Coil Module and Wireless Power Transmission Device

Abstract

To provide an improved coil module provided with a holder and a coil.SOLUTION: A coil module 1 includes: a holder 2 having a flat-plate part 10 for placing thereon a target device, a side stopper 15 extending in a y direction along a side 11 of the flat-plate part 10, and a lower stopper 16 extending in an x direction along a side 12 of the flat-plate part 10; and a coil 3 provided on the flat-plate part 10 of the holder 2. As viewed in a coil axis direction, an outer size of the coil 3 in an A direction inclined at a predetermined angle with respect to the y direction is larger than an outer size of the coil in a B direction. Thus, various target devices of different sizes can be charged.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a coil module and a wireless power transmission device.

Background Art

[0002] A holder for placing a target device such as a smartphone may include a coil for charging the target device in a non-contact manner as described in Patent Document 1.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the holder described in Patent Document 1 can only place target devices of a predetermined size. For this reason, it was not possible to charge various target devices of different sizes.

[0005] Therefore, an object of the present disclosure is to provide an improved coil module and a wireless power transmission device including a holder and a coil.

Means for Solving the Problems

[0006] A coil module according to an embodiment of the present disclosure includes a flat plate portion for placing a target device, a first stopper extending in a first direction along a first side of the flat plate portion, and a second stopper extending in a second direction perpendicular to the first direction along a second side of the flat plate portion, and a coil provided on the flat plate portion of the holder. The coil has an outer shape size in a third direction having a predetermined inclination with respect to the first direction larger than an outer shape size in a fourth direction perpendicular to the third direction when viewed from the coil axis direction.

Advantages of the Invention

[0007] According to the present disclosure, it becomes possible to charge various target devices having different sizes.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

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Figure 11

Modes for Carrying Out the Invention

[0009] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0010] FIG. 1 is a schematic perspective view showing the appearance of the coil module 1 according to one embodiment.

[0011] As shown in FIG. 1, the coil module 1 according to the present embodiment includes a holder 2 on which a target device such as a smartphone is placed, and a charging coil 3 built in the holder 2. The holder 2 has a flat plate portion 10 for placing the target device. The surface of the flat plate portion 10 has an xy plane, and has sides 11, 13 extending in the y direction which is the first direction, and sides 12, 14 extending in the x direction which is the second direction. Side 11 is the first side, and side 13 is located on the side opposite to side 11. Side 12 is the second side, and side 14 is located on the side opposite to side 12. The shape of the flat plate portion 10 is a vertically long shape in which the height in the y direction is larger than the width in the x direction.

[0012] The holder 2 further has a side stopper 15 extending in the y direction along side 11 of the flat plate portion 10, and a lower stopper 16 extending in the x direction along side 12 of the flat plate portion 10. The side stopper 15 protrudes in the z direction, and is an example of a first stopper that serves to position the target device placed on the flat plate portion 10 in the x direction. The lower stopper 16 protrudes in the z direction, and is an example of a second stopper that serves to position the target device placed on the flat plate portion 10 in the y direction. The side stopper 15 may be provided over the entire side 11 of the flat plate portion 10, or may be provided only on a part of side 11. Similarly, the lower stopper 16 may be provided over the entire side 12 of the flat plate portion 10, or may be provided only on a part of side 12.

[0013] The coil 3 is provided on the flat plate portion 10 of the holder 2. The coil axis of the coil 3 is in the z direction. The coil 3 is a power transmission coil used for wireless power transmission. When a target device such as a smartphone is placed on the holder 2, the target device can be charged by wireless power transmission. The holder 2 may have a stand for self-standing, or may have a structure that facilitates operation of a target device such as a smartphone while charging by eliminating such a stand. The size of the target device that can be placed on the holder 2 is not fixed, and various target devices with somewhat different sizes can be placed. The target device is provided with a power receiving coil used for wireless power transmission. By flowing a current through the coil 3 with the power receiving coil and the power transmission coil 3 overlapping, the target device is charged in a non-contact manner.

[0014] FIG. 2 is a schematic diagram for explaining the shape of the coil 3 and its position on the flat plate portion 10.

