JP2011045045A - Power transmitting/receiving antenna and power transmitter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power transmitting/receiving antenna which can increase a power transmission efficiency and also can be made thin based on a resonance system. <P>SOLUTION: A power transmitting/receiving antenna 100 transmits/receives power between a power supply 13 and a battery 25 for receiving power from the power supply 13 in a non-contact manner. The antenna 100 includes a resonance antenna unit 40 which has a plate-like substrate 30 and a spiral pattern 43 which is made of a conductive material spirally formed on the substrate 30 along its surface direction and which is set at a predetermined resonance frequency; and a loop antenna unit 60 which has a loop pattern 63 made of a conductive material annularly formed along the surface direction and which is connected magnetically to the resonance antenna unit 40 and also connected electrically to the power supply 13 side or the battery 25 side. With such an arrangement, since an arrangement requiring power transmission based on a resonance system can be formed on the plate-like substrate 30, a power transmitting/receiving antenna of a resonance type can transmit power with a high efficiency and be made thin. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a power transmission / reception antenna that transmits power in a contactless manner between a power source and a device to which power is supplied from the power source, and a power transmitter including the antenna.

  Conventionally, a technique using electromagnetic induction is known as a method for transmitting non-contact power. In this electromagnetic induction method, the antenna on the power transmission side causes a change in the magnetic field, and the antenna on the power reception side is arranged in an environment where the magnetic field fluctuates to generate an induced current in the antenna. Power transmission. As one type of such an electromagnetic induction type power transmission or power reception antenna, for example, Patent Document 1 discloses that a conductive wire is spirally formed along the surface direction of the surface that intersects the plate thickness direction of the housing inside the housing. A configuration in which a coil wound around is used as an antenna is disclosed.

  In recent years, as a method different from the electromagnetic induction method described above, a method using resonance of an electric field or a magnetic field has been proposed by Non-Patent Document 1, for example. According to the transmission of power by this resonance method, power can be transmitted more efficiently than the electromagnetic induction method even when the antennas on the power transmission side and the power reception side are separated from each other.

  In the configuration described in Non-Patent Document 1, on each of the power transmission side and the power reception side, a loop-shaped copper wire, a coil that is formed in a three-dimensional spiral shape and is magnetically connected to the loop-shaped copper wire, It is set as the structure provided with. In this configuration, the resonance frequencies of the coils on the power transmission side and the power reception side are set to be the same as each other, and are set to values corresponding to the frequency of the alternating current applied from the power source to the loop-shaped copper wire on the power transmission side. The

  In the resonance type configuration described above, the fluctuation of the magnetic field due to the alternating current applied from the power source to the loop-shaped copper wire on the power transmission side generates an induced current in the coil magnetically connected to the loop-shaped copper wire. Let The induced current causes the magnetic field and electric field around the coil on the power transmission side to vibrate at the resonance frequency. Here, since the resonance frequencies of the coils on the power transmission side and the power reception side are the same, these coils resonate due to vibration propagating through an electric field or a magnetic field. Therefore, the transmission of electric power from the coil on the power transmission side installed away from each other to the coil on the power reception side is realized. And according to the fluctuation | variation of the magnetic field by the electric current which generate | occur | produced in the coil at the receiving side, an induced current is induced in the loop-shaped copper wire of the receiving side magnetically connected to the coil. Therefore, power can be supplied to the device electrically connected to the loop-shaped copper wire.

JP 2002-323352 A

Andre Kurs, 5 others, “Wireless Power Transfer via Strongly Coupled Magnetic Resonances”, Science <URL: http://www.sciencemag.org/>, VOL 317, July 6, 2007, p. 83-86

  In the configuration of the resonance method described in Non-Patent Document 1, the power transmission side and power reception side antennas are different from the looped copper wires in addition to the looped copper wires connected to the power supply or the device. Requires a coil. In addition, it is difficult to reduce the size of the coil whose full length needs to be set corresponding to a predetermined resonance frequency by shortening the full length. Further, according to the three-dimensional spiral shape, the coil is a factor for increasing the size of the antenna. According to the above, in the power transmission by the resonance method, the power transmission efficiency can be obtained even when the distance between the antennas on the power transmission side and the power reception side is separated, but the antenna configuration becomes large. Had occurred.

  The present invention has been made in view of the above problems, and an object of the present invention is to improve power transmission efficiency by a resonance method, and to realize a thin transmission / reception antenna and a power transmitter including the antenna. Is to provide.

  To achieve the above object, the invention described in claim 1 is a power transmission / reception antenna for transmitting or receiving power in a contactless manner between a power source and a device to which power is supplied from the power source. And a spiral portion formed by spirally forming a conductive material on the substrate along the surface direction of the surface intersecting the thickness direction of the substrate, and a predetermined resonance frequency is set. A resonance antenna part, and an annular part formed by forming a conductive material in an annular shape on the base material along the surface direction. The resonance antenna part is magnetically connected to the resonance antenna part and electrically connected to the power supply side or the device side. A power transmission / reception antenna comprising a connected loop antenna unit.

  According to the present invention, the resonant antenna unit having a spiral portion formed by spirally forming a conductive material on the base material along the surface direction of the surface intersecting the plate thickness direction of the base material has a predetermined resonance frequency. The thickness along the plate thickness direction of the base material is reduced while maintaining the entire length of the spiral portion required for obtaining the thickness. In addition to the resonant antenna portion, the annular portion of the loop antenna portion is also formed by annularly forming a conductive material along the surface direction of the base material. Can be formed together on a substrate that is shaped. Therefore, it is possible to reduce the thickness of the resonant transmission / reception antenna that can obtain high power transmission efficiency between the power source and the device.

  In general, an antenna formed in a ring shape can improve sensitivity as the area of the ring-shaped area is increased. However, when the loop antenna part and the resonance antenna part are formed on the same base material for thinning and the spiral part of the resonance antenna part is formed in the annular region, the magnetic flux passing through the region There is a possibility that the generation is hindered by the spiral portion. Accordingly, the invention according to claim 2 is characterized in that the spiral portion is formed on the outer peripheral side of the region surrounded by the annular portion. According to this invention, the magnetic flux generated in the region surrounded by the annular portion is not disturbed by the spiral portion. Therefore, the efficiency of power transfer by electromagnetic induction between the loop antenna unit and the resonant antenna unit can be further improved. Therefore, it is possible to further improve the power transmission efficiency of the thinned resonance type power transmitting and receiving antenna.

  In the invention according to claim 3, the resonant antenna portion has a connecting portion for connecting the inner peripheral end and the outer peripheral end of the spiral portion, and the connecting portion is the spiral portion of the base material. It is formed in the surface which opposes. Here, the resonance frequency of the resonance antenna unit is defined by the induction coefficient and the capacitance of the resonance antenna unit. Therefore, when both ends of the spiral portion are in an open state, the resonance frequency of the resonance antenna section varies due to the capacitance of the space between the both ends, and variations tend to occur. Therefore, by connecting the end portion on the inner peripheral side and the end portion on the outer peripheral side of the spiral portion by the connecting portion, variation in the resonance frequency of the resonance antenna portion can be easily suppressed. In addition, by forming the connecting portion on the surface of the substrate facing the spiral portion, the connecting portion can straddle the spiral portion in the radial direction without interfering with the spiral portion.

  The invention according to claim 4 is characterized in that the resonant antenna section includes a capacitance section that is connected to the spiral section and has a predetermined capacitance set. As described above, the factor that defines the resonant frequency of the resonant antenna unit is the capacitance of the resonant antenna unit. According to the configuration in which the electrostatic capacitance portion having a predetermined electrostatic capacitance is connected to the spiral portion, the resonance frequency of the resonance antenna portion can be easily adjusted. As described above, according to the resonance antenna unit that can easily obtain the predetermined resonance frequency, the advantage of the resonance method that realizes high power transmission efficiency between the power transmitting and receiving antennas that are separated can be effectively exhibited. It can be done.

  The invention according to claim 5 is a pair of electrode portions that are arranged on the surface of the base material so as to face each other in the thickness direction and are formed by forming a conductive material into a film shape. According to this invention, an electrostatic capacity part having an electrostatic capacity can be formed by a configuration in which electric charges are stored in a region sandwiched between a pair of electrode parts arranged opposite to each other in the plate thickness direction. And, by changing the capacitance of the capacitance portion according to the area where the electrode portions face each other, the resonance frequency of the resonance antenna portion can be finely adjusted by changing the area. It becomes. In addition, according to the film-like electrode portion, the electrode portion cannot be configured to prevent thinning. According to the above, it is possible to provide a power transmission / reception antenna that achieves a reduction in thickness and also realizes an improvement in transmission efficiency with a resonance antenna unit that can accurately set a predetermined resonance frequency.

  The invention according to claim 6 is characterized in that at least a part of the electrode part is easily formed from the surface of the substrate. According to this invention, it is possible to reduce the amount of charge that can be accumulated between the opposing electrode parts by making part of the electrode parts easy to peel from the base material, and by peeling part of the electrode parts. . As described above, according to the configuration in which the capacitance of the capacitance portion can be easily adjusted, for example, a deviation from the predetermined frequency of the resonance frequency of the resonance coil portion due to, for example, variation in manufacturing or secular change can be easily performed. It can be corrected. Therefore, it is possible to provide a power transmission / reception antenna that can reliably perform transmission of electric power exhibiting high efficiency by the resonance method.

