JP2003107173A - Manufacturing method of light transmissive metal-toned display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the hole size of a small hole to a visually unrecognizable degree, provide a light transmitting property of a wide angle, and provide a sufficient light effect even when a metal plate is thickened so that decoration workability of a surface is not impaired. SOLUTION: When forming a plurality of small holes 12 on the metal plate 11 by an electroforming and a photolithography, a hole size R1 of a hole part 18 on the upper face side is formed smaller than a hole size R2 of a hole part 19 on the lower face side. Accordingly, the hole size R1 of the hole part 18 on the upper face side can be reduced to the visually unrecognizable degree even when thickness of the metal plate 11 is made thick, an effective light transmitting property can be provided even when the hole size R1 of the hole part 18 on the upper face side is reduced by enlarging the hole size R2 of the hole part 19 in the lower face side, the sufficient light effect can be provided by this, and the metal plate 11 can be used by singularly applying decoration work without impairing the decoration workability of the surface by thickening the thickness T of the metal plate 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a light-transmissive metallic tone display plate used for a timepiece dial, a liquid crystal display device or the like.

[0002]

2. Description of the Related Art For example, in a wristwatch, a backlight device such as an EL element (electroluminescence element) is provided on the back side of a light-transmitting timepiece dial, and when the backlight device is turned on, the light is emitted. There is one that allows the time to be known even in a dark place by transmitting the timepiece dial and illuminating its upper surface. Also,
In a liquid crystal display device used for an electronic device such as a wristwatch or a mobile phone, a reflective / transmissive plate is provided on the back side of a liquid crystal display panel, and a backlight device such as an EL element is provided on the back side of the reflective / transmissive plate in a bright place. By collecting external light from the surface of the liquid crystal display panel and reflecting the collected light with a reflective / transmissive plate, the displayed information can be visually recognized, and the backlight device is turned on in a dark place.
There is a device in which the displayed information can be visually recognized by transmitting the light through a reflection / transmission plate and illuminating the back side of the liquid crystal display panel.

As such a timepiece dial and a reflective / transmissive plate for a liquid crystal display device, conventionally, the surface of transparent plastic (for example, polycarbonate, acrylic) is provided with unevenness, printing, painting, or the like. Although it was realized by combining them in combination, its reflection efficiency was low, and it was almost impossible to obtain a metallic feeling. Further, in the case where the metallic decoration effect is prioritized, a metal plate having a large number of small holes through which light is transmitted is used. However, in order to form a hole, its diameter generally requires a numerical value equal to or larger than the plate thickness of a metal plate, and it is difficult to obtain a preferable one in terms of appearance. When giving priority to the hole diameter and considering the material plate thickness, it becomes very thin, and the surface is decorated with mirror finishing, light diffusing surface processing, hairline processing, plating, painting, printing, etc. It was almost difficult to process it. Further, when a material having a plate thickness having a certain level of strength is used while giving a metallic feeling by using a metal material, a hole smaller than the plate thickness is provided, but the conventional method is very expensive. Even if actually formed, the plate thickness is larger than the hole diameter, and the light diffusion angle θ is small as shown in FIG.

[0004]

In such a conventional transmissive metal tone display plate, as shown in FIG. 13, the hole diameter R of the cylindrical small hole 2 and the plate thickness t of the metal plate 1 are almost the same. As shown, the diffusion angle θ of the light passing through the small hole 2 is as large as about 90 °, and a good illumination effect can be expected, but the hole diameter R of the small hole 2 is large.
If the plate thickness t of the metal plate 1 is thicker than that, as shown in FIG. 14, the diffusion angle θ of the light transmitted through the small hole 2 becomes smaller. Therefore, in such a case, even if the light from the backlight device 3 passes through the small hole 2, the diffusion angle θ of the light is small, so that the upper surface side thereof cannot be uniformly illuminated, and it is sufficient. Lighting effect is not obtained. Further, when the plate thickness t of the metal plate 1 is made smaller than the hole diameter R of the small hole 2, the light diffusion angle θ
Becomes larger, but the plate thickness t is changed to the hole diameter R of the small hole 2 (for example, 30 mm).
Since it is necessary to make it thinner than about 10 μm), it is difficult to decorate the surface as a transmissive metal tone display plate by using the metal plate 1 alone. Therefore, complicated processing such as attaching a transparent reinforcing plate is required. There is a problem that becomes.

The object of the present invention is to reduce the diameter of small holes to the extent that they cannot be visually recognized even if the metal plate is thickened to the extent that the decorating workability of the surface is not impaired, and to achieve wide-angle light transmission. In order to obtain a sufficient lighting effect.

[0006]

According to a first aspect of the present invention, when a plurality of small holes through which light is transmitted are formed in a metal plate by using an electroforming method, the hole diameter on the front surface side and the back surface of the small holes are formed. The method for producing a light-transmissive metal tone display plate is characterized in that the hole diameter on the side is formed to have a different size. According to this invention, when a plurality of small holes through which light is transmitted is formed in the metal plate by electroforming, for example, by forming the hole diameter on the front surface side smaller than the hole diameter on the back surface side, Even if the plate thickness is large, the hole diameter on the front surface side can be made so small that it cannot be visually recognized, and even if the hole diameter on the front surface side is made small, by increasing the hole diameter on the back surface side, it is possible to have wide-angle light transmittance. It is possible to obtain a sufficient lighting effect by this, and by increasing the plate thickness of the metal plate, the decorative workability of the surface is not impaired, and the metal plate can be used by applying the decorative process alone. .

According to a second aspect of the present invention, in the method for manufacturing the light-transmissive metal tone display plate according to the first aspect, the depth of the hole portion located on the front surface side of the small hole and the back surface side thereof are located. A method of manufacturing a light-transmissive metallic tone display plate, characterized in that the depth of the hole is formed to be different from that of the hole. According to this invention, in addition to the same effects as the invention described in claim 1, especially when a plurality of small holes through which light is transmitted are formed in a metal plate by using an electroforming method, for example, on the surface side. By forming the depth of the hole portion of the above to be shallower than the depth of the hole portion on the back surface side, it is possible to have a light transmittance of a wider angle than that of the invention described in claim 1, and to further enhance the lighting effect. You can get the high one.

