JP7414773B2 - clock with solar panel - Google Patents

Description

The present invention relates to a solar panel watch.

Patent Documents 1 and 2 disclose radio-controlled watches that include a solar panel and a loop antenna. In Patent Document 1, a circular opening is formed in a solar panel, and a loop antenna is arranged so as to overlap the opening in plan view. Patent Document 2 discloses a loop antenna having a larger diameter than a solar panel.

JP2019-132684 JP2013-64723

In Patent Document 1, the opening formed in the solar panel becomes a region that does not contribute to power generation, and the amount of power generation in the solar panel decreases accordingly. Further, in Patent Document 2, depending on the diameter of the antenna, the diameter of the solar panel (power generation area) becomes small, and the amount of power generation decreases.

The present invention has been made in view of the above problems, and its purpose is to suppress the influence of the solar panel on the sensitivity of the loop antenna while maintaining the amount of power generation.

(1) It has a dial, a solar panel that generates electricity when light transmitted through the dial is incident, and a loop antenna, and the extreme position of the loop antenna where the current distribution is extreme is , a solar panel-equipped watch located at a position along a non-power generation area of the solar panel that does not contribute to power generation in plan view.

(2) In (1), the loop antenna includes a first feeding position on one end side and a second feeding position on the other end side, and the extreme position is the first feeding position or the second feeding position. A solar panel watch, wherein the length from the power feeding position is one half of the circumferential length of the loop antenna.

(3) In (1) or (2), at least a part of the non-power generation area is equipped with a solar panel located between the center position of the loop antenna and the extreme position in plan view. clock.

(4) The solar panel watch according to any one of (1) to (3), wherein the loop antenna is disposed between the non-power generation area and the outer edge of the solar panel in plan view.

(5) In any one of (1) to (4), the solar panel-equipped watch, wherein the extreme position is located radially outside the non-power generation area and adjacent to the non-power generation area.

(6) The solar panel watch according to any one of (1) to (5), wherein the extreme value position is located at a position where at least a part of the magnetic field generated around the extreme value position is generated in the non-power generation area.

(7) In any one of (1) to (6), the display device further includes a display screen, and the dial plate is formed with a first opening that allows the display screen to be viewed from the outside. In the solar panel watch, the non-power generation area is a second opening that overlaps the first opening in plan view and allows the display screen to be viewed from the outside.

(8) In (7), the loop antenna is arranged so as to form a gap with the display device in the vertical direction, and the extreme position is such that at least a portion of the magnetic field generated around the loop antenna is located. A clock with a solar panel in which the space is located in the gap.

(9) In (7) or (8), the display device includes at least a liquid crystal layer and a pair of electrode layers sandwiching the liquid crystal layer, and the solar panel includes at least: A solar panel watch comprising a semiconductor layer and a pair of electrode layers sandwiching the semiconductor layer, the thickness of the pair of electrode layers sandwiching the liquid crystal layer being thinner than the thickness of the pair of electrode layers sandwiching the semiconductor layer. .

(10) In any one of (7) to (9), the display device includes a nonmetallic edge surrounding the display screen in plan view, and at least a part of the loop antenna , a clock with a solar panel provided so as to overlap the edge.

(11) The solar panel watch according to any one of (7) to (10), wherein the loop antenna includes a bent portion that bends to match the outer shape of the display screen.

(12) The solar panel watch according to (11), wherein the extreme position is located in a portion of the loop antenna other than the bent portion.

(13) In any one of (1) to (6), the dial plate has a non-metallic display plate having a small window and a display that is visible through the small window. In the solar panel watch, the non-power generation area is provided so as to overlap the small window when viewed from above.

According to the above aspects (1) to (13) of the present invention, it is possible to suppress the influence of the solar panel on the sensitivity of the loop antenna while maintaining the amount of power generation.

