JP6445306B2 - Timepiece with solar cell and method for hiding deformation marks - Google Patents

Description

  The present invention relates to a timepiece with a solar cell and a method for hiding deformation marks.

  The dial of the timepiece with solar cell is formed of a light-transmitting material so as to transmit light necessary for power generation of the solar cell. In addition, in order to give the dial a metallic luster and improve the appearance, there are cases where a material that transmits light and reflects light is adopted as the material and structure of the dial.

  The following Patent Document 1 describes a timepiece dial with a solar cell having a transmissive dial plate having a prism reflecting surface on the lower surface and a transflective plate provided on the lower surface side of the transmissive dial plate.

JP 2011-174948 A

  In the timepiece dial with a solar cell described in Patent Document 1, the prism surface of the transmissive dial and the transflective plate are provided, so that the light necessary for power generation of the solar cell is transmitted and the surface of the dial. Is bright and clear. However, diversification of design is required for timepiece dials with solar cells, and it is necessary to use transflective reflectors with various reflectivities. Options are limited. And when the light transmissive reflecting plate suitable for these conditions is made of a thermoplastic resin, the light transmissive reflecting plate may be softened when the solar cell timepiece is used in a relatively high temperature environment. . When the light-transmitting reflector is softened, the surface shape of the solar cell is transferred to the light-transmitting reflector, and the light-transmitting reflector is deformed to form deformation marks, which may impair the appearance of the dial.

  An object of the present invention is to maintain the appearance of a dial in a timepiece with a solar cell including a light transmissive reflecting plate.

  The invention disclosed in the present application in order to solve the above problems has various aspects, and the outline of typical ones of these aspects is as follows.

(1) A solar cell, a light-transmitting reflector disposed on the front side of the solar cell, formed of a thermoplastic resin, and having a metallic luster by causing interference reflection by multilayer lamination, and the light-transmitting reflection A light-transmitting substrate disposed on the front side of the plate, the light-transmitting reflector side is an uneven surface, the cross-sectional shape of the protrusions of the uneven surface is a triangle, and the uneven pitch of the uneven surface is 100 μm or less; When the critical angle of the light-transmitting substrate is represented by θc and the apex angle of the triangle is represented by θ, the apex angle θ of the triangle satisfies the relationship of π / 2−θ / 2 ≧ θc Clock with battery.

( 2 ) In (1), the light transmissive reflecting plate is a timepiece with a solar cell having a heat resistant temperature of 60 ° C. or lower.

( 3 ) The timepiece with solar cell according to (1) or (2) , wherein the apex angle of the triangle is 90 ° or less.

( 4 ) The timepiece with solar cell according to any one of (1) to ( 3 ), wherein the uneven surface has a spiral pattern in a plan view.

( 5 ) The solar cell timepiece according to any one of (1) to ( 4 ), wherein the uneven surface has a plurality of line patterns extending from 12 o'clock to 6 o'clock in plan view.

( 6 ) The solar cell timepiece according to any one of (1) to ( 5 ), wherein the light-transmitting reflector is provided with a matte layer on a front surface.

( 7 ) The timepiece with a solar cell according to any one of (1) to ( 6 ), wherein the solar cell and the light transmissive reflecting plate are fixed in a pressed state.

(8) Dial plate provided with a solar cell and a light-transmitting reflecting plate that is arranged on the front side of the solar cell, is formed of a thermoplastic resin, and has a metallic luster by causing interference reflection by multilayer lamination. In this method, the projections formed on the front surface of the solar cell conceal deformation marks formed on the light-transmitting reflector, and the back surface is an uneven surface, and the uneven surface is a convex portion. A light transmissive substrate having a triangular cross-sectional shape and a concavo-convex pitch of the concavo-convex surface of 100 μm or less is placed on the front side of the light transmissive reflector plate, and a critical angle of the light transmissive substrate is set. When the vertical angle θ of the triangle is expressed as θc and the vertical angle θ of the triangle is expressed as θ, the triangular angle θ satisfies the relationship of π / 2−θ / 2 ≧ θc, and the light transmissive substrate is replaced with the light transmissive reflector plate. A method of hiding deformation marks that are fixed together.

According to the above aspect (1) of the present invention, even when deformation marks are formed on the light-transmitting reflector, the aesthetic appearance of the dial is maintained, and when the deformation marks are viewed from the front. Thus, a solar cell timepiece in which deformation marks formed on the light-transmitting substrate are most difficult to visually recognize is obtained.

Further, according to the above aspect ( 2 ) of the present invention, even a light-transmitting reflector that can be thermoformed at a relatively low temperature such as the heat-resistant temperature required for a wristwatch and is easily deformed by heat is aesthetically pleasing. A solar cell timepiece that can be used in a state in which is maintained is obtained.

Moreover, according to the side surface of ( 3 ) of the said invention, the timepiece with a solar cell in which a dotted deformation trace is hard to be visually recognized is obtained.

In addition, according to the above aspect ( 4 ) of the present invention, it is possible to obtain a solar cell timepiece in which generation of structural colors due to light interference is suppressed.

Moreover, according to the side surface of ( 5 ) of the said invention, the timepiece with a solar cell from which a dotted deformation trace is hard to be visually recognized compared with the case where the direction which visually recognizes a line pattern and a dial plate is orthogonal is obtained.

Moreover, according to the side surface of the said ( 6 ) of this invention, the timepiece with a solar cell from which a dotted | punctate deformation trace is hard to be visually recognized is obtained.

