Coil component and wireless power transmission device comprising the same

Abstract

This suppresses the decrease in power transmission efficiency when using the first coil and the second coil separately. [Solution] The coil component 1 comprises a first coil 10, a second coil 20 positioned above the first coil 10, and a magnetic material 32 positioned between the first coil 10 and the second coil 20. The first coil 10 is configured to be connectable to some of the turns of the second coil 20.

Description

Technical Field

[0001] The present disclosure relates to a coil component and a wireless power transmission device including the same.

Background Art

[0002] A wireless power transmission device is known as a charging system for mobile devices such as smartphones. For example, Patent Document 1 discloses a wireless power supply system that transmits and receives power using magnetism. This wireless power supply system includes a power transmission device including a power supply coil and a transmission coil, a power reception device including a power reception coil, a measurement unit that measures a load current or a load voltage, and an impedance matching mechanism that performs impedance matching processing according to the measurement result of the measurement unit. The power supply coil is divided into a plurality of power supply coil parts having different relative positions with respect to the transmission coil, and by supplying power to at least one of the plurality of power supply coil parts, adjustment of the input-side impedance with respect to the transmission coil is performed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, wireless power transmission devices compliant with both the EPP (Extended Power Profile) standard and the MPP (Magnetic Power Profile) standard have attracted attention. In this wireless power transmission device, it is required that each of the first coil compatible with EPP and the second coil compatible with MPP transmits power with high efficiency.

[0005] Therefore, the present disclosure aims to provide a coil component capable of suppressing the decrease in power transmission efficiency when using the first coil and the second coil, respectively, and a wireless power transmission device equipped therewith. [Means for solving the problem]

[0006] A coil component according to one embodiment of the present disclosure comprises a first coil, a second coil disposed above the first coil, and a magnetic material disposed between the first coil and the second coil, wherein the first coil is configured to be connectable to a portion of the turns of the second coil. [Effects of the Invention]

[0007] According to this disclosure, it is possible to provide a coil component that can suppress the decrease in power transmission efficiency when using the first coil and the second coil respectively, and a wireless power transmission device equipped therewith. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a substantially cross-sectional view showing the structure of a coil component according to an embodiment of the present disclosure. [Figure 2] Figure 2 is a schematic plan view of the coil component as seen from the direction of the coil axis. [Figure 3] Figure 3 is a schematic diagram showing the electrical connection relationship between the first coil and the second coil. [Figure 4] Figure 4 is an explanatory diagram of the operation of coil component 1. [Figure 5] Figure 5 is an explanatory diagram of the operation of coil component 1. [Figure 6] Figure 6 is a schematic diagram showing another example of the electrical connection relationship between the first and second coils. [Figure 7] Figure 7 is a block diagram showing the configuration of a wireless power transmission device using coil components. [Figure 8] Figure 8 is a block diagram showing another example of the configuration of a wireless power transmission device using coil components. [Modes for carrying out the invention]

[0009] The embodiments of this disclosure will be described in detail below with reference to the attached drawings.

[0010] Figure 1 is a schematic cross-sectional view showing the structure of the coil component 1 according to an embodiment of the present disclosure. Figure 2 is a schematic plan view of the coil component 1 as seen from the direction of the coil axis.

[0011] As shown in Figures 1 and 2, a coil component 1 according to one embodiment includes a first coil 10, a second coil 20 positioned above the first coil 10, a first magnetic material 31 positioned below the first coil 10, a second magnetic material 32 positioned between the first coil 10 and the second coil 20, and a magnet 40 positioned radially outward of the second coil 20.

[0012] The vertical direction of coil component 1 is defined by the Z direction, which is the coil axis direction of the first coil 10 and the second coil 20. An electronic device 60 (device to be charged), such as a smartphone, is placed above coil component 1, and wireless power transmission takes place from coil component 1 to the electronic device 60. In other words, the Z direction in Figure 1 is the power transmission direction. Note that the vertical direction is used to represent the arrangement and is unrelated to the direction of gravity. Therefore, it also includes cases where power is transmitted downwards, which is the direction of gravity.

