Antennas installed in wearable devices

Abstract

To provide an antenna that can be mounted on a wearable device with little dead space.SOLUTION: The antenna includes a first dielectric substrate having a first plane and a second plane located on opposite sides of each other, a ground plate provided in the first plane of the first dielectric substrate, a second dielectric substrate having third and fourth planes located on opposite sides of each other, the third plane being laminated to the second plane and located at least partially inside the contour of the second plane, and a radiating element provided in the fourth plane of the second dielectric substrate.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] An embodiment of the present invention relates to an antenna mounted on a wearable device. [Background technology]

[0002] Wearable devices have, for example, communication functions. These types of wearable devices are equipped with antennas. Furthermore, it is desirable for wearable devices to be small. Therefore, it is desirable for the antenna to be installed in the wearable device with minimal dead space. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2005-519557 Summary of the Invention [Problem to be solved by the invention]

[0004] The problem to be solved by the present invention is to provide an antenna that can be mounted on a wearable device with little dead space. [Means for solving the problem]

[0005] The antenna of an embodiment mounted on a wearable device includes a first dielectric substrate having a first plane and a second plane located opposite each other, a ground plate provided on the first plane of the first dielectric substrate, and a third plane and a fourth plane located opposite each other, and the third plane of the first dielectric substrate Laminated with the second plane Ta a second dielectric substrate; and a radiating element provided on a fourth plane of the second dielectric substrate. a first conductive portion extending through the first dielectric substrate and the second dielectric substrate and electrically connecting the ground plane and the radiating element; It has. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a perspective view showing a wearable device according to an embodiment. [Figure 2] FIG. 2 is a perspective view showing the wearable device according to the embodiment as seen from a different direction than that shown in FIG. [Figure 3] FIG. 3 is an exploded perspective view of a wearable device according to an embodiment, showing a sensor device. [Figure 4] FIG. 4 is a plan view of the antenna shown in FIG. [Figure 5] FIG. 5 is a plan view of the antenna shown in FIG. 4 as seen from the back side. [Figure 6] FIG. 6 is a cross-sectional view of the antenna taken along line AA shown in FIGS. [Figure 7] FIG. 7 is a diagram showing an example of how the wearable device according to the embodiment is worn and the reading range of the sensor device. [Figure 8] FIG. 8 is a perspective view of a wearable device according to an embodiment with a USB cover removed from a sensor device. [Figure 9] FIG. 9 is a cross-sectional view of the sensor device taken along line BB shown in FIG. [Figure 10] FIG. 10 is a cross-sectional view of the sensor device taken along line CC shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, embodiments will be described with reference to the drawings, in which like elements are designated by the same reference numerals, and the drawings are schematic or conceptual.

[0008] Fig. 1 is a perspective view showing a wearable device 10 according to an embodiment. Fig. 2 is a perspective view showing the wearable device 10 according to the embodiment as seen from a different direction than that in Fig. 1.

[0009] As shown in FIGS. 1 and 2, the wearable device 10 includes a wristwatch-type device 20 and a sensor device 50 attached to the wristwatch-type device 20.

[0010] The wristwatch-type device 20 includes a smart device 30 and a band 40 that allows the smart device 30 to be worn on the front end of the user's forearm. Here, the front end of the forearm refers to the distal end of the forearm, i.e., the end of the forearm closest to the hand. Accordingly, in the following description, expressions relating to front and back will follow this. That is, the side closer to the hand is referred to as the front, and the side closer to the elbow is referred to as the rear. Here, the hand refers to the part forward of the wrist.

[0011] For example, the smart device 30 is a smartwatch. The smart device 30 has a variety of functions, such as a date and time display function, a health management function, an incoming call notification function, a voice call function, an information communication function, and a music playback function.

[0012] The smart device 30 has a display unit 31 (see FIG. 2) that displays information. For example, the display unit 31 has a touch screen that uses a liquid crystal display or the like. In other words, the display unit 31 functions as an information input / output device. Although not shown, the smart device 30 also has a built-in microcomputer that processes information displayed on the display unit 31 and information input from the display unit 31. The microcomputer also works with necessary devices to perform the various functions described above.

[0013] The smart device 30 has a pair of attachment portions 32, 33 for attaching the band 40. Each of the attachment portions 32, 33 has a pair of protrusions and a pin (not shown) supported by the pair of protrusions.