According to a third aspect of the present invention, when a plurality of small holes through which light is transmitted are formed in the metal plate by using the photolithography method, the hole diameter on the front surface side and the hole diameter on the back surface side of the small holes are different. It is a method of manufacturing a light-transmissive metal tone display plate, which is characterized in that it is formed in a size. According to this invention, when a plurality of small holes through which light is transmitted is formed in the metal plate by using the photolithography method, for example, by forming the hole diameter on the front surface side smaller than the hole diameter on the back surface side, Even if the plate thickness is large, the hole diameter on the front surface side can be made so small that it cannot be visually recognized, and even if the hole diameter on the front surface side is made small, by increasing the hole diameter on the back surface side, it is possible to have wide-angle light transmittance. It is possible to obtain a sufficient lighting effect by this, and by increasing the plate thickness of the metal plate, the decorative workability of the surface is not impaired, and the metal plate can be used by applying the decorative process alone. .

According to a fourth aspect of the present invention, in the method of manufacturing the light-transmissive metallic tone display plate according to the third aspect, the depth of the hole portion located on the front surface side of the small hole and the back surface side thereof are located. A method of manufacturing a light-transmissive metallic tone display plate, characterized in that the depth of the hole is formed to be different from that of the hole. According to this invention, in addition to the same effect as the invention described in claim 3, especially when a plurality of small holes through which light is transmitted are formed in the metal plate by using the photolithography method, for example, on the front surface side. By forming the depth of the hole portion of the above to be shallower than the depth of the hole portion on the back surface side, it is possible to have light transmittance of a wider angle than that of the invention described in claim 3, and to further enhance the lighting effect. You can get the high one.

According to a fifth aspect of the present invention, when a plurality of small holes through which light is transmitted are formed in a metal plate by using an etching method,
The method for producing a light-transmissive metal tone display plate is characterized in that the hole diameter on the front surface side and the hole diameter on the back surface side of the small holes are formed in different sizes. According to the present invention, when a plurality of small holes through which light is transmitted are formed in a metal plate by using an etching method, for example, by forming the hole diameter on the front surface side smaller than the hole diameter on the back surface side, Even if the thickness is thick, the hole diameter on the front surface side can be made small enough to be visually unrecognizable, and even if the hole diameter on the front surface side is made small, it is possible to have wide-angle light transmittance by increasing the hole diameter on the back surface side. As a result, a sufficient lighting effect can be obtained, and the decorative workability of the surface is not impaired by increasing the thickness of the metal plate, and the metal plate can be used after being subjected to the decorative process alone.

According to a sixth aspect of the present invention, in the method for manufacturing the light-transmissive metallic tone display plate according to the fifth aspect, the depth of the hole portion located on the front surface side of the small hole and the back surface side thereof are located. A method of manufacturing a light-transmissive metallic tone display plate, characterized in that the depth of the hole is formed to be different from that of the hole. According to this invention, in addition to the same effect as the invention described in claim 5, when a plurality of small holes through which light is transmitted are formed in a metal plate by using an etching method, for example, on the surface side, By forming the depth of the hole portion to be shallower than the depth of the hole portion on the back surface side, it is possible to have light transmission with a wider angle than that of the invention described in claim 5, and to further improve the illumination effect. You can get a high price.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION [First Embodiment] A first embodiment of a method for manufacturing a light-transmissive metallic tone display plate according to the present invention will be described below with reference to FIGS. In this case,
First, the structure of the light-transmissive metal tone display plate manufactured by the manufacturing method of the present invention will be described. FIG. 1 is an enlarged cross-sectional view of a main part of a light-transmissive metal tone display plate manufactured by the manufacturing method of the present invention, and FIG. 2 (a) is a conceptual view of the light-transmissive metal tone display plate as viewed from the top side. The top view shown in FIG. 2B is a bottom view conceptually showing the light transmissive metal tone display plate as viewed from the bottom side.

As shown in FIG. 1, this light-transmissive metal tone display plate 10 has a large number of stepped small holes 12 formed in a metal plate 11, and a surface processed portion 13 is formed on the upper surface of the small hole 12 and plated. The layer 14 and the coating layer 15 are laminated, and a printing portion 16 is provided at a predetermined position on the upper surface thereof, and a backlight device 17 is arranged on the lower surface side of the metal plate 11. The small holes 12 of the metal plate 11 have different hole diameters, namely, a hole portion 18 located on the upper surface side of the metal plate 11 and a hole portion 19 located on the lower surface side of the metal plate 11, which are different from each other as shown in FIG. Are formed in a matrix so as to be coaxial with each other.

In this case, the hole portion 18 on the upper surface side is formed in such a size that the hole diameter R1 cannot be visually confirmed, that is, in a size of about 10 to 80 μm depending on the application. For example, the dial plate of a wristwatch or the transmission / reflection plate of a liquid crystal display device has a thickness of 30 μm or less, and the meters of automobiles have a thickness of 5 μm or less.
It is about 0 μm, and about 80 μm for signboards. Also,
The hole portion 19 on the lower surface side has a hole diameter R2 as shown in FIG.
Is larger than the hole diameter R1 of the hole portion 18 on the upper surface side (R2> R
1) and the depth t2 is the depth t1 of the hole portion 18 on the upper surface side.
Is formed deeper (t2> t1). For example, in the case of a wristwatch dial having a thickness T of the metal plate 11 of about 100 μm, the hole 18 on the upper surface side is formed with a hole diameter R1 of about 30 μm and a depth t1 of about 30 μm, and a hole on the lower surface side. The portion 19 has a hole diameter R2 of about 150 μm and a depth t2 of about 70 μm.

Further, the hole portion 18 on the upper surface side and the hole portion 1 on the lower surface side
As shown in FIGS. 2 (a) and 2 (b), 9 is formed in a circular shape, but the shape is not limited to a circular shape, and may be an oval shape or a polygonal shape such as a quadrangle. The pitch of the small holes 12 is the hole diameter R1 of the holes 18 on the upper surface side.
Is the minimum pitch, and the pitch does not have to be constant, and may be set arbitrarily. Further, the small holes 12 may be partially provided depending on the design, or may be arranged in a gradation pattern.

