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US 2015/0090996 A1Published application
Semiconductor device and driving method thereof
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorHajime Kimura
Life of this patent
Estimating the term…
Abstract
A voltage equal to the threshold value of a TFT (106) is held in capacitor unit (109). When a video signal is inputted from a source signal line, the voltage held in the capacitor unit is added thereto and a resultant signal is applied to a gate electrode of the TFT (106). Even when a threshold value is varied for each pixel, each threshold value is held in the capacitor unit (109) for each pixel. Thus, the influence of a variation in threshold value can be eliminated. Further, holding of the threshold value is conducted by only the capacitor unit (109) and a charge does not move at writing of a video signal so that a voltage between both electrodes is not changed. Thus, it is not influenced by a variation in capacitance value.
Claims19
(canceled)
A semiconductor device comprising:
- a first transistor comprising:
- a semiconductor layer over a substrate with a base film therebetween;
- and
- a conductive layer over the semiconductor layer with a gate insulating film therebetween;
- a second transistor;
- a third transistor;
- a fourth transistor;
- a fifth transistor;
- and
- a first capacitor,
- wherein a gate of the first transistor is electrically connected to a first electrode of the first capacitor,
- wherein one of a source and a drain of the second transistor is directly connected to the gate of the first transistor,
- wherein the other of the source and the drain of the second transistor is electrically connected to one of a source and a drain of the first transistor,
- wherein one of a source and a drain of the third transistor is directly connected to a second electrode of the first capacitor,
- wherein one of a source and a drain of the fourth transistor is directly connected to a pixel electrode of a light-emitting element,
- wherein the other of the source and the drain of the fourth transistor is electrically connected to the one of the source and the drain of the first transistor, and
- wherein one of a source and a drain of the fifth transistor is electrically connected to the one of the source and the drain of the first transistor.
14 more elements
A semiconductor device comprising:
- a flexible print circuit;
- a driver circuit;
- and
- a pixel portion comprising:
- a first transistor comprising:
- a semiconductor layer over a substrate with a base film therebetween;
- and
- a conductive layer over the semiconductor layer with a gate insulating film therebetween;
- a second transistor;
- a third transistor;
- a fourth transistor;
- a fifth transistor;
- and
- a first capacitor,
- wherein a gate of the first transistor is electrically connected to a first electrode of the first capacitor,
- wherein one of a source and a drain of the second transistor is directly connected to the gate of the first transistor,
- wherein the other of the source and the drain of the second transistor is electrically connected to one of a source and a drain of the first transistor,
- wherein one of a source and a drain of the third transistor is directly connected to a second electrode of the first capacitor,
- wherein one of a source and a drain of the fourth transistor is directly connected to a pixel electrode of a light-emitting element,
- wherein the other of the source and the drain of the fourth transistor is electrically connected to the one of the source and the drain of the first transistor,
- wherein one of a source and a drain of the fifth transistor is electrically connected to the one of the source and the drain of the first transistor,
- wherein the driver circuit is configured to control a gate signal line electrically connected to a gate of the third transistor, and
- wherein the flexible print circuit is electrically connected to the driver circuit.
20 more elements
An electronic device comprising:
- an operation key;
- and
- a display portion comprising:
- a first transistor comprising:
- a semiconductor layer over a substrate with a base film therebetween;
- and
- a conductive layer over the semiconductor layer with a gate insulating film therebetween;
- a second transistor;
- a third transistor;
- a fourth transistor;
- a fifth transistor;
- and
- a first capacitor,
- wherein a gate of the first transistor is electrically connected to a first electrode of the first capacitor,
- wherein one of a source and a drain of the second transistor is directly connected to the gate of the first transistor,
- wherein the other of the source and the drain of the second transistor is electrically connected to one of a source and a drain of the first transistor,
- wherein one of a source and a drain of the third transistor is directly connected to a second electrode of the first capacitor,
- wherein one of a source and a drain of the fourth transistor is directly connected to a pixel electrode of a light-emitting element,
- wherein the other of the source and the drain of the fourth transistor is electrically connected to the one of the source and the drain of the first transistor, and
- wherein one of a source and a drain of the fifth transistor is electrically connected to the one of the source and the drain of the first transistor.
17 more elements
Dependencies are inferred from the claim text.