JP2008262008A - Light emission display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a light emission display panel which causes the effective light emission display of different luminescence colors to be made at points where light emission display patterns overlap. <P>SOLUTION: The light emission display panel independently displays one single color display pattern by switching the luminescence colors of a light source. The single color display pattern 11b includes an overlap color display region 16 where the single color display pattern 11b overlaps on at least one among the other single color display patterns. Relating to each of the single color display patterns 11b, the luminance satisfies the following relation between the one discrete color display region 17b and the overlap color display region 16: Formula (1): 0.5≤(cE<SB>S</SB>/cE<SB>OL</SB>)≤1.5 (in the formula (1), cE<SB>S</SB>is the luminance in the discrete color display region during light source lighting of the c color, cE<SB>OL</SB>is the luminance in the overlap color display region during light source lighting of the c color). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a light-emitting display panel that displays patterns such as display characters, display scales, and marks, which are used for small electronic devices such as home appliances, acoustic devices, and mobile phones, and indicators for automobiles and the like.

  The inventors of the present invention have provided a light emitting display panel in which two or more light sources having different emission colors and two or more different light emitting display patterns made of materials having different wavelengths that can be transmitted among the light from the light source are formed on the display layer. A light-emitting display panel that can switch the light-emitting display pattern by switching the light-emitting color has been proposed (see, for example, Patent Document 1).

  FIG. 14 is a schematic plan view showing an example of a display layer of a conventional light emitting display panel. Referring to FIG. 14A, which is a schematic plan view of the display layer, and FIG. 14B, which is a partially enlarged view thereof, the display layer 110 includes a light emitting display pattern 111r that transmits light from a red light source and a blue light source. The light emitting display pattern 11 b that transmits light from the light emitting display pattern 11 b is overlapped, and the light emitting display pattern 111 r and the light emitting display pattern 111 b overlap in the overlapping region 116. FIG. 14C illustrates characters displayed when the red light source is lit, and FIG. 14D illustrates characters displayed when the blue light source is lit.

  In this conventional light emitting display panel, when there are two or more light emitting display patterns in the same area and there are places where each pattern overlaps, the light emitting display pattern is composed of halftone dots or a matrix. In combination, each light emission display pattern is effectively displayed independently when the emission color is switched.

WO 2006/115031

  However, the conventional light emitting display panel needs to have high alignment accuracy because it is necessary to arrange each pattern on the display layer so that the halftone dots that transmit different colors do not overlap each other at the place where the light emitting display patterns overlap. Is done.

  Further, since the halftone dots of the respective patterns are arranged so as not to overlap, the light emission amount is reduced because the light emission area is shared at the place where the light emission display patterns overlap. For example, if the light emitting pattern is composed of two colors, each light emitting area is 50% at a portion where the light emitting display patterns overlap.

  Furthermore, in order not to overlap the halftone dots of the respective patterns, it is necessary to provide a fine boundary region that does not transmit a plurality of emission colors between the halftone dots. For this reason, each light emission display area will further decrease, and the loss of irradiation light will become large. For example, if the light emission display patterns of two colors overlap, each light emission area is less than 50% at the portion where the light emission display patterns overlap.

  Therefore, an object of the present invention is to obtain a light-emitting display panel that effectively displays different light emission colors in places where light-emitting display patterns overlap.

  Other problems of the present invention will become apparent from the description of the present invention.

In order to solve the above problems, a light-emitting display panel according to one embodiment of the present invention includes a display layer having a plurality of light-emitting display patterns, and is disposed on the back side of the display layer to irradiate the display layer with light. The light irradiation means includes a light source that emits N colors (N is a positive integer of 2 or more) having different emission colors, and the display layer has a single color in the N colors. Light emission having a single color display pattern made of a material that can transmit light for each single color, and switching the light emission color of the light source to independently display the single color display pattern In the display panel,
The single color display pattern includes an overlapping color display region overlapping at least one of the other single color display patterns;
For each single color display pattern, from the single color display pattern including the overlapping color display area, one individual color display area that is an area excluding the overlapping color display area,
Between the overlapping color display area,
A light emitting display panel characterized in that the luminance satisfies the relationship of the formula (1).
_{0.5 ≦ (cE S / cE OL} ) ≦ 1.5 Formula (1)
(In Formula (1),
cE _S luminance at the individual color display area is an area excluding the overlapping color display area of a single color display pattern at the time of the light source lighting the c colors,
cE _OL is the luminance in the overlapping color display area in the single color display pattern when the c color light source is turned on. )

   In equation (1), color c refers to the emission color of the light source that should be transmitted through the overlapping color display area. The c color is a color of 2 or more and N or less, and the formula (1) is established for the plurality of c colors.

