Power receiving device

Abstract

To improve the power supply efficiency of the power receiving device. [Solution] The power receiving device 20 comprises a base 30 and an antenna section 40 on which a power receiving antenna for receiving radio waves for power supply is arranged and connected to the base 30. The base 30 has an installation surface 31A which constitutes a part of the outer surface of the base 30. The antenna section 40 has a power receiving surface 41B based on the installation direction of the power receiving antenna. The antenna section 40 is connected to the base 30 so as to be tiltable such that the angle of the power receiving surface 41B with respect to the installation surface 31A changes.

Description

Technical Field

[0001] The present invention relates to a power receiving device used in radio power feeding by a radio wave method.

Background Art

[0002] In recent years, so-called wireless power feeding that performs power feeding to electronic devices without contact has been proposed. For example, Patent Document 1 describes wireless power feeding by a radio wave method. A power transmission device used in wireless power feeding by a radio wave method has a power transmission antenna. Power supply radio waves are emitted from the power transmission antenna. A power receiving device used in wireless power feeding by a radio wave method has a power receiving antenna and a rectifying circuit. The power receiving antenna receives radio waves emitted from the power transmission device. The rectifying circuit is a circuit having diodes for rectification, and converts the radio waves received by the power receiving antenna into DC power. The converted DC power is used as the power supply power of an electric device or for charging a built-in battery of the electric device.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In radio wave-based wireless power transmission, improving power transmission efficiency is required. Power transmission efficiency depends on the angle and area of ​​the receiving device that receives radio waves emitted from the transmitting device. More specifically, the receiving device has a receiving surface determined by the direction in which the receiving antenna is installed. The power transmission efficiency of the receiving device decreases as the angle of the receiving surface moves away from a specific angle (for example, the angle directly facing the transmitting device). Furthermore, if there is an obstruction between the receiving surface of the receiving device and the transmitting device, the power transmission efficiency of the receiving device decreases as the area of ​​the receiving surface hidden by the obstruction increases. For example, in the case of a receiving device used while held in the hand, the part of the receiving surface covered by the user's hand becomes the aforementioned obstruction. [Means for solving the problem]

[0005] The following describes various configurations of power receiving devices to solve the above problems. [Aspect 1] A power receiving device used in radio wave wireless power transfer, comprising a base and an antenna section on which a power receiving antenna for receiving radio waves for power transfer is arranged and connected to the base, wherein the base has an installation surface that constitutes a part of the outer surface of the base, the antenna section has a power receiving surface based on the installation direction of the power receiving antenna, and the antenna section is tiltably connected to the base such that the angle of the power receiving surface with respect to the installation surface changes.

[0006] With the above configuration, the antenna can be tilted to adjust the position of the receiving surface, depending on the usage mode, such as using the power receiving device while it is placed on a mounting surface, or using a portable terminal with the power receiving device attached while it is held in the hand. Therefore, the position of the antenna can be changed to a position where the power supply efficiency is high.

[0007] [Aspect 2] The power receiving device according to aspect 1, wherein the base has a first main surface which is the mounting surface and a second main surface located on the opposite side of the first main surface, and the antenna portion is configured to be able to change position including a retracted position and an unfolded position, the retracted position being a position in which the antenna portion is in contact with the second main surface of the base, and the unfolded position being a position in which the antenna portion is separated from the second main surface of the base.

[0008] According to the above configuration, the second main surface of the base faces the antenna section, and the first main surface, which is the opposite side of the second main surface, is the mounting surface. In other words, the first main surface, which is the mounting surface, is the side that does not face the antenna section. As a result, when the antenna section is in the deployed position, a gap is formed between the base and the antenna section, allowing for the operation of devices attached to the base without damaging the received radio waves.

[0009] [Aspect 3] A power receiving device according to aspect 1 or aspect 2, comprising a support structure that tiltably supports the antenna portion with respect to the base, wherein the support structure includes a shaft provided on one of the base and the antenna portion, and a bearing hole provided on the other of the base and the antenna portion into which the shaft is inserted.

[0010] [Aspect 4] The power receiving device according to aspect 3, wherein the shaft is press-fitted into the bearing hole, and the friction generated between the shaft and the inner wall surface of the bearing hole due to press-fitting into the bearing hole is set to a magnitude that allows for angle adjustment of the antenna portion with respect to the base portion.

[0011] [Aspect 5] A power receiving device according to any one of aspects 1 to 3, comprising a drive device, wherein the antenna portion tilts based on the drive of the drive device. [Aspect 6] A power receiving device according to any one of aspects 1 to 5, comprising a relay structure for electrically connecting the base portion and the antenna portion, wherein the relay structure includes a terminal provided on one of the base portion and the antenna portion, and a connection hole provided on the other of the base portion and the antenna portion into which the terminal is inserted, and the terminal is supported on the inner wall surface so as to rotate while in contact with the inner wall surface of the connection hole.

[0012] [Aspect 7] A power receiving device according to any one of aspects 1 to 6, comprising a rectifier circuit that converts radio waves received by the power receiving antenna into DC power, wherein the rectifier circuit is located in the antenna section.

[0013] [Aspect 8] The power receiving device according to aspect 7, comprising an output unit that outputs DC power converted by the rectifier circuit, and a control unit that performs operation control of the output unit, wherein the output unit and the control unit are arranged on the base.

[0014] [Aspect 9] A power receiving device according to any one of aspects 1 to 8, comprising: a rectifier circuit that converts radio waves received by the power receiving antenna into DC power; a storage battery that stores the DC power converted by the rectifier circuit; and an output unit that supplies the power stored in the storage battery to an electrical device by contactless power supply. [Effects of the Invention]

[0015] According to the present invention, the power supply efficiency of the power receiving device can be improved. [Brief explanation of the drawing]

[0016] [Figure 1] Figure 1 is a schematic diagram showing the relationship between the power receiving device and the power transmitting device in the embodiment. [Figure 2] Figure 2 is a block diagram illustrating the schematic configuration of the power receiving device and power transmitting device according to the embodiment. [Figure 3] Figure 3 is a perspective view of the power receiving device of the embodiment. [Figure 4] Figure 4 is a side view of the power receiving device of the embodiment. [Figure 5] Figure 5 is a partial cross-sectional view showing a part of the internal structure of the antenna section of the embodiment. [Figure 6] Figure 6 is a front view of the power receiving device of the embodiment. [Figure 7] Figure 7 is an enlarged view of the X portion of Figure 6. [Figure 8]FIG. 8 is a front view showing the base and the antenna portion of the power receiving device of the embodiment separately. [Figure 9] FIG. 9 is an exploded perspective view showing the support structure of the power receiving device of the embodiment. [Figure 10] FIG. 10 is an exploded perspective view showing the relay structure of the power receiving device of the embodiment. [Figure 11] FIG. 11 is an explanatory view showing the first power supply mode of the power receiving device of the embodiment. [Figure 12] FIG. 12 is an explanatory view showing the second power supply mode of the power receiving device of the embodiment. [Figure 13] FIG. 13 is a perspective view showing the support structure of the modification example. [Figure 14] FIG. 14 is a side view of the power receiving device of the modification example.

