JP2006211050A - Electronic tag system, electronic tag and power control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To operate an electronic tag without imposing a load on a reader/writer even when a distance between the reader/writer and the electronic tag is long. <P>SOLUTION: An antenna A111 receives a radio wave with a first frequency from the reader/writer 20 and generates an induced electromotive force by electromagnetic induction. Further, a reception section A121 generates a first power for activating an IC chip section 12 by the induced electromotive force. An antenna B112 receives a radio wave with a second frequency from the reader/writer 20 and generates an induced electromotive force by electromagnetic induction. Further, a reception section B123 generates a second power for activating the IC chip section 12 by the induced electromotive force. Moreover, a power management section 125 controls the generated first and second powers to supply the powers to each section of the electronic tag 10. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electronic tag system using an electronic tag, and more particularly to an electronic tag system using a power control method for controlling electric power supplied to an electronic tag. The present invention also relates to a power control method for controlling power supplied to an electronic tag and an electronic tag of an electronic tag system.

  In recent years, a system using an electronic tag such as Radio Frequency Identification (RFID) (hereinafter also simply referred to as an electronic tag system) has been used as an automatic recognition system using wireless technology. An electronic tag system generally includes an electronic tag such as an RFID tag, an IC tag, or an RF tag attached to an article or the like and having a data storage area, and a reader / writer that transmits / receives data to / from the electronic tag. The electronic tag system includes a back-end system such as a server that manages the reader / writer (for example, exchanges data with the reader / writer).

  In the electronic tag system, data can be transmitted and received in a non-contact state where there is no physical connection between the reader / writer and the electronic tag by using a wireless signal. Therefore, when an electronic tag is used, there is an advantage that communication is possible as long as radio waves reach even if there are some physical obstacles between the reader / writer and the electronic tag. Due to such advantages, the electronic tag system is expected to be applied to various fields including the distribution industry.

  As a technique using an electronic tag, for example, Patent Document 1 describes an information card that can be used for both remote use and proximity use in a single contactless IC card.

JP-A-5-258127 (paragraphs 0008-0017, FIGS. 2 and 7)

  However, when using a passive electronic tag without a built-in battery, the electronic tag cannot generate enough power for operation from the radio waves generated by the reader / writer when there is an electronic tag away from the reader / writer. There is. Therefore, data may not be transmitted / received between the reader / writer and the electronic tag.

  FIG. 5 is an explanatory diagram illustrating an example of a passive electronic tag that does not incorporate a battery. In FIG. 5, a case where the electronic tag is an inlay type tag will be described as an example. As shown in FIG. 5, an electronic tag 910 includes an antenna portion 911 and an IC chip portion 912 formed on a substrate 913 such as a PET film. FIG. 6 is a block diagram illustrating an example of a functional configuration of the electronic tag illustrated in FIG. As shown in FIG. 6, the electronic tag includes an antenna portion 911 and an IC chip portion 912. The IC chip unit 912 includes a data receiving unit 9121, a data transmitting unit 9122, a control unit 9126, and a memory unit 9127.

  FIG. 7 is an explanatory diagram illustrating an example in the case where power necessary for the operation of the electronic tag is generated in the electronic tag illustrated in FIGS. 5 and 6. In the electronic tag shown in FIGS. 5 and 6, electromagnetic waves are generated by a change in magnetic flux that passes through the antenna coil of the antenna unit 911 of the electronic tag 910 due to the radio wave generated by the reader / writer 920. The electronic tag 910 generates an induced electromotive force by electromagnetic induction. In this case, the electronic tag 910 generates electric power necessary for the operation of the electronic tag 910 based on the generated induced electromotive force, and supplies the electric power to the control unit 9126, the memory unit 9127, and the data transmission unit 9122. The electronic tag 910 performs processing for writing data (for example, ID data) from the reader / writer 920 into the memory unit 9127 and reading data from the memory unit 9127 according to a predetermined communication protocol.

  As illustrated in FIG. 7, the passive electronic tag operates by generating electric power when the antenna unit 911 receives a radio wave from the reader / writer 920. For this reason, the electronic tag 910 cannot operate when there is insufficient supply of radio waves to generate power necessary for operation, such as away from the electromagnetic field generated by the reader / writer.

  In order to enable the electronic tag to operate even when the electronic tag is away from the reader / writer, the antenna 921 of the reader / writer 920 may be increased or the transmission output of the reader / writer 920 may be increased. However, if the antenna 921 is increased or the transmission output is increased, the transmission burden on the reader / writer 920 is increased, which is not suitable for downsizing the reader / writer 920. Also, due to radio wave-related laws and regulations, it may be difficult to increase the antenna of the reader / writer 920 or increase the transmission output.

