Wearable devices

Abstract

To mitigate the impact exerted on a biological body by electromagnetic waves and the impact exerted on a power receiving antenna by the surface potential of the biological body.SOLUTION: A wearable device 20 comprises a power receiving device 21 that constitutes a portion of a contactless power feeding system 15, and a drive unit 26 that operates by electric power supplied from the power receiving device 21. The power receiving device 21 includes a power receiving antenna 22 that receives a power transmission signal transmitted from a power transmission device 16 of the contactless power feeding system 15 and composed of electromagnetic waves, a power reception conversion unit 23 that convers the power transmission signal received by the power receiving antenna 22 into DC electric power, a received power storage unit 24 that is connected to the drive unit 26 and that stores DC electric power having been converted by the power reception conversion unit 23, and a power reception control unit 25 that manages control of the power receiving device 21. Furthermore, a flexible sheet 31 equipped with a sheet body unit 32 that shields electromagnetic waves is provided between a contact unit 28 that is in contact with a body surface 12 of a worn part 11 of a biological body 10 and the power receiving antenna 22.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a wearable device that is attached to a living body in contact with the body surface. [Background technology]

[0002] A contactless power supply system is known that performs contactless power supply from a power transmitting device to a power receiving device using a power transmission signal formed of electromagnetic waves (see, for example, Patent Document 1). In this system, a power transmission signal is transmitted from the power transmitting device. This power transmission signal is received by a power receiving antenna of the power receiving device. The power transmission signal received by the power receiving antenna is converted into DC power by a power receiving conversion unit, and is then stored in a power receiving storage unit or consumed within the power receiving device circuitry. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6725531 Summary of the Invention [Problem to be solved by the invention]

[0004] When the contactless power supply system is applied to, for example, a wearable device that is attached to a living body in contact with the body surface, there is a possibility that the power receiving antenna will be placed in close contact with the living body due to structural constraints.

[0005] In this case, there are concerns about the effects of exposure to electromagnetic waves on living bodies. Furthermore, the characteristics of the receiving antenna are strongly affected by the surrounding electric field. Therefore, a receiving antenna placed in close contact with the body surface may be affected by the surface potential (charged potential) of the body, which may cause the performance of the receiving antenna, such as the receiving gain, to become unstable. [Means for solving the problem]

[0006] A wearable device that solves the above problem is a wearable device that has a contact portion and is attached to a part of a living body that is fitted with the contact portion in contact with the body surface, and includes a power receiving device that forms part of a contactless power supply system, and a drive unit that operates with power supplied from the power receiving device, and the power receiving device includes a power receiving antenna that receives a power transmission signal consisting of electromagnetic waves transmitted from a power transmitting device of the contactless power supply system, a power receiving conversion unit that converts the power transmission signal received by the power receiving antenna into DC power, a power receiving storage unit that is connected to the drive unit and stores the DC power converted by the power receiving conversion unit, and a power receiving control unit that controls the power receiving device, and further includes a flexible sheet between the contact portion and the power receiving antenna that includes a sheet main body that shields the electromagnetic waves.

[0007] According to the above configuration, a power transmission signal consisting of electromagnetic waves is transmitted from the power transmitting device of the contactless power supply system to the power receiving antenna of the power receiving device in the wearable device. Of the transmitted power transmission signals, those not received by the power receiving antenna are shielded by the sheet main body of the flexible sheet. That is, the electromagnetic waves are attenuated in the sheet main body by reflection, absorption, multiple reflection, and the like. As a result, the electromagnetic waves that penetrate the living body are reduced by the amount of shielding described above, and the effects of the electromagnetic waves on the living body are reduced. Furthermore, the sheet main body reduces the effects of the electric field on the living body surface on the power receiving antenna.

[0008] In the above-described wearable device, it is preferable that the flexible sheet is made of a conductive material and has a conductive portion to which the power receiving antenna is connected. According to the above configuration, the power receiving antenna is electrically connected to the conductive part.

[0009] Furthermore, the conductive portion formed of a conductive material has the ability to shield electromagnetic waves. Therefore, a portion of the electromagnetic waves that are not received by the receiving antenna is reflected by the conductive portion. Some of the reflected electromagnetic waves may be re-input to the receiving antenna, increasing the received power. The conductive portion also reduces the effect of the electric field on the body surface of the living body on the receiving antenna.

