Organic light emitting display panel and method of manufacturing the same

• US 9,601,709 B2
• Filed: 12/03/2015
• Issued: 03/21/2017
• Est. Priority Date: 03/18/2015
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Group)
• Original Assignee: Samsung Display Company Limited (Samsung Group)
• Inventors: Kitabayashi, Atsushi
• Primary Examiner(s): Lebentritt, Michael
• Application Number:
  US14/957,750
• Publication Number:
  US 20160276615A1
• Time in Patent Office: 474 Days
• Field of Search: None
• US Class Current: 1/1
• 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 50/852 comprising a resonant cavity structure, e.g. Bragg reflector pair
• CPC Class Codes: H10K 59/122 Pixel-defining structures or layers, e.g. banks
• CPC Class Codes: H10K 59/30 Devices specially adapted for multicolour light emission
• CPC Class Codes: H10K 59/352 the areas of the RGB subpixels being different
• 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: H10K 71/12 using liquid deposition, e.g. spin coating

Abstract

An exemplary embodiment discloses an organic light emitting display panel including a base substrate comprising first pixels configured to emit a light having a first wavelength and second pixels configured to emit a light having a second wavelength and a pixel definition layer disposed on the base substrate. The pixel definition layer includes first and second openings. The first opening corresponds to light emitting areas of n (n is a natural number equal to or greater than 2) first pixels among the first pixels. The second opening corresponds to light emitting areas of m (m is a natural number equal to or greater than 1 and smaller than n) second pixels among the second pixels. An area of the light emitting area of each of the first pixels is smaller than an area of the light emitting area of each of the second pixels.

Claims

1. An organic light emitting display panel comprising:

a base substrate comprising first pixels configured to emit a light having a first wavelength and second pixels configured to emit a light having a second wavelength; and

a pixel definition layer disposed on the base substrate, the pixel definition layer comprising first and second openings, wherein the first opening corresponds to light emitting areas of n (n is a natural number equal to or greater than

     2) first pixels among the first pixels, the second opening corresponds to light emitting areas of m (m is a natural number equal to or greater than 1 and smaller than n) second pixels among the second pixels, and an area of the light emitting area of each of the first pixels is smaller than an area of the light emitting area of each of the second pixels.

2. The organic light emitting display panel of claim 1, wherein the base substrate further comprises third pixels configured to emit a light having a third wavelength, the pixel definition layer further comprises a third opening, the third opening corresponds to light emitting areas of k (k is a natural number equal to or greater than 1 and smaller than m) third pixels, and the area of the light emitting area of each of the second pixels is smaller than an area of the light emitting area of each of the third pixels.

3. The organic light emitting display panel of claim 2, wherein the first wavelength is longer than the second wavelength and the second wavelength is longer than the third wavelength.

4. The organic light emitting display panel of claim 3, wherein the light emitting area of each of the first pixels is defined by an area in which a first anode disposed on the base substrate is overlapped with a first light emitting layer disposed on the first anode, the light emitting area of each of the second pixels is defined by an area in which a second anode disposed on the base substrate is overlapped with a second light emitting layer disposed on the second anode, and the light emitting area of each of the third pixels is defined by an area in which a third anode disposed on the base substrate is overlapped with a third light emitting layer disposed on the third anode.

5. The organic light emitting display panel of claim 4, wherein the first opening is configured to expose the n first anodes and areas defined between the n first anodes of the base substrate, the second opening is configured to expose the m second anodes and areas defined between the m second anodes of the base substrate, and the third opening is configured to expose the k third anodes and areas defined between the k third anodes of the base substrate.

6. The organic light emitting display panel of claim 5, further comprising:

a cathode disposed on the first, second, and third light emitting layers, wherein a first length measured from the first anode to the cathode along a thickness direction of the first light emitting layer is longer than a second length measured from the second anode to the cathode along the thickness direction of the second light emitting layer, and the second length measured from the second anode to the cathode along the thickness direction of the second light emitting layer is longer than a third length measured from the third anode to the cathode along the thickness direction of the third light emitting layer.

