Organic light emitting display and method for driving the same

Patent metadata

Field	Value
Publication number	US-9280932-B2
Application number	US-201313901475-A
Country	US
Kind code	B2
Filing date	May 23, 2013
Priority date	Dec 14, 2012
Publication date	Mar 8, 2016
Grant date	Mar 8, 2016

Abstract

An organic light emitting diode (OLED) display and a method for driving the same, which can display an image with more uniform luminance is disclosed. In one aspect, the OLED display includes a plurality of pixels arranged in a matrix of a plurality of rows and a plurality of columns; a data driver supplying second data signals corresponding to a second data obtained by converting a first data, in response to first data signals corresponding to the first data or a data control signal; and a compensator converting output currents output from the pixels, corresponding to the first data signals into a output voltages, and supplying, to the data driver, the data control signal for converting the first data into the second data, corresponding to the output voltages and the first data based on the output voltages and the first data.

First claim

What is claimed is:

1. An organic light emitting diode (OLED) display, comprising:
a plurality of pixels, wherein the pixels are arranged in a matrix of a plurality of rows and a plurality of columns and each pixel includes an organic light emitting diode (OLED);
a data driver, responsive to first data signals corresponding to the first data or a data control signal, configured to supply second data signals corresponding to second data obtained by conversion of first data; and
a compensator configured to convert output currents received from the pixels and corresponding to the first data signals into a output voltages, and configured to supply to the data driver the data control signal for converting the first data into the second data based on the output voltages and the first data, the compensator further configured to receive a current having an amplitude corresponding to that of any one of the first data signals as any one of the output currents during a first period in horizontal period, and supplying to the OLED a current having an amplitude corresponding to that of any one of the second data signals after the horizontal period.

2. The OLED display of claim 1 , wherein the data driver supplies the first data signals to pixels on one of the plurality of rows during a first period in a horizontal period, and supplies to the pixels on the one row the second data signals corresponding to the second data during a second period in the horizontal period.

3. The OLED display of claim 2 , wherein each output current is supplied from each pixel to the compensator through a driving transistor included in each of the pixels on the one row during the first period.

4. The OLED display of claim 3 , further comprising a scan driver progressively supplying a scan signal to the pixels through scan lines, and progressively supplying an emission control signal to the pixels through emission control lines.

5. The OLED display of claim 4 , wherein the scan driver supplies the scan signal during the horizontal period, and supplies the emission control signal after the horizontal period.

6. The OLED display of claim 3 , wherein the compensator includes:
a sensing unit converting the output currents into the output voltages, and converting the output voltages into digital signals; and
a controller outputting the data control signal for converting the first data into the second data based on the digital signals and the first data.

7. The OLED display of claim 6 , wherein the sensing unit includes:
a current-voltage converter converting the output currents into first voltages; and
an analog-digital converter converting the first voltages into the digital signals.

8. The OLED display of claim 6 , wherein the controller reads, from a look-up table, the second data corresponding to a combination of the digital signal and the first data, and supplies the read second data as the data control signal to the data driver.

9. An organic light emitting diode (OLED) display, comprising:
a plurality of pixels, wherein the pixels are arranged in a matrix of a plurality of rows and a plurality of columns;
a data driver, responsive to first data signals corresponding to the first data or a data control signal, configured to supply second data signals corresponding to second data obtained by conversion of first data, wherein the data driver supplies the first data signals to pixels on one of the plurality of rows during a first period in a horizontal period, and supplies to the pixels on the one row the second data signals corresponding to the second data during a second period in the horizontal period;
a compensator configured to convert output currents received from the pixels and corresponding to the first data signals into a output voltages, and configured to supply to the data driver the data control signal for converting the first data into the second data based on the output voltages and the first data, wherein each output current is supplied from each pixel to the compensator through a driving transistor included in each of the pixels on the one row during the first period; and
a scan driver progressively supplying a scan signal to the pixels through scan lines, and progressively supplying an emission control signal to the pixels through emission control lines, wherein the scan driver supplies the scan signal during the horizontal period, and supplies the emission control signal after the horizontal period
wherein each pixel includes:
an organic light emitting diode (OLED); and
a pixel circuit supplying, to the compensator, current having an amplitude corresponding to that of any one of the first data signals as any one of the output currents during the first period, and supplying to the OLED current having an amplitude corresponding to that of any one of the second data signals after the horizontal period.

10. The OLED display of claim 9 , wherein the pixel circuit includes:
a storage capacitor coupled between a first power source and a first node;
a first transistor charging, via the storage capacitor, a voltage having an amplitude corresponding to that of any one of the first data signals or any one of the second data signals, in response to the scan signal;
a second transistor coupled between the first power source and a second node, and allowing a first current having an amplitude corresponding to that of the voltage charged in the storage capacitor to pass from the first power source through the second node;
a mirror circuit coupled among the first power source, the second node, an anode electrode of the organic light emitting diode and a feedback line, and supplying the first current to the feedback line and supplying, to the OLED, a second current having an amplitude in proportion to that of the first current; and
a third transistor controlling the coupling between the mirror circuit and the anode electrode of the organic light emitting diode, in response to the emission control signal.

11. The OLED display of claim 10 , wherein the amplitudes of the first and second currents are identical to each other.

12. The OLED display of claim 10 , wherein the mirror circuit includes:
a fourth transistor coupled between the second node and the feedback line, and having a gate electrode coupled between a third node and the feedback line; and
a fifth transistor coupled between the first power source and the third transistor, and having a gate electrode coupled to the third node.

13. An organic light emitting diode (OLED) display, comprising:
a plurality of pixels, wherein the pixels are arranged in a matrix of a plurality of rows and a plurality of columns;
a data driver, responsive to first data signals corresponding to the first data or a data control signal, configured to supply second data signals corresponding to second data obtained by conversion of first data, wherein the data driver supplies the first data signals to pixels on one of the plurality of rows during a first period in a horizontal period, and supplies to the pixels on the one row the second data signals corresponding to the second data during a second period in the horizontal period; and
a compensator configured to convert output currents received from the pixels and corresponding to the first data signals into a output voltages, and configured to supply to the data driver the data control signal for converting the first data into the second data based on the output voltages and the first data,
wherein each output current is supplied from each pixel to the compensator through a driving transistor included in each of the pixels on the one row during the first period, and
wherein the compensator in

Assignees

• Kim Jong-Soo
• Kang Jee-Yoon
• Samsung Display Co Ltd

Inventors

• Kim Jong-Soo
• Kang Jee-Yoon

Classifications

• G09G2320/045

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

• G09G2300/0861

  with additional control of the display period without amending the charge stored in a pixel memory, e.g. by means of additional select electrodes · CPC title

• G09G3/3233 Primary

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

• G09G3/3291

  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

• G09G2300/0819

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