Electronic device, electronic device control method, and program

Abstract

To provide an electronic device, a control method of the electronic device, and a program capable of receiving power more efficiently in the electronic device having a plurality of antennas.SOLUTION: An electronic device has a plurality of antennas, a circuit for charging a battery using power received by one of the plurality of antennas, and control means for controlling whether or not to receive the power by the antenna based on power the one of the plurality of antennas capable of receiving and power required for receiving by the antenna.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an electronic device that supports wireless power transmission. [Background technology]

[0002] In recent years, energy harvesting using microwaves such as wireless LAN and mobile phone communications has been considered. One technology for receiving microwaves is a wireless power receiving system using a rectenna. For example, Patent Document 1 discloses a rectenna that includes a receiving means for receiving microwaves, first and second rectifier circuits for rectifying the received microwaves, and a hybrid circuit interposed between the receiving means and the first and second rectifier circuits. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-23857 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the above-mentioned technology does not consider the case where power is received using multiple antennas. In particular, when the resonant frequencies of the multiple antennas are different, the radio wave strength of each frequency band of the multiple antennas generally changes over time. In such a radio wave environment, even if all antennas receive power and try to receive as much power as possible, efficiency may deteriorate. For example, during the period T1, the radio wave strength 301 of the 2.4 GHz band is high, and a sufficiently high power can be received from the 2.4 GHz antenna. However, the radio wave strength 302 of the 5.0 GHz band and the radio wave strength 303 of the 60 GHz band are low, and the power that can be received is small. Therefore, the power required to drive the antenna for receiving power and the power required for rectification are greater than the power that can be received from the antenna, resulting in the electronic device consuming power. As a result, the electronic device receives power and charges the battery, but the battery is further consumed.

[0005] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide an electronic device equipped with a plurality of antennas that is capable of receiving power more efficiently. [Means for solving the problem]

[0006] An electronic device comprising: a plurality of antennas; a circuit for charging a battery using power received by one of the plurality of antennas; and a control means for controlling whether or not to receive power through one of the plurality of antennas based on the power that can be received by the one of the plurality of antennas and the power required for receiving power through the one of the antennas. Effect of the Invention

[0007] According to the present invention, it is possible to provide an electronic device capable of receiving power more efficiently. [Brief description of the drawings]

[0008] [Figure 1] 1 is a block diagram of an electronic device according to a first embodiment. [Diagram 2]4 is a flowchart of antenna control of the electronic device according to the first embodiment. [Diagram 3] 1A is a diagram for explaining instability of a radio wave environment due to differences in frequency bands, and FIG. 1B is a diagram for explaining on / off of each antenna in a time series according to the first embodiment. [Figure 4] 1 is a diagram showing a system including an electronic device according to an embodiment of the present invention and an external wireless device; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0010] The embodiment described below is an example of a means for realizing the present invention, and may be appropriately modified or changed depending on the configuration of the device to which the present invention is applied and various conditions. Also, each embodiment may be appropriately combined.

[0011] [First embodiment] <About electronic devices> In FIG. 1, reference numeral 100 denotes a battery-operated electronic device, typified by mobile devices such as cameras and smartphones.

[0012] The main control unit 101 controls each unit of the electronic device 100 in accordance with input signals and programs described below. Note that instead of the control unit 101 controlling the entire device, the entire device may be controlled by multiple hardware devices sharing the processing.

[0013] The control unit 102 is an auxiliary control unit that controls the electronic device 100, and is a sub-control unit 102 that operates with lower power consumption than the main control unit 101. It mainly controls the power supply and part of the wireless communication function in the electronic device 100. In this case, the sub-control unit 102 controls the connection switching between the antenna and the control unit.

[0014] The storage unit 103 is a non-volatile memory that stores settings and the like even when power is not supplied, and communicates with the main control unit 101. For example, the storage unit 103 stores UI display settings, display language, and other settings of the electronic device 100, and the main control unit 101 of the electronic device 100 reads the settings from the storage unit 103 at startup to set up the electronic device 100.

