Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
  • H02J50/00—Circuit arrangements or systems for wireless supply or distribution of electric power
  • H02J50/10—Circuit arrangements or systems for wireless supply or distribution of electric power using inductive coupling

Definitions

• the present invention relates to a wireless power supply sheet, a wireless power supply device, and a wireless power supply system.
• Patent Document 1 discloses a technology that uses a meandering conductor to shorten the wavelength of electromagnetic waves propagating within a power supply sheet, thereby improving power supply efficiency.
• the power supply sheet it is also desirable for the power supply sheet to be used outdoors. In this case, it is desirable for it to be unaffected by water from rain, etc.
• the present invention provides a two-dimensional wireless power supply sheet and wireless power supply system that are less affected by water, etc.
• a two-dimensional wireless power supply sheet includes a dielectric layer, a first conductive layer, and a second conductive layer.
• the dielectric layer is sandwiched between the first conductive layer and the second conductive layer to guide an electromagnetic wave in a predetermined direction.
• the first conductive layer includes a conductor of a first shape.
• the first shape is a shape that shortens the wavelength of the electromagnetic wave and generates a magnetic field perpendicular to the direction in which the electromagnetic wave is guided and in a direction that penetrates the first conductive layer and the second conductive layer.
• the second conductive layer includes a conductor of a second shape that is disposed in a position facing the first conductive layer with the dielectric layer in between. The second shape is different from the first shape.
• FIG. 1 is a perspective view showing a configuration of a two-dimensional wireless power supply sheet 10.
• FIG. FIG. 1 is a diagram for explaining an overview of power supply.
• 1A and 1B are diagrams showing examples of the shape of a planar coil.
• 1A and 1B are diagrams showing examples of the shape of a planar coil.
• 1A and 1B are diagrams showing examples of the shape of a planar coil.
• 1A and 1B are diagrams showing examples of the shape of a planar coil.
• FIG. 1A and 1B are diagrams showing a first shape and a second shape including a plurality of planar coils; 1A and 1B are diagrams showing a first shape and a second shape including a plurality of planar coils; 1 is a diagram for explaining a magnetic field generated by the two-dimensional wireless power supply sheet 10.
• FIG. 13A and 13B are diagrams showing other examples of a first shape and a second shape including a plurality of planar coils.
• FIG. 1 is a diagram for explaining an overview of reflex control.
• the two-dimensional wireless power feeding sheet 10, the power feeding section 20, the reflection control section 30, and the power receiving terminal 50 are represented as a circuit.
• FIG. 13 is a diagram showing an equivalent circuit of the circuit shown in FIG. 12 .
• FIG. 13 is a diagram showing an equivalent circuit of the circuit shown in FIG. 12 .
• FIG. 1 is a diagram illustrating an example of a configuration of a wireless power supply device.
• FIG. 2 is an enlarged view of a coil element.
• FIG. 2 is a diagram showing an example of a waveform drawn by a magnetic field.
• FIG. 2 is a diagram showing an example of an emitted magnetic field.
• FIG. 13 is a diagram showing another example of an emitted magnetic field.
• FIG. 13 is a diagram illustrating another example of the configuration of a wireless power supply device.
• FIG. 13 is a diagram illustrating another example of the configuration of a wireless power supply device.
• the term "unit” may include, for example, a combination of hardware resources implemented by a circuit in the broad sense and software information processing that can be specifically realized by these hardware resources.
• various information is handled, and this information is represented, for example, by physical values of signal values representing voltage and current, high and low signal values as a binary bit set consisting of 0 or 1, or quantum superposition (so-called quantum bits), and communication and calculation can be performed on the circuit in the broad sense.
• a circuit in the broad sense is a circuit that is realized by at least appropriately combining a circuit, circuitry, a processor, and memory.
• ASICs application specific integrated circuits
• SPLDs simple programmable logic devices
• CPLDs complex programmable logic devices
• FPGAs field programmable gate arrays
• FIG. 1 is a perspective view showing the configuration of a two-dimensional wireless power supply sheet 10.
• the two-dimensional wireless power supply sheet 10 includes a dielectric layer 11, a first conductive layer 12, and a second conductive layer 13.
• a power supply unit (not shown) is connected to one end in the x-axis direction of the first conductive layer 12 and the second conductive layer 13, and a voltage is applied between them.
• the other end in the x-axis direction of the first conductive layer 12 and the second conductive layer 13 is electrically connected.
• the dielectric layer 11 has a flat plate shape, and is sandwiched between the first conductive layer 12 and the second conductive layer 13 to guide an electromagnetic wave in a predetermined direction.