[0010] In the wearable device, it is preferable that at least one of the power receiving conversion unit, the power receiving control unit, and the power receiving storage unit is disposed between the contact unit and the flexible sheet.

[0011] Here, the power receiving conversion unit, the power receiving control unit, and the power receiving storage unit each contain a certain amount of metal, which has the property of blocking electromagnetic waves. Therefore, with the above configuration, electromagnetic waves are also shielded by the power receiving conversion unit, the power receiving control unit, and the power receiving storage unit that are arranged between the contact unit and the flexible sheet. This further reduces the amount of electromagnetic waves absorbed by the living body, further reducing the influence of the electromagnetic waves on the living body. In addition, the influence of the surface potential of the living body on the power receiving antenna is further reduced.

[0012] In the above wearable device, the contact portion is preferably configured as an adhesive pad. According to the above configuration, the contact portion made of the adhesive pad is attached to the body surface of the attachment portion, so that the wearable device is attached to the attachment portion in a state of contact with the body surface. Even if the attachment portion moves, the adhesive pad maintains a stable state of contact with the body surface, which has the effect of stabilizing the electrical characteristics. [Effects of the Invention]

[0013] The wearable device described above can reduce the influence of electromagnetic waves on the living body and the influence of the surface potential of the living body on the power receiving antenna. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a conceptual diagram of a wearable device according to one embodiment. [Figure 2] FIG. 2 is a schematic configuration diagram of a contactless power supply system according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment of a wearable device will be described with reference to the drawings. As shown in FIG. 1 , the wearable device 20 has a contact portion 28 and is worn on a living organism 10, such as a human body, with the contact portion 28 in contact with a body surface 12. Examples of the portion 11 on the living organism 10 to which the wearable device 20 is worn include the hand, wrist, finger, arm, ear, neck, head, and foot. The wearable device 20 includes so-called wearable terminals such as a smart watch and smart glasses. In addition, the wearable device 20 includes devices with sensor functions that measure health management items of the living organism 10, such as the body temperature, heart rate, blood pressure, and blood oxygen concentration. The wearable device 20 also includes sensors that measure skin gases, blood flow sensors, sweat sensors, and the like.

[0016] The wearable device 20 includes a power receiving device 21, a driving unit 26, and a housing 27. The power receiving device 21 constitutes part of the contactless power supply system 15. The driving unit 26 is a part that performs functions of the wearable device 20, such as the sensor function, and is operated by power supplied from the power receiving device 21. The housing 27 constitutes the outer shell of the wearable device 20 and covers the power receiving device 21 and the driving unit 26. The contact unit 28 is formed of an adhesive pad and is fixed to the outer surface of the housing 27 by adhesion or the like. The contact unit 28 can be repeatedly peeled off and attached to the body surface 12 of the attachment part 11.

[0017] [Overall configuration of the non-contact power supply system 15] 1 and 2, the contactless power feeding system 15 includes a power transmitting device 16 in addition to the power receiving device 21. The power transmitting device 16 feeds power to the power receiving device 21 by contactless feeding using a power transmission signal, for example. More specifically, the contactless power feeding system 15 transmits power wirelessly using a microwave method for contactless feeding. That is, a power transmission signal for contactless feeding is transmitted and received between a power receiving antenna 22 of the power receiving device 21 and a power transmitting antenna 17 of the power transmitting device 16. At this time, the power transmission signal is transmitted from the power transmitting antenna 17 to the power receiving antenna 22. Microwaves are electromagnetic waves having a wavelength of 1 mm to 1 m (300 MHz to 300 GHz).

[0018] The wireless power transmission method (contactless power transmission method) applied to the contactless power supply system 15 is not limited to the microwave method, but may be an electromagnetic induction method, a magnetic field resonance method, an electric field resonance method, a method using a laser, or the like.

[0019] [Configuration of power receiving device 21] As shown in FIG. 2, the power receiving device 21 includes a power receiving conversion unit 23, a power receiving storage unit 24, a power feeding terminal 24a, and a power receiving control unit 25 in addition to the power receiving antenna 22 described above.

[0020] The power receiving antenna 22 is used for various communications with the power transmitting device 16. The power receiving antenna 22 is configured to be able to receive a power transmission signal transmitted from the power transmitting device 16. In this embodiment, a patch antenna (also called a microstrip antenna), which is a type of planar antenna, is used as the power receiving antenna 22. A patch antenna has a structure in which a dielectric substrate is sandwiched between ground plates and patch-shaped elements on both sides in the thickness direction. A patch antenna is capable of receiving higher power, i.e., it is a type of antenna with high gain. In this embodiment, a flexible patch antenna is used.

