JP7175661B2 - solar powered clock - Google Patents

Description

The present invention relates to a solar-powered timepiece.

2. Description of the Related Art A solar-powered timepiece uses a light-transmitting dial to allow light to enter the solar cell. The solar cell has a unique dark purple color, and if the solar cell is seen through the dial, it may spoil the appearance. Therefore, for example, in the dial disclosed in Patent Document 1, unevenness is formed on the lower surface, which is composed of mountain and valley portions whose cross-sectional shape is approximately right-angled, thereby dispersing and diffusing light. It is devised to erase the color tone of the battery.

JP 2011-174948 A

As disclosed in Patent Document 1, when the lower surface of the dial is uneven, the reflectance of light on the dial increases, and the visibility of the internal structure of the watch provided on the lower side of the dial decreases. On the other hand, there is a possibility that the amount of power generated by the solar cell will decrease due to the decrease in light transmittance.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a solar-powered timepiece capable of ensuring a sufficient amount of power generation without impairing its aesthetic appearance.

The invention disclosed in the present application for solving the above problems has various aspects, and the outlines of typical aspects are as follows.

(1) A dial including a high-transmittance region with high light-transmittance and a low-transmittance region with lower light-transmittance than the high-transmittance region; and the low-transmittance region overlaps, in plan view, at least a non-power generation region of the solar cell that does not contribute to power generation or a non-placement region where the solar cell is not provided A solar-powered watch, wherein the high-transmittance region is provided so as to overlap at least the power generation region in a plan view.

(2) In (1), the lower surface of the dial in the high-transmittance region and the low-transmittance region includes a groove recessed toward the upper surface of the dial and the lower surface adjacent to the groove. At least the cross-sectional shape of the bottom of the valley is rounded, and the cross-sectional shape of the bottom in the high-transmittance region is the low-transmittance. A solar-powered timepiece having a shape that is larger and more rounded than the cross-sectional shape of the bottom in an area.

(3) In (2), the cross-sectional shape of the apex of the ridge portion is a rounded shape, and the cross-sectional shape of the apex in the high transmission region is the cross-sectional shape of the apex in the low transmission region. A solar-powered clock that is larger and has a rounded shape.

(4) The solar battery watch according to (2) or (3), wherein the radius of curvature of the bottom portion of the valley portion is larger than the radius of curvature of the top portion of the mountain portion.

(5) In any one of (1) to (4), the dial has an intermediate transmission area with lower light transmission than the high transmission area and higher light transmission than the low transmission area. and wherein the medium transmission region is provided between the high transmission region and the low transmission region.

(6) The solar battery watch according to (5), wherein the light transmittance in the middle transmittance region increases stepwise or continuously from the low transmittance region toward the high transmittance region.

(7) In (1), the lower surface of the dial in the high-transmittance region and the low-transmittance region includes a groove recessed toward the upper surface of the dial and the lower surface adjacent to the groove. A solar battery-equipped watch, wherein at least in the high transmittance region, the shape of the bottom of at least the valley portion is flat.

(8) In (7), the dial has a middle transmission region having lower light transmission than the high transmission region and higher light transmission than the low transmission region, and the middle transmission region has , including at least the valley portion provided between the high transmission region and the low transmission region and having a flat bottom shape, in the medium transmission region, extending from the low transmission region side toward the high transmission region According to the above, the area of the plane of the bottom of the valley portion is gradually increased.

(9) In (1), the lower surface of the dial in the high-transmittance region and the low-transmittance region includes a groove recessed toward the upper surface of the dial and the lower surface adjacent to the groove. At least one of the cross-sectional shape of the bottom of the valley streak in the high transmission region and the cross-sectional shape of the top of the mountain streak is rounded. and at least one of the cross-sectional shape of the bottom of the valley portion and the cross-sectional shape of the top of the mountain portion in the low transmittance region is rectangular.

(10) A solar-powered timepiece according to any one of (1) to (9), wherein paint is applied to at least one of the high-transmittance region and the low-transmittance region on the lower surface of the dial.

(11) The solar cell watch according to (1) or (2), wherein the high transmittance region includes a surface having a sine curve in cross section.

