Power transmission and receiving system

Abstract

To provide a power transmission / reception system in which the efficiency of supplying power from a power transmission side to a power reception side is high, and the degree of freedom of an installation position is improved.SOLUTION: An electronic shelf label system includes a power transmission section 11, a power reception section 18, and a holding section 17. The power transmission section 11 is connected to a power source section, and is long. The power reception section 18 receives power from the power transmission section 11, and is shorter than the power transmission section. The holding section 17 holds one of the power transmission section 11 and the power reception section 18 to the other section. The power transmission section 11 includes three transmission-side conductive sheets and a transmission-side support. The power reception section 18 includes three reception-side conductive sheets and a reception-side support. The three transmission-side conductive sheets are each formed into a sheet-like shape extending in the longitudinal direction of the power transmission section 11, and have a constant width in the longitudinal direction. The spaces between the transmission-side conductive sheets are shorter than the width of each transmission-side conductive sheet. One end, in the longitudinal direction, of each transmission-side conductive sheet is connected to the power source section. The three reception-side conductive sheets are each formed into a sheet-like shape that is shorter than the transmission-side conductive sheets, and are disposed so as to face the three transmission-side conductive sheets.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a power transmission and reception system Regarding. [Background technology]

[0002] Wireless power transmission is known as a technology for supplying power to a power receiving side that is located far from the power transmitting side. Power transmission methods include electric field coupling and magnetic field coupling. Wireless power transmission is used for charging smartphones, advertising using electronic paper, and supplying power to electronic shelf labels.

[0003] For example, Patent Document 1 discloses a display system that employs a magnetic field coupling method. This display system improves power supply efficiency by forming a closed magnetic circuit between a power transmission coil and a power receiving coil provided in the display device, thereby reducing magnetic flux leakage. Patent Document 2 also discloses an electronic shelf label system that employs an electric field coupling method or a magnetic field coupling method. Specifically, the positional relationship between the amplitudes of the fundamental wave and the second harmonic is adjusted by adjusting the positional relationship between the two transmission lines to achieve optimal electromagnetic wave intensity. This optimizes power utilization efficiency. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-208793 [Patent Document 2] Japanese Patent Application Laid-Open No. 2013-162626 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the display system of Patent Document 1, the power supply efficiency varies depending on the position of the power receiving coil relative to the power transmitting coil, such that the power supply efficiency decreases as the power receiving coil is farther away from the power transmitting coil. This means that there is no flexibility in the installation location of the display device. Furthermore, the electronic shelf label system of Patent Document 2 supplies power using two transmission lines, using the fundamental wave and the second harmonic, and there are concerns that this alone will still result in low power supply efficiency.

[0006] Therefore, an object of the present invention is to provide a power transmission and reception system that is highly efficient in supplying power from the power transmission side to the power reception side and has improved freedom in terms of installation location. [Means for solving the problem]

[0007] The power transmission and reception system of the present invention comprises a power transmission unit, a power receiving unit, and a holding unit. The power transmission unit is connected to a power supply unit and is formed to be long. The power receiving unit receives power from the power transmission unit and is formed to be shorter than the power transmission unit. The holding unit holds one of the power transmission unit and the power receiving unit to the other. The power transmission unit has three power transmission side conductive sheets and a power transmission side support, and the power receiving unit has three power receiving side conductive sheets and a power receiving side support. The three power transmission side conductive sheets are formed in a sheet shape extending in the longitudinal direction of the power transmission unit, have a constant width in the longitudinal direction, are spaced apart from each other by a smaller distance than the respective widths, and have one end in the longitudinal direction connected to the power supply unit. The power transmission side support supports the three power transmission side conductive sheets. The three power receiving side conductive sheets are formed in a sheet shape shorter than the power transmission side conductive sheets and are arranged to face the three power transmission side conductive sheets. The power receiving side support supports the three power receiving side conductive sheets. Sheet Support. The power transmission side support is columnar with three power transmission side conductive sheets arranged near its outer peripheral surface, and the power receiving side support has an inner wall surface with a concave cross section that faces the outer peripheral surface of the power transmission side support, with three power receiving side conductive sheets arranged near the inner wall surface.