The surface processing portion 13 on the upper surface of the metal plate 11 is a mirror finish by polishing, a light diffusing surface processing by honing, a hairline processing or the like. It is desirable to process before forming the small hole 12, but the small hole is preferable. It may be processed after forming 12. The metal plate 1 provided with the surface-treated portion 13
The plating layer 14 on 1 is a metal plating layer of silver, gold, other metal, or the like. Coating layer 15 on this plating layer 14
Is a transparent film or a semi-transparent color film, and is formed by applying a paint. The printing portion 16 on the coating layer 15 is a mark, a symbol, a figure, or the like, and is formed at a predetermined position by screen printing, pad printing, or the like. The backlight device 17 has a structure in which light from a flat light emitter such as an EL element or a light source such as a light emitting diode is introduced from a side surface of a flat light guide plate and is substantially uniformly emitted from an upper surface of the light guide plate, or For example, it has a structure in which light from a light source such as a fluorescent tube is diffused by a light diffusion plate.

Next, with reference to FIGS. 3 (a) to 3 (h), a method of manufacturing the above-mentioned transmissive metallic tone display plate 10 will be described. First, in FIG. 3A, a substrate 20 made of stainless steel or the like is prepared, the surface of the substrate 20 is degreased and released, and then dried, and then a resist is applied to the entire upper surface of the substrate 20 to form a first resist film 21. To form. in this case,
It is desirable that the surface of the substrate 20 is previously provided with a throat surface processing portion 22 such as a hairline processing. And FIG.
As shown in (b), the applied first resist film 21 is formed into a predetermined shape by photolithography. That is, at this time, by exposing and developing the first resist film 21 using a photomask, the first resist film 21 is left in the portion corresponding to the hole portion 18 on the upper surface side of the small hole 12, and other portions are left. The first resist film 21 is removed. As a result, for example, a diameter of 3
A cylindrical first resist film 21 of about 0 μm is formed.

In this state, as shown in FIG. 3 (c), the first metal layer 23 is formed on the substrate 20 on which the first resist film 21 is not formed by electroforming, to a predetermined thickness, for example, 30.
It is formed to a thickness t1 of about μm. Then, as shown in FIG. 3D, the first metal layer 23 and the first resist film 21.
A resist is applied again thereon, and the second resist film 24 is formed into a predetermined shape by photolithography. Also at this time, by exposing and developing using a photomask, the second resist film 24 larger than the hole diameter R1 of the hole portion 18 on the upper surface side is formed in the portion corresponding to the hole portion 19 on the lower surface side of the small hole 12. And the second resist film 24 other than this is removed. As a result, a cylindrical second resist film 24 having a diameter of, for example, about 150 μm is formed at a predetermined position on the first resist film 21 and the first metal layer 23 so as to be coaxial with the first resist film 21.

After that, as shown in FIG. 3E, the first resist film 24 on which the second resist film 24 is not formed by electroforming plating is used.
The second metal layer 25 is formed on the metal layer 23 with a predetermined thickness, for example, 7
It is formed to a thickness t2 of about 0 μm. As a result, the thickness T
A metal plate 11 having a thickness of about 100 μm is formed. Then
As shown in FIG. 3F, the second resist film 24 and the first resist film 21 are all removed, and the first metal layer 23 having the second metal layer 25 laminated thereon is peeled from the upper surface of the substrate 20.
Then, as shown in FIG. 3G, when the metal plate 11 in which the first metal layer 23 and the second metal layer 25 are laminated is turned upside down, the hole diameter R1 of the hole portion 18 on the upper surface side becomes the lower surface side. Hole 19
Is smaller than the hole diameter R2, and the depth t1 of the hole portion 18 on the upper surface side is shallower than the depth t2 of the hole portion 19 on the lower surface side. A large number of stepped small holes 12 (only one is shown in the figure). The formed metal plate 11 is obtained.

At this time, since the surface processing portion 22 such as hairline processing is applied to the upper surface of the substrate 20, the surface processing portion 22 of the substrate 20 is transferred to the upper surface of the metal plate 11, that is, the surface of the first metal layer 22. Thus, the surface processed portion 13 is applied to the upper surface of the metal plate 11. If the upper surface of the substrate 20 is not provided with the surface processing portion 22 in advance, the surface processing portion 13 may be provided on the upper surface of the metal plate 11 after peeling the metal plate 11. Thereafter, as shown in FIG. 3 (h), metal plating is applied to the upper surface of the metal plate 11 to form a plating layer 14, and the plating layer 14 is coated with a transparent film or a semitransparent color film. The coating layer 15 is formed. Then, the printing portion 16 is formed by printing at a predetermined position on the coating layer 15. Thereby, the light transmissive metal tone display plate 10 with the upper surface of the metal plate 11 decorated is obtained.

As described above, the light transmission type metallic tone display plate 1
According to the manufacturing method of No. 0, when the large number of small holes 12 through which light is transmitted are formed in the metal plate 11 by using the electroforming method and the photolithography method, the hole diameter R1 of the hole portion 18 on the upper surface side is set to the lower surface side. The diameter is smaller than the hole diameter R2 of the hole portion 19, and
By forming the depth t1 of the hole portion 18 on the upper surface side to be shallower than the depth t2 of the hole portion 19 on the lower surface side, the hole diameter R1 of the hole portion 18 on the upper surface side can be reduced even if the plate thickness T of the metal plate 11 is large. It can be made so small that it cannot be visually recognized. For this reason,
When the light transmission type metallic tone display plate 10 is viewed from the upper surface side in a bright place, the small holes 12 are not conspicuous, and the metal plate 11 is
Further, it is possible to obtain a metallic-like decorative effect by the plating layer 14 and a decorative effect such as a hairline pattern by the surface processed portion 13. In this case, if the decoration layer 15 is a translucent color film, a colored metallic decoration effect can be obtained.