(12) A solar-powered timepiece according to any one of (2) to (4), wherein the valley portion and the mountain portion are concentrically or spirally formed on the lower surface.

(13) The solar battery watch according to any one of (1) to (12), wherein the dial is made of polycarbonate resin or acrylic resin.

According to aspects (1) to (13) of the present invention, it is possible to provide a solar-powered timepiece capable of ensuring a sufficient amount of power generation without impairing its appearance.

1 is a plan view showing an electronic timepiece according to this embodiment; FIG. FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1; 1 is a cross-sectional view showing an outline of a dial and a solar cell of this embodiment; FIG. It is the top view which looked at the dial|plate of this embodiment from the lower surface side. FIG. 4 is a schematic diagram illustrating transmission of light in grooves and grooves formed on the dial of the present embodiment. 1 is a plan view showing a solar cell in this embodiment; FIG. FIG. 2 is a plan view schematically showing a dial in this embodiment; FIG. 8 is a cross-sectional view taken along line BB of FIG. 7 and a diagram showing the relationship between transmittance and reflectance; FIG. 5 is a cross-sectional view showing an outline of a dial and a solar cell of a first modified example of the present embodiment; FIG. 11 is a cross-sectional view showing an outline of a dial and a solar cell of a second modified example of the present embodiment;

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention (hereinafter referred to as the present embodiment) will be described in detail below with reference to the drawings.

FIG. 1 is a plan view showing a solar battery watch according to this embodiment. FIG. 2 is a cross-sectional view taken along line AA of FIG. In FIG. 2, the crown 13, which will be described later, is omitted from the illustration, and in order to make the arrangement of the hands easier to understand, the minute hand 16 is directed toward 9 o'clock, and the hour hand 15 and second hand 17 are directed toward 3 o'clock. It shows a state facing the direction of

FIG. 1 shows a case 10, which is the exterior (watch case) of the solar-powered timepiece 1, a dial 14 arranged inside the case 10, and an hour hand 15, a minute hand 16, and a second hand 17, which are hands indicating the time. there is In addition, hour characters 49 are provided at predetermined positions on the dial 14 . Band fixing portions 11 for fixing the band extend from the sides of the trunk 10 on the 12 o'clock side and the 6 o'clock side. A button 12 and a crown 13 for the user to perform various operations are arranged on the side of the barrel 10 on the 3 o'clock side.

Note that the clock design shown in FIG. 1 is an example. In addition to what is shown here, for example, the barrel 10 may be rectangular instead of round, and the presence/absence, number, and arrangement of buttons 12 and crown 13 are arbitrary. In addition, in this embodiment, three hands, the hour hand 15, the minute hand 16, and the second hand 17, are used. However, the present invention is not limited to this. , radio wave reception status, remaining battery level, pointers for various displays, date display, and the like may be added.

In this specification, the solar-powered timepiece 1 receives a satellite signal from a satellite that transmits a satellite signal including information on date and time, such as a GPS (Global Positioning System) satellite, and 1 shows a satellite radio-controlled wristwatch having the function of correcting the internal time held inside the watch based on information about the time. However, it is not limited to this, and it may be a radio-controlled watch that receives a general standard radio wave and adjusts the internal time, or a watch that does not have such a time-adjusting function.

As shown in FIG. 2 , the solar-powered timepiece 1 has a windshield 32 made of a transparent material such as glass so as to cover the dial 14 , and the windshield 32 is attached to the case 10 . A back cover 36 is attached to the case 10 on the opposite side of the windshield 32 . In this specification, the side on which the windshield 32 of the watch is arranged (the front side of the page in FIG. 1) is called the upper side, and the side on which the back cover 36 is arranged (the back side of the page in FIG. 1) is called the lower side.

A solar cell 30 is arranged on the lower side of the dial 14, and power is generated by the light that passes through the dial 14 and is incident on the solar cell 30 from the upper side. Therefore, the dial 14 is made of a material that transmits light rays to some extent. For example, the dial 14 may be made of polycarbonate resin or acrylic resin. Further, the resin is not limited to those resins, and any transparent resin such as a fluorinated resin or an ethylene resin may be used.

