JP2006208221A - Display plate and electronic display apparatus having it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin display plate capable of providing uniform illumination and brightness. <P>SOLUTION: The display plate 10 is constituted by disposing a display layer 13 on the upper face of a permeable substrate 11 and disposing a plurality of V-shaped projections 11a or V-shaped recessed grooves arranged about a light source 15 formed on the lower face 11b of the permeable substrate 11. The V-shaped projections 11a or V-shaped recessed grooves are formed in a circular pattern concentrically about the light source 15 or in a radiation pattern about the light source 15. The pitch interval of the plurality of V-shaped projections 11a or V-shaped recessed grooves is large near the light source 15 and small away from the light source 15. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a display panel of a timepiece, an instrument display panel of an automobile, and other various electronic display devices.

  Some display boards of watches, instrument display boards of automobiles, and display boards of various other electronic display devices are equipped with illumination devices so that the display can be read even in the dark at night. Many of the lighting devices have an illumination structure including a backlight on the back surface of the display panel. For example, a portable timepiece or the like has a structure in which EL (electroluminescence) is disposed on the back side of a transmissive display plate, and the display plate is illuminated by emitting EL. However, although the illumination structure using EL can make the entire watch relatively thin, if the EL light emission luminance is low, the display brightness of the display panel is low, and the illumination color tone is limited. I have a problem. Therefore, in order to increase the display brightness, a structure in which a light source serving as an LED is disposed on the side surface of the display board to illuminate the display board has been used in part. FIG. 11 shows a conventional illumination structure in which a light source serving as an LED is arranged on the side surface of a display panel of a portable timepiece to illuminate the display panel. FIG. 11 (a) is a plan view, and FIG. b) shows a side view.

  Hereinafter, the related art will be described with reference to FIG. The display panel 1 is provided with an index 3 composed of time characters on the upper surface of the transparent substrate 2. The transparent substrate 2 is formed of a transparent polycarbonate resin or the like, and the surface thereof is decorated as a display board using a paint or the like. Two light sources 4 made of LEDs are disposed on the left and right sides of the display panel 1, and the display panel 1 is illuminated from both sides by the light emission of the light source 4. The light source 4 disposed on the side surface of the display board 1 emits light, and the light enters the inside of the transmissive substrate 2 formed of a transparent polycarbonate resin or the like, and the display board 1 is illuminated with the incident light. It has a structure.

  However, in this structure, as shown in FIG. 11A, the areas A1 and A2 near the left and right light sources 4 are illuminated brightly, but the area B indicated by diagonal lines is darkened, and the illumination clearly Unevenness of brightness is visually recognized. In this way, as it gets farther from the light source, it becomes darker and uneven in brightness, and has a problem that it is inferior in appearance and function and cannot be used for a luxury watch.

  As long as such a structure is adopted, the same thing occurs not only on the display board of the portable watch but also on the display board of other electronic display devices. This problem can be solved to some extent by increasing the number of light sources. However, increasing the number of light sources leads to an increase in cost, and a new problem arises that a large installation space is required. In particular, a watch with a limited size, such as a portable watch, is required to have bright illumination and non-uniform illumination without increasing the number of light sources.

  The present invention has been made in view of the above problems, and an object of the present invention is to obtain a display panel that can provide bright illumination and non-uniform illumination without increasing the number of light sources. In addition, bright and uniform illumination can be achieved in a thin display plate, and the display device can be made thinner.

  As a means for solving the above-mentioned problems, the display board according to claim 1 of the present invention is a display board comprising a light-transmitting substrate having a display layer on the upper surface side and reflecting means on the lower surface side. The reflecting means comprises a plurality of V-shaped protrusions or V-shaped grooves formed on the lower surface of the transmissive substrate centering on a light source disposed on the side surface of the light transmissive substrate. To do. The V-shaped projection in the present invention refers to a V-shaped projection.

  Further, the display panel according to claim 2 of the present invention includes a plurality of V-shaped projections arranged side by side between adjacent V-shaped projections or V-shaped concave grooves adjacent to each other. It has a flat surface between them.

  The display board according to claim 3 of the present invention is characterized in that the plurality of the display panels are arranged side by side, and the width of the V-shaped projection or the V-shaped groove is 20 to 70 μm.

  The display board according to claim 4 of the present invention is characterized in that the plurality of the display boards are arranged side by side, and the V-shaped projections or the V-shaped grooves are mirror surfaces.

  The display board according to claim 5 of the present invention is characterized in that the plurality of V-shaped protrusions or V-shaped grooves formed side by side form a circle pattern or a radial pattern.

  Further, the display board according to claim 6 of the present invention is characterized in that the circle pattern is provided concentrically with the light source as the center, and the pitch of the circles decreases as the distance from the light source increases. is there.

  The display board according to claim 7 of the present invention is characterized in that the radial pattern has a larger number of radial lines as the distance from the light source increases.

  Further, in the display board according to claim 8 of the present invention, two light sources are provided on the left and right on the substantially center line of the transparent substrate, and the plurality of V-shaped projections or V-shaped grooves formed side by side are symmetrical. Is provided.

  The display panel according to claim 9 of the present invention is characterized in that the lower surface of the transparent substrate has a rising slope from the outer peripheral side of the substrate toward the center side of the substrate.

  The display board according to claim 10 of the present invention is characterized in that a reflective film is provided on the lower surface of the light-transmitting substrate provided with the V-shaped protrusions or V-shaped grooves.

  The display panel according to claim 11 of the present invention is characterized in that a light diffusion layer is provided between the display layer and the light-transmitting substrate.

  An electronic display device according to a twelfth aspect of the present invention is an electronic display device having an illumination structure of a display plate, and includes the display plate according to any one of the first to eleventh aspects. In addition, the brightness of the display is uniformly illuminated and the display device is made thin.

