Contactless inductive data-transmission system
US5345231A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 23, 1991 |
| Grant date | Sep 6, 1994 |
| Priority date | — |
| Expiry date | Aug 23, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K19/0723
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A contactless inductive data transmission system provides bidirectional signal transfer between a sending-and-receiving station and one or more batteryless transponders. A high-frequency signal from the sending-and-receiving station is pulse width modulated for data transmission to a transponder and provides a system clock, which is extracted in both the sending-and-receiving station and in the transponder for synchronization, and provides the electrical power for operation of the transponder. The pulse width modulated signal is demodulated in the transponder for triggering a response wherein a modulating signal is applied by load modulation to the pulse width modulated high-frequency signal to form an information-carrying load modulated high-frequency signal, which is demodulated in the sending-and-receiving station.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.