Organic light emitting display device and method of driving the same

Patent metadata

Field	Value
Publication number	US-9767734-B2
Application number	US-201514720477-A
Country	US
Kind code	B2
Filing date	May 22, 2015
Priority date	Jan 20, 2015
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

An display device includes a display panel including a plurality of pixels; a scan driver configured to provide scan signals to the pixels; a data driver configured to provide data signals to the pixels; a look-up table (LUT), wherein an efficiency curve indicating a relationship between an accumulated driving time and an efficiency value is stored in the LUT; a lifespan register, wherein an efficiency changing region for deriving the efficiency value of each of the pixels from the LUT is stored in the lifespan register and the lifespan register is configured to accumulatively store deterioration data of the pixels; and a controller configured to derive the accumulated driving time from the lifespan register, to update the efficiency changing region and the LUT based on the accumulated driving time, and to convert input image data into output image data using the efficiency changing region and the LUT.

First claim

What is claimed is:

1. An organic light emitting display device comprising:
a display panel comprising a plurality of pixels;
a scan driver configured to provide scan signals to the pixels;
a data driver configured to provide data signals to the pixels;
a look-up table (LUT), wherein an efficiency curve indicating a relationship between an accumulated driving time and an efficiency value is stored in the LUT;
a lifespan register including an efficiency changing region for deriving the efficiency value of each of the pixels from the LUT, the lifespan register being configured to accumulatively store deterioration data of the pixels; and
a controller configured to derive the accumulated driving time from the lifespan register, to update the efficiency changing region and the LUT based on the accumulated driving time, to convert input image data into output image data using the efficiency changing region and the LUT, and to provide control signals corresponding to the output image data to the scan driver and the data driver,
wherein the efficiency changing region is updated to increase a period of the efficiency curve by shifting the efficiency changing region in the lifespan register.

2. The display device of claim 1 , wherein the deterioration data for each of the pixels is stored in the lifespan register.

3. The display device of claim 1 , wherein the deterioration data for each pixel block among a plurality of pixel blocks is stored in the lifespan register.

4. The display device of claim 1 , wherein the controller comprises:
a deterioration data controller configured to accumulatively store the deterioration data in the lifespan register based on the input image data;
an update signal generator configured to generate an update signal based on the accumulated driving time;
a compensation criterion updater configured to update the efficiency changing region and the LUT in response to the update signal such that an efficiency changing period increases as the accumulated driving time increases;
an efficiency value deriver configured to derive the efficiency value using the efficiency changing region and the LUT; and
a deterioration compensator configured to convert the input image data into the output image data using the efficiency value.

5. The display device of claim 4 , wherein the compensation criterion updater shifts the efficiency changing region by one bit in response to the update signal.

6. The display device of claim 4 , wherein the compensation criterion updater is configured to load the efficiency curve corresponding to the efficiency changing region from a non-volatile memory device into the LUT in response to the update signal.

7. The display device of claim 4 , wherein the compensation criterion updater is included in a micro control unit (MCU).

8. The display device of claim 4 , wherein the efficiency value deriver is configured to derive the efficiency value from the LUT using a value of the efficiency changing region as an index of the LUT.

9. The display device of claim 4 , wherein the deterioration compensator is configured to derive compensation weight for each of the pixels using the efficiency value, and to generate the output image data by multiplying the input image data by the compensation weight.

10. The display device of claim 4 , wherein the deterioration data controller is configured to periodically read the deterioration data from the lifespan register, and to store the deterioration data in a non-volatile memory device.

11. The display device of claim 4 , wherein the deterioration data controller is configured to read the deterioration data from the lifespan register, and to store the deterioration data in a non-volatile memory device at a predetermined time.

12. The display device of claim 4 , wherein the controller further comprises:
an efficiency curve adjuster configured to scale the efficiency curve corresponding to the efficiency changing region, and
wherein the compensation criterion updater is configured to update the LUT using the scaled efficiency curve in response to the update signal.

13. The display device of claim 12 , wherein the efficiency curve adjuster is configured to scale the efficiency curve to approximately double the efficiency changing period in response to the update signal.

14. The display device of claim 4 , wherein the update signal generator is configured to generate the update signal when a value of a monitoring region included in the lifespan register is changed.

15. The display device of claim 14 , wherein a size of the monitoring region is one bit, and
wherein the monitoring region is shifted by one bit when the value of the monitoring region is changed.

16. The display device of claim 14 , wherein a size of the monitoring region is larger than one bit.

17. A method of driving an organic light emitting display device, the method comprising:
accumulatively storing deterioration data of pixels in a lifespan register based on input image data;
deriving an accumulated driving time of the pixels from the lifespan register;
generating an update signal based on the accumulated driving time;
updating an efficiency changing region in the lifespan register and a look-up table (LUT) in response to the update signal such that an efficiency changing period increases as the accumulated driving time increases, an efficiency curve indicating a relation between the accumulated driving time, and an efficiency value stored in the LUT;
deriving the efficiency value of each of the pixels from the LUT using a value of the efficiency changing region as an index of the LUT;
converting the input image data into output image data using the efficiency value; and
displaying an image using the output image data,
wherein the efficiency changing region is updated to increase the efficiency changing period by shifting the efficiency changing region in the lifespan register.

18. The method of claim 17 , wherein the update signal is generated when a value of a monitoring region in the lifespan register is changed.

19. The method of claim 17 , wherein the efficiency changing region is shifted by one bit in response to the update signal.

20. The method of claim 17 , wherein the efficiency curve corresponding to the efficiency changing region is loaded from a non-volatile memory device into the LUT in response to the update signal.

21. The method of claim 17 , wherein the efficiency curve is scaled in response to the update signal to update the LUT.

22. The method of claim 21 , wherein the efficiency curve is scaled to approximately double the efficiency changing period in response to the update signal.

Assignees

• Samsung Display Co Ltd

Inventors

• Jun Bong-Ju
• Chung Won-Chang
• Shin Kwang-Suk

Classifications

• G09G3/20 Primary

  for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix {no fixed position being assigned to or needed to be assigned to the individual characters or partial characters} · CPC title

• G09G2320/0233

  Improving the luminance or brightness uniformity across the screen · CPC title

• G09G2300/0819

  used for counteracting undesired variations, e.g. feedback or autozeroing · CPC title

• G09G2320/0295

  by monitoring each display pixel · CPC title

• G09G3/3208

  organic, e.g. using organic light-emitting diodes [OLED] · CPC title