Electronic clock

Abstract

Even when the dial is made of metal, this design minimizes the decrease in the power generation efficiency of the solar panel and reduces the impact of the metal material on the surrounding environment. [Solution] The clock 100 comprises a metal plate-shaped member (dial 2) having a through hole 22 that penetrates from one side to the other side, and a solar panel 12 positioned below the plate-shaped member (dial 2), wherein the opening area of ​​the opening on one side (opening area of ​​one-side opening 221) and the opening area of ​​the opening on the other side (opening area of ​​other-side opening 222) are different.

Description

Technical Field

[0001] The present invention relates to an electronic clock.

Background Art

[0002] Patent Document 1 describes a clock that generates electricity by forming through holes in a metal dial plate (clock dial plate in Patent Document 1) disposed above a solar panel (solar cell in Patent Document 1) and receiving external light incident through the through holes with the solar panel.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the configuration described in Patent Document 1, when external light is incident obliquely with respect to the through holes, there is a problem that the external light is blocked by the inner surface of the through holes, resulting in a decrease in power generation efficiency.

[0005] The present invention is for improving and solving the problems in such a situation, and provides an electronic clock that can suppress a decrease in the power generation efficiency of a solar panel even when the dial plate is formed of metal, and can also reduce the influence on the surrounding metal material.

Means for Solving the Problems

[0006] To solve the above problems, an electronic clock according to the present invention includes a metal plate-like member having a through hole penetrating from one surface side to the other surface side, and a solar panel disposed below the plate-like member. The through hole is characterized in that the opening area of the opening on one surface side and the opening area of the opening on the other surface side are different.

Effects of the Invention

[0007] According to the present invention, even when the dial is made of metal, the decrease in the power generation efficiency of the solar panel can be suppressed, and the impact of the metal material on the surroundings can also be reduced. [Brief explanation of the drawing]

[0008] [Figure 1] This is a front view of the clock according to the embodiment. [Figure 2] Figure 1 is a perspective view of the dial of the clock shown. [Figure 3] This is an enlarged view of section III, enclosed by the dashed line in Figure 1. [Figure 4] This is a perspective view showing an example of a dial with a straight opening. [Figure 5] This is an enlarged view of the V-shaped area enclosed by the dashed line in Figure 4. [Figure 6] Figure 2 is a magnified perspective view of a portion of the dial shown. [Figure 7] This is an enlarged cross-sectional view of the main part of the through-hole portion of the dial along the line VII-VII in Figure 6. [Figure 8] This is an enlarged cross-sectional view of the main part of the through-hole portion of the dial in one modified example. [Figure 9] This is a magnified perspective view showing a portion of the dial in one modified example. [Figure 10] This is an enlarged cross-sectional view of the main part of the through-hole portion of the dial along line XX in Figure 9. [Figure 11] Figure 9 is an enlarged cross-sectional view of a key part of a modified example of the through-hole portion. [Figure 12] This is an explanatory diagram illustrating an example of a case where the dial has areas with different through-hole opening configurations. [Figure 13] This is a plan view showing an example of a solar panel. [Figure 14] This is a magnified view of a key part showing one modified example of the shape of the through-hole provided in the dial. [Figure 15] This is a schematic diagram showing one modified example of the shape of a through-hole in the dial. [Figure 16] This is an enlarged cross-sectional view of the main part of the through-hole portion of the dial in one modified example. [Figure 17] This is a plan view showing a dial in one modified example. [Modes for carrying out the invention]

[0009] An embodiment of the electronic clock according to the present invention will be described with reference to the drawings. In this embodiment, it is assumed that the electronic clock is a wristwatch (hereinafter simply referred to as "clock 100") worn on the wrist. Note that in Figure 1 and other figures, the band for wearing the clock on the wrist and the internal structure of the clock are omitted. As will be described later, the clock 100 according to this embodiment comprises at least a plate-shaped member and a solar panel 12 (see Figure 13) arranged below the plate-shaped member. In this embodiment, the plate-shaped member is a dial 2 arranged on the viewing side (surface side) of the clock 100. Note that the embodiments described below are subject to various technically preferred limitations for carrying out the present invention, but the scope of the present invention is not limited to the following embodiments and illustrated examples.

