Display device and electronic device

• US 6,825,820 B2
• Filed: 08/07/2001
• Issued: 11/30/2004
• Est. Priority Date: 08/10/2000
• Status: Expired due to Term

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Osame, Mitsuaki, Koyama, Jun, Yamazaki, Shunpei, Inukai, Kazutaka
• Primary Examiner(s): Mengistu, Amare
• Application Number:
  US09/922,715
• Publication Number:
  US 20020018060A1
• Time in Patent Office: 1,211 Days
• Field of Search: 345/92, 345/76, 345/211, 345/214, 257/59, 257/57, 257/72, 257/204, 257/350, 257/758, 315/169.3
• US Class Current: 345/76
• CPC Class Codes: G09G 2300/0408 Integration of the drivers onto the display substrate
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• CPC Class Codes: G09G 2300/0452 Details of colour pixel setup, e.g. pixel composed of a red, a blue and two green components
• CPC Class Codes: G09G 2300/0814 used for selection purposes, e.g. logical AND for partial update
• CPC Class Codes: G09G 2300/0838 with level shifting
• 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 2310/0289 Details of voltage level shifters arranged for use in a driving circuit
• CPC Class Codes: G09G 2310/061 for resetting or blanking
• CPC Class Codes: G09G 3/3275 Details of drivers for data 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: H05B 44/00 Circuit arrangements for operating electroluminescent light sources for operating light emitting diodes H05B45/00
• CPC Class Codes: H10K 59/1201 Manufacture or treatment
• CPC Class Codes: H10K 59/131 Interconnections, e.g. wiring lines or terminals
• CPC Class Codes: H10K 59/1315 comprising structures specially adapted for lowering the resistance
• CPC Class Codes: H10K 59/35 comprising red-green-blue [RGB] subpixels
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

A display device capable of displaying a picture of vivid colors maintaining a good balance of colors and a good balance of light-emitting brightnesses of the EL elements. The widths of the detour wirings supplying current to the power source feed lines are increased for those EL elements into which a current of a large density flows. This constitution decreases the wiring resistances of the detour wirings, decreases the potential drop through the detour wirings, and suppresses the amount of electric power consumed by the detour wirings.

Claims

1. A display device comprising plural EL elements, plural power source feed lines, plural detour wirings and external connection terminals;

wherein

the external connection terminals and the plural power source feed lines are electrically connected together through the plural detour wirings;

the plural power source feed lines are electrically connected to the pixel electrodes possessed by the plural EL elements; and

the widths of the plural detour wirings connected to the plural power source feed lines are increased for those plural power source feed lines through which an electric current of an increased absolute value flows when the plural EL elements are driven.

2. A device according to claim 1, wherein the widths of the plural power source lines are increased for those plural power source feed lines through which an electric current of an increased absolute value flows when the plural EL elements are driven.

3. An electronic device having a display device of claim 1.

4. An electronic device of claim 3, which is an EL display, a video camera, a light-emitting device of the type attached to the head, a picture-reproducing device, a goggle type display, a personal computer, a cellular phone or an acoustic reproducing device.

5. A display device comprising plural pixels, plural power source feed lines, plural detour wirings and external connection terminals;

wherein

each of the plural pixels includes any one of the plural power source feed lines, an EL element, a switching TFT and an EL drive TFT;

the switching TFT controls the switching of the EL drive TFT;

a potential of any one of the plural power source feed lines is applied to a pixel electrode possessed by the EL element through the EL drive TFT;

the external connection terminals and the plural power source feed lines are electrically connected together through the plural detour wirings; and

the widths of the plural detour wirings connected to the plural power source feed lines are increased for those plural power source feed lines through which an electric current of an increased absolute value flows when the EL elements are driven.

6. A device according to claim 5, wherein the channel widths of the channel-forming regions possessed by the EL drive TFTs are increased for those plural power source feed lines through which an electric current of an increased absolute value flows when the EL elements are driven.

7. A device according to claim 5, wherein the lengths of the LDD regions possessed by the EL drive TFTs are increased for those plural power source feed lines through which an electric current of an increased absolute value flows when the EL elements are driven.

