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EP-3968314-B1 - PIXELS, DISPLAY DEVICE COMPRISING PIXELS, AND DRIVING METHOD THEREFOR

EP3968314B1EP 3968314 B1EP3968314 B1EP 3968314B1EP-3968314-B1

Inventors

  • JEONG, IL HUN

Dates

Publication Date
20260506
Application Date
20191108

Claims (7)

  1. A display device comprising: a display (50) including pixels (PX) connected to scan lines (S11-S3n) and data lines; a scan driver (30) configured to supply scan signals to the scan lines(S11-S3n); a data driver (20) configured to supply data signals to the data lines (D1-Dm); an emission driver (40) supplying a light emission signal to light emission control lines; and a timing controller (10) configured to control the scan driver (30), the data driver (20), and the emission driver (40); wherein at least one of the pixels (PX) is located in an i-th horizontal line, where i is a natural number, and the at least one of the pixels comprises: a first transistor (T1) connected between a first power source (ELVDD) and a fourth node (N4) and having a gate electrode connected to a first node (N1); a second transistor (T2) connected between a third node (N3) and a data line (Dj), and turned on in response to a scan signal supplied to an i-th first scan line, where i is a natural number; a third transistor (T3) connected between the first node (N1) and the fourth node (N4), and turned on in response to a scan signal supplied to an i-th third scan line; a fourth transistor (T4) connected between a second node (N2) and an initialization voltage (Vint), and turned on in response to a scan signal supplied to an i-th second scan line; a first capacitor (C1) connected between the third node (N3) and the first node (N1); a second capacitor (C2) connected between the first node (N1) and the second node (N2); and an organic light emitting diode (OLED) connected between the second node (N2) and a second power source (ELVSS), a fifth transistor (T5) connected between a reference voltage (Vref) and the third node (N3), wherein the fifth transistor comprises a gate electrode connected to a light emission control line and is configured to be turned on in response to a light emission signal supplied to the light emission control line; and a sixth transistor (T6) connected between the fourth node (N4) and the second node (N2), wherein the sixth transistor comprises a gate electrode connected to the light emission control line and is configured to be turned on in response to the light emission signal supplied to the light emission control line; wherein the third transistor (T3) is an N-type transistor, wherein the scan driver is configured to supply the scan signals such that the second transistor (T2) and the third transistor (T3) are turned on for a first period (P1) in a data write period (WP) of a frame, and the fourth transistor (T4) is turned on for a second period (P3) of the data write period subsequent to the first period (P1), wherein the frame comprises the data write period (WP) and an emission period (EP) subsequent to the data write period; and wherein the emission driver is configured to provide the light emission signal such that the fifth transistor (T5) and the sixth transistor (T6) are turned on for the emission period (EP) of the frame.
  2. The display device of claim 1, wherein at least one of the second transistor (T2) and the fourth transistor (T4) is the N-type transistor.
  3. The display device of claim 2, wherein the fourth transistor (T4) is the N-type transistor and the i-th second scan line is the same as an (i+1)-th third scan line.
  4. The display device of claim 2 or claim 3, wherein the second transistor (T2) is the N-type transistor and the i-th first scan line is the same as the i-th third scan line.
  5. The display device of any preceding claim, wherein the i-th second scan line is the same as an (i+1)-th first scan line.
  6. The display device (1) of any preceding claim, wherein the scan driver (30) supplies a scan signal with one of a first polarity and a second polarity opposite the first polarity to the first to third scan lines.
  7. A method of driving a display device (1) according to any preceding claim, the method comprising: turning on the second transistor (T2) and a third transistor (T3) for a first period (P1) in the data write period (WP) ; turning on the fourth transistor (T4) for a second period (P2) subsequent to the first period (P1) in the data write period (WP); and turning on the fifth transistor (T5) and the sixth transistor (T6) in the emission period subsequent to the data write period (WP).

Description

Technical Field The present disclosure relates to a pixel, a display device including the pixel, and a method of driving the display device. Background Art A display device includes pixels connected to data lines and scan lines. The pixel commonly includes a light emitting element and a driving transistor for controlling an amount of a current flowing to the light emitting element. The driving transistor controls an amount of a current flowing from a first driving power source through the light emitting element to a second driving power source in response to a data signal. In this case, the light emitting element generates light of a certain brightness corresponding to the amount of the current from the driving transistor. A method of implementing high brightness by setting a voltage of the second driving power source to a low level or minimizing power consumption by driving the display device at a low frequency is used these days. However, in the case of setting the second driving power source to a low level or driving the display device at a low frequency, a certain leakage current is generated from a gate electrode of the driving transistor. In this case, the voltage of the data signal is not maintained for a single frame, and accordingly, an image with a desired brightness is not displayed. Japanese patent application publication JP2008191450A describes a pixel circuit including an electro-optical element having a grayscale, corresponding to a drive current flowing through a path, a drive transistor disposed in the path and controlling the drive current according to the potential at the gate, and a capacitive element having electrodes. United States Patent Application Publication US2011/018855A1 describes a gate of a driving transistor set to an offset level corresponding to the threshold of the driving transistor by an initializing current flowing between a source and a drain of the driving transistor or a compensating transistor for the driving transistor. A conduction state of the driving transistor is set according to a gate voltage of the gate of the driving transistor that corresponds to a data signal and the threshold of the driving transistor. A current of which a level corresponds to the conduction state and of which the direction is opposite to the direction of the initializing current flows through driving transistor. United States Patent Application Publication US2011/115764A1 relates to a pixel circuit including N-type transistors. The pixel circuit includes a light emitting device driven by a driving current according to a gate voltage of a driving transistor. The pixel circuit also includes a first capacitor, a second transistor for transferring a data signal to a first terminal of the first capacitor in response to a scan control signal, a third transistor for diode-connecting the driving transistor in response to the scan control signal, a fourth transistor for applying a first power voltage to a first electrode of the driving transistor in response to an emission control signal, a fifth transistor for applying a sustain voltage to the first terminal of the first capacitor in response to the emission control signal, and a sixth transistor for applying the first power voltage to a second terminal of the first capacitor in response to an initialization control signal. Disclosure Technical Problem The present disclosure is directed to a pixel, a display device including the pixel, and a method of driving the display device, which may display an image with a desired brightness by minimizing a leakage current from a gate electrode of a driving transistor. The present disclosure is also directed to a pixel, a display device including the pixel, and a method of driving the display device, which may prevent deterioration of a light emitting element and a brightness deviation due to an IR drop of a driving power source. Technical Solution According to an embodiment of the present disclosure, a display device comprises a display including pixels connected to scan lines and data lines; a scan driver configured to supply scan signals to the scan lines; and a data driver configured to supply data signals to the data lines, an emission driver supplying a light emission signal to light emission control lines; a timing controller configured to control the scan driver, the data driver and the emission driver; wherein at least one of the pixels is located in an i-th horizontal line, where i is a natural number, and the at least one of the pixels includes a first transistor connected between a first power source and a fourth node and having a gate electrode connected to a first node, a second transistor connected between a third node and a data line and turned on in response to a scan signal supplied to an i-th first scan line, where i is a natural number, a third transistor connected between the first node and the fourth node and turned on in response to a scan signal supplied to an i-th third scan line,