Light-emitting device and electric appliance

• US 20020044111A1
• Filed: 05/09/2001
• Published: 04/18/2002
• Est. Priority Date: 05/12/2000
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Takayama, Toru, Koyama, Jun, Yamazaki, Shunpei
• Granted Patent: US 7,633,471 B2
• Time in Patent Office: Days
• US Class Current: 345/83
• CPC Class Codes: G09G 2300/0408 Integration of the drivers onto the display substrate
• CPC Class Codes: G09G 2300/0809 Several active elements per pixel in active matrix panels
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2300/0857 Static memory circuit, e.g. flip-flop
• CPC Class Codes: G09G 3/32 semiconductive, e.g. using light-emitting diodes [LED]
• 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: H01L 27/156 two-dimensional arrays
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays

Abstract

An inexpensive light emitting device capable of displaying a bright image and an electric appliance using the light emitting device. In the light emitting device having a pixel portion and a driver circuit formed on one insulating member, all of semiconductor elements for the pixel portion and the driver circuit are formed by n-channel semiconductor elements, thereby enabling the manufacturing process to be simplified. Each of light-emitting elements provided in the pixel portion emits light in such a direction that most of the light travels away from the insulating member, so that substantially the whole of the pixel-forming segment electrode (corresponding to a cathode of an EL element) is formed as an effective light-emitting area. Therefore, a low-priced light-emitting device capable of displaying a bright image can be obtained.

Claims

1. A light-emitting device comprising:

a pixel portion comprising a plurality of pixels formed over a substrate; and

a driver circuit formed over said substrate,

wherein all semiconductor elements constituting said pixel portion and said driver circuit are n-channel type semiconductor elements.

2. A light-emitting device according to claim 1, wherein said substrate comprises a plastic substrate covered with a protective film.

3. A light-emitting device according to claim 1, wherein said semiconductor elements comprise thin-film transistors.

4. A light-emitting device according to claim 1, wherein said driver circuit comprises at least one of an EEMOS circuit and an EDMOS circuit.

5. A light-emitting device according to claim 1, wherein an electro-luminescent element is provided in each of said plurality of pixels.

6. 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 mobile computer, a mobile telephone, and an audio.

7. A light-emitting device comprising:

a pixel portion formed over a substrate, said pixel portion comprising a switching element and a current control element; and

a driver circuit comprising an inverter circuit formed over said substrate,

wherein all semiconductor elements constituting said switching element, said current control element, and said inverter circuit are n-channel type semiconductor elements.

8. A light-emitting device according to claim 7, wherein said substrate comprises a plastic substrate covered with a protective film.

9. A light-emitting device according to claim 7, wherein said semiconductor elements comprise thin-film transistors.

10. A light-emitting device according to claim 7, wherein said driver circuit comprises at least one of an EEMOS circuit and an EDMOS circuit.

11. A light-emitting device according to claim 7, wherein an electro-luminescent element is provided in each of said plurality of pixels.

12. A light-emitting device according to claim 7, wherein said light-emitting device is one selected from the group consisting of a video camera, a digital camera, a mobile computer, a mobile telephone, and an audio.

14. A light-emitting device according to claim 13, wherein said semiconductor elements comprise n n-channel type semiconductor elements connected in series, and n n-channel type semiconductor elements connected in parallel.

15. A light-emitting device according to claim 13, wherein said substrate comprises a plastic substrate covered with a protective film.

16. A light-emitting device according to claim 13, wherein said semiconductor elements comprise thin-film transistors.

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

18. 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 mobile computer, a mobile telephone, and an audio.

20. A light-emitting device according to claim 19, wherein said substrate comprises a plastic substrate covered with a protective film.

21. A light-emitting device according to claim 19, wherein said semiconductor elements comprise thin-film transistors.

22. A light-emitting device according to claim 19, wherein an electro-luminescent element is provided in each of said pixels.

23. A light-emitting device according to claim 19, wherein said light-emitting device is one selected from the group consisting of a video camera, a digital camera, a mobile computer, a mobile telephone, and an audio.

25. A light-emitting device according to claim 24, wherein said substrate comprises a plastic substrate covered with a protective film.

26. A light-emitting device according to claim 24, wherein an electro-luminescent element is provided in each of said pixels.

27. A light-emitting device according to claim 24, wherein said light-emitting device is one selected from the group consisting of a video camera, a digital camera, a mobile computer, a mobile telephone, and an audio.