MODE FOR CARRYING OUT THE INVENTION

[0017] Hereinafter, an embodiment of the present invention will be described. <Overview of the Wireless Power Supply System> As shown in FIG. 1, the wireless power supply system includes a power transmission device 10 and a power receiving device 20. The power transmission device 10 supplies power to the power receiving device 20 by wireless power supply using radio waves. The power receiving device 20 is charged by the power sent from the power transmission device 10. That is, power supply radio waves are transmitted and received between the power transmission antenna 11 of the power transmission device 10 and the power receiving antenna 21 of the power receiving device 20. The power supply radio waves are, for example, microwaves.

[0018] The power receiving device 20 transmits a beacon signal including position information to the power transmission device 10 at a predetermined time interval. When the power receiving device 20 is within the power transmission range AR of the power transmission device 10, the power transmission device 10 receives the beacon signal of the power receiving device 20. When the power transmission device 10 receives the beacon signal of the power receiving device 20, it specifies the position of the power receiving device 20 based on the beacon signal. The power transmission device 10 performs wireless power supply to the power receiving device 20 by transmitting radio waves (hereinafter, may be referred to as power transmission signals) toward the specified position.

[0019] <Power Transmission Device> As shown in Figure 2, the power transmission device 10 comprises a power transmission antenna 11 and a control unit 12. The power transmission antenna 11 is used for various communications with the power receiving device 20. The power transmission antenna 11 is used for transmitting power transmission signals and receiving beacon signals.

[0020] The control unit 12 is, for example, a microcontroller unit. The control unit 12 includes, for example, a processor and a memory unit. The memory unit includes, for example, ROM (Read Only Memory) and RAM (Random Access Memory). The control unit 12 performs various controls related to communication with the power receiving device 20. The control unit 12 controls the power transmitting antenna 11 to receive beacon signals transmitted by the power receiving device 20. The control unit 12 converts the power supplied from the power supply unit (not shown) into a power transmission signal and transmits this power transmission signal using the power transmitting antenna 11.

[0021] <Power receiving device> (Outline configuration of the power receiving device) As shown in Figure 2, the power receiving device 20 comprises a power receiving antenna 21, a power receiving conversion unit 22, a storage battery 23, an output unit 24, and a control unit 25. The power receiving antenna 21 and the power receiving conversion unit 22 constitute the part that receives power sent from the power transmitting device 10 by radio wave wireless power transmission.

[0022] The receiving antenna 21 is used for various communications with the power transmitting device 10. For example, the receiving antenna 21 is used to receive power transmission signals transmitted from the power transmitting device 10 and to transmit beacon signals to the power transmitting device 10.

[0023] The power receiving conversion unit 22 constitutes the part that converts the power transmission signal received by the power receiving antenna 21 into DC power. In the power receiving device 20 of this embodiment, the DC power converted by the power receiving conversion unit 22 is supplied to the storage battery 23, thereby charging the storage battery 23. The power receiving conversion unit 22 includes a rectifier circuit 22A for converting radio waves received by the power receiving antenna 21 into DC power. The rectifier circuit 22A is, for example, a single-phase full-wave rectifier circuit. The power receiving conversion unit 22 may also include components other than the rectifier circuit 22A, such as a balun transformer for impedance matching between the power receiving antenna 21 and the rectifier circuit 22A.

[0024] The battery 23 is a rechargeable secondary battery, such as a nickel-metal hydride battery or a lithium-ion battery. The battery 23 is connected to the output terminal of the rectifier circuit 22A via a charging circuit (not shown). The charging circuit is a circuit that adjusts the power supplied to the battery 23 (specifically, the charging current and charging voltage). The DC power converted by the rectifier circuit 22A is supplied to the battery 23 via the charging circuit, thereby charging the battery 23.

[0025] The output unit 24 is configured to output the power stored in the battery 23 to the electrical device 26 to be charged. The type of electrical device 26 is not particularly limited. Examples of electrical devices 26 include mobile devices such as smartphones and tablet terminals, and wearable devices such as smartwatches, smart glasses, and wireless earphones.

[0026] The output unit 24 includes, for example, a DC-DC conversion circuit (not shown) and a connection unit (not shown). The DC-DC conversion circuit is connected to the battery 23. DC power stored in the battery 23 is input to the DC-DC conversion circuit. The DC-DC conversion circuit boosts the voltage of the DC power input from the battery 23 to a voltage suitable for output from the output unit 24. The DC-DC conversion circuit is connected to the connection unit.

[0027] The connection section is configured to electrically connect the DC-DC conversion circuit and the electrical equipment 26, and to supply power stored in the battery 23 to the electrical equipment 26. The connection section may be a contact connection section such as a metal contact, connector, or connecting cable. Alternatively, the connection section may be a non-contact connection section that supplies power using a contactless (wireless) power transmission method (non-contact power supply) that can transmit power without going through the above-mentioned contacts. Examples of non-contact power supply methods include electromagnetic induction, magnetic field resonance, electric field coupling, and radio wave reception.

[0028] The control unit 25 is, for example, a microcontroller unit. The control unit 25 includes, for example, a processor and a memory unit. The memory unit includes, for example, ROM and RAM. The control unit 25 performs various controls related to the operation control of the power receiving device 20. The control unit 25 controls the power receiving antenna 21 to transmit a beacon signal to the power transmitting device 10. The control unit 25 controls the power receiving antenna 21 to receive power transmission signals transmitted from the power transmitting device 10. The control unit 25 performs operation control of the output unit 24.