FIG. 1 is a plan view showing a solar panel watch according to the present embodiment. FIG. 2 is a plan view showing the movement in this embodiment as viewed from above. FIG. 2 is a plan view showing the movement in this embodiment as viewed from above. FIG. 4 is a sectional view showing a cross section taken along the line IV-IV in FIGS. 1 and 3. FIG. FIG. 4 is a sectional view showing a cross section taken along the line VV in FIGS. 1 and 3. FIG. FIG. 1 is a diagram schematically showing a loop antenna according to the present embodiment. It is a figure showing the current distribution of the loop antenna of this embodiment. It is a top view which shows the solar panel in a modification.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention (hereinafter referred to as the present embodiment) will be described in detail below based on the drawings.

[Overview of watches with solar panels]
FIG. 1 is a plan view showing a solar panel watch 1 (hereinafter also simply referred to as "watch 1") according to the present embodiment.

FIG. 1 shows a case 10 that forms part of the outer case (watch case) of a watch 1, a dial 3 disposed inside the case 10, an hour hand 15, a minute hand 16, and a second hand 17, which are time hands that indicate the time. It is shown. The outer case is preferably made of metal such as stainless steel or titanium alloy. Further, hour characters 18 are provided at predetermined positions on the dial plate 3. Furthermore, band fixing portions 11 for fixing the band extend from the 12 o'clock and 6 o'clock side surfaces of the trunk 10. Further, on the side surface of the barrel 10 on the 3 o'clock side, buttons 12 and a crown 13 are arranged for the user to perform various operations. Further, sub-dials SD are provided on each of the 1 o'clock side and the 11 o'clock side of the dial 3. Note that the design of the watch shown in FIG. 1 is an example.

The watch 1 has a windshield made of a transparent material such as glass so as to cover a dial 3, and the windshield is attached to a body 10. Further, on the opposite side of the windshield, a back cover is attached to the body 10. In this specification, in the thickness direction of the watch 1, the side where the windshield is provided is referred to as the upper side, and the side where the back cover is provided is referred to as the lower side. That is, the front side of the page in FIG. 1 is called the upper side, and the back side of the page in FIG. 1 is called the bottom side.

The watch 1 houses a movement 50 shown in FIG. 2 inside a hollow exterior case. The movement 50 includes a base plate 51 made of synthetic resin, and the base plate 51 includes a circuit board 80 (see FIGS. 4 and 5) on which various electronic components are mounted, a secondary battery, a motor, a wheel train, and other drive mechanisms, and a drive mechanism that will be described later. A plurality of parts such as the antenna board 41 (see FIG. 3) are assembled.

The movement 50 is provided with a pointer shaft 19 protruding from the upper surface of the dial 3, and a second hand 17, a minute hand 16, and an hour hand 15 are attached to the tips of the pointer shaft 19.

The watch 1 further includes a liquid crystal display device 30 including a display screen M. On the display screen M, numbers indicating the time and characters and symbols indicating other information may be digitally displayed. FIG. 1 shows how a display screen M of the liquid crystal display device 30 is viewed from the outside through an opening (first opening) 3h formed in the dial plate 3. Note that in FIG. 1, the specific display on the display screen M is omitted. As shown in FIG. 1, the planar shape of the display screen M is approximately rectangular. However, the present invention is not limited to this, and the planar shape of the display screen M may be circular or the like.

Although detailed illustrations are omitted, the liquid crystal display device 30 includes a laminated structure in which at least a liquid crystal layer and a pair of electrode layers (an upper electrode layer and a lower electrode layer) sandwiching the liquid crystal layer are laminated. Ru. This laminated structure allows digital display to be performed on the display screen M. Note that the pair of electrode layers included in the liquid crystal display device 30 are preferably made of metal.

Further, the liquid crystal display device 30 preferably has a nonmetallic (for example, resin) edge 31 that surrounds the display screen M in a plan view (see FIG. 3). Further, it is preferable that a liquid crystal driver circuit unit 32 including a driver circuit for driving the liquid crystal display device 30 is disposed in a region between the display screen M and the edge 31 in plan view (see FIG. 3). ).

The watch 1 further includes a solar panel 2 and a loop antenna 40 (see FIGS. 1 to 5).

[Solar panel]
Next, the details of the solar panel 2 of this embodiment will be described mainly with reference to FIG. 2. FIG. 2 is a plan view showing the movement in this embodiment viewed from above. Note that in FIG. 2, members such as the dial plate 3 that are arranged above the solar panel 2 are omitted.

