3659920

Information

• Patent Grant
• 3659920

• References
• Source

• Patent Number

  3,659,920

• Date Filed

  Not available

• Date Issued

  Tuesday, May 2, 1972
  52 years ago

• CPC

  • G09B9/34 - by cathode-ray screen display
  • G09B9/32 - by projected image

• US Classifications

  • 359 - Optical: systems and elements
  • 348 - Television
  • 434 - Education and demonstration