Wireless power supply sensor

Abstract

The sensor (1) measures data. The battery (2) supplies power to the sensor (1). The communication control unit (6) has a data transmitter (9) that transmits data and a memory (10). The power receiving antenna (5) receives the power transmission radio waves on which the control signal is superimposed. The wireless power supply control unit (8) charges the battery (2) using the power transmission radio waves. The power supply communication unit (7) receives the control signal. If the control signal includes a stop command, the communication control unit (6) stores the reception of the stop command in the memory (10) and prevents data transmission. The communication control unit (6) transmits data only if the control signal does not include a stop command and the reception of the stop command is not stored in the memory (10).

Description

[Technical Field]

[0001] The present disclosure relates to a wirelessly powered sensor. [Background technology]

[0002] Conventional sensors that transmit data wirelessly require frequent battery replacement, which requires a great deal of time and money. To address this issue, wirelessly powered sensors have been devised (see, for example, Patent Document 1). Wirelessly powered sensors receive power transmission radio waves, convert them into direct current, and charge a storage battery inside the sensor to operate the sensor. This eliminates the need for battery replacement, allowing the sensor to be used for a long period of time by being powered any number of times until it breaks down. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2024-21166 Summary of the Invention [Problem to be solved by the invention]

[0004] When a large number of wirelessly powered sensors are installed in a vast area such as a field or forest, it is difficult to retrieve all of the sensors, and some end up being abandoned. When radio waves for power transmission are irradiated into the area, the abandoned sensors will continue to transmit data for decades until they are destroyed. Even if new sensors are installed in the area, the transmission of unnecessary radio waves will cause radio wave interference, making it difficult to obtain data from the desired sensors.

[0005] The present disclosure has been made to solve the above-mentioned problems, and its purpose is to obtain a wirelessly powered sensor that prevents unnecessary radio wave transmission by remaining sensors, eliminates crosstalk and radio wave interference, and makes it easy to obtain data from desired sensors. [Means for solving the problem]

[0006] A first wireless power supply sensor according to the present disclosure includes a sensor that measures data, a battery that supplies power to the sensor, a communication antenna, a data transmitter that transmits the data via the communication antenna, a communication control unit having a memory, a power receiving antenna that receives power transmission radio waves superimposed with a control signal, a wireless power supply control unit that charges the battery using the power transmission radio waves, and a power supply communication unit that receives the control signal, wherein when the control signal includes a stop command, the communication control unit stores the receipt of the stop command in the memory and does not transmit the data, and the communication control unit transmits the data only when the control signal does not include the stop command and the receipt of the stop command is not stored in the memory.

[0007] A second wireless power supply sensor according to the present disclosure includes a sensor that measures data, a battery that supplies power to the sensor, a communication antenna, a data transmitter that transmits the data via the communication antenna, a communication control unit having a memory that stores identification information, a power receiving antenna that receives power transmission radio waves superimposed with a control signal, a wireless power supply control unit that charges the battery using the power transmission radio waves, and a power supply communication unit that receives the control signal, and is characterized in that the communication control unit transmits the data only if the identification information included in the control signal matches the identification information stored in the memory.

[0008] A third wireless power supply sensor according to the present disclosure includes a sensor that measures data, a battery that supplies power to the sensor, a communication antenna, a data transmitter that transmits the data via the communication antenna, a communication control unit having a memory that stores a lifespan date and time, a power receiving antenna that receives power transmission radio waves superimposed with a control signal, a wireless power supply control unit that charges the battery using the power transmission radio waves, and a power supply communication unit that receives the control signal, and is characterized in that the communication control unit transmits the data only if the date and time information included in the control signal is earlier than the lifespan date and time stored in the memory.

[0009] A fourth wireless power supply sensor according to the present disclosure includes a sensor that measures data, a battery that supplies power to the sensor, a communication antenna, a data transmitter that transmits the data via the communication antenna, a communication control unit having a counter, a power receiving antenna that receives power transmission radio waves on which a control signal is superimposed, and a wireless power supply control unit that charges the battery using the power transmission radio waves, wherein the counter counts the number of times power is supplied by the power transmission radio waves, the number of times the voltage of the battery changes, or the number of times the data is transmitted, and the communication control unit transmits the data only when the number of times counted by the counter is equal to or less than a predetermined upper limit.

