Method for driving liquid crystal display device
First Claim
1. A driving method of a display device having a touch panel function, the display device comprising:
- a display panel comprising a pixel circuit portion, the pixel circuit portion comprising a pixel electrode and a transistor electrically connected to the pixel electrode, wherein the transistor comprises an oxide semiconductor layer including a channel formation region, wherein the oxide semiconductor layer comprises indium and zinc;
the driving method comprising;
displaying a moving image in a first period at a first refresh rate; and
displaying a still image in a second period at a second refresh rate which is smaller than the first refresh rate,wherein an off current per micrometer in a channel width of the transistor is less than or equal to 1×
10−
17 A/μ
m.
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Abstract
The liquid crystal display device includes a first substrate provided with a terminal portion, a switching transistor, a driver circuit portion, and a pixel circuit portion including a pixel transistor and a plurality of pixels, a second substrate provided with a common electrode electrically connected to the terminal portion through the switching transistor, and liquid crystal between a pixel electrode and the common electrode. In a period during which a still image is switched to a moving image, the following steps are sequentially performed: a first step of supplying the common potential to the common electrode; a second step of supplying a power supply voltage to the driver circuit portion; a third step of supplying a clock signal to the driver circuit portion; and a fourth step of supplying a start pulse signal to the driver circuit portion.
152 Citations
22 Claims
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1. A driving method of a display device having a touch panel function, the display device comprising:
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a display panel comprising a pixel circuit portion, the pixel circuit portion comprising a pixel electrode and a transistor electrically connected to the pixel electrode, wherein the transistor comprises an oxide semiconductor layer including a channel formation region, wherein the oxide semiconductor layer comprises indium and zinc; the driving method comprising; displaying a moving image in a first period at a first refresh rate; and displaying a still image in a second period at a second refresh rate which is smaller than the first refresh rate, wherein an off current per micrometer in a channel width of the transistor is less than or equal to 1×
10−
17 A/μ
m. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A driving method of a display device having a touch panel function, the display device comprising:
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a display panel comprising a pixel circuit portion and a gate line driver circuit for driving the pixel circuit portion; the driving method comprising; displaying a moving image in a first period at a first refresh rate; stopping supply of a start pulse to the gate line driver circuit in a second period after the first period; stopping supply of a clock signal to the gate line driver circuit in the second period after stopping the supply of the start pulse; and displaying a still image in a third period after the second period at a second refresh rate which is smaller than the first refresh rate, wherein the pixel circuit portion comprises a pixel electrode and a first transistor electrically connected to the pixel electrode, the first transistor comprising a first oxide semiconductor layer including a channel formation region over a substrate, wherein the first oxide semiconductor layer comprises indium and zinc, and wherein the gate line driver circuit comprises a second transistor, the second transistor comprising a second oxide semiconductor layer including a channel formation region over the substrate. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17)
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18. A display device comprising:
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a display panel comprising a pixel circuit portion and a gate line driver circuit for driving the pixel circuit portion; a comparison circuit configured to compare image signals in each of pixels in order to determine if an image is a moving image or a still image; and a display control circuit configured to control operation of the gate line driver circuit in accordance with a determination by the comparison circuit, wherein, when the image is a moving image, the display control circuit is configured to control the gate line driver circuit so that the moving image is displayed at a first refresh rate, wherein, when the image is a still image, the display control circuit is configured to control the gate line driver circuit so that the still image is displayed at a second refresh rate smaller than the first refresh rate, wherein the pixel circuit portion comprises a pixel electrode and a first transistor electrically connected to the pixel electrode, the first transistor comprising a first oxide semiconductor layer including a channel formation region over a substrate, wherein the gate line driver circuit comprises a second transistor, the second transistor comprising a second oxide semiconductor layer including a channel formation region over the substrate, and wherein an off current per micrometer in a channel width of the first transistor is less than or equal to 1×
10−
17 A/μ
m. - View Dependent Claims (19, 20, 21, 22)
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Specification