In the following description, in the solar panel 2, an area radially inside the outer edge of the solar panel 2 that does not contribute to power generation is defined as a "non-power generation area", and an area that contributes to power generation is defined as a "power generation area". . Note that in this specification, the "radial direction" is defined as a direction perpendicular to an axis passing through a certain center position, and a direction outward from the center position in plan view. That is, the radial direction in the solar panel 2 is a direction perpendicular to the direction in which the pointer shaft 19 shown in FIG. 2 extends, and is a direction outward from the pointer shaft 19.

The solar panel 2 is arranged below the dial 3 and is used to generate electricity when the light that passes through the dial 3 is incident, and to charge the secondary battery assembled in the movement 50. It is. The secondary battery supplies power to the movement 50 and also stores the power generated by the solar panel 2, and is preferably a button-shaped lithium secondary battery, for example.

The solar panel 2 includes at least a semiconductor layer and a pair of electrode layers (an upper electrode layer and a lower electrode layer) sandwiching the semiconductor layer. The semiconductor layer of the solar panel 2 is a layer that has a function of converting incident light into electricity, and is preferably made of, for example, amorphous silicon. However, the present invention is not limited to this, and other semiconductors such as crystalline silicon may be used as the semiconductor layer. The upper electrode layer of the solar panel 2 is preferably made of a transparent electrode having light transmittance. The upper electrode layer of the solar panel 2 may be made of, for example, ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), FTO (Fluorine-doped Tin Oxide), or the like. Further, the lower electrode layer of the solar panel 2 is preferably made of, for example, Al (aluminum), Au (gold), Ag (silver), or the like.

The solar panel 2 includes a plurality of solar cells C arranged adjacent to each other with a divided region D interposed therebetween, as shown in FIG. 2 . FIG. 2 shows a solar panel 2 including six solar cells C each having a substantially fan-like planar shape. That is, the solar panel 2 is divided into six solar cells C via the divided region D. The divided region D is a region in which the above-described lower electrode layer, semiconductor layer, and upper electrode layer are not provided. Note that the number and arrangement of divided regions D shown in FIG. 2 are merely examples, and are not limited thereto.

The solar panel 2 is provided above the liquid crystal display device 30. Therefore, as shown in FIG. 2, the solar panel 2 is formed with an opening (second opening) 2h that allows the display screen M of the liquid crystal display device 30 to be viewed externally. The opening 2h is a non-power generation area that does not contribute to power generation.

The opening 2h has a planar shape that follows the outline of the display screen M. That is, in this embodiment, the planar shape of the opening 2h is rectangular. The opening 2h of the solar panel 2, which is a non-power generation area, may be a through hole or may be made of a non-metallic transparent member that allows the display screen M to be viewed from the outside. The same applies to the opening 2h formed in the dial 2.

At least a portion of the power generation area of the solar panel 2 is preferably provided so as to overlap with the liquid crystal driver circuit section 32 of the liquid crystal display device 30 in plan view. This is because when external light enters the liquid crystal driver circuit section 32, light excitation may occur, which may increase current consumption in the liquid crystal display device 30. In this embodiment, as shown in FIG. 2, the size of the opening 2h is approximately the same as the size of the display screen M. That is, only the display screen M of the liquid crystal display device 30 overlaps with the opening 2h in plan view. Therefore, the liquid crystal driver circuit section 32 of the liquid crystal display device 30 is shielded by the power generation area of the solar panel 2.

Further, the solar panel 2 is disposed between the movement 50 and the dial 3 in the vertical direction, and has a through hole through which the pointer shaft 19 passes. In the example shown in FIG. 2, in addition to the through hole through which the pointer shaft 19 for the time hand located at the center of the circular movement 50 passes, there are two through holes through which the pointer shafts for other function hands pass. An example of the formation is shown. These function hands are points placed on the subdial SD shown in FIG. However, the solar panel 2 shown in FIG. 2 is just one example, and in a watch that is not equipped with any functional hands other than the time hand, the solar panel 2 does not have a through hole through which the pointer shaft for the functional hands passes. It's good not to have it.