[0008] The power supply unit preferably supplies three-phase AC or pseudo three-phase AC to the three power-transmitting-side conductive sheets. When the power supply unit supplies three-phase AC, the power transmitting and receiving system preferably further includes a rectifier that rectifies the three-phase AC from the three power-receiving-side conductive sheets. When the power supply unit supplies pseudo three-phase AC, the power transmitting and receiving system preferably further includes a rectifier that rectifies the pseudo three-phase AC from the three power-receiving-side conductive sheets.

[0009] The width of the power-receiving-side conductive sheet is preferably the same as the width of the power-transmitting-side conductive sheet.

[0013] It is preferable that the device further includes a display unit, and one end of the power-receiving-side conductive sheet is connected to the display unit.

[0014] The display unit may be an electronic shelf label. [Effects of the Invention]

[0015] According to the present invention, the efficiency of supplying power from the power transmitting side to the power receiving side is high, and the degree of freedom in the installation location is improved. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a schematic diagram of an electronic shelf label system according to an embodiment. [Figure 2] FIG. 2 is a schematic diagram of a power transmitting unit and a power receiving unit. [Figure 3] FIG. 2 is an explanatory diagram of a power transmitting unit and a power receiving unit. [Figure 4] FIG. [Figure 5] FIG. [Figure 6] FIG. 2 is an explanatory diagram illustrating a state in which the power receiving unit is attached to the power transmitting unit. DETAILED DESCRIPTION OF THE INVENTION

[0017] The electronic shelf label system 10 shown in FIG. 1 is an example of a power transmission and reception system and includes a power transmission unit 11, a shelf label device 12, and a power supply unit 14. The shelf label device 12 displays product information such as the product name (product name, stock item name) and price of a product or stock item placed on a shelf board 13a of a shelf 13 installed in, for example, a store or warehouse. The shelf board 13a is arranged horizontally by a support post 13b installed in an upright position. The power transmission unit 11 is formed in the shape of a long sheet and constitutes a power transmission unit together with a housing 15 and the power supply unit 14. The housing 15 is hollow and can accommodate the power transmission unit 11, as described below. The power transmission unit 11 is used with part or all of it pulled out of the housing 15. One end of this power transmission unit 11 is fixed inside housing 15, and by fixing housing 15 to support column 13b of shelf 13 and fixing the other end of power transmission unit 11 to another support column 13b, power transmission unit 11 is disposed, for example, on the front surface of shelf board 13a. Power transmission unit 11 is connected to power supply unit 14 by wiring L1. In this example, wiring L1 is passed through the inside of hollow support column 13b, and one end of wiring L1 is connected to power transmission unit 11 inside housing 15, and the other end is connected to power supply unit 14.

[0018] The shelf label device 12 is composed of a display unit 16 that displays the item information, a power receiving unit 18, and the like. In this example, the display unit 16 uses electronic paper as an electronic shelf label. The power receiving unit 18 is provided on the rear side of the display unit 16 (the depth side of the paper in FIG. 1 ). The shelf label device 12 is attached to the power transmitting unit 11 by a holder 17 provided on the power receiving unit 18. The power receiving unit 18 receives power supplied from the power supply unit 14 from the power transmitting unit 11 and supplies it to the display unit 16. In this way, the shelf label device 12 is an example of a device to which power is supplied. The power receiving unit 18 is detachable from the power transmitting unit 11. The power transmitting unit 11 transmits power supplied from the power supply unit 14 to the power receiving unit 18, and the display unit 16 receives power from the power transmitting unit 11 via the power receiving unit 18. In this example, the power transmitting unit 11 and the power receiving unit 18 transmit and receive power using an electric field coupling method, the details of which will be described later using another figure.

