Patent Publication Number: US-2021191329-A1

Title: Timepiece display plate, timepiece, and method of manufacturing timepiece display plate

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to Japanese patent application No. 2019-231322, filed on Dec. 23, 2019 and Japanese patent application No. 2020-004295, filed on Jan. 15, 2020, the entire contents of each of which are incorporated by reference herein in their entireties and made a part of this specification. 
     FIELD OF THE INVENTION 
     The present disclosure relates to a timepiece display plate, a timepiece, and a method of manufacturing the timepiece display plate. 
     BACKGROUND 
     A timepiece display plate (hereinafter, display plate) made of a metal material for use in, for example, a dial of a timepiece is popular because such a metal display plate offers a sense of luxury. High brightness reflection is one reason that the metal material exhibits a sense of luxury. 
     However, the metal display plate hardly transmits light and radio wave. For this reason, such a metal display plate cannot be used for a solar cell timepiece in which the solar cell for receiving solar light is disposed under a display plate and a wave correction timepiece in which an antenna for receiving radio wave is disposed under a display plate. 
     Accordingly, a display plate capable of obtaining reflection light (metal tone reflection light) similar to the reflection light by metal while transmitting light and radio wave is demanded. For example, JP2012-063342A describes such a display plate including a base capable of transmitting electromagnetic wave and a dispersion film in which metal powders are dispersed. The dispersion film is laminated on the base. 
     However, in the display plate described in JP 2012-063342A, the metal powders are separated from each other in the thickness direction of the dispersion film and also disposed to be parallel to the surface direction of the dispersion film. It is therefore necessary to form the dispersion film by a plurality of steps, which complicates the manufacturing process, and increases the costs. 
     The present disclosure has been made in view of the above circumstance, and an object of the present disclosure is to provide a timepiece display plate capable of simplifying a manufacturing process and reducing the costs, and also obtaining reflection light (metal tone reflection light) similar to reflection light by metal while transmitting light and radio wave, a timepiece, and a method of manufacturing the timepiece display plate. 
     SUMMARY 
     The present disclosure relates to a timepiece display plate including a flat plate base that transmits light, a plurality of metallic foil pieces that are disposed on one face of the base, each of the plurality of metallic foil pieces having a thin thickness that transmits the light, and a protection layer that is laminated on the one face to cover the metallic foil pieces and transmit the light. 
     The present disclosure relates to a timepiece display plate including a flat plate base that transmits light, a dispersion film in which a plurality of metallic foil pieces are dispersed, the metallic foil pieces reflecting the light to a resin that transmits the light, wherein the flat plate base and the dispersion film are laminated, and the dispersion film includes an opening portion without the metallic foil piece at a predetermined ratio in a planer view. 
     The present disclosure relates to a timepiece including the timepiece display plate according to the present disclosure as a dial. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a plan view illustrating a timepiece having a dial as a first embodiment of a timepiece display plate according to the present disclosure. 
         FIG. 2  is a sectional view, along an I-I line, of the timepiece illustrated in  FIG. 1 . 
         FIG. 3  is a sectional view similar to  FIG. 2 , illustrating the dial of the first embodiment. 
         FIG. 4  is a sectional view corresponding to  FIG. 3 , illustrating a base in the dial. 
         FIG. 5  is a photography showing aluminum flakes and opening portions in a planer view when observing the dial with an electron microscope, as one example. 
         FIG. 6  is a sectional view corresponding to  FIG. 3 , illustrating the base just after a coating film is formed by splaying a paint onto a surface of the base in a manufacturing process of the dial. 
         FIG. 7  is a sectional view corresponding to  FIG. 6 , illustrating the base from which solution of the paint is volatilized after the coating film is formed by spraying the paint onto the surface of the base in the manufacturing process of the dial. 
         FIG. 8  is a photography showing the metal tone dial visually recognized by a viewer from a front face of the dial, as one example. 
         FIG. 9  is a sectional view corresponding to  FIG. 3 , illustrating a second modified example of the dial of the first embodiment. 
         FIG. 10  is a sectional view corresponding to  FIG. 3 , illustrating a third modified example of the dial of the first embodiment. 
         FIG. 11  is a sectional view similar to  FIG. 2 , illustrating a dial of a second embodiment. 
         FIG. 12  is a photography showing aluminum flakes and opening portions in a planer view when observing the dial with an optical microscope, as one example. 
         FIG. 13  is a sectional view corresponding to  FIG. 11 , illustrating a base just after a dispersion film is formed by spraying a paint onto a surface of the base in a manufacturing process of the dial. 
         FIG. 14  is a photography showing the metal tone dial visually recognized by a viewer from a front face of the dial, as one example. 
         FIG. 15  is a sectional view corresponding to  FIG. 11 , illustrating a first modified example of the dial of the second embodiment. 
         FIG. 16  is a sectional view corresponding to  FIG. 11 , illustrating a second modified example of the dial of the second embodiment. 
         FIG. 17  is a sectional view corresponding to  FIG. 11 , illustrating a third modified example of the dial of the second embodiment in which the first modified example of the second embodiment is incorporated into the second modified example of the second embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     With respect to the use of plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity. 
     Hereinafter, embodiments of a timepiece display plate, a timepiece, and a method of manufacturing the timepiece display plate according to the present disclosure will be described with reference to the drawings. 
     First Embodiment 
     A configuration of a timepiece will be described.  FIG. 1  is a plan view illustrating a timepiece  100  including a dial  10  as a first embodiment of the timepiece display plate according to the present disclosure. The timepiece  100  is the first embodiment of the timepiece according to the present disclosure.  FIG. 2  is a sectional view, along an I-I line, of the timepiece  100  illustrated in  FIG. 1 . In addition,  FIGS. 1, 2  are commonly referred in the first embodiment and a second embodiment. 