In this embodiment, as indicated by the dashed line in FIG. 1, the solar cell 30 has a substantially circular shape and is fan-shaped from the 10 o'clock direction to the 2 o'clock direction. A patch antenna 20 for receiving satellite signals is arranged in this notched portion (area where the solar cell 30 does not exist) on the lower side of the dial 14 . In this way, by arranging patch antenna 20 so as not to overlap solar cell 30 in plan view, it is possible to suppress the influence of the electrodes included in solar cell 30 on the reception sensitivity of patch antenna 20 .

As shown in FIG. 2 , the solar-powered timepiece 1 further includes a transflective plate 47 provided between the dial 14 and the solar battery 30 and a movement 38 provided below the solar battery 30 . The movement 38 includes a train wheel and a motor for driving hands, a clock circuit including a crystal oscillator for keeping time, a controller for controlling the entire solar-powered clock 1, etc., all assembled together in a frame called a main plate. be. The movement 38 operates by receiving power from a storage battery attached to the movement 38 . The storage battery stores power generated by the solar cell 30 while supplying power to the movement 38, and is, for example, a button-type lithium secondary battery.

In this embodiment, the solar cell 30 is provided integrally with the movement 38 . Further, the movement 38 is provided with a needle shaft projecting from the upper surface of the dial plate 14, and a second hand 17, a minute hand 16 and an hour hand 15 are attached to the tip of the needle shaft. A windshield 32 is fixed to the trunk 10 so as to cover them.

Next, the configuration of the dial 14 of this embodiment will be described with reference to FIGS. 3 and 4. FIG. FIG. 3 is a cross-sectional view showing the outline of the dial and solar cell of this embodiment. FIG. 4 is a plan view of the dial of this embodiment as viewed from below.

Between the dial 14 and the solar cell 30, as shown in FIG. 2, a semi-transmissive reflector 47 may be provided in order to properly transmit and reflect incident light. 3, illustration of the semi-transmissive reflector 47 is omitted. Also, in FIG. 3, hatching is omitted to avoid complicating the drawing. Further, as shown in FIG. 3, the space between the lower surface of the dial 14 and the solar cell 30 is an air layer 24 . Since the dial 14 and the air layer 24 have different refractive indices, light is refracted or reflected at the interface between the lower surface of the dial 14 and the air layer 24 .

In the description below, as shown in FIG. The region a, and the region adjacent to the region c among the regions overlapping the solar cells 30 in plan view are called the region b. In this embodiment, the region a is a high-transmittance region with high light transmittance, the region c is a low-transmittance region with a lower light transmittance than the region a, and the region b is a region b with a lower light transmittance than the region a. A medium transmission region having a higher light transmittance than c was used.

In the present embodiment, the lower surface of the dial 14 in the region a has unevenness composed of a valley portion 141 recessed upward and a mountain portion 142 adjacent to the valley portion 141 and protruding downward. formed. The reason why the unevenness is formed on the lower surface of the dial 14 is that light is reflected at the interface between the lower surface of the dial 14 and the air layer 24, so that the lower surface of the dial 14, such as the solar cell 30, is visible from the outside. This is to make the internal structure provided in the inconspicuous. The height and pitch of the unevenness are preferably several tens of μm to one hundred and several tens of μm. In this embodiment, on the lower surface of the dial 14, the most recessed portion is called the bottom portion, and the most projecting portion is called the top portion.

In the present embodiment, the valley portion 141 is a portion above the intermediate portion between the bottom portion 141a and the top portion 142a in the thickness direction of the dial 14, and the mountain portion 142 is a portion in the thickness direction of the dial 14. It is defined as a portion below the middle between the bottom portion 141a and the top portion 142a. That is, in this embodiment, the depth of the valley portion 141 and the height of the mountain portion 142 in the thickness direction of the dial 14 are equal. The same applies to the root and ridge portions of region b and region c, which will be described later.

In the present embodiment, the lower surface of the dial 14 in the region c is composed of a valley portion 143 recessed upward and a mountain portion 144 adjacent to the valley portion 143 and protruding downward. Unevenness is formed.

Further, in this embodiment, the lower surface of the dial 14 in the region b is composed of a valley portion 147 recessed upward and a mountain portion 148 adjacent to the valley portion 147 and protruding downward. Unevenness is formed.

