Optical compensation method and driving method for organic light emitting display device

Patent metadata

Field	Value
Publication number	US-9087482-B2
Application number	US-201213623015-A
Country	US
Kind code	B2
Filing date	Sep 19, 2012
Priority date	Sep 19, 2011
Publication date	Jul 21, 2015
Grant date	Jul 21, 2015

Abstract

An optical compensation method for an organic light emitting display device comprises: setting initial gain values of RGB subpixels; making each of the RGB subpixels converge on target luminance; selecting subpixels to emit light with the W subpixel from the RGB subpixels, and setting an initial gain value of the W subpixel; measuring color coordinates and luminance of the W subpixel to which the initial gain value is applied; calculating the luminance ratio of the W subpixel and the selected subpixels; adjusting maximum gains of the W subpixel and the selected subpixels; measuring maximum color coordinates and luminance ratio of the W subpixel and the selected subpixels; and making the W subpixel and the selected subpixels converge on target color coordinates and luminance.

First claim

What is claimed is:

1. An optical compensation method for an organic light emitting display device, the method comprising:
setting initial gain values of red (R), green (G), and blue (B) subpixels;
making each of the R, G and B subpixels converge on a target luminance for each subpixel;
wherein the making each of the R, G, and B subpixels converge on the target luminance comprises:
measuring color coordinates of each of the R, B, and B subpixels to which the initial gain values are applied;
calculating a luminance ratio of the R, G, and B subpixels; and
adjusting maximum gains of the R, G, and B subpixels;

selecting subpixels to emit light with a white (W) subpixel from the R, G and B subpixels, and setting an initial gain value of the W subpixel;
measuring color coordinates and a luminance of the W subpixel to which the initial gain value is applied;
calculating a luminance ratio of the W subpixel and the selected subpixels;
adjusting maximum gains of the W subpixel and the selected subpixels;
measuring maximum color coordinates and a maximum luminance ratio of the W subpixel and the selected subpixels; and
making the W subpixel and the selected subpixels converge on target color coordinates and luminance.

2. The method of claim 1 , wherein, in the converging of the W subpixel and the selected subpixels on the target color coordinates and luminance, responsive to the W subpixel and the selected subpixels diverging from the target color coordinates and luminance, the process subsequent to the adjusting of maximum gains of the W subpixel and the selected subpixels is repeated.

3. The method of claim 1 , wherein, upon completion of the W subpixel and the selected subpixels converging on the target color coordinates and luminance, calculating of the luminance ratio the W subpixel and the selected subpixels, adjusting of gains of the W subpixel and the selected subpixels for each point, and measuring of per-point gamma curve luminance for each of the W subpixel and the selected subpixels are performed, and
responsive to the per-point gamma curve luminance of each of the W subpixel and the selected subpixels diverging from the target color coordinates and luminance, the process subsequent to the adjusting of gains of the W subpixel and the selected subpixels for each point is repeated.

4. The method of claim 1 , wherein the setting of initial gain values of R, G and B subpixels comprises setting initial gain values of the selected subpixels.

5. The method of claim 1 , wherein the making of each of the R, G and B subpixels converge on the target luminance comprises:
measuring a maximum luminance of each of the R, G and B subpixel, and
responsive to each of the R, G and B subpixels diverging from the target luminance, repeating the process subsequent to the adjusting of maximum gains of the R, G and B subpixels.

6. The method of claim 1 , wherein, upon completion of the R, G and B subpixels converging on target color coordinates and the target luminance, calculating of the luminance ratio the R, G and B subpixels, adjusting of gains of the R, G and B subpixels for each point, and measuring of the per-point gamma curve luminance for each of the R, G and B subpixels are performed, and
when the per-point gamma curve luminance of each of the R, G and B subpixels diverge from the target color coordinates and luminance, the process subsequent to the adjusting of gains of the R, G and B subpixels for each point is repeated.

7. The method of claim 1 , wherein a number of selected subpixels is one, two, or three selected from the R, G and B subpixels.

8. The method of claim 1 , wherein the selected subpixels are selected from one of: the G and B subpixels, the R and G subpixels, and the R and B subpixels.

9. A driving method for an organic light emitting display device, the method comprising:
analyzing an input image to detect whether the input image is video or a still image;
responsive to detecting that the input image is video:
analyzing an amount of white (W) data signal included in the input image compared to a threshold value;
determining an amount of data signals selected from red (R), green (G) and blue (B) data signals according to an analysis result of the amount of W data signal, wherein the amount of selected data signals is determined to be increased or decreased relative to a reference amount;

responsive to detecting that the input image is a still image:
determining an amount of selected data signals to be the reference amount corrected with the target color coordinates for white gray level;

applying the amount of selected data signals to generate R, G, B and W data signals and outputting the R, G, B and W data signals; and
displaying the image by using the R, G, B and W data signals.

10. The method of claim 9 , further comprising, responsive to detecting that the input image is a still image applying the reference amount to the amount of selected data signals and outputting R, G, B and W data signals.

11. The method of claim 9 , wherein, in the determining of the amount of selected data signals, responsive to the amount of W data signal being less than a threshold value, the amount of selected data signals is decreased compared to a reference amount, and responsive to the amount of W data signal being greater than the threshold value, the amount of selected data signals is increased compared to the reference amount.

12. The method of claim 9 , wherein the amount of selected data signals has a larger reduction compared to a reference amount when the image corresponding to video has a lower gray level.

13. The method of claim 9 , wherein a number of selected data signals is one, two, or three selected from the R, G and B data signals.

14. The method of claim 9 , wherein the selected data signals are selected from one of: the G and B data signals, the R and G data signals, and the R and B data signals.

Assignees

• Lg Display Co Ltd

Inventors

• Park Ilkwon
• Oh Dongkyoung
• Mun Kyeongsu

Classifications

• G09G2320/0666

  for control of colour parameters, e.g. colour temperature · CPC title

• G09G2320/103

  Detection of image changes, e.g. determination of an index representative of the image change · CPC title

• G09G3/3233 Primary

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

• G09G2300/0452

  Details of colour pixel setup, e.g. pixel composed of a red, a blue and two green components · CPC title

• G09G2360/147

  the originated light output being determined for each pixel · CPC title