Hollow Resonance Type Power Transmission Device and Wireless Power Transmission System

Abstract

The cavity resonance type power transmission device 100 includes a structure 10 entirely surrounded by an electromagnetic wave shielding member having conductivity, a power transmitter 20 that wirelessly supplies power to a product 31 via a power receiver 30 disposed in the internal space of the structure 10, and a partition body 40 that separates the power receiver 30 and the power transmitter 20. The structure 10 has a bottom portion 11, a top portion 12 facing the bottom portion 11, and side portions 13 connecting the outer edges of the bottom portion 11 and the top portion 12. The power transmitter 20 is provided in contact with the inner surface of the bottom portion 11.

Description

Technical Field

[0001] The present invention relates to a cavity resonance type power transmission device and a wireless power transmission system. In particular, it relates to a cavity resonance type power transmission device and a wireless power transmission system for efficiently transmitting wireless power.

Background Art

[0002] In recent years, many electronic devices are equipped with secondary batteries so that they can be repeatedly charged. These products are manufactured by manufacturers, then packaged, shipped, and displayed at storefronts such as mass retailers.

[0003] The secondary batteries mounted on the electronic devices displayed in this way gradually lose battery power due to leakage current. If it enters an over-discharge state where it discharges beyond the range where it can be safely discharged, it may cause deterioration or damage to the secondary battery.

[0004] To avoid the over-discharge state, the shipped electronic devices must be charged after a certain period has elapsed. However, since the electronic devices displayed at storefronts are generally packaged in some way, in order to return the electronic devices to a charged state, the package must be unpacked, the electronic device must be taken out and then charged, and then the package must be repacked after charging is completed.

[0005] High costs are required to unpack and repack after charging. However, if the electronic device can be charged while still in the packaged state, the cost can be reduced. The number of electronic devices collected from mass retailers etc. for charging varies depending on the product throughput. Therefore, it is sometimes desirable to be able to uniformly charge a large number of products at once.

[0006] In Patent Document 1, by supplying energy to at least one wireless energy source using electrical energy from a solar cell module, a step of generating a vibrating magnetic field and a step of configuring the source to exhibit impedance with respect to the solar cell module are included, and a method of extracting energy from the solar cell module by the impedance is disclosed. By utilizing the wireless power supply of Patent Document 1, it is possible to charge a battery without unpacking a plurality of products. However, in the method of Patent Document 1, there is a problem that the amount of charge that can be charged by the power receiver decreases as the distance from the power transmitter increases.

[0007] On the other hand, Patent Document 2 discloses a method of efficiently supplying power even at a position far from the power transmitter by exciting a resonance mode throughout the space surrounded by a conductor and utilizing this.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0009] However, in Patent Document 2, since the power transmitter is arranged at the top of the housing, it can only cope with wireless power supply of small energy. In order to perform power transmission for a large number of products as in Patent Document 1, enlargement of the power transmitter is inevitable, and the stability of the housing decreases.

[0010] To solve this problem, it is conceivable to arrange a power transmitter at the bottom of the housing. However, in a device with a power transmitter arranged at the bottom of the housing, when using stacked receivers, it has been found that it is difficult to sufficiently charge the receivers arranged on the bottom side of the housing. This is a discovery of a new problem by the present inventor.

[0011] The present invention has been made to solve the above problems, and an object thereof is to provide an apparatus and a system that can simultaneously transmit power to a plurality of receivers and uniformly supply power without attenuation with respect to the distance from the power transmitter.

Means for Solving the Problems

[0012] The cavity resonance type power transmission device of the present invention includes a structure entirely surrounded by an electromagnetic wave shielding member having conductivity, a power transmitter that wirelessly supplies power to a product via a receiver arranged in the internal space of the structure, and a partition that separates the receiver and the power transmitter. The structure has a bottom, a top facing the bottom, and side portions connecting the outer edges of the bottom and the top. The power transmitter is provided in contact with the inner surface of the bottom.

[0013] The wireless power transmission system of the present invention includes the cavity resonance type power transmission device of the present invention and a receiver arranged in the internal space of the structure of the cavity resonance type power transmission device, and is configured to wirelessly supply power to a product via the receiver by the power transmitter.

Effects of the Invention

[0014] According to the present invention, it is possible to provide an apparatus and a system that can simultaneously transmit power to a plurality of receivers and uniformly supply power without attenuation with respect to the distance from the power transmitter.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Mode for Carrying Out the Invention

[0016] Hereinafter, the cavity resonance type power transmission device and the wireless power transmission system of the present invention will be described. However, the present invention is not limited to the following embodiments, and can be appropriately modified and applied without changing the gist of the present invention. In addition, a combination of two or more of the individual preferred configurations of the present invention described below is also the present invention.