[0014] In this embodiment, one end of the band 40 is connected to the attachment portion 32 by a pin (not shown). For example, the band 40 has a through-hole at one end, and a pin supported by a pair of protrusions is passed through this through-hole, thereby connecting the band 40 to the attachment portion 32.

[0015] The band 40 is folded back around the pin of the attachment portion 33. A fastening portion 42 is provided at the other end of the band 40, and this fastening portion 42 fastens the other end of the band 40 at a desired position in the middle of the band 40.

[0016] The sensor device 50 has a function of reading information by wireless communication. For example, the sensor device 50 is an RFID reader. The sensor device 50 has a function of reading information written in an RF tag by using radio waves or electromagnetic waves. The sensor device 50 may also have a function of writing information to an RF tag by using radio waves or electromagnetic waves. The sensor device 50 also has a function of transmitting the read information to the smart device 30 by wireless communication.

[0017] The sensor device 50 has an external shape of a rounded rectangular parallelepiped. Here, a rounded rectangular parallelepiped means a rectangular parallelepiped that is rounded overall. For example, the rounded rectangular parallelepiped has rounded corners where three planes intersect and corners where two planes intersect in a normal rectangular parallelepiped. Furthermore, the rounded rectangular parallelepiped has smooth curved surfaces that convex outward in areas that would be flat in a normal rectangular parallelepiped.

[0018] For convenience, the surface of the sensor device 50 that faces the forearm when the wearable device 10 is worn will be referred to as the bottom surface, and the surface opposite the bottom surface will be referred to as the top surface. Furthermore, the side of the sensor device 50 that extends along the forearm when the wearable device 10 is worn will be referred to as the long side, and the side of the sensor device 50 that extends across the forearm will be referred to as the short side. Furthermore, with respect to the sensor device 50, the side of the top surface relative to the bottom surface will be referred to as the top or upper side, and conversely, the side of the bottom surface relative to the top surface will be referred to as the bottom or lower side. Additionally, the direction along the long side will be referred to as the vertical direction, and the direction along the short side will be referred to as the horizontal direction.

[0019] The sensor device 50 is attached to the band 40 so as to be positioned on the opposite side of the smart device 30 with respect to the user's forearm when the wearable device 10 is worn. The sensor device 50 is attached to the wristwatch type device 20 so that the short side of the sensor device 50 extends along the band 40. In other words, the sensor device 50 is attached to the wristwatch type device 20 so that the long side of the sensor device 50 extends perpendicular to the band 40.

[0020] The sensor device 50 has a mounting portion 56 near the bottom surface of the sensor device 50 that is attached to the band 40. For example, the mounting portion 56 is an elongated through-hole through which the band 40 is threaded. The through-hole extends through the sensor device 50 along the short side of the sensor device 50.

[0021] However, the configuration of the attachment portion 56 is not limited to this. The attachment portion 56 may have any configuration as long as it can attach the sensor device 50 to the band 40. For example, the attachment portion 56 may be a pair of U-shaped pins fixed to the sensor device 50. In this configuration example, the band 40 is passed through the gap between the sensor device 50 and the U-shaped pins.

[0022] FIG. 3 is a perspective view of the wearable device 10 according to the embodiment, showing the sensor device 50 in an exploded state.

[0023] As shown in FIG. 3, the sensor device 50 includes a bottom cover 51, a unit base 52, a middle part 53, a top cover 54, a USB cover 55, and an internal part 60.

[0024] The bottom cover 51 defines the lower surface of the sensor device 50, and the top cover 54 defines the upper surface of the sensor device 50. The bottom cover 51 has an attachment portion 56 near the lower surface of the sensor device 50, which is an elongated through-hole through which the band 40 is passed. The bottom cover 51 and the top cover 54 are joined to each other via a middle part 53.

[0025] The middle part 53 extends along the periphery of the sensor device 50 except for a portion of one long side of the sensor device 50. That is, the middle part 53 has a cutout portion along the long side of the sensor device 50. The USB cover 55 fits exactly into the cutout portion of the middle part 53 and complements the cutout portion of the middle part 53. That is, the middle part 53 and the USB cover 55 are disposed between the bottom cover 51 and the top cover 54 and form the side periphery of the sensor device 50.