[0021] The power receiving converter 23 converts the power transmission signal received by the power receiving antenna 22 into DC power. The specific form of the power receiving converter 23 is arbitrary, but the power receiving converter 23 includes, for example, a rectifier circuit, a smoothing circuit, etc.

[0022] The power receiving storage unit 24 stores the DC power converted by the power receiving conversion unit 23. The power receiving device 21 operates using the power stored in the power receiving storage unit 24. In this embodiment, the power receiving storage unit 24 is made of a flexible material and is formed into a sheet shape, and is flexible so that it is easy to bend and stretch. As described above, the power transmission signal received by the power receiving antenna 22 is stored in the power receiving storage unit 24 or consumed within the power receiving device circuitry.

[0023] The power supply terminal 24a is connected to the power receiving and storage unit 24. The power supply terminal 24a is configured to be connectable to the drive unit 26. The drive unit 26 is connected to the power supply terminal 24a, and is thereby electrically connected to the power receiving and storage unit 24 via the power supply terminal 24a. The power stored in the power receiving and storage unit 24 is supplied to the drive unit 26 via the power supply terminal 24a.

[0024] The power receiving control unit 25 controls the power receiving device 21. The power receiving control unit 25 is realized, for example, by a hardware processor such as a CPU (Central Processing Unit) executing a program (software). Some or all of these components may be realized by hardware (including circuitry) such as an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a GPU (Graphics Processing Unit), or may be realized by a combination of software and hardware. The program may be stored in advance in a storage device (not shown) equipped with a non-transitory storage medium such as an HDD (Hard Disk Drive) or flash memory provided in the power receiving device 21.

[0025] [Flexible Sheet 31] As shown in FIG. 1, wearable device 20 further includes a flexible sheet 31 inside housing 27. Flexible sheet 31 is disposed between contact portion 28 and power receiving antenna 22. The main portion of flexible sheet 31 is made up of a flexible and easily bendable sheet main body 32. Sheet main body 32 is made of a material that has the ability to shield electromagnetic waves.

[0026] The flexible sheet 31 further includes a conductive portion 33 made of a conductive material. The conductive portion 33 is laminated on the sheet main body 32. The power receiving antenna 22 is formed on the sheet main body 32 via the conductive portion 33.

[0027] Although not shown, the conductive portion 33 penetrates the sheet main body 32 in the thickness direction or bypasses the sheet main body 32 and is electrically connected to the power receiving conversion portion 23 and the like. [Regarding the arrangement of the power receiving conversion unit 23, the power receiving control unit 25, and the power receiving storage unit 24] In the wearable device 20, the control board 35 and the power receiving and storing unit 24 are disposed between the contact unit 28 and the flexible sheet 31. The power receiving conversion unit 23 and the power receiving control unit 25 are included in the control board 35 as parts that constitute the control board 35.

[0028] In wearable device 20, portions that require insulation for proper circuit function (functional insulation) and insulation for protection against electric shock (basic insulation) are formed of insulating materials.

[0029] Next, the operation of the present embodiment configured as described above will be described, along with the effects that accompany the operation. <(1) Attaching the wearable device 20 to the attachment part 11> When the wearable device 20 is attached to the attachment part 11 , the wearable device 20 is bent so as to conform to the shape of the body surface 12 of the attachment part 11 .

[0030] (1-1) Here, in the wearable device 20, the sheet main body 32 of the flexible sheet 31 and the power receiving antenna 22 are flexible. In addition, the power receiving and storage unit 24 is also sheet-shaped and flexible. Therefore, the power receiving antenna 22, the sheet main body 32, and the power receiving and storage unit 24 can be easily bent to match the curvature of the body surface 12 of the attachment unit 11. In this respect, in this embodiment, the attachment of the wearable device 20 to the attachment unit 11 can be improved.

[0031] (1-2) Next, the wearable device 20 bent as described above is attached to the body surface 12 of the attachment part 11 at the contact part 28 formed by an adhesive pad. Therefore, the wearable device 20 can be easily attached to the attachment part 11.

[0032] Furthermore, by attaching the wearable device 20 as described above, it is possible to wear the wearable device 20 in a state of contact with the attachment portion 11. Therefore, even if the attachment portion 11 moves, the contact portion 28 can maintain a stable contact state with the body surface 12, thereby stabilizing the electrical characteristics. The driving portion 26 can stably perform the sensor function.

