JP2002148362A - Timepiece with solar cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of an interference fringe due to superposed light receiving surface and light transmitting plate of a solar cell in a timepiece with a solar cell formed by disposing the light transmitting plate on the light receiving surface of the solar cell. SOLUTION: A thin film layer 17 having a designated thickness is partially formed between the light receiving surface 12a of the solar cell 12 and the back of the light transmitting plate 13. The thin film layer 17 is, preferably formed on the back of the light transmitting plate 13 selectively by print forming such as screen printing or pad-printing or the like. It is sufficient that the thickness of the thin film layer 17 is enough larger than the wavelength of light in the visible region, and the color tone and transmittance are arbitrary.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a timepiece with a solar cell, and more particularly to an improvement of a timepiece having a structure in which a light receiving surface of a solar cell is formed on a time display surface.

[0002]

2. Description of the Related Art Conventionally, in a timepiece with a solar cell, power is generated by external light applied to a light receiving surface of the solar cell, and the timepiece is driven by the electric power obtained by the power generation. In recent years, the power conversion efficiency of the solar cell has been improved, but it is still advantageous to make the light receiving surface of the solar cell as large as possible in order to secure sufficient driving power. In order to increase the light receiving area, for example, in a small wristwatch, it is conceivable that almost the entire time display surface is used as the light receiving surface.

As described above, it is possible to obtain a large amount of power generation by using almost the entire time display surface as the light receiving surface, while the portion where the conventional dial is located becomes the light receiving surface of the solar cell. As a result, the appearance of the time display surface becomes inferior in design, and the design restrictions increase, which hinders free design of the timepiece.

Therefore, recently, the surface of the light-receiving surface is covered with a light-transmitting plate while almost the entire time display surface is used as a light-receiving surface. There is a commercially available product that allows design and has a sufficient light transmission amount with respect to the light receiving surface. Such a translucent plate has an advantage that it also protects the light receiving surface of the solar cell.

[0005]

In such a timepiece with a solar cell as described above, for example, when a light-transmitting plate is disposed on the light-receiving surface of the solar cell, the surface between the light-receiving surface and the light-transmitting plate is not provided. There is a problem in that interference fringes occur due to reflection, which impairs the appearance of the timepiece. In particular, even if the design of the angle time display surface is satisfactorily improved by the translucent plate, the presence of the interference fringes may cause the quality of the product to be doubted.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a timepiece with a solar cell in which a translucent plate is arranged on a light receiving surface of the solar cell. An object of the present invention is to prevent interference fringes from being generated by a surface and a light-transmitting plate, and to realize interference fringes by a method that is simple and can suppress manufacturing costs.

[0007]

Means taken by the present invention to solve the above-mentioned problem is a solar cell-equipped timepiece having a light-receiving surface of a solar cell provided on a time display surface, which is disposed on the time display surface. A light-transmitting plate is provided on the light-receiving surface of the solar cell so as to cover the light-receiving surface, and a wavelength of light in a visible region between the light-receiving surface and the light-transmitting plate is larger than that of the light-receiving surface. A thin film layer formed sufficiently thick is partially formed, and the light-receiving surface and the light-transmitting plate are fixed in an overlapping state via the thin film layer.

According to this means, the distance between the light receiving surface of the solar cell and the back surface of the light-transmitting plate is sufficiently thicker than the wavelength of light in the visible region due to the thickness of the thin film layer. It is possible to prevent the occurrence of interference fringes caused by reflection between the rear surface of the conductive plate and the transparent plate. In addition, since the light receiving surface and the back surface of the translucent plate can be fixed in a state of being directly superimposed on each other, the component structure is simplified and assembly is facilitated, so that the manufacturing cost can be reduced.

Here, it is preferable that the thin film layer is formed at a portion where at least one of the solar cell and the translucent plate is pressed and fixed by another member.

According to this means, the thickness of the thin film layer is formed by forming the thin film layer at a position where the solar cell and / or the translucent plate is pressed and fixed by another member, for example, a dial receiving ring or a dial ring. Thereby, the interval between the solar cell and the translucent plate can be more reliably specified.

It is preferable that the thin film layer is formed in a color tone and a pattern that cancels a pattern of a light receiving portion structure formed on a light receiving surface of the solar cell.