[0010] A fifth wireless power supply sensor according to the present disclosure includes a sensor that measures data, a battery that supplies power to the sensor, a communication antenna, a data transmitter that transmits the data via the communication antenna, a communication control unit having a counter, a power receiving antenna that receives power transmission radio waves superimposed with a control signal, a wireless power supply control unit that charges the battery using the power transmission radio waves, and an external environment sensor that measures the external environment, wherein the counter counts the number of changes in the external environment measured by the external environment sensor, and the communication control unit transmits the data only when the number of times counted by the counter is equal to or less than a predetermined upper limit.

[0011] A sixth wireless power supply sensor according to the present disclosure includes a sensor that measures data, a battery that supplies power to the sensor, a communication antenna that receives communication radio waves superimposed with a control signal, a data transceiver that transmits the data via the communication antenna, a communication control unit having a memory, a power receiving antenna that receives power transmission radio waves, and a wireless power supply control unit that charges the battery using the power transmission radio waves, wherein the data transceiver receives the control signal superimposed on the communication radio waves, and when the control signal includes a stop command, the communication control unit stores the receipt of the stop command in the memory and does not transmit the data, and the communication control unit transmits the data only when the control signal does not include the stop command and the receipt of the stop command is not stored in the memory. [Effects of the Invention]

[0012] The first wireless power transmission sensor according to the present disclosure receives a control signal superimposed on a power transmission radio wave used to charge a battery, and if the control signal includes a stop command, stores the received stop command in memory and does not transmit data. Data is transmitted only if the control signal does not include a stop command and the received stop command is not stored in memory. Therefore, by issuing a stop command at a desired timing, the wireless power transmission sensor will no longer transmit data. As a result, unnecessary radio wave transmission by remaining sensors is prevented, eliminating radio interference and facilitating the acquisition of data from desired sensors.

[0013] The second wirelessly powered sensor according to the present disclosure receives a control signal superimposed on a power transmission radio wave used to charge an all-solid-state secondary battery, and transmits data only if the identification information included in the control signal matches the identification information pre-stored in memory. Therefore, the wirelessly powered sensor will not transmit data unless it receives a power transmission radio wave superimposed with a control signal containing identification information matching the pre-stored identification information. Therefore, by setting the identification information of a desired wirelessly powered sensor different from the identification information set in the remaining wirelessly powered sensors, data transmission from the remaining wirelessly powered sensors can be stopped. As a result, unnecessary radio wave transmission by the remaining sensors is prevented, eliminating radio interference and facilitating data acquisition from the desired sensors. Furthermore, even when multiple types of wirelessly powered sensors are dispersed in the same area, only data from the desired wirelessly powered sensors can be acquired.

[0014] The third wirelessly powered sensor according to the present disclosure receives a control signal superimposed on a power transmission radio wave used to charge an all-solid-state secondary battery, and transmits data only when the date and time information included in the control signal is before the end-of-life date and time pre-stored in memory. Therefore, data transmission is no longer performed after the end-of-life date and time. As a result, unnecessary radio wave transmission from remaining sensors is prevented, eliminating crosstalk and radio wave interference, and facilitating data acquisition from desired sensors. Furthermore, because the wirelessly powered sensor does not have an internal clock, there is no need to frequently transmit power to keep the clock running or to prepare a large-capacity all-solid-state secondary battery, thereby reducing the maintenance and initial costs of the wirelessly powered sensor.

[0015] A fourth wirelessly powered sensor according to the present disclosure counts the number of times power is supplied by power transmission radio waves, the number of times the battery voltage changes, or the number of times data is transmitted, and transmits data only when the number of times is equal to or less than a preset upper limit. Therefore, data transmission is no longer performed once the upper limit is exceeded, and the lifespan of the wirelessly powered sensor can be set using these counts. As a result, unnecessary radio wave transmission by remaining sensors is prevented, eliminating crosstalk and radio wave interference, and making it easier to obtain data from desired sensors. Furthermore, because a control signal is not superimposed on the power transmission radio waves, a power transmission communication unit for receiving the superimposed signal is not required, thereby reducing the cost of the wirelessly powered sensor.