[0033] (1-3) The wearable device 20 can be removed from the attachment part 11 by peeling off the contact part 28 made of an adhesive pad from the body surface 12. Thereafter, the wearable device 20 can be attached again to the attachment part 11 by attaching the contact part 28 to the body surface 12. Furthermore, the above peeling and attachment can be repeated.

[0034] <(2) Reducing the effects of electromagnetic waves on living organisms> A power transmission signal consisting of electromagnetic waves is transmitted from the power transmitting antenna 17 of the power transmitting device 16 to the power receiving antenna 22 of the power receiving device 21. A portion of the transmitted power transmission signal is received by the power receiving antenna 22. The received power transmission signal is converted into DC power by the power receiving conversion unit 23. This DC power is stored in the power receiving storage unit 24. The drive unit 26 is operated by the power stored in the power receiving storage unit 24.

[0035] (2-1) A portion of the power transmission signal not received by the power receiving antenna 22 is shielded by the sheet main body 32 of the flexible sheet 31. That is, in the sheet main body 32, the electromagnetic waves are attenuated by reflection, absorption, multiple reflection, etc. As a result, the electromagnetic waves that penetrate into the living body 10 are reduced by the amount that is shielded as described above. This reduces the impact of the electromagnetic waves on the living body 10.

[0036] (2-2) Furthermore, the conductive portion 33 made of a conductive material has the ability to block electromagnetic waves. Therefore, a portion of the electromagnetic waves that are not received by the power receiving antenna 22 is reflected by the conductive portion 33. Some of the reflected electromagnetic waves may be re-input to the power receiving antenna 22, thereby increasing the received power.

[0037] Furthermore, the reflection of the electromagnetic waves at the conductive portion 33 can further reduce the electromagnetic waves that penetrate into the living body 10, thereby further reducing the influence of the electromagnetic waves on the living body 10. (2-3) Here, each of the power receiving conversion unit 23, the power receiving control unit 25, and the power receiving storage unit 24 contains a metal to a certain extent. Metal has the property of blocking electromagnetic waves.

[0038] In this regard, in this embodiment, the power receiving conversion unit 23, the power receiving control unit 25, and the power receiving storage unit 24 are arranged between the contact unit 28 and the flexible sheet 31. Therefore, in addition to the sheet body 32 and conductive portion 33 of the flexible sheet 31, the power receiving conversion unit 23, the power receiving control unit 25, and the power receiving storage unit 24 can also shield electromagnetic waves.

[0039] Therefore, the electromagnetic waves absorbed by the living body 10 can be further reduced, and the influence of the electromagnetic waves on the living body 10 can be further reduced. <(3) Reducing the influence of the surface potential of the living body 10 on the power receiving antenna 22> (3-1) Furthermore, as described above, the sheet main body portion 32 of the flexible sheet 31 arranged between the body surface 12 of the attachment portion 11 and the power receiving antenna 22 reduces the influence of the electric field of the body surface 12 on the power receiving antenna 22.

[0040] This makes it possible to prevent the performance of the power receiving antenna 22 to receive the power transmission signal from being affected by the electric field on the body surface 12. This reduces the effect of the electrically charged living body 10 on the gain of the power receiving antenna 22, enabling stable power reception.

[0041] (3-2) The conductive portion 33 of the flexible sheet 31 also reduces the influence of the electric field on the body surface 12 of the attachment portion 11 on the power receiving antenna 22. The same effect can be obtained for the power receiving conversion unit 23, the power receiving control unit 25, and the power receiving storage unit 24, which are arranged between the contact portion 28 and the flexible sheet 31. This further reduces the influence of the charged living body 10 on the gain of the power receiving antenna 22, enabling more stable power reception.

[0042] <(4) Other matters> (4-1) In this embodiment, the power receiving antenna 22 is layered on the sheet main body 32 via the conductive portion 33, and the power receiving antenna 22 and the flexible sheet 31 are integrated together. Therefore, the power receiving antenna 22 and the flexible sheet 31 can be handled as a single component, which improves ease of handling.

[0043] [Variations] The above embodiment can also be implemented as a modified example in which it is modified as follows: The above embodiment and the following modified example can be implemented in combination with each other within a range where no technical contradiction occurs.