  For example, using different light sources of two colors, red and blue, different single color display patterns are formed with materials that individually transmit only the emission wavelengths of the respective light sources, and the overlapping color display areas where the single color display patterns overlap are displayed in red / In a light-emitting display panel made of a material that transmits both blue emission colors, red light is transmitted from both the red individual color display area and the red-blue overlapping color display area that transmit only red light when red light is emitted. A red single color display pattern is displayed. When blue light is emitted, blue light is transmitted from both the blue individual color display area that transmits only blue light and the red-blue overlapping color display area, and a blue single color display pattern is displayed. In this example, c color represented by Formula (1) is red emitted from a red light source and blue emitted from a blue light source. Expression (1) is established for the two colors of red and blue.

  In one embodiment of the present invention, in the light emitting display panel, the light irradiating means is a light guide having a light emitting means on the back side, and a light source disposed in a light incident portion of the light guide. Also good.

  According to this embodiment, the thickness of the light emitting display panel can be reduced. However, in the present invention, the light irradiation means may be a light source that directly irradiates the display layer with light emitted from the light source.

  In another embodiment of the present invention, the light-emitting display panel is provided with pattern exposure prevention means on the surface side of the display layer to prevent exposure of the light-emitting display pattern due to reflection of external light when the light source is not lit. You may do.

  In this embodiment, the single color display pattern can be more effectively hidden when the light source is not turned on. By arranging the pattern exposure prevention means, it is possible to increase the effect of expressing different single color display patterns only with transmitted light.

  In another embodiment of the present invention, a light-emitting display panel that uses a light guide and a light source as light irradiating means may have light absorbing means disposed on the back side of the light guide.

  Light entering the light-emitting display panel from the outside passes through the single color display pattern of the display layer, and further passes through the light guide and is reflected by the structure below the light guide to return to the surface side. Some come. By providing light absorbing means for absorbing incident light from the outside on the back side of the light guide, the single color display pattern of the display layer can be more effectively hidden. This hiding effect is particularly effective when the light source is not lit.

  The light absorbing means may be arranged in contact with the back surface of the light guide or spaced from the light guide to dispose a film or plate on the back side of the light guide. Alternatively, the frame of the housing on which the light guide is placed may be painted black. The film or plate may be black, or may have a function of suppressing reflection by forming fine irregularities on the surface.

  In still another embodiment of the present invention, the light emitting display panel may be provided with an antireflection layer between the display layer and the light irradiation means.

  According to this embodiment, reflection of external light can be more effectively removed.

  In still another embodiment of the present invention, the light emitting display panel may be provided with an antireflection layer on the surface and / or the back surface of the light guide.

  According to this embodiment, reflection of external light can be more effectively removed.

  The embodiments of the present invention described above and the components included in the embodiments can be implemented in combination as much as possible.

  The light emitting display panel according to the present invention can display the entire region where different single color display patterns overlap with each emission color, so that the single color display pattern can be clearly displayed. As a result, the emission area can be increased. Further, the light from the light source can be effectively used for the light emission display.

  Hereinafter, a light emitting display panel according to an embodiment of the present invention will be further described with reference to the drawings. The dimensions, materials, shapes, relative positions, etc. of the members and parts described in the embodiments of the present invention are not intended to limit the scope of the present invention only to those unless otherwise specified. It is just an illustrative example.

  FIG. 1 is a schematic cross-sectional view showing a configuration of a light emitting display panel according to the present invention. The first light emitting display panel 1 includes a display layer 10 and a light irradiation means 30. The front side and the back side of the first light emitting display panel 1 are indicated by arrows 8 in the figure. The front side is the side where the display of the light emitting display panel is observed.

  2, 3, 7, 8, 9, 10, and 11 similarly indicate the front side and the back side of the light emitting display panel.

  The display layer 10 includes a plurality of single color display patterns 11. The light irradiation means 30 is disposed on the back side of the display layer 10. The light irradiation means 30 includes a plurality of light sources 31 having different emission colors.

  FIG. 2 is a schematic cross-sectional view showing a specific configuration of another light emitting display panel according to the present invention. The 2nd light emission display panel 2 contains blue LED31b, red LED31r, and green LED31g which are the light sources arrange | positioned at the light-incidence part edge part of the light guide 32 and the light guide 32. FIG. The light guide 32 and the blue LED 31b, the red LED 31r, and the green LED 31g, which are light sources, are light irradiation means.

  The light incident part of the light guide 32 used in the present embodiment is an end face of the light guide 32, and the blue LED 31b, the red LED 31r, and the green LED 31g, which are light sources, are arranged at the ends.

  The light guide 32 is formed with a fine concavo-convex shape 33 as a light emitting means on the back side thereof. Light emitted from the blue LED 31b, the red LED 31r, and the green LED 31g is emitted toward the display layer 10 by the light guide.

  The light guide 32 may be a molded product made of a transparent resin such as acrylic, polycarbonate, ABS, polystyrene, acrylic styrene, or polyvinyl chloride. In the present invention, the light guide 32 is not limited to a flat plate, but includes a thin molded product having a three-dimensional shape. For example, a housing of a small electronic device such as a home appliance, an acoustic device, or a mobile phone. It may be. The light guide 32 may be flexible, and may be a flexible film made of silicon resin, for example.