Further, in this embodiment, as shown in FIG. 3, the unevenness is formed so that the shapes of the bottom of the valley portion and the top of the mountain portion in a cross-sectional view are different for each of the regions a to c. The details of the difference in light transmittance due to the difference in the shape of the unevenness will be described later with reference to FIG. 5 and the like.

The unevenness may be formed concentrically as shown in FIG. 4(a) on the lower surface of the dial 14, or may be formed in a spiral shape as shown in FIG. 4(b). In FIGS. 4(a) and 4(b), the solid lines indicate the tops of the ridges, and the portions between the solid lines indicate the bottoms of the valleys. However, the shape of the unevenness shown in FIGS. 4A and 4B is an example, and may be formed, for example, in a stripe shape or a radial shape, and is not limited to a uniform pattern. pattern may be formed.

Furthermore, with reference to FIG. 5, the details of light transmission through the unevenness formed on the dial 14 will be described. FIG. 5 is a diagram for explaining the transmission of light in the uneven grooves formed on the dial of the present embodiment.

A dashed line in FIG. 5 indicates a bottom portion 143a of the valley portion 143 having a rectangular cross-sectional shape. The dashed arrow in FIG. 5 indicates the optical path of the light incident on the bottom portion 143a of the valley portion 143 formed in a rectangular shape. Light 11, transmitted light (refracted light) 12, and reflected light 13 at the interface are shown. 5 indicates the optical path of light incident on the bottom portion 141a of the groove portion 141 having a rounded cross section, and is incident on the interface between the lower surface of the dial 14 and the air layer 24. The incident light L1 at the interface and the transmitted light (refracted light) L2 at the interface are shown.

Here, it is known that the reflectance of light depends on the angle of incidence (Fresnel's equation). Specifically, it is known that the reflectance increases as the incident angle of light incident on the interface increases, and the reflectance decreases as the incident angle decreases. In other words, it is known that the transmittance decreases as the incident angle of light incident on the interface increases, and the transmittance increases as the incident angle decreases. In other words, the transmittance of light (incidence angle of 0 degrees) that is perpendicularly incident on the interface is the highest. Here, the reflectance is the ratio of the reflected light flux to the light flux incident on the interface between substances having different refractive indices. Also, the transmittance is the ratio of the transmitted light flux to the light flux incident on the interface between different substances.

In FIG. 5, to simplify the explanation, the light incident perpendicularly (at 90 degrees) to the upper surface 145 of the dial 14 is reflected at the interface between the dial and the air layer at the bottom of the groove. A transparent example is shown. In this embodiment, the upper surface 145 of the dial 14 is flat.

Here, the cross-sectional shape of the bottom portion 143a of the valley portion 143 is rectangular, and a slope inclined at a predetermined angle with respect to the upper surface 145 is formed. The light l1 that is incident perpendicularly to the upper surface 145 of the dial 14 is incident on the slope forming the bottom 143a at a predetermined angle of incidence, and is partially reflected.

On the other hand, the rounded cross-sectional shape of the bottom portion 141a of the valley portion 141 is less inclined with respect to the upper surface of the dial 14 compared to the configuration of the square bottom portion 143a. Therefore, the incident angle of light incident on the interface between the bottom portion 141a of the valley portion 141 and the air layer 24 is small. Therefore, the light reflectance at the interface between the bottom 141a of the valley portion 141 having a rounded cross section and the air layer 24 is small and the transmittance is large. Therefore, the amount of light reaching the solar cell 30 arranged on the lower side of the dial 14 is greater than that of the bottom portion 143a having a rectangular cross section, and the amount of power generated by the solar cell 30 is large.

As described above, by making the bottom portion 141a of the valley portion 141 rounded, the transmittance of light can be improved and the amount of power generated by the solar cell 30 can be improved. By forming the top portion 142a of the strip portion 142 into a rounded shape, the light transmittance can be improved and the power generation amount of the solar cell 30 can be increased. Note that when the bottom portion 141a and the top portion 142a are rounded with the same radius of curvature, the transmittance is improved by rounding the bottom portion 141a more than the transmittance is improved by rounding the top portion 142a. Greater than improvement. This is because the bottom portion 141a is expected to have improved transmittance for all incident light, while the top portion 142a is rounded for light incident on the top portion 142a from the outside of the dial 14. This is because an improvement in transmittance due to the tinge cannot be expected. Therefore, in order to improve the transmittance, it is preferable to make the radius of curvature of the bottom larger than the radius of curvature of the top.