  As an effect of the invention, the display panel of the present invention comprises a light-transmitting substrate having a display layer on the upper surface side and reflecting means on the lower surface side, and the reflecting means is disposed on the side surface side of the light-transmitting substrate. A plurality of V-shaped protrusions or V-shaped grooves formed side by side with respect to the light source. The light incident on the light-transmitting substrate from the side surface is reflected by the V-shaped protrusion or the V slope of the V-shaped groove, and is emitted to the display layer side to illuminate the display layer. Since a plurality of V-shaped protrusions or V-shaped concave grooves are provided side by side with the light source as the center, the reflected light from the V slope increases, and the brightness at the same distance from the light source is the same.

  Further, the V-shaped projection or the V-shaped groove is formed in a circle pattern or a radial pattern as described in claims 5, 6 and 7, and the circle pattern is concentric with the light source as a center, and further away from the light source. The pitch of the circle is small. Similarly, the number of radiating eyes increases as the distance from the light source increases. As a result, as the distance from the light source increases, more reflected light from the V slope is obtained, and the illumination brightness becomes uniform throughout.

  Also, the V-shaped projection or the V-shaped groove is a mirror surface under the fourth aspect. As a result, total reflection occurs on the mirror-shaped V slope, and a large amount of reflected light is emitted to the display layer to illuminate the display layer even more brightly.

  Further, as described in claim 3 of the present invention, when the width of the V-shaped protrusion or the V-shaped groove is 20 to 70 μm, the reflection efficiency is not deteriorated, and the V-shaped protrusion or the V-shaped groove is visually recognized. Therefore, good appearance quality can be obtained.

  Further, as described in claim 2 of the present invention, a plurality of V-shaped protrusions formed side by side between adjacent V-shaped protrusions, or between adjacent V-shaped grooves of V-shaped grooves, When a flat surface is provided, external light is transmitted downward from the portion of the flat surface. The present invention can also be applied to a structure in which a solar cell is provided below the display panel, and the display panel can be provided with functions of both illumination and solar cell power generation.

  Further, as described in claim 8 of the present invention, when two light sources are provided on the left and right on the substantially center line of the transparent substrate, a plurality of V-shaped protrusions or V-shaped grooves formed side by side are symmetrical. By providing in, the illumination brightness of the right and left of a display board becomes uniform.

Further, as described in claim 9 of the present invention, when the lower surface of the transparent substrate has a rising slope from the outer peripheral side of the substrate toward the center side of the substrate, many Light enters the V-shaped projection of the V-shaped protrusion or the V-shaped groove. And even if it is far from the light source, the amount of reflected light on the V slope increases and the brightness is increased.
It is characterized by having.

  Further, as described in claim 10 of the present invention, when a reflective film is provided on the lower surface of the light transmitting substrate provided with V-shaped projections or V-shaped grooves, the reflectance is increased and brighter illumination is obtained.

  Further, as described in claim 11 of the present invention, by providing a light diffusion layer between the display layer and the light transmissive substrate, the light reflected upward from the V-shaped protrusion or the V-shaped groove is It diffuses in this diffusion layer. Diffuse light to make the illumination brightness uniform.

  Moreover, in the electronic display device provided with the illumination structure of the display panel, a display device in which the entire display panel is uniformly and brightly illuminated can be obtained by using the display panel of the present invention. In addition, since the display panel and the light source disposed on the side surface are only used, the display device only needs to be designed in consideration of the thickness of the display panel, so that the thickness can be significantly reduced.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to FIGS. In the description of the embodiment of the display board of the present invention, the explanation will be made using a clock display board. However, the display board of the present invention is not limited to the timepiece display board, and can be commonly applied to display boards of other instruments, display boards of electronic display devices, or display boards used alone. Here, the figure will be described. 1A and 1B are diagrams showing a configuration of a timepiece display panel according to a first embodiment of the present invention. FIG. 1A is a plan view, and FIG. 1B is a DD in FIG. A cross-sectional view is shown. 2 is a rear view schematically showing the rear surface of the display board in FIG. 1, and FIG. 3 is an enlarged cross-sectional view of an E portion in FIG. FIG. 4 is a cross-sectional view of a main part of the timepiece display panel according to the second embodiment of the present invention, and FIG. 5 is an enlarged view of a portion F in FIG. FIG. 6 is a cross-sectional view of a main part of a timepiece display panel according to a third embodiment of the present invention, and FIG. 7 is an enlarged view of a portion G in FIG. FIG. 8 is a view showing the structure of a timepiece display panel according to the fourth embodiment of the present invention. FIG. 8 (a) is a plan view, and FIG. 8 (b) is D in FIG. -D shows a cross-sectional view. 9 is a rear view schematically showing the rear surface of the display board in FIG. 8, and FIG. 10 is a perspective view showing an enlarged main part of the H portion in FIG. Show.

  First, the timepiece display panel according to the first embodiment of the present invention will be described with reference to FIGS. 1, 2, and 3. As shown in FIG. 1A, the display plate 10 has a round outer diameter and has a center hole 11c for attaching a pointer at the center thereof. The display panel 10 includes a light transmissive substrate 11 provided with a reflecting means on the lower surface side, and a display layer 13 provided on the upper surface side of the light transmissive substrate 11. The display layer 13 is composed of a decorative film 13b and an indicator 13a that indicates a clock time character. Two light sources 15 made of LEDs are disposed on the left and right side surfaces of the display board 10. The two light sources 15 are provided almost on the center line of the display panel 10 in order to illuminate with equal brightness. As shown in FIG. 1B and FIG. 2, the reflecting means provided on the lower surface side of the light transmissive substrate 11 includes a plurality of V-shaped protrusions formed side by side on the lower surface 11b of the transmissive substrate 11 (in the present invention, The V-shaped protrusion is formed in a V shape and protrudes from the lower surface 11b, and is formed in a circle pattern with concentric circles around the light source 15. It is what. And this display board 10 is a structure which reflects the incident light from the light source 15 to the display layer 13 side using the reflection means of the V-shaped protrusion 11a formed in the shape of a circle side by side, and illuminates the display layer 13 brightly. Is taking. Although not shown, a solar cell is disposed on the lower surface side of the display board 10.

