ORGANIC LIGHT-EMITTING DISPLAY DEVICE AND DRIVING METHOD THEREOF

• US 20150130785A1
• Filed: 10/23/2014
• Published: 05/14/2015
• Est. Priority Date: 11/14/2013
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: SHIN, HunKi, KIM, BumSik
• Granted Patent: US 9,437,167 B2
• Time in Patent Office: Days
• US Class Current: 345/213
• CPC Class Codes: G09G 2300/0465 Improved aperture ratio, e.g. by size reduction of the pixel circuit, e.g. for improving the pixel density or the maximum displayable luminance or brightness
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2310/0262 The addressing of the pixel, in a display other than an active matrix LCD, involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependent on signals of two data electrodes
• CPC Class Codes: G09G 2320/0295 by monitoring each display pixel
• CPC Class Codes: G09G 2320/043 Preventing or counteracting the effects of ageing
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element
• CPC Class Codes: G09G 3/3291 in which the data driver supplies a variable data voltage for setting the current through, or the voltage across, the light-emitting elements
• CPC Class Codes: G09G 5/18 Timing circuits for raster scan displays specially adapted for television H04N ; synchronisation between the display unit and other display units, videodisc player G09G5/12

Abstract

Disclosed is an organic light-emitting display device and operating method thereof that may include an organic light-emitting diode, a first transistor controlled by a sensing signal and connected to a data line, a second transistor controlled by a scanning signal and connected to the data line, and a driving transistor having first to third nodes, wherein a reference voltage is applied to the first node through the first transistor, a data voltage is applied to the second node through the second transistor, and the third node is connected to a driving voltage line.

Claims

1. An organic light-emitting display device comprising:

a display panel including a plurality of data lines, a plurality of first gate lines and a plurality of second gate lines, which define a plurality of pixels;

a data driver supplying a data signal through at least one of the plurality of data lines;

a first gate driver supplying a sensing signal through at least one of the plurality of first gate lines that cross the plurality of data lines in the display panel;

a second gate driver supplying a scanning signal through at least one of the plurality of second gate lines that are substantially parallel with the plurality of first gate lines in the display panel; and

a timing controller controlling driving timings of the data driver, the first gate driver and the second gate driver,

wherein one of the plurality of pixels includes an organic light-emitting diode, a driving transistor having a first node, a second node and a third node, a first transistor controlled by the sensing signal and connected between the respective data line and the first node of the driving transistor, a second transistor controlled by the scanning signal and connected between the respective data line and the second node of the driving transistor, and a storage capacitor connected between the first and second nodes of the driving transistor.

2. The organic light-emitting display device according to claim 1, wherein the respective data line operates as a signal line supplying a reference voltage or a signal line supplying a data voltage according to an operation timing of a corresponding pixel.

3. The organic light-emitting display device according to claim 1, wherein, when the one of the plurality of pixels operates in an emission mode, the first transistor is turned on so that a reference voltage is output to the respective data line and the reference voltage is applied to the second node of the driving transistor, the first transistor is turned off and the second transistor is turned on so that a data voltage is output to the respective data line and is applied to the first node of the driving transistor having the second node to which the reference voltage is applied, and a predetermined voltage is applied between the second node and the first node of the driving transistor so that a current flows through the organic light-emitting diode.

4. The organic light-emitting display device according to claim 1, further comprising a sensing unit sensing one or more of a threshold voltage and a mobility of the driving transistor.

5. The organic light-emitting display device according to claim 4, wherein the sensing unit is connected to a driving voltage line connected to the third node of the driving transistor.

6. The organic light-emitting display device according to claim 5, wherein the sensing unit comprises:

an analog-to-digital converter measuring a voltage of a sensing node connected to the driving voltage line; and

a switch switching a connection between a precharge voltage supply node and the sensing node and switching a connection between a connection node of the analog-to-digital converter and the sensing node.

7. The organic light-emitting display device according to claim 5, wherein the sensing unit comprises:

a current measuring unit measuring a current flowing through a sensing node connected to the driving voltage line; and

a switch switching a connection between a precharge voltage supply node and the sensing node and switching a connection between a connection node of the current measuring unit and the sensing node.

8. A driving method of an organic light-emitting display device, the method comprising:

turning on a first transistor connected between a data line and a first node of the driving transistor and applying a reference voltage supplied by the data line to the first node of the driving transistor;

turning off the first transistor to float a voltage of the first node of the driving transistor, and applying a data voltage supplied by the data line to the second node of the driving transistor through a second transistor connected between the data line and the second node of the driving transistor; and

turning off the second transistor to allow a current to flow through an organic light-emitting diode connected to a third node of the driving transistor.

9. An organic light-emitting display device comprising:

an organic light-emitting diode;

a first transistor controlled by a sensing signal and connected to a data line;

a second transistor controlled by a scanning signal and connected to the data line; and

a driving transistor driving the organic light-emitting diode, the driving transistor including a first node to which a reference voltage is applied through the first transistor, a second node to which a data voltage is applied through the second transistor, and a third node connected to a driving voltage line.