1870464

Information

• Patent Grant
• 1870464

• References
• Source

• Patent Number

  1,870,464

• Date Filed

  Not available

• Date Issued

  Tuesday, August 9, 1932
  92 years ago

• CPC

  • G01J1/40 - using limit or visibility or extinction effect

• US Classifications

  • 352 - Optics: motion pictures
  • 356 - Optics: measuring and testing