Wireless power transmission device

Abstract

A wireless power transmission device includes: a shielding plate; a transmission coil on the shielding plate; and a shielding member disposed on the shielding plate and surrounding the transmission coil. The shielding plate can shield the magnetic field formed on the lower side of the transmission coil. The shielding member can cancel out the magnetic field formed on the side of the transmission coil. Therefore, in an embodiment, EMI or EMF caused by the magnetic fields formed below and on the side of the transmission coil can be minimized.

Description

Technical Field

[0001] This embodiment relates to a wireless power transmission device. Background Art

[0002] Recently, wireless power transmission that can transmit power wirelessly has attracted attention.

[0003] Wireless power transmission or wireless energy transfer is a technology that wirelessly transmits electrical energy from a transmitter to a receiver using the principle of magnetic field induction.

[0004] Wireless power transmission can be used in various industries such as IT, railways, automobiles, display devices (such as TVs), household electrical appliances, and mobile devices.

[0005] In addition, the transmission of power tends to increase in line with the recent trend of fast charging of smartphone wireless chargers for home use or vehicles. In addition, research / development / standardization of wireless charging for relatively high-power mobile devices such as tablet PCs and notebook PCs is being actively carried out. Although this increase in power transmission provides the convenience of fast charging for users, the problem is that due to the leakage magnetic field, the electromagnetic interference (EMI) effect on other devices and the electromagnetic wave human exposure (EMF) increase. Summary of the Invention

[0006] Technical Problem

[0007] One object of the embodiment is to solve the above problems and other problems.

[0008] Another object of the embodiment is to provide a wireless power transmission device that minimizes EMI.

[0009] Another object of the embodiment is to provide a wireless power transmission device that minimizes EMF.

[0010] Another object of the embodiment is to provide a wireless power transmission device that can reduce the component size of a resonance capacitor.

[0011] Technical Solution

[0012] According to one aspect of the embodiment for achieving the above or other objects, a wireless power transmission device includes: a shielding plate; a transmission coil on the shielding plate; and a shielding member disposed on the shielding plate and configured to surround the transmission coil.

[0013] Advantageous Effects

[0014] The effects of the wireless power transmission device according to the embodiment are as follows.

[0015] According to at least one of the embodiments, a shielding plate is disposed below the transmitting coil, and a shielding member is disposed on the side of the transmitting coil. Accordingly, the magnetic field formed behind the transmitting coil is shielded by the shielding plate, and the magnetic field formed on the side of the transmitting coil is canceled out by the shielding member, thereby minimizing EMI or EMF caused by the magnetic field of the transmitting coil.

[0016] According to at least one of the embodiments, a shielding layer is disposed around the transmitting coil, and when a magnetic field is generated in the transmitting coil, the phase of the current flowing in the transmitting coil is reversed due to the magnetic field generated in the transmitting coil in the shielding layer, and a current having the same amplitude flows, and the magnetic field formed on the side of the transmitting coil is canceled out by the magnetic field generated by the current, thereby minimizing EMI or EMF on the side of the transmitting coil.

[0017] According to at least one of the embodiments, by forming at least one patterned coil to form a shielding layer, the total inductance value can be increased due to the at least one patterned coil, and the capacitance value of the resonance capacitor can be reduced, thereby reducing the component size of the resonance capacitor, increasing the transmission efficiency, and improving the shielding performance.

[0018] According to at least one of the embodiments, a closed-loop opening is formed in the bottom substrate such that when the bottom substrate is placed on the shielding plate, the transmitting coil is easily guided to the closed-loop opening, thereby being disposed on the shielding plate without obstructing the transmitting coil.

[0019] The further applicable scope of the embodiments will become apparent from the following detailed description. However, since those skilled in the art can clearly understand various changes and modifications within the spirit and scope of the embodiments, it should be understood that the detailed description and specific embodiments such as preferred embodiments are given only by way of example. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a magnetic induction type equivalent circuit.

[0021] Figure 2 is a magnetic resonance type equivalent circuit.

[0022] Figure 3a and Figure 3b is a block diagram illustrating a wireless power transmitting device as one of wireless power transmission systems.

[0023] Figure 4 is a block diagram illustrating an electronic device as one of wireless power transmission systems.

[0024] Figure 5 is a plan view illustrating a wireless power transmitting device according to a first embodiment.

[0025] Figure 6is a cross-sectional view illustrating a wireless power transmission device according to the first embodiment.

[0026] Figure 7 is an exploded perspective view illustrating a wireless power transmission device according to the first embodiment.

[0027] Figure 8 is a cross-sectional view illustrating a wireless power transmission device according to the second embodiment.

[0028] Figure 9 illustrates Figure 8 a cross-sectional view of a shielding member.

[0029] Figure 10 is a cross-sectional view illustrating a shielding member in a wireless power transmission device according to the third embodiment.

[0030] Figure 11 is a cross-sectional view illustrating a wireless power transmission device according to the fourth embodiment.

[0031] Figure 12 illustrates Figure 11 a plan view of a shielding member.

[0032] Figure 13 illustrates the magnetic field distribution according to the capacitance of a resonance capacitor when the shielding layer is composed of a single layer of patterned coils.

[0033] Figure 14 illustrates the leakage magnetic field according to the capacitance of a resonance capacitor when the shielding layer is composed of a single layer of patterned coils.

[0034] Figure 15 illustrates the magnetic field distribution according to the relationship among the capacitance, resonance frequency, and coupling coefficient of a resonance capacitor when the shielding layer is composed of a single layer of patterned coils.

[0035] Figure 16 illustrates the magnetic field distribution according to the capacitance of a resonance capacitor when the shielding layer is composed of two layers of patterned coils.

[0036] Figure 17 illustrates the leakage magnetic field according to the capacitance of a resonance capacitor when the shielding layer is composed of two layers of patterned coils.

[0037] Figure 18 illustrates the magnetic field distribution according to the relationship among the capacitance, resonance frequency, and coupling coefficient of a resonance capacitor when the shielding layer is composed of two layers of patterned coils.

[0038] Figure 19 illustrates the transmission efficiency according to the capacitance of a resonance capacitor when the shielding layer is composed of a single layer of patterned coils.

[0039] Figure 20Illustrates the transmission efficiency according to the capacitance of the resonance capacitor when the shielding layer is composed of two layers of patterned coils.

[0040] Figure 21 Illustrates the shielding performance according to the capacitance of the resonance capacitor when the shielding layer is composed of one layer of patterned coils.

[0041] Figure 22 Illustrates the shielding performance according to the capacitance of the resonance capacitor when the shielding layer is composed of two layers of patterned coils.

[0042] Figure 23 Illustrates the transmission efficiency according to the coupling coefficient in each of the one layer of patterned coils and the two layers of patterned coils.

[0043] Figure 24 Illustrates the shielding performance according to the coupling coefficient in each of the one layer of patterned coils and the two layers of patterned coils. Detailed implementation

[0044] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. However, the technical idea of the present disclosure is not limited to some of the described embodiments, but can be implemented in various different forms, and if it is within the scope of the technical idea of the present disclosure, one or more of the components in the embodiments can be used by selectively combining and replacing. In addition, the terms (including technical and scientific terms) used in the embodiments of the present disclosure can be interpreted as having the meanings that can be generally understood by those of ordinary skill in the art to which the present disclosure pertains, unless specifically defined and described explicitly, and common terms such as those defined in a dictionary can be interpreted in consideration of the context meaning of the related technology. In addition, the terms used in the embodiments of the present disclosure are used to describe the embodiments and are not intended to limit the present disclosure. In this specification, unless otherwise specified in a phrase, the singular form may also include the plural form, and when described as "at least one (or one or more) of B and C", it may include one or more of any combination that can be combined with A, B, and C. In addition, terms such as first, second, A, B, (a), and (b) may be used to describe the components of the embodiments of the present disclosure. These terms are only used to distinguish components from other components, and the terms are not limited to the nature, order, or sequence of the corresponding components. In addition, when a component is described as "connected", "coupled", or "joined" to another component, it may include not only the case where the component is directly "connected", "combined", or "joined" to the other component, but also the case where the component is "connected", "combined", or "joined" to the other component through another component. In addition, when described as formed or provided "on the top (upper) or bottom (lower) of each component", it may include not only the case where two components are in direct contact with each other, but also the case where another component is formed or provided between the two components. In addition, when expressed as "up (upward) or down (downward)", it may include not only the meaning of the upward direction, but also the meaning of the downward direction based on one component.