[0017] Each of the embodiments shown below is an exemplification, and it goes without saying that partial substitution or combination of the configurations shown in different embodiments is possible. In the following embodiments from the second embodiment onward, descriptions of matters common to the first embodiment will be omitted, and only different points will be described. In particular, for the same operational effects due to the same configurations, they will not be sequentially mentioned for each embodiment.

[0018] In the following description, when not particularly distinguishing each embodiment, it is simply referred to as "the cavity resonance type power transmission device of the present invention" and "the wireless power transmission system of the present invention".

[0019] The drawings shown below are schematic diagrams, and their dimensions, aspect ratios, scales, etc. may be different from those of actual products. In the figures, the same or corresponding parts shall be denoted by the same reference numerals. Also, in each figure, the same elements shall be denoted by the same reference numerals and redundant descriptions shall be omitted.

[0020] In this specification, terms indicating the relationship between elements (such as "vertical", "parallel", "orthogonal", etc.) and terms indicating the shape of elements are not expressions representing only strict meanings, but are expressions meaning including substantially equivalent ranges, for example, differences of about several percent. Also, in this specification, "constant" is not an expression meaning only completely constant, but is an expression meaning substantially constant, for example, including differences of about several percent.

[0021] In this specification, the width direction, length direction, and height direction are defined as the directions defined by X, Y, and Z, respectively, as shown in FIG. 1 etc. The width direction X, length direction Y, and height direction Z are orthogonal to each other. Also, the direction orthogonal to the height direction Z and including the width direction X and length direction Y is defined as the plane direction (XY plane direction). In this specification, it is preferable that the height direction Z is the vertical direction. In this case, the XY plane becomes the horizontal plane.

[0022] A first embodiment of the wireless power transmission system of the present invention will be described below with reference to FIG. 1. FIG. 1 is a perspective schematic diagram showing an example of a wireless power transmission system according to the first embodiment of the present invention. In FIG. 1, the wireless power transmission system 500 includes a cavity resonance type power transmission device 100 and a power receiver 30 disposed in the internal space of the structure 10 of the cavity resonance type power transmission device 100, and is configured to wirelessly supply power to the product 31 via the power receiver 30 by the power transmitter 20. The cavity resonance type power transmission device 100 includes a structure 10 entirely surrounded by an electromagnetic wave shielding member having conductivity, a power transmitter 20 that wirelessly supplies power to a product 31 via a power receiver 30 disposed in the internal space of the structure 10, and a partition body 40 that separates the power receiver 30 and the power transmitter 20.

[0023] The structure 10 is, for example, in the shape of a rectangular parallelepiped and has a bottom 11, a top 12 facing the bottom 11, and side portions 13 connecting the outer edges of the bottom 11 and the top 12. The bottom 11 and the top 12 face each other in the Z direction, with the bottom 11 positioned on the lower side in the Z direction and the top 12 positioned on the upper side in the Z direction. The bottom 11 and the top 12 are, for example, planes parallel to the XY plane as shown in FIG. 1. The structure 10 preferably has a shape with a longitudinal direction in the Z direction from the bottom 11 toward the top 12 as shown in FIG. 1. Note that the shape of the structure 10 is not limited to a rectangular parallelepiped shape, and may be, for example, a pentagonal prism shape in which the XY plane is a pentagon, a quadrangular prism shape in which the XY plane is a trapezoid, a semi-cylindrical shape in which the XY plane is a semi-circle, etc. However, in any shape, it is preferable that the structure 10 has a longitudinal direction in the Z direction from the bottom 11 toward the top 12.

[0024] The cavity resonance type power transmission device 100 utilizes the resonance mode in the structure 10. Since the structure 10 has an internal space shielded by an electromagnetic wave shielding member, it can be considered as a resonator. When the length in the width direction of the resonator is a (X direction), the length in the length direction is b (Y direction), and the length in the vertical direction is c (Z direction), the resonance frequency f r can be determined as shown in Equation 1.

[0025] [Equation 1] f r = v / (2π × (μ r × ε r )) × {(mπ / a) 1 / 2 + (nπ / b) 2 + (pπ / c) 2} 2 1 / 2

[0026] Here, v is the speed of light, μ r is the relative permeability, εr where εr is the relative permittivity, and m, n, and p are integers respectively. In the cavity resonance type power transmission device 100, m is an index in the width direction (X direction) of the resonator (structure 10), n is an index in the length direction (Y direction) of the resonator (structure 10), and p is an index in the vertical direction (Z direction) of the resonator (structure 10).