[0010] As shown in FIG. 1, the clock 100 includes a main body case 1 that opens at least on the visible side (front side) of the clock 100 and has a hollow accommodation space inside. The main body case 1 is formed of a metal material such as various resins or stainless steel (SUS). In the illustrated example, the main body case 1 and the clock 100 including the same are illustrated as being substantially circular in plan view, but the shape of the clock 100 is not limited thereto, and may be, for example, rectangular or elliptical in plan view. A module (not shown) is disposed in the accommodation space inside the main body case 1. The module includes, for example, a substrate (not shown) and various electronic components, and is a functional unit that operates the clock 100. An antenna 11 is disposed on the substrate included in the module. The antenna 11 receives, for example, a standard radio wave including time information. The arrangement of the antenna 11 is not particularly limited. For example, in FIG. 12, a case where the antenna 11 is disposed at the 12 o'clock side position in an analog clock is illustrated. The clock 100 performs time correction or the like based on the standard radio wave received by the antenna 11. In FIG. 12, the antenna 11 disposed below the dial 2 is virtually shown by a two-dot chain line. Further, a solar panel 12 is provided on the module, and a dial 2, which is a plate-like member, is disposed thereon.

[0011] The solar panel 12 is a solar cell that generates electricity by receiving light, and the generated electric power obtained by the photovoltaic power generation by the solar panel 12 is stored in a secondary battery (not shown). The solar panel 12 in the embodiment is composed of a plurality (eight in the illustrated example) of divided cells 12a, as shown in FIG. 13, for example, and a dividing line 122 is provided between the divided cells 12a. At least a part of the dividing line preferably passes through the approximate center of the main body case 1 and is provided so as to be orthogonal to each other. By configuring the solar panel 12 by connecting a plurality of divided cells 12a in series, it is possible to obtain a higher voltage than in the case of configuring the solar panel with a single cell. The number of divided cells 12a constituting the solar panel 12 and the shape of the divided cells 12a into which the solar panel 12 is divided are not limited to the illustrated example and are matters that can be set as appropriate.

[0012] When the clock 100 is viewed from the viewing side (front side), a substantially annular cut-off member 13 is provided along the opening of the main body case 1 at the opening portion of the main body case 1. The cut-off member 13 is arranged along the outer peripheral edge of the dial 2 from above the dial 2. As shown in FIG. 1, hour markers 15 serving as indicators for time display are provided along the circumferential direction on the cut-off member 13 and the dial 2 arranged inside the cut-off member 13. The hour markers 15 may be provided three-dimensionally or may be provided flatly by printing or the like, for example. Note that the arrangement, shape, etc. of the hour markers 15 are not limited to the illustrated example. For example, the hour markers 15 may be provided only on the dial 2 or only on the cut-off member 13. Further, at approximately the 3 o'clock position of the clock 100, a date window 16 capable of selectively exposing a date provided on a date wheel (not shown) is provided. Note that it is not essential for the clock 100 to have the date window 16. Further, the arrangement, shape, configuration, etc. of the date window 16 are not limited to the illustrated example.

[0013] At a substantially central portion of the clock 100, a pointer shaft 31 projects from a module inside the main body case 1, and a pointer 3 is rotatably attached to the pointer shaft 31 about the pointer shaft 31. As shown in FIG. 1, the clock 100 of the embodiment includes two pointers 3 (for example, an hour hand and a minute hand). Insertion holes (the insertion hole 21 of the dial; see FIGS. 2 and 12, the insertion hole 121 of the solar panel; see FIG. 13) for inserting the pointer shaft 31 are formed at substantially corresponding central portions of the dial 2 and the solar panel 12, respectively. Note that the number, shape, etc. of the pointers 3 are not limited to the illustrated example.

[0014] Here, the detailed configuration of the dial 2 will be described with reference to Figures 2, 3, etc. The dial 2, which is a plate-shaped member in this embodiment, is a metal dial made of a metal material such as stainless steel (SUS). In this embodiment, the dial 2 has through holes 22 that penetrate from one side to the other. In the example shown in Figures 1 and 2, the through holes 22 are arranged in a staggered pattern across the entire surface of the dial 2. The number and arrangement of the through holes 22 are not particularly limited. However, since the dial 2 is provided on the surface side of the clock 100, from the viewpoint of appearance, it is preferable that at least the portion that is visible on the exterior of the clock be provided in a shape and size that is as uniform as possible overall.

[0015] In this embodiment, one side of the dial 2 is, for example, the viewing side (front side) of the dial 2, and the other side is the back side of the dial 2. In the embodiment, the dial 2 has, at least some of the through holes 22, an opening area on one side (one-side opening 221 in Figure 6, etc.) and an opening area on the other side (other-side opening 222 in Figure 6, etc.) that are different. For example, the through hole 22 is formed in a shape that widens from one-side opening 221 to the other-side opening 222. Specifically, it is preferable that the cross-section be formed in a substantially tapered shape so that it gradually widens from one-side opening 221 to the other-side opening 222.