     As illustrated in  FIGS. 1, 2 , the timepiece  100  includes a metal casing  50 , the dial  10 , a hand  80 , a dial trim ring  52 , and a movement  70 . The dial  10 , the hand  80 , the dial trim ring  52 , and the movement  70  are provided inside the metal casing  50 . One end of the casing  50  which corresponds to a front face of the timepiece  100  is closed by a windshield  60 , and the other end of the casing  50  which corresponds to a rear face of the timepiece  100  is closed by a metal rear lid  51 . 
     The dial trim ring  52  is disposed in a circumference rim of the dial  10 . A hand shaft  75  projecting along a center C from the movement  70  disposed in the rear face of the dial  10  passes through the dial  10 , and the hand  80  is fixed to the hand shaft  75 . The hand  80  rotates by the rotation of the hand shaft  75  about the center C, and indicates an hour mark (index) provided on the front face of the dial  10  in accordance with the rotation position, so as to display a time. 
     A configuration of the dial will be described.  FIG. 3  is a sectional view similar to  FIG. 2 , illustrating the dial  10  of the first embodiment.  FIG. 4  is a sectional view corresponding to  FIG. 3 , illustrating a base  20  of the dial  10 . In addition,  FIG. 4  is also commonly referred in the first embodiment and the second embodiment.  FIG. 5  is a photography showing aluminum flakes  31  and opening portions  11  in a planer view when observing the dial  10  with an electron microscope, as one example. 
     As illustrated in  FIG. 3 , the dial  10  includes, on a rear face  10   b  (close to movement  70 ) thereof, the base  20 , on a front face  10   a  thereof, a protection layer  40 , and a plurality of aluminum flakes  31  disposed between the base  20  and the protection layer  40 . The base  20 , the protection layer  40 , and the aluminum flakes  31  are laminated. 
     The base  20  is made of a light transmitting material that transmits light L. The light transmitting material includes polycarbonate, for example, but it is not limited thereto as long as it has a light transmitting property. Such a material may include acrylic resin and glass. The base  20  may be colored or colorless. 
     As illustrated in  FIG. 4 , the base  20  is a plate base including the flat front face  20   a  and the flat rear face  20   b . The base  20  has a circular external contour or an oval external contour. However, the base  20  is not limited to such external contours, and the base  20  may have an elliptical external contour or a rectangular external contour. 
     The base  20  has a thickness of 500 μm, for example. The thickness of the base  20  is not limited to 500 μm. The base  20  may have a thickness smaller than or larger than 500 μm, and have a thickness of 300 to 650 μm, for example, as long as the base  20  has a strength and a rigidity as the dial  10 . 
     As illustrated in  FIG. 3 , a plurality of aluminum flakes  31  (aluminum foil pieces as one example of metal foil pieces) are laminated on the most part of one face (front face  20   a ) of the base  20 . 
     The aluminum flake  31  is a minute aluminum material, and is formed as a thin foil piece having a size in a specific direction significantly smaller than that in the other direction. The aluminum flake  31  is extremely thin, and has a thickness of about 10 to 30 nm, for example. Although this thin aluminum flake  31  is a metal foil piece, it may transmit the light L. 
     The aluminum flake  31  has a flat smooth surface. In the example illustrated in  FIG. 3 , some of the aluminum flakes  31  are bent. A part of the extremely thin aluminum flake  31  is laminated on another aluminum flake  31 , so that the aluminum flake  31  follows the surface of another aluminum flake  31  and the front face  20   a  of the base  20 . The border part of the aluminum flake  31  is thereby bent. 
     As described above, a plurality of aluminum flakes  31  lie on the front face  20   a  of the base  20  such that the flat faces of the aluminum flakes  31  are arranged substantially parallel to the front face  20   a  of the base  20 . 
     The front face  20   a  may include an opening portion  11  (refer to  FIG. 3 ) without the aluminum flake  31  in a planar view as seen in a thickness direction from the front face  10   a  to the rear face  10   b  of the dial  10 . The photography of  FIG. 5  by the electron microscope shows some parts of the front face  20   a  without the aluminum flakes  31  in a planer view as the opening portions  11 . 
     The opening portion  11  without the aluminum flake  31  in a planer view transmits the light L such as visible light from the front face  10   a  to the rear face  10   b  of the dial  10 . On the other hand, some parts of the front face  20   a  with the aluminum flakes  31  in a planer view (some parts except opening portions  11 ) generally reflect the light L traveling from the front face  10   a  toward the rear face  10   b  of the dial  10  by the flat faces of the aluminum flakes  31 . 
     As the aluminum flake  31  in the first embodiment is extremely thin as described above, even though about one to four aluminum flakes  31  are laminated, the aluminum flakes  31  transmit a part of the light L incident from the front face  10   a  of the dial  10  to the rear face  20   b  of the base  20 . In other words, even though the front face  20   a  has no opening portion  11  (opening ratio of 0%), the transmittance of the light L to the rear face  20   b  is not 0%, i.e., a part of the light L is transmitted through the aluminum flake  31 . 
     The protection layer  40  that covers the aluminum flakes  31  is provided on the front face  20   a  of the base  20 . The protection layer  40  is made of a light transmitting material that transmits the light L. In the first embodiment, the protection layer  40  is made of resin, for example. Such resin includes not only urethan resin but also resin except the urethan resin. The protection layer  40  may be made of not only a material except the resin but also glass, for example. 
     A method of manufacturing the dial will be described. The above described dial  10  is manufactured by the following manufacture process as one example.  FIG. 6  is a sectional view corresponding to  FIG. 3 , illustrating the base  20  just after a coating film  30  is formed by spraying a paint onto the surface of the base  20  in the manufacturing process of the dial  10 .  FIG. 7  is a sectional view corresponding to  FIG. 6 , illustrating the dial  10  in which solution  33  contained in the coating film  30  is volatilized after the coating film  30  is formed by spraying the paint onto the front face  20   a  of the base  20 . 
       FIG. 8  is a photography showing the metal tone dial visually recognized by a viewer from the front face  10   a  of the dial  10 , as one example. 
     At first, the paint for forming the coating film  30  on the base  20  is produced. This paint is liquid, and is produced by mixing mainly the solution (for example, thinner)  33  and the aluminum flakes  31 . An additive agent that does not obstruct the volatilization of the solution  33  or an additive agent that promotes the volatilization may be added into the paint. The excess solution  33  is not required to the aluminum flakes  31  because the solution  33  is only required to disperse the aluminum flakes  31  on the surface of the base  20  as the coating film  30  to be temporarily fixed. 