[0019] 2, housing 15 is formed with an opening 21 for pulling out or winding up and storing long power transmission unit 11. A winding core 25 is provided inside housing 15 so as to be rotatable in the circumferential direction, and one end 24 of power transmission unit 11 in the longitudinal direction is fixed to winding core 25, and a stopper 22 is provided at the other end 26.

[0020] The housing 15 has a cylindrical shape, and each of the circular end faces is closed. The shape of the housing 15 may be determined depending on the state in which the power transmission unit 11 is housed. For example, when the power transmission unit 11 is housed in a rolled state, the housing 15 is preferably cylindrical in shape from the viewpoint of making the power transmission unit compact. On the other hand, when the power transmission unit 11 is housed in a folded state, the housing 15 may be rectangular in shape. When the power transmission unit 11 is housed in a folded state, the power transmission unit 11 may have grooves (not shown) extending in the width direction perpendicular to the longitudinal direction, at equal intervals along the longitudinal direction, alternately formed on one side and the other side along the longitudinal direction. This facilitates mountain folding along the grooves, enabling a foldable structure. However, the shape of the housing 15 may be determined by prioritizing the installation location and installation method of the power transmission unit 11 over the housing state. In this example, the power transmission unit 11 is housed in the housing 15 in a rolled state, as described below.

[0021] A winding core 25 fixed to a winding shaft 27 is disposed inside the housing 15. When the lower side of the housing 15 fixed to the support 13b (see FIG. 1) is considered to be the bottom, one end of the winding shaft 27 is located at the center of the bottom surface inside the housing 15, and the other end of the winding shaft 27 is disposed so as to penetrate from the top surface to the outside of the housing 15. The winding core 25 has a cylindrical shape with a perfectly circular cross section and rotates around the center of the cross section. The winding shaft 27 is disposed and fixed in a cavity that communicates from the top to the bottom of the winding core 25 at the rotation center. Because the winding core 25 is fixed to the winding shaft 27, rotating the winding shaft 27 in the circumferential direction also rotates the winding core 25 in the circumferential direction. In addition, a handle 28 is provided on the other end of the winding shaft 27. Because one end 24 of the power transmission unit 11 is fixed to the winding core 25, the power transmission unit 11 is wound around the winding core 25 by turning the handle 28. As a result, power transmission unit 11 is accommodated inside housing 15. The method for winding power transmission unit 11 is not limited to this, and a power spring may be used. Also, power transmission unit 11 may be accommodated by folding it.

[0022] A spatula-shaped plate 23 made of rubber is provided at the entrance 21, and the spatula-shaped plate 23 prevents contact between the entrance 21 and the power transmission unit 11, thereby reducing wear on the power transmission unit 11. It also removes foreign matter attached to the housed power transmission unit 11, thereby preventing foreign matter such as sand, dust, and dirt from entering the inside of the housing 15. The spatula-shaped plate 23 is not limited to being made of rubber, and may be made of a brush-like raised material, and can be made of any material as long as it does not impair its function of removing foreign matter.

[0023] Stopper 22 provided at the other end of power transmission unit 11 functions as a pull-out member that an operator holds between their fingertips, for example, when pulling power transmission unit 11 out of housing 15. By pulling stopper 22 in a direction away from housing 15, the housed power transmission unit 11 is pulled out. Furthermore, by releasing the force applied to stopper 22 in the direction away from housing 15, power transmission unit 11 is rewound. This allows for easy and quick start of pulling out power transmission unit 11.

[0024] Stopper 22 need only be larger than entrance / exit 21. In the illustrated embodiment, stopper 22 extends longer than the short-side length (width) of power transmission unit 11, but the size can be determined as appropriate as long as it does not impair the function of keeping other end 26 of power transmission unit 11 outside housing 15. A flange (not shown) is formed at other end 26 of power transmission unit 11, and a groove (not shown) is formed in stopper 22 in a shape corresponding to the flange, so that stopper 22 fits onto other end 26 of power transmission unit 11. Stopper 22 prevents the other end of power transmission unit 11 from entering housing 15.

