Display device

• US 8,400,379 B2
• Filed: 05/25/2012
• Issued: 03/19/2013
• Est. Priority Date: 04/18/2000
• Status: Expired due to Term

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei, Koyama, Jun, Osame, Mitsuaki, Osada, Mai
• Primary Examiner(s): OSORIO, RICARDO
• Application Number:
  US13/480,545
• Publication Number:
  US 20120235155A1
• Time in Patent Office: 298 Days
• Field of Search: 345 76- 84, 315/169.3
• US Class Current: 345/76
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2300/0866 by means of changes in the pixel supply voltage
• CPC Class Codes: G09G 2310/0251 Precharge or discharge of pixel before applying new pixel voltage
• CPC Class Codes: G09G 2310/0262 The addressing of the pixel, in a display other than an active matrix LCD, involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependent on signals of two data electrodes
• CPC Class Codes: G09G 2310/027 Details of drivers for data electrodes, the drivers handling digital grey scale data, e.g. use of D/A converters
• CPC Class Codes: G09G 2310/0281 Arrangement of scan or data electrode driver circuits at the periphery of a panel not inherent to a split matrix structure
• CPC Class Codes: G09G 2320/029 by monitoring one or more pixels in the display panel, e.g. by monitoring a fixed reference pixel
• CPC Class Codes: G09G 2320/041 Temperature compensation
• CPC Class Codes: G09G 2320/043 Preventing or counteracting the effects of ageing
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2330/028 Generation of voltages supplied to electrode drivers in a matrix display other than LCD
• CPC Class Codes: G09G 3/2022 using sub-frames
• CPC Class Codes: G09G 3/3258 with pixel circuitry controlling the voltage across the light-emitting element
• CPC Class Codes: G09G 3/3266 Details of drivers for scan electrodes
• 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 59/00 Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays

Abstract

The present invention is intended to suppress power consumption of an EL display. In accordance with the brightness of an image to be displayed in a pixel portion, the contrast of the image is determined whether to be inverted or not, and the number of bits of the digital video signal to be input into the pixel portion is reduced, and the magnitude of a current to flow through the EL element is allowed to be maintained at a constant level even when a temperature of an EL layer changes by providing the EL display with another EL element to be used for monitoring a temperature.

Claims

1. A display device comprising:

a transistor including a semiconductor region, a gate insulating film, and a gate electrode;

an interlayer insulating film over the transistor;

a pixel electrode over the interlayer insulating film, wherein the pixel electrode is electrically connected with the semiconductor region;

a first resin partly overlapping the pixel electrode;

a second resin over the first resin; and

a light emitting layer including an organic compound over the pixel electrode and the second resin.

2. The display device according to claim 1, wherein each of the first resin and the second resin is a bank.

3. The display device according to claim 1, wherein the first resin and the second resin is formed of a same material.

4. The display device according to claim 1, wherein the first resin and the second resin is formed of different materials.

5. The display device according to claim 1, wherein the second resin is wider than the first resin.

6. The display device according to claim 1, wherein the light emitting layer includes a first portion over the second resin and a second portion over the pixel electrode, and the first portion is spaced apart from the second portion.

7. The display device according to claim 1, wherein the display device is incorporated in one selected from the group consisting of a telephone, a video camera, a digital camera, a goggle type display, an image reproduction apparatus, and a personal computer.

8. A display device comprising:

a transistor including a semiconductor region, a gate insulating film, and a gate electrode;

an interlayer insulating film over the transistor;

a pixel electrode over the interlayer insulating film, wherein the pixel electrode contains indium tin oxide, and is electrically connected with the semiconductor region;

a first resin partly overlapping the pixel electrode;

a second resin over the first resin; and

a light emitting layer including an organic compound over the pixel electrode and the second resin.

9. The display device according to claim 8, wherein each of the first resin and the second resin is a bank.

10. The display device according to claim 8, wherein the first resin and the second resin is formed of a same material.

11. The display device according to claim 8, wherein the first resin and the second resin is formed of different materials.

12. The display device according to claim 8, wherein the second resin is wider than the first resin.

13. The display device according to claim 8, wherein the light emitting layer includes a first portion over the second resin and a second portion over the pixel electrode, and the first portion is spaced apart from the second portion.

14. The display device according to claim 8, wherein the display device is incorporated in one selected from the group consisting of a telephone, a video camera, a digital camera, a goggle type display, an image reproduction apparatus, and a personal computer.

15. A display device comprising:

a transistor including a semiconductor region, a gate insulating film, and a gate electrode;

an interlayer insulating film over the transistor;

a pixel electrode over the interlayer insulating film, wherein the pixel electrode contains indium tin oxide, and is electrically connected with the semiconductor region;

a first resin partly overlapping the pixel electrode;

a second resin over the first resin;

a light emitting layer including an organic compound over the pixel electrode and the second resin; and

a cathode over the light emitting layer and the second resin, wherein the cathode contains Mg and Ag.

16. The display device according to claim 15, wherein each of the first resin and the second resin is a bank.

17. The display device according to claim 15, wherein the first resin and the second resin is formed of a same material.

18. The display device according to claim 15, wherein the first resin and the second resin is formed of different materials.

19. The display device according to claim 15, wherein the second resin is wider than the first resin.

20. The display device according to claim 15, wherein the light emitting layer includes a first portion over the second resin and a second portion over the pixel electrode, and the first portion is spaced apart from the second portion.

21. The display device according to claim 15, wherein the display device is incorporated in one selected from the group consisting of a telephone, a video camera, a digital camera, a goggle type display, an image reproduction apparatus, and a personal computer.