[0013] The first magnetic material 31, the first coil 10, the second magnetic material 32, and the second coil 20 are stacked in this order in the coil axis direction (power transmission direction).

[0014] Both the first coil 10 and the second coil 20 function as power transmission coils for wireless power transmission. In particular, the first coil 10 is mainly used to secure a wide charging area, and the second coil 20 is mainly used to improve power transmission efficiency in the central region of the charging area.

[0015] The first coil 10 is mainly used for wireless power transmission in the EPP mode, and the second coil 20 is mainly used for wireless power transmission in the MPP mode. EPP is one of the wireless charging standards, capable of rapid charging with a maximum output of 15W, and enabling safe wireless power transmission through two-way communication between the power transmission side and the power reception side. MPP is one of the wireless charging standards also known as the Qi2 standard, which realizes high power transmission efficiency and convenience by using a magnet to accurately align the power transmission coil and the power reception coil.

[0016] The first coil 10 is composed of a planar coil pattern 12 formed on the surface of a base material 11 made of a resin film. Examples of the resin film include PET (polyethylene terephthalate) and PI (polyimide). The coil pattern is a conductor pattern, and the conductor may be copper, aluminum, or an alloy thereof. This enables the realization of a very thin planar coil.

[0017] The planar shape of the first coil 10 has a longitudinal direction in which the width in the Y direction is wider than the width in the X direction. The outer size of the first coil 10 may be larger than the outer size of the second coil 20. According to this, a wide charging area can be ensured. Note that the outer size of the coil is the maximum width of the area surrounded by the outermost turns of the coil.

[0018] Although details will be described later, the first coil 10 is configured to be connectable to some turns of the second coil 20. By connecting the first coil 10 to some turns of the second coil 20, some turns of the second coil 20 can be driven together with the first coil 10 during power transmission using the first coil 10 to perform power transmission, thereby improving the power transmission efficiency.

[0019] The second coil 20 is composed of a planar coil pattern 22 formed on the surface of a base material 21 made of a resin film. Examples of resin films include PET and PI. The coil pattern is a conductive pattern, and the conductor may be copper, aluminum, or an alloy thereof. The second coil 20 may also be a wound coil made by winding copper wire. When the second coil 20 is constructed using a wound coil, a coil with a high inductance value for high-current applications can be realized at low cost. Furthermore, the formation of intermediate taps and the like is also easy.

[0020] The second coil 20 has a roughly circular planar shape, and its width in the Y direction is approximately equal to its width in the X direction. The external dimensions of the second coil 20 may be smaller than those of the first coil 10. This allows for increased magnetic coupling in the central region of the charging area.

[0021] As will be described in detail later, the second coil 20 consists of a first winding section 20A, which is the outer coil pattern, and a second winding section 20B, which is the inner coil pattern, and has a configuration in which pull-out sections are provided at three locations: the outer end of the second coil 20, the inner end of the second coil 20, and the connection point between the first winding section 20A and the second winding section 20B. When the total number of turns of the second coil 20 is, for example, 6 turns, the first winding section 20A can consist of 2 turns on the outer side, and the second winding section 20B can consist of 4 turns on the inner side. The ratio of the number of turns of the first winding section 20A to the number of turns of the second winding section 20B is not particularly limited, but the number of turns of the first winding section 20A may be 1 or more and less than the number of turns of the second winding section 20B. When the first winding section 20A includes the outermost turn of the second coil 20, the inner diameter (opening) of the second coil 20 becomes larger, which suppresses a decrease in magnetic coupling even if a misalignment occurs between the transmitting coil and the receiving coil.

[0022] The first magnetic material 31 and the second magnetic material 32 function as magnetic paths for the magnetic flux generated by the first coil 10 and the second coil 20. The first magnetic material 31 and the second magnetic material 32 may be magnetic materials with a relative permeability of 300 or more. This makes it possible to obtain a high inductance value.