In addition, according to the above aspect ( 7 ) of the present invention, the solar cell and the light-transmitting substrate can be securely fixed, and even when placed in a high-temperature environment, dotted deformation marks are visually recognized. A hard watch with a solar battery is obtained.

Further, according to the above aspect ( 8 ) of the present invention, even when deformation marks are formed on the light-transmitting reflector , the appearance of the dial is maintained, and the deformation marks are viewed from the front. Sometimes, a method of concealing the deformation trace formed on the light-transmitting substrate is most difficult to visually recognize .

It is a top view which shows the timepiece with a solar cell which concerns on the 1st Embodiment of this invention. It is sectional drawing of a timepiece with a solar cell. It is an enlarged view of a section of a timepiece with a solar cell. It is a figure explaining reflection of the light at the time of seeing a dial from the front. It is a figure explaining the visible range at the time of seeing a dial from the diagonal. It is a figure explaining the visible range in case the apex angle of the convex part of the back side of a light-transmitting board | substrate is an angle larger than 90 degrees. It is a figure explaining the visible range in case the apex angle of the convex part of the back side of a light transmissive board | substrate is an angle smaller than 90 degrees. It is a top view which shows the inner frame which accommodated the solar cell. It is a top view which shows the light transmissive reflecting plate fitted by the inner frame. It is a top view which shows the timepiece with a solar cell which concerns on the 2nd Embodiment of this invention. It is a top view which shows the timepiece with a solar cell which concerns on the 3rd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a plan view showing a wristwatch 1 with a solar cell according to an embodiment of the present invention. FIG. 1 shows a bezel 2a, a dial ring 2b, a dial plate 3, a spiral pattern 4a, a time letter 5, a date window 6, a pointer 7, and a crown 8. 2 is a cross-sectional view of the solar cell timepiece 1 taken along the line II-II in FIG. FIG. 2 shows a dial 3 composed of a bezel 2a, a dial ring 2b, a time character 5, a windshield 9, a trunk 10, a back cover 11, a movement 12, a light transmissive substrate 20 and a light transmissive reflector 21, a sun A battery 30 is shown.

  The design of the solar cell timepiece 1 shown in FIG. 1 is merely an example. In addition to those shown here, for example, the outer shape of the dial 3 and the solar cell timepiece 1 may be a square shape instead of a round shape, or an index for displaying the second may be attached to the dial ring 2b. Good. Further, the facing ring 2b may be omitted. In the present embodiment, the hands 7 are the hour hand and the minute hand. However, the second hand may be added, and the date is displayed on the date window 6, but not limited thereto, the day of the week is displayed. Also good. Moreover, it is good also as providing the auxiliary | assistant pointer | guide which performs the presence or absence of a time zone or daylight saving time, the battery remaining amount, and various displays. In that case, the user may be able to perform various operations by providing a button in addition to the crown 8 on the outside of the bezel 2a.

  A windshield 9 made of a transparent material such as glass is attached to the bezel 2 a so as to cover the dial 3 in the solar cell timepiece 1. In addition, the dial 3, the solar cell 30, and the movement 12 are accommodated in the exterior part in which the body 10, the bezel 2a, the turn ring 2b, and the windshield 9 are integrated, and the back side is closed by the back cover 11. ing. In this specification, the side (upper side in FIG. 2) on which the windshield 9 of the solar cell timepiece 1 is arranged is the front side, the side on which the back cover 11 is arranged (lower side in FIG. 2) is the back side, and the front side. The surfaces corresponding to the back side and the back side are referred to as a front side surface and a back side surface, respectively.

  A solar cell 30 is disposed on the back side of the dial 3 and power is generated by light incident from the front side. Therefore, the light-transmitting substrate 20 and the light-transmitting reflecting plate 21 constituting the dial plate 3 are formed of a material that transmits light to some extent. Moreover, the light transmissive reflecting plate 21 is formed of a thermoplastic resin and has a relatively high light reflectance of 30% to 70%, and preferably has a metallic luster. Any material having such characteristics may be used as the material for forming the light transmissive reflecting plate 21. As a preferred example, interference reflection is performed by multilayer lamination of PET (polyethylene terephthalate). Mention may be made of the resulting film. Such a light transmissive reflecting plate 21 improves the aesthetic appearance of the dial plate 3 with gloss similar to metal while allowing light to pass through the solar cell 30 arranged on the back side. Such a light transmissive reflector 21 may have a relatively low heat-resistant temperature due to its material or structure. For example, as the light transmissive reflector 21, a Picasas (registered trademark) manufactured by Toray Industries, Inc. is used. In this case, the heat resistant temperature is 60 ° C. In addition, the heat-resistant temperature of the light transmissive reflecting plate 21 may be indicated as a material characteristic, or may be indicated as a lower limit value of the applicable temperature of the hot press. The light transmissive substrate 20 is disposed on the front side of the light transmissive reflective plate 21, and the light transmissive reflective plate 21 side (back side) is an uneven surface.