  The V-shaped projections 11a are provided concentrically with the light source 15 as the center, but since the two light sources 15 are provided on both the left and right sides of the display board 10, the light transmissive substrate 11 is shown in FIG. As described above, a plurality of concentric V-shaped projections 11a formed with the right light source 15 as the center are provided on the right half of the light-transmitting substrate 11, and the left light source 15 is formed with the left half as the center. A plurality of concentric V-shaped protrusions 11a are provided. Therefore, the right half V-shaped protrusion 11a and the left half V-shaped protrusion 11a are symmetrical with respect to the center of the display panel.

  As shown in FIG. 3, the V-shaped protrusion 11 a has a pitch p <b> 1 that is wider near the light source 15 on the lower surface 11 b side of the light-transmitting substrate 11, and a pitch p <b> 2 is narrower as it is farther from the light source 15. As the distance from the light source 15 increases, the V-shaped protrusion 11a is formed in a denser state. Moreover, the lower surface 11b which made the flat surface remains between the adjacent V-shaped protrusion 11a, and has comprised the continuous surface of V-shaped protrusion-flat surface-V-shaped protrusion-flat surface -.... The surface and flat surface of the V-shaped protrusion 11a are finished to be mirror surfaces.

  In FIG. 3, L1 and L2 indicate incident light from the light source 15, and the direction of the arrow indicates the direction in which the light travels. The shape of the V-shaped protrusion 11a may be set so that the tip angle is within a range of 85 ° ± 15 ° (70 ° to 100 °), more preferably within a range of 80 ° to 90 °. This range of angles maximizes the reflectance at the V slope, and efficiently reflects the incident light L1 and L2 upward (to the display layer side). The height h of the V-shaped protrusion 11a is in the range of 10 to 35 μm. The height h of the V-shaped protrusion 11a is determined by the width m of the V-shaped protrusion 11a, and the width m of the V-shaped protrusion 11a is set in the range of 20 to 70 μm. When the width m is smaller than 20 μm, the reflection efficiency is deteriorated and bright illumination cannot be obtained. On the other hand, if it is larger than 70 μm, the V-shaped projection 11a has a mirror surface, so that it can be viewed from above the display panel 10 and the appearance quality is impaired.

  Light (L1, L2) which hits the V slope of the V-shaped protrusion 11a with light from the light source 15 is reflected and reflected upward. In general, the display panel is illuminated brightly near the light source because a large amount of radiated light from the light source is applied. On the other hand, the distance from the light source becomes dark because the amount of light decreases. However, since the plurality of V-shaped protrusions 11a are formed concentrically around the light source 15, and further away from the light source 15, the pitch is narrowed and densely formed. The amount of reflected light from the V-shaped projection 11a also increases, thereby increasing the brightness and obtaining a uniform brightness as a whole.

  The light transmissive substrate 11 is formed by an injection molding method using a transparent plastic material such as a transparent polycarbonate resin. At that time, the V-shaped protrusion 11a and the mirror finish on the lower surface side of the light-transmitting substrate 11, that is, the mirror finish of the surface of the V-shaped protrusion 11a and the flat surface between adjacent V-shaped protrusions are transferred from the mold. Form by the method. The light transmissive substrate 11 is formed to have a thickness in the range of about 0.4 to 0.6 mm. The material used for the light transmissive substrate 11 is not limited to polycarbonate resin, and is excellent in heat resistance, moisture resistance, light resistance, etc., such as polyimide resin, polyethylene resin, polypropylene resin, polyacetal resin, polystyrene resin, and acrylic resin. Resin material can be used.

  The display layer 13 is a display layer that plays a display role as a display board. The clock display board is decorated with indicators such as time characters and decoration for enhancing the appearance of the clock. In FIG. 1, the display layer 13 is composed of a decorative film 13b and an index 13a indicating time characters. The decorative film 13b is a decoration provided to enhance the appearance of the watch, and has light transmittance. This decorative film 13b is made of a known printing method or coating method using a colored ink or a colored resin paint produced by mixing a pigment, a dye, or the like with a resin such as a transparent acrylic resin, urethane resin, alkyd resin, or epoxy resin. Form with. When using colored inks or colored resin paints, the required permeability must be ensured. Therefore, 5-10 parts by weight of a colorant such as a pigment or a dye is blended with the above resin to obtain a colored ink or colored resin paint. Is preferably formed to a thickness of 5 to 20 μm. Further, it can be formed of a metal thin film having light transmission properties by a dry plating method such as a vacuum deposition method, a sputtering method, or an ion plating method. Even when the decorative film 13b is formed of a metal thin film, it is preferable to form the decorative film 13b with a thickness of 50 to 200 mm in order to obtain the required transmittance. With this thickness, a transmittance in the range of 30 to 70% can be obtained. In addition, as the metal to be used, metals such as Au, Ag, Al, Cu, Co, Cr, Ni, Pt, and Pd, and alloy metals thereof can be used to obtain a decorative film 13b having various metal colors. Can do. The decorative film 13b may be formed of a film in which a metal thin film and a colored resin film are laminated. Various decorations can be applied to enhance the decorativeness and the decoration variations. The indicator 13a is formed by a known printing method such as screen printing or pad printing using colored ink, or a metal indicator formed by a method such as a cutting method, a pressing method, or an electroforming plating method is pasted. Form.