  If the technique described in Patent Document 1 is used, the electronic tag is provided with two antennas for remote use and proximity, so that the electronic tag is not limited to being close to the reader / writer, but is separated from the reader / writer to some extent. Even so, power can be generated. However, in order to be able to generate power even when the electronic tag is away from the reader / writer, it is necessary to increase the antenna of the reader / writer or increase the transmission output. For this reason, the burden on the reader / writer is large and it is not suitable for downsizing. In addition, due to legal restrictions, it may not be possible to use a large antenna or increase the transmission output.

  Therefore, the present invention provides an electronic tag system, an electronic tag, and a power control method capable of operating an electronic tag even when the distance between the reader / writer and the electronic tag is long without imposing a burden on the reader / writer. The purpose is to provide. It is another object of the present invention to provide an electronic tag system, an electronic tag, and a power control method capable of operating an electronic tag more reliably even when there are laws and regulations related to radio waves.

  An electronic tag system according to the present invention includes an electronic tag and a reader / writer that writes or reads data to or from the electronic tag. The reader / writer generates electromagnetic waves that generate a plurality of electromagnetic waves having different frequencies (for example, an antenna unit). The electronic tag includes a plurality of electromagnetic wave receiving means (for example, realized by the antenna A111 and the antenna B112) that respectively receive electromagnetic waves generated by the reader / writer, and each electromagnetic wave receiving means receives the electronic tag. Power generation means for generating power based on electromagnetic waves (for example, realized by the reception units 121 and 123), and the power generated by the power generation means for each part of the electronic tag (for example, the control unit 126, the memory unit 127, and the transmission unit) 122, 124), for example, by the power management unit 125. Characterized in that it comprises a to) and.

  Preferably, the electromagnetic wave receiving means receives radio waves generated by the reader / writer, and the power generation means generates power by electromagnetic induction using the radio waves received by each electromagnetic wave receiving means.

  The electromagnetic wave receiving means inputs light generated by the reader / writer, and the power generating means generates electric power using a predetermined photovoltaic element based on the light input by each electromagnetic wave receiving means. May be.

  The electromagnetic wave receiving means inputs sound waves generated by the reader / writer, and the power generating means generates electric power using a predetermined electromotive force element based on the sound waves input by the respective electromagnetic wave receiving means. May be.

  Further, the power supply unit may combine the power generated by the power generation unit when the power generation unit generates power based on a plurality of electromagnetic waves, and supply the combined power to each part of the electronic tag. . According to such a configuration, even if a single radio wave cannot generate sufficient power to operate the electronic tag, the electronic tag can be operated more reliably by supplying the combined power. can do.

  The electromagnetic wave generating means generates an electromagnetic wave using a predetermined first frequency and an electromagnetic wave using a second frequency different from the first frequency, and the electronic tag uses an electromagnetic wave using the first frequency. First electromagnetic wave receiving means (for example, realized by the antenna A111), second electromagnetic wave receiving means (for example, realized by the antenna B112) for receiving electromagnetic waves using the second frequency, First power generation means (for example, realized by the receiving unit A121) that generates power based on the electromagnetic wave received by the first electromagnetic wave reception means, and power based on the electromagnetic wave received by the second electromagnetic wave reception means Second power generation means (for example, realized by the receiving unit B123), and the power supply means is generated by the first power generation means and the second power generation means. Power may be one that controls that.

  The electronic tag includes power storage means (for example, realized by the power storage unit 125b) that stores the power generated by the first power generation means, and the power supply means includes the power stored in the power storage means or the second power The power generated by the power generation means may be supplied to each part of the electronic tag. According to such a configuration, since the time for generating the radio wave of the first frequency and the radio wave of the second frequency is not overlapped, the radio waves can be prevented from interfering with each other, and the electronic tag, the reader / writer, Data can be transmitted and received smoothly.

  The power supply unit may combine the power stored in the power storage unit and the power generated by the second power generation unit, and supply the combined power to each part of the electronic tag. According to such a configuration, even if a single radio wave cannot generate sufficient power to operate the electronic tag, the electronic tag can be operated more reliably by supplying the combined power. can do.

