Organic EL display

• US 20050253494A1
• Filed: 05/16/2005
• Published: 11/17/2005
• Est. Priority Date: 05/17/2004
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Choi, Hong Seok
• Granted Patent: US 7,755,262 B2
• Time in Patent Office: Days
• US Class Current: 313/112
• CPC Class Codes: G02B 27/28 for polarising used in stereoscopes G02B30/25
• CPC Class Codes: G02B 5/3033 in the form of a thin sheet or foil, e.g. Polaroid
• CPC Class Codes: H10K 50/86 Arrangements for improving contrast, e.g. preventing reflection of ambient light
• CPC Class Codes: H10K 59/8791 Arrangements for improving contrast, e.g. preventing reflection of ambient light

Abstract

An organic EL display having a polarizing plate is disclosed. The present invention includes an organic EL display panel, a first polarizing plate on the panel to convert a circularly or linearly polarized light to a linearly or circularly polarized light, and a second polarizing plate on the first polarizing plate to have a polarization characteristic of absorbing light in a high light efficiency wavelength range more than light in a low light efficiency wavelength range.

Claims

1. An organic EL display comprising:

an organic EL display panel;

a first polarizing plate on the panel to convert a circularly or linearly polarized light to a linearly or circularly polarized light; and

a second polarizing plate on the first polarizing plate to have a polarization characteristic of absorbing light in a high light efficiency wavelength range more than light in a low light efficiency wavelength range.

2. The organic EL display of claim 1, wherein the first polarizing plate is a λ

/4 retarder.

3. The organic EL display of claim 1, wherein the second polarizing plate is a dichroic dye based polarizing plate fabricated by aligning dichroic dye in one direction by extension wherein the dichroic dye has a light absorption characteristic differing according to a light wavelength and a polarized direction.

4. The organic EL display of claim 1, wherein a maximum value of polarization efficiency of the second polarizing plate is tuned to a wavelength corresponding to a maximum value of a visual curve.

5. The organic EL display of claim 1, wherein a maximum value of polarization efficiency of the second polarizing plate is tuned to a wavelength corresponding to a maximum value of an external light.

6. The organic EL display of claim 1, wherein polarization efficiency and transmittance of the second polarizing plate are differently set per a red, green or blue wavelength.

7. The organic EL display of claim 1, wherein the second polarizing plate raises transmittance in ranges of red and blue wavelengths and wherein the second polarizing plate lowers polarization efficiency in the ranges of the red and blue wavelengths.

8. The organic EL display of claim 1, wherein the second polarizing plate raises transmittance in a range of a blue wavelength and wherein the second polarizing plate lowers polarization efficiency in the range of the blue wavelength.

11. The organic EL display of claim 1, wherein a maximum value of polarization efficiency of the dichroic dye based polarizing plate is tuned to a wavelength corresponding to a maximum value of a visual curve.

9. An organic EL display comprising:

a substrate;

an anode on one surface of the substrate;

an organic EL layer on the anode;

a cathode on the organic EL layer;

a λ

/4 retarder on the other surface of the substrate to convert a circularly or linearly polarized light to a linearly or circularly polarized light; and

a dichroic dye based polarizing plate on the λ

/4 retarder to have a polarization characteristic of absorbing light in a high light efficiency wavelength range more than light in a low light efficiency wavelength range.

10. The organic EL display of claim 9, wherein the dichroic dye based polarizing plate is fabricated by aligning dichroic dye in one direction by extension wherein the dichroic dye has a light absorption characteristic differing according to a light wavelength and a polarized direction.

12. The organic EL display of claim 9, wherein polarization efficiency and transmittance of the dichroic dye based polarizing plate are differently set per a red, green or blue wavelength.

13. The organic EL display of claim 12, wherein the dichroic dye based polarizing plate raises transmittance in ranges of red and blue wavelengths and wherein the dichroic dye based polarizing plate lowers polarization efficiency in the ranges of the red and blue wavelengths.

14. The organic EL display of claim 12, wherein the dichroic dye based polarizing plate raises transmittance in a range of a blue wavelength and wherein the dichroic dye based polarizing plate lowers polarization efficiency in the range of the blue wavelength.