[0029] (Layout of the power receiving equipment) A specific example of the layout of the power receiving device 20 will be described with reference to Figures 3 to 10. As shown in Figure 3, the power receiving device 20 comprises a base unit 30 and an antenna unit 40. The base unit 30 is a box-shaped casing, and the storage battery 23, output unit 24, and control unit 25 described above are arranged inside the base unit 30. The antenna unit 40 is a box-shaped casing, and the power receiving antenna 21 and power receiving conversion unit 22 described above are arranged inside the antenna unit 40. Note that a part of the control unit 25, namely the part related to the control of the power receiving antenna 21 and power receiving conversion unit 22, may be located in the antenna unit 40.

[0030] [base] Hereinafter, in order to define the various parts of the base 30, two mutually orthogonal directions will be referred to as the width direction and the length direction, and the direction perpendicular to both directions will be referred to as the thickness direction. Furthermore, with respect to the base 30, a plan view means viewing the base 30 in the thickness direction.

[0031] As shown in Figures 3 and 4, the base portion 30 comprises a base body 31 and two base-side connecting portions 32. The base body 31 has a flattened, rectangular box-like outer shape. The base body 31 has a rectangular first main surface 31A and a second main surface 31B extending in the longitudinal direction, and a first side surface 31C and a second side surface 31D connecting the first main surface 31A and the second main surface 31B. Hereinafter, the first main surface 31A of the base body 31 may be referred to as the installation surface 31A. The first main surface 31A constitutes the outer surface of the base 30. The first side surface 31C is a side surface located at both ends in the width direction of the base body 31 and extending in the longitudinal direction. The second side surface 31D is a side surface located at both ends in the longitudinal direction of the base body 31 and extending in the width direction.

[0032] The storage battery 23, output unit 24, and control unit 25 described above are arranged inside the base body 31. The base-side connecting portion 32 is located at one end of the second side surface 31D on the second main surface 31B of the base body 31. The base-side connecting portion 32 is formed integrally with the base body 31 as a projection that protrudes toward the second main surface 31B. The two base-side connecting portions 32 are arranged at a predetermined distance apart in the width direction.

[0033] One end of the base-side connection portion 32 is a part for supporting the antenna portion 40 on the base portion 30, and together with the antenna portion-side connection portion 42 provided on the antenna portion 40 (described later), it constitutes the support structure SS described later. The other end of the base-side connection portion 32 is a part for electrically connecting the base portion 30 and the antenna portion 40, and together with the antenna portion-side connection portion 42 provided on the antenna portion 40 (described later), it constitutes the relay structure RS described later.

[0034] [Antenna section] The antenna section 40 will also be described using the width, length, and thickness directions specified in the description section for the base section 30. As will be explained in more detail later, the antenna section 40 is connected to the base section 30 so as to be tiltable between the retracted position P1 and the deployed position P2. The following description will be based on the state where the antenna section 40 is in the retracted position P1.

[0035] As shown in Figures 3 and 4, the antenna unit 40 comprises an antenna unit body 41 and two antenna unit side connection parts 42. The antenna body 41 has a flattened, rectangular box-like outer shape. The antenna body 41 has a rectangular first main surface 41A and a second main surface 41B extending in the longitudinal direction, and a first side surface 41C and a second side surface 41D connecting the first main surface 41A and the second main surface 41B. The first side surface 41C is a side surface located at both ends in the width direction of the antenna body 41 and extending in the longitudinal direction. The second side surface 41D is a side surface located at both ends in the longitudinal direction of the antenna body 41 and extending in the width direction.

[0036] In the storage position, the antenna body 41 is positioned on top of the second main surface 31B of the base body 31. The first main surface 41A of the antenna body 41 faces the base 30 side, and the second main surface 41B faces the opposite side of the base 30.

[0037] The antenna-side connection portion 42 is located on one of the second side surfaces 41D of the antenna body 41. The antenna-side connection portion 42 is formed integrally with the antenna body 41 as a projection that protrudes toward the second side surface 41D. The two antenna-side connection portions 42 are arranged with a predetermined distance between them in the width direction.

[0038] One of the antenna section-side connection parts 42 is a part for supporting the antenna section 40 on the base section 30, and together with one of the base-side connection parts 32 provided on the base section 30, it constitutes the support structure SS described later. The other of the antenna section-side connection parts 42, together with the other of the base-side connection parts 32 provided on the base section 30, constitutes the relay structure RS described later.

[0039] As shown in Figure 5, a receiving antenna 21 and a rectifier circuit 22A are arranged inside the antenna unit body 41. More specifically, a circuit board 43 is arranged inside the antenna unit body 41. The circuit board 43 has a first circuit board surface 43A that faces the same direction as the first main surface 41A of the antenna unit body 41, and a second circuit board surface 43B that is located on the opposite side of the first circuit board surface 43A and faces the same direction as the second main surface 41B of the antenna unit body 41.

[0040] One or more receiving antennas 21 are mounted on the second main surface 41B of the circuit board 43. The receiving antennas 21 have directivity in the direction that the second main surface 41B of the circuit board 43 faces, that is, in the direction that the second main surface 41B of the antenna unit body 41 faces. Therefore, the second main surface 41B of the antenna unit body 41 functions as a receiving surface that receives radio waves emitted from the power transmission device 10. Hereinafter, the second main surface 41B of the antenna unit body 41 may be referred to as the receiving surface 41B of the antenna unit 40. As described above, the receiving surface 41B is determined based on the installation direction of the receiving antennas 21.

[0041] Figure 5 illustrates a case where multiple receiving antennas 21 are mounted. The receiving antennas 21 are not particularly limited, and known antenna elements used in power receiving devices can be applied. The rectifier circuit 22A of the power receiving conversion unit 22 is mounted on the first main surface 41A of the substrate 43. When multiple receiving antennas 21 are mounted, one rectifier circuit 22A is provided for each receiving antenna 21. It is preferable that the rectifier circuit 22A be positioned close to the receiving antenna 21 to which it is connected. For example, the rectifier circuit 22A is positioned in the thickness direction of the substrate 43 so as to overlap with the receiving antenna 21 to which it is connected. Note that the receiving antenna 21 may be an element that includes the rectifier circuit 22A as a component, a so-called rectenna. In this case, it is not necessary to provide a separate rectifier circuit 22A from the receiving antenna 21 which is a rectenna.