  FIG. 3 is an enlarged view of a cross section of the solar cell timepiece 1 according to the present embodiment. FIG. 3 is an enlarged view of the enlarged region 50 shown in FIG. The light-transmitting substrate 20 in which the time characters 5 are arranged on the front side surface has an uneven surface on the back side. The cross-sectional shape of the convex part of the irregular surface is a triangle, and the apex angle θ is, for example, 90 ° or less. The triangular slope forming the convex portion is a smooth surface and is a surface that easily reflects light. Further, the uneven pitch p of the uneven surface is, for example, 100 μm or less. Here, the concavo-convex pitch p means a distance between vertices of a triangle forming the convex portion. On the back side of the light transmissive substrate 20, a light transmissive reflecting plate 21 is disposed. A solar cell 30 is disposed on the back side of the light transmissive reflecting plate 21. In the present embodiment, the uneven surface on the back side of the light-transmitting substrate 20 forms the spiral pattern 4a in plan view, but the pattern may be a concentric pattern. However, the generation of structural colors due to light interference is suppressed in the spiral pattern than in the concentric pattern. Therefore, it is desirable to form a spiral pattern rather than a concentric pattern. However, it is also possible to form a concentric pattern on the light-transmitting substrate 20 and positively use the structural color as part of the beauty of the dial 3.

  In the solar cell timepiece 1 according to this embodiment, the light transmissive substrate 20 has a thickness of 400 μm to 500 μm, and the light transmissive reflector 21 has a thickness of 100 μm. If the light transmissive reflecting plate 21 having this thickness is used as a standard in a watch manufactured in the past, it is not necessary to change the design of members other than the dial 3 by selecting the same thickness. The benefits are great. For example, the aforementioned Picasas (registered trademark) is suitable as the light transmissive reflector 21 having a thickness of 100 μm and a selectable reflectance type. However, the optimal thickness of the light-transmitting reflecting plate 21 constituting the dial plate 3 is not limited to 100 μm, and the light-transmitting reflecting plate 21 having a thickness other than 100 μm is typically used in a watch manufactured in the past. If so, its thickness is optimal.

  The solar cell 30 may have minute irregularities on the surface. For example, in the case of an amorphous silicon solar cell, when an amorphous silicon thin film is formed by plasma CVD (Chemical Vapor Deposition) or a transparent electrode such as ITO (Indium Tin Oxide) is formed, sputter traces with a diameter of several hundreds μm are formed on the surface. May be formed. When there is a sputter mark on the surface of the solar cell 30, the solar cell timepiece 1 is placed near the heat-resistant temperature of the light transmissive reflector 21 or at a temperature higher than that, for example, in the dashboard of an automobile. In some cases, the sputter traces of the solar cell 30 may be transferred to the softened light transmissive reflecting plate 21. When the sputter marks are transferred to the light transmissive reflector 21, even if the solar cell timepiece 1 is cooled again, the dot-shaped deformation marks having the same size as the transferred sputter marks are transferred to the light transmissive reflector 21. The appearance of the dial 3 may be impaired. It should be noted that the shape of the deformation trace remaining on the light transmissive reflector 21 varies depending on the shape of the sputtering trace of the solar cell 30 and is not necessarily a dot shape, but may be a linear shape or the like.

  FIG. 4 is a diagram for explaining the reflection of light when the dial 3 is viewed from the front. As described above, when the sputter traces of the solar cell 30 are transferred to the light transmissive reflective plate 21, the dotted deformation marks 60 may be formed on the surface on the front side of the light transmissive reflective plate 21. However, according to the timepiece 1 with the solar cell according to the present embodiment, when the dial 3 is viewed from the front, the light is totally reflected on the slope of the uneven surface if the following condition is satisfied. Therefore, it becomes difficult to visually recognize the point-like deformation marks 60 formed on the back side of the uneven surface. In that case, since the observer 70 who sees the dial 3 from the front visually recognizes the light traveling through the light beam path 61, it becomes difficult to visually recognize the dot-shaped deformation marks 60 formed on the back side of the uneven surface.

  In the following, a description will be given of a condition in which light is totally reflected on the slope of the concavo-convex surface and the point-shaped deformation mark 60 formed on the back side of the concavo-convex surface is most difficult to visually recognize. As shown in FIG. 4, when light is incident on the inclined surface of the concavo-convex surface at an incident angle θi, the reflection angle is equal to the incident angle and is θi. Here, the angle formed between the line of sight of the observer 70 (direction orthogonal to the dial 3) and the slope of the concavo-convex surface is π / 2−θi radians. As is apparent from FIG. 4, the apex angle θ of the triangle forming the convex portion of the concavo-convex surface has a relationship of θ / 2 = π / 2−θi. The incident angle and the reflection angle are defined by angles measured from the normal line of the reflection surface (the slope of the uneven surface).

