Data driver and organic light emitting display panel, display device, and driving method for sensing and compensating a mobility of the driving transistor

Patent metadata

Field	Value
Publication number	US-10062327-B2
Application number	US-201615167419-A
Country	US
Kind code	B2
Filing date	May 27, 2016
Priority date	May 29, 2015
Publication date	Aug 28, 2018
Grant date	Aug 28, 2018

Abstract

The present exemplary embodiments relate to measurement of a characteristic of a driving transistor and sensing driving therefor. Provided are a data driver, an organic light emitting display panel, an organic light emitting display device, and a driving method thereof which are capable of measuring characteristics of a driving transistor even at a data voltage which is not so high within a short sensing time by simultaneously sensing the characteristics of the driving transistors for two or more sub pixels, among a plurality of sub pixels commonly connected to the sensing lines, while measuring characteristics (for example, a threshold voltage or a mobility) of the driving transistor.

First claim

What is claimed is:

1. An organic light emitting display device, comprising:
an organic light emitting display panel in which a plurality of data lines and a plurality of gate lines are disposed, a plurality of sub pixels each including an organic light emitting diode and a driving transistor which drives the organic light emitting diode are disposed, and at least one sensing line is disposed to correspond to K data lines, wherein K≥2;
a data driver which outputs a data voltage to each of the plurality of data lines; and
a gate driver which drives the plurality of gate lines,
wherein the data driver simultaneously outputs sensing data voltages to S data lines among K data lines corresponding to the at least one sensing line, while measuring a characteristic of the driving transistors, where 2≤S≤K, and outputs a non-sensing data voltage to K−S data lines excluding the S data lines to which the sensing data voltage is output,
wherein the data driver outputs the sensing data voltage to the S data lines a same number of times for a predetermined time, and outputs the non-sensing data voltage to the K−S data lines a same number of times for the predetermined time, and
wherein the organic light emitting display further comprises:
an analog to digital converter which is electrically connected to the at least one sensing line, senses a voltage of the at least one sensing line to convert the voltage into a digital value and outputs the digital value, and
a timing controller which calculates an integrated current capability value obtained by adding individual current capability values for driving transistors in S sub pixels connected each to one of the S data lines, based on the sensed voltage of the at least one sensing line confirmed from the digital value received from the analog to digital converter and calculates individual current capability values of the driving transistors in the S sub pixels from the calculated integrated current capability values, and compensates a mobility of the driving transistors in the S sub pixels, based on the calculated individual current capability value.

2. The organic light emitting display device according to claim 1 , wherein a current which flows in the at least one sensing line corresponding to the K data lines corresponds to a sum of currents which flow through the driving transistors in the S sub pixels connected to the S data lines, among K sub pixels which are connected to the K data lines and commonly connected to the at least one sensing line.

3. The organic light emitting display device according to claim 1 , wherein the analog to digital converter is included in the data driver.

4. The organic light emitting display device according to claim 1 , wherein the timing controller calculates 1/S of the calculated integrated current capability value as individual current capability values of the driving transistor in each of S sub pixels.

5. The organic light emitting display device according to claim 1 , wherein the timing controller calculates the individual current capability values of the driving transistors in the S sub pixels from the calculated integrated current capability values, based on a ratio of the size or the channel width between the driving transistors in the S sub pixels.

6. The organic light emitting display device according to claim 1 , wherein the data driver outputs a predetermined black data voltage which is defined as the non-sensing data voltage, to the K−S data lines excluding the S data lines to which the sensing data voltage is output, from the K data lines, while measuring the characteristic of the driving transistors.

7. The organic light emitting display device according to claim 1 , wherein the S sub pixels connected to the S data lines are selected, as sub pixels which are simultaneously sensed, from K sub pixels which are connected to the K data lines.

8. The organic light emitting display device according to claim 1 , wherein the data driver outputs the sensing data voltage to the S data lines during one blank time period.

9. The organic light emitting display device according to claim 1 , wherein the data driver simultaneously outputs sensing data voltages having the same voltage values to data lines connected to sub pixels including driving transistors having the same characteristic, among the S data lines, and
the data driver outputs sensing data voltages having different voltage values to data lines connected to sub pixels including driving transistors having different characteristics.

10. A driving method of an organic light emitting display device which includes an organic light emitting display panel in which a plurality of data lines and a plurality of gate lines are disposed, a plurality of sub pixels each including an organic light emitting diode and a driving transistor which drives the organic light emitting diode are disposed, and at least one sensing line is disposed corresponding to K data lines where K≥2; a data driver which outputs a data voltage to each of the plurality of data lines; and a gate driver which drives the plurality of gate lines, the driving method comprising:
simultaneously outputting sensing data voltages to S data lines among K data lines corresponding to the at least one sensing line, while measuring a characteristic of the driving transistors, wherein 2≤S≤K;
outputting a non-sensing data voltage to K−S data lines excluding the S data lines to which the sensing data voltage is output; and
sensing a voltage of the at least one sensing line corresponding to the K data lines,
wherein the sensing data voltage is output to the S data lines a same number of times for a predetermined time, and the non-sensing data voltage is output to the K−S data lines a same number of times for the predetermined time, and
wherein the driving method further comprises:
sensing a voltage of the at least one sensing line to convert the voltage into a digital value and outputting the digital value; and
calculating an integrated current capability value obtained by adding individual current capability values for the driving transistors in S sub pixels of the plurality of sub pixels connected each to one of to the S data lines, based on the sensed voltage of the at least one sensing line confirmed from the digital value received and calculating individual current capability values of the driving transistors in the S sub pixels from the calculated integrated current capability values, and compensating a mobility of the driving transistors in the S sub pixels, based on the calculated individual current capability value.

11. The driving method according to claim 10 , wherein in the outputting of sensing data voltages, the organic light emitting display device outputs a predetermined black data voltage which is defined in advance as the non-sensing data voltage to the K−S data lines while outputting the sensing data voltage to the S data lines.

12. An organic light emitting display panel, comprising:
a plurality of data lines disposed in a first direction;
a plurality of gate lines disposed in a second direction;
a plurality of sub pixels each including an organic light emitting diode and a driving transistor which drives the organic light emitting diode; and
at least one sensing line which is disposed for every K sub pixel columns, where K ≥2,
wherein while measuring a characteristic of the driving transistors, S sub pixels among K sub pixels commonly connected to each of the sensing lines are simultaneously supplied with a sensing data voltage and K−S sub pixels are simultaneously supplied with a non-sensing data voltage, where 2 ≤S≤K,
wherein the sensing data voltage is supplied to the S sub

Assignees

• Lg Display Co Ltd

Inventors

• Tani Ryosuke
• Choi Kyunghyun
• Han Changhoon

Classifications

• G09G3/3233 Primary

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

• G09G2300/0417

  Special arrangements specific to the use of low carrier mobility technology · CPC title

• G09G3/3291 Primary

  in which the data driver supplies a variable data voltage for setting the current through, or the voltage across, the light-emitting 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

• G09G2320/0693

  Calibration of display systems · CPC title