[0042] Next, an example of the dimensions of the antenna section 40 will be described. Note that the dimensions of the antenna section 40 are not limited to those described below. As shown in Figure 6, the widthwise dimension W1 of the antenna body 41 is equal to the widthwise dimension W2 of the base body 31.

[0043] The longitudinal dimension L1 of the antenna body 41 is shorter than the longitudinal dimension L2 of the base body 31. The longitudinal dimension L1 of the antenna body 41 is equal to the difference between the longitudinal dimension L2 of the base body 31 and the longitudinal dimension L3 of the base-side connection part 32. In other words, the longitudinal dimension L2 of the base body 31 is equal to the sum of the longitudinal dimension L1 of the antenna body 41 and the longitudinal dimension L3 of the base-side connection part 32. The longitudinal dimension L4 of the antenna-side connection part 42 is equal to the longitudinal dimension L3 of the base-side connection part 32.

[0044] As shown in Figure 4, the thickness dimension T1 of the antenna body 41 is either thicker than or equal to the thickness dimension T2 of the base-side connection portion 32. Alternatively, the thickness dimension T1 of the antenna body 41 may be thinner than the thickness dimension T2 of the base body 31. Note that the thickness dimension T2 of the base body 31 refers to the thickness dimension of the portion where the base-side connection portion 32 is not formed.

[0045] As shown in Figure 3, one or both of the first side surfaces 41C of the antenna body 41 are coplanar with the first side surface 31C of the base body 31 located on the same side in the width direction. Preferably, one or both of the first side surfaces 41C of the antenna body 41 are flush with the first side surface 31C of the base body 31 located on the same side in the width direction.

[0046] As shown in Figure 4, the second side surface 41D of the antenna body 41 on the side where the antenna-side connection portion 42 is not provided is on the same plane as the second side surface 31D of the base body 31 located on the same side in the longitudinal direction. Preferably, the second side surface 41D of the antenna body 41 on the side where the antenna-side connection portion 42 is not provided is flush with the second side surface 31D of the base body 31 located on the same side in the longitudinal direction.

[0047] [Support structure] As shown in Figures 3 and 6-9, one of the base-side connection parts 32 of the base 30 (hereinafter referred to as base-side connection part 32A) and one of the antenna-side connection parts 42 of the antenna 40 (hereinafter referred to as antenna-side connection part 42A) constitute a support structure SS. The antenna 40 is mechanically supported by the support structure SS relative to the base 30. The support structure SS allows the position of the antenna 40 relative to the base 30 to tilt between a retracted position P1 and an deployed position P2. The following description is based on the state in which the antenna 40 is in the retracted position P1. Figures 9 and 10 show the state in which the antenna 40 is in the deployed position P2.

[0048] As shown in Figures 3 and 8, the antenna-side connection portion 42A is a projection that extends longitudinally from the antenna body 41. As shown in Figure 9, the tip surface 42A1 of the antenna-side connection portion 42A is a curved surface that curves in an arc shape and is convex outward. The curved tip surface 42A1 is provided to prevent the antenna-side connection portion 42A from interfering with the base portion 30 when the antenna portion 40 is tilted.

[0049] The antenna-side connection portion 42A is provided with a shaft 42A2 that extends along an axis AL parallel to the width direction, fixed to the antenna-side connection portion 42A. The shaft 42A2 protrudes from the antenna-side connection portion 42A to one side in the width direction.

[0050] As shown in Figures 3 and 6, the base-side connecting portion 32A of the base portion 30 is a projection that protrudes toward the first main surface 31A of the base body 31. As shown in Figure 9, the lower surface 32A1 of the base-side connecting portion 32A is a curved surface that curves in an arc shape and is convex outward. In other words, within the tilting range of the antenna portion 40, the surface (lower surface 32A1) of the base-side connecting portion 32A that can face the second side surface 41D on one side of the antenna body 41 is the curved surface described above. The curved lower surface 32A1 is provided to prevent the base-side connecting portion 32A from interfering with the antenna portion 40 when the antenna portion 40 is tilted.

[0051] The base-side connector 32A is positioned next to the antenna-side connector 42A in the width direction. More specifically, it is positioned next to the antenna-side connector 42A in the direction in which the axis 42A2 protrudes from the antenna-side connector 42A.

[0052] In the base-side connection portion 32A, a bearing hole 32A2 is formed at a location that is parallel to the axis AL, into which the shaft 42A2 of the antenna-side connection portion 42A is inserted. The bearing hole 32A2 opens on the side surface located at the widthwise end of the base-side connection portion 32A and extends along the axis AL.

[0053] The shaft 42A2 of the antenna section connection part 42A is inserted by press-fitting into the bearing hole 32A2 of the base section connection part 32A. The dimensions and surface shape of the bearing hole 32A2 and the shaft 42A2 are designed so that a specific frictional force is generated between the inner wall surface 32A3 of the bearing hole 32A2 and the outer circumferential surface of the shaft 42A2. This specific frictional force is sufficient to support the weight of the antenna section 40 and is set to a magnitude that allows for angle adjustment of the antenna section 40 relative to the base section 30. The support structure SS supports the antenna section 40 so that it can tilt relative to the base section 30, based on the rotation of the shaft 42A2 in the bearing hole 32A2 while generating the specific frictional force.

[0054] As shown in Figures 3 and 4, the antenna section 40 is tiltable relative to the base section 30 around the axis AL between the retracted position P1 and the deployed position P2. In other words, the antenna section 40 is connected to the base section 30 so as to be tiltable relative to the base section 30, such that the angle of the receiving surface 41B of the antenna section 40 with respect to the mounting surface 31A of the base section 30 changes between the retracted position P1 and the deployed position P2. In Figures 3 and 4, the antenna section 40 in the retracted position P1 is shown by a solid line, and the antenna section 40 in the deployed position P2 is shown by a dashed line.

[0055] The storage position P1 is the position where the entire antenna section 40 overlaps the base section 30. In the storage position P1, the first main surface 41A of the antenna section body 41 is facing, close to, or in contact with the second main surface 31B of the base body 31 on the base section 30. In the storage position P1, the antenna section 40 is parallel to the base section 30, or in other words, parallel to the second main surface 31B of the base body 31.

