OLED displays having improved contrast
View Patent ↗An OLED display device includes a substrate; an array of OLED elements disposed over one side of the substrate to emit light in a direction; circuitry to drive the OLED elements located beside the array of OLED elements on the substrate; a light absorbing material located above the circuitry in the direction of light emission; and a circular polarizer located above the circuitry, the OLED elements, and the light absorbing material in the direction of light emission.
1. An OLED display device, comprising:
a) a substrate;
b) an array of OLED elements disposed over one side of the substrate to emit light in a direction;
c) circuitry to drive the OLED elements located beside the array of OLED elements on the substrate;
d) a black matrix located above the circuitry in the direction of light emission; and
e) a circular polarizer located above the circuitry, the OLED elements, and the black matrix in the direction of light emission.
2. The display device claimed in claim 1 , wherein the OLED display further includes an encapsulating cover located above the OLED elements and affixed to the substrate and the circular polarizer is located on the outside of the encapsulating cover.
3. The display device claimed in claim 1 , wherein the OLED display further includes an encapsulating cover located above the OLED elements and affixed to the substrate and the circular polarizer is located on the inside of the encapsulating cover.
4. The display device claimed in claim 1 , wherein the OLED elements are a plurality of elements and wherein the plurality of elements includes multiple colors.
5. The display device claimed in claim 4 , wherein the OLED elements include a white-light emitter having color filter arrays.
6. The display device claimed in claim 5 , wherein the black matrix is composed of a combination of color filters.
7. The display device claimed in claim 5 , wherein the black matrix has desiccating properties.
8. The display device claimed in claim 1 , wherein the OLED elements further include a first electrode, OLED light-emissive elements, and a second electrode, and wherein the light emission is through the second electrode.
9. The display device claimed in claim 8 , wherein the first electrode is reflective or has a reflective layer adjacent to it.
10. The display device claimed in claim 1 , wherein the display device is a top-emitter.
11. The display device claimed in claim 1 , wherein the display device is a bottom-emitter.
12. The display device claimed in claim 11 , wherein the circular polarizer is located on the substrate.
13. The display device claimed in claim 1 , wherein the OLED display further includes an encapsulating cover located above the OLED elements and affixed to the substrate and the black matrix is located on the inside of the cover.
14. The display device claimed in claim 1 , wherein the black matrix is black.
15. The display device claimed in claim 1 , wherein the black matrix is selected from the group consisting of dyes and pigments.
16. The display device claimed in claim 1 , wherein the black matrix is selected from the group consisting of carbon black, graphite, metal oxides, and metal sulfides.
17. The display device claimed in claim 1 , wherein the black matrix is also provided around the perimeter of the device.
18. The display device claimed in claim 1 , wherein the black matrix comprises a plurality of layers.
19. The display device claimed in claim 1 , wherein the black matrix is a thick film layer.
20. The display device claimed in claim 1 , wherein the black matrix is conformable to the surface of the materials deposited over the substrate.
21. The display device claimed in claim 1 , further comprising a transparent cover that is conformable to the surface of the materials deposited over the substrate.
22. A method of manufacturing an OLED display device, comprising the steps of:
a) providing a substrate;
b) forming an array of OLED elements on one side of the substrate to emit light in a direction;
c) forming circuitry located beside the array of OLED elements on the substrate to drive the OLED elements;
d) forming a black matrix above the circuitry in the direction of light emission; and
e) locating a circular polarizer above the circuitry, the OLED elements, and the black matrix in the direction of light emission.
23. The method claimed in claim 22 , wherein photolithographic processes are used to deposit the black matrix.
24. The method claimed in claim 22 , wherein thick film screening printing processes are used to deposit the black matrix.
25. The method claimed in claim 22 , wherein black matrix is applied using a thermal transfer process from a donor substrate.