[0015] The switch 104 is a switch operated by the user, and is a power switch for turning on / off the power of the electronic device 100. For example, it is a lever type or a push button type.

[0016] The main battery 120 is a main battery that is the main power source for operating the electronic device 100, and is a secondary battery such as a rechargeable lithium ion battery. The main functions of the electronic device 100 are driven by the main battery 120, and the electronic device 100 will not operate unless the main battery 120 is inserted.

[0017] The auxiliary battery 121 is an auxiliary battery for operating the electronic device 100, and is a battery with a smaller battery capacity than the main battery 120, such as a coin battery that plays an auxiliary role when the main power source is not available. The auxiliary battery 121 is a rechargeable secondary battery. The wireless communication control unit 151, the sub-control unit 102, and the storage unit 103 are driven by the auxiliary battery 121, and the wireless communication control unit 151, the sub-control unit 102, and the storage unit 103 operate even when the main battery 120 is not available.

[0018] The battery detection unit 122 detects the presence or absence of the main battery 120, the remaining battery power, etc. The main control unit 101 communicates with the battery detection unit 122, acquires remaining battery power information of the main battery 120, and controls the electronic device 100.

[0019] The battery detection unit 123 detects the presence or absence of the auxiliary battery 121, the remaining battery power, etc. The sub-control unit 102 communicates with the battery detection unit 123 and acquires the remaining battery power information of the auxiliary battery 121.

[0020] The power supply control unit 124 controls the power supply of the electronic device 100, and receives power from the main battery 120 or the like, and supplies power to the main control unit 101, the sub-control unit 102, the storage unit 103, and the like.

[0021] The power receiving control unit 125 is a charging circuit that controls the power received from microwaves and the like.

[0022] The power reception detection unit 126 detects the amount of power received by the power reception control unit 125. The power reception detection unit 126 communicates with the sub-control unit 102 and transmits the amount of power received from the power reception detection unit 126 to the sub-control unit 102.

[0023] The wireless communication control unit 150 is a wireless communication control unit 150 that transmits and receives data wirelessly. As the wireless communication control unit 150, a wireless LAN that uses radio waves in the 2.4 GHz band can be adopted.

[0024] The wireless communication control unit 151 transmits and receives data wirelessly, consumes less power than the wireless communication control unit 150, and can operate on the auxiliary battery 121 with a smaller battery capacity. As the wireless communication control unit 151, for example, Bluetooth or Bluetooth Low Energy that uses radio waves in the 2.4 GHz band can be adopted.

[0025] The wireless communication control unit 152 is a wireless communication control unit that transmits and receives data wirelessly, and uses a different frequency band for communication from the wireless communication control unit 150. The wireless communication control unit 152 may be, for example, a wireless LAN that uses radio waves in the 5 GHz band.

[0026] The wireless communication control unit 153 is a wireless communication control unit that transmits and receives wireless data, and uses a different frequency band for communication from the wireless communication control units 150 and 152. As the wireless communication control unit 153, a fifth generation communication system using the 28 GHz band, 60 GHz, or the like can be adopted.

[0027] The rectifier circuit 160 is a rectifier circuit that rectifies radio waves in the frequency band used by the wireless communication control unit 150 for data communication and supplies power to the power receiving control unit 125. The radio waves received by the antenna 175 are AC voltage and therefore need to be rectified to a constant voltage in order to supply them to the electronic device 100. The rectified power charges the auxiliary battery 121 via the power receiving control unit 125. Power is also needed to drive the rectifier circuit 160 and the power receiving control unit 125, and if the power that can be received by the antenna 175 is less than the power needed to drive the rectifier circuit 160, the auxiliary battery 121 will be consumed.

[0028] The rectifier circuit 161 rectifies radio waves in a frequency band used by the electronic device 100 for data communication, and supplies power to the power reception control unit 125. The control operation is the same as that of the rectifier circuit 160.