  The invention according to claim 7 is characterized in that the capacitance section is a capacitor element having a predetermined capacitance. According to the present invention, by using a capacitor element having a predetermined capacitance as the capacitance portion, the capacitance portion can be realized with a simple configuration, and variations in the capacitance can be suppressed. easy. Therefore, it is possible to provide a power transmission / reception antenna that can reliably perform high-efficiency power transmission by the resonance method.

  Here, the efficiency of power transfer between the annular part of the loop antenna part and the spiral part of the resonance antenna part is such that the inductance of the resonance antenna part is large and the electric resistance of the loop antenna part and the resonance antenna part is small. ,improves. Among these, the inductance of the resonant antenna portion increases as the number of spiral turns of the conductive material forming the spiral portion increases. On the other hand, the electrical resistance of the loop antenna part and the resonance antenna part increases the distance between the spiral part and the annular part and the distance between the conductive materials adjacent in the radial direction in the spirally formed conductive material. Get smaller.

  And when the magnitude | size of a plate-shaped base material is predetermined, in order to increase the winding number of a spiral part, between the conductive materials which form the space | interval of a spiral part and an annular part, and a spiral part It is necessary to narrow at least one of the intervals in the radial direction. Conversely, if these intervals are widened, the number of turns in the spiral must be reduced. Thus, an increase in inductance and a decrease in electrical resistance are contradictory.

  Therefore, by adjusting the number of spiral windings, the distance between adjacent conductive materials, and the distance between the spiral part and the annular part, in the base material with a limited area, the spiral part and the annular part It is possible to maximize the efficiency of power transfer between the two. Therefore, as in the invention described in claim 8, the resonance method that can achieve both reduction in thickness and improvement in power transmission efficiency by determining the number of turns and the interval described above so that the efficiency of power transfer is maximized. The power transmission / reception antenna is realized.

  As described above, the sensitivity of the loop antenna part can be improved as the area of the region surrounded by the annular part is increased. On the other hand, in the resonant antenna unit, it is desirable to widen the radial interval of the spiral part in order to suppress mutual induction occurring in the spiral part. Accordingly, the invention according to claim 9 is characterized in that the annular portion is formed at a position overlapping with the innermost periphery of the spiral portion in the plate thickness direction. According to the present invention, when the area of the power transmission / reception antenna is constant, both the area of the region surrounded by the annular portion and the radial spacing of the spiral portion of the resonance antenna portion can be ensured to the maximum. . Therefore, the arrangement according to claim 9 is suitable as a power transmission / reception antenna that achieves high transmission efficiency within a limited area.

  The invention according to claim 10 is characterized in that the annular portion and the spiral portion are formed on different surfaces of the substrate. According to the present invention, even in the power transmission / reception antenna including both the resonant antenna unit and the loop antenna unit on the same base material, the annular part and the spiral part of each antenna part are formed on different surfaces of the base material. Thus, it is possible to prevent interference on the arrangement of the antenna units and to simplify the configuration. Therefore, it is possible to easily provide a power transmission / reception antenna that achieves high power transmission efficiency and thinning.

  In the invention described in claim 11, alternating currents having different phases are applied to each of the plurality of annular portions arranged along the surface direction of the substrate. The magnetic field lines of the magnetic field generated by this alternating current may be radiated from a region surrounded by one of the plurality of annular portions and may be in a loop shape incident on the region surrounded by the other annular portions. Therefore, even if the axial direction of the spiral portion of the resonant antenna portion of the power receiving side antenna is along the surface direction of the base material of the power transmitting side antenna, the looped magnetic field lines radiated from the power transmitting side antenna are It can penetrate the area surrounded by the spiral. Therefore, the resonance antenna unit on the power receiving side and the resonance antenna unit on the power transmission side can resonate by vibration propagating through the magnetic field. As described above, power can be transmitted from the power transmitting antenna to the power receiving antenna.

  Therefore, by providing a power source that applies an alternating current of a different phase to each of the plurality of annular portions connected to the power source, the power transmitter can be contactless regardless of the orientation of the power receiving side antenna with respect to the power transmitting side antenna. Electric power can be transmitted.

  In the invention according to claim 12, in the case where the power source applies an alternating current having the same phase to each of the plurality of annular portions, the magnetic field lines of the magnetic field generated by the alternating current are regions surrounded by the plurality of annular portions. What radiates from infinity toward the infinity along the thickness direction of the base material becomes dominant. Therefore, when the power-receiving-side antenna faces the power-transmitting-side antenna included in the power transmitter, high-density magnetic lines penetrate the region surrounded by the power-receiving-side spiral portion. Therefore, the resonance antenna unit on the power receiving side and the resonance antenna unit on the power transmission side can resonate strongly by vibration propagating through the magnetic field. This enables highly efficient power transmission from the power transmission side antenna to the power reception side antenna.

  On the other hand, when the power source applies alternating currents having different phases to each of the plurality of annular portions, the above-described loop-shaped magnetic field lines are formed. According to such a loop-shaped magnetic field line, even if the axial direction of the spiral portion on the power receiving side is along the surface direction of the base material of the power transmitting side antenna, the antenna on the power transmitting side to the antenna on the power receiving side Power transmission becomes possible.

  As described above, by providing each of the plurality of annular portions with a power supply that alternately applies an alternating current having a different phase and an alternating current having the same phase, the power transmitter is a power receiving side antenna with respect to the power transmitting side antenna. Regardless of the direction, it is possible to perform highly efficient and reliable power transmission.

  The case where the phases of the alternating current applied to each of at least one set of the annular portions among the plurality of annular portions are different from each other by a half cycle as in the invention described in claim 13 will be described. The direction of the magnetic field lines generated in the region surrounded by the annular portion by the alternating current applied to one of the set of annular portions is determined by the alternating current applied to the other of the set of annular portions. The direction of the magnetic field lines of the magnetic field generated in the region surrounded by the annular portion is opposite. Therefore, a loop-shaped magnetic field line radiated from a region surrounded by one annular portion of the set of annular portions and incident on the region surrounded by the other annular portion is reliably formed. As a result, even if the axial direction of the spiral portion on the power receiving side is along the surface direction of the base material of the power transmitting antenna, the magnetic field lines reliably ensure the region surrounded by the spiral portion on the power receiving side. Can penetrate. Therefore, the resonance antenna unit on the power receiving side and the resonance antenna unit on the power transmission side can reliably resonate due to vibration propagating through the magnetic field. Therefore, regardless of the orientation of the power receiving side antenna with respect to the power transmitting side antenna, the power transmitter can reliably transmit power from the power transmitting side antenna to the power receiving side antenna.

It is a schematic diagram for demonstrating non-contact electric power transmission using the antenna by this invention. It is a figure explaining the mechanical structure of the antenna by 1st embodiment of this invention, Comprising: (a) The front surface side of an antenna, (b) The figure which shows the back surface side of an antenna. It is a figure for demonstrating the mode of the magnetic field formed around the antenna by this invention, Comprising: About the antenna by (a)-(c) 1st embodiment, (d)-(f) By 2nd embodiment. It is a figure explaining an antenna. In the antenna by 1st embodiment of this invention, it is a figure which shows the relationship between the frequency of the alternating current input into a loop antenna part, and the energy transmitted to the resonance antenna part from the said loop antenna part. It is a figure explaining the mechanical structure of the antenna by 2nd embodiment by this invention, Comprising: (a) The front surface side of an antenna, (b) The figure which shows the back surface side of an antenna. It is a figure explaining the mechanical structure of the antenna by 3rd embodiment by this invention, Comprising: (a) The front surface side of an antenna, (b) The figure which shows the back surface side of an antenna. It is a figure explaining the antenna of the state which peeled a part of electrode pattern which an electrostatic capacitance part comprises, Comprising: (a) The front surface side of an antenna, (b) The figure which shows the back surface side of an antenna is there. It is a figure explaining the antenna of the state which peeled all the electrode patterns which an electrostatic capacitance part comprises, Comprising: (a) The front surface side of an antenna, (b) The figure which shows the back surface side of an antenna. It is a figure for demonstrating the relationship between the area of an electrode pattern, and the resonant frequency of a resonant antenna part. It is a figure for demonstrating the mechanical structure of the antenna by 4th embodiment of this invention. It is a figure for demonstrating the structure of the antenna which expanded the space | interval of a loop pattern and a spiral pattern by reducing the winding number of a spiral pattern. It is a figure which shows the change of the resonance characteristic of the antenna which arises by changing the space | interval of a loop pattern and a spiral pattern. It is a figure for demonstrating the correlation with the space | interval between a loop pattern and a spiral pattern, and a resonance characteristic. It is a figure for demonstrating the structure of the antenna which expanded the space | interval of a loop pattern and a spiral pattern by narrowing the space | interval of a spiral pattern. It is a figure for demonstrating that the energy transmitted to the resonant antenna part from the said loop antenna part changes by narrowing a line interval. It is a figure for demonstrating the mechanical structure of the antenna by 5th embodiment of this invention. It is a figure for demonstrating the mode of the magnetic field formed in the vicinity of the antenna by 5th embodiment of this invention, Comprising: (a) About the case where the alternating current of the same phase is applied to a set of loop patterns ( b) It is a figure for demonstrating each about the case where the alternating current given the phase difference for a half cycle is applied to a set of loop patterns. It is a figure for demonstrating the mechanical structure of the antenna by 6th embodiment of this invention.

  Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. In addition, the overlapping description may be abbreviate | omitted by attaching | subjecting the same code | symbol to the corresponding component in each embodiment. When only a part of the configuration is described in each embodiment, the configuration of the other embodiment described above can be applied to the other part of the configuration. In addition, not only combinations of configurations explicitly described in the description of each embodiment, but also the configurations of a plurality of embodiments can be partially combined even if they are not explicitly specified unless there is a problem with the combination. .

(First embodiment)
FIG. 1 shows a configuration example of a power transmitter 10 and a power receiver 20 including an antenna 100 according to the first embodiment of the present invention. The power transmitter 10 includes a drive circuit 15 in addition to the antenna 100. The drive circuit 15 is electrically connected to the power supply 13 and the antenna 100, generates a sine wave alternating current based on the power supplied from the power supply 13, and applies it to the antenna 100. The power receiver 20 includes a rectifier circuit 23 in addition to the antenna 100. The rectifier circuit 23 is electrically connected to the antenna 100 and a load such as a processor that consumes electric power or a battery 25 that accumulates electric power, and converts the alternating current transmitted from the antenna 100 side into direct current. Apply to the load or battery 25. Specifically, the rectifier circuit 23 mainly includes a rectifier element such as a diode, and applies the rectified direct current to the load or the battery 25 to drive the load or charge the battery. . In the first embodiment, the frequency of the sine wave generated by the drive circuit 15 is 10 megahertz (MHz). Further, the load or the battery 25 to which the current is applied by the rectifier circuit 23 is not limited in any way as long as it uses electric power, such as a DC motor or a lighting element.

  In the overall configuration described above, the non-contact power between the power source 13 and the load or battery 25 supplied with power from the power source 13 is measured by the antenna 100 provided in each of the power transmitter 10 and the power receiver 20. Transmission is realized. First, the configuration of the antenna 100 will be described in detail.

  As shown in FIGS. 2A and 2B, the antenna 100 includes a substrate 30, a resonant antenna unit 40, a loop antenna unit 60, and the like. The substrate 30 is made of, for example, an epoxy resin containing glass fiber and is formed in a rectangular plate shape. The substrate 30 is a single-layer substrate, and a wiring pattern made of a copper foil or the like that is a conductive material is formed on both surfaces thereof. In addition, the board | substrate 30 in 1st embodiment is a square whose length of one side is 270 millimeters (mm), The plate | board thickness is about 1.6 mm.

  The resonant antenna unit 40 is a parasitic antenna, and includes a spiral pattern 43, a connection unit 45, and a chip capacitor 50. The spiral pattern 43 and the connection part 45 are wiring patterns formed on the substrate 30. The spiral pattern 43 is spirally formed on the substrate 30 along the surface direction intersecting the plate thickness direction at regular intervals in the radial direction. The spiral pattern 43 of the first embodiment is spirally wound in a rectangular shape following the outer shape of the substrate 30. The surface (FIG. 2B) of the substrate 30 on which the spiral pattern 43 is formed is referred to as the back side for convenience.

  The chip capacitor 50 is an element having a predetermined capacitance, and is mounted on the outer peripheral side of the spiral pattern 43 on the back surface of the substrate 30 (FIG. 2B). The chip capacitor 50 is connected at one end to the outer peripheral end 43 b of the spiral pattern 43 and at the other end is connected to the inner peripheral end 43 c of the spiral pattern 43 via the connecting portion 45. The connection portion 45 for connecting the chip capacitor 50 and the spiral pattern 43 is once extended from the end portion 43c to the front surface of the substrate 30 by a configuration such as a through hole (FIG. 2A). The connection portion 45 is formed so as to face the outer edge side of the substrate 30 on the front surface of the substrate 30 so as to straddle the pattern 43 without interfering with the spiral pattern 43, and to the back surface again by the configuration of a through hole or the like. It has been returned. The connecting portion 45 is connected to the capacitor 50 toward the chip capacitor 50 along the outermost periphery of the spiral pattern 43 on the back surface of the substrate 30.

  The resonance antenna unit 40 is set with a predetermined resonance frequency. This resonance frequency corresponds to the frequency of the alternating current applied to the antenna 100 by the drive circuit 15. Specifically, when the frequency of the alternating current applied by the drive circuit 15 is 10 MHz, the electromagnetic wave generated around the loop antenna unit 60 by the alternating current is a sine wave having a wavelength of about 30 meters (m). Become. By setting the total length of the spiral pattern 43 and the connection portion 45 of the resonance antenna unit 40 to a length of about 15 m, which is a half wavelength of the sine wave, it becomes a configuration in which resonance easily occurs due to the above-described electromagnetic waves.

  Furthermore, the resonance frequency of the resonance antenna unit 40 is a value given by 1 / (2π√ (LC)), where L is the induction coefficient of the resonance antenna unit 40 and C is the capacitance. This electrostatic coefficient L is related to the length of the spiral pattern 43 set as described above. On the other hand, the capacitance C is mainly related to the stray capacitance resulting from the form of the spiral pattern 43. The stray capacitance is a capacitance generated between patterns adjacent in the radial direction of the spiral pattern 43 and a capacitance generated between both ends of the pattern 43. In the first embodiment, the spiral pattern 43 is formed as the wiring pattern on the substrate 30 to keep the interval between adjacent patterns constant and suppress the variation in capacitance. Further, by connecting both ends of the spiral pattern 43 with the chip capacitor 50 and the connection portion 45, variation in electrostatic capacitance generated between both ends of the pattern 43 is suppressed. Accordingly, the resonance antenna unit 40 can stably acquire a predetermined resonance frequency while maintaining a simple configuration.

  The loop antenna unit 60 is a power feeding antenna and is magnetically connected to the resonance antenna unit 40, and is connected to the drive circuit 15 on the power source 13 side or the rectifier circuit 23 on the 25 side such as a load or a battery (see FIG. 1). Electrically connected. The loop antenna unit 60 has a loop pattern 63 and a feeding point 65. The loop pattern 63 is a wiring pattern formed on the front surface of the substrate 30 which is a surface different from the spiral pattern 43 (FIG. 2A). The loop pattern 63 is formed in a rectangular ring shape on the substrate 30 along the surface direction of the substrate 30. In addition, the loop pattern 63 is arranged so that the center position in the plane direction is substantially the same as the center position in the plane direction of the spiral pattern 43, and overlaps with the innermost circumference 43a of the spiral pattern 43 in the plate thickness direction. . According to the arrangement of the loop pattern 63, the spiral pattern 43 is formed on the outer peripheral side of the region 67 surrounded by the loop pattern 63. The feeding point 65 is a pair of end portions of the loop pattern 63 formed in this way. The feed point 65 is electrically connected to the drive circuit 15 or the rectifier circuit 23 by wiring or the like, and is a place where power is input or output.

  Next, the principle of non-contact power transmission by the so-called resonance method realized by the power transmitter 10 and the power receiver 20 including the antenna 100 described so far will be described below.

  According to this power transmission by the resonance method, even when the antennas of the power transmitter 10 and the power receiver 20 are separated from each other, power can be transmitted more efficiently than, for example, the conventional electromagnetic induction method. Specifically, in the antenna 100 on the power transmitter 10 side, the application of the alternating current from the drive circuit 15 causes the loop antenna unit 60 to change the magnetic field around the antenna 100 at the same frequency as the frequency of the alternating current. This fluctuation of the magnetic field causes an induced current mainly in the spiral pattern 43 of the resonant antenna unit 40. The induced current causes the magnetic field and electric field around the resonant antenna unit 40 on the power transmitter 10 side to vibrate at the resonance frequency. Here, since the resonant frequencies of the resonant antenna units 40 on the power transmitter 10 side and the power receiver 20 side are the same, these resonant antenna units 40 resonate due to vibration propagating through an electric field or a magnetic field. Therefore, the transmission of electric power from the resonance antenna unit 40 on the power transmitter 10 side that is installed apart from each other to the resonance antenna unit 40 on the power receiver 20 side is realized. An induced current is induced in the loop antenna unit 60 on the power receiving side due to a change in magnetic field due to a current generated in the coil on the power receiving device 20 side. Therefore, power supply to the load or the battery 25 connected to the loop antenna unit 60 via the rectifier circuit 23 is realized.

  Next, the state of the magnetic field around the antenna 100 generated by the application of the alternating current to the loop antenna unit 60 described above will be described below with reference to FIGS.

  In the antenna 100 in which the loop pattern 63 is arranged on the inner peripheral side of the spiral pattern 43 (FIG. 3A), when a current is applied to the loop pattern 63, the region 67 is formed in the thickness direction of the substrate 30 (FIG. 3B). ) In the Z direction) is formed (within the two-dot chain line in FIG. 3B). On the other hand, on the outer peripheral side of the loop pattern 63, penetration of the magnetic flux in the plate thickness direction is prevented by the spiral pattern 43. This is because the radial interval of the spiral pattern 43 is shorter than the wavelength of the applied alternating current. And what connected the area | region where the strength of a magnetic field is the same in the circumference | surroundings of the antenna 100 is shown as a continuous line in FIG.3 (c). According to the application of current to the loop antenna unit 60, a magnetic field having the form shown in FIG. 3C is formed around the antenna 100.