8. A device according to claim 5, wherein the widths of the plural power source feed lines are increased for those plural power source feed lines through which an electric current of an increased absolute value flows when the EL elements are driven.

9. An electronic device having a display device of claim 5.

10. An electronic device of claim 9, which is an EL display, a video camera, a light-emitting device of the type attached to the head, a picture-reproducing device, a goggle type display, a personal computer, a cellular phone or an acoustic reproducing device.

11. A device comprising plural EL elements, plural power source feed lines, plural detour wirings and external connection terminals;

wherein

each of the plural EL elements includes a pixel electrode, an opposing electrode, and an EL layer formed between the pixel electrode and the opposing electrode;

the external connection terminals and the plural power source feed lines are electrically connected together through the plural detour wirings;

the plural power source wirings are electrically connected to the pixel electrodes possessed by the plural EL elements; and

the widths of the plural detour wirings connected to the plural power source feed lines are increased for those EL layers possessed by the plural EL elements through which an electric current of an increased density flows when the plural EL elements are driven.

12. A device according to claim 11, wherein the widths of the plural power source feed lines are increased for those EL layers possessed by the plural EL elements into which an electric current of a large density flows when the plural EL elements are driven.

13. An electronic device having a display device of claim 11.

14. An electronic device of claim 13, which is an EL display, a video camera, a light-emitting device of the type attached to the head, a picture-reproducing device, a goggle type display, a personal computer, a cellular phone or an acoustic reproducing device.

15. A display device comprising plural pixels, plural power source feed lines, plural detour wirings and external connection terminals;

wherein

each of the plural pixels includes any one of the plural power source feed lines, an EL element, a switching TFT and an EL drive TFT;

the EL element includes a pixel electrode, an opposing electrode and an EL layer provided between the pixel electrode and the opposing electrode;

the switching TFT controls the switching of the EL drive TFT;

a potential of any one of the plural power source feed lines is applied to a pixel electrode possessed by the EL element through the EL drive TFT;

the external connection terminals and the plural power source feed lines are electrically connected together through the plural detour wirings; and

the widths of the plural detour wirings connected to the plural power source feed lines are increased for those EL layers possessed by the EL elements into which an electric current of a large density flows when the EL elements are driven.

16. A device according to claim 15, wherein the channel widths of the channel-forming regions possessed by the EL drive TFTs are increased for those EL layers possessed by the EL elements into which an electric current of a large density flows when the EL elements are driven.

17. A device according to claim 15, wherein the lengths of the LDD regions possessed by the EL drive TFTs are increased for those EL layers possessed by the EL elements into which an electric current of a large density flows when the EL elements are driven.

18. A device according to claim 15, wherein the widths of the plural power source feed lines are increased for those EL layers possessed by the EL elements into which an electric current of a large density flows when the EL elements are driven.

19. An electronic device having a display device of claim 15.

20. An electronic device of claim 19, which is an EL display, a video camera, a light-emitting device of the type attached to the head, a picture-reproducing device, a goggle type display, a personal computer, a cellular phone or an acoustic reproducing device.

21. A display device comprising plural pixels, plural power source feed lines, plural detour wirings and external connection terminals;

wherein

each of the plural pixels includes any one of the plural power source feed lines, an EL element, a switching TFT and an EL drive TFT;

a video signal is input to the gate electrode of the EL drive TFT through the switching TFT;

a potential of any one of the plural power source feed lines is applied to the pixel electrode possessed by the EL element through the EL drive TFT;

the external connection terminals and the plural power source feed lines are electrically connected together through the plural detour wirings;

the widths of the plural detour wirings connected to the plural power source feed lines are increased for those plural power source feed lines through which an electric current of a large absolute value flows when the EL elements are driven; and

the video signal of an increased amplitude is input to the gate electrodes of the EL drive TFTs for those pixels into which an electric current of a large absolute value flows through the plurality of power source feed lines when the EL elements are driven.

22. A device according to claim 21, wherein the channel widths of the channel-forming regions possessed by the EL drive TFTs are increased for those plural power source feed lines through which an electric current of a large absolute value flows when the EL elements are driven.