[0045] Hereinafter, a wireless power transmission system including a wireless power transmission device having a function of wirelessly transmitting power and an electronic device wirelessly receiving power according to an embodiment of the present disclosure will be described in detail with reference to the accompanying drawings. For example, it may include a wireless power receiving device that wirelessly receives power from an electronic device, but is not limited thereto. The following introduced embodiments are provided as examples to fully convey the spirit of the present disclosure to those skilled in the art. Accordingly, the present disclosure can be implemented in other forms and is not limited to the embodiments described below. In addition, in the drawings, for convenience, the sizes and thicknesses of the devices may be exaggerated. Throughout the specification, like reference numerals indicate like elements.

[0046] The wireless power transmission device according to an embodiment may be configured in a pad type, a cradle type, an access point (AP) type, etc.

[0047] The wireless power receiving device according to the embodiment can be used in small electronic devices such as wearable devices including mobile phones, smartphones, laptop computers, digital broadcast terminals, personal digital assistants (PDAs), portable multimedia players (PMPs), navigation devices, MP3 players, electric toothbrushes, electronic tags, lighting devices, remote controls, fishing floats, and smart watches, but not limited thereto, and the present disclosure can be used in devices capable of charging a battery equipped with the wireless power receiving device according to the embodiment.

[0048] The embodiment can consider a system capable of transmitting power to one or more electronic devices using a wireless power transmitting device including one or more transmitting coils.

[0049] The terms used in the embodiment are as follows.

[0050] Wireless power transmission system: A system that provides wireless power transmission within a magnetic field.

[0051] Wireless power transmitting device: A device that provides wireless power transmission to an electronic device within a magnetic field and manages the entire system.

[0052] Wireless power receiving device: A device that receives wireless power transmission from a wireless power transmitting device within a magnetic field.

[0053] Charging area: An area where actual wireless power transmission occurs within a magnetic field area, and this area can vary according to the size, required power, and operating frequency of applications such as electronic devices.

[0054] From the perspective of the wireless power transmission principle, as the wireless power transmission principle, there are mainly the magnetic induction method and the magnetic resonance method.

[0055] The magnetic induction method is the following non-contact energy transmission technology: An electromotive force is generated in the load inductor through the magnetic flux generated when the transmitting inductor and the load inductor are brought close to each other and current passes through one of the transmitting inductors. The magnetic resonance method is a technique that combines two resonators, and magnetic resonance occurs at the natural frequency between the two resonators, vibrating at the same frequency and generating an electric field and a magnetic field within the same wavelength range.

[0056] Figure 1 Is a magnetic induction type equivalent circuit.

[0057] Refer to Figure 1, in a magnetic induction type equivalent circuit, a wireless power transmission device can be implemented by a source voltage Vs of a device for supplying power, a transmission resistor Rs, a transmission capacitor Cs for impedance matching, and a transmission inductor Ls that is magnetically coupled to a wireless power receiving device, and a wireless power receiving device can be implemented by a load resistor Rl that is an equivalent resistor of the wireless power receiving device, a load capacitor Cl for impedance matching, and a load coil Ll for magnetically coupling with the wireless power receiving device, and the degree of magnetic coupling between the transmission coil Ls and the load coil Ll can be expressed as a mutual inductance Msl.

[0058] The transmission capacitor Cs can be added to the wireless power transmission device as a compensation capacitor for impedance matching, and the load capacitor Cl can be added to the wireless power receiving device. The compensation capacitors Cs and Cl can be connected to the receiving coil Ls and the load coil Ll respectively, for example. Additionally, passive components such as additional capacitors and inductors and compensation capacitors can be further added to each of the wireless power transmission device and the wireless power receiving device for impedance matching.

[0059] Figure 2 is a magnetic resonance type equivalent circuit.

[0060] Referring to Figure 2 , in a magnetic resonance type equivalent circuit, a wireless power transmission device is implemented by a source coil that forms a closed circuit through the series connection of a source voltage Vs, a transmission resistor Rs, and a transmission inductor Ls, and a resonance coil that forms a closed circuit through the series connection of a resonance inductor L1 and a resonance capacitor C1, a wireless power receiving device is implemented by a load coil that forms a closed circuit through the series connection of a load resistor R and a load inductor Ll, and a resonance coil that forms a closed circuit through the series connection of the load coil, a resonance inductor L2, and a resonance capacitor C2, and the transmission inductor Ls and the inductor L1 are magnetically coupled with a coupling coefficient of K01, the load inductor Ll and the load side resonance inductor L2 are magnetically coupled with a coupling coefficient of K23, and the resonance inductor L1 and the resonance inductor L2 are magnetically coupled with a coupling coefficient of L12. In an equivalent circuit of another embodiment, the source coil and / or the load coil can be omitted, and only the resonance coil and the resonance coil can be formed.

[0061] In the magnetic resonance method, when the resonance frequencies of two resonators are the same, most of the energy of the resonator of the wireless power transmission device is transferred to the resonator of the wireless power receiving device, so that the power transmission efficiency can be improved.

[0062] To improve the efficiency in the self-resonance method, impedance matching elements can be added, and the impedance matching elements can be passive components such as inductors and capacitors.

[0063] Based on the principle of wireless power transmission, a wireless power transmission system for transmitting power by means of magnetic induction or magnetic resonance will be described.

[0064] <Wireless power transmitting device>

[0065] Figure 3a and Figure 3b is a block diagram illustrating a wireless power transmitting device as one of the wireless power transmission systems.

[0066] Referring to Figure 3a , according to an embodiment, the wireless power transmission system may include a wireless power transmitting device 100 and a wireless power receiving device 200 that wirelessly receives power from the wireless power transmitting device 100. For example, the wireless power receiving device 200 may include a wireless power receiving device that wirelessly receives power, but is not limited thereto.

[0067] The wireless power transmitting device 100 may include: a power converter 101 that performs power conversion of an input AC signal to output it as an AC signal; a resonance circuit unit 102 that generates a magnetic field based on the AC signal output from the power converter 101 to supply power to the wireless power receiving device 200 within a charging area; and a controller 103 that is configured to control the power conversion of the power converter 101, adjust the amplitude and frequency of the output signal of the power converter 101, perform impedance matching of the resonance circuit unit 102, sense impedance, voltage, and current information from the power converter 101 and the resonance circuit unit 102, and communicate wirelessly with the wireless power receiving device 200.

[0068] The power converter 101 may include at least one of a power converter that converts an AC signal to a DC signal, a power converter that outputs a DC by changing the level of the DC, and a power converter that converts a DC to an AC. The resonance circuit unit 102 may include a coil and an impedance matching unit that can resonate with the coil. Additionally, the controller 103 may include a sensing unit for sensing impedance, voltage, and current information and a wireless communication unit. For example, the sensing unit may include a current measurement unit for measuring current, but is not limited thereto. For example, the communication unit may be capable of communicating in a Bluetooth manner. For example, the communication unit may be capable of communicating by an in-band communication method or an out-of-band communication method.