     Next, the above described liquid paint is sprayed onto a top face of the base  20 . The top face of the base  20  onto which the paint is spayed may be the front face or the rear face. Hereinafter, the top face onto which the paint is splayed is used as the front face  20   a  of the base  20 . 
     As illustrated in  FIG. 6 , in the coating film  30  formed by spaying the paint, the liquid solution  33  forms the film together with the solid aluminum flakes  31  in the beginning. The aluminum flakes  31  are almost horizontally arranged. One aluminum flake  31  covers the front face  20   a  of the base  20 , or the two or more aluminum flakes  31  are laminated to cover the front face  20   a  of the base  20 . 
     Next, the dial  10  in which the coating film  30  is formed on the base  20  is heated. As illustrated in  FIG. 7 , the solution  33  is volatilized by this heating, so that the aluminum flakes  31  are only left on the front face  20   a  of the baes  20 , and the aluminum flakes  31  are almost horizontally fixed. 
     The solution  33  may be volatilized by air drying (by leaving the dial  10  in an environment to be air dried according to a temperature and a humidity of the environment without actively drying the solution for volatilization). 
     The fixed power of the laminated aluminum flakes  31  and the fixed power of the front face  20   a  and the aluminum flakes  31  can be enhanced by adding an additive agent having an adhesive property into the paint in addition to the solution  33  and the aluminum flakes  31 . 
     When the coating film  30  is formed, the opening ratio, which is a ratio of forming the opening portion  11 , depends on the spraying amount of the paint (applying time, discharge amount, atomization pressure of coating gun, and distance to coating gun). Namely, the opening ratio decreases in accordance with the increase in the spraying amount of the paint, and the opening ratio increases in accordance with the decrease in the spraying amount of the paint. 
     After the solution  33  is volatilized, a resin paint is sprayed onto the front face  20   a  of the base  20  to cover at least the aluminum flakes  31 , so as to form the protection layer  40  that protects the aluminum flakes  31 , as illustrated in  FIG. 3 , when the aluminum flakes  31  are fixed onto the front face  20   a  of the base  20  ( FIG. 7 ). 
     A curing agent that promotes the thermal curing of the protection layer  40  may be added into the paint for forming the protection layer  40 . 
     The operation will be described. According to the dial  10  configured as described above, the light L incident from the front face  10   a  toward the rear face  10   b  of the dial  10  is transmitted through the protection layer  40 , but is mostly reflected by the aluminum flakes  31 . Namely, the light L incident on the almost horizontally arranged aluminum flakes  31  is mostly reflected by the flat faces of the aluminum flakes  31 , and returns to the front face  10   a  of the dial  10 . 
     The aluminum flakes  31 , which are almost horizontally arranged, align the directions of the reflection light toward the front face  10   a  of the dial  10 . The reflection light is thereby visually recognized as high brightness reflection light. A viewer can therefore visually recognize the metal tone (metallic) dial  10  from the front face  10   a  by the high brightness reflection light from the dial  10 , as illustrated in  FIG. 8 . 
     In this embodiment, the aluminum flakes  31 , which are laminated in the thickness direction, prevent the incident light from scattering among a plurality of aluminum flakes fixed in different positions in the dispersion film in the thickness direction, different from a dial in which the aluminum flakes are separated in the thickness direction. 
     The aluminum flakes  31  laminated in the thickness direction in the first embodiment can therefore improve the uniformity of the brightness of the reflection light. The opening portion  11  formed in the thickness range corresponding to the first layer of the aluminum flake  31  can be closed by the second layer or more of the aluminum flake  31  to be laminated, so that the opening ratio can be adjusted. 
     The aluminum flakes  31 , which are extremely thin, transmit the light L at a predetermined volume. Accordingly, the light L is partially transmitted to the rear face  20   b  of the base  20  even though the dial  10  has no opening portion  11  without the aluminum flake  31 . 
     With this configuration, even when the timepiece  100  is a solar cell timepiece in which a solar cell that generates electricity with the light L is disposed under the rear face  10   b  of the dial  10 , the solar cell can be irradiated with the light L, and the solar cell timepiece can be thereby effectively operated. 
     Accordingly, it is possible for the dial  10  of the first embodiment to obtain the reflection light (metal tone reflection light) similar to the reflection light by metal while transmitting light and radio wave. According to the dial  10 , the timepiece  10 , and the method of manufacturing the dial  10  of the first embodiment, a plurality of the aluminum flakes  31 , which are laminated in the thickness direction, eliminate a need for forming the layers of the aluminum flakes  31  by a plurality of steps, different from a dial in which the aluminum flakes  31  are separated in the thickness direction, and thus simplifies the manufacturing process and reduces the costs. 
     The extremely thin aluminum flakes  31  also transmit the radio wave. Accordingly, even when the timepiece  100  is a wave correction timepiece in which an antenna for receiving the radio wave is disposed under the rear face  10   b  of the dial  10 , and the dial  10  has no opening portion  11 , the antenna can receive the radio wave, and the wave correction timepiece can be thereby effectively operated. 
     When the extremely thin aluminum flake  31  is exposed, such an aluminum flake  31  has a little resistance to humidity, physical contact, and friction. For this reason, such an aluminum flake  31  is easily removed from the base  20 . However, in the dial  10  of the first embodiment, the aluminum flakes  31  are covered by the protection layer  40 , so that the aluminum flakes  31  can be protected from humidity, physical contact, and friction. 
     (Experimental Example) Table 1 describes an experimental example showing results of an external appearance evaluation, a transmittance (transmittance of display plate) which is a ratio at which the light L transmits from the front face  10   a  to the rear face  10   b  of the dial  10 , and an overall evaluation based on these. Under the experimental example, the thickness of the protection layer  40  is changed from less than 1 μm to more than 5 μm, and the opening ratio % of the opening portion  11  is changed from less than 3% to more than 45% in a planar view of the dial  10 . 
     
