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:
Aug. 12, 1980
Filed:
Jun. 30, 1978
Georges M Giraud, Le Vesinet, FR;
Abstract
A system for transmitting digital signals between a fixed transmitter and a portable receiver which are temporarily interconnected by physical contacts which employs a single pair of contacts and a bidirectional data transfer technique to enhance the integrity of the data transfer. The single pair of contacts minimizes the possibility of data loss or contamination due to problems associated with temporary interconnecting and support a time-shared data transfer from a transmitter, which provides both data and synchronizing signals via a duration modulation technique on a pair of bipolar generators to a comparison receiver. The receiver synchronously acknowledges reception and provides, in turn, data back to the transmitter via a digital modulation of a signal current generator. A basic embodiment teaches the use of the apparatus as a secure data transmission means in a credit card reader, while an expanded embodiment shows the organization of a digital memory interconnection and data transfer scheme using the apparatus discloses.