  The reader / writer includes an error determination unit (for example, realized by the control unit 22) that determines whether an error has occurred in the received signal when receiving a radio signal from the electronic tag, and includes an electromagnetic wave generation unit. May generate an electromagnetic wave for supplying power when the error determination means determines that an error has occurred in the signal. According to such a configuration, when an error occurs in a signal transmitted by the electronic tag due to insufficient power, the electronic tag can be supplied with power, and communication between the electronic tag and the reader / writer can be performed more smoothly. be able to.

  In addition, the electronic tag is based on quality measurement means (for example, realized by the control unit 126) that measures the signal quality of a plurality of radio signals having different frequencies received from the reader / writer, and the measurement result of the quality measurement means. Using a frequency selection unit (for example, realized by the control unit 126) that selects one of the frequencies corresponding to each radio signal and the frequency selected by the frequency selection unit, the reader / writer transmits and receives the radio signal. Transmission / reception means (for example, realized by the control unit 126 and the transmission units 122 and 124) may be included. According to such a configuration, it is possible to more reliably perform communication between the electronic tag and the reader / writer by determining the signal quality of the radio signal for each frequency.

  An electronic tag according to the present invention includes a plurality of electromagnetic wave receiving means for receiving a plurality of electromagnetic waves having different frequencies, which are generated by a reader / writer that writes or reads data on the electronic tag, and an electromagnetic wave received by each electromagnetic wave receiving means. It is characterized by comprising power generation means for generating power based on power and power supply means for supplying the power generated by the power generation means to each part of the electronic tag.

  The electronic tag includes a first electromagnetic wave receiving unit that receives an electromagnetic wave using a predetermined first frequency, and a second electromagnetic wave receiving unit that receives an electromagnetic wave using a second frequency different from the first frequency. A first power generating means for generating power based on the electromagnetic wave received by the first electromagnetic wave receiving means, and a second power generating means for generating power based on the electromagnetic wave received by the second electromagnetic wave receiving means. And power storage means for storing the power generated by the first power generation means, wherein the power supply means supplies the power stored by the power storage means or the power generated by the second power generation means to each part of the electronic tag. You may do. According to such a configuration, since the time for generating the radio wave of the first frequency and the radio wave of the second frequency is not overlapped, the radio waves can be prevented from interfering with each other, and the electronic tag, the reader / writer, Data can be transmitted and received smoothly.

  A power control method for an electronic tag according to the present invention is a power control method for controlling power supplied to an electronic tag, the step of generating a plurality of electromagnetic waves having different frequencies, and a plurality of electromagnetic wave receiving means for generating the generated electromagnetic waves. Each of the electromagnetic wave receiving means, a step of generating electric power based on the electromagnetic wave received by each electromagnetic wave receiving means, and a step of supplying the generated electric power to each part of the electronic tag.

  The power control method for the electronic tag uses the first frequency and the step of generating an electromagnetic wave using a predetermined first frequency and an electromagnetic wave using a second frequency different from the first frequency. Receiving the electromagnetic wave using the first electromagnetic wave receiving means, receiving the electromagnetic wave using the second frequency using the second electromagnetic wave receiving means, and the electromagnetic wave received by the first electromagnetic wave receiving means. A step of generating first power based on the step, a step of generating second power based on the electromagnetic wave received by the second electromagnetic wave receiving means, a step of storing the generated first power, And supplying the first electric power or the generated second electric power to each part of the electronic tag. According to such a configuration, since the time for generating the radio wave of the first frequency and the radio wave of the second frequency is not overlapped, the radio waves can be prevented from interfering with each other. Data can be transmitted and received smoothly.

  According to the present invention, power is generated based on a plurality of electromagnetic waves having different frequencies, and power is supplied to each part of the electronic tag. Therefore, even when only one electromagnetic wave is used and sufficient power cannot be generated, sufficient power can be generated to operate the electronic tag using a plurality of electromagnetic waves. Therefore, the electronic tag can be operated even when the distance between the reader / writer and the electronic tag is long without imposing a burden on the reader / writer.

Embodiment 1 FIG.
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an example of the configuration of an electronic tag system using a power control method according to the present invention. As shown in FIG. 1, the electronic tag system includes an electronic tag 10, a reader / writer 20 that writes and reads data to and from the electronic tag 10, and a server 30 that manages the reader / writer 20.

  In the present embodiment, the electronic tag 10 is attached to an article such as a store product. Moreover, the electronic tag 10 is attached to household appliances, such as a mobile telephone and a DVD recorder, for example. In the present embodiment, the electronic tag 10 includes a plurality of antennas, and receives a plurality of radio waves having different frequencies from the reader / writer 20 using the respective antennas. And the electronic tag 10 produces | generates electric power based on each received electromagnetic wave. In the present embodiment, as an example, the case where the electronic tag 10 includes two antennas will be described.