• the direction in which the electromagnetic wave is guided is the x-axis direction shown in the figure.
• the first conductive layer 12 is arranged so as to be in contact with the dielectric layer 11 and one surface of the dielectric layer 11, and includes a conductor of a first shape described later.
• the second conductive layer 13 is disposed at a position facing the first conductive layer 12 with the dielectric layer 11 interposed therebetween, and includes a conductor of a second shape, which will be described later. This second shape is different from the first shape.
• the dielectric layer 11 may be formed of hollow structures made of dielectric materials, such as dielectric foams and honeycomb structures.
• materials with high conductivity such as gold, silver, copper, aluminum, and iron, may be appropriately adopted.
• an insulator several millimeters thick is placed over the surface, which can significantly reduce the absorption and scattering of electromagnetic waves when the two-dimensional wireless power supply sheet 10 comes into contact with the human body or other objects.
• FIG. 2 is a diagram for explaining an overview of power supply.
• electromagnetic waves EM are propagated in the x-axis direction within the dielectric layer 11, and this electromagnetic wave EM is emitted to the outside of the two-dimensional wireless power supply sheet 10 as a magnetic field H.
• this magnetic field H is magnetically coupled to the power receiving terminal 50, and the power receiving terminal 50 receives power.
• the magnetic field H can be generated by at least the first shape of the conductor included in the first conductor.
• the first shape needs to be a shape that generates a magnetic field perpendicular to the direction in which the electromagnetic wave EM is guided (x-axis direction) and in a direction that penetrates the first conductive layer 12 and the second conductive layer 13 (z-axis direction).
• the first shape be a shape that shortens the wavelength of the electromagnetic wave.
• first shape which is the shape of the conductor included in the first conductive layer 12, and a second shape, which is the shape of the conductor included in the second conductive layer 13, will be described.
• first shape and the second shape are shapes that generate a magnetic field and shorten the wavelength of the electromagnetic wave.
• the wavelength ⁇ of the electromagnetic wave propagated in the dielectric layer 11 can be expressed by Equation 1.
• L is the reactance of the first conductive layer 12 and the second conductive layer 13
• C is the capacitance between the first conductive layer 12 and the second conductive layer 13
• ⁇ is the angular frequency of the electromagnetic wave.
• the wavelength of the electromagnetic waves can be shortened. Furthermore, the reactance L of the first conductive layer 12 and the second conductive layer 13 affects the strength of the magnetic field generated from the two-dimensional wireless power supply sheet 10, and the larger the value of the reactance L, the stronger the generated magnetic field. For this reason, it is desirable to increase the reactance L of the first conductive layer 12 and the second conductive layer 13.
• the first shape is a shape including at least one planar coil.
• the second shape does not have to include a planar coil.
• the second shape may include a planar coil.
• the first shape does not include a planar coil
• the second shape is a shape including at least one planar coil.
• both the first shape and the second shape may include a planar coil.
• the first shape that is, the planar coil of the conductor included in the first conductive layer 12 and the planar coil of the conductor included in the second conductive layer 13 have different winding directions. This is to match the direction of the generated magnetic field.
• Figures 3 to 6 are diagrams showing examples of the shape of the planar coil.
• the first shape includes planar coil 12-1, planar coil 12-2, planar coil 12-3, planar coil 12-4, etc.
• the second shape includes planar coils with shapes that are inverted from planar coil 12-1, planar coil 12-2, planar coil 12-3, planar coil 12-4, etc.
• FIGs 7 and 8 are diagrams showing a first shape and a second shape that include multiple planar coils.
• the first shape is a shape that includes multiple planar coils 12-1 or planar coil 12-2 that are arranged in succession in the direction in which the electromagnetic waves are guided (x direction).
• the second shape is a shape that includes multiple planar coils 13-1 or planar coils 13-2 that are arranged in succession in the direction in which the electromagnetic waves are guided (x direction).
• the center of the planar coil 12-1, etc. included in the first conductive layer (first shape) and the center of the planar coil 13-1, etc. included in the second conductive layer (second shape) are at different positions on the xy plane in the direction in which the electromagnetic waves are guided, and it is further preferable that the center of the planar coil 12-1, etc. included in the second conductive layer (second shape) and the center between the adjacent planar coils 12-1, etc. included in the first conductive layer (first shape) are at the same position. This is because by making the center of the planar coil 12-1 and the center of the planar coil 13-1 different, the strength of the generated magnetic field can be made nearly uniform.
• FIG. 9 is a diagram for explaining the magnetic field generated by the two-dimensional wireless power supply sheet 10.
