Organic light emitting display device

• US 10,644,265 B2
• Filed: 10/12/2016
• Issued: 05/05/2020
• Est. Priority Date: 06/28/2016
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Noh, Seonghee, Lim, YoungNam, Lee, SangHo, Ryu, DaeWon
• Primary Examiner(s): Le, Thao X
• Assistant Examiner(s): Swan, Gardner W. S.
• Application Number:
  US15/291,349
• Publication Number:
  US 20170373277A1
• Time in Patent Office: 1,301 Days
• CPC Class Codes: H10K 2102/00 Constructional details relating to the organic devices covered by this subclass
• CPC Class Codes: H10K 2102/351 Thickness
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/81 Anodes
• CPC Class Codes: H10K 50/82 Cathodes
• CPC Class Codes: H10K 50/844 Encapsulations
• CPC Class Codes: H10K 50/852 comprising a resonant cavity structure, e.g. Bragg reflector pair
• CPC Class Codes: H10K 50/858 comprising refractive means, e.g. lenses
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/873 Encapsulations
• CPC Class Codes: H10K 59/876 comprising a resonant cavity structure, e.g. Bragg reflector pair
• CPC Class Codes: H10K 59/879 comprising refractive means, e.g. lenses

Abstract

An organic light emitting display device has an optical multilayer film on an organic light emitting diode. The organic light emitting display device includes an organic light emitting element with a cathode, an anode, and an organic light emitting layer, and an optical multilayer film on the organic light emitting element. The optical multilayer film is constructed such that a full width at half maximum of light emitted from the organic light emitting element is larger than a full width at half maximum of light emitted from a structure in which the optical multilayer film is not used. The color shift depending on a viewing angle of the organic light emitting display device may be reduced to improve efficiency of the organic light emitting element.

Claims

1. An organic light emitting display device, comprising:

an organic light emitting element including a cathode, an anode, and an organic light emitting layer;

an optical multilayer film with a specific layer stacking order of at least three optical layers including a first optical layer on the cathode, a second optical layer on the first optical layer, and a third optical layer on the second optical layer;

an insulating layer between the organic light emitting element and the optical multilayer film such that a bottom surface of the insulating layer is in direct contact with an upper surface of the cathode, the insulating layer formed of an organic material; and

an atomic deposition layer between the insulating layer and the optical multilayer film such that an upper surface of the atomic deposition layer is in direct contact with a bottom surface of the first optical layer, the atomic deposition layer formed of one or more of silicon oxide SiO_x and aluminum oxide Al₂O₃,

wherein a refractive index of the first optical layer is larger than that of the cathode, and a refractive index of the second optical layer is smaller than those of the first optical layer and the third optical layer,

wherein an upper surface of the insulating layer is in direct contact with a bottom surface of the atomic deposition layer, and wherein the at least three optical layers all have different thicknesses from each other.

2. The organic light emitting display device according to claim 1, further comprising:

a passivation layer in direct contact with the optical multilayer film.

3. The organic light emitting display device according to claim 1, further comprising:

a passivation layer on the optical multilayer film; and

an organic layer between the optical multilayer film and the passivation layer.

4. The organic light emitting display device according to claim 3, wherein a thickness of the passivation layer is between 0.05 μ

m and 1.5 μ

m, and a thickness of the organic layer is between 5 μ

m and 20 μ

m.

5. The organic light emitting display device according to claim 1, wherein:

the organic light emitting display device having the optical multilayer film with the specific layer stacking order exhibits reduced color shift characteristics depending on a viewing angle, when compared to an otherwise identical organic light emitting display device that lacks the optical multilayer film with the specific layer stacking order, and

the color shift characteristics include a spectral full width at half maximum of light emitted from the organic light emitting element being larger than a spectral full width at half maximum of light emitted from the otherwise identical organic light emitting display device.

6. The organic light emitting display device according to claim 1, wherein the optical multilayer film includes a fourth optical layer and a refractive index of the fourth optical layer is smaller than that of the third optical layer.