[0023] The first magnetic material 31 consists of a thin magnetic sheet and is positioned below the first coil 10. The external dimensions of the first magnetic material 31 are larger than those of the first coil 10. Therefore, the first magnetic material 31 completely covers the back surface of the first coil 10.

[0024] The second magnetic material 32 is a thin magnetic core that is circular in plan view and approximately E-shaped in cross-section, and is positioned between the first coil 10 and the second coil 20. The external dimensions of the second magnetic material 32 are larger than those of the second coil 20 and smaller than those of the first coil 10. Therefore, the second magnetic material 32 completely covers the back surface of the second coil 20.

[0025] The second magnetic material 32 has a circular base plate portion 32a in plan view, a cylindrical central projection 32b located in the center of the upper surface of the base plate portion 32a, and a substantially annular outer projection 32c located on the periphery of the upper surface of the base plate portion 32a. The central projection 32b and the outer projection 32c protrude upward from the upper surface of the base plate portion 32a. The second coil 20 is housed in a recess formed between the central projection 32b and the outer projection 32c of the second magnetic material 32.

[0026] The outer projection 32c is an annular side wall portion that covers the outer end surface of the second coil 20. The height h of the upper end of the outer projection 32c 32 The height h of the upper surface of the second coil 20 is 20 It is acceptable for it to be higher than this. If the height of the upper surface of the second coil 20 is not constant, the maximum height of the upper surface of the second coil 20 shall be used as the upper surface height. Magnets 40 are arranged in a roughly circular pattern on the outside of the second magnetic body 32, and the second coil 20 is susceptible to the influence of the magnets 40. However, the height h of the upper end of the outer protrusion 32c 32 The height h of the upper surface of the second coil 20 20If the value is higher than this, the influence of the magnet 40 can be reduced, and the decrease in the power transmission efficiency of the second coil 20 can be suppressed.

[0027] In the longitudinal direction (Y direction) of the first coil 10, the outer protrusion 32c of the second magnetic material 32 may be located at a position that overlaps with the inner circumference edge 10E of the winding region of the first coil 10, or it may be located inside the inner circumference edge 10E as shown in the figure. With this configuration, the influence of the second magnetic material 32 on the first coil 10 can be reduced, and the decrease in the magnetic coupling of the first coil 10 can be suppressed.

[0028] In actual use, an electronic device 60 including a power receiving coil 61 is placed on the mounting surface S shown in Figure 1, and power is transmitted wirelessly from the coil component 1 to the electronic device 60 by magnetic coupling between the power transmitting coil, which is either the first coil 10 or the second coil 20, and the power receiving coil 61.

[0029] The magnet 40 is arranged in a ring shape along the outer shape of the second coil 20 so as not to overlap with the second coil 20. Here, "arranged in a ring shape" includes not only arrangement in a complete ring shape, but also arrangement in a state where a part of the magnet 40 is removed, as shown in Figure 2. The positional relationship of the magnet 40 to the second coil in the XY plane is fixed, and the positioning of the power receiving coil 61 relative to the second coil 20 is performed by the attractive force acting between the magnet 40 and the magnet 62 provided on the electronic device 60 side. The magnet 40 may be supported by a support such as resin.

[0030] A non-metallic spacer block 35 is provided between the first coil 10 and the second magnetic material 32, and the first coil 10 is positioned at a predetermined distance from the second coil 20 in the Z direction. The height difference between the top surface of the first coil 10 and the top surface of the second coil 20 may be 5 mm or more. This allows a large step 51 to be formed on the top surface of the housing 50 that houses the coil component 1, corresponding to the height difference between the top surface of the first coil 10 and the top surface of the second coil 20. The height of the step 51 may be 5 mm or more, and may be particularly 6 to 7 mm. The distance between the first coil 10 and the second coil 20 is sufficiently greater than the thickness of the first coil 10 and the second coil 20.