[0029] The rectifier circuit 162 rectifies radio waves in a frequency band used by the electronic device 100 for data communication, and supplies power to the power reception control unit 125. The control operation is the same as that of the rectifier circuit 160.

[0030] The switching circuit 163 switches the connection of the antenna 175 between the rectifier circuit 160 and the power switch 104, both of which use the same frequency band. For example, WiFi and Bluetooth use the same 2.4 GHz radio frequency band. However, since the communication protocols are different, the control units are different. The wireless communication control unit 150 is in charge of controlling the WiFi communication, and the wireless communication control unit 151 is in charge of controlling the Bluetooth communication. The switching circuit 163 is controlled by selecting which communication to use.

[0031] The switching circuit 164 switches between performing wireless data communication with the wireless communication control unit 150 or the wireless communication control unit 151, and supplying wireless communication radio waves as power to the power receiving control unit 125 via the rectifier circuit 160. This switching circuit 164 is controlled according to the state of the environmental radio waves. For example, when the power required to drive the rectifier circuit 160 is greater than the power that can be received by the antenna 175, the switching circuit 164 is switched to the communication side.

[0032] Switching circuit 165 switches the antenna matching circuit between antenna matching circuit 171 and antenna matching circuit 172. In general, the antenna matching circuit is set to increase the sensitivity of a specific frequency band for communication. If the sensitivity is increased outside of that frequency band, it will be received as noise, resulting in a decrease in communication quality. The circuit in which the matching constant for communication is implemented is antenna matching circuit 171.

[0033] However, when receiving environmental radio waves, it is desirable to increase the sensitivity in as wide a frequency band as possible other than the frequencies used for communication.

[0034] That is, when communication is performed using antenna 175, switching circuit 165 is switched to antenna matching circuit 171 side, and when power is received, switching circuit 165 is switched to antenna matching circuit 172 side.

[0035] The switching circuit 166 switches between performing wireless data communication in the wireless communication control unit 152 and supplying wireless communication radio waves as power to the power receiving control unit 125 via the rectifier circuit 161. The operation control is the same as that of the switching circuit 164.

[0036] The switching circuit 167 switches between performing wireless data communication in the wireless communication control unit 153 and supplying wireless communication radio waves as power to the power receiving control unit 125 via the rectifier circuit 162. The operation control is the same as that of the switching circuit 164.

[0037] The input filter circuit 168 is an input filter circuit 168 that passes the frequency band used by the wireless communication control unit 150 or the wireless communication control unit 151 for data communication. Therefore, it is disposed in the subsequent stage of the antenna matching circuit 171 for removing noise when performing communication. On the other hand, when receiving environmental radio waves, it is desirable to receive a wide frequency band without passing through the input filter circuit 168 in order to receive many radio waves.

[0038] The input filter circuit 169 passes the frequency band used for data communication by the rectifier circuit 161. The purpose and operation of the input filter circuit 169 are the same as those of the input filter circuit 168.

[0039] The input filter circuit 170 passes a frequency band used for data communication by the electronic device 100. The purpose and operation of the input filter circuit 170 are the same as those of the input filter circuit 168.

[0040] Antenna matching circuit 171 is an antenna matching circuit that matches the impedance with antenna 175 at the frequency used. When an antenna is incorporated in a metal housing such as an electronic device, it is necessary to match the impedance by arranging a capacitive or inductive component between the antenna and GND so that the antenna has the best sensitivity at the frequency it receives while it is incorporated. Antenna 175 is designed by antenna matching circuit 171 so that it has the best sensitivity in the communication frequency band.

[0041] Antenna matching circuit 172 matches the impedance with antenna 175 at the operating frequency. In contrast to antenna matching circuit 171, antenna matching circuit 172 is a matching circuit for power reception, and is matched with a constant that allows radio waves to be received over a wide frequency band.

[0042] The antenna matching circuit 173 matches the impedance with the antenna 176 at the operating frequency. The purpose and operation of the antenna matching circuit 173 are the same as those of the antenna matching circuit 171.

