Light emitting device used for display device

• US 6,057,647 A
• Filed: 12/22/1998
• Issued: 05/02/2000
• Est. Priority Date: 02/24/1998
• Status: Expired due to Term

• Current Assignee: Solas OLED Limited (Atlantic IP Services Limited)
• Original Assignee: Casio Computer Company Limited
• Inventors: Kurosawa, Hiroshi, Shirasaki, Tomoyuki, Jobetto, Hiroyasu
• Primary Examiner(s): Philogene, Haissa
• Application Number:
  US09/218,278
• Time in Patent Office: 497 Days
• Field of Search: 315/169.3, 315/169.1, 315/167, 313/505, 313/506, 313/509, 313/512, 313/498, 313/292, 313/257, 313/268
• US Class Current: 315/169.3
• CPC Class Codes: G09G 2300/0809 Several active elements per pixel in active matrix panels
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 3/3208 organic, e.g. using organic light-emitting diodes [OLED]
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/122 Pixel-defining structures or layers, e.g. banks
• CPC Class Codes: H10K 59/173 comprising banks or shadow masks

Abstract

In the present invention, a partition wall having a matrix shape is formed on anode electrodes so as to divide them further into dots of a small region, which are surrounded by the partition wall. With this structure, if a dark spot which is a non-light emitting region, is created in one dot, the growth of the spot can be stopped by the partition wall. Therefore, good display property can be maintained for a long time.

Claims

1. A display device having a plurality of pixels each comprising:

a first electrode;

a partition wall having a plurality of openings, formed on said first electrode;

a plurality of light emitting layers surrounded by said partition wall, formed respectively in said plurality of openings of said partition wall;

a plurality of conductive layers surrounded by said partition wall, formed respectively on said plurality of light emitting layers; and

a second electrode formed to cover said plurality of conductive layers and said partition wall.

2. A display device according to claim 1, wherein said plurality of conductive layers are separated from each other by said partition wall.

3. A display device according to claim 1, wherein said partition wall is formed thicker than a sum of a thickness of said light emitting layers and a thickness of said conductive layers.

4. A display device according to claim 1, wherein said second electrode is made thicker than said partition wall.

5. A display device according to claim 1, wherein said partition wall contains an electro-insulator.

6. A display device according to claim 1, wherein said partition wall contains an electro-conductive material.

7. A display device according to claim 1, wherein said plurality of light emitting layers are made of an organic electroluminescent material.

8. A display device according to claim 1, wherein said plurality of conductive layers are made of a single metal such as lithium or magnesium, or an alloy containing said single metal.

9. A display device according to claim 1, wherein said second electrode is made of a single metal such as aluminum or chromium, or an alloy containing said single metal.

10. A display device according to claim 1, wherein said second electrode is a cathode.

11. A display device according to claim 1, further comprising:

an address driver circuit for outputting an address signal;

a data driver circuit for outputting a data signal;

a plurality of selection transistors connected to said address driver circuit and said data driver circuit; and

a plurality of drive transistors, a gate of one of which is connected a respective one of the selection transistor, and a source of that one of which is connected to one of said first electrode and said second electrode.

12. A display device according to claim 11, wherein said first electrode, said partition wall, said plurality of light emitting layers, said plurality of conductive layers and said second electrode are formed on an insulation film formed on said elective transistors and said drive transistors.

13. A display device comprising:

a plurality of anodes;

a plurality of cathodes;

wherein one of said plurality of anodes and one of said plurality of cathodes cross to make a region which functions as a pixel,

a partition wall having a plurality of openings to expose the anode, formed on each pixel;

light emitting layers formed in said plurality of openings of said partition wall, to be separated from each other; and

electro-conductive layers formed on said light emitting layers formed in said plurality of openings of said partition wall, to be separated from each other;

wherein said cathodes covers the electro-conductive layers and said partition wall.