• the solid arrows in the figure represent some of the magnetic field lines of the magnetic field generated by the planar coil included in the first shape, for example, planar coil 12-1, and the dashed arrows represent some of the magnetic field lines of the magnetic field generated by the planar coil included in the second shape, for example, planar coil 13-1.
• Arrow 12H indicates the center of the magnetic field generated by the planar coil included in the first shape
• arrow 13H indicates the center of the magnetic field generated by the planar coil included in the second shape.
• planar coil 13-1 shown in FIG. 7 has a shape obtained by inverting planar coil 12-1
• planar coil 13-2 shown in FIG. 8 has a shape obtained by inverting planar coil 12-2
• the planar coil included in the second shape is not limited to the planar coil included in the first shape
• the first shape and the second shape may each include planar coils of different shapes.
• FIG. 10 is a diagram showing another example of a first shape and a second shape including multiple planar coils.
• the first shape includes planar coil 13-1
• the second shape includes planar coil 13-4.
• each of the first shape and the second shape may include planar coils of different shapes.
• the two-dimensional wireless power supply sheet 10 has a relative dielectric constant of 2.2, a characteristic impedance of 50 ⁇ , a sheet inductance of 13.4 ⁇ H, a sheet resistance of 8.79 ⁇ , a sheet Q value of 65, a sheet capacitance of 5.36 pF, and a propagation loss of ⁇ 0.706 dB/m.
• the half wavelength of the electromagnetic wave in the sheet is about 23 mm, so that it is possible to supply power to the power receiving terminal 50 by disposing a receiving coil with a diameter of about 10 to 20 mm in the power receiving terminal 50.
• FIG. 11 is a diagram for explaining an overview of the reflection control.
• Reflection control is performed by connecting a reflection control unit 30 to the two-dimensional wireless power supply sheet 10, as shown in FIG. 11.
• the reflection control unit 30 is disposed at one end in the direction in which the electromagnetic wave EM is guided (x-axis direction) when the power supply unit 20 is connected to the other end, and controls the reflection of the electromagnetic wave EM at this other end.
• the control by this reflection control unit 30 cancels the reflected wave of the electromagnetic wave reflected at the position of the power receiving terminal 50 when the power receiving terminal 50 is located between the one end and the other end, due to the reflected wave at the other end.
• the reflection control unit 30 controls the reflected electromagnetic wave EM3 so as to cancel out the electromagnetic wave EM2. This makes it possible to reduce or eliminate the electromagnetic waves EM2 and EM3, and as a result, to reduce the influence on the electromagnetic wave EM.
• the reflection control unit 30 can be realized by including a circuit having an impedance according to a circuit constant including the circuit constants of the dielectric layer 11, the first conductive layer 12, and the second conductive layer 13.
• FIG. 12 shows the two-dimensional wireless power supply sheet 10, the power supply unit 20, the reflection control unit 30, and the power receiving terminal 50 represented as a circuit.
• Fig. 13 is a diagram showing an equivalent circuit of the circuit shown in Fig. 12.
• the part indicated by the symbol A in Fig. 12 is replaced with a power source with impedance Z0
• the coil (such as a planar coil included in the first conductive layer 12) included in the two-dimensional wireless power supply sheet 10 and the power receiving coil included in the power receiving terminal 50 in the part indicated by the symbol B in Fig. 12 are replaced with a magnetic field coupling circuit with a coefficient k
• the part indicated by the symbol C in Fig. 12 from the position of the power receiving terminal 50 to the reflection control unit 30 is replaced with an impedance Zterm2 .
• Lm in Fig. 13 is the reactance of the magnetic field coupling circuit.
• Equation 5 the result shown in Equation 5 is obtained when the efficiency of power supply to the power receiving terminal 50 is maximized.
• R Lopt means R L when the efficiency of power supply is maximized. This makes it possible to maximize the efficiency by adjusting the reflection control unit 30.
• a wireless power supply system can be configured by including the above-described two-dimensional wireless power supply sheet 10 and the power receiving terminal 50.
• the power receiving terminal 50 includes a power receiving coil having a size equal to or smaller than half the wavelength of the electromagnetic wave propagated within the two-dimensional wireless power supply sheet 10.
• a coil included in the first conductive layer 12 and a coil included in the second conductive layer 13 form a capacitor.
• the number of conductive layers (layers including the first conductive layer 12 and the second conductive layer 13 in the case of the first embodiment) formed by arranging the coils forming the capacitor in this manner is one (i.e., one layer), but it may be two or more (i.e., two layers).
• FIG. 14 is a diagram showing an example of the configuration of a wireless power supply device.