  The light emitting means is a means for reflecting the light guided to the back by the inner surface reflection (total reflection) of the light guide 32 so as to be able to emit light toward the display layer 10. For example, a fine uneven shape 33 is formed. . The fine concavo-convex shape can obtain uniform light emission by changing from sparse to dense as the distance from the light source increases.

  The fine uneven shape may be a matte textured surface or a fine microlens shape. By using a concave-convex shape in which the shape of a microlens or the like is controlled, the light reflection characteristics can be improved, and more effective light emission can be obtained. In general, the fine uneven shape is preliminarily imparted to the molding die of the light guide 32 and transferred at the time of molding. Further, instead of directly imparting the shape to the molding die, a shape transfer foil provided with a fine uneven shape on the base sheet is used, and the above-mentioned transfer foil is inserted into the die when the light guide 32 is molded. By arranging it on the mold surface, the fine uneven shape may be transferred to the light guide simultaneously with the molding.

  The light emitting means is not limited to the one in which a fine uneven shape is formed on the back side of the light guide 1, and the light guide 32 may be subjected to dot printing for light diffusion. Further, the light emitting means may not be directly reflected by the fine uneven shape or dot printing, but may be emitted once toward the display layer 10 by a reflecting plate such as a lower white sheet after being once transmitted.

  In addition, when it is desired to emit light partially instead of emitting light from the entire light exit surface of the light guide 32, a light emitting means is provided according to the position of the light emitting area, corresponding to the position of the area where light is not emitted. It is better not to provide light emitting means at the location. As a result, the light from the light source can be used effectively without wasting light. Further, the light incident portion of the light guide 32 is not limited to the end portion of the light guide, and may be a side surface or a lower portion of the light guide 32.

  FIG. 3 is a schematic cross-sectional view showing another specific configuration of the light emitting display panel according to the present invention. In the third light emitting display panel 3, a light source 31 is disposed on the back side of the display layer 10. The light source 31 is the light irradiation means 30.

  A diffusion plate that diffuses light may be disposed between the display layer 10 and the light source 31.

  As the light source 31 included in the light irradiation means 30, N-color LEDs having different emission colors can be used. N is a positive integer of 2 or more. N-color LEDs can be driven to turn on and off independently for each emission color. Here, the total number of LEDs may exceed N. For example, one R (red) element and one G (green) element may be arranged, and only two B (blue) elements may be arranged to arrange a total of four LEDs. In this case, N is 3.

  The LED serving as the light source 31 may be arranged by arranging different packages for each emission color in the light incident portion of the light guide 32. Side-emitting LEDs are thin and effective for products that require a reduction in the thickness of the entire unit. Some LED packages have elements such as R, G, and B having different emission colors mounted in one package. By using such an LED package in which a plurality of elements are combined, a more space-saving design can be achieved. In addition to R, G, and B, the light source 31 has various emission colors such as yellow and orange.

The single color light emitted from each light source is not limited to a light source having a wavelength range within 100 nm, such as a monochromatic LED, and may be light having a wavelength range of 200 nm, for example.
The wavelength range refers to a wavelength range from a wavelength on the low wavelength side that gives 15% of the strongest wavelength intensity to a wavelength on the high wavelength side that gives 15% of the strongest wavelength intensity in the emission spectrum of the light source. The wavelength range of single color light that can be used varies depending on the spectrum of light transmitted through the single color display pattern (described later) and the number of light source colors (N) used in the same light emitting display panel. To do.

  However, if the wavelength range of single color light is narrow, the design of a single color display pattern, an overlapping color display pattern, etc. of the light emitting display panel becomes easy. From this point of view and for reasons such as low power consumption and small size, a monochromatic LED is suitable as a light source.

  However, the light source 31 is not limited to an LED, and a fluorescent lamp that emits a single color may be used. Further, the light source 31 may be a light source that emits light with a reduced spectral width of light by combining a white light source (for example, a tungsten lamp) and spectral means such as a diffraction grating and a prism.

  The display layer 10 includes a single color display pattern 11 formed of a material that can transmit light of a single color. The single color display pattern corresponds to each light of the N colors emitted from the light source 31, and includes at least one single color display pattern for each single color light. For example, when the light source 31 emits three colors of red (R), green (G), and blue (B), one single color display pattern made of a material that transmits only red (R) light is arranged, One single color display pattern made of a material that transmits only green (G) light is arranged, and two single color display patterns made of a material that transmits only blue (B) color are arranged, for a total of four light emitting displays. Patterns can be placed.