[0016] A fifth wireless power transmission sensor according to the present disclosure counts the number of changes in the external environment and transmits data only when the number of changes is equal to or less than a preset upper limit. Therefore, data transmission is no longer performed once the upper limit is exceeded, and the lifespan of the wireless power transmission sensor can be set using the number of changes in the external environment. As a result, unnecessary radio wave transmission by remaining sensors is prevented, eliminating crosstalk and radio wave interference, and making it easier to obtain data from desired sensors. Furthermore, because a control signal is not superimposed on the power transmission radio waves, a power transmission communication unit for receiving the superimposed signal is not required, thereby reducing the cost of the wireless power transmission sensor.

[0017] A sixth wirelessly powered sensor according to the present disclosure receives a control signal superimposed on a communication radio wave. If the control signal includes a stop command, the sensor stores the received stop command in memory and does not transmit data. Data transmission is performed only if the control signal does not include a stop command and the received stop command is not stored in memory. Therefore, by issuing a stop command at a desired timing, the wirelessly powered sensor will no longer transmit data. This prevents unnecessary radio wave transmission from remaining sensors, eliminating interference and facilitating data acquisition from desired sensors. Furthermore, even in wirelessly powered sensors with built-in data transceivers for operational control, not only data transmission from remaining sensors but also transmissions for handshakes can be stopped. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a diagram illustrating a wireless power supply sensor according to a first embodiment. [Figure 2] FIG. 2 is a diagram illustrating a power supply communication unit according to the first embodiment. [Figure 3] 4 is a flowchart illustrating an operation of the wireless power supply sensor according to the first embodiment. [Figure 4] FIG. 1 is a diagram illustrating a wireless power supply sensor according to a first comparative example. [Figure 5] FIG. 10 is a diagram illustrating a wireless power supply sensor according to a second comparative example. [Figure 6] 10 is a flowchart illustrating an operation of the wireless power supply sensor according to the second embodiment. [Figure 7] 10 is a flowchart illustrating an operation of the wireless power supply sensor according to the third embodiment. [Figure 8] FIG. 10 is a diagram illustrating a wireless power supply sensor according to a fourth embodiment. [Figure 9] FIG. 10 is a diagram illustrating a wireless power supply sensor according to a fifth embodiment. [Figure 10] FIG. 13 is a diagram illustrating a wireless power supply sensor according to a sixth embodiment. [Figure 11] 13 is a flowchart illustrating the operation of the wireless power supply sensor according to the sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0019] A wireless power supply sensor according to an embodiment will be described with reference to the drawings. The same or corresponding components will be denoted by the same reference numerals, and repeated description may be omitted. The present disclosure is not limited to the following embodiments, and various modifications are possible without departing from the spirit of the present disclosure. Furthermore, the present disclosure includes all possible combinations of the configurations shown in the following embodiments.

[0020] Embodiment 1 1 is a diagram showing a wirelessly powered sensor according to embodiment 1. A sensor unit 100 of the wirelessly powered sensor includes a sensor 1, an all-solid-state secondary battery 2, a substrate 3, a communication antenna 4, and a power receiving antenna 5.

[0021] The sensor 1 is a sensor that measures desired data, such as a temperature sensor, humidity sensor, light amount sensor, vibration sensor, etc. The all-solid-state secondary battery 2 is a battery that stores electric charge and supplies power to the sensor 1, etc., such as an electric double layer capacitor.

[0022] A communication control unit 6, a power supply communication unit 7, and a wireless power supply control unit 8 are provided on the substrate 3. The communication control unit 6 has a data transmitter 9 and a memory 10. The data transmitter 9 superimposes the data measured by the sensor 1 onto a transmission radio wave and transmits it to the outside via the communication antenna 4. An external communication device receives the signal radio wave emitted from this wireless power supply sensor and acquires the data. The transmission radio wave is in the 800 MHz band, 2.4 GHz, 1.9 GHz, or 3.5 GHz band, which are Wi-Fi or 4G or 5G communication bands for mobile phones.