[0027] The material of the electromagnetic wave shielding member is not particularly limited as long as it has conductivity, but preferably metal materials such as copper, aluminum, iron, stainless steel, and nickel can be mentioned. Alternatively, conductive oxide materials such as zinc oxide, titanium oxide, indium tin oxide (ITO), graphite, organic conductive materials, etc. can be mentioned. Also, as long as it has conductivity, it may be an alloy or a mixture. The electromagnetic wave shielding member may have a multilayer structure made of these materials.

[0028] The shape of the electromagnetic wave shielding member may be plate-like, mesh-like, film-like, porous, etc. as long as it shields electromagnetic waves at the frequency for power supply. Also, the electromagnetic wave shielding member may be coated with an electromagnetic wave transmitting material for the purpose of surface protection or the like. Note that the electromagnetic wave shielding in the electromagnetic wave shielding member only needs to be able to shield electromagnetic waves at the frequency used for wireless power transmission. That is, it is also possible to use it in a way that does not shield communication at a frequency different from the wireless power transmission frequency.

[0029] The power transmitter 20 is provided, for example, as shown in FIG. 1, at the center of the bottom 11 of the structure 10 and in contact with only the inner surface of the bottom 11. The position of the power transmitter 20 may be in contact with the inner surface of the side portion 13 as long as it is in contact with the inner surface of the bottom 11. Also, the position of the power transmitter 20 may be deviated from the center of the bottom 11 of the structure 10.

[0030] The configuration of the power transmitter 20 will be described with reference to FIG. 2. FIG. 2 is a schematic diagram of an example of the power transmitter according to the present invention. The power transmitter 20 is composed of, for example, a metal rod 21 and a power transmission antenna wiring 22 arranged in a direction perpendicular thereto. The metal rod 21 is preferably installed substantially perpendicular to the electromagnetic wave shielding member. At this time, while the metal rod 21 is installed so as not to be in electrical contact with the electromagnetic wave shielding member, it penetrates the electromagnetic wave shielding member and is electrically connected to a matching circuit and a high-frequency power source (not shown) installed outside the resonator (structure 10).

[0031] The matching circuit is connected between the power transmitter 20 and the high-frequency power source. The matching circuit is adjusted to achieve impedance matching with the resonator at a preset power transmission frequency. When the reference potential of the matching circuit and the high-frequency power source is substantially the same as the reference potential of the electromagnetic wave shielding member, a connector such as an SMA (Sub Miniature Type A) terminal may be appropriately interposed during connection. When the reference potential of the matching circuit and the high-frequency power source is different from the reference potential of the electromagnetic wave shielding member, the same effect can be obtained by using a dipole antenna 37 or a loop antenna (not shown) in the same manner as the power receiver 30 described later. The power transmission antenna wiring 22 may be wired on a printed circuit board or the like, but the metal rod 21 may be bent to form the wiring. Also, the power transmission antenna wiring 22 may be appropriately bent within the plane in which it is wired. The power transmission antenna wiring 22 is preferably formed substantially parallel to the wall surface of the resonator (structure 10) made of the electromagnetic wave shielding member when power is transmitted using an electric field, and substantially perpendicular to the wall surface of the resonator (structure 10) made of the electromagnetic wave shielding member when power is transmitted using a magnetic field.

[0032] The partition 40 is, for example, as shown in FIG. 1, a flat plate with a rectangular main surface. The partition 40 is preferably provided such that the main surface is parallel to the bottom 11 of the structure 10. In FIG. 1, the partition 40 has the ends of four legs 41 joined to the four corners of the rectangle, and the other ends of the legs 41 are in contact with the bottom 11 of the structure 10. The other ends of the legs 41 may be fixed to the bottom 11 of the structure 10. The partition body 40 may have the same shape on the main surface as the bottom 11 of the structure 10. In this case, the edge of the main surface of the partition body 40 may be joined to the inside of the side part 13 of the structure 10. The partition body 40 may be a flat plate having a shape other than a rectangle. The partition body 40 is preferably made of a material having insulating properties in the resonance frequency band used in the present invention. Examples of such materials include synthetic resin-based materials, paper, wood, etc. More desirable materials include fluororesins and polystyrene resins having a low relative dielectric constant. If the mechanical strength permits, the partition body 40 does not have to be bulk-like like expanded polystyrene.

[0033] If the power receiver 30 is too close to the power transmitter 20, the impedance change becomes significant, the resonance frequency shifts, and charging cannot be performed sufficiently. In order to separate the power receiver 30 and the power transmitter 20, in FIG. 1, the partition body 40 is provided separated from the power transmitter 20. The separation distance between the partition body 40 and the power transmitter 20 is preferably 1 / 3 or more of the wavelength of the resonance frequency used for wireless power supply. On the other hand, the separation distance between the partition body 40 and the power transmitter 20 is limited to a position where the antenna of the power receiver 30 described later can be separated from the top 12 by at least 1 / 3 of the wavelength of the resonance frequency used for wireless power supply. The resonance frequency used for wireless power supply is, for example, 2.00 GHz or more and 3.00 GHz or less. When the resonance frequency is in the above range, the wavelength is 99.93 mm or more and 149.90 mm or less. The partition body 40 is preferably arranged closer to the bottom 11 than the top 12 in order to provide a wider space for arranging the power receiver 30.