[0043] The antenna matching circuit 174 matches the impedance with the antenna 177 at the operating frequency. The purpose and operation of the antenna matching circuit 174 are the same as those of the antenna matching circuit 171.

[0044] The antenna 175 is an antenna that receives radio waves in the frequency band used by the wireless communication control units 150 and 151 .

[0045] The antenna 176 receives radio waves in the frequency band used by the wireless communication control unit 152 .

[0046] Antenna 177 is an antenna that receives radio waves in the frequency band used by wireless communication control unit 153 .

[0047] That is, antenna 175, antenna 176, and antenna 177 have different resonant frequencies.

[0048] <Operation of electronic devices> 2 is a flowchart showing the operation of the electronic device 100. When the electronic device 100 is turned off by the user using the power switch 104, or when it detects that no operation has been performed for a certain period of time and turns off, it starts receiving ambient radio waves at each antenna (step S101).

[0049] First, the switching circuit 165 connected to the first antenna 175 is switched to the antenna matching circuit 172 that is optimal for the power receiving side. The antenna matching circuit 172 has constants set so that the antenna efficiency is high over a wide frequency band. This allows the design to receive radio waves over a wide frequency band, not only signal radio waves but also noise radio waves unrelated to communication.

[0050] Also, the switching circuit 164 is controlled to connect the input of the antenna 175 to the upper side of the block diagram, i.e., the rectifier circuit 160 on the power receiving side. The power received by the antenna 175 is output as a voltage having a shape close to a sine wave with positive and negative amplitude. At this time, the rectifier circuit 160 is required to rectify the AC voltage waveform to a constant voltage. The voltage rectified by the rectifier circuit 160 is applied to the power receiving control unit 125 (step S102).

[0051] At this time, the power reception detection unit 126 measures the received power and notifies the sub-control unit 102. The sub-control unit 102 measures the power received by the antenna 175 from the environmental radio waves. At the same time, it also measures the power consumption of a block that is operating because the antenna 175 is set to the power receiving side, such as the rectifier circuit 160. Additionally, it compares the measured power consumption with the received power (step S103).

[0052] If the comparison in step S103 shows that the power consumption is greater than the received power, the antenna matching circuit connected to antenna 175 is connected to antenna matching circuit 171 and set for communication. The signal of switching circuit 165 is also set to the communication side (step S104).

[0053] The second antenna 176 is connected to the switching circuit 166 via the input filter circuit 169. Next, the switching circuit 166 is controlled to connect the input of the antenna to the upper side of the block diagram, that is, the rectifier circuit 161 on the power receiving side. As with the first antenna, the power received by the antenna is output as a voltage having a shape close to a sine wave with positive and negative amplitudes. At this time, the rectifier circuit 161 is required to rectify the AC voltage waveform to a constant voltage. The voltage rectified by the rectifier circuit 161 is applied to the power receiving control unit 125. (Step S105).

[0054] At this time, the power reception detection unit 126 measures the received power and notifies the sub-control unit 102. The sub-control unit 102 measures the power received by the antenna 176 from the environmental radio waves. At the same time, it also measures the power consumption of the block rectifier circuit 161, which is operating because the antenna 176 is set to the power receiving side, and the power reception control unit 125, etc. At the same time, it compares the measured power consumption with the received power. (Step S106) If it is determined in step S106 that the power consumption is greater than the received power, the switching circuit 166 connected to the antenna 176 is controlled to set it to the communication side (step S107).

[0055] The third antenna 177 is connected to the rectifier circuit 102 via the input filter circuit 170. Next, the switching circuit 167 is controlled to connect the input of the antenna to the upper side of the block diagram, that is, the rectifier circuit 102 on the power receiving side. As with the first antenna, the power received by the antenna is output as a voltage having a shape close to a sine wave with positive and negative amplitudes. At this time, the rectifier circuit 162 is required to rectify the AC voltage waveform to a constant voltage. The voltage rectified by the rectifier circuit 162 is applied to the power receiving control unit 125. The applied voltage charges the auxiliary battery 121 (step S108).

