JP2012178958A - Antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna for a power transmission system which informs people around the antenna that the antenna transmits electric power.SOLUTION: An antenna according to this invention has: a case body 260 having a bottom plate part 261 and side plate parts extending from the bottom plate part 261 and transmitting light in at least a part thereof; a coil body 270 placed on the case body 260; and a circuit board where a loop coil 312 having a resonance frequency different from a resonance frequency of the coil body 270 and a light emitting element 313 connecting with the loop coil 312 are disposed.

Description

  The present invention relates to an antenna that is used in a magnetic resonance wireless power transmission system and receives power or transmits power.

  In recent years, development of technology for transmitting electric power (electric energy) wirelessly without using a power cord or the like has become active. Among wireless transmission methods, there is a technique called magnetic resonance as a technology that has attracted particular attention. This magnetic resonance method was proposed by a research group of Massachusetts Institute of Technology in 2007, and a technology related to this is disclosed in, for example, Japanese Patent Application Laid-Open No. 2009-501510.

  A magnetic resonance wireless power transmission system efficiently transmits energy from a power transmission side antenna to a power reception side antenna by making the resonance frequency of the power transmission side antenna and the resonance frequency of the power reception side antenna the same. One of the major features is that the power transmission distance can be several tens of centimeters to several meters.

Some proposals have been made on the specific configuration of the antenna used in the above-described magnetic resonance type wireless power transmission system. For example, Patent Document 2 (Japanese Patent Application Laid-Open No. 2010-73976) discloses a structure of a communication coil provided in each of the power feeding circuit and the power receiving circuit of a wireless power transmission apparatus that wirelessly transmits power from the power feeding circuit to the power receiving circuit. A printed circuit board made of a material having a relative dielectric constant greater than 1, a primary coil provided on the first layer of the printed circuit board and formed of a conductive pattern forming at least one loop, and a second layer of the printed circuit board And a resonance coil formed of a conductive pattern having a spiral shape. The communication coil structure of the wireless power transmission device is disclosed.
Special table 2009-501510 JP 2010-73976 A

  However, the power transmission antenna used in the conventional power transmission system has a problem in that it is impossible to notify the surroundings during power transmission. In addition, in the conventional power transmission by the antenna for power transmission, there is a problem that the amount of leakage magnetic field is large and the temperature of the metal part of the vehicle around the antenna rises.

  In order to solve the above problem, the invention according to claim 1 includes a case having a bottom plate portion and a side plate portion extending from the bottom plate portion, at least a part of which can transmit light, and the case. And a circuit board on which a loop coil having a resonance frequency different from the resonance frequency of the magnetic resonance antenna part and a light emitting element connected to the loop coil are arranged. Antenna.

  The invention according to claim 2 is the antenna according to claim 1, wherein the loop coil is arranged at a distance from the magnetic resonance antenna section.

  The invention according to claim 3 is the antenna according to claim 1, wherein the light emitting element is a light emitting diode, a plurality of the light emitting diodes are connected in the loop coil, and a plurality of the light emitting diodes are connected. Among them, there is one in which the anode of one of the light emitting diodes is connected to the cathode of the other light emitting diode.

  The invention according to claim 4 is the antenna according to claim 1, wherein the light emitting element is a light emitting diode, the plurality of light emitting diodes are connected in the loop coil, and the plurality of light emitting diodes are The resistors are connected in series with resistors having different resistance values.

  The invention according to claim 5 is the antenna according to claim 1, wherein the light emitting element is a light emitting diode, and a parallel connection of the plurality of light emitting diodes connected in series is connected to the loop coil. It is characterized by.

  The invention according to claim 6 is the antenna according to claim 1, characterized in that a circuit for blinking the light emitting element is included in the loop coil.

  The invention according to claim 7 is a case having a bottom plate portion and a side plate portion extending from the bottom plate portion, a magnetic resonance antenna portion placed on the bottom plate portion of the resin case, and the magnetic resonance antenna. An antenna comprising: a loop coil having a resonance frequency different from the resonance frequency of the portion; and a circuit board on which sounding means connected to the loop coil is arranged.

