Display device
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorsKenichi Wakimoto, Masahiko Hayakawa
Life of this patent
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Abstract
To reduce power consumption of a display device with the use of a simple structure and a simple operation. The display device includes an input device. Input of an image signal to a driver circuit is controlled in accordance with an image operation signal output from the input device. Specifically, input of image signals at the time when the input device is not operated is less frequent than that at the time when the input device is operated. Accordingly, display degradation (deterioration of display quality) caused when the display device is used can be prevented and power consumed when the display device is not used can be reduced.
Claims20
An active matrix type liquid crystal display device comprising:
- a plurality of pixels, each pixel comprising a transistor and a liquid crystal element;
- a driver circuit configured to input signals to the plurality of pixels;
- and
- an input device operationally connected to the driver circuit,
- wherein a frequency of inputting image signals to the driver circuit when the input device is not operated is less than a frequency of inputting image signals to the driver circuit when the input device is operated,
- wherein the transistor comprises:
- a gate electrode over a substrate;
- a gate insulating layer over the gate electrode;
- an oxide semiconductor layer over the gate insulating layer;
- a source electrode and a drain electrode over and in contact with the oxide semiconductor layer;
- a silicon oxide film over the source electrode and the drain electrode;
- and
- a silicon nitride film over the silicon oxide film,
- wherein the oxide semiconductor layer comprises at least indium, gallium, and zinc,
- wherein the oxide semiconductor layer includes a crystalline region with c-axis alignment, and
- wherein the oxide semiconductor layer has a region being in contact with the silicon oxide film.
An active matrix type liquid crystal display device comprising:
- a plurality of pixels, each pixel comprising a transistor and a liquid crystal element;
- a driver circuit configured to input signals to the plurality of pixels;
- and
- an input device operationally connected to the driver circuit,
- wherein a frequency of inputting the signals from the driver circuit to the plurality of pixels when the input device is not operated is less than a frequency of inputting the signals from the driver circuit to the plurality of pixels when the input device is operated,
- wherein the transistor comprises:
- a gate electrode over a substrate;
- a gate insulating layer over the gate electrode;
- an oxide semiconductor layer over the gate insulating layer;
- a source electrode and a drain electrode over and in contact with the oxide semiconductor layer;
- a silicon oxide film over the source electrode and the drain electrode;
- and
- a silicon nitride film over the silicon oxide film,
- wherein the oxide semiconductor layer comprises at least indium, gallium, and zinc,
- wherein the oxide semiconductor layer includes a crystalline region with c-axis alignment, and
- wherein the oxide semiconductor layer has a region being in contact with the silicon oxide film.
Dependencies are inferred from the claim text.