[Basic configuration of loop antenna]
Next, the basic configuration of the loop antenna will be explained with reference to FIG. 3. FIG. 3 is a plan view showing the movement in this embodiment viewed from above. Note that in FIG. 3, members disposed above the loop antenna 40, such as the dial 3 and the solar panel 2, are omitted.

In this embodiment, an antenna for near field communication (NFC) using a frequency of 13.56 MHz is used as the loop antenna 40. Therefore, the loop antenna 40 has a length that can receive radio waves of 13.56 MHz. In this embodiment, the loop antenna 40 is a so-called magnetic field type one-wavelength loop antenna whose length in the circumferential direction is λ.

However, the loop antenna 40 may be, for example, an antenna for other short-range wireless communication using Bluetooth (registered trademark) or Wi-Fi (registered trademark), or may be an antenna for standard radio waves or GPS (Global Positioning System). It may also be an antenna that receives a satellite signal containing time information, such as a satellite.

The loop antenna 40 is preferably provided on an antenna substrate 41 that is an FPC (Flexible Printed Circuit). FIG. 3 shows an example in which an annular loop antenna 40 is provided on an annular antenna substrate 41. In FIG. The antenna substrate 41 may be made of, for example, an insulating dielectric material.

Although FIG. 3 schematically shows the planar shape of the loop antenna 40, in reality, the loop antenna 40 is preferably formed by winding one wire (electric wire) multiple times. .

The loop antenna 40 has a power feeding section 40a including a first power feeding position 40a1 on one end side of the winding and a second power feeding position 40a2 on the other end side of the winding. In the example of FIG. 3, the power feeding section 40a is arranged radially outward from the main body portion of the loop antenna 40 forming an annular outer shape. Further, in this embodiment, the power feeding section 40a is arranged near the 2 o'clock position.

The first power supply position 40a1 is a position connected to a power supply spring 61 (see FIG. 5) extending downward, and the second power supply position 40a2 is a position connected to a power supply spring 62 extending downward. The power supply springs 61 and 62 are electrically connected to a circuit board 80 assembled to the movement 50. Thereby, the loop antenna 40 can transfer signals (current) to and from the circuit board 80 through the first feeding position 40a1 and the second feeding position 40a2. Note that the circuit board 80 may be equipped with a communication circuit for transmitting and receiving data via the loop antenna 40. However, the present invention is not limited to this, and the communication circuit may be mounted on a board other than the circuit board 80.

[Cross-sectional structure]
Next, the cross-sectional structure of the timepiece 1 will be described with reference to FIGS. 4 and 5. FIG. 4 is a cross-sectional view taken along the line IV--IV in FIGS. 1 and 3. FIG. Specifically, FIG. 4 is a sectional view showing a cross section taken along a cutting line passing through the liquid crystal display device. FIG. 5 is a cross-sectional view taken along the line VV in FIGS. 1 and 3. FIG. Specifically, FIG. 5 is a sectional view showing a cross section taken along a cutting line passing near the power feeding section 40a.

Note that in FIGS. 4 and 5, illustration of the antenna substrate 41 on which the loop antenna 40 is provided is omitted. Further, in FIGS. 4 and 5, members having little relevance to the technical features of the loop antenna 40 and the solar panel 2 are omitted as appropriate. Further, in FIG. 5, members located deeper than the cut end surface are also shown. Specifically, a portion of the button 12 located inside the watch 1 and power supply springs 61 and 62 are shown.

As shown in FIGS. 4 and 5, the solar panel 2 is arranged below the dial 3. As shown in FIG. 4, the solar panel 2 is preferably supported by a panel support plate 21. The panel support plate 21 may be a part of the base plate 51 or may be separate from the base plate 51 and fixed to the base plate 51.

Further, the loop antenna 40 is arranged below the solar panel 2. Specifically, the loop antenna 40 is provided on the lower surface of the solar panel 2. Further, the loop antenna 40 is arranged above the liquid crystal display device 30. Specifically, as shown in FIG. 4, the loop antenna 40 is arranged so that a gap G is formed between it and the liquid crystal display device 30 in the vertical direction. Further, as shown in FIG. 5, a magnetic sheet 70 is provided below the loop antenna 40.