• the wireless power supply device 2a shown in FIG. 14 is a device that wirelessly supplies power to the power receiving terminal 50 shown in FIG. 2, and includes a two-dimensional wireless power supply sheet 10a and a power supply unit 20a.
• the two-dimensional wireless power supply sheet 10a transmits electromagnetic waves by passing an alternating current inside, similar to the two-dimensional wireless power supply sheet 10 shown in FIG. 1, and supplies power to the power receiving terminal 50 by magnetically coupling the magnetic field (also called a magnetic field) formed by emitting the electromagnetic waves to the outside of the two-dimensional wireless power supply sheet 10a with the power receiving terminal 50.
• the magnetic field also called a magnetic field
• the two-dimensional wireless power supply sheet 10a is a sheet-like device that stretches in the stretching direction D2 and transmits electromagnetic waves in the transmission direction D1.
• the two-dimensional wireless power supply sheet 10a has a length in the stretching direction D2 of several tens of cm (centimeters) to several meters, a dimension in the thickness direction D3 of several mm (millimeters), and a dimension in the width direction D4 of several tens of cm. Note that this size is just an example and can be changed as necessary.
• the power supply unit 20a is a power supply source that supplies alternating current to the two-dimensional wireless power supply sheet 10a.
• the power supply unit 20a includes a power supply unit 21a, a power supply unit 22a, and a power supply unit 23a.
• the two-dimensional wireless power supply sheet 10a includes a first conductive layer 41a, a second conductive layer 42a, and a third conductive layer 43a.
• the first conductive layer 41a, the second conductive layer 42a, and the third conductive layer 43a are each conductive layers including a coil that forms a capacitor.
• the power supply unit 21a is connected to the end of the first conductive layer 41a in the extension direction D2 (the end opposite the transmission direction D1; the same applies below) and supplies AC current to the first conductive layer 41a.
• the power supply unit 22a is connected to the end of the second conductive layer 42a in the extension direction D2 and supplies AC current to the second conductive layer 42a.
• the power supply unit 23a is connected to the end of the third conductive layer 43a in the extension direction D2 and supplies AC current to the third conductive layer 43a.
• the first conductive layer 41a comprises a first circuit portion 61a and a second circuit portion 71a.
• a power supply portion 21a is connected between the first circuit portion 61a and the second circuit portion 71a, and an AC current is supplied from the power supply portion 21a to the first circuit portion 61a and the second circuit portion 71a.
• the AC current supplied by the power supply portion 21a flows while alternately switching between a direction approaching the power supply portion 21a and a direction away from the power supply portion 21a, but the direction of the current flowing through the first circuit portion 61a is opposite to the direction of the current flowing through the second circuit portion 71a.
• the first circuit section 61a and the second circuit section 71a form a plurality of coil elements 80a and a plurality of coil elements 90a.
• the coil elements 80a and the coil elements 90a are arranged alternately along the extension direction D2.
• the coil element 90a has a first coil 91a and a second coil 92a.
• the first coil 91a and the second coil 92a share a common axis and are wound in opposite directions. Furthermore, the coil element 90a is wound in the opposite direction to the coil element 80a. In other words, when viewed from above in the figure, the first coil 91a is wound counterclockwise and the second coil 92a is wound clockwise.
• the first coil 91a is a coil formed by the first circuit portion 61a
• the second coil 92a is a coil formed by the second circuit portion 71a.
• the magnetic fields generated by the first coil 91a and the second coil 92a are oriented in the same direction at the same timing.
• the second conductive layer 42a and the third conductive layer 43a have the same configuration as the first conductive layer 41a.
• the second conductive layer 42a has a first circuit portion 62a and a second circuit portion 72a, and a power supply portion 22a is connected between the first circuit portion 62a and the second circuit portion 72a to supply AC current.
• the first circuit portion 62a and the second circuit portion 72a form a plurality of coil elements 80a and a plurality of coil elements 90a, and the coil elements 80a and the coil elements 90a are arranged alternately along the extension direction D2.
• the third conductive layer 43a includes a first circuit portion 63a and a second circuit portion 73a, and a power supply portion 23a is connected between the first circuit portion 63a and the second circuit portion 73a to supply AC current.
• the first circuit portion 63a and the second circuit portion 73a form a plurality of coil elements 80a and a plurality of coil elements 90a, and the coil elements 80a and the coil elements 90a are arranged alternately along the extension direction D2.
• the coil element 80a and the coil element 90a each form a capacitor.
• the first coil 81a and the second coil 82a may be arranged with an inductor between them, and the first coil 91a and the second coil 92a may be arranged with an inductor between them to form a capacitor, but in the second embodiment, the capacitor is formed in a different manner.
