Wireless power supply system

Abstract

To improve transmission efficiency in a wireless power supply system.SOLUTION: A wireless power supply system 100 includes: a power supply device 10 that has power supply electrodes 12, 13 and is provided in a building 1; a power receiving device 20 that receives power from the power supply device 10 through power receiving electrodes 22, 23 disposed to face the power supply electrodes 12, 13; and a floor finishing material 30 that is provided between the power supply electrodes 12, 13 and the power receiving electrodes 22, 23. The floor finishing material 30 includes a base material and a mixing material that has a higher dielectric constant than the base material and is mixed into the base material.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a wireless power supply system. [Background technology]

[0002] Patent Document 1 discloses a wireless power supply system including a power supply device provided in a building and a power receiving device that receives power from the power supply device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-180001 Summary of the Invention [Problem to be solved by the invention]

[0004] In the wireless power supply system described in Patent Document 1, a finishing material is provided between the power supply device and the power receiving device. Therefore, the transmission efficiency from the power supply device to the power receiving device is affected by the thickness and material of the finishing material, and depending on the specifications of the finishing material installed, the transmission efficiency may be significantly reduced.

[0005] An object of the present invention is to improve the transmission efficiency in a wireless power supply system. [Means for solving the problem]

[0006] The present invention is a wireless power supply system comprising: a power supply device having a power supply electrode and installed in a building; a power receiving device that receives power from the power supply device through a power receiving electrode arranged opposite the power supply electrode; and a floor finishing material installed between the power supply electrode and the power receiving electrode, wherein the floor finishing material includes a base material and an intermixed material having a higher dielectric constant than the base material and intermixed into the base material. [Effects of the Invention]

[0007] According to the present invention, it is possible to improve the transmission efficiency in a wireless power supply system. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic diagram showing an elevational cross section of a building equipped with a wireless power supply system according to a first embodiment of the present invention. [Figure 2] 1 is a plan view of a wireless power supply system according to a first embodiment of the present invention, viewed from above. [Figure 3] FIG. 2 is an enlarged view showing a part A in FIG. 1. [Figure 4] 1 is a circuit configuration diagram of a wireless power supply system according to a first embodiment of the present invention. [Figure 5] 10 is a graph showing the characteristics of an electromagnetic wave absorbing member. [Figure 6] FIG. 10 is a cross-sectional elevation view of a building equipped with a wireless power supply system according to a second embodiment of the present invention. [Figure 7] FIG. 10 is a plan view of a wireless power supply system according to a second embodiment of the present invention, as viewed from above. [Figure 8] FIG. 7 is an enlarged view showing a portion C in FIG. 6. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0010] First Embodiment First, a wireless power supply system 100 according to a first embodiment will be described with reference to Fig. 1 to Fig. 5. Fig. 1 is a schematic diagram showing an elevational cross section of a building 1 equipped with the wireless power supply system 100, and shows a cross section along line BB in Fig. 2. Fig. 2 is a plan view of the wireless power supply system 100 seen from above, Fig. 3 is an enlarged view showing a portion A in Fig. 1, and Fig. 4 is a circuit configuration diagram of the wireless power supply system 100.

[0011] The building 1 to which the wireless power supply system 100 is applied is, for example, a reinforced concrete building, and includes an underfloor material 2 and a floor finishing material 30 installed on the upper surface of the underfloor material 2. The building 1 may be made of wood, steel, reinforced concrete, or steel-reinforced concrete.

[0012] The underfloor material 2 is, for example, a concrete slab or a wooden board, and the floor finishing material 30 is, for example, a carpet tile or a flooring material, which are adhered to the upper surface of the underfloor material 2 with an acrylic resin adhesive or the like to form the floor surface of the building 1. Note that a member such as an insulating member 17, which will be described later, may be provided between the underfloor material 2 and the floor finishing material 30.

[0013] The wireless power supply system 100 includes a power supply device 10 having power supply electrodes 12 and 13 and installed in a building 1, a power receiving device 20 that receives power from the power supply device 10 through power receiving electrodes 22 and 23 that are arranged opposite the power supply electrodes 12 and 13, and the above-mentioned floor finishing material 30 that is installed between the power supply electrodes 12 and 13 and the power receiving electrodes 22 and 23. Note that the following description will be given assuming that the floor finishing material 30 is a tile carpet having a pile portion 34 that forms the pile that appears on the surface and a backing portion 32 to which the pile portion 34 is fixed, as shown in Fig. 3, and is a substantially square sheet member that is laid on the top surface of an underfloor material 2 as shown in Fig. 2.