[0025] Stopper 22 functions as a position-maintaining member for maintaining power transmission unit 11 in the pulled-out position when power transmission unit 11 is installed in an upright position on shelf 13 (see FIG. 1). In this case, the shape of stopper 22 can be determined according to the shape of shelf 13 to be used.

[0026] Power receiving unit 18, which is formed to be shorter than power transmitting unit 11, has a holding portion 17 on its upper end surface, and holding portion 17 holds power receiving unit 18 to power transmitting unit 11. Note that display unit 16 is not shown in Figure 2.

[0027] The "longitudinal direction," "width direction," and "thickness direction" in FIG. 3 refer to the longitudinal direction, width direction, and thickness direction of the power transmission unit 11. The power transmission unit 11 is mounted on the shelf 13a in an upright position with its longitudinal direction aligned horizontally. When held by the holder 17, the power receiving unit 18 is in contact with the power transmission unit 11. The holder 17 is mounted on the upper end surface of the power receiving unit 18 and protrudes from the surface of the power receiving unit 18 facing the power transmission unit 11 by a distance greater than the thickness of the upper part of the power receiving-side support 50 (see FIG. 5). The protruding tip has a bent shape that bends toward the underside of the power receiving unit 18. By hooking the holder 17 onto the upper part of the power transmission unit 11, the power receiving unit 18 is positioned in the width direction of the power transmission unit 11. The holder 17 ensures that the power transmission unit 11 and the power receiving unit 18 are in contact with each other at a fixed position. Thus, the shape and size of holding portion 17 are not limited to this example, as long as it positions and holds power transmitting portion 11 and power receiving portion 18 so that they are in contact with each other. In this example, holding portion 17 is provided on the upper portion of power receiving portion 18 in FIG. 3 , but a holding portion (not shown) may be provided, for example, on the lower portion of power receiving portion 18 in addition to or instead of the upper portion. In this example, holding portion 17 is provided on power receiving portion 18 in consideration of the fact that power transmitting portion 11 is housed in housing 15. However, holding portion 17 may be provided on power transmitting portion 11 in addition to or instead of power receiving portion 18 depending on the presence or absence of housing 15, the shape of the housing, etc.

[0028] As shown in FIG. 4 , the power transmission unit 11 includes a power transmission-side support 40 and three power transmission-side conductive sheets 42. The power transmission-side conductive sheets 42 are made of metal (copper in this example) and are formed as sheets extending in the longitudinal direction of the power transmission unit 11. The power transmission-side support 40 supports each power transmission-side conductive sheet 42 and covers the entire surface of the power transmission-side conductive sheet 42 except for the end face on the one end 24 side. The power transmission-side support 40 is formed of an insulating material such as an organic polymer (plastic), and is preferably thick enough to ensure flexibility for rolled-up storage in the housing 15 or for installation on a shelf or the like. The thickness of the power transmission-side support 40 in this example is 0.1 mm. Each of the power transmission-side conductive sheets 42 has a constant width and thickness in the longitudinal direction.

[0029] The width direction, thickness direction, and longitudinal direction of the power-transmission-side conductive sheet 42 correspond to the width direction, thickness direction, and longitudinal direction of the power-transmission-side support 40. The three power-transmission-side conductive sheets 42 have the same width, are constant in the longitudinal direction, and are arranged side by side in the width direction. The three power-transmission-side conductive sheets 42 are spaced apart from each other by a distance smaller than the width of each power-transmission-side conductive sheet 42 and are arranged parallel to each other in the longitudinal direction.