[0016] The method for forming the dial 2 having such through holes 22 is not particularly limited. For example, Figures 6 and 7 illustrate a dial 2 formed by joining multiple thin metal sheets 2a to 2e, each having a different opening area for the through holes 22. When forming the dial 2 using this method, first, the thin metal sheets 2a to 2e are hollowed out in the portions that will become the through holes 22 when assembled as the dial 2, so that the opening area gradually increases from 2a to 2e. The method for hollowing out the thin metal sheets 2a to 2e is not particularly limited, but can be, for example, by etching. Then, the thin metal sheets 2a to 2e are stacked so that the hollowed-out portions of the thin metal sheets 2a to 2e correspond to each other, and joined together into a single plate by a method such as diffusion bonding. This forms a dial 2 composed of five thin metal sheets 2a to 2e.

[0017] For example, by diffusion bonding five thin metal sheets (metal sheets 2a to 2e) with a thickness of 0.1 mm, a dial 2 with a total thickness of 0.5 mm can be formed. The number of metal sheets used to form one dial 2 is not particularly limited; it may be fewer or more than five sheets. When forming the dial 2 with a single sheet, for example, through holes 22 can be formed by cutting, but it is easier to process and reduce manufacturing costs to stack metal sheets with different opening areas in the cut-out portions to form a dial 2 with different opening areas on one side and the other side of the through hole 22, rather than forming through holes 22 with different opening areas on one side and the other side by cutting, etc. Note that when the dial 2 is composed of multiple metal sheets 2a to 2e, the method of joining the multiple metal sheets 2a to 2e is not limited to diffusion bonding. For example, the multiple metal sheets 2a to 2e may be joined by adhesive to form the dial 2.

[0018] As shown in Figures 6 and 7, in this embodiment, among the metal sheets 2a to 2e that constitute the dial 2, the metal sheet 2a arranged on one side is designated as the first layer, and the metal sheet 2e arranged on the other side is designated as the fifth layer. The metal sheets 2a to 2e of each layer are formed such that the through-holes 22 gradually increase in size from the first layer to the fifth layer on the front side of the dial 2. This reduces the influence of the edges on the back side of the dial 2 when the dial 2 is tilted with respect to ambient light (incident light), and the degree of shielding of the opening by the inner surface 20 of the through-holes 22 (see Figure 3). In the dial 2 formed in this way, when a cross-section is taken at the portion of the through-holes 22, as shown in Figure 7, the cross-sectional shape is stepped, gradually widening from one side to the other, and is generally tapered overall.

[0019] When a through-hole is provided in the dial that penetrates from one side to the other, if the inner surface of the through-hole is straight and not angled, then, as shown in Figures 4 and 5, when the dial 9 is tilted relative to ambient light (incident light), the inner surface of the through-hole 92 (inner surface 90 in Figures 4 and 5) partially blocks the opening. In this case, light incident from an oblique angle is blocked by the inner surface 90 and does not pass sufficiently to the other side. Therefore, if a solar panel is installed below the dial 9, the amount of light that the solar panel can receive is reduced. In contrast, when the through-hole 22 is formed in a shape that gradually widens from one side to the other side, as in the embodiment, the inner surface of the through-hole 22 (inner surface 20 in Figures 3, 6, and 7) does not obstruct the incident light even when light is incident from an oblique angle. Therefore, sufficient light can pass through to the bottom of the dial 2, and even when a solar panel 12 is placed below the dial 2, a sufficient amount of light received for power generation can be secured. Furthermore, if the opening area of ​​the other side opening 222 is made larger than the opening area of ​​the one side opening 221, more material is removed on the other side to enlarge the opening area of ​​the through hole 22. This reduces the volume of the metal part of the dial 2 compared to the case where the inner surface 90 of the through hole 92 has a straight shape as shown in Figures 4 and 5. For this reason, for example, when the antenna 11 is placed below (on the back side of) the dial 2 as shown in Figure 12, it is expected that the reduction in the radio wave reception sensitivity of the antenna 11 due to the influence of the metal dial 2 will be suppressed.

[0020] Note that the dial 2 is not limited to being composed of multiple thin metal plates. For example, when forming a dial 2 with a thickness of 0.5 mm, the dial 2 may be formed from a single plate with a thickness of 0.5 mm. In this case as well, as shown in Figure 8, when a cross-section is taken at the portion of the through-hole 22, the cross-sectional shape gradually widens from one side to the other side, and the through-hole 22 is formed such that the inner surface 20 is generally tapered. When forming the dial 2 from a single plate, the through-hole 22 is formed, for example, by cutting. In this case as well, the inner surface 20 of the through-hole 22 does not obstruct light from entering the through-hole 22 from an oblique direction, and sufficient light can pass through to the bottom of the dial 2 (the "other side" in the embodiment).

