Organic EL display panel, display device using same, and method for producing organic EL display panel

• US 9,761,638 B2
• Filed: 11/13/2014
• Issued: 09/12/2017
• Est. Priority Date: 11/15/2013
• Status: Active Grant

• Current Assignee: JDI Design and Development GK
• Original Assignee: JOLED Inc.
• Inventors: Komatsu, Takahiro
• Primary Examiner(s): Tran, Dzung
• Application Number:
  US15/035,335
• Publication Number:
  US 20160293676A1
• Time in Patent Office: 1,034 Days
• Field of Search: 257 40
• CPC Class Codes: G02B 5/20 Filters polarising elements G02B5/30
• CPC Class Codes: H05B 33/145 Arrangements of the electroluminescent material
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/125 specially adapted for multicolour light emission, e.g. for emitting white light
• CPC Class Codes: H10K 50/13 comprising stacked EL layers within one EL unit
• CPC Class Codes: H10K 50/86 Arrangements for improving contrast, e.g. preventing reflection of ambient light
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/1201 Manufacture or treatment
• CPC Class Codes: H10K 59/32 Stacked devices having two or more layers, each emitting at different wavelengths
• CPC Class Codes: H10K 59/35 comprising red-green-blue [RGB] subpixels
• CPC Class Codes: H10K 59/351 comprising more than three subpixels, e.g. red-green-blue-white [RGBW]
• CPC Class Codes: H10K 59/38 comprising colour filters or colour changing media [CCM]
• CPC Class Codes: H10K 59/8791 Arrangements for improving contrast, e.g. preventing reflection of ambient light
• CPC Class Codes: H10K 71/00 Manufacture or treatment specially adapted for the organic devices covered by this subclass
• CPC Class Codes: H10K 71/12 using liquid deposition, e.g. spin coating
• CPC Class Codes: H10K 71/135 using ink-jet printing
• CPC Class Codes: H10K 71/16 using physical vapour deposition [PVD], e.g. vacuum deposition or sputtering

Abstract

An organic EL display panel includes: a first pixel electrode and a red organic light-emitting layer sequentially disposed in red subpixel region; a second pixel electrode and a green organic light-emitting layer sequentially disposed in green subpixel region; a third pixel electrode and a first blue organic light-emitting layer sequentially disposed in blue subpixel region; a charge generation layer disposed above the red, green, and first blue light-emitting layers; a second blue organic light-emitting layer disposed on the charge generation layer in the entire subpixel regions; a counter electrode disposed above the second blue light-emitting layer in the entire subpixels regions; a first light conversion layer disposed above the second blue light-emitting layer in the red subpixel region, and converts blue light to red light; and a second light conversion layer disposed above the second blue light-emitting layer in the green subpixel region, and converts blue light to green light.

Claims

1. An organic EL display panel that includes pixels each of which is composed of a red subpixel, a green subpixel, and a blue subpixel, the organic EL display panel comprising:

a substrate;

a barrier rib that is disposed on the substrate, and partitions between a red subpixel region, a green subpixel region, and a blue subpixel region of the respective red, green, and blue subpixels;

a first pixel electrode and a red organic light-emitting layer that are disposed above the substrate sequentially from a side of the substrate in the red subpixel region;

a second pixel electrode and a green organic light-emitting layer that are disposed above the substrate sequentially from the side of the substrate in the green subpixel region;

a third pixel electrode and a first blue organic light-emitting layer that are disposed above the substrate sequentially from the side of the substrate in the blue subpixel region;

a charge generation layer that is disposed above the red, green, and first blue organic light-emitting layers;

a second blue organic light-emitting layer that is disposed on the charge generation layer in the red, green, and blue subpixel regions;

a counter electrode of the first, second, and third pixel electrodes that is disposed above the second blue organic light-emitting layer in the red, green, and blue subpixels regions;

a first light conversion layer that is disposed above the second blue organic light-emitting layer in the red subpixel region, and converts blue light to red light; and

a second light conversion layer that is disposed above the second blue organic light-emitting layer in the green subpixel region, and converts blue light to green light.

2. The organic EL display panel of claim 1, wherein

the red, green, and first blue organic light-emitting layers have an organizational structure obtained by a wet process, and

the second blue organic light-emitting layer and the charge generation layer have an organizational structure obtained by a dry process.

3. The organic EL display panel of claim 1, further comprising:

a first filter that is disposed on the first light conversion layer in the red subpixel region, and blocks blue light; and

a second filter that is disposed on the second light conversion layer in the green subpixel region, and blocks blue light.

