US 6,982,645 B2
Device for detecting the presence of a transponder around the device
Claudio Ricci, Corso Italia, 52, 20025 Legnano (Italy)
Assigned to Claudio Ricci, Legnano (Italy); and Overton Consultadoria E Serviços LDA, Funchal Madeira (Portugal)
Filed on Jul. 28, 2003, as Appl. No. 10/627,635.
Claims priority of application No. MI2002A1685 (IT), filed on Jul. 29, 2002.
Prior Publication US 2004/0113755 A1, Jun. 17, 2004
Int. Cl. G08B 13/14 (2006.01)
U.S. Cl. 340—572.1 22 Claims
OG exemplary drawing
 
7. A device for detecting the presence of a transponder in its proximity, comprising:
an antenna;
pulse generation means;
means adapted to feed said antenna with said pulses;
means for measuring the damped oscillations of said antenna as a consequence of being fed with said pulses;
said means for measuring the damped oscillations of said antenna being suitable to determine whether a transponder is present or not in the proximity of said antenna by counting the number of said damped oscillations whose amplitude exceeds a preset threshold, said number being lower if said transponder is in the vicinity of said antenna with respect to when said transponder is not present.