  Here, as in the first embodiment, the strength of the magnetic field formed around the antenna 100 in which the spiral pattern 43 is arranged on the outer periphery side of the loop pattern 63 and the periphery of the antenna 200 according to the second embodiment to be described later. The strength of the applied magnetic field (see FIG. 3F) is compared. Here, in the antenna 200 according to the second embodiment, the loop pattern 263 is disposed on the outer peripheral side of the spiral pattern 43 (see FIG. 3D). When the same alternating current is applied to the antenna 100 according to the first embodiment and the antenna 200 according to the second embodiment, the distance D1 from the substrate 30 to the position indicating a specific magnetic field strength in the antenna 100 is equal to the antenna 200. It was found that the distance D2 is about 1.5 times the distance D2 from the substrate 30 to the position indicating the strength of the specific magnetic field. This is because the magnetic flux generated in the region 67 surrounded by the loop pattern 63 is hardly disturbed by the spiral pattern 43 due to the form in which the spiral pattern 43 is arranged on the outer peripheral side of the loop pattern 63. Thereby, the loop antenna part 60 can form a strong magnetic field.

  Next, the relationship between the frequency of the alternating current applied to the loop antenna unit 60 and the power transmitted from the loop antenna unit 60 to the resonant antenna unit 40 will be described with reference to FIG. The vertical axis (Return Loss) in FIG. 4 is a value based on the S parameter indicating the reflected power characteristic at the antenna 100 and indicates how much power input to the loop antenna unit 60 has returned. When power is transmitted from the loop antenna unit 60 to the resonant antenna unit 40, the power for the return is reduced, so the S parameter takes a negative value. Specifically, in the antenna 100 according to the first embodiment, when an alternating current of 10 MHz that is a resonance frequency set in the resonance antenna unit 40 is applied, power is transmitted from the loop antenna unit 60 to the resonance antenna unit 40. It will occur at maximum.

  In the first embodiment described so far, the entire length of the spiral pattern 43 required to obtain a predetermined resonance frequency is maintained by forming the spiral pattern 43 along the surface direction of the substrate 30 as shown in FIG. However, the thickness of the resonant antenna unit 40 along the plate thickness direction can be reduced. In addition, when the loop pattern 63 is formed along the surface direction of the substrate 30 similarly to the spiral pattern 43, the resonance antenna unit 40 and the loop antenna unit 60 required for power transmission by the resonance method are formed in a rectangular plate shape. It can be formed together on the substrate 30.

  In addition, in the first embodiment, the strength of the magnetic field formed by the loop antenna unit 60 can be increased by arranging the spiral pattern 43 on the outer peripheral side of the loop pattern 63. (See FIG. 3C). Therefore, even when the loop antenna unit 60 and the resonant antenna unit 40 are formed on the same substrate 30 for thinning, power is transferred between the loop antenna unit 60 and the resonant antenna unit 40. It is possible to improve the efficiency.

  In addition, the loop antenna unit 60 can improve sensitivity as the area of the region 67 formed by the loop pattern 63 is increased. On the other hand, in the resonant antenna unit 40, the current passing through the spiral pattern 43 generates a magnetic field around the pattern 43. In the spiral pattern 43 having a spiral shape, a magnetic field that hinders the flow of current between the adjacent patterns in the radial direction is formed. Therefore, it is desirable to widen the radial interval of the spiral pattern 43. Therefore, according to the arrangement in which the loop pattern 63 overlaps the innermost circumference 43a of the spiral pattern 43 in the plate thickness direction, the area of the region 67 of the loop pattern 63 and the diameter of the spiral pattern 43 are within a certain limited area. Both the distances in the direction can be secured to the maximum. Therefore, the present invention is particularly suitable as a mode for realizing high transmission efficiency in the antenna 100 in which the installation area is likely to be limited. In addition, according to this arrangement, since the loop pattern 63 straddles the spiral pattern 43, the loop pattern 63 does not interfere with the connection portion 45 that needs to be formed on the front surface on the substrate 30.

  Furthermore, in the first embodiment, the resonance antenna unit 40 is defined by the induction coefficient L and the capacitance C by connecting both end portions 43b and 43c of the spiral pattern 43 via the chip capacitor 50 and the connection unit 45. The resonance frequency variation of the resonance antenna unit 40 is suppressed with a simple configuration. As described above, the resonance antenna unit 40 configured to surely show a predetermined resonance frequency can exchange the maximum amount of power with the loop antenna unit 60, and can be separated from the power transmission side. Alternatively, high power transmission efficiency can be exhibited even between the antennas 100 on the power receiving side. According to the above, by providing the chip capacitor 50 in the resonance antenna unit 40, the antenna 100 that effectively exhibits the advantages of power transmission by the resonance method can be obtained.

  Therefore, it is possible to provide the antenna 100 that achieves high power transmission efficiency while realizing a reduction in thickness by consolidating the configuration required for the resonance-type power transmission on the plate-like substrate 30. In addition, according to the arrangement in which the loop pattern 63 and the spiral pattern 43 are formed on different surfaces of the substrate, the configuration can be simplified while preventing interference on the arrangement. Therefore, it is possible to easily provide an antenna that realizes both high power transmission efficiency and thinning.

  In the first embodiment, the load or the battery 25 is the “device” according to the claims, the substrate 30 is the “base material” according to the claims, and the spiral pattern 43 is the “spiral shape” according to the claims. In the section, the chip capacitor 50 is in the “capacitance section” and “capacitor element” described in the claims, the loop pattern 63 is in the “annular section” in the claims, and the antenna 100 is in the claims. It corresponds to the “transmission / reception antenna”.

(Second embodiment)
An antenna 200 according to the second embodiment of the present invention shown in FIGS. 5A and 5B is a modification of the antenna 100 according to the first embodiment. In this antenna 200, the spiral pattern 43 included in the resonance antenna unit 240 is disposed in a region 267 surrounded by the loop pattern 263 included in the loop antenna unit 260. In addition, the loop pattern 263 overlaps the outermost periphery 43d of the spiral pattern 43 in the plate thickness direction. Further, the connecting portion 245 of the resonant antenna portion 240 is substantially the same as the connecting portion 45 in the first embodiment, and the width direction of the substrate 30 (see FIG. 5A) on the surface on which the loop antenna portion 260 is formed. It is formed near the center). In the above configuration, the loop pattern 263 that overlaps the outermost periphery 43d of the spiral pattern 43 in the thickness direction is similar to the loop pattern 63 that overlaps the innermost periphery 43a of the first embodiment on the connection portion 245 and the substrate 30. Does not interfere.

  Hereinafter, the influence of the difference in the arrangement of the loop pattern 263 with respect to the spiral pattern 43 on the distribution of the magnetic field generated by the loop antenna unit 260 when an alternating current is applied to the loop antenna unit 260 will be described with reference to FIGS. This will be described with reference to (d) to (f) in FIG.

  When the spiral pattern 43 is arranged so as to overlap with the region 267 surrounded by the loop pattern 263 in the plate thickness direction (FIG. 3D), the magnetic flux cannot penetrate the spiral pattern 43 in the plate thickness direction (FIG. 3). (E)). These magnetic fluxes are the region 247 inside the innermost circumference 43a of the spiral pattern 43, and the region 247 having the same area as the region 67 (FIG. 3B) of the first embodiment is arranged in the plate thickness direction. It only penetrates (within the two-dot chain line in FIG. 3 (e)). In addition, the induced current induced in the spiral pattern 43 by the magnetic field generated by the loop pattern 263 generates a magnetic field that cancels the magnetic field. Therefore, the magnetic field generated around the antenna 200 by the loop pattern 263 (FIG. 3F) is weaker than the magnetic field formed around the antenna 100 (see FIG. 3C).

  In the antenna 200 according to the second embodiment shown in FIG. 5 described so far, the efficiency of power transfer between the loop antenna unit 260 and the resonance antenna unit 240 is lower than the efficiency in the first embodiment. Become. However, power transfer between the loop antenna unit 260 and the resonant antenna unit 240 is sufficiently possible. In addition, the resonance antenna unit 240 and the loop antenna unit 260 required for power transmission by the resonance method can be formed on the substrate 30 having a rectangular plate shape.

  Therefore, as in the first embodiment, it is possible to realize an antenna 200 that achieves high power transmission efficiency while realizing a reduction in thickness by consolidating the configuration required for resonant power transmission.

  In the first embodiment, the loop pattern 263 corresponds to the “annular portion” recited in the claims, and the antenna 200 corresponds to the “power transmitting / receiving antenna” recited in the claims.

(Third embodiment)
An antenna 300 according to the third embodiment of the present invention shown in FIGS. 6A and 6B is a modification of the antenna 200 according to the second embodiment. The antenna 300 according to the third embodiment has a capacitance portion 350 instead of the chip capacitor 50 (see FIG. 5B) of the antenna 200 of the second embodiment. Hereinafter, the configuration of the antenna 300 according to the third embodiment will be described in detail with reference to FIG.