[0034] The partition body 40 may be in contact with the power transmitter 20. In that case, in order to separate the power receiver 30 and the power transmitter 20, the partition body 40 preferably has a thickness of 1 / 3 or more of the wavelength of the resonance frequency used for wireless power supply in the Z direction. The partition body 40 may have a space inside.

[0035] In the cavity resonance type power transmission device 100, it is preferable that a guide 50 for restricting the position and direction of the power receiver 30 is provided in the region where the power receiver 30 in the internal space is arranged. The guide 50 is, for example, a rectangular plate-like member, and recesses for fitting the power receiver 30 are evenly provided on the main surface. When a plurality of power receivers 30 are provided in the internal space, it is preferable that the guide 50 is provided in order to supply power evenly to all the power receivers 30. When the mode has characteristics in the power supply direction like TE110, it is preferable to restrict the direction of the power receiver 30.

[0036] In FIG. 1, the guide 50 is fixed in the vertical direction to the upper main surface of the partition body 40. The guide 50 may not be fixed to the partition body 40 so that it can be taken in and out of the cavity resonance type power transmission device 100. For example, a frame (not shown) for fitting the guide 50 to the upper main surface of the partition body 40 may be provided. By fitting the guide 50 into the frame, the position of the guide 50 in the cavity resonance type power transmission device 100 can be fixed. When the guide 50 is a plate-like member, it may be one in the internal space or two or more. When there are two or more guides 50, for example, they can be arranged side by side in the Y direction, but are not particularly limited. The shape of the guide 50 is not limited to a plate-like member as long as it restricts the position and direction of the power receiver 30.

[0037] In the wireless power transmission system 500 shown in FIG. 1, three power receivers 30 are arranged in the X direction and ten power receivers 30 are arranged in the Z direction in the cavity resonance type power transmission device 100. The number and arrangement direction of the power receivers 30 are not particularly limited, but from the viewpoint of efficiency, it is preferable that a plurality of power receivers 30 are provided, it is preferable that a plurality of power receivers 30 are arranged in the Z direction, and it is preferable that the directions of all the power receivers 30 are the same.

[0038] The configuration of the power receiver 30 will be described with reference to FIG. 3. FIG. 3 is a schematic diagram of an example of the power receiver according to the present invention. The power receiver 30 is composed of, for example, an electrical wiring section 37 serving as an antenna and a rectifier circuit 38. A switch, a matching circuit, etc. may be attached as necessary. Typically, a dipole antenna 37, a loop antenna (not shown), etc. are suitable as the antenna. The dipole antenna 37 may be bent as appropriate. Also, an inverted-F structure in which a part of the wiring is short-circuited to the ground or a part that becomes the reference potential of the power receiver 30 may be adopted. It is also possible to adjust the corresponding frequency by inserting a capacitor or an inductor into a part of the antenna wiring. These may be selected according to the resonance frequency derived from the resonator formed of the electromagnetic wave shielding member.

[0039] In this embodiment, as shown in FIG. 1, a product 31 having the power receiver 30 inside is arranged in the internal space of the structure 10. Examples of the product 31 include IoT devices such as wireless earphones, smart watches, electronic pens, rechargeable toys, power tools, drive recorders, notebook computers, remote controls, drones, and electronic devices such as smart meters, wireless speakers, batteries, and sensor modules.

[0040] As shown in FIG. 4, the power receiver 30 may be separable from the product 31. FIG. 4 is a schematic diagram of an example of the power receiver and the product according to the present invention. The wireless power transmission system 500 may be one that connects the power receiver 30 to the charging terminal provided in the product 31 and wirelessly supplies power in a state where the product 31 and the power receiver 30 are arranged in the internal space of the structure 10.

[0041] In the cavity resonance type power transmission device 100, it is preferable to switch at least one of the indices m and n of the resonance frequency in the internal space between odd and even numbers for power transmission. In this specification, 0 is not included in the even numbers. The indices m and n are preferably odd or even numbers of 1 or more and 10 or less, and more preferably odd or even numbers of 1 or more and 5 or less. Specific examples include TE110, TE210, TE120, etc.

