Light emitting device and manufacturing method thereof

• US 6,717,359 B2
• Filed: 01/29/2002
• Issued: 04/06/2004
• Est. Priority Date: 01/29/2001
• Status: Expired due to Term

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Kimura, Hajime
• Primary Examiner(s): O'Shea, Sandra
• Assistant Examiner(s): Dong, Dalei
• Application Number:
  US10/061,018
• Publication Number:
  US 20020101155A1
• Time in Patent Office: 798 Days
• Field of Search: 313/506, 313/498, 313/505, 313/499, 313/500, 313/501, 257/79, 257/88, 257/91, 257/93, 257/99
• US Class Current: 313/506
• CPC Class Codes: H10K 50/82 Cathodes
• 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 59/8052 Cathodes
• CPC Class Codes: H10K 59/8791 Arrangements for improving contrast, e.g. preventing reflection of ambient light

Abstract

There is provided a technique for obtaining a light emitting device in which no copy-in is caused in the case of a method of manufacturing a light emitting device having a glossy cathode. When an uneven portion is formed on the surface of a cathode which is in contact with an organic layer in a pixel portion, incident light is reflected in all directions. Further, since an insulating film having a high light absorption property is formed in a driver circuit portion, the copy-in becomes invisible to the observer.

Claims

1. A light emitting device comprising:

at least a transparent protrusion;

a pixel electrode over and along the transparent protrusion;

an organic layer over the pixel electrode and in contact with a portion of the pixel electrode; and

a cathode over and along the organic layer,

wherein a surface of the cathode in contact with the organic layer is uneven by forming the transparent protrusion.

2. A device according to claim 1, further comprising:

an insulating film in a transverse direction of the transparent protrusion,

wherein the insulating film has a high light absorption property.

3. A device according to claim 1,

wherein the transparent protrusion is a microlens.

4. A device according to claim 1,

wherein the light emitting device is combination with an electrical apparatus,

wherein the electrical apparatus is one selected from the group consisting of a personal computer, a video camera, a portable information terminal, a digital camera, a digital video disk player, a monitor for viewing the rear of a car for an automobile, a television telephone, a car navigation system, and an electronic game device.

5. A light emitting device comprising:

a plurality of transparent protrusions over a transparent substrate;

a transparent pixel electrode over said plurality of transparent protrusions;

a light emitting layer comprising an organic material over said transparent pixel electrode; and

a cathode over said pixel electrode with the light emitting layer interposed therebetween.

6. A device according to claim 5, wherein said light emitting device is active matrix type.

7. A device according to claim 5, wherein said transparent substrate is selected from the group consisting of an amorphous glass, a crystallized glass, a ceramics glass, a glass, and a polymer.

8. A device according to claim 7, wherein said amorphous glass is a borosilicate glass or a quartz.

9. A device according to claim 5, wherein said plurality of transparent protrusion are acrylic materials.

10. A device according to claim 5, wherein said plurality of transparent protrusion are micro lenses.

11. An active matrix type light emitting device comprising:

a thin film transistor provided over a transparent substrate;

an insulating film having an opening provided over said thin film transistor;

a plurality of transparent protrusions formed in said opening;

a transparent pixel electrode provided over said plurality of transparent protrusions;

a light emitting layer comprising an organic material over said transparent pixel electrode; and

a cathode over said pixel electrode with the light emitting layer interposed therebetween;

wherein said thin film transistor is electrically connected to said transparent pixel electrode.

12. A device according to claim 11, wherein said insulating film has a high light absorption property.

13. A device according to claim 11, wherein said transparent substrate is selected from the group consisting of an amorphous glass, a crystallized glass, an ceramics glass, a glass, and a polymer.

14. A device according to claim 13, wherein said amorphous glass is a borosilicate glass or a quartz.

15. A device according to claim 11, wherein the plurality of transparent protrusion are acrylic materials.

16. A device according to claim 11, wherein the plurality of transparent protrusion are micro lenses.

17. An active matrix type light emitting device comprising:

a thin film transistor over a transparent substrate;

a transparent insulating film over said thin film transistor;

a transparent pixel electrode connected to said thin film transistor electrically;

a light emitting layer comprising an organic material over said transparent pixel electrode; and

,

a cathode over said pixel electrode with the light emitting layer interposed therebetween;

wherein a plurality of transparent protrusions are interposed between said transparent insulating film and said transparent insulating film.

18. A device according to claim 17, wherein said plurality of transparent protrusions and an insulating film having a high light absorption property are in the same layer.

19. A device according to claim 17, wherein said transparent substrate is selected from the group consisting of an amorphous glass, a crystallized glass, a ceramics glass, a glass, and a polymer.

20. A device according to claim 19, wherein an amorphous glass is a borosilicate glass or a quartz.

21. A device according to claim 17, wherein the plurality of transparent protrusions are acrylic materials.

22. A device according to claim 17, wherein the plurality of transparent protrusions are microlenses.