×

Security system for electronic device

  • US 4,421,977 A
  • Filed: 07/19/1982
  • Issued: 12/20/1983
  • Est. Priority Date: 07/19/1982
  • Status: Expired due to Fees
First Claim
Patent Images

1. An electronic calculating device comprising a memory means having accounting information registered thereon, a control means for calculating the accounting information and entering the information into the memory means, a power supply providing power to the control means, a switch means having a first position in which an electrical connection is provided between the power supply and the control means and a second position in which the power supply is disconnected from the control means, the switch being in the first position during normal operation of the calculating device, a secured housing enclosing the memory means, the control means, and the switch means and preventing access thereto during normal operation of the calculating device, and an aperture in the housing permitting access to the memory means to read out accounting information registered thereon, wherein movement of the switch from the first position to the second position to disconnect the control circuit from the power supply disables the calculating device from further normal operation but permits readout of the accounting information through the aperture.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×