[0042] The value of the index and the electric field strength distribution will be described with reference to FIG. 5. FIG. 5 is a schematic diagram showing an example of the electric field strength distribution in the TE mode in the internal space of the cavity resonance type power transmission device. As shown in FIG. 5, in the TE110 mode where the indices m and n are 1 and p is 0, the electric field in the central portion in the X direction in the internal space becomes strong. In the TE210 mode where the index m is 2, n is 1, and p is 0, the electric field in the central portion in the X direction in the internal space becomes weak, and the electric field around it becomes strong. In the TE310 mode where the index m is 3, n is 1, and p is 0, regions with strong electric fields, regions with weak electric fields, and regions with strong electric fields appear from the central portion in the X direction toward both ends. By switching the power transmission by changing at least one of the indices m and n between odd and even numbers, even when a plurality of power receivers are widely arranged in the X and Y directions, efficient and uniform power transmission can be achieved to all the power receivers 30.

[0043] The cavity resonance type power transmission device 100 preferably has a resonance frequency in the TE110 mode in the internal space. This is because when a plurality of power receivers are arranged in the Z direction from the bottom to the top, efficient power supply can be achieved to all the power receivers.

[0044] In the cavity resonance type power transmission device 100, when the resonance frequency is in the (m, n, p) mode, it is preferable to switch the power transmission so that any one of m, n, and p becomes 0. When any one of m, n, and p is 0, the electric field in the direction that is 0 becomes constant. Therefore, by switching the power transmission, even when a plurality of power receivers 30 are randomly arranged, uniform power transmission can be achieved to all the power receivers 30.

[0045] In the cavity resonance type power transmission device 100, it is preferable to perform the switching of the resonance frequency with an interval of 0.3 seconds or more. When the switching of the resonance frequency is performed with an interval of 0.3 seconds or more, sufficient power can be ensured and the DC / DC converter that operates the power transmitter can be normally operated. On the other hand, the switching of the resonance frequency is preferably performed with an interval of 1 second or less.

[0046] A wireless power transmission system 510, which is a second embodiment of the wireless power transmission system of the present invention, will be described below with reference to FIG. 6. Here, only the parts different from the wireless power transmission system 500 will be described.

[0047] FIG. 6 is a perspective schematic view showing an example of a wireless power transmission system according to the second embodiment of the present invention. The wireless power transmission system 510 includes a cavity resonance type power transmission device 110. The cavity resonance type power transmission device 110 does not include a guide 50. In the wireless power transmission system 510 shown in FIG. 6, a product 31 having a power receiver 30 inside is packed in a box 32, and the box 32 is directly placed on the main surface of the partition 40. Three boxes 32 are arranged in the X direction and stacked in five stages in the Z direction. The number and arrangement of the boxes 32 placed on the partition 40 are not particularly limited, but it is preferable that a plurality of boxes are stacked in the Z direction.

[0048] In order to transmit power evenly to a plurality of power receivers 30, it is preferable that the directions of the power receivers 30 are unified, but the directions of the power receivers 30 do not have to be unified. The product 31 having the power receiver 30 inside does not have to be packed in the box 32.

[0049] A wireless power transmission system 520, which is a third embodiment of the wireless power transmission system of the present invention, will be described below with reference to FIG. 7. Here, only the parts different from the wireless power transmission system 510 will be described.

[0050] FIG. 7 is a perspective schematic view showing an example of a wireless power transmission system according to the third embodiment of the present invention. The wireless power transmission system 520 includes a cavity resonance type power transmission device 120. In the cavity resonance type power transmission device 120, a shelf 42 for arranging the power receiver 30 is further provided between the partition body 40 and the top portion 12. The shelf 42 is, for example, a rectangular flat plate having the same main surface area as the partition body 40 as shown in FIG. 7. The shelf 42 is preferably provided such that the main surface is parallel to the main surface of the partition body 40. In FIG. 7, the shelf 42 has the ends of four legs 43 joined to the four corners of the rectangle, and the other ends of the legs 43 are in contact with the main surface on the top portion 12 side of the partition body 40. The other ends of the legs 43 may be fixed to the partition body 40. The shelf 42 may have the same shape of the main surface as the bottom portion 11 of the structure 10, and in that case, the edge portion of the main surface of the shelf 42 may be joined to the inside of the side portion 13 of the structure 10. The shelf 42 may be a flat plate having a shape other than a rectangle. Two or more shelves 42 may be provided at intervals in the Z direction.

[0051] In the cavity resonance type power transmission device 120, products 31 each having a power receiver 30 inside are arranged in three rows in the X direction on the main surface of the partition body 40 and on the main surface of the shelf 42 in a state of being packed in a box 32. The number and arrangement of the boxes 32 placed on the partition body 40 and the shelf 42 are not particularly limited. For example, a plurality of boxes 32 may be stacked in the Z direction on the partition body 40 and the shelf 42, respectively. Also, the box 32 may not be placed on the partition body 40.