As shown in FIG. 5, the feeding spring 61 has its upper end connected to the first feeding position 40a1 of the loop antenna 40, and its lower end connected to the circuit board 80. Similarly, the feed spring 62 has its upper end connected to the second feed position 40a2 of the loop antenna 40, and its lower end connected to the circuit board 80.

In this embodiment, the power supply springs 61 and 62 are shown as members that electrically connect the power supply unit 40a and the circuit board 80, but the present invention is not limited to this, and power supply wiring, pins, etc. may also be used. I do not care.

Further, as shown in FIG. 4, the liquid crystal display device 30 includes a light guide plate 35 disposed below a laminated structure including a liquid crystal layer constituting the display screen M, an LED 36 as a light source, and a liquid crystal driver circuit section. The FPC 37 is connected to the FPC 32. Note that the shape of the liquid crystal display device 30 and the arrangement of each member shown in FIG. 4 are merely examples, and are not limited thereto.

[Magnetic field generated around the loop antenna]
The magnetic field generated around the loop antenna 40 will be described mainly with reference to FIGS. 3, 6A, and 6B.

In this embodiment, when an external radio wave (magnetic field) passes through the receiving surface, which is the inner region of the annular winding of the loop antenna 40, a current is generated in the winding of the loop antenna 40. Also, as known as Ampere's law, the magnitude of the current is proportional to the magnitude of the magnetic field generated around it, so the larger the current distribution in the loop antenna 40, the more it will affect the sensitivity. Become.

Here, the current distribution in the loop antenna of this embodiment will be explained with reference to FIGS. 6A and 6B. FIG. 6A is a diagram schematically showing the loop antenna of this embodiment. FIG. 6B is a diagram showing the current distribution of the loop antenna of this embodiment. Note that although FIG. 6A shows an example in which the loop antenna 40 is a perfect circle, this is shown schematically for convenience of explanation of the current distribution.

The loop antenna 40 is a so-called one-wavelength loop antenna whose length in the circumferential direction is λ. Therefore, the position on the opposite side of the power feeding part 40a is a position separated by λ/2 from the power feeding part 40a in the circumferential direction. FIG. 6B shows a state in which the loop antenna is expanded at a position λ/2 apart from the power feeding part 40a in the circumferential direction and is represented in a straight line. Note that in FIGS. 6A and 6B, one end of the loop antenna 40 when it is unfolded is indicated by "a", and the other end thereof is indicated by "a'".

As shown in FIG. 6B, in the loop antenna 40, the feeding portion 40a becomes the antinode of the current distribution. Further, a position λ/4 away from the power feeding section 40a becomes a node of the current distribution. Further, a position λ/2 away from the power feeding section 40a becomes the antinode of the current distribution.

That is, in the loop antenna 40, the current distribution takes extreme values at the feeding section 40a and a position λ/2 away from the feeding section 40a (hereinafter referred to as an extreme position 40b). The extreme position 40b is a position where the length from the power feeding section 40a is one half of the circumferential length (λ) of the loop antenna 40. More precisely, the length of the extreme position 40b from either the first feeding position 40a1 or the second feeding position 40a2 is half the circumferential length (λ) of the loop antenna 40. It's the location.

Here, if the magnetic field generated around the loop antenna 40 is influenced by metal, the sensitivity of the loop antenna 40 will decrease. In particular, if the magnetic field generated around the position where the current distribution has an extreme value is influenced by metal, the sensitivity of the loop antenna 40 tends to decrease.

In this embodiment, a configuration is adopted in which the sensitivity (communication performance) of the loop antenna 40 is improved by reducing the influence of metal etc. around the extreme value position 40b. Specifically, in this embodiment, as shown in FIG. 3, the extreme position 40b is set along the opening 2h, which is a non-power generation area of the solar panel 2 that does not contribute to power generation, in plan view. . That is, the extreme value position 40b was set adjacent to the opening 2h in plan view. More specifically, the extreme value position 40b was set to be a position adjacent to the opening 2h on the outside of the opening 2h in the radial direction in plan view. Therefore, at least a portion of the external magnetic field that contributes to the current flowing to the extreme value position 40b occurs in the opening 2h where the magnetic influence is small. As a result, a decrease in the sensitivity of the loop antenna 40 due to the influence of the solar panel 2 can be suppressed.

