3400212

Information

• Patent Grant
• 3400212

• References
• Source

• Patent Number

  3,400,212

• Date Filed

  Not available

• Date Issued

  Tuesday, September 3, 1968
  56 years ago

• CPC

  • H02P5/50 - by comparing electrical values representing the speeds
  • G02B7/04 - with mechanism for focusing or varying magnification
  • G02B7/08 - adapted to co-operate with a remote control mechanism
  • G02B15/14 - by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective
  • G03B17/14 - interchangeably
  • G05D3/14 - using an analogue comparing device
  • G05D3/1409 - with dc amplifier chain

• US Classifications

  • 348 - Television
  • 318 - Electricity: motive power systems
  • 352 - Optics: motion pictures
  • 388 - Electricity: motor control systems