[0030] The wider the power transmission-side conductive sheet 42, the more efficient the power transmission, i.e., the amount of power transmitted per unit time, becomes. For this reason, a sheet-like (including flat) power transmission-side conductive sheet 42, as in this example, is preferable to a wire-like or rod-like one. Also, from the viewpoint of storage, a thin, flat sheet is preferable. Also, from the viewpoint of bending or folding the power transmission unit 11, it is preferable that the power transmission-side support 40 be made of a material that can be elastically deformed, such as silicone.

[0031] Each of the three power transmission side conductive sheets 42 has an end portion on the side of one end 24 of the power transmission unit 11 electrically connected to the power supply unit 14. The power supply unit 14 is composed of a generating circuit 46 that generates three-phase AC, a first matching circuit 45 that matches the impedance between this generating circuit 46 and each of the power transmission side conductive sheets 42 to improve power transmission efficiency, and the like.

[0032] As shown in Fig. 5, the power receiving unit 18 has a power receiving side support 50 and three power receiving side conductive sheets 52. The power receiving side conductive sheets 52 are made of metal (copper in this example) and are formed into sheets that extend in the longitudinal direction of the power transmitting unit 11 when attached facing the power transmitting unit 11. The power receiving side support 50 supports each power receiving side conductive sheet 52 and covers the entire surface of the power receiving side conductive sheet 52 except for the end face on one end 54 side. The power receiving side support 50 is made of an insulating material such as an organic polymer (plastic).

[0033] The power-receiving-side conductive sheet 52 is shorter than the power-transmitting-side conductive sheet 42. The wider the sheet, the higher the power receiving efficiency, i.e., the amount of power received per unit time. For this reason, the power-receiving-side conductive sheet 52 is preferably in a sheet shape (including a flat plate shape) rather than a linear or rod-like shape. Furthermore, when the power receiving unit 18 is attached to, for example, a curved display unit (not shown), the power-receiving-side support 50 may be formed from an elastically deformable material, such as silicone.

[0034] The shelf label device 12 of this example (see FIG. 1 ) includes a power receiving unit 18 and a display unit 16, as well as a second matching circuit 55, a three-phase full-wave rectifier (hereinafter simply referred to as the “rectifier”) 56, a power supply control unit 57, and a battery 58. The power receiving unit 18, together with the second matching circuit 55, the rectifier 56, the power supply control unit 57, and the battery 58, constitute a power receiving unit. The end 54 of the power receiving-side conductive sheet 52 exposed from the power receiving-side support 50 is connected to the rectifier 56 via the second matching circuit 55. The second matching circuit 55 matches the impedance between the power receiving-side conductive sheet 52 and the circuit on the rectifier 56 side, thereby improving power receiving efficiency. The rectifier 56 full-wave rectifies the three-phase AC input from each power receiving-side conductive sheet 52 and converts the three-phase AC into DC. The battery 58 is for storing power, and under the control of the power supply control unit 57, stores power from the rectifier unit 56 and supplies power to the display unit 16. Note that although an example using three-phase AC has been described above, a pseudo three-phase AC may instead be used, for example. When a pseudo three-phase AC is used, the power supply unit 14 (see FIG. 4) may be configured to use a generating circuit 46 that generates a pseudo three-phase AC from two-phase AC, and the rectifier unit 56 of the power receiving unit may be configured to rectify the pseudo three-phase AC to obtain a direct current. The pseudo three-phase AC may be generated from the two-phase AC by a well-known method using multiple coils or capacitors.

[0035] The power supply control unit 57 is electrically connected to each of the rectifier unit 56, the battery 58, and the display unit 16. The power supply control unit 57 controls power transmission, such as controlling the charging and discharging of the battery 58 and allocating how much power from the rectifier unit 56 is sent to the battery 58 or the display unit 16. The power supply control unit 57 in this example also functions as a regulator, controlling the current and voltage to be constant. Because the power supply control unit 57 is electrically connected to the display unit 16, supplying power to the display unit 16 causes the display unit 16 to output predetermined product information. Because the power supply control unit 57 is electrically connected to the rectifier unit 56, the battery 58, and the display unit 16, the power supplied from the rectifier unit 56 is output to the battery 58 or the display unit 16. When no power is supplied from the rectifier unit 56, the power stored in the battery 58 is output to the display unit 16. The control by the power supply control unit 57 may be active control, i.e., autonomous control by the power supply control unit 57, or passive control, in which control (on / off, current management, etc.) is performed in response to an external signal. When passive control is performed, for example, the power supply control unit 57 may be configured to receive and control signals from an external device using a microcomputer equipped with a communication function.

