Data carrier system
First Claim
1. A data carrier system in an automatic management system comprising:
- a plurality of adjacent fixed facilities each having a constant two-way communication area;
a data carrier for carrying out a two-way communication with a selected one of the plurality of adjacent fixed facilities; and
selective detecting means installed in each of the plurality of adjacent fixed facilities for detecting the data signal from the data carrier;
the selected one of the plurality of fixed facilities recognizing stored data of a data carrier present in the constant communication area after receiving a data signal induced by an AC magnetic field generated by the data carrier present in the constant communication area of the fixed facilities, and the selected one of the plurality of fixed facilities rewriting the stored data of the data carrier by transmitting to the data carrier a rewriting signal induced by the AC magnetic field;
the selective detecting means detecting the data signal by discriminating the data signal induced by the AC magnetic field generated by the data carrier, from the data signals induced by the AC magnetic fields from the fixed facilities other than the selected one of the plurality of fixed facilities.
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Accused Products
Abstract
A data carrier system which uses a power sourceless electromagnetically coupled data carrier, wherein two-way data communication is made possible between a fixed facility and a data carrier. Provision is made for a synchronizing means which renders the frequencies and phases of AC magnetic fields emitted from the fixed facilities to be the same among a plurality of fixed facilities, such that interference will not take place among the plurality of fixed facilities even when they are arranged close to one another. Moreover, the electric power induced in the antenna of the fixed facility by the AC magnetic field generated from the data carrier is synchronously detected by using a synchronizing signal controlled by said synchronizing means.
33 Citations
26 Claims
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1. A data carrier system in an automatic management system comprising:
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a plurality of adjacent fixed facilities each having a constant two-way communication area; a data carrier for carrying out a two-way communication with a selected one of the plurality of adjacent fixed facilities; and selective detecting means installed in each of the plurality of adjacent fixed facilities for detecting the data signal from the data carrier; the selected one of the plurality of fixed facilities recognizing stored data of a data carrier present in the constant communication area after receiving a data signal induced by an AC magnetic field generated by the data carrier present in the constant communication area of the fixed facilities, and the selected one of the plurality of fixed facilities rewriting the stored data of the data carrier by transmitting to the data carrier a rewriting signal induced by the AC magnetic field; the selective detecting means detecting the data signal by discriminating the data signal induced by the AC magnetic field generated by the data carrier, from the data signals induced by the AC magnetic fields from the fixed facilities other than the selected one of the plurality of fixed facilities. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 20, 21, 22)
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- 17. A data carrier system according to clam 10, comprising an individual AC generating means in at least one of the plurality of fixed facilities, the same AC signals being fed from the at least one of the fixed facilities having the individual AC signal generating means to other fixed facilities.
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23. In a fixed facility used in a power sourceless electromagnetically coupled data carrier system, an antenna for a data carrier generates an AC electromagnetic field to feed electric power to the data carrier and has a winding that is wound in a vortex shape on nearly a plane, the density of said winding being lower near the center of vortex and higher toward the outer periphery of the vortex.
- 24. A data carrier system comprising a power sourceless electromagnetically coupled data carrier and fixed facilities that effect two-way data communication relative to said data carrier, wherein a synchronizing signal is transmitted from a synchronizing signal generating means contained in a particular fixed facility to a plurality of other fixed facilities in order to render to be the same among the plurality of fixed facilities the frequencies and phases of AC magnetic fields that are generated from the fixed facilities to transmit electric power and data to the data carrier, the synchronizing signal being transmitted from the synchronizing signal generating means contained in said particular fixed facility to other fixed facilities through an insulation means that is insulated in a DC manner from the synchronizing signal generating means.
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26. A fixed facility in a data carrier system wherein an AC magnetic field is radiated from an antenna coil to feed electric power and data to a data carrier in the form of the AC magnetic field, a change in the AC magnetic field generated by the data carrier is detected through the antenna coil, and the data transmitted from the data carrier is received, the fixed facility comprising
AC signal generating means for generating an AC voltage output; -
a signal modulating circuit for modulating the AC voltage output to superpose the data; an antenna drive circuit for amplifying the modulated AC voltage and feeding the amplified electric power to said antenna coil to generate the AC magnetic field; a synchronous detecting circuit for detecting and rectifying the current flowing through the antenna coil to demodulate the data from the data carrier received by the antenna coil, said synchronizing detecting circuit being brought into synchronism with the AC voltage output from said AC signal generating means; and adjusting means for adjusting the frequency and phase of the AC voltage output from said AC signal generating circuit.
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Specification