[0023] The power receiving antenna 5 receives the power transmission radio waves superimposed with the control signal. The power transmission radio waves are microwaves in the range of 0.6 to 110 GHz, for example, the ISM band of 900 MHz or 5 GHz. The wireless power supply control unit 8 charges the battery using the power transmission radio waves. The power supply communication unit 7 receives the control signal superimposed on the power transmission radio waves.

[0024] 2 is a diagram showing a power supply communication unit according to the first embodiment. A control signal is superimposed on the power transmission radio wave by AM modulation. Note that the control signal may be superimposed on the power transmission radio wave by other modulation methods such as FM modulation, PSK, or QPSK, instead of AM modulation. In the power supply communication unit 7, after the diode 7a detects the power transmission radio wave, the low-pass filter 7b separates the DC component from the power transmission radio wave, and the wireless power supply control unit 8 charges the all-solid-state secondary battery 2 using the DC component. The high-pass filter 7c separates the AM-modulated component from the power transmission radio wave, and the receiving circuit 7d receives the control signal. Separation of the DC component and the AM-modulated component may be performed by other methods such as heterodyne demodulation.

[0025] 3 is a flowchart of the operation of the wireless power supply sensor according to the first embodiment. First, the power transmission antenna 200 external to the wireless power supply sensor irradiates the power receiving antenna 5 with power transmission radio waves (step S1). Next, the power supply communication unit 7 extracts a DC component from the power transmission radio waves to charge the all-solid-state secondary battery 2 (step S2). The wireless power supply control unit 8 checks whether the charge level has reached a level sufficient to drive the circuitry of the wireless power supply sensor (step S3).

[0026] If the charge amount is sufficient, the memory 10 is checked to see if a stop command has been received (step S4). If a stop command has been received, the communication control unit 6 stops the operation of the wireless power transmission sensor to prevent data transmission, thereby preventing radio wave interference with other wireless power transmission sensors (step S5).

[0027] If the received stop command is not stored in the memory 10, the receiving circuit 7d of the power supply communication unit 7 is operated to acquire the control signal superimposed on the power transmission radio waves (step S6). The communication control unit 6 checks whether the control signal superimposed on the power transmission radio waves currently being received includes a stop command (step S7). If the control signal includes a stop command, the communication control unit 6 stores the received stop command in the memory 10 and prevents data transmission (step S8). On the other hand, if the control signal does not include a stop command, the communication control unit 6 drives the data transmitter 9 to transmit data (step S9).

[0028] The memory 10 is a non-volatile memory or the like that can retain data even if the amount of stored power in the all-solid-state secondary battery 2 decreases. When the all-solid-state secondary battery is charged again by irradiating it with power transmission radio waves and the power supply communication unit 7 starts operating, it can be confirmed whether the reception of the stop command has been stored in the memory 10.

[0029] Next, the effects of this embodiment will be described in comparison with Comparative Examples 1 and 2. FIG. 4 is a diagram showing a wireless power supply sensor according to Comparative Example 1. Comparative Example 1 does not include a power supply communication unit 7 and a memory 10. A power transmission antenna 200 provided outside the wireless power supply sensor transmits power transmission radio waves, which are received by a power receiving antenna 5 and sent to a wireless power supply control unit 8. The wireless power supply control unit 8 rectifies the power transmission radio waves and converts them into direct current to charge the all-solid-state secondary battery 2. The sensor 1 and communication control unit 6 are operated using power from the charged all-solid-state secondary battery 2. The all-solid-state secondary battery 2 can be repeatedly charged and used, so the sensor can be used for a long period of time.

[0030] When a large number of wirelessly powered sensors are installed over a vast area, it is difficult to retrieve all of the sensors, and some end up being abandoned. When radio waves for power transmission are irradiated over the area, the abandoned sensors continue to transmit data for decades until they are destroyed. Therefore, in Comparative Example 1, even if a new sensor is installed in the area, wireless radio wave interference occurs due to the transmission of unnecessary radio waves, making it difficult to obtain data from the desired sensor.