[0031] Smartphones, a typical device to be charged, have a camera lens on their back, and many recent camera lenses protrude significantly from the back. When a protrusion exists on the back of a smartphone, this protrusion interferes with the casing surface of the wireless power transmission system (wireless charger) that houses the coil component 1. Depending on the position of the receiving coil 61 inside the smartphone, it may not be possible to align the receiving coil 61 with the center of the transmitting coil. Furthermore, even if the smartphone is equipped with a magnet 62 for alignment, the camera lens may interfere with the casing surface, preventing the magnet 62 from being attracted to the magnet 40 on the coil component 1 side, which may prevent the MPP mode from functioning effectively.

[0032] However, in this embodiment, by positioning the second coil 20 sufficiently far from the first coil 10 in the coil axis direction, a step 51 can be formed on the upper surface (mounting surface S) of the housing 50 in which the coil component 1 is housed, thereby avoiding interference with the protruding part of the device to be charged.

[0033] Figure 3 is a schematic diagram showing the electrical connection relationship between the first coil 10 and the second coil 20.

[0034] As shown in Figure 3, the first coil 10 is a planar spiral coil, and its inner circumference end 10i is led out to the outside of the winding region of the first coil 10 by a lead wire, and is further connected to the outer circumference end 20o of the second coil 20 via switch SW1 (first switch). For the sake of explanation, the number of turns of the first coil 10 is assumed to be approximately 4 turns.

[0035] The second coil 20 has a first winding section 20A (outer winding section) that constitutes the outer winding portion of the second coil 20, and a second winding section 20B that constitutes the inner winding portion of the second coil 20. Lead wires are connected to the outer and inner ends of the first winding section 20A and the second winding section 20B, respectively. For the sake of explanation, the second coil 20 has 4 turns, with the first winding section 20A being approximately the outermost 1 turn, and the second winding section 20B being the remaining approximately 3 turns.

[0036] The outer circumference 20Ao of the first winding section 20A corresponds to the outer circumference 20o of the second coil 20, and the inner circumference 20Bi of the second winding section 20B corresponds to the inner circumference 20i of the second coil 20. The inner circumference 20Ai of the first winding section 20A and the outer circumference 20Bo of the second winding section 20B are led out to the outside of the winding region of the second coil 20 by lead wires. Furthermore, the inner circumference 20Ai of the first winding section 20A is configured to be connectable to the outer circumference 20Bo of the second winding section 20B via switch SW2 (second switch). Therefore, when switch SW2 is ON, the first winding section 20A and the second winding section 20B are connected in series to form a single coil.

[0037] The first winding section 20A is a planar spiral coil, and the second winding section 20B is also a planar spiral coil provided on the same plane as the first winding section 20A. The second winding section 20B is provided on the inner circumference side of the first winding section 20A, and the position of the outer circumference end 20Bo of the second winding section 20B is adjacent to the position of the inner circumference end 20Ai of the first winding section 20A. That is, the winding of the second winding section 20B starts near the inner circumference end 20Ai of the first winding section 20A and is wound along the innermost turn of the first winding section 20A. Therefore, the apparent configuration of the second coil 20 is almost the same as a single planar spiral coil made by continuously winding a single wire.

[0038] The number of turns in the first winding portion 20A of the second coil 20 may be less than the number of turns in the first coil 10. For example, if the first coil 10 has 8 turns, the number of turns in the first winding portion 20A of the second coil 20 may be less than 8 turns. When the number of turns in the first winding portion 20A is less than that of the first coil 10, the action of the first coil 10 becomes dominant, allowing the first coil 10 to function correctly as an EPP coil and secure a wide charging area.

[0039] The above relationship can also be expressed in terms of inductance values. That is, the inductance value of the first winding portion 20A of the second coil 20 may be smaller than the inductance value of the first coil 10. This allows the first coil 10 to function correctly as an EPP coil and ensures a wide charging area. Furthermore, the combination of the first coil 10 and the first winding portion 20A suppresses the decrease in magnetic coupling near the center of the first coil 10, thereby improving power transmission efficiency.