[0052] In the wireless power transmission system 500 shown in FIG. 1, for the wireless power transmission system 520 shown in FIG. 7, the power receiver 30 and the product 31 are not packed, and the power transmitter 20 is configured to wirelessly supply power to the product 31 through the unpacked power receiver 30.

[0053] The wireless power transmission system 600, which is a fourth embodiment of the wireless power transmission system of the present invention, will be described below with reference to FIG. 8. Here, only the parts different from the wireless power transmission system 500 will be described.

[0054] FIG. 8 is a schematic cross-sectional view showing an example of a wireless power transmission system according to the fourth embodiment of the present invention. The wireless power transmission system 600 includes a cavity resonance type power transmission device 200. The structure 10 is, for example, in the shape of a rectangular parallelepiped, and has a bottom 11, a top 12 facing the bottom 11, a first side 14 connecting the outer edges of the bottom 11 and the top 12, and a second side 15 facing the first side 14. The structure 10 further has a third side 16 adjacent to the first side 14 or the second side 15, and a fourth side (not shown) facing the third side 16. As shown in FIG. 8, the structure 10 preferably has a shape with a longitudinal direction from the first side 14 toward the second side 15. The shape of the structure 10 in this embodiment is not limited to a rectangular parallelepiped shape. For example, it may be a pentagonal prism shape in which the XY plane is a pentagon, a quadrangular prism shape in which the XY plane is a trapezoid, a semi-cylindrical shape in which the XY plane is a semi-circle, etc. However, in any shape, it is preferable that the structure 10 has a longitudinal direction in the Y direction from the first side 14 toward the second side 15.

[0055] In the cavity resonance type power transmission device 200, the power transmitter 20 is provided in contact with the inner surface of the bottom 11 and the inner surface of the first side 14. In the cavity resonance type power transmission device 200, when the width lengths of the resonator (structure 10) are a (X direction) and b (Y direction), and the vertical length is c (Z direction), the resonance frequency f r can be determined as shown in Equation 2.

[0056] [Equation 2] f r = v / (2π×(μ r × ε r )) ×{(mπ / a) 1 / 2 +(pπ / b) 2 +(nπ / c) 2 +(nπ / c) 2} 1 / 2

[0057] Here, v is the speed of light, μ r is the relative permeability, ε r is the relative permittivity, and m, n, and p each represent an integer. In the cavity resonance type power transmission device 200, m is an index in the width direction (X direction) of the resonator (structure 10), n is an index in the vertical direction (Z direction) of the resonator (structure 10), and p is an index in the length direction (Y direction) of the resonator (structure 10).

[0058] In the cavity resonance type power transmission device 200, the partition body 40 is preferably a flat plate having the same height as the first side portion 14 of the structure 10 and is provided so as to be parallel to the first side portion 14. In FIG. 8, the partition body 40 has edge portions in contact with the bottom portion 11 and the top portion 12 of the structure 10. The partition body 40 is preferably arranged closer to the first side portion 14 than the second side portion 15 in order to provide a wider space for arranging the power receiver 30.

[0059] Next, a wireless power transmission system 610, which is a modification of the fourth embodiment, will be described below with reference to FIG. 9. Here, only the parts different from the wireless power transmission system 600 will be described.

[0060] FIG. 9 is a schematic cross-sectional view showing another example of the wireless power transmission system according to the fourth embodiment of the present invention. The wireless power transmission system 610 includes a cavity resonance type power transmission device 210. In the cavity resonance type power transmission device 210, the power transmitter 20 is arranged at the center of the inner surface of the first side portion 14, is in direct contact with the inner surface of the first side portion 14, and is indirectly in contact with the inner surface of the bottom portion 11. A scaffold 23 for applying the load of the power transmitter 20 to the bottom portion 11 is provided below the power transmitter 20.

[0061] The wireless power transmission system of the present invention may include two or more cavity resonance type power transmission devices. FIG. 10 is a schematic cross-sectional view showing another example of the wireless power transmission system of the present invention. The wireless power transmission system 611 includes three cavity resonance type power transmission devices 210. As shown in FIG. 10, the wireless power transmission system 611 can be provided in a plurality in the height direction by placing the cavity resonance type power transmission device 210 on the gantry 300.

[0062] When the wireless power transmission system of the present invention includes two or more cavity resonance type power transmission devices, it is preferable that at least one cavity resonance type power transmission device is the cavity resonance type power transmission device of the present invention, and it is more preferable that all cavity resonance type power transmission devices are the cavity resonance type power transmission devices of the present invention. When two or more cavity resonance type power transmission devices are the cavity resonance type power transmission devices of the present invention, they may all be cavity resonance type power transmission devices of the same embodiment, or some or all of them may be cavity resonance type power transmission devices of different embodiments.

[0063] The cavity resonance type power transmission device provided in the wireless power transmission system of the present invention is also one of the present invention.