[0014] 1 and 4, the power supply device 10 includes an AC voltage generation unit 11 that generates an AC voltage, and a first power supply electrode 12 and a second power supply electrode 13 that are electrically connected to the AC voltage generation unit 11. Note that in FIG. 1, the conductors connecting the AC voltage generation unit 11 to the first power supply electrode 12 and the second power supply electrode 13 are shown schematically. In FIG. 4, the first power supply electrode 12 and the second power supply electrode 13 are covered by the floor finishing material 30 and are not visible, but are shown hatched to make the arrangement of the first power supply electrode 12 and the second power supply electrode 13 easier to understand.

[0015] The AC voltage generating unit 11 is connected to a commercial power supply 7 that outputs an AC voltage of 50 Hz to 60 Hz, and generates an AC voltage with a frequency of several hundred kHz to several tens of MHz, preferably 6 to 7 MHz or 12 to 14 MHz. The commercial power supply 7 is, for example, a single-phase two-wire power supply that outputs an AC voltage of 100 V. Note that the commercial power supply 7 is not shown in FIG. 4.

[0016] The AC voltage generator 11 has a first terminal 11a and a second terminal 11b that output AC voltages of opposite phases to each other, and the first power supply electrode 12 and the second power supply electrode 13 are electrically connected to these terminals 11a and 11b, respectively. That is, AC voltages of opposite phases to each other are applied to the first power supply electrode 12 and the second power supply electrode 13.

[0017] As shown in Figures 1 and 2, the first power supply electrode 12 and the second power supply electrode 13 are plate-like members formed in strips extending parallel to each other along the underfloor material 2, and are made of, for example, iron, stainless steel, copper, or aluminum.

[0018] 3, the first power supply electrode 12 has a first width W1 of a predetermined size, the second power supply electrode 13 has a second width W2 of a predetermined size, and the first power supply electrode 12 and the second power supply electrode 13 are disposed with a predetermined distance W3 therebetween. The first width W1 and the second width W2 are approximately the same size, and the distance W3 is larger than the first width W1 and the second width W2, and is preferably set to be approximately 1.3 to 2 times larger.

[0019] Furthermore, insulating members 17 are provided between the first power supply electrode 12 and the underfloor material 2 and between the second power supply electrode 13 and the underfloor material 2, and the first power supply electrode 12 and the second power supply electrode 13 are electrically insulated from the underfloor material 2. By providing the insulating members 17 in this manner, current is prevented from flowing from the first power supply electrode 12 and the second power supply electrode 13 to the underfloor material 2, and as a result, the efficiency of power transmission from the power supply device 10 to the power receiving device 20 can be improved.

[0020] The power receiving device 20 has a case 21 that houses a rectifier 24 (described later) and the like, and a first power receiving electrode 22 and a second power receiving electrode 23 provided on the bottom surface of the case 21.

[0021] The case 21 is provided with an outlet into which a plug 9 of an electric device (not shown) is inserted, and when the plug 9 is inserted into the outlet of the power receiving device 20, power is supplied from the power supply device 10 to the electric device through the power receiving device 20. Note that the interior of the case 21 is not shown in Figures 1 and 3.

[0022] The first power receiving electrode 22 and the second power receiving electrode 23 are plate-shaped members arranged parallel to each other along the underside of the case 21, and like the first power supply electrode 12 and the second power supply electrode 13, are formed from, for example, iron, stainless steel, copper, or aluminum.

[0023] The case 21 is placed at any location on the floor finishing material 30 so that the first power receiving electrode 22 is positioned above the first power supply electrode 12 with the floor finishing material 30 in between, and the second power receiving electrode 23 is positioned above the second power supply electrode 13 with the floor finishing material 30 in between.

[0024] By positioning the case 21 in this manner so that the first power supply electrode 12 and the first power receiving electrode 22 face each other across the floor finishing material 30, and the second power supply electrode 13 and the second power receiving electrode 23 face each other across the floor finishing material 30, a capacitor is formed by the first power supply electrode 12, the floor finishing material 30, and the first power receiving electrode 22, and a capacitor is also formed by the second power supply electrode 13, the floor finishing material 30, and the second power receiving electrode 23. As a result, as will be described later, a voltage is excited in the first power receiving electrode 22 by the AC voltage applied to the first power supply electrode 12, and a voltage is excited in the second power receiving electrode 23 by the AC voltage applied to the second power supply electrode 13.

