CN100428488C - Organic electroluminescent display panel - Google Patents

Abstract

An organic electroluminescent display panel comprises a substrate having a first sub-pixel region and a second sub-pixel region on the surface thereof, an organic electroluminescent element disposed on the substrate and capable of being driven to emit light, and a first optical film and a second optical film respectively disposed in the first sub-pixel region and the second sub-pixel region of the organic electroluminescent element for absorbing or converting the light emitted by the organic electroluminescent element into a first color light and a second color light respectively, wherein the first optical film and the second optical film have different areas.

Description

Organic Electroluminescent Display Panel

technical field

The present invention relates to a display panel, in particular to an organic electroluminescence display panel.

Background technique

With the rapid development of science and technology, organic materials are gradually and widely used in various circuit components, such as an organic electroluminescent display panel (organic electroluminescent display, OLED) made of organic materials, with a simple structure and excellent Due to the advantages of operating temperature, contrast ratio, viewing angle, and light-emitting diode (LED) rectification and light-emitting characteristics, it has gradually attracted attention in the display market.

The full-color technology widely used in the current organic electroluminescent display panel industry can be roughly divided into red, green and blue sequential evaporation (RGB side-by-side pattern) and white light plus color filter (CFA) ) method, because the latter only needs to manufacture white light display elements on the substrate, and does not need to form red, green, and blue display elements separately, so there is no need to use a mask, so the process can be greatly simplified. In addition, since the restriction on the size of the mask is exempted, the image quality and fineness of the display panel can be further improved, and the production rate can be further improved because there is no need to perform alignment according to different colors when evaporating display elements. The architecture of white light plus color filters has become the mainstream of the organic electroluminescence display panel industry.

Please refer to FIG. 1 , which is a schematic diagram of a conventional organic electroluminescence display panel. As shown in FIG. 1 , an organic electroluminescence display panel 10 includes a substrate 12 , and a plurality of pixels are arranged on the surface of the substrate 12 . For convenience of description, only one pixel is represented in FIG. 1 . In this pixel, the surface of the substrate 12 has a first sub-pixel area 20 , a second sub-pixel area 30 and a third sub-pixel area 40 . A display element 14, such as an organic electroluminescent display element, is provided on the surface of the substrate 12 to generate a white light, and the first pixel region 20, the second pixel region 30 and the third pixel region above the display element 14 In the pixel area 40, a red light filter 22, a green light filter 24 and a blue light filter 26 are respectively provided, so that the white light generated by the display unit 14 passes through the red light filter 22, the green light After the light filter 24 and the blue light filter 26 , three different colored lights of red (R), green (G) and blue (B) are generated for image display.

However, due to the material properties of the display element 14, the red light filter 22, the green light filter 24 and the blue light filter 26, the red light (R), green light (G) and blue light (B) usually formed ) often have different intensities, therefore, in the subsequent image display operation, it is often found that under the same electric field, the image displayed by the combination of red light (R), green light (G) and blue light (B) will be different The phenomenon of color shift occurs, for example, assuming that after passing through the red light filter 22 and the blue light filter 26, a large decrease in light intensity will be caused (that is, the green light generated in the pixel has a relatively large Intensity), then when the display panel 10 wants to display white and drives the display element 14 with the same electric field or current intensity, it will be found that the actually formed light color will be a white-greenish situation, which will seriously affect the display quality. Influence.

In the prior art, there are also some solutions to the above-mentioned color shift problem. For example, by selectively increasing the electric field of the display element 14 at the sub-pixel regions of other colors, a larger light intensity output to improve the color balance of the light passing through the filter. However, this method of overcoming the problem of color difference by increasing the electric field will often cause the disadvantage of rapid aging of the display element and shorten the life of the display panel 10 .

Therefore, we urgently need a new organic electroluminescent display panel structure to solve the problem of light and color imbalance in the prior art.

Contents of the invention

One of the objectives of the present invention is to provide an organic electroluminescent display panel capable of achieving balanced white light, so as to overcome the problems in the prior art.

In order to achieve the above and other purposes, the organic electroluminescent display panel of the present invention mainly includes a substrate, the surface of the substrate has at least one first pixel region, one second pixel region and one third pixel region, an organic electroluminescent display panel The luminescent element is arranged on the substrate, the organic electroluminescent element can be driven to emit light, and at least one first optical film, a second optical film and a third optical film are respectively arranged on the organic electroluminescent element correspondingly The first pixel area, the second pixel area and the third sub pixel area, and the light emitted by the organic electroluminescent element, respectively from the first pixel area and the second sub pixel area Generate a first color light, a second color light and a third color light, the first color light, the second color light and the third color light are red light, green light and blue light respectively; wherein the first optical film, the The second optical film and the third optical film have different areas, and the thickness of the second optical film is greater than that of the first optical film or the third optical film.