       
         
           
               
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                   
                 THICKNESS OF PROTECTION LAYER 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 LESS THAN 
                   
                   
                   
                   
                   
                 THICKER 
               
            
           
           
               
               
               
               
            
               
                   
                 1 μm 
                 1~5 μm 
                 THAN 5 μm 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 OPENING 
                 — 
                 45% 
                 40% 
                  8% 
                  6% 
                  3% 
                 — 
               
               
                 RATIO 
                   
                   
                   
                   
                   
                   
                   
               
               
                 EXTERNAL 
                 A PART OF 
                 GOOD 
                 EXCELLENT 
                 EXCELLENT 
                 EXCELLENT 
                 EXCELLENT 
                 COATING 
               
               
                 APPEARANCE 
                 ALUMINUM 
                 SLIGHT 
                 METAL 
                 METAL 
                 METAL 
                 METAL 
                 FEELING 
               
               
                   
                 FLAKE IS 
                 TRANSLUCENCY 
                 TONE 
                 TONE 
                 TONE 
                 TONE 
                   
               
               
                   
                 EXPOSED 
                   
                   
                   
                   
                   
                   
               
               
                 TRANSMISSION 
                 — 
                 EXCELLENT 
                 EXCELLENT 
                 EXCELLENT 
                 EXCELLENT 
                 GOOD 
                 — 
               
               
                   
                   
                 50% 
                 40% 
                 30% 
                 15% 
                 10% 
                   
               
               
                 OVERALL 
                 BAD 
                 GOOD 
                 EXCELLENT 
                 EXCELLENT 
                 EXCELLENT 
                 GOOD 
                 BAD 
               
               
                 EVALUATION 
               
               
                   
               
            
           
         
       
     
