Light-emitting device, and electric device using the same

• US 20020011796A1
• Filed: 05/04/2001
• Published: 01/31/2002
• Est. Priority Date: 05/08/2000
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Koyama, Jun
• Granted Patent: US 6,583,576 B2
• Time in Patent Office: Days
• US Class Current: 315/169.1
• CPC Class Codes: G09G 2300/0417 Special arrangements specific to the use of low carrier mobility technology
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• CPC Class Codes: G09G 2300/0465 Improved aperture ratio, e.g. by size reduction of the pixel circuit, e.g. for improving the pixel density or the maximum displayable luminance or brightness
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2300/0861 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 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 3/2018 by time modulation using two or more time intervals
• CPC Class Codes: G09G 3/2022 using sub-frames
• CPC Class Codes: G09G 3/30 using electroluminescent panels
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element
• CPC Class Codes: G09G 3/3266 Details of drivers for scan electrodes
• CPC Class Codes: G09G 3/3275 Details of drivers for data electrodes
• CPC Class Codes: G09G 3/3283 in which the data driver supplies a variable data current for setting the current through, or the voltage across, the light-emitting elements
• 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

Abstract

A light-emitting device having a higher aperture ratio in pixels than that of the prior art.

A source signal line and a current supply line to be connected with a pixel unit are switched by a switching circuit to use a common wiring line so that the number of wiring lines in the pixel unit is reduced to realize the high aperture ratio.

Claims

1. A light-emitting device comprising:

a plurality of pixels over a substrate;

a plurality of gate signal lines, and a plurality of source signal lines;

a plurality of current supply lines; and

a plurality of thin film transistors electrically connected with said plurality of pixels,

wherein said plurality of source signal lines and said plurality of current supply lines are electrically interchanged alternately.

2. A light-emitting device according to claim 1, wherein said source signal lines and said plurality of current supply lines are electrically interchanged for every one frame period.

3. A light-emitting device according to claim 2, wherein said one frame period is 1/240 to 1/120 sec.

4. A light-emitting device according to claim 1, wherein said plurality of source signal lines and said plurality of current supply lines are electrically connected with a switching circuit.

5. A light-emitting device according to claim 4, wherein in response to a switching signal for controlling said switching circuit, said source signal lines or said current supply lines are electrically connected with a switching TFT of a pixel unit.

6. A light-emitting device according to claim 1, wherein said source signal lines or said current supply lines are electrically connected with a current controlling TFT of the pixel unit.

7. A light-emitting device according to claim 4, wherein said switching circuit comprises a transmission gate.

8. A light-emitting device according to claim 1, wherein said light emitting device is an electro-luminescence display device.

9. A light-emitting device according to claim 1, wherein said light-emitting device is one selected from the group consisting of a video camera, a digital camera, a goggle type display, a personal computer, and a mobile telephone.

10. A light-emitting device comprising:

a plurality of pixels over a substrate;

a plurality of gate signal lines, and a plurality of source signal lines; and

a plurality of switching TFTs, and a plurality of current controlling TFTs,

wherein either drain regions or source regions of said switching TFTs are electrically connected with said plurality of source signal lines and with source regions of said current controlling TFTs of adjacent pixels.

11. A light-emitting device according to claim 10, wherein said light emitting device is an electro-luminescence display device.

12. A light-emitting device according to claim 10, wherein said light-emitting device is one selected from the group consisting of a video camera, a digital camera, a goggle type display, a personal computer, and a mobile telephone.

13. A light-emitting device comprising:

a plurality of pixels;

a plurality of gate signal lines, and a plurality of source signal lines;

a plurality of current supply lines; and

a plurality of switching TFTs, and a plurality of current controlling TFTs,

wherein either source regions or drain regions of said switching TFTs in pixels of (x-−

1)-th column are electrically connected with said plurality of current supply line of said pixels of said (x−

2)-th column, when either drain regions or source regions of said switching TFTs in pixels of (x−

2)-th column are electrically connected with said plurality of source signal lines.

14. A light-emitting device according to claim 13, wherein said light emitting device is an electro-luminescence display device.

15. A light-emitting device according to claim 13, wherein said light-emitting device is one selected from the group consisting of a video camera, a digital camera, a goggle type display, a personal computer, and a mobile telephone.

16. A light-emitting device comprising:

a plurality of pixels over a substrate;

a plurality of gate signal lines, and a plurality of source signal lines; and

a plurality of thin film transistors electrically connected with said plurality of pixels,

wherein one of said plurality of source signal lines function as a current supply line.

17. A light-emitting device according to claim 16, wherein said source signal lines and said plurality of current supply lines are electrically interchanged for every one frame period.

18. A light-emitting device according to claim 17, wherein said one frame period is 1/240 to 1/120 sec.

19. A light-emitting device according to claim 16, wherein said light emitting device is an electro-luminescence display device.

20. A light-emitting device according to claim 16, wherein said light-emitting device is one selected from the group consisting of a video camera, a digital camera, a goggle type display, a personal computer, and a mobile telephone.

21. A light-emitting device comprising:

a plurality of pixels over a substrate;

a plurality of gate signal lines electrically connected with a gate signal line driver circuit over said substrate;

a plurality of source signal lines electrically connected with a source signal line driver circuit over said substrate;

a plurality of current supply lines;

a switching circuit over said substrate; and

a plurality of thin film transistors electrically connected with said plurality of pixels,

wherein said plurality of source signal lines and said plurality of current supply lines are electrically interchanged alternately by said switching circuit.

22. A light-emitting device according to claim 21, wherein said source signal lines and said plurality of current supply lines are electrically interchanged for every one frame period.

23. A light-emitting device according to claim 22, wherein said one frame period is 1/240 to 1/120 sec.

24. A light-emitting device according to claim 21, wherein said switching circuit comprises a transmission gate.

25. A light-emitting device according to claim 21, wherein said light emitting device is an electro-luminescence display device.

26. A light-emitting device according to claim 21, wherein said light-emitting device is one selected from the group consisting of a video camera, a digital camera, a goggle type display, a personal computer, and a mobile telephone.