[0064] The following content is disclosed in this specification.

[0065] <1> A structure entirely surrounded by an electromagnetic wave shielding member having conductivity, a power transmitter that wirelessly supplies power to a product via a power receiver disposed in the internal space of the structure, and a partition that separates the power receiver and the power transmitter. The structure has a bottom, a top facing the bottom, and side portions connecting the outer edges of the bottom and the top. The power transmitter is a cavity resonance type power transmission device provided in contact with the inner surface of the bottom.

[0066] <2> The partition is the cavity resonance type power transmission device described in <1>, provided at a distance from the power transmitter.

[0067] <3> The cavity resonance type power transmission device according to <1> or <2>, wherein the separation distance between the partition and the power transmitter is 1 / 3 or more of the wavelength of the resonance frequency used for wireless power supply.

[0068] <4> The cavity resonance type power transmission device according to any one of <1> to <3>, wherein a guide for restricting the position and direction of the power receiver is provided in the region of the internal space where the power receiver is disposed.

[0069] <5> The cavity resonance type power transmission device according to any one of <1> to <4>, which transmits power by switching at least one of the indexes m and n of the resonance frequency in the internal space between odd and even numbers.

[0070] <6> The cavity resonance type power transmission device according to any one of <1> to <5>, which transmits power by switching so that any one of m, n, and p becomes 0 when the resonance frequency is in the (m, n, p) mode.

[0071] <7> The cavity resonance type power transmission device according to <5> or <6>, characterized in that the switching of the resonance frequency is performed with an interval of 0.3 seconds or more.

[0072] <8> The cavity resonance type power transmission device according to any one of <1> to <7>, wherein the power transmitter is provided in contact with only the inner surface of the bottom of the structure.

[0073] <9> The cavity resonance type power transmission device according to any one of <1> to <8>, wherein the structure has a shape with a longitudinal direction from the bottom to the top.

[0074] <10> The cavity resonance type power transmission device according to <9>, wherein the partition is arranged closer to the bottom than the top.

[0075] <11> The cavity resonance type power transmission device according to <9> or <10>, wherein a shelf for arranging the power receiver is further provided between the partition and the top.

[0076] <12> The cavity resonance type power transmission device according to any one of <1> to <11>, wherein the resonance frequency in the internal space is in the TE110 mode.

[0077] <13> The side part of the above structure has a first side part and a second side part facing the first side part. The cavity resonance type power transmission device according to any one of <1> to <7>, wherein the power transmitter is provided in contact with the inner surface of the bottom part and the inner surface of the first side part.

[0078] <14> The cavity resonance type power transmission device according to <13>, wherein the structure has a longitudinal direction from the first side part toward the second side part.

[0079] <15> The cavity resonance type power transmission device according to <13> or <14>, wherein the partition body is arranged closer to the first side part than the second side part.

[0080] <16> The cavity resonance type power transmission device according to any one of <13> to <15>, wherein the power transmitter is provided in indirect contact with the inner surface of the bottom part and in direct contact with the inner surface of the first side part.

[0081] <17> A cavity resonance type power transmission device according to any one of <1> to <16>, and a power receiver arranged in the internal space of the structure of the cavity resonance type power transmission device, A wireless power transmission system configured to wirelessly power a product via the power receiver by a power transmitter.

[0082] <18> The wireless power transmission system according to <17>, wherein a plurality of the power receivers are provided.

[0083] <19> The power receiver is separable from the product, the power receiver is connected to a charging terminal provided in the product, The wireless power transmission system according to <17> or <18>, wherein the product is wirelessly powered in a state where the product is arranged in the internal space of the structure.

[0084] <20> The power receiver is in an unpacked state, The power transmitter wirelessly powers the product through the unpacked power receiver, which is a wireless power transmission system described in any one of <17> to <19>.

[0085] <21> The power receiver and the product are in a packed state, The power transmitter wirelessly powers the product through the packed power receiver, which is a wireless power transmission system described in any one of <17> to <19>.

[0086] <22> The wireless power transmission system according to <21>, wherein the power receiver and the product are stacked on a partition in a packed state.

Description of Reference Numerals

[0087] 10 Structure 11 Bottom 12 Top 13 Side 14 First Side 15 Second Side 16 Third Side 20 Power Transmitter 21 Metal Rod 22 Power Transmission Antenna Wiring 23 Scaffold 30 Power Receiver 31 Product 32 Box 37 Dipole Antenna (Electrical Wiring Part) 38 Rectifier Circuit 40 Partition 41, 43 Legs 42 Shelf 50 Guide 100, 110, 120, 200, 210 Cavity Resonance Type Power Transmission Device 300 Stand 500, 510, 520, 600, 610, 611 Wireless Power Transmission System

Claims

1. A structure entirely surrounded by an electromagnetic wave shielding member having conductivity, a power transmitter that wirelessly powers a product via a power receiver disposed in the internal space of the structure, and a partition that separates the power receiver and the power transmitter. The structure has a bottom, a top facing the bottom, and side portions connecting the outer edges of the bottom and the top. The power transmitter is provided in contact with the inner surface of the bottom. A cavity resonance type power transmission device, wherein the separation distance between the partition and the power transmitter is 1 / 3 or more of the wavelength of the resonance frequency used for wireless power transmission.