  The antenna 300 includes a substrate 330, a loop antenna unit 260, a resonance antenna unit 340, and the like. Both the spiral pattern 43 and the loop pattern 263 are formed on the substrate 330 by extending the length in a specific direction (the vertical direction in FIG. 6, hereinafter referred to as the longitudinal direction) of the substrate 30 of the second embodiment. A non-arranged region 333 is formed. The side on which the loop antenna 260 having the same configuration as that of the second embodiment is disposed is defined as the front surface side of the substrate 330 (FIG. 6A).

  The resonant antenna unit 340 includes a spiral pattern 43, a capacitance unit 350 in which a predetermined capacitance is set, and a connection unit 345. The electrostatic capacitance part 350 has a pair of electrode patterns 353a and 353b which are arranged on both surfaces of the substrate 330 so as to face each other in the thickness direction and are formed by forming a conductive material into a film shape. The electrode patterns 353 a and 353 b have the same shape as each other, and are formed in a rectangular shape having a longitudinal direction in the width direction orthogonal to the longitudinal direction of the substrate 330. The electrode pattern 353 a formed on the front surface is connected to the inner peripheral end 43 c of the spiral pattern 43 via the connection portion 345. The connection part 345 is a wiring pattern formed over both surfaces of the substrate 330. The connecting portion 345 extends from the end portion 43c to the front surface by a configuration such as a through hole. The connection portion 345 formed from this position toward the outer peripheral side along the longitudinal direction of the substrate 330 bypasses the back surface by a through hole or the like in order to avoid the loop pattern 263 disposed on the front surface. It has been returned to. The connecting portion 345 is connected to the electrode pattern 353a near the center in the longitudinal direction of the electrode pattern 353a. The electrode pattern 353 b is connected to the end 43 b of the spiral pattern 43 that extends along the outer edge shape of the adjacent substrate 330 on the back surface of the substrate 330. Furthermore, these electrode patterns 353a and 353b are easily formed from the surface of the substrate 330.

  Since the region sandwiched between the pair of electrode patterns 353a and 353b can store electric charge, the electrostatic capacitance unit 350 including the electrostatic capacitance is configured. The electrostatic capacity of the electrostatic capacity portion 350 changes according to the area where the electrode patterns 353a and 353b are opposed in the plate thickness direction. Therefore, compared with a capacitor element that has only to select a value having a value close to a desired capacitance from those having a predetermined capacitance value set in advance at a constant interval, the capacitance portion 350 Can be set to a value closely close to the desired capacitance. Based on the above, the resonant frequency of the resonant antenna unit 340 can be set accurately.

  Further, by peeling a part of the electrode patterns 353a and 353b having an easily peelable configuration, it is possible to adjust to reduce the amount of charge that can be accumulated between the electrode patterns 353a and 353b. According to this configuration, it is easy to adjust the capacitance of the capacitance unit 350 even after the antenna 300 is manufactured. Hereinafter, based on FIGS. 6-9, the change of the resonant frequency of the resonant antenna part 340 which arises by peeling of a part of electrode pattern 353a, 353b is demonstrated in detail. Note that the resonance frequency in the state where all of the electrode patterns 353a and 353b remain without being peeled (FIG. 6) is approximately 10 MHz.

  Specifically, when about half of the electrode pattern 353a formed on the front surface of the substrate 330 is peeled off (FIG. 7A), the capacitance value of the capacitance unit 350 decreases. . As a result, the resonance frequency of the resonance antenna unit 340 given by the above-described equation is slightly increased. This increase in resonance frequency can also be read from the correlation indicated by the one-dot chain line in FIG. According to the antenna 300 having such an adjustment structure, it is possible to easily correct the deviation from the predetermined frequency of the resonance frequency of the resonance antenna unit 340 due to, for example, variations in manufacturing or aging. .

  When all of the electrode patterns 353a and 353b are peeled off (FIGS. 8A and 8B), the resonance frequency of the resonance antenna unit 340 is remarkably increased due to a significant decrease in the capacitance value of the capacitance unit 350. The value becomes high (broken line in FIG. 9).

  According to the third embodiment described above, the resonance frequency of the antenna 300 can be easily set and corrected to a predetermined frequency while suppressing the thickness of the antenna 300 by forming the film-like electrode patterns 353a and 353b. Can do. Accordingly, it is possible to provide the antenna 300 that can achieve a reduction in thickness as in the first and second embodiments and can efficiently and reliably transmit power by resonance.

  In the third embodiment, the substrate 330 is the “base” described in the claims, the electrode patterns 353a and 353b are the “electrode portions” described in the claims, and the antenna 300 is the “power transmission / reception” described in the claims. Corresponding to “antenna”.

(Fourth embodiment)
An antenna 400 according to the fourth embodiment of the present invention shown in FIG. 10 is another modification of the antenna 100 according to the first embodiment. In this antenna 400, a space is secured between the spiral pattern 443 included in the resonance antenna unit 440 and the loop pattern 463 included in the loop antenna unit 460. Similar to the resonant antenna unit 40 of the first embodiment, the resonant antenna unit 440 has a characteristic of resonating at the frequency of the alternating current applied to the loop antenna unit 460.

  In the fourth embodiment, the spiral pattern 443 is formed so that the efficiency of power transfer with the loop pattern 463 is maximized. Specifically, in the antenna 400, the number of turns N of the spiral wiring pattern of the spiral pattern 443, the line interval S between adjacent portions in the radial direction of the wiring pattern, and the spiral pattern 443 and the loop pattern 463 are arranged. The interval X is optimized. By optimizing the number of turns N, the line interval S, and the interval X, the resonance characteristics between the resonance antenna unit 440 and the loop antenna unit 460 are improved. Therefore, power can be exchanged efficiently between the spiral pattern 443 and the loop pattern 463.

  The resonance characteristic of the resonance antenna unit 440 and the loop antenna unit 460 related to the efficiency of power transfer between the loop pattern 463 and the spiral pattern 443 is indicated by a Q value. This Q value is given by Equation 1 below.

  In Equation 1 above, ω is the angular velocity of the alternating current, L is the inductance of the resonant antenna unit 440, and R is the electrical resistance associated with the loop antenna unit 460 and the resonant antenna unit 440. As is clear from Equation 1, the resonance characteristics improve as the inductance L of the resonant antenna unit 440 increases and as the electrical resistance R decreases.

  Among these, the inductance L of the resonant antenna unit 440 is given by the following Equation 2.

In the above formula, A is represented by the following formula 3.

Here, in Equations 2 and 3, D ₀ is the length of one side at the outer edge of the spiral pattern 443, D ₁ is the length of one side at the inner edge of the spiral pattern 443, and W is the line of the wiring pattern forming the spiral pattern 443. In the spiral pattern 443, the width and S are line intervals between the wiring patterns adjacent in the radial direction, and N represents the number of turns of the spiral pattern 443. According to Formula 2 above, the inductance L of the resonant antenna unit 440 increases as the number N of turns of the spiral wiring pattern in the spiral pattern 443 increases.

  On the other hand, the electrical resistance R related to the loop antenna unit 460 and the resonance antenna unit 440 decreases as the distance X between the spiral pattern 443 and the loop pattern 463 and the line interval S of the spiral pattern 443 are increased. The details of the correlation between the spacing X and the line spacing S and the electrical resistance R will be described later.

  When the size of the substrate 30 is predetermined, in order to increase the number N of turns of the spiral pattern 443, it is necessary to narrow at least one of the interval X and the line interval S. On the other hand, if the interval X and the line interval S are to be increased, the number of turns N must be reduced. Thus, an increase in inductance L and a decrease in electrical resistance R are contradictory.

  Based on the above correlation, changes in resonance characteristics when the number of turns N and the interval X are changed in the antenna 400 in which the size of the substrate 30 is determined in advance will be described with reference to FIGS.

  11 (a) to 11 (f) show an antenna in which the interval X is enlarged by making the line interval S between adjacent portions in the spiral pattern 443 constant and reducing the number N of turns. Specifically, in the antenna shown in FIG. 11A, the spiral pattern 443 and the loop pattern 463 are closest to each other among the antennas shown in FIGS. Then, the antenna shown in FIG. 11 (a), in which the number of turns N is reduced by one turn, is shown in order in FIGS. 11 (b) to 11 (f). In the antenna shown in FIG. 11, the interval X is increased by DL / 8 (DL is the length of one side of the loop pattern 463) by deleting one round of the spiral pattern 443.

  As shown in FIG. 12, the Q value indicating the resonance characteristics is improved by reducing the number of turns N, and the antenna shown in FIG. 11 (e) in which the wiring pattern for four turns is deleted from the antenna shown in FIG. 11 (a). 400 is the maximum. And if a wiring pattern is further deleted from the antenna 400 shown in FIG.11 (e), the resonance characteristic of an antenna will deteriorate. FIG. 12 shows values obtained by simulation and measured values. According to these simulation values and actual measurement values, the antenna 400 shown in FIG. 11E shows a Q value about twice that of the antenna shown in FIG.

  The change in the resonance characteristics resulting from the change in the number of turns N and the interval X will be described in more detail with reference to FIG. FIG. 13 shows the Q value, the inductance L, and the current amount I flowing through the loop pattern 463. In FIG. 13, the Q value, the inductance L, and the current amount I are normalized by their maximum values.

  In FIG. 13, the inductance L in the antenna shown in FIGS. 11A to 11F is indicated by a broken line. In the resonant antenna unit 440, the inductance L due to the spiral pattern 443 decreases as the number of turns N decreases, as is apparent from Equation 2 described above.

