Organic light emitting display device

Patent metadata

Field	Value
Publication number	US-10325552-B2
Application number	US-201414508792-A
Country	US
Kind code	B2
Filing date	Oct 7, 2014
Priority date	Oct 8, 2013
Publication date	Jun 18, 2019
Grant date	Jun 18, 2019

Abstract

Discussed is an organic light emitting display device capable of reducing power consumption and increasing lifespan of the device. The device includes a display panel including pixels in respective pixel regions defined by a plurality of gate lines, data lines and driving voltage lines, wherein each pixel includes an organic light emitting diode which emits light by a current, and a pixel circuit having a driving transistor for controlling a current flowing from the driving voltage line to the organic light emitting diode on the basis of data voltage; and a panel driver for converting frame video data into the data voltage, supplying the data voltage to each pixel, calculating peak luminance value and maximum grayscale value by analyzing the frame video data, and varying the driving voltage based on the peak luminance value and maximum grayscale value.

First claim

What is claimed is:

1. An organic light emitting display device comprising:
a display panel including a plurality of pixels respectively formed in pixel regions defined by a plurality of gate lines, data lines and driving voltage lines, wherein each of the pixels includes an organic light emitting diode which emits light by a current, and a pixel circuit having a driving transistor for controlling a current flowing from the corresponding driving voltage line to the corresponding organic light emitting diode on the basis of a data voltage supplied to the corresponding data line and a driving voltage supplied to the corresponding driving voltage line; and
a panel driver including a driving voltage supplier for:
converting frame video data into the data voltage,
supplying the data voltage to each of the pixels,
calculating a frame representative value by analyzing grayscale values of the frame video data,
calculating a peak luminance value based on the frame representative value and calculating a maximum grayscale value by analyzing the grayscale values of the frame video data to decrease the driving voltage,
generating driving voltage setting data based on the maximum grayscale value and a driving voltage margin according to the peak luminance value, wherein the driving voltage margin varies based on the peak luminance value, and the peak luminance value is set based on the frame representative value,
changing the driving voltage based on the driving voltage setting data to generate an adjusted driving voltage, and
supplying the adjusted driving voltage to the plurality of driving voltage lines.

2. The organic light emitting display device according to claim 1 , wherein the panel driver controls a peak luminance of image by the frame video data displayed on the display panel using the peak luminance value.

3. The organic light emitting display device according to claim 2 , wherein the panel driver includes:
a timing controller including a processor, the timing controller for:
calculating the peak luminance value and the maximum grayscale value by analyzing the frame video data, generating reference gamma voltage data based on the peak luminance value, and generating the driving voltage setting data based on the peak luminance value and the maximum grayscale value, and
generating a plurality of reference gamma voltages based on the reference gamma voltage data;

a data driver for converting the frame video data, which is input from the timing controller on the basis of the plurality of reference gamma voltages, into the data voltage, and supplying the data voltage to the corresponding data line; and
a gate driver for sequentially supplying a gate signal to the plurality of gate lines under control of the timing controller, and
wherein the driving voltage supplier for generating the driving voltage corresponding to the driving voltage setting data, and supplying the driving voltage to the plurality of driving voltage lines.

4. The organic light emitting display device according to claim 3 , wherein the timing controller generates the reference gamma voltage data and the driving voltage setting data,
calculates the frame representative value by analyzing the frame video data,
sets the peak luminance value based on the frame representative value,
sets the reference gamma voltage data to change the peak luminance of image by the frame video data to the peak luminance value on the basis of the peak luminance value,
calculates the maximum grayscale value by analyzing the frame video data, and
generates the driving voltage setting data based on the peak luminance value and the maximum grayscale value.

5. The organic light emitting display device according to claim 4 , wherein the timing controller generates the driving voltage value corresponding to the peak luminance value, generates the grayscale compensation value corresponding to the maximum grayscale value, and generates the driving voltage setting data by reflecting the grayscale compensation value on the driving voltage value.

6. The organic light emitting display device according to claim 5 , wherein the timing controller generates the driving voltage value by using a first look-up table in which the driving voltage value is mapped in accordance with the peak luminance value, and generates the grayscale compensation value by using a second look-up table in which the grayscale compensation value for additionally reducing the driving voltage is mapped in accordance with the maximum grayscale value.

7. The organic light emitting display device according to claim 4 ,
wherein the timing controller generates a gamma compensation value based on the driving voltage setting data, and sets the reference gamma voltage data by correcting the reference gamma voltage value based on the gamma compensation value.

8. The organic light emitting display device according to claim 7 , wherein the timing controller generates the driving voltage value corresponding to the peak luminance value, generates the grayscale compensation value corresponding to the maximum grayscale value, and generates the driving voltage setting data by reflecting the grayscale compensation value on the driving voltage value.

9. The organic light emitting display device according to claim 8 , wherein the timing controller generates the driving voltage value by using a first look-up table in which the driving voltage value is mapped in accordance with the peak luminance value, and generates the grayscale compensation value by using a second look-up table in which the grayscale compensation value for additionally reducing the driving voltage is mapped in accordance with the maximum grayscale value.

10. The organic light emitting display device according to claim 7 , wherein the timing controller calculates a data deviation between the reference driving voltage data and the driving voltage setting data, and generates the gamma compensation value based on the calculated data deviation.

11. The organic light emitting display device according to claim 10 , wherein the timing controller generates the gamma compensation value by using a third look-up table in which the gamma compensation value is mapped in accordance with the data deviation, and the gamma compensation value is increased according to the increase of data deviation.

12. The organic light emitting display device according to claim 1 , wherein the frame representative value is an average grayscale value of the frame video data.

13. The organic light emitting display device according to claim 1 , wherein the peak luminance value is set in accordance with the frame representative value by a look-up table, and
wherein the look-up table maps peak luminance values to corresponding frame representative values, respectively.

14. The organic light emitting display device according to claim 1 , wherein the driving voltage supplier is a digital-to-analog converter for converting the driving voltage setting data to the adjusted driving voltage.

15. The organic light emitting display device according to claim 1 , wherein the driving voltage supplier is a DC-to-DC converter for generating the adjusted driving voltage through pulse width modulation based on the driving voltage setting data.

Assignees

• Lg Display Co Ltd

Inventors

• Jeong Jae Hyeong
• Park Sang Jae

Classifications

• G09G2360/16

  Calculation or use of calculated indices related to luminance levels in display data · CPC title

• G09G2320/0626

  for control of overall brightness · CPC title

• G09G3/3225 Primary

  using an active matrix · CPC title

• G09G2320/043

  Preventing or counteracting the effects of ageing · CPC title

• G09G2320/0276

  for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction · CPC title