  Since the antenna according to the present invention is provided with a circuit board on which the light emitting element is arranged, according to the antenna according to the present invention, the light emitting element emits light during power transmission, and the antenna It is possible to notify the surroundings that transmission is in progress. In addition, since small animals such as cats have a habit of hating light emitters, the effects of the light emitting element can prevent the small animals from approaching the antenna during power transmission.

  Further, since the antenna according to the present invention is provided with a loop coil having a resonance frequency different from the resonance frequency of the magnetic resonance antenna portion, the leakage magnetic field can be consumed by the loop coil, and the vehicle metal portion around the antenna, etc. It is possible to suppress the temperature rise.

  Further, since the loop coil is arranged at a distance from the magnetic resonance antenna unit, it is possible to reduce the change in the resonance frequency of the magnetic resonance antenna unit and the influence on the transmission efficiency.

1 is a block diagram of a power transmission system in which an antenna according to an embodiment of the present invention is used. It is a figure which shows the inverter part of an electric power transmission system. 1 is an exploded perspective view of a power receiving antenna 201 according to a first embodiment of the present invention. It is a schematic diagram of the cross-sectional structure of the power receiving antenna 201 which concerns on 1st Embodiment of this invention. It is a figure which shows the circuit structure provided in the circuit board 310 provided in the power receiving antenna 201 which concerns on 1st Embodiment of this invention. It is a figure which shows the circuit structure provided in the circuit board 310 provided in the power receiving antenna 201 which concerns on 2nd Embodiment of this invention. It is a figure which shows the circuit structure provided in the circuit board 310 provided in the power receiving antenna 201 which concerns on 3rd Embodiment of this invention. It is a figure which shows the circuit structure provided in the circuit board 310 provided in the power receiving antenna 201 which concerns on 4th Embodiment of this invention. It is a figure which shows the circuit structure provided in the circuit board 310 provided in the power receiving antenna 201 which concerns on 5th Embodiment of this invention. It is a figure which shows the circuit structure provided in the circuit board 310 provided in the power receiving antenna 201 which concerns on 6th Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a power transmission system in which an antenna according to an embodiment of the present invention is used. The antenna according to the present invention can be applied to both a power receiving antenna and a power transmitting antenna constituting the power transmission system. However, in the following embodiments, the antenna of the present invention is used as the power receiving antenna. The applied example will be described.

  As a power transmission system using the antenna of the present invention, for example, a system for charging a vehicle such as an electric vehicle (EV) or a hybrid electric vehicle (HEV) is assumed. Since the electric power transmission system transmits electric power to the vehicle as described above in a non-contact manner, the electric power transmission system is provided in a stop space where the vehicle can be stopped. The stop space, which is a vehicle charging space, is configured such that the power transmission antenna 105 and the like are buried in the ground. A user of the vehicle stops the vehicle in a stop space where the power transmission system is provided, and makes the power reception antenna 201 mounted on the vehicle and the power transmission antenna 105 face each other to thereby generate power from the power transmission system. Receive power. When the vehicle is stopped in the stop space, the power receiving antenna 201 mounted on the vehicle has a positional relationship with good transmission efficiency with respect to the power transmission antenna 105.

  In the power transmission system, when power is efficiently transmitted from the power transmission antenna 105 on the power transmission system 100 side to the power reception antenna 201 on the power reception side system 200 side, the resonance frequency of the power transmission antenna 105 and the resonance frequency of the power reception antenna 201 are By making the same, energy transmission is efficiently performed from the power transmission side antenna to the power reception side antenna.

  The AC / DC conversion unit 101 in the power transmission side system 100 is a converter that converts input commercial power into a constant direct current. The output from the AC / DC conversion unit 101 is boosted to a predetermined voltage by the voltage adjustment unit 102. Setting of the voltage generated by the voltage adjustment unit 102 can be controlled from the main control unit 110.