[0036] The width direction, thickness direction, and longitudinal direction of the power-receiving-side conductive sheet 52 correspond to the width direction, thickness direction, and longitudinal direction of the power-receiving-side support body 50. The three power-receiving-side conductive sheets 52 are arranged side by side in the width direction, at equal intervals, and parallel to one another. The center-to-center distance in the width direction of the three power-receiving-side conductive sheets 52 is the same as the center-to-center distance in the width direction of the three power-transmitting-side conductive sheets 42. As a result, when the power transmitting unit 11 and the power receiving unit 18 are held in a position facing each other, the power-transmitting-side conductive sheet 42 and the power-receiving-side conductive sheet 52 are positioned facing each other in the width direction.

[0037] When the power receiving unit 18 is attached to the power transmitting unit 11, their surfaces contact each other, as shown in FIG. 6 in this example. However, the power transmitting unit 11 and the power receiving unit 18 do not need to contact each other as long as the three power transmitting-side conductive sheets 42 and the three power receiving-side conductive sheets 52 are positioned facing each other. The three power transmitting-side conductive sheets 42 are located at the same position in the thickness direction and at the same distance in the thickness direction from the surface on the power receiving unit 18 side. For example, the three power transmitting-side conductive sheets 42 each have the same thickness T3 at T1 and the same widths W11, W12, and W13. The distance D1 between the widths W11 and W12 and the distance D2 between the widths W12 and W13 are also the same. The distances D1 and D2 are smaller than the widths W11, W12, and W13.

[0038] The three power-receiving-side conductive sheets 52 have a thickness T4 at the same position within the thickness T2 of the power-receiving-side support 50, and are disposed at the same distance in the thickness direction from the surface on the power-transmitting unit 11 side. The three power-receiving-side conductive sheets 52 have the same widths W21, W22, and W23, and the distance D3 between the widths W21 and W22 is equal to the distance D4 between the widths W22 and W23. Furthermore, the thickness T3 of the three power-transmitting-side conductive sheets 42 is equal to the thickness T4 of the three power-receiving-side conductive sheets 52, and the widths W11, W12, and W13 of the three power-transmitting-side conductive sheets 42 are equal to the widths W21, W22, and W23 of the three power-receiving-side conductive sheets 52. The distances D1 and D2 between the three power-transmitting-side conductive sheets 42 are also equal to the distances D3 and D4 between the three power-receiving-side conductive sheets 52. In Figure 6, the thickness T1 of the power transmitting unit 11 and the thickness T2 of the power receiving unit 18 are greatly exaggerated relative to the widths W11, W12, and W13 of the power transmitting side conductive sheet 42 and the widths W21, W22, and W23 of the power receiving side conductive sheet 52.

[0039] In this example, the widths W11, W12, and W13 of the power transmitter-side conductive sheet 42 are the same as each other, and the widths W21, W22, and W23 of the power receiver-side conductive sheet 52 are also the same as each other. From the perspective of power supply efficiency, it is preferable that the widths W11, W12, and W13 are the same as the widths W21, W22, and W23. Note that the widths of the power transmitter-side conductive sheet 42 and the power receiver-side conductive sheet 52 may be different as long as the centers of the widths W11, W21, and W22 of the power transmitter-side conductive sheet 42 and the power receiver-side conductive sheet 52 are the same in the width direction, the centers of the widths W12, W22, and W23 are the same in the width direction. From the perspective of ensuring higher power supply efficiency, it is preferable that the spacing D1 and the spacing D2 of the three power transmitter-side conductive sheets 42 are the same, and it is preferable that the spacing D3 and the spacing D4 of the three power receiver-side conductive sheets 52 are the same. In this example, the widths W11 to W13 and the widths W21 to W23 are 10 mm, the intervals D1 to D4 are 4 mm, the thicknesses T1 and T2 are 0.4 mm, and the thicknesses T3 and T4 are 35 μm, but are not limited to these.