[0044] <Regarding the power receiving antenna 22> A patch antenna that can easily receive higher power is suitable as the power receiving antenna 22, but other types, such as an inverted F antenna, may also be used.

[0045] The size of a patch antenna is determined by the wavelength of the radio wave (specifically, the power transmission signal) to be received, the dielectric constant and thickness of the dielectric substrate, etc. Therefore, depending on the size of the wearable device 20, it may not be possible to use a patch antenna as the power receiving antenna 22. In such cases, a commonly used inverted-F antenna may be used as the power receiving antenna 22.

[0046] <Regarding the arrangement of the power receiving conversion unit 23, the power receiving control unit 25, and the power receiving storage unit 24> At least one of the power receiving conversion unit 23, the power receiving control unit 25, and the power receiving storage unit 24 may be disposed in a location other than between the contact unit 28 and the flexible sheet 31, for example, on the side of the flexible sheet 31.

[0047] At least two of the power receiving conversion unit 23, the power receiving control unit 25, and the power receiving storage unit 24 may be arranged in a stacked state between the contact unit 28 and the flexible sheet 31 or outside.

[0048] <Other matters> The sheet body 32 of the flexible sheet 31 can function as a base material (substrate). In this case, if the components of the power receiving conversion unit 23 and the power receiving control unit 25 are directly mounted on the sheet body 32, the substrate can be omitted.

[0049] The wearable device 20 can be attached to the attachment target 11 by forming the contact portion 28 from an adhesive pad and attaching it to the body surface 12, as in the above embodiment. However, repeated peeling and attaching of the contact portion 28 may reduce the adhesive strength of the adhesive pad. Therefore, a strap, such as a watch strap used to wear a wristwatch on the wrist, may be used in combination with the adhesive pad.

[0050] Furthermore, the above-mentioned belt may be used instead of the adhesive pad as a means for attaching the wearable device 20 to the attachment portion 11. In this case, a part of the housing 27 may be used as the contact portion 28. Furthermore, a non-adhesive pad may be used instead of the above-mentioned adhesive pad, and this may be used as the contact portion 28.

[0051] The components constituting the power receiving conversion unit 23, the components constituting the power receiving control unit 25, and the power receiving storage unit 24 are arranged on the sheet main body 32 of the flexible sheet 31 while being spaced apart from one another. The flexible sheet 31 may have a bendable portion between adjacent components that can be bent in the thickness direction of the flexible sheet 31.

[0052] In this way, the wearable device 20 as a whole is flexible. The wearable device 20 is bent at the bendable portion to fit the outer shape of the attachment portion 11. Then, the entire wearable device 20 takes a shape that matches the shape of the attachment portion 11. This improves the fit of the wearable device 20 on the attachment portion 11. [Explanation of symbols]

[0053] 10... Living organisms 11…Attachment part 12…Body surface 15...Non-contact power supply system 16...Power transmission device 20...Wearable devices 21...Power receiving device 22...Receiving antenna 23... Power receiving conversion unit 24...Power receiving and storage unit 25...Power receiving control unit 26...Drive unit 28...Contact part 31...Flexible sheet 32...Seat body 33...Conductive part

Claims

1. a wearable device having a contact portion and attached to a target portion of a living body with the contact portion in contact with a body surface, The wireless power supply system includes a power receiving device that constitutes a part of the wireless power supply system, and a drive unit that operates by power supplied from the power receiving device, the power receiving device includes a power receiving antenna that receives a power transmission signal composed of electromagnetic waves and that is transmitted from a power transmitting device of the contactless power supply system; a power receiving conversion unit that converts the power transmission signal received by the power receiving antenna into DC power; a power receiving storage unit that is connected to the drive unit and that stores the DC power converted by the power receiving conversion unit; and a power receiving control unit that controls the power receiving device; Furthermore, the wearable device further includes a flexible sheet provided between the contact portion and the power receiving antenna, the flexible sheet having a sheet main body portion that blocks the electromagnetic waves.

2. The wearable device according to claim 1 , wherein the flexible sheet is made of a conductive material and has a conductive portion to which the power receiving antenna is connected.

3. The wearable device according to claim 1 or 2, wherein at least one of the power receiving conversion unit, the power receiving control unit, and the power receiving storage unit is disposed between the contact unit and the flexible sheet.

4. The wearable device according to any one of claims 1 to 3, wherein the contact portion is constituted by an adhesive pad.

Images