  In the display panel having the above structure, light that enters the light-transmitting substrate 11 from the light source 15 and travels toward the lower surface side of the light-transmitting substrate 11 is reflected by the V slope of the V-shaped protrusion 11a provided on the lower surface side. Is emitted toward the display layer 13. Since the V slope forms a mirror surface and forms an angle of 70 ° to 100 °, a large amount of light is reflected to greatly increase the reflection efficiency. The display layer is illuminated with a large amount of reflected light. Since the decoration film 13b of the display layer 13 is transmissive, light is emitted through the decoration film 13b. And the decoration of the decoration film 13b is visually recognized as a bright decoration under a large amount of reflected light. In addition, a plurality of V-shaped protrusions 11a are arranged side by side so as to be closer to the center of the light-transmitting substrate 11 (this is closer to the central portion of the light-transmitting substrate 11). However, a large amount of reflected light is obtained, and the illumination brightness of the display layer 13 is made uniform. Of course, light directly emitted from the light source 15 toward the display layer 13 also appears. The display layer 13 is uniformly and brightly illuminated with the directly emitted light or the light reflected by the V-shaped protrusion 11a of the light-transmitting substrate 11. The LED used as the light source 15 has a bright emission brightness and can have various emission colors. Therefore, the display board 10 can be illuminated with a bright and uniform brightness. The emission color can be appropriately selected according to the required specifications.

  The light-transmitting substrate 11 has a flat surface between adjacent V-shaped protrusions 11a. This flat surface is provided to transmit external light incident from above the display panel 10, and a large amount of light is transmitted through the display panel through this flat surface to generate power in a solar cell disposed on the lower surface side of the display panel. Causes action. Solar cells in recent years have also become very high in photoelectric conversion efficiency, and solar cells that can generate satisfactory power with a light transmittance of 15% are also being used. The flat surface on the lower surface side of the light transmissive substrate 11 is formed with an area that does not hinder the power generation of the solar cell.

  The display panel 10 having the above structure has a structure that illuminates the display panel itself and can also be applied to a solar cell. And since the illumination of the display board 10 can be achieved by the structure of one light transmissive board | substrate, the illumination structure made thin is obtained.

  In the display panel 10 according to the present embodiment, a V-shaped protrusion 11a is provided on the lower surface side of the light-transmitting substrate 11, and the V-shaped protrusion 11a is used as a reflecting means. A similar effect can be obtained by providing a letter-shaped groove and using the V-shaped groove as a reflecting means.

  Next, a display panel according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a cross-sectional view of an essential part of a timepiece display panel according to a second embodiment of the present invention, and FIG. 5 is an enlarged view of a portion F in FIG. As shown in FIG. 4, the display board 20 according to the second embodiment has an illumination structure that performs illumination by arranging two light sources 15 made of LEDs on the left and right side surfaces of the display board 20. is there. Here, the display panel 20 is provided with a reflecting means on the lower surface side of the light-transmitting substrate 21, and a light diffusion layer 22, a display layer 23 composed of a decorative film 23b and an indicator 23a on the upper surface side. Yes. The reflecting means provided on the lower surface side of the light-transmitting substrate 21 is configured by a plurality of circle-shaped V-shaped projections 21a formed around the left and right light sources 15 and a reflecting film 24 provided thereon. taking it.

  The plurality of V-shaped protrusions 21a provided on the lower surface of the light transmissive substrate 21 have the same shape as that described with reference to FIG. 2 in the first embodiment. That is, a plurality of concentric V-shaped protrusions 21a formed around the right light source 15 are provided in the right half of the light-transmitting substrate 21, and a concentric circle formed around the left light source 15 is provided in the left half. A plurality of V-shaped protrusions 21 a arranged in a line are provided, and the right-half V-shaped protrusion 21 a and the left-half V-shaped protrusion 21 a are symmetrical with respect to the center of the light-transmitting substrate 21. Further, the plurality of V-shaped protrusions 21 a arranged in a circle shape have a larger pitch nearer to the light source 15, and the pitch becomes narrower as the distance from the light source 15 increases. The tip angle of the V-shaped projection 21a is formed in the range of 70 ° to 100 °, and the V-shaped projection 21a has a width of 20 to 70 μm and a height of 10 to 35 μm. The surface of the V-shaped protrusion 21a is mirror-finished.

  Further, the lower surface 21b forming the flat surface of the light-transmitting substrate 21 has a rising inclination angle θ as it goes from the outer periphery to the center of the light-transmitting substrate 21, as shown in FIG. And mirror finish is given. The inclination angle θ is determined by the thickness and outer size of the light-transmitting substrate 21. For example, in a timepiece display panel, the inclination angle θ can take a value of about 1/100. The larger the inclination angle θ, the greater the effect. Therefore, the inclination angle θ may be appropriately set according to the thickness and the outer size of the light-transmitting substrate 21. When the rising inclination angle θ increases with distance from the light source 15, the amount of light (L3, L4) incident on the V-slope of the V-shaped convex groove 21a increases, and therefore the amount of light reflected by the V-slope also increases. Become more. This also increases the brightness.

  Further, a reflective film 24 is provided on the lower surface side of the light-transmitting substrate 21, that is, on the surface of the lower surface 21b that forms the surface of the V-shaped projection 21a or a flat surface and has an inclination angle θ. The reflective film 24 is formed of a highly reflective metal film or white resin film. The metal film having a high reflectance can be formed by a dry plating method such as a vacuum evaporation method or a sputtering method using a metal such as Al, Cr, Pd, Ag, Au, or Pt. Moreover, as a white resin film, it can form by the coating method etc. using a white resin coating material. When the reflection film 24 is provided in this way, most of the light incident from the light source 15 is effectively reflected to the display layer 23 side of the light-transmitting substrate 21 to illuminate the display layer 23 brightly.