[0069] Specifically, referring to Figure 3b , the wireless power transmitting device 100 may include an AC / DC converter 110, a DC / AC converter 120, an impedance matching unit 130, a transmitting coil unit 140, and a communication and control unit 150.

[0070] The AC / DC converter 110 is a power converter that converts an AC signal provided from the outside into a DC signal under the control of the communication and control unit 150 and the DC / DC converter 114.

[0071] The rectifier 112 is a system that converts the supplied AC signal into a DC signal, and as an implementation for achieving this, it can be a diode rectifier that has relatively high efficiency during high-frequency operation, a single-chip synchronous rectifier, or a hybrid rectifier that can save costs and space and has a high degree of freedom during dead time. However, it is not limited to this, and any system that converts alternating current to direct current can be applied.

[0072] In addition, the DC / DC converter 114 adjusts the level of the DC signal provided from the rectifier 112 under the control of the communication and control unit 150. As an example for achieving this, it can be a buck converter that reduces the input signal level, a boost converter that increases the input signal level, a buck-boost converter that can reduce or increase the input signal level, or a cuk converter. Additionally, the DC / DC converter 114 can include a switching element for power conversion control, an inductor and a capacitor for power conversion mediation or output voltage smoothing, and a converter for adjusting voltage gain or electrical isolation (isolation), etc., and can be used to remove the ripple component or pulsating component (AC component included in the DC signal) included in the input DC signal. The error between the command value and the actual output value of the output signal of the DC / DC converter 114 can be adjusted by a feedback method, and this can be performed by the communication and control unit 150.

[0073] The DC / AC converter 120 is a system that can convert the DC signal output from the AC / DC converter 110 into an AC signal and adjust the frequency of the converted AC signal under the control of the communication and control unit 150. As an example for achieving this, there are a half-bridge inverter or a full-bridge inverter. As a wireless power transmission system, various amplifiers that convert direct current to alternating current can be applied, and as examples, there are class A, class B, class AB, class C, class E, and class F amplifiers. Additionally, the DC / AC converter 120 can include an oscillator that generates the frequency of the output signal and a power amplifier that amplifies the output signal.

[0074] The impedance matching unit 130 improves the signal flow by minimizing the reflected waves at points with different impedances. Since the two coils of the wireless power transmission device 100 and the wireless power reception device 200 are spatially separated and there is a large amount of magnetic field leakage, the power transmission efficiency can be improved by correcting the impedance difference between the two connection ends of the wireless power transmission device 100 and the wireless power reception device 200. The impedance matching unit 130 can be composed of an inductor and a capacitor resistor element, and can adjust the impedance value for impedance matching by changing the resistance value of the inductance of the inductor and the capacitance resistance of the capacitor under the control of the communication and control unit 150.

[0075] When the wireless power transmission system transmits power by the magnetic induction method, the impedance matching unit 130 can have a series resonance structure or a parallel resonance structure, and can minimize the energy loss by increasing the inductive coupling coefficient between the wireless power transmission device 100 and the wireless power reception device 200.

[0076] When the wireless power transmission system transmits power by the magnetic resonance method, the impedance matching unit 130 can change the separation distance between the wireless power transmission device 100 and the wireless power reception device 200, or can enable real-time correction of impedance matching according to the change of the matching impedance on the energy transmission line due to the change of the coil characteristics caused by the mutual influence of metal foreign objects (FO) and multiple devices, and its correction method can be a multi-matching method using a capacitor, a matching method using multiple antennas, a method using multiple loops, etc.

[0077] The coil 140 can be implemented as multiple coils or a single coil. When multiple coils 140 are provided, the coils can be spaced apart from each other or overlapped with each other. When the coils overlap with each other, the overlapping area can be determined considering the change of the magnetic flux density. In addition, when manufacturing the coil 140, the internal resistance and the radiation resistance can be considered for manufacturing the coil. At this time, if the resistance component is small, the quality factor can be increased and the transmission efficiency can be improved.

[0078] The communication and control unit 150 may include a controller 152 and a communication unit 154. Considering the power demand, current charge amount, and wireless power method of the wireless power receiving device 200, the controller 152 may function to adjust the output voltage of the AC / DC converter 110. Considering the maximum power transfer efficiency, the power to be transmitted can be controlled by generating a frequency and a switching waveform for driving the DC / AC converter 120. Additionally, the controller 152 may determine the size of the wireless power receiving device based on unique information (RXID) received from the wireless power receiving device. In other words, one of multiple transmission coils can be selected according to the size of the wireless power receiving device. The unique information (RXID) may include, but is not limited to, an RXID message, certificate information (certificate version), identification information, and an error detection code (CRC). The RXID message may include the size and power information of the wireless power receiving device.

[0079] Additionally, algorithms, programs, or applications required for control read from a storage unit (not illustrated) of the wireless power receiving device 200 may be used to control the overall operation of the wireless power receiving device 200. Further, the controller 152 may be referred to as a microprocessor, a microcontroller unit, or a microcomputer. The communication unit 154 may perform communication with the communication unit 264, and as an example of a communication method, short-range communication methods such as Bluetooth, NFC, or Zigbee may be used. The communication unit 154 and the communication unit 264 may send / receive charge status information, charge control commands, etc. The charge status information may include the number of wireless power receiving devices 200, remaining battery capacity, number of charging times, usage, battery capacity, battery ratio, and transmitted power of the wireless power transmitting device 100. Additionally, the communication unit 154 may send a charge function control signal for controlling the charging function of the wireless power receiving device 200, and the charge function control signal may be a control signal for controlling the wireless power receiving device 200 to enable or disable the charging function.

[0080] Thus, the communication unit 154 may communicate in an out-of-band format consisting of separate modules, but is not limited thereto, and may perform communication in an in-band format using a feedback signal sent from the wireless power receiving device to the wireless power transmitting device by using a power signal sent from the wireless power transmitting device. For example, the wireless power receiving device may modulate the feedback signal and send information such as charging start, charging end, battery status, etc. to the transmitter through the feedback signal. Additionally, the communication unit 154 may be configured separately from the controller 152, and the wireless power receiving device 200 may also include the communication unit 264 in the controller 262 of the receiving device, or may be configured separately.

[0081] <Wireless Power Receiving Device>

[0082] Figure 4 It is a block diagram of an electronic device that exemplifies a wireless power transmission system.

[0083] Referring to Figure 4 , the wireless power transmission system may include a wireless power transmitting device 100 and a wireless power receiving device 200 that wirelessly receives power from the wireless power transmitting device 100. The wireless power receiving device 200 may include a receiving coil unit 210, an impedance matching unit 220, an AC / DC converter 230, a DC / DC converter 240, a load 250, and a communication and control unit 2600.

[0084] The receiving coil unit 210 may receive power by a magnetic induction method or a magnetic resonance method. Thus, according to the power receiving method, it may include at least one of an induction coil and a resonance coil. The receiving coil unit 210 may also include an antenna for near field communication (NFC). The receiving coil unit 210 may be the same as the coil unit 140, and the size of the receiving antenna may vary according to the electrical characteristics of the wireless power receiving device 200.

[0085] The impedance matching unit 220 performs impedance matching between the wireless power transmitting device 100 and the wireless power receiving device 200.

[0086] The AC / DC converter 230 rectifies the AC signal output from the receiving coil unit 210 to generate a DC signal.

[0087] The DC / DC converter 240 may adjust the level of the DC signal output from the AC / DC converter 230 according to the capacity of the load 250.

[0088] The load 250 may include a battery, a display, an audio output circuit, a main processor, and various sensors.

