3639768

Information

• Patent Grant
• 3639768

• References
• Source

• Patent Number

  3,639,768

• Date Filed

  Not available

• Date Issued

  Tuesday, February 1, 1972
  52 years ago

• CPC

  • G01J1/4204 - with determination of ambient light
  • G01J1/30 - using electric radiation detectors
  • G08B13/183 - by interruption of a radiation beam or barrier
  • H03F3/08 - controlled by light

• US Classifications

  • 250 - Radiant energy
  • 315 - Electric lamp and discharge devices: systems