[0021] Furthermore, in the embodiment, the dial 2 only needs to have different opening areas for one side opening 221 and the other side opening 222, and is not necessarily limited to having opening areas that gradually change from one side to the other. In order to avoid reducing the radio wave reception sensitivity of the antenna 11, it is preferable to remove as much material as possible from the dial 2. Therefore, when the dial 2 is composed of multiple plate members, for example, as shown in Figures 9 and 10, the opening (one side opening 221) of the through hole 22 formed in the first layer (metal sheet 2f in Figure 10) that is located on the side that is visible (surface side) related to the appearance of the clock 100 may be made relatively small, while the opening areas (other side openings 222) of the openings in the second layer and subsequent layers (metal sheets 2g to 2j in Figure 10) may be uniformly made larger. Furthermore, it is not necessary to divide the layers in parts where the opening area of ​​the opening is the same, and as shown in Figure 11, the dial 2 may be composed of two layers (metal sheets 2k and 2l in Figure 11).

[0022] Furthermore, it is preferable that the opening of the through-hole 22 located near where the antenna 12 is positioned in the plate-shaped dial 2 has a larger opening area than the openings of the through-hole 22 located in other parts. That is, in the region where the antenna 11 is positioned below the dial 2 (first region Ar1 in Figure 12), the opening area of ​​the through-hole 22 may be made larger than that of the through-hole 22 in other regions, and the amount of material removed may be increased to reduce the amount of metal around the antenna 11. The more materials with high relative permeability, such as metal, are placed near the antenna 11, the more likely eddy currents are to be generated, which can lead to a loss of electrical energy (eddy current loss) and a decrease in the radio wave reception sensitivity of the antenna 11. In this respect, it is expected that the reduction in the radio wave reception sensitivity of the antenna 11 can be suppressed by reducing the amount of metal around the antenna 11. In this case, in order to maintain the appearance, it is preferable to make the opening area of ​​the one-sided opening 221 located on the viewing side the same as the other parts, and to make only the opening area of ​​the other-sided opening 222 larger.

[0023] Furthermore, the dial 2 tends to bend easily in the central part in the in-plane direction. In particular, when through holes 22 are formed throughout the entire dial 2, as in the embodiment, the strength may decrease and it may become more prone to bending. For this reason, when multiple through holes 22 are formed, it is preferable that the opening area of ​​the through holes 22 located on any of the lines perpendicular to the approximately central part of the dial 2 in the in-plane direction (around the insertion hole 21 through which the pointer shaft 31 is inserted) is smaller than the opening area of ​​the through holes 22 located in other parts. For example, Figures 12 and 13 show an example in which a roughly cross-shaped region formed by the approximately central part of the dial 2 in the in-plane direction and the line connecting 12 o'clock to 6 o'clock and the line connecting 3 o'clock to 9 o'clock passing through it is designated as a second region Ar2 in which the opening area of ​​the through holes 22 is reduced.

[0024] In this case as well, in order to maintain the aesthetic appearance, it is preferable to make the opening area of ​​the one-sided opening 221 located on the viewing side the same as the other parts, and to make the opening area of ​​the other-sided opening 222 smaller than that of the other areas. "Making the opening area of ​​the other-sided opening 222 smaller" includes the case where the opening area of ​​the other-sided opening 222 is the same as the opening area of ​​the one-sided opening 221 (i.e., the inner surface 20 is not sloped and is a straight shape). By making the opening area of ​​the through-holes 22 in the roughly cross-shaped region (second region Ar2) including the area around the central part of the easily flexible dial 2 smaller, the second region Ar2 can support the entire dial 2 like a skeleton, and the strength of the dial 2 can be maintained even when multiple through-holes 22 are provided. However, in this case, light that enters obliquely from one side of the through-hole 22 in the second region Ar2 will have difficulty passing to the other side. Therefore, it is preferable to arrange the solar panel 12 so that its dividing line 122 overlaps the second region Ar2. The part of the dividing line 122 is a region that is not used for power generation. Therefore, by ensuring that the second region Ar2 overlaps with the dividing line 122 of the solar panel 12, the impact on the effective power generation area used for power generation can be minimized, thereby reducing power generation losses in the solar panel 12.