Further, in this light transmission type metallic tone display plate 10, even if the hole diameter R1 of the hole portion 18 on the upper surface side is made small, the hole diameter R2 of the hole portion 19 on the lower surface side is made large,
When the backlight device 17 is turned on in a dark place, when the light passes through the small hole 12 of the metal plate 11, the light can be sufficiently taken in by the hole portion 19 on the lower surface side having a large hole diameter R2. It can have wide-angle light transmission.
Further, since the depth t1 of the hole portion 18 on the upper surface side is formed to be shallower than the depth t2 of the hole portion 19 on the lower surface side, as shown in FIG. When the light from the device 17 passes through the hole portion 18 on the upper surface side, the light is emitted at a wide angle, so that the diffusion angle θ1 of the light can be widened, whereby the entire upper surface side of the metal plate 11 can be almost entirely. Since it is possible to uniformly illuminate, it is possible to obtain a high illumination effect.

[Second Embodiment] Next, FIG. 6A to FIG.
A second embodiment of the method of manufacturing the transmissive metallic tone display plate of the present invention will be described with reference to (g). In the second embodiment, the transmissive metallic tone display plate 10 is formed by using an etching method.
The manufacturing method is the same as that of the first embodiment shown in FIGS. In this manufacturing method, first, in FIG.
A metal plate 30 of about 0 μm, such as stainless steel, is prepared, the upper surface of the metal plate 30 is degreased, and a resist is applied to form a first resist film 31. In this case, it is preferable that the upper surface of the metal plate 30 is previously provided with a surface processing portion 13 such as hairline processing. Further, a protective film (not shown) is provided on the lower surface of the metal plate 30.

Then, as shown in FIG. 6B, the applied first resist film 31 is formed into a predetermined shape by photolithography. At this time, by exposing and developing the first resist film 31 using a photomask,
The first resist film 31 in the portion corresponding to the hole portion 18 on the upper surface side of the small hole 12 is removed, and the first resist film 31 is left in the other portions. As a result, the first resist film 31 having the small-diameter holes 32 having a diameter of, for example, about 30 μm is formed on the upper surface of the metal plate 30. In this state, as shown in FIG. 6C, the metal plate 30 in the portion corresponding to the small diameter hole portion 32 of the first resist film 31 is removed by etching from the upper surface side, and the hole diameter R1 of the metal plate 30 is 30 μm. The hole portion 18 is formed so as to extend substantially from the upper surface to the lower surface.

Next, as shown in FIG. 6 (d), the lower surface of the metal plate 30 is degreased, and then a resist is applied to the second surface.
A resist film 33 is formed. Then, as shown in FIG. 6E, the second resist film 3 is formed by photolithography.
3 is formed into a predetermined shape. Also at this time, by exposing and developing the second resist film 33 using the photomask, the second resist film 33 in the portion corresponding to the hole portion 19 on the lower surface side of the small hole 12 is exposed.
The resist film 33 is removed so as to have a diameter larger than the hole diameter R1 of the hole 18 on the upper surface side, and the second resist film 33 is left in the other portions. This allows the bottom surface of the metal plate 30 to have, for example, a diameter of 150.
A second resist film 33 having large-diameter holes 34 of about μm is formed. At this time, the large-diameter holes 34 of the second resist film 33 are formed coaxially with the holes 18 of the metal plate 30.

In this state, as shown in FIG. 6F, the metal plate 30 in the portion corresponding to the large-diameter hole portion 34 of the second resist film 33 is etched from the lower surface side for a predetermined time to a predetermined depth. , For example, to a depth of about 70 μm. As a result, a recessed hole portion 19 is formed on the lower surface side of the metal plate 30 so as to be coaxial with the hole portion 18 on the upper surface side. The recessed hole 19 has a hole diameter R2 of about 150 μm and a depth t2 of about 70 μm. Accordingly, the hole portion 18 located on the upper surface side of the metal plate 30 has a hole diameter R1.
Is about 30 μm, and the depth t1 is about 30 μm. Therefore, when forming the hole 18 on the upper surface side in the metal plate 30, it is not always necessary to penetrate the hole 18 from the upper surface to the lower surface of the metal plate 30, and the predetermined depth t1,
For example, it may be formed to a depth of about 30 μm.

Then, when the first resist film 31 and the second resist film 33 are removed from the upper surface and the lower surface of the metal plate 30, the hole diameter R1 of the hole portion 18 on the upper surface side becomes the hole portion 19 on the lower surface side.
A metal plate 30 having a number of step-like small holes 12 smaller than the hole diameter R2 and having a depth t1 of the hole portion 18 on the upper surface side smaller than a depth t2 of the hole portion 19 on the lower surface side is obtained. In this case, the surface processing portion 13 such as hairline processing is previously applied to the upper surface of the metal plate 30, but the surface processing portion 13 may be applied after forming a large number of small holes 12. After this, FIG.
As shown in (g), metal plating is applied to the upper surface of the metal plate 30 to form a plating layer 14, and a coating layer 15 made of a transparent film or a semitransparent color film is formed on the plating layer 14 by coating. To do. Then, the printing portion 16 is formed by printing at a predetermined position on the coating layer 15. As a result, similarly to the first embodiment, the light transmissive metal tone display plate 10 in which the upper surface of the metal plate 30 is decorated is obtained.

According to the method of manufacturing the light-transmissive metallic tone display plate 10 as described above, when the plurality of small holes 12 through which light is transmitted are formed in the metal plate 30, the upper surface is formed by the photolithography method and the etching method. The hole diameter R1 of the side hole portion 18 is formed smaller than the hole diameter R2 of the lower surface side hole portion 19, and
By forming the depth t1 of the hole portion 18 on the upper surface side to be shallower than the depth t2 of the hole portion 19 on the lower surface side, even when the plate thickness T of the metal plate 30 is thick, the depth t1 of the upper surface side is formed as in the first embodiment. The hole diameter R1 of the hole 18 can be made so small that it cannot be visually recognized.
Therefore, when the light-transmissive metallic tone display plate 10 is viewed from the upper surface side in a bright place, the small holes 12 are not conspicuous, and the metallic plate 30 and the plating layer 14 provide a metallic tone decorative effect and the surface processed portion 13. It is possible to obtain a decorative effect such as a hairline pattern.