[0025] The case 21 is provided with a plurality of (for example, four) protrusions 21a that protrude downward from the underside to prevent misalignment relative to the floor finishing material 30. The tips of the protrusions 21a are rounded, and when the protrusions 21a are inserted so as to pierce the pile portion 34, the case 21 is held in place by the pile of the pile portion 34 via the protrusions 21a. The protrusion length of the protrusions 21a is set shorter than the thickness T1 of the floor finishing material 30 so as not to penetrate the floor finishing material 30, and is preferably set shorter than the thickness of the pile portion 34. Note that the protrusions 21a may have sharp tips that pierce the backing portion 32, but from a safety standpoint, a rounded shape is preferred.

[0026] By inserting the multiple protrusions 21a formed in this manner into the floor finishing material 30, the position of the case 21 relative to the floor finishing material 30 is maintained, and the first power receiving electrode 22 and the second power receiving electrode 23 are maintained facing the first power supply electrode 12 and the second power supply electrode 13, respectively, thereby improving the stability of power supply.

[0027] Furthermore, in order to maintain the position of the case 21 relative to the floor finishing material 30, the first power supply electrode 12 and the second power supply electrode 13 may be formed from a magnetic material such as iron, ferritic stainless steel, or martensitic stainless steel, and a magnet may be provided on the underside of the case 21. In this case, the force of attraction of the magnet provided on the case to the power supply electrodes 12, 13 made of a magnetic material will prevent the position of the power receiving device 20 from shifting on the floor.

[0028] In addition, in order to clearly indicate the position where the case 21 should be placed, i.e., the position where the first power supply electrode 12 and the second power supply electrode 13 are placed, the color of the pile portion 34, which is the color of the surface of the floor finishing material 30, is set to be different in the area where the first power supply electrode 12 and the second power supply electrode 13 are provided and the area where the first power supply electrode 12 and the second power supply electrode 13 are not provided.

[0029] Specifically, as shown in Figures 2 and 3, the pile portion 34 is colored a different color from other parts over an installation width W4 that includes the installation range of the first power supply electrode 12 and the second power supply electrode 13.

[0030] By clearly color-coding the areas where the first power supply electrode 12 and the second power supply electrode 13 are provided in this manner, it is possible to reliably position the case 21 on the floor finishing material 30 so that the first power receiving electrode 22 is positioned above the first power supply electrode 12, with the floor finishing material 30 in between, and the second power receiving electrode 23 is positioned above the second power supply electrode 13, with the floor finishing material 30 in between.

[0031] Next, with reference to the circuit configuration diagram shown in FIG. 4, the excitation of voltages in the first power receiving electrode 22 and the second power receiving electrode 23 will be described.

[0032] When a positive voltage is applied to the first power supply electrode 12 by the AC voltage generation unit 11, a positive charge is injected into the first power supply electrode 12. At this time, negative charges are collected at the first power receiving electrode 22 due to the electrostatic induction phenomenon. On the other hand, a voltage of opposite phase to the first power supply electrode 12, i.e., a negative voltage, is applied to the second power supply electrode 13, so that negative charges are injected into the second power supply electrode 13, and positive charges are collected at the second power receiving electrode 23 due to the electrostatic induction phenomenon.

[0033] In this way, negative charges are collected on the first power receiving electrode 22 and positive charges are collected on the second power receiving electrode 23, so that current appears to flow from the first power receiving electrode 22 to the second power receiving electrode 23, i.e., a positive voltage is excited on the first power receiving electrode 22 and a negative voltage is excited on the second power receiving electrode 23.

[0034] In addition, in Figure 4, we have explained the case where the first power supply electrode 12 and the first power receiving electrode 22 are opposite to each other and the second power supply electrode 13 and the second power receiving electrode 23 are opposite to each other. However, even when the first power supply electrode 12 and the second power receiving electrode 23 are opposite to each other and the second power supply electrode 13 and the first power receiving electrode 22 are opposite to each other, a voltage is excited in the first power receiving electrode 22 and the second power receiving electrode 23.

[0035] In other words, in the wireless power supply system 100, power can be supplied as long as the first power receiving electrode 22 faces one of the first power supply electrode 12 and the second power supply electrode 13, and the second power receiving electrode 23 faces the other of the first power supply electrode 12 and the second power supply electrode 13.

[0036] This type of wireless power supply is performed by placing a pair of electrodes facing each other and using an electric field between the electrodes, and is therefore also called an "electric field coupling method."

[0037] Here, the amount of power transmitted in the electric field coupling method varies depending on the capacitance and applied voltage, but as mentioned above, when a floor finishing material 30 is provided between the power supply electrodes 12, 13 and the power receiving electrodes 22, 23, the capacitance varies depending on the thickness T1 of the floor finishing material 30 and the dielectric constant of the floor finishing material 30, so the power transmission efficiency is affected by the material of the floor finishing material 30, etc., and depending on the specifications of the floor finishing material 30, the transmission efficiency may be significantly reduced.

