Method and apparatus for transmitting a digital information signal and vending system incorporating same
US6446049B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 29, 1998 |
| Grant date | Sep 3, 2002 |
| Priority date | — |
| Expiry date | Sep 29, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06Q30/06
- WIPO fieldIT methods for management
- WIPO sectorElectrical engineering
Abstract
A cashless business transaction system (e.g., a vending system, a material tracking system, or a highway toll system) incorporates a method and apparatus for transmitting a digital information signal. A signal generator (311) generates a constant frequency signal. A phase modulator (305) varies the instantaneous phase of the constant frequency signal to represent digital information, thereby producing a phase modulated signal (325). A tuned resonant circuit (307) filters and averages the phase modulated signal to produce a simulated FM signal, and transmits the simulated FM signal via its antenna (309). One such business transaction system (e.g., a vending system) incorporates such a transmitter to facilitate transmission of billing information from a device located within a substantially electrically shielded environment. Another such business transaction system preferably incorporates such a transmitter to facilitate half-duplex transmission of digital information regardless of whether or not the digital information is transmitted from a device located within a substantially electrically shielded environment.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.