In order to make the above and other objects, features and advantages of the present invention more comprehensible, preferred embodiments are listed below and described in detail in conjunction with the accompanying drawings.

Description of drawings

1 is a schematic cross-sectional view of a conventional organic electroluminescence display panel;

2 is a schematic cross-sectional view of an organic electroluminescence display panel in an embodiment of the present invention;

3 is a schematic cross-sectional view of an organic electroluminescence display panel in another embodiment of the present invention;

FIG. 4 is a schematic cross-sectional view of an organic electroluminescent display panel in yet another embodiment of the present invention.

Symbol Description

10～organic electroluminescent display panel; 12～substrate;

14～display components; 20～the first pixel area;

22～red light filter; 24～green light filter;

26～blue light filter; 30～second pixel area;

40～the third pixel area; 110～display panel;

112～substrate; 114～display components;

120～the first pixel area; 122～the first optical film;

124～second optical film; 126～third optical film;

130 to the second pixel area; 140 to the third pixel area;

132～first color light; 134～second color light;

136～third color light; 210～display panel;

212～substrate; 214～display components;

222～the first optical film; 224～the second optical film;

226～third optical film; 310～display panel;

312～substrate; 314～display components;

322～the first optical film; 324～the second optical film;

326～third optical film; 316～substrate;

318 ~ adhesive layer.

Detailed ways

Please refer to FIG. 2 . FIG. 2 is a schematic cross-sectional view of an organic electroluminescent display panel according to an embodiment of the present invention. As shown in FIG. 2, an organic electroluminescent display panel 110 includes a substrate 112. Similarly, only one pixel is shown in FIG. pixels.

In this pixel, the surface of the substrate 112 has a first sub-pixel area 120 , a second sub-pixel area 130 and a third sub-pixel area 140 . A display element 114 is disposed on the surface of the substrate 112 and can be driven to generate light. In one embodiment of the present invention, the display element 114 is an organic electroluminescent display element that can generate white light, but the present invention is not limited thereto, and can be an organic electroluminescent display element of other colors, for example, an organic electroluminescent display element that can generate white light. Organic electroluminescence display elements of green, red, blue, orange or any other color light.

In the first sub-pixel area 120, the second sub-pixel area 130, and the third sub-pixel area 140 above the display element 114, a first optical film 122, a second optical film 124, and a third optical film are respectively provided. film 126, so that the light generated by the display element 114 will generate a first color light 132, a second color light 134 and a third color light after passing through the first optical film 122, the second optical film 124 and the third optical film 126 The color light 136 is used for image display through the combination of these color lights.

In an embodiment of the present invention, the first optical film 122, the second optical film 124, and the third optical film 126 are color filters (color filter, CF) of different colors, such as red light filters, A green light filter and a blue light filter, and the display element 114 is an organic electroluminescent display element that can generate white light, so when the display element 114 generates white light, it will pass upward through the first optical film 122, the second optical film film 124 and the third optical film 126, and generate red first color light 132, green second color light 134 and blue The tertiary shade 136 of color.

In addition to the foregoing embodiments, the display element 114 , the first optical film 122 , the second optical film 124 and the third optical film 126 can still have other combinations depending on the needs of the product. For example, the first optical film 122, the second optical film 124, and the third optical film 126 can be different color filters or color conversion (CCM) layers, and the display element 114 is not limited to a white organic electroluminescent display. components, but organic electroluminescence display components of other colors. For example, the display element 114 can be a blue light display element, and the first optical film 122 and the third optical film 126 are color conversion (CCM) layers that can convert short-wavelength blue into long-wavelength red and green respectively, and the second The second optical film is a blue filter film or a transparent optical film, so that the light formed by the display element 114 can still pass through the first optical film 122, the second optical film 124 and the third optical film 126, respectively. Red light, blue light and green light are generated in the first sub-pixel area 120 , the second sub-pixel area 130 and the third sub-pixel area 140 .

In addition, in another embodiment of the present invention, in a pixel of the organic electroluminescence display panel 110, in addition to the first sub-pixel region 120, the second sub-pixel region 130 and the third sub-pixel region 140, It includes a fourth sub-pixel area (not shown), so that the display element 114 can generate a fourth color light in the fourth sub-pixel area, wherein a fourth optical film (such as the aforementioned filter, color conversion layer, or a combination of both), or without any optical film.

It should be emphasized that among the optical films (the first optical film 122, the second optical film 124 and the third optical film 126) in the present invention, the area of at least one optical film is different from the area of other optical films, thus The light intensity of the first color light 132, the second color light 134 and the third color light 136 can be properly adjusted, so that in one pixel, red light (R), green light (G) and blue light (B) The CIE coordinates (Commission Internationaled'Eclairage (CIE) coordinates) displayed after combining under the same electric field are the required values.