According to this means, since the pattern of the light receiving portion structure of the solar cell is canceled by the color tone and the pattern of the thin film layer, the structure of the solar cell is not displayed on the time display surface, and the design is improved. Can be improved, and the degree of freedom in designing the time display surface can be increased.

Further, it is preferable that the thin film layer constitutes a time display pattern on the time display surface.

According to this means, a time display pattern, that is, a time scale, a numeral of the time, and the like can be constituted by the thin film layer. Therefore, the structure for preventing interference fringes and the dial pattern can be used.

In each of the above-mentioned means, it is preferable that the thin film layer is formed by printing on the back surface of the translucent plate.

According to this means, the thin film layer can be formed easily and at low cost by printing on the back surface of the light-transmitting substrate, and the light-transmitting substrate is placed on the light-receiving surface during assembly. , Assembly work becomes easy.

[0017]

Next, an embodiment according to the present invention will be described with reference to the accompanying drawings. This embodiment relates to an electronic wristwatch, and FIG. 1 is an enlarged partial longitudinal sectional view showing the embodiment. A substantially disk-shaped solar cell 12 is attached to a synthetic resin dial receiving ring 11 fixed to the body of a wristwatch.
Is attached.

The solar cell 12 has a light receiving surface 12a on its surface.
The light receiving surface 12a is provided as shown in FIG.
Are four light receiving regions 12a formed on a silicon substrate
-1, 12a-2, 12a-3, and 12a-4, and a gap 12a-0 formed between these light receiving regions. The photocurrent generated in each light receiving area is converted into a voltage by current-voltage conversion, and this voltage is connected in series between the light receiving areas to obtain a high voltage.

A terminal array 12b having external terminals connected to the respective light receiving regions is formed on the periphery of the solar cell 12, and the solar cell 12 is connected to an electric clock formed in the timepiece through the terminal array 12b. Connected to the circuit.

The solar cell 12 and the translucent plate 13 are arranged so as to overlap each other, and the periphery of the translucent plate 13 is pressed from above by a dial ring 14. Reference numeral 15 denotes a pointer portion, and reference numeral 16 denotes a transparent glass.

The translucent plate 13 may be formed of a transparent substrate made of synthetic resin or glass, or may be formed of a translucent plate having a white or other color tone. In the case of using a translucent plate, it is necessary to adjust the transmittance of the translucent plate 13 so that the power generation efficiency of the solar cell 12 is within a range that does not hinder the operation of the clock function. The translucent plate 13 is formed of a material whose transmittance is controlled, and / or a plate formed to have a predetermined thickness in order to control the transmissivity, and a transmissivity on the front surface and / or the back surface of the transparent substrate. In consideration of the above, a material having a translucent layer formed of an appropriate material and / or thickness may be used.

Light receiving surface 12a of solar cell 12 and translucent plate 1
3, a thin film layer 17 having a predetermined thickness is partially formed. The thin film layer 17 is preferably selectively formed on the rear surface of the translucent plate 13 by print molding such as screen printing or octopus printing. The thin film layer 17
It may be formed by vapor deposition, sputtering, or the like, or may be adhered by transferring a metal foil into a desired shape by etching or the like and transferring it with a transfer sheet that has been adhered. Further, the thin film layer 17 may be deposited on the light receiving surface of the solar cell 12.

The thickness of the thin film layer 17 may be any thickness that is sufficiently larger than the wavelength of light in the visible region.
The transmittance and the like are also arbitrary. However, if it is formed of a transparent layer, the power generation efficiency of the solar cell 12 will not be reduced even if it is formed over an arbitrary area at an arbitrary place on the time display surface.

The light-receiving surface 12a of the solar cell 12 is usually divided into a plurality of light-receiving regions as shown in FIG. 2 in order to increase the generated voltage. Unit is configured. In order to make the gap invisible, it is very effective to form the thin film layer 17 along the gap with a color tone substantially similar to that of the light receiving region. In this case, the thin film layer 17 improves the appearance of the time display surface, and since the thin film layer 17 is formed just above the gap, it hardly affects the power generation efficiency of the solar cell 12.