[0026] The unit base 52 is fixed to the inner bottom surface of the bottom cover 51. The unit base 52 also holds the internal parts 60.

[0027] The internal parts 60 include, for example, an RFID module 61, an I / F board 62, a charging board 63, a battery 64, and an antenna 70.

[0028] The RFID module 61 cooperates with the antenna 70 to achieve the function of reading information through wireless communication.

[0029] The I / F board 62 has, for example, a USB terminal 65 and a micro USB terminal 66 that are connected to the outside and receive supplies of power and information. The battery 64 is a power storage element that supplies power to the RFID module 61 and is charged by the charging board 63.

[0030] Fig. 4 is a plan view of the antenna 70 shown in Fig. 3. Fig. 5 is a plan view of the antenna 70 shown in Fig. 4 as seen from the back side. Fig. 6 is a cross-sectional view of the antenna 70 taken along line AA shown in Figs. 4 and 5.

[0031] As shown in FIGS. 4 to 6, the antenna 70 has a first dielectric substrate 71, a second dielectric substrate 72, a ground plate 73, and a radiating element 74.

[0032] The first dielectric substrate 71 has a first plane 711 and a second plane 712 located opposite to each other, and the ground plane 73 is provided on the first plane 711 of the first dielectric substrate 71 .

[0033] The second dielectric substrate 72 has a third plane 721 and a fourth plane 722 positioned opposite to each other, and the radiating element 74 is provided on the fourth plane 722 of the second dielectric substrate 72 .

[0034] The third plane 721 of the second dielectric substrate 72 is bonded to the second plane 712 of the first dielectric substrate 71 .

[0035] The area of ​​the third plane 721 of the second dielectric substrate 72 is smaller than the area of ​​the second plane 712 of the first dielectric substrate 71. The third plane 721 of the second dielectric substrate 72 is located inside the outline of the second plane 712 of the first dielectric substrate 71.

[0036] For example, the second dielectric substrate 72 is disposed at the center of the second plane 712 of the first dielectric substrate 71. Therefore, as shown in FIG. 6, for example, the cross section of the antenna 70 has a convex shape. FIG. 6 shows the cross section of the antenna 70 taken along the horizontal direction. Therefore, FIG. 6 shows that the cross section of the antenna 70 in the horizontal direction has a convex shape. However, as can be easily imagined from FIG. 4, for example, the cross section of the antenna 70 in the vertical direction also has a convex shape.

[0037] However, the third plane 721 of the second dielectric substrate 72 does not necessarily have to be located inside the outline of the second plane 712 of the first dielectric substrate 71. In other words, it is sufficient that the third plane 721 of the second dielectric substrate 72 is at least partially located inside the outline of the second plane 712 of the first dielectric substrate 71. In other words, it is sufficient that the second dielectric substrate 72 at least partially overlaps the first dielectric substrate 71.

[0038] 4, the radiating element 74 is formed to be slightly smaller than the fourth plane 722 of the second dielectric substrate 72. A pair of cutout portions extending parallel to each other is formed in the radiating element 74. As a result, the radiating element 74 has one strip line 741 extending between the pair of cutout portions.

[0039] Therefore, the radiating element 74 covers the fourth plane 722 of the second dielectric substrate 72 except for the peripheral edge portion of the fourth plane 722 of the second dielectric substrate 72 and the pair of notches.

[0040] However, the radiating element 74 does not necessarily have to be formed one size smaller than the fourth plane 722 of the second dielectric substrate 72, and may also cover the peripheral portion of the fourth plane 722 of the second dielectric substrate 72.

[0041] The tip of the strip line 741 is electrically connected to a feed terminal 77 provided on the first plane 711 of the first dielectric substrate 71 via a conductive portion 76 that extends through the first dielectric substrate 71 and the second dielectric substrate 72. The feed terminal 77 is formed at a distance from the ground plate 73 and is electrically insulated from the ground plate 73.

[0042] The radiating element 74 is electrically connected to a ground plane 73 provided on a first plane 711 of the first dielectric substrate 71 via a conductive portion 75 extending through the first dielectric substrate 71 and the second dielectric substrate 72 at each of a pair of portions located on either side of the tip of the strip line 741.

[0043] 5, the ground plate 73 is formed on the entire first plane 711 of the first dielectric substrate 71 except for the feed terminal 77 and its surrounding area. In other words, the ground plate 73 covers the entire first plane 711 of the first dielectric substrate 71 except for the feed terminal 77 and its surrounding area.

