3917402

Information

• Patent Grant
• 3917402

• References
• Source

• Patent Number

  3,917,402

• Date Filed

  Not available

• Date Issued

  Tuesday, November 4, 1975
  49 years ago

• CPC

  • G06K9/74 - Arrangements for recognition using optical reference masks
  • A61B5/1172 - using fingerprinting
  • G07C9/00158 - by means of a personal physical data
  • G07D7/12 - Visible light, infra-red or ultra violet radiation
  • H01J31/286 - correlater tubes
  • H01J43/24 - Dynodes having potential gradient along their surfaces

• US Classifications

  • 356 - Optics: measuring and testing
  • 250 - Radiant energy