Power transmitter, power transmitting / receiving device, human-body communication device, and power transmitting / receiving system

Abstract

To provide a power transmitter, power transmitting / receiving device, a human-body communication device, and a power transmitting / receiving system, capable of supplying power efficiently via a human body.SOLUTION: A power transmitter comprises an antenna unit and a signal generation circuit. The antenna unit includes: a first antenna conductor that, when used, is brought into contact with a human body that is not grounded; and a second antenna conductor that is capacitively coupled to the ground without being brought into contact with the human body. The signal generation circuit applies an AC power signal between the first antenna conductor and the second antenna conductor.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present technology relates to a power transmitter, a power transmitting and receiving apparatus, a human body communication apparatus, and a power transmitting and receiving system that supply power to a device worn on a human body. [Background technology]

[0002] Conventionally, technologies for capturing power via the human body have been developed. For example, Patent Document 1 describes a power supply device that captures the energy of radio waves propagating through the air via the human body. This power supply device is provided with an antenna terminal for contacting the human body. When the antenna terminal is in contact with the human body, the human body acts as a virtual antenna. After undergoing impedance matching by a matching section, AC waveform power output from the antenna terminal is rectified by a rectifier section and supplied as DC waveform power to a secondary battery or an electrical load (see, for example, paragraphs

[0023] ,

[0026] ,

[0074] , and

[0078] , and Figures 13 and 14 of the specification of Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-88005 Summary of the Invention [Problem to be solved by the invention]

[0004] By using the human body to draw in power in this way, it becomes possible to power a variety of devices worn on the human body, for example. Such devices are expected to become widespread in the future, and there is a demand for technology that can efficiently supply power via the human body.

[0005] In view of the above circumstances, an object of the present technology is to provide a power transmitter, a power transceiver, a human body communication device, and a power transceiver system that are capable of efficiently supplying power via the human body. [Means for solving the problem]

[0006] In order to achieve the above object, a power transmitter according to an embodiment of the present technology includes an antenna unit and a signal generating circuit. The antenna section has a first antenna conductor that is used in contact with the human body and is not grounded to the earth, and a second antenna conductor that is not in contact with the human body and is capacitively coupled to the earth ground. The signal generating circuit applies an AC power signal between the first antenna conductor and the second antenna conductor.

[0007] This power transmitter is provided with a first antenna conductor that contacts the human body when the human body is not grounded, and a second antenna conductor that does not contact the human body. Of these, the second antenna conductor is capacitively coupled to the earth ground. This makes the human body a conductor capable of transmitting AC power. In this state, an AC power signal is applied to each antenna conductor. This makes it possible to efficiently supply power via the human body.

[0008] The first antenna conductor may be a conductive electrode made of at least one of gold, silver, aluminum, copper, iron, nickel, an alloy, conductive resin, and conductive rubber, and brought into contact with the human body.

[0009] The conductor electrode may have a surface that comes into contact with the human body coated with a resin.

[0010] The conductive electrode may be a flat, pin-shaped, hemispherical, or uneven electrode.

[0011] The portion other than the conductor electrodes that comes into contact with the human body may be housed in a housing made of an insulating material.

[0012] The second antenna conductor may be one of a ground pattern provided on a circuit board of the power transmitter, another pattern provided on the circuit board separately from the ground pattern, or a conductive member provided in a part of the housing that houses the power transmitter that does not come into contact with the human body.

[0013] The power signal may be a pulsed signal or a sinusoidal signal.

[0014] The frequency of the power signal may be set to a frequency that easily induces an electric charge in the human body.

[0015] The signal generating circuit may generate the power signal in response to a control signal output from a control unit that controls transmission of power by the power transmitter.

[0016] The control signal may be at least one of a signal that specifies whether the power signal is turned on or off, or a signal that specifies the frequency of the power signal.

[0017] The power transmitter may be mounted on either a portable device that contacts the human body or a stationary device that contacts the human body.

[0018] A power transmitting and receiving device according to an embodiment of the present technology includes the power transmitter mounted thereon, a power receiver, and a switch circuit. The power receiver has a rectifier circuit connected to the first antenna conductor, and receives AC power generated in the antenna unit after rectifying it with the rectifier circuit. The switch circuit switches and connects the antenna unit to either the signal generating circuit or the rectifying circuit.

[0019] The power transmitting and receiving device may further include a storage element that stores the power rectified by the rectifier circuit. In this case, the signal generating circuit may generate the power signal using the storage element as a power source.

[0020] A human body communication device according to an embodiment of the present technology includes the power transmitter, a communication unit, and a separation circuit. The communication unit is connected to the antenna unit and performs human body communication. The separation circuit has a first path that connects the antenna unit and the signal generating circuit and passes signals having a frequency lower than the frequency of the human body communication, and a second path that connects the antenna unit and the communication unit and passes signals having the frequency of the human body communication. The signal generating circuit generates the power signal at a frequency lower than the frequency of the human body communication.

[0021] A power transmission and reception system according to one embodiment of the present technology includes at least one power transmitter and at least one power receiver. The at least one power transmitter has an antenna unit having a first antenna conductor that is used by contacting the human body and is not grounded to the earth, and a second antenna conductor that is not in contact with the human body and is capacitively coupled to the earth ground, and a signal generating circuit that applies an AC power signal between the first antenna conductor and the second antenna conductor. The at least one power receiver receives power in response to the electrical signal via the human body.

[0022] The power transmitting and receiving system may further include a control unit that controls the transmission of power by the at least one power transmitter.

[0023] The control unit may set the power signal output from the power transmitter to on / off depending on the status of the device in which at least one of the power transmitter or the power receiver is installed, or the status of the human body.

[0024] The control unit may set a frequency of the power signal based on a spectrum of a power waveform induced in the human body. [Brief explanation of the drawings]

[0025] [Figure 1]1 is a block diagram showing an example of a functional configuration of a power transmission and reception system according to a first embodiment of the present technology. [Figure 2] 1 is a schematic diagram illustrating transmission of power via a human body by a power transmission and reception system. FIG. [Figure 3] 1A and 1B are schematic diagrams illustrating an example of a planar configuration and a cross-sectional configuration of a power transmitting device. [Figure 4] FIG. 2 is a schematic diagram illustrating an example of the configuration of a circuit board. [Figure 5] FIG. 10 is a schematic diagram showing another example of the configuration of the circuit board. [Figure 6] 1A and 1B are schematic diagrams showing an example of a planar configuration and a cross-sectional configuration of a power receiving device. [Figure 7] FIG. 2 is a circuit diagram illustrating an example of a rectifier circuit mounted on the power receiving device. [Figure 8] 3A and 3B are schematic diagrams for explaining the operation of the antenna units on the transmitting and receiving sides. [Figure 9] 10 is a graph showing the waveform of power excited in a human body. [Figure 10] FIG. 2 is a block diagram illustrating an example of a functional configuration of a power transmitting and receiving device. [Figure 11] FIG. 10 is a schematic diagram illustrating an overview of a power transmission and reception system according to a second embodiment. [Figure 12] 1 is a block diagram showing an example of a functional configuration of a power transmitting device that performs human body communication; [Figure 13] 1 is a block diagram showing an example of a functional configuration of a power receiving device that performs human body communication; [Figure 14] 1 is a block diagram illustrating an example of a functional configuration of a power transmitting and receiving device that performs human body communication. [Figure 15] FIG. 1 is a schematic diagram showing an application example of power transmission and reception involving human body communication. [Figure 16] FIG. 10 is a block diagram showing an example of the configuration of a power transmission and reception system according to a third embodiment. [Figure 17] 17 is a schematic diagram showing the operation of the power transmitting and receiving system shown in FIG. 16. FIG. [Figure 18] FIG. 1 is a block diagram showing an application example of a power transmission and reception system. [Figure 19] FIG. 10 is a block diagram showing another application example of the power transmitting and receiving system. [Figure 20] FIG. 10 is a block diagram showing another application example of the power transmitting and receiving system. [Figure 21] FIG. 10 is a block diagram showing another application example of the power transmitting and receiving system. DETAILED DESCRIPTION OF THE INVENTION

[0026] Hereinafter, embodiments of the present technology will be described with reference to the drawings. First Embodiment [Outline of the power transmission and reception system] FIG. 1 is a block diagram showing an example of a functional configuration of a power transmission and reception system 100 according to a first embodiment of the present technology. The power transmission / reception system 100 is a system that transmits and receives power via a human body 2 of a user 1. Therefore, in this system, the human body 2 functions as a power transmission medium. The power transmission and reception system 100 includes a power transmission device 10 and a power reception device 20. The power transmission device 10 is a device including a power transmitter 11 (power transmission unit) that transmits power via a human body 2. The power reception device 20 is a device including a power receiver 21 (power receiving unit) that receives power via the human body 2.

[0027] The power transmitting device 10 and the power receiving device 20 are configured, for example, as portable devices that come into contact with the human body 2. For example, the power transmitting device 10 and the power receiving device 20 are configured by incorporating the power transmitter 11 and the power receiver 21 into a UI (User Interface) device such as a wearable device that is worn by the user 1. Alternatively, for example, a dedicated device for transmitting and receiving power may be used.

[0028] In the power transmission / reception system 100, power is transmitted and received when the human body 2 is not grounded to the earth's ground (earth ground). For example, assume that a user 1 is wearing shoes and standing on the earth (ground, floor, etc.). In this case, the human body 2 is not grounded to the earth ground, and the potential of the human body 2 is electrically floating with respect to the earth ground. In this case, it is possible to prevent the power generated in the human body 2 from escaping to the earth ground, and it is possible to transmit and receive power efficiently.

[0029] The number of power transmitters 10 and power receivers 20 provided in the power transmission and reception system 100 is not limited. For example, a plurality of power receivers 20 may be used for a single power transmitter 10. Also, for example, a single power receiver 20 may be used for a plurality of power transmitters 10. Of course, a plurality of power transmitters 10 and a plurality of power receivers 20 may be used. In this way, the power transmission and reception system 100 is composed of at least one power transmitter 10 (power transmitter 11) and at least one power receiver 20 (power receiver 21).

[0030] Furthermore, the power transmitting device 10 and the power receiving device 20 are not limited to any particular type or form as long as they are devices that come into contact with the human body 2 of the user 1. For example, the power transmitting device 10 may be configured as a stationary device, and the power receiving device 20 may be configured as a portable device. Conversely, the power transmitting device 10 may be configured as a portable device, and the power receiving device 20 may be configured as a stationary device. In either case, when the user 1 touches the stationary device, power from the power transmitting device 10 can be supplied to the power receiving device 20 via the user 1's body 2.

[0031] As shown in FIG. 1, the power transmitter 10 includes an antenna unit 12, a signal generating circuit 13, and a power supply unit (not shown). The antenna unit 12 functions as a transmitting antenna for transmitting power via the human body 2 . The signal generating circuit 13 generates an AC power signal and outputs it to the antenna unit 12 . The power supply unit supplies power (power for the power signal) to drive the signal generating circuit 13. In this embodiment, the antenna unit 12 and the signal generating circuit 13 form a power transmitter 11. In addition, the power transmitter 10 is provided with a control unit that controls the operation of the signal generating circuit 13, a communication unit for communicating with other devices, and the like, as appropriate.