[0044] However, the ground plane 73 does not necessarily have to be formed over the entire first plane 711 of the first dielectric substrate 71, and may only partially cover the first plane 711 of the first dielectric substrate 71.

[0045] 5, the radiating element 74 is located inside the outline of the ground plate 73 when projected onto the first plane 711 of the first dielectric substrate 71 on which the ground plate 73 is provided. However, the radiating element 74 is not necessarily limited to this, and it is sufficient that the radiating element 74 at least partially overlaps with the ground plate 73 when projected onto the first plane 711.

[0046] For example, the ground plane 73 may be partially formed on the first plane 711 of the first dielectric substrate 71, and the radiating element 74 may have a portion that does not overlap with the ground plane 73 when projected onto the first plane 711.

[0047] The antenna 70 only needs to have a portion where the radiating element 74 overlaps with the ground plate 73 when projected onto the first plane 711. To that extent, the antenna 70 will function. Of course, the larger the area of ​​the overlapping portion between the radiating element 74 and the ground plate 73, the better.

[0048] In the antenna 70 according to the embodiment, the range in which information can be read by the antenna 70 extends above the radiating element 74, that is, in the space on the opposite side of the first dielectric substrate 71 with respect to the second dielectric substrate 72. Fig. 7 is a diagram showing an example of how the wearable device 10 according to the embodiment is worn and the range in which the sensor device 50 can read information.

[0049] 7, wearable device 10 is attached to a user's forearm 90 by band 40. Antenna 70 is mounted inside sensor device 50 such that radiating element 74 is located on the side opposite attachment portion 56 of band 40 that is wrapped around forearm 90. As described above, attachment portion 56 of band 40 is provided near the bottom surface of sensor device 50. Therefore, antenna 70 is mounted inside sensor device 50 such that radiating element 74 is located on the top surface side.

[0050] As a result, in wearable device 10 worn on forearm 90, antenna 70 mounted inside sensor device 50 has first dielectric substrate 71 arranged on the inner side, i.e., the side closer to forearm 90, and second dielectric substrate 72 arranged on the outer side, i.e., the side farther from forearm 90. As a result, reading range R of antenna 70 does not overlap with forearm 90 and preferably extends into the space above sensor device 50.

[0051] FIG. 8 is a perspective view of the wearable device 10 according to the embodiment with the USB cover 55 removed from the sensor device 50. FIG.

[0052] As shown in FIG. 8 , the USB terminal 65 and the micro USB terminal 66 are exposed from the cutout portion of the middle part 53. As described above, the USB cover 55 fits snugly into the cutout portion of the middle part 53. The USB cover 55 is made of a magnetic material. A plurality of magnets 57 are provided on the exposed portion of the middle part 53 that is exposed from the cutout portion. The USB cover 55 is held in the cutout portion of the middle part 53 by these magnets 57.

[0053] Fig. 9 is a diagram showing a cross section of the sensor device taken along line BB shown in Fig. 8. Fig. 10 is a diagram showing a cross section of the sensor device taken along line CC shown in Fig. 8.

[0054] 9 and 10, the sensor device 50 has a rounded exterior shape, as described above. Therefore, the outer surface of the top cover 54 is rounded. Accordingly, the inner surface of the top cover 54 is also rounded. Therefore, the internal space of the sensor device 50, particularly the portion defined by the top cover 54, is significantly reduced from the center toward the edges.

[0055] The antenna 70 is disposed at the uppermost part of the internal parts 60. As described above, the antenna 70 has a convex cross section. Therefore, the antenna 70 occupies less space inside the sensor device 50 at the ends of the antenna 70. Therefore, the antenna 70 is conveniently accommodated in the internal space of the sensor device 50, in other words, with little dead space.

[0056] As described above, in the wearable device 10 according to the embodiment, the antenna 70 has a ground plate 73 provided on a first dielectric substrate 71, and a radiating element 74 provided on a second dielectric substrate 72 that is smaller than the first dielectric substrate 71, and the first dielectric substrate 71 and the second dielectric substrate 72 are bonded together so that the ground plate 73 and the radiating element 74 are on the outside and the second dielectric substrate 72 is positioned inside the outline of the first dielectric substrate 71.