     The transmittance increases in accordance with the increase in the opening ratio whereas the transmittance decreases in accordance with the decrease in the opening ratio. However, the transmittance does not reach 0% even when the opening ratio is 0%, as described above. Accordingly, the transmittance of the light L is easily secured even though the number of opening portions  11  is decreased. 
     When the opening portions  11  are largely distributed in the dial  10 , the reflection light volume is reduced, which is likely to offer the rough feeling (granular quality) from the dial  10 . However, the dial  10  of the first embodiment, which increases the transmittance of the light L without increasing the opening ratio, hardly offers the rough feeling. Moreover, the aluminum flakes  31 , which are almost horizontally arranged in a simple way, improves the smoothness, and offers the high brightness reflection light having shiny appearance such as a plating metal. 
     Furthermore, the dial  10  of the first embodiment, which includes a downsized side face (thickness face) by the extremely thin aluminum flake  31 , makes it difficult to occur the scattering by the reflection at the side face, and thus controls the rough feeling. When the transmittance increases, the transmitting light volume to the rear face  10   b  of the dial  10  increases, and the light volume that reaches the solar cell which may be disposed under the rear face  10   b  of the dial  10  increases, and the radio wave that reaches the antenna which may be disposed under the rear face  10   b  of the dial  10  increases. 
     On the other hand, when the transmittance decreases, the ratio of the reflection light by the aluminum flakes  31  increases. The metal feeling of the dial  10  thereby improves while the transmitting light volume to the rear face  10   b  of the dial  10  decreases. Accordingly, the light volume that reaches the solar cell which may be disposed under the rear face  10   b  of the dial  10  decreases, and also the radio wave that reaches the antenna which may be disposed under the rear face  10   b  of the dial  10  decreases. 
     In the experimental example shown in Table 1, the transmittance of the light L of 10 to 50% can be maintained in the range of the opening ratio of 3 to 45%. With the transmittance of the light L of 10 to 50%, the light L can be sufficiently supplied to the rear face  10   b  of the dial  10 , and the metal tone external appearance can be obtained. Accordingly, it is preferable for a predetermined opening ratio, as one example, to be in a range of 3 to 45% as the overall evaluation (good or excellent in Table 1). In addition, it is preferable for the thickness of the protection layer  40  to be in a range of 5 to 1 μm in the experimental example in accordance with the opening ratio of 3 to 45%. 
     When the thickness of the protection layer  40  is less than 1 μm, the aluminum flakes  31  may be exposed. When the thickness of the protection layer  40  is more than 5 μm, the thickness of the protection layer  40  increases, resulting in the strengthening in the coating feeling on the metal tone surface, which weakens the metal feeling. 
     In a range of the opening ratio of 6 to 40%, the metal tone external appearance without translucency can be obtained while maintaining the transmittance of more than 15%. As a result, it is preferable for the opening ratio to be in the range of 6 to 40% as one example (excellent in Table 1). 
     In the above experimental example, the thickness of the aluminum flake  31  was 10 to 30 nm. However, the size except the thickness was about several to 30 μm (mean value 10 to 20 μm). 
     The extremely thin thickness of the aluminum flake  31 , which is about 10 to 30 μm, makes it easy to follow the surface of another aluminum flake  31  and the contour shape of the front face  20   a  of the base  20  even though the aluminum flake  31  is made of metal. 
     Accordingly, even when an uneven pattern for use as the dial  10  is provided on the front face  20   a  of the base  20 , the aluminum flakes  31  laminated on the front face  20   a  do not render futile the uneven pattern of the front face  20   a , and the reflection light corresponding to the uneven shape following the minute unevenness on the front face  20   a  can be emitted. The uneven pattern includes Hairline Finish (uneven pattern by extremely minute groove), a radial pattern, an embossed pattern, and a sand pattern. 
     (First Modified Example) The dial  10  of the first embodiment includes the colorless transparent protection layer  40 , but may include the colored transparent protection layer  40 . The yellowish protection layer  40  can obtain gold reflection light by the superimposition of the silver reflection light from the aluminum flakes  31  and the yellow of the protection layer  40 . The color of the protection layer  40  is not limited to yellow, and another color can be used. 
     (Second Modified Example)  FIG. 9  is a sectional view corresponding to  FIG. 3  illustrating the second modified example of the dial  10  of the first embodiment. In the dial  10  of the first embodiment, the aluminum flakes  31  are provided on the front face  20   a  of the base  20 , and the front face  40   a  of the protection layer  40  corresponds to the front face  10   a  of the dial  10 . However, as illustrated in  FIG. 9 , in the timepiece display plate according to the present disclosure, the base  20  may be provided on the front face  10   a  of the dial  10 , and the protection layer  40  may be provided on the rear face  10   b  of the dial  10 . 
     Namely, the dial  10  illustrated in  FIG. 9  includes the front face and the rear face opposite to the front face and the rear face of the dial  10  illustrated in  FIG. 3  such that the rear face  20   b  of the base  20  in  FIG. 3  is the front face  10   a  of the dial  10  and the front face  40   a  of the protection layer  40  in  FIG. 3  is the rear face  10   b  of the dial  10 . 
     Even when the lamination order of the base  20  and the protection layer  40  in the dial  10  is changed as described above, the effects similar to those of the dial  10  and the timepiece  100  of the first embodiment can be obtained. 
     In this case, the base  20  may be colored instead of coloring the protection layer  40  in the dial  10  illustrated in  FIG. 3 . 
     (Third Modified Example)  FIG. 10  is a sectional view corresponding to  FIG. 3 , illustrating a dial  10  of the third modified example in which a topcoat  45  is further provided on the rear face  20   b  of the base  20  of the dial  10  of the second modified example. 
     As described above, with the configuration in which the topcoat  45  is laminated on the base  20 , the effects similar to those of the dial  10  and the timepiece  100  of the first embodiment can be obtained, and the color of the dial  10  can be changed by changing the color of the topcoat  45  only while standardizing the basic structural portions of the dial  10  such as the base  20  and the protection layer  40 . 
     When the topcoat  45  has a special function (for example, UV cut function and IR cut function), the dial  10  can be prevented from being burned by the sun and being a high temperature. 
     In the dial  10  of the first embodiment and the modified examples, the aluminum flakes  31  are used as the metal foil pieces which are disposed on the front face  20   a  of the base  20 . However, another metal foil piece different from the aluminum or the aluminum alloy can be used instead of the aluminum flakes  31  in the timepiece display plate according to the present disclosure. Metal thin pieces which are colored by a painting process, a vapor disposition process, or another surface process may also be used. 
     Second Embodiment 
       FIG. 11  is sectional view similar to  FIG. 2 , illustrating a dial  10  of the second embodiment. In addition, as a basic configuration of a timepiece of the second embodiment is the same as the configuration of the timepiece of the first embodiment illustrated in  FIGS. 1, 2 , the description thereof is omitted. A sectional view corresponding to  FIG. 11 , illustrating a base  20  of the dial  10  of the second embodiment is the same as  FIG. 4 .  FIG. 12  is a photography showing aluminum flakes  31  and opening portions  11  in a planar view when observing the dial  10  with an electron microscope, as one example. In the second embodiment, the same reference numbers are applied to the same components as those in the first embodiment. Hereinafter, in the second embodiment, the description will be omitted for the components which are the same as the components described in the first embodiment. 
     As illustrated in  FIG. 11 , the dial  10  includes, on a rear face Ob (close to movement  70 ) thereof, the base  20  and, on a front face  10   a  thereof, a dispersion film  300  that is laminated on the base  20 . 