  In this embodiment, as an example, the case where the electronic tag 10 generates power using radio waves will be described. However, the electronic tag 10 may generate power using electromagnetic waves other than radio waves. For example, the electronic tag 10 may generate electric power using light from the reader / writer 20. In this case, the electronic tag 10 includes, for example, a plurality of photovoltaic elements (for example, InSb photovoltaic elements and InAs photovoltaic elements) using a semiconductor, and generates electric power using the photovoltaic elements. Also good. For example, the electronic tag 10 may generate electric power using sound waves from the reader / writer 20. In this case, the electronic tag 10 may include a plurality of sound electromotive elements using, for example, a piezoelectric material (for example, polyvinylidene fluoride), and generate electric power using the sound electromotive elements.

  The electronic tag 10 is, for example, an RFID tag, an IC tag, an RF tag, or the like. As shown in FIG. 1, the electronic tag 10 includes an antenna unit 11 and an IC chip unit 12. The electronic tag 10 includes two antennas 111 and 112. The IC chip unit 12 includes receiving units 121 and 123, transmitting units 122 and 124, a power management unit 125, a control unit 126, and a memory unit 127. As shown in FIG. 1, in this embodiment, the electronic tag 10 is provided with receiving units 121 and 123 and transmitting units 122 and 124 for each of the antennas 111 and 112.

  In this embodiment, the antenna A111 has a function of radiating radio waves having a predetermined frequency. Further, the antenna B112 has a function of radiating a radio wave having a frequency different from that of the radio wave radiated by the antenna A111. In the present embodiment, the frequency of the radio wave radiated from the antenna A111 is referred to as a first frequency. The frequency of the radio wave radiated from the antenna B112 is referred to as a second frequency.

  Each of the antenna A111 and the antenna B112 includes an antenna coil unit, and has a function of generating electromagnetic induction by causing a change in magnetic flux passing through the antenna coil unit by radio waves from the reader / writer 20. Moreover, the antenna A111 and the antenna B112 have a function of generating an induced electromotive force by the generated electromagnetic induction.

  The receiving unit A121 has a function of receiving data (for example, ID data) from the reader / writer 20 as a radio signal of the first frequency via the antenna A111. Further, the receiving unit A121 has a function of generating power and a clock signal for IC chip operation using induced electromotive force generated by the antenna A111. In the present embodiment, the power for IC chip operation generated by the receiving unit A121 is referred to as first power.

  The receiving unit B123 has a function of receiving data from the reader / writer 20 as a radio signal of the second frequency via the antenna B112. The receiving unit B123 has a function of generating power and a clock signal for operating the IC chip using induced electromotive force generated by the antenna B112. In the present embodiment, the power for IC chip operation generated by the receiving unit B123 is referred to as second power.

  The transmitting unit A122 has a function of transmitting data to the reader / writer 20 as a radio signal having the first frequency via the antenna A111. The transmission unit B124 has a function of transmitting data to the reader / writer 20 as a radio signal of the second frequency via the antenna B112.

  The power management unit 125 has a function of controlling the first power generated by the reception unit A121 and the second power generated by the reception unit B123, and supplying power to each unit of the IC chip unit 12. In the present embodiment, the power management unit 125 supplies power to the control unit 126, the memory unit 127, and the transmission units 122 and 124.

  The control unit 126 has a function of executing data reading and writing processing. In the present embodiment, control unit 126 reads out data stored in memory unit 127 and outputs the data to transmission units 122 and 124. Further, the control unit 126 writes the data input from the receiving units 121 and 123 into the memory unit 127. The memory unit 127 has a function of storing data in accordance with an instruction from the control unit 126.

  As shown in FIG. 1, the reader / writer 20 includes an antenna unit 21 and a control unit 22. The antenna unit 21 has a function of transmitting and receiving data to and from the electronic tag 10 as a radio signal. In the present embodiment, the antenna unit 21 has a function of transmitting and receiving radio signals of two frequencies, the first frequency and the second frequency. For example, the antenna unit 21 includes a first antenna that radiates radio waves of a first frequency and a second antenna that radiates radio waves of a second frequency. And the antenna part 21 transmits / receives data with the electronic tag 10 as a radio signal of a 1st frequency using a 1st antenna. The antenna unit 21 transmits / receives data to / from the electronic tag 10 as a radio signal having the second frequency using the second antenna.