  FIG. 4 is a schematic plan view showing an example of the display layer. FIG. 14A is a schematic plan view of the display layer 10a, and FIG. 14B is a partially enlarged view thereof. The display layer 10a is combined with a light irradiation means including a blue LED and a red LED as a light source. Referring to FIG. 4A, the display layer 10a is formed by overlapping a blue display single color display pattern 11b and a red display single color display pattern 11r in one region. The blue display single color display pattern 11b has the shape of the alphabet letter S. The red display single color display pattern 11r has the shape of the alphabet letter N. The blue display single color display pattern 11b and the red display single color display pattern 11r are partially overlapped. That is, referring to FIG. 4B, there is an overlapping color display region 16 in which two single color display patterns overlap.

  As shown in FIG.4 (c), the letter N is displayed on the display layer 10a at the time of red light source (red LED) light emission. As shown in FIG. 4D, the letter S is displayed on the display layer 10a when the blue light source (blue LED) emits light.

FIG. 5 is an explanatory diagram for explaining the single color display pattern 11 and the overlapping color display area.
In the display layer 10b, the blue display single color display pattern 11b and the red display single color display pattern 11r partially overlap. The overlapping area is a blue-red overlapping display area 16br. A region obtained by removing the blue-red overlapping display region 16br from the blue display single color display pattern 11b is a blue individual color display region 17b. A region obtained by removing the blue-red overlapping display region 16br from the red display single color display pattern 11r is a red individual color display region 17r.

  Here, the regions where the blue LEDs are desired to emit light and are translucently displayed are the blue individual color display region 17b and the blue-red overlapping display region 16br, that is, the blue display single color display pattern 11b. In addition, the regions where the red LED emits light and are desired to be translucently displayed are the red individual color display region 17r and the blue-red overlapping display region 16br, that is, the red display single color display pattern 11b.

Therefore, the blue LED emission color is a particular color, the material relationship luminance _{bE OL} of which constitutes the brightness bE _S and blue red overlap display area 16br of the material constituting the blue separate color display area 17b, a formula 1-1 Satisfied.
_{Vmin ≦ (bE S / bE OL} ) ≦ Vmax formula (1-1)
(In Formula 1-1, the alphabet b attached to the left of E indicating luminance indicates that the specific color is blue,
bE _S luminance of the blue separate color display region 17b at the time of the blue LED lights,
bE _OL is the luminance in the blue-red overlapping display area 16br when the blue LED is lit,
Is shown.

At the same time, the red LED emission color is a particular color, the relationship of the red individual color display region 17r luminance _rE of the material constituting the luminance rE _S and blue red overlap display area 16br of the material constituting the _OL is the formula 1-2 Satisfied.

Vmin ≦ (rE _S / rE _OL ) ≦ Vmax Formula (1-2)
(In Formula 1-2, the alphabet r attached to the left of E indicating luminance indicates that the specific color is red,
rE _S luminance of the red separate color display region 17r when the red LED lights,
rE _OL is the luminance in the blue-red overlapping display area 16br when the red LED is lit,
Is shown.

  In Formula (1-1) and Formula (1-2), the value of Vmin is usually 0.5, preferably 0.8, and the value of Vmax is usually 1.5, preferably 1.2. It is.

  FIG. 6 is a graph showing an example of the light transmission spectrum of the individual color display region, the light transmission spectrum of the overlapping color display region, and the emission spectrum of the single color light source.

  In this graph, the blue individual color display area 17b is configured by using blue ink as a material, and its transmission spectrum is displayed on a line 21, and the red individual color display area 17r is configured by using red ink as a material, and its transmission spectrum is shown. The blue-red overlap display area 16br, which is indicated by the line 22 and is the overlap color display area, is made of an intermediate color ink of red and blue, and its transmission spectrum is indicated by the line 23. Further, the emission spectrum of the blue LED is indicated by a dotted line 24, and the emission spectrum of the red LED is indicated by a dotted line 25.

The emission spectrum of the blue LED has a maximum emission intensity around 450 nm. At this wavelength, the transmittance 21 of the blue individual color display area 17b and the transmittance 23 of the blue-red overlapping display area 16br are both about 50%. That is, the light emitted from the blue LED passes through the blue individual color display area 17b and the blue-red overlapping display area 16br with substantially the same transmittance. When the blue individual color display region 17b and the blue-red overlap display region 16br are irradiated with light of the same intensity from the blue LED, the blue individual color display region 17b and the blue-red overlap display region 16br are visually recognized with the same brightness. Is done. The value of _(bE S / _{bE OL)} is substantially 1.

The emission spectrum of the red LED has a maximum emission intensity around 660 nm. At this wavelength, the transmittance 22 of the red individual color display region 17r and the transmittance 23 of the blue-red overlapping display region 16br are both about 50%. That is, the light emitted from the red LED is emitted from the red individual color display region. 17r and the blue-red overlapping display region 16br are transmitted with substantially the same transmittance. When the red individual color display area 17r and the blue-red overlapping display area 16br are irradiated with light having the same intensity from the red LED, the red individual color display area 17r and the blue-red overlapping display area 16br are visually recognized with the same brightness. Is done. The value of (rE _S / rE _OL )) is approximately 1.