For example, if the brightness (light intensity per unit area) of the generated second color light 134 is higher than that of red light (R), green light (G) and blue light (B) under the same electric field, when the three-color light of red light (R), green light (G) and blue light (B) is to form white light The required brightness of the two-color light will reduce the area of the second optical film 124 or increase the area of the first optical film 122 and the third optical film 126 to make the first color light 132, the second color light 134 and the whole pixel The third color light 136 roughly achieves the color balance of white light, that is, the obtained CIE coordinates are (0.31±0.03, 0.32±0.03). Except that the area of each optical film is not the same, each optical film still has a different thickness or shape according to the requirements of the product, so as to further improve the chromaticity balance among the shades of each color.

Please refer to FIG. 3 , which is a schematic cross-sectional view of an organic electroluminescent display panel 210 in another embodiment of the present invention. Compared with the organic electroluminescent display panel 110 in the foregoing embodiments, the organic electroluminescent display panel 210 is a downward-emitting organic electroluminescent display panel, so the first optical film 222, the second optical film 224 and the third optical film The optical film 226 is located below the display element 214, and the substrate 212 is a transparent substrate, such as a glass substrate. Since the other operating principles are the same as those of the foregoing embodiments except that the direction of light emission is changed, it should be easily accessible to those skilled in the art. I understand, so I won't go into details here.

Please refer to FIG. 4 , which is a schematic cross-sectional view of an organic electroluminescent display panel 310 in yet another embodiment of the present invention. Similar to the down-emitting organic electroluminescence display panel 210 in the previous embodiment, but only the display element 314 is located above the substrate 312, and the first optical film 322, the second optical film 324 and the third optical film 326 are located on the other side. On a substrate 316, and the substrate 312 and the substrate 316 are both a transparent substrate, such as a glass substrate, and a glue layer 318 is provided between the two substrates 312 and 316, such as a UV glue that can be cured by ultraviolet light (UV glue). 312 and 316 bonded. Except that the optical films are located on different substrates, other operating principles are the same as those of the foregoing embodiments, which should be easily understood by those skilled in the art, so details are not repeated here.

Compared with the prior art, the present invention provides an organic electroluminescent display panel with different sub-pixel area areas, so as to correct the brightness difference of each color light by using the difference in the area of each sub-pixel area, so that The shades of each color can have roughly the same intensity, so as to achieve a balance of hue and improve display quality. In addition, since the present invention does not need to apply an additional electric field to the display element, it can further prolong the lifetime of the organic electroluminescent display panel.

Although the present invention has been disclosed above with several preferred embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make arbitrary modifications and changes without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims (10)

1. An organic electroluminescent display panel, comprising: A substrate, the surface of the substrate has at least a first sub-pixel area, a second sub-pixel area and a third sub-pixel area; An organic electroluminescent element is disposed on the substrate, and the organic electroluminescent element can be driven to emit light; and at least one first optical film, one second optical film, and one third optical film, respectively corresponding to the first pixel area, the second sub pixel area and the third sub pixel area of the organic electroluminescence element and make the light emitted by the organic electroluminescent element generate a first color light, a second color light and a first color light from the first pixel area, the second sub pixel area and the third sub pixel area respectively. Three colors of light, the first color light, the second color light and the third color light are red light, green light and blue light respectively; Wherein, the first optical film, the second optical film and the third optical film have different areas, and the second optical film is thicker than the first optical film or the third optical film. 2. The organic electroluminescence display panel as claimed in claim 1, wherein the first optical film and the third optical film have different thicknesses. 3. The organic electroluminescence display panel as claimed in claim 1, wherein the first optical film, the second optical film and the third optical film have different shapes. 4. The organic electroluminescent display panel as claimed in claim 1, wherein the light emitted by the organic electroluminescent element is white light. 5. The organic electroluminescence display panel as claimed in claim 1, wherein the first color light, the second color light, and the third color light can achieve white light color balance, and its CIE coordinate value is (0.31±0.03, 0.32 ±0.03). 6. The organic electroluminescent display panel as claimed in claim 1, wherein the surface of the substrate has a fourth sub-pixel area, and the light emitted by the organic electroluminescent element is generated from the fourth sub-pixel area a fourth shade. 7. The organic electroluminescent display panel as claimed in claim 6, wherein the panel further has a fourth optical film disposed on the fourth sub-pixel region of the organic electroluminescent element. 8. The organic electroluminescent display panel as claimed in claim 6, wherein the panel further has a fourth conversion film disposed on the fourth sub-pixel region of the organic electroluminescent element. 9. The organic electroluminescence display panel as claimed in claim 1, wherein the second optical film corresponding to the green light has a smaller area than other optical films. 10. The organic electroluminescence display panel as claimed in claim 1, wherein the first optical film is a filter, a color conversion layer, or a combination of the two, and the second optical film is a filter, a color conversion layer , or a combination of the two, the third optical film is a filter, a color conversion layer, or a combination of the two.

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