[0015] In FIG. 2, reference numeral 3a is a wiring region where a spiral coil pattern constituting the coil 3 is arranged, and reference numeral 3b is an opening region surrounded by the wiring region 3a. As shown in FIG. 2, the planar shape of the coil 3 viewed from the z direction is not a perfect circle, but an elliptical shape with its major axis having a predetermined inclination with respect to the y direction. More specifically, when the coil axis of the coil 3 is C0, the outer dimension D1 in the A direction, which is an example of a third direction passing through the coil axis C0, is larger than the outer dimension D2 in the B direction, which is an example of a fourth direction passing through the coil axis C0. Here, the A direction and the B direction are orthogonal to each other and have a predetermined inclination with respect to the x direction and the y direction. Both the A direction and the B direction are orthogonal to the z direction. The coil axis C0 does not coincide with the center of the flat plate portion 10 and is offset in the x direction and the y direction. Also, the distance W1 in the y direction between the coil axis C0 and the side 12 of the flat plate portion 10 is larger than the distance W2 in the x direction between the coil axis C0 and the side 11 of the flat plate portion 10.

[0016] As described above, on the flat plate portion 10 of the holder 2, a target device such as a smartphone is placed. The position of the power receiving coil provided in the target device is often the central portion in the x direction and the central portion in the y direction of the target device, especially in the case of a smartphone. For this reason, even when a relatively small target device S1 is placed on the holder 2 or when a relatively large target device S2 is placed on the holder 2, all or part of the power receiving coils provided in the target device S1 or S2 overlaps with the coil 3. Although not shown, the same applies when a target device that is larger than the target device S1 and smaller than the target device S2 is placed on the holder 2. As an example, when a relatively small target device S1 is placed on the holder 2, the center position C1 of the power receiving coil provided in the target device S1 overlaps with the lower right portion of the opening region 3b of the coil 3, while when a relatively large target device S2 is placed on the holder 2, the center position C2 of the power receiving coil provided in the target device S2 overlaps with the upper left portion of the opening region 3b of the coil 3.

[0017] In this way, regardless of whether either of the target devices S1 and S2 of different sizes is placed on the holder 2, all or part of the power receiving coils provided in the target devices S1 and S2 overlaps with the coil 3. Preferably, the opening region 3b of the coil 3 and the center positions C1 and C2 of the power receiving coils built in the target devices S1 and S2 overlap in the z direction. As a result, the magnetic flux generated from the coil 3 efficiently links with the power receiving coils built in the target devices S1 and S2, making it possible to obtain high power transmission efficiency.

[0018] As shown in Fig. 2, when assuming a virtual line L1 passing through the coil axis C0 on the flat plate portion 10 and extending in the A direction, the virtual line L1 intersects the sides 12 and 14 of the flat plate portion 10 without intersecting the sides 11 and 13 of the flat plate portion 10. Also, the virtual line L1 does not intersect the corner portion 17 formed by the sides 11 and 12 of the flat plate portion 10, nor the corner portion 18 located diagonally to the corner portion 17 and formed by the sides 13 and 14 of the flat plate portion 10. And when the angle formed by the virtual line L1 and the side 12 of the flat plate portion 10 is θ1, and the angle formed by the diagonal line L2 connecting the corner portions 17 and 18 and the side 12 of the flat plate portion 10 is θ2, then θ1 > θ2. As described above, since the flat plate portion 10 has a vertically long shape, the angle θ2 is greater than 45°, but the angle θ1 is even larger than that.

[0019] The reason for such a shape is that if designed such that θ1 = θ2 with the virtual line L1 overlapping the diagonal line L2, as shown in Fig. 3, it is necessary to use a coil 3c with a smaller area of the wiring region 3a than the above-described coil 3, because the inductance is reduced. In particular, as shown in Fig. 4, if designed such that the virtual line L1 passes through the corner portion 17 and θ1 < θ2, the central positions C1 and C2 of the power receiving coils of the vertically long target devices S1 and S2 and the opening region 3b of the coil 3c will not overlap, resulting in a significant reduction in power transmission efficiency. On the other hand, as shown in Fig. 2, by designing such that θ1 > θ2, it is possible to obtain high power transmission efficiency while ensuring a sufficient area of the wiring region 3a of the coil 3.