[0031] FIG. 5 is a diagram showing a wirelessly powered sensor according to Comparative Example 2. In Comparative Example 2, a data transceiver 11 is provided instead of the data transmitter 9 of Comparative Example 1. After charging the all-solid-state secondary battery 2, the data transceiver 11 receives a control signal contained in a communication radio wave from the communication antenna 4 and controls various operations. Therefore, the wirelessly powered sensor of Comparative Example 2 performs a handshake to establish communication with an external communication device. For this reason, even if a control signal is sent from the outside to prevent data transmission, the remaining sensor still transmits and receives data for the handshake. Therefore, wireless radio wave interference also occurs in Comparative Example 2, making it difficult to obtain data from the desired sensor.

[0032] In contrast, in this embodiment, a control signal superimposed on the power transmission radio waves used to charge the all-solid-state secondary battery 2 is received, and if the control signal includes a stop command, the reception of the stop command is stored in the memory 10 and data transmission is not performed, and data transmission is performed only if the control signal does not include a stop command and the reception of the stop command is not stored in the memory 10. Therefore, by issuing a stop command at a desired timing, the wirelessly powered sensor will no longer transmit data. As a result, unnecessary radio wave transmission by the remaining sensors is prevented, eliminating crosstalk and radio wave interference, and making it easier to obtain data from the desired sensor.

[0033] Furthermore, the power supply communication unit 7 that acquires the control signal superimposed on the power transmission radio wave can be configured with a simple circuit as shown in Fig. 2. Therefore, since a large-scale circuit that involves a handshake in the communication band as in Comparative Example 2 is not required, a wireless power supply sensor can be realized at low cost.

[0034] Embodiment 2 The configuration of the wireless power transmission sensor according to the second embodiment is the same as that of the first embodiment. Unlike the first embodiment, the memory 10 of the communication control unit 6 pre-stores identification information that enables the wireless power transmission sensor to be identified from other wireless power transmission sensors. The identification information is superimposed on the control signal of the power transmission radio wave, and the communication control unit 6 transmits data only when the identification information included in the control signal matches the identification information stored in the memory 10.

[0035] 6 is a flowchart of the operation of the wireless power supply sensor according to embodiment 2. First, the power transmission antenna 200 external to the wireless power supply sensor irradiates the power receiving antenna 5 with a power transmission radio wave (step S11). Identification information for identifying the desired wireless power supply sensor is superimposed on a control signal of the power transmission radio wave.

[0036] Next, the power supply communication unit 7 extracts a DC component from the power transmission radio wave and charges the all-solid-state secondary battery 2 (step S12). The wireless power supply control unit 8 checks whether the charge amount has reached a level sufficient to drive the circuit of the wireless power supply sensor (step S13).

[0037] If the charge level is sufficient, the receiving circuit 7d of the power supply communication unit 7 is operated to acquire the identification information contained in the power transmission radio waves (step S14). The communication control unit 6 checks whether the identification information contained in the control signal matches the identification information pre-stored in the memory 10 (step S15). If they do not match, the operation of the wireless power supply sensor is stopped to prevent data transmission, thereby preventing radio wave interference with other wireless power supply sensors (step S16). On the other hand, if they match, the communication control unit 6 drives the data transmitter 9 to transmit data (step S17).

[0038] As described above, in this embodiment, a control signal superimposed on a power transmission radio wave used to charge the all-solid-state secondary battery 2 is received, and data transmission is performed only when the identification information included in the control signal matches the identification information pre-stored in the memory 10. Therefore, the wirelessly powered sensor will not transmit data unless it receives a power transmission radio wave superimposed with a control signal including identification information matching the pre-stored identification information. Therefore, by setting the identification information of a desired wirelessly powered sensor different from the identification information set in the remaining wirelessly powered sensors, data transmission from the remaining wirelessly powered sensors can be stopped. As a result, unnecessary radio wave transmission by the remaining sensors is prevented, eliminating radio interference and facilitating data acquisition from the desired sensors. Furthermore, when multiple types of wirelessly powered sensors are dispersed in the same area, only data from the desired wirelessly powered sensors can be acquired.