In the light-transmissive metallic tone display plate 10 thus manufactured, even if the hole diameter R1 of the hole portion 18 on the upper surface side is reduced, the hole diameter R2 of the hole portion 19 on the lower surface side is increased and The depth t1 of the hole portion 18 on the upper surface side is set to the hole portion 19 on the lower surface side.
When the light from the backlight device 17 arranged below the metal plate 30 passes through the hole portion 18 on the upper surface side, a wide angle can be obtained by making the depth from the depth t2 smaller than the depth t2. Since the light is emitted in this manner, the diffusion angle θ1 of the light can be widened, and thereby the entire upper surface side of the metal plate 30 can be illuminated substantially uniformly, so that a high illumination effect can be obtained.

[Third Embodiment] Next, FIG. 7A to FIG.
With reference to (e), a third embodiment of the method of manufacturing a transmissive metallic tone display plate of the present invention will be described. In the manufacturing method of the third embodiment, the depth t1 of the hole portion 18 on the upper surface side of the small hole 12 and the depth t2 of the hole portion 19 on the lower surface side of the small hole 12 are formed to be substantially the same depth by using the etching method. Method, and FIG.
The same parts as those in the second embodiment shown in FIGS. 6A to 6G are designated by the same reference numerals for description. In this manufacturing method, first, as shown in FIG. 7A, a metal plate 35 such as stainless steel having a thickness T of about 100 μm is prepared, and this metal plate 3 is then prepared.
The upper and lower surfaces of 5 are degreased, and resists are applied respectively to form a first resist film 31 and a second resist film 33. Also in this case, it is desirable that the surface processing portion 13 such as hairline processing is previously provided on the upper surface of the metal plate 35.

Thereafter, as shown in FIG. 7B, the first resist film 31 and the second resist film 33 are formed into a predetermined shape by photolithography. At this time, the first photomask is made to correspond to the first resist film 31, and the second photomask is made to correspond to the second resist film 33. In this state, the first resist film 31 and the second resist film 33 are simultaneously exposed. To develop. As a result, on the upper surface of the metal plate 35, for example, the small diameter hole portion 3 having a diameter of about 30 μm is formed.
The first resist film 31 having 2 is formed, and the metal plate 35 is formed.
A second resist film 33 having a large diameter hole portion 34 having a diameter of, for example, about 150 μm is formed on the lower surface of the second resist film 33. At this time, the small-diameter holes 32 of the first resist film 31 and the large-diameter holes 34 of the second resist film 33 are coaxially formed.

After that, as shown in FIG. 7C, the metal plate 35 is simultaneously half-etched from the upper and lower surfaces through the first resist film 31 and the second resist film 33 by the etching method. As a result, a hole 18 having a hole diameter R1 of about 30 μm is formed on the upper surface side of the metal plate 35, and a concave hole 19 having a hole diameter R2 of about 150 μm is formed on the lower surface side of the metal plate 35 coaxially with the hole portion 18 on the upper surface side. Corresponding to the above, they are simultaneously formed with the same depth. That is, the depth t1 of the hole 18 on the upper surface side
And the depth t2 of the hole portion 19 on the lower surface side is formed to a depth of about 50 μm since the thickness T of the metal plate 35 is about 100 μm.

From the upper and lower surfaces of the metal plate 35,
When the second resist films 31 and 33 are removed, the hole diameter R1 of the hole portion 18 on the upper surface side is smaller than the hole diameter R2 of the hole portion 19 on the lower surface side as shown in FIG. ,
Stepped small holes 12 having the same depth t1 and t2 of 19
Thus, the metal plate 35 having a large number of formed is obtained. Also at this time, the surface processing portion 13 such as the hairline processing is provided on the upper surface of the metal plate 35 in advance, but the surface processing portion 13 may be provided after forming a large number of small holes 12. After this, FIG. 7 (e)
As shown in FIG. 3, metal plating is applied to the upper surface of the metal plate 35 to form a plating layer 14, and a coating layer 15 made of a transparent film or a semitransparent color film is formed on the plating layer 14 by coating.
To form. Then, the printing portion 16 is formed by printing at a predetermined position on the coating layer 15. As a result, similarly to the first and second embodiments, the light transmission type metallic tone display plate 10 in which the upper surface of the metal plate 35 is decorated is obtained.

In the method of manufacturing the light-transmissive metal tone display plate 10 as described above, the first and second coatings applied to both the upper and lower surfaces of the metal plate 35.
When forming the second resist films 31 and 33 into a predetermined shape by photolithography, the first and second resist films 3 are formed.
Since 1 and 33 are simultaneously exposed and developed, the first and second resist films 31 and 33 can be simultaneously formed on the upper and lower surfaces of the metal plate 35, and the metal plate 35 can be formed by the etching method.
When forming the hole portion 18 on the upper surface side and the hole portion 19 on the lower surface side at the same time, the hole portion 18 on the upper surface side and the hole portion 19 on the lower surface side are simultaneously formed by half etching.
The respective depths t1 and t2 of 19 can be formed at the same depth at the same time, and therefore, the manufacturing process and the manufacturing time can be significantly simplified as compared with the above-described second embodiment.

In the first to third embodiments, the thickness T of the metal plates 11, 30, 35 is about 100 μm, the hole diameter R1 of the hole portion 18 on the upper surface side of the small hole 12 is about 30 μm, and the hole diameter R1 on the lower surface side is about 30 μm. Although the hole diameter R2 of the hole portion 19 is formed to be about 150 μm, it is not limited to this, and the hole diameter R1 of the hole portion 18 on the upper surface side of the small hole 12 is 10 to 80 μm depending on the application.
The metal plate 11, 30, 35 according to this.
The thickness T, the hole diameter R2 of the hole portion 19 on the lower surface side of the small hole 12, and the depths t1 and t2 of the hole portions 18 and 19 may be appropriately set to form an appropriate size. In this case, the holes 19 on the lower surface side do not need to have the adjacent holes 19 separated from each other, and the adjacent holes 19 bite into each other, that is, the holes 19 partially overlap each other. It may be formed in an open state, or the hole portion 19 on the lower surface side may be formed to be large and a plurality of small holes on the upper surface side may be opposed to one hole portion (not coaxial). .

