3921040

Information

• Patent Grant
• 3921040

• References
• Source

• Patent Number

  3,921,040

• Date Filed

  Not available

• Date Issued

  Tuesday, November 18, 1975
  49 years ago

• CPC

  • G07F7/10 - together with a coded signal
  • G06Q20/347 - Passive cards
  • G07F7/1058 - PIN is checked locally

• US Classifications

  • 340 - Communications: electrical
  • 361 - Electricity: electrical systems and devices