  As a material constituting the single color display pattern and the overlapping color display region, a material (for example, ink) containing a colorant such as a pigment or a dye in a resin binder can be used.

  Examples of red pigments include azo lake pigments such as brilliant carmine 6B and lake red C, barium red 2B, toluidine red, brilliant first scarlet, naphthol red, quinacridone pigment, and rhodamine 6G.

  Examples of the green pigment include phthalocyanine green, brilliant green lake, and diamond green lake, and examples of the blue pigment include phthalocyanine blue pigment and Victoria pure blue BO toner.

Examples of inorganic pigments include red pigments such as Fe ₂ O ₃ , Pb ₃ O ₄ , 2Sb ₂ S, Sb ₂ O ₃ , Sb ₂ S ₃ , and Sb ₂ O ₃ , and green pigments such as Cr ₂ O ₃ and Cr ₂ O. (OH) ₄ , Cu (CH ₃ CO ₂ ) ₂ .3CuO (AsO ₂ ) ₂ , CoO—ZnO—MgO, TiO ₂ —CoC—NiO—ZnO, etc. The blue pigment is 3NaAl.SiO ₄ .Na ₂ S ₂ , _{2 (Na 2 O · Al 2} O 3 · 2SiO 2) · Na 2 S 2, Fe 4 [Fe (CN) 6] 3nH 2 O, CoO · nAl 2 O 3, ( or n = 2~3), CoO _{· nSnO 2 · mMgO (n =} 1.5~3.5, m = 2~6), and CoO-Al ₂ O ₃ and the like.

  A plurality of laminated optical thin films can also be used as the material constituting the light emitting display pattern. For example, a light interference film in which a plurality of inorganic substances such as titanium oxide and silicon oxide are laminated by coating, dipping, vapor deposition, sputtering, or the like is used as a pattern. In the present invention, the wavelength that can be transmitted among the light from the light emitting means 30 means a wavelength that can be transmitted in a direction perpendicular to the display panel. It does not describe the material differences.

  As a material constituting the overlapping color display area, for example, an intermediate color ink constituting the single color display area can be used. The ink may be printed or applied (so-called solid coating) on the entire surface of the overlapping color display region, or may be printed with halftone dots.

  In order to make the luminance a preferable ratio, for example, the amount of pigment or dye in the resin binder may be increased or decreased, or the ink coating film thickness may be increased or decreased.

  The display layer 10 can be provided on one surface of the light guide 32 by a method such as direct printing or painting. Further, the display layer 10 can be formed on one side of the light guide 32 simultaneously with the formation of the light guide 32 by inserting it into a mold when the light guide 32 is formed using a transfer foil or an insert film. . Moreover, what formed the display layer 10 in the transparent film may be laminated on the single side | surface of the light guide 32, and may be arrange | positioned only on the light guide 32. FIG. The display layer 10 is only formed on a transparent film when the light guide 32 is not used.

  Further, the wavelength that can be transmitted by the single color transmission pattern 11 does not have to correspond to the entire wavelength region emitted from the light source 31. For example, only the wavelength of a narrower region closer to green in the wavelength region emitted from the red LED may be used. In this case, the emission color displayed in the emission display pattern is the emission color of the red LED. Will be different.

  Since the light source 31 can be driven independently for each emission color, the wavelength of the light applied to the display layer 10 can be changed at any time by selectively driving the light source 31. In the present invention, the driving of the light source 31 means light emission, quenching, changing the light emission amount, and the like. The light source 31 may be driven by changing the amount of electricity supplied to the light source 31, or may be performed by mechanical means using a light shielding plate or a slit.

  Since the display layer 10 is formed with two or more single color display patterns made of materials with different wavelengths that can be transmitted, the single color pattern can be selected by changing the irradiation color from the light irradiation means.

  FIG. 7 is a schematic cross-sectional view showing the configuration of another light emitting display panel according to the present invention. In the fourth light emitting display panel 4, a semi-transmissive layer 41 is disposed on the surface side of the display layer 10. The semi-transmissive layer 41 is a pattern exposure prevention means. The display layer 10, the light irradiation means 30, and the like are the same as those of the first light emitting display panel described with reference to FIG.

  When the light-emitting display panel is used in a place where there is external light, the external light 42 enters the light-emitting display panel from the display layer 10, is reflected by the light irradiation means 30 on the back side, and passes through the display layer 10. I will come out. Since the display layer 10 has the single color display pattern 11, the light derived from the external light reveals the single color display pattern.