[0038] Therefore, in this embodiment, the dielectric constant of the floor finishing material 30 is increased to improve the power transmission efficiency.

[0039] Specifically, a material with a relatively high dielectric constant, such as titanium oxide or alumina, is mixed into the backing portion 32 of the floor finishing material 30. Note that the material with a high dielectric constant is not limited to these, and any material that has a relative dielectric constant of 20 or more, preferably 100 or more, and that can be mixed into the backing portion 32 may be used.

[0040] Generally, calcium carbonate and polyvinyl chloride are used as the base material for the backing portion 32, but by mixing a predetermined weight ratio of an additive material with a higher dielectric constant than the base material, the dielectric constant of the backing portion 32 can be increased. The mixing ratio of the additive material is set within a range that does not significantly reduce the functions of the conventional backing portion 32, such as the ability to prevent the pile portion 34 from slipping out, the flexibility of the floor finishing material 30, and the strength of the floor finishing material 30.

[0041] In this way, by increasing the dielectric constant of the floor finishing material 30, which is sandwiched between the power supply electrodes 12, 13 and the power receiving electrodes 22, 23 and functions as a dielectric, the capacitance of the capacitor formed by the first power supply electrode 12, the floor finishing material 30, and the first power receiving electrode 22 and the capacitance of the capacitor formed by the second power supply electrode 13, the floor finishing material 30, and the second power receiving electrode 23 each increase, resulting in improved power transmission efficiency.

[0042] Furthermore, if the dielectric constant of the floor finishing material 30 is increased uniformly, there is a concern that the first power supply electrode 12 and the second power receiving electrode 23 may be short-circuited (conductive) or the second power supply electrode 13 and the first power receiving electrode 22 may be short-circuited (conductive). Therefore, the size of the gap W3 between the first power supply electrode 12 and the second power supply electrode 13 is set to at least four times, and preferably at least six times, the thickness T1 of the dielectric floor finishing material 30, and the size of the gap W3 is set to at least ten times the thickness T2 of the backing portion 32 into which titanium oxide or alumina is mixed as an additive.

[0043] That is, the distance between the first power supply electrode 12 and the second power receiving electrode 23 and the distance between the second power supply electrode 13 and the first power receiving electrode 22 are set to be sufficiently larger than the gap between the opposing first power supply electrode 12 and the first power receiving electrode 22 and the gap between the opposing second power supply electrode 13 and the second power receiving electrode 23. This prevents a short circuit between the first power supply electrode 12 and the second power receiving electrode 23 and between the second power supply electrode 13 and the first power receiving electrode 22.

[0044] Furthermore, since the above-described short circuit is avoided, the mixed material can be mixed uniformly throughout the backing portion 32, thereby reducing the manufacturing costs of the floor finishing material 30 containing the mixed material compared to mixing the mixed material only in a portion of the backing portion 32. Note that, to increase the capacitance, the mixed material may be mixed only in the portion of the backing portion 32 sandwiched between the first power supply electrode 12 and the first power receiving electrode 22 or the portion of the backing portion 32 sandwiched between the second power supply electrode 13 and the second power receiving electrode 23. However, mixing the mixed material only in specific portions of the backing portion 32 increases the manufacturing costs of the floor finishing material 30, so it is preferable to mix the mixed material uniformly throughout the backing portion 32.

[0045] Furthermore, in order to increase the dielectric constant of the floor finishing material 30, instead of or in addition to mixing a material with a relatively high dielectric constant into the backing portion 32, a material with a relatively high dielectric constant, such as titanium oxide or alumina, may be mixed into the nylon or polypropylene base material of the pile portion 34.

[0046] Next, the supply of power to an electric device (not shown) connected to the power receiving device 20 will be described with reference to the circuit configuration diagram shown in FIG.

[0047] As described above, the voltage excited in the first power receiving electrode 22 and the second power receiving electrode 23 is the same AC voltage as the voltage applied to the first power supply electrode 12 and the second power supply electrode 13, and its frequency is the frequency of the AC voltage generated by the AC voltage generation unit 11, i.e., several hundred kHz to several MHz. Therefore, if an electrical device (not shown) connected to the power receiving device 20 is an device compatible with the commercial power source 7, the voltage excited in the first power receiving electrode 22 and the second power receiving electrode 23 cannot be used as is.

[0048] Therefore, in the wireless power supply system 100, a rectifier 24 is provided to connect the first power receiving electrode 22 and the second power receiving electrode 23, thereby converting the voltage excited at the first power receiving electrode 22 and the second power receiving electrode 23 into a DC voltage, and a DC / AC converter 25 is provided between the power extraction terminal 26 and the rectifier 24, thereby converting the DC voltage output from the rectifier 24 into an AC voltage equivalent to that of the commercial power source 7 (for example, an AC voltage of 50 Hz to 60 Hz).

