Display device
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorJun Koyama
Life of this patent
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Abstract
A signal line driving circuit which includes a digital signal sampling circuit, a storage circuit, a time setting circuit and a constant current circuit, is fabricated of TFTs on an insulating substrate which is made of the same substance as that of a pixel portion substrate. Thus, in a passive type EL display device, the problem of a distortion in the case of bonding the signal line driving circuit onto the pixel portion substrate can be eliminated. Besides, in an active type EL display device, each pixel is constructed of one transistor and an EL element. Thus, the aperture factor of the EL display device is enlarged.
Claims36
A personal computer having a display device, said display device comprising:
- a plurality of source signal lines;
- a plurality of gate signal lines;
- a plurality of pixels;
- a source signal line driving circuit configured to input signals to the plurality of source signal lines, and
- a gate signal line driving circuit configured to input signals to the plurality of gate signal lines,
- wherein each of the plurality of pixels includes an EL element and one switching thin film transistor, said switching thin film transistor comprising
- a gate electrode connected with one of said plurality of gate signal lines;
- and
- a semiconductor layer having a least two channel regions, first impurity regions, and second impurity regions, wherein one of the first impurity regions is connected with one of said plurality of source signal lines, and another one of the first impurity regions is connected with either of a cathode and an anode included in said EL element.
A camera having a display device, said display device comprising:
- a plurality of source signal lines;
- a plurality of gate signal lines;
- a plurality of pixels;
- a source signal line driving circuit configured to input signals to the plurality of source signal lines, and
- a gate signal line driving circuit configured to input signals to the plurality of gate signal lines,
- wherein each of the plurality of pixels includes an EL element and one switching thin film transistor, said switching thin film transistor comprising
- a gate electrode connected with one of said plurality of gate signal lines;
- and
- a semiconductor layer having a least two channel regions, first impurity regions, and second impurity regions, wherein one of the first impurity regions is connected with one of said plurality of source signal lines, and another one of the first impurity regions is connected with either of a cathode and an anode included in said EL element.
A portable telephone having a display device, said display device comprising:
- a plurality of source signal lines;
- a plurality of gate signal lines;
- a plurality of pixels;
- a source signal line driving circuit configured to input signals to the plurality of source signal lines, and
- a gate signal line driving circuit configured to input signals to the plurality of gate signal lines,
- wherein each of the plurality of pixels includes an EL element and one switching thin film transistor, said switching thin film transistor comprising;
- a gate electrode connected with one of said plurality of gate signal lines;
- and
- a semiconductor layer having a least two channel regions, first impurity regions, and second impurity regions, wherein one of the first impurity regions is connected with one of said plurality of source signal lines, and another one of the first impurity regions is connected with either of a cathode and an anode included in said EL element.
Dependencies are inferred from the claim text.