  The light transmissive substrate 21 is formed by an injection molding method using a transparent plastic material such as a transparent polycarbonate resin. At that time, the shape of the V-shaped protrusion 21a and the mirror finish on the lower surface side of the light-transmitting substrate 21 are formed by a transfer method from a mold. The light transmissive substrate 21 is formed to have a thickness in the range of about 0.4 to 0.6 mm. The material used for the light transmissive substrate 21 is not limited to polycarbonate resin, and is excellent in heat resistance, moisture resistance, light resistance, etc., such as polyimide resin, polyethylene resin, polypropylene resin, polyacetal resin, polystyrene resin, acrylic resin. Resin material can be used.

The light diffusion layer 22 provided on the upper surface of the light-transmitting substrate 21 is provided to scatter light and make the illumination brightness more uniform. The light diffusion layer 22 is formed by dispersing scattering fine particles such as silicon oxide (SiO ₂ ) powder in a resin such as a transparent acrylic resin, epoxy resin, or urethane resin. When light reflected from the V-shaped protrusion 21a provided on the lower surface side of the light-transmitting substrate 21 or the reflection film 24 or direct light from the light source 15 passes through the light diffusion layer 22, the light is scattered by the action of scattering fine particles. Then, it becomes scattered light and passes through the light diffusion layer 22. This light scattering further makes the brightness of the illumination uniform. In the present embodiment, the resin film is formed by dispersing the scattering fine particles. However, instead of the resin film, the upper surface of the transmissive substrate 21 is subjected to a satin treatment to provide minute irregularities, and the pear ground is used as a light diffusion layer. It is also good.

  The display layer 23 is a display layer that plays a display role as a display board. The clock display board is provided with decorations for enhancing the appearance of the indicator such as time letters and clocks. In FIG. 4, the index 23 a indicates a time character, and the decorative film 23 b is a decoration provided to enhance the appearance texture as a watch and has light transmittance. The decoration film 23b is formed of a colored resin film formed by mixing a pigment, a dye, or the like with a transparent resin, a metal film formed of a metal thin film, or the like, similar to the decoration film 13b of the first embodiment described above. Can do. The indicator 23a is formed by a known printing method such as screen printing or pad printing using colored ink, or a metal indicator formed by a method such as a cutting method, a pressing method, or an electroforming plating method is pasted. Form.

  The display panel 20 having the above structure can be clearly viewed under uniform illumination and brighter illumination. Further, since the display plate 20 is configured by a single substrate of the light transmissive substrate 21, the thickness can be reduced.

  Next, a display panel according to a third embodiment of the present invention will be described with reference to FIGS. The display board according to the third embodiment of the present invention is used in a state where the light source 15 composed of two LEDs is disposed on the left and right side surfaces of the display board 30 as in the first embodiment. The display board 30 here has a display layer 33 composed of a light diffusing layer 32 made of a satin surface on the upper surface of a light-transmitting substrate 31, a decorative film 33b, and an index 33a. The lower surface of the substrate 31 has reflecting means composed of a plurality of circle-shaped V-shaped grooves 31a arranged concentrically around the left and right light sources 15. Therefore, the same pattern as shown in FIG. 2 is taken regardless of the difference in shape from the V-shaped protrusion described in the first embodiment. In other words, a concavo-convex pattern formed by a circle-shaped V-shaped groove 31 a that is symmetric with respect to the center of the light-transmitting substrate 31 is provided. The V-shaped groove 31a has a V shape and forms a groove recessed from the lower surface 31b. Further, the lower surface 31b of the light transmissive substrate 31 and the surface of the V-shaped groove 31a provided on the lower surface 31b are mirror surfaces. Although not shown, a solar cell is disposed on the lower surface side of the light transmissive substrate 31.

  As shown in FIG. 7, the V-shaped groove 31 a has a larger pitch near the light source 15 on the lower surface 31 b side of the light-transmitting substrate 31, and a narrow pitch as the distance from the light source 15 increases. As the distance from the light source 15 increases, the V-shaped groove 31a is formed in a denser state. Further, a flat bottom surface 31b is left between adjacent V-shaped grooves 31a, and a continuous surface of V-shaped grooves, flat surfaces, V-shaped grooves, flat surfaces, and so on is formed. ing. The surface and flat surface of the V-shaped groove 31a are finished to be mirror surfaces.

  In FIG. 7, L1 and L2 indicate incident light from the light source 15, and the direction of the arrow indicates the direction in which the light travels. The shape of the V-shaped groove 31a is preferably provided so that the angle of the groove tip is within a range of 85 ° ± 15 ° (70 ° to 100 °), more preferably within a range of 80 ° to 90 °. This range of angles maximizes the reflectance at the V slope, and efficiently reflects the incident light L1 and L2 upward (to the display layer side). Further, the depth t of the V-shaped groove 31a is in the range of 10 to 35 μm. The depth t of the V-shaped groove 31a is determined by the width n of the V-shaped groove 11a, and the width n of the V-shaped groove 31a is set in the range of 20 to 70 μm. When the width n is smaller than 20 μm, the reflection efficiency is deteriorated and bright illumination cannot be obtained. On the other hand, if the thickness is larger than 70 μm, the V-shaped groove 31a has a mirror surface and is visible from above the display panel 30 and deteriorates the appearance quality.

  The light (L1, L2) which hits the V slope of the V-shaped groove 31a by the light from the light source 15 is reflected and reflected upward. In general, the display panel is illuminated brightly near the light source because a large amount of radiated light from the light source is applied. On the other hand, the distance from the light source becomes dark because the amount of light decreases. However, since the plurality of V-shaped concave grooves 31a are formed concentrically with the light source 15 as the center, they are further away from the light source 15 and thus are formed densely with a smaller pitch. Accordingly, the amount of reflected light from the V-shaped concave groove 31a increases, and as a result, the brightness becomes bright even when distant from the light source 15, and a uniform brightness can be obtained as a whole.