[0025] In addition, the through-hole 22 provided on the outer periphery of the dial 2 may also be configured to increase the strength of the outer periphery of the dial 2 by reducing the opening area, and the overall strength of the dial 2 may be maintained by the outer periphery region and the second region Ar2. Since the trim member 13 and bezel (not shown) are arranged on the outer periphery of the dial 2 from above, it is difficult for light to enter, and even if the opening area of ​​the through-hole 22 is increased, not much light can be expected to enter. For this reason, for example, the opening areas of one side opening 221 and the other side opening 222 may be the same, and the inner surface 20 of the through-hole 22 may not be sloped, resulting in a straight shape. Note that the shapes of one side opening 221 and the other side opening 222 do not have to be the same. For example, even if not much light can be expected to enter the outer periphery of the dial 2 from the outer periphery side where the trim member 13 is provided, it is conceivable that light may enter from the opposite side (the central part of the dial 2). For this reason, the cross-section of the through-hole 22 portion of the dial 2 in the radial direction may be asymmetrical, for example, by making the inner surface of the other opening 222 of the through-hole 22 on the central part side of the dial 2 straight, and the inner surface on the outer edge side of the dial inclined so as to widen toward the lower side of the trim member 13.

[0026] Next, the operation of the clock 100 in this embodiment will be described. In the clock 100 of this embodiment, various modules are arranged inside the main body case 1, and a solar panel 12 is placed on top of them. If the clock 100 includes an antenna 11, the antenna 11 is included in the module. Furthermore, a metal dial 2, which is a plate-shaped member, is superimposed on top of the solar panel 12. In this case, if the clock 100 is equipped with an antenna, a first region Ar1 with a relatively large opening area of ​​the through-hole 22 is provided in a part of the dial 2, and the first region Ar1 is positioned on top of the antenna 11 (see Figure 12).

[0027] In this embodiment, as described above, the solar panel 12 is provided such that, for example, at least a portion of the dividing line 122 passes through the approximate center of the main case 1 and is perpendicular to each other. In this embodiment, as shown in Figure 13, in the approximate center of the dial 2 in the in-plane direction and the approximately cross-shaped region (second region Ar2 shown by a dashed line in Figure 13) formed by the line connecting 12 o'clock to 6 o'clock and the line connecting 3 o'clock to 9 o'clock passing through it, the opening area of ​​the through hole 22 is reduced to maintain the strength of the dial 2. For this reason, as shown in Figure 13, it is preferable that the solar panel 12 is arranged so that the dividing line 122 overlaps the second region Ar2 of the dial 2.

[0028] Furthermore, if there is a difference in the output current value between each divided cell 12a, the output current value of the solar panel 12 will decrease to match the divided cell 12a with the smallest output current value. For this reason, in order to increase power generation efficiency, it is preferable to configure the solar panel 12 so that the area of ​​the effective power generation region of each divided cell 12a is as equal as possible. As shown in Figure 13, the dividing line 122, which is positioned to overlap with the second region Ar2, is narrower than the second region Ar2, and the amount of incident light decreases in the area outside the dividing line 122 within the overlapping portion with the second region Ar2. However, in the example shown in Figure 13, since the effective power generation region of each divided cell 12a overlaps with the second region Ar2 to an almost equal extent, there is no significant difference in the amount of light received between each divided cell 12a. On the other hand, at the 12 o'clock position on the clock, a first region Ar1 is provided, in which the opening area of ​​the through hole 22 is larger than in other parts. Therefore, the light-receiving amount will be higher for the divided cell 12a on the 12 o'clock side, which overlaps with this area, but the output current value of these divided cells 12a will be the same as that of the other divided cells 12a. However, depending on the arrangement of the second region Ar2, it is possible that some divided cells 12a may have a significantly lower light-receiving amount than the other divided cells 12a due to overlapping with the second region Ar2. In such cases, it is preferable to adjust the cell division position and the size of each cell, such as making the size of the divided cell 12a with the lower light-receiving amount (area of ​​the effective power generation region) larger than that of the other divided cells 12a, so that the light-receiving amount of each divided cell 12a is approximately the same.

[0029] Once the dial 2 is positioned as shown in the embodiment, the trim member 13 is placed on top of the dial 2, and then a crystal member (cover member) (not shown) is attached to close the viewing-side opening of the main case 1. This completes the watch 100.

[0030] The direction of light incidence on the clock 100 is random, with light incident from the front of the clock 100 perpendicular to the dial 2 and light incident from an oblique direction to the dial 2. In the embodiment, as shown in Figure 1, through holes 22 are formed over almost the entire surface of the dial 2, and are configured to allow light to enter the solar panel 12 located below the dial 2. In particular, the through holes 22 in the embodiment have different opening areas for the opening on one side of the clock 100 that is the viewing side (one-side opening 221) and the opening on the other side (other-side opening 222), and the cross-sectional shape of the inner surface 20 is a substantially tapered inclined surface that widens from one side to the other. As a result, not only when light is incident from the front on one side, but also when light is incident at an oblique angle, the light passes through to the other side without being blocked by the edge portion of the through hole 22 or the inner surface 20. Therefore, a sufficient amount of light can be received by the solar panel 12 located below the dial 2, making it possible to generate power more stably.