  The control unit 22 has a function of executing various processes such as reading of data from the electronic tag 10 and writing of data to the electronic tag 10. For example, the control unit 22 causes the antenna unit 21 to receive (read) data as a radio signal from the electronic tag 10. Then, the control unit 22 outputs the data read from the electronic tag 10 to the server 30. Further, the control unit 22 inputs data to be written to the electronic tag 10 from the server 30. Then, the control unit 22 causes the antenna unit 21 to transmit write data as a radio signal to the electronic tag 10.

  Specifically, the server 30 is an information processing apparatus such as a workstation or a personal computer. The server 30 has a function of controlling and managing the reader / writer 20. For example, the server 30 outputs data to the reader / writer 20 and controls the reader / writer 20 to write data to the electronic tag 10. Further, the server 30 causes the reader / writer 20 to read data from the electronic tag 10 and inputs the read data from the reader / writer 20.

  Next, the operation will be described. FIG. 2 is a flowchart illustrating an example of a power control process for generating and controlling power supplied to the electronic tag in the electronic tag system. For example, when the user wants to automatically recognize a product to which the electronic tag 10 is attached, the user brings the portion of the product to which the electronic tag 10 is attached closer to the reader / writer 20.

  For example, the reader / writer 20 generates radio waves of the first frequency at a predetermined timing. The antenna A111 of the electronic tag 10 receives the first frequency radio wave from the reader / writer 20 (step S11). Then, the receiving unit A121 generates first power based on the received radio wave having the first frequency (step S12). In the present embodiment, antenna A111 generates electromagnetic induction by radio waves having the first frequency. The antenna A111 generates an induced electromotive force by electromagnetic induction. Then, the receiving unit A121 generates a clock signal and first power for IC chip operation by the induced electromotive force generated by the antenna A111.

  Further, the reader / writer 20 generates radio waves of the second frequency at a predetermined timing, for example. The antenna B112 of the electronic tag 10 receives the radio wave of the second frequency from the reader / writer 20 (step S13). Then, the receiving unit B123 generates second power based on the received radio wave having the second frequency (step S14). In the present embodiment, antenna B112 generates electromagnetic induction by radio waves of the second frequency. The antenna B112 generates an induced electromotive force by electromagnetic induction. Then, the receiving unit B123 generates a clock signal and second power for IC chip operation by the induced electromotive force generated by the antenna B112.

  The power management unit 125 controls the first power generated by the reception unit A121 and the second power generated by the reception unit B123, and supplies power to the control unit 126, the memory unit 127, and the transmission units 122 and 124 ( Step S15). For example, when it is not possible to receive the first frequency radio wave and only the second power can be generated based on the second frequency radio wave, the power management unit 125 uses the second frequency generated by the reception unit B123. Is supplied to the control unit 126, the memory unit 127, and the transmission units 122 and 124. In addition, for example, when it is impossible to receive the second frequency radio wave and only the first power can be generated based on the first frequency radio wave, the power management unit 125 is generated by the receiving unit A121. The first power is supplied to the control unit 126, the memory unit 127, and the transmission units 122 and 124.

  In addition, for example, when both the first power and the second power can be generated, the power management unit 125 combines the generated first power and the second power to generate the control unit 126, the memory unit 127, You may supply to the transmission parts 122 and 124. FIG. For example, when the radio wave intensity of the received first frequency radio wave and second frequency radio wave is small, the electronic tag 10 can use only the first frequency radio wave or the second frequency radio wave. May not be able to generate sufficient power to operate 12. In this case, the power management unit 125 can combine the first power and the second power to supply the IC chip unit 12 more reliably.

  When power is supplied, the electronic tag 10 transmits / receives data to / from the reader / writer 20 as a wireless signal (step S16). For example, when the receiving unit A 121 or the receiving unit B 123 receives data from the reader / writer 20, the control unit 126 stores the received data in the memory unit 127. Further, for example, the control unit 126 reads data stored in the memory unit 127 and outputs the read data to the transmission unit A122 or the transmission unit B124. Then, the transmission unit A122 or the transmission unit B124 transmits data to the reader / writer 20 as a radio signal.

  As described above, according to the present embodiment, when the electronic tag 10 cannot generate sufficient power to operate the IC chip unit 12 based on the first frequency radio wave from the reader / writer 20, Electric power generated based on the radio wave of the second frequency is supplied to each part of the IC chip unit 12. Therefore, even when sufficient power cannot be generated based on radio waves having a single frequency, power can be supplied to the IC chip unit 12 of the electronic tag 10, and data can be transferred between the electronic tag 10 and the reader / writer 20. Can send and receive.

