Pixel structure of electroluminescent display panel

• US 8,847,857 B2
• Filed: 11/11/2012
• Issued: 09/30/2014
• Est. Priority Date: 12/08/2011
• Status: Active Grant

• Current Assignee: AU Optronics Corporation
• Original Assignee: AU Optronics Corporation
• Inventors: Liu, Meng-Yu, Liu, Chih-Che, Hsu, Shih-Feng
• Primary Examiner(s): GIESY, ADAM
• Application Number:
  US13/674,088
• Publication Number:
  US 20130147689A1
• Time in Patent Office: 688 Days
• Field of Search: None
• US Class Current: 345/76
• CPC Class Codes: G09G 3/30 using electroluminescent panels
• CPC Class Codes: H10K 50/17 Carrier injection layers
• CPC Class Codes: H10K 50/852 comprising a resonant cavity structure, e.g. Bragg reflector pair
• CPC Class Codes: H10K 59/30 Devices specially adapted for multicolour light emission
• CPC Class Codes: H10K 59/876 comprising a resonant cavity structure, e.g. Bragg reflector pair
• CPC Class Codes: H10K 71/00 Manufacture or treatment specially adapted for the organic devices covered by this subclass
• CPC Class Codes: Y10T 29/49002 Electrical device making

Abstract

A pixel structure of electroluminescent display panel has a first sub-pixel region, a second sub-pixel region, and a third sub-pixel region. The pixel structure of electroluminescent display panel includes a first organic light-emitting layer, and a second organic light-emitting layer. The first organic light-emitting layer is disposed in the first sub-pixel region for generating a first primary color light in the first sub-pixel region. The second organic light-emitting layer is disposed in the second sub-pixel region, and the third sub-pixel region for generating a second primary color light in the second sub-pixel region, and for generating a third primary color light in the third sub-pixel region. The first sub-pixel region, the second sub-pixel region, and the third sub-pixel region have different cavity lengths.

Claims

1. A pixel structure of an electroluminescent display panel having a first sub-pixel region, a second sub-pixel region, and a third sub-pixel region, the pixel structure of the electroluminescent display panel comprising:

a first anode, disposed in the first sub-pixel region;

a second anode, disposed in the second sub-pixel region;

a third anode, disposed in the third sub-pixel region;

a first organic light-emitting layer, disposed on the first anode and corresponding to the first sub-pixel region, wherein the first organic light-emitting layer comprises a first organic light-emitting material for generating a first primary color light;

a second organic light-emitting layer, disposed on the second anode and the third anode, and corresponding to the second sub-pixel region and the third sub-pixel region, for generating a second primary color light in the second sub-pixel region and generating a third primary color light in the third sub-pixel region, wherein the first primary color light, the second primary color light, and the third primary color light have different spectra of wavelength;

a first cathode, disposed on the first organic light-emitting layer and corresponding to the first sub-pixel region;

a second cathode, disposed on the second organic light-emitting layer and corresponding to the second sub-pixel region; and

a third cathode, disposed on the second organic light-emitting layer and corresponding to the third sub-pixel region;

wherein a first micro cavity is formed between the first anode and the first cathode in the first sub-pixel region, a second micro cavity is formed between the second anode and the second cathode in the second sub-pixel region, and a third micro cavity is formed between the third anode and the third cathode in the third sub-pixel region, and the first micro cavity, the second micro cavity, and the third micro cavity have different cavity lengths.

2. The pixel structure of the electroluminescent display panel of claim 1, wherein the second organic light-emitting layer is a composite-layered organic light-emitting layer.

3. The pixel structure of the electroluminescent display panel of claim 1, wherein the second organic light-emitting layer is a single-layered organic light-emitting layer.

4. The pixel structure of the electroluminescent display panel of claim 1, further comprising:

at least one first hole injection layer, disposed in the first sub-pixel region;

at least one second hole injection layer, disposed in the second sub-pixel region; and

at least one third hole injection layer, disposed in the third sub-pixel region;

wherein the at least one first hole injection layer, the at least one second hole injection layer, and the least one third hole injection layer have different thicknesses to render the first micro cavity, the second micro cavity, and the third micro cavity different cavity lengths.

5. The pixel structure of the electroluminescent display panel of claim 1, further comprising:

at least one first hole injection layer, disposed in the first sub-pixel region;

at least one second hole injection layer, disposed in the second sub-pixel region; and

at least one third hole injection layer, disposed in the third sub-pixel region;

wherein one of the at least one first hole injection layer, the at least one second hole injection layer, and the at least one third hole injection layer has a different thickness from the thicknesses of the other two of the at least one first hole injection layer, the at least one second hole injection layer, and the at least one third hole injection layer, and one of the first anode, the second anode, and the third anode has a different thickness from the thicknesses of the other two of the first anode, the second anode, and the third anode to render the first micro cavity, the second micro cavity, and the third micro cavity different cavity lengths.

6. The pixel structure of the electroluminescent display panel of claim 1, wherein the electroluminescent display panel is a top emission type electroluminescent display panel, each of the first cathode, the second cathode, and the third cathode comprises a transflective electrode, and each of the first anode, the second anode, and the third anode comprises a reflective electrode.

7. The pixel structure of the electroluminescent display panel of claim 1, wherein the electroluminescent display panel is a bottom emission type electroluminescent display panel, each of the first anode, the second anode, and the third anode comprises a transflective electrode, and each of the first cathode, the second cathode, and the third cathode comprises a reflective electrode.

8. The pixel structure of the electroluminescent display panel of claim 1, wherein the second organic light-emitting layer comprises a second organic light-emitting material and a third organic light-emitting material, the first organic light-emitting material comprises a blue light-emitting material, and the second organic light-emitting material and the third organic light-emitting material are selected from one of a red light-emitting material and a green light-emitting material respectively.

9. The pixel structure of the electroluminescent display panel of claim 1, wherein the second organic light-emitting layer comprises a second organic light-emitting material and a third organic light-emitting material, the first organic light-emitting material comprises a red light-emitting material, and the second organic light-emitting material and the third organic light-emitting material are selected from one of a green light-emitting material and a blue light-emitting material respectively.

10. The pixel structure of the electroluminescent display panel of claim 1, wherein the second organic light-emitting layer comprises a second organic light-emitting material and a third organic light-emitting material, the first organic light-emitting material comprises a green light-emitting material, and the second organic light-emitting material and the third organic light-emitting material are selected from one of a red light-emitting material and a blue light-emitting material respectively.

11. The pixel structure of the electroluminescent display panel of claim 1, wherein the first organic light-emitting material comprises a red light-emitting material and the second organic light-emitting layer comprises a cyan light-emitting material.

12. The pixel structure of the electroluminescent display panel of claim 1, wherein the first organic light-emitting material comprises a blue light-emitting material and the second organic light-emitting layer comprises a yellow light-emitting material.