[0056] The deployed position P2 is the position in which the antenna section 40 is tilted by a predetermined angle around the axis 42A2. The antenna section 40 in the deployed position P2 is spaced apart from the second main surface 31B of the base body 31. The antenna section 40 in the deployed position P2 is inclined (including a vertical position) with respect to the base 30, or in other words, with respect to the second main surface 31B of the base body 31.

[0057] The tiltable angular range θ of the antenna portion 40 between the storage position P1 and the deployed position P2 is, for example, 120 degrees or more, preferably 150 degrees or more, and more preferably 180 degrees or more. The angular range θ is also, for example, 270 degrees or less, 180 degrees or less, 120 degrees or less, and 90 degrees or less.

[0058] As described above, the bearing hole 32A2 and the shaft 42A2 are designed so that a frictional force is generated between the two members that can support the weight of the antenna section 40. Therefore, when a force resisting the frictional force is applied to the antenna section 40 by the user's hand or the like, the antenna section 40 tilts around the shaft 42A2. Then, when the force is removed while the antenna section 40 is tilted at an angle within the angular range θ, the antenna section 40 is held at that tilt angle based on the frictional force.

[0059] [Relay structure] As shown in Figures 3, 6, 8, and 10, the other end of the base-side connection portion 32 of the base portion 30 (hereinafter referred to as the base-side connection portion 32B) and the other end of the antenna-side connection portion 42 of the antenna portion 40 (hereinafter referred to as the antenna-side connection portion 42B) constitute a relay structure RS. The antenna portion 40 is electrically connected to the base portion 30 by the relay structure RS.

[0060] As shown in Figures 3 and 6, the antenna-side connection portion 42B is a projection that extends longitudinally from the antenna body 41. As shown in Figure 10, the tip surface 42B1 of the antenna-side connection portion 42B is a curved surface that curves in an arc shape and is convex outward. The curved tip surface 42B1 is provided to prevent the antenna-side connection portion 42B from interfering with the base portion 30 when the antenna portion 40 is tilted.

[0061] The antenna section connection part 42B is provided with a terminal 42B2 that extends along an axis AL parallel to the width direction and is fixed to the antenna section connection part 42B. The terminal 42B2 protrudes from the antenna section connection part 42B to one side in the width direction. The terminal 42B2 is electrically connected to the receiving antenna 21 and the rectifier circuit 22A, etc., which are located on the antenna section body 41.

[0062] As shown in Figures 3 and 6, the base-side connecting portion 32B of the base portion 30 is a projection that protrudes toward the first main surface 31A of the base body 31. As shown in Figure 10, the lower surface 32B1 of the base-side connecting portion 32B is a curved surface that curves in an arc shape and is convex outward. In other words, within the tilting range of the antenna portion 40, the surface (lower surface 32B1) of the base-side connecting portion 32B that can face the second side surface 41D on one side of the antenna body 41 is the curved surface described above. The curved lower surface 32B1 is provided to prevent the base-side connecting portion 32B from interfering with the antenna portion 40 when the antenna portion 40 is tilted.

[0063] The base-side connector 32B is positioned next to the antenna-side connector 42B in the width direction. More specifically, it is positioned next to the antenna-side connector 42B in the direction from which the terminal 42B2 protrudes.

[0064] As shown in Figure 10, in the base-side connection portion 32B, a connection hole 32B2 is formed at a location that is parallel to the axis AL, into which the terminal 42B2 of the antenna-side connection portion 42B is inserted. The connection hole 32B2 opens on the side surface located at the widthwise end of the base-side connection portion 32A and extends along the axis AL. A terminal (not shown) is formed on the inner wall surface 32B3 of the connection hole 32B2 that is electrically connected to components such as the storage battery 23 located on the base body 31.

[0065] The terminal 42B2 of the antenna section connection part 42B is inserted into the connection hole 32B2 of the base section connection part 32B. The dimensions and surface shape of the connection hole 32B2 and the terminal 42B2 are set so that they can rotate about the axis AL while maintaining a state in which at least a part of the outer surface of the terminal 42B2 is in contact with the inner wall surface 32B3 of the bearing hole 32A2. The relay structure RS electrically connects the antenna section 40 and the base section 30 based on the contact between the inner wall surface 32B3 of the connection hole 32B2 and the terminal 42B2. The terminal 42B2, which is located on the same line as the axis 42A2, auxiliaryly supports the antenna section 40 so that it can tilt relative to the base section 30.

[0066] <effect> Next, the operation of this embodiment will be described. Figure 11 shows a first power supply configuration in which the power receiving device 20 is placed on a horizontal mounting surface PS, and wireless power is supplied from the power transmitting device 10, which is positioned at approximately the same height as the mounting surface PS, to the power receiving device 20. The power receiving device 20 is positioned with its mounting surface 31A facing the mounting surface PS.

[0067] When used in the first power supply configuration, the radio waves emitted from the power transmission device 10 propagate while spreading out in a direction F1 from the power transmission device 10 toward the power receiving device 20. Direction F1 is a direction along the mounting surface PS (horizontal direction), or a direction close to the same direction.

[0068] When the antenna section 40 of the power receiving device 20 is in the storage position P1, the power receiving surface 41B of the antenna section 40 faces upward. In this case, the power receiving surface 41B is positioned parallel or nearly parallel to the direction F1 in which the radio waves emitted from the power transmitting device 10 travel, making it difficult for the power receiving surface 41B to receive the radio waves emitted from the power transmitting device 10. As a result, the power supply efficiency of the power receiving device 20 decreases.

[0069] Here, the power receiving device 20 is capable of tilting the antenna section 40 about the axis 42A2 relative to the base 30. Therefore, by positioning the antenna section 40 at an deployed position P2, which is tilted from the stored position P1 within the above angular range θ, or at an intermediate deployed position P3 between the stored position P1 and the deployed position P2, the power receiving surface 41B can be positioned at an angle that intersects the direction F1 in which the radio waves travel. It is preferable to tilt the antenna section 40 so that the power receiving surface 41B is positioned at an angle that is directly opposite or close to the direction F1 in which the radio waves travel, for example, by rotating it 90 degrees from the stored position P1.