[0031] Furthermore, in the first region Ar1 of the dial 2, which is located near the antenna, the opening area of ​​the through-hole 22 is larger than in other parts, making the antenna 11 less susceptible to the influence of the metal dial 2. Therefore, even if the dial 2 is made of a metal material, the impact on the radio wave reception sensitivity of the antenna 11 is suppressed, and good radio wave reception sensitivity can be maintained. In this way, the clock 100 of this embodiment can obtain sufficient power to operate each part from the solar panel 12. In addition, it is possible to appropriately control the time display and other functions using standard radio waves received by the antenna 11.

[0032] As described above, in this embodiment, the clock 100 comprises a dial 2 which is a metal plate-shaped member having a through hole 22 that penetrates from one side to the other side, and a solar panel 12 positioned below the dial 2, wherein the opening area of ​​the through hole 22 on one side (the opening area of ​​the one-side opening 221) and the opening area on the other side (the opening area of ​​the other-side opening 222) are different.

[0033] If the opening on one side and the opening on the other side are connected by a straight inner surface, light incident from the front on one side of the through-hole can pass through to the other side without being obstructed. However, light incident from an oblique direction is blocked by the inner surface of the through-hole and has difficulty passing through (reaching) to the other side. In this respect, in the dial 2 provided in the clock 100 of this embodiment, the opening on one side 221 and the opening on the other side 222 are not connected by a straight inner surface. Instead, they have a shape that widens from the opening on one side (opening on one side 221) to the opening on the other side (opening on the other side 222). More specifically, when the cross-section of the through-hole 22 is taken, the inner surface 20 is tapered, widening from the opening on one side 221 to the opening on the other side 222. As a result, not only light incident from the front of the through-hole 22, but also light incident from an oblique direction can pass through to the other side and reach the solar panel 12 located below the dial 2. This allows the solar panel 12 to receive a larger amount of light, improving power generation efficiency and ensuring that the solar panel 12 can provide sufficient power to operate each part of the clock 100.

[0034] Furthermore, the dial 2, which is a plate-shaped member in the embodiment, is formed by joining together multiple thin metal plates 2a to 2e, each with a different opening area. By constructing the dial 2 from multiple thin metal plates 2a to 2e in this way, the dial 2 can be manufactured more easily and at a lower cost than when a single plate member is processed by cutting or other methods to create through holes 22.

[0035] Furthermore, in this embodiment, one side is the surface side (top side) of the dial 2, which is a plate-shaped member, and multiple through holes 22 are formed therein. At least one side opening (one-side opening 221) of the multiple through holes 22 is formed to be substantially uniform in shape. This makes it possible to make the openings (one-side opening 221) of the through holes small and uniform in shape and size on the viewing side (surface side) of the dial 2, which is related to the appearance design of the watch 100, while making the openings (other-side opening 222) on the back side of the dial 2 larger, or even partially changing the size of the openings, without affecting the appearance design of the watch, and improving the appearance quality. In addition, it is envisioned that various logos, etc., may be placed on the viewing side of the dial 2 in addition to the hour markers 15, and by making the one-side opening 221 small, the variations in the appearance design can also be expanded.

[0036] Furthermore, in this embodiment, the antenna 11 is placed inside the case (main body case 1) on which the plate-shaped member, the dial 2, is placed. Multiple through holes 22 are formed, and it is preferable that the openings of the through holes 22 located near where the antenna 11 is placed on the plate-shaped member, the dial 2, have a larger opening area than the openings of the through holes 22 located in other parts. This reduces the amount of metal placed around the antenna 11, thereby reducing the risk of the antenna 11's radio wave reception sensitivity being reduced by the surrounding metal material, and enabling the maintenance of high reception sensitivity.

[0037] Furthermore, when multiple through holes 22 are formed as in the embodiment, it is preferable that the openings of the through holes 22 located on any of the lines perpendicular to each other, with the central part of the dial 2 in the in-plane direction as the intersection point, have a smaller opening area than the openings of the through holes 22 located in other parts. The dial 2 is particularly prone to bending around the center, and when multiple through holes 22 are provided, the overall strength of the dial 2 may decrease, making it more susceptible to bending. In this regard, by reducing the area of ​​the openings of the through holes 22 located on lines perpendicular to each other with the central part of the dial 2 in the in-plane direction as the intersection point (through holes 22 in the second region Ar2 in Figure 12), the second region Ar2 can, so to speak, act as the skeletal part of the dial 2, supporting the entire dial 2 and improving its strength, thereby preventing the dial 2 from bending or becoming distorted.