[0089] The communication and control unit 2600 may be activated by the wake-up power from the communication and control unit 150, communicate with the communication and control unit 150, and control the operation of the subsystems of the wireless power receiving device 200.

[0090] One or more wireless power receiving devices 200 may be set to wirelessly receive energy from the wireless power transmitting device 100 simultaneously. In other words, in a magnetic resonance type wireless power transmission system, multiple target wireless power receiving devices 200 may receive power from one wireless power transmitting device 100. In this case, the matching unit 130 of the wireless power transmitting device 100 may adaptively perform impedance matching between the multiple wireless power receiving devices 200. This may also be applied in the same way even when multiple independent coil units are set by the magnetic induction method.

[0091] In addition, when multiple wireless power receiving devices 200 are configured, the power receiving method may be the same system or different types of systems. In this case, the wireless power transmitting device 100 may be a system that transmits power by a magnetic induction method or a magnetic resonance method, or a system that uses both methods together.

[0092] <First Embodiment>

[0093] Figure 5 is a plan view illustrating a wireless power transmitting device according to the first embodiment, Figure 6 is a cross-sectional view illustrating a wireless power transmitting device according to the first embodiment, and Figure 7 is an exploded perspective view illustrating a wireless power transmitting device according to the first embodiment.

[0094] Referring to Figures 5 to 7 According to the first embodiment, the wireless power transmitting device 100 may include a shielding plate 110, a transmitting coil 120, and a shielding member 130.

[0095] The shielding plate 110 may prevent the magnetic field generated by the transmitting coil 120 from affecting the lower portion of the shielding plate 110.

[0096] The magnetic field generated by the current flowing through the transmitting coil 120 may be distributed in front of, behind, and on the sides of the transmitting coil 120.

[0097] In an embodiment, the wireless power receiving device may be located in front of the transmitting coil 120 for charging.

[0098] Various electronic components for operating or controlling the wireless power transmitting device may be provided behind the transmitting coil 120. Accordingly, the shielding plate 110 may shield the magnetic field formed behind the transmitting coil 120 so that the electronic components provided behind the shielding plate 110 are not damaged by the magnetic field.

[0099] In addition, a person may be located around the side of the transmitting coil 120. In this way, the magnetic field formed on the side of the transmitting coil 120 may affect the person. As will be described later, in an embodiment, the shielding member 130 is provided on the side of the transmitting coil 120 to cancel or eliminate the magnetic field formed on the side of the transmitting coil 120 by the shielding member 130 so that the magnetic field does not affect the person.

[0100] For example, the size of the shielding plate 110 is larger than the size of the transmitting coil 120 so that the magnetic field formed behind the transmitting coil 120 can be completely shielded.

[0101] The shielding plate 110 may be made of a shielding material. For example, the shielding plate 110 may be made of a ferromagnetic material having a high magnetic permeability such as ferrite, but is not limited thereto.

[0102] The transmitting coil 120 may be disposed on the shielding plate 110. The transmitting coil 120 may generate a magnetic field. The magnetic field generated in this way induces a current in the receiving coil of the wireless power receiving device, and the received power may be generated based on this current.

[0103] The magnetic field may be generated by the current flowing through the transmitting coil 120. The current flows through the transmitting coil 12 due to the transmitted power, and the magnetic field may be generated by this current. As the transmitted power increases, the current flowing through the transmitting coil 120 increases, which may mean an increase in the intensity of the magnetic field.

[0104] In order to increase the received power generated by the wireless power receiving device, it is necessary to increase the intensity of the magnetic field generated by the transmitting coil 120 of the wireless power transmitting device 100, or it is necessary to increase the coupling coefficient between the wireless power transmitting device 100 and the wireless power receiving device. In order to increase the coupling coefficient, impedance matching may be performed between the wireless power transmitting device 100 and the wireless power receiving device, or the wireless power receiving device may be made closer to the wireless power receiving device.

[0105] In addition, the efficiency between the transmitted power transmitted by the wireless power transmitting device 100 and the received power generated by the wireless power receiving device based on the transmitted power may be referred to as the transmission efficiency or the charging efficiency. The higher the transmission efficiency, the higher the received power compared to the same transmitted power.

[0106] The transmitting coil 120 may be, for example, a Litz coil coated with an insulating material, but is not limited thereto. The transmitting coil 120 may have a central hollow portion and may be wound multiple times along the outer periphery of the central hollow portion.

[0107] The transmitting coil 120 may include one transmitting coil or two or more transmitting coils. For example, when three transmitting coils are provided, two transmitting coils may be provided on the lower layer, and the remaining one transmitting coil may be provided on the upper layer. In this case, the remaining one transmitting coil may be provided to partially overlap each of the two transmitting coils. The plurality of transmitting coils may be arranged in one direction, arranged in a matrix, or arranged in a honeycomb shape.

[0108] When viewed from above, the transmitting coil 120 may have a circular shape, an elliptical shape, a square shape, a hexagonal shape, etc. For example, when the transmitting coil 120 has a quadrilateral shape, the corners may be rectangular or rounded.

[0109] The transmitting coil 120 may be attached to the shielding member 130 using an adhesive material, but is not limited thereto.

[0110] The shielding member 130 may be disposed on the shielding plate 110.

[0111] The shielding member 130 can prevent the magnetic field generated by the transmitting coil 120 from affecting the sides.

[0112] The shielding member 130 can include a bottom substrate 140, a shielding layer 150, and a resonance capacitor 160.

[0113] The shielding member 130 can generate a current capable of inverting the phase of the current flowing through the transmitting coil 120. In other words, the shielding member 130 can generate a magnetic field to cancel out the magnetic field generated by the transmitting coil 120. Here, the magnetic field generated by the transmitting coil 120 can be magnetic flux. The magnetic flux can form a closed loop from the outside of the transmitting coil 120 to the lower side of the transmitting coil 120 after penetrating from the lower side to the upper side of the transmitting coil 120.

[0114] The magnetic flux formed in front of the transmitting coil 120 can be used to generate received power of the wireless power receiving device. This will be described in detail later.

[0115] The bottom substrate 140 can include an opening 147.

[0116] The bottom substrate 140 can support or protect the shielding layer 150 and the resonance capacitor 160. For example, the bottom substrate 140 can include a rigid bottom substrate or a flexible bottom substrate. For example, the bottom substrate 140 can be a printed circuit board made of FR-4. FR-4 is classified according to the resin type of the printed circuit board and can be made of, for example, epoxy resin.

[0117] FR-4 can be the NEMA grade name of a glass-reinforced epoxy laminate. FR-4 can be a composite material composed of a woven fiberglass cloth with a flame-retardant (self-extinguishing) epoxy resin binder.

[0118] FR-4 glass epoxy resin has an excellent strength-to-weight ratio and can be various high-voltage thermosetting plastic laminates. In the case of extremely low water absorption, FR-4 can be an electrical insulator with a relatively large mechanical strength. FR-4 can have high mechanical values and electrical insulation properties under both dry and wet conditions.

[0119] The size of the bottom substrate 140 can be larger than the size of the shielding plate 110, but is not limited thereto.

[0120] The bottom substrate 140 and the transmitting coil 120 can be disposed on the same surface. In other words, the bottom substrate 140 can also be disposed on the upper surface of the shielding plate 110, and the transmitting coil 120 can also be disposed on the upper surface of the shielding plate 110. For this purpose, an opening 147 can be provided in the bottom substrate 140, and the transmitting coil 120 can be provided in the opening 147. The transmitting coil 120 can be disposed on the shielding plate 110 through the opening 147 of the bottom substrate 140.

[0121] The opening 147 may be a hole that penetrates the upper and lower surfaces of the bottom substrate 140. The opening 147 may be located at the center of the bottom substrate 140, but is not limited thereto.