  The light-transmitting substrate 31 provided with the V-shaped groove 31a is formed by an injection molding method using a transparent plastic material such as a transparent polycarbonate resin. At that time, the V-shaped groove 31a and the mirror finish on the lower surface side of the light-transmitting substrate 31, that is, the surface finish of the V-shaped groove 31a and the mirror surface finish of the lower surface 31b are formed by a transfer method from a mold. The light transmissive substrate 31 has a thickness in the range of about 0.4 to 0.6 mm. The material used for the light transmissive substrate 31 is not limited to polycarbonate resin, and is excellent in heat resistance, moisture resistance, light resistance, etc., such as polyimide resin, polyethylene resin, polypropylene resin, polyacetal resin, polystyrene resin, acrylic resin, etc. Resin material can be used.

The light diffusion layer 32 provided on the upper surface of the light-transmitting substrate 31 is provided to scatter light and make the illumination brightness more uniform. In the present embodiment, the light diffusion layer 32 is subjected to a satin treatment on the upper surface of the transmissive substrate 31 to provide minute irregularities, and this textured surface is used as the light diffusion layer. The light diffusing layer 32 has no problem even if a transparent resin film formed by dispersing scattering fine particles such as silicon oxide (SiO ₂ ) powder in a resin such as a transparent acrylic resin, epoxy resin, or urethane resin is used. By providing the light diffusion layer 32, light scattering occurs, and the brightness of the illumination becomes even more uniform.

  The display layer 33 is a display layer that plays a display role as a display board, and includes a decoration film 33b and an index 33a that indicates time characters and the like. The decoration film 33b is a decoration provided to enhance the appearance texture of the watch, and is formed of a colored resin film or a metal film having light transmittance. When forming with a colored resin film, a known printing method using a colored ink or colored resin paint produced by mixing pigments or dyes with a resin such as a transparent acrylic resin, urethane resin, alkyd resin, or epoxy resin It is formed by the painting method. When using colored inks or colored resin paints, the required permeability must be ensured, so colored inks or colored resins containing 5 to 10 parts by weight of a colorant such as a pigment or dye in the above resin It is preferable to form a paint and form it to a thickness of 5 to 20 μm. Moreover, when forming with a metal film, it forms with the metal thin film which gave the light transmittance by dry-type plating methods, such as a vacuum evaporation method, sputtering method, and an ion plating method. Since the transmittance is required, it is preferably formed to a thickness of 50 to 200 mm. With this thickness, a transmittance in the range of 30 to 70% can be obtained. In addition, as the metal to be used, metals such as Au, Ag, Al, Cu, Co, Cr, Ni, Pt, and Pd and their alloy metals can be used to obtain a decorative film 33b having various metal colors. Can do. Further, the decorative film 33b may be configured by a film in which a metal thin film and a colored resin film are laminated. When the structure in which the metal thin film and the colored resin film are laminated is used, the decorative property is improved and the decoration variation is widened. it can. The indicator 33a is formed by a known printing method such as screen printing or pad printing using colored ink, or a metal indicator formed by a method such as a cutting method, a pressing method, or an electroforming plating method is pasted. Form.

  In the display panel 30 having the above-described structure, the light that enters the light-transmitting substrate 31 from the light source 15 and travels toward the lower surface side of the light-transmitting substrate 31 is the V slope of the V-shaped groove 31a provided on the lower surface side. The light is reflected and emitted toward the light diffusion layer 32 and the display layer 33. Since the V slope forms a mirror surface and forms an angle of 70 ° to 100 °, a large amount of light is reflected to greatly increase the reflection efficiency. Further, since a plurality of V-shaped concave grooves 31a are arranged side by side so as to become denser as they become farther from the light source 15 (which approaches the center of the light-transmitting substrate 31), Even when it is far away, a large amount of reflected light is obtained, and the amount of reflected light reflected toward the light diffusion layer 32 and the display layer 33 is also made uniform. Then, a large amount of reflected light is incident on the light diffusion layer 32, and is transmitted through the display layer 33 and scattered outside the display panel 30 in a light scattered state. The brightness of illumination is further uniformed by the light scattering action of the light diffusion layer 32, and a bright display decoration is obtained.

  The light-transmitting substrate 31 has a flat surface between adjacent V-shaped grooves 31a. This flat surface is provided to transmit external light incident from above the display plate 30, and a large amount of light is transmitted through the display plate through the flat surface to generate power in a solar cell disposed on the lower surface side of the display plate. Causes action.

  The display panel 30 having the above structure has a structure that illuminates the display panel itself and can also be applied to a solar cell. And since the illumination of the display board 30 can be achieved by the structure of one light transmissive board | substrate, the illumination structure made thin is obtained.

  In the display panel 30 according to the present embodiment, a V-shaped groove 31a is provided on the lower surface side of the light-transmitting substrate 31, and the V-shaped groove 31a is used as a reflecting means. Instead, similar effects can be obtained by providing a V-shaped projection and using the V-shaped projection as the reflecting means, as in the first embodiment.

  Next, a display panel according to a fourth embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 8, the display board 40 according to the fourth embodiment of the present invention is used with a light source 15 composed of two LEDs on the left and right side surfaces. The display board 40 is provided with a light diffusing layer 42, a display layer 43 composed of a decorative film 43 b and an index 43 a on the upper surface of the light transmissive substrate 41, and left and right light sources 15 on the lower surface of the light transmissive substrate 41. And a plurality of V-shaped protrusions 41a arranged radially with respect to the center. A plurality of V-shaped protrusions 41a arranged in a radial manner constitute the reflecting means. Although not shown, a solar cell is disposed on the lower surface side of the light transmissive substrate 41.