7. The organic light emitting display device according to claim 6, wherein a thickness of the topmost optical layer among the four optical layers is between 100 nm and 5000 nm.

8. The organic light emitting display device according to claim 1, wherein a thickness of the insulating layer is less than 5 nm so as to hardly apply an optical effect.

9. The organic light emitting display device according to claim 1, wherein the optical multilayer film includes a plurality of optical layers and an optical layer having a relatively small refractive index among the plurality of optical layers is formed of silicon oxynitride (SiON).

10. An organic light emitting display device, comprising:

an organic light emitting element including a cathode, an anode, and an organic light emitting layer;

an optical multilayer film including a first pair composed of a first and a second optical layers and a second pair composed of a third and a fourth optical layers, wherein the first pair and the second pair are sequentially stacked on the organic light emitting element;

an insulating layer between the organic light emitting element and the optical multilayer film such that a bottom surface of the insulating layer is in direct contact with an upper surface of the cathode, the insulating layer formed of an organic material;

an organic layer in direct contact with an upper surface of the fourth optical layer whose thickness is between 5 μ

m and 20 μ

m; and

an atomic deposition layer between the insulating layer and the optical multilayer film such that an upper surface of the atomic deposition layer is in direct contact with a bottom surface of the first optical layer, the atomic deposition layer formed of one or more of silicon oxide SiO_x and aluminum oxide Al₂O₃,

wherein an upper surface of the insulating layer is in direct contact with a bottom surface of the atomic deposition layer, and

wherein two optical layers in each of the first pair and the second pair have different refractive indexes from each other, and a first optical layer having a relatively larger refractive index is located under a second optical layer having a relatively smaller refractive index.

11. The organic light emitting display device according to claim 10, wherein the first optical layer and the second optical layer are sequentially disposed, and the refractive index of the first optical layer is larger than a refractive index of the cathode.

12. The organic light emitting display device according to claim 11, wherein the optical multilayer film further includes another pair of optical layers in which a third optical layer having a relatively larger refractive index and a fourth optical layer having a relatively smaller refractive index are sequentially disposed, and a refractive index of the third optical layer is larger than a refractive index of the second optical layer.

13. The organic light emitting display device according to claim 10, wherein a difference of the refractive indexes of the pair of optical layers is between 0.01 and 0.6.

14. The organic light emitting display device according to claim 10, further comprising:

a functional layer on the organic light emitting layer and configured to reduce separation due to a difference of expansion coefficients of the optical multilayer film and the organic light emitting layer.

15. An organic light emitting display device, comprising:

an organic light emitting element including a cathode;

an optical multilayer film with a specific layer stacking order of at least three optical layers including a first optical layer on the cathode of the organic light emitting element, a second optical layer on the first optical layer, and a third optical layer on the second optical layer;

an insulating layer between the organic light emitting element and the optical multilayer film such that a bottom surface of the insulating layer is in direct contact with an upper surface of the cathode, the insulating layer formed of an organic material;

an organic layer on the optical multilayer film whose thickness is between 5 μ

m and 20 μ

m; and

an atomic deposition layer between the insulating layer and the optical multilayer film such that a bottom surface of the atomic deposition layer is in direct contact with an upper surface of the insulating layer, the atomic deposition layer formed of one or more of silicon oxide SiO_x and aluminum oxide Al₂O₃,

wherein a refractive index of the first optical layer is larger than a refractive index of the second optical layer and the cathode, which provides a spectral full width at half maximum of light emitted from the organic light emitting element to be larger than a spectral full width at half maximum of light emitted from an otherwise identical organic light emitting display device in which the optical multilayer film is not present.

16. The organic light emitting display device according to claim 15, wherein the refractive index of the second optical layer is smaller than a refractive index of the third optical layer.

17. The organic light emitting display device according to claim 16, wherein the optical multilayer film further includes a fourth optical layer on the third optical layer and the refractive index of the third optical layer is larger than a refractive index of the fourth optical layer.