[0040] According to the above configuration, the other end of power transmission unit 11 is held outside housing 15 by stopper 22. Doorway 21 is formed in a slit shape, allowing power transmission unit 11 housed in housing 15 to be easily pulled out. By holding housing 15 and stopper 22 in a predetermined position on shelf 13, power transmission unit 11 is arranged in a state where it is pulled out to a predetermined length. In this way, power transmission unit 11 is formed in a sheet (thin film) shape, and the length pulled out from housing 15 can be freely set, making it easy to install on an installation target such as a curved shelf (not shown). Power transmission unit 11 can be installed in a manner suited to the situation, environment, etc. of use, making it highly versatile.

[0041] Since a stopper 22 is provided at the other end of the power transmission unit 11, the power transmission unit 11 can be quickly pulled out from the other end, and the installation work is easy.

[0042] Power receiving unit 18 is held by power transmitting unit 11 by hooking holding portion 17 onto power transmitting unit 11. Because holding portion 17 is provided on the upper end surface of power receiving unit 18, it can be reliably held by the simple operation of hooking it onto the upper edge of power transmitting unit 11. Furthermore, because holding portion 17 is held simply by being hooked onto the upper edge of power transmitting unit 11, it is easy to move holding portion 17 in the longitudinal direction of power transmitting unit 11, allowing for flexibility in the installation position and improving workability.

[0043] There are three power transmitting-side conductive sheets 42 and three power receiving-side conductive sheets 52. For example, using three-phase AC or pseudo three-phase AC allows for more efficient power supply than using two-phase AC. Furthermore, with two-phase AC, when focusing on a specific position in the longitudinal direction of the power transmitting-side conductive sheet 42, the amplitude decreases as the node of the standing wave approaches, resulting in power not being received. However, using three-phase AC or pseudo three-phase AC prevents power not being received due to the power receiving position in the longitudinal direction of the power transmitting-side conductive sheet 42. Therefore, there is a high degree of freedom in the installation position of the short power receiving unit 18 in the longitudinal direction of the long transmitting unit 11, and the electronic shelf label system 10, which is an example of a power transmitting and receiving system, offers excellent installation positioning flexibility. Furthermore, the power receiving-side conductive sheets 52 have widths W21 to W23 equal to the widths W11 to W13 and spacings D3 and D4 equal to the spacings D1 and D2 so as to face each of the power transmitting-side conductive sheets 42. As a result, when the power receiving unit 18 is attached to the power transmitting unit 11 by the holding unit 17, the power receiving unit 18 is positioned so that each power receiving side conductive sheet 52 faces each power transmitting side conductive sheet 42, thereby ensuring reliable and efficient power supply.

[0044] Because intervals D1 and D2 are smaller than widths W11, W12, and W13, and because intervals D3 and D4 are smaller than widths W21, W22, and W33, widths W11 to W13 and widths W21 to W23 ensure sufficient power supply efficiency, while still providing compact (small-sized) power transmitting unit 11 and power receiving unit 18, which provides an excellent balance between power supply efficiency and compactness and can be used in small applications such as electronic shelf labels, thereby expanding the range of applications. Furthermore, because intervals D1 and D2 are smaller than widths W11, W12, and W13, high power supply efficiency is ensured even if there is some misalignment between power transmitting unit 11 and power receiving unit 18 in the width direction of power transmitting unit 11.