The inverter unit 103 generates a predetermined AC voltage from the high voltage supplied from the voltage adjustment unit 102 and inputs it to the matching unit 104. FIG. 2 is a diagram illustrating an inverter unit of the power transmission system. For example, as shown in FIG. 2, the inverter unit 103 includes four field effect transistors (FETs) composed of Q _{A to} Q _D connected in a full bridge system.

In the present embodiment, between the connection portion T1 between the switching elements Q _A and Q _B connected in series and the connection portion T2 between the switching elements Q _C and Q _D connected in series. The matching device 104 is connected to the switching element Q _A.
When the switching element Q _D is on, the switching element Q _B and the switching element Q _C are off. When the switching element Q _B and the switching element Q _C are on, the switching element Q _A and the switching element Q _D are off. As a result, a rectangular wave AC voltage is generated between the connection portion T1 and the connection portion T2. In the present embodiment, the range of the frequency of the rectangular wave generated by switching of each switching element is about several hundred kHz to several thousand kHz.

Drive signals for the switching elements Q _{A to} Q _D constituting the inverter unit 103 as described above are input from the main control unit 110. The frequency for driving the inverter unit 103 can be controlled from the main control unit 110.

  The matching unit 104 is composed of a passive element having a predetermined circuit constant, and receives an output from the inverter unit 103. The output from the matching unit 104 is supplied to the power transmission antenna 105. The circuit constants of the passive elements constituting the matching unit 104 can be adjusted based on a command from the main control unit 110. The main control unit 110 instructs the matching unit 104 so that the power transmitting antenna 105 and the power receiving antenna 201 resonate.

  The power transmission antenna 105 is composed of a coil having an inductance component, and resonates with the vehicle-mounted power reception antenna 201 arranged so as to face each other, whereby electric energy output from the power transmission antenna 105 is supplied to the power reception antenna 201. You can send.

  The main control unit 110 of the power transmission system 100 is a general-purpose information processing unit that includes a CPU, a ROM that holds a program that runs on the CPU, and a RAM that is a work area of the CPU. The main control unit 110 operates in cooperation with the components connected to the main control unit 110 shown in the figure.

  The communication unit 120 is configured to perform wireless communication with the vehicle-side communication unit 220 so that data can be transmitted to and received from the vehicle. Data received by the communication unit 120 is transferred to the main control unit 110, and the main control unit 110 can transmit predetermined information to the vehicle side via the communication unit 120.

  Next, a configuration provided on the vehicle side will be described. In the system on the power receiving side of the vehicle, the power receiving antenna 201 receives electric energy output from the power transmitting antenna 105 by resonating with the power transmitting antenna 105. Such a power receiving antenna 201 is adapted to be attached to the bottom portion of the vehicle.

  The AC power received by the power receiving antenna 201 is rectified by the rectification unit 202, and the rectified power is stored in the battery 204 through the charge control unit 203. The charging control unit 203 controls the storage of the battery 205 based on a command from the main control unit 210. In addition, the charging control unit 203 is configured to perform the remaining amount management of the battery 204 and the like.

  The main control unit 210 is a general-purpose information processing unit that includes a CPU, a ROM that holds programs that run on the CPU, and a RAM that is a work area of the CPU. The main controller 210 operates in cooperation with the components connected to the main controller 210 shown in the figure.

  The interface unit 230 is provided in the driver's seat of the vehicle and provides predetermined information to the user (driver) or accepts operation / input from the user. A touch panel, a speaker, and the like. When a predetermined operation by the user is executed, it is sent as operation data from the interface unit 230 to the main control unit 210 and processed. Further, when providing predetermined information to the user, display instruction data for displaying the predetermined information is transmitted from the main control unit 210 to the interface unit 230.

Further, the vehicle-side communication unit 220 is configured to perform wireless communication with the power transmission-side communication unit 120 and to transmit and receive data to and from the power transmission-side system. Data received by the communication unit 220 is transferred to the main control unit 210, and the main control unit 210 can transmit predetermined information to the power transmission system side via the communication unit 220.