[0032] The power receiving device 20 includes an antenna unit 22, a rectifier circuit 23, a charger 24, a power storage element 25, and a load 26. The antenna unit 22 functions as a receiving antenna for receiving power via the human body 2. For example, the antenna unit 22 receives power generated in the human body 2 in response to the above-mentioned power signal. The antenna unit 22 also receives electric field energy of radio waves and quasi-electrostatic fields in the space surrounding the human body 2 as power. This will be described in detail later with reference to FIG. 8 etc. The rectifier circuit 23 is directly connected to the antenna unit 22 and rectifies the received AC power. In this embodiment, the antenna unit 22 and the rectifier circuit 23 form a power receiver 21. As described above, the power receiver 21 can extract, as power, in addition to power corresponding to the power signal, the energy of the electric field present around the human body 2. In other words, the power receiver 21 can perform energy harvesting (environmental power generation) to harvest power from the surrounding environment.

[0033] Charger 24 charges power storage element 25 with the DC power output from rectifier circuit 23 . The power storage element 25 is an element that stores the power rectified by the rectifier circuit (power received by the antenna unit 22), and supplies the power to the load 26 as needed. The load 26 is a circuit or element that is driven by the power of the storage element 25. For example, a control unit such as a microcomputer, a communication unit, various sensors, and the like are used as the load 26.

[0034] Fig. 2 is a schematic diagram illustrating the transmission of power via a human body 2 by the power transmission and reception system 100. Fig. 2 schematically illustrates the basic configurations of a power transmitter 11 and a power receiver 21. The antenna unit 12 of the power transmitter 11 is provided with a first antenna conductor 31 and a second antenna conductor 32. The first antenna conductor 31 is a conductor that is used in contact with the human body 2 that is not grounded to the earth. The second antenna conductor 32 is a conductor that is not in contact with the human body 2 and is capacitively coupled to the earth ground.

[0035] In the power transmitter 11, the signal generating circuit 13 applies an AC power signal between the first antenna conductor 31 and the second antenna conductor 32. This induces an electric charge in the human body 2 that is in contact with the first antenna conductor 31. By inducing an electric charge in the human body 2 in this manner, it becomes possible to extract AC power from the human body 2 in accordance with the power signal.

[0036] The antenna unit 22 of the power receiver 21 is provided with a third antenna conductor 33 and a fourth antenna conductor 34. The third antenna conductor 33 is a conductor that is used in contact with the human body 2 that is not grounded to the earth. The fourth antenna conductor 34 is a conductor that is not in contact with the human body 2 and is capacitively coupled to the earth ground. The third antenna conductor 33 and the fourth antenna conductor 34 correspond to the first antenna conductor 31 and the second antenna conductor 32 in the power transmitter 11, respectively.

[0037] In the power receiver 21, AC power (power corresponding to the power signal or power of electric field energy) received by the antenna unit 22 (third antenna conductor 33 and fourth antenna conductor 34) is directly input to the rectifier circuit 23. Then, the rectifier circuit 23 outputs power rectified to DC. In this way, the power receiver 21 receives power corresponding to the electric signal via the human body 2.

[0038] 2, the flow of power supplied from the power transmitter 11 (power transmitting device 10) to the power receiver 21 (power receiving device 20) via the human body 2 is schematically illustrated using thick dotted arrows. In this way, the power transmission and reception system 100 can increase the amount of power that can be extracted from the human body by intentionally transmitting power using a power signal. This makes it possible to efficiently supply power via the human body 2 to devices that come into contact with the human body 2, such as the power receiver 21 (power receiving device 20). The power transmitted via the human body 2 does not travel along a fixed path, but is transmitted to the entire body of the user 1. Therefore, it is possible for any part of the human body 2 of the user 1 to receive power corresponding to the power signal.

[0039] The configuration of each part of the power transmitting device 10 and the power receiving device 20 will be specifically described below.

[0040] [Configuration of power transmission device] Fig. 3 is a schematic diagram showing an example of a planar configuration and a cross-sectional configuration of the power transmitter 10. Fig. 3A and Fig. 3B are a schematic plan view and a cross-sectional view of the power transmitter 10. Fig. 3C is a schematic cross-sectional view showing another example of the configuration of the power transmitter 10. 3A and 3B, the power transmitter 10 includes a conductor electrode 40, a dielectric portion 41, a conductive pin 42, a circuit board 43, a board ground 44, a circuit portion 45, and a case 46. In the power transmitter 10, the conductor electrode 40, the dielectric portion 41, and the circuit board 43 are arranged in layers in this order.

[0041] The conductor electrode 40 is a conductor used in contact with the human body 2 that is not grounded to the earth, and is arranged in a position where it can come into contact with the human body 2. Here, the conductor electrode 40 is arranged so as to be exposed from the surface of the case 46. The conductor electrode 40 functions as the first antenna conductor 31 described with reference to FIG. 2.

[0042] The conductor electrode 40 may be, for example, an electrode made of a metal. Examples of metals that can be used for the conductor electrode 40 include gold, silver, aluminum, copper, iron, nickel, and alloys. For example, by using gold or silver, it is possible to form a low-resistance electrode. Furthermore, by using aluminum, copper, iron, nickel, or the like, it is possible to reduce the cost of the conductor electrode 40. Furthermore, by using these metals or alloys with other metals, it is possible to appropriately form lightweight electrodes, highly durable electrodes, and the like. Conductive resin or conductive rubber containing, for example, carbon or metal may be used as the conductor electrode 40. By using conductive resin, for example, electrodes of various shapes can be easily formed. Furthermore, by using conductive rubber, it is possible to form electrodes that are elastically deformable or have high adhesion. In addition, the material of the conductor electrode 40 is not limited, and the above-mentioned materials may be used alone, or the electrode may be formed by combining the materials.

[0043] In this embodiment, a thin plate-like (patch-like) conductor electrode 40 is used. That is, the conductor electrode 40 is a planar electrode. In this case, the conductor electrode 40 functions as a patch antenna that comes into contact with the human body 2, and it is possible to make the area that is capacitively coupled with the human body 2 (see FIG. 8, etc.) sufficiently large. The shape of the conductor electrode 40 is not limited, and may be a shape that matches the shape of the power transmission device 10 or the part of the human body 2 to which it is attached. For example, the conductor electrode 40 may be a pin-shaped, hemispherical, or uneven electrode in addition to a planar electrode.

[0044] The conductor electrode 40 may be configured so that the conductor constituting the electrode directly contacts the human body 2, or the surface that contacts the human body 2 may be resin-coated. The conductor electrode 40 is coated with a resin that is water-resistant, such as waterproof and drip-proof, and weather-resistant to ultraviolet rays and the like. This prevents the conductor electrode 40 from corroding when the power transmitting device 10 is used outdoors or in a pool. In addition, the conductor electrode 40 can be protected from sweat, moisture, and the like that may occur when the user 1 exercises.

[0045] The dielectric portion 41 is a plate-shaped dielectric provided between the conductor electrode 40 and the circuit board 43. The dielectric portion 41 is arranged, for example, so as to contact the surface of the conductor electrode 40 opposite to the surface that comes into contact with the human body 2. By providing the dielectric portion 41, for example, it is possible to improve the efficiency of power transmission from the conductor electrode 40 to the human body 2. Alternatively, a certain space may be formed between the conductor electrode 40 and the circuit board 43 without providing the dielectric portion 41 . The conductive pin 42 is a pin-shaped wire that passes through the dielectric portion 41 and connects the conductor electrode 40 to the circuit board 43. One end of the conductive pin 42 is connected to the conductor electrode 40, and the other end is connected to an electrode (connection point 47) of the circuit board 43.

[0046] Circuit board 43 is a board on which board ground 44 and circuit section 45 are provided. In the example shown in FIG. 3B , board ground 44, circuit section 45, and connection point 47 are formed on the surface of circuit board 43 opposite dielectric section 41. Connection point 47 is an electrode that connects circuit section 45 and conductor electrode 40. Conductive pin 42 penetrates circuit board 43 and is soldered to connection point 47. In addition, the board ground 44, the circuit section 45, etc. may be formed on the surface of the circuit board 43 facing the dielectric section 41. Also, the board ground 44, the circuit section 45, etc. may be formed on both sides of the circuit board 43.

[0047] The board ground 44 is a conductor pattern (ground pattern) that serves as a ground on the circuit board 43. As the board ground 44, a copper foil ground pattern is typically used. The board ground 44 is configured so as not to come into contact with the human body 2 and to be capacitively coupled to the earth ground. For example, a conductor that is not electrically connected to the earth ground and is not shielded from the earth ground will be capacitively coupled to the earth ground via the space between them. The board ground 44 is configured to be such a conductor.

[0048] 3B, the board ground 44 functions as the second antenna conductor 32. That is, the second antenna conductor 32 is configured by a ground pattern provided on the circuit board 43 of the power transmitting device 10 (power transmitter 11). The conductor electrode 40 (first antenna conductor 31) and the substrate ground 44 (second antenna conductor 32) form the antenna section 12 of the power transmission device 10 (power transmitter 11).

[0049] The circuit section 45 is a unit including various circuits that are provided so as not to overlap with the substrate ground 44. In this embodiment, the signal generating circuit 13 is formed in the circuit section 45. In addition, a power supply section for the signal generating circuit 13, a control unit for controlling the signal generating circuit 13, a communication unit for communicating with other devices, etc. may be provided in the circuit section 45. The power supply section and other units may also be provided separately from the circuit section 45.

[0050] As described above, the signal generating circuit 13 applies an AC power signal between the conductor electrode 40 (first antenna conductor 31) and the substrate ground 44 (second antenna conductor 32). The signal generating circuit 13 is driven by a power supply unit (not shown) and generates an AC signal whose voltage changes at a predetermined cycle. The power signal is typically a pulse signal or a sine signal, which is output to each antenna conductor constituting the antenna unit 12. In the example shown in FIG. 3B, the signal generating circuit 13 applies an AC power signal between the conductor electrode 40 (first antenna conductor 31) and the substrate ground 44 (second antenna conductor 32).

[0051] The signal generating circuit 13 may be, for example, an AC power supply circuit such as a DC-AC converter that converts DC power into AC power. The signal generating circuit 13 may also be configured to be able to switch the power signal on / off by a control signal output from a control unit, for example. The signal generating circuit 13 may also be configured to be able to change the frequency of the power signal. Alternatively, any circuit that can output an AC power signal may be used as the signal generating circuit 13.

[0052] The case 46 is a housing for the power transmitter 10. The case 46 accommodates the power transmitter 11, which is configured by the antenna unit 12 and the signal generating circuit 13, as well as other boards, circuits, and the like. Furthermore, the portions of the case 46 that come into contact with the human body 2 other than the conductor electrodes 40 are made of insulating material. Therefore, even if the case 46 comes into contact with the human body 2, other than the portions (conductor electrodes 40) that are provided to come into contact with the human body 2, the main body of the case 46 does not conduct electricity to the human body 2. Materials such as insulating resin and rubber are used as the insulating member. 3B, case 46 is configured using insulating material on the side and opposite surfaces of the case in addition to the surface that comes into contact with human body 2. This leaves board ground 44 (second antenna conductor) unshielded, making it possible to achieve good capacitive coupling with the earth ground.