7. The organic light emitting display panel of claim 6, wherein the n is 4, the m is 2, and the k is 1.

8. The organic light emitting display panel of claim 6, wherein the n first pixels are arranged in a first line, the m second pixels are arranged in a second line, and an arrangement direction in which the n first pixels are arranged is equal to the arrangement direction in which the m second pixels area are arranged.

9. The organic light emitting display panel of claim 6, wherein the n first pixels are arranged in two first lines and the second pixels are arranged in a second line.

10. The organic light emitting display panel of claim 9, wherein a direction in which the n first pixels are arranged is equal to the direction in which the m second pixels are arranged.

11. The organic light emitting display panel of claim 10, comprising:

first pixel columns in which the first pixels are arranged in the first line;

second pixel columns in which the second pixels are arranged in a second line; and

third pixel columns in which the third pixels are arranged in a third line, wherein one first pixel column of the first pixel columns is disposed between another first pixel column and one second pixel column of the second pixel columns, one second pixel column of the second pixel columns is disposed between one first pixel column and one third pixel column of the third pixel columns, and one third pixel column of the third pixel columns is disposed between another third pixel column and one second pixel column of the second pixel columns.

12. The organic light emitting display panel of claim 6, wherein the n first pixels are arranged in two rows by two columns and the m second pixels are arranged in two rows by one column.

13. The organic light emitting display panel of claim 12, comprising:

a first pixel row in which two first pixels are alternately arranged with two second pixels; and

a second pixel row in which the third pixels are arranged in a line, wherein a first pixel of the first pixel row is disposed adjacent to the second and third pixels of the second pixel row to form one pixel group.

14. A method of manufacturing an organic light emitting display panel, comprising:

disposing an anode layer comprising first anodes and second anodes, each second anode having an area greater than each of the first anodes on a base substrate;

disposing a pixel definition layer comprising a first opening exposing n (n is a natural number equal to or greater than

     2) first anodes of the first anodes and a second opening exposing m (m is a natural number equal to or greater than 1 and smaller than n) second anodes of the second anodes;

disposing a liquefied material to areas corresponding to the first and second openings to form hole transport regions on the n first anodes and the m second anodes;

disposing a first liquefied organic material to an area corresponding to the first opening to form a first light emitting layer and a second liquefied organic material to an area corresponding to the second opening to form a second light emitting layer;

disposing electron transport regions on the first and second light emitting layers; and

disposing a cathode on the electron transport regions.

15. The method of claim 14, wherein:

the anode layer further comprises third anodes, each of the third anodes having an area greater than each of the second anodes, and

the pixel definition layer further comprises a third opening to expose k (k is a natural number equal to or greater than 1 and smaller than m) of the third anodes,

the method further comprising;

disposing a third liquefied organic material corresponding to the third opening to form a third light emitting layer; and

disposing a liquefied material to an area corresponding to the third opening to form the hole transport regions on the k third anodes.

16. The method of claim 15, wherein the disposing of the electron transport regions comprises disposing a liquefied material on the first, second, and third light emitting layers to form the electron transport regions.

17. The method of claim 16, wherein:

the first light emitting layer formed by the first organic material to emit a light having a first wavelength;

the second light emitting layer formed by the second organic material to emit a light having a second wavelength; and

the third light emitting layer formed by the third organic material to emit a light having a third wavelength, the first wavelength is longer than the second wavelength, and the second wavelength is longer than the third wavelength.

18. The method of claim 17, wherein the n first anodes are arranged in a first line and the m second anodes are arranged in a second line.

19. The method of claim 17, wherein the n first anodes are arranged in two first lines and the m second anodes are arranged in a second line.

20. The method of claim 17, wherein the n is 4, the m is 2, the n first anodes are arranged in two rows by two columns, and the m second anodes are arranged in two rows by one column.