[0070] By positioning the receiving surface 41B at an angle that intersects with the direction F1 in which the radio waves travel, preferably at an angle that is directly opposite to direction F1, it becomes possible to receive radio waves emitted from the power transmitting device 10 over a wide area of ​​the receiving surface 41B. As a result, the power supply efficiency of the power receiving device 20 is improved.

[0071] Figure 12 shows a second power supply configuration in which the power receiving device 20 is used while attached to the mobile terminal 26A, which is an electrical device 26. The second power supply configuration is used, for example, when the mobile terminal 26A is used while wireless power is being supplied from the power transmitting device 10 to the power receiving device 20 and the power receiving device 20 is being charged to the electrical device 26 simultaneously.

[0072] In this case, the power receiving device 20 is attached to the mobile terminal 26A with the mounting surface 31A of the base 30 superimposed on the back surface 26A1 of the mobile terminal 26A. This attachment is done, for example, by using a magnet placed inside the base 30 to attract the base 30 to a fixed position on the mobile terminal 26A. Note that the mounting configuration for attaching the power receiving device 20 to the electrical equipment 26 is not limited to a configuration using magnets, and known mounting configurations can be adopted. Furthermore, the mounting configuration may be omitted.

[0073] When using the second power supply mode, if the antenna portion 40 of the power receiving device 20 is in its retracted position when the mobile terminal 26A is held in the user's hand H, a situation may occur where the power receiving surface 41B of the antenna portion 40 is covered by a part of the hand H holding the mobile terminal 26A. In this case, a part of the hand H holding the mobile terminal 26A shields the space between the power transmitting device 10 and the power receiving surface 41B, resulting in a decrease in the power supply efficiency of the power receiving device 20. The power supply efficiency of the power receiving device 20 decreases significantly as the area of ​​the power receiving surface 41B hidden by the shielding increases.

[0074] Here, the power receiving device 20 is capable of tilting its antenna section 40 about the axis 42A2 relative to the base section 30. Therefore, by positioning the antenna section 40 at a predetermined angle (for example, 45 degrees) within the above-mentioned angular range θ, to an intermediate deployed position P3 tilted from the storage position P1, a space can be formed between the base section 30 and the antenna section 40. This allows the user to position their hand H in this space to grasp the mobile terminal 26A to which the power receiving device 20 is attached. In this case, since the antenna section 40 is located outside the hand H that is grasping the mobile terminal 26A, the situation in which the power receiving surface 41B is covered by the hand H is eliminated. As a result, the entire power receiving surface 41B can receive radio waves emitted from the power transmitting device 10, and the power supply efficiency of the power receiving device 20 is improved.

[0075] <Effects> Next, the effects of this embodiment will be described. (1) The power receiving device 20 comprises a base 30 and an antenna section 40 on which a power receiving antenna 21 for receiving radio waves for power supply is arranged and connected to the base 30. The base 30 has an installation surface 31A which constitutes a part of the outer surface of the base 30. The antenna section 40 has a power receiving surface 41B based on the installation direction of the power receiving antenna 21. The antenna section 40 is connected to the base 30 so as to be tiltable such that the angle of the power receiving surface 41B with respect to the installation surface 31A changes.

[0076] With the above configuration, the position of the power receiving surface 41B can be adjusted by tilting the antenna section 40 depending on the usage mode, such as using the power receiving device 20 placed on the mounting surface PS, or using the portable terminal 26A with the power receiving device 20 attached held in the hand H. Therefore, the position of the antenna section 40 can be changed to a position where the power supply efficiency is high.

[0077] (2) The base 30 has a first main surface 31A which is the installation surface 31A, and a second main surface 31B located on the opposite side of the first main surface 31A. The antenna section 40 is configured to be able to change position, including a retracted position P1 and an deployed position P2. The retracted position P1 is the position in which the antenna section 40 is in contact with the second main surface 31B of the base 30. The deployed position P2 is the position in which the antenna section 40 is separated from the second main surface 31B of the base 30.

[0078] With the above configuration, it is easy to secure a large tiltable angle range θ for the antenna section 40. In addition, the shape of the power receiving device 20 can be made compact when the antenna section 40 is in the stowed position P1.

[0079] Furthermore, according to the above configuration, the second main surface 31B of the base 30 faces the antenna section 40, and the first main surface 31A, which is the opposite side of the second main surface 31B, is used as the mounting surface. In other words, the first main surface 31A, which is the mounting surface, is not the side facing the antenna section 40. As a result, when the antenna section 40 is in the deployed position P2, a gap is formed between the base 30 and the antenna section 40, allowing a hand to be inserted, and enabling the operation of a device such as a mobile terminal 26A attached to the base 30 without damaging the received radio waves.

[0080] (3) The antenna section 40 is supported by a support structure SS that allows it to tilt relative to the base 30. The support structure SS includes a shaft 42A2 provided on the antenna section 40 and a bearing hole 32A2 provided on the base 30 into which the shaft 42A2 is inserted. The shaft 42A2 is press-fitted into the bearing hole 32A2. The friction generated between the shaft 42A2 and the inner wall surface 32A3 of the bearing hole 32A2 as a result of press-fitting into the bearing hole 32A2 is set to a magnitude that allows for angle adjustment of the antenna section 40 relative to the base 30. With the above configuration, the antenna section 40 can be held in an inclined state relative to the base 30 at the deployed position P2 or any intermediate deployed position P3 with a simple configuration.

[0081] (4) The base 30 and the antenna 40 are electrically connected by a relay structure RS. The relay structure RS includes a terminal 42B2 provided on the antenna 40 and a connection hole 32B2 provided on the base 30 into which the terminal 42B2 is inserted. The terminal 42B2 is supported on the inner wall surface 32B3 so as to rotate while in contact with the inner wall surface 32B3 of the connection hole 32B2.

[0082] With the above configuration, the shaft 42A2 can be rotated within the bearing hole 32A2 while maintaining electrical connection, and the terminal 42B2 can be rotated within the connection hole 32B2. Furthermore, it is possible to prevent the terminal 42B2 and the connection hole 32B2 from hindering the rotation of the shaft 42A2 within the bearing hole 32A2.

[0083] (5) The system includes a rectifier circuit 22A that converts radio waves received by the receiving antenna 21 into DC power. The rectifier circuit 22A is located in the antenna section 40. With the above configuration, the antenna section 40 and the rectifier circuit 22A can be placed closer together. This reduces the transmission loss between the antenna section 40 and the rectifier circuit 22A. As a result, the antenna gain of the receiving antenna 21 is improved.