[0053] The power transmission device 10 (power transmitter 11) shown in FIG. 3C has a different configuration of the case 46 from that shown in FIG. 3B. Here, case 46a and case 46b are used as the case 46. Case 46a is a housing that covers the side on which the conductor electrode 40 is provided, and is made of an insulating material. Case 46b is a housing that covers the side opposite to the side on which the conductor electrode 40 is provided, and is made of a conductive material such as metal. The case 46a and the case 46b are connected via a connection part 48 using screws or fittings.

[0054] 3C, the side that does not come into contact with the human body 2 is configured using the conductive case 46b. In this case, the case 46b can be used as the second antenna conductor 32. For example, a board ground 44 provided on the circuit board 43 and a conductive case 46b are electrically connected using a metal wire 49 or the like. That is, the second antenna conductor 32 is formed of a conductive member (case 46b) provided in a portion of the housing (case 46) of the power transmission device 10 (power transmitter 11) that does not come into contact with the human body. This makes it possible to realize the second antenna conductor 32 that is sufficiently capacitively coupled to the earth ground.

[0055] Fig. 4 is a schematic diagram showing an example of the configuration of the circuit board 43. Fig. 4 shows a schematic diagram of an example of the planar configuration of the circuit board 43 described with reference to Fig. 3. The shaded area in the figure is the board ground 44 (second antenna conductor 32). The board ground 44 is configured so as not to overlap with a circuit section 45 in which the signal generating circuit 13 and the like are provided. The shape and arrangement of the board ground 44 are not limited and may be set appropriately depending on the configuration of the circuit section 45, for example. Furthermore, the wiring connecting the conductor electrode 40 (first antenna conductor 31) and the circuit section 45 is configured so as not to overlap with the board ground 44. This makes it possible to prevent interference between the potential of the board ground 44 and the power signal generated by the signal generating circuit 13.

[0056] 4, the signal generating circuit 13 has two output terminals 50a and 50b that output AC or pulse wave power signals. One output terminal 50a is connected to the conductor electrode 40 via a connection point 47. The other output terminal 50b is connected to the substrate ground 44. Furthermore, an electrostatic protection component 51 is provided between the conductor electrode 40 and the board ground 44 as a countermeasure against static electricity. A varistor or the like is used as the electrostatic protection component 51. When a high voltage is applied between the conductor electrode 40 and the board ground 44, the elements on the circuit section 45 side can be protected.

[0057] 3C, when a conductive case 46b is used for the portion of case 46 that does not come into contact with human body 2, case 46b and board ground 44 are connected via metal wire 49. In this case, board ground 44 and case 46b both function as second antenna conductor 32. When case 46b is used as the ground, the area of board ground 44 may be reduced.

[0058] Fig. 5 is a schematic diagram showing another configuration example of the circuit board 43. In the example shown in Fig. 5, the second antenna conductor 32 is formed by another conductor pattern 52 provided on the circuit board 43 separately from the board ground 44. Here, the board ground 44 and the conductor pattern 52 electrically isolated from the board ground 44 are formed so as not to overlap the circuit section 45 (signal generating circuit 13, etc.). The conductor pattern 52 is configured so as not to come into contact with the human body 2 and so as to be capacitively coupled to the earth ground.

[0059] In the circuit board 43 configured in this manner, the output terminal 50a of the signal generating circuit 13 is connected to the conductor electrode 40 via the connection point 47, and the output terminal 50b is connected to the conductor pattern 52. This allows an AC or pulse wave power signal to be applied between the conductor electrode 40 and the conductor pattern 52. 4, an electrostatic protection component 51 such as a varistor is provided between the conductor electrode 40 and the board ground 44 as a countermeasure against static electricity.

[0060] 3C, when a conductive case 46b is used for the portion of case 46 that does not come into contact with human body 2, case 46b and conductor pattern 52 are connected via metal wire 49. In this case, conductor pattern 52 and case 46b together function as second antenna conductor 32. When connecting to case 46b, it is also possible to reduce the area of conductor pattern 52 and increase the area of board ground 44.

[0061] [Configuration of power receiving device] 6A and 6B are schematic diagrams showing an example of a planar configuration and a cross-sectional configuration of the power receiving device 20. A plan view and a cross-sectional view of the power receiving device 20 are shown in FIG. As shown in FIGS. 6A and 6B, the power receiving device 20 includes a conductor electrode 60, a dielectric portion 61, a conductive pin 62, a circuit board 63, a board ground 64, a circuit portion 65, and a case 66.

[0062] These components of the power receiving device 20 can be substantially the same as those of the power transmitting device 10, except for the circuit unit 65. Therefore, the above-mentioned descriptions of the conductor electrode 40, the dielectric portion 41, the conductive pin 42, the circuit board 43, the board ground 44, and the case 46 can be read as descriptions of the conductor electrode 60, the dielectric portion 61, the conductive pin 62, the circuit board 63, the board ground 64, and the case 66. In the following, parts that overlap with the description of the power receiving device 20 will be omitted as appropriate.

[0063] The conductor electrode 60 is an electrode that is provided exposed on the case 66, and is used in contact with the human body 2 that is not grounded to the earth. The dielectric portion 61 is a dielectric provided between the conductor electrode 60 and the circuit board 63 . The conductive pin 62 is a wire that connects the conductive electrode 60 and the circuit board 63 . The circuit board 63 is a board on which a board ground 64 and a circuit section 65 are provided. The connection portion between the circuit board 63 and the conductive pin 62 serves as a power supply point 67a from the conductor electrode 60 to the circuit section 65. The board ground 64 is a conductor pattern (ground pattern) that serves as a ground on the circuit board 63, and is configured so as not to come into contact with the human body 2 and to be capacitively coupled to the earth ground. As the board ground 64, for example, a ground pattern similar to the board ground 44 described with reference to FIG. 4 is used. The case 66 is a housing for the power receiving device 20 and houses each part of the power receiving device 20 therein. In the example shown in FIG. 6, the conductor electrode 60 and the substrate ground 64 function as the third antenna conductor 33 and the fourth antenna conductor 34 of the antenna section 22 described with reference to FIG.

[0064] The circuit section 65 is a unit including various circuits arranged so as not to overlap with the substrate ground 64. In this embodiment, the rectifier circuit 23 is formed in the circuit section 65. In addition, the charger 24, the storage element 25, the load 26, and the like shown in FIG. 1 may be provided in the circuit section 65. The charger 24 and the like may also be provided separately from the circuit section 65.

[0065] FIG. 7 is a circuit diagram showing an example of the rectifier circuit 23 mounted on the power receiving device 20. As shown in FIG. In the power receiving device 20, for example, a voltage of several volts is generated between the conductor electrode 60 and the substrate ground 64, but the current that can be extracted is considered to be relatively small. When rectifying such a signal, it is important to sufficiently suppress leakage current, etc. For this reason, the rectifier circuit 23 uses a circuit that does not include a capacitor or the like used in a voltage doubler rectifier circuit, for example, and that suppresses excess leakage current.

[0066] As shown in FIG. 7, the rectifier circuit 23 is configured as a full-wave rectifier circuit. The rectifier circuit 23 has four diodes 68a-68d, two Zener diodes 69a and 69b, a backflow prevention diode 70, and output terminals 71a and 71b. Diodes 68a and 68b are connected in series in the forward direction, with diode 68a at the head. A power feed point 67a is provided between diodes 68a and 68b. Diodes 68c and 68d are connected in series in the forward direction, with diode 68c at the head. The cathodes of the diode 68a, the diode 68c, the Zener diode 69a, and the Zener diode 69b are connected to the anode of the backflow prevention diode 70. The cathode of the backflow prevention diode 70 is connected to the output terminal 71a. The anodes of the diode 68b, the diode 68d, the Zener diode 69a, and the Zener diode 69b are connected to the output terminal 71b.

[0067] The conductor electrode 60 is connected to a feed point 67a between the diodes 68a and 68b, and the substrate ground 64 is connected to a connection point 67b between the diodes 68c and 68d. For example, AC power received by the antenna unit 22 (conductor electrode 60 and substrate ground 64) is full-wave rectified by four diodes 68a-68d and output as DC power from output terminals 71a and 71b. As such, the rectifier circuit 23 shown in Fig. 7 is configured using the minimum number of diodes 68a-68d required for full-wave rectification. This suppresses unnecessary leakage current and makes it possible to sufficiently improve the power receiving efficiency.

[0068] The Zener diode 69a is an element for dissipating static electricity or the like that occurs between the conductor electrode 60 and the substrate ground 64. For example, when a high voltage such as static electricity occurs, the Zener diode 69a functions as an electrostatic protection component that dissipates the static electricity. The Zener diode 69b is an element for protecting a downstream IC circuit (such as the charger 24) connected to the output terminals 71a and 71b. For example, if the voltage between the conductor electrode 60 and the substrate ground 64 becomes 6.5 V or higher, the Zener diode 69b functions as a low-resistance conductor. This makes it possible to prevent damage to downstream circuits. The backflow prevention diode 70 is a diode that prevents a reverse current flow. By providing the backflow prevention diode 70, it becomes possible to stably operate a circuit at a subsequent stage, for example.

[0069] The configuration of the rectifier circuit 23 is not limited. For example, a voltage doubler rectifier circuit or a voltage quadruple rectifier circuit that multiplies the voltage using a capacitor, or a rectifier circuit incorporating a Cockcroft-Walton circuit may be used. Alternatively, for example, a half-wave rectifier circuit may be used. Alternatively, the rectifier circuit 23 may be configured as appropriate depending on the power reception characteristics of the antenna unit 22, the characteristics of the elements and circuits used as the load 26, and the like.

[0070] The above describes a configuration in which the board ground 64 of the power receiving device 20 functions as the fourth antenna conductor 34. In the power receiving device 20, as in the power transmitting device 10, a conductor other than the board ground 64 can be used as the fourth antenna conductor 34. For example, the portion of case 66 that does not come into contact with human body 2 may be made of a conductive material (see FIG. 3C). In this case, the conductive material and board ground 64 are connected using a metal wire or the like. This allows the portion of case 66 made of the conductive material to function as fourth antenna conductor 34.

[0071] Furthermore, for example, a conductor pattern different from the board ground 64 may be provided on the circuit board 63 (see FIG. 5). In this case, the rectifier circuit 23 is connected to the conductor electrode 60 and the conductor pattern, and the conductor pattern functions as the fourth antenna conductor 34. Furthermore, if the portion of the case 66 that does not come into contact with the human body 2 is made of a conductive material, the conductor pattern and the conductive material that makes up the case 66 may be connected by a metal wire or the like. Besides this, the configuration of the fourth antenna conductor 34 is not limited.

[0072] [Antenna operation] Fig. 8 is a schematic diagram for explaining the operation of the transmitting and receiving antenna units 12 and 22. Fig. 8A and Fig. 8B are schematic diagrams showing the transmitting antenna unit 12 and the receiving antenna unit 22 in contact with the human body 2. Fig. 8C is a schematic diagram showing the human body 2 that is not grounded to the earth ground 4, and the power transmitting device 10 and the power receiving device 20 worn on the human body 2. Here, the power transmitting device 10 is worn on the arm, and the power receiving device 20 is worn on the wrist.

[0073] First, the operation of the antenna unit 12 on the transmitting side will be described. 8A, the first antenna conductor 31 (conductor electrode 40) of the antenna unit 12 and the human body 2 can be considered to be in an electrically capacitively coupled state. The human body 2 is also considered to be electrically floating with respect to the earth ground 4. In this case, the human body 2 is an ungrounded antenna element as viewed from the power transmitting device 10 (power transmitter 11).