[0056] Here, the power reception control unit 125 measures the power received by the antenna 177 from the environmental radio waves. At the same time, it also measures the power consumption of the block rectifier circuit 162, which is operating because the antenna 177 is set to the power receiving side. In addition, it compares the measured power consumption with the received power (step S109). If the power consumption is greater than the received power, the switching circuit 167 connected to the antenna 177 is controlled to set it to the communication side (step S110).

[0057] In the flow from step S101 to step S110, if there is an unused antenna on the power receiving side, that antenna is connected to the communication side by a switch. Communication with an external wireless device is performed using the antenna connected to the communication side. However, if antenna 175 is connected to the communication side, communication is performed by wireless communication control unit 151 via switching circuit 163. This is because wireless communication control unit 151 consumes less current than wireless communication control unit 150 (step S111).

[0058] Next, the antenna not being used for power reception is connected to the communication side.

[0059] When the antenna 175 is switched to the communication side, the switching circuit 165 is connected to the antenna matching circuit 171 side, the switching circuit 164 is connected to the switching circuit 163 side, and the switching circuit 163 is connected to the wireless communication control unit 151 .

[0060] When the antenna 176 is switched to the communication side, the switching circuit 166 is connected to the wireless communication control unit 152 .

[0061] When the antenna 177 is switched to the communication side, the switching circuit 167 is connected to the wireless communication control unit 153 (step S112).

[0062] The connected wireless communication control unit 151, wireless communication control unit 152, or wireless communication control unit 153 is controlled to communicate with the external device, and the communication frequency, channel, and communication data amount are changed so that the receiving power is maximized at the receiving antenna. The method of controlling the external device will be described later with reference to FIG. 4 (step S113).

[0063] If a specified time has elapsed since the antenna was set and power reception started (step S114) and the auxiliary battery 121 is not fully charged (step S115), the sub-control unit 102 executes the above steps S101 to S113 again.

[0064] Through the above-mentioned operations, communication with an external wireless device is performed, and the radio wave environment is improved so that the power that can be received by the antenna used for receiving power is increased.

[0065] For example, as shown in FIG. 4, when power is received by antenna 176, an external wireless device, for example, when antenna 175 is used for communication, operates a wireless router to emit radio waves in a frequency band that can be received by antenna 176.

[0066] Furthermore, it is also possible to set radio waves emitted by an external wireless device to a channel (a channel numbered by dividing radio waves into a certain frequency band) with the best power reception sensitivity among the frequency bands that can be received by the antenna 176. At this time, it is also possible to detect the power reception state by the power reception detection unit 126, and change the channel setting by the sub-control unit 102 as needed.

[0067] When antenna 176 and antenna 177 are receiving power, if the device with which antenna 175 can communicate is a smartphone, the command operation flow to the external wireless device is different.

[0068] When electronic device 100 communicates with smartphone 401, smartphone 401 alone cannot increase the radio waves to a level sufficient for reception by antennas 176 and 177. In that case, smartphone 401 further controls external wireless device, router 402 in Fig. 4, and issues an instruction to change the frequency so as to maximize the power received by antenna 176. Smartphone 401 also communicates with public wireless base station 403, and issues an instruction to base station 403 to change the frequency, channel, strength, and communication data volume so as to maximize the power received by antenna 177.

[0069] The graph of ambient radio wave strength versus time in Figure 3 explains antenna control when using the flow of this project.

[0070] Fig. 3(a) is a diagram for explaining the instability of the radio wave environment due to different frequency bands in a general environment. Fig. 3(a) is a diagram showing the radio wave strength of each frequency band with the horizontal axis representing time. Reference numeral 301 denotes the radio wave strength 301 of the 2.4 GHz band received by the antenna of the electronic device. Reference numeral 302 denotes the radio wave strength 302 of the 5.0 GHz band received by the antenna of the electronic device. Reference numeral 303 denotes the radio wave strength 303 of the 60 GHz band received by the antenna of the electronic device.

