System and method for detecting persons or objects in definite areas provided each with at least an entrance
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Accused Products
Abstract
A system and a method are described for detection of individuals (8) or objects in a plurality of delimited spaces (10), each having at least one entrance (6). The detection system comprises LF transmission means (4, 4*, 5, 5*) located at the entrance, for transmitting a LF electromagnetic signal, HF transmission-reception means (12, 13) for transmitting-receiving a HF electromagnetic signal (C, ACK), cards or portable electronic units (36) equipping each individual or object, for receiving the LF signal and for transmitting and receiving the HF signal, and a central processing unit (20) for recording data relating to the entry and exit of the portable electronic units. The system can operate according to at least two distinct modes of operation and the LF signal comprises selection information (SELECT) indicating which of the two modes of operation should be used by the electronic units during their passage through the entrance. The system is preferably configured to pass, at least temporarily, in one of the said delimited spaces, from one mode of operation to the other.
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Citations
20 Claims
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1-10. -10. (canceled)
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11. A system for detecting individuals or objects in a plurality of delimited spaces each having at least one entrance, the detection system comprising, for each of the said delimited spaces:
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low frequency transmission means associated with the delimited space and located at the said entrance to transmit at least one low frequency electromagnetic signal in a communication region substantially covering the said entrance; and
high frequency transmission-reception means associated with the delimited space for receiving and transmitting at least one high frequency electromagnetic signal, the detection system further comprising;
cards or portable electronic units, each equipping an individual or object, each electronic unit comprising a low frequency reception module for receiving the said low frequency electromagnetic signal and a high frequency transmission-reception module for transmitting and receiving the said high frequency electromagnetic signal; and
at least one central processing unit associated with the said delimited spaces and connected to the said low frequency transmission means as well as to the said high frequency transmission-reception means for recording data relative to the entrance and exit of the said portable electronic units, wherein the system is configured to operate according to at least two distinct modes of operation in which said electronic units communicate with said high-frequency transmission-reception means, and wherein the said low frequency electromagnetic signal comprises selection information indicating which of the said at least two modes of operation should be utilised by the said electronic units during their passage through an entrance of any one of the said plurality of delimited spaces. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification