Electroluminescent display and driving method thereof

Patent metadata

Field	Value
Publication number	US-10916204-B2
Application number	US-201816204143-A
Country	US
Kind code	B2
Filing date	Nov 29, 2018
Priority date	Nov 30, 2017
Publication date	Feb 9, 2021
Grant date	Feb 9, 2021

Abstract

Disclosed are an electroluminescent display and a driving method thereof, the method comprising: generating a predicted value, indicating a degree of degradation of pixels, by accumulating pixel data of an input image at each pixel: and generating a compensation value by adjusting the predicted value to a current measurement value which is obtained by measuring a current in a power line connected to the pixels. Compensation data, which is to be written into each of the pixels, is generated by modulating the pixel data with the compensation value.

First claim

What is claimed is:

1. An electroluminescent display comprising:
a display panel having a plurality of data lines and a plurality of scan lines intersecting with each other, and a plurality of pixels arranged thereon;
a power supply configured to be separated from the display panel and supply a pixel driving voltage to a power line;
a compensation device configured to generate a predicted value indicating a degree of degradation of pixels by accumulating pixel data of an input image at each pixel, generate a compensation value by adjusting the predicted value to a current measurement obtained by measuring a current directly on the power line between the display panel and the power supply, and generate compensation data by modulating the pixel data with the compensation value; and
a display panel driving circuit configured to write the compensation data into the plurality of pixels,
wherein each of the pixels includes:
a light emitting element; and
a driving element for driving the light emitting element,
wherein the power line extends into the display panel and is connected to the driving element in all the pixels to supply the pixel driving voltage to the pixels.

2. The electroluminescent display of claim 1 , wherein the compensation device includes:
a prediction unit configured to generate the predicted value based on a consumption amount of each pixel obtained by accumulating the pixel data of the input image at each pixel;
a measurement unit configured to measure a current flowing in the power line connected to the plurality of pixels;
an adjustment unit configured to compensate for the compensation value by reflecting a current measurement value, measured by the measurement unit, in the predicted value; and
a compensation unit configured to generate the compensation data by adding the compensation value to the pixel data.

3. The electroluminescent display of claim 1 , wherein the prediction unit converts the consumption amount of each pixel into a predicted value of a threshold voltage of a driving device which drives a light emitting device of a corresponding pixel, and calculates a current predicted value for each pixel based on the predicted value of the threshold voltage.

4. The electroluminescent display of claim 1 , wherein the adjustment unit calculates a current ratio of the current predicted value to a sum of currents of all pixels of the display panel, adjusts the current predicted value by reflecting the current measurement to the current ratio, and determines the compensation value by converting the current predicted value into a compensation value of the threshold voltage.

5. A driving method of an electroluminescent display comprising a plurality of pixels including a driving element for driving a light emitting element, and a power line connected to the driving element in all the pixels to supply a pixel driving voltage to the pixels, the method comprising:
supplying the pixel driving voltage generated from the power supply to the power line;
generating a predicted value indicative of a degree of degradation of a plurality of pixels, by accumulating pixel data of an input image at each pixel;
generating a compensation value by adjusting the predicted value to a current measurement value measured by measuring a current directly on the power line between the power supply and the pixels;
generating compensation data by modulating the pixel data with the compensation value; and
writing the compensation data into each pixel of the display panel.

6. The driving method of claim 5 , wherein the generating of a predicted value comprises generating the predicted value based on a consumption amount of each pixel which is obtained by accumulating the pixel data of the input image at each pixel.

7. The driving method of claim 5 , wherein the generating of compensation data comprises determining the compensation value by reflecting the current measurement value in the predicted value, and generating the compensation data by adding the compensation value to the pixel data.

8. The driving method of claim 6 , wherein the generating of a predicted value comprises generating the predicted value based on the consumption amount of each pixel which is obtained by adding a result of adding the compensation data to the pixel data of the input image to each pixel.

9. The driving method of claim 6 , wherein the generating of compensation data comprises determining the compensation value by reflecting the current measurement value in the predicted value, and generating the compensation data by adding the compensation value to the pixel data.

10. The driving method of claim 5 , wherein the generating of a predicted value includes converting the consumption amount of each pixel into a predicted value of a threshold voltage of a driving device which drives a light emitting device of the pixels, and generating the predicted value by calculating a current predicted value for each pixel based on the predicted value of the threshold voltage.

11. The driving method of claim 5 , wherein the generating of compensation data comprises generating a current ratio of the current predicted value regarding a sum of currents of all pixels of the display panel, adjusting the current predicted value for each pixel by reflecting the current measurement value in the current ratio, and determining the compensation value by converting the current predicted value for each pixel into the threshold voltage compensation value.

12. An electroluminescent display comprising:
a display panel having a plurality of data lines and a plurality of scan lines intersecting with each other, and a plurality of pixels including a driving element for driving a light emitting element and a power line connected to the driving element in all the pixels to supply a pixel driving voltage to the pixels, wherein sensing lines are not connected to the a plurality of pixels;
a power supply configured to be separated from the display panel and supply the pixel driving voltage to the power line; and
a compensation device configured to:
generate a predicted value, indicating a degree of degradation of pixels, by accumulating pixel data of an input image at each pixel,
generate a compensation value by adjusting the predicted value to a current measurement obtained by measuring a current directly on the power line between the display panel and the power supply, and
generate compensation data by modulating the pixel data with the compensation value; and
a display panel driving circuit configured to write the compensation data at each pixel.

13. The electroluminescent display of claim 12 , wherein the compensation device includes:
a prediction unit generating the predicted value based on a consumption amount of each pixel obtained by accumulating the pixel data of the input image at each pixel;
a measurement unit measuring a current flowing in the power line connected to the plurality of pixels;
an adjustment unit compensating for the compensation value by reflecting a current measurement value, measured by the measurement unit, in the predicted value; and
a compensation unit generating the compensation data by adding the compensation value to the pixel data.

14. The electroluminescent display of claim 13 , wherein the prediction unit converts the consumption amount of each pixel into a predicted value of a threshold voltage of a driving device which drives a light emitting device of a corresponding pixel and calculates a current predicted value for each pixel based on the predicted value of the threshold voltage.

15. The electroluminescent display of c

Assignees

• Lg Display Co Ltd

Inventors

• An Jooyoung
• Park Hyojung
• LEE Jeisung
• Oh Euiyeol

Classifications

• G09G2320/043

  Preventing or counteracting the effects of ageing · CPC title

• G09G2320/0257

  Reduction of after-image effects · CPC title

• G09G2300/043

  Compensation electrodes or other additional electrodes in matrix displays related to distortions or compensation signals, e.g. for modifying TFT threshold voltage in column driver · CPC title

• G09G2300/0828

  forming a digital to analog [D/A] conversion circuit · CPC title

• G09G3/3233 Primary

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