  In the power transmission system, a user who wants to receive power inputs the information indicating that charging is performed from the interface unit 230 by stopping the vehicle in the stop space where the power transmission side system as described above is provided. Receiving this, the main control unit 210 obtains the remaining amount of the battery 205 from the charge control unit 203 and calculates the amount of power necessary for charging the battery 205. The calculated amount of power and information to request power transmission are transmitted from the vehicle side communication unit 220 to the communication unit 120 of the power transmission side system. The main control unit 110 of the power transmission side system that has received the information controls the voltage adjustment unit 102, the inverter unit 103, and the matching unit 104 to transmit power to the vehicle side.

  Next, a specific configuration of the antenna used in the power transmission system 100 configured as described above will be described. Hereinafter, although the example which employ | adopted the structure of this invention for the power receiving antenna 201 is demonstrated, the antenna of this invention is applicable also to the power transmission antenna 105. FIG.

  3 is an exploded perspective view of the power receiving antenna 201 according to the first embodiment of the present invention, FIG. 4 is a schematic view of a cross-sectional structure of the power receiving antenna 201 according to the first embodiment of the present invention, and FIG. It is a figure which shows the circuit structure provided in the circuit board 310 provided in the power receiving antenna 201 which concerns on 1st Embodiment of invention. In the following embodiments, a rectangular flat plate is described as an example of the coil body 270, but the antenna of the present invention is not limited to such a coil having such a shape. For example, a circular flat plate or the like can be used as the coil body 270.

  Such a coil body 270 functions as a magnetic resonance antenna unit in the power receiving antenna 201. This “magnetic resonance antenna section” includes not only the inductance component of the coil body 270 but also a capacitance component based on its floating capacity, or a capacitance component based on an intentionally added capacitor. In addition, the invention specific matter that is referred to as the coil body 270 in the specification may be expressed as a “magnetic resonance antenna portion” in the claims as including the capacitance component as described above.

  The resin case 260 is used to accommodate the coil body 270 having the inductance component of the power receiving antenna 201. The resin case 260 has a box shape having an opening made of a resin such as polycarbonate. In the present invention, a transparent or translucent material is used as a material constituting the resin case 260 so that light emitted from a light emitting element such as the light emitting diode 313 accommodated in the resin case 260 is transmitted to the outside. The resin case 260 does not have to be transparent or semi-transparent as a whole, and it is sufficient that at least a part of the resin case 260 can transmit light.

  Side plate portions 262 are provided from each side of the rectangular bottom plate portion 261 of the resin case 260 so as to extend in a direction perpendicular to the bottom plate portion 261. An upper opening 263 is formed above the resin case 260 so as to be surrounded by the side plate 262. A flange portion 264 is formed at the periphery of the upper opening 263, and the power receiving antenna 201 packaged in the resin case 260 is attached to the vehicle main body portion by the flange portion 264. In order to attach the resin case 260 to the vehicle body, any conventionally known method can be used.

The coil body 270 includes a rectangular flat plate-like base material 271 made of glass epoxy and a spiral conductive portion 272 formed on the base material 271. A conductive line (not shown) is electrically connected to the first end portion 273 on the inner peripheral side and the second end portion 274 on the outer peripheral side of the spiral conductive portion 272. As a result, the power received by the power receiving antenna 201 can be guided to the rectifying unit 202. Such a coil body 270 is placed on the rectangular bottom plate portion 261 of the resin case 260 and fixed on the bottom plate portion 261 by an appropriate fixing means. In addition, a rectangular hollow portion 275 is formed at the center of the rectangular flat base material 271, and light is emitted from the light emitting diode 313 to the outside through the hollow portion 275.

  The circuit board 310 is provided with a circuit 311 including a one-loop loop coil 312 and a light emitting diode 313 connected in the loop coil 312. The circuit 311 on the circuit board 310 is physically disposed so as to overlap the hollow portion 275 of the coil body 270 when viewed from the stacking direction. An adjustment resistor 314 is connected in the loop coil 312 so that the voltage applied to the light emitting diode 313 can be adjusted. An electromotive force is generated in the loop coil 312 by a part of the magnetic field formed by the power transmission antenna 105, and the electromotive force is applied to the light emitting diode 313, whereby the light emitting diode 313 emits light. The light emitted from the light emitting diode 313 is transmitted through the transparent or translucent resin case 260 and irradiates the outside of the receiving antenna 201.