  As shown in FIG. 9, the radial line formed by the plurality of V-shaped protrusions 41a arranged in the right half of the light-transmitting substrate 41 has a plurality of V-shaped lines formed in a radial pattern around the right light source 15. A protrusion 41a is provided, and a V-shaped protrusion 41a formed in a radial pattern around the left light source 15 is provided in the left half. The right half V-shaped projection 41 a and the left half V-shaped projection 41 a are symmetrical at the center of the light-transmitting substrate 41. The plurality of radial V-shaped protrusions 41a are composed of three types of protrusions 41a having a long length, a short length, and an intermediate length between the long and short ones. The long one is formed from the outer peripheral edge of the transmissive substrate 41 closest to the light source 15, the short one is formed from a position far from the light source 15, and the intermediate one is It is formed from a substantially middle position. The three types of V-shaped protrusions 41a are formed at approximately equal intervals in a place far from the light source 15. Therefore, the number of V-shaped projections 41a is small at a position close to the light source 15, and the number of V-shaped projections 41a is increased as the distance from the light source 15 increases. In the present embodiment, the length of the V-shaped protrusion 41a formed in a radial pattern is a long one, a short one, or an intermediate length between a long one and a short one. However, the present invention is not limited to the three types, and may be set appropriately in consideration of the size of the display panel, the width of the protrusions, and the like.

  FIG. 10 shows a perspective view of the light transmissive substrate 41 as viewed from the back side, in which the upper side is the lower surface side of the light transmissive substrate 41 and the lower side is the upper surface side of the light transmissive substrate. . The V-shaped protrusion 41a formed on the lower surface 41b of the light-transmitting substrate 41 is formed so as to protrude from the lower surface 41b, the tip angle is in the range of 70 ° to 100 °, the width is 20 to 40 μm, and the height is It is formed within a range of 10 to 35 μm. Further, the lower surface 41b of the light-transmitting substrate 41 and the surface of the V-shaped protrusion 41a are mirror surfaces so that the light reflectivity is enhanced.

  The light incident from the light source 15 hits both inclined surfaces (o, p) of the V-shaped protrusion 41a, and most of the light reflected there is a light diffusion layer 42 or a display layer 43 on the upper surface side of the light-transmitting substrate 41. Radiated towards. Since the number of the V-shaped protrusions 41a increases as the distance from the light source 15 increases, the amount of reflected light from both inclined surfaces (m, n) of the V-shaped protrusion 41a also increases, thereby increasing the brightness of the illumination.

  The transparent substrate 41 is formed by an injection molding method using a transparent plastic material such as polycarbonate resin. At that time, the V-shaped convex groove 41a and the mirror finish of the surface of the V-shaped convex groove 41a and the mirror finish of the lower surface 41b of the transmissive substrate 41 are also formed by a transfer method from a mold. The material used for the light-transmitting substrate 41 is not limited to polycarbonate resin, and is excellent in heat resistance, moisture resistance, light resistance, etc. such as polyimide resin, polyethylene resin, polypropylene resin, polyacetal resin, polystyrene resin, acrylic resin, etc. Resin material can be used.

The light diffusion layer 42 provided on the upper surface of the transmissive substrate 41 is provided in order to scatter light and make the illumination brightness more uniform. The light diffusion layer 42 is formed by dispersing scattering particles such as silicon oxide (SiO ₂ ) powder in a resin such as a transparent acrylic resin, epoxy resin, or urethane resin. When light reflected from the radial V-shaped projection 41a provided on the lower surface side of the light-transmitting substrate 41 or direct light from the light source 15 passes through the light diffusion layer 42, the light is scattered by the action of scattering fine particles. Then, it becomes scattered light and passes through the light diffusion layer 42. This light scattering makes the illumination brightness even more uniform. In the present embodiment, the resin coating is formed by dispersing the scattering fine particles. However, instead of the resin coating, the upper surface of the light-transmitting substrate 41 is subjected to a satin treatment to provide minute irregularities, and the pear ground is diffused into the light. It does not matter as a layer.

  The display layer 43 is a display layer that plays a display role as a display board, and includes a decoration film 43b and an index 43a that indicates time characters and the like. The decorative film 43b is a decoration provided to enhance the appearance texture of the watch, and is formed of a colored resin film or a metal film having light transmittance. When forming with a colored resin film, a known printing method using a colored ink or colored resin paint produced by mixing pigments or dyes with a resin such as a transparent acrylic resin, urethane resin, alkyd resin, or epoxy resin It is formed by the painting method. When using colored inks or colored resin paints, the required permeability must be ensured, so colored inks or colored resins containing 5 to 10 parts by weight of a colorant such as a pigment or dye in the above resin It is preferable to form a paint and form it to a thickness of 5 to 20 μm. Moreover, when forming with a metal film, it forms with the metal thin film which gave the light transmittance by dry-type plating methods, such as a vacuum evaporation method, sputtering method, and an ion plating method. Since the transmittance is required, it is preferably formed to a thickness of 50 to 200 mm. With this thickness, a transmittance in the range of 30 to 70% can be obtained. In addition, as the metal to be used, metals such as Au, Ag, Al, Cu, Co, Cr, Ni, Pt, and Pd and their alloy metals can be used to obtain a decorative film 33b having various metal colors. Can do. Further, the decorative film 43b may be configured by a film in which a metal thin film and a colored resin film are laminated. When the structure in which the metal thin film and the colored resin film are laminated is used, the decorative property is enhanced and the decoration variation is widened. it can. The indicator 43a is formed by a known printing method such as screen printing or pad printing using colored ink, or a metal indicator formed by a method such as a cutting method, a pressing method, or an electroforming plating method is pasted. Form.

  The display panel 40 having the above structure can visually recognize a clear display decoration under illumination with uniform brightness. Further, since the illumination structure can be obtained with only one thickness of the light transmissive substrate 41, the watch can be thinned.