[0049] This makes it possible to extract from terminal 26 an AC voltage equivalent to the AC voltage output from commercial power supply 7, and to supply power to devices compatible with commercial power supply 7.

[0050] Furthermore, by changing the color of the pile portion 34 of the floor finishing material 30 in the area corresponding to the positions where the first power supply electrode 12 and the second power supply electrode 13 are placed as described above, even if the user of the wireless power supply system 100 is able to place the case 21 in the appropriate position, there is a risk that they will not be able to confirm whether or not power is actually being supplied.

[0051] Therefore, in the wireless power supply system 100, the power receiving device 20 is provided with an alarm 27 that notifies that a voltage has been excited at the first power receiving electrode 22 and the second power receiving electrode 23. The alarm 27 is, for example, a lamp, and emits light using the DC voltage output from the rectifier 24.

[0052] In this way, the alarm 27 notifies the user that a voltage has been excited in the first power receiving electrode 22 and the second power receiving electrode 23, so that the user of the wireless power supply system 100 can easily determine whether the first power receiving electrode 22 and the second power receiving electrode 23 are facing the first power supply electrode 12 and the second power supply electrode 13 and whether power is being supplied.

[0053] The power receiving device 20 also includes a storage battery 28 that stores the voltage excited at the first power receiving electrode 22 and the second power receiving electrode 23. Therefore, when the voltage excitation at the first power receiving electrode 22 and the second power receiving electrode 23 stops, a voltage is output from the storage battery 28. This makes it possible to prevent a momentary power interruption due to the power receiving device 20 being misaligned, thereby improving the stability of power supply.

[0054] The rectifier 24, the DC / AC converter 25, and the storage battery 28 are housed in a case 21.

[0055] Furthermore, the first power supply electrode 12 and the second power supply electrode 13 of the wireless power supply system 100 configured as described above emit electromagnetic waves having a frequency that correlates with the power transmission frequency PF of a predetermined magnitude, for example, 6 to 7 MHz or 12 to 14 MHz, such as the frequency of the AC voltage generated in the AC voltage generation unit 11, for example, a frequency that is an integer multiple of the power transmission frequency PF. Such electromagnetic waves with a relatively high frequency may affect the operation of electronic devices used near the wireless power supply system 100 and communications using electromagnetic waves (radio waves).

[0056] In order to suppress such an influence, the wireless power supply system 100 further includes an electromagnetic wave absorbing member 40 capable of absorbing electromagnetic waves having a frequency higher than the frequency of the AC voltage generated by the AC voltage generating unit 11.

[0057] The electromagnetic wave absorbing member 40 is a sheet member formed by blending, for example, iron oxide (Fe2O3) with metal oxides such as NiO, CuO, and ZnO, and as shown in FIG. 5, the blend is set to have electromagnetic wave absorption properties that mainly attenuate electromagnetic waves of frequencies higher than the power transmission frequency PF without attenuating the power transmission frequency PF.

[0058] The electromagnetic wave absorbing characteristics of the electromagnetic wave absorbing member 40 are not limited to those shown in FIG. 5, but may be any characteristics that can attenuate electromagnetic waves in a frequency range excluding the frequency of the AC voltage generated in the AC voltage generating unit 11, i.e., frequencies around the power transmission frequency PF, and may have electromagnetic wave absorbing characteristics that attenuate not only electromagnetic waves with frequencies higher than the power transmission frequency PF, but also electromagnetic waves with frequencies lower than the power transmission frequency PF.

[0059] 1 and 3, the electromagnetic wave absorbing member 40 is provided on the back surface of the floor finishing material 30, i.e., between the floor finishing material 30 and the power feeding electrodes 12, 13. The surface on which the electromagnetic wave absorbing member 40 is provided is not limited to the back surface of the floor finishing material 30, but may also be between the floor finishing material 30 and the power receiving electrodes 22, 23 or inside the floor finishing material 30. For example, the electromagnetic wave absorbing member 40 may be provided between the backing portion 32 and the pile portion 34 of the floor finishing material 30, or may be provided inside the backing portion 32 to also serve as a reinforcing material. The electromagnetic wave absorbing member 40 may also be provided on multiple surfaces rather than just one of these surfaces, and multiple electromagnetic wave absorbing members 40 may be arranged so as to overlap each other in layers.