[0057] Therefore, the antenna 70 has a convex cross section and can be mounted on the sensor device 50, which has a rounded outer shape, with little dead space.

[0058] Therefore, according to the embodiment, an antenna 70 is provided that can be mounted on the wearable device 10 with little dead space.

[0059] In the embodiment, the first dielectric substrate 71 and the second dielectric substrate 72 are illustrated as rectangular plate members. However, the shapes of the first dielectric substrate 71 and the second dielectric substrate 72 are not limited to this and may be any shape. For example, the first dielectric substrate 71 and the second dielectric substrate 72 may be rectangular plate members with rounded corners.

[0060] Furthermore, the areas of the first plane 711 and the second plane 712 of the first dielectric substrate 71 do not necessarily have to be the same and may be different from each other. Similarly, the areas of the third plane 721 and the fourth plane 722 of the second dielectric substrate 72 do not necessarily have to be the same and may be different from each other.

[0061] Although the embodiments of the present invention have been described, they are presented as examples and are not intended to limit the scope of the invention. The novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. The embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the inventions and their equivalents as defined in the claims. The inventions described in the original claims of this application are set forth below. [1] An antenna mounted on a wearable device, a first dielectric substrate having a first planar surface and a second planar surface located opposite each other; a ground plane provided on the first plane of the first dielectric substrate; a second dielectric substrate having a third planar surface and a fourth planar surface opposite each other, the third planar surface being laminated to the second planar surface and at least partially located within the contour of the second planar surface; a radiating element provided on the fourth plane of the second dielectric substrate; antenna. [2] the radiating element at least partially overlaps the ground plane when projected onto the first plane; [1] The antenna described in [1]. [3] the radiating element is located inside the outline of the ground plane when projected onto the first plane. [2] The antenna described in [2]. [4] the ground plate covers the entire first plane, the radiating element covers the fourth plane except for a peripheral portion of the fourth plane. [3] The antenna described in [3]. [5] The radiating element is mounted inside a wearable device having a device and a band, so that the radiating element is located on the opposite side of an attachment portion of the band to the device. [1] An antenna according to any one of [1] to [4]. [Explanation of symbols]

[0062] 10...wearable device, 20...wristwatch-type device, 30...smart device, 31...display unit, 32...mounting unit, 33...mounting unit, 40...band, 42...clasp, 50...sensor device, 51...bottom cover, 52...unit base, 53...middle part, 54...top cover, 55...USB cover, 56...mounting unit, 57...magnet, 60...internal part, 61...RFID module, 62...I / F board, 63...charging board, 64...battery, 65...USB terminal, 66...micro USB terminal, 70...antenna, 71...dielectric substrate, 72...dielectric substrate, 73...ground plate, 74...radiating element, 75...conductive part, 76...conductive part, 77...power supply terminal, 90...forearm, 711...first plane, 712...second plane, 721...third plane, 722...fourth plane, 741...strip line.

Claims

1. An antenna mounted on a wearable device, a first dielectric substrate having a first planar surface and a second planar surface located opposite each other; a ground plane provided on the first plane of the first dielectric substrate; a second dielectric substrate having a third plane and a fourth plane positioned opposite to each other, the third plane being bonded to the second plane of the first dielectric substrate; a radiating element provided on the fourth plane of the second dielectric substrate; a first conductive portion extending through the first dielectric substrate and the second dielectric substrate and electrically connecting the ground plane and the radiating element; antenna.

2. a power supply terminal provided on the first plane of the first dielectric substrate and electrically insulated from the ground plane; a second conductive portion extending through the first dielectric substrate and the second dielectric substrate and electrically connecting the radiating element and the feeding terminal; The antenna of claim 1 .

3. the second dielectric substrate is smaller than the first dielectric substrate when projected onto the second plane and is located inside the first dielectric substrate; 3. The antenna of claim 2.

4. The wearable device is worn on the forearm, the first dielectric substrate and the second dielectric substrate have a convex cross section along a lateral direction extending across the forearm when the wearable device is worn; the first dielectric substrate and the second dielectric substrate have a convex cross section along a longitudinal direction extending along the forearm when the wearable device is worn; 4. The antenna of claim 3.

5. The radiating element has a pair of cutout portions extending parallel to each other, and has a single strip line extending between the pair of cutout portions. The antenna of claim 1 .

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