[0038] Although embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention. For example, in the above embodiments, the case in which the dial 2, which is a plate-like member, is made only of metal was illustrated, but the plate-like member may include materials other than metal. For example, the viewing side (surface side) of the dial 2, which affects the appearance quality, may be made of a thin metal plate, and plates made of various resins may be bonded to the back side of the dial 2 using an adhesive, or simply overlapped, to form a plate-like member (dial) composed of layers of metal and resin. In this case, when an antenna is placed near the plate-like member, the impact on the radio wave reception sensitivity of the antenna can be reduced compared to when the entire plate-like member is made of metal. In addition, by not making the entire dial 2 out of metal, the weight of the entire dial can be reduced. Furthermore, the dial 2 can be made stronger than when the dial is made of resin alone. In this case, the resin part is easier to process than metal and may be formed in a single layer.

[0039] Furthermore, although the above embodiment illustrates a case where the through-hole 22 is approximately rectangular in plan view (see Figures 1, 2, 6, etc.), the shape of the through-hole 22 is not limited to the illustrated example. For example, as shown in Figure 14, the through-hole 22a may have a honeycomb structure or the like in plan view. By making the through-hole 22a formed in the dial 2 a honeycomb structure or the like, it is expected that the strength of the dial 2 can be improved compared to making it rectangular.

[0040] Furthermore, in the above embodiment, an example was given where the opening 221 on one side of the through hole 22 and the opening 222 on the other side differ only in size and are both rectangular in shape (see Figures 2, 6, 9, etc.), but the shape of the through hole 22 is not limited to the illustrated example. For example, as shown in Figure 15, the opening 221 on one side and the opening 222 on the other side may differ not only in size but also in shape. Figure 15 illustrates a case where the opening 221b on one side of the through hole 22b is substantially rectangular and the opening 222b on the other side is substantially circular. Note that the shapes of the opening 221b on one side and the opening 222b on the other side are not limited to the illustrated example.

[0041] Furthermore, in the above embodiment, an example was given in which multiple through holes 22 having substantially the same shape for at least one opening 221 are provided throughout the dial 2. However, the shape of the one opening 221 of the through holes 22 may differ depending on the location, as well as the other opening 222 that opens to the back side of the dial 2. For example, in the first region Ar1 located near the antenna 11, through holes 22 with larger one opening 221 and other opening 222 than in other parts may be provided. Also, for example, in the second region Ar2 which functions as a reinforced part of the dial 2, through holes 22 with smaller one opening 221 and other opening 222 than in other parts may be provided. Furthermore, through holes 22 may not be provided in the second region Ar2 or in the outer periphery of the dial 2 that is hidden by a bezel or trim member 13 (not shown). In areas where through holes 22 are not provided, a shape similar to that of through holes 22 may be added by printing or the like to minimize any visual incongruity.

[0042] Furthermore, in the above embodiment, the example given is that one side of the through-hole 22 is the viewing side (front side) of the dial 2, and the through-hole 22 expands from the viewing side (front side) of the dial 2 toward the back side. However, the through-hole 22 only needs to have different opening areas on one side and the other side. For example, the other side of the through-hole 22 may be the viewing side (front side) of the dial 2, and the through-hole 22 may expand from the back side of the dial 2 toward the viewing side (front side). For example, Figure 16 illustrates a case where the opening area of ​​the opening 221c on the viewing side (front side) of the dial 2 in the through-hole 22c is larger than the opening area of ​​the opening 222c on the back side, and the through-hole has a tapered shape that narrows from the viewing side (front side) toward the back side. Figure 16 shows a case where the dial 2 is formed by joining together multiple thin metal plates with different opening areas (from the viewing side (front side) of the dial 2 to the back side, in order: thin metal plates 2m, 2n, 2o, 2p, 2q). However, the method of forming the dial 2 is not limited to this. For example, the dial 2 may be formed from a single plate (for example, a single plate as shown in Figure 8, in which the shape of the inner surface 20 of the through hole 22 is tapered, widening from the back side to the viewing side).

[0043] Furthermore, in the above embodiment, the clock 100 is equipped with multiple hands 3 attached to a pointer shaft 31 located approximately in the center of a dial 2, which is a plate-shaped member, and displays the time in an analog manner. However, the configuration of the clock is not limited to this. The dial 2 (decorative plate) below the hands 3 may be provided not on the entire surface, but only on a part such as the 6 o'clock side, and a digital display unit, such as a liquid crystal panel, may be provided on the viewing side of the clock in addition to the dial 2. In this case, it becomes a so-called combination clock that includes both an analog display unit and a digital display unit. Alternatively, it is also applicable to a digital clock that is equipped only with a digital display unit instead of an analog system such as hands, and has a plate-shaped member such as a decorative member having through holes 22 similar to those of the dial 2 in this embodiment on the outer circumference of the digital display unit. In either case, the plate-shaped member has through holes formed on one side and the other side with different opening areas.