[0039] Embodiment 3 The configuration of the wireless power transmission sensor according to the third embodiment is the same as that of the first and second embodiments. Unlike the first embodiment, the memory 10 of the communication control unit 6 pre-stores a lifespan date and time that determines the lifespan of the wireless power transmission sensor. Date and time information is superimposed on the control signal of the power transmission radio wave, and the communication control unit 6 transmits data only if the date and time information included in the control signal is earlier than the lifespan date and time stored in the memory 10.

[0040] 7 is a flowchart of the operation of the wireless power supply sensor according to embodiment 3. First, the power transmission antenna 200 external to the wireless power supply sensor irradiates the power reception antenna 5 with a power transmission radio wave (step S21). Information indicating the date and time of transmission is superimposed on the control signal of the power transmission radio wave.

[0041] Next, the power supply communication unit 7 extracts a DC component from the power transmission radio wave and charges the all-solid-state secondary battery 2 (step S22). The wireless power supply control unit 8 checks whether the charge amount has reached a level sufficient to drive the circuit of the wireless power supply sensor (step S23).

[0042] If the charge level is sufficient, the receiving circuit 7d of the power supply communication unit 7 is operated to acquire the date and time information included in the control signal (step S24). The communication control unit 6 checks whether the date and time information included in the control signal is before the end of life date and time pre-stored in the memory 10 (step S25). If the date and time information is after the end of life date and time, the operation of the wireless power supply sensor is stopped to prevent data transmission and prevent radio wave interference with other wireless power supply sensors (step S26). On the other hand, if the date and time information is before the end of life date and time, the communication control unit 6 drives the data transmitter 9 to transmit data (step S27).

[0043] As described above, in this embodiment, a control signal superimposed on a power transmission radio wave used to charge the all-solid-state secondary battery 2 is received, and data is transmitted only when the date and time information included in the control signal is before the end-of-life date and time pre-stored in the memory 10. Therefore, data transmission is no longer performed after the end-of-life date and time. As a result, unnecessary radio wave transmission by remaining sensors is prevented, eliminating crosstalk and radio wave interference, and making it easier to obtain data from desired sensors. Furthermore, since the wirelessly powered sensor does not have an internal clock, there is no need to frequently transmit power to keep the clock running, or to prepare a large-capacity all-solid-state secondary battery, thereby reducing the maintenance and initial costs of the wirelessly powered sensor.

[0044] Embodiment 4 FIG. 8 is a diagram showing a wireless power transmission sensor according to a fourth embodiment. Unlike the first embodiment and the like, there is no power transmission communication unit 7, and the communication control unit 6 has a counter 12 instead of the memory 10. As in the first embodiment and the like, the received power transmission radio waves are rectified and converted into a direct current to charge the all-solid-state secondary battery 2. The counter 12 increments the count by 1 using the power of the charged all-solid-state secondary battery 2. In this way, the counter 12 counts the number of times power has been supplied by the power transmission radio waves. Note that the counter 12 may count the number of voltage changes of the all-solid-state secondary battery 2, or may count the number of times the data transmitter 9 has transmitted data.

[0045] If the number of times counted by the counter 12 is equal to or less than a preset upper limit, the communication control unit 6 transmits data. On the other hand, if the number of times counted by the counter 12 exceeds the upper limit, the operation of the wireless power transmission sensor is stopped to prevent data transmission, thereby preventing radio wave interference with other wireless power transmission sensors.

[0046] As described above, in this embodiment, the number of times power is supplied by the power transmission radio waves, the number of times the battery voltage changes, or the number of times data is transmitted is counted, and data is transmitted only when the number of times is equal to or less than a preset upper limit. Therefore, since data transmission is no longer performed after the upper limit is exceeded, the lifespan of the wirelessly powered sensor can be set using these numbers. As a result, unnecessary radio wave transmission by remaining sensors is prevented, eliminating crosstalk and radio wave interference, and making it easier to obtain data from desired sensors. Furthermore, because a control signal is not superimposed on the power transmission radio waves, the power transmission communication unit 7 that receives the superimposed signal is not required, thereby reducing the cost of the wirelessly powered sensor.