  When the light totally reflected on the slope of the uneven surface is viewed by the observer 70, when the dial plate 3 is viewed from the front, the point-shaped deformation mark 60 formed on the back side of the uneven surface is most difficult to be viewed. Conceivable. When the critical angle of the light transmissive reflector 21 is expressed as θc, θi ≧ θc must be satisfied in order for total reflection to occur. Therefore, when considering the relationship of θ / 2 = π / 2−θi, when the dial plate 3 is viewed from the front, the point-shaped deformation marks 60 formed on the back side of the uneven surface are most difficult to be visually recognized. It can be seen that the condition is π / 2−θ / 2 ≧ θc. For example, if the critical angle is 45 ° (π / 4 radians), the condition for making the point-shaped deformation mark 60 most difficult to be visually recognized is θ ≦ π / 2, and the apex angle θ is 90 ° or less. It can be seen that total reflection occurs and the point-shaped deformation marks 60 formed on the back side of the uneven surface are difficult to be visually recognized. The critical angle is an angle determined by the relationship sin (θc) = 1 / n, where n is the refractive index of the light-transmitting substrate 20 and 1 is the refractive index of air. In addition, even if the apex angle θ of the convex portion does not satisfy the condition of π / 2−θ / 2 ≧ θc, the effect that it is difficult to visually recognize the point-like deformation marks 60 formed on the back side of the uneven surface is Demonstrated. For example, even when the critical angle is 45 ° and the apex angle of the convex portion is slightly larger than 90 °, the amount of light transmitted through the slope of the uneven surface does not increase significantly, but exceeds 90 °. It will increase slightly according to the increased angle. Therefore, even when total reflection does not occur on the slope of the uneven surface, a part of the light is reflected according to the apex angle, so that the point-like deformation mark 60 is visually recognized as compared with the case without the uneven surface. It becomes difficult. In addition, the deformation | transformation trace formed in the light transmissive reflecting plate 21 has a concave surface on the back side or the inside of the light transmissive reflecting plate 21 without being deformed at a place other than the surface on the front side, for example, the surface on the front side is flat. Even in the case of being formed in a state, if the above-described condition that the light is totally reflected by the inclined surface of the uneven surface on the back side of the light-transmitting substrate 20 is satisfied, the deformation trace is similarly difficult to be visually recognized.

  FIG. 5 is a diagram for explaining the visible range when the dial 3 is viewed from an oblique direction. Among the cases where the dial 3 is viewed from an oblique direction, it is considered that the dot-shaped deformation marks 60 formed on the light-transmissive reflecting plate 21 are most easily recognized when light is not totally reflected on the uneven surface. In this case, the dial 3 is viewed from an angle orthogonal to the slope of the irregular surface. In this case, the surface of the range L among the surfaces on the front side of the light transmissive reflecting plate 21 is visually recognized over the slope of one convex portion. In FIG. 5, strictly speaking, the light refracted according to the surface state reaches the observer 70 on the surface on the front side of the light-transmitting substrate 20 but does not affect the visible range, and thus is not shown. And simplified. The same applies to other figures (in the case of FIGS. 6A and 6B described later) showing the dial 3 viewed from an oblique direction.

  If the entire point-shaped deformation mark 60 falls within the range L, it is considered that the observer 70 can visually recognize the point-shaped deformation mark 60 when viewing the dial plate 3 from an oblique direction. On the other hand, when the entire point-like deformation mark 60 does not fit in the range L, that is, when the range L is smaller than the size of the point-like deformation mark 60, the point-like deformation mark 60 is divided and visually recognized by the slopes of the plurality of convex portions. This is considered to make it difficult to visually recognize the point-like deformation mark 60. Therefore, when the diameter of the dotted deformation mark 60 is D, a condition that makes it difficult to visually recognize the dotted deformation mark 60 when the dial 3 is viewed obliquely is L ≦ D. When the deformation trace formed on the light-transmissive reflecting plate 21 has a shape other than a circle in plan view, consider a circle having an area equal to the area of the deformation trace when viewed in plan. It may be defined as the size of the deformation mark.

  Further, when the dial 3 is viewed from an oblique direction, the surface on the front side of the light transmissive substrate 20 is viewed from an oblique direction, so that the amount of reflection of light generated on the surface on the front side of the light transmissive substrate 20 increases. Also, it is difficult for the dot-shaped deformation marks 60 to be visually recognized. Thus, when the dial 3 is viewed obliquely, it seems that the dotted deformation marks 60 are divided at both the peaks and valleys of the concave and convex surfaces, and therefore the diameter D and the concave and convex pitch P of the dotted deformation marks 60. If it is D ≧ P / 2, it seems that the point-like deformation mark 60 is difficult to be visually recognized, but the condition is that D ≧ P as described above.

  Next, the visual field range when the apex angle of the convex part on the back side of the light-transmitting substrate 20 is 90 ° and when the vertex angle is other than 90 ° will be described. When the apex angle of the convex portion on the back side of the light transmissive substrate 20 is 90 °, the visual field range L when the dial 3 is viewed from an angle orthogonal to the slope of the concavo-convex surface is equal to the concavo-convex pitch P. In this case, the angle formed by the two slopes in the pitch P shown in FIG. 5 is 90 °, and when viewed from the angle orthogonal to the right slope in the pitch P, the line of sight is the left slope in the pitch P. Since they are parallel, the tip of the left slope becomes the end of the visual field range L. Similarly, since the end portion of the right slope in the pitch P becomes the other end portion of the visual field range L, the visual field range L is the length between both ends of the two slopes in the pitch P shown in FIG. This length is the pitch P.

  FIG. 6A is a diagram illustrating the visible range when the apex angle θ1 of the convex portion on the back side of the light-transmitting substrate 20 is an angle larger than 90 °. FIG. 6B is a diagram illustrating the visible range when the apex angle θ2 of the convex portion on the back side of the light transmissive substrate 20 is an angle smaller than 90 °. In FIG. 6A and FIG. 6B, the case where the apex angle of the convex part on the back side of the light-transmitting substrate 20 is 90 ° is drawn with a broken line, the main part is enlarged, and the other parts are not shown.