In the first to third embodiments described above, the case where the depth t1 of the hole portion 18 on the upper surface side is formed shallower than the depth t2 of the hole portion 19 on the lower surface side is mainly described. Not limited to this, for example, as shown in FIG. 5, the depth t1 of the hole portion 18 on the upper surface side and the depth t2 of the hole portion 19 on the lower surface side may be formed at substantially the same depth (t1 = t2). . In this case, the diffusion angle θ2 at which the light passes through the small holes 12 and diffuses is slightly narrower than that of the first embodiment (θ2 <θ1), but the pitch of the small holes 12 is made smaller and the density of the small holes 12 is reduced. Since the upper surface side of the metal plate 11 can be illuminated substantially uniformly if the height is increased, a sufficient illumination effect can be obtained in this case as well.
Further, t1 <t2 may be set depending on the conditions of the required hole diameter and the amount of light (brightness).

[First Use Example] Next, referring to FIG. 8, the transmission type metallic tone display plate 10 manufactured by the manufacturing method of the first to third embodiments was used as a timepiece dial of a wristwatch. The case will be described. As shown in FIG. 8, this wristwatch includes a wristwatch case 40, and a watch glass 41 is attached to the upper portion of the wristwatch case 40 via a packing 42. Also, inside the wristwatch case 40,
The watch dial 43 and the watch module 44 are housed in a state of being attached to the inner frame 45, and the watch case 4
A back cover 46 is attached to the lower surface of 0 through a waterproof ring 47.

The timepiece module 44 has at least an analog function of an analog function and a digital function, and is constructed so that the hands 48 such as an hour hand and a minute hand move above the timepiece dial 43. The watch case 40
On the inner peripheral surface of the watch, the upper part of the middle frame 45 is covered, and the timepiece dial 4
A parting portion 49 that abuts the upper surface of the outer peripheral portion of No. 3 is formed so as to project inward. The timepiece dial plate 43 has the same structure as the transmissive metal tone display plate 10 of the first embodiment, and is arranged on the upper surface of the timepiece module 44 via the backlight device 17. That is, in the timepiece dial plate 43, similar to the first embodiment shown in FIG. 1, a large number of stepped small holes 12 are formed in the metal plate 11, and the surface processed portion 13 is provided on the upper surface thereof. , The plating layer 14 and the coating layer 15 are laminated,
With a structure in which the printing unit 16 is provided at a predetermined position on the upper surface,
A pointer 48 moves above it.

According to such a wristwatch, in a bright place, external light is taken in through the watch glass 41, and the taken light is reflected by the surface of the timepiece dial plate 43 other than the many small holes 12, The time can be known by the timepiece dial 43 and the hands 48. At this time, since the timepiece dial plate 43 has the same structure as the transmissive metal tone display plate 10 of the first embodiment, even if a large number of small holes 12 are formed in the metal plate 11, these small holes 12 are not formed. Not noticeable,
The metallic plate 11 and the plating layer 14 can provide a metallic-like decorative effect, and the surface-processed portion 13 can provide a decorative effect such as a hairline pattern. In this case, the decorative layer 15
Is a translucent color film, it is possible to obtain a colored metallic effect.

In a dark place, the backlight device 17
When the light is turned on, the light is emitted from the metal plate 1 of the timepiece dial 43.
Since a large number of small holes 12 formed in 1 are transmitted, it is possible to illuminate the upper part of the timepiece dial plate 43, so that the time can be known even in a dark place. Backlight device 17
The light from is diffused in a wide range from the hole 18 on the upper surface side,
The entire upper surface side of the metal plate 11 can be illuminated substantially uniformly, whereby a sufficient illumination effect can be obtained.

[Second Use Example] Next, with reference to FIGS. 9 and 10, the transmission type metallic tone display plate 10 manufactured by the manufacturing method of the first to third embodiments is used in a liquid crystal display device of a wristwatch. The case where it is used as a reflection / transmission plate will be described. Note that FIG.
The same parts as those of the first use example shown in FIG. This wristwatch has the same structure as the first usage example except that the timepiece module 50 housed in the wristwatch case 40 is different from the first usage example described above. That is, the timepiece module 50 is provided with at least a digital function having the liquid crystal display device 51 out of the analog function and the digital function, and is configured to display information such as time on the liquid crystal display device 51.

In this case, the liquid crystal display device 51 has a reflective / transmissive plate 5 on the lower surface of the liquid crystal display panel 52, as shown in FIG.
3 is provided, and the backlight device 17 is arranged below the reflection / transmission plate 53. Liquid crystal display panel 5
2 is a liquid crystal 5 between a pair of upper and lower transparent electrode substrates 54 and 55.
6, a liquid crystal cell 57 is formed by sealing 6 with a sealing material 57a. Polarizing plates 58 are provided on the upper and lower surfaces of the liquid crystal cell 57, respectively.
The structure is provided with 59. Similar to the transmissive metal tone display plate 10 of the first embodiment shown in FIG. 1, the reflective / transmissive plate 53 has a large number of stepped small holes 12 formed in the metal plate 11, and the surface processed portion 13 is formed on the upper surface thereof. It has a structure in which the plating layer 14 and the coating layer 15 are laminated by applying. In this case,
The printing unit 16 does not necessarily have to be provided.