  Further, according to the present embodiment, when the distance between the electronic tag 10 and the reader / writer 20 is long, two radio waves having different frequencies can be obtained without increasing the antenna of the reader / writer 20 or increasing the transmission output. Based on this, sufficient power can be supplied to the IC chip portion 12 of the electronic tag 10. Therefore, the electronic tag can be operated even when the distance between the reader / writer 20 and the electronic tag 10 is long without imposing a burden on the reader / writer 20. In addition, even when there are radio wave-related laws and regulations, the electronic tag 10 can be operated more reliably.

  In the present embodiment, the case has been described in which the electronic tag 10 receives the second frequency radio wave and generates power after receiving the first frequency radio wave, but the reader / writer 20 The radio wave of the first frequency and the radio wave of the second frequency may be generated at the same timing. In this case, the electronic tag 10 receives the first frequency radio wave and the second frequency radio wave at the same timing, and generates electric power based on the received first frequency radio wave and second frequency radio wave. .

  The reader / writer 20 may generate radio waves as a dedicated radio signal for supplying power when generating radio waves of the first frequency or radio waves of the second frequency. Radio waves may be generated as radio signals for transmission and reception. When the electronic tag 10 is received as a dual-purpose radio signal, the electronic tag 10 generates power based on the radio wave from the reader / writer 20 and stores the received data in the memory unit 127.

  The control unit 22 of the reader / writer 20 may determine whether or not a data error has occurred in the received signal when receiving a wireless signal from the electronic tag 10. In this case, when the control unit 22 determines that a data error has occurred, the control unit 22 may generate a radio wave for supplying power to the antenna unit 21 to supply power to the electronic tag 10.

Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a block diagram showing another configuration example of the electronic tag system using the power control method. In the present embodiment, the function of the power management unit 125A of the electronic tag 10 is different from the function of the power management unit 125 described in the first embodiment. Note that the functions of the antennas 111 and 112, the receiving units 121 and 123, the transmitting units 122 and 124, the control unit 126, and the memory unit 127 of the electronic tag 10 are the same as those described in the first embodiment. . The functions of the reader / writer 20 and the server 30 are the same as those described in the first embodiment.

  As illustrated in FIG. 3, the power management unit 125A includes a control unit 125a and a power storage unit 125b. The control unit 125a has a function of storing the first power generated by the reception unit A121 in the power storage unit 125b. The control unit 125a has a function of controlling the first power stored in the power storage unit 125b and the second power generated by the reception unit B123, and supplying power to each unit of the IC chip unit 12.

  The power storage unit 125b is realized by a power storage component such as a capacitor, for example. The power storage unit 125b has a function of storing the first power generated by the reception unit A121 in accordance with an instruction from the control unit 125a.

  Next, the operation will be described. FIG. 4 is a flowchart showing another example of the power control process for generating and controlling the power supplied to the electronic tag in the electronic tag system. The antenna A111 of the electronic tag 10 receives the radio wave of the first frequency from the reader / writer 20 similarly to step S11 shown in the first embodiment (step S21). And the receiving part A121 produces | generates 1st electric power based on the received electromagnetic wave of the 1st frequency similarly to step S12 shown in 1st Embodiment (step S22).

  When the first power is generated, the control unit 125a of the power management unit 125A stores the first power generated by the reception unit A121 in the power storage unit 125b (step S23).

  Further, the antenna B112 of the electronic tag 10 receives the radio wave of the second frequency from the reader / writer 20 in the same manner as Step S13 shown in the first embodiment (Step S24). And the receiving part B123 produces | generates 2nd electric power based on the received electromagnetic wave of the 2nd frequency similarly to step S14 shown in 1st Embodiment (step S25).

  The power management unit 125A controls the first power stored in advance by the power storage unit 125b and the second power generated by the reception unit B123, and supplies power to the control unit 126, the memory unit 127, and the transmission units 122 and 124. (Step S15). For example, when the radio wave of the second frequency cannot be received and the second power cannot be generated in step S25, the power management unit 125A controls the first power stored in the power storage unit 125b in advance. 126, the memory unit 127, and the transmission units 122 and 124. In addition, when the radio wave intensity of the received radio wave of the second frequency is small and the IC chip unit 12 cannot be operated only by the generated second power, the power management unit 125A stores the generated second power and power storage The first power stored in the unit 125b is combined and supplied to the control unit 126, the memory unit 127, and the transmission units 122 and 124.