[0060] By providing the electromagnetic wave absorbing member 40 so as to cover the power feeding electrodes 12, 13 in this manner, it is possible to suppress the emission of relatively high frequency electromagnetic waves from the power feeding electrodes 12, 13 into the surrounding area, thereby suppressing the influence on the operation of electronic devices used in the vicinity of the wireless power feeding system 100 and on radio wave communications. Note that the frequency of the AC voltage generated in the AC voltage generating unit 11, i.e., the power transmission frequency PF, is hardly attenuated by the electromagnetic wave absorbing member 40, and therefore, even if the electromagnetic wave absorbing member 40 is provided, a significant decrease in the transmission efficiency of the wireless power feeding system 100 can be avoided.

[0061] According to the first embodiment described above, the following advantageous effects are achieved.

[0062] In the above-described wireless power supply system 100, the floor finishing material 30 provided between the power supply electrodes 12, 13 of the power supply device 10 and the power receiving electrodes 22, 23 of the power receiving device 20 includes a base material and a mixed material having a higher dielectric constant than the base material and mixed into the base material.

[0063] By mixing such a material with a relatively high dielectric constant into the floor finishing material 30 provided between the power supply electrodes 12, 13 of the power supply device 10 and the power receiving electrodes 22, 23 of the power receiving device 20 and increasing the dielectric constant of the floor finishing material 30, which functions as a dielectric, the capacitance of the capacitor formed by the power supply electrodes 12, 13, the floor finishing material 30, and the power receiving electrodes 22, 23 increases, thereby improving the transmission efficiency of the wireless power supply system 100.

[0064] In addition, in the wireless power supply system 100, an electromagnetic wave absorbing member 40 capable of absorbing electromagnetic waves having a frequency higher than the frequency of the AC voltage generated in the AC voltage generating unit 11 is provided to cover the power supply electrodes 12, 13 of the power supply device 10.

[0065] By providing the electromagnetic wave absorbing member 40 so as to cover the power supply electrodes 12 and 13, it is possible to suppress the emission of relatively high frequency electromagnetic waves from the power supply electrodes 12 and 13 into the surrounding area, and as a result, it is possible to suppress the impact on the operation of electronic devices used in the vicinity of the wireless power supply system 100 and on communications using radio waves.

[0066] Second Embodiment Next, a wireless power supply system 200 according to a second embodiment will be described with reference to Fig. 6 to Fig. 8. Differences from the first embodiment will be mainly described below, and the same or corresponding configurations as those described in the first embodiment will be denoted by the same reference numerals in the drawings and will not be described again.

[0067] Fig. 6 is a schematic diagram showing an elevation cross section of a building 1 equipped with a wireless power supply system 200, and shows a cross section along line DD in Fig. 7. Fig. 7 is a plan view of the wireless power supply system 200 seen from above, and Fig. 8 is an enlarged view showing a portion C in Fig. 6.

[0068] Similar to the wireless power supply system 100 according to the first embodiment, the wireless power supply system 200 according to the second embodiment includes a power supply device 10 having power supply electrodes 12 and 13 and installed in a building 1, a power receiving device 20 that receives power from the power supply device 10 through power receiving electrodes 22 and 23 that are arranged opposite the power supply electrodes 12 and 13, and a floor finishing material 136 that is installed between the power supply electrodes 12 and 13 and the power receiving electrodes 22 and 23.

[0069] The wireless power supply system 200 according to the second embodiment differs from the wireless power supply system 100 according to the first embodiment described above mainly in that the floor finishing material 136 provided between the power supply electrodes 12, 13 and the power receiving electrodes 22, 23 is a vinyl chloride sheet member formed in a strip shape, as shown in FIGS. 6 to 8.

[0070] In Figure 7, the approximately square floor finishing material 130 laid between adjacent floor finishing materials 136 is a tile carpet having a pile portion that forms the pile that appears on the surface and a backing portion to which the pile portion is fixed, like the floor finishing material 30 of the first embodiment described above.

[0071] The configurations of the power supply device 10 and the power receiving device 20 are the same as those of the power supply device 10 and the power receiving device 20 of the first embodiment described above, and therefore a description thereof will be omitted.

[0072] As shown in FIG. 7, the floor finishing material 136 is a strip-shaped sheet member arranged along the first and second power supply electrodes 12 and 13, which extend parallel to each other along the underfloor material 2, so as to cover the first and second power supply electrodes 12 and 13, and is mixed with a material having a higher dielectric constant than the base material, such as titanium oxide or alumina, at a predetermined weight ratio relative to the base material, polyvinyl chloride.