In the liquid crystal display device 51 using such a reflection / transmission plate 53, external light taken in from the upper surface side is transmitted through the liquid crystal display panel 52, and the transmitted light is reflected by a large number of small reflection / transmission plates 53. Since the light is reflected by the surface other than the hole 12, it is possible to visually recognize information such as the time without turning on the backlight device 17 in a bright place. At this time, since the reflective / transmissive plate 53 has the same structure as the transmissive metallic tone display plate 10 of the first embodiment, even if a large number of small holes 12 are formed in the metal plate 11, these small holes 12 are conspicuous. Without
The metallic plate 11 and the plating layer 14 can provide a metallic-like decorative effect, and the surface-processed portion 13 can provide a decorative effect such as a hairline pattern. Also in this case, if the decoration layer 15 is a semitransparent color film, a colored metallic decoration effect can be obtained.

In a dark place, the backlight device 17
When the light is turned on, the light is reflected by the metal plate 11 of the reflection / transmission plate 53.
Since the light passes through the small holes 12 formed in a large number, it is possible to illuminate the lower surface side of the liquid crystal display panel 52, so that information such as the time can be known even in a dark place. Light from the backlight device 17 is diffused in a wide range from the hole portion 18 on the upper surface side, and the entire lower surface of the liquid crystal display panel 52 can be illuminated substantially uniformly, whereby a sufficient illumination effect can be obtained. At the same time, the information displayed on the liquid crystal display device 51 can be seen clearly.

[Third Use Example] Next, FIG. 11 and FIG.
With reference to, the case where the transmissive metallic tone display plate 10 manufactured by the manufacturing method of the first to third embodiments is used as a reflective / transmissive plate of a liquid crystal display device of a mobile phone will be described. The same parts as those of the second use example shown in FIGS. 9 and 10 are designated by the same reference numerals for description. FIG. 11 is an external perspective view of the mobile phone, and FIG. 12 is an enlarged sectional view taken along the line AA. As shown in FIG. 11, this mobile phone includes a device case 60 made of synthetic resin.
Has a structure in which an upper case 61 and a lower case 62 are joined.

On the upper surface of the device case 60, that is, the upper surface of the upper case 61, a protective glass 63 is attached to an opening provided on the upper side thereof, and various key buttons 64 necessary for a telephone function are provided. It is provided. Further, an antenna 65 is attached to the upper side surface of the device case 60 so as to be retractable. Furthermore, this device case 60
As shown in FIG. 12, a module 66 for a telephone is housed inside. The module 66 includes various components necessary for a telephone function such as the liquid crystal display device 51. The liquid crystal display device 51 has the same structure as the second use example shown in FIG. 10, and is arranged corresponding to the lower side of the protective glass 63.

That is, this liquid crystal display device 51 is shown in FIG.
As shown in FIG. 2, the reflective / transmissive plate 53 is provided on the lower surface of the liquid crystal display panel 52, and the backlight device 17 is disposed below the reflective / transmissive plate 53. The liquid crystal display panel 52 includes a liquid crystal cell 57 in which a liquid crystal 56 is sealed between a pair of upper and lower transparent electrode substrates 54 and 55, similarly to the second use example shown in FIG. It has a structure in which polarizing plates 58 and 59 are provided respectively. The reflective / transmissive plate 53 is similar to the transmissive metallic tone display plate 10 of the first embodiment shown in FIG.
2 is formed in a large number, the surface processed portion 13 is provided on the upper surface thereof, and the plating layer 14 and the coating layer 15 are laminated. Also in this case, the printing unit 16 does not necessarily have to be provided.

A liquid crystal display device 51 of such a mobile phone.
Then, in a bright place, external light is taken in through the protective glass 63, the external light taken in is transmitted through the liquid crystal display panel 52, and the transmitted light is reflected by the large number of small holes 1 in the reflection / transmission plate 53.
Since the light is reflected on a surface other than 2, the displayed information can be visually recognized in a bright place without turning on the backlight device 17. Also at this time, since the reflective / transmissive plate 53 has the same structure as the transmissive metal-tone display plate 10 of the first embodiment,
Even if a large number of small holes 12 are formed in the metal plate 11, these small holes 12 are not conspicuous, and the metal plate 11 and the plating layer 14 provide a metal-like decorative effect, and the surface processed portion 1
A decorative effect such as a hairline pattern according to 3 can be obtained. Also in this case, if the decoration layer 15 is a semitransparent color film, a colored metallic decoration effect can be obtained.

In a dark place, the backlight device 17
When the light is turned on, the light is reflected by the metal plate 11 of the reflection / transmission plate 53.
Since a large number of small holes 12 are formed in the lower surface of the liquid crystal display panel 52, the lower surface side of the liquid crystal display panel 52 can be illuminated, so that the displayed information can be seen through the protective glass 63 even in a dark place. The light from the backlight device 17 diffuses in a wide range from the hole 18 on the upper surface side, and the liquid crystal display panel 5
The entire back surface of 2 can be illuminated substantially uniformly, and thus a sufficient illumination effect can be obtained and the information displayed on the liquid crystal display device 51 can be clearly viewed.

[0050]

As described above, according to the present invention, when forming a plurality of small holes through which light is transmitted in a metal plate, for example, the hole diameter on the front surface side is made smaller than the hole diameter on the back surface side. This makes it possible to reduce the hole diameter on the front side to the extent that it cannot be visually recognized even if the plate thickness of the metal plate is large.Also, even if the hole diameter on the front surface side is reduced, the hole diameter on the back surface side can be increased to allow wide-angle light transmission. It is possible to obtain a sufficient lighting effect by using the metal plate, and by increasing the thickness of the metal plate, the decorative workability of the surface is not impaired, and the metal plate alone is used for the decoration process. Can be used.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of a main part showing a first embodiment of a transmissive metallic tone display plate manufactured by a manufacturing method of the present invention.

2 conceptually shows the entire transmissive metal tone display plate of FIG. 1, (a) is a top view of the transmissive metal tone display plate seen from the upper side, and (b) is a transmissive metal tone display plate. The bottom view which looked at from the lower surface side.