[0045] The power-receiving-side conductive sheets 52 have the same thickness T4 in the thickness direction, the same widths W21, W22, and W23, and the same spacings D3 and D4. Furthermore, the center of width W11 of the power-transmitting-side conductive sheet 42 and the center of width W21 of the power-receiving-side conductive sheet 52 are located at the same position, and the same relationships exist between widths W12 and W22, and between widths W13 and W31. Because the widths W11, W12, and W13 of the three power-transmitting-side conductive sheets 42 and the widths W21, W22, and W23 of the three power-receiving-side conductive sheets 52 are the same, power is supplied stably and efficiently.

[0046] The power transmission unit is not limited to a long sheet shape, but may be, for example, a long columnar or cylindrical shape. The cross section of the outer peripheral surface of the columnar or cylindrical shape may be a perfect circle or an ellipse. In this case, three power transmission side conductive sheets extending in the longitudinal direction of the power transmission side support may be provided on a columnar or cylindrical power transmission side support extending in one direction. The power transmission side conductive sheets are provided near the outer peripheral surface of the power transmission side support. In this case, the power receiving unit has a curved shape that follows the outer peripheral surface of the power transmission unit, i.e., a curved shape with an inner wall surface with a concave cross section that faces the outer peripheral surface of the power transmission side support, and the three power receiving side conductive sheets are arranged near this inner wall surface. [Explanation of symbols]

[0047] 10 Electronic shelf label system 11 Power Transmission Unit 12 Shelving label device 14 Power supply section 16 Display section 17 Holding part 18 Power receiving unit 21 Antenna entrance / exit 40 Power transmission side support 42 Power transmission side conductive sheet 45 1st matching circuit 50 Power receiving side support 52 Receiving side conductive sheet

Claims

1. a power transmission unit connected to the power supply unit and formed in an elongated shape; a power receiving unit that receives power from the power transmitting unit and is formed to be shorter than the power transmitting unit; a holding unit that holds one of the power transmitting unit and the power receiving unit to the other; Equipped with The power transmission unit is three power-transmission-side conductive sheets each having a sheet shape extending in a longitudinal direction, a constant width in the longitudinal direction, a spacing between each of the power-transmission-side conductive sheets smaller than the respective widths, and one end of each of the power-transmission-side conductive sheets in the longitudinal direction connected to the power supply unit; a power-transmission-side support member for supporting the three power-transmission-side conductive sheets; and The power receiving unit is three power-receiving-side conductive sheets formed in a sheet shape shorter than the power-transmitting-side conductive sheets and arranged to face the three power-transmitting-side conductive sheets; a power-receiving-side support body that supports the three power-receiving-side conductive sheets; and the power-transmission-side support body is a columnar body having the three power-transmission-side conductive sheets disposed near an outer circumferential surface thereof; A power transmission and receiving system in which the receiving side support has an inner wall surface with a concave cross section that faces the peripheral surface of the transmitting side support, and the three receiving side conductive sheets are arranged near the inner wall surface.

2. the power supply unit supplies three-phase AC or pseudo three-phase AC to the three power-transmission-side conductive sheets, The power transmission and receiving system according to claim 1, wherein when the power supply unit supplies three-phase AC, the power transmission and receiving system further comprises a rectifier unit that rectifies the three-phase AC from the three power receiving side conductive sheets, and when the power supply unit supplies pseudo three-phase AC, the power transmission and receiving system further comprises a rectifier unit that rectifies the pseudo three-phase AC from the three power receiving side conductive sheets.

3. The power transmitting and receiving system according to claim 1 or 2, wherein the width of the power receiving side conductive sheet is the same as the width of the power transmitting side conductive sheet.

4. Further comprising a display unit, The power transmitting and receiving system according to claim 1 , wherein one end of the power receiving side conductive sheet is connected to a display unit.

5. The power transmitting and receiving system according to claim 4 , wherein the display unit is an electronic shelf label.

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