Organic light emitting display panel and method of manufacturing the same

Patent metadata

Field	Value
Publication number	US-9653520-B2
Application number	US-201514725677-A
Country	US
Kind code	B2
Filing date	May 29, 2015
Priority date	Nov 15, 2011
Publication date	May 16, 2017
Grant date	May 16, 2017

Abstract

An organic light emitting display panel with improved efficiency and lifespan and a method of manufacturing the same are disclosed. The organic light emitting display panel according to the present invention includes a substrate having red, green, blue, and white sub-pixel regions, red, green, and blue color filters respectively formed in the red, green, and blue sub-pixel regions, an overcoat layer that is formed in the red and green sub-pixel regions except for the blue and white sub-pixel regions or is formed in the sub-pixel regions such that a thickness of the overcoat layer in the red and green sub-pixel regions is greater than a thickness of the overcoat layer in the blue and white sub-pixel regions; and organic emitting cells respectively formed in the red, green, blue, and white sub-pixel regions.

First claim

What is claimed is:

1. An organic light emitting display panel comprising:
a substrate having red, green, blue, and white sub-pixel regions;
red, green, and blue color filters respectively disposed in the red, green, and blue sub-pixel regions;
an overcoat layer disposed in at least two sub-pixel regions of the red, green, and blue sub-pixel regions; and
organic emitting cells having a first electrode respectively disposed in the red, green, blue, and white sub-pixel regions,
wherein a lower surface of the first electrode disposed in one sub-pixel region of the red, green, and blue sub-pixel regions is disposed on a plane different from lower surfaces of the first electrodes disposed in the other two sub-pixel regions of the red, green, and blue sub-pixel regions.

2. The organic light emitting display panel of claim 1 , wherein:
the organic emitting cells in the red and green sub-pixel regions are disposed on the overcoat layer;
the organic emitting cell in the blue sub-pixel region is disposed on the blue color filter; and
the organic emitting cell in the white sub-pixel region is disposed on a protection layer to cover a thin film transistor disposed on the substrate.

3. The organic light emitting display panel of claim 2 ,
wherein the first electrode directly contacts the blue color filter and indirectly contacts the red and green color filters, the overcoat layer disposed between the first electrode and the red and green color filters.

4. The organic light emitting display panel of claim 1 , further comprising a buffer layer disposed between the overcoat layer and each of the organic emitting cells in the red and green sub-pixel regions, between the blue color filter and the organic emitting cell in the blue sub-pixel region, and between the protection layer and the organic emitting cell in the white sub-pixel region,
wherein the buffer layer is composed of an inorganic insulating material comprising SiNX or SiOx.

5. The organic light emitting display panel of claim 1 , wherein:
a thickness of the overcoat layer in the at least one sub-pixel region of the red, green, and blue sub-pixel regions is different from a thickness of the overcoat layer in the other sub-pixel region of the red, green, and blue sub-pixel regions.

6. The organic light emitting display panel of claim 5 , wherein:
the overcoat layer in the red, green, and blue sub-pixel regions is disposed in the red, green, and blue color filters such that the thickness of the overcoat layer in the red and green sub-pixel regions is greater than the thickness of the overcoat layer in the blue and white sub-pixel regions; and
the overcoat layer in the white sub-pixel region is disposed on a protection layer to cover a thin film transistor disposed on the substrate.

7. A method of manufacturing an organic light emitting display panel, the method comprising:
forming a substrate having red, green, blue, and white sub-pixel regions;
forming red, green, and blue color filters respectively in the red, green, and blue sub-pixel regions;
forming an overcoat layer in at least two sub-pixel regions of the red, green, and blue sub-pixel regions; and
forming organic emitting cells having a first electrode respectively in the red, green, blue, and white sub-pixel regions,
wherein a lower surface of the first electrode disposed in the one sub-pixel region of the red, green, and blue sub-pixel regions is disposed on a plane different from lower surfaces of the first electrodes disposed in the other two sub-pixel regions of the red, green, and blue sub-pixel regions.