[0040] Figures 4 and 5 are diagrams illustrating the operation of coil component 1, with Figure 4 showing the EPP mode and Figure 5 showing the MPP mode.

[0041] As shown in Figure 4, when operating coil component 1 in EPP mode (first power transmission mode), switch SW1 is turned ON and switch SW2 is turned OFF. This connects the first winding portion 20A of the second coil 20 in series with the first coil 10, and disconnects the first winding portion 20A from the second winding portion 20B. In other words, the combination of the first coil 10 and the first winding portion 20A forms a single coil, and the first winding portion 20A functions as part of the EPP coil. The pair of terminals of the EPP coil are the outer circumference 10o of the first coil 10 and the inner circumference 20Ai of the first winding portion 20A, and a power transmission circuit is connected between these terminals to supply power.

[0042] When current flows from the outer circumference 10o to the inner circumference 10i of the first coil 10, the current flows clockwise. Similarly, when current flows from the outer circumference 20Ao to the inner circumference 20Ai of the first winding section 20A, the current also flows clockwise. Therefore, the direction of the loop current from the first coil 10 and the direction of the loop current from the first winding section 20A can be made to match, and the first winding section 20A can be used as part of the first coil 10. Thus, in EPP mode, the first coil 10 is mainly used, but a part of the second coil 20 is also used auxiliaryly.

[0043] As shown in Figure 5, when operating coil component 1 in MPP mode (second power transmission mode), switch SW1 is turned off and switch SW2 is turned on. This disconnects the first coil 10 from the first winding portion 20A of the second coil 20, and connects the first winding portion 20A in series with the second winding portion 20B. In other words, the combination of the first winding portion 20A and the second winding portion 20B forms a single coil, and the entire second coil 20 functions as an MPP coil. The pair of terminals of the MPP coil are the outer circumference end 20Ao of the first winding portion 20A and the inner circumference end 20Bi of the second winding portion 20B, and a power transmission circuit is connected between these terminals to supply power. Thus, the second coil 20 is used in MPP mode.

[0044] When power transmission in EPP mode is performed using the first coil 10, the presence of the second magnetic material 32 in the power transmission direction reduces magnetic coupling in the central region of the charging area. However, as in this embodiment, by connecting the first winding portion 20A, which is part of the second coil 20 located on the receiving coil 61 side of the second magnetic material 32, to the first coil 10, and driving the first coil 10 together with the part of the second coil 20, the reduction in magnetic coupling in the central region of the charging area can be suppressed. The first winding portion 20A of the second coil 20 is located above the first coil 10 and is positioned between it and the first coil 10 via the magnetic material 32, but it can function as a coil in EPP mode. Therefore, the power transmission efficiency in EPP mode using the first coil 10 can be increased.

[0045] The above applies when the winding direction of the second coil 20 is the same as that of the first coil 10. When the winding direction of the second coil 20 is opposite to that of the first coil 10, the result is as follows.

[0046] Figure 6 is a schematic diagram showing another example of the electrical connection relationship between the first coil 10 and the second coil 20.

[0047] As shown in Figure 6, the winding direction of the first coil 10 is clockwise from the outer circumference 10o to the inner circumference 10i, while the winding direction of the second coil 20 is counterclockwise from the outer circumference 20o to the inner circumference 20i. In this case, the inner circumference 10i of the first coil 10 is connected to the inner circumference 20Ai of the first winding portion 20A of the second coil 20, not to the outer circumference 20Ao of the first winding portion 20A. The other configurations are the same as in Figure 3.

[0048] When current flows from the outer circumference 10o to the inner circumference 10i of the first coil 10, the current flows clockwise. Similarly, when current flows from the inner circumference 20Ai to the outer circumference 20Ao of the first winding section 20A, the current flows clockwise. Therefore, the direction of the loop current from the first coil 10 and the direction of the loop current from the first winding section 20A can be made to coincide, and the first winding section 20A can be used as part of the first coil 10.

