Organic light emitting display device and driving method thereof

Patent metadata

Field	Value
Publication number	US-9478156-B2
Application number	US-201314055531-A
Country	US
Kind code	B2
Filing date	Oct 16, 2013
Priority date	Dec 21, 2012
Publication date	Oct 25, 2016
Grant date	Oct 25, 2016

Abstract

Disclosed is an organic light emitting display device. The organic light emitting display device includes a display panel arranged to include a plurality of unit pixels having red, green, blue, and white sub-pixels, a four-color data converter configured to convert input data of red, green, and blue of each unit pixel into data of red, green, blue, and white respectively corresponding to the red, green, blue, and white sub-pixels, and a panel driver configured to accumulate data of each of the sub-pixels at every accumulation period, store the accumulated data in a memory, decide a color correction mode for correcting a color of each unit pixel on the basis of the accumulated data of the white sub-pixel stored in the memory, drive the white sub-pixel of each unit pixel according to the decided color correction mode, and selectively drive the red, green, and blue sub-pixels.

First claim

What is claimed is:

1. An organic light emitting display device comprising:
a display panel arranged to include including a plurality of pixels having red, green, blue, and white sub-pixels comprising different organic light emitting elements;
a four-color data converter configured to convert input data of red, green, and blue of each of the plurality of pixels into data of red, green, blue, and white respectively corresponding to the red, green, blue, and white sub-pixels of each pixel;
a data accumulating unit, as part of a display panel driver to drive the display panel, to read a accumulated data of red, green, blue and white sub-pixels stored in a memory, accumulate the data of the red, green, blue, and white sub-pixels supplied from the four-color data converter to the data read from the memory at every accumulation period and store the accumulated data of the red, green, blue, and white sub-pixels in the memory, and
a color correction mode deciding unit configured to determine a color correction mode, a mode of driving the plurality of pixels in the display panel for correcting a color of each pixel on the basis of the accumulated data of the white sub-pixel stored in the memory,
wherein the white sub-pixel of each pixel is driven and the red, green, and blue sub-pixels are selectively driven with the driving of the white sub-pixel according to the determined color correction mode.

2. The organic light emitting display device of claim 1 , wherein,
when in the color correction mode, all of the red, green, blue, and white sub-pixels of each pixel are simultaneously driven, and
when not in the color correction mode, two of the red, green, and blue sub-pixels of each pixel and a white sub-pixel are simultaneously driven.

3. The organic light emitting display device of claim 1 further comprising:
a deterioration compensation value calculating unit to calculate a deterioration compensation gain value of each sub-pixel for compensating for a deterioration of the organic light emitting element of each sub-pixel on the basis of the accumulated data of each sub-pixel; and
a data modulating unit to modulate converted data of each sub-pixel according to the deterioration compensation gain value to further generate modulation data of each sub-pixel.

4. The organic light emitting display device of claim 3 , further comprising:
a three-color correction value generating unit to generate color correction values of red, green, and blue for color-correcting the modulation data of red, green, and blue of each pixel according to the determined color correction mode.

5. The organic light emitting display device of claim 4 ,
wherein the color correction mode deciding unit compares the accumulated data of the white sub-pixel with a predetermined white deterioration reference value to generate a first or a second color correction mode signal based on the comparison result, and
wherein the three-color correction value generating unit generates color correction values of red, green, and blue having a value of zero when a color correction mode signal having a first logic level is supplied from the color correction mode deciding unit, and when a color correction mode signal having a second logic level is supplied from the color correction mode deciding unit, generate color correction values of red, green, and blue having a real number value exceeding zero on the basis of the white modulation data of each pixel.

6. A method of driving an organic light emitting display device, including a pixel that includes red, green, blue, and white sub-pixels having different organic light emitting elements, the method comprising:
converting input data of red, green, and blue of the pixel into data of red, green, blue, and white respectively corresponding to the red, green, blue, and white sub-pixels of the pixel;
accumulating data by reading a data of red, green, blue, and white sub-pixels stored in a memory, accumulating the data of the red, green, blue, and white sub-pixels supplied from the four-color data converter to the data read from the memory at every accumulation period, and storing the accumulated data of the red, green, blue, and white sub-pixels in the memory; and
determining a color correction mode, a mode of driving the pixel for correcting a color of the pixel on the basis of the accumulated data of the white sub-pixel stored in the memory, and
driving the white sub-pixel and selectively driving the red, green, and blue sub-pixels simultaneously with the driving of the white sub-pixel according to the determined color correction mode.

7. The method of claim 6 , wherein the determining a color correction mode comprises:
when there is the color correction mode, simultaneously driving all of the red, green, blue, and white sub-pixels; and
when there is no color correction mode, simultaneously driving two of the red, green, and blue sub-pixels and a white sub-pixel.

8. The method of claim 6 , further comprising:
calculating a deterioration compensation gain value of each sub-pixel for compensating for a deterioration of the organic light emitting element of each sub-pixel on the basis of the accumulated data of each sub-pixel, and
modulating converted data of each sub-pixel according to the deterioration compensation gain value to further generate modulation data of each sub-pixel.

9. The method of claim 8 , wherein the determining a color correction mode comprises:
comparing the accumulated data of the white sub-pixel with a predetermined white deterioration reference value to generate a first or a second color correction mode signal for deciding the color correction mode according to a compared result; and
selectively color-correcting the modulation data of the red, green, and blue sub-pixels according to the first or the second color correction mode signal, driving the white sub-pixel, and generating correction data of red, green, blue, and white for selectively driving the red, green, and blue sub-pixels simultaneously with the driving of the white sub-pixel.

10. The method of claim 9 , wherein the selectively color-correcting the modulation data comprises:
generating color correction values of red, green, and blue having a value of zero according to the color correction mode signal having a first logic level, or generating color correction values of red, green, and blue having a real number value exceeding zero on the basis of the white modulation data of the pixel according to the color correction mode signal having a second logic level; and
reflecting the color correction values of red, green, and blue respectively corresponding to the modulation data of red, green, and blue to generate the correction data of red, green, blue, and white.

11. The organic light emitting display device of claim 4 , further comprising:
a data correcting unit to color-correct the modulation data of red, green, and blue of each pixel according to the color correction values of red, green, and blue supplied from the three-color correction value generating unit to generate correction data of red, green, blue, and white of each pixel,
wherein the red, green, blue, and white sub-pixels of each pixel are driven according to the correction data of red, green, blue, and white of each pixel.

Assignees

• Lg Display Co Ltd

Inventors

• Jeong Uitaek
• Byeon Boeon

Classifications

• G09G2300/0452

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

• G09G3/2003 Primary

  Display of colours (specific for liquid crystal displays G09G3/3607) · CPC title

• G09G2340/06

  Colour space transformation · CPC title

• G09G2320/048

  using evaluation of the usage time · CPC title

• G09G2320/0666

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