  In the fourth light emitting display panel, external light passes through the semi-transmissive layer 41 twice for convenience when entering and exiting light. For example, if the light transmittance of the semi-transmissive layer is 30%, the light output intensity of external light is 0.09 (0.3 × 0.3) as compared to the case without the semi-transmissive layer. Therefore, the exposure of the single color display pattern 11 derived from the external light 42 can be prevented. Here, the light emitted from the light source 31 and displaying the single color display pattern 11 also passes through the semi-transmissive layer 41, but the light is only transmitted through the semi-transmissive layer 41 once. In the above example, light is emitted to the surface side with a transmittance of 30%.

  The light transmittance of the semi-transmissive layer is preferably 20 to 40%. Here, the light transmittance refers to the transmittance in the entire wavelength region in the wavelength region of visible light (360 nm to 830 nm).

  The semi-transmissive layer includes a smoke-like resin or a film in which a semi-permeable design is printed on at least one of a transparent resin plate and a glass plate. Alternatively, a molded product using a transparent resin may be formed by inserting a film having a translucent design printed on at least one of the surfaces at the time of molding into a molding die and simultaneously transferring the design to the molded product.

  Semi-transparent designs include smoke-printed ones and metal half-deposited.

  As other pattern exposure prevention means, a circularly polarizing plate layer can be used. The circularly polarizing plate layer functions to block the emitted light by utilizing the difference in circular polarization between the incoming external light and the outgoing light derived from the external light. As the circularly polarizing plate layer, a circularly polarizing plate may be bonded to either one of a transparent resin plate and a glass plate. Examples of the material for the transparent resin plate include acrylic, polycarbonate, polystyrene, and polyolefin resin.

  The pattern exposure prevention means may be arranged on the surface side of the display layer 10 so as to be separated from the display layer, or may be arranged on the surface side of the display layer 10 in a manner integrated with the display layer.

By providing the pattern exposure prevention layer, the following effects can be obtained.
(1) When the light source is not turned on, it is possible to prevent the presence of the plurality of single color display patterns 11 from being exposed.
(2) In the state where the light source 31 of one color is turned on, the single color display pattern selected according to the wavelength of the light source is emitted and displayed, and at the same time, the unselected single color display pattern is reflected by the reflection of external light. It is possible to prevent exposure.

  FIG. 8 is a schematic cross-sectional view showing the configuration of another light emitting display panel according to the present invention. The fifth light emitting display panel 5 includes a light guide 32 and light sources 31b, 31r, and 31g as light irradiating means, and has a light absorbing sheet 51 disposed on the back side of the light guide 32.

  When the light emitting display panel is used in a place where there is external light, the external light 52 enters the light emitting display panel from the display layer 10, passes through the light guide 32, and the frame on which the fifth light emitting display panel 5 is placed. Then, the light is reflected by a housing structure and the like, passes through the display layer 10, and emits light. Since the display layer 10 has the single color display pattern 11, the light derived from the external light 52 reveals the single color display pattern.

  Therefore, in order to suppress reflection of the external light 52, the light absorption sheet 51 is disposed. The light absorbing sheet 51 is a black film.

  The light absorbing means may be arranged in contact with the back surface of the light guide or spaced from the light guide to dispose a film or plate on the back side of the light guide. Alternatively, the frame of the housing on which the light guide is placed may be painted black. The film or plate may be black, or may have a function of suppressing reflection by forming fine irregularities on the surface.

By providing the light absorbing means, the following effects can be obtained.
(1) When the light source is not turned on, it is possible to prevent the plurality of single color display patterns 11 from being exposed.
(2) In the state where the light source 31 of one color is lit, the single color display pattern selected by the wavelength of the light source is emitted and displayed. At the same time, the single color display pattern not selected is reflected by the reflection of external light. It is possible to prevent exposure.

  FIG. 9 is a schematic cross-sectional view showing the configuration of another light emitting display panel according to the present invention. The sixth light emitting display panel 6 is provided with an antireflection layer 61 on the back surface of the single color display pattern 11. The display layer 10, the light irradiation means 30, and the like are the same as those of the first light emitting display panel described with reference to FIG.

  FIG. 10 is an explanatory diagram for explaining external light incident on the light-emitting display panel and its reflection. Referring to FIG. 10, when external light 65 enters the light emitting display panel, the external light 65 is reflected by the surface 14 of the single color display pattern 11. The reflected light is indicated by an arrow 66. This reflected light (arrow 66) absorbs a part of the wavelength region by the action of the single color display pattern and generates a color.

  The external light 65 is reflected by the back surface 15 of the single color display pattern 11. The reflected light is indicated by an arrow 67. Since this reflected light (arrow 67) is transmitted through the single color display pattern, a color is generated. In this manner, the light reflected by the front surface 14 and the back surface 15 of the single color display pattern 11 reveals the single color display pattern 11 formed on the display layer 10.

  The sixth light emitting display panel 6 prevents the single color display pattern 11 from being exposed by the antireflection layer 61. The antireflection layer 61 may be formed by applying a low refractive material, printing, or attaching an antireflection film or a low reflection film.