  On the other hand, in FIG. 13, the current amount I in the antenna shown in FIGS. 11A to 11F is indicated by a one-dot chain line. In the loop antenna unit 460, the current amount I flowing through the loop pattern 463 increases as the interval X increases. The reason why the amount of current I increases as the interval X is increased will be described.

  When a current flows through the loop pattern 463, a magnetic field is generated in the vicinity of the loop pattern 463. By this magnetic field, a reverse current that flows in a direction opposite to the current flowing through the loop pattern 463 is induced in the spiral pattern 443 adjacent to the loop pattern 463. By reducing the interval X between the spiral pattern 443 and the loop pattern 463, the strength of the magnetic field acting on the spiral pattern 443 increases. Therefore, a strong reverse current is induced in the spiral pattern 443.

  As described above, when the energy of the current flowing through the loop pattern 463 is transmitted to the spiral pattern 443 via the magnetic field, the amount of current I flowing through the loop pattern 463 decreases. As the reverse current induced in the spiral pattern 443 increases, the decrease in the current amount I increases. Therefore, the current amount I decreases as the distance X decreases.

  As shown in Equation 1, the Q value of the antenna corresponds to the product of the reciprocal of the inductance L and the electrical resistance R. As described above, the inductance L decreases as the interval X increases. On the other hand, since the current easily flows through the loop pattern 463 as the interval X is increased, the reciprocal of the electric resistance R increases. Therefore, by determining the interval X so that these products are maximized, it is possible to obtain an antenna 400 having excellent resonance characteristics, for example, shown in FIG.

  Next, in the antenna 400 in which the size of the substrate 30 is determined in advance, the change in the resonance characteristics when the interval X is expanded by narrowing the line interval S by keeping the number of turns N of the spiral pattern 443 constant is shown in FIG. 14 and FIG.

  14A to 14D show an antenna in which the interval X is enlarged by making the number N of turns of the spiral pattern 443 constant and reducing the line interval S of the spiral pattern 443. FIG. Specifically, the antenna 400 illustrated in FIG. 14A has a configuration in which the line spacing of the spiral pattern 443 is the widest (for example, S = 6 millimeters). The antenna shown in FIGS. 14B to 14D is obtained by reducing the line spacing S by a predetermined value (for example, 1 millimeter) with respect to the antenna 400 shown in FIG.

  As shown in FIG. 15, when the line spacing S is narrowed, the Q value indicating the resonance characteristics deteriorates. The change in resonance characteristics caused by such changes in the line spacing S and the spacing X will be described in more detail. Note that the vertical axis (Return Loss) in FIG. 15 is a value based on the S parameter indicating the reflected power characteristics at the antenna 400, as in FIG. The resonance characteristics of the resonant antenna unit 440 and the loop antenna unit 460 are good, and in the antenna having a high Q value, power is efficiently transmitted from the loop antenna unit 460 to the resonant antenna unit 440. Electric power is reduced. That is, the value of the S parameter becomes small.

  In the resonant antenna unit 440, the inductance L due to the spiral pattern 443 has only a slight change even if the line spacing S is changed because the number of turns N is constant.

  On the other hand, the electrical resistance R of the resonant antenna unit 440 increases as the line spacing S decreases. More specifically, in the wiring pattern forming the spiral pattern 443, the current flowing in one of the portions adjacent in the radial direction induces a current in the opposite direction to the current. Then, the reverse current flowing in the reverse direction interferes with the regular current flowing through the spiral pattern 443 and acts as an electric resistance in the spiral pattern 443. Then, by narrowing the line spacing S between the wiring patterns adjacent in the radial direction, a high-intensity magnetic field interacts between the adjacent wiring patterns, which causes an increase in reverse current. Therefore, the electrical resistance R of the resonant antenna unit 440 increases. Therefore, by determining the interval X so that the line interval S of the spiral pattern 443 is ensured, for example, the antenna 400 shown in FIG. 14A having excellent resonance characteristics can be obtained.

  In addition, the frequency which resonates changes to a low frequency periphery area | region, so that the line | wire space | interval S is narrowed. This is because the entire length of the spiral pattern 443 extends as the spiral pattern 443 approaches the outer peripheral side of the substrate 30.

  As described above, by adjusting the winding number N, the line interval S, and the interval X, the efficiency of power transfer between the loop pattern 463 and the spiral pattern 443 is maximized in the substrate 30 having a limited area. obtain. As described above, the number of turns N, the interval X, and the line interval S are determined so that the efficiency of power transfer is maximized, that is, the resonance characteristics are improved, thereby reducing the thickness and improving the power transmission efficiency. A resonant antenna 400 that can be achieved together is realized.

  In the fourth embodiment, the spiral pattern 443 is in the “spiral portion” described in the claims, the loop pattern 463 is in the “annular portion” in the claims, and the antenna 400 is in “transmission / reception” in the claims. Corresponding to “antenna”.

(Fifth embodiment)
An antenna 500 according to the fifth embodiment of the present invention shown in FIG. 16 is a modification of the antenna 400 according to the fourth embodiment. When the number of loop patterns is one as in the above embodiment, the magnetic field lines of the magnetic field generated by applying a current to the loop pattern are changed from the region surrounded by the loop pattern in the substrate 30 to the plate thickness of the substrate 30. The one that radiates along the direction and goes to infinity becomes dominant. Therefore, when the axial direction of the spiral pattern of the resonant antenna portion of the power receiving side antenna is along the surface direction of the substrate 30 of the power transmitting side antenna, the lines of magnetic force radiated from the power transmitting side antenna are spirals of the power receiving side antenna. It becomes impossible to penetrate the pattern. In this case, the vibration of the magnetic field generated by the antenna on the power transmission side is not transmitted to the antenna on the power transmission side. Therefore, the resonance antenna unit on the power reception side and the resonance antenna unit on the power transmission side cannot resonate due to the vibration propagating through the magnetic field. . Therefore, there is a possibility that non-contact power cannot be transmitted.

  Therefore, the antenna 500 has a set of loop patterns 563 a and 563 b arranged along the surface direction of the substrate 30. In a power transmitter including the antenna 500, a power source 13 (see FIG. 1) that supplies power to the antenna 500 is connected to each of a pair of loop patterns 563a and 563b via a drive circuit (not shown) or the like. Yes. The power supply 13 alternately applies alternating currents having different phases and alternating currents having the same phase to the pair of loop patterns 563a and 563b via a drive circuit or the like. The phase difference given to the alternating current applied to the pair of loop patterns 563a and 563b by the power source 13 is a half cycle (180 °).

  In the antenna 500, the loop antenna unit 560 includes a pair of loop patterns 563a and 563b as described above and feeding points 565a and 565b provided in both the loop patterns 563a and 563b. The loop patterns 563a and 563b are configured such that the loop pattern 463 (see FIG. 10) of the fourth embodiment is divided into two, and surround the rectangular regions 564a and 564b with the wiring pattern. The feeding points 565a and 565b are a pair of end portions formed on the loop patterns 563a and 563b, respectively. The feed points 565a and 565b are electrically connected to a drive circuit (not shown) by wiring or the like, and receive AC power from the power source 13 (see FIG. 1).

  Next, the power source 13 (see FIG. 1) alternately applies the alternating current having the same phase and the alternating currents having different phases to the feeding points 565a and 565b of the loop patterns 563a and 563b, thereby the antenna 500. The state of the magnetic field generated in the vicinity of will be described with reference to FIG.

  FIG. 17A shows a state of a magnetic field generated in the vicinity of the antenna 500 when the alternating currents applied to the feeding points 565a and 565b (see FIG. 16) have the same phase. When an alternating current having the same phase is applied to each of the feeding points 565a and 565b (see FIG. 16), the main magnetic lines of force of the magnetic field generated by the alternating current are from the pair of regions 564a and 564b to the plate thickness of the substrate 30. Radiated toward infinity along the direction. The state of the magnetic field formed by applying an alternating current of the same phase to each of the feeding points 565a and 565b (see FIG. 16) is substantially the same as the state of the magnetic field generated in the vicinity of the antenna having one loop pattern. It will be the same.

  When the antenna 500a on the power receiving side is arranged to face the antenna 500, high-density magnetic lines penetrate the region surrounded by the spiral pattern (not shown) of the antenna 500a. Therefore, the resonance antenna unit 540 of the antenna 500 on the power transmission side and the resonance antenna unit (not shown) of the antenna 500a on the power reception side can strongly resonate due to vibration propagating through the magnetic field. This enables highly efficient power transmission from the antenna 500 on the power transmission side to the antenna 500a on the power reception side.

  On the other hand, FIG. 17B shows a case where the phase difference of half a period (180 °) is given to the alternating current applied to each of the feeding points 565a and 565b (see FIG. 16) in the vicinity of the antenna 500. The state of the generated magnetic field is shown. When a half-cycle phase difference is given to the alternating current applied to each of the feeding points 565a and 565b (see FIG. 16), the direction of the magnetic field lines generated in the region 564a is the magnetic field lines generated in the region 564b. This is the opposite direction. Therefore, a loop-shaped magnetic field line radiated from one region 564a and incident on the other region 564b is reliably formed.