  As shown by the solid line in FIG. 6A, when the apex angle θ1 of the convex portion on the back side of the light transmissive substrate 20 is larger than 90 °, the observer 70a moves the dial 3 from the direction perpendicular to the slope of the concavo-convex surface. When viewed, the range L1 on the surface of the light transmissive reflecting plate 21 is visually recognized. The range L1 is narrower than the visible range L of the observer 70 when the apex angle of the convex portion indicated by the broken line in FIG. 6A is 90 °.

  In addition, as shown by the solid line in FIG. 6B, when the apex angle θ2 of the convex portion on the back side of the light-transmitting substrate 20 is smaller than 90 °, the observer 70b dials the dial from the direction perpendicular to the slope of the uneven surface. 3, a range L <b> 2 on the surface of the light transmissive reflecting plate 21 is visually recognized. The range L2 is narrower than the visible range L of the observer 70 when the apex angle of the convex portion indicated by the broken line in FIG. 6B is 90 °. In FIG. 6B, the field of view of the region on the vertex Tb side of the line S1 passing through the vertex Ta is blocked by the slope between the vertices Ta to Tb. Similarly, the visual field of the region on the vertex Tc side of the line S2 passing through the vertex Td is blocked by the slopes of the vertices Tc to Td. Thus, when the observer 70b views the dial 3 from a direction orthogonal to the slope of the concavo-convex surface, the field of view becomes the widest when the apex angle of the convex portion on the back side of the light-transmitting substrate 20 is 90 °.

  In order to support the above-mentioned theory, the inventors of the present invention respectively create a light-transmitting substrate 20 in which the apex angle θ of the convex portion is 90 ° and the uneven pitch P is 50 μm, 100 μm, and 150 μm, An experiment was conducted to see how much the dot-shaped deformation mark 60 is visually recognized. As a result, when the concavo-convex pitch P is 150 μm, the spot-shaped deformation marks 60 are visually recognized. When the concavo-convex pitch P is 100 μm, the point-shaped deformation marks 60 are hardly visible, and when the concavo-convex pitch P is 50 μm. The dotted deformation marks 60 were not visually recognized at all. Here, since the thing with a diameter of 100 micrometers or less among the dotted | punctate deformation traces 60 cannot be visually recognized in the first place, it is thought that the magnitude | size of the deformation | transformation traces which can be visually recognized is about 100 micrometers. Therefore, the experimental result that the spot-like deformation marks 60 are hardly visually recognized if the uneven pitch P is 100 μm or less is consistent with the above theory. When the dial 3 is viewed from the angle between the angle perpendicular to the slope of the concavo-convex surface and the front surface, light is totally reflected on the slope of the concavo-convex surface, and the point-shaped deformation traces are caused by the plurality of convex portions. It is considered that the point-shaped deformation marks 60 are difficult to be visually recognized for both reasons that the 60 is divided and visually recognized. Further, even if the deformation trace formed on the light transmissive reflective plate 21 is formed on a place other than the surface on the front side, for example, on the back surface or inside of the light transmissive reflective plate 21, the deformation trace is not present. Similarly, when the above-described condition of being divided by a plurality of convex portions is satisfied, it is difficult to visually recognize the deformation trace.

  Based on the above theory and experimental results, the field of view is the widest when the apex angle of the convex portion on the back side of the light-transmitting substrate 20 is 90 °, so the pitch on the back side of the light-transmitting substrate 20 is 100 μm or less. If there is, the point-like deformation marks 60 are divided by the slopes of the plurality of convex portions and viewed at an arbitrary angle where the apex angle of the convex portion on the back side of the light-transmitting substrate 20 is less than 180 °. It becomes difficult to visually recognize the deformation mark 60. Moreover, even if a design change that changes the apex angle of the convex portion occurs or the apex angle of the convex portion cannot be accurately formed at 90 °, the pitch on the back side of the light transmissive substrate 20 is changed or corrected. There is no need. That is, by setting the pitch on the back side of the light transmissive substrate 20 to 100 μm or less, the light transmissive substrate 20 can be easily applied to the dial 3. Furthermore, when the apex angle of the convex part on the back side of the light-transmitting substrate 20 is 90 ° or more, the diameter D of the spot-like deformation mark 60 for making it difficult to visually recognize the point-like deformation mark 60 as follows. And the concavo-convex pitch P can be obtained.

As can be seen from FIG. 5, the length of the slope of the convex portion is P / (2 cos (π / 2−θ / 2)). Since 1 / cos (π / 2−θ / 2) of the length of the slope is L, the relationship between the range L and the apex angle θ of the convex portion and the concave / convex pitch P is L = P / (2cos ² ( π / 2−θ / 2)). Therefore, when the apex angle of the convex portion is 90 ° or more, the condition for the apex angle θ of the convex portion and the concave / convex pitch P for making it difficult to visually recognize the point-shaped deformation mark 60 is D ≧ P / (2cos ² (π / 2-θ / 2)). For example, when the apex angle θ of the convex portion is a right angle (π / 2 radians), D ≧ P, and when the concavo-convex pitch is smaller than the size of the point-like deformation mark 60, the point-like deformation mark 60 is difficult to be visually recognized. . Thus, when the apex angle of the convex part on the back side of the light transmissive substrate 20 is 90 ° or more, based on the conditional expression D ≧ P / ( ² cos ² (π / 2−θ / 2)), By setting the concavo-convex pitch P to a value larger than 100 μm, the design of the dial 3 can be further diversified.

