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

Patent metadata

Field	Value
Publication number	US-2016125801-A1
Application number	US-201514677133-A
Country	US
Kind code	A1
Filing date	Apr 2, 2015
Priority date	Nov 3, 2014
Publication date	May 5, 2016
Grant date	—

Abstract

An organic light-emitting display apparatus includes a plurality of color pixels. Each of the color pixels includes an organic light-emitting diode (OLED), a driving transistor to control current to the OLED, and a compensation transistor connected between an anode electrode of the OLED and a gate electrode of the driving transistor. The compensation transistor turns on based on a compensation control signal. The compensation control signals for different color pixels have different on-times.

First claim

What is claimed is:

1 . An organic light-emitting display apparatus, comprising:
a plurality of color pixels, each of the color pixels including: an organic light-emitting diode (OLED); a driving transistor to control current to the OLED; and a compensation transistor connected between an anode electrode of the OLED and a gate electrode of the driving transistor, wherein the compensation transistor is to be turned on based on a compensation control signal and wherein compensation control signals have different on-times for different color pixels.

2 . The display apparatus as claimed in claim 1 , wherein the color pixels include at least two of a red pixel, a green pixel, a blue pixel, or a white pixel.

3 . The display apparatus as claimed in claim 2 , wherein the on-time of the compensation control signal of each of the color pixels is based on a time when a current value of the driving transistor at a compensation period termination point becomes a current value of a predetermined grayscale value.

4 . The display apparatus as claimed in claim 1 , wherein each of the color pixels includes:
a second capacitor having a first electrode connected to a gate electrode of the driving transistor; a first capacitor having a first electrode connected to a second electrode of the second capacitor and a second electrode connected to a first power source, the first power source to supply a first source voltage; and a first transistor connected between the second electrode of the second capacitor and a data line, the first transistor to be turned on based on a scan signal to transfer a data signal to the first electrode of the first capacitor.

5 . The display apparatus as claimed in claim 4 , wherein each of the color pixels includes a fourth transistor connected between the data line and an anode electrode of the OLED, the fourth transistor to be turned on based on a sensing signal to sense deterioration of the driving transistor or the OLED.

6 . The display apparatus as claimed in claim 1 , wherein each of the color pixels includes:
a first capacitor connected between a data line and a first node; a first transistor to connect the first node to a second node; a second capacitor connected between the second node and a gate electrode of the driving transistor; a fifth transistor to transfer a reference voltage to the first node; and a fourth transistor connected between the second node and a first power source supplying a first source voltage, the fourth transistor to turn on based on an initialization control signal to transfer the first source voltage to the second node.

7 . The display apparatus as claimed in claim 6 , wherein the fifth transistor is to be turned on based on a scan signal to transfer the reference voltage to the first node.

8 . The display apparatus as claimed in claim 6 , wherein the first transistor is to be turned on by a relay control signal to connect the first node to the second node.

9 . The display apparatus as claimed in claim 6 , wherein when operation of emitting light from the OLED is simultaneously performed in the color pixels:
the first transistor is to be turned off, the fifth transistor is to be turned on, the reference voltage is to be transferred to the first node, and a voltage corresponding to a data signal applied to the data line is to be stored in the first capacitor.

10 . A method for driving an organic light-emitting display apparatus, the method comprising:
turning on a compensation transistor in each of a plurality of color pixels based on a compensation control signal, the compensation control signal to diode-connect a driving transistor in each of the color pixels; sequentially applying a scan signal to the color pixels to apply a data signal to each of the color pixels connected to s scan line; and simultaneously emitting light from the color pixels at a luminance corresponding to a current output to a driving transistor of each of the color pixels, wherein an on-time of the compensation control signal is differently set for different color pixels.

11 . The method as claimed in claim 10 , wherein the color pixels are at least two of a red pixel, a green pixel, a blue pixel, or a white pixel.

12 . The method as claimed in claim 11 , wherein the on-time of the compensation control signal of each of the color pixels is based on a time when a current value of the driving transistor at a compensation period termination point becomes a current value of a predetermined grayscale value.

13 . The method as claimed in claim 10 , wherein each of the color pixels includes:
a second capacitor having a first electrode connected to a gate electrode of the driving transistor; a first capacitor having a first electrode, connected to a second electrode of the second capacitor and a second electrode connected to a first power source, the first power source to supply a first source voltage; and a first transistor connected between a second electrode of the second capacitor and a data line, the first transistor to be turned on by a scan signal to transfer a data signal to the first electrode of the first capacitor.

14 . The method as claimed in claim 13 , wherein each of the color pixels includes a fourth transistor connected between the data line and an anode electrode of an organic light emitting diode (OLED), the fourth transistor to be turned on based on a sensing signal to sense deterioration of the driving transistor or the OLED.

15 . The method as claimed in claim 10 , wherein each of the color pixels includes:
a first capacitor connected between a data line and a first node; a first transistor to connect the first node to a second node; a second capacitor connected between the second node and a gate electrode of the driving transistor; a fifth transistor to transfer a reference voltage to the first node; and a fourth transistor connected between the second node and a first power source to supply a first source voltage, the fourth transistor to be turned on by an initialization control signal to transfer the first source voltage to the second node.

16 . The method as claimed in claim 15 , wherein sequentially supplying the scan signal includes:
turning off the first transistor, turning on the fifth transistor; transferring the reference voltage to the first node; and storing a voltage in the first capacitor, the voltage corresponding to a data signal applied to the data line.

17 . The method as claimed in claim 15 , wherein simultaneously emitting light includes:
emitting light from an organic light emitting diode (OLED) according to current from the driving transistor based on the voltage stored in the second capacitor, wherein the voltage stored in the second capacitor is a voltage which is stored in the first capacitor during a scan operation of a previous frame.

18 . The method as claimed in claim 10 , wherein a scan period overlaps an emission period.

19 . An apparatus, comprising:
an output; and a driver to supply signals to first and second pixels through the output, wherein the first and second pixels are to emit light of different colors and wherein the driver is to supply a first compensation control signal to the first pixel and a second compensation control signal to the second pixel, the first compensation control signal having a first period and the second compensation control signal having a second period different from the first period, the first and second compensation control signals to compensate for deviations i

Assignees

• Samsung Display Co Ltd

Inventors

• Chung Boyong
• In Haijung
• Hwang Youngin

Classifications

• G09G2300/0819

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

• G09G2320/045

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

• G09G2320/0233

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

• G09G3/3266

  Details of drivers for scan electrodes · CPC title

• G09G3/3225 Primary

  using an active matrix · CPC title