[0122] The diameter of the opening 147 may be equal to or greater than the size of the transmitting coil 120. Thus, when the shielding member 130 is disposed on the shielding plate 110, the transmitting coil 120 disposed on the shielding plate 110 may be set to protrude upward through the opening 147 without being obstructed by the bottom substrate 140. In other words, the opening 147 may be formed in the bottom substrate 140 such that the shielding member 130 can be easily disposed on the shielding plate 110.

[0123] Since the diameter of the opening 147 is smaller than the size of the shielding plate 110 and the size of the bottom substrate 140 is larger than the size of the shielding plate 110, when the bottom substrate 140 is disposed on the shielding plate 110, a part of the lower surface of the bottom substrate 140 may rest on the shielding plate 110. The bottom substrate 140 may be attached to the shielding plate 110 using an adhesive material, but is not limited thereto.

[0124] The resonance capacitor 160 may be mounted on the bottom substrate 140 and connected to the shielding layer 150. For example, the resonance capacitor 160 may be mounted on the lower surface of the bottom substrate 140, but is not limited thereto. At least one resonance capacitor 160 may be provided.

[0125] The resonance capacitor 160 may adjust the phase and amplitude of the current generated in the shielding layer 150. In other words, according to the capacitance value of the resonance capacitor 160, the phase of the current generated in the shielding layer 150 may be changed and its amplitude may be increased. Thus, by adjusting the resonance capacitor 160, a current having a phase opposite to the phase of the current generated by the transmitting coil 120 and an amplitude equal to the amplitude of the current may flow through the shielding layer 150. Therefore, the magnetic field generated in the transmitting coil 120 may be canceled by the magnetic field generated in the shielding layer 150. Thus, the magnetic field generated by the transmitting coil 120 of the resonance capacitor 160 is canceled, thereby minimizing or blocking the lateral EMI or EMF.

[0126] When the magnetic field generated by the transmitting coil 120 is sufficiently canceled only by the shielding layer 150, the resonance capacitor 160 may be omitted.

[0127] The shielding layer 150 may be spaced apart from the outside of the transmitting coil 120. The shielding layer 150 may have a shape corresponding to the shape of the transmitting coil 120. For example, when the transmitting coil 120 has a circular shape, the shielding layer 150 may also have a circular shape. In this way, since the shielding layer has a shape corresponding to the shape of the transmitting coil 120, the shielding layer 150 can maintain the same distance from the transmitting coil 120 along the outer periphery of the shielding layer 150. Therefore, a current can be easily induced in the shielding layer 150 by the magnetic field of the transmitting coil 120.

[0128] The shielding layer 150 may be disposed on the bottom substrate 140, but is not limited thereto.

[0129] The shielding layer 150 may include a patterned coil 151 formed by a patterning process. For example, after forming a metal film on the bottom substrate 140, an etching process may be performed to form the patterned coil 151 on the bottom substrate 140. Therefore, the patterned coil 151 may include metal. For example, the patterned coil 151 may be made of copper, aluminum, platinum, etc., but is not limited thereto.

[0130] The patterned coils 151 may be wound into a plurality. Since the patterned coils 151 are metallic, the wound coils may be spaced apart from each other to prevent electrical short circuits.

[0131] Since the patterned coil 151 is formed by a patterning process, the patterned coil 151 can be freely formed into a desired shape.

[0132] The patterned coil 151 and the resonance capacitor 160 may form a closed loop. In other words, one side of the patterned coil 151 may be connected to one side of the resonance capacitor 160, and the other side of the patterned coil 151 may be connected to the other side of the resonance capacitor 160.

[0133] In an embodiment, when the wireless power receiving device is adjacent to the wireless power receiving device, when a current flows through the transmitting coil 120 according to the transmitted power determined in the wireless power receiving device, a magnetic field corresponding to the current may be generated. The generated magnetic field may be formed in front of, behind, and on the sides of the transmitting coil 120. In this case, the magnetic field formed behind the transmitting coil 120 is blocked by the shielding plate 110, and damage to the electronic components disposed below the shielding plate 110 can be prevented. A current is induced in the receiving coil of the wireless power receiving device by the magnetic field formed in front of the transmitting coil 120 to generate received power, and the generated received power may be charged into a battery or the like.

[0134] In addition, current flows through the shielding layer 150 due to the magnetic field formed on the side of the transmitting coil 120, and this current can form a magnetic field. At this time, the phase and amplitude of the current flowing through the shielding layer 150 are adjusted by the resonance capacitor 160 connected to the shielding layer 150, and the magnetic field formed on the side of the transmitting coil 120 is canceled by the magnetic field generated by the shielding layer 150. Therefore, a magnetic field is no longer formed on the side of the transmitting coil 120, and EMI or EMF on the side of the transmitting coil 120 is minimized or blocked, thereby preventing damage to electronic components or the human body located on the side of the transmitting coil 120.

[0135] <Second Embodiment>

[0136] Figure 8 is a cross-sectional view illustrating a wireless power transmission device according to the second embodiment, and Figure 9 illustrates Figure 8 a cross-sectional view of the shielding member.

[0137] The second embodiment is similar to the first embodiment except for the two-layer patterned coils 151 and 152. In the second embodiment, the same reference numerals are assigned to components having the same functions, shapes, and / or structures as the components in the first embodiment, and detailed descriptions thereof are omitted.

[0138] Referring to Figure 8 and Figure 9 , the wireless power transmission device 100A according to the second embodiment may include a shielding plate 110, a transmitting coil 120, and a shielding member 130.

[0139] The shielding member 130 may include a bottom substrate 140, a shielding layer 150, and a resonance capacitor 160.

[0140] The bottom substrate 140 may include an opening 147 and through-holes 145 and 146. For example, the opening 147 may be located at the center of the bottom substrate 140. The through-hole 145 and the through-hole 146 may be formed in a part of the region where the shielding layer 150 is provided at the edge of the bottom substrate 140.

[0141] In an embodiment, the shielding layer 150 may include two layers of patterned coils 151 and 152. For example, the first patterned coil 151 may be disposed on the upper surface of the bottom substrate 140, and the second patterned coil 152 may be disposed on the lower surface of the bottom substrate 140. In this case, the first patterned coil 151 and the second patterned coil 152 may be electrically connected through vias 145 and 146. Connection portions 155 and 156 may be disposed in the vias 145 and 146. For example, the connection portions 155 and 156 may be formed of the same material as the first patterned coil 151 and the second patterned coil 152, but are not limited thereto. For example, the connection portions 155 and 156 may be integrally formed with the first patterned coil 151 and the second patterned coil 152.

[0142] For example, the first connection portion 155 is disposed in the first via 151, and one side 151a of the first patterned coil 151 and one side 152a of the second patterned coil 152 may be electrically connected through the first connection portion 155. For example, the second connection portion 156 is disposed in the second via 152, and the other side 151b of the first patterned coil 151 and the other side 152b of the second patterned coil 152 may be electrically connected through the second connection portion 156.

[0143] Figure 9 is a view without considering the resonance capacitor 160, and when the resonance capacitor 160 is considered, it may be illustrated differently. In other words, when the resonance capacitor 160 is mounted on the lower surface of the bottom substrate 140, for example, the second connection portion 156 connected to the other side 151b of the first patterned coil 151 is connected to one side of the resonance capacitor 160, and the other side of the resonance capacitor 160 may be connected to one side 152a of the second patterned coil 152. Figure 9 Alternatively, the resonance capacitor 160 may be disposed on the upper surface of the bottom substrate 140. In this case, for example, the second connection portion 156 connected to the other side 152b of the second patterned coil 152 may be connected to one side of the resonance capacitor 160, and the other side of the resonance capacitor 160 may be connected to one side 151a of the first patterned coil 151.