[0074] Furthermore, the second antenna conductor 32 (such as the board ground 44) is not directly connected to the earth ground 4, but is capacitively coupled to the earth ground 4 as shown in Fig. 8C. Therefore, the second antenna conductor 32 can be considered to form a pseudo ground with the earth ground 4 as a reference. As a result, the second antenna conductor 32 functions as a ground for the human body 2, which serves as an antenna element.

[0075] In this state, if the voltage generated in the first antenna conductor 31 is changed, that is, if the electric field acting on the human body 2 is intentionally changed, an electric charge is induced in the human body 2. This is the same as when AC power is applied to the human body 2, which is an antenna element. This makes it possible to transmit AC or pulse wave power corresponding to the change in voltage (power signal) of the first antenna conductor 31 using the human body 2 as a transmission path. FIG. 8A schematically illustrates AC power transmitted via the human body 2 using a sinusoidal waveform. It should be noted that neither the human body 2 nor the second antenna conductor 32 is grounded to the earth ground 4. This prevents the energy of the power signal from being dissipated to the earth ground 4.

[0076] Next, the operation of the receiving antenna section 22 will be described. Generally, various types of electric field energy exist in the environment in which humans live, and these electric field energies can be classified into low-frequency components and high-frequency components. For example, the leakage electric field (50Hz / 60Hz) from a home AC power supply, noise near a personal computer, and the voltage generated when a person walks (see Figure 8C) are electric field energy with low frequency components and are called quasi-electrostatic fields (near fields).On the other hand, radio broadcasts (AM / FM), television broadcasts, and mobile phone communication radio waves are electric field energy with high frequency components and are called radio waves (far fields).

[0077] As shown in Figure 8B, the third antenna conductor 33 (conductor electrode 60) of the antenna section 22 and the human body 2 are electrically capacitively coupled, and as in the case of the transmitting side, the human body 2 becomes an ungrounded antenna element as seen from the power receiving device 20 (power receiver 21). 8C, the fourth antenna conductor 34 (such as the substrate ground 64) is capacitively coupled to the earth ground 4 to form a pseudo ground. As a result, the fourth antenna conductor 34 functions as a ground for the human body 2, which serves as an antenna element.

[0078] With this configuration, the antenna section 22 can take in both electric field energy of a quasi-electrostatic field such as noise, which is leakage current, and electric waves such as broadcast waves, using the human body 2 as an antenna element. Of course, the electric field energy taken in by the antenna unit 22 also includes the electric field energy of the power signal output from the power transmitting device 10 (power transmitter 11). Therefore, the antenna unit 22 receives power that is a combination of the energies of the quasi-electrostatic field, the radio wave, and the power signal. 8B is a schematic diagram showing the waveform of the power received through the human body 2. The power waveform contains a wide range of frequency components.

[0079] The antenna unit 22 configured as described above can receive quasi-electrostatic field energy at a low frequency, such as 50 Hz. The reason why the antenna unit 22 resonates at such a low frequency is thought to be that, for example, iron contained in the blood inside the human body 2 functions as an antenna. This action enables the antenna unit 22 to receive electric field energy over an extremely wide band.

[0080] [Electricity induced in the human body] FIG. 9 is a graph showing the waveform of the power excited in the human body 2. As shown in FIG. The graphs shown in the upper, middle, and lower parts of Fig. 9 are graphs showing waveforms of power excited in the human body 2 detected by the power receiving device 20 (antenna unit 22). The horizontal axis of the graph represents frequency, with a range from 2 Hz to 150 kHz being plotted. The vertical axis of the graph represents the intensity of the frequency component, with the scale being in 10 dB increments.

[0081] The upper graph in Fig. 9 is a graph measured when the human body 2 or the like is not in contact with the conductor electrode 60 of the antenna unit 22. This is a plot of the power received by the antenna unit 22 alone, and the intensity of the frequency components is at a level of approximately 0 dB or less.

[0082] The graph in the middle of Fig. 9 is a graph measured when the human body 2 is in contact with the conductor electrode 60 of the antenna unit 22. At this time, the human body 2 is not in contact with any device that may be a noise source. Therefore, this graph can be said to be a plot of the power taken in by receiving electric field energy of a quasi-electrostatic field when the human body 2 is functioning as an antenna element. 9, the upper graph and the middle graph show that the received power has increased by about 10 dB overall in the middle graph. As such, it can be seen that by bringing the human body 2 into contact with the conductor electrode 60 of the antenna unit 22, power can be received evenly across a wide frequency band. Furthermore, in the graph in the middle of Figure 9, a peak appears at 60 kHz, as indicated by the diamond 1 marker in the graph. This is thought to be due to the reception of 60 kHz power as a result of noise from a noise source (such as a computer) that is present in the vicinity of the human body 2 but is not in contact with the human body 2. Therefore, such a low frequency, for example, a band centered around 60 kHz, is a band in which electric charges are likely to be induced in the human body 2.

[0083] 9 is a graph measured when the human body 2 is in contact with the conductor electrode 60 of the antenna unit 22 and is also in contact with a computer, which is a noise source. Therefore, this graph can be said to be a plot of the power (electric field energy of the quasi-electrostatic field) from the noise source that is transmitted to the human body 2, which is the antenna element. Comparing the middle graph with the bottom graph in Figure 9, the received power in the bottom graph has increased by about 20 dB overall. As such, it can be seen that when the human body 2 in contact with the conductor electrode 60 comes into contact with the noise source, high power can be received evenly across a wide frequency band. Furthermore, a broad peak centered at 60 kHz is measured in the lower graph of Figure 9. As can be seen, in the band where electric charges are easily induced, it is possible to receive relatively strong power.

[0084] Thus, there exists a frequency at which electric charges are easily induced by an electric field in the human body 2. This characteristic also applies when a power signal is applied to the human body 2 to intentionally generate electric power (electric field energy). For example, at frequencies where charge is easily induced, the intensity of the power corresponding to the power signal increases, improving the power transmission efficiency. Conversely, at frequencies where charge is less likely to be induced, the intensity of the power corresponding to the power signal decreases, potentially reducing the receivable power. In particular, in the human body 2, charge is less likely to be induced at frequencies greater than 1 GHz.

[0085] [Signal generation circuit operation] The present inventor has discovered a method for setting the frequency of a power signal in accordance with the characteristics of the human body 2. That is, in the power transmitter 11 (power transmitting device 10), the frequency of the power signal generated by the signal generating circuit 13 is set to a frequency that easily induces an electric charge in the human body 2.

[0086] For example, the frequency of the power signal is set to 60 kHz, which increases the intensity of the power corresponding to the power signal and significantly improves transmission efficiency compared to when other frequencies are used. The frequency of the power signal is not limited to this, and may be set within the range of 60 kHz ± 10 kHz, for example. Furthermore, in the graph in the middle of Figure 9, the received power intensity is also high around 120 kHz, which is twice 60 kHz. Thus, a frequency that is an integer multiple of 60 kHz (such as 120 kHz or 180 kHz) may be used. Alternatively, the frequency of the power signal may be set to any frequency that easily induces an electric charge in the human body 2.

[0087] The power transmitting device 10 may be provided with a control unit that controls the transmission of power by the power transmitter 11. Specifically, the control unit is a unit that controls the operation of the signal generating circuit 13 using a control signal. In this case, the signal generating circuit 13 generates a power signal in response to a control signal output from the control unit. In this embodiment, the control unit corresponds to a control unit.

[0088] For example, the control signal is a signal that specifies whether the power signal is on or off, and the signal generating circuit 13 turns the power signal on or off in response to such a control signal. For example, the control unit monitors the state of the power supply that drives the signal generating circuit 13, and when the remaining charge of the battery or the like is low, the power signal is set to off. Alternatively, the power signal may be set to on / off in response to an operation by the user 1. Furthermore, if a communication unit or the like is provided, communication may be performed between the control unit and other power receiving devices 20. In this case, it is possible to set the power signal to ON when the power receiving device 20 requests power, and to set the power signal to OFF when the request for power is completed, thereby enabling effective power supply.

[0089] Alternatively, for example, the control signal may be a signal that specifies the frequency of the power signal. In this case, the signal generating circuit 13 is configured to be able to change the frequency of the power signal. For example, if the power transmitting device 10 transmits a power signal in a frequency band that is used for communication, there is a possibility that the communication may be disrupted. For this reason, for example, the control unit appropriately changes the frequency of the power signal depending on the communication status of the device. This makes it possible to supply power without disrupting communication.

[0090] It should be noted that a control unit is not necessarily provided. For example, a switch element or the like that switches on / off depending on the voltage supplied from the power supply unit may be incorporated into the signal generating circuit 13. In this case, it is possible to automatically turn off the power signal when the voltage of the power supply unit drops. By using such a switch element, the configuration of the power transmitting device 10 can be simplified and power consumption can be reduced. Besides this, the method of controlling the operation of the signal generating circuit 13 is not limited.

[0091] [Power transmission and reception device] In the above, the case where the power transmitting device 10 (power transmitter 11) and the power receiving device 20 (power receiver 21) are configured as separate devices has been described. In addition to devices with separate power transmitting and receiving functions, it is also possible to configure a device (power transmitting / receiving device) that has both power transmitting and receiving functions.

[0092] FIG. 10 is a block diagram illustrating an example of the functional configuration of the power transmitting and receiving device. The power transmitting and receiving device 80 is a device capable of transmitting and receiving power via the human body 2. The power transmitting and receiving device 80 has an antenna unit 81, a transmission / reception switch 82, a signal generating circuit 83, a rectifying circuit 84, a charger 85, a power storage element 86, and a load 87. This configuration is a combination of the power transmitting device 10 and the power receiving device 20 described above.

[0093] The antenna unit 81 functions as an antenna that transmits and receives power via the human body 2. The antenna unit 81 is configured similarly to the antenna unit 12 of the power transmitter 11 (or the antenna unit 22 of the power receiver 21) described with reference to FIG. 1 etc. Hereinafter, of the two antenna conductors that make up the antenna unit 81, the conductor that is used in contact with the human body 2 will be referred to as the first antenna conductor 31, and the conductor that is not in contact with the human body 2 will be referred to as the second antenna conductor 32.

[0094] The transmit / receive switch 82 switches and connects the antenna unit 81 to either the signal generating circuit 83 or the rectifying circuit 84. In this embodiment, the transmit / receive switch 82 corresponds to a switch circuit. A method for switching the connection with the antenna unit 81 will be described later.

[0095] The signal generating circuit 83 generates an AC power signal and outputs it to the antenna unit 81. A power storage element 86 is also connected to the signal generating circuit 83. Therefore, the signal generating circuit 83 generates the power signal using the power storage element 86 as a power source. In the power transmitting / receiving device 80, an antenna unit 81 and a signal generating circuit 83 are connected by a transmission / reception switch 82, thereby realizing a power transmitter 11. In this case, the power transmitter 11 applies an AC power signal generated by the signal generating circuit 83 to the antenna unit 81 to transmit AC power.

