Display device and method for driving the same

Patent metadata

Field	Value
Publication number	US-9280929-B2
Application number	US-201414504331-A
Country	US
Kind code	B2
Filing date	Oct 1, 2014
Priority date	Apr 16, 2014
Publication date	Mar 8, 2016
Grant date	Mar 8, 2016

Abstract

Each pixel of a display device includes: an organic light emitting diode between a first and a second power supply; a first transistor to transmit a drive current based on data signals; a second transistor to couple a gate electrode of the first transistor to the data line in response to a scan signal; a first capacitor between the first power supply and the gate electrode of the first transistor; a light receiving element coupled to a third power supply; a second capacitor between the light receiving element and a fourth power supply; a third transistor between the data line and a first electrode of the second capacitor, the third transistor including a gate electrode coupled to a selection signal line; and a fourth transistor between the fourth power supply and the third transistor, the fourth transistor including a gate electrode coupled to the first electrode of the second capacitor.

First claim

What is claimed is:

1. A display device comprising:
a scan driver configured to transmit a plurality of scan signals to a plurality of scan lines;
a data driver configured to transmit a plurality of data signals to a plurality of data lines;
a selector driver configured to transmit a plurality of selection signals to a plurality of selection signal lines;
a sensor driver configured to receive a plurality of output signals through the plurality of data lines; and
a plurality of pixels coupled to the scan lines, the data lines, and the selection signal lines,
wherein each of the plurality of pixels comprises:
an organic light emitting diode between a first power supply and a second power supply;
a first transistor configured to transmit a drive current based on the data signals to the organic light emitting diode;
a second transistor configured to couple a gate electrode of the first transistor to a corresponding data line of the data lines in response to one of the plurality of scan signals;
a first capacitor between the first power supply and the gate electrode of the first transistor;
a light receiving element coupled to a third power supply;
a second capacitor between the light receiving element and a fourth power supply;
a third transistor between the corresponding data line and a second electrode of the second capacitor, the third transistor comprising a gate electrode coupled to one of the plurality of selection signal lines; and
a fourth transistor between the fourth power supply and the third transistor, the fourth transistor comprising a gate electrode coupled to a first electrode of the second capacitor.

2. The display device of claim 1 , wherein the light receiving element comprises at least one of a PIN diode in which a cathode is coupled to the third power supply and an anode is coupled to the first electrode of the second capacitor, a PN diode, or a photocoupler.

3. The display device of claim 1 , wherein the third transistor comprises a first electrode coupled to the corresponding data line and a second electrode coupled to the first electrode of the fourth transistor.

4. The display device of claim 1 , wherein the fourth transistor comprises a first electrode coupled to a second electrode of the third transistor and comprises a second electrode coupled to the fourth power supply.

5. The display device of claim 1 , further comprising a first switch between the data driver and the corresponding data line.

6. The display device of claim 5 , further comprising a second switch between the sensor driver and the corresponding data line.

7. The display device of claim 6 , further comprising:
a fifth power supply; and
a third switch between the fifth power supply and the second switch.

8. The display device of claim 6 , wherein the sensor driver comprises an analog-to-digital converter (ADC) coupled to the corresponding data line.

9. A method of driving a display device comprising: a scan driver configured to transmit a plurality of scan signals to a plurality of scan lines; a data driver configured to transmit a plurality of data signals to a plurality of data lines; a selector driver configured to transmit a plurality of selection signals to a plurality of selection signal lines; a sensor driver configured to receive a plurality of output signals through the plurality of data lines; and a plurality of pixels coupled to the scan lines, the data lines, and the selection signal lines; a first switch between the data driver and a corresponding data line of the data lines; a second switch between the sensor driver and the corresponding data line; and a third switch between a fifth power supply and the second switch,
wherein each of the plurality of pixels comprises: an organic light emitting diode (OLED) between a first power supply and a second power supply; a first transistor configured to transmit a drive current based on the data signals to the OLED; a second transistor configured to couple a gate electrode of the first transistor to the corresponding data line in response to one of the plurality of scan signals; a first capacitor between the first power supply and the gate electrode of the first transistor; a light receiving element coupled to a third power supply; a second capacitor between the light receiving element and a fourth power supply; a third transistor between the corresponding data line and a second electrode of the second capacitor, the third transistor comprising a gate electrode coupled to one of the plurality of selection signal lines; and a fourth transistor between the fourth power supply and the third transistor, the fourth transistor comprising a gate electrode coupled to a first electrode of the second capacitor, the method comprising:
initial voltage storing in which a voltage of a first electrode of the third transistor is stored in the sensor driver through the corresponding data line;
photosensing in which the OLED emits light by the drive current based on one of the plurality of data signals and a voltage of the second capacitor varies with photo-leakage current generated according to intensity of light incident onto the light receiving element; and
detected voltage storing in which the voltage of the first electrode of the third transistor reflecting the varying voltage of the second capacitor is stored in the sensor driver through the corresponding data line.

10. The method of claim 9 , further comprising:
calculating a voltage variation of the second capacitor by a comparison of the initial voltage and the detected voltage by the sensor driver;
determining degradation information of each pixel utilizing the voltage variation of the second capacitor; and
transmitting a corrected data signal to a degraded pixel.

11. The method of claim 9 , wherein the initial voltage storing comprises:
a first step in which the first switch is turned off, the second switch is turned on, the third switch is turned on, a third power supply voltage is applied to a cathode of the light receiving element, the third transistor is switch-operated in accordance with the selection signals so as to couple a first electrode of the fourth transistor to the corresponding data line, the second transistor is turned off, and a fifth power supply voltage is applied to the first electrode of the third transistor through the corresponding data line; and
a second step in which the third switch is turned off, and the voltage of the first electrode of the third transistor is stored in the sensor driver through the corresponding data line.

12. The method of claim 11 , wherein during the first step, the first switch is turned off so as to disconnect the data driver from the corresponding data line, the second switch is turned on so as to couple the sensor driver and the corresponding data line, the third switch is turned on so as to couple the fifth power supply voltage and the corresponding data line, and the third power supply voltage is applied to the cathode of the light receiving element such that a voltage corresponding to the third power supply voltage is stored in the second capacitor.

13. The method of claim 9 , wherein during the photosensing, the first switch is turned on, the second switch is turned off, the third switch is turned off, the second transistor is switch-operated based on the scan signals such that the gate electrode of the first transistor is coupled to the corresponding data line, the third transistor is turned off, and the voltage of the second capacitor varies with photo-leakage current generated according to intensity of light incident onto the light receiving element.

14. The method of cl

Assignees

• Samsung Display Co Ltd

Inventors

• In Hai-Jung
• Park Yong-Sung

Classifications

• G09G5/18

  Timing circuits for raster scan displays (specially adapted for television H04N {; synchronisation between the display unit and other display units, videodisc player G09G5/12}) · CPC title

• G09G3/3208 Primary

  organic, e.g. using organic light-emitting diodes [OLED] · CPC title

• G09G2300/0426

  Layout of electrodes and connections · CPC title

• G09G2230/00

  Details of flat display driving waveforms · CPC title

• G09G2310/063

  Waveforms for resetting the whole screen at once · CPC title