Light-emitting element and display device using same

• US 8,049,405 B2
• Filed: 12/04/2009
• Issued: 11/01/2011
• Est. Priority Date: 12/12/2002
• Status: Expired due to Term

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Hitachi Displays Limited (Japan Display Incorporated)
• Inventors: Nishimura, Etsuko, Adachi, Masaya, Murakami, Hajime, Tsuji, Kazutaka
• Primary Examiner(s): Williams; Joseph L
• Application Number:
  US12/631,326
• Publication Number:
  US 20100135040A1
• Time in Patent Office: 697 Days
• Field of Search: 313500-512, 257/40, 257/72
• US Class Current: 313/503
• CPC Class Codes: H05B 33/02 Details
• CPC Class Codes: H05B 33/04 Sealing arrangements , e.g. against humidity
• CPC Class Codes: H05B 33/14 characterised by the chemical or physical composition or the arrangement of the electroluminescent material , or by the simultaneous addition of the electroluminescent material in or onto the light source
• CPC Class Codes: H05B 33/22 characterised by the chemical or physical composition or the arrangement of auxiliary dielectric or reflective layers
• CPC Class Codes: H10K 2102/3026 Top emission
• CPC Class Codes: H10K 2102/321 Inverted OLED, i.e. having cathode between substrate and anode
• CPC Class Codes: H10K 50/805 Electrodes
• CPC Class Codes: H10K 50/81 Anodes
• CPC Class Codes: H10K 50/82 Cathodes
• CPC Class Codes: H10K 50/828 Transparent cathodes, e.g. comprising thin metal layers
• CPC Class Codes: H10K 50/84 Passivation; Containers; Encapsulations
• CPC Class Codes: H10K 50/841 Self-supporting sealing arrangements
• CPC Class Codes: H10K 50/8426 Peripheral sealing arrangements, e.g. adhesives, sealants
• CPC Class Codes: H10K 50/8428 Vertical spacers, e.g. arranged between the sealing arrangement and the OLED
• CPC Class Codes: H10K 50/85 Arrangements for extracting light from the devices
• CPC Class Codes: H10K 50/856 comprising reflective means
• CPC Class Codes: H10K 50/858 comprising refractive means, e.g. lenses
• CPC Class Codes: H10K 50/86 Arrangements for improving contrast, e.g. preventing reflection of ambient light
• CPC Class Codes: H10K 59/1213 the pixel elements being TFTs
• CPC Class Codes: H10K 59/1216 the pixel elements being capacitors
• CPC Class Codes: H10K 59/122 : Pixel-defining structures or layers, e.g. banks
• CPC Class Codes: H10K 59/123 : Connection of the pixel electrodes to the thin film transistors [TFT]
• CPC Class Codes: H10K 59/124 : Insulating layers formed between TFT elements and OLED elements
• CPC Class Codes: H10K 59/35 : comprising red-green-blue [RGB] subpixels
• CPC Class Codes: H10K 59/38 : comprising colour filters or colour changing media [CCM]

Abstract

A self light emitting display device having high level of the external coupling efficiency and high grade image presentation as no optical cross-talk or blur can be obtained by a new light-emitting element. The device is constructed as follows. A plurality of picture elements, each of which picture elements has an organic layer composing light emitting areas, a transparent electrode and a reflective electrodes, are formed on a substrate. Between the picture elements, a bank which has a tilted reflective surface is formed so that the light emitting area is surrounded by the bank wherein the transparent optical waveguide layer is formed as optically isolated for each of the picture elements.

Claims

1. A light-emitting device having a flat surface at least a portion therein;

and

a bank provided at least in a peripheral area surrounding the flat surface or on the flat surface of the light-emitting device, wherein

the bank comprises a tilted surface tilted relative to the flat surface,

a reflective surface is provided on this tilted surface,

an optical waveguide layer is provided in an area surrounded by the tilted surface, and

the optical waveguide layer is transparent, has a refractive index larger than that of air, and has a thinness larger than 1μ

.

2. The light-emitting device according to claim 1, wherein a cross sectional area of the optical waveguide layer becomes wider as a distance from the flat surface of the light-emitting device becomes farther.

3. The light-emitting device according to claim 1, wherein the optical waveguide layer is optically isolated per the bank.

4. The light-emitting device according to claim 1, wherein the optical waveguide layer comprises a transparent inorganic material that has gas-barrier characteristics.

5. A light-emitting device comprising:

a light-emitting element having a flat surface disposed at least on a portion thereon, and

a bank disposed on the flat surface or on a periphery of the flat surface of the light-emitting element;

wherein the bank has a tilted surface having a tilt angle against the flat surface;

a reflective surface is formed on the tilted surface;

an optical waveguide layer is formed within an area surrounded by the tilted surface, is transparent, and is optically separated by the bank;

a refractive index of the optical waveguide layer is larger than the refractive index of air;

the light-emitting element includes a light-emitting layer; and

a height of the optical waveguide layer from the flat surface of the light-emitting layer becomes a minimum at a center of the area surrounded by the tilted surface.

6. A light-emitting device comprising:

a light-emitting element having a flat surface disposed at least on a portion thereon, and

a bank disposed on the flat surface or on a periphery of the flat surface of the light-emitting element;

wherein the bank has a tilted surface having a tilt angle against the flat surface;

a reflective surface is formed on the tilted surface;

an optical waveguide layer is formed within an area surrounded by the tilted surface, is transparent, and is optically separated by the bank;

a refractive index of the optical waveguide layer is larger than the refractive index of air;

the light-emitting element include as a light-emitting layer; and

a height of the optical waveguide layer from the flat surface of the light-emitting layer becomes a maximum at a center of the area surrounded by the tilted surface.

7. A light-emitting device comprising:

a light-emitting element having a flat surface disposed at least on a portion thereon, and

a bank disposed on the flat surface or on a periphery of the flat surface of the light-emitting element;

wherein the bank has a tilted surface having a tilt angle against the flat surface;

a reflective surface is formed on the tilted surface;

an optical waveguide layer is formed within an area surrounded by the tilted surface, is transparent, and is optically separated by the bank;

a refractive index of the optical waveguide layer is larger than the refractive index of air;

the light-emitting element includes a blue light-emitting layer; and

the optical waveguide layer includes a color changing medium layer consisting of fluorescent dye that converts blue light emitting from the blue light-emitting layer to a green or a red light.

8. A light-emitting device comprising:

a light-emitting element having a flat surface disposed at least on a portion thereon, and

a bank disposed on the flat surface or on a periphery of the flat surface of the light-emitting element;

wherein the bank has a tilted surface having a tilt angle against the flat surface;

a reflective surface is formed on the tilted surface;

an optical waveguide layer is formed within an area surrounded by the tilted surface, is transparent, and is optically separated by the bank;

the light-emitting element includes a light-emitting layer; and

a pigment is mixed and dispersed in the optical waveguide layer.