Next, the configuration of the solar cell 30 and the configuration of the dial 14 will be described with reference to FIGS. 6 to 8. FIG. FIG. 6 is a plan view showing the solar cell in this embodiment. FIG. 7 is a plan view schematically showing the dial in this embodiment. In addition, in FIG. 7, illustration of unevenness|corrugation is abbreviate|omitted. FIG. 8 is a cross-sectional view taken along line BB in FIG. 7 and a diagram showing the relationship between transmittance and reflectance.

As shown in FIG. 6, the solar cell 30 includes a substrate 30b having a fan-shaped notch extending from the 10 o'clock direction to the 2 o'clock direction. In the example shown in FIG. 6, the angle formed by the notch 30c is 120°. As described above, the patch antenna 20 is arranged in the region inside the notch 30c (the region where the solar cells 30 do not exist; hereinafter referred to as the non-placement region M) so that the receiving surface faces the windshield 32 side. be done. The angle formed by the notch portion 30c may be any angle as long as the patch antenna 20 can be accommodated.

In the present embodiment, the region where the solar cells 30 do not exist is called the non-arranged region M, whereas the region where the solar cells 30 exist and generate power is called the power generation region E, and the solar cells 30 exist. A non-power generation region N is defined as a region in which power generation is not performed.

A plurality of engaging portions (concavo-convex shape) are provided at positions spaced apart from each other on the peripheral edge of the substrate 30b. It engages the cell support frame. As a result, the substrate 30b is unrotatably supported within the solar battery timepiece 1. As shown in FIG. Furthermore, an opening is formed in the center of the solar cell 30 for inserting the pointer shaft, and a plurality of cells 30a, which are power generating units each having a semiconductor thin film and electrodes, are formed on the surface. The area where the cells 30a are provided corresponds to the power generation area E described above. In addition, the regions where the openings are formed and the regions where the dividing lines dividing the cells 30a are formed correspond to the non-power generating regions N described above. Hereinafter, the region in which the opening is formed will be referred to as the non-power generation region N1, and the region in which the dividing line will be formed will be referred to as the non-power generation region N2.

In the present embodiment, unevenness having different shapes is formed on the lower surface of the dial 14 in the area overlapping the power generation area E and the area overlapping the non-arrangement area M in plan view. That is, in the dial 14, the area a overlapping the power generation area E in plan view is formed with unevenness that increases the transmittance, and the area c overlapping the non-placement area M is formed with unevenness so that the transmittance is low. formed. Furthermore, in the region b, which overlaps with the region adjacent to the non-placement region M, among the regions overlapping with the power generation region E, the unevenness is formed so that the transmittance is lower than that of the region a and higher than that of the region c.

As shown in the upper part of FIG. 8, the light transmittance and reflectance of the dial 14 are in such a relationship that when one increases, the other decreases, and when one decreases, the other increases. That is, the higher the transmittance, the lower the reflectance, the more light passes through the dial 14, and the more the solar cell 30 generates power. On the other hand, the lower the transmittance, the higher the reflectance, the less the amount of light that passes through the dial 14, and the less the amount of power generated by the solar cell 30.

In the present embodiment, unevenness is formed on the lower surface of the dial 14 so that the light transmittance of the dial 14 in the region a overlapping the power generation region E is high in plan view. Specifically, as shown in FIG. 3, the unevenness is formed so that the cross-sectional shapes of the bottom portion 141a and the top portion 142a are rounded. With such a configuration, the amount of light transmitted through the dial 14 is increased, and the amount of power generated by the solar cell 30 can be maintained and improved. According to the findings of the inventors of the present application, the light transmittance increases when the cross-sectional shape of the unevenness constitutes a sine curve. Therefore, as shown in FIG. 3, in the present embodiment, the cross-sectional shape of the unevenness of the lower surface of the dial 14 in the region a is a sine curve.