  As the low refractive material used for the antireflection layer, metal oxides such as magnesium fluoride and silicon oxide can be used. An organometallic compound containing at least one of silica and organopolysiloxane can also be used. Moreover, the porous body of these organometallic compounds can also be used. An organic compound such as a fluorine-based synthetic resin can also be used.

  As the structure of the antireflection layer, silicon oxide or aluminum oxide having fine pores is dispersed in silicon oxide and used as a single layer, or magnesium fluoride is used as a single layer, or a titanium oxide layer / silicon oxide layer 2 It can be used as an antireflection layer with a layer structure, or as an antireflection layer with a multilayer structure using multiple interference such as a four-layer antireflection layer such as titanium oxide layer / silicon oxide layer / titanium oxide layer / silicon oxide layer. Good.

  As a manufacturing method of these antireflection layers, there are a vacuum deposition method, a sputtering method, an ion plating method and the like. Alternatively, an organic metal compound such as a metal alcoholate or metal chelate is applied onto a substrate sheet by an immersion method, a printing method or a coating method, and then a metal oxide film is formed by light irradiation or drying to obtain an antireflection layer. There is also a method.

  The thickness of the antireflection layer may be appropriately selected within the range of 0.01 to 2 μm. These film thicknesses depend on the refractive index of the low-refractive material. Is preferably selected so as to satisfy the low reflection center wavelength.

  Examples of the antireflection film include those obtained by forming an antireflection layer on the surface of a film excellent in light transmittance such as polyethylene terephthalate by the above method. Low reflection films are made by depositing a metal oxide made of a low refractive material such as magnesium fluoride or silicon oxide together with a metal oxide made of a single material or a high refractive material on the surface of a film excellent in light transmittance such as polyethylene terephthalate. And those coated with a low-refractive material such as a fluororesin.

  For example, a pattern made of a material that uses red and blue LEDs as a light source arranged on the opposite side of the display surface of the display layer, and transmits red light and transmits blue light. When a pattern made of a material that transmits blue light emission and blocks red light emission is formed on one display surface, the reflectance of the red transmission part is 15.5% and the reflectance of the blue transmission part Is 11.5%, when antireflection treatment is performed on one side, the reflectance of the red transmissive part is reduced by 12.6% and the reflectance of the blue transmissive part is 10.4%, which is reduced by about 3%.

  In the configuration in which the antireflection treatment is not performed, the transflective layer arranged on the light emitting surface side of the display layer can hide each display pattern when the light source is not turned on when the transmittance is set to 24%. On the other hand, when the antireflection treatment is performed, the transmittance of the semi-transmissive layer can be increased to 34%. Therefore, when light sources having the same brightness are used, the brightness is improved by 42% by performing the antireflection process as compared with the configuration in which the antireflection process is not performed.

  FIG. 11 is a schematic cross-sectional view showing the configuration of another light emitting display panel according to the present invention. The seventh light emitting display panel 7 is provided with an antireflection layer 71 on the surface of the light guide. The display layer 10, the light guide 32, and the like are the same as those of the second light emitting display panel described with reference to FIG.

  Referring to FIG. 10, when external light 65 enters the light emitting display panel, the external light 65 is reflected by the surface 34 of the light guide 32. The reflected light is indicated by an arrow 76. Further, the external light 65 is reflected by the back surface 35 of the light guide 32. The reflected light is indicated by an arrow 77. Since these reflected lights (arrow 76 and arrow 77) are transmitted through the single color display pattern 11 and emitted to the surface side, a color is generated. In this way, the light reflected by the front surface 34 and the back surface 35 of the light guide 32 reveals the single color display pattern 11 formed on the display layer 10.

  The seventh light emitting display panel 7 prevents the single color display pattern 11 from being exposed by the antireflection layer 71. The antireflection layer 71 may be provided on the back surface 35 of the light guide 32. Further, the antireflection layer 71 may be provided on both the front surface 34 and the rear surface 35 of the light guide 32.

  The formation material, the formation method, and the like of the antireflection layer 71 are the same as described for the antireflection layer 61.

  In the display layer 10 of the present invention, the planar region 13 having no single color display pattern may be provided with a light shielding layer. By forming the light shielding layer, the contrast of the single color display pattern is improved. Examples of the light shielding layer include black ink or white ink. Moreover, the light-shielding effect can be improved by overlapping a plurality of ink layers.

  In addition, when a light guide and a light source are used as the light irradiating means, if a reflective layer such as metal vapor deposition is formed as a light shielding layer, it is possible to return a light beam irradiated to a portion that does not require light emission to the light guide. Thus, the light from the light source can be used effectively without wasting light.

  A hard coat layer may be formed on the outermost surface of the display layer.