4. The organic EL display panel of claim 1, further comprising

a third light conversion layer that is disposed above the counter electrode in the blue subpixel region, and converts blue light that is emitted from at least one of the first and second blue organic light-emitting layers in the blue subpixel region to blue light having a different luminescence spectrum from the emitted blue light.

5. The organic EL display panel of claim 1, further comprising

a third filter that is disposed above the counter electrode in the blue subpixel region, and partially blocks blue light that is emitted from at least one of the first and second blue organic light-emitting layers in the blue subpixel region.

6. The organic EL display panel of claim 1, further comprising:

a third light conversion layer that is disposed above the counter electrode in the blue subpixel region, and converts blue light that is emitted from at least one of the first and second blue organic light-emitting layers in the blue subpixel region to blue light having a different luminescence spectrum from the emitted blue light; and

a third filter that is disposed on the third light conversion layer, and partially blocks the blue light that is emitted upwards from the third light conversion layer.

7. The organic EL display panel of claim 1, further comprising:

a first electron transport layer that is disposed between the entire red, green, and first blue organic light-emitting layers and the charge generation layer; and

a second electron transport layer that is disposed between the second blue organic light-emitting layer and the counter electrode in the red, green, and blue subpixel regions, wherein

the second electron transport layer has a larger thickness than the first electron transport layer.

8. The organic EL display panel of claim 1, wherein

the charge generation layer supplies holes to the second blue organic light-emitting layer, and supplies electrons from at least one of respective parts of the red, green, and blue subpixel regions to a corresponding one of the red, green, and first blue organic light-emitting layers in the red, green, and blue subpixel regions, respectively.

9. The organic EL display panel of claim 1, wherein

the charge generation layer is discontinuous above the red, green, and first blue organic light-emitting layers.

10. The organic EL display panel of claim 1, wherein

the second blue organic light-emitting layer is discontinuous in the red, green, and blue subpixel regions.

13. A manufacturing method of the organic EL display panel of claim 1, the manufacturing method comprising the steps of:

forming each of the first, second, third pixel electrodes, the red, green, and first blue organic light-emitting layers by a wet process; and

forming each of the charge generation layer, the second blue organic light-emitting layer, and the counter electrode by a dry process.

14. The manufacturing method of claim 13, wherein

the wet process is one or more of a printing method, a spin coating method, an inkjet method, and a photolithography method, and

the dry process is one or more of a vapor deposition method, a sputtering method, and an ion plating method.

15. The organic EL display panel of claim 1, wherein

the first and second light conversion layers contain a fluorescent colorant which absorbs light emitted from the second blue organic light-emitting layer and which performs wavelength conversion on the light.

16. The organic EL display panel of claim 1, wherein

the first and second light conversion layers include a wavelength converter which converts 30% to 90% of the blue light to red light and green light, respectively.

11. An organic EL display panel that includes pixels each of which is composed of a red subpixel, a green subpixel, and a blue subpixel, the organic EL display panel comprising:

a substrate;

a barrier rib that is disposed on the substrate, and partitions between a red subpixel region, a green subpixel region, and a blue subpixel region of the respective red, green, and blue subpixels;

a first pixel electrode and a red organic light-emitting layer that are disposed above the substrate sequentially from a side of the substrate in the red subpixel region;

a second pixel electrode and a green organic light-emitting layer that are disposed above the substrate sequentially from the side of the substrate in the green subpixel region;

a third pixel electrode and a first blue organic light-emitting layer that are disposed above the substrate sequentially from the side of the substrate in the blue subpixel region;

a charge generation layer that is disposed above the red, green, and first blue organic light-emitting layers;

a second blue organic light-emitting layer that is disposed on the charge generation layer in the red, green, and blue subpixel regions;

a counter electrode of the first, second, and third pixel electrodes that is disposed above the second blue organic light-emitting layer in the red, green, and blue subpixels regions;

a first filter that is disposed above the second blue organic light-emitting layer in the red subpixel region, and blocks blue light; and

a second filter that is disposed above the second blue organic light-emitting layer in the green subpixel region, and blocks blue light.

12. The organic EL display panel of claim 11, further comprising

a third filter that is disposed above the counter electrode in the blue subpixel region, and partially blocks blue light that is emitted from at least one of the first and second blue organic light-emitting layers in the blue subpixel region.