Light-emitting device and electric appliance

• US 7,633,471 B2
• Filed: 05/09/2001
• Issued: 12/15/2009
• Est. Priority Date: 05/12/2000
• Status: Expired due to Fees

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Takayama, Toru, Koyama, Jun, Yamazaki, Shunpei
• Primary Examiner(s): Hjerpe; Richard
• Assistant Examiner(s): ABDULSELAM, ABBAS I
• Application Number:
  US09/852,220
• Publication Number:
  US 20020044111A1
• Time in Patent Office: 3,142 Days
• Field of Search: 345/83, 345/84, 345/92, 345/98, 345/100, 345/204, 345/76, 345/80, 345/82, 345/211, 438/488, 438/149, 438/159, 438/146, 438/147, 438/213, 257/57, 257/72, 257/350, 257/59, 315/169.3, 315/169.2, 349/143, 445/24, 445/25
• 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 display 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 comprising enhancement-type n-channel thin film transistors and depletion-type n-channel thin film transistors,

wherein all semiconductor elements in said display portion and said driver circuit are n-channel type semiconductor elements, and

wherein each of said plurality of pixels comprises a light-emitting element.

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

3. A light-emitting device according to claim 1, wherein said light-emitting device is incorporated in one selected from the group consisting of an EL display, an image playback device, a personal computer, a video camera, a digital camera, a mobile computer, a mobile telephone, and an audio.

4. A light-emitting device according to claim 1, wherein each of said plurality of flip-flop circuits comprises an enhancement-type n-channel thin film transistor and two circuits.

5. A light-emitting device according to claim 4, wherein one of the circuits is an EEMOS circuit.

6. A light-emitting device according to claim 4, wherein one of the circuits is an EDMOS circuit.

7. A light-emitting device according to claim 4, wherein each of said plurality of flip-flop circuits further comprises an inverter circuit.

8. A light-emitting device according to claim 4, wherein said plurality of flip-flop circuits are connected in series.

9. A light-emitting device according to claim 1, wherein one of the enhancement-type n-channel thin film transistors is electrically connected with one of the depletion-type n-channel thin film transistors.

10. A light-emitting device according to claim 1, wherein a semiconductor element in the display portion has at least two channel forming regions.

11. A light-emitting device according to claim 1, wherein each of said plurality of pixels comprises two semiconductor elements a switching element, a current control element for controlling an amount of current to the light-emitting element, and a capacitor.

12. A light-emitting device according to claim 1, wherein the semiconductor element is an inverted stagger thin film transistor including a microcrystalline semiconductor film.

13. A light-emitting device comprising:

a display 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 comprising enhancement-type n-channel thin film transistors and depletion-type n-channel thin film transistors, and comprises a plurality of NAND circuits each comprising first and second enhancement-type n-channel thin film transistors and a depletion-type n-channel thin film transistor,

wherein a gate electrode of first enhancement-type n-channel thin film transistor is connected to a first output line,

wherein a source electrode of first enhancement-type n-channel thin film transistor is connected to a ground power supply line,

wherein a drain electrode of first enhancement-type n-channel thin film transistor is connected to second enhancement-type n-channel thin film transistor,

wherein all semiconductor elements in said display portion and said driver circuit are n-channel type semiconductor elements, and

wherein each of said plurality of pixels comprises a light-emitting element.

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

15. A light-emitting device according to claim 13, wherein said light-emitting device is incorporated in one selected from the group consisting of an EL display, an image playback device, a personal computer, a video camera, a digital camera, a mobile computer, a mobile telephone, and an audio.

16. A light-emitting device according to claim 13, wherein a semiconductor element in the display portion has at least two channel forming regions.

17. A light-emitting device according to claim 13, wherein each of said plurality of pixels comprises two semiconductor elements a switching element, a current control element for controlling an amount of current to the light-emitting element, and a capacitor.

18. A light-emitting device according to claim 13, wherein the semiconductor element is an inverted stagger thin film transistor including a microcrystalline semiconductor film.

19. A light-emitting device comprising:

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

a driver circuit formed over said substrate,

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

wherein all semiconductor elements in said display portion and said driver circuit are n-channel type semiconductor elements, and

wherein each of said plurality of pixels comprises a light-emitting element.

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

21. A light-emitting device according to claim 19, wherein said light-emitting device is incorporated in one selected from the group consisting of an EL display, an image playback device, a personal computer, a video camera, a digital camera, a mobile computer, a mobile telephone, and an audio.

22. A light-emitting device according to claim 19, wherein a semiconductor element in the display portion has at least two channel forming regions.

23. A light-emitting device according to claim 19, wherein each of said plurality of pixels comprises two semiconductor elements a switching element, a current control element for controlling an amount of current to the light-emitting element, and a capacitor.

24. A light-emitting device according to claim 19, wherein the semiconductor element is an inverted stagger thin film transistor including a microcrystalline semiconductor film.

25. A light-emitting device comprising:

a display 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,

wherein all semiconductor elements in said display portion and said driver circuit are n-channel type semiconductor elements, and

wherein each of said plurality of pixels comprises a light-emitting element.

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

27. A light-emitting device according to claim 25, wherein said light-emitting device is incorporated in one selected from the group consisting of an EL display, an image playback device, a personal computer, a video camera, a digital camera, a mobile computer, a mobile telephone, and an audio.

28. A light-emitting device according to claim 25, wherein a semiconductor element in the display portion has at least two channel forming regions.

29. A light-emitting device according to claim 25, wherein each of said plurality of pixels comprises two semiconductor elements a switching element, a current control element for controlling an amount of current to the light-emitting element, and a capacitor.

30. A light-emitting device according to claim 25, wherein the semiconductor element is an inverted stagger thin film transistor including a microcrystalline semiconductor film.