Light-emitting device and electronic device using the same

• US 9,461,258 B2
• Filed: 08/08/2014
• Issued: 10/04/2016
• Est. Priority Date: 12/16/2004
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Seo, Satoshi, Kimura, Hajime, Yamazaki, Shunpei
• Primary Examiner(s): Boddie, William
• Assistant Examiner(s): Shapiro, Leonid
• Application Number:
  US14/455,376
• Publication Number:
  US 20140346538A1
• Time in Patent Office: 788 Days
• US Class Current: 1/1
• CPC Class Codes: G09G 2330/028 Generation of voltages supplied to electrode drivers in a matrix display other than LCD
• CPC Class Codes: G09G 3/2011 by amplitude modulation
• CPC Class Codes: G09G 3/2022 using sub-frames
• CPC Class Codes: G09G 3/2074 using sub-pixels
• CPC Class Codes: G09G 3/2077 by a combination of two or more gradation control methods
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element
• CPC Class Codes: G09G 3/3291 in which the data driver supplies a variable data voltage for setting the current through, or the voltage across, the light-emitting elements
• CPC Class Codes: H10K 2101/10 Triplet emission
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/125 specially adapted for multicolour light emission, e.g. for emitting white light
• CPC Class Codes: H10K 59/351 comprising more than three subpixels, e.g. red-green-blue-white [RGBW]
• CPC Class Codes: H10K 59/353 characterised by the geometrical arrangement of the RGB subpixels

Abstract

It is an object to provide a light-emitting device and an electronic device which can provide an image with excellent image quality. One of the present inventions is a light-emitting device including a plurality of light-emitting elements each exhibiting a different emission color. At least one of the plurality of light-emitting elements has n light-emitting layers (n is a natural number, n≧2) between a pair of electrodes. Further, at least one of the n light-emitting layers includes a substance which provides emission from a triplet excitation state. In a light-emitting device having such a structure, an image is displayed by combining emissions from the plurality of light-emitting elements.

Claims

1. A light-emitting device comprising:

a first light-emitting element comprising a first light-emitting layer between a first electrode and a second electrode;

a second light-emitting element comprising a second light-emitting layer between a third electrode and a fourth electrode;

a third light-emitting element comprising a third light-emitting layer between a fifth electrode and a sixth electrode; and

a fourth light-emitting element comprising the first light-emitting layer, the second light-emitting layer, and the third light-emitting layer between a seventh electrode and an eighth electrode,

wherein the first light-emitting layer is shared by the first light-emitting element and the fourth light-emitting element,

wherein the first light-emitting layer is not included in the second light-emitting element and the third light-emitting element,

wherein the first light-emitting layer is configured to emit a first color,

wherein the second light-emitting layer is configured to emit a second color, and

wherein the third light-emitting layer is configured to emit a third color.

2. The light-emitting device according to claim 1, further comprising a charge generation layer between the first light-emitting layer and the second light-emitting layer in the fourth light-emitting element.

3. The light-emitting device according to claim 1,

wherein the first light-emitting element, the second light-emitting element, and the fourth light-emitting element are arranged in a line in a first direction,

wherein the third light-emitting element and the fourth light-emitting element are arranged in a line in a second direction, and

wherein the first direction is vertical to the second direction.

4. The light-emitting device according to claim 1, wherein the second electrode, the fourth electrode, the sixth electrode, and the eighth electrode are the same layer.

5. The light-emitting device according to claim 1, wherein the second electrode, the fourth electrode, the sixth electrode, and the eighth electrode are electrically connected to one another.

6. The light-emitting device according to claim 1, wherein the first electrode, the third electrode, the fifth electrode, and the seventh electrode are separated from one another.

7. The light-emitting device according to claim 1, wherein at least one of the first light-emitting layer, the second light-emitting layer, and the third light-emitting layer comprises a substance exhibiting emission from a triplet excited state.

8. The light-emitting device according to claim 1, wherein the first color, the second color, and the third color are red, green and blue, respectively.

9. The light-emitting device according to claim 1, wherein the fourth light-emitting element is configured to emit white light.

10. A light-emitting device comprising:

a first light-emitting element comprising a first light-emitting layer between a first electrode and a second electrode;

a second light-emitting element comprising a second light-emitting layer between a third electrode and a fourth electrode; and

a third light-emitting element comprising the first light-emitting layer and the second light-emitting layer between a fifth electrode and a sixth electrode,

wherein the first light-emitting layer is shared by the first light-emitting element and the third light-emitting element,

wherein the first light-emitting layer is not included in the second light-emitting element,

wherein the first light-emitting layer is configured to emit a first color, and

wherein the second light-emitting layer is configured to emit a second color.

11. The light-emitting device according to claim 10, further comprising a charge generation layer between the first light-emitting layer and the second light-emitting layer in the third light-emitting element.

12. The light-emitting device according to claim 10,

wherein the first light-emitting element and the third light-emitting element are arranged in a line in a first direction,

wherein the second light-emitting element and the third light-emitting element are arranged in a line in a second direction, and

wherein the first direction is vertical to the second direction.

13. The light-emitting device according to claim 10, wherein the second electrode, the fourth electrode, and the sixth electrode are the same layer.

14. The light-emitting device according to claim 10, wherein the second electrode, the fourth electrode, and the sixth electrode are electrically connected to one another.

15. The light-emitting device according to claim 10, wherein the first electrode, the third electrode, and the fifth electrode are separated from one another.

16. The light-emitting device according to claim 10, wherein at least one of the first light-emitting layer and the second light-emitting layer comprises a substance exhibiting emission from a triplet excited state.

17. The light-emitting device according to claim 10, wherein the first color and the second color are blue and yellow, respectively.

18. The light-emitting device according to claim 10, wherein the third light-emitting element is configured to emit white light.