1657894

Information

• Patent Grant
• 1657894

• References
• Source

• Patent Number

  1,657,894

• Date Filed

  Not available

• Date Issued

  Tuesday, January 31, 1928
  97 years ago

• CPC

  • G03B13/26 - with magnifiers for inspecting image formed on screen

• US Classifications

  • 396 - Photography