3876841

Information

• Patent Grant
• 3876841

• References
• Source

• Patent Number

  3,876,841

• Date Filed

  Not available

• Date Issued

  Tuesday, April 8, 1975
  49 years ago

• CPC

  • G11B7/0908 - for focusing only
  • G02B27/40 - Optical focusing aids
  • G11B7/0916 - Foucault or knife-edge methods
  • G11B7/0917 - Focus-error methods other than those covered by G11B7/0909 - G11B7/0916
  • G11B2007/0924 - Skewed beams methods (using an angled beam

• US Classifications

  • 369 - Dynamic information storage or retrieval
  • 250 - Radiant energy
  • 356 - Optics: measuring and testing
  • 386 - Motion video signal processing for recording or reproducing
  • G9B - INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER