3558217

Information

• Patent Grant
• 3558217

• References
• Source

• Patent Number

  3,558,217

• Date Filed

  Not available

• Date Issued

  Tuesday, January 26, 1971
  53 years ago

• CPC

  • G05D3/1409 - with dc amplifier chain
  • G02B7/08 - adapted to co-operate with a remote control mechanism
  • G02B7/10 - by relative axial movement of several lenses
  • 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
  • G02B27/40 - Optical focusing aids
  • G03B17/14 - interchangeably
  • G05D3/14 - using an analogue comparing device

• US Classifications

  • 359 - Optical: systems and elements