  If the light-emitting display panel according to the present invention is employed in a product, it is possible to realize a simple, robust, and inexpensive configuration for changing the pattern that is conventionally expressed by a liquid crystal display. Since a plurality of patterns can be displayed on the same plane area, the pattern display area can be saved. And the picture is expressed clearly. FIG. 12 shows an embodiment in which character display switching is realized by the light emitting display panel according to the present invention. In the figure, (a) is a schematic plan view of the display layer, (b) is a light-emitting display panel when light is not emitted, (c) is a light-emitting display panel when red light is emitted, and (d) is when blue light is emitted. A light emitting display panel is shown.

  The product using both the light emitting display panel and the touch panel according to the present invention can assign the same surface to switches having different functions. Therefore, the touch panel area can be saved. FIG. 13 shows an embodiment in which switching of key display is expressed by the light emitting display panel according to the present invention. In the figure, (a) is a schematic plan view of the display layer, (b) is a light-emitting display panel when light is not emitted, (c) is a light-emitting display panel when red light is emitted, and (d) is when blue light is emitted. A light emitting display panel is shown.

It is a schematic cross section which shows the structure of the light emission display panel concerning this invention. It is a schematic cross section which shows the specific structure of the other light emission display panel concerning this invention. It is a schematic cross section which shows the other specific structure of the light emission display panel concerning this invention. It is the plane schematic diagram which showed an example of the display layer. It is explanatory drawing for demonstrating the single color display pattern 11 and an overlapping color display area. It is a graph which shows an example of the light transmission spectrum of an individual color display area, the light transmission spectrum of an overlapping color display area, and the emission spectrum of a single color light source.

It is a schematic cross section which shows the structure of the other light emission display panel concerning this invention. It is a schematic cross section which shows the structure of the other light emission display panel concerning this invention. It is a schematic cross section which shows the structure of the other light emission display panel concerning this invention. It is explanatory drawing explaining the external light which injects into a light emission display panel, and its reflection. It is a schematic cross section which shows the structure of the other light emission display panel concerning this invention. It is the Example which implement | achieved switching of the character display with the light emission display panel concerning this invention. It is the Example which expressed switching of the key display with the light emission display panel concerning this invention. It is the plane schematic diagram which showed an example of the display layer of the conventional light emission display panel.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st light emission display panel 2 2nd light emission display panel 3 3rd light emission display panel 4 4th light emission display panel 5 5th light emission display panel 6 6th light emission display panel 7 7th light emission display panel 10 Display layer 11 Single color display pattern 11b Blue display single color display pattern 11r Red display single color display pattern 13 Shading pattern 16 Overlapping color display area 16br Blue red overlapping color display area 17b Blue individual color display area 17r Red individual color display area

21 Light transmission spectrum of individual blue color display area 22 Light transmission spectrum of red individual color display area 23 Light transmission spectrum of blue red overlapping color display area 24 Blue LED emission spectrum 25 Red LED emission spectrum 30 Light irradiation means 31 Light source 31b Blue LED, a light source that emits blue light
31g Green LED, a light source that emits green light
31r Red LED as a light source emitting red light
32 Light guide 33 Uneven shape 34 Surface of light guide 35 Back surface of light guide 41 Semi-transparent layer as pattern exposure prevention means 51 Light absorption sheet as light absorption means 61 Antireflection sheet as antireflection layer

Claims (6)

The display layer includes a display layer having a plurality of light emitting display patterns, and a light irradiation unit disposed on the back side of the display layer to irradiate the display layer with light. The light irradiation unit includes N colors (N Is a positive integer greater than or equal to 2), and the display layer displays a single color display pattern formed of a material capable of transmitting a single color of the N colors for each single color. In each of the light emitting display panels that display the single color display pattern independently by switching the light emission color of the light source,
The single color display pattern includes an overlapping color display region overlapping at least one of the other single color display patterns;
For each single color display pattern, from the single color display pattern including the overlapping color display area, one individual color display area that is an area excluding the overlapping color display area,
Between the overlapping color display area,
A light emitting display panel characterized in that the luminance satisfies the relationship of the formula (1).
_{0.5 ≦ (cE S / cE OL} ) ≦ 1.5 Formula (1)
(In Formula (1),
cE _S luminance at the individual color display area is an area excluding the overlapping color display area of a single color display pattern at the time of the light source lighting the c colors,
cE _OL is the luminance in the overlapping color display area in the single color display pattern when the c color light source is turned on. )   The light emitting display panel according to claim 1, wherein the light irradiating means includes a light guide having a light emitting means on the back side, and a light source disposed in a light incident portion of the light guide.   The pattern exposure prevention means is arranged on the surface side of the display layer to prevent exposure of the light-emitting display pattern due to reflection of external light when the light source is not lit. Luminous display panel.   The light emitting display panel according to claim 2, wherein a light absorbing means is disposed on the back side of the light guide.   The light emitting display panel according to claim 1, wherein an antireflection layer is provided on a front surface and / or a back surface of the single color display pattern.   The light emitting display panel according to claim 2, wherein an antireflection layer is provided on a front surface and / or a back surface of the light guide.

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