Organic light-emitting display device and method for driving the same

Patent metadata

Field	Value
Publication number	US-2017193900-A1
Application number	US-201615393662-A
Country	US
Kind code	A1
Filing date	Dec 29, 2016
Priority date	Dec 30, 2015
Publication date	Jul 6, 2017
Grant date	—

Abstract

The present invention provides an organic light-emitting display device including a display panel, a power supply, a selective driver and a gamma change driver. The display panel includes sub-pixels. The power supply is configured to output a drive voltage for driving the sub-pixels. The selective driver is configured to generate a control signal to enable selective drive between first and second driving schemes for a drive transistor in each sub-pixel, wherein the first and second schemes employ saturation and linear regions of the drive voltage curve respectively. The gamma change driver is configured to change a gamma based on the driving scheme selected by the selective driver.

First claim

What is claimed is:

1 . A display device, comprising:
a display panel including at least one data line, at least one gate line, and a sub-pixel connected to the data line and the gate line, the sub-pixel including a drive transistor; a timing controller configured to provide a data signal and a data control signal based on an input image data and one or more timing control signals; a data driver configured to provide a data voltage to the data line based on the data signal and the data control signal; a power supply configured to provide a first high level voltage and a second high level voltage different from the first high level voltage; and a selective driver configured to control a selection between the first high level voltage and the second high level voltage to be supplied to a drain of the drive transistor based on the data signal.

2 . The display device of claim 1 , wherein the first high level voltage is higher than the data voltage, and the second high level voltage is lower than the data voltage.

3 . The display device of claim 1 , wherein the sub-pixel further includes an organic light-emission diode (OLED) connected in series with the drive transistor, and the drive transistor is configured to generate a current for driving the OLED.

4 . The display device of claim 3 , wherein:
when the drive transistor is driven in a linear region of a current-voltage curve, the selective driver is configured to cause the first high level voltage to be supplied to the drain of the drive transistor, and when the drive transistor is driven in a saturation region of the current-voltage curve, the selective driver is configured to cause the second high level voltage to be supplied to the drain of the drive transistor.

5 . The display device of claim 1 , wherein the selective driver includes:
a non-linear driver configured to provide a first drive control signal to enable a first driving scheme in which the drive transistor is configured to be to be driven in a saturation region of a current-voltage curve; a linear driver configured to provide a second drive control signal to enable a second driving scheme in which the drive transistor is configured to be driven in a linear region of the current-voltage curve; and a gamma change driver configured to output a gamma change signal indicating a gamma change point based on a change in a driving scheme between the first driving scheme and the second driving scheme.

6 . The display device of claim 5 , further comprising:
a gamma circuit configured to selectively provide a first gamma voltage on a first gamma curve or a second gamma voltage on a second gamma curve to the data driver based on the gamma change signal, wherein the data driver is configured to provide the data voltage to the data line based on the first gamma voltage or the second gamma voltage selectively provided by the gamma circuit.

7 . The display device of claim 5 , further comprising:
a compensation circuit configured to provide a compensation signal to the display panel to compensate for a characteristic variation in the display panel based one or more of the data signal, a change in the driving scheme, and a change in the gamma change point.

8 . The display device of claim 7 , wherein one or both of the selective driver and the compensation circuit are included in the timing controller.

9 . The display device of claim 6 , wherein the second high level voltage is varied gradually in response to changes in the threshold voltage of the drive transistor.

10 . The display device of claim 6 , further comprising a timing controller configured to monitor the threshold voltage of the drive transistor, to generate a power variable signal to increase a level of the second high level voltage gradually in response to changes in the threshold voltage of the drive transistor, and to deliver the power variable signal to the power supply.

11 . A display device, comprising:
a display panel having at least one data line, at least one gate line, and a sub-pixel connected to the data line and the gate line, the sub-pixel including a drive transistor; a first circuit board including:
a host system configured to provide an input image data and one or more timing signals, and
a power supply configured to provide a first high level voltage and a second high level voltage different from the first high level voltage;
a second circuit board including:
a timing controller configured to provide a data signal and a data control signal based on the input image data and the one or more timing control signals, and
a selective driver configured to control a selection between the first high level voltage and the second high level voltage to be supplied to a drain of the drive transistor; and
a data driver configured to provide a data voltage to the data line based on the data signal and the data control signal.

12 . The display device of claim 11 , wherein the sub-pixel further includes an organic light-emission diode (OLED) connected in series with the drive transistor, and the drive transistor is configured to generate a current for driving the OLED.

13 . The display device of claim 11 , wherein the selective driver includes:
a non-linear driver configured to provide a first drive control signal to enable a first driving scheme in which the drive transistor is configured to be to be driven in a saturation region of a current-voltage curve; a linear driver configured to provide a second drive control signal to enable a second driving scheme in which the drive transistor is configured to be driven in a linear region of the current-voltage curve; and a gamma change driver configured to output a gamma change signal indicating a gamma change point based on a change in a driving scheme between the first driving scheme and the second driving scheme.

14 . The display device of claim 13 , wherein the second circuit board further includes:
a gamma circuit configured to selectively provide a first gamma voltage on a first gamma curve or a second gamma voltage on a second gamma curve to the data driver based on the gamma change signal, wherein the data driver is configured to provide the data voltage to the data line based on the first gamma voltage or the second gamma voltage selectively provided by the gamma circuit.

15 . The display device of claim 13 , further comprising:
a compensation circuit configured to provide a compensation signal to compensate for a characteristic variation in the display panel based one or more of the data signal, a change in the driving scheme, and a change in the gamma change point, wherein one or both of the selective driver and the compensation circuit are included in the timing controller.

16 . A method of driving a display device comprising a display panel having at least one data line, at least one gate line, and a sub-pixel at an intersection of the data line and the gate line, the sub-pixel including a drive transistor, the method comprising:
receiving an input image data and one or more timing signals; generating a data signal and a data control signal based on the input image data and the one or more timing signals; providing a data voltage to the data line based on the data signal and the data control signal; and selectively supplying a first high level voltage higher than the data voltage and a second high level voltage lower than the data voltage to a drain of the drive transistor based on the data signal.

17 . The method of claim 16 , wherein the selectively supplying includes:
selectively ge

Assignees

• Lg Display Co Ltd

Inventors

• Kwon Yongchul
• Park Dongwon
• Park Jongmin
• Lee Joonhee

Classifications

• G09G2310/08

  Details of timing specific for flat panels, other than clock recovery · CPC title

• G09G3/3266

  Details of drivers for scan electrodes · CPC title

• G09G2320/0673

  for control of gamma adjustment, e.g. selecting another gamma curve · CPC title

• G09G2330/021

  Power management, e.g. power saving · CPC title

• G09G3/3233 Primary

  with pixel circuitry controlling the current through the light-emitting element · CPC title