29. A light-emitting device according to claim 28, wherein said substrate comprises a plastic substrate covered with a protective film.

30. A light-emitting device according to claim 28, wherein an electro-luminescent element is provided in each of said pixels.

31. A light-emitting device according to claim 28, wherein said light-emitting device is one selected from the group consisting of a video camera, a digital camera, a mobile computer, a mobile telephone, and an audio.

13. A light-emitting device comprising:

a pixel portion comprising a plurality of pixels formed over a substrate; and

a driver circuit formed over said substrate,

wherein said driver circuit comprises a decoder circuit containing a plurality of NAND circuits, and

wherein all semiconductor elements constituting said plurality of NAND circuit are n-channel type semiconductor elements.

19. A light-emitting device comprising:

a pixel portion comprising a plurality of pixels formed over a substrate; and

a driver circuit comprising a buffer circuit formed over said substrate,

wherein all semiconductor elements constituting said buffer circuit are n-channel type semiconductor elements, and

wherein said buffer circuit comprises a first semiconductor element and a second semiconductor element connected in series with said first semiconductor element, and a gate of said second semiconductor element is connected to a drain of said first semiconductor element.

24. A light-emitting device comprising:

a pixel portion comprising a plurality of pixels formed over a substrate; and

a driver circuit comprising a decoder circuit formed over said substrate, said decoder circuit comprising a plurality of NAND circuits and a buffer circuit,

wherein all semiconductor elements constituting said plurality of NAND circuits and said buffer circuit are n-channel thin film transistors, and

wherein said buffer circuits comprises a first thin film transistor and a second thin film transistor connected in series with said first thin film transistor, and a gate of said second thin film transistor is connected to a drain of said first thin film transistor.

28. A light-emitting device comprising:

a pixel portion comprising a plurality of pixels formed over a substrate; and

a driver circuit formed over said substrate,

wherein said driver circuit comprises a shift register containing a plurality of flip-flop circuits formed by enhancement-type n-channel thin film transistors and depletion-type n-channel thin film transistors.

32. A light-emitting device comprising:

a pixel portion comprising a plurality of pixels formed over a substrate; and

a driver circuit formed over said substrate,

wherein said driver circuit comprises a shift register containing a plurality of flip-flop circuits formed by enhancement-type n-channel thin film transistors and depletion-type n-channel thin film transistors, and comprises a plurality of NAND circuits formed by enhancement-type n-channel thin film transistors and depletion-type n-channel thin film transistors.

33. A light-emitting device according to claim 32, wherein said substrate comprises a plastic substrate covered with a protective film.

34. A light-emitting device according to claim 32, wherein an electro-luminescent element is provided in each of said pixels.

35. A light-emitting device according to claim 32, wherein said light-emitting device is one selected from the group consisting of a video camera, a digital camera, a mobile computer, a mobile telephone, and an audio.

37. A light-emitting device according to claim 36, wherein said substrate comprises a plastic substrate covered with a protective film.

38. A light-emitting device according to claim 36, wherein said substrate comprises a plastic substrate covered with a protective film.

39. A light-emitting device according to claim 36, wherein an electro-luminescent element is provided in each of said pixels.

40. A light-emitting device according to claim 36, wherein said light-emitting device is one selected from the group consisting of a video camera, a digital camera, a mobile computer, a mobile telephone, and an audio.

36. A light-emitting device comprising:

a pixel portion comprising a plurality of pixels formed over a substrate; and

a driver circuit formed over said substrate,

wherein each of said pixels comprises a plurality of enhancement-type n-channel thin film transistors and a plurality of depletion-type n-channel thin film transistors.

41. A light-emitting device comprising:

a pixel portion comprising a plurality of pixels formed over a substrate; and

a driver circuit formed over said substrate,

wherein each of said pixels comprises an SRAM formed by a plurality of enhancement-type n-channel thin film transistors and a plurality of depletion-type n-channel thin film transistors.

42. A light-emitting device according to claim 41, wherein said substrate comprises a plastic substrate covered with a protective film.

43. A light-emitting device according to claim 41, wherein said substrate comprises a plastic substrate covered with a protective film.

44. A light-emitting device according to claim 41, wherein an electro-luminescent element is provided in each of said pixels.

45. A light-emitting device according to claim 41, wherein said light-emitting device is one selected from the group consisting of a video camera, a digital camera, a mobile computer, a mobile telephone, and an audio.