[0044] Furthermore, when sub-dials are provided on the dial 2 of the watch, it is conceivable to provide the necessary power generation by providing a solar panel 12 only in the area where the sub-dials are provided (region Ar3 in Figure 17). In such cases, through-holes 22 may be provided only in the area corresponding to region Ar3 where the sub-dials are provided. For example, Figure 17 shows an example in which sub-dials are provided on the 12 o'clock and 9 o'clock sides of the watch, and through-holes 22d are provided in an area roughly corresponding to region Ar3, and the solar panel 12d is arranged to correspond to these through-holes 22d. In this case as well, the through-holes 22d are formed so that the opening area of ​​the opening on one side and the opening on the other side are different. The number and arrangement of through-holes 22d are not particularly limited. Through-holes 22d may be provided slightly outside of region Ar3, or through-holes 22d may be provided only slightly inside of region Ar3. Note that the position, number, shape, size, etc. of the sub-dials are not limited to the illustrated example, and there may be three or more sub-dials. In this case, through-holes 22 may be provided for all sub-dials, or for only some of them. By providing through-holes 22d only in the area Ar3 corresponding to the sub-dials and arranging the solar panel 12d there, it is not necessary to take measures to allow light to pass through to the back side of the dial 2 in areas other than Ar3 where the solar panel 12d is placed, thus increasing the freedom of the design.

[0045] Furthermore, while the above embodiments illustrate the case where the plate-shaped member is the dial 2 of a watch (wristwatch) 100, the plate-shaped member is not limited to the dial 2. For example, the plate-shaped member may be various decorative plates or the like that are placed on the surface side (the viewing side in the watch) of the solar panel 12, or it may be an anti-magnetic plate or the like that provided to suppress the influence of external magnetic forces.

[0046] Furthermore, the devices to which the plate-shaped member according to the present invention can be applied are not limited to watches. The plate-shaped member can be broadly applied to devices that have components such as a solar panel 12 that generates electricity from light incident on the plate-shaped member. For example, it can be broadly applied to electronic devices such as various smartwatches and sports watches, and wearable devices that acquire not only time but also biometric information such as heart rate and blood flow information.

[0047] Although several embodiments of the present invention have been described above, the scope of the present invention is not limited to the embodiments described above. The specific configurations, structures, and positional relationships shown in the above embodiments can be modified as appropriate without departing from the spirit of the present invention. Furthermore, the present invention includes the scope of the invention as described in the claims and its equivalents. [Explanation of Symbols]

[0048] 2…Dial (plate-shaped component), 12…Solar panel, 22…Through-hole, 100…Clock (electronic clock)

Claims

1. A metal plate-shaped member having a through hole that penetrates from one side to the other side, A solar panel is positioned below the plate-shaped member, Equipped with, The through-hole has different opening areas for the opening on one side and the opening on the other side. An electronic clock characterized by the following features.

2. The through-hole is formed in a shape that widens from the opening on one side to the opening on the other side. The electronic clock according to feature 1.

3. The through-hole is formed with a substantially tapered cross-section so that it gradually widens from the opening on one side to the opening on the other side. The electronic clock according to feature 1.

4. The plate-like member is formed by joining together multiple thin metal plates, each having a different opening area for corresponding openings. The electronic clock according to feature 1.

5. The aforementioned one side is the surface side of the plate-like member, Multiple through holes are formed, The multiple through holes are formed such that at least the opening on one side is substantially uniform in shape. The electronic clock according to feature 1.

6. An antenna is located inside the housing where the plate-shaped member is placed. Multiple through holes are formed, In the plate-shaped member, the opening of the through-hole located near where the antenna is positioned has a larger opening area than the openings of the through-holes located in other parts. The electronic clock according to feature 1.

7. Multiple through holes are formed, At least the openings of through holes located on any of the lines perpendicular to each other, with the central part of the plate-like member in the in-plane direction as the intersection point, are formed with a smaller opening area than the openings of through holes located in other parts. The electronic clock according to feature 1.

8. Includes a solar panel composed of segmented cells, The through-holes, whose opening area is smaller than that of the through-holes located in other parts, are arranged in accordance with the dividing regions that divide the dividing cells. The electronic clock according to feature 7.

9. The through-holes provided on the outer periphery of the plate-like member have a different shape from the through-holes provided on other parts. The electronic clock according to feature 1.

10. The plate-like member is a dial. The electronic clock according to feature 1.

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