Patent · US Expired

Transaction system

US4845347A · kind A · utility

85Cited by
5References
7Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 8, 1986
Grant dateJul 4, 1989
Priority date
Expiry dateApr 8, 2006

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG07C9/28
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A transaction system enables a portable token to co-operate with a fixed terminal. The token is inductively coupled to the terminal, and receives data from the terminal via a frequency modulated carrier signal. Data is sent from the token to the terminal by amplitude modulation of the carrier signal from the terminal, i.e. by modulating the power driven by the token from the terminal. The power needed to energize the on-board processing capability of the token is also obtained from the terminal via the inductive coupling. The token includes an arrangement for commencing processor operation in an orderly manner when it is brought into the proximity of the terminal, and for providing an orderly shut down when the token is withdrawn.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.