  When power is supplied, the electronic tag 10 transmits and receives data to and from the reader / writer 20 as a radio signal, similarly to step S16 described in the first embodiment (step S27).

  As described above, according to the present embodiment, the electronic tag 10 stores in advance the first power generated based on the radio wave of the first frequency. Further, when the electronic tag 10 cannot generate sufficient power to operate the IC chip unit 12 based on the radio wave of the second frequency, the electronic tag 10 supplies first power stored in advance to each unit of the IC chip unit 12. To do. Therefore, even when sufficient power cannot be generated based on radio waves of a single frequency, power can be supplied to the IC chip unit 12 of the electronic tag 10 and data can be transmitted to and received from the reader / writer 20. Can do. In addition, according to the present embodiment, since the time for generating the first frequency radio wave and the second frequency radio wave is not overlapped, the radio waves can be prevented from interfering with each other. It is possible to smoothly transmit and receive data to and from the reader / writer 20.

Embodiment 3 FIG.
Next, a third embodiment of the present invention will be described with reference to the drawings. In the present embodiment, the functions of the electronic tag 10, the reader / writer 20, and the server 30 are the same as those functions described in the first embodiment.

  In the present embodiment, the control unit 126 of the electronic tag 10 is a signal between the data received by the receiving unit A121 as a radio signal having the first frequency and the data received by the receiving unit B123 as the radio signal having the second frequency. Measure quality. Further, based on the measurement result, the control unit 126 determines which of the data received as the radio signal of the first frequency and the data received as the radio signal of the second frequency has better signal quality. . In addition, the control unit 126 selects a frequency of a radio signal that is determined to have good signal quality, and determines the selected frequency as a frequency used for data transmission / reception with the reader / writer 20. The electronic tag 10 transmits / receives data to / from the reader / writer 20 as a radio signal using a frequency selected from the first frequency and the second frequency.

  For example, the control unit 126 measures the error rate of the data received as the first frequency radio signal and the data received as the second frequency radio signal. In this case, the control unit 126 selects a frequency having a smaller error rate out of the first frequency and the second frequency based on the measurement result. The electronic tag 10 transmits / receives data as a radio signal to / from the reader / writer 20 using the selected frequency.

  As described above, according to the present embodiment, the control unit 126 of the electronic tag 10 measures the signal quality of the radio signal of each frequency and selects the frequency based on the measurement result of the signal quality. The electronic tag 10 transmits / receives data to / from the reader / writer 20 using the selected frequency. Therefore, it is possible to more reliably perform communication between the electronic tag 10 and the reader / writer 20 by determining the signal quality of the radio signal for each frequency. For example, even when there is interference due to an interference wave or the like, the electronic tag 10 can select a frequency that is not affected by the interference and transmit / receive data to / from the reader / writer 20.

  The present invention can be applied to a system using an electronic tag such as an RFID tag or an IC tag. In particular, by controlling the power of the electronic tag using the present invention, the electronic tag can be operated even when the distance between the reader / writer and the electronic tag is long.

It is a block diagram which shows an example of a structure of the electronic tag system using the power control method by this invention. 5 is a flowchart illustrating an example of a power control process for generating and controlling power supplied to an electronic tag in the electronic tag system. It is a block diagram which shows the other structural example of the electronic tag using a power control method. 6 is a flowchart showing another example of power control processing for generating and controlling power supplied to an electronic tag in the electronic tag system. It is explanatory drawing which shows an example of the passive electronic tag which does not incorporate a battery. FIG. 6 is a block diagram illustrating an example of a functional configuration of the electronic tag illustrated in FIG. 5. FIG. 7 is an explanatory diagram showing an example of generating electric power necessary for the operation of the electronic tag in the electronic tag shown in FIGS. 5 and 6.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Electronic tag 11 Antenna part 12 IC chip part 20 Reader / writer 21 Antenna part 22 Control part 30 Server 111 Antenna A
112 Antenna B
121 Receiver A
122 Transmitter A
123 Receiver B
124 Transmitter B
125 Power management unit 126 Control unit 127 Memory unit

Claims (14)

