ORGANIC ELECTROLUMINESCENCE DISPLAY DEVICE

Abstract

The recent invention provide an organic electroluminescence display device with color purity adjustment, particularly white purity increased, without increasing formation processes. For each of unit pixels formed on an insulating film INS formed on a principal surface of a glass substrate, a bank BNK is provided on a bottom electrode BEL being a pixel electrode. The bank BNK has the shape of a bank that surrounds a pixel concerned, for each of pixels, and an organic electroluminescence light emitting layer is charged within a region surrounded by the banks BNKs. Between the banks BNKs, a green light emitting layer (G light emitting layer), a blue light emitting layer (B light emitting layer), and a red light emitting layer (R light emitting layer) are provided. At the same time as the formation of these color light emitting layers, light emitting layers of three colors, the green light emitting layer (G light emitting layer), the blue light emitting layer (B light emitting layer), and the red light emitting layer (R light emitting layer) are stacked on a region of a white pixel to form a white light emitting layer (G+B+R). An upper electrode UEL is formed over the green light emitting layer (G light emitting layer), the blue light emitting layer (B light emitting layer), the red light emitting layer (R light emitting layer), and the white light emitting layer (G+B+R light emitting layer).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of one pixel of full color for explaining one embodiment of an organic electroluminescence display device of the R-G-B-W method of the present invention;

FIGS. 2A, 2B, 2C, and 2D are drawings for explaining a variation of pixel arrangement in an image display device of high-brightness full color;

FIGS. 3A, 3B, 3C, 3D, and 3E are drawings for explaining an example of evaporation masks used for the formation of organic electroluminescence light emitting layers of an organic electroluminescence display device of the R-G-B-W method of the present invention;

FIGS. 4A, 4B, 4C, 4D, and 4E are drawings for explaining another example of an evaporation mask used for the formation of organic electroluminescence light emitting layers of the organic electroluminescence display device of the R-G-B-W method of the present invention;

FIG. 5 is a schematic diagram for explaining more concretely the formation of an organic electroluminescence of the present invention that uses evaporation masks;

FIG. 6 is a drawing for explaining a relationship between the layer thickness of color pixels and white pixel that are shown in FIG. 3E or 4E, and the height of banks;

FIGS. 7A and 7B are drawings for explaining the structure of an organic electroluminescence display device of bottom emission type; and

FIGS. 8A and 8B are drawings for explaining the structure of an organic electroluminescence display device of top emission type.

Claims

1. An organic electroluminescence display device comprising: a plurality of first electrodes each formed for each of unit pixels on a principal surface of an insulating substrate; a plurality of organic electroluminescence layers that are each stacked on each of the first electrodes and emit color light different from each other; and a second electrode formed over the plurality of organic electroluminescence layers, wherein the plurality of organic electroluminescence layers, for each of unit pixels, are surrounded by banks that partition the region of a pixel concerned, and the plurality of organic electroluminescence layers form a full color pixel by unit pixels respectively having color organic electroluminescence layers that emit three primary colors of light, and a unit pixel that emits white light, andan organic electroluminescence layer of the unit pixel that emits white light is a multilayered film of the color organic electroluminescence layers that emit the three primary colors.

2. The organic electroluminescence display device of claim 1, wherein the thickness of the organic Electroluminescence layer of the unit pixel that emits white light is larger than that of the color organic electroluminescence layers.

3. The organic electroluminescence display device of claim 1, wherein the distance difference between the top of the banks and the top of the organic electroluminescence layer of the unit pixel that emits white light is smaller than the distance difference between the top of the banks and the top of the color organic electroluminescence layers.

4. An organic electroluminescence display device comprising: a plurality of first electrodes each formed for each of unit pixels on a principal surface of an insulating substrate; a plurality of organic electroluminescence layers that are each stacked on each of the first electrodes and emit color light different from each other; and a second electrode formed over the plurality of organic electroluminescence layers, wherein the plurality of organic electroluminescence layers, for each of unit pixels, are surrounded by banks that partition the region of a pixel concerned, and the plurality of organic electroluminescence layers form a full color pixel by unit pixels respectively having color organic electroluminescence layers that emit three primary colors of light, and a unit pixel that emits white light,wherein an organic electroluminescence layer of the unit pixel that emits white light is a multilayered film of the color organic electroluminescence layers that emit the three primary colors, andone layer of the multilayered film is made to continue to the color organic electroluminescence layers of pixels adjacent to the unit pixel that emits white light, over the banks.

5. The organic electroluminescence display device of claim 4, wherein a plurality of pixels of different colors that emit the three primary colors are disposed in a scanning direction, andpixels adjacent to the unit pixel that emits white light are the color pixels that are adjacent to one side or both sides in the scanning direction with respect to the unit pixel that emits white light.

6. The organic electroluminescence display device of claim 1, wherein the color organic electroluminescence layers that emit the three primary colors are stacked on the banks that surround pixels adjacent to the unit pixel that emits white light.

7. The organic electroluminescence display device of claim 1, wherein organic electroluminescence layers of two colors of the color organic electroluminescence layers that emit three primary colors are stacked on the banks that surround pixels not adjacent to the unit pixel that emits white light.