• FIG. 15 is an enlarged view of the coil element.
• the first conductive layer 41a is shown enlarged.
• the coil base 15a shown in FIG. 15 is a plate-shaped member that serves as a base for winding the coil, and has a groove on the side for winding the conductor.
• multiple coil bases 15a are arranged along the extension direction D2.
• Each coil base 15a has a rectangular shape when viewed from above, and is arranged so that its long side is aligned along the width direction D4 and its short side is aligned along the extension direction D2.
• the conductor that will become the first circuit portion 61a is wound clockwise when viewed from above around the coil base 15a that serves as the base of the coil element 80a, and the conductor that will become the second circuit portion 71a is wound counterclockwise when viewed from above.
• the conductor that will become the first circuit portion 61a is wound counterclockwise when viewed from above around the coil base 15a that serves as the base of the coil element 90a, and the conductor that will become the second circuit portion 71a is wound clockwise when viewed from above.
• the conductors are wound in order so that the coil elements 80a and coil elements 90a alternate.
• the coil elements 80a and 90a of the first conductive layer 41a, the second conductive layer 42a, and the third conductive layer 43a are offset by a length L1 in the transmission direction D1 (extension direction D2) of their respective axes.
• the length L1 is one-third of the length of the transmission direction D1 of the coil element 80a, and one-third of the length of the transmission direction D1 of the coil element 90a.
• the coil element 80a of the second conductive layer 42a is arranged at a position shifted by length L1 in the transmission direction D1 from the coil element 80a of the third conductive layer 43a, and the coil element 80a of the first conductive layer 41a is arranged at a position shifted by length L1 in the transmission direction D1 from the coil element 80a of the second conductive layer 42a.
• the coil element 90a of the third conductive layer 43a is arranged at a position shifted by length L1 in the transmission direction D1 from the coil element 80a of the first conductive layer 41a. In this way, the coil elements 80a and coil elements 90a of the first conductive layer 41a, the second conductive layer 42a, and the third conductive layer 43a are repeatedly arranged, shifted by length L1 each.
• the power supply unit 21a, the power supply unit 22a, and the power supply unit 23a supply AC current, which generates a magnetic field in each of the first conductive layer 41a, the second conductive layer 42a, and the third conductive layer 43a.
• the power supply unit 21a, the power supply unit 22a, and the power supply unit 23a each supply AC currents with a phase difference of 120 degrees, so-called three-phase AC currents.
• the magnetic field emitted outside the two-dimensional wireless power supply sheet 10a forms a smoother waveform than when there is only one conductive layer.
• FIG. 16 is a diagram showing an example of a waveform drawn by a magnetic field.
• a graph is shown where the vertical axis indicates magnetic field strength and the horizontal axis indicates the position in the transmission direction D1.
• the magnetic field strength is shown with the horizontal axis position set to "0", and the strength when the magnetic field is pointing upward and the strength when the magnetic field is pointing downward are shown.
• the horizontal axis indicates the axial position of coil element 80a on the third conductive layer 43a as "0", the axial position of coil element 80a on the second conductive layer 42a as "0.5", the axial position of coil element 80a on the first conductive layer 41a as “1”, the axial position of coil element 90a on the third conductive layer 43a as "1.5”, the axial position of coil element 90a on the second conductive layer 42a as "2”, the axial position of coil element 90a on the first conductive layer 41a as "2.5”, and the axial position of coil element 80a on the third conductive layer 43a as "3".
• the distance between each coil element in the transmission direction D1 is "L1".
• the magnetic field strength is a composite of the magnetic fields generated by not only the coil element 80a of the first conductive layer 41a, but also the coil elements 80a of the second conductive layer 42a and 90a of the third conductive layer 43a.
• Figures 16(a), (b), and (c) show that the waveform indicated by the magnetic field strength moves in the transmission direction D1 over time.
• Figure 17 is a diagram showing an example of an emitted magnetic field.
• Figure 17 shows the results of a simulation of the magnetic field generated when a three-phase AC current with a frequency of 100 kHz is passed through a two-dimensional wireless power supply sheet 10a with a length of 500 mm.
• an upward magnetic field H1 and a downward magnetic field H2 are emitted alternately outside the two-dimensional wireless power supply sheet 10a.
• the length including each of the magnetic fields H1 and H2 represents one wavelength, and in the example of Figure 17, a magnetic field of 2.5 wavelengths is generated, so one wavelength is approximately 200 mm.
• FIG. 18 is a diagram showing another example of the emitted magnetic field.