  A matte layer may be provided on the front surface of the light transmissive reflector 21. If a matte layer is provided on the front surface of the light transmissive reflector 21, light is diffused, and the dot-shaped deformation marks formed on the light transmissive reflector 21 are more difficult to visually recognize. Further, it is possible to prevent the moire pattern from being generated when the light-transmitting substrate 20 is attached to the light-transmitting reflecting plate 21.

  A light-transmitting colored layer may be provided on the front surface of the light-transmitting reflecting plate 21. If a light-transmitting colored layer is provided on the surface of the light-transmitting reflecting plate 21, the transmission of light of a specific wavelength is hindered, and the point-shaped deformation marks formed on the light-transmitting reflecting plate 21 are more difficult to visually recognize. Become. Moreover, you may employ | adopt the structure which combined the light transmissive colored layer and the matte layer. In that case, it is desirable to form the light-transmitting colored layer on the back side of the matte layer so as not to fill the irregularities formed on the surface of the matte layer. That is, it is desirable to form a light transmissive colored layer on the front side of the light transmissive reflective plate 21 and to form a matte layer on the front side of the light transmissive colored layer.

  A matte layer may be provided on the front surface of the light transmissive substrate 20. If a matte layer is provided on the front surface of the light-transmitting substrate 20, light is diffused, and the point-shaped deformation marks formed on the light-transmitting reflecting plate 21 are more difficult to visually recognize. Of course, it is good also as employ | adopting the structure which combined said structure.

  FIG. 7 is a plan view showing the middle frame 40 in which the solar cells 30 are housed. The middle frame 40 is a case for accommodating the movement 12 and the like inside. The solar cell 30 is arranged so as to overlap the front side of the movement 12. The solar cell 30 is positioned and arranged by aligning the notch formed on the periphery of the solar cell 30 with the notch formed on the periphery of the middle frame 40. The middle frame 40 includes a first fitting part 41 and a second fitting part 42. The first fitting portion 41 and the second fitting portion 42 are members for aligning the light transmissive reflecting plate 21 and overlapping the light transmissive substrate 20 that are arranged on the front side of the solar cell 30. .

  FIG. 8 is a plan view showing the light transmissive reflecting plate 21 arranged in the middle frame 40. The light transmissive reflecting plate 21 is aligned by the first fitting portion 41 and the second fitting portion 42 of the middle frame 40. The light transmissive substrate 20 is held without dropping from the middle frame 40 by fixing the light transmissive substrate 20 to the first fitting portion 41 and the second fitting portion 42 by fitting. At this time, the light transmissive reflecting plate 21 and the solar cell 30 are in contact with each other and fixed in a pressed state. This is one of the factors that cause the sputter marks of the solar cell 30 to be transferred to the light transmissive reflector 21. In addition, the fixing structure of the solar cell 30 and the light transmissive reflecting plate 21 shown in FIGS. 7 and 8 is an example. In order to prevent the members constituting the dial 3 from moving without being limited to such a structure, it is necessary to fix the light transmissive reflecting plate 21 in a pressed state against the solar cell 30.

  Whether or not the sputter traces of the solar cell 30 are transferred to the light transmissive reflecting plate 21 can be determined by the following method. First, a solar cell 30 that may have a sputter mark is prepared. In order to reproduce the conditions under which the solar cell timepiece is used as a product, it is desirable to prepare the solar cell 30 in a state of being disposed in the middle frame 40.

  Next, the light transmissive reflecting plate 21 and the light transmissive substrate 20 are disposed on the front side of the solar cell 30. The light transmissive reflecting plate 21 is aligned by the first fitting portion 41 and the second fitting portion 42 of the middle frame 40, and the light transmissive substrate 20 is fitted and fixed to these fitting portions. It is desirable.

  Thereafter, the solar cell 30, the light transmissive reflector 21, and the light transmissive substrate 20 are heated to a predetermined temperature that is a heat-resistant temperature required for the solar cell timepiece 1, for example, 60 ° C. When the light transmissive reflecting plate 21 is softened by heating, the sputter marks of the solar cell 30 may be transferred to the light transmissive reflecting plate 21.

  Finally, the front side surface, the inside, and the back side surface of the light transmissive reflecting plate 21 are observed. Thereby, it is inspected whether or not deformation traces such as dot-like deformation traces are formed on the light transmissive reflecting plate 21.

  Even when deformation marks such as dot-shaped deformation marks are observed on the light-transmissive reflecting plate 21, it is possible to design a watch with a solar cell in which the deformation marks are difficult to be visually recognized by the following method. First, the size of what can be visually recognized among the deformation | transformation traces observed in the light transmissive reflecting plate 21 is measured. Here, the size of the deformation mark is the diameter of the point-like deformation mark when the deformation mark is a point-like deformation mark when viewed in plan. When the deformation trace is not a point-like deformation trace, a circle having an area equal to the area of the deformation trace when the deformation trace is viewed in plan may be considered, and the diameter of the circle may be the size of the deformation trace.

  Next, the concavo-convex pitch of the concavo-convex surface formed on the back surface of the light transmissive substrate 20 is set based on the measurement result of the size of the deformation trace that can be visually recognized. The upper limit value of the uneven pitch is determined so that deformation marks of all sizes are difficult to be visually recognized. The concavo-convex pitch may be determined by adjusting so that a clear pattern appears on the dial 3 while being below the upper limit value. The concavo-convex pitch may be designed based on a critical angle derived from the refractive index of the light-transmitting substrate 20, and may be adjusted based on a measurement result of the size of deformation marks that can be visually recognized.