2. A structure entirely surrounded by an electromagnetic wave shielding member having conductivity, a power transmitter that wirelessly powers a product via a power receiver disposed in the internal space of the structure, and a partition that separates the power receiver and the power transmitter. The structure has a bottom, a top facing the bottom, and side portions connecting the outer edges of the bottom and the top. The power transmitter is provided in contact with the inner surface of the bottom. A cavity resonance type power transmission device that transmits power by switching at least one of the indices m and n of the resonance frequency in the internal space between odd and even numbers.

3. A structure entirely surrounded by an electromagnetic wave shielding member having conductivity, a power transmitter that wirelessly powers a product via a power receiver disposed in the internal space of the structure, and a partition that separates the power receiver and the power transmitter. The structure has a bottom, a top facing the bottom, and side portions connecting the outer edges of the bottom and the top. The power transmitter is provided in contact with the inner surface of the bottom. A cavity resonance type power transmission device that transmits power by switching so that any one of m, n, and p becomes 0 when the resonance frequency is in the (m, n, p) mode.

4. A structure entirely surrounded by an electromagnetic wave shielding member having conductivity, a power transmitter that wirelessly powers a product via a power receiver disposed in the internal space of the structure, and a partition that separates the power receiver and the power transmitter. The structure has a bottom, a top facing the bottom, and side portions connecting the outer edges of the bottom and the top. The power transmitter is provided in contact with the inner surface of the bottom. The side portion of the structure has a first side portion and a second side portion facing the first side portion. A cavity resonance type power transmission device, wherein the power transmitter is provided in contact with the inner surface of the bottom and the inner surface of the first side portion.

5. The partition body is provided separately from the power transmitter, and the cavity resonance type power transmission device according to any one of claims 1 to 4.

6. The cavity resonance type power transmission device according to any one of claims 1 to 4, wherein a guide for restricting the position and direction of the power receiver is provided in a region of the internal space where the power receiver is disposed.

7. The cavity resonance type power transmission device according to claim 2 or 3, characterized in that switching of the resonance frequency is performed with a gap of 0.3 seconds or more.

8. The cavity resonance type power transmission device according to any one of claims 1 to 3, wherein the power transmitter is provided in contact with only the inner surface of the bottom of the structure.

9. The cavity resonance type power transmission device according to any one of claims 1 to 4, wherein the structure has a shape with a longitudinal direction from the bottom to the top.

10. The cavity resonance type power transmission device according to claim 9, wherein the partition body is disposed closer to the bottom than the top.

11. The cavity resonance type power transmission device according to claim 9, wherein a shelf for disposing the power receiver is further provided between the partition body and the top.

12. The cavity resonance type power transmission device according to any one of claims 1 to 4, wherein the resonance frequency in the internal space is in the TE110 mode.

13. The cavity resonance type power transmission device according to claim 4, wherein the structure has a shape with a longitudinal direction from the first side portion to the second side portion.

14. The cavity resonance type power transmission device according to claim 4, wherein the partition body is disposed closer to the first side portion than the second side portion.

15. The cavity resonance type power transmission device according to claim 4, wherein the power transmitter is provided in indirect contact with the inner surface of the bottom and in direct contact with the inner surface of the first side portion.

16. A cavity resonance type power transmission device according to any one of claims 1 to 4, and a power receiver disposed in the internal space of the structure of the cavity resonance type power transmission device, and a wireless power transmission system configured to wirelessly power a product via the power receiver by the power transmitter.

17. The wireless power transmission system according to claim 16, wherein a plurality of power receivers are provided.

18. The power receiver is separable from the product, the power receiver is connected to a charging terminal provided in the product, and the wireless power transmission system according to claim 16, wherein the product is wirelessly powered in a state where the product is disposed in the internal space of the structure.

19. The state where the power receiver is not packaged, The wireless power transmission system according to claim 16, wherein the power transmitter wirelessly supplies power to the product via the receiver in an unpacked state.

20. The receiver and the product are in a packed state, The wireless power transmission system according to claim 16, wherein the power transmitter wirelessly supplies power to the product via the receiver in the packed state.

21. The wireless power transmission system according to claim 20, wherein the receiver and the product are stacked on a partition in a packed state.

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