Organic light-emitting display device and method of driving the same

Patent metadata

Field	Value
Publication number	US-2016155380-A1
Application number	US-201514660808-A
Country	US
Kind code	A1
Filing date	Mar 17, 2015
Priority date	Dec 1, 2014
Publication date	Jun 2, 2016
Grant date	—

Abstract

An organic light-emitting display device includes: pixels; and a data driver including a plurality of current measurers connected to the pixels via at least one data line, each of the current measurers including: a first measurement circuit including: a first operational amplifier including a non-inverted input terminal to which a first reference voltage is applied, and an inverted input terminal connected to a first pixel from among the pixels; and a first feedback capacitor connected between the inverted input terminal and an output terminal of the first operational amplifier; and a second measurement circuit including: a second operational amplifier including a non-inverted input terminal to which a second reference voltage is applied, and an inverted input terminal connected to a second pixel from among the pixels; and a second feedback capacitor connected between the inverted input terminal and an output terminal of the second operational amplifier.

First claim

What is claimed is:

1 . An organic light-emitting display device, comprising:
a plurality of pixels, each of the pixels comprising an organic light-emitting diode (OLED); and a data driver comprising a plurality of current measurers connected to the plurality of pixels via at least one data line, each of the current measurers comprising: a first measurement circuit comprising: a first operational amplifier comprising a non-inverted input terminal to which a first reference voltage is applied, and an inverted input terminal connected to a first pixel from among the plurality of pixels; and a first feedback capacitor connected between the inverted input terminal and an output terminal of the first operational amplifier; and a second measurement circuit comprising: a second operational amplifier comprising a non-inverted input terminal to which a second reference voltage having a different level from that of the first reference voltage is applied, and an inverted input terminal connected to a second pixel from among the plurality of pixels; and a second feedback capacitor connected between the inverted input terminal and an output terminal of the second operational amplifier.

2 . The organic light-emitting display device of claim 1 , wherein each of the current measurers further comprises a correlated double sampling unit connected to the output terminals of the first and second operational amplifiers.

3 . The organic light-emitting display device of claim 2 , wherein the data driver further comprises a data processor comprising:
an analog-to-digital converter (ADC) configured to convert an output of the correlated double sampling unit into digital data; and a multiplexer connected between the correlated double sampling unit and the ADC.

4 . The organic light-emitting display device of claim 1 , wherein:
the first measurement circuit further comprises a first feedback switch connected in parallel to the first feedback capacitor between the inverted input terminal and the output terminal of the first operational amplifier; and the second measurement circuit further comprises a second feedback switch connected in parallel to the second feedback capacitor between the inverted input terminal and the output terminal of the second operational amplifier.

5 . The organic light-emitting display device of claim 1 , wherein:
the first measurement circuit further comprises a first switch connected between the first pixel and the inverted input terminal of the first operational amplifier; and the second measurement circuit further comprises a second switch connected between the second pixel and the inverted input terminal of the second operational amplifier.

6 . The organic light-emitting display device of claim 1 , wherein each of the plurality of pixels comprises:
a driving transistor comprising a first electrode connected to a first power source, and a second electrode connected to a second power source via the OLED that is connected to a first node; a switching transistor comprising a first electrode connected to the data line, a second electrode connected to a gate electrode of the driving transistor, and a gate electrode connected to a scan line; a sensing transistor comprising a first electrode connected to the data line, a second electrode connected to the first node, and a gate electrode connected to a sensing line; and a first capacitor comprising a first terminal connected to the first electrode of the driving transistor, and a second terminal connected to the gate electrode of the driving transistor.

7 . The organic light-emitting display device of claim 6 , wherein the first reference voltage is greater than or equal to a threshold voltage of the OLED, and the second reference voltage is less than the threshold voltage of the OLED.

8 . The organic light-emitting display device of claim 6 , further comprising:
a power supply connected to the first and second power sources via power lines, wherein each of the current measurers further comprises: a first initialization switch connected between the power supply and the data line connected to the plurality of pixels; and a second initialization switch connected between the power supply and the first electrode of the switching transistor.

9 . The organic light-emitting display device of claim 6 , wherein each of the plurality of pixels further comprises a power switch connected between a power line connected to the first electrode of the driving transistor and the first and second power sources.

10 . An organic light-emitting display device, comprising:
a plurality of pixels, each of the pixels comprising an OLED; and a data driver comprising a plurality of current measurers configured to measure a current flowing in each of the plurality of pixels during a sensing period, each of the current measurers being further configured to: apply a first reference voltage to an anode electrode of an OLED included in a first pixel from among the plurality of pixels and a second reference voltage, which has a different level from that of the first reference voltage, to an anode electrode of an OLED included in a second pixel from among the plurality of pixels, during a reference voltage supply period of the sensing period; and measure a first measurement voltage corresponding to a current flowing in the first pixel to which the first reference voltage is applied and a second measurement voltage corresponding to a current flowing in the second pixel to which the second reference voltage is applied, during a measurement period of the sensing period, which follows the reference voltage supply period.

11 . The organic light-emitting display device of claim 10 , wherein each of the current measurers comprises:
a first measurement circuit comprising: a first operational amplifier comprising a non-inverted input terminal to which the first reference voltage is applied, and an inverted input terminal connected to the first pixel; a first feedback capacitor connected between the inverted input terminal and an output terminal of the first operational amplifier; and a first feedback switch connected in parallel to the first feedback capacitor between the inverted input terminal and the output terminal of the first operational amplifier; a second measurement circuit comprising: a second operational amplifier comprising a non-inverted input terminal to which the second reference voltage is applied, and an inverted input terminal connected to the second pixel; a second feedback capacitor connected between the inverted input terminal and an output terminal of the second operational amplifier; and a second feedback switch connected in parallel to the second feedback capacitor between the inverted input terminal and the output terminal of the second operational amplifier; and a correlated double sampler configured to perform correlated double sampling (CDS) on the first and second measurement voltages provided at the output terminals of the first and second operational amplifiers, respectively.

12 . The organic light-emitting display device of claim 11 , wherein the data driver further comprises:
a data processor comprising an ADC configured to convert an output of the correlated double sampler into digital data, and a multiplexer configured to provide the output of the correlated double sampler to the ADC via a switching operation; and a data driving circuit configured to provide a data signal to the plurality of pixels during a display period.

13 . The organic light-emitting display device of claim 12 , wherein:
the first measurement circuit further comprises a firs

Assignees

• Samsung Display Co Ltd

Inventors

• Kwon Oh Jo
• Min Kyung Youl
• Shin Choong Sun
• Won Young Uk

Classifications

• G09G2320/0233

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

• G09G2310/0294

  Details of sampling or holding circuits arranged for use in a driver for data electrodes · CPC title

• G09G2310/0297

  Special arrangements with multiplexing or demultiplexing of display data in the drivers for data electrodes, in a pre-processing circuitry delivering display data to said drivers or in the matrix panel, e.g. multiplexing plural data signals to one D/A converter or demultiplexing the D/A converter output to multiple columns · CPC title

• G09G2310/0291

  Details of output amplifiers or buffers arranged for use in a driving circuit · CPC title

• G09G3/3258

  with pixel circuitry controlling the voltage across the light-emitting element · CPC title