     As illustrated in  FIG. 11 , the dispersion film  300  is provided on one face (front face  20   a ) of the base  20 . The dispersion film  30  is made of a resin  32  having a light transmitting property that transmits the light L and a plurality of aluminum flakes  31  (aluminum foil pieces as one example of metal foil pieces). The resin  32  includes urethan resin, but may include resin except the urethan resin. 
     The aluminum flake  31  is a minute aluminum material, and is formed as a thin foil piece having a size in a specific direction significantly smaller than that in another direction. The thickness of the aluminum flake  31  is 1 μm or less, for example. 
     The aluminum flake  31  has a flat smooth surface. In the example illustrated in  FIG. 11 , some of the aluminum flakes  31  are bent. A part of the extremely thin aluminum flake  31  is laminated on another aluminum flake  31 , so that the aluminum flake  31  follows the surface of another aluminum flake  31  and the front face  20   a  of the base  20 . The border part of the aluminum flake  31  is thereby bent. 
     As described above, a plurality of aluminum flakes  31  are dispersed in the dispersion film  300 . The aluminum flakes  31  lie in the dispersion film  300  such that the flat face of the aluminum flake  31  is substantially parallel to the front face  20   a  of the base  20 . 
     The dispersion film  300  includes opening portions  11  (refer to  FIG. 11 ) without the aluminum flakes  31  at a predetermined ratio in a planar view as seen in the thickness direction from the front face  10   a  to the rear face  10   b  of the dial  10 . The photography of  FIG. 12  by the electron microscope shows some parts of the front face  20   a  without the aluminum flakes  31  in a planer view as the opening portions  11 . 
     In the dispersion film  300 , the opening portions  11  without the aluminum flakes  31  in a planar view transmit the light L such as visible light from the front face  10   a  to the rear face  10   b  of the dial  10 . On the other hand, in the dispersion film  300 , the portions with the aluminum flakes  31  (portions except opening portions) in a planar view reflect the light L traveling from the front face  10   a  to the rear face  10   b  of the dial  10  by the flat faces of the aluminum flakes  31 . 
     A method of manufacturing the dial will be described. The above dial  10  is manufactured by the following manufacturing process as one example.  FIG. 13  is a sectional view corresponding to  FIG. 3  just after the dispersion film  300  is formed by spraying a paint onto the surface of the base  20  in the manufacturing process of the dial  10 .  FIG. 14  is a photography showing the metal tone dial  10  visually recognized by a viewer from the front face  10   a  of the dial  10  as one example. 
     At first, the paint for forming the dispersion film  300  is produced. This liquid paint is formed by mixing mainly solution (for example, thinner)  33 , the resin  32 , and the aluminum flakes  31 . A small amount of curing agent may be added into the paint to promote the thermal curing of the resin  32 . 
     Next, the above liquid paint is sprayed onto the top face of the base  20 . The top face of the base  20  onto which the paint is spayed may be a front face or a rear face. However, hereinafter, the top face onto which the paint is sprayed is used as the front face  20   a  of the base  20 . 
     As illustrated in  FIG. 13 , in the dispersion film  300  formed by spraying the paint, in the beginning, the solid aluminum flakes  31  float in the liquid solution  33  and resin  32 , and the aluminum flakes  31  are irregularly arranged. 
     The dial  10  in which the dispersion film  300  is formed on the base  20  is then heated. The solution  33  is volatilized by the heating, and the thickness of the dispersion film  300  is reduced to be thinner than that in the beginning of the spraying ( FIG. 13 ), and the resin  32  is thermally cured. 
     As the thickness of the liquid in which the aluminum flakes  31  float is reduced by the volatilization of the solution  33 , the aluminum flakes  31  lie to be substantially parallel in the dispersion film  300 , and the aluminum flakes  31  are almost horizontally fixed by thermally curing the resin  32 , as illustrated in  FIG. 11 . 
     The opening portions  11  are formed in the dispersion film  300  mainly depending on the blending amount of the aluminum flakes  31  in the paint for forming the dispersion film  300  (ratio (e.g. percentage) of aluminum flakes  31  to total of resin  32  and aluminum flakes  31 ) and the thickness of the dispersion film  300  (after cured) to be formed. 
     For example, the opening ratio %, which is a ratio of the area of the opening portions  11  to the entire area, in a planer view of the dial  10  can be changed by fixing the blending amount of the aluminum flakes  31  and changing the thickness of the dispersion film  300 , for example. 
     An operation will be described. According to the dial  10  configured as described above, the light L incident from the front face  10   a  to the rear face  10   b  of the dial  10  is transmitted through the resin  32  in the dispersion film  300 , but is not transmitted through the aluminum flakes  31  in the dispersion film  300 . The light L incident on the flat aluminum flakes  31  in the dispersion film  300  from the front face  10   a  is reflected by the flat faces of the aluminum flakes  31 , and returns to the front face  10   a.    
     The aluminum flakes  31 , which are almost horizontally arranged in the dispersion film  300 , align the directions of the reflection light toward the front face  10   a  to be visually recognized as high brightness reflection light. As shown in  FIG. 14 , the high brightness reflection light from the dial  10  can offer the metal tone (metal feeling) dial  10  to a viewer who visually recognizes the dial  10  from the front face  10   a.    
     The aluminum flakes  31  in the dispersion film  300 , are laminated in the thickness direction, prevent the incident light from scattering among a plurality of aluminum flakes fixed in different positions in the thickness direction of the dispersion film, different from a dial in which the aluminum flakes are separated in the thickness direction. 
     The dispersion film  300  of the second embodiment can thus improve the uniformity of the brightness of the reflection light. The opening portion  11  formed in the first layer of the aluminum flake  31  may be closed by the second layer or more of the aluminum flake  31  to be laminated, so that the opening ratio can be adjusted. 
     On the other hand, as the opening portions  11  are formed at a predetermined ratio, a part of the light L incident from the front face  10   a  toward the rear face  10   b  of the dial  10  is transmitted through the opening portions  11  and the base  20  to reach the rear face  10   b  of the dial  10 . With this configuration, even when the timepiece  100  is a solar cell timepiece in which a solar cell that generates electricity by the light L is disposed under the rear face  10   b  of the dial  10 , the solar cell can be irradiated with the light L, and the solar cell timepiece can be effectively operated. 
     Accordingly, it is possible for the dial  10  of the second embodiment to obtain the reflection light (metal tone reflection light) similar to the reflection light by metal while transmitting the light and the radio wave. According to the dial  10 , the timepiece  100 , and the method of manufacturing the dial  10  in the second embodiment, the aluminum flakes  31  in the dispersion film  300 , which are laminated in the thickness direction, eliminate the need for forming the dispersion film by a plurality of steps, different from a dial in which the aluminum flakes are separated in the thickness direction, and simplifies the manufacturing process and reduces the costs. 
     The opening portions  11  also transmits the radio wave. Accordingly, even when the timepiece  100  is a wave correction timepiece in which an antenna that receives radio wave is disposed under the rear face  10   b  of the dial  10 , the antenna can receive the radio wave, and the wave correction timepiece can be thereby effectively operated. 
     (Experimental Example) Table 2 describes an experimental example showing results of an external appearance evaluation, a transmittance (transmittance of display plate) which is a ratio at which the light L transmits from the front face  10   a  to the rear face  10   b  of the dial  10 , and an overall evaluation based on these. Under the experimental example, the blending amount of the aluminum flakes  31  is fixed to 1.7%, the discharge of the paint is set to 5 to 30 ml/min, the thickness of the dispersion film  300  is changed from less than 1 μm to more than 5 μm, and the opening ratio % of the opening portions  11  is changed from less than 10% to more than 50%. 
     