In FIG. 3, the width of the valley portion 141 and the width of the mountain portion 142 in the direction orthogonal (intersecting) to the thickness direction of the dial 14 are assumed to be the same in the region a of the lower surface of the dial 14 . However, it is not limited to this, and the width of the valley portion 141 in the direction perpendicular to the thickness direction of the dial 14 may be larger than the width of the mountain portion.

On the other hand, unevenness was formed on the lower surface of the dial plate 14 so that the transmittance of the dial plate 14 in the region c overlapping the non-arrangement region M in plan view was low. Specifically, as shown in FIG. 3, the unevenness is formed so that the cross-sectional shape of the bottom portion 143a and the top portion 144a is square. This is because the solar cell 30 is not arranged below the dial 14 in the area c, so the light transmitted through the area c does not contribute to power generation. Further, when the transmittance is high, the amount of light reflected inside the watch and emitted to the outside through the dial 14 increases accordingly. This is because the internal structure of the timepiece is visible from the outside through the dial 14, which is undesirable from an aesthetic point of view.

In the region b, the cross-sectional shapes of the bottom portion 147a and the top portion 148a are rounded with a radius of curvature smaller than that of the bottom portion 141a and the top portion 142a of the region a. Also, in the region b, unevenness was formed so that the light transmittance increased stepwise or continuously from the region c side toward the region a side. Specifically, as shown in FIG. 3, the cross-sectional shape of the bottom portion 147a and the top portion 148a is rounded with a larger radius of curvature in the region a side than in the region c side in the region b. Concavities and convexities were formed. By adopting such a configuration, it becomes difficult to see from the outside the boundary between the area where the solar cell 30 is arranged and the area where the solar cell 30 is not arranged, thereby suppressing deterioration of the appearance.

In the present embodiment, unevenness is formed on the lower surface of the dial 14 so as to reduce the transmittance of the dial 14 in the region c of the dial 14 that overlaps with the non-placement region M, but this is not the only option. In addition, unevenness is formed on the lower surface of the dial 14 so that the transmittance is low even in the regions overlapping the non-power generation regions N1 where the openings of the solar cells 30 are formed and the non-power generation regions N2 where the dividing lines are formed. You may As a result, the reflectance in the regions overlapping the openings and the dividing lines of the solar cells 30 is increased, and the openings and the dividing lines are difficult to be visually recognized from the outside, thereby suppressing deterioration of the appearance.

In addition, the shape of the solar cell is not limited to one in which a fan-shaped notch is formed as shown in FIG. For example, it may be a ring-shaped (doughnut-shaped) solar cell in which the central portion is cut off, or a C-shaped solar cell in which a part of the ring shape is cut off. Alternatively, the solar cell may be provided only in the vicinity of the central portion of the dial, and the vicinity of the outer periphery of the dial may be the non-placement area M, contrary to the ring shape. Furthermore, the outer shape is not limited to a circular one, and a solar cell having a rectangular outer shape may be used. Regardless of the shape of the solar cell, the light transmittance of the region of the dial 14 that overlaps the power generation region E of the solar cell is increased, and the region that overlaps the non-power generation region N and the non-arrangement region M is made highly transparent. It is preferable to lower the light transmittance.