[0047] Fifth embodiment FIG. 9 is a diagram showing a wireless power transmission sensor according to a fifth embodiment. In addition to the configuration of the fourth embodiment, an external environment sensor 13 is provided. The external environment sensor 13 is provided outside the sensor unit 100 and measures the external environment. The counter 12 counts the number of changes in the external environment measured by the external environment sensor 13. The communication control unit 6 transmits data only when the number of times counted by the counter 12 is equal to or less than a preset upper limit. On the other hand, when the number of times counted by the counter 12 exceeds the upper limit, the operation of the wireless power transmission sensor is stopped to prevent data transmission, thereby preventing radio wave interference with other wireless power transmission sensors.

[0048] As described above, in this embodiment, the number of changes in the external environment is counted, and data is transmitted only when the number of changes is equal to or less than a preset upper limit. Therefore, data transmission is no longer performed after the upper limit is exceeded, and the lifespan of the wireless power transmission sensor can be set using the number of changes in the external environment. As a result, unnecessary radio wave transmission by remaining sensors is prevented, eliminating crosstalk and radio wave interference, and making it easier to obtain data from desired sensors. Furthermore, because a control signal is not superimposed on the power transmission radio waves, the power transmission communication unit 7 that receives the superimposed signal is not required, thereby reducing the cost of the wireless power transmission sensor.

[0049] The external environment sensor 13 is a light intensity detection sensor, a solar cell, a vibration detection sensor, a moisture detection sensor, or a temperature detection sensor. The light intensity detection sensor and the solar cell can determine whether it is day or night based on the amount of light, so they can count the number of days and nights. The moisture detection sensor detects the amount of water or moisture, so they can count the number of rainfalls, the number of times water is supplied to farmland, and the number of tides. The vibration sensor can count earthquakes or the number of vehicles passing nearby. The temperature detection sensor can count the number of days due to temperature changes between day and night, or the number of times people are present due to changes in room temperature. Note that the sensor 1 may also serve as the external environment sensor 13.

[0050] Sixth embodiment FIG. 10 is a diagram showing a wireless power supply sensor according to a sixth embodiment. Unlike the first embodiment and the like, the wireless power supply sensor according to this embodiment has a function of transmitting and receiving radio waves for communication. The communication antenna 4 receives radio waves for communication on which a control signal is superimposed. The data transceiver 11 receives the control signal superimposed on the radio waves for communication. If the control signal includes a stop command, the communication control unit 6 stores the reception of the stop command in the memory 10 and prevents data transmission. The communication control unit 6 transmits data only if the control signal does not include a stop command and the reception of the stop command is not stored in the memory 10. The other configurations and functions are the same as those of the first embodiment and the like.

[0051] 11 is a flowchart of the operation of the wireless power supply sensor according to the sixth embodiment. First, the power transmission antenna 200 external to the wireless power supply sensor irradiates the power receiving antenna 5 with power transmission radio waves (step S31). Next, the power supply communication unit 7 extracts a DC component from the power transmission radio waves to charge the all-solid-state secondary battery 2 (step S32). The wireless power supply control unit 8 checks whether the charge level has reached a level sufficient to drive the circuitry of the wireless power supply sensor (step S33).

[0052] If the charge amount is sufficient, the communication control unit 6 checks whether a stop command has been received in the memory 10 (step S34). If a stop command has been received, the communication control unit 6 stops the operation of the wirelessly powered sensor to prevent data transmission and prevent radio wave interference with other wirelessly powered sensors (step S35).

[0053] If the reception of the stop command is not stored in memory 10, the data transceiver 11 of the communication control unit 6 is operated to acquire the control signal superimposed on the communication radio waves (step S36). The power supply communication unit 7 checks whether the control signal superimposed on the power transmission radio waves currently being received includes a stop command (step S37). If the control signal includes a stop command, the communication control unit 6 stores the reception of the stop command in memory 10 and prevents data transmission (step S38). On the other hand, if the control signal does not include a stop command, the communication control unit 6 drives the data transceiver 11 to transmit data (step S39).

