Light emitting device, driving method of light emitting device and electronic device

Patent metadata

Field	Value
Publication number	US-9847381-B2
Application number	US-201615340074-A
Country	US
Kind code	B2
Filing date	Nov 1, 2016
Priority date	Sep 21, 2001
Publication date	Dec 19, 2017
Grant date	Dec 19, 2017

Abstract

By controlling the luminance of light emitting element not by means of a voltage to be impressed to the TFT but by means of controlling a current that flows to the TFT in a signal line drive circuit, the current that flows to the light emitting element is held to a desired value without depending on the characteristics of the TFT. Further, a voltage of inverted bias is impressed to the light emitting element every predetermined period. Since a multiplier effect is given by the two configurations described above, it is possible to prevent the luminance from deteriorating due to a deterioration of the organic luminescent layer, and further, it is possible to maintain the current that flows to the light emitting element to a desired value without depending on the characteristics of the TFT.

First claim

What is claimed is:

1. A display device comprising:
a semiconductor layer including a first channel region and a second channel region;
a first gate electrode overlapping the first channel region;
a second gate electrode overlapping the second channel region;
a first insulating film over the semiconductor layer, the first gate electrode and the second gate electrode;
a first connection wiring over the first insulating film;
a second connection wiring over the first insulating film;
a pixel electrode electrically connected to the first connection wiring;
a light emitting layer over the pixel electrode;
a cathode over the light emitting layer,
wherein the first connection wiring and the second connection wiring can be electrically conductive with each other through the first channel region and the second channel region.

2. The display device according to claim 1 , further comprising a base film under the semiconductor layer.

3. The display device according to claim 1 , wherein the first insulating film includes a silicon oxide film, a silicon nitride oxide film, a silicon nitride film, or a laminated film of a combination thereof.

4. A display module comprising an FPC and the display device according to claim 1 .

5. An electronic device comprising an operation key, a main body, a speaker portion and the display module according to claim 4 .

6. A display device comprising:
a semiconductor layer including a first channel region and a second channel region;
a first gate electrode overlapping the first channel region;
a second gate electrode overlapping the second channel region;
a first insulating film over the semiconductor layer, the first gate electrode and the second gate electrode;
a first connection wiring over the first insulating film;
a second connection wiring over the first insulating film;
a pixel electrode electrically connected to the first connection wiring;
a light emitting layer over the pixel electrode;
a cathode over the light emitting layer,
wherein the first connection wiring and the second connection wiring can be electrically conductive with each other through the first channel region and the second channel region,
wherein the first gate electrode is provided in a different conductive layer from the second gate electrode.

7. The display device according to claim 6 , further comprising a base film under the semiconductor layer.

8. The display device according to claim 6 , wherein the first insulating film includes a silicon oxide film, a silicon nitride oxide film, a silicon nitride film, or a laminated film of a combination thereof.

9. A display module comprising an FPC and the display device according to claim 6 .

10. An electronic device comprising an operation key, a main body, a speaker portion and the display module according to claim 9 .

11. A display device comprising:
a semiconductor layer including a first channel region and a second channel region;
a first gate electrode overlapping the first channel region;
a second gate electrode overlapping the second channel region;
a first insulating film over the semiconductor layer, the first gate electrode and the second gate electrode;
a first connection wiring over the first insulating film;
a second connection wiring over the first insulating film;
a pixel electrode electrically connected to the first connection wiring;
a light emitting layer over the pixel electrode;
a cathode over the light emitting layer,
wherein the first connection wiring and the second connection wiring can be electrically conductive with each other through the first channel region and the second channel region, and
wherein a potential of the first gate electrode is independently controlled from a potential of the second gate electrode.

12. The display device according to claim 11 , further comprising a base film under the semiconductor layer.

13. The display device according to claim 11 , wherein the first insulating film includes a silicon oxide film, a silicon nitride oxide film, a silicon nitride film, or a laminated film of a combination thereof.

14. A display module comprising an FPC and the display device according to claim 11 .

15. An electronic device comprising an operation key, a main body, a speaker portion and the display module according to claim 14 .

Assignees

• Semiconductor Energy Lab

Inventors

• Yamazaki Shunpei
• Akiba Mai
• Koyama Jun

Classifications

• G09G2300/0866

  by means of changes in the pixel supply voltage · CPC title

• G09G2300/0861

  with additional control of the display period without amending the charge stored in a pixel memory, e.g. by means of additional select electrodes · CPC title

• G09G2300/0426

  Layout of electrodes and connections · CPC title

• G09G2320/0233

  Improving the luminance or brightness uniformity across the screen · CPC title

• G09G2330/045

  Protection against panel overheating · CPC title