Organic light emitting display device and method of manufacturing the same

Abstract

Provided are a method of manufacturing an organic light emitting display device and an organic light emitting display device manufactured by the method. The method includes calculating a peak-luminance current density for each of a red sub-pixel, a blue sub-pixel, a green sub-pixel, and a white sub-pixel, calculating an average use current density for each of the red sub-pixel, blue sub-pixel, green sub-pixel, and white sub-pixel; determining a size of each sub-pixel with the peak-luminance current density and the average use current density, and forming the sub-pixels with the determined sizes of the respective sub-pixels. The present invention sets the size of each sub-pixel in consideration of a peak-luminance current density and an average use current density, thus easily achieving the peak luminance and enhancing the color-coordinate life.

What is claimed is: 
     
       1. An organic light emitting display device, comprising:
 a pixel including: a single red sub-pixel formed on a substrate;   a single blue sub-pixel formed on the substrate;   a single green sub-pixel formed on the substrate; and   a single white sub-pixel formed on the substrate,   
 wherein the sub-pixels are arranged in the order of the red sub-pixel, the white sub-pixel, the green sub-pixel, and the blue sub-pixel in one direction, and 
 wherein, in the sub-pixels;
 a sub-pixel having a greatest area is one of a sub-pixel having a highest peak-luminance current density and a sub-pixel having a highest average use current density among the red, blue, green, and white sub-pixels has one of a largest area and a second largest area among the red, blue, green, and white sub-pixels, and has a larger area than at least one of the other three sub-pixels, and 
 a sub-pixel having a second greatest area is the other of the sub-pixel having the highest peak-luminance current density and the sub-pixel having the highest average use current density, 
 the peak-luminance current density for each sub-pixel is a current density necessary for the sub-pixel for realizing peak luminance that is predetermined maximum peak, and 
 the average use current density is a current density that is averagely used with a use time of the sub-pixel to realize a predetermined maximum luminance value for the sub-pixel. 
 
 
     
     
       2. The organic light emitting display device of  claim 1 , wherein,
 an area of the red sub-pixel is 1.25 to 1.5 times an area of the white sub-pixel; 
 an area of the blue sub-pixel is 1.25 or less times and exceeds 1.0 times an area of the white sub-pixel; and 
 an area of the green sub-pixel is 1.25 or less times and exceeds 1.0 times an area of the white sub-pixel. 
 
     
     
       3. The organic light emitting display device of  claim 1 , wherein the sub-pixels have the same height, and are arranged in the order of the red sub-pixel, the white sub-pixel, the green sub-pixel, and the blue sub-pixel. 
     
     
       4. A method of manufacturing an organic light emitting display device, comprising:
 forming a TFT array;   forming a 2-peak white OLED emitting white light by combination of light emitted from first and second emission layers (EMLs), on the TFT array; and   forming a red sub-pixel, a blue sub-pixel, a green sub-pixel and a white sub-pixel,   wherein, in the forming the sub-pixels:
 one of a sub-pixel having a highest peak-luminance current density and a sub-pixel having a highest average use current density have a greatest area, and 
 the other of the sub-pixel having the highest peak-luminance current density and the sub-pixel having the highest average use current density have a second greatest area. 
   
     
     
       5. The method of claim  4  22, wherein the sub-pixel having the highest determined peak-luminance current density is the red sub-pixel. 
     
     
       6. The method of  claim 4 , wherein, in the forming the sub-pixels:
 an average use current density of the sub-pixel having the highest average use current density is 6 or less times an average use current density of the sub-pixel having the lowest average use current density,   a peak-luminance design achievement degree of a sub-pixel having a highest peak-luminance design achievement degree is 2 or less times a peak-luminance design achievement degree of a sub-pixel having the lowest peak-luminance design achievement degree, and   a color-coordinate life of the organic light emitting display device is 20,000 hours or more, the color-coordinate life being a time taken until reaching a predetermined color-coordinate threshold change amount, the predetermined color-coordinate threshold change amount calculated by a color-coordinate change amount being 0.015, the color-coordinate change amount being expressed as [u′ t −u′ 0 ) 2 +(v′ t −v′ 0 ) 2 ] 1/2 , the color-coordinate change amount being a color-coordinate difference between initial color coordinates (u′0, v′0) and color coordinates (u′t, v′t) after a certain time “t” elapses.   
     
     
       7. The organic light emitting display device of claim 1, wherein a sub-pixel having a highest average use current has the other of the largest area and the second largest area, an average use current of each sub-pixel being a current of the sub-pixel averaged over a use time of the sub-pixel, and
 wherein the sub-pixel having the highest average use current is the blue sub-pixel.   
     
     
       8. The organic light emitting display device of claim 7, wherein the blue sub-pixel has the second largest area, the second largest area being smaller than the largest area. 
     
     
       9. The organic light emitting display device of claim 1, wherein the organic light emitting display device has a spectrum characteristic in which intensity at a wavelength corresponding to a color of the sub-pixel having the highest peak-luminance current among red, green, and blue is lower than intensity at wavelengths respectively corresponding to the other two of red, green, and blue. 
     
     
       10. The organic light emitting display device of claim 1, the sub-pixel having the highest peak-luminance current is the red sub-pixel, and
 wherein the red sub-pixel has the larger area than each of the green, blue, and white sub-pixels.   
     