The thin film layer 17 is a light receiving surface 12a of the solar cell 12.
Since the distance between the light-transmitting plate 13 and the rear surface of the light-transmitting plate 13 is increased, the occurrence of interference fringes can be prevented. Here, in order to prevent the occurrence of interference fringes, the thickness of the thin film layer 17 may be 2 μm or more. The thickness of the thin film layer 17 roughly determines the distance between the light receiving surface 12a of the solar cell 12 and the rear surface of the translucent plate 13, and the distance is sufficiently large so as not to generate interference fringes in the visible region. Need to be formed.

In addition to this, it is necessary to determine the amount by considering the amount of warpage and distortion of the light receiving surface 12a of the solar cell 12 and the back surface of the light transmitting plate 13. The thickness of the thin film layer 17 is warped,
Taking into account the strain and the flatness of other parts, it is better to be about 8 μm. According to a printing method such as screen printing or octopus printing, a thin film layer having a thickness of about 5 to 200 μm can be easily formed.

The thin film layer 17 also functions as a buffer layer between the solar cell 12 and the translucent plate 13 which are directly superimposed on each other. In particular, a thick thin film layer formed by a printing method sufficiently exerts a buffering function between the two, and the two firmly adhere to each other via the thin film layer. Therefore, each component is securely fixed by a pressing member such as a dial ring. be able to.

FIG. 3 is a schematic plan view of the thin film layer 17 according to the present embodiment. The thin film layer 17 includes the pointer 1
5, an inner peripheral portion 17a formed in a substantially circular shape along a peripheral portion of a portion perforated in the solar cell 12 and the translucent plate 13, and an outer peripheral edge of the solar cell 12 and the translucent plate 13. And an outer peripheral portion 17b formed in a substantially circular shape along the outer periphery.
Further, the inner peripheral portion 17a and the outer peripheral portion 17b are connected to the four light receiving regions 12a-1, 12a-2, 1 of the solar cell 12.
Directly above the four gaps 12a-0 formed between each of 2a-3 and 12a-4, a connecting portion 17c extending in a strip shape in the radial direction is connected.

The inner peripheral portion 17a and the connecting portion 17c can be visually recognized in the same shape even after the timepiece is assembled.
In particular, this is useful in making the gap 12a-0 reflecting the shape of the light receiving area of the light receiving surface 12a of the lower solar cell 12 invisible. In this case, the thin film layer 17 is formed as the light receiving areas 12a-1, 12a-2, 12a-3,
By making the color tone similar to the color tone of 12a-4, the structure of the solar cell 12 can be made invisible from the outside. Since the thin film layer 17 is formed on the back surface of the translucent plate 13, the thin film layer 17 having a color tone similar to that of the light receiving region can be almost visually distinguished from the light receiving region of the solar cell 12. Disappears.

The thin film layer 17 is provided for determining the decoration and appearance of the time display surface as in the case of the connection portion 17c, and is preferably formed on the periphery of the solar cell 12 and the translucent plate 13. By providing the thin film layer 17 on the peripheral portion, the light receiving surface 12a of the solar cell 12 which is in direct contact can be pressed down in a stable state. In FIG. 3, what is indicated by a dashed line is the inner peripheral edge of the dial ring 14 that presses the peripheral edge of the translucent plate 13, and the portion that is pressed by the dial ring 14 is the outer peripheral edge 17b.
, The light receiving surface 1 of the solar cell 12
The distance between 2a and the back surface of the translucent plate 13 can be reliably obtained.

The same applies to the dial receiving ring 11 on which the solar cell 12 is supported. In the present embodiment, the supporting portion of the dial receiving ring 11 is located at a position separated from the translucent plate 13. However, if the solar cell 12 and the light-transmitting plate 1
If there is an opposing portion of 3, the solar cell 12 and the translucent plate 13 can be reliably overlapped by forming a thin film layer on the portion.

FIG. 4 shows another pattern shape of the thin film layer 17. The inner peripheral portion 17a and the connecting portion 17c are the same as those described above, but a time scale portion for indicating the time position of the hands is also provided. 17d and a window frame portion 17e which borders the calendar window portion 19 are provided. In this manner, the thin film layer 17 can be formed as a required display or pattern on the dial, and for example, characters indicating time, characters indicating a manufacturer name, a brand name, a product name, and various figures, and various figures can be formed. It can also be formed by the thin film layer 17.