• a simulation result of the magnetic field generated when a three-phase AC current with a frequency of 100 kHz is passed through a two-dimensional wireless power supply sheet 10x (length 500 mm) in which each of three conductive layers has only a first coil is shown.
• a magnetic field of two wavelengths is generated, so one wavelength is about 250 mm.
• the two-dimensional wireless power supply sheet 10a is an example of a wireless power supply sheet that includes N or more (N is a natural number of 2 or more) conductive layers in which multiple coil elements are arranged in the transmission direction.
• N is 3, and the sheet includes three conductive layers: a first conductive layer 41a, a second conductive layer 42a, and a third conductive layer 43a.
• These N or more conductive layers function as waveguides that transmit electromagnetic waves.
• each conductive layer a plurality of coil elements, namely, a plurality of coil elements 80a and a plurality of coil elements 90a, are arranged in the transmission direction D1.
• Each coil element has a first coil and a second coil.
• coil element 80a has a first coil 81a and a second coil 82a
• coil element 90a has a first coil 91a and a second coil 92a. These second coils share a common axis with the first coil and are wound in the opposite direction.
• the transmission direction D1 is the direction in which electromagnetic waves are transmitted through the aforementioned waveguide when an alternating current flows through a circuit including a first circuit section 61a in which a plurality of first coils are connected in series, and a second circuit section 71a in which a plurality of second coils are connected in series.
• the positions of the coil elements in the N or more conductive layers are shifted from one another in the transmission direction D1.
• the positions of the coil elements 80a and 90a included in the first conductive layer 41a, the second conductive layer 42a, and the third conductive layer 43a in the transmission direction D1 are shifted by a length L1 as shown in FIG. 14.
• the center of the planar coil (corresponding to the first coil) included in the first shape and the center of the planar coil (corresponding to the second coil) included in the second shape are located at different positions, so that the strength of the generated magnetic field becomes close to uniform, but this is the case when there is one conductive layer.
• the axis of one coil element (a set of the first coil and the second coil) may be common, and the axes of the coil elements of different conductive layers may be shifted to increase the uniformity of the magnetic field.
• the distance between the first coil and the second coil becomes closer than when this axis is shifted, and the capacitance of the capacitor formed by the coil element is increased, and the group velocity (the speed at which the composite wave of the magnetic field travels) described above can be slowed down.
• the positions of the coil elements in the transmission direction D1 are shifted from each other by 1/N of the length of the transmission direction D1 of the coil elements.
• the number N of conductive layers is 3, and the positions of the coil elements in the transmission direction D1 are shifted by a length L1, which is 1/3 of the length of the transmission direction D1 of each coil element (coil element 80a and coil element 90a).
• first coil 81a shown in FIG. 14 has a conductor wound clockwise when viewed from above
• first coil 91a has a conductor wound counterclockwise when viewed from above
• second coil 82a has a conductor wound counterclockwise when viewed from above
• second coil 92a has a conductor wound clockwise when viewed from above.
• the coil winding direction shown in FIG. 14 is just one example.
• the winding direction of the multiple first coils may all be the same, and the winding direction of the multiple second coils may all be the same (however, the winding direction of the first coil is opposite to that of the second coil).
• the magnetic field generated by the coil elements traces a trajectory as shown in FIG. 9, after being emitted from the two-dimensional wireless power supply sheet 10a and then returning, so that the returning part and the emitted part cancel each other out.
• This cancellation occurs when the magnetic fields generated by the coil elements have the same direction, as shown in FIG. 9. Therefore, by alternately reversing the winding direction of the coil elements as in the example of FIG. 14, the cancellation of the magnetic fields between adjacent coil elements is reduced compared to when all the winding directions are the same, and electromagnetic waves can be transmitted with low loss.
• the first coil (first coil 81a and first coil 91a) and the second coil (second coil 82a and second coil 92a) are formed from a conductor coated with a dielectric, and as shown in FIG. 15, the conductor of the first coil and the conductor of the second coil are in close contact with each other.
• the conductor of the first coil and the conductor of the second coil are in close contact with each other to form a capacitor simply by winding the conductor around a member such as the coil base 15a shown in FIG. 15. Therefore, a coil that functions as a capacitor can be easily created compared to a configuration in which a dielectric layer is sandwiched between two conductive layers as in the example of FIG. 2.
• the wireless power supply device 2a includes the two-dimensional wireless power supply sheet 10a and the power supply unit 20a.
• the power supply unit 20a is connected to one end of the two-dimensional wireless power supply sheet 10a, and supplies AC current to the first circuit unit (first circuit units 61a, 62a, 63a) and the second circuit unit (second circuit units 71a, 72a, 73a). This configuration eliminates the need to provide a separate power source.