[0020] Also, even if θ1 > θ2, if designed such that the virtual line L1 passes through the corner portion 17, as shown in Fig. 5, the width of the flat plate portion 10 in the x direction will become larger than that of the relatively small target device S1, making it difficult to grip the target device S1 when placed on the holder 2. On the other hand, as shown in Fig. 2, by designing such that the virtual line L1 intersects the side 12, since the relatively small target device S1 protrudes from the side 13, it becomes easier to grip the target device S1 when placed on the holder 2.

[0021] Fig. 6 is a schematic cross-sectional view showing the configuration of the coil 3.

[0022] As shown in FIG. 6, the coil 3 includes a first coil pattern 100 formed on one surface 21 of the base material 20 and a second coil pattern 200 formed on the other surface 22 of the base material 20. The inner peripheral ends of the first coil pattern 100 and the second coil pattern 200 are connected to each other via a plurality of through-hole conductors (only the through-hole conductor 305 appears in the cross-section shown in FIG. 6) provided through the base material 20. Then, the coil 3 is embedded in the holder 2 such that one surface 21 of the base material 20 faces the mounting surface side of the flat plate portion 10. It is preferable to dispose a magnetic sheet 30 made of a magnetic material such as ferrite on the other surface 22 side of the base material 20.

[0023] The material of the base material 20 is not particularly limited, and a transparent or translucent flexible insulating material such as a PET resin can be used. Further, the base material 20 may be a flexible substrate in which a glass cloth is impregnated with an epoxy resin.

[0024] FIG. 7 is a plan view for explaining the pattern shape of the first coil pattern 100, showing a state as viewed from one surface 21 side of the base material 20.

[0025] The first coil pattern 100 has a six-turn configuration consisting of turns 110, 120, 130, 140, 150, and 160. The turn 110 is located at the outermost periphery, and the turn 160 is located at the innermost periphery. The turns 110, 120, 130, 140, 150, and 160 are radially divided into eight parts by seven spiral slits. That is, the turn 110 is divided into eight parts in parallel lines 111 to 118, the turn 120 is divided into eight parts in parallel lines 121 to 128, the turn 130 is divided into eight parts in parallel lines 131 to 138, the turn 140 is divided into eight parts in parallel lines 141 to 148, the turn 150 is divided into eight parts in parallel lines 151 to 158, and the turn 160 is divided into eight parts in parallel lines 161 to 168.

[0026] And lines 111, 121, 131, 141, 151, 161 form continuous lines that spiral six turns, lines 112, 122, 132, 142, 152, 162 form continuous lines that spiral six turns, lines 113, 123, 133, 143, 153, 163 form continuous lines that spiral six turns, lines 114, 124, 134, 144, 154, 164 form continuous lines that spiral six turns, lines 115, 125, 135, 145, 155, 165 form continuous lines that spiral six turns, lines 116, 126, 136, 146, 156, 166 form continuous lines that spiral six turns, lines 117, 127, 137, 147, 157, 167 form continuous lines that spiral six turns, and lines 118, 128, 138, 148, 158, 168 form continuous lines that spiral six turns. Among these, lines 111, 121, 131, 141, 151, 161 are the outermost lines, and lines 118, 128, 138, 148, 158, 168 are the innermost lines.

[0027] The outer peripheral ends of lines 111 to 118 are commonly connected to the terminal electrode pattern 101. On the other hand, the inner peripheral ends of lines 161 to 168 are respectively connected to through-hole conductors 301 to 308 provided through the base material 20. The through-hole conductors 301 to 308 are arranged in the B direction.

[0028] The pattern shape of the second coil pattern 200 as viewed from the other surface 22 side of the base material 20 is the same as the pattern shape of the first coil pattern 100 as viewed from one surface 21 side of the base material 20. And the eight lines constituting the innermost turn of the second coil pattern 200 are respectively connected to the eight lines constituting the innermost turn of the first coil pattern 100 via the through-hole conductors 301 to 308. The first coil pattern 100 and the second coil pattern 200 are formed on the front and back of the base material 20 so that the coil axes coincide. Thus, as shown in FIG. 8, each line constituting the first coil pattern 100 and each line constituting the second coil pattern 200 overlap each other in the z direction. The eight lines constituting the outermost turn of the second coil pattern 200 are commonly connected to the terminal electrode pattern 102.