When the thin film layer is formed also as a display or a pattern, night display can be performed by forming the thin film layer from various known fluorescent and luminous materials.

In this embodiment, since a thin film layer is interposed between the light receiving surface of the solar cell and the back surface of the light transmitting plate, the generation of interference fringes due to the interference between the light receiving surface and the light transmitting plate. In addition, the thin film layer itself can stabilize the superimposed state between the light receiving surface and the light transmitting plate, and can also be used as a means for covering the structure of the light receiving portion of the solar cell. It can be used and has the effect that various characters and graphic patterns can be formed on the time display surface constituting the conventional dial.

Further, since the translucent plate can be arranged directly on the light receiving surface of the solar cell, there is no need to provide a space between the two, so that the parts structure can be simplified and the assembly of the timepiece is easy. And the manufacturing cost can be reduced.

[0036]

As described above, according to the present invention, the following effects can be obtained.

According to the first aspect, the distance between the light receiving surface of the solar cell and the back surface of the light transmitting plate is sufficiently thicker than the wavelength of light in the visible region due to the thickness of the thin film layer. It is possible to prevent the occurrence of interference fringes caused by reflection between the optical plate and the back surface. In addition, since the light receiving surface and the back surface of the translucent plate can be fixed in a state of being directly superimposed on each other, the component structure is simplified and assembly is facilitated, so that the manufacturing cost can be reduced.

According to the second aspect, the thin film layer is formed at a position where the solar cell and / or the light transmitting plate is pressed and fixed by another member, so that the solar cell and the light transmitting plate are formed depending on the thickness of the thin film layer. Can be more reliably defined.

According to the third aspect, the structure of the light receiving portion of the solar cell is canceled by the color tone and pattern of the thin film layer. Performance can be improved, and the degree of freedom in designing the time display surface can be increased.

According to the fourth aspect, the time display pattern, that is, the time scale, the numeral of the time, and the like can be formed by the thin film layer, so that the structure for preventing interference fringes and the dial pattern can be used.

According to the fifth aspect, the thin film layer can be easily and inexpensively formed by printing on the rear surface of the light-transmitting substrate, and the light-transmitting substrate is formed on the light-receiving surface during assembly. Since it is only necessary to mount the device, the assembling work is facilitated.

[Brief description of the drawings]

FIG. 1 is an enlarged partial longitudinal sectional view showing a part of an embodiment of a timepiece with a solar cell according to the present invention.

FIG. 2 is a plan view showing a planar structure of the solar cell in the same embodiment.

FIG. 3 is a plan view showing a plane pattern of a thin film layer in the same embodiment.

FIG. 4 is a plan view showing another planar pattern of the thin film layer in the same embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 Dial receiving ring 12 Solar cell 12a Light receiving surface 12a-1, 12a-2, 12a-3, 12a-4 Light receiving area 12a-0 Gap 13 Translucent plate 14 Dial ring 17 Thin film layer 17a Inner peripheral part 17b Outside Peripheral part 17c Connecting part 17d Time scale part 17e Window frame part

Claims (5)

[Claims] 1. A timepiece with a solar cell having a light receiving surface of a solar cell provided on a time display surface, such that the light receiving surface of the solar cell disposed on the time display surface is covered with the light receiving surface. Providing a light-transmitting plate to be disposed, partially forming a thin film layer formed sufficiently thicker than the wavelength of light in the visible region between the light-receiving surface and the light-transmitting plate, A timepiece with a solar cell, wherein the light-receiving surface and the light-transmitting plate are fixed in a state of being overlapped with each other via 2. The solar cell module according to claim 1, wherein the thin film layer is formed at a portion where at least one of the solar cell and the translucent plate is pressed and fixed by another member. clock. 3. The solar cell module according to claim 1, wherein the thin film layer is formed in a color tone and a pattern that cancels out a pattern of a light receiving portion structure formed on a light receiving surface of the solar cell. clock. 4. The timepiece with a solar cell according to claim 1, wherein the thin film layer forms a time display pattern on the time display surface. 5. The timepiece with a solar cell according to claim 1, wherein the thin film layer is formed by printing on the back surface of the translucent plate.