  According to such an antenna according to the present invention, during power transmission, a light emitting element such as the light emitting diode 313 emits light, and it is possible to notify the surroundings that the antenna is transmitting power. Become. In addition, since small animals such as cats have a habit of hating light emitters, the effects of the light emitting element can prevent the small animals from approaching the antenna during power transmission.

  Note that the light-emitting element provided in the loop coil 312 is not limited to the light-emitting diode 313, and other displays such as a blister bulb can be used.

  The loop coil 312 is configured to have a resonance frequency different from the resonance frequency of the coil body 270. Thereby, the magnetic field leaking from the coil body 270 can be consumed by the loop coil 312, and the temperature rise of the vehicle metal part and the like around the antenna can be suppressed.

  The circuit board 310 is disposed in the resin case 260 at a predetermined distance d above the coil body 270. Thereby, the resonance frequency of the coil body 270 functioning as a power receiving antenna is affected, and a decrease in efficiency of the power receiving antenna can be suppressed. The distance d is preferably about 20 to 100 mm.

  The magnetic shield 280 is a flat magnetic member having a hollow portion 285. In order to construct the magnetic shield 280, a magnetic material such as ferrite can be used. The magnetic shield 280 is arranged with a certain amount of space above the circuit board 310 by being fixed to the resin case 260 by an appropriate means. With such a layout, the lines of magnetic force generated on the power transmission antenna 105 side have a high rate of transmission through the magnetic shield 280, and the lines of magnetic force generated by metal objects constituting the vehicle main body in power transmission from the power transmission antenna 105 to the power reception antenna 201. The impact on is minor.

In the antenna according to the present invention, the flat magnetic shield 280 disposed above the coil body 270 is preferably provided with a hollow portion 285. By providing the hollow portion 285 in the magnetic shield 280, the loss of the magnetic shield 280 itself is reduced, and the shielding effect of the magnetic shield 280 can be maximized. Further, in the magnetic shield 280 having the hollow portion 285, the member area is small, and the cost of the antenna can be reduced. Note that the width of the hollow portion 285 is preferably limited to such a size that the magnetic shield 280 itself and the conductive portion 272 of the coil body 270 do not overlap each other when viewed from the stacking direction.

  As described above, since the antenna according to the present invention is provided with the circuit board on which the light emitting element is arranged, according to the antenna according to the present invention, the light emitting element emits light during power transmission, and the antenna Can be notified to the surroundings that power is being transmitted. In addition, since small animals such as cats have a habit of hating light emitters, the effects of the light emitting element can prevent the small animals from approaching the antenna during power transmission.

  In addition, since the antenna according to the present invention is provided with a loop coil having a resonance frequency different from the resonance frequency of the coil body, the leakage magnetic field can be consumed by the loop coil, and the temperature of a vehicle metal part or the like around the antenna It is possible to suppress the rise.

  Next, a second embodiment of the present invention will be described. The second embodiment is different from the first embodiment only in the configuration of the circuit 311 provided on the circuit board 310, and the other configurations are the same. Therefore, the circuit 311 will be described below. FIG. 6 is a diagram showing a circuit configuration provided on the circuit board 310 provided in the power receiving antenna 201 according to the second embodiment of the present invention.

  Also in this embodiment, the circuit 311 is provided with a loop coil 312 having a resonance frequency different from the resonance frequency of the coil body 270. In the loop coil 312, a parallel connection of two light emitting diodes 313 and an adjustment resistor 314 are provided. In parallel connection, among the two light emitting diodes 313, the anode of one of the light emitting diodes and the cathode of the other light emitting diode 313 are connected in parallel. In the above configuration, when power transmission is performed by the power transmission antenna 105, an electromotive force is generated in the loop coil 312, and a voltage is applied to each light emitting diode 313.

