JP2009032576A - Organic el display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive organic EL display capable of displaying a clear image, and exhibiting excellent visibility. <P>SOLUTION: This organic EL display 10 includes: a substrate 11; first electrodes 12; a transparent second electrode 15; a red light-emitting organic EL film 13R, a blue light-emitting organic EL film 13B and a green light-emitting organic EL film 13G; and a first color filter 16 and a second color filter 18. The first color filter 16 has optical characteristics transmitting red light and blue light, and blocking green light, and is arranged to allow passage of light emitted by the red light-emitting organic EL film 13R, and the blue light-emitting organic EL film 13B. The second color filter 18 has optical characteristics transmitting green light, and blocking at least either of red light and blue light, and is arranged to allow passage of light emitted by the green light-emitting organic EL film 13G. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an organic EL display including an organic EL element.

  An organic EL element, that is, an organic electroluminescence element is an element for emitting light. A display can be constructed by using a large number of organic EL elements. An organic EL display having a typical configuration includes a plurality of organic EL elements that emit red light, a plurality of organic EL elements that emit green light, and a plurality of organic EL elements that emit blue light. Each of these organic EL elements has a function as a pixel and is arranged in a matrix.

  At present, organic EL elements cannot emit light with sufficient color purity. That is, the organic EL film, which is a light emitter included in the organic EL element, has already been made of various materials, but no material that emits light having good monochromaticity has been found. In order to improve monochromaticity, some organic EL displays transmit only red light, green light, and blue light corresponding to organic EL elements that emit red light, green light, and blue light, respectively. A color filter is further provided. However, the addition of three types of color filters causes an increase in the cost of the organic EL display.

  Focusing on this problem, Patent Document 1 discloses an organic EL display having one type of color filter. A schematic configuration thereof is shown in FIG. The organic EL display 90 includes a substrate 91, a red light emitting organic EL film 93R, a green light emitting organic EL film 93G, and a blue light emitting organic EL film 93B. These organic EL films are sandwiched between the first electrode 92 and the transparent second electrode 95. The insulating film 94 and the protective film 97 occupy the remaining space. Further, the organic EL display 90 is characteristically provided with a color filter 96 at locations corresponding to the red light emitting organic EL film 93R and the blue light emitting organic EL film 93B. The color filter 96 is magenta transmissive, that is, has a property of blocking green light while transmitting only red and blue light. The first effect of this configuration is that the monochromaticity of red light and blue light emitted from the pixels is improved.

Furthermore, the second effect of this configuration is not explicitly mentioned in Patent Document 1, but is that visibility of the organic EL display 90 is improved by suppressing unnecessary reflection of external light. is there. In general, light incident from the outside is reflected at the first electrode 92 or at a region between adjacent pixels on the surface of the substrate 91 and then returns to the outside. For this reason, an external scenery or the like is reflected on the organic EL display 90, and the display content becomes difficult to see. The color filter 96 absorbs part of the light incident from the outside. Thereby, the visibility of display content improves.
JP 2003-178879 A

  However, there still remains room for further improvement in the monochromaticity of green light in the above-described configuration. In addition, the above-described configuration leaves room for further reducing unnecessary reflections.

  Accordingly, an object of the present invention is to provide an organic EL display capable of displaying a clear image by including an organic EL element that emits light exhibiting good monochromaticity. Furthermore, an object of the present invention is to provide an organic EL display showing good visibility by reducing reflection of external light. In addition, the present invention aims to provide those effects at a low cost.

  An organic EL display provided by the present invention includes a substrate, a first electrode provided on the substrate, a transparent second electrode, and a first electrode sandwiched between the first electrode and the second electrode. An organic EL film, a second organic EL film, a third organic EL film, a first color filter, and a second color filter are provided. The first organic EL film, the second organic EL film, and the third organic EL film are for emitting one of red light, green light, and blue light, which are different from each other. . The first color filter has an optical characteristic of transmitting light emitted from the first organic EL film and the second organic EL film and blocking light emitted from the third organic EL film, and The first organic EL film and the second organic EL film are disposed so as to pass light. The second color filter has an optical characteristic of transmitting light emitted from the third organic EL film and blocking light emitted from any one of the first organic EL film and the second organic EL film. And the light emitted by the third organic EL film is arranged to pass therethrough.

  Preferably, the organic EL display blocks light coming from a region sandwiched between two adjacent ones of the first organic EL film, the second organic EL film, and the third organic EL film. The light shielding plate is further provided.

  FIG. 1 shows a first embodiment of the present invention.

  The organic EL display 10 includes a substrate 11, a first electrode 12, and a transparent second electrode 15. The first electrode 12 and the second electrode 15 sandwich the red light emitting organic EL film 13R, the green light emitting organic EL film 13G, and the blue light emitting organic EL film 13B. Further, the organic EL display 10 characteristically includes two types of color filters, that is, a first color filter 16 and a second color filter 18. The remaining space is occupied by the insulating film 14 and the protective film 17.

  The first color filter 16 is magenta transmissive, that is, has a property of blocking green light while transmitting red and blue light. The first color filter 16 is provided at locations corresponding to the red light emitting organic EL film 13R and the blue light emitting organic EL film 13B. On the other hand, the second color filter 18 is cyan transmissive, that is, has a property of blocking red light while transmitting green and blue light. The second color filter 18 is provided at a location corresponding to the green light emitting organic EL film 13G.