FIG. 3 shows a manufacturing process of the transmission type metallic tone display plate of FIG.
(A) is a sectional view in which a resist is applied on a substrate, (b) is a sectional view in which the applied resist is formed on a first resist film having a predetermined shape by a photolithography method, and (c) is a first view
A cross-sectional view in which a first metal layer is formed on a substrate on which a resist film is formed by an electroforming method, (d) shows a second resist film on a top surface of the first metal layer and the first resist film in a predetermined shape by photolithography. (E) is a cross-sectional view of the second metal layer formed on the first metal layer having the second resist film formed thereon by electroforming, and (f) is the cross-sectional view of the first and second resist films. A cross-sectional view in which the first metal layer on which the second metal layer has been removed and which has been removed is peeled off from the substrate, (g) is a cross-sectional view in which a metal plate on which the first and second metal layers are stacked is turned upside down, h) is a cross-sectional view in which a plating layer, a coating layer, and a printing portion are provided on the upper surface of a metal plate which is turned upside down.

FIG. 4 is a diagram showing a light transmission state of a transmissive metallic tone display plate manufactured through the process of FIG. 3;

FIG. 5 is a diagram showing a light transmission state in a modification of the transmissive metallic tone display plate having a structure in which the depth of the hole on the upper surface side and the depth of the hole on the lower surface side are formed to be substantially the same.

FIG. 6 shows a manufacturing process in a second embodiment of a method for manufacturing a transmissive metallic tone display plate of the present invention, (a) is a cross-sectional view of a metal plate coated with a resist, and (b) is a coated resist. Is a sectional view in which a first resist film having a predetermined shape is formed by photolithography, (c) is a sectional view in which a hole corresponding to a hole portion on the upper surface side is formed by etching a metal plate on which the first resist film is formed, (D) is a sectional view in which a resist is applied to the lower surface of a metal plate, (e) is a sectional view in which the applied resist is formed on a second resist film having a predetermined shape by a photolithography method, and (f) is a second resist film. A cross-sectional view in which the metal plate on which is formed is removed by etching to a predetermined depth, (g) shows that the first and second resist films are removed and a plating layer, a coating layer, and a printing portion are provided on the upper surface of the metal plate. Sectional view.

FIG. 7 shows a manufacturing process in a third embodiment of a method for manufacturing a transmissive metallic tone display plate of the present invention, wherein (a) shows a method of applying a resist on both upper and lower surfaces of a metal plate to form first and second resist films. The formed cross-sectional view, (b) is a cross-sectional view in which the first and second resist films are formed into predetermined shapes by photolithography, and (c) is the metal plate half-etched through the first and second resist films. Sectional view, (d) is a sectional view in which the first and second resist films are removed from both upper and lower surfaces of the metal plate, (e)
Is a cross-sectional view in which a plating layer, a coating layer, and a printing portion are provided on the upper surface of the metal plate.

FIG. 8 is an enlarged cross-sectional view of a main part showing an internal structure of a wrist watch in a first use example in which the transparent metal tone display plate of the present invention is applied to a timepiece dial of a wrist watch.

FIG. 9 is an enlarged cross-sectional view of a main part showing an internal structure of a wrist watch in a second use example in which the transmissive metallic tone display plate of the present invention is applied to a reflective / transmissive plate of a liquid crystal display device of a wrist watch.

10 is an enlarged cross-sectional view of the main part of the liquid crystal display device of FIG.

FIG. 11 is an external perspective view of a mobile phone in a third use example in which the transmissive metallic tone display plate of the present invention is applied to a reflection / transmission plate of a liquid crystal display device of the mobile phone.

12 is a sectional view taken along the line AA of FIG.

FIG. 13 is a diagram showing a diffusion state of light when the diameter of the small holes and the thickness of the metal plate are formed to have substantially the same size in the conventional transmissive metal tone display plate.

FIG. 14 is a diagram showing a diffusion state of light when the metal plate is formed thicker than the hole diameter of the small holes in the conventional transmissive metal tone display plate.

[Explanation of symbols]

10 Transmissive metal tone display board 11, 30, 35 Metal plate 12 small holes 18 Top side hole 19 Hole on the bottom side 21, 31 First resist film 23 First metal layer 24, 33 second resist film 25 Second metal layer 32 Small diameter hole 34 Large diameter hole R1 Hole diameter on the upper surface side R2 Hole diameter on the bottom side Thickness of T metal plate t1 Depth of hole on the upper surface side t2 Depth of hole on the bottom side θ1, θ2 Light diffusion angle

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shunji Minami             Casio 3-2-1 Sakaemachi, Hamura-shi, Tokyo             Computer Co., Ltd. Hamura Technical Center (72) Inventor Kiichiro Morita             5-2 Kitamachi Kitamachi, Warabi-shi, Saitama Co., Ltd.             Shokosha Warabi Factory

Claims (6)

[Claims] 1. When forming a plurality of small holes through which light is transmitted through a metal plate by electroforming, it is possible to form the small holes on the front surface side and the rear surface side in different sizes. A method of manufacturing a light-transmissive metal tone display plate, which is characterized. 2. The method of manufacturing a light-transmissive metallic tone display plate according to claim 1, wherein the depth of the hole portion located on the front surface side of the small hole and the depth of the hole portion located on the back surface side are different. A method for manufacturing a light-transmissive metal tone display plate, which is characterized in that it is formed to a depth. 3. When forming a plurality of small holes through which light is transmitted on a metal plate by using a photolithography method, it is possible to form the small holes on the front surface side and the rear surface side in different sizes. A method of manufacturing a light-transmissive metal tone display plate, which is characterized. 4. The method of manufacturing a light-transmissive metal tone display plate according to claim 3, wherein the depth of the hole portion located on the front surface side of the small hole and the depth of the hole portion located on the back surface side are different. A method for manufacturing a light-transmissive metal tone display plate, which is characterized in that it is formed to a depth. 5. When forming a plurality of small holes through which light is transmitted on a metal plate by using an etching method, the hole diameter on the front surface side and the hole diameter on the back surface side of the small holes are formed to have different sizes. And a method of manufacturing a light-transmissive metallic tone display board. 6. The method of manufacturing a light-transmissive metal tone display plate according to claim 5, wherein the depth of the hole portion located on the front surface side of the small hole and the depth of the hole portion located on the back surface side are different. A method for manufacturing a light-transmissive metal tone display plate, which is characterized in that it is formed to a depth.