[0054] As described above, in this embodiment, a control signal superimposed on a communication radio wave is received. If the control signal includes a stop command, the reception of the stop command is stored in memory 10 and data transmission is not performed. Data transmission is performed only if the control signal does not include a stop command and the reception of the stop command is not stored in memory 10. Therefore, by issuing a stop command at a desired timing, the wirelessly powered sensor will no longer transmit data. As a result, unnecessary radio wave transmission by remaining sensors is prevented, eliminating interference and making it easier to obtain data from desired sensors. Furthermore, even in a wirelessly powered sensor that has a built-in data transceiver 11 for operational control, not only data transmission from remaining sensors but also transmission for handshakes can be stopped. [Explanation of symbols]

[0055] 1 sensor, 2 all-solid-state secondary battery, 4 communication antenna, 5 power receiving antenna, 6 communication control unit, 7 power supply communication unit, 8 wireless power supply control unit, 9 data transmitter, 10 memory, 12 counter, 11 data transceiver, 13 external environment sensor

Claims

1. a sensor for measuring data; a battery for powering the sensor; A communication antenna; a data transmitter that transmits the data via the communication antenna; and a communication control unit having a memory. a power receiving antenna for receiving the power transmission radio wave on which the control signal is superimposed; a wireless power supply control unit that charges the battery using the power transmission radio waves; a power supply communication unit that receives the control signal; If the control signal includes a stop command, the communication control unit stores the reception of the stop command in the memory and does not transmit the data; The wireless power supply sensor is characterized in that the communication control unit transmits the data only when the control signal does not include the stop command and the memory does not store any information indicating that the stop command has been received.

2. a sensor for measuring data; a battery for powering the sensor; A communication antenna; a communication control unit having a data transmitter that transmits the data via the communication antenna and a memory that stores the lifespan date and time; a power receiving antenna for receiving the power transmission radio wave on which the control signal is superimposed; a wireless power supply control unit that charges the battery using the power transmission radio waves; a power supply communication unit that receives the control signal; The wireless power supply sensor is characterized in that the communication control unit transmits the data only when date and time information included in the control signal is earlier than the life date and time stored in the memory.

3. a sensor for measuring data; a battery for powering the sensor; A communication antenna; a communication control unit having a data transmitter that transmits the data via the communication antenna and a counter; a power receiving antenna for receiving the power transmission radio wave on which the control signal is superimposed; a wireless power supply control unit that charges the battery using the power transmission radio waves, the counter counts the number of times power is supplied by the power transmission radio waves, the number of times the voltage of the battery changes, or the number of times the data is transmitted; The wireless power supply sensor is characterized in that the communication control unit transmits the data only when the number of times counted by the counter is equal to or less than a preset upper limit number.

4. a sensor for measuring data; a battery for powering the sensor; A communication antenna; a communication control unit having a data transmitter that transmits the data via the communication antenna and a counter; a power receiving antenna for receiving the power transmission radio wave on which the control signal is superimposed; a wireless power supply control unit that charges the battery using the power transmission radio waves; an external environment sensor that measures the external environment; the counter counts the number of changes in the external environment measured by the external environment sensor; The wireless power supply sensor is characterized in that the communication control unit transmits the data only when the number of times counted by the counter is equal to or less than a preset upper limit number.

5. The wireless power transfer sensor according to claim 4 , wherein the external environment sensor is a light amount detection sensor, a solar cell, a vibration detection sensor, a moisture detection sensor, or a temperature detection sensor.

6. a sensor for measuring data; a battery for powering the sensor; a communication antenna for receiving communication radio waves on which a control signal is superimposed; a data transceiver that transmits the data via the communication antenna; and a communication control unit having a memory. a power receiving antenna for receiving power transmission radio waves; a wireless power supply control unit that charges the battery using the power transmission radio waves, the data transceiver receives the control signal superimposed on the communication radio wave; If the control signal includes a stop command, the communication control unit stores the reception of the stop command in the memory and does not transmit the data; The wireless power supply sensor is characterized in that the communication control unit transmits the data only when the control signal does not include the stop command and the memory does not store any information indicating that the stop command has been received.

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