Compensation margin control device, organic light emitting display device, and method of driving the same

Patent metadata

Field	Value
Publication number	US-10181292-B2
Application number	US-201615250453-A
Country	US
Kind code	B2
Filing date	Aug 29, 2016
Priority date	Aug 31, 2015
Publication date	Jan 15, 2019
Grant date	Jan 15, 2019

Abstract

A compensation margin control device, an organic light emitting display device, and a driving method thereof according to the present disclosure provide an effect to improve the image quality by ensuring a margin of a negative bios shift compensation region of a driving transistor of a non-driven sub-pixel without affecting a gray level representation and positive compensation.

First claim

What is claimed is:

1. An organic light emitting display device comprising:
a display panel on which a plurality of data lines and a plurality of gate lines are arranged and a plurality of sub-pixels are arranged in a matrix form;
a data driver driving the data lines;
a gate driver driving the gate lines; and
a timing controller controlling the data driver and the gate driver,
wherein each of the sub-pixels comprises an organic light emitting diode, a driving transistor, a first transistor, a second transistor, and a capacitor,
each of the sub-pixels constitutes a pixel with four sub-pixels, wherein a white sub-pixel or more of three sub-pixels is driven and at least one of the three sub-pixels is not driven when a white color driving scheme is implemented, and
the data driver has a source driver integrated circuit that supplies a different voltage to the driven white sub-pixel or more and the non-driven at least one sub-pixel when the pixel is driven with a driving voltage to represent a color and maintains a same reference voltage for the driven white sub-pixel or more and the at least one non-driven sub-pixel,
wherein the driving voltage includes a compensation region voltage to compensate for a shift in a threshold voltage of the driving transistor, and the compensation region voltage has a different voltage range for the driven the white sub-pixel or more and the non-driven at least one sub-pixel,
wherein the driving voltage of the source driver integrated circuit comprises a black gray level region voltage for representing a black gray level of a displayed image and the compensation region voltage comprises a negative bios shift compensation region voltage for compensating for a negative shift in the threshold voltage of the driving transistor,
wherein the negative bios shift compensation region voltage is increased for the non-driven at least one sub-pixel by reducing the black gray level region voltage for a corresponding driven white sub-pixel or more.

2. The organic light emitting display device of claim 1 , wherein the driving transistor comprises a first node connected to a first electrode of the organic light emitting diode, a second node corresponding to a gate node, and a third node connected to a driving voltage line,
the first transistor is electrically connected between the first node of the driving transistor and a reference voltage line,
the second transistor is electrically connected between the second node of the driving transistor and the data line, and
the capacitor is connected between the first node and second node of the driving transistor.

3. The organic light emitting display device of claim 1 , wherein the driving transistor of the driven white sub-pixel or more sub-pixel has the threshold voltage shifted in a positive direction, and the driving transistor of the non-driven at least one sub-pixel has a threshold voltage shifted in a negative direction.

4. The organic light emitting display device of claim 1 , wherein the driving voltage of the source driver integrated circuit further comprises a gray level representation region voltage corresponding to a gray level,
wherein the compensation region voltage comprises a positive bios shift compensation region voltage for compensating for a positive shift in the threshold voltage of the driving transistor, and an auxiliary available region voltage existing between the positive bios shift compensation region voltage and the negative bios shift compensation region voltage.

5. The organic light emitting display device of claim 4 , wherein a sum of the voltage range of the black gray level region voltage and the voltage range of the negative bios shift compensation region voltage of the driven white sub-pixel or more sub-pixel is the same as a sum of the voltage range of the black gray level region voltage and the voltage range of the negative bios shift compensation region voltage of the non-driven at least one sub-pixel.

6. The organic light emitting display device of claim 4 , wherein the voltage range of the negative bios shift compensation region voltage of the non-driven at least one sub-pixel is greater than the voltage range of the negative bios shift compensation region voltage of the driven white sub-pixel or more sub-pixel.

7. The organic light emitting display device of claim 1 , wherein the pixel is composed of a red R sub-pixel, white W sub-pixel, blue B sub-pixel, and green G sub-pixel, and
the non-driven at least one sub-pixel is one of the sub-pixels among the red R sub-pixel, blue B sub-pixel, and green G sub-pixel when the pixel represents white color.

8. A method of driving an organic light emitting display device in which a plurality of sub-pixels includes a white sub-pixel or more of the four sub-pixels to be driven and at least one of three sub-pixels not to be driven when a white color driving scheme is implemented, and includes an organic light emitting diode, a driving transistor having a first node connected to a first electrode of the organic light emitting diode, a second node corresponding to a gate node, and a third node electrically connected to a driving voltage line, a first transistor connected between the first node of the driving transistor and a reference voltage line, a second transistor electrically connected between the second node of the driving transistor and a data line, and a storage capacitor electrically connected between the first node and second node of the driving transistor are arranged in a matrix form, the method comprising:
sensing a threshold voltage shift of the driving transistors in the plurality of sub-pixels;
obtaining a sensing value in the sensing of the threshold voltage shift, and determining whether each sensing value is a sensing value of the driven white sub-pixel or more sub-pixels or a sensing value of the non-driven at least one sub-pixel;
configuring a first voltage driving value for the driven white sub-pixel or more sub-pixel and a second voltage driving value for the non-driven at least one sub-pixel; and
performing data compensation on based on the first and second voltage driving values by maintaining a same reference voltage for the driven white sub-pixel or more sub-pixel and non-driven at least one sub-pixel,
wherein the first and second voltage driving values include a compensation region voltage to compensate for a shift in a threshold voltage of the driving transistor, and the compensation region voltage has a different voltage driving values for the first and second voltage driving values,
wherein the driving voltage of the source driver integrated circuit comprises a black gray level region voltage for representing a black gray level of a displayed image and the compensation region voltage comprises a negative bios shift compensation region voltage for compensating for a negative shift in the threshold voltage of the driving transistor,
wherein the negative bios shift compensation region voltage is increased for the non-driven at least one sub-pixel by reducing the black gray level region voltage for a corresponding driven white sub-pixel or more.

9. The method of claim 8 , wherein the first and second voltage driving values further comprises a gray level representation region voltage corresponding to a gray level,
wherein the compensation region voltages comprise a voltage of a positive bios shift compensation region voltage compensating for a positive shift in the threshold voltage of the driving transistor, and an auxiliary available region voltage existing between the positive bios shift compensation region voltage and the negative bios shift compensation region voltage.

10. The method of claim 9 , wherein a sum of the voltage of the black g

Assignees

• Lg Display Co Ltd

Inventors

• Jung Kimoon
• Park Chonghun
• PARK Geondo

Classifications

• G09G2320/0295

  by monitoring each display pixel · CPC title

• G09G3/3233

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

• G09G2320/0271

  Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping · CPC title

• G09G2320/045

  Compensation of drifts in the characteristics of light emitting or modulating elements · CPC title

• G09G2300/0452

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