[0049] Figure 7 is a block diagram showing an example of the configuration of a wireless power transmission device 80 using coil component 1.

[0050] The wireless power transmission device 80 shown in Figure 7 comprises a coil component 1 having a first coil 10 and a second coil 20, a power transmission circuit 81A connected to a series circuit of the first coil 10 and the first winding portion 20A of the second coil 20, a power transmission circuit 81B connected to the second coil 20 consisting of the first winding portion 20A and the second winding portion 20B, and a control circuit 82 that controls the power transmission circuits 81A and 81B.

[0051] The wireless power transmission device 80 also includes switches SW1 and SW2 for switching the power transmission mode. Switch SW1 (first switch) is for switching the connection state between the first coil 10 and the first winding section 20A, and switch SW2 (second switch) is for switching the connection state between the first winding section 20A and the second winding section 20B. Switches SW1 and SW2 may be semiconductor switches mounted on a circuit board on which the power transmission circuits 81A and 81B and the control circuit 82 are mounted, or they may be part of the power transmission circuits 81A and 81B or the control circuit 82.

[0052] The control circuit 82 controls switches SW1 and SW2 according to the power transmission mode, and also exclusively activates one of the power transmission circuits 81A and 81B.

[0053] In EPP mode, switch SW1 is turned ON and switch SW2 is turned OFF, connecting the series circuit of the first coil 10 and the first winding section 20A to the power transmission circuit 81A, and disconnecting the second winding section 20B from the first winding section 20A. Then, by supplying power from the power transmission circuit 81A, power transmission in EPP mode is performed using the first coil 10 and a portion of the second coil 20.

[0054] In MPP mode, switch SW1 is turned off and switch SW2 is turned on, connecting the second coil 20 to the power transmission circuit 81B and disconnecting the first coil 10 from the first winding section 20A. Then, power is supplied from the power transmission circuit 81B, enabling power transmission in MPP mode using the second coil 20.

[0055] Figure 8 is a block diagram showing another example of the configuration of a wireless power transmission device 80 using coil component 1.

[0056] The wireless power transmission device 80 shown in Figure 8 comprises a coil component 1 having a first coil 10 and a second coil 20; a power transmission circuit 81 connected to a series circuit of the first coil 10 and the second coil 20 and a first winding portion 20A, or to a second coil 20 consisting of a first winding portion 20A and a second winding portion 20B; a switch SW3 (third switch) provided between the first coil 10 and the second coil 20 and the power transmission circuit 81; and a control circuit 82 that controls the power transmission circuit 81 and the switch SW3.

[0057] The wireless power transmission device 80 also includes switches SW1 and SW2 for switching the power transmission mode. Switches SW1 and SW2 may be semiconductor switches mounted on a circuit board on which the power transmission circuit 81 and control circuit 82 are mounted. Alternatively, switches SW1 and SW2 may be part of the power transmission circuits 81A and 81B and the control circuit 82.

[0058] The control circuit 82 controls switches SW1 and SW2 according to the power transmission mode, and also exclusively activates one of the power transmission circuits 81A and 81B.

[0059] In EPP mode, by turning switch SW1 on, turning switch SW2 off, and connecting switch SW3 to contact a, the series circuit of the first winding portion 20A of the first coil 10 and the second coil 20 is connected to the power transmission circuit 81, and the second winding portion 20B is disconnected from the first winding portion 20A. Subsequently, by driving the power transmission circuit 81, power transmission in EPP mode is performed using a portion of the first coil 10 and the second coil 20.

[0060] In MPP mode, by turning switch SW1 off, switching switch SW2 on, and connecting switch SW3 to contact b, the second coil 20 is connected to the power transmission circuit 81, and the first coil 10 is disconnected from the first winding section 20A. Subsequently, by driving the power transmission circuit 81, power transmission in MPP mode using the second coil 20 is performed.