[0029] With such a configuration, as shown in FIG. 9, the first coil pattern 100 and the second coil pattern 200 are connected in series between the first terminal electrode pattern 101 and the second terminal electrode pattern 102. And since both the first and second coil patterns 100 and 200 are of a six-turn configuration, a coil of a total of twelve-turn configuration is formed. Moreover, since the line located at the outermost periphery in the first coil pattern 100 is connected to the line located at the innermost periphery in the second coil pattern 200, and the line located at the innermost periphery in the first coil pattern 100 is connected to the line located at the outermost periphery in the second coil pattern 200, the difference between the inner and outer circumferences is also canceled out.

[0030] FIG. 10 is a block diagram of a wireless power transmission device 40 using the coil module 1 according to the present embodiment.

[0031] The wireless power transmission device 40 shown in FIG. 10 includes a coil 3 included in the coil module 1, a power transmission circuit 41 connected to the coil 3, and a control circuit 42 connected to the power transmission circuit 41. Thereby, the power supplied by the power source 43 can be wirelessly transmitted to target devices S1, S2 such as smartphones via the coil 3 for wireless power transmission.

[0032] FIG. 11 is a schematic diagram of a coil module 1A according to a modification.

[0033] As shown in FIG. 11, the coil module 1A according to the modification further includes a movable stopper 19 extending in the y direction along the side 13 of the flat plate portion 10. Since other basic configurations are the same as those of the coil module 1 described above, the same elements are denoted by the same reference numerals, and redundant descriptions are omitted.

[0034] The position of the movable stopper 19 is variable in the x direction. Therefore, when placing the small target device S1 on the flat plate portion 10, the position of the movable stopper 19 in the x direction is set as P1, and when placing the large target device S2 on the flat plate portion 10, the position of the movable stopper 19 in the x direction is set as P2. By doing so, when the target devices S1, S2 are held in a state of being placed on the holder 2, it becomes difficult for the target devices S1, S2 to drop off from the holder 2.

[0035] As described above, the preferred embodiments of the present disclosure have been described. However, the present disclosure is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present disclosure, and it goes without saying that those are also included in the scope of the present disclosure.

[0036] The technology according to the present disclosure includes, but is not limited to, the following configuration examples.

[0037] A coil module according to an embodiment of the present disclosure includes a flat plate portion for placing a target device, a first stopper extending in a first direction along a first side of the flat plate portion, and a second stopper extending in a second direction orthogonal to the first direction along a second side of the flat plate portion. A holder having a coil provided on the flat plate portion of the holder, the coil having an outer dimension in a third direction having a predetermined inclination with respect to the first direction larger than an outer dimension in a fourth direction orthogonal to the third direction when viewed from the coil axis direction.

[0038] According to this, it becomes possible to charge various target devices of different sizes without contact.

[0039] Also, the planar shape of the coil viewed from the coil axis direction may be elliptical. According to this, it is possible to efficiently charge various target devices of different sizes.

[0040] Also, a virtual line passing through the coil axis and extending in the third direction on the flat plate portion may not intersect a first corner portion formed by the first and second sides of the flat plate portion. According to this, it becomes easier to grip the target device in a state where it is placed on the holder. In this case, the flat plate portion has a second corner portion located diagonally to the first corner portion, and the angle formed by the virtual line and the second side of the flat plate portion may be larger than the angle formed by the diagonal line connecting the first and second corner portions and the second side of the flat plate portion. According to this, it is possible to sufficiently secure the area of the wiring region of the coil.

[0041] Also, the coil axis may not coincide with the center position of the flat plate portion. According to this, it is possible to efficiently charge various target devices of different sizes.

[0042] Also, the distance in the first direction between the coil axis and the second side of the flat plate portion may be larger than the distance in the second direction between the coil axis and the first side of the flat plate portion. According to this, it is possible to improve the power transmission efficiency for a target device having a vertically long shape.