  Note that the display panel 40 in the present embodiment is configured by a plurality of V-shaped protrusions 41a formed in a radial pattern so as to protrude from the lower surface of the light-transmitting substrate 41, but instead of the V-shaped protrusions 41a. The same effect can be obtained by forming a V-shaped concave groove.

  Moreover, in the structure of the display board 40 of this embodiment, the lower surface 41b of the light transmissive board | substrate 41 can also be made into the shape which gave the inclination. If there is a rising slope from the outer peripheral edge toward the center, the amount of light incident on the V slope of the V-shaped protrusion 41a increases as the distance from the light source increases, and thus the amount of light reflected by the V slope increases. . This also increases the brightness.

  In the display panel 40 of the present embodiment, the lower surface 41b is flat between the adjacent V-shaped grooves 31a of the plurality of V-shaped projections 41a provided radially on the lower surface side of the light-transmitting substrate 41. The surface remains and is provided. This flat surface is provided to transmit external light incident from above the display panel 40, and a large amount of light is transmitted through the flat surface to cause a power generation effect on the solar cells disposed on the lower surface side of the display panel. Let

  The display panel 40 having the above structure has a structure for brightly illuminating the display panel itself and a structure applicable to a solar cell.

  The embodiment of the present invention described above has been described using two light sources. A small display panel can illuminate sufficiently brightly even with a single light source. The number of light sources may be set appropriately according to the size of the display board. If the display panel is large and multiple light sources are required, the display panel is equally divided by the number of light sources to determine an area corresponding to the light source, and the area is a circle around the corresponding light source. Or V-shaped projections or V-shaped grooves may be provided in a radial pattern. In any case, the number of light sources can be reduced as compared with the structure in the prior art.

  In addition, the structure of the display board of the present invention has been described by taking the display panel for a clock as an example, but the structure of the present invention is not limited to a clock, but can be applied to a display board for instruments and other electronic display devices. An electronic display device using the structure of the present invention can be thinned because the display can be illuminated with the thickness of one display panel. Among them, display illumination with uniform brightness can be obtained.

1A and 1B are diagrams illustrating a configuration of a timepiece display panel according to a first embodiment of the present invention, in which FIG. 1A is a plan view, and FIG. 1B is a cross-sectional view taken along line DD in FIG. is there. FIG. 2 is a rear view schematically showing the rear surface of the display board in FIG. 1. It is the E section expanded sectional view in (b) of Drawing 1. It is principal part sectional drawing of the display panel for timepieces concerning 2nd Embodiment of this invention. It is an enlarged view of the F section in FIG. It is principal part sectional drawing of the display panel for timepieces concerning 3rd Embodiment of this invention. It is an enlarged view of the G section in FIG. FIGS. 8A and 8B are diagrams illustrating a configuration of a timepiece display panel according to a fourth embodiment of the present invention, in which FIG. 8A is a plan view and FIG. 8B is a cross-sectional view taken along line DD in FIG. is there. FIG. 9 is a rear view schematically showing the rear surface of the display board in FIG. 8. It is the perspective view which expanded and showed the principal part of H part in FIG. FIG. 11A is a plan view and FIG. 11B is a side view showing a conventional illumination structure in which a light source that is an LED is disposed on the side surface side of a display plate of a portable watch. FIG.

Explanation of symbols

10, 20, 30, 40 Display board 11, 21, 31, 41 Light-transmitting substrate 11a, 21a, 41a V-shaped protrusion 31a V-shaped groove 11b, 21b, 31b, 41b Lower surface 13, 23, 33, 43 Display layer 13a, 23a, 33a, 43a Indicators 13b, 23b, 33b, 43b Decoration film 15 Light source 22, 32, 42 Light diffusion layer 24 Reflection film

Claims (12)

A display plate comprising a light transmissive substrate having a display layer on the upper surface side and a reflecting means on the lower surface side, wherein the reflecting means is centered on a light source disposed on a side surface of the light transmissive substrate. And a plurality of V-shaped protrusions or V-shaped grooves formed on the lower surface of the transparent substrate. The flat surface is provided between adjacent V-shaped protrusions of the plurality of V-shaped protrusions formed side by side or between adjacent V-shaped grooves of V-shaped grooves. Display board of description. 3. The display panel according to claim 1, wherein a plurality of the V-shaped protrusions or the V-shaped concave grooves formed side by side have a width of 20 to 70 μm. The display board according to claim 1, wherein the plurality of V-shaped protrusions or V-shaped grooves are mirror surfaces. 5. The display board according to claim 1, wherein the plurality of V-shaped protrusions or V-shaped grooves formed side by side form a circle pattern or a radial pattern. 6. 6. The display board according to claim 5, wherein the circle pattern is provided concentrically with a light source as a center, and a pitch of the circles decreases as the distance from the light source increases. The display board according to claim 5, wherein the radial pattern has a larger number of radial patterns as the distance from the light source increases. 8. The light source is provided in two on the left and right on a substantially center line of the transparent substrate, and the plurality of V-shaped protrusions or V-shaped grooves formed side by side are provided symmetrically. The display board of any one of 9. The display panel according to claim 1, wherein the lower surface of the transparent substrate has a rising slope from the outer peripheral side of the substrate toward the center side of the substrate. 10. The display panel according to claim 1, wherein a reflective film is provided on a lower surface of the light transmissive substrate provided with the V-shaped protrusion or the V-shaped groove. The display panel according to claim 1, further comprising a light diffusion layer between the display layer and the light transmissive substrate. An electronic display device having a display panel illumination structure, comprising the display plate according to any one of claims 1 to 11, wherein the brightness of the display plate is uniformly illuminated and the display device is made thin. Electronic display device characterized by

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