FIG. 9 is a cross-sectional view showing an outline of a dial and a solar cell of a first modified example of this embodiment. Although FIG. 3 and the like show a configuration in which unevenness having a rounded cross-sectional shape is formed on the lower surface of the dial 14, the present invention is not limited to this. The most recessed portion of the bottom portion 141 a in the region a overlapping the power generation region E may be a plane parallel to the upper surface 145 . Similarly, the most projecting portion of the top portion 142a may be a plane parallel to the top surface 145. FIG. This is because the cross-sectional shape of the bottom portion 141a and the top portion 142a is not inclined with respect to the upper surface 145, thereby improving the transmittance. In the region c overlapping the non-placement region M that does not contribute to power generation, the cross-sectional shape of the bottom portion 141a and the top portion 142a should be square. Also, in the region b between the region a and the region c, unevenness was formed so that the light transmittance increased stepwise or continuously from the region c side toward the region a side. Specifically, as shown in FIG. 9, in the area c side of the area b, the cross-sectional shape of the bottom portion 147a is rectangular, and the most protruding portion of the top portion 148a is a plane parallel to the top surface 145. As shown in FIG. In addition, in the area a side of the area b, in addition to making the most projecting part of the top part 148 a parallel to the top surface 145 , the most recessed part of the bottom part 147 a is made parallel to the top surface 145 . flat surface. By gradually changing the shape of the unevenness in the region b in this way, the boundary between the region where the solar cells 30 are arranged and the region where the solar cells 30 are not arranged becomes indistinguishable from the outside while ensuring the amount of power generation in the power generation region E. . Further, for example, in the region b, the planar area of the bottom portion 147a of the valley portion 147 and the planar area of the top portion 148a of the mountain portion 148 increase stepwise from the region c side toward the region a side. Concavities and convexities may be formed as follows.

Whether the cross-sectional shape of the bottom portion or the top portion should be rectangular, rounded, or how rounded can be appropriately adopted. Regardless of where and what shape is adopted, it is preferable to form unevenness on the lower surface of the dial 140 so that the light transmittance is high at least in the area a and the light transmittance is low in the area c.

FIG. 10 is a cross-sectional view showing an outline of a dial and a solar cell of a second modified example of this embodiment. In the dials shown in FIGS. 3, 9, etc., a configuration is adopted in which the shape of the unevenness differs depending on which region of the solar cell 30 the region overlaps. A configuration is adopted in which unevenness is formed on the surface and a paint 50 is applied on the unevenness so that the transmittance differs for each area.

Specifically, in the second modified example, in any of the regions a to c, unevenness having a rectangular cross section is formed on the lower surface of the dial plate 240 . Then, paint 50 is applied to the unevenness of the area a overlapping the power generation area E in plan view, and the unevenness of the area b adjacent to the area c that does not overlap the power generation area E among the areas overlapping the power generation area E is thinner than the area a. Paint 50 was applied. Also, in the area c that does not overlap with the power generation area E, the paint 50 is not applied.

In the area where the paint 50 is applied, the paint 50 forms an interface with the air layer 24, and the interface forms a gentle slope. Further, for example, when the refractive index of the paint 50 and the dial 240 is substantially the same and is greater than the refractive index of the air layer 24, the reflection and refraction of light is greater than the interface between the dial 240 and the paint 50. , becomes dominant at the interface between the paint 50 and the air layer 24 . Therefore, by applying the paint 50, the light transmittance increases in the region a where the gentle slope is formed.

The light transmittance of the dial 14 can be adjusted by applying the paint 50 to any area of the lower surface of the dial 14 and adjusting the amount (film thickness) of the applied paint 50 for each area. good too. Further, depending on the material of the paint 50, the area coated with the paint 50 may have lower light transmittance than the area not coated. When applying such paint 50, it is preferable to reduce the amount of paint 50 applied in area a and increase the amount of paint 50 applied in area c.

Further, it is not always necessary to form irregularities on the lower surface of the dial 240, and the transmittance in each area may be made different only by applying the paint 50. FIG. In any case, it is sufficient that the light transmittance in the region a overlapping the power generation region E is high and the light transmittance in the region c not overlapping the power generation region E is low.

Although the embodiment according to the present invention has been described above, the specific configuration shown in this embodiment is shown as an example, and it is not intended to limit the technical scope of the present invention to this. Those skilled in the art may modify these disclosed embodiments as appropriate, and it should be understood that the technical scope of the invention disclosed herein includes such modifications.

1 solar battery watch 10 case 11 band fixing part 12 button 13 crown 14, 140, 240 dial 141, 143, 147 root part 141a, 143a, 147a bottom part 142, 144, 148 mountain Streaks 142a, 144a, 148a Top 145 Upper surface 15 Hour hand 16 Minute hand 17 Second hand 20 Patch antenna 30 Solar battery 30a Cell 32 Windshield 36 Back cover 38 Movement 47 Transflective reflector 49 Time letters, 50 paints.

