DISPLAY DEVICE

• US 20140146033A1
• Filed: 11/21/2013
• Published: 05/29/2014
• Est. Priority Date: 11/28/2012
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: KOYAMA, Jun, MIYAKE, Hiroyuki
• Granted Patent: US 9,805,676 B2
• Time in Patent Office: Days
• US Class Current: 345/212
• CPC Class Codes: G09G 2320/041 Temperature compensation
• CPC Class Codes: G09G 2320/103 Detection of image changes, e.g. determination of an index representative of the image change
• CPC Class Codes: G09G 2340/0435 Change or adaptation of the frame rate of the video stream
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 3/3655 Details of drivers for counter electrodes, e.g. common electrodes for pixel capacitors or supplementary storage capacitors
• CPC Class Codes: G09G 3/3696 Generation of voltages supplied to electrode drivers

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.

Claims

1. 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; and

a memory device storing a correction table,

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 voltage generated in accordance with an output of the temperature sensing unit by using the correction table is applied to a second electrode of the capacitor.

2. The display device according to claim 1,

wherein the transistor comprises an oxide semiconductor layer comprising a channel formation region.

3. The display device according to claim 1,

wherein the pixel portion is configured to display a still image at a frame frequency of 30 Hz or less.

4. The display device according to claim 3,

wherein the frame frequency is 0.2 Hz or less.

5. The display device according to claim 1, wherein the display element is a liquid crystal element.

6. 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 memory device storing a correction table; and

a control circuit,

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 the control circuit is configured to output a voltage generated in accordance with an output of the temperature sensing unit by using the correction table, to a second electrode of the capacitor.

7. The display device according to claim 6,

wherein the transistor comprises an oxide semiconductor layer comprising a channel formation region.

8. The display device according to claim 6,

wherein the pixel portion is configured to display a still image at a frame frequency of 30 Hz or less.

9. The display device according to claim 8,

wherein the frame frequency is 0.2 Hz or less.

10. The display device according to claim 6,

wherein the display element is a liquid crystal element.

11. A display device comprising:

a display panel comprising a pixel portion configured to display a still image at a frame frequency of 30 Hz or less;

a temperature sensing unit configured to sense a temperature of the display panel;

a memory device storing a correction table containing correction data; and

a control circuit to which a piece of the correction data selected from the correction table is input in accordance with an output of the temperature sensing unit,

wherein the pixel portion comprises a plurality of pixels,

wherein each of the plurality of pixels comprises a transistor, a display element, and a capacitor, and

wherein the control circuit is configured to output a voltage based on the piece of the correction data input to the control circuit, to a common terminal of the capacitor included in each of the plurality of pixels.

12. The display device according to claim 11,

wherein the transistor comprises an oxide semiconductor layer comprising a channel formation region.

13. The display device according to claim 11, wherein the frame frequency is 0.2 Hz or less.

14. The display device according to claim 11, wherein the display element is a liquid crystal element.