       
         
           
               
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                   
                 THICKNESS OF DISPERSION FILM 
               
            
           
           
               
               
               
               
            
               
                   
                 LESS THAN 
                   
                 THICKER 
               
               
                   
                 1 μm 
                 1~5 μm 
                 THAN 5 μm 
               
               
                   
               
            
           
           
               
               
               
               
            
               
                 BLENDING AMOUNT 
                 — 
                 1.70% 
                 — 
               
               
                 OF ALUMINUM FLAKE 
                   
                   
                   
               
               
                 DISCHARGE 
                 — 
                 5~30 ml/min 
                 — 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 OPENING  
                 — 
                 50% 
                 40% 
                 30% 
                 15% 
                 10% 
                 — 
               
               
                 RATIO 
                   
                   
                   
                   
                   
                   
                   
               
               
                 EXTERNAL 
                 BAD 
                 GOOD 
                 EXCELLENT 
                 EXCELLENT 
                 EXCELLENT 
                 EXCELLENT 
                 BAD 
               
               
                 APPEARANCE 
                 A PART OF 
                 SLIGHT 
                 METAL 
                 METAL 
                 METAL 
                 METAL 
                 COATING 
               
               
                   
                 ALUMINUM 
                 TRANSLUCENCY 
                 TONE 
                 TONE 
                 TONE 
                 TONE 
                 FEELING 
               
               
                   
                 FLAKE IS 
                   
                   
                   
                   
                   
                   
               
               
                   
                 EXPOSED 
                   
                   
                   
                   
                   
                   
               
               
                 TRANSMISSION 
                 — 
                 EXCELLENT 
                 EXCELLENT 
                 EXCELLENT 
                 EXCELLENT 
                 GOOD 
                 — 
               
               
                   
                   
                 50% 
                 40% 
                 30% 
                 15% 
                 10% 
                   
               
               
                 OVERALL 
                 BAD 
                 GOOD 
                 EXCELLENT 
                 EXCELLENT 
                 EXCELLENT 
                 GOOD 
                 BAD 
               
               
                 EVALUATION 
               
               
                   
               
            
           
         
       
     