Note that in this embodiment, the magnetic field generated around the extreme value position 40b is influenced by the liquid crystal display device 30. This is because the liquid crystal display device 30 includes a metal electrode layer, as described above. However, the magnetic influence of the liquid crystal display device 30 is smaller than that of the solar panel 2. This is because the thickness of the pair of electrode layers included in the liquid crystal display device 30 is thinner than the thickness of the pair of electrode layers included in the solar panel 2. Note that the thickness of the pair of electrode layers is the total thickness of the upper electrode layer and the lower electrode layer.

Further, the liquid crystal display device 30 does not include an electrode layer over the entire surface in plan view. That is, in the liquid crystal display device 30, the edge 31 around the display screen M does not contain metal. Therefore, at least a portion of the magnetic field generated around the extreme value position 40b will occur in the edge 31 where the magnetic influence is small. This suppresses the sensitivity of the loop antenna 40 from decreasing.

Furthermore, as shown in FIG. 4, in this embodiment, the loop antenna 40 is arranged to form a gap G between it and the liquid crystal display device 30 in the vertical direction (thickness direction of the watch 1). . Therefore, at least a portion of the magnetic field generated around the extreme value position 40b will occur in this gap G. This suppresses the sensitivity of the loop antenna 40 from decreasing.

[Details of the planar shape of the loop antenna]
Furthermore, the details of the planar shape of the loop antenna 40 of this embodiment will be explained mainly with reference to FIG.

As shown in FIG. 3, in this embodiment, the display screen M is arranged at a position on the 6 o'clock side of the pointer shaft 19, and is a substantially rectangular shape whose longitudinal direction is the direction connecting the 3 o'clock side and the 9 o'clock side. be. Further, as shown in FIG. 3, the right corner MR of the display screen M is located near the 5 o'clock position, and the left corner ML of the display screen M is located near the 7 o'clock position.

The loop antenna 40 is annular and includes a bent portion 42R that is bent to match the shape of the right corner MR of the display screen M, a bent portion 42L that is bent to match the shape of the left corner ML of the display screen M, and a display. The shape includes a straight line portion 43 along the lower side of the screen M.

The bent portions 42L and 42R of the loop antenna 40 are provided so as not to overlap the display screen M of the liquid crystal display device 30 and to overlap the edge portion 31 of the liquid crystal display device 30 and the liquid crystal driver circuit portion 32 in plan view. There is. Similarly, the linear portion 43 of the loop antenna 40 is provided so as not to overlap the display screen M of the liquid crystal display device 30 and to overlap the edge portion 31 of the liquid crystal display device 30 and the liquid crystal driver circuit portion 32 in plan view. ing.

Since the loop antenna 40 has a shape including the bent portions 42L, 42R and the straight portion 43, it is possible to increase the area of the display screen M of the liquid crystal display device 30. Therefore, the visibility of the digital display on the display screen M can be improved.

Further, since the loop antenna 40 has a shape including the bent portions 42L, 42R and the straight portion 43, the extreme value position 40b can be set closer to the opening 2h. Therefore, the magnetic field generated around the extreme position 40b is less affected by the solar panel 2, and the sensitivity of the loop antenna 40 can be further improved.

Further, in this embodiment, as shown in FIG. 3, the above-mentioned extreme position 40b is located in the straight line portion 43. That is, the extreme position 40b is located at a location other than the bent portions 42L and 42R, which are located close to the metal body 10. Therefore, the loop antenna 40 is configured to be less affected by the metal body 10 than when the extreme position 40b is located at the bent portions 42L, 42R. Furthermore, compared to the case where the extreme value position 40b is located at the bending portions 42L and 42R, the current flowing to the extreme value position 40b is stabilized, and a decrease in the sensitivity of the loop antenna 40 is suppressed.