[0096] The rectifier circuit 84 is connected to the first antenna conductor 31 and the second antenna conductor 32 that constitute the antenna unit 81, and rectifies the AC power received by the antenna unit 81. In the power transmitting / receiving device 80, the antenna unit 81 and the rectifier circuit 84 are connected by the transmission / reception switch 82, thereby realizing the power receiver 21. In this case, the power receiver 21 rectifies the AC power generated in the antenna unit 81 by the rectifier circuit 84 and receives the rectified power. In this way, the power transmitting and receiving device 80 is configured so that the power transmitter 11 and the power receiver 21 share the antenna unit 81.

[0097] The charger 85 charges the power output from the rectifier circuit 84 into the power storage element 86 . The power storage element 86 is an element that stores the power rectified by the rectifier circuit 84, and supplies the power to a load 87 as needed. The load 87 is a circuit or element that is driven by the power of the storage element 86 . The power transmitting and receiving device 80 is provided with, for example, a communication unit that communicates with other devices as the load 87. The communication unit is, for example, a unit that supports short-range wireless communication such as BLE (Bluetooth (registered trademark) Low Energy) or Zigbee.

[0098] For example, information such as the power reception status of other devices and the remaining battery level is read using BLE or the like. At this time, if there is a device or the like that is short of power, the transmit / receive switch 82 is controlled to connect the antenna unit 81 to the signal generating circuit 83. The signal generating circuit 83 also generates a power signal based on the power of the storage element 86 and applies it to the antenna unit 81. This makes it possible to supply power to the device that is short of power via the human body 2.

[0099] Furthermore, when power is no longer needed or when the remaining charge of the storage element 86 is low, the transmit / receive switch 82 is controlled to connect the antenna unit 81 and the rectifier circuit 84, and the electric field energy generated in the human body 2 is supplied to the storage element 86 via the antenna unit 81, the rectifier circuit 84, and the charger 85. This makes it possible to recharge the storage element 86, and to appropriately supply power to devices that come into contact with the human body 2 without charging using an external power source.

[0100] The power transmitting / receiving device 80 may be provided with a filter element that separates frequency components instead of the above-described transmission / reception switch 82. In this case, the filter element is configured to output, for example, the frequency components of the power signal output from the signal generating circuit 80 to the antenna unit 81. The filter element is also configured to output, from the power received by the antenna unit 81, frequency components other than the same frequency component as the power signal to the rectifier circuit 84. By using a filter element, for example, a switch operation or the like is not required, making it possible to reduce power consumption.

[0101] As described above, the power transmitter 11 according to this embodiment is provided with a first antenna conductor 31 that contacts the human body 2 and a second antenna conductor 32 that does not contact the human body 2 when the human body 2 is not grounded to the earth ground 4. Of these, the second antenna conductor 32 is capacitively coupled to the earth ground 4. Therefore, the human body 2 serves as a conductor that can transmit AC power. In this state, an AC power signal is applied to each of the antenna conductors 31 and 32. This makes it possible to efficiently supply power via the human body 2.

[0102] <Second embodiment> A power transmission and reception system according to a second embodiment of the present technology will be described. In the following description, the description of the same configurations and operations as those in the power transmission and reception system 100 described in the above embodiment will be omitted or simplified. FIG. 11 is a schematic diagram showing an overview of a power transmission and reception system according to the second embodiment. The power transmission and reception system 200 includes a power transmission device 210 and a power reception device 220. In this embodiment, the power transmission device 210 and the power reception device 220 function as human body communication devices that perform human body communication with each other. Human body communication is a communication method that transmits and receives communication signals using the dielectric body 2 as a medium. For example, human body communication is used for communication between devices attached to the human body 2, or between a device attached to the human body and an external device.

[0103] In the power transmission and reception system 200, power transmission and human body communication are performed in response to a power signal while the power transmitting device 210 and the power receiving device 220 are in contact with the human body 2 of the user 1. Therefore, as shown in FIG. 11 , in addition to the power signal, a communication signal for performing human body communication is output to the human body 2. Note that power transmission and human body communication can be performed simultaneously by using different frequency bands. For example, the frequency for performing human body communication can be 1 MHz or higher, and the frequency for transmitting power can be less than 1 MHz. 11, the power corresponding to the power signal is schematically shown by a thick arrow, and the communication signal of the human body communication is schematically shown by a thin arrow. The configurations of the power transmitting device 210 and the power receiving device 220 will be described below.

[0104] FIG. 12 is a block diagram showing an example of the functional configuration of a power transmitting device 210 that performs human body communication. The power transmitting device 210 includes an antenna unit 212, a diplexer 201, a signal generating circuit 213, and a human body communication unit 218. This configuration combines the power transmitting device 10 shown in FIG. 1 with the human body communication unit 218 via the diplexer 201.

[0105] Diplexer 201 is a three-terminal device consisting of one main terminal and two sub-terminals. For example, a signal input to the main terminal is separated into components higher than a predetermined frequency and components lower than a predetermined frequency, and output from each sub-terminal. Furthermore, a signal input to each sub-terminal is output from the main terminal as a signal in which the frequency components are mixed. In this way, diplexer 201 is a separation circuit that separates frequencies.

[0106] The main terminal of diplexer 201 is connected to antenna unit 212 (first antenna conductor 31). One sub-terminal is connected to signal generating circuit 213, and the other sub-terminal is connected to human body communication unit 218. Hereinafter, the path connecting antenna unit 212 and signal generating circuit 213 will be referred to as a first path, and the path connecting antenna unit 212 and human body communication unit 218 will be referred to as a second path.

[0107] The first path is a path that passes frequency components below a threshold frequency, and the second path is a path that passes frequency components equal to or greater than the threshold frequency. Here, the threshold frequency is set to match the frequency used in human body communication. Generally, the frequency used in human body communication is 1 MHz or higher. Therefore, the threshold frequency of the diplexer 201 is set to 1 MHz. Alternatively, the threshold frequency may be set appropriately to match the frequency of human body communication.

[0108] Therefore, the first path connects the antenna unit 212 and the signal generating circuit 213 and serves as a path through which signals of a lower frequency than the frequency of human body communication pass. The second path connects the antenna unit 212 and the human body communication unit 218 and serves as a path through which signals of the human body communication frequency pass. This makes it possible to handle the power signal and the communication signal for human body communication separately, or to combine the signals and output them to the antenna unit 212.

[0109] In this embodiment, the signal generating circuit 213 generates a power signal with a frequency lower than the frequency of the human body communication. More specifically, the frequency of the power signal is set to a frequency lower than the threshold frequency (here, 1 MHz) set in the diplexer 201. This makes it possible to transmit power through the human body 2 without interfering with the human body communication.

[0110] The human body communication unit 218 is a communication unit that is connected to the antenna unit 212 and performs human body communication. In this embodiment, the human body communication unit 218 corresponds to a communication unit. The communication signal used in the human body communication unit 218 is a signal with a frequency higher than a threshold frequency (such as 1 MHz). The human body communication unit 218 includes a transmit / receive switch 90 , an amplifier 91 , a bandpass filter 92 , a demodulation circuit 93 , a modulation circuit 94 , a transmission driver 95 , a communication control unit 96 , and an interface unit 97 .

[0111] The transmit / receive switch 90 is connected to the antenna unit 212 via the diplexer 201. The transmit / receive switch 90 switches between transmitting a communication signal to the antenna unit 212 and receiving a communication signal from the antenna unit 212.

[0112] The amplifier 91 is a differential amplifier that differentially amplifies the communication signal output from the transmit / receive switch 90. This suppresses common mode noise and the like that is common to each antenna conductor. The bandpass filter 92 extracts a signal (communication signal) of a frequency used for human body communication from the output of the amplifier 91. This cuts out signal components unnecessary for communication. The demodulation circuit 93 demodulates the analog communication signal extracted by the band-pass filter 92 and converts it into a digital signal. The demodulated communication signal is input to the interface unit 97.

[0113] The modulation circuit 94 modulates the digital signal output from the interface unit 97 and converts it into an analog communication signal. The modulated communication signal is input to the transmission driver 95. The transmission driver 95 adjusts the voltage level of, for example, an analog communication signal. The communication signal output from the transmission driver 95 is input to the transmit / receive switch 90.

[0114] The communication control unit 96 controls the operation of each unit of the human body communication unit 218 based on control signals and the like output from the interface unit 97. For example, the connection destination of the transmission / reception changeover switch 90 is appropriately controlled to switch between transmission and reception. Also, the demodulation circuit 93, transmission driver 95, modulation circuit 94, etc. are appropriately switched on / off to manage power during communication and standby. The interface unit 97 is a computing unit that performs various types of computational processing, such as communication processing with other devices via human body communication and processing according to the content of that communication.

[0115] For example, a communication signal output from the human body communication unit 218 passes through the diplexer 201 and is output to the antenna unit 212. A communication signal received by the antenna unit 212 from another device passes through the diplexer 201 and is input to the human body communication unit 218. In this way, even during a period in which a communication signal is being transmitted and received, a power signal having a frequency lower than that of the communication signal output from the signal generating circuit 213 is applied to the antenna unit 212 via the diplexer 201. This makes it possible to simultaneously realize power transmission and human body communication.

[0116] 13 is a block diagram showing an example of the functional configuration of a power receiving device 220 that performs human body communication. The power receiving device 220 includes an antenna unit 222, a diplexer 202, a rectifier circuit 223, a charger 224, a power storage element 225, a load 226, and a human body communication unit 228. 1 is combined with a human body communication unit 228 via a diplexer 202. The human body communication unit 228 may be configured as a load 226 driven by a power storage element 225.

[0117] The main terminal of diplexer 202 is connected to antenna unit 222 (third antenna conductor 33). One sub-terminal is connected to rectifier circuit 223, and the other sub-terminal is connected to human body communication unit 228. The path connecting antenna unit 222 and rectifier circuit 223 is a path that passes frequency components below the threshold frequency (e.g., 1 MHz) of diplexer 202. The path connecting antenna unit 222 and human body communication unit 228 is a path that passes frequency components equal to or higher than the threshold frequency of diplexer 202.

[0118] For example, a communication signal output from the human body communication unit 228 passes through the diplexer 202 and is output to the antenna unit 222. A communication signal received by the antenna unit 222 from another device passes through the diplexer 202 and is input to the human body communication unit 228. In this way, even during a period in which communication signals are transmitted and received, signals having frequencies below the threshold frequency received by the antenna unit 222 are input as power to the rectifier circuit 223. As described above, the frequency of the power signal output from the power transmitter 210 is set to be below the threshold frequency. Therefore, the rectifier circuit 223 can receive AC power corresponding to the power signal. This makes it possible to simultaneously achieve power reception and human body communication.

[0119] In the above, the case where the power transmitting device 210 and the power receiving device 220 that perform human body communication are configured as separate devices has been described. In addition to this, it is also possible to configure a device (power transmitting / receiving device) that performs human body communication by having both a power transmitting function and a power receiving function.

[0120] 14 is a block diagram showing an example of the functional configuration of a power transmitting and receiving device that performs human body communication. The power transmitting and receiving device 280 includes an antenna unit 281, a diplexer 203, a transmission / reception switch 282, a signal generating circuit 283, a rectifying circuit 284, a charger 285, a power storage element 286, a load 287, and a human body communication unit 288. 10 and a human body communication unit 288 via a diplexer 203. The human body communication unit 288 may be configured as a load 287 driven by a power storage element 286.

