Device for locating objects by RFID communication
First Claim
1. A device for determining a position, with respect to known fixed positions, of an object provided with an electronic radiofrequency identification (RFID) tag having an inductive antenna, the device comprising:
- an array of N fixed RFID tags each provided with a respective inductive antenna, said N fixed RFID tags placed at said known fixed positions with respective each other, N being an integer greater than 1; and
an RFID tag reader provided with a fixed inductive reading antenna passing in proximity to the N respective inductive antennas of the N fixed RFID tags,a configuration of the fixed inductive reading antenna with respect to each of the N antennas of the N fixed RFID tags being such that the mutual inductance between the inductive antenna of any one of the N fixed RFID tags and the inductive reading antenna is zero in the absence of the object, andmeans for determining a proximity of the object to a given fixed RFID tag from a non-zero coupling between said given fixed RFID tag and the inductive reading antenna, said non-zero coupling induced by a proximity between the inductive antenna of the RFID tag of the object, the inductive antenna of said given fixed RFID tag and the inductive reading antenna of the reader,wherein the array of fixed RFID tags is organized into rows linking centres of the antennas of the fixed RFID tags, the array defining zones situated between the rows, the device further comprising means for receiving data from several RFID tags whose antennas bracket a zone in which the object is placed.
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Accused Products
Abstract
The invention relates to the locating and identifying of objects with radiofrequency communication by inductive coupling, without electrical contact, between a reader and a tag. The device includes an array of N fixed RFID markers of RFID tag type, with inductive antennas placed at known positions, N being an integer greater than 1 and an RFID tag reader provided with a fixed reading inductive antenna passing in proximity to the N markers. The position of the N markers with respect to the inductive reading antenna is such that the mutual inductance between the inductive antenna of any marker and the inductive reading antenna is zero when no object to be located is present in the vicinity of the array of markers, and nonzero when an RFID tag is present in the vicinity of the marker considered. A coupling is established in the presence of a mobile tag in proximity to a marker.
13 Citations
19 Claims
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1. A device for determining a position, with respect to known fixed positions, of an object provided with an electronic radiofrequency identification (RFID) tag having an inductive antenna, the device comprising:
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an array of N fixed RFID tags each provided with a respective inductive antenna, said N fixed RFID tags placed at said known fixed positions with respective each other, N being an integer greater than 1; and an RFID tag reader provided with a fixed inductive reading antenna passing in proximity to the N respective inductive antennas of the N fixed RFID tags, a configuration of the fixed inductive reading antenna with respect to each of the N antennas of the N fixed RFID tags being such that the mutual inductance between the inductive antenna of any one of the N fixed RFID tags and the inductive reading antenna is zero in the absence of the object, and means for determining a proximity of the object to a given fixed RFID tag from a non-zero coupling between said given fixed RFID tag and the inductive reading antenna, said non-zero coupling induced by a proximity between the inductive antenna of the RFID tag of the object, the inductive antenna of said given fixed RFID tag and the inductive reading antenna of the reader, wherein the array of fixed RFID tags is organized into rows linking centres of the antennas of the fixed RFID tags, the array defining zones situated between the rows, the device further comprising means for receiving data from several RFID tags whose antennas bracket a zone in which the object is placed. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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Specification