• FIG. 19 is a diagram showing another example of the configuration of a wireless power supply device.
• the wireless power supply device 2b shown in FIG. 19 includes a two-dimensional wireless power supply sheet 10b and a power supply unit 20b.
• the two-dimensional wireless power supply sheet 10b includes a first conductive layer 41b and a second conductive layer 42b.
• the first conductive layer 41b and the second conductive layer 42b are each a conductive layer including a coil that forms a capacitor.
• the power supply unit 20b includes a power supply unit 21b and a power supply unit 22b.
• the first conductive layer 41b includes a first circuit portion 61b and a second circuit portion 71b.
• a power supply portion 21b is connected between the first circuit portion 61b and the second circuit portion 71b, and an alternating current is supplied from the power supply portion 21b to the first circuit portion 61b and the second circuit portion 71b.
• the first circuit portion 61b and the second circuit portion 71b form a plurality of coil elements 80b.
• the coil element 80b has a first coil 81b and a second coil 82b.
• the first coil 81b and the second coil 82b are coils that share a common axis and are wound in opposite directions.
• the first coil 81b is a coil formed by the first circuit portion 61b
• the second coil 82b is a coil formed by the second circuit portion 71b. Since the direction of current flowing through the first circuit portion 61b is opposite to the direction of current flowing through the second circuit portion 71b, the magnetic fields generated by the first coil 81b and the second coil 82b have the same direction when AC current flows through the first circuit portion 61b and the first circuit portion 62b. Also, in the example of FIG. 19, the magnetic fields generated by the multiple coil elements 80b at the same timing all have the same direction.
• the second conductive layer 42b has a similar configuration to the first conductive layer 41b.
• the second conductive layer 42b has a first circuit section 62b and a second circuit section 72b, and a power supply section 22b is connected between the first circuit section 62b and the second circuit section 72b to supply AC current.
• the first circuit section 62b and the second circuit section 72b form a plurality of coil elements 80b.
• the plurality of coil elements 80b provided in the second conductive layer 42b all generate magnetic fields with the same direction at the same timing. Note that the direction of the magnetic field H1 shown in FIG. 19 only indicates that the magnetic field direction in each conductive layer is the same, and the direction and strength of the magnetic field generated differ depending on the phase of the AC current supplied to each conductive layer.
• the positions of the coil elements 80b in the first conductive layer 41b and the second conductive layer 42b in the transmission direction D1 (extension direction D2) of their respective axes are shifted by a length L2.
• the length L2 is half the length of the coil element 80b in the transmission direction D1.
• power supply unit 21b and power supply unit 22b supply AC current, which generates a magnetic field in each of the first conductive layer 41b and the second conductive layer 42b.
• AC current which generates a magnetic field in each of the first conductive layer 41b and the second conductive layer 42b.
• power supply unit 21b and power supply unit 22b each supply AC current with a phase difference of 180 degrees, so-called two-phase AC current. This reduces the cancellation of magnetic fields between adjacent coil elements compared to when AC currents of the same phase are passed, making it possible to transmit electromagnetic waves with low loss.
• the power supply unit 21c is connected between the first circuit unit 61c and the second circuit unit 71c, and AC current is supplied from the power supply unit 21c to the first circuit unit 61c and the second circuit unit 71c.
• the first circuit unit 61c and the second circuit unit 71c form a plurality of coil elements 80c.
• the coil element 80c has a first coil 81c and a second coil 82c.
• the first coil 81c and the second coil 82c have a common axis and are wound in opposite directions.
• the first coil 81c is a coil formed by the first circuit portion 61c
• the second coil 82c is a coil formed by the second circuit portion 71c.
• the first circuit portion 61c first forms the first coil 81c of the second conductive layer 42c, then forms the first coil 81c of the first conductive layer 41c, and then forms the first coil 81c of the second conductive layer 42c again.
• the first circuit portion 61c is configured by repeatedly forming the first coil 81c of the second conductive layer 42c and the first coil 81c of the first conductive layer 41c in sequence, with these first coils 81c connected in series.
• the second circuit section 71c first forms the second coil 82c on the second conductive layer 42c, then forms the second coil 82c on the first conductive layer 41c, and then forms the second coil 82c on the second conductive layer 42c again. In this way, the second circuit section 71c forms the second coil 82c on the second conductive layer 42c and the second coil 82c on the first conductive layer 41c in a repeated order, and forms a configuration in which these second coils 82c are connected in series.