[0144] The first patterned coil 151 and the second patterned coil 152 may be arranged to vertically overlap each other with the bottom substrate 140 interposed therebetween. Specifically, each winding coil of the first patterned coil 151 and each winding coil of the second patterned coil 152 may vertically overlap each other in a one-to-one manner with the bottom substrate 140 interposed therebetween.

[0145]

[0146] ​If each of the first pattern coil 151 and the second pattern coil 152 is coated with an insulating material, the first pattern coil 151 and the second pattern coil 152 may also overlap each other on the same surface of the bottom substrate 140.

[0147] In the second embodiment, since the total inductance value is increased by the first pattern coil 151 and the second pattern coil 152 so that the capacitance value of the resonance capacitor 160 can be reduced compared to the first embodiment, the component size of the resonance capacitor 160 can be reduced, the transmission efficiency can be improved, and the shielding performance can be improved.

[0148] <Third Embodiment>

[0149] Figure 10 FIG. is a cross-sectional view illustrating a shielding member in a wireless power transmission device according to a third embodiment.

[0150] The third embodiment is similar to the first or second embodiment except that it has pattern coils 171 to 173 of three or more layers. In the third embodiment, the same reference numerals are assigned to components having the same functions, shapes, and / or structures as those of the components in the first or second embodiment, and their detailed descriptions are omitted.

[0151] Referring to Figure 5 and Figure 10 , a wireless power transmission device according to the third embodiment may include a shielding plate 110, a transmission coil 120, and a shielding member 130.

[0152] The shielding member 130 may include a bottom substrate 140, a shielding layer 170, and a resonance capacitor 160.

[0153] The bottom substrate 140 may include an opening 147, and through-holes 161 and 162. For example, the opening 147 may be located at the center of the bottom substrate 140. The through-holes 161 and 162 may be formed in a part of the region where the shielding layer 170 is provided at the edge of the bottom substrate 140.

[0154] The bottom substrate 140 may include a first layer 141, a second layer 142, and a third layer 143. The second layer 142 may be provided below the first layer 141, and the third layer 143 may be provided below the second layer 142. In this case, the first through-hole 161 may be formed in the first layer 141, and the second through-hole 162 may be formed in the second layer 142.

[0155] The shielding layer 170 may be provided on the bottom substrate 140. For example, the shielding layer 170 may include three or more layers of pattern coils 171 to 173.

[0156] In Figure 10In [the figure], for the convenience of drawing, three-layer pattern coils 171 to 173 are illustrated, but the embodiment may also include four or more layers of pattern coils.

[0157] For example, the first pattern coil 171 may be disposed on the upper surface of the first layer 141. The lower surface of the first pattern coil 171 may be connected to the upper surface of the first connection portion 157 disposed in the through hole 161 of the first layer 141.

[0158] For example, the second pattern coil 172 may be disposed between the first layer 141 and the second layer 142. For example, the second pattern coil 172 may be disposed on the upper surface of the second layer 142. The upper surface of the second pattern coil 172 is connected to the lower surface of the first connection portion 157, and the lower surface of the second pattern coil 172 is connected to the upper surface of the second connection portion 158 disposed in the through hole 162 of the second layer 142.

[0159] For example, the third pattern coil 173 may be disposed between the second layer 142 and the third layer 143. For example, the third pattern coil 173 may be disposed on the upper surface of the third layer 143. The upper surface of the third pattern coil 173 may be connected to the lower surface of the second connection portion 158.

[0160] In Figure 10 [the figure], although only one is provided in each of the first through hole 161 and the second through hole 162, two first through holes and two second through holes may be provided. For example, the first through hole 161 may include a 1-1 through hole and a 1-2 through hole, and the second through hole 162 may include a 2-1 through hole and a 2-2 through hole. In this case, one side of the first pattern coil 171 and one side of the second pattern coil 172 may be connected through the 1-1 through hole, and the other side of the first pattern coil 171, the other side of the second pattern coil 172, or one side of a first resonance capacitor (not illustrated) may be connected through the 1-2 through hole. One side of the second pattern coil 172 and one side of the third pattern coil 173 may be connected through the 2-1 through hole, and the other side of the second pattern coil 172 and the other side of the third pattern coil 173, or one side of a second resonance capacitor (not illustrated) may be connected through the 2-2 through hole.

[0161] The first pattern coil 171 to the third pattern coil 173 may be made of the same metal, but is not limited thereto.

[0162] For example, the first layer 141 with the first pattern coil 171, the second layer 142 with the second pattern coil 172, and the third layer 143 with the third pattern coil 173 may be sequentially laminated, and then a thermal compression process may be performed to form Figure 10The shielding layer 170 illustrated in the example, but the shielding layer 170 can be formed by various other processes. When the shielding layer 170 is formed by a thermal compression process, the boundaries between the first layer 141, the second layer 142, and the third layer disappear, such that the first layer 141, the second layer 142, and the third layer 143 can be formed of one layer, but not limited thereto.

[0163] In the third embodiment, since the total inductance value is increased by three or more layer pattern coils 171 to 173 such that the capacitance value of the resonance capacitor 160 can be reduced compared to the first or second embodiment, the component size of the resonance capacitor 160 can be reduced, the transmission efficiency can be improved, and the shielding performance can be improved.

[0164] <Fourth Embodiment>

[0165] Figure 11 is a cross-sectional view illustrating a wireless power transmission device according to the fourth embodiment, and Figure 12 illustrates Figure 11 a plan view of the shielding member.

[0166] Except for the bottom substrate 140 of the shielding member 130, the fourth embodiment is similar to the first to third embodiments. In the fourth embodiment, the same reference numerals are given to components having the same functions, shapes, and / or structures as the components of the first to third embodiments, and their detailed descriptions are omitted.

[0167] Referring to Figure 11 and Figure 12 , the wireless power transmission device 100B according to the fourth embodiment may include a shielding plate 110, a transmission coil 120, and a shielding member 130.

[0168] The shielding member 130 may include a bottom substrate 140, a shielding layer 150, and a resonance capacitor 160.

[0169] The bottom substrate 140 may include, for example, a closed-loop opening 148. For example, the closed-loop opening 148 may have a shape corresponding to the size of the plurality of winding coils of the transmission coil 120. The width of the closed-loop opening 148 may be equal to or greater than the width of the plurality of winding coils of the transmission coil 120.

[0170] The transmission coil 120 may include a coil having a hollow portion at the center and wound multiple times along the outer periphery of the hollow portion. In this case, since the closed-loop opening 148 has a shape corresponding to the plurality of winding coils, when the bottom substrate 140 is disposed on the shielding plate 110, the transmission coil 120 disposed on the shielding plate 110 may protrude through the closed-loop opening 148 of the bottom substrate 140.

[0171] Therefore, when the bottom substrate 140 is disposed on the shielding plate 110, a part of the bottom substrate 140 can be disposed in the hollow portion of the transmitting coil 120.

[0172] According to the fourth embodiment, a closed-loop opening 148 is formed in the bottom substrate 140. Therefore, when the bottom substrate 140 is placed on the shielding plate 110, the transmitting coil 120 is guided to the closed-loop opening 148, so that the bottom substrate 140 can be placed on the shielding plate 110 without being obstructed by the transmitting coil 120.

[0173] <Verification of the technical effects of the embodiment>

[0174] Figure 13 Illustrated is the magnetic field distribution according to the capacitance of the resonance capacitor when the shielding layer is composed of a single layer of patterned coil, Figure 14 Illustrated is the leakage magnetic field according to the capacitance of the resonance capacitor when the shielding layer is composed of a single layer of patterned coil, and Figure 15 Illustrated is the magnetic field distribution according to the relationship among the capacitance of the resonance capacitor, the resonance frequency, and the coupling coefficient when the shielding layer is composed of a single layer of patterned coil.

