Noncontact data carrier
First Claim
1. A noncontact data carrier which performs radio communication with a reader/writer, using electromagnetic wave or electromagnetically-induced binding via an antenna, comprising:
- a power supply unit for obtaining a power source from a reception signal received by the antenna;
a demodulation unit for demodulating the reception signal;
a decoding unit for decoding the demodulated signal;
a signal processing unit for performing data processing based on the contents of the decoded signal, and generation of a signal to be transmitted to the reader/writer;
a coding unit for coding the signal to be transmitted to the reader/writer, which signal is generated in the signal processing unit;
a modulation unit for changing the signal coded by the coding unit to a modulated signal;
a battery for performing supply of electric power to a part of the noncontact data carrier or to the whole circuit; and
a power supply control unit for controlling start or stop of the supply of electric power from the battery to a part of the noncontact data carrier or to the whole circuit, on the basis of the signal state of the reception signal,whereinsaid power supply control unit comprises;
a frequency judgment unit for performing a first judgment as to whether the frequency of the reception signal is included in a predetermined frequency range or not, anda time judgment unit for performing a second judgment as to whether the state where the frequency of the reception signal is included in the predetermined frequency range is continued for a predetermined period of time or not, after the first judgment is made by the frequency judgment unit, andsaid power supply control unit starts supply of electric power from the battery to the noncontact data carrier when the second judgment is made by the time judgment unit after the first judgment has been made by the frequency judgment unit.
3 Assignments
0 Petitions
Accused Products
Abstract
When performing radio communication with a reader/writer (1), supply of a power source S4 from a battery (14) is started when a level judgment circuit (9) judges that the signal level of a reception signal S2 received by an antenna (5) of a noncontact data carrier (4) is equal to or higher than a predetermined amplitude and a timer circuit (10) judges that the state where the amplitude is equal to or higher than the predetermined value has continued for a predetermined period T1 or more, and further, the supply of the power source S4 from the battery is stopped when the level judgment circuit (9) judges that the signal level of the reception signal S2 is lower than the predetermined amplitude and the timer circuit (10) judges that state where the amplitude is lower than the predetermined value has continued for a predetermined period T2 or more, thereby ensuring communication reliability that causes no problem in practical use of the noncontact data carrier (4), and avoiding insignificant dissipation of the battery.
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Citations
6 Claims
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1. A noncontact data carrier which performs radio communication with a reader/writer, using electromagnetic wave or electromagnetically-induced binding via an antenna, comprising:
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a power supply unit for obtaining a power source from a reception signal received by the antenna; a demodulation unit for demodulating the reception signal; a decoding unit for decoding the demodulated signal; a signal processing unit for performing data processing based on the contents of the decoded signal, and generation of a signal to be transmitted to the reader/writer; a coding unit for coding the signal to be transmitted to the reader/writer, which signal is generated in the signal processing unit; a modulation unit for changing the signal coded by the coding unit to a modulated signal; a battery for performing supply of electric power to a part of the noncontact data carrier or to the whole circuit; and a power supply control unit for controlling start or stop of the supply of electric power from the battery to a part of the noncontact data carrier or to the whole circuit, on the basis of the signal state of the reception signal, wherein said power supply control unit comprises; a frequency judgment unit for performing a first judgment as to whether the frequency of the reception signal is included in a predetermined frequency range or not, and a time judgment unit for performing a second judgment as to whether the state where the frequency of the reception signal is included in the predetermined frequency range is continued for a predetermined period of time or not, after the first judgment is made by the frequency judgment unit, and said power supply control unit starts supply of electric power from the battery to the noncontact data carrier when the second judgment is made by the time judgment unit after the first judgment has been made by the frequency judgment unit. - View Dependent Claims (2)
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3. A noncontact data carrier which performs radio communication with a reader/writer, using electromagnetic wave or electromagnetically-induced binding via an antenna, comprising:
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a power supply unit for obtaining a power source from a reception signal received by the antenna; a demodulation unit for demodulating the reception signal; a decoding unit for decoding the demodulated signal; a signal processing unit for performing data processing based on the contents of the decoded signal, and generation of a signal to be transmitted to the reader/writer; a coding unit for coding the signal to be transmitted to the reader/writer, which signal is generated in the signal processing unit; a modulation unit for changing the signal coded by the coding unit to a modulated signal; a battery for performing supply of electric power to a part of the noncontact data carrier or to the whole circuit; and a power supply control unit for controlling start or stop of the supply of electric power from the battery to a part of the noncontact data carrier or to the whole circuit, on the basis of the signal state of the reception signal, wherein said power supply control unit comprises; a frequency judgment unit for performing a first judgment as to whether the frequency of the reception signal is included in a predetermined frequency range or not, and a time judgment unit for performing a second judgment as to whether the state where the frequency of the reception signal is included in the predetermined frequency range is continued for a predetermined period of time or not, after the first judgment is made by the frequency judgment unit, and said power supply control unit starts supply of electric power from the battery to the noncontact data carrier when the first judgment is made by the frequency judgment unit, continues the supply of electric power when the second judgment is made by the time judgment unit, and stops the supply of electric power when the second judgment is not made. - View Dependent Claims (4)
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5. A noncontact data carrier which performs radio communication with a reader/writer, using electromagnetic wave or electromagnetically-induced binding via an antenna, comprising:
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a power supply unit for obtaining a power source from a reception signal received by the antenna; a demodulation unit for demodulating the reception signal; a decoding unit for decoding the demodulated signal; a signal processing unit for performing data processing based on the contents of the decoded signal, and generation of a signal to be transmitted to the reader/writer; a coding unit for coding the signal to be transmitted to the reader/writer, which signal is generated in the signal processing unit; a modulation unit for changing the signal coded by the coding unit to a modulated signal; a battery for performing supply of electric power to a part of the noncontact data carrier or to the whole circuit; and a first power supply control unit for controlling start or stop of the supply of electric power from the battery to a part of the noncontact data carrier or to the whole circuit, on the basis of the signal state of the reception signal; a sensor element; and a second power supply control unit for controlling start or stop of supply of electric power from the battery to the noncontact data carrier on the basis of a measurement amount that is measured by the sensor element; and said signal processing unit performing data processing based on the contents of the decoded signal, and/or data processing based on the measurement amount obtained by the sensor element, and/or generation of a signal to be transmitted to the reader/writer, and/or recording into the memory. - View Dependent Claims (6)
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Specification