The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 02, 1990
Filed:
Apr. 13, 1989
David A Rieker, Cambridge, OH (US);
NCR Corporation, Dayton, OH (US);
Abstract
An electronic keylock system comprises a key which includes a precision resistance, a receiver for receiving the key, an analog-to-digital converter coupled to the receiver for measuring the resistance of the precision resistance of the key, circuitry for controlling the analog-to-digital converter, decoding logic for receiving data from the analog-to-digital converter and decrypting the data to provide information with respect to the type of key applied to the receiver, and circuitry for controlling the decoding logic. Two system embodiments are disclosed, one of which employs separate components, and the other of which employs a microcontroller combining several functions.