  In the present embodiment, two light emitting diodes 313 are provided in the loop coil 312, but three or more light emitting diodes 313 may be provided. In that case, it is assumed that among the plurality of light emitting diodes 313, there is one in which the anode of one light emitting diode 313 is connected to the cathode of the other light emitting diode 313. Also by such 2nd Embodiment, it is possible to enjoy the effect similar to previous embodiment.

Due to the magnetic field generated by the power transmission antenna 105, currents I ₁ and I ₂ having different directions are alternately generated in the loop coil 312. However, in the second embodiment, when the current I ₁ flows, L 1
With a current flows through the light emitting diode 313 of ED ₁ LED ₁ emits light, so that the LED ₂ emits light current flows through the light emitting diodes 313 of the LED ₂ when the current I ₂ flows. As a result, since no reverse polarity voltage is applied to any of the light emitting diodes 313, an inexpensive one that does not have high withstand voltage performance when the reverse polarity is applied can be used as the light emitting diode 313. In addition, since a reverse polarity voltage is not applied to the light emitting diode 313, the life of the light emitting diode 313 can be extended.

  Next, a third embodiment of the present invention will be described. The third embodiment is different from the first embodiment only in the configuration of the circuit 311 provided on the circuit board 310, and the other configurations are the same. Therefore, the circuit 311 will be described below. FIG. 7 is a diagram showing a circuit configuration provided on the circuit board 310 provided in the power receiving antenna 201 according to the third embodiment of the present invention.

Also in this embodiment, the circuit 311 is provided with a loop coil 312 having a resonance frequency different from the resonance frequency of the coil body 270. In the loop coil 312, three light emitting diodes 313 (LED ₁ , LED ₂ , LED ₃ ) are connected in series with three resistors 314 (R ₁ , R ₂ , R ₃ ) having different resistance values. However, the configuration connected in parallel is connected. In the above configuration, when power transmission is performed by the power transmission antenna 105, an electromotive force is generated in the loop coil 312, and a voltage is applied to each light emitting diode 313.

  In the present embodiment, the loop coil 312 is provided with the parallel connection of the three light emitting diodes 313 and the resistors connected in series thereto, but the four or more light emitting diodes 313 are connected in series to these. A parallel connection of resistors may be provided, or two light emitting diodes 313 and a parallel connection of resistors connected in series may be provided. Also according to the third embodiment, it is possible to enjoy the same effect as the previous embodiment.

Furthermore, in the third embodiment, since each light emitting diode 313 is connected to resistors having different resistance values, currents I ₁ , I ₂ , I ₃ flowing in LED ₁ , LED ₂ , and LED _3, respectively. Therefore, it is possible to change the light emission intensity by using different light emitting diodes 313 as LED ₁ , LED ₂ , and LED _3. Become. According to this, the light emitting diodes 313 of LED ₁ , LED ₂ and LED ₃ can be used like an indicator.

  Next, a fourth embodiment of the present invention will be described. The fourth embodiment is different from the first embodiment only in the configuration of the circuit 311 provided on the circuit board 310, and the other configurations are the same. Therefore, the circuit 311 will be described below. FIG. 8 is a diagram showing a circuit configuration provided on the circuit board 310 provided in the power receiving antenna 201 according to the fourth embodiment of the present invention.

  Also in this embodiment, the circuit 311 is provided with a loop coil 312 having a resonance frequency different from the resonance frequency of the coil body 270. In the loop coil 312, a parallel connection of a plurality of light emitting diodes 313 connected in series and an adjustment resistor 314 are connected. In the above configuration, when power transmission is performed by the power transmission antenna 105, an electromotive force is generated in the loop coil 312, and a voltage is applied to each light emitting diode 313.

  In addition, in 4th Embodiment, although the parallel connection number at the time of performing the parallel connection of the several light emitting diode 313 connected in series is illustrated, it is not restricted to this, Arbitrary numbers of parallel connection are illustrated. The number of connections can be employed. As a parallel connection, the number of parallel connections may be one. Also according to the fourth embodiment, it is possible to enjoy the same effect as the previous embodiment.