  In FIG. 17B, the power receiving side antenna 500 a is orthogonal to the antenna 500. With such an arrangement, even if the axial direction of the spiral pattern (not shown) of the antenna 500a is along the surface direction of the substrate 30 of the antenna 500, the lines of magnetic force radiated from the antenna 500 are surrounded by the spiral pattern on the power receiving side. Can penetrate the area. Therefore, the resonance antenna unit 540 of the antenna 500 on the power transmission side and the resonance antenna unit (not shown) of the antenna 500a on the power reception side can resonate due to vibration propagating through the magnetic field. As described above, power can be transmitted from the power transmitting side antenna 500 to the power receiving side antenna 500a.

  In the fifth embodiment described so far, the alternating current of the different phase and the alternating current of the same phase are alternately applied to each of the set of loop patterns 563a and 563b, so that the relative power of the antenna 500a on the power receiving side can be increased. Highly efficient and reliable power transmission is possible regardless of the direction.

  In addition, in the fifth embodiment, the phase difference of the alternating current applied to the pair of loop patterns 563a and 563b is a half cycle, so that a loop-shaped magnetic field can be reliably formed. Therefore, in the antenna 500a on the power receiving side, even if the axial direction of the spiral pattern is along the surface direction of the substrate 30 of the antenna 500 on the power transmitting side, the lines of magnetic force are not surrounded by the spiral pattern on the power receiving side. It can penetrate reliably. Therefore, regardless of the orientation of the power receiving side antenna 500a with respect to the power transmitting side antenna 500, power can be reliably transmitted from the power transmitting side antenna 500 to the power receiving side antenna 500a.

  In the fifth embodiment, the loop pattern 563a and the loop pattern 563b correspond to the “annular portion” recited in the claims, and the antenna 500 corresponds to the “power transmitting / receiving antenna” recited in the claims.

(Sixth embodiment)
An antenna 600 according to the sixth embodiment of the present invention shown in FIG. 18 is a modification of the fifth example. The loop antenna unit 660 of the antenna 600 has four loop patterns 663a, 663b, 663c, 663d, and four feeding points 665a, 665b, 665c, 665d.

  The four loop patterns 663 a, 663 b, 663 c, 663 d are arranged along the X direction and the Y direction that are the planar directions of the substrate 30. These loop patterns 663a, 663b, 663c, 663d are configured such that the loop patterns 563a, 563b (see FIG. 16) of the fifth embodiment are further divided. The loop pattern 663a is aligned with the loop pattern 663b in the X direction. The loop pattern 663c is aligned with the loop pattern 663d in the X direction. The loop pattern 663a is aligned with the loop pattern 663c in the Y direction. The loop pattern 663b is aligned with the loop pattern 663d in the Y direction. The rectangular regions surrounded by the loop patterns 663a, 663b, 663c, and 663d are referred to as regions 664a, 664b, 664c, and 664d, respectively.

  The four feeding points 665a, 665b, 665c, and 665d are a pair of ends of the wiring pattern formed on each of the loop patterns 663a, 663b, 663c, and 663d. Feed points 665a, 665b, 665c, and 665d are electrically connected to a drive circuit (not shown) by wiring or the like, and receive AC power input.

  In the sixth embodiment, the power source 13 (see FIG. 1) applies an alternating current to the feeding points 665a, 665b, 665c, and 665d in three different modes. The power supply 13 repeats three modes. One of the three modes applies an alternating current having the same phase to all the feeding points 665a, 665b, 665c, and 665d. The remaining two of the three modes apply AC currents having different phases to the feeding points 665a, 665b, 665c, and 665d. Hereinafter, an alternating current applied to each of the feeding points 665a, 665b, 665c, and 665d and a magnetic field generated in the vicinity of the antenna 500 by the alternating current will be described.

  When the alternating currents applied to the feeding points 665a, 665b, 665c, and 665d are all in the same phase, the direction of the magnetic field lines of the magnetic field radiated from the regions 664a, 664b, 664c, and 664d is the thickness of all the substrates 30. It faces the same direction along the direction. The state of the magnetic field formed by applying in-phase alternating current to each of the feeding points 665a, 665b, 665c, and 665d is substantially the same as the state of the magnetic field generated in the vicinity of the antenna having one loop pattern. It will be something.

  When the antenna on the power receiving side is arranged to face the antenna 600 on the power transmission side (not shown), the high-density magnetic field lines penetrate the region surrounded by the spiral pattern of the antenna. Therefore, the resonance antenna unit 640 of the antenna 600 on the power transmission side and the resonance antenna unit (not shown) of the antenna on the power reception side can resonate strongly by vibration propagating through the magnetic field. This enables highly efficient power transmission from the antenna 600 on the power transmission side to the antenna on the power reception side.

  In the next mode, the power source 13 (see FIG. 1) applies an alternating current having the same phase to the feeding point 665a and the feeding point 665b. In addition, the power supply 13 applies an alternating current having the same phase to the feeding point 665c and the feeding point 665d. However, the phase of the alternating current applied to the feeding points 665a and 665b is shifted by a half period (180 °) with respect to the phase of the alternating current applied to the feeding points 665c and 665d. In this case, the direction of the magnetic field lines generated in the regions 664a and 664b is opposite to the direction of the magnetic field lines generated in the regions 664c and 664d. Therefore, a loop-shaped magnetic field line radiated from one region 664a, 664b and incident on the other region 664c, 664d is reliably formed.

  By forming the loop-shaped magnetic field lines as described above, power can be transmitted to the antenna 600a even when the plate thickness direction of the antenna 600a on the power receiving side is directed to the Y direction of the antenna 600. . Specifically, the magnetic field lines of the magnetic field that circulate around the regions 664a and 664b and the regions 664a and 664d can penetrate the region surrounded by the spiral pattern (not shown) of the antenna 600a. Therefore, the resonance antenna unit 640 of the antenna 600 on the power transmission side and the resonance antenna unit (not shown) of the antenna 600a on the power reception side can resonate due to vibration propagating through the magnetic field. As described above, power can be transmitted from the power transmission side antenna 600 to the power reception side antenna 600a.

  In the next mode, the power source 13 (see FIG. 1) applies an alternating current having the same phase to the feeding point 665a and the feeding point 665c. In addition, the power supply 13 applies an alternating current having the same phase to the feeding point 665b and the feeding point 665d. However, the phase of the alternating current applied to the feeding points 665a and 665c is shifted by a half period (180 °) with respect to the phase of the alternating current applied to the feeding points 665b and 665d. In this case, the direction of the magnetic field lines generated in the regions 664a and 664c is opposite to the direction of the magnetic field lines generated in the regions 664b and 664d. Therefore, a loop-shaped magnetic field line radiated from one of the regions 664a and 664c and incident on the other region 664b and 664d is reliably formed.

  By forming the loop-shaped magnetic field lines as described above, power can be transmitted to the antenna 600b even when the plate thickness direction of the antenna 600b on the power receiving side is directed to the X direction of the antenna 600. Become. More specifically, the magnetic field lines of the magnetic field that circulate around the regions 664a and 664c and the regions 664b and 664d can penetrate the region surrounded by the spiral pattern (not shown) of the antenna 600b. Therefore, the resonance antenna unit 640 of the antenna 600 on the power transmission side and the resonance antenna unit (not shown) of the antenna 600b on the power reception side can resonate by vibration propagating through the magnetic field. As described above, power can be transmitted from the power transmission side antenna 600 to the power reception side antenna 600b.

  In the sixth embodiment described so far, in the four loop patterns 663 a, 663 b, 663 c, and 663 d, the magnetic field lines of the magnetic field formed in the vicinity of the antenna 600 are changed by sequentially changing the combination of applying alternating currents having different phases. The direction can be changed freely. Thereby, regardless of the relative direction of the antenna on the power receiving side with respect to the antenna 600 on the power transmission side, highly efficient and reliable power transmission becomes possible.

  In the sixth embodiment, the loop patterns 663a, 663b, 663c, and 663d correspond to the “annular portion” in the claims, and the antenna 600 corresponds to the “power transmitting / receiving antenna” in the claims.

(Other embodiments)
Although a plurality of embodiments of the present invention have been described above, the present invention is not construed as being limited to the above-described embodiments, and can be applied to various embodiments and combinations without departing from the scope of the present invention. it can.

  In the above embodiment, by using a double-sided substrate mainly composed of epoxy resin containing glass fiber and capable of forming a wiring pattern on both sides, the loop pattern of the loop antenna portion and the spiral pattern of the resonant antenna portion are different surfaces of the substrate. Was formed. However, the loop pattern and the spiral pattern may be formed on the same wiring surface of the substrate by using, for example, a single-sided substrate mainly composed of paper and phenol resin or epoxy resin and capable of forming a wiring pattern only on one side. Specifically, a loop antenna portion having a loop pattern in which both ends are connected to a power source or the like by an electric wire or the like is formed near the center of the wiring surface. A resonant antenna part having a spiral pattern is formed on the outer periphery side of the loop antenna part. Then, both ends of the spiral pattern are connected by an electric wire or the like. By applying the above configuration and realizing the use of a single-sided substrate, an antenna that can exhibit performance corresponding to the above embodiment can be provided at low cost.