[0121] The main terminal of diplexer 203 is connected to antenna unit 281 (first antenna conductor 31). One sub-terminal is connected to transmit / receive switch 282, and the other sub-terminal is connected to human body communication unit 288. The path connecting antenna unit 281 and transmit / receive switch 282 is a path that passes frequency components below the threshold frequency (e.g., 1 MHz) of diplexer 203. The path connecting antenna unit 281 and human body communication unit 288 is a path that passes frequency components equal to or higher than the threshold frequency of diplexer 203.

[0122] For example, when transmitting power according to a power signal, the diplexer 203 and the signal generating circuit 283 are connected by the transmit / receive switch 282. In this case, the power signal output from the signal generating circuit 283 passes through the transmit / receive switch 282 and the diplexer 203 and is applied to the antenna unit 281. Furthermore, when power is received via antenna unit 281, diplexer 203 and rectifier circuit 284 are connected by transmit / receive switch 282. In this case, of the signals received by antenna unit 281, signals having a frequency lower than the threshold frequency of diplexer 203 pass through diplexer 203 and transmit / receive switch 282 and are input to rectifier circuit 284. The signal rectified by rectifier circuit 284 is charged in power storage element 286 via charger 285. Charger 285 may also be used as a power supply source for human body communication unit 288. In this case, human body communication unit 288 is directly driven using the power received by antenna unit 281. This makes it possible to drive human body communication unit 288 in conjunction with the contact action of human body 2.

[0123] Furthermore, a communication signal output from the human body communication unit 288 passes through the diplexer 203 and is output to the antenna unit 281. Furthermore, a communication signal received by the antenna unit 281 from another device passes through the diplexer 203 and is input to the human body communication unit 288. In this way, even during a period in which a communication signal is being transmitted and received, it is possible to apply a power signal output from the signal generating circuit 283 to the antenna unit 281, and to input a power signal having a frequency lower than the threshold frequency received by the antenna unit 281 to the rectifier circuit 284. This makes it possible to simultaneously realize power transmission and reception and human body communication.

[0124] 12, 13, and 14, a configuration has been described in which the antenna units (antenna unit 212, antenna unit 222, and antenna unit 281) used for transmitting and receiving power are also used with the human body communication units (human body communication unit 218, human body communication unit 228, and human body communication unit 288). This is not limiting, and for example, the antenna units used for transmitting and receiving power and the antenna units used by the human body communication units for human body communication may be configured separately. Even in such a case, it is possible to simultaneously realize transmission and reception of power and human body communication by setting the frequency of the power signal lower than the frequency of the human body communication.

[0125] 15 is a schematic diagram showing an application example of power transmission and reception involving human body communication. In this example, power transmission and reception and human body communication are performed between a stationary power transmitting device 210 provided at a location where the user 1 comes into contact and a portable power receiving device 220 worn by the user 1. Note that either or both of the power transmitting device 210 and the power receiving device 220 may be configured as a power transmitting and receiving device 280.

[0126] 15, when unlocking a door, authentication processing for user 1 is performed using human body communication. In this case, the conductor electrode (first antenna conductor 31) of the power transmitting device 210 is configured as a doorknob 230 that the user 1 grasps, and the main body of the power transmitting device 210 is embedded in the periphery of the doorknob 230 (first antenna conductor 31). In addition, the power receiving device 220 is configured as a device that transmits the ID of user 1, etc., in response to a request from the power transmitting device 210.

[0127] For example, when user 1 touches the doorknob 230 (first antenna conductor 31), a power signal is applied to the doorknob 230 (first antenna conductor 31) by the power transmitting device 210 (signal generating circuit 213). As a result, AC power corresponding to the power signal is generated in the human body 2 of user 1. The power receiving device 220 is activated by receiving the AC power via the human body 2. Then, information such as the ID of user 1 is transmitted from the power receiving device 220 via human body communication. Upon receiving this information, the power transmitting device 210 (signal generating circuit 213) compares the ID information with pre-registered data and performs authentication processing for user 1. If it is determined that user 1 is a registered person, the door is unlocked.

[0128] In this way, by combining human body communication and power transmission, it is possible to realize a system in which a door is automatically unlocked when the user 1 simply touches the doorknob 230 (first antenna conductor 31). Furthermore, because power is transmitted via the human body 2, it is possible to properly perform authentication processing even if the power receiving device 220 does not have a battery. This makes it possible to realize, for example, a lightweight and small authentication device that does not have a battery or the like.

[0129] <Third embodiment> Fig. 16 is a block diagram showing an example of the configuration of a power transmission and reception system according to the third embodiment. In Fig. 16, the flow of power is schematically shown using dotted arrows. The power transmission and reception system 300 is composed of a UI device 30 (power transmission device 310 or power transmission and reception device 380) equipped with a power transmitter that transmits power through the human body 2, and a UI device 30 (power reception device 320 or power transmission and reception device 380) equipped with a power receiver that receives power through the human body 2. The power transmission and reception system 300 is provided with at least one UI device 30 equipped with a power transmitter and at least one UI device 30 equipped with a power receiver. For example, the power transmission and reception system 300 is configured as any one of a system including at least a power transmission device 310 and a power reception device 320, a system including at least a power transmission device 310 and a power transmission and reception device 380, a system including at least a power transmission and reception device 380 and a power reception device 320, and a system including at least two or more power transmission and reception devices 380.

[0130] The power transmitting and receiving system 300 also includes a host terminal 35 . The host terminal 35 may be configured as any UI device 30 that transmits and receives power, or may be configured as a terminal device that does not have the function of transmitting and receiving power. In the power transmission and reception system 300, the host terminal 35 controls the power transmission operations of the UI devices 30 equipped with power transmitters. That is, the host terminal 35 controls the transmission of power by at least one power transmitter constituting the power transmission and reception system 300. In addition, when the host terminal 35 is configured as a UI device 30 (power receiving device 320 or power transmitting / receiving device 380) that receives power, the host terminal 35 that uses power may be provided with a power source (battery) separate from the power source (battery) stored by the power receiver. In this embodiment, the host terminal 35 corresponds to a control unit.

[0131] Specifically, the host terminal 35 sets the power signal output from the power transmitter to on / off depending on the status of the UI device 30 in which at least one of the power transmitter and the power receiver is installed, or the status of the human body 2. Here, the status of the UI device 30 refers to, for example, the usage status, communication status, remaining battery level status, etc. of each UI device 30. The host terminal 35 communicates with the UI device 30 to appropriately acquire information indicating the status of each UI device 30. The state of the human body 2 refers to, for example, the posture of the user 1, the environment in which the user 1 is located, or the movement state of the user 1. The host terminal 35 appropriately acquires information indicating the state of the human body 2 using sensors provided in the host terminal 35 itself, sensors provided in each UI device 30, etc.

[0132] For example, the host terminal 35 determines the timing for transmitting power based on information indicating the status of the UI device 30 and the human body 2. Also, a power transmitter (UI device 30) to be used for power transmission is selected. Then, based on these results, a control signal is generated to control the on / off of a power signal from each power transmitter (signal generating circuit). This makes it possible to supply the required power at the appropriate timing.

[0133] Examples of UI devices 30 equipped with a power transmitter and a power receiver include mobile devices such as smartphones, tablet devices, and mobile batteries, as well as wearable devices worn by a user 1, such as wristwatch-type devices, headphone-type devices, contact lens-type devices (such as ICL: Intelligent Contact Lens), and ring-type devices. Since the contact lens type device and the ring type device are very small in size, they are configured as UI devices 30 for reception only, for example. Furthermore, a stationary device such as a PC, an electronic musical instrument, a training device, a car, a game controller, or a device attached to a pillow or blanket may also be used as the UI device 30. Such a stationary device is typically equipped with a power transmitter.

[0134] FIG. 17 is a schematic diagram showing the operation of the power transmission and reception system 300 shown in FIG. 17A and 17B schematically illustrate the relationship between a UI device 30 equipped with a power transmitter (power transmitting device 310) and a UI device 30 equipped with a power receiver (power receiving device 320), showing the transmission and reception of power via a human body 2. The UI device 30 (310) equipped with a power transmitter includes, for example, a wristwatch-type device. The UI device 30 (320) equipped with a power receiver includes, for example, an ICL or a ring-type device. Hereinafter, a UI device 30 configured as a power transmitting device 310 will be referred to as UI device 30(310), a UI device 30 configured as a power receiving device 320 will be referred to as UI device 30(320), and a UI device 30 configured as a power transmitting / receiving device 380 will be referred to as UI device 30(380).

[0135] In each figure, devices equipped with power transmitter A, power transmitter B, power transmitter C, etc. are shown as UI devices 30 (310) equipped with power transmitters. It is also possible to use a UI device 30 (380) configured as a power transmitting / receiving device 380 instead of the UI device 30 (310) equipped with a power transmitter or the UI device 30 (320) equipped with a power receiver.

[0136] 17A, the UI device 30 (310) equipped with a power transmitter is switched depending on the situation. In the host terminal 35, for example, a UI device 30 (310) with a high remaining battery level or a UI device 30 (310) that is not in use is preferentially selected as the device to transmit power. Also, a device close to the device receiving power may be selected as the device to transmit power. Furthermore, when the user 1 touches a stationary UI device 30 (310) (such as a PC or a game controller), the device transmitting power can be switched to the stationary UI device 30 (310).

[0137] 17B, power is transmitted from a plurality of UI devices 30 (310) equipped with power transmitters. In this case, the power transmitted from the plurality of devices is combined. For example, when the remaining capacity of the battery (such as a power storage element) of the device receiving the power is low or when the amount of power consumption increases, a plurality of UI devices 30 (310) are selected as devices to transmit power. This makes it possible to supply sufficient power via the human body 2. In addition, if the efficiency of receiving power is low, it is also possible to gradually add devices that transmit power. In this way, by appropriately combining the operations shown in FIG. 17A and FIG. 17B, it is possible to realize power transmission suited to the situation.

[0138] FIG. 18 is a block diagram showing an application example of the power transmitting and receiving system 300. 18A includes a contact lens type device 30a, a ring type device 30b, a wristwatch type device 30c, a power supply UI device 30s, and a host terminal 35. An external antenna 36 is connected to the human body 2.

[0139] The contact lens type device 30a is a UI device 30 that is used by contacting the eye of the user 1. The ring type device 30b is a UI device 30 that is used by contacting the finger of the user 1. The watch type device 30c is a UI device 30 that is used by contacting the arm (wrist) of the user 1. Each of the devices 30a, 30b, and 30c is configured to have either a power receiving function, a power transmitting function, or a power transmitting and receiving function. Here, the contact lens type device 30a and the ring type device 30b are configured as UI devices 30 dedicated to receiving power (power receiving devices 320), while the wristwatch type device 30c is configured as a UI device 30 capable of transmitting and receiving power (power transmitting and receiving device 380).

[0140] The UI device 30s is configured as a power transmitting / receiving device 380, and includes an antenna unit 53, a power receiving unit 54, a power storage unit 55, a power transmitting unit 56, and a communication unit 57. Here, it is assumed that the UI device 30s (380) supplies power to other UI devices 30 in contact with the human body 2 (the contact lens type device 30a (320), the ring type device 30b (320), and the wristwatch type device 30c (380)).