  The substrate 11 is made of an insulator such as glass. The first electrode 12 functions as an anode, and is made of, for example, metal or ITO with a metal reflection film. The second electrode 15 functions as a cathode and is made of a transparent material such as ITO or IZO. The insulating film 14 is made of an insulating material. The protective film 17 is made of a transparent material.

  A voltage is selectively applied to the red light emitting organic EL film 13R, the green light emitting organic EL film 13G, and the blue light emitting organic EL film 13B through the first electrode 12 and the second electrode 15. Thereby, the red light emitting organic EL film 13R, the green light emitting organic EL film 13G, and the blue light emitting organic EL film 13B emit red light, green light, and blue light, respectively. These lights are transmitted through the transparent second electrode 15. The monochromaticity of red light and blue light is improved by the first color filter 16, while the monochromaticity of green light is improved by the second color filter 18. Furthermore, the first color filter 16 and the second color filter 18 absorb light incident from the outside, and thereby prevent unnecessary reflected light from returning to the outside.

  The organic EL display 10 has two types of color filters. For this reason, the manufacturing cost of the organic EL display 10 is reduced as compared with an organic EL display including three types of color filters that respectively transmit only red, green, and blue light. That is, according to the present invention, all of the monochromaticity of pixels, reduction of unnecessary reflections, and cost reduction are achieved at the same time.

  As described above, the second color filter 18 is used to transmit only green light emitted from the green light-emitting organic EL film 13G. Therefore, in the present embodiment, the second color filter 18 may be yellow transmissive instead of cyan transmissive. Yellow transparency refers to the property of blocking blue light while transmitting red and green light.

  Various variations can be created based on this embodiment. For example, the first color filter 16 is provided at a location corresponding to the red light emitting organic EL film 13R and the green light emitting organic EL film 13G, and the second color filter 18 is provided at a location corresponding to the blue light emitting organic EL film 13B. May be. In this case, it is desirable that the first color filter 16 has yellow transparency. The second color filter 18 preferably has cyan transparency or magenta transparency.

  Alternatively, the first color filter 16 is provided at a location corresponding to the green light emitting organic EL film 13G and the blue light emitting organic EL film 13B, and the second color filter 18 is provided at a location corresponding to the red light emitting organic EL film 13R. May be. In this case, it is desirable that the first color filter 16 has cyan transparency. The second color filter 18 preferably has magenta transparency or yellow transparency.

  FIG. 2 shows a second embodiment of the present invention. The organic EL display 20 according to the present embodiment is different from the first embodiment in that it further includes a light shielding plate 29. The same elements as those of the first embodiment of the present embodiment are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  The first color filter 16 is magenta transmissive, and is provided at a position corresponding to the red light emitting organic EL film 13R and the blue light emitting organic EL film 13B. The second color filter 18 is yellow transmissive and is provided at a location corresponding to the green light emitting organic EL film 13G.

  A light shielding plate 29 is provided in a region between adjacent pixels. The light shielding plate 29 prevents external light from being reflected in a region between adjacent pixels on the surface of the substrate 11 and then returning to the outside. Thereby, the visibility of the organic EL display 20 is improved.

  The optical characteristics and arrangement of the first color filter 16 and the second color filter 18 may be changed according to the same concept as in the first embodiment.

  The present invention is not limited to the embodiment described above. The specific configuration of each part of the present invention can be changed as appropriate. For example, the configuration of the organic EL display of the present invention is not limited to the top emission type, that is, the one that emits light through a transparent protective film, as in the first and second embodiments. It may be an emission type, that is, one that emits light through a transparent substrate. The material forming each element is freely selected as long as the function of the element is achieved. The polarity of the first electrode and the second electrode may be reversed with respect to the described embodiment.

It is sectional drawing which shows the structure of the organic electroluminescent display which concerns on the 1st Embodiment of this invention. It is sectional drawing which shows the structure of the organic electroluminescent display which concerns on the 2nd Embodiment of this invention. It is sectional drawing which shows the structure of the conventional organic EL display.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 20 Organic EL display 11 Substrate 12 First electrode 13R Red light emitting organic EL film 13G Green light emitting organic EL film 13B Blue light emitting organic EL film 14 Insulating film 15 Second electrode 16 First color filter 17 Protective film 18 Second color filter 29 Shading plate

Claims (2)

A substrate,
A first electrode provided on the substrate;
A transparent second electrode;
A first organic EL film, a second organic EL film, and a third organic EL film sandwiched between the first electrode and the second electrode;
A first color filter and a second color filter;
An organic EL display comprising:
The first organic EL film, the second organic EL film, and the third organic EL film are for emitting one of red light, green light, or blue light, which are different from each other. ,
The first color filter has an optical characteristic of transmitting light emitted from the first organic EL film and the second organic EL film and blocking light emitted from the third organic EL film, and The first organic EL film and the second organic EL film are disposed so as to pass light,
The second color filter has an optical characteristic of transmitting light emitted from the third organic EL film and blocking light emitted from any one of the first organic EL film and the second organic EL film. And an organic EL display arranged to pass light emitted from the third organic EL film.   Further comprising a light shielding plate for blocking light coming from a region sandwiched between two adjacent ones of the first organic EL film, the second organic EL film, and the third organic EL film. Item 10. An organic EL display according to Item 1.

Images