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US 9,805,676 B2Granted
Display device
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorsJun Koyama, Hiroyuki Miyake
Life of this patent
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Abstract
To provide a novel display device without deterioration of display quality, the display device includes a display panel including a pixel portion that displays still images at a frame frequency of 30 Hz or less, a temperature sensing unit that senses the temperature of the display panel, a memory device that stores a correction table containing correction data, and a control circuit to which correction data selected from the correction table is input in accordance with an output of the temperature sensing unit. The pixel portion includes a plurality of pixels. Each of the pixels includes a transistor, a display element, and a capacitor. The control circuit outputs a voltage based on the correction data input to the control circuit, to the capacitor included in each of the pixels.
Claims10
A display device comprising:
- a pixel portion comprising a transistor, a display element, and a capacitor;
- a driver circuit configured to drive the pixel portion in a first mode or in a second mode;
- a temperature sensing unit configured to sense a temperature;
- a first memory device storing a first correction table;
- a control circuit comprising:
- a D/A converter;
- a second memory device storing a second correction table;
- and
- a D/A converter control circuit configured to read a second correction data corresponding to frame frequency from the second correction table and output the second correction data to the D/A converter;
- and
- an image processing circuit configured to read a first correction data corresponding to the temperature from the first correction table and output the first correction data to the control circuit,
- wherein the transistor comprises an oxide semiconductor layer comprising a channel formation region,
- wherein one of a source and a drain of the transistor is electrically connected to the display element,
- wherein a first electrode of the capacitor is electrically connected to the display element,
- wherein the pixel portion is driven with a first frame frequency during the first mode,
- wherein the pixel portion is driven with a second frame frequency lower than the first frame frequency during the second mode,
- wherein a potential output from the D/A converter is applied to a second electrode of the capacitor, and
- wherein the potential applied to the second electrode of the capacitor is a first potential at a beginning of each frame period and the potential applied to the second electrode of the capacitor gradually rises or drops over time during each frame period.
15 more elements
A display device comprising:
- a pixel portion comprising a transistor, a display element, and a capacitor;
- a driver circuit configured to drive the pixel portion in a first mode or in a second mode;
- a temperature sensing unit configured to sense a temperature;
- a first memory device storing a first correction table;
- a control circuit comprising:
- a D/A converter;
- a second memory device storing a second correction table;
- and
- a D/A converter control circuit configured to read a second correction data corresponding to frame frequency from the second correction table and output the second correction data to the D/A converter;
- and
- an image processing circuit configured to read a first correction data corresponding to the temperature from the first correction table and output the first correction data to the control circuit,
- wherein the transistor comprises an oxide semiconductor layer comprising a channel formation region,
- wherein one of a source and a drain of the transistor is electrically connected to the display element,
- wherein a first electrode of the capacitor is electrically connected to the display element,
- wherein the pixel portion is driven with a first frame frequency during the first mode,
- wherein the pixel portion is driven with a second frame frequency lower than the first frame frequency during the second mode, and
- wherein a potential output from the D/A converter is applied to a second electrode of the capacitor.
14 more elements
A display device comprising:
- a pixel portion comprising a transistor, a display element, and a capacitor;
- a temperature sensing unit configured to sense a temperature;
- a first memory device storing a first correction table;
- a control circuit comprising:
- a D/A converter;
- a second memory device storing a second correction table;
- and
- a D/A converter control circuit configured to read a second correction data corresponding to frame frequency from the second correction table and output the second correction data to the D/A converter;
- and
- an image processing circuit configured to read a first correction data corresponding to the temperature from the first correction table and output the first correction data to the control circuit,
- wherein the transistor comprises an oxide semiconductor layer comprising a channel formation region,
- wherein one of a source and a drain of the transistor is electrically connected to the display element,
- wherein a first electrode of the capacitor is electrically connected to the display element, and
- wherein a potential output from the D/A converter is applied to a second electrode of the capacitor.
11 more elements
Dependencies are inferred from the claim text.