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US 8,520,159 B2Granted
Display device and electronic device
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorsAtsushi Umezaki, Hiroyuki Miyake
Life of this patent
Estimating the term…
Abstract
An object of the invention is to provide a circuit technique which enables reduction in power consumption and high definition of a display device. A switch controlled by a start signal is provided to a gate electrode of a transistor, which is connected to a gate electrode of a bootstrap transistor. When the start signal is input, a potential is supplied to the gate electrode of the transistor through the switch, and the transistor is turned off. The transistor is turned off, so that leakage of a charge from the gate electrode of the bootstrap transistor can be prevented. Accordingly, time for storing a charge in the gate electrode of the bootstrap transistor can be shortened, and high-speed operation can be performed.
Claims16
A display device comprising:
- a pixel;
- and
- a driver circuit,
- wherein the driver circuit includes a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, a sixth transistor, a seventh transistor, and an eighth transistor;
- a first terminal of the first transistor is electrically connected to a fourth wiring, and a second terminal of the first transistor is electrically connected to a third wiring;
- a first terminal of the second transistor is electrically connected to a sixth wiring, and a second terminal of the second transistor is electrically connected to the third wiring;
- a first terminal of the third transistor is electrically connected to a seventh wiring, a second terminal of the third transistor is electrically connected to a gate of the second transistor, and a gate of the third transistor is electrically connected to the seventh wiring;
- a first terminal of the fourth transistor is electrically connected to the sixth wiring, a second terminal of the fourth transistor is electrically connected to the gate of the second transistor, and a gate of the fourth transistor is electrically connected to a gate of the first transistor;
- a first terminal of the fifth transistor is electrically connected to a fifth wiring, a second terminal of the fifth transistor is electrically connected to the gate of the first transistor, and a gate of the fifth transistor is electrically connected to a first wiring;
- a first terminal of the sixth transistor is electrically connected to the sixth wiring, a second terminal of the sixth transistor is electrically connected to the gate of the first transistor, and a gate of the sixth transistor is electrically connected to the gate of the second transistor;
- a first terminal of the seventh transistor is electrically connected to the sixth wiring, a second terminal of the seventh transistor is electrically connected to the gate of the first transistor, and a gate of the seventh transistor is electrically connected to a second wiring;
- and
- a first terminal of the eighth transistor is electrically connected to the sixth wiring, a second terminal of the eighth transistor is electrically connected to the gate of the second transistor, and a gate of the eighth transistor is electrically connected to the first wiring,
- wherein a value of a ratio W/L of a channel width W to a channel length L of the first transistor is the highest among values of W/L of the first to eighth transistors.
11 more elements
A computer comprising:
- a main body including a keyboard and an LED lamp;
- and
- a housing including a display portion, the display portion including a pixel and a driver circuit,
- wherein the driver circuit includes a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, a sixth transistor, a seventh transistor, and an eighth transistor;
- a first terminal of the first transistor is electrically connected to a fourth wiring, and a second terminal of the first transistor is electrically connected to a third wiring;
- a first terminal of the second transistor is electrically connected to a sixth wiring, and a second terminal of the second transistor is electrically connected to the third wiring;
- a first terminal of the third transistor is electrically connected to a seventh wiring, a second terminal of the third transistor is electrically connected to a gate of the second transistor, and a gate of the third transistor is electrically connected to the seventh wiring;
- a first terminal of the fourth transistor is electrically connected to the sixth wiring, a second terminal of the fourth transistor is electrically connected to the gate of the second transistor, and a gate of the fourth transistor is electrically connected to a gate of the first transistor;
- a first terminal of the fifth transistor is electrically connected to a fifth wiring, a second terminal of the fifth transistor is electrically connected to the gate of the first transistor, and a gate of the fifth transistor is electrically connected to a first wiring;
- a first terminal of the sixth transistor is electrically connected to the sixth wiring, a second terminal of the sixth transistor is electrically connected to the gate of the first transistor, and a gate of the sixth transistor is electrically connected to the gate of the second transistor;
- a first terminal of the seventh transistor is electrically connected to the sixth wiring, a second terminal of the seventh transistor is electrically connected to the gate of the first transistor, and a gate of the seventh transistor is electrically connected to a second wiring;
- and
- a first terminal of the eighth transistor is electrically connected to the sixth wiring, a second terminal of the eighth transistor is electrically connected to the gate of the second transistor, and a gate of the eighth transistor is electrically connected to the first wiring,
- wherein a value of a ratio W/L of a channel width W to a channel length L of the first transistor is the highest among values of W/L of the first to eighth transistors.
11 more elements
Dependencies are inferred from the claim text.