[0061] As described above, the wireless power transmission device 80 shown in Figure 7 uses separate power transmission circuits for each power transmission mode. On the other hand, the wireless power transmission device 80 shown in Figure 8 uses a common power transmission circuit to drive the first coil 10 and the second coil 20, regardless of the power transmission mode.

[0062] As described above, the coil component 1 according to this embodiment comprises a first magnetic material 31, a first coil 10 arranged on the first magnetic material 31, a second coil 20 arranged above the first coil 10 and having a smaller external size than the first coil 10, and a second magnetic material 32 provided between the first coil 10 and the second coil 20. In the power transmission mode using the first coil 10, a portion of the turns of the second coil 20 are utilized, so a wide charging area can be secured while suppressing a decrease in the magnetic coupling of the first coil 10 due to the influence of the second magnetic material 32. Furthermore, since the second magnetic material 32 is provided between the first coil 10 and the second coil 20, the power transmission efficiency can be increased in the power transmission mode using the second coil 20.

[0063] The technology relating to this disclosure includes, but is not limited to, the following configuration examples.

[0064] A coil component according to one embodiment of the present disclosure comprises a first coil, a second coil positioned above the first coil, and a magnetic material positioned between the first and second coils, wherein the first coil is configured to be connectable to a portion of the turns of the second coil. According to the present disclosure, it is possible to suppress the decrease in the magnetic coupling of the first coil due to the influence of the magnetic material provided between the first and second coils. Therefore, it is possible to suppress the decrease in power transmission efficiency when using the first and second coils respectively.

[0065] In the above-described coil component, the external dimensions of the first coil may be larger than those of the second coil. This allows for a wider charging area to be secured.

[0066] In the above coil component, the first coil may be positioned at a predetermined distance from the second coil in the coil axis direction. This allows charging of a device, such as a smartphone, to be performed while avoiding interference with any protrusions on the device.

[0067] In the above coil component, the second coil has a first winding portion located on the outer circumference of the second coil and a second winding portion located on the inner circumference of the second coil relative to the first winding portion, and the first coil may be configured to be connectable to the first winding portion. This allows a portion of the second coil to be used in wireless power transmission using the first coil, and suppresses the reduction in the magnetic coupling of the first coil due to the influence of magnetic materials.

[0068] In the above coil component, the number of turns of the first coil may be greater than the number of turns of the first winding section. This allows for a wider charging area while suppressing the reduction in magnetic coupling of the first coil due to the influence of magnetic materials, thereby improving power transmission efficiency.

[0069] In the above coil component, the inductance value of the first coil may be greater than the inductance value of the first winding. This makes it possible to secure a wide charging area while suppressing the decrease in magnetic coupling of the first coil due to the influence of magnetic materials, thereby improving power transmission efficiency.

[0070] In the above-described coil component, the planar shape of the first coil may have a longitudinal direction. This makes it possible to suppress a decrease in power transmission efficiency even if the center position of the receiving coil is slightly shifted from the center position of the first coil in one direction along the longitudinal direction of the first coil. In other words, a wide charging area can be secured, and the misalignment of the receiving coil can be accommodated.

[0071] The periphery of the magnetic material may be provided with a protrusion that extends toward the second coil. This makes it possible to reduce the influence of surrounding magnets while ensuring the inductance value of the second coil.

[0072] The height of the upper end of the magnetic material's protrusion may be higher than the upper surface of the second coil. This allows for the reduction of the influence of the magnets placed around the second coil while ensuring the inductance value of the second coil.

[0073] The protruding portion may overlap with the inner edge of the winding region of the first coil in a plan view. This makes it possible to suppress the reduction in the magnetic coupling of the first coil due to the influence of the magnetic material.

[0074] The protruding portion of the magnetic material may be located inside the inner edge of the winding region of the first coil in a plan view. This makes it possible to suppress the reduction in the magnetic coupling of the first coil due to the influence of the magnetic material.

[0075] Furthermore, the wireless power transmission device according to this disclosure comprises one of the above-mentioned coil components and a power transmission circuit connected to the first and second coils. This makes it possible to provide a wireless power transmission device with a wide charging area and high power transmission efficiency.