Further, in this embodiment, as shown in FIG. 3, the loop antenna 40 is provided inside the main plate 51 of the movement 50 at a position spaced apart from the outer edge of the main plate 51 in the radial direction in plan view. There is. Therefore, the loop antenna 40 is placed at a sufficient distance from the metal body 10 (not shown in FIG. 3). Therefore, the sensitivity of the loop antenna 40 is not easily affected by the body 10.

Further, in this embodiment, as shown in FIG. 3, at least a portion of the display screen M is arranged between the pointer shaft 19 and the extreme value position 40b in plan view. That is, at least a portion of the opening 2h of the solar panel 2 is arranged between the center position of the loop antenna 40 and the extreme position 40b in plan view.

Moreover, the loop antenna 40 is arranged between the opening 2h and the outer edge of the solar panel 2 in plan view. That is, the diameter of the solar panel 2 is larger than the diameter of the loop antenna 40. With such a configuration, the amount of power generation in the solar panel 2 can be maintained while ensuring the diameter of the loop antenna 40.

[summary]
In the present embodiment described above, since the extreme value position 40b is located at a position along the opening 2h of the solar panel 2 that does not contribute to power generation in plan view, the loop by the solar panel 2 is The influence on the sensitivity of the antenna 40 can be suppressed. Furthermore, since there is no need to form an opening in the solar panel 2 that matches the shape of the loop antenna 40, it is possible to increase the diameter of the loop antenna 40 and maintain the amount of power generation compared to the configuration of Patent Document 1. can. Furthermore, since the diameter of the solar panel 2 is made larger than the diameter of the loop antenna 40, the area of the power generation area of the solar panel 2 can be secured compared to the configuration of Patent Document 2, and the amount of power generation can be improved. can be maintained.

[Modified example]
Next, with reference to FIG. 7, a solar panel 102 according to a modification of this embodiment will be described. FIG. 7 is a plan view showing a solar panel in a modified example. In FIG. 7, the loop antenna 140 arranged below the solar panel 2 is schematically shown with a broken line. Note that the modified example is the same as the present embodiment described with reference to FIGS. 1 to 6, except that the non-power generation area of the solar panel 2 and the arrangement of the loop antenna are different. Therefore, description of similar configurations will be omitted.

The solar panel 102 has a small window portion 102h that is a non-power generation area that does not contribute to power generation. The small window portion 102h may be, for example, a through hole.

Although not shown, a date board (display board) on which numbers indicating the date are displayed is arranged below the solar panel 102. The date board display is visible from the outside through the small window 102h. Further, although not shown in the drawings, in a modified example, it is preferable that a small window portion is also provided on the dial plate so as to overlap with the small window portion 102h in a plan view. Note that a display board or the like on which characters indicating the day of the week are displayed may be provided instead of the date board.

The loop antenna 140 has the same current distribution as the loop antenna 40 described in this embodiment. That is, the power feeding position 140a and a position λ/2 away from the power feeding position 140a (extreme value position 140b shown in FIG. 7) are the extreme values of the current distribution.

As shown in FIG. 7, in the modified example, the power feeding position 140a is placed at the 9 o'clock position, and the extreme value position 140b is placed at the 3 o'clock position. Further, the small window portion 102h is placed at the 3 o'clock position. That is, the extreme position 140b is located in a portion of the loop antenna 140 along the small window portion 102h. Therefore, at least a portion of the magnetic field generated around the extreme value position 140b will be generated in the small window portion 102h. By employing such a configuration, the magnetic influence of the solar panel 102 can be suppressed and the sensitivity of the loop antenna 140 can be improved.

Note that the modified example shows a solar panel 102 in a watch that does not have the liquid crystal display device 30 described in this embodiment. That is, the solar panel 102 does not have the opening 2h shown in FIG. 2. However, the present invention is not limited to this, and may include an opening 2h shown in FIG. 2 in addition to the small window 102h.