  In the timepiece 1 with a solar cell according to the present embodiment, deformation marks such as dotted deformation marks are formed on the light transmissive reflector 21 by protrusions such as sputter marks formed on the front surface of the solar cell 30. There is a case. Even in such a case, the deformation trace can be hidden by applying a method in which the light-transmitting substrate 20 is placed on the front side of the light-transmitting reflecting plate 21 and is fixed to the dial 3. The light-transmitting substrate 20 has a concavo-convex surface having a triangular cross-sectional shape on the back surface and a concavo-convex pitch of 100 μm or less. For this reason, when the dial 3 is viewed from the front or obliquely, the deformation marks formed on the light transmissive reflecting plate 21 are difficult to be visually recognized. The light transmissive substrate 20 is fixed by pressing the light transmissive reflecting plate 21. Therefore, it is necessary to use a material that does not deform at least at 60 ° C. as the material of the light transmissive substrate 20 so that the similar deformation marks are not formed on the light transmissive substrate 20 due to the deformation marks formed on the light transmissive reflector 21. There is. Here, since the light transmissive reflecting plate 21 may be formed using a material that is deformed at 60 ° C. or lower, in other words, the light transmissive substrate 20 is a material having a higher heat resistance temperature than the light transmissive reflecting plate 21. It is formed using.

[Second Embodiment]
FIG. 9 is a plan view showing a timepiece 1 with a solar cell according to the second embodiment of the present invention. The difference between the solar cell timepiece 1 according to this embodiment and the solar cell timepiece 1 according to the first embodiment shown in FIG. 1 is that the dial 3 has a plurality of line patterns 4b in a plan view. This is the point that appears. The stripe pattern 4 b is formed by an uneven surface on the back side of the light transmissive substrate 20. The stripe pattern 4b is formed by unevenness extending from 12 o'clock to 6 o'clock, and the uneven pitch is, for example, 100 μm or less. Here, the uneven pitch is the distance between the apexes of adjacent convex portions. The cross-sectional shape of the convex portion is a triangle, and the apex angle is, for example, 90 ° or less.

  According to the solar cell timepiece 1 according to the present embodiment, even if a spot-shaped deformation mark having a size that can be visually recognized is formed on the light-transmissive reflective plate 21, the dot-shaped deformation mark is separated by two or more irregularities. It will be visually recognized, and it becomes difficult to visually recognize the point-like deformation trace. Further, the stripe pattern 4b extends in the 12 o'clock to 6 o'clock direction, so that the dial plate 3 is viewed obliquely from the 6 o'clock direction, or when the dial plate 3 is viewed from the front, the slopes constituting the irregularities are viewed obliquely. In other words, since the light is reflected on the inclined surface, the point-like deformation marks are more difficult to be visually recognized. On the other hand, when the dial 3 is viewed obliquely from the 3 o'clock direction or the 9 o'clock direction, the inclined surface is viewed from a direction orthogonal to the inclined surface forming the unevenness, and the amount of light transmission increases and the point-like deformation marks are visually recognized. It becomes easy to be done. Since the dial plate 3 is usually viewed obliquely from the 6 o'clock direction or the dial plate 3 is viewed from the front, the stripe pattern 4b is formed to extend in the 12 o'clock to 6 o'clock direction as in this embodiment. By doing so, it becomes difficult to visually recognize the point-like deformation trace. Further, a condition where π / 2−θ / 2 ≧ θc is established between the apex angle θ of the triangle forming the convex portion of the uneven surface on the back side of the light transmissive substrate 20 and the critical angle θc of the light transmissive substrate 20. If satisfied, the light is totally reflected on the slope of the uneven surface, and the point-shaped deformation marks are hardest to be visually recognized. Specifically, when the critical angle θc is 45 °, if the apex angle θ of the convex portion is 90 ° or less, the point-shaped deformation traces are most difficult to be visually recognized. In addition, when the size of the spot-like deformation mark that can be visually recognized is 100 μm, when the uneven pitch P is 100 μm or less, the dial 3 is viewed obliquely without depending on the apex angle θ of the protrusions. Even so, the point-like deformation marks are separated and visually recognized by the two or more irregularities, and the point-like deformation marks are more difficult to be visually recognized.

[Third Embodiment]
FIG. 10 is a plan view showing a solar cell timepiece 1 according to the third embodiment of the present invention. The difference between the solar cell timepiece 1 according to the present embodiment and the solar cell timepiece 1 according to the first embodiment shown in FIG. 1 is that a square pyramid pattern 4 c appears on the dial 3. The prism pattern 4 c is formed by an uneven surface on the back side of the light transmissive substrate 20. The quadrangular pyramid pattern 4 c is formed in a quadrangular pyramid shape protruding from the back surface of the light transmissive substrate 20 toward the back side. The quadrangular pyramid pattern 4c is formed such that the ridge line of the quadrangular pyramid forming the pattern extends in the 12 o'clock to 6 o'clock direction, and the uneven pitch is, for example, 100 μm or less. In this embodiment, the uneven pitch is the distance between the apexes of adjacent quadrangular pyramids. The quadrangular pyramid is a regular quadrangular pyramid, and the cross-sectional shape is a triangle. The apex angle of the triangle is, for example, 90 ° or less.