[0141] The antenna unit 53 has a first shared antenna conductor 75 and a second shared antenna conductor 76. The first shared antenna conductor 75 is an antenna conductor that is used in contact with the human body 2, and the second shared antenna conductor 75 is an antenna conductor that is not in contact with the human body 2 and is capacitively coupled to the earth ground 4. The antenna unit 53 is also used as an antenna shared by the power receiving unit 54 and the power transmitting unit 56. For example, when transmitting power, the first shared antenna conductor 75 functions as the first antenna conductor 31, and the second shared antenna conductor 76 functions as the second antenna conductor 32. When receiving power, the first shared antenna conductor 75 functions as the third antenna conductor 33, and the second shared antenna conductor 76 functions as the fourth antenna conductor 34.

[0142] The power receiving unit functions as a power generating device that extracts power from the human body 2 via the antenna unit 53. In the UI device 30s (380), the antenna unit 53 and the power receiving unit form a power receiver. The power storage unit 55 is a power storage element (such as a battery) that stores the power received by the power receiving unit 54. The power stored in the power storage unit 55 is output to the power transmitting unit 56. The power transmitting unit 56 functions as a power feeding device that transmits power to another UI device 30 in contact with the human body 2 via the antenna unit 53. In the UI device 30s (380), the antenna unit 53 and the power transmitting unit 56 form a power transmitter.

[0143] The communication unit 57 communicates with the host terminal 35 to obtain a control signal that controls the transmission and reception of power by the UI device 30s (380). In response to this control signal, the operation of the power transmitter 56 (turning power transmission on / off, etc.) and the operation of the power receiver 54 (turning power reception on / off, etc.) are controlled. As the communication unit 57, for example, a short-range wireless communication unit such as BLE or Zigbee, or a human body communication unit is used.

[0144] The host terminal 35 controls the transmission of power by the UI device 30s (380). For example, the on / off of the power transmission unit 56 is controlled in accordance with the status of the other UI device 30 (usage status, communication status, remaining battery level, etc.) and the status of the human body 2 (posture, environment, movement, etc. of the user 1). Furthermore, the on / off of the transmission of power may be controlled in accordance with a request from the other UI device 30. The host terminal 35 may also control the on / off of the power transmission function of devices other than the UI device 30s (380). Here, the transmission of power by the wristwatch-type device 30c (380) having a power transmission / reception function is appropriately controlled.

[0145] Furthermore, the host terminal 35 may control the on / off of the power receiving function of each device, including the UI device 30s (380). For example, the power receiving function is set to off for devices that transmit power or devices that are fully charged. Conversely, the power receiving function is set to on for devices that require power. This makes it possible to selectively supply power to devices that require power, thereby reducing power loss.

[0146] The host terminal 35 also reads data measured by sensors mounted on the UI device 30s (380), the contact lens type device 30a (320), the ring type device 30b (320), and the wristwatch type device 30c (380). For example, data such as the pulse rate, body temperature, and blood oxygen concentration of the user 1 is read as appropriate. This data may be provided to an application that monitors the condition of the user 1, or may be output to another device such as a PC. The host terminal 35 is configured as a device having an independent power source (a battery or other cell or a fixed power source), but may also be a device powered by, for example, the power storage unit 55 of the UI device 30s.

[0147] The external antenna 36 is an antenna attached to the human body 2 . For example, the external antenna 36 is configured as the second shared antenna conductor 76 of the antenna unit 53 of the UI device 30s (380). In this case, the external antenna 36 functions as an antenna that is not in direct contact with the human body 2 and is capacitively coupled to the earth ground 4. This makes it possible to improve the power reception efficiency of the UI device 30s (380). The external antenna 36 may also be configured as the first shared antenna conductor 75. In this case, the external antenna 36 functions as an antenna that is in direct contact with the human body 2. This can improve the efficiency of power transmission by the UI device 30s (380).

[0148] The external antenna 36 may be configured as an independent antenna that is not connected to the UI device 30s (380). In this case, for example, it is possible to extend the function of the human body 2 as an antenna, and it is possible to improve the power reception efficiency. It should be noted that a plurality of external antennas 36 may be attached to the human body 2, or no external antenna 36 may be attached to the human body 2.

[0149] The power transmission / reception system 300 shown in FIG. 18B includes a power supply UI device 30s (380), a contact lens type device 30a (320), a ring type device 30b (320), and a wristwatch type device 30c (380). Of these, the UI device 30s (380) is provided with a host processing unit 58 that executes processing similar to that of the host terminal 35 shown in Fig. 18A. In this case, the host processing unit 58 communicates with the other UI device 30 via a communication unit (not shown) and controls the transmission of power by the UI device 30s (380), etc. As a result, the UI device 30s (380) functions as the host terminal 35. In this way, the host terminal 35 may be configured as a device having a power transmission function and a power reception function. If the host processing unit 58 (host terminal 35) consumes a large amount of power, a power source (such as a battery) for operating the host processing unit 58 may be provided in addition to the power storage unit 55 of the UI device 30s.

[0150] FIG. 19 is a block diagram showing another application example of the power transmitting and receiving system 300. In FIG. The power transmission / reception system 300 shown in Fig. 19 includes a contact lens type device 30a (320), a ring type device 30b (320), a wristwatch type device 30c (380), and a host terminal 35. In the configuration shown in Fig. 19, power is transmitted by the wristwatch type device 30c (380) instead of the UI device 30s (380) shown in Fig. 18A.

[0151] The wristwatch-type device 30c (380) includes an antenna section 53, a power receiving section 54, a power storage section 55, a power transmitting section 56, and a communication unit 57. The antenna section 53 serves as an antenna shared by the power receiving section 54 and the power transmitting section 56. The communication unit 57 also receives control signals for controlling the operation of the power receiving section 54 and the power transmitting section 56 from a host terminal 35 that is provided separately from the wristwatch-type device 30c (380).

[0152] The host terminal 35 may be a device such as a smartphone. The host terminal 35 transmits power from the power transmission unit 56 of the wristwatch type device 30c (380) in accordance with the timing when the contact lens type device 30a (320) and the ring type device 30b (320) are used. Alternatively, the power may be transmitted in accordance with the timing when the contact lens type device 30a (320) and the ring type device 30b (320) are not communicating. In addition, processing such as transmitting power when the remaining battery power of each device is low may be performed. Note that a wristwatch-type device 30c (380) may be configured as the host terminal 35, similar to the UI device 30s (380) shown in FIG. 18B.

[0153] FIG. 20 is a block diagram showing another application example of the power transmitting and receiving system 300. In FIG. The power transmission / reception system 300 shown in Fig. 20 includes a contact lens type device 30a (320), a ring type device 30b (320), a wristwatch type device 30c (380), a headphone type device 30d (380), and a host terminal 35. In the configuration shown in Fig. 20, power is transmitted by the headphone type device 30d (380) instead of the UI device 30s (380) shown in Fig. 18A. The headphone-type device 30d includes an antenna section 53, a power receiving section 54, a power storage section 55, a power transmitting section 56, a communication unit 57, and a headband-type antenna 37. It is also assumed that the user 1 is wearing a mask shield type antenna 38. In this case, the headband type antenna 37 and the mask shield type antenna 38 both function as the external antenna 36 .

[0154] For example, the headband antenna 37 and the mask shield antenna 38 are configured as a second shared antenna conductor 76 that is capacitively coupled to the earth ground 4 in the headphone device 30d (380). This makes it possible to improve the efficiency of receiving power. Furthermore, the headband antenna 37 and the mask shield antenna 38 may be configured as a first shared antenna conductor 75 that directly contacts the human body 2 in the headphone device 30d (380), thereby improving the power transmission efficiency. The headband antenna 37 and the mask shield antenna 38 may be configured as independent antennas that are not connected to the headphone device 30d (380). This expands the function of the human body 2 as an antenna, thereby improving the efficiency of receiving power. In addition, the headband type antenna 37 and the mask shield type antenna 38 may be configured appropriately to function as an external antenna 36 attached to the human body 2.

[0155] In the headphone-type device 30d (380), the power receiving unit 54 supplies power received through the human body 2 and power received by the headband-type antenna 37 and the mask shield-type antenna 38 to the power storage unit 55. In addition, the power transmitting unit 56 generates a power signal using the power storage unit 55 as a power source, and outputs the power signal to the human body 2 via the antenna unit 53. Power corresponding to the power signal is supplied to the contact lens type device 30a (320), the ring type device 30b (320), and the wristwatch type device 30c (380).

[0156] 20, the headphone-type device 30d (380) is provided with the external antenna 36 (and the headband-type antenna 37 and mask shield-type antenna 38), thereby enabling it to receive power efficiently. The headphone-type device 30d (380) is also sufficiently larger than the contact lens-type device 30a (320), etc., and can easily incorporate a relatively large-capacity power storage unit 55, etc. This makes it possible to supply sufficient power to other UI devices 30.

[0157] Depending on the situation, it may be possible to switch the device transmitting power from the headphone-type device 30d (380) to the wristwatch-type device 30c (380). For example, when the wristwatch-type device 30c (380) and the ring-type device 30b (320) are worn on the same hand, the ring-type device 30b (320) is powered by the nearby wristwatch-type device 30c (380). Similarly, the contact lens-type device 30a (320) is powered by the nearby headphone-type device 30d (380). This allows for efficient power supply. In addition, it is also possible to switch the device to which power is transmitted depending on the remaining battery power of the headphone-type device 30d (380) or the wristwatch-type device 30c (380).

[0158] Fig. 21 is a block diagram showing another application example of the power transmitting and receiving system 300. In the example shown in Fig. 21, in addition to the configuration described with reference to Fig. 19, a frequency analysis unit 77 is provided in the host terminal 35. Note that the following description is also applicable to the configuration shown in Fig. 20.

[0159] The frequency analysis unit 77 analyzes the power waveform induced in the human body 2. The power waveform data is read using, for example, an AD converter or the like provided in the host terminal 35 main body. Alternatively, power waveform data read by another UI device 30 may be used. The frequency analysis unit 77 performs a fast Fourier transform (FFT) on the power waveform data (the electromagnetic wave frequency received from the human body 2) to calculate the spectrum of the power waveform. By analyzing this spectrum, the state of the electric field energy applied to the human body 2 (distribution of frequency components, etc.) is analyzed.

[0160] For example, it is possible to monitor in real time the frequency at which an electric charge is likely to be induced in the human body 2 from the spectrum of the electric power waveform (see FIG. 9). The host terminal 35 calculates the frequency at which an electric charge is likely to be induced in each situation (posture, clothing, environment, etc. of the user 1) and sets this frequency as the transmission frequency of the electric power signal. In this way, the host terminal 35 sets the transmission frequency of the electric power signal based on the spectrum of the electric power waveform induced in the human body 2. In this case, the electric power transmitting unit 56 (power transmitter) outputs an electric power signal at a frequency at which an electric charge is likely to be induced. For example, there are individual differences in the human body 2 of the user 1, including weight, body shape, etc. Therefore, the optimal frequency for power transmission differs for each user 1's human body 2. The transmission frequency of the power signal output by the power transmitter 56 is set based on the power waveform actually generated in the human body 2, and is a frequency suitable for power transmission regardless of the individual differences in the human body 2. This makes it possible to generate high-intensity power in the human body 2, and to sufficiently improve the power reception efficiency.

[0161] Note that when the power waveform is monitored, the input resistance of the power receiving unit 54 may decrease, resulting in the consumption of power extracted from the human body 2. For this reason, when measuring the power waveform, it is preferable to measure it at short intervals rather than constantly. This makes it possible to reduce unnecessary power consumption.

