Light-emitting device and electric appliance
View Patent ↗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.
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.