8. The method of claim 7 , wherein:
the organic emitting cells in the red and green sub-pixel regions are disposed on the overcoat layer;
the organic emitting cell in the blue sub-pixel region is disposed on the blue color filter; and
the organic emitting cell in the white sub-pixel region is disposed on a protection layer to cover a thin film transistor disposed on the substrate.

9. The method of claim 7 , further comprising forming a buffer layer between the overcoat layer and each of the organic emitting cells in the red and green sub-pixel regions except for in the blue and white sub-pixel regions, between the blue color filter and the organic emitting cell in the blue sub-pixel region, and between the protection layer and the organic emitting cell in the white sub-pixel region,
wherein the buffer layer is composed of an inorganic insulating material comprising SiNX or SiOx.

10. The method of claim 7 , wherein the forming of the overcoat layer in the at least two sub-pixel regions of the red, green, and blue sub-pixel regions comprises:
forming an organic layer over the entire surface of the substrate provided with the red, green, and blue color filters;
forming the overcoat layer in the red, green, blue, and white sub-pixel regions by patterning the organic layer using a mask including a shielding unit corresponding to the red and green sub-pixel regions, a semi-transmissive unit corresponding to the blue and white sub-pixel regions, and a transmissive unit corresponding to a contact hole of the thin film transistor; and
removing portions of the overcoat layer in the blue and white sub-pixel regions.

11. The method of claim 7 , wherein a thickness of the overcoat layer in the at least one sub-pixel region of the red, green, and blue sub-pixel regions is different from than a thickness of the overcoat layer in the other sub-pixel region of the red, green, and blue sub-pixel regions.

12. The method of claim 11 , wherein:
the overcoat layer in the red, green, and blue sub-pixel regions are disposed on the red, green, and blue color filters such that the thickness of the overcoat layer in the red and green sub-pixel regions is greater than the thickness of the overcoat layer in the blue and white sub-pixel regions; and
the overcoat layer in the white sub-pixel region is disposed on a protection layer to cover a thin film transistor disposed on the substrate.

13. The method of claim 11 , wherein the forming the overcoat layer in the at least two sub-pixel regions of the red, green, and blue sub-pixel regions comprises:
forming an organic insulating material over the entire surface of the substrate provided with the red, green, and blue color filters; and
forming the overcoat layer by patterning the organic insulating material using a mask including a shielding unit corresponding to the red and green sub-pixel regions, a semi-transmissive unit corresponding to the blue and white sub-pixel regions, and a transmissive unit corresponding to a contact hole of the thin film transistor.

14. An organic light emitting display panel, comprising:
a substrate having red, green, blue, and white sub-pixel regions;
red, green, and blue color filters respectively disposed in the red, green, and blue sub-pixel regions;
an overcoat layer disposed in at least two sub-pixel regions of the red, green, and blue sub-pixel regions; and
organic emitting cells having a first electrode respectively disposed in the red, green, blue, and white sub-pixel regions,
wherein a lower surface of the first electrode disposed in one sub-pixel region of the red, green, and blue sub-pixel regions is disposed on a plane different from lower surfaces of the first electrodes disposed in the other two sub-pixel regions of the red, green, and blue sub-pixel regions; and
wherein:
the organic emitting cells in the red and green sub-pixel regions are disposed on the overcoat layer;
the organic emitting cell in the blue sub-pixel region is disposed on the blue color filter; and
the organic emitting cell in the white sub-pixel

Assignees

• Lg Display Co Ltd

Inventors

• Kim Ji-Min
• Kim Do-Hyung
• Oh Hye-Min

Classifications

• F21V9/08

  for producing coloured light, e.g. monochromatic; for reducing intensity of light (with provision for controlling the colour F21V9/40) · CPC title

• H10K2102/3023

  Direction of light emission · CPC title

• H10K59/1201

  Manufacture or treatment · CPC title

• H10K71/00

  Manufacture or treatment specially adapted for the organic devices covered by this subclass · CPC title

• H10K59/805

  Electrodes · CPC title