[0162] Furthermore, if the frequency of the power signal interferes with the frequency used for communication between UI devices 30 (such as human body communication or near field communication), communication errors may occur. For this reason, the host terminal 35 identifies the band used for communication from the spectrum of the power waveform, and sets the frequency of the power signal to avoid that band. This makes it possible to supply power without interfering with communication. Note that the present invention is not limited to changing the frequency of the power signal, and the frequency of a signal used for communication may also be changed, for example.

[0163] Alternatively, the power receiving unit 54 (power receiver) may be controlled to select a frequency that does not interfere with the frequency of the power signal output from the power transmitting unit 56. In this case, the frequency of the power signal is read from the spectrum of the power waveform, for example. Then, the power receiving unit 54 is controlled to receive a frequency component that does not interfere with that frequency. This makes it possible to avoid interference between power generation and power supply, and to efficiently supply power to the UI device 30 that requires power.

[0164] <Other embodiments> The present technology is not limited to the above-described embodiments, and various other embodiments can be realized.

[0165] The above description mainly focuses on a power transmitter that transmits power via a human body and a power receiver that receives power via a human body. However, the present technology is not limited to this and can be applied to conductors other than the human body. A typical example of a conductor other than the human body is a metal body. Here, a metal body is an object whose components, such as a housing, frame, or wiring, are made of metal, and includes a variety of objects such as electronic devices, home appliances, automobiles, steel racks, and wire mesh.

[0166] The power transmitter is provided with a first antenna conductor in contact with the metal body and a second antenna conductor that is not in contact with the metal body and is capacitively coupled to the earth ground, while the power receiver is provided with a third antenna conductor in contact with the metal body and a fourth antenna conductor that is not in contact with the metal body and is capacitively coupled to the earth ground. When a power signal is applied between the first and second antenna conductors by the power transmitter, power corresponding to the power signal is generated in the metal body. In this case, the power receiver can receive the power generated in the metal body from the third and fourth antenna conductors. In this way, by using the present technology, it is possible to transmit power via a metal body in the same way as a human body. Furthermore, in the contents described in each of the above embodiments, descriptions related to a human body can be appropriately interpreted as descriptions related to a metal body.

[0167] It is also possible to combine at least two of the features of the present technology described above. That is, the various features described in each embodiment may be arbitrarily combined without distinction between the embodiments. Furthermore, the various effects described above are merely examples and are not limiting, and other effects may also be achieved.

[0168] In this disclosure, the terms "same," "equal," "orthogonal," etc. are concepts that include "substantially the same," "substantially equal," "substantially orthogonal," etc. For example, they also include states that fall within a predetermined range (e.g., a range of ±10%) based on "completely the same," "completely equal," "completely orthogonal," etc.

[0169] The present technology can also be configured as follows. (1) An antenna unit having a first antenna conductor that is used in contact with a human body and is not grounded to the earth, and a second antenna conductor that is not in contact with the human body and is capacitively coupled to the earth ground; a signal generating circuit that applies an AC power signal between the first antenna conductor and the second antenna conductor; A power transmitter comprising: (2) The power transmitter according to (1), The first antenna conductor is made of at least one of gold, silver, aluminum, copper, iron, nickel, an alloy, conductive resin, and conductive rubber, and is a conductive electrode that comes into contact with the human body. Power transmitter. (3) The power transmitter according to (2), The conductor electrode has a resin-coated surface that comes into contact with the human body. Power transmitter. (4) The power transmitter according to (2) or (3), The conductor electrode is a flat, pin-shaped, hemispherical, or uneven electrode. Power transmitter. (5) A power transmitter according to any one of (2) to (4), The part that comes into contact with the human body other than the conductor electrodes is housed in a housing made of an insulating material. Power transmitter. (6) A power transmitter according to any one of (1) to (5), The second antenna conductor is any one of a ground pattern provided on a circuit board of the power transmitter, another pattern provided on the circuit board separately from the ground pattern, and a conductive member provided in a part of a housing that accommodates the power transmitter and that does not come into contact with the human body. power transmitter (7) A power transmitter according to any one of (1) to (6), The power signal is a pulse signal or a sinusoidal signal. Power transmitter. (8) A power transmitter according to any one of (1) to (7), The frequency of the power signal is set to a frequency that easily induces an electric charge in the human body. Power transmitter. (9) A power transmitter according to any one of (1) to (8), The signal generating circuit generates the power signal in response to a control signal output from a control unit that controls the transmission of power by the power transmitter. Power transmitter. (10) The power transmitter according to (9), The control signal is at least one of a signal that specifies whether the power signal is on or off and a signal that specifies the frequency of the power signal. Power transmitter. (11) A power transmitter according to any one of (1) to (10), The device is mounted on either a portable device that comes into contact with the human body or a stationary device that comes into contact with the human body. Power transmitter. (12) A power transmitting and receiving device equipped with the power transmitter according to any one of (1) to (11), a power receiver having a rectifier circuit connected to the first antenna conductor, which rectifies AC power generated in the antenna unit by the rectifier circuit and receives the rectified power; A switch circuit is provided to switch and connect the antenna unit to either the signal generating circuit or the rectifying circuit. Power transmitting and receiving device. (13) The power transmitting and receiving device according to (12), further comprising: a storage element for storing the power rectified by the rectifier circuit; The signal generating circuit generates the power signal using the power storage element as a power source. Power transmitting and receiving device. (14) A human body communication device equipped with the power transmitter according to any one of (1) to (13), a communication unit connected to the antenna unit and performing human body communication; a separation circuit having a first path connecting the antenna unit and the signal generating circuit and passing a signal having a frequency lower than the frequency of the human body communication, and a second path connecting the antenna unit and the communication unit and passing a signal having the frequency of the human body communication, The signal generating circuit generates the power signal at a frequency lower than the frequency of the human body communication. Human body communication device. (15) At least one power transmitter having an antenna unit including a first antenna conductor that is used by contacting a human body that is not grounded to the earth, and a second antenna conductor that is not in contact with the human body and is capacitively coupled to the earth ground, and a signal generating circuit that applies an AC power signal between the first antenna conductor and the second antenna conductor; at least one power receiver that receives power in response to the electrical signal via the human body; A power transmitting and receiving system comprising: (16) The power transmission and reception system according to (15), further comprising: and a control unit that controls the transmission of power by the at least one power transmitter. Power transmission and reception system. (17) The power transmission and reception system according to (16), The control unit sets the power signal output from the power transmitter to be on / off depending on the status of a device in which at least one of the power transmitter and the power receiver is installed, or the status of the human body. Power transmission and reception system. (18) The power transmission and reception system according to (16) or (17), The control unit sets the frequency of the power signal based on a spectrum of a power waveform induced in the human body. Power transmission and reception system. [Explanation of symbols]

[0170] 1...User 2…Human body 4...Daichi Ground 10, 210, 310...Power transmitting device 11...Power transmitter 12, 212...Antenna section 13, 213...Signal generating circuit 31...First antenna conductor 32...Second antenna conductor 35...Host terminal 40...Conductor electrode 44...Board ground 46, 46a, 46b…case 52...Conductor pattern 77...Frequency analysis section 80, 280, 380... Power transmitter / receiver 201, 202, 203...Diplexer 218, 228, 288...Human Body Communication Unit 100, 200, 300... Power transmission and reception system

Claims

1. an antenna unit having a first antenna conductor that is used in contact with a human body and is not grounded to the earth, and a second antenna conductor that is not in contact with the human body and is capacitively coupled to the earth ground; a signal generating circuit that applies an AC power signal between the first antenna conductor and the second antenna conductor; A power transmitter comprising:

2. 2. The power transmitter of claim 1, The first antenna conductor is made of at least one of gold, silver, aluminum, copper, iron, nickel, an alloy, conductive resin, and conductive rubber, and is a conductive electrode that comes into contact with the human body. Power transmitter.

3. 3. The power transmitter of claim 2, The conductor electrode has a resin-coated surface that comes into contact with the human body. Power transmitter.

4. 3. The power transmitter of claim 2, The conductor electrode is a flat, pin-shaped, hemispherical, or uneven electrode. Power transmitter.

5. 3. The power transmitter of claim 2, The part that comes into contact with the human body other than the conductor electrodes is housed in a housing made of an insulating material. Power transmitter.

6. 2. The power transmitter of claim 1, The second antenna conductor is any one of a ground pattern provided on a circuit board of the power transmitter, another pattern provided on the circuit board separately from the ground pattern, and a conductive member provided in a part of a housing that houses the power transmitter and that does not come into contact with the human body. power transmitter

7. 2. The power transmitter of claim 1, The power signal is a pulse signal or a sinusoidal signal. Power transmitter.

8. 2. The power transmitter of claim 1, The frequency of the power signal is set to a frequency that easily induces an electric charge in the human body. Power transmitter.

9. 2. The power transmitter of claim 1, The signal generating circuit generates the power signal in response to a control signal output from a control unit that controls the transmission of power by the power transmitter. Power transmitter.

10. 10. The power transmitter of claim 9, The control signal is at least one of a signal that specifies whether the power signal is on or off and a signal that specifies the frequency of the power signal. Power transmitter.

11. 2. The power transmitter of claim 1, The device is mounted on either a portable device that comes into contact with the human body or a stationary device that comes into contact with the human body. Power transmitter.

12. A power transmitting and receiving device equipped with the power transmitter according to claim 1, a power receiver having a rectifier circuit connected to the first antenna conductor, the power receiver rectifying AC power generated in the antenna unit by the rectifier circuit and receiving the rectified AC power; A switch circuit is provided to switch and connect the antenna unit to either the signal generating circuit or the rectifying circuit. Power transmitting and receiving device.

13. The power transmitting and receiving device according to claim 12, further comprising: a storage element for storing the power rectified by the rectifier circuit; The signal generating circuit generates the power signal using the power storage element as a power source. Power transmitting and receiving device.

14. A human body communication device equipped with the power transmitter according to claim 1, a communication unit connected to the antenna unit and performing human body communication; a separation circuit having a first path connecting the antenna unit and the signal generating circuit and passing a signal having a frequency lower than the frequency of the human body communication, and a second path connecting the antenna unit and the communication unit and passing a signal having the frequency of the human body communication, The signal generating circuit generates the power signal at a frequency lower than the frequency of the human body communication. Human body communication device.

15. at least one power transmitter having an antenna unit including a first antenna conductor that is used by contacting a human body that is not grounded to the earth, and a second antenna conductor that is not in contact with the human body and is capacitively coupled to the earth ground, and a signal generating circuit that applies an AC power signal between the first antenna conductor and the second antenna conductor; at least one power receiver that receives power according to the electrical signal via the human body; A power transmitting and receiving system comprising:

16. The power transmitting and receiving system according to claim 15, further comprising: a control unit that controls the transmission of power by the at least one power transmitter. Power transmission and reception system.

17. 17. The power transmission and reception system according to claim 16, The control unit sets the power signal output from the power transmitter to be on / off depending on the status of a device in which at least one of the power transmitter and the power receiver is installed, or the status of the human body. Power transmission and reception system.

18. 18. The power transmission and reception system according to claim 17, The control unit sets the frequency of the power signal based on a spectrum of a power waveform induced in the human body. Power transmission and reception system.

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