ORGANIC LIGHT EMITTING DIODE DISPLAY

• US 20110037683A1
• Filed: 01/29/2010
• Published: 02/17/2011
• Est. Priority Date: 08/13/2009
• Status: Abandoned Application

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Mobile Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: JEONG, Hee-Seong, KWAK, Noh-Min, KIM, Eun-Ah, PARK, Soon-Ryong, JEON, Hee-Chul, JEONG, Chul-Woo, LEE, Joo-Hwa, KIM, Jae-Yong, JUNG, Woo-Suk
• Application Number:
  US12/696,871
• Publication Number:
  US 20110037683A1
• Time in Patent Office: Days
• US Class Current: 345/76
• CPC Class Codes: G02F 1/1396 the liquid crystal being selectively controlled between a twisted state and a non-twisted state, e.g. TN-LC cell G02F1/141 takes precedence
• 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 59/50 OLEDs integrated with light modulating elements, e.g. with electrochromic elements, photochromic elements or liquid crystal elements

Abstract

An organic light emitting diode display includes a substrate main body, an organic light emitting diode including a first electrode, an organic emissive layer, and a second electrode sequentially arranged on the substrate main body, a selective reflection layer arranged on the organic light emitting diode, a phase retardation film arranged on the selective reflection layer, a first linear polarizing film arranged on the phase retardation film, a twisted nematic liquid crystal layer arranged on the first linear polarizing film, a liquid crystal driving electrode arranged on the twisted nematic liquid crystal layer and a second linear polarizing film arranged on the liquid crystal driving electrode.

Claims

1. An organic light emitting diode display, comprising:

a substrate main body;

an organic light emitting diode including a first electrode, an organic emissive layer, and a second electrode sequentially arranged on the substrate main body;

a selective reflection layer arranged on the organic light emitting diode;

a phase retardation film arranged on the selective reflection layer;

a first linear polarizing film arranged on the phase retardation film;

a twisted nematic liquid crystal layer arranged on the first linear polarizing film;

a liquid crystal driving electrode arranged on the twisted nematic liquid crystal layer; and

a second linear polarizing film arranged on the liquid crystal driving electrode.

2. The organic light emitting diode display of claim 1, wherein when the organic light emitting diode is emitting light, an electric field is applied between the second electrode of the organic light emitting diode and the liquid crystal driving electrode, and when the organic light emitting diode is not emitting light, no electric field is applied between the second electrode of the organic light emitting diode and the liquid crystal driving electrode.

3. The organic light emitting diode display of claim 2, wherein when an electric field is applied between the second electrode of the organic light emitting diode and the liquid crystal driving electrode, liquid crystal molecules within the twisted nematic liquid crystal layer are vertically oriented in a direction crossing the liquid crystal driving electrode.

4. The organic light emitting diode display of claim 3, wherein external light linearly polarized by passing through the second linear polarizing film transparently passes through the twisted nematic liquid crystal layer and the first linear polarizing film.

5. The organic light emitting diode display of claim 3, wherein light produced by the organic light emitting diode and linearly polarized by passing through the first linear polarizing film transparently passes through the twisted nematic liquid crystal layer and the second linear polarizing film.

6. The organic light emitting diode display of claim 2, wherein when no electric field is applied between the second electrode of the organic light emitting diode and the liquid crystal driving electrode, liquid crystal molecules within the twisted nematic liquid crystal layer are horizontally oriented while being twisted by 90 degrees.

7. The organic light emitting diode display of claim 6, wherein, among the horizontally oriented liquid crystal molecules, the liquid crystal molecules arranged closest to the liquid crystal driving electrode and the liquid crystal molecules arranged closest to the first linear polarizing film are twisted by 90 degrees with respect to each other.

8. The organic light emitting diode display of claim 7, wherein among the horizontally oriented liquid crystal molecules, the orientation direction of the liquid crystal molecules arranged closest to the liquid crystal driving electrode coincides with the direction of the polarizing axis of the second linear polarizing film.

9. The organic light emitting diode display of claim 7, wherein among the horizontally oriented liquid crystal molecules, the orientation direction of the liquid crystal molecules arranged closest to the first linear polarizing film form a 90 degree angle with a direction of the polarizing axis of the first linear polarizing film.

10. The organic light emitting diode display of claim 7, wherein the direction of the axis of polarization of external light passing through the twisted nematic liquid crystal layer crosses a direction of the polarizing axis of the first linear polarizing film.

11. The organic light emitting diode display of claim 1, wherein the direction of the polarizing axis of the first linear polarizing film coincides with the direction of the polarizing axis of the second linear polarizing film.

12. The organic light emitting diode display of claim 11, wherein the selective reflection layer is a cholesteric liquid crystal (CLC) layer.

13. The organic light emitting diode display of claim 11, wherein the selective reflection layer passes one of the left-circular polarized light and the right-circular polarized light while reflecting the other.

14. The organic light emitting diode display of claim 11, wherein external light linearly polarized by passing through the first linear polarizing film becomes circularly polarized upon passing through the phase retardation film

15. The organic light emitting diode display of claim 14, wherein the circular polarized light passing through the phase retardation film transparently passes through the selective reflection layer.

16. The organic light emitting diode display of claim 11, wherein the phase retardation film is a ¼

wavelength film, and the polarizing axis of the phase retardation film forms a 45 degree angle to the polarizing axis of the first linear polarizing film.

17. The organic light emitting diode display of claim 11, wherein light produced by the organic light emitting diode and circularly polarized by passing through the selective reflection layer becomes linearly polarized in a same direction as the direction of the polarizing axis of the first linear polarizing film upon passing through the phase retardation film.

18. The organic light emitting diode display of claim 11, wherein the organic light emitting diode emits light in a direction of the twisted nematic liquid crystal layer.