  According to the solar cell timepiece 1 according to the present embodiment, even if the uneven surface of the light-transmitting substrate 20 forms a dot-shaped deformation mark having a size that can be visually recognized on the light-transmitting reflecting plate 21, the dot-shaped deformation is achieved. The traces are separated and visually recognized by two or more irregularities, and the dot-shaped deformation traces are more difficult to visually recognize. Further, when the ridgeline of the quadrangular pyramid forming the quadrangular pyramid pattern 4c extends in the 12 o'clock to 6 o'clock direction, the dial 3 is viewed obliquely from the 6 o'clock direction, or when the dial 3 is viewed from the front, The inclined surface constituting the pyramid is viewed from an oblique direction, and light is reflected on the inclined surface, so that the spot-like deformation marks are more difficult to visually recognize. On the other hand, when the dial plate 3 is viewed obliquely from the 3 o'clock direction or the 9 o'clock direction, the inclined surface is viewed from a direction orthogonal to the inclined surface forming the quadrangular pyramid, and the amount of light transmission increases, resulting in point-shaped deformation marks. It becomes easy to be visually recognized. Since the dial plate 3 is usually viewed obliquely from the 6 o'clock direction or the dial plate 3 is viewed from the front, the ridgeline of the quadrangular pyramid that forms the quadrangular pyramid pattern 4c as in the present embodiment is 12: 00- By forming so as to extend in the 6 o'clock direction, it is possible to make it more difficult to visually recognize the point-like deformation marks. Deformation marks Also, the apex angle θ of the quadrangular pyramid that forms the convex portion of the uneven surface on the back side of the light transmissive substrate 20 is π / 2−θ / 2 ≧ with respect to the critical angle θc of the light transmissive substrate 20. If the condition of [theta] c is satisfied, the light is totally reflected on the slope of the concavo-convex surface, and the dot-shaped deformation mark is most difficult to be visually recognized. Specifically, when the critical angle θc is 45 °, if the apex angle θ of the quadrangular pyramid is 90 ° or less, the point-shaped deformation marks are most difficult to be visually recognized. Further, when the size of the spot-like deformation mark that can be visually recognized is 100 μm, when the uneven pitch P is 100 μm or less, the dial 3 is viewed obliquely without depending on the apex angle θ of the quadrangular pyramid. Even so, the point-like deformation marks are separated and visually recognized by the two or more irregularities, and the point-like deformation marks are more difficult to be visually recognized.

  1 watch with solar battery, 2a bezel, 2b turn ring, 3 dial, 4a spiral pattern, 4b stripe pattern, 4c square pyramid pattern, 5 hour letter, 6 day window, 7 pointer, 8 crown, 9 windshield, 10 trunk, DESCRIPTION OF SYMBOLS 11 Back cover, 12 Movement, 20 Light transmissive board | substrate, 21 Light transmissive reflecting plate, 30 Solar cell, 40 Middle frame, 41 1st fitting part, 42 2nd fitting part, 50 Expansion area, 60 Point-like deformation Trace, 61 ray path, 70, 70a, 70b Observer.

Claims (8)

Solar cells,
A light-transmitting reflecting plate disposed on the front side of the solar cell, formed of a thermoplastic resin, and having a metallic luster by causing interference reflection by multilayer lamination ;
Light that is disposed on the front side of the light transmissive reflective plate, the light transmissive reflective plate side is an uneven surface, the cross-sectional shape of the convex portion of the uneven surface is a triangle, and the uneven pitch of the uneven surface is 100 μm or less. A transparent substrate;
Equipped with a,
When the critical angle of the light-transmitting substrate is expressed as θc and the apex angle of the triangle is expressed as θ, the apex angle θ of the triangle satisfies the relationship of π / 2−θ / 2 ≧ θc. Clock with solar battery. The timepiece with solar cell according to claim 1, wherein the light transmissive reflector has a heat resistant temperature of 60 ° C. or less. The timepiece with solar cell according to claim 1 or 2 , wherein an apex angle of the triangle is 90 ° or less. The timepiece with solar cell according to any one of claims 1 to 3 , wherein the uneven surface has a spiral pattern in plan view. The timepiece with solar cell according to any one of claims 1 to 4 , wherein the uneven surface has a plurality of line patterns extending from 12 o'clock to 6 o'clock in plan view. The timepiece with solar cell according to any one of claims 1 to 5 , wherein a matte layer is provided on a front side surface of the light transmissive reflecting plate. The timepiece with a solar cell according to any one of claims 1 to 6 , wherein the solar cell and the light-transmissive reflecting plate are fixed while being pressed against each other. In a dial plate comprising a solar cell and a light-transmitting reflecting plate that is arranged on the front side of the solar cell, is formed of a thermoplastic resin, and has a metallic luster by causing interference reflection by multilayer lamination ,
A method of concealing deformation marks formed on the light transmissive reflector plate by protrusions formed on the front surface of the solar cell,
A light-transmitting substrate in which the back surface is an uneven surface, the cross-sectional shape of the convex portion of the uneven surface is a triangle, and the uneven pitch of the uneven surface is 100 μm or less, the front side of the light-transmitting reflector Placed on top of each other
When the critical angle of the light transmissive substrate is represented as θc and the apex angle of the triangle is represented as θ, the apex angle θ of the triangle satisfies the relationship of π / 2−θ / 2 ≧ θc,
A method of concealing a deformation trace, wherein the light transmissive substrate is fixed integrally with the light transmissive reflector.

Images