[0073] That is, also in the second embodiment, the dielectric constant of the floor finishing material 136, which is sandwiched between the power feeding electrodes 12, 13 and the power receiving electrodes 22, 23 and functions as a dielectric, is increased. Therefore, also in the second embodiment, as in the first embodiment, the capacitance of the capacitor formed by the power feeding electrodes 12, 13, the floor finishing material 136, and the power receiving electrodes 22, 23 is increased, and therefore the efficiency of power transmission between the power feeding device 10 and the power receiving device 20 can be improved.

[0074] As in the first embodiment, the size of the gap W3 between the first power supply electrode 12 and the second power supply electrode 13 is set to at least four times, preferably at least six times, the thickness T3 of the floor finishing material 136 into which titanium oxide or alumina is mixed as an additive.

[0075] Furthermore, similar to the wireless power supply system 100 according to the first embodiment described above, the wireless power supply system 200 further includes an electromagnetic wave absorbing member 140 capable of absorbing electromagnetic waves having a frequency higher than the frequency of the AC voltage generated in the AC voltage generating unit 11.

[0076] 6 and 8, the electromagnetic wave absorbing member 140 is provided on the back surface of the floor finishing material 136, i.e., between the floor finishing material 136 and the power feeding electrodes 12 and 13. The surface on which the electromagnetic wave absorbing member 140 is provided is not limited to the back surface of the floor finishing material 136, but may also be between the floor finishing material 136 and the power receiving electrodes 22 and 23 or inside the floor finishing material 136. For example, the electromagnetic wave absorbing member 140 may be provided inside the floor finishing material 136 to also serve as a reinforcing material. The electromagnetic wave absorbing member 140 may also be provided on multiple surfaces rather than just one of these surfaces, and multiple electromagnetic wave absorbing members 140 may be arranged so as to overlap each other in layers.

[0077] By providing the electromagnetic wave absorbing member 140 so as to cover the power supply electrodes 12 and 13 in this manner, in the second embodiment as in the first embodiment, it is possible to suppress the emission of relatively high frequency electromagnetic waves from the power supply electrodes 12 and 13 into the surrounding area, and as a result, it is possible to suppress the effects on the operation of electronic devices used in the vicinity of the wireless power supply system 200 and on communication using radio waves.

[0078] Furthermore, in the wireless power supply system 200, the power supply electrodes 12 and 13 are attached in advance to the rear surface of the floor finishing material 136 together with the electromagnetic wave absorbing member 140. In other words, the power supply electrodes 12 and 13, the electromagnetic wave absorbing member 140, and the floor finishing material 136 are provided integrally.

[0079] Therefore, by placing the floor finishing material 136 on the upper surface of the underfloor material 2, it is possible to place the power supply electrodes 12, 13 and the electromagnetic wave absorbing member 140 together, which makes it easier to install the wireless power supply system 200 compared to when the power supply electrodes 12, 13 and the electromagnetic wave absorbing member 140 are placed separately from the floor finishing material 136.

[0080] 6 and 8, in the wireless power supply system 200, the thickness T3 of the floor finishing material 136 is set to be thinner than the thickness of the floor finishing material 130 laid around it. In other words, the surface of the floor finishing material 136 on which the power receiving device 20 is installed is lower than the surface of the floor finishing material 130 laid around it.

[0081] 6 and 8, the position of the power receiving device 20 installed on the surface of the floor finishing material 136 is prevented from shifting left or right in the figure by the floor finishing material 130 laid around the floor finishing material 136. This maintains the position of the case 21 relative to the floor finishing material 136, so that the first power receiving electrode 22 and the second power receiving electrode 23 are maintained facing the first power supply electrode 14 and the second power supply electrode 15, respectively, thereby improving the stability of power supply.

[0082] In order to reliably prevent the power receiving device 20 from shifting position, the case 21 may be provided with a protrusion 21a or a magnet, as in the first embodiment.

[0083] According to the second embodiment described above, the following advantageous effects are achieved, similar to the first embodiment.

[0084] In the above-described wireless power supply system 200, the floor finishing material 136 provided between the power supply electrodes 12, 13 of the power supply device 10 and the power receiving electrodes 22, 23 of the power receiving device 20 includes a base material and a mixed material having a higher dielectric constant than the base material and mixed into the base material.

[0085] By mixing such a material with a relatively high dielectric constant into the floor finishing material 136 provided between the power supply electrodes 12, 13 of the power supply device 10 and the power receiving electrodes 22, 23 of the power receiving device 20 and increasing the dielectric constant of the floor finishing material 136, which functions as a dielectric, the capacitance of the capacitor formed by the power supply electrodes 12, 13, the floor finishing material 136, and the power receiving electrodes 22, 23 increases, and as a result, the transmission efficiency of the wireless power supply system 200 can be improved.

