Stacked OLED display having improved efficiency
View Patent ↗An OLED device having a pixel, including a plurality of light transmissive filters; a first electrode layer defining a corresponding plurality of separately addressable electrodes; a first layer of white light emitting OLED material; a doped organic conductor layer; a second layer of white light emitting OLED material; and a second electrode layer defining a single electrode coextensive with the plurality of color filters.
1. An OLED device having a pixel, comprising:
a) a plurality of light transmitting filters;
b) a first electrode layer defining a corresponding plurality of separately addressable electrodes;
c) a first layer of white light emitting OLED material;
d) a doped organic conductor layer;
e) a second layer of white light emitting OLED material; and
f) a second electrode layer defining a single electrode coextensive with the plurality of filters.
2. The OLED device claimed in claim 1 , wherein the filters include red, green and blue light transmitting filters.
3. The OLED device claimed in claim 1 , wherein the filters include a white light transmitting filter.
4. The OLED device claimed in claim 1 , wherein the light transmitting filters have different sizes.
5. The OLED device claimed in claim 1 , wherein the device is a top emitting OLED device.
6. The OLED device claimed in claim 1 , wherein the device is a bottom emitting OLED device.
7. The OLED device claimed in claim 1 , wherein two or more of the light transmitting filters transmit the same color of light.
8. The OLED device claimed in claim 7 , wherein the two or more filters transmit green light.
9. The OLED device claimed in claim 7 , wherein the two or more filters transmit white light.
10. The OLED device claimed in claim 1 , wherein the first and second layers of white light emitting OLED material are the, same material.
11. The OLED device claimed in claim 1 , wherein the first and second layers of white light emitting OLED material are different materials.
12. The OLED device claimed in claim 1 wherein the white point of the white light emitting OLED materials matches the white point of the display.
13. The OLED device claimed in claim 1 , wherein the filters are absorption filters.
14. The OLED device claimed in claim 1 , wherein the filters are dichroic filters.
15. The OLED device claimed in claim 1 , wherein the relative areas of the light transmitting filters is chosen to match the relative usage of the color of light transmitting filter.
16. The OLED device claimed in claim 1 , wherein the pixel has a square shape and the filters are arranged in a stripe pattern in the square shape.
17. The OLED device claimed in claim 1 , wherein the pixel has a square shape and the filters are arranged in a rectangular array in the square shape.
18. The OLED device claimed in claim 1 , wherein the filters include red, green, blue and white filters, and further comprising a controller for converting an RGB color image signal to an RGBW signal.
19. The OLED device claimed in claim 18 , wherein the controller determines the minimum (MIN) of the RGB signal and produces the RGBW signal as R=R−MIN, G=G−MIN, B=B−MIN, W=MIN.