Claims (12)

a dial including a high transmission area with high light transmission and a low transmission area with lower light transmission than the high transmission area;
a solar cell including at least a power generation region that generates power when light transmitted through the dial is incident;
has
The low-transmittance region is provided so as to overlap at least a non-power generation region of the solar cell that does not contribute to power generation or a non-placement region where the solar cell is not provided,
The high transmission region is provided so as to overlap at least the power generation region in plan view ,
The lower surface of the high transmission region and the low transmission region of the dial includes a valley portion recessed toward the upper surface of the dial and a mountain portion protruding toward the lower surface adjacent to the valley portion. including irregularities consisting of
At least the cross-sectional shape of the bottom of the valley portion is rounded,
The cross-sectional shape of the bottom in the high-transmittance region is larger and more rounded than the cross-sectional shape of the bottom in the low-transmittance region,
A clock with a solar battery. The cross-sectional shape of the apex of the ridge portion is a rounded shape,
The cross-sectional shape of the apex in the high-transmittance region is larger and more rounded than the cross-sectional shape of the apex in the low-transmittance region,
The solar-powered timepiece according to claim 1 . The radius of curvature of the bottom of the valley portion is larger than the radius of curvature of the top of the mountain portion.
The solar cell watch according to claim 1 or 2 . The dial has a medium transmission area with lower light transmission than the high transmission area and higher light transmission than the low transmission area,
The intermediate transmission region is provided between the high transmission region and the low transmission region,
A solar-powered timepiece according to any one of claims 1 to 3 . In the intermediate transmission region, the light transmittance increases stepwise or continuously from the low transmission region side to the high transmission region side,
The solar-powered timepiece according to claim 4 . a dial including a high transmission area with high light transmission and a low transmission area with lower light transmission than the high transmission area;
a solar cell including at least a power generation region that generates power when light transmitted through the dial is incident;
has
The low-transmittance region is provided so as to overlap at least a non-power generation region of the solar cell that does not contribute to power generation or a non-placement region where the solar cell is not provided,
The high transmission region is provided so as to overlap at least the power generation region in plan view,
The lower surface of the high transmission region and the low transmission region of the dial includes a valley portion recessed toward the upper surface of the dial and a mountain portion protruding toward the lower surface adjacent to the valley portion. including irregularities consisting of
At least in the high transmission region, at least the shape of the bottom of the valley is flat.
A clock with a solar battery. The dial has a medium transmission area with lower light transmission than the high transmission area and higher light transmission than the low transmission area,
the intermediate transmission region is provided between the high transmission region and the low transmission region and includes at least the valley portion having a flat bottom,
In the intermediate transmission region, the planar area of the bottom of the valley portion increases stepwise from the low transmission region toward the high transmission region.
The solar-powered timepiece according to claim 6 . a dial including a high transmission area with high light transmission and a low transmission area with lower light transmission than the high transmission area;
a solar cell including at least a power generation region that generates power when light transmitted through the dial is incident;
has
The low-transmittance region is provided so as to overlap at least a non-power generation region of the solar cell that does not contribute to power generation or a non-placement region where the solar cell is not provided,
The high transmission region is provided so as to overlap at least the power generation region in plan view,
The lower surface of the high transmission region and the low transmission region of the dial includes a valley portion recessed toward the upper surface of the dial and a mountain portion protruding toward the lower surface adjacent to the valley portion. including irregularities consisting of
At least one of the cross-sectional shape of the bottom of the valley portion and the cross-sectional shape of the top of the mountain portion in the high transmission region is rounded,
At least one of the cross-sectional shape of the bottom portion of the valley portion and the cross-sectional shape of the top portion of the mountain portion in the low transmission region is rectangular.
A clock with a solar battery. At least one of the high-transmittance region and the low-transmittance region on the lower surface of the dial is coated with paint.
A solar-powered watch according to any one of claims 1 to 8 . The high transmission region includes a surface having a sine curve in cross section,
The solar-powered timepiece according to claim 1 . The valley section and the mountain section are formed concentrically or spirally on the lower surface,
The solar-powered timepiece according to any one of claims 1 to 3 . The dial is made of polycarbonate resin or acrylic resin,
A solar-powered timepiece according to any one of claims 1 to 11 .

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