Detection of the presence of a contactless communication element within the range of a terminal
US8258970B2 · kind B2 · utility
2Cited by
5References
22Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 23, 2009 |
| Grant date | Sep 4, 2012 |
| Priority date | — |
| Expiry date | Oct 29, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K7/10128
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method of detection of the presence of a contactless communication element by a terminal emitting an electromagnetic field, in which an oscillating circuit of the terminal is excited at a frequency which is made variable between two values surrounding a nominal tuning frequency of the oscillating circuit; a signal representative of the load of the oscillating circuit being interpreted to detect that a reference voltage has not been exceeded, which indicates the presence of an element in the field. A presence-detection circuit and a corresponding terminal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.