     
       11. An organic light emitting display device, comprising:
 a pixel including a red sub-pixel, a blue sub-pixel, a green sub-pixel, and a white sub-pixel arranged consecutively in one direction on a substrate;   wherein, among the red, blue, green, and white sub-pixels, the red sub-pixel has one of a largest area and a second largest area, and has a larger area than at least one of the blue, green, and white sub-pixels.   
     
     
       12. The organic light emitting display device of claim 11, wherein, among the red, blue, green, and white sub-pixels, the blue sub-pixel has the other of the largest area and the second largest area. 
     
     
       13. The organic light emitting display device of claim 12, wherein the second largest area is larger than an area of the white sub-pixel, and
 wherein the white sub-pixel has a smallest area among the red, blue, green, and white sub-pixels.   
     
     
       14. The organic light emitting display device of claim 11, wherein:
 an area of the red sub-pixel is 1.25 to 1.5 times an area of the white sub-pixel;   the area of the blue sub-pixel is 1.0 to 1.25 times the area of the white sub-pixel; and   an area of the green sub-pixel is 1.0 to 1.25 times the area of the white sub-pixel.   
     
     
       15. The organic light emitting display device of claim 11, wherein the organic light emitting display device has a spectrum characteristic in which intensity at a wavelength corresponding to red is lower than intensity at wavelengths respectively corresponding to green and blue. 
     
     
       16. An organic light emitting display device, comprising:
 a pixel including:
 a single red sub-pixel on a substrate; 
 a single blue sub-pixel on the substrate; 
 a single green sub-pixel on the substrate; and 
 a single white sub-pixel on the substrate, 
   wherein the sub-pixels are arranged in the order of the red sub-pixel, the white sub-pixel, the green sub-pixel, and the blue sub-pixel in one direction, and   wherein the organic light emitting display device has a spectrum characteristic with respective intensity at wavelengths respectively corresponding to red, green, and blue, and   wherein a sub-pixel having a color with a lowest corresponding intensity in the spectrum characteristic among red, blue, and green has a largest area among the red, blue, green, and white sub-pixels, and has a larger area than at least one of the other three sub-pixels.   
     
     
       17. The organic light emitting display device of claim 16, wherein the sub-pixel having the color with the lowest corresponding intensity in the spectrum characteristic among red, blue, and green is red, and the red sub-pixel has the largest area among the red, blue, green, and white sub-pixels. 
     
     
       18. The organic light emitting display device of claim 16, wherein the sub-pixel having the color with the lowest corresponding intensity in the spectrum characteristic among red, blue, and green has a highest peak-luminance current among the red, blue, green, and white sub-pixels. 
     
     
       19. The organic light emitting display device of claim 16, wherein a sub-pixel having a highest average use current has a second largest area among the red, blue, green, and white sub-pixels, an average use current of each sub-pixel being a current of the sub-pixel averaged over a use time of the sub-pixel. 
     
     
       20. The organic light emitting display device of claim 19, wherein the sub-pixel having the highest average use current is the blue sub-pixel, and
 the second largest area is smaller than the largest area.   
     
     
       21. The organic light emitting display device of claim 16, wherein the white sub-pixel has a smallest area among the red, blue, green, and white sub-pixels. 
     
     
       22. A method of fabricating an organic light emitting display device having a substrate, the method comprising:
 determining a peak-luminance current density for each of a red sub-pixel, a blue sub-pixel, a green sub-pixel, and a white sub-pixel having a same area;   determining an average use current density for each of the red, blue, green, and white sub-pixels having the same area;   determining a primary size of each of the red, blue, green, and white sub-pixels based on the determined peak luminance current density;   determining a secondary size of each of the red, blue, green, and white sub-pixels based on the determined average use current density;   forming on the substrate a red sub-pixel, a blue sub-pixel, a green sub-pixel, and a white sub-pixel, each having a respective size determined based on the primary size and the secondary size,   wherein the forming of the red, blue, green, and white sub-pixels includes:
 respectively setting the size of each of the red, blue, green, and white sub-pixels based on the primary size and the secondary size; and 
 forming each of the red, blue, green, and white sub-pixels on the substrate based on the respectively set size, and 
   wherein:   a sub-pixel having a highest determined peak-luminance current density is formed to have a largest size among the red, blue, green, and white sub-pixels, and to have a greater size than at least one of the other three sub-pixel,   an average use current density of the sub-pixel having the highest determined average use current density is 6 or less times an average use current density of the sub-pixel having the lowest determined average use current density,   a peak-luminance design achievement degree of a sub-pixel having a highest peak-luminance design achievement degree is 2 or less times a peak-luminance design achievement degree of a sub-pixel having the lowest peak-luminance design achievement degree, and   a color-coordinate life of the organic light emitting display device is 20,000 hours or more, the color-coordinate life being a time taken until reaching a predetermined color-coordinate threshold change amount, the predetermined color-coordinate threshold change amount calculated by a color-coordinate change amount being 0.015, the color-coordinate change amount being expressed as [u′ t −u′ 0 ) 2 +(v′ t −v′ 0 ) 2 ] 1/2 , the color-coordinate change amount being a color-coordinate difference between initial color coordinates (u′0, v′0) and color coordinates (u′t, v′t) after a certain time “t” elapses.   
     
     
       23. The method of claim 22, wherein a sub-pixel having a highest determined average use current density is formed to have a second largest area smaller than the largest area, and
 wherein the sub-pixel having the highest determined average use current density is the blue sub-pixel.