  Further, in the fourth embodiment, since a plurality of light emitting diodes 313 connected in series are connected in parallel in the loop coil 312, there is an advantage that a wide range of irradiation can be performed.

  Next, a fifth embodiment of the present invention will be described. The fifth embodiment is different from the first embodiment only in the configuration of the circuit 311 provided on the circuit board 310, and the other configurations are the same. Therefore, the circuit 311 will be described below. FIG. 9 is a diagram showing a circuit configuration provided on the circuit board 310 provided in the power receiving antenna 201 according to the fifth embodiment of the present invention.

Also in this embodiment, the circuit 311 is provided with a loop coil 312 having a resonance frequency different from the resonance frequency of the coil body 270. In the loop coil 312, a circuit (switching circuit unit 316) that blinks the light emitting diode 313 is connected.

In the circuit 311 shown in FIG. 9, the power transmission is performed by the transmission antenna 105, an electromotive force generated in the loop coil 312, is applied to the smoothing circuit 315 composed Toka diode D and the capacitor C _11. The electromotive force generated in the loop coil 312 is converted into a substantially DC voltage by the smoothing circuit unit 315 and applied to the switching circuit unit 316.

In the switching circuit unit 316, the current I ₁₁ flows, so that charges are accumulated in the capacitor C ₁₂ until the capacitor C ₁₁ reaches a predetermined voltage. Predetermined amount of charge stored in the capacitor C _12, the base of the transistor Tr becomes the predetermined voltage, the transistor Tr is turned on, then current I ₁₁ flows, thereby, current flows to a light-emitting diode 313, light emitting diodes 313 emits light. On the other hand, with that charge accumulated in the capacitor C ₁₁ is flows out, the base voltage falls below the predetermined voltage, the transistor Tr is turned off. As a result, no current flows through the light emitting diode 313 and the light emitting diode 313 disappears. Then, the current I ₁₁ flows again, whereby the capacitor C ₁₁ is charged up. By repeating the above operation, the switching circuit unit 316 can cause the light emitting diode 313 to emit light intermittently.

  According to such an embodiment, the same effect as the previous embodiment can be enjoyed, and further, the light emitting diode 313 blinks. It becomes possible to deter approaching.

  Next, a sixth embodiment of the present invention will be described. Since the sixth embodiment is different from the first embodiment only in the configuration of the circuit 311 provided on the circuit board 310, and the other configurations are the same, the circuit 311 will be described below. FIG. 10 is a diagram showing a circuit configuration provided on the circuit board 310 provided in the power receiving antenna 201 according to the sixth embodiment of the present invention.

  Also in this embodiment, the circuit 311 is provided with a loop coil 312 having a resonance frequency different from the resonance frequency of the coil body 270. In this embodiment, the loop coil 312 is connected with sounding means such as a speaker Sp and a buzzer.

In the circuit 311 shown in FIG. 10, the power transmission is performed by the transmission antenna 105, an electromotive force generated in the loop coil 312, it is applied to the smoothing circuit 315 composed Toka diode D and the capacitor C _11. The electromotive force generated in the loop coil 312 is converted into a substantially DC voltage by the smoothing circuit unit 315 and applied to the switching circuit unit 316.

In the switching circuit unit 316, the current I ₁₁ flows, so that charges are accumulated in the capacitor C ₁₂ until the capacitor C ₁₁ reaches a predetermined voltage. Predetermined amount of charge stored in the capacitor C _12, the base of the transistor Tr becomes the predetermined voltage, the transistor Tr is turned on, then current I ₁₁ flows, by which a current to a light-emitting diode 313, and a speaker Sp Then, the light emitting diode 313 emits light, and sound is produced from the speaker Sp. On the other hand, with that charge accumulated in the capacitor C ₁₁ is flows out, the base voltage falls below the predetermined voltage, the transistor Tr is turned off. As a result, no current flows through the light emitting diode 313, the light emitting diode 313 disappears, and sound generation from the speaker Sp is also stopped. Then, the current I ₁₁ flows again, whereby the capacitor C ₁₁ is charged up. By repeating the above operation, the switching circuit unit 316 can operate the light emitting diode 313 and the speaker Sp intermittently.