[0071] Generally, the radio wave strength of each frequency band changes over time. In such a radio wave environment, even if all antennas receive power and try to receive as much power as possible, efficiency may deteriorate. For example, during a period of time T1, the radio wave strength 301 of the 2.4 GHz band is high, and a sufficiently high power can be received from the 2.4 GHz antenna. However, the radio wave strength 302 of the 5.0 GHz band and the radio wave strength 303 of the 60 GHz band are low, and the power that can be received is small. Therefore, the power required to drive the antenna for receiving power and the power required for rectification are greater than the power that can be received from the antenna, resulting in the electronic device consuming more power. As a result, the electronic device receives power and charges the battery, but the battery is further consumed.

[0072] FIG. 3(b) is a diagram for explaining the on / off of antennas in the case of the radio wave strength of each frequency in FIG. 3(a). 310 in FIG. 3(a) is a threshold value at which the consumed power becomes greater than the received power. When the radio wave strength 301 of the 2.4 GHz band is higher than the threshold value 310, the antenna 175 is turned on. When the radio wave strength 302 of the 5.0 GHz band is higher than the threshold value 310, the antenna 176 is turned on. When the radio wave strength 303 of the 60 GHz band is higher than the threshold value 310, the antenna 177 is turned on. From T1 to T7, the on / off control of each antenna is performed depending on the strength of each radio wave strength. As a result, when the radio wave strength is weak, the antenna is not turned on and unnecessary power consumption is not consumed.

[0073] <Other embodiments> The present invention can also be realized by executing the following process: That is, software (programs) that realize the functions of the above-described embodiments are supplied to a system or device via a network or various storage media, and the computer (or CPU, MPU, etc.) of the system or device reads and executes the programs.

Claims

1. A plurality of antennas; a circuit for charging a battery using power received by one of the plurality of antennas; a control means for controlling whether or not to receive power through one of the plurality of antennas based on the power that can be received through the antenna and the power required for receiving power through the antenna; 1. An electronic device comprising:

2. 2. The electronic device according to claim 1, characterized in that the electronic device is controlled to receive power when the power that can be received by one of the plurality of antennas is greater than the power consumed by a rectifier circuit that rectifies the power of the antenna.

3. 2. The electronic device according to claim 1, wherein, when it is determined that any one of the antennas is not receiving power, the electronic device communicates with the external wireless device using the antenna that is not receiving power.

4. 4. The electronic device according to claim 3, wherein one of the plurality of antennas has a different resonant frequency from one of the other antennas.

5. The electronic device according to claim 3, characterized in that the electronic device communicates with an external device other than the electronic device using an antenna that has been determined not to receive power, and at least one of the frequency band and communication data amount of the communication of the external device is changed to increase the power received by the antenna that is receiving power.

6. The electronic device according to claim 3, characterized in that the electronic device communicates with an external device other than the electronic device using an antenna determined not to receive power, and the external device changes at least one of the frequency band and the amount of communication data of the communication performed by the external device other than the external device, thereby increasing the power received by the antenna that is receiving power.

7. A method for controlling an electronic device having a plurality of antennas and a circuit for charging a battery using power received by one of the plurality of antennas, comprising the steps of: A method for controlling an electronic device, comprising controlling whether or not to receive power through one of the plurality of antennas, based on the power that can be received through the antenna and the power required for receiving power through the antenna.

8. The control method for an electronic device according to claim 7, characterized in that the control is performed so that power is received when the power that can be received by one of the plurality of antennas is greater than the power consumed by a rectifier circuit that rectifies the power of the antenna.

9. 8. The method for controlling an electronic device according to claim 7, wherein, when it is determined that no power is received from any of the antennas, the antenna that is not receiving power is used to communicate with the external wireless device.

10. 10. The method for controlling an electronic device according to claim 9, wherein one of the plurality of antennas has a different resonant frequency from one of the other antennas.

11. A computer readable program for causing a computer to function as each of the means of the electronic device according to any one of claims 1 to 6.

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