[0086] In addition, in the wireless power supply system 200, an electromagnetic wave absorbing member 140 capable of absorbing electromagnetic waves having a frequency higher than the frequency of the AC voltage generated in the AC voltage generating unit 11 is provided to cover the power supply electrodes 12 and 13 of the power supply device 10.

[0087] By providing the electromagnetic wave absorbing member 140 so as to cover the power supply electrodes 12 and 13, it is possible to suppress the emission of relatively high frequency electromagnetic waves from the power supply electrodes 12 and 13 into the surrounding area, and as a result, it is possible to suppress the impact on the operation of electronic devices used in the vicinity of the wireless power supply system 200 and on communications using radio waves.

[0088] The following modified examples are also within the scope of the present invention, and it is possible to combine the configurations shown in the modified examples with the configurations described in the above-mentioned embodiments, or to combine the configurations described in the different modified examples below.

[0089] In each of the above embodiments, an AC voltage of opposite phase is applied to the first power supply electrode 12 and the second power supply electrode 13 to excite a voltage in the first power receiving electrode 22 and the second power receiving electrode 23. However, an AC voltage may be applied to one of the first power supply electrode 12 and the second power supply electrode 13, and the other of the first power supply electrode 12 and the second power supply electrode 13 may be a neutral line with a potential of 0 (zero). Even in this case, power can be supplied from the power supply device 10 to the power receiving device 20.

[0090] Furthermore, when the other of the first power supply electrode 12 and the second power supply electrode 13 is used as the neutral line, it is sufficient that an electrical insulator is provided between one of the power supply electrodes and the building substrate, and no electrical insulator is required between the other power supply electrode and the building substrate. In this case, the alarm 27 is configured to notify that a voltage has been excited in the first power receiving electrode 22, and the storage battery 28 is configured to store the voltage excited in the first power receiving electrode 22.

[0091] In addition, as a method for making the other of the first and second power supply electrodes 12 and 13 a neutral conductor, in addition to the method of doing so within an electrical circuit, it is also possible to omit the insulating coating of the other power supply electrode and actively make it the same potential as the building structure or the floor ground, etc., to make it a neutral conductor.

[0092] In each of the above embodiments, the power receiving device 20 is formed separately from the electric device and includes an outlet into which the plug 9 of the electric device is inserted. Alternatively, the power receiving device 20 may be provided integrally with the electric device, in which case power is supplied directly from the power supply device 10 to the electric device.

[0093] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above embodiments. [Explanation of symbols]

[0094] 100,200...Wireless power supply system 1. Building 2. Underfloor material 10. Power supply device 11. AC voltage generation unit 12: First power supply electrode (power supply electrode) 13... Second feed electrode (feed electrode) 20 Power receiving device 21a...Protrusion 22: First power receiving electrode (power receiving electrode) 23... Second power receiving electrode (power receiving electrode) 30,136···Floor finishing materials 32 Backing section 34 Pile section 40,140...Electromagnetic wave absorbing material

Claims

1. a power supply device having a power supply electrode and installed in the building; a power receiving device that receives power from the power feeding device through a power receiving electrode that is disposed opposite to the power feeding electrode; a floor finishing material provided between the power supply electrode and the power receiving electrode, The floor finishing material includes a base material and an admixture having a higher dielectric constant than the base material and admixed into the base material. Wireless power supply system.

2. the power supply device further includes an AC voltage generation unit connected to the power supply electrode and generating an AC voltage; the wireless power supply system further includes an electromagnetic wave absorbing member capable of absorbing electromagnetic waves having a frequency higher than a frequency of the AC voltage generated by the AC voltage generating unit; The electromagnetic wave absorbing member is provided at least one of between the floor finishing material and the power supply electrode, between the floor finishing material and the power receiving electrode, and inside the floor finishing material. The wireless power supply system according to claim 1 .

3. The floor covering material is formed in a strip shape, The power supply electrode and the electromagnetic wave absorbing member are provided integrally with the floor finishing material. The wireless power supply system according to claim 2 .

4. a pile portion is provided on the power receiving electrode side of the floor finishing material, the pile portion has a different color in an area where the power supply electrode is provided and an area where the power supply electrode is not provided; The wireless power supply system according to claim 1 .

5. the power supply electrode includes a first power supply electrode and a second power supply electrode each having a strip shape extending parallel to each other; The size of the gap between the first power supply electrode and the second power supply electrode is at least four times the thickness of the floor covering material. The wireless power supply system according to claim 1 .

6. The power receiving device has a protrusion that penetrates the floor finishing material. The wireless power supply system according to claim 1 .

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