According to such an embodiment, the same effects as in the previous embodiment can be enjoyed, and further, the light emitting diode 313 blinks and the speaker Sp has a pronunciation, so it dislikes the blinking light emitter and sound. It becomes possible to prevent small animals such as cats with habits from approaching the antenna.

  An invention configured by combining any of the first to sixth embodiments of the present invention described above also falls within the scope of the present invention.

  As described above, since the antenna according to the present invention is provided with the circuit board on which the light emitting element is arranged, according to the antenna according to the present invention, the light emitting element emits light during power transmission, and the antenna Can be notified to the surroundings that power is being transmitted. In addition, since small animals such as cats have a habit of hating light emitters, the effects of the light emitting element can prevent the small animals from approaching the antenna during power transmission.

  In addition, since the antenna according to the present invention is provided with a loop coil having a resonance frequency different from the resonance frequency of the coil body, the leakage magnetic field can be consumed by the loop coil, and the temperature of a vehicle metal part or the like around the antenna It is possible to suppress the rise.

  Further, since the loop coil is arranged at a distance from the magnetic resonance antenna unit, it is possible to reduce the change in the resonance frequency of the magnetic resonance antenna unit and the influence on the transmission efficiency.

DESCRIPTION OF SYMBOLS 100 ... Power transmission system 101 ... AC / DC conversion part 102 ... Voltage adjustment part 103 ... Inverter part 104 ... Matching device 105 ... Power transmission antenna 110 ... Main control part 120- ..Communication unit 201 ... Receiving antenna 202 ... Rectification unit 203 ... Charge control unit 204 ... Battery 210 ... Main control unit 220 ... Communication unit 230 ... Interface unit 260 ... · Resin case 216 ··· Bottom plate portion 262 ··· Side plate portion 263 ··· Upper opening portion 264 ··· Flange portion 270 ··· Coil body 271 ··· Base material 272 ··· Conductive portion 273 ··· First end portion 274 ... second end portion 275 ... hollow portion 280 ... magnetic shield 281 ... shield holding plate 282 ... magnetic shield divided piece 285 ... hollow portion 310 ...・Road substrate 311 ... circuit 312 ... loop coils 313 ... light-emitting diodes 314 ... adjusting resistor 315 ... smoothing circuit 316 ... switching circuit portion

Claims (7)

A case having a bottom plate portion and a side plate portion extending from the bottom plate portion, at least a part of which can transmit light;
A magnetic resonance antenna unit mounted on the case;
An antenna comprising: a loop coil having a resonance frequency different from a resonance frequency of the magnetic resonance antenna unit; and a circuit board on which a light emitting element connected to the loop coil is arranged. The antenna according to claim 1, wherein the loop coil is disposed at a distance from the magnetic resonance antenna unit. The light emitting element is a light emitting diode;
A plurality of the light emitting diodes are connected in the loop coil;
2. The antenna according to claim 1, wherein among the plurality of light emitting diodes, there is one in which an anode of one of the light emitting diodes is connected to a cathode of the other light emitting diode. The light emitting element is a light emitting diode;
A plurality of the light emitting diodes are connected in the loop coil;
The antenna according to claim 1, wherein the plurality of light emitting diodes are connected in series with resistors having different resistance values. The light emitting element is a light emitting diode;
The antenna according to claim 1, wherein a parallel connection of the plurality of light emitting diodes connected in series is connected to the loop coil. The antenna according to claim 1, wherein a circuit for blinking the light emitting element is included in the loop coil. A case having a bottom plate portion and a side plate portion extending from the bottom plate portion;
A magnetic resonance antenna portion placed on the bottom plate portion of the resin case;
An antenna, comprising: a loop coil having a resonance frequency different from a resonance frequency of the magnetic resonance antenna unit; and a circuit board on which sounding means connected to the loop coil is arranged.

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