Stacked OLED display having improved efficiency
View Patent ↗An OLED device includes a pixel having a plurality of individually addressable light emitting elements including a light emitting element for emitting white light, and one or more light emitting elements for emitting colored light; at least one of the light emitting elements being stacked on top of another of the light emitting elements; and the white light emitting element(s) being more efficient than at least one of the colored light emitting element(s).
1. An OLED device, comprising:
a) a pixel including a plurality of individually addressable light emitting elements including a light emitting element for emitting white light, and one or more light emitting elements for emitting colored light;
b) at least one of the light emitting elements being stacked on top of another of the light emitting elements; and
c) the white light emitting element being more efficient than at least one of the colored light emitting element(s).
2. The OLED device claimed in claim 1 , including two or more colored light emitting elements and wherein two or more of the colored light emitting elements are stacked and the white light emitting element is located adjacent the stack of colored light emitting elements.
3. The OLED device claimed in claim 2 , wherein the colored light emitting elements include red, green and blue light emitting elements.
4. The OLED device claimed in claim 1 , wherein the light emitting elements are the same size and are arranged in a single stack.
5. The OLED device claimed in claim 4 , wherein the colored light emitting elements include red, green and blue light emitting elements.
6. The OLED device claimed in claim 1 , wherein two or more of the colored light emitting elements are arranged adjacent to each other and stacked with the white emitting element.
7. The OLED device claimed in claim 6 , wherein the colored light emitting elements include red, green and blue light emitting elements arranged adjacent to each other.
8. The OLED device claimed in claim 1 , wherein the light emitting elements are arranged in a plurality of stacks.
9. The OLED device claimed in claim 8 , wherein the colored light emitting elements include red, green and blue light emitting elements and the green and white light emitting elements are arranged in one stack and the red and blue elements are arranged in another stack.
10. The OLED device claimed in claim 8 , wherein stacks of light emitting elements have different light emitting areas.
11. The OLED device claimed in claim 10 , wherein the colored light emitting elements include red, green and blue light emitting elements and the green and white light emitting elements are arranged in one stack and the red and blue elements are arranged in another stack, and wherein the light emitting area of the red and blue stack is larger than the light emitting area of the green and white stack.
12. The OLED device claimed in claim 10 , wherein the colored light emitting elements include red, green, and blue light emitting elements and the green and red light emitting elements are arranged in one stack and the white and blue light emitting elements are arranged in another stack.
13. The OLED device claimed in claim 10 , wherein the colored light emitting elements include red, green, and blue light emitting elements and the green and white light emitting elements are arranged in one stack and the red and blue light emitting elements are arranged in another stack.
14. The OLED device claimed in claim 1 , wherein two or more of the individually addressable light emitting elements emit the same color of light or white light and are not located in the same stack.
15. The OLED device claimed in claim 14 , wherein the pixel comprises stacks of white and red; white and blue; and white and green light emitting elements.
16. The OLED device claimed in claim 14 , wherein the pixel comprises stacks of white and green; white and red; and green and blue light emitting elements.
17. The OLED device claimed in claim 14 , wherein the pixel comprises stacks of white and green; white and blue; and green and red light emitting elements.
18. The OLED device claimed in claim 14 , wherein the pixel comprises two stacks of white, green and red; and a stack of white, green and blue light emitting elements.
19. The OLED device claimed in claim 1 , wherein the pixel comprises a plurality of stacks of light emitting elements, each stack including an element for emitting white light.
20. The OLED device claimed in claim 19 , wherein the white light emitting elements are biased toward different colors.
21. The OLED device claimed in claim 20 , wherein the stacks include a red light emitting element; a white light emitting element that is biased toward red; a green light emitting element; a white light emitting element that is biased toward green; a blue light emitting element; and a white light emitting element that is biased toward blue.
22. The OLED device claimed in claim 1 , wherein the pixel comprises more than three colored light emitting elements.
23. The OLED device claimed in claim 22 , wherein the colored light emitting elements produce red, green, blue, and cyan colored light respectively.
24. The OLED device in claim 22 , wherein the colored light emitting elements produce red, blue, and two other colors of light near the peak human visual sensitivity.
25. The OLED device in claim 22 , wherein the two other colors of light are yellow and cyan.
26. The OLED device claimed in claim 1 , wherein the stacks include a stack having a red light emitting element and a white light emitting element that is biased toward red; a stack having a green light emitting element; a stack having a blue light emitting element and a white light emitting element that is biased toward blue.
27. An OLED device, comprising:
a) a first layer of independently addressable light emitting elements;
b) a second layer of independently addressable light emitting elements located on top of the first layer; and
c) wherein the resolution of the first and second layers of independently addressable light emitting elements is different.
28. The OLED device claimed in claim 27 , wherein light emitting elements within a layer have different light emitting areas.
29. The OLED device claimed in claim 27 , wherein one of the layers includes white light emitting elements and the other layer includes colored light emitting elements.
30. The OLED device claimed in claim 29 , wherein the white light emitting elements are more efficient than one or more of the colored light emitting elements.
31. The OLED device claimed in claim 29 , wherein the colored light emitting elements include red, green, and blue light emitting elements.
32. An OLED device, comprising:
a) a pixel including a plurality of individually addressable light emitting elements for emitting different colors of light, wherein at least one of the light emitting elements emits white light and at least one other of the light emitting elements emits a saturated color of light; and
b) the light emitting elements of the pixel being arranged in two or more stacks.
33. The OLED device claimed in claim 32 , wherein the white light emitting element is more efficient than one or more of the colored light emitting elements.
34. The OLED device claimed in claim 32 wherein the light emitting areas of the stacks are different in size.
35. The OLED device claimed in claim 32 , wherein the number of light emitting elements in the stacks are different.