23. A device according to claim 21, wherein the lengths of the LDD regions possessed by the EL drive TFTs are increased for those plural power source feed lines through which an electric current of a large absolute value flows when the EL elements are driven.

24. A device according to claim 21, wherein the widths of the plural power source feed lines are increased for those plural power source feed lines through which an electric current of a large absolute value flows when the EL elements are driven.

25. An electronic device having a display device of claim 21.

26. An electronic device of claim 25, which is an EL display, a video camera, a light-emitting device of the type attached to the head, a picture-reproducing device, a goggle type display, a personal computer, a cellular phone or an acoustic reproducing device.

27. A display device comprising plural pixels, plural power source feed lines, plural detour wirings and external connection terminals;

wherein

each of the plural pixels includes any one of the plural power source feed lines, an EL element, a switching TFT and an EL drive TFT;

the EL element includes a pixel electrode, an opposing electrode, and an EL layer provided between the pixel electrode and the opposing electrode;

a video signal is input to the gate electrode of the EL drive TFT through the switching TFT;

a potential of any one of the plural power source feed lines is applied to the pixel electrode possessed by the EL element through the EL drive TFT;

the external connection terminals and the plural power source feed lines are electrically connected together through the plural detour wirings;

the widths of the plural detour wirings connected to the plural power source feed lines are increased for those EL layers possessed by the EL elements into which an electric current of a large density flows when the EL elements are driven; and

the video signal of an increased amplitude is input to the gate electrodes of the EL drive TFTs for those pixels into which an electric current of a large density flows for the EL layers of the EL elements when the EL elements are driven.

28. A device according to claim 27, wherein the channel widths of the channel-forming regions possessed by the EL drive TFTs are increased for those EL layers of the EL elements for which an electric current of a large density flows when the EL elements are driven.

29. A device according to claim 27, wherein the lengths of the LDD regions possessed by the EL drive TFTs are increased for those EL layers of the EL elements for which an electric current of a large density flows when the EL elements are driven.

30. A device according to claim 27, wherein the widths of the plural power source feed lines are increased for those EL layers of the EL elements for which an electric current of a large density flows when the EL elements are driven.

31. An electronic device having a display device of claim 27.

32. An electronic device of claim 31, which is an EL display, a video camera, light-emitting device of the type attached to the head, a picture-reproducing device, a goggle type display, a personal computer, a cellular phone or an acoustic reproducing device.

33. A display device comprising:

a plurality of power source feed lines;

a plurality of detour wirings, and

a plurality of pixels, each of the plurality of pixels comprising an EL element,

wherein;

the amplitude of voltage of a signal input to each of the plurality of pixels differs depending upon the color of light emitted by the EL element,

each of the plurality of power source feed lines is electrically connected to corresponding one of the plurality of detour wirings,

each of the plurality of power source feed lines is electrically connected to corresponding one of the plurality of pixels, and

each of the widths of the plurality of detour wirings differs depending upon the color of light emitted by the EL element.

34. An electronic device having a display device of claim 33.

35. An electronic device of claim 34, which is an EL display, a video camera, a light-emitting device of the type attached to the head, a picture-reproducing device, a goggle type display, a personal computer, a cellular phone or an acoustic reproducing device.

36. A display device comprising plural EL elements, plural power source feed lines, plural detour wirings and external connection terminals, wherein:

the external connection terminals and the plural power source feed lines are electrically connected together through different ones of the plural detour wirings;

the pixel electrodes possessed by the plural EL elements are connected to different ones of the plural power source feed lines;

the plural EL elements have different EL materials; and

the plural detour wirings have different widths.

37. An electronic device having a display device of claim 36.

38. An electronic device of claim 37, which is an EL display, a video camera, a light-emitting device of the type attached to the head, a picture-reproducing device, a goggle type display, a personal computer, a cellular phone or an acoustic reproducing device.

39. A display device comprising plural EL elements, plural power source feed lines, plural detour wirings and external connection terminals, wherein:

the external connection terminals and the plural power source feed lines are electrically connected together through different ones of the plural detour wirings;

the pixel electrodes possessed by the plural EL elements are connected to different ones of the plural power source feed lines;

the plural EL elements have different EL materials; and

the plural power source feed lines have different widths.