[0175] Figures 13 to 15 is the test result for the case where the shielding layer includes a single layer of patterned coil in the first embodiment ( Figures 5 to 7 ).

[0176] It can be seen that, compared with the prior art ( Figure 13 's (a)), as in the first embodiment ( Figure 13 's (b), Figure 13 's (c), and Figure 13 's (d)), a shielding layer including a single layer of patterned coil is provided, and as the resonance capacitor increases, the intensity of the magnetic field decreases. For example, when using a 2,300 nF resonance capacitor ( Figure 13 's (b)), compared with the conventional case ( Figure 13 's (a)), the intensity of the magnetic field can be reduced. When using a 3,000 nF resonance capacitor ( Figure 13 's (c)), compared with using a 2,300 nF resonance capacitor ( Figure 13 's (b)), the intensity of the magnetic field can be lower. Additionally, when using a 4,000 nF resonance capacitor ( Figure 13 's (d)), compared with using a 3,000 nF resonance capacitor ( Figure 13 's (c)), the intensity of the magnetic field can be lower.

[0177] In Figure 14 , the conventional case ( Figure 13 's (a)) can be (1), and the case of using a 2,300 nF resonance capacitor ( Figure 13(b) can be (2), and in the case where a 3,000 nF resonance capacitor is used ( Figure 13 (c) is (3), and in the case where a 4,000 nF resonance capacitor is used ( Figure 13 (d) can be (4).

[0178] The dashed line is the ICNIRP reference level, and it is required that the leakage magnetic field be managed below this reference level.

[0179] Generally, (1) has a much larger leakage magnetic field than (2), (3), and (4). Therefore, when the capacitance value of the resonance capacitor is different according to the first embodiment, it can be seen that the leakage magnetic field is significantly lower than the leakage magnetic field in the conventional case (1). Here, the leakage magnetic field can be the magnetic field on the transmitting coil side.

[0180] In particular, in the conventional case (1), commercialization is difficult because it exceeds the ICNIRP standard level, but in the case of the first embodiment (3), (4), it can be managed at the ICNIRP standard level or lower at a distance of 20 mm or more from the transmitting coil, so commercialization becomes possible.

[0181] In Figure 15 , the conventional case (1) and the first embodiment (2), (3), (4) are illustrated along the horizontal direction from the upper side, and the resonance frequency (fres, r) of the shielding layer is illustrated along the horizontal direction from the lower side, and the coupling coefficient k0r between the transmitting coil and the shielding layer is illustrated along the longitudinal direction on the left side. The resonance frequency (fres, r) of the shielding layer can be determined by the inductance of the shielding layer and the capacitance of the resonance capacitor.

[0182] For example, in the case of (2), when a 2,300 nF resonance capacitor is used, the resonance frequency (fres, r) of the shielding layer can be 85 kHz to 88 kHz. For example, in the case of (3), when a 3,000 nF resonance capacitor is used, the resonance frequency (fres, r) of the shielding layer can be 74 kHz to 77 kHz. For example, in the case of (4), when a 4,000 nF resonance capacitor is used, the resonance frequency (fres, r) of the shielding layer can be 64 kHz to 67 kHz.

[0183] As Figure 15 illustrated, as can be seen along the horizontal direction from the upper side, it can be seen that the intensity of the magnetic field is reduced in the first embodiment (2), (3), (4) compared to the conventional case (1).

[0184] In addition, as can be seen along the horizontal direction from the lower side, it can be seen that the intensity of the magnetic field is reduced as the resonance frequency of the shielding layer decreases.

[0185] In addition, as can be seen along the vertical direction on the left side, it can be seen that as the coupling coefficient k0r between the transmitting coil and the shielding layer decreases, the intensity of the magnetic field decreases.

[0186] Figure 16 Illustrates the magnetic field distribution according to the capacitance of the resonance capacitor when the shielding layer is composed of two layers of patterned coils, Figure 17 Illustrates the leakage magnetic field according to the capacitance of the resonance capacitor when the shielding layer is composed of two layers of patterned coils, and Figure 18 Illustrates the magnetic field distribution according to the relationship between the capacitance, resonance frequency, and coupling coefficient of the resonance capacitor when the shielding layer is composed of two layers of patterned coils.

[0187] Figures 16 to 18 Is for the second embodiment ( Figure 8 and Figure 9 ) in the case where the shielding layer includes two layers of patterned coils.

[0188] Compared with the prior art ( Figure 16 (a)), as in the second embodiment ( Figure 16 (b), Figure 16 (c)), a shielding layer including two layers of patterned coils is provided, and as the resonance capacitor increases, the intensity of the magnetic field decreases. For example, when using an 800 nF resonance capacitor ( Figure 16 (b)), compared with the conventional case ( Figure 16 (a)), the intensity of the magnetic field can be reduced. When using a 1000 nF resonance capacitor ( Figure 16 (c)), compared with the case of using an 800 nF resonance capacitor ( Figure 16 (b)), the intensity of the magnetic field can be reduced.

[0189] In Figure 17 , the conventional case ( Figure 16 (a)) is (1), the case of using an 800 nF resonance capacitor ( Figure 16 (b)) can be (5), and the case of using a 1000 nF resonance capacitor ( Figure 16 (c)) can be (6).

[0190] Generally, (1) has a much larger leakage magnetic field than (5) and (6). Therefore, when the capacitance value of the resonance capacitor is different according to the second embodiment, it can be seen that the leakage magnetic field is significantly lower than the leakage magnetic field of the conventional case (1). Here, the leakage magnetic field can be the magnetic field on the side of the transmitting coil.

[0191] In particular, in the normal case (1), commercialization is difficult because it exceeds the ICNIRP standard level. However, in the case of the second embodiment (5), (6), it can be managed at or below the ICNIRP standard level at a distance of 20 mm or more from the transmitting coil, making commercialization possible.

[0192] In Figure 18 it, the normal case (1) and the second embodiment (5), (6), (7) are illustrated along the horizontal direction from the upper side, the resonance frequency (fres, r) is illustrated along the horizontal direction from the lower side, and the coupling coefficient k0r between the transmitting coil and the shielding layer is illustrated along the longitudinal direction on the left side. (7) is the case of using a 1,200 nF resonance capacitor. The resonance frequency (fres, r) of the shielding layer can be determined by the inductance of the shielding layer and the capacitance of the resonance capacitor.

[0193] For example, in the case of (5), when using an 800 nF resonance capacitor, the resonance frequency (fres, r) of the shielding layer can be 75 kHz to 78 kHz. For example, in the case of (6), when using a 1,000 nF resonance capacitor, the resonance frequency (fres, r) of the shielding layer can be 67 kHz to 70 kHz. For example, in the case of (7), when using a 1,200 nF resonance capacitor, the resonance frequency (fres, r) of the shielding layer can be 61 kHz to 64 kHz.

[0194] As Figure 18 illustrated in it, as can be seen along the horizontal direction from the upper side, it can be seen that the intensity of the magnetic field is reduced in the second embodiment (5), (6), (7) compared with the normal case (1).

[0195] In addition, as can be seen along the horizontal direction from the lower side, it can be seen that the magnetic field intensity decreases as the resonance frequency (fres, r) of the shielding layer decreases.

[0196] In addition, as can be seen along the vertical direction on the left side, it can be seen that the intensity of the magnetic field decreases as the coupling coefficient k0r between the transmitting coil and the shielding layer decreases.

[0197] Figure 19 The transmission efficiency according to the capacitance of the resonance capacitor is illustrated when the shielding layer is composed of a single-layer pattern coil, and Figure 20 The transmission efficiency according to the capacitance of the resonance capacitor is illustrated when the shielding layer is composed of a two-layer pattern coil.