• the positions of the coil elements 80c in the first conductive layer 41c and the second conductive layer 42c in the transmission direction D1 (extension direction D2) of their respective axes are shifted by a length L2.
• the length L2 is half the length of the transmission direction D1 of the coil element 80c.
• a magnetic field is generated in each of the first conductive layer 41c and the second conductive layer 42c when the power supply unit 21c supplies an alternating current.
• the first circuit section is a series circuit in which first coils of different conductive layers are sequentially connected to each other
• the second circuit section is a series circuit in which second coils of different conductive layers are sequentially connected to each other.
• the number N of conductive layers (N is a natural number of 2 or more) and the number M of power supply parts (M is a natural number of 1 or more) may or may not be the same (provided that N ⁇ M).
• N is increased, the spacing of the coil element axes in the transmission direction D1 becomes shorter, thereby improving the uniformity of the magnetic field.
• M may also be increased to shift the phase of the AC current, or the winding directions of the coil elements may be alternately reversed as in the example of Figure 14, thereby reducing the cancellation of magnetic fields.
• reducing M may simplify the structure of the device and reduce costs.
• a clockwise wound coil may be wound counterclockwise, or a counterclockwise wound coil may be wound clockwise.
• coil elements with different winding directions may be arranged alternately as in the example of Fig. 14.
• each coil element may be a planar coil as in embodiment 1, so long as the first coil and second coil share a common axis and are wound in opposite directions. Furthermore, it is preferable that the number of turns of the conductor wire of the first coil and second coil be the same, but they may differ slightly. Furthermore, the reflection control in embodiment 1 may be performed in embodiment 2 and the modified examples.
• the AC current supplied by each supply unit may have a phase different from that in the above example.
• the phases shifted by 120 degrees in a three-phase AC may be shifted by 60 degrees or by 90 degrees.
• the phase may be shifted by 90 degrees.
• the AC current may be supplied without a phase shift. In any case, if the positions of the coil elements of each conductive layer in the transmission direction D1 are shifted from each other, a more uniform magnetic field can be generated compared to when these positions are aligned.
• the present invention may be provided in the following aspects:
• a two-dimensional wireless power supply sheet comprising a dielectric layer, a first conductive layer, and a second conductive layer, the dielectric layer being sandwiched between the first conductive layer and the second conductive layer to guide an electromagnetic wave in a predetermined direction
• the first conductive layer including a conductor having a first shape, the first shape being a shape that shortens the wavelength of the electromagnetic wave and generates a magnetic field perpendicular to the direction in which the electromagnetic wave is guided and in a direction that penetrates the first conductive layer and the second conductive layer
• the second conductive layer including a conductor having a second shape disposed in a position facing the first conductive layer across the dielectric layer, the second shape being different from the first shape.
• the first shape is a shape that includes at least one planar coil.
• the second shape is a shape that includes at least one planar coil.
• a two-dimensional wireless power supply sheet according to any one of (5) to (7) above, in which the planar coil included in the first conductive layer and the planar coil included in the second conductive layer have different winding directions.
• a two-dimensional wireless power supply sheet according to any one of (1) to (8) above, further comprising a reflection control section, which is disposed at one end in a direction in which the electromagnetic wave is guided when a power supply circuit is connected to the other end, and controls the reflection of the electromagnetic wave at the other end, and the control cancels out the reflected wave of the electromagnetic wave reflected at the position of the power receiving terminal when a power receiving terminal is present between the one end and the other end, due to the reflected wave at the other end.
• a reflection control section which is disposed at one end in a direction in which the electromagnetic wave is guided when a power supply circuit is connected to the other end, and controls the reflection of the electromagnetic wave at the other end, and the control cancels out the reflected wave of the electromagnetic wave reflected at the position of the power receiving terminal when a power receiving terminal is present between the one end and the other end, due to the reflected wave at the other end.
• the reflection control unit includes a circuit having an impedance according to a circuit constant including the dielectric layer, the first conductive layer, and the second conductive layer.
• a wireless power supply system comprising: a two-dimensional wireless power supply sheet described in any one of (1) to (10) above; and a power receiving terminal, the power receiving terminal comprising a power receiving coil having a size equal to or smaller than half the wavelength of an electromagnetic wave propagating within the two-dimensional wireless power supply sheet.
• a power receiving terminal comprising a power receiving coil having a size equal to or smaller than half the wavelength of an electromagnetic wave propagating within the two-dimensional wireless power supply sheet.

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• 2024
  • 2024-04-30 JP JP2025521910A patent/JPWO2024241842A1/ja active Pending
  • 2024-04-30 WO PCT/JP2024/016657 patent/WO2024241842A1/ja active Pending

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