  Further, an antenna using a multilayer substrate in which a plurality of insulating layers and wiring layers are stacked may be used. Specifically, a resonant pattern is formed by forming spiral patterns in a plurality of wiring layers and electrically connecting them in the thickness direction by peer holes. Then, a loop antenna part is provided by forming a loop pattern in a wiring layer in which a spiral pattern is not formed. According to the above, an antenna having a high degree of freedom in arrangement of the spiral pattern and the loop pattern can be realized.

  In addition, the material of the substrate is not limited to those described above, and may be polyimide or the like as long as it has insulating properties. By using this polyimide film material, it is possible to configure a flexible antenna having a flexible substrate as a base material. Further, the shape of the substrate is not limited in any way, and it follows a shape other than the rectangular plate shape such as the substrate of the above embodiment, for example, a disk shape, an elliptical plate shape, or a surrounding space where the substrate is arranged. It may be formed in an irregular polygon shape or the like. Alternatively, a curved plate-shaped substrate, a bent plate-shaped substrate, a substrate having a hole, or the like may be used as the base material.

  In the first embodiment, the loop pattern 63 is disposed at a position overlapping the innermost circumference 43a of the spiral pattern 43 of the resonance antenna unit 40 in the plate thickness direction. In the second and third embodiments, the loop pattern 263 is disposed. Was arranged so as to overlap with the outermost periphery 43d of the spiral pattern 43 in the plate thickness direction. However, the position where the loop pattern and the spiral pattern are arranged is not limited as long as the loop antenna unit and the resonant antenna unit are magnetically connected and formed on the substrate. For example, in the above-described embodiment, the loop pattern and the spiral pattern are arranged so that the centroid positions are substantially the same, but the center positions of the patterns may be arranged so as to be shifted. Further, the loop pattern may be arranged so as to overlap with any portion from the innermost periphery to the outermost periphery of the spiral pattern in the plate thickness direction. In this arrangement, unlike the above-described embodiment in which the loop pattern overlaps with the innermost circumference or the outermost circumference of the spiral pattern in the plate thickness direction, the interference between the loop pattern and the connecting portion that connects both ends of the spiral pattern is the front of the substrate. Can occur on the surface. Therefore, the above-described arrangement can be established by allowing the connecting portion to pass between the pair of end portions of the loop pattern.

  In the above-described embodiment, the spiral pattern and the loop pattern are formed in a rectangular shape and a rectangular ring shape following the outer shape of the substrate. Moreover, the electrode patterns 353a and 353b were formed in a rectangular shape. However, the shape of each wiring pattern is not limited to the above shape. For example, an antenna in which a spiral pattern and a loop pattern are formed in a circumferential shape and an annular shape may be used. In addition, the electrode pattern may be formed in an L shape, a T shape, or the like as long as the electrode pattern is disposed to face the plate thickness direction.

  In the first and second embodiments, the resonance antenna unit is provided with a chip capacitor as a capacitance unit. However, as long as a predetermined capacitance is provided, the capacitance portion may be a capacitor element other than a chip capacitor. In the third embodiment, the resonant antenna portion is provided with the electrostatic capacitance portion 350 having a pair of electrode patterns, and the electrode pattern is peeled from the substrate, so that the resonant frequency of the resonant antenna portion can be easily adjusted. It was. Even in other configurations, for example, one of the electrode patterns is divided into a plurality of sections in advance, and one specific section is connected to the end of the spiral pattern, and the section and the section are connected to the section. As a configuration that enables adjustment of the resonance frequency by connecting the other sections via a configuration that allows electrical connection and disconnection of a switch or the like to be freely switchable, and increasing or decreasing the capacitance value by switching the switch. Also good. Furthermore, a resonance antenna unit that does not have a configuration corresponding to the capacitance unit may be used.

  In the above-described embodiment, the frequency used for power transmission is defined as 10 MHz. However, this frequency is not limited, and a desired frequency can be set as long as it is within the frequency range of electromagnetic waves approved by laws and regulations. You may select suitably. For example, by transmitting power using a frequency band higher than 10 MHz, it is possible to reduce the size of the antenna by shortening the overall length of the spiral pattern.

  In the above embodiment, only the loop antenna portion and the resonant antenna portion are formed on the substrate. However, for example, a drive circuit used as a power transmitter configuration, a rectifier circuit used as a power receiver configuration, or the like may be formed on the substrate. Alternatively, a part of the substrate constituting the device that receives power supply may be used as the base material of the loop antenna unit and the resonance antenna unit. In this case, it is desirable to consider the arrangement so that the formation of the magnetic field by the loop antenna portion is not easily disturbed by the surrounding configuration.

  In the fifth and sixth embodiments, the configuration has been described in which power can be transmitted regardless of the direction of the antenna on the power receiving side by applying alternating currents having different phases to one or two loop patterns. However, the number of loop patterns is not limited to one or two sets as described above. In addition, the phase difference given to the alternating current applied to the plurality of loop patterns is limited to a half cycle as long as a magnetic field having a magnetic field line penetrating the power receiving antenna can be generated in the vicinity of the antenna. It is not a thing.

  And although the power transmitter and power receiver provided with the antenna by this invention were demonstrated in the said embodiment, the installation place of these power transmitters and the apparatus in which a power receiver is mounted are not limited, respectively. It is conceivable that the power transmitter is installed in a room of a residence, an automobile, a train, a ship, an aircraft, or the like. The power receiver can be used for charging and driving terminal devices such as mobile phones and computers. Alternatively, for example, power transmission may be laid in a parking lot and a power receiver may be mounted on the vehicle side to be used for charging an electric vehicle or a hybrid vehicle using an electric motor as a power source.

DESCRIPTION OF SYMBOLS 10 Power transmitter, 13 Power supply, 15 Drive circuit, 20 Power receiver, 23 Rectifier circuit, 25 Load or battery etc. (apparatus), 30, 330 Board | substrate (base material), 333 area | region, 40,240,340,440,540, 640 resonance antenna part, 43,443 spiral pattern (spiral part), 43a innermost periphery, 43b end, 43c end, 43d outermost periphery, 45,245,345 connection part, 247 region, 50 chip capacitor (electrostatic (Capacitance part, capacitor element), 350 electrostatic capacity part, 353a, 353b electrode pattern (electrode part), 60, 260, 460 loop antenna part, 63, 263, 463, 563a, 563b, 663a, 663b, 663c, 663d loop Pattern (annular part), 564a, 564b, 664a, 664b, 664c, 6 4d region, 65,565a, 565b, 665a, 665b, 665c, 665d feed point, 67,267 regions, 100,200,300,400,500,600 antenna (transmitting and receiving antennas)

Claims (13)

A power transmitting and receiving antenna for transmitting or receiving power in a contactless manner between a power source and a device to which power is supplied from the power source,
A plate-like substrate;
Resonance antenna unit having a spiral portion formed by spirally forming a conductive material on the substrate along the surface direction of the surface intersecting the plate thickness direction of the substrate, and having a predetermined resonance frequency set When,
An annular portion formed by annularly forming a conductive material on the base member along the surface direction is magnetically connected to the resonance antenna portion and electrically connected to the power supply side or the device side A power transmission / reception antenna.   The power transmission / reception antenna according to claim 1, wherein the spiral portion is formed on an outer peripheral side of a region surrounded by the annular portion. The resonant antenna part has a connection part that connects an end part on the inner peripheral side and an end part on the outer peripheral side of the spiral part,
The power transmission / reception antenna according to claim 1, wherein the connection portion is formed on a surface of the base material facing the spiral portion.   The power transmission / reception according to any one of claims 1 to 3, wherein the resonance antenna unit includes a capacitance unit that is connected to the spiral unit and has a predetermined capacitance set. antenna.   5. The electrostatic capacitance portion is a pair of electrode portions that are arranged on the surface of the base material so as to face each other in the plate thickness direction and are formed by forming a conductive material into a film shape. The power transmitting / receiving antenna described.   6. The power transmitting / receiving antenna according to claim 5, wherein at least a part of the electrode part is easily formed from the surface of the base material.   The power transmission / reception antenna according to any one of claims 4 to 6, wherein the capacitance section is a capacitor element in which a predetermined capacitance is set.   The spiral portion has a spiral number of the conductive material and a radial direction in the spirally formed conductive material so that the efficiency of power transfer with the annular portion is maximized. The power transmission / reception antenna according to any one of claims 1 to 7, which has a shape in which a distance between adjacent conductive materials and a distance between the annular portions are determined.   The power transmission / reception antenna according to any one of claims 1 to 7, wherein the annular portion is formed at a position overlapping with an innermost circumference of the spiral portion in a plate thickness direction.   The power transmission / reception antenna according to claim 1, wherein the annular portion and the spiral portion are formed on opposing surfaces of the base material. The power transmitting and receiving antenna according to any one of claims 1 to 10,
The power source connected to the power transmitting and receiving antenna, and a power transmitter comprising:
The loop antenna part has a plurality of the annular parts arranged along the surface direction,
The power source is connected to each of the plurality of annular portions, and applies alternating currents having different phases to each of the plurality of annular portions.   The power transmitter according to claim 11, wherein the power supply alternately applies an alternating current having a different phase and an alternating current having the same phase to each of the plurality of annular portions.   13. The power supply according to claim 11 or 12, wherein an alternating current having a half-cycle phase difference is applied to each of at least one set of the annular portions among the plurality of annular portions. Power transmitter.

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