Display device and method of driving the same

Patent metadata

Field	Value
Publication number	US-10170049-B2
Application number	US-201615274003-A
Country	US
Kind code	B2
Filing date	Sep 23, 2016
Priority date	Sep 25, 2015
Publication date	Jan 1, 2019
Grant date	Jan 1, 2019

Abstract

Provided are a display device and method of driving the same. A display device includes: a display panel including: intersecting data lines and gate lines, and pixels in a matrix, a timing controller allowing the pixels to be driven at a lower refresh rate in low-speed driving mode than in normal driving mode, and controlling a horizontal blank time to be longer in the low-speed driving mode than the normal driving mode, the horizontal blank time being a period of time during which no data voltage exists, between an n th data voltage and an (n+1) th data voltage consecutively supplied through the data lines, “n” being a positive integer, and a display panel driving circuit writing one frame of image data to the pixels during one frame period in the normal driving mode, and in a distributed manner during a second to fourth frame period in the low-speed driving mode.

First claim

What is claimed is:

1. A display device, comprising:
a display panel comprising:
data lines and gate lines intersecting each other; and
pixels in a matrix;

a timing controller configured to:
allow the pixels to be driven at a lower refresh rate in low-speed driving mode than in normal driving mode; and
control a horizontal blank time to be longer in the low-speed driving mode than in the normal driving mode, the horizontal blank time being a period of time during which no data voltage exists, between an n th data voltage, supplied to the pixels on an nth horizontal line of the display panel, and an (n+1) th data voltage, supplied to the pixels on an (n+1) th horizontal line of the display panel, that are consecutively supplied through the data lines, where “n” is a positive integer greater than or equal to 1; and

a display panel driving circuit configured to:
write data to the display panel;
write one frame of image data to the pixels during one frame period in the normal driving mode; and
write one frame of image data to the pixels in a distributed manner during an i-frame period in the low-speed driving mode, where “i” is a positive integer from 2 to 4,
wherein the horizontal blank time is extended so that a next data voltage is supplied to the data lines after discharging the parasitic capacitance of the data lines in the low-speed driving mode.

2. The display device of claim 1 , wherein, in the low-speed driving mode, each pixel:
charges itself with a data voltage once in the i-frame period; and
holds the data voltage during a unit of time set for the low-speed driving mode, except for the i-frame period.

3. The display device of claim 1 , wherein the pixels are driven by progressive scanning or interlaced scanning in the normal driving mode and low-speed driving mode.

4. The display device of claim 1 , wherein the pixels are driven by:
progressive scanning in the normal driving mode; and
interlaced scanning in the low-speed driving mode.

5. The display device of claim 1 , wherein the pixels are driven by:
interlaced scanning in the normal driving mode; and
progressive scanning in the low-speed driving mode.

6. The display device of claim 1 , wherein the timing controller controls the horizontal blank time in the low-speed driving mode to be two times or more longer than the horizontal blank time in the normal driving mode.

7. The display device of claim 1 , wherein the pixels comprise oxide transistors.

8. The display device of claim 1 , wherein the pixels comprise:
oxide transistors; and
polycrystalline transistors.

9. The display device of claim 1 , wherein the pixels are driven by progressive scanning or interlaced scanning in the normal driving mode and the low-speed driving mode.

10. A method of driving a display device comprising a display panel, comprising data lines and gate lines intersecting each other and pixels in a matrix, and a display panel driving circuit for writing data to the display panel, the method comprising:
reducing the driving frequency and power consumption of the display panel driving circuit in low-speed driving mode compared to normal driving mode;
controlling a horizontal blank time to be longer in the low-speed driving mode than in the normal driving mode, the horizontal blank time being a period of time during which no data voltage exists, between an n th data voltage, supplied to the pixels on an nth horizontal line of the display panel, and an (n+1) th data voltage, supplied to the pixels on an (n+1) th horizontal line of the display panel, that are consecutively supplied through the data lines, where “n” is a positive integer greater than or equal to 1, the horizontal blank time being extended so that a next data voltage is supplied to the data lines after discharging the parasitic capacitance of the data lines in the low-speed driving mode;
writing, by the display panel driving circuit, one frame of image data to the pixels during one frame period in the normal driving mode; and
writing, by the display panel driving circuit, one frame of image data to the pixels in a distributed manner during an i-frame period in the low-speed driving mode, where “i” is a positive integer from 2 to 4.

11. The method of claim 10 , further comprising, in the low-speed driving mode, each pixel:
charging itself with a data voltage once in the i-frame period; and
holding the data voltage during a unit of time set for the low-speed driving mode, except for the i-frame period.

12. The method of claim 10 , wherein the pixels are driven by progressive scanning or interlaced scanning in the normal driving mode and low-speed driving mode.

13. The method of claim 10 , wherein the pixels are driven by:
progressive scanning in the normal driving mode; and
interlaced scanning in the low-speed driving mode.

14. The method of claim 10 , wherein the pixels are driven by:
interlaced scanning in the normal driving mode; and
progressive scanning in the low-speed driving mode.

15. The method of claim 10 , wherein the timing controller controls the horizontal blank time in the low-speed driving mode to be two times or more longer than the horizontal blank time in the normal driving mode.

16. A display device, comprising:
a display panel comprising:
a plurality of data lines and gate lines intersecting each other; and
a plurality of pixels in a matrix;

a timing controller configured to:
allow the pixels to be driven at a lower refresh rate in a low-speed driving mode than in a normal driving mode; and
control a horizontal blank time to be longer in the low-speed driving mode than in the normal driving mode, the horizontal blank time being a period of time during which no data voltage exists, between an n th data voltage, supplied to the pixels on an nth horizontal line of the display panel, and an (n+1) th data voltage, supplied to the pixels on an (n+1) th horizontal line of the display panel, that are consecutively supplied through the data lines, where “n” is a positive integer greater than or equal to 1; and

a display panel driving circuit configured to write data to the display panel;
wherein the horizontal blank time is longer in the low-speed driving mode than in the normal driving mode to ensure enough time to discharge a parasitic capacitance, thereby minimizing a pixel voltage variation by residual charge in the parasitic capacitance connected to the data lines.

17. The display device of claim 16 , wherein:
less than one frame of data is written to some pixels during one frame period; and
a remaining data is written to some other pixels in the low-speed driving mode.

18. The display device of claim 16 , wherein the display panel driving circuit is configured to write one frame of image data to the pixels in a distributed manner during an i-frame period in the low-speed driving mode, where “i” is a positive integer from 2 to 4.

19. The display device of claim 16 , wherein the horizontal blank time in the low-speed driving mode is two times or more longer than the horizontal blank time in the normal driving mode.

20. The display device of claim 16 , wherein the pixels comprise:
oxide transistors; and
polycrystalline transistors.

Assignees

• Lg Display Co Ltd

Inventors

• Ryu Sungbin
• Lee Youngjang

Classifications

• G09G3/20 Primary

  for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix {no fixed position being assigned to or needed to be assigned to the individual characters or partial characters} · CPC title

• G09G2340/0435

  Change or adaptation of the frame rate of the video stream · CPC title

• G09G2330/022

  in absence of operation, e.g. no data being entered during a predetermined time · CPC title

• G09G2300/0819

  used for counteracting undesired variations, e.g. feedback or autozeroing · CPC title

• G09G2300/0814

  used for selection purposes, e.g. logical AND for partial update · CPC title