     As the blending amount of the aluminum flakes  31  is fixed, the opening ratio deceases in accordance with the increase in the thickness of the dispersion film  300  whereas the opening ratio increases in accordance with the decrease in the thickness of the dispersion film  300 . The transmittance increases in accordance with the increase in the opening ratio whereas the transmittance decreases in accordance with the decrease in the opening ratio. 
     When the transmittance increases, the ratio of the reflection light by the aluminum flakes  31  decreases. In this case, the dial  10  deteriorates its external appearance to be the translucent external appearance which weakens the metal feeling while the transmittance light volume to the rear face  10   b  of the dial  10  increases, the light volume that reaches the solar cell which may be disposed under the rear face  10   b  of the dial  10  increases, and the radio wave that reaches the antenna which may be disposed under the rear face  10   b  of the dial  10  increases. 
     On the other hand, when the transmittance decreases, the ratio of the reflection light by the aluminum flakes  31  increases. In this case, the dial  10  improves its metal feeling while the transmittance light volume to the rear face  10   b  of the dial  10  decreases, the light volume that reaches the solar cell which may be disposed under the rear face  10   b  of the dial  10  decreases, and the radio wave that reaches the antenna which may be disposed under the rear face  10   b  of the dial  10  decreases. 
     In the experimental example illustrated in Table 2, the transmittance of the light L of 10 to 50% can be maintained in the range of the opening ratio of 10 to 50%. With the transmittance of the light L of 10 to 50%, the light L can be sufficiently supplied to the rear face  10   b  of the dial  10 , and the metal feeling external appearance can be obtained. It is therefore preferable for a predetermined opening ratio to be in the range of 10 to 50% as the overall evaluation (good and excellent in Table 2). The thickness of the dispersion film  300  corresponding to the opening ratio of 10 to 50% is 5 to 1 μm in the experimental example. 
     The metal feeling external appearance without translucency can be obtained and the transmittance of 15% or more can be maintained in the range of the opening ratio of 15 to 40%. It is therefore more preferable for the predetermined opening ratio to be in the range of 15 to 40% as the overall evaluation (excellent in Table 2). In addition, the thickness of the dispersion film  300  corresponding to the opening ratio of 15 to 40% is 4 to 2 μm in the experimental example. 
     In the above experimental example, the thickness of the aluminum flake  31  was 1 m or less, in particular, 0.08 to 0.62 μm. The preferable thickness of the dispersion film  300  as the overall evaluation is 1.6 (=1/0.62) to 62.5 (=5/0.08) times the thickness of the aluminum flake  31 . Accordingly, the preferable thickness of the dispersion film  300  as the overall evaluation is 1.6 to 62.5 times the thickness of the aluminum flake  31 . 
     In addition, the more preferable thickness of the dispersion film  300  as the overall evaluation may be 3.2 (=2/0.62) to 50 (=4/0.08) times the thickness of the aluminum flake  31 . 
     The aluminum flake  31 , which is extremely thin of 1 μm or less, makes it easy to follow the surface of another aluminum flake and the contour shape of the front face  20   a  of the base  20  even though the metal aluminum flake is used. 
     Accordingly, even when, for example, an uneven pattern is formed on the front face  20   a  of the base  20 , the aluminum flake  31  laminated onto the front face  20   a  does not render futile the uneven pattern of the front face  20   a , and the reflection light corresponding to the uneven shape following the minute unevenness of the front face  20   a  can be emitted. The uneven pattern includes Hairline Finish (uneven pattern formed by extremely minute grooves, for example), a radial pattern, an embossed pattern, and a sand pattern. 
     In the above described experimental example, the blending amount of the aluminum flakes  31  was 1.7%. However, the blending amount is not limited to 1.7%. It is preferable for the blending amount to be in the range of 1.5 to 2.0%, for example. When the blending amount of the aluminum flakes  31  is in the range of 1.5 to 2.0%, the opening ratio is easily controlled according to the thickness of the dispersion film  300 . However, the blending amount of the aluminum flakes  31  is not limited to this preferable range. 
     In the above described experimental example, the blending amount of the aluminum flakes  31  was fixed to 1.7% to change the opening ratio according to the thickness of the dispersion film  300 . However, the thickness of the dispersion film  300  may be fixed to change the opening ratio according to the blending amount of the aluminum flakes  31 . 
     (First Modified Example)  FIG. 15  is a sectional view corresponding to  FIG. 11 , illustrating the first modified example of the dial  10  of the second embodiment. In the dial  10  of the above second embodiment, the dispersion film  300  is laminated on the front face  20   a  of the base  20 , and the front face  300   a  of the dispersion film  300  corresponds to the front face  10   a  of the dial  10 . However, in the timepiece display plate according to the present disclosure, as illustrated in  FIG. 15 , a topcoat  40  that transmits the light L may be laminated on the front face  300   a  of the dispersion film  300 . 
     With the configuration in which the topcoat  40  is laminated as described above, the effects similar to those of the dial  10  and the timepiece  100  of the above second embodiment can be obtained, and the color of the dial  10  can be changed by changing only the color of the topcoat  40  while standardizing the basic structural portions of the dial  10  such as the dispersion film  300  and the base  20 . 
     When the topcoat  45  has a special function (for example, UV cut function and IR cut function), the dial  10  can be prevented from being burned by the sun or being a high temperature. 
     (Second Modified Example)  FIG. 16  is a sectional view corresponding to  FIG. 11 , illustrating the second modified example of the dial  10  of the second embodiment. In the dial  10  of the second embodiment, the dispersion film  300  is provided on the front face  10   a  of the dial  10  and the base  20  is provided on the rear face  10   b  of the dial  10 . However, as illustrated in  FIG. 16 , in the timepiece display plate according to the present disclosure, the base  20  may be provided on the front face  10   a  of the dial  10  and the dispersion film  300  may be provided on the rear face  10   b  of the dial  10 . 
     Namely, the dial  10  illustrated in  FIG. 16  includes the front face and the rear face opposite to the front face and the rear face of the dial  10  illustrated in  FIG. 11  such that the rear face  20   b  of the base  20  in  FIG. 11  is the front face  10   a  of the dial  10 , and the front face  300   a  of the dispersion film  300  in  FIG. 11  is the rear face  10   b  of the dial  10 . 
     Even when the lamination order of the base  20  and the protection layer  40  in the dial  10  is changed as described above, the effects similar to those of the dial  10  and the timepiece  100  of the second embodiment can be obtained. 
     In this case, the base  20  may be used as the topcoat  45  illustrated in  FIG. 15 , so that the base  20  may be colored. 
     (Third Modified Example)  FIG. 17  is a sectional view corresponding to  FIG. 11 , illustrating a dial  10  of the third modified example in which the second modified example is combined with the first modified example. In the dial  10  of the third modified example, the topcoat  45  is provided on the rear face  20   b  of the base  20 . 
     As described above, with the configuration in which the topcoat  45  is laminated on the base  20 , the effects similar to those of the dial  10  and the timepiece  100  of the second embodiment can be obtained, and the color of the dial  10  can be changed by changing only the color of the topcoat  45  while standardizing the basic structural portions of the dial  10  such as the base  20  and the dispersion film  300 . 
     When the topcoat  45  has a special function (for example, UV cut function and IR cut function), the dial  10  can be prevented from being burned by the sun and being a high temperature. 
     In the dial  10  of the above described second embodiment and the modified examples, the aluminum flakes  31  are used as the metal foil flakes dispersed in the dispersion film  300 . However, in the timepiece display plate of the present disclosure, another metal foil piece different from aluminum or aluminum alloy can be used instead of the aluminum flake  31 . 
     In the dial  10 , a metal thin piece colored by a painting process, a vapor deposition process, or another surface process can be used. 
     Although the present disclosure has been described in terms of exemplary embodiments, it should not be limited thereto. It should be appreciated that variations or modifications may be made in the embodiments described by persons skilled in the art without departing from the scope of the present invention as defined by the following claims.