[0198] As Figure 19As illustrated in [the relevant content], in the first embodiments (2), (3), and (4), as the capacitance value of the resonance capacitor increases, the transmission efficiency can increase. Additionally, as the coupling coefficient between the transmitting coil and the shielding layer decreases, the transmission efficiency can increase.

[0199] As Figure 20 illustrated in [the relevant content], in the second embodiments (5), (6), and (7), as the capacitance value of the resonance capacitor increases, the transmission efficiency can increase. Additionally, as the coupling coefficient between the transmitting coil and the shielding layer decreases, the transmission efficiency can increase.

[0200] In Figure 19 and Figure 20 when the coupling coefficient between the transmitting coil and the shielding layer increases, the current induced in the shielding layer by the magnetic field generated by the transmitting coil increases, and the magnetic field generated by the increased current can also increase. Therefore, since the magnetic field generated by the shielding layer even cancels or suppresses the magnetic field formed from the transmitting coil to the front wireless power receiving device, the transmission efficiency may decrease.

[0201] Figure 21 illustrates the shielding performance according to the capacitance of the resonance capacitor when the shielding layer is composed of a single-layer patterned coil, and Figure 22 illustrates the shielding performance according to the capacitance of the resonance capacitor when the shielding layer is composed of a two-layer patterned coil.

[0202] As Figure 21 illustrated in [the relevant content], in the first embodiments (2), (3), and (4), as the capacitance value of the resonance capacitor increases, the shielding performance can increase. Additionally, as the coupling coefficient between the transmitting coil and the shielding layer decreases, the shielding performance can be improved.

[0203] As Figure 22 illustrated in [the relevant content], in the second embodiments (5), (6), and (7), as the capacitance value of the resonance capacitor increases, the shielding performance can increase. Additionally, as the coupling coefficient between the transmitting coil and the shielding layer decreases, the shielding performance can be improved.

[0204] In Figure 21 and Figure 22 when the coupling coefficient between the transmitting coil and the shielding layer increases, the current induced in the shielding layer by the magnetic field generated by the transmitting coil increases, and the magnetic field generated by the increased current can also increase. Therefore, the magnetic field generated by the shielding layer is more than sufficient to cancel the magnetic field formed on the transmitting coil side, and the remaining magnetic field is lost as a leakage magnetic field, resulting in a decrease in shielding performance.

[0205] Therefore, when the coupling coefficient between the transmitting coil and the shielding layer is large, the shielding performance can be improved by using a resonance capacitor with a large capacitance value.

[0206] Figure 23 Illustrates the transmission efficiency according to the coupling coefficient in each of the single-layer pattern coil and the two-layer pattern coil, and Figure 24 Illustrates the shielding performance according to the coupling coefficient in each of the single-layer pattern coil and the two-layer pattern coil.

[0207] In Figure 23 and Figure 24 a shielding layer and a resonance capacitor with a resonance frequency of 74 kHz to 78 kHz are used.

[0208] As Figure 23 illustrated in, it can be seen that the shielding layer (second embodiment) with the two-layer pattern coil has a higher transmission efficiency than the shielding layer (first embodiment) with the single-layer pattern coil.

[0209] As Figure 24 illustrated in, when the coupling coefficient between the transmitting coil and the shielding layer exceeds 0.3, the shielding layer (first embodiment) with the single-layer patterned coil is superior to the shielding layer (second embodiment) with the two-layer patterned coil in terms of shielding performance. When the coupling coefficient between the transmitting coil and the shielding layer is 0.3 or less, the shielding performance is similar between the shielding layer (first embodiment) with the single-layer pattern coil and the shielding layer (second embodiment) with the two-layer pattern coil.

[0210] From Figures 13 to 24 when the following conditions are satisfied in the embodiment, the shielding performance can be improved without reducing the transmission efficiency.

[0211] For example, the ratio of the resonance frequency of the shielding layer to the driving frequency of the wireless power transmission device can be 0.7 or less.

[0212] For example, the difference between the driving frequency of the wireless power transmission device and the resonance frequency of the shielding layer can be 55 kHz or less.

[0213] For example, the coupling coefficient between the transmitting coil and the shielding layer can be 0.35 or less.

[0214] The above detailed description should not be construed as restrictive in all respects and should be regarded as illustrative. The scope of the embodiment should be determined by a reasonable interpretation of the appended claims, and all changes within the equivalent scope of the embodiment are included within the scope of the embodiment.

[0215] Industrial Applicability

[0216] The embodiment can be differently applied to all industries such as the IT, vehicle, railway, and household appliance industries, as well as mobile devices.

Claims

1. A wireless power transmission device, the wireless power transmission device comprising: A shielding plate; A transmission coil on the shielding plate; And A shielding member, the shielding member being disposed on the shielding plate and configured to surround the transmission coil, Wherein, the shielding member includes: A bottom substrate, the bottom substrate including an opening; A shielding layer, the shielding layer being disposed on the bottom substrate and configured to surround the transmission coil; and A resonant capacitor, the resonant capacitor being mounted on the bottom substrate and connected to the shielding layer, Wherein, the shielding layer includes two or more layers of pattern coils that are vertically overlapped, Wherein, the bottom substrate includes a through hole, Wherein, among the two layers of pattern coils, a first pattern coil is disposed on the upper surface of the bottom substrate, Wherein, among the two layers of pattern coils, a second pattern coil is disposed on the lower surface of the bottom substrate, and Wherein, the first pattern coil and the second pattern coil are connected through the through hole, The wireless power transmission device further includes a connection portion disposed in the through hole, One side of the first pattern coil and one side of the second pattern coil are electrically connected through the connection portion.

2. The wireless power transmission device according to claim 1, Among them, The shielding layer includes a pattern coil disposed on the bottom substrate.

3. The wireless power transmission device according to claim 1, Among them, The bottom substrate is disposed between three or more layers of pattern coils, and Wherein, the three or more layers of pattern coils are connected through the through hole.

4. The wireless power transmission device according to claim 1, Among them, The shielding layer has a shape corresponding to the shape of the transmission coil.

5. The wireless power transmission device according to claim 1, Among them, The shielding layer includes metal.

6. The wireless power transmission device according to claim 1, Among them, The transmission coil is disposed in the opening.

7. The wireless power transmission device according to claim 6, Among them, The diameter of the opening is equal to or greater than the size of the transmission coil.

8. The wireless power transmission device according to claim 6, Among them, The opening is a closed-loop opening corresponding to the shape of the transmission coil.

9. The wireless power transmission device according to claim 1, Among them, The transmission coil and the bottom substrate are disposed on the same surface.

10. The wireless power transmission device according to claim 1, Among them, The shielding layer is spaced apart from the outside of the transmission coil.

11. The wireless power transmission device according to claim 1, Among them, The ratio of the resonant frequency of the shielding layer to the driving frequency of the wireless power transmission device is 0.7 or less.

12. The wireless power transmission device according to claim 1, Among them, The difference between the driving frequency of the wireless power transmission device and the resonant frequency of the shielding layer is 55 kHz or less.

13. The wireless power transmission device according to claim 1, Among them, The coupling coefficient between the transmission coil and the shielding layer is 0.35 or less.

14. The wireless power transmission device according to claim 1, Among them, The bottom substrate includes a rigid bottom substrate or a flexible bottom substrate.

15. The wireless power transmission device according to claim 1, Among them, The shielding member generates a second current obtained by inverting the phase of the first current flowing in the transmission coil.

16. The wireless power transmission device according to claim 1, Among them, The shielding member generates a second magnetic field for canceling the first magnetic field generated by the transmission coil.

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