[0043] Further, the coil includes a first coil pattern provided on one surface of the base material, a second coil pattern provided on the other surface of the base material, and a through-hole conductor provided through the base material to connect the inner peripheral end of the first coil pattern and the inner peripheral end of the second coil pattern. Each turn constituting the first and second coil patterns is divided into a plurality of parallel lines. The through-hole conductor may be assigned to each of the plurality of lines and arranged in the fourth direction. According to this, the difference between the inner and outer circumferences is offset, and it becomes possible to sufficiently secure the width in the fourth direction of the opening region of the coil.

[0044] Further, the holder may further have a movable stopper that extends in the first direction along the third side located on the side opposite to the first side of the flat plate portion and whose position in the second direction is variable. According to this, when the target device is held in a state of being placed on the holder, it becomes difficult for the target device to fall off the holder.

[0045] Further, the wireless power transmission device according to the present disclosure includes the above-described coil module and a power transmission circuit connected to the coil. According to this, it becomes possible to provide a wireless power transmission device capable of non-contact charging for various target devices having different sizes.

Explanation of Signs

[0046] 1, 1A Coil module 2 Holder 3, 3c Coil 3a Wiring region 3b Opening region 10 Flat plate portion 11 First side 12 Second side 13 Third side 14 Fourth side 15 Side stopper 16 Lower stopper 17, 18 Corner 19 Movable stopper 20 Base material 21 One surface 22 The surface of the other party 30 Magnetic sheet 40 Wireless power transmission device 41 Power transmission circuit 42 Control circuit 43 Power source 100 First coil pattern 101, 102 Terminal electrode pattern 110, 120, 130, 140, 150, 160 Turns 111~118, 121~128, 131~138, 141~148, 151~158, 161~168 Lines 301~308 Through-hole conductors C0 Coil axis C1, C2 Center positions of the power receiving coils D1, D2 Outer dimensions of the coil L1 Virtual line L2 Diagonal line S1, S2 Target devices W1, W2 Distances θ1, θ2 Angles

Claims

1. A holder having a flat plate portion for placing a target device, a first stopper extending in a first direction along a first side of the flat plate portion, and a second stopper extending in a second direction orthogonal to the first direction along a second side of the flat plate portion, a coil provided on the flat plate portion of the holder, wherein the first side is longer than the second side, the coil extends in a third direction having a predetermined inclination with respect to the first direction when viewed from the coil axis direction, and an outer dimension in the third direction is larger than an outer dimension in a fourth direction orthogonal to the third direction, a virtual line passing through the coil axis and extending in the third direction on the flat plate portion does not intersect a first corner portion formed by the first and second sides of the flat plate portion, the flat plate portion has a second corner portion located diagonally opposite to the first corner portion, an angle formed by the virtual line and the second side of the flat plate portion is larger than an angle formed by a diagonal line connecting the first and second corner portions and the second side of the flat plate portion, the coil module.

2. The coil module according to claim 1, wherein a planar shape of the coil when viewed from the coil axis direction is an ellipse.

3. The coil module according to claim 1 or 2, wherein the first stopper positions the target device placed on the flat plate portion in the second direction regardless of a size of the target device in the second direction.

4. The coil module according to claim 3, wherein the second stopper positions the target device placed on the flat plate portion in the first direction regardless of a size of the target device in the first direction.

5. The coil module according to any one of claims 1 to 4, wherein the coil axis does not coincide with a central position of the flat plate portion.

6. The coil module according to any one of claims 1 to 5, wherein a distance between the coil axis and the second side of the flat plate portion in the first direction is larger than a distance between the coil axis and the first side of the flat plate portion in the second direction.

7. The coil includes a first coil pattern provided on one surface of a base material, a second coil pattern provided on the other surface of the base material, and a through-hole conductor provided through the base material and connecting an inner peripheral end of the first coil pattern and an inner peripheral end of the second coil pattern. Each turn constituting the first and second coil patterns is divided into a plurality of parallel lines, The coil module according to any one of claims 1 to 6, wherein the through-hole conductors are respectively assigned to the plurality of lines and are arranged in the fourth direction.

8. The coil module according to any one of claims 1 to 7, wherein the holder further has a movable stopper that extends in the first direction along a third side located on the side opposite to the first side of the flat plate portion and is variable in position in the second direction.

9. A wireless power transmission device comprising the coil module according to any one of claims 1 to 8, and a power transmission circuit connected to the coil.

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