[others]
In the present embodiment, the extreme value position 40b is a position along the opening 2h, which is a non-power generation area of the solar panel 2 that does not contribute to power generation in plan view, but the extreme value position 40b is not limited to this. The power feeding part 40a (power feeding position 40a1 or power feeding position 40a2) located at the position may be located along the opening 2h, which is a non-power generation area of the solar panel 2 that does not contribute to power generation, in plan view.

In addition, in this embodiment, although the liquid crystal display device 30 was mentioned as an example and demonstrated as a display device, it is not restricted to this. For example, an organic EL (Electro Luminescence) display or the like may be used as the display device. Further, although the solar panel watch 1 has been described using a wristwatch as an example, the present invention is not limited to this, and may be a pocket watch or the like.

1 Clock with solar panel, 2,102 Solar panel, 2h, 102h opening, 21 Panel support plate, 3 Dial plate, 3h opening, 10 Body, 11 Band fixing part, 12 Button, 13 Crown, 15 Hour hand, 16 Minute hand , 17 second hand, 18 hour mark, 19 pointer shaft, 30 liquid crystal display device, 31 edge, 32 liquid crystal driver circuit section, 35 light guide plate, 36 LED, 37 FPC, 40,140 loop antenna, 40a, 140a power supply section, 40a1 1st power supply position, 40a2 2nd power supply position, 40b, 140b extreme position, 41 antenna board, 42L, 42R bent part, 43 straight part, 50 movement, 51 main plate, 61, 62 power supply spring, 80 circuit board, M display screen.

Claims (13)

The dial and
a solar panel that generates electricity when light transmitted through the dial is incident;
loop antenna and
has
The extreme value position of the loop antenna, which is the extreme value of the current distribution, is located at a position along a non-power generation area of the solar panel that does not contribute to power generation, in plan view.
A clock with a solar panel. The loop antenna includes a first feeding position on one end side and a second feeding position on the other end side,
The extreme position is a position where the length from the first feeding position or the second feeding position is one half of the circumferential length of the loop antenna,
The solar panel watch according to claim 1. At least a part of the non-power generation region is arranged between a center position of the loop antenna and the extreme position in plan view.
The solar panel watch according to claim 1 or 2. The loop antenna is arranged between the non-power generation area and the outer edge of the solar panel in plan view.
The solar panel watch according to any one of claims 1 to 3. The extreme value position is located at a position adjacent to the non-power generation area on the outer side of the non-power generation area in the radial direction.
The solar panel watch according to any one of claims 1 to 4. The extreme value position is located at a position where at least a part of the magnetic field generated around the extreme value position is generated in the non-power generation area.
A solar panel watch according to any one of claims 1 to 5. further comprising a display device comprising a display screen;
The dial is formed with a first opening that allows the display screen to be viewed from the outside,
The non-power generation area is a second opening that overlaps the first opening in plan view and allows the display screen to be viewed from the outside.
The solar panel watch according to any one of claims 1 to 6. The loop antenna is arranged to form a gap with the display device in the vertical direction,
The extreme value position is at a position where at least a part of the magnetic field generated around the extreme value position is generated in the gap,
The solar panel watch according to claim 7. The display device is a liquid crystal display device including at least a liquid crystal layer and a pair of electrode layers sandwiching the liquid crystal layer,
The solar panel includes at least a semiconductor layer and a pair of electrode layers sandwiching the semiconductor layer,
The thickness of the pair of electrode layers sandwiching the liquid crystal layer is thinner than the thickness of the pair of electrode layers sandwiching the semiconductor layer.
The solar panel watch according to claim 7 or 8. The display device includes a non-metallic edge surrounding the display screen in plan view,
At least a portion of the loop antenna is provided so as to overlap the edge in plan view;
The solar panel watch according to any one of claims 7 to 9. The loop antenna includes a bent portion that is bent to match the outer shape of the display screen.
The solar panel watch according to any one of claims 7 to 10. The extreme position is located in a portion of the loop antenna other than the bent portion,
The solar panel watch according to claim 11. The dial has a small window,
A non-metallic display board is provided with a display that is visible through the small window,
The non-power generation area is provided so as to overlap the small window section in a plan view.
A solar panel watch according to any one of claims 1 to 6.

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