adjustment (AREA)
• Facsimile Scanning Arrangements (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=19831595

Family Applications (1)

Country Status (17)

Families Citing this family (17)

Family Cites Families (9)

• 1978
  • 1978-09-22 NL NL7809635A patent/NL7809635A/nl not_active Application Discontinuation
  • 1978-12-11 US US05/968,644 patent/US4253019A/en not_active Expired - Lifetime
• 1979
  • 1979-08-28 ZA ZA00794547A patent/ZA794547B/xx unknown
  • 1979-09-06 AR AR277977A patent/AR223848A1/es active
  • 1979-09-13 CA CA335,578A patent/CA1123640A/en not_active Expired
  • 1979-09-15 DE DE19792937427 patent/DE2937427A1/de active Granted
  • 1979-09-18 AU AU50936/79A patent/AU530291B2/en not_active Ceased
  • 1979-09-19 JP JP11947079A patent/JPS5545200A/ja active Granted
  • 1979-09-19 DK DK391279A patent/DK391279A/da unknown
  • 1979-09-19 IT IT68838/79A patent/IT1165709B/it active
  • 1979-09-19 SE SE7907748A patent/SE437579B/sv not_active IP Right Cessation
  • 1979-09-19 GB GB7932504A patent/GB2033187B/en not_active Expired
  • 1979-09-19 BR BR7905978A patent/BR7905978A/pt unknown
  • 1979-09-20 DD DD79215678A patent/DD146118A5/de unknown
  • 1979-09-20 ES ES484316A patent/ES484316A1/es not_active Expired
  • 1979-09-20 BE BE0/197241A patent/BE878905A/fr not_active IP Right Cessation
  • 1979-09-21 FR FR7923575A patent/FR2437043B1/fr not_active Expired

Also Published As

Similar Documents