An electronic tag,
A reader / writer for writing or reading data to or from the electronic tag,
The reader / writer includes electromagnetic wave generating means for generating a plurality of electromagnetic waves having different frequencies,
The electronic tag is
A plurality of electromagnetic wave receiving means for receiving the electromagnetic waves generated by the reader / writer, and
A power generating means for generating power based on the electromagnetic wave received by each of the electromagnetic wave receiving means;
And a power supply means for supplying the power generated by the power generation means to each part of the electronic tag. The electromagnetic wave receiving means receives radio waves generated by the reader / writer,
The electronic tag system according to claim 1, wherein the power generation means generates power by electromagnetic induction by radio waves received by each electromagnetic wave reception means. The electromagnetic wave receiving means inputs light generated by the reader / writer,
The electronic tag system according to claim 1, wherein the power generation means generates power using a predetermined photovoltaic element based on the light input by each electromagnetic wave reception means. The electromagnetic wave receiving means inputs sound waves generated by the reader / writer,
The electronic tag system according to claim 1, wherein the power generation means generates power using a predetermined sound electromotive force element based on the sound wave input by each electromagnetic wave reception means.   The power supply means, when the power generation means generates power based on a plurality of electromagnetic waves, combines the power generated by the power generation means and supplies the combined power to each part of the electronic tag. 5. The electronic tag system according to claim 1. The electromagnetic wave generating means generates an electromagnetic wave using a predetermined first frequency and an electromagnetic wave using a second frequency different from the first frequency,
The electronic tag
First electromagnetic wave receiving means for receiving an electromagnetic wave using the first frequency;
Second electromagnetic wave receiving means for receiving an electromagnetic wave using the second frequency;
First power generation means for generating power based on the electromagnetic wave received by the first electromagnetic wave reception means;
Second power generation means for generating power based on the electromagnetic wave received by the second electromagnetic wave reception means,
The electronic tag system according to any one of claims 1 to 4, wherein the power supply unit controls the power generated by the first power generation unit and the second power generation unit. The electronic tag includes power storage means for storing the power generated by the first power generation means,
The electronic tag system according to claim 6, wherein the power supply means supplies the power stored in the power storage means or the power generated by the second power generation means to each part of the electronic tag.   8. The electronic tag system according to claim 7, wherein the power supply means combines the power stored by the power storage means and the power generated by the second power generation means, and supplies the combined power to each part of the electronic tag. The reader / writer includes error determination means for determining whether or not an error has occurred in the received signal when receiving a radio signal from the electronic tag,
The electromagnetic wave generation unit generates an electromagnetic wave for supplying power when the error determination unit determines that an error has occurred in the signal. Tag system. The electronic tag
Quality measuring means for measuring the signal quality of a plurality of radio signals having different frequencies received from the reader / writer;
Frequency selecting means for selecting one of the frequencies corresponding to each radio signal based on the measurement result of the quality measuring means;
10. The electronic tag system according to claim 1, further comprising: a transmitter / receiver that transmits / receives a radio signal to / from a reader / writer using the frequency selected by the frequency selection unit. 11. A plurality of electromagnetic wave receiving means for receiving a plurality of electromagnetic waves having different frequencies, generated by a reader / writer that writes or reads data to or from an electronic tag;
A power generating means for generating power based on the electromagnetic wave received by each electromagnetic wave receiving means;
An electronic tag comprising: power supply means for supplying the power generated by the power generation means to each part of the electronic tag. First electromagnetic wave receiving means for receiving an electromagnetic wave using a predetermined first frequency;
Second electromagnetic wave receiving means for receiving an electromagnetic wave using a second frequency different from the first frequency;
First power generation means for generating power based on the electromagnetic wave received by the first electromagnetic wave reception means;
Second power generation means for generating power based on the electromagnetic wave received by the second electromagnetic wave reception means;
Power storage means for storing the power generated by the first power generation means,
The electronic tag according to claim 11, wherein the power supply means supplies the power stored in the power storage means or the power generated by the second power generation means to each part of the electronic tag. A power control method for controlling power supplied to an electronic tag,
Generating a plurality of electromagnetic waves having different frequencies;
Receiving each of the generated electromagnetic waves using a plurality of electromagnetic wave receiving means;
Generating electric power based on the electromagnetic wave received by each electromagnetic wave receiving means;
Supplying the generated power to each part of the electronic tag. A method for controlling the power of the electronic tag, comprising: Generating an electromagnetic wave using a predetermined first frequency and an electromagnetic wave using a second frequency different from the first frequency;
Receiving an electromagnetic wave using the first frequency using a first electromagnetic wave receiving means;
Receiving an electromagnetic wave using the second frequency using a second electromagnetic wave receiving means;
Generating a first power based on the electromagnetic wave received by the first electromagnetic wave receiving means;
Generating second power based on the electromagnetic wave received by the second electromagnetic wave receiving means;
Storing the generated first power;
The power control method for an electronic tag according to claim 13, further comprising: supplying the stored first power or the generated second power to each unit of the electronic tag.

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