[0084] (6) The device comprises an output unit 24 that outputs DC power converted by the rectifier circuit 22A, and a control unit 25 that performs operation control of the output unit 24. The output unit 24 and the control unit 25 are located on the base unit 30.

[0085] According to the above configuration, the components for receiving radio waves and the components for outputting the received radio waves as power are separately arranged in the antenna section 40 and the base section 30. This allows for easy replacement of components, for example, when it becomes necessary to replace some parts, by replacing only one of the antenna section 40 or base section 30 that houses the component in question.

[0086] (7) The system includes a battery 23 that stores the DC power converted by the rectifier circuit 22A. The output unit 24 supplies the power stored in the battery 23 to the electrical equipment 26 by contactless power supply. With the above configuration, power stored in the battery 23 of the power receiving device 20 can be easily supplied to the electrical equipment 26 by attaching the power receiving device 20 to the electrical equipment 26, without having to worry about the connection status between the electrical equipment 26 and the power receiving device 20. In addition, convenience is improved because there is no need to prepare a separate cable.

[0087] <Example of changes> This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0088] Regarding the support structure SS, a drive device may be provided on either the base 30 or the antenna portion 40, and the antenna portion 40 may be configured to tilt based on the drive of the drive device. For example, as shown in Figure 13, an external gear 51 is attached to the tip of the shaft 42A2 of the antenna-side connection part 42A, and an internal gear 52 is formed in the bearing hole 32A2 of the base-side connection part 32A. The external gear 51 and the internal gear 52 are formed in a shape that extends along the axis AL. The external teeth of the external gear 51 mesh with the internal teeth of the internal gear 52, thereby connecting the antenna-side connection part 42A and the base-side connection part 32A so that they can rotate as a single unit. A motor (not shown) is connected to the shaft 42A2 as a drive device to rotate the shaft 42A2.

[0089] Furthermore, in a configuration in which the antenna section 40 is tilted by the above-described drive device, the system may also include a position control unit for adjusting the tilt angle of the antenna section 40 by controlling the drive of the drive device. The position control unit adjusts the tilt angle of the antenna section 40 by controlling the drive device so that the power supply efficiency becomes a specific value, based on measurement information from a separately provided measuring unit that measures the power supply efficiency. Examples of the specific value include a preset value, a value arbitrarily set by the user, and the maximum value of the power supply efficiency within the tiltable angle range θ of the antenna section 40. The position control unit may also be configured to control the position of the antenna section 40 so that it becomes an arbitrary tilt angle input by the user to a separately provided input unit.

[0090] In the above embodiment, the antenna section 40 could be held at any position within the angular range θ between the retracted position P1 and the deployed position P2, but it is sufficient if it can be held at least at two positions: the retracted position P1 and the deployed position P2. In other words, the antenna section 40 only needs to be configured to be able to change its position, including the two positions of the retracted position P1 and the deployed position P2.

[0091] Regarding the support structure SS, the relationship between the bearing hole 32A2 and the shaft 42A2 in the base-side connection part 32A and the antenna-side connection part 42A may be reversed. In other words, the shaft may be provided in the base-side connection part 32A and the bearing hole in the antenna-side connection part 42A. The same applies to the relay structure RS.

[0092] The tilting direction of the antenna portion 40 relative to the base portion 30 is not limited to the direction of the above embodiment. For example, in the above embodiment, the antenna portion 40 was tiltable around an axis AL extending in the width direction, but it may be tiltable around an axis extending in a direction other than the width direction (for example, the length direction). Also, the antenna portion 40 may be tiltable in multiple different directions.

[0093] The antenna section 40 may be configured to allow displacement other than tilting. For example, in the above embodiment, the antenna section body 41 is composed of two members: a first member on which the receiving antenna 21 is arranged, and a second member on which the antenna section side connection section 42 is arranged. The second member is then connected to the first member in a displaceable (for example, rotatable) manner.

[0094] The configuration in which the base 30 and the antenna 40 are connected such that the angle of the power receiving surface 41B relative to the mounting surface 31A changes is not limited to the configuration of the above embodiment. For example, the base 30 and the antenna 40 may be connected as shown in Figure 14.

[0095] In the example shown in Figure 14, the dimensions of the base 30 in each direction are greater than the dimensions of the antenna section 40. The base 30 is provided with a housing section 60 for the antenna section 40. The housing section 60 is large enough to accommodate the entire antenna section 40, for example, it is a space slightly larger than the antenna section 40. The housing section 60 opens on one side of the base 30 (for example, the second side 31D extending in the width direction).

[0096] On the inner wall surface 60A of the housing section 60, a pair of groove-shaped bearing holes 61 extending in the longitudinal direction are formed at opposite locations in the width direction. On the other hand, shafts 62 protruding outward in the width direction are provided on both sides of the antenna section 40. These shafts 62 are located on the same line as each other. The antenna section 40 is housed in the housing section 60 so as to be able to move in and out, with the shafts 62 engaged with the groove-shaped bearing holes 61 so as to be able to slide in the longitudinal direction. In other words, the antenna section 40 is arranged to slide relative to the base section 30 in a direction perpendicular to the thickness direction. A relay mechanism (not shown) is provided between the antenna section 40 and the base section 30 to electrically connect the two. For example, one of the shafts 62 may have the same configuration as the terminal 42B2 in the above embodiment, and the bearing hole 61 into which the shaft 62 engages may have the same configuration as the connection hole 32B2 in the above embodiment.

[0097] In Figure 14, the antenna section 40 in the first deployed position P2A is shown by a solid line, and the antenna section 40 in the second deployed position P2B is shown by a dashed line. The retracted position P1 (not shown) is the position where the antenna section 40 is housed in the housing section 60 of the base section 30. The first deployed position P2A is the position where the antenna section 40 is pulled out from the housing section 60 of the base section 30 along the groove-shaped bearing hole 61. In the first deployed position P2A, the antenna section 40 is configured to be tiltable about the shaft 62 relative to the base section 30. The second deployed position P2B is the position where the antenna section 40 has been tilted from the first deployed position P2A. In the groove-shaped bearing hole 61, the dimensions and surface shape of the portion where the shaft 62 is located when the antenna section 40 is in the first deployed position P2A are designed to generate a specific frictional force. This specific frictional force is sufficient to support the weight of the antenna section 40.