[0076] Furthermore, the wireless power transmission device according to this disclosure comprises one of the above-mentioned coil components, a first switch for switching the connection state between the first coil and the first winding section, a second switch for switching the connection state between the first winding section and the second winding section, a power transmission circuit connected to the first and second coils, a third switch for connecting the power transmission circuit to a series circuit between the first coil and the first winding section or to the second coil, and a control circuit for controlling the first switch, the second switch, the third switch and the power transmission circuit. This makes it possible to provide a wireless power transmission device with a wide charging area and high power transmission efficiency.

[0077] In the first power transmission mode using the first coil, the control circuit may control the first switch to connect the first winding section in series with the first coil, control the second switch to disconnect the first winding section from the second winding section, and control the third switch to connect the power transmission circuit to the series circuit of the first coil and the first winding section. This makes it possible to suppress a decrease in power transmission efficiency in EPP mode.

[0078] Furthermore, in the second power transmission mode using the second coil, the control circuit may control the first switch to disconnect the first winding section from the first coil, control the second switch to connect the first winding section in series with the second winding section, and control the third switch to connect the power transmission circuit to the second coil. This makes it possible to suppress the decrease in power transmission efficiency in MPP mode. [Explanation of symbols]

[0079] 1. Coil component 10. First coil 10E Inner edge of the winding region of the first coil 10i Inner end of the first coil 10° Outer edge of the first coil 11 Base material 12 Planar coil patterns 20 Second coil 20i Inner end of the second coil 20° Outer edge of the second coil 20A Second coil, first winding section 20Ai Inner end of the first winding section 20Ao Outer edge of the first turn 20B Second coil, second winding section 20Bi Inner end of the second turn 20Bo Outer edge of the second coil section 21 Base material 22 Planar coil patterns 31 First magnetic body 32 Second magnetic body 32a Bottom plate part 32b Central protrusion 32c Outer protrusion 35 Spacer Blocks 40 magnets 50 cabinets 51 steps 60 Electronic equipment 61 Power receiving coil 62 Magnets 80 Wireless Power Transmission Devices 81, 81A, 81B power transmission circuits 82 Control circuits S Top surface of the enclosure (mounting surface) SW1 Switch (First Switch) SW2 Switch (Second Switch) SW3 Switch (Third Switch)

Claims

1. The first coil and A second coil positioned above the first coil, The system comprises a magnetic material disposed between the first coil and the second coil, The first coil is a coil component configured to be connectable to some of the turns of the second coil.

2. The coil component according to claim 1, wherein the external dimensions of the first coil are larger than the external dimensions of the second coil.

3. The coil component according to claim 1, wherein the first coil is arranged at a predetermined distance from the second coil in the coil axis direction.

4. The second coil has a first winding portion located on the outer circumference side of the second coil and a second winding portion located on the inner circumference side of the second coil than the first winding portion. The coil component according to claim 1, wherein the first coil is configured to be connectable to the first winding portion.

5. The coil component according to claim 4, wherein the number of turns of the first coil is greater than the number of turns of the first winding portion.

6. The coil component according to claim 4, wherein the inductance value of the first coil is greater than the inductance value of the first winding portion.

7. The coil component according to claim 1, wherein the planar shape of the first coil has a longitudinal direction.

8. The coil component according to claim 1, wherein the periphery of the magnetic material is provided with a protrusion that protrudes toward the second coil side.

9. The coil component according to claim 8, wherein the height of the upper end of the protrusion is higher than the upper surface of the second coil.

10. The coil component according to claim 8, wherein the protruding portion overlaps with the inner circumference edge of the winding region of the first coil in a plan view.

11. The coil component according to claim 8, wherein the protruding portion is located inside the inner circumference edge of the winding region of the first coil in a plan view.

12. A coil component according to any one of claims 1 to 11, A wireless power transmission device comprising a power transmission circuit connected to the first and second coils.

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