[0098] The relay structure RS is not limited to a configuration based on contact between the connection hole 32B2 and the terminal 42B2. For example, the relay structure RS may be configured to electrically connect the antenna section 40 and the base section 30 by a wire extending from the antenna section 40 to the base section 30.

[0099] In the above embodiment, a support structure SS was provided separately from the relay structure RS, but a support structure SS having the relay structure RS is also possible. For example, a through hole is provided in the shaft 42A2 of the antenna section side connection section 42A, and wiring connecting the antenna section 40 and the base section 30 is inserted through the through hole.

[0100] The number of base-side connection parts 32A and antenna-side connection parts 42A constituting the support structure SS may be 1 or 3 or more. The number of base-side connection parts 32B and antenna-side connection parts 42B constituting the relay structure RS may be 1 or 3 or more.

[0101] The antenna section 40 may be configured to be detachable from the base section 30. For example, in the embodiment shown in Figure 6, the shaft 42A2 and terminal 42B2 are configured to be removable from the bearing hole 32A2 and connection hole 32B2 by the relative movement of the base section 30 and the antenna section 40. More specifically, a space is provided between the base-side connection section 32 and the antenna section-side connection section 42 to allow sliding movement of the antenna section 40 relative to the base section 30 to one side in the axial direction AL (left side of the page in Figure 6). The aforementioned one side in the axial direction AL is the direction opposite to the direction in which the shaft 42A2 and terminal 42B2 protrude in the axial direction AL.

[0102] In this case, by sliding the antenna section 40 to one side in the direction of the axis AL, the shaft 42A2 and terminal 42B2 detach from the bearing hole 32A2 and connection hole 32B2. This makes it possible to remove the antenna section 40 from the base section 30. Conversely, by performing the reverse procedure described above, the antenna section 40 can be attached to the base section 30.

[0103] - Of the elements constituting the power receiving device 20, such as the power receiving antenna 21, power receiving conversion unit 22, storage battery 23, output unit 24, and control unit 25, elements other than the power receiving antenna 21 may be located in either the base unit 30 or the antenna unit 40. For example, the rectifier circuit 22A constituting the power receiving conversion unit 22 may be located in the base unit 30, or the elements constituting the storage battery 23 and the control unit 25 may be located in the antenna unit 40.

[0104] A measuring unit for measuring power supply efficiency and a display unit for displaying the power supply efficiency measured by the measuring unit may be provided. In this case, the user can easily adjust the tilt angle of the antenna unit 40 to a position where the power supply efficiency is higher by checking the display contents of the display unit.

[0105] The power supplied from the power receiving device 20 to the electrical equipment 26 may be used for purposes other than the storage of energy in the electrical equipment 26. For example, the power may be used to enable the electrical equipment 26 to perform its intended function. Furthermore, if the electrical equipment 26 is equipped with an electric component that performs a function not directly related to the electrical equipment 26's intended function, the power may be used to operate that electric component. An example of such an electric component is a cooling fan.

[0106] The power receiving device 20 may also constitute part of the electrical equipment 26. For example, the base 30 of the power receiving device 20 is part of the housing that forms the back surface of the mobile terminal 26A, and the antenna portion 40 of the power receiving device 20 is tiltably connected to the back surface of the mobile terminal 26A. [Explanation of Symbols]

[0107] P1...Storage position P2…Development position RS…Relay structure SS…Support structure 20... Power receiving device 21... Receiving antenna 22... Power receiving conversion unit 22A… Rectifier circuit 23… Storage battery 24…Output section 25... Control Unit 26… Electrical equipment 30…Base 31A…1st main surface (installation surface) 40… Antenna section 41B...Second main surface (power receiving surface)

Claims

1. A power receiving device used in radio wave wireless power transfer, The base and, An antenna section is provided, which is connected to the base and includes a receiving antenna for receiving radio waves for power supply, The base has an installation surface which constitutes a part of the outer surface of the base, The antenna section has a power receiving surface based on the installation direction of the power receiving antenna. The antenna portion is connected to the base portion so as to be tiltable, such that the angle of the power receiving surface relative to the mounting surface changes.

2. The base has a first main surface which is the installation surface and a second main surface located on the opposite side of the first main surface. The aforementioned antenna section is configured to be able to change its position, including a retracted position and a deployed position. The aforementioned storage position is the position in which the antenna portion is in contact with the second main surface of the base. The power receiving device according to claim 1, wherein the deployment position is a position in which the antenna portion is spaced apart from the second main surface of the base.

3. The antenna portion is supported by a support structure that allows it to tilt relative to the base, The power receiving device according to claim 1 or claim 2, wherein the support structure includes a shaft provided on one of the base and the antenna portion, and a bearing hole provided on the other of the base and the antenna portion into which the shaft is inserted.

4. The shaft is press-fitted into the bearing hole, The power receiving device according to claim 3, wherein the friction generated between the shaft and the inner wall surface of the bearing hole due to press-fitting into the bearing hole is set to a magnitude that allows for angle adjustment of the antenna portion with respect to the base portion.

5. Equipped with a drive mechanism, The power receiving device according to claim 1 or claim 2, wherein the antenna portion tilts based on the drive of the drive device.

6. The base portion and the antenna portion are electrically connected by a relay structure, The relay structure includes a terminal provided on one of the base portion and the antenna portion, and a connection hole provided on the other of the base portion and the antenna portion into which the terminal is inserted. The power receiving device according to claim 1 or claim 2, wherein the terminal is supported on the inner wall surface of the connection hole so as to rotate while in contact with the inner wall surface of the connection hole.

7. The system includes a rectifier circuit that converts radio waves received by the receiving antenna into DC power, The rectifier circuit is arranged in the antenna section, as described in claim 1 or claim 2.

8. An output section that outputs the DC power converted by the rectifier circuit, The system comprises a control unit that performs operation control of the output unit, The power receiving device according to claim 7, wherein the output unit and the control unit are arranged on the base.

9. A rectifier circuit that converts radio waves received by the aforementioned receiving antenna into DC power, A storage battery that stores the DC power converted by the rectifier circuit, The power receiving device according to claim 1 or claim 2, further comprising: an output unit that supplies power stored in the aforementioned battery to an electrical device by contactless power supply.

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