Display device with gray voltage for controlling a luminance deviation
Embodiments of the disclosure relate to a display device and a display driving method. A display device according to the disclosure may comprise a display panel where a plurality of subpixels are disposed, a gate driving circuit applying a gate signal to the display panel, a data driving circuit converting image data into a data voltage and applying the data voltage to the display panel, and a timing controller controlling a sensing process for detecting a sensing voltage for a subpixel characteristic value in a blank period and a data update process for updating the image data according to the sensing voltage. The data driving circuit may apply a gray voltage for controlling a luminance deviation in the data update process to the display panel.
1 . A display device, comprising:
a display panel including a plurality of subpixels;
a gate driving circuit configured to apply a gate signal to the display panel;
a data driving circuit configured to convert image data into a data voltage and apply the data voltage to the display panel; and
a timing controller configured to control a sensing process for detecting a sensing voltage for a subpixel characteristic value in a blank period and to control a data update process for updating the image data according to the sensing voltage,
wherein the data driving circuit is configured to apply a gray voltage through all data lines of the display panel in a turned-off state of a driving transistor for controlling a luminance deviation in the data update process to the display panel.
2 . The display device of claim 1 , wherein the timing controller includes:
an oscillator configured to generate a fixed clock having a constant frequency;
a spread clock generator configured to generate a spread clock by varying the frequency of the fixed clock;
a multiplexer configured to output the spread clock in a display driving period and the fixed clock in the blank period in response to a selection signal;
an internal data enable signal generator configured to generate an internal data enable signal by counting a data enable signal based on the fixed clock received from the multiplexer in the blank period;
a switch control signal generator configured to generate a switch control signal by counting the internal data enable signal based on the fixed clock; and
an output buffer configured to sample the image data based on the data enable signal in the display driving period and outputting the switch control signal in the blank period.
3 . The display device of claim 2 , wherein the internal data enable signal includes:
a sensing data enable signal for controlling the sensing process; and
a gray data enable signal for controlling a time of applying the gray voltage.
4 . The display device of claim 3 , wherein the gray data enable signal is generated based on the data enable signal and the sensing data enable signal.
5 . The display device of claim 3 , wherein the sensing process is a real-time sensing process performed in a vertical blank period in a middle of display driving.
6 . The display device of claim 5 , wherein the real-time sensing process includes:
a first real-time sensing process where, after a sensing voltage is detected for one or more selected gate lines, a recovery voltage for resetting an applied voltage is applied; or
a second real-time sensing process where, after the sensing voltage is detected for the one or more selected gate lines, the recovery voltage for resetting the applied voltage and the gray voltage are sequentially applied.
7 . The display device of claim 6 , wherein the first real-time sensing process and the second real-time sensing process are selected according to a driving frequency.
8 . The display device of claim 7 , wherein the recovery voltage and the gray voltage are generated using the sensing data enable signal.
9 . The display device of claim 7 , wherein the recovery voltage is generated using the sensing data enable signal, and
wherein the gray voltage is generated using the gray data enable signal.
10 . The display device of claim 7 , wherein the gray voltage has a level lower than a level of the recovery voltage.
11 . The display device of claim 1 , wherein the blank period has a time interval configured to vary based on a driving frequency.
12 . A method for driving a display device comprising a display panel including a plurality of subpixels, a gate driving circuit configured to apply a gate signal to the display panel, and a data driving circuit configured to convert image data into a data voltage and apply the data voltage to the display panel, the method comprising:
in a blank period,
a sensing process for detecting a sensing voltage for a subpixel characteristic value for one or more selected gate lines; and
a data update process for updating the image data according to a sensing voltage detected in the sensing process,
wherein a gray voltage for controlling a luminance deviation is applied through all data lines of the display panel in a turned-off state of a driving transistor in the data update process.
13 . The method of claim 12 , wherein the sensing process includes a first sensing process where a recovery voltage for resetting an applied voltage is applied after the sensing voltage is detected.
14 . The method of claim 12 , wherein the sensing process includes a second sensing process where a recovery voltage for resetting an applied voltage and the gray voltage are sequentially applied after the sensing voltage is detected.
15 . The method of claim 12 , further comprising:
generating a fixed clock having a constant frequency;
generating a spread clock by varying the frequency of the fixed clock;
outputting the spread clock in a display driving period and the fixed clock in the blank period in response to a selection signal;
generating an internal data enable signal by counting a data enable signal based on the fixed clock in the blank period;
generating a switch control signal by counting the internal data enable signal based on the fixed clock; and
sampling the image data based on the data enable signal in the display driving period and transmitting the switch control signal in the blank period.
16 . The method of claim 15 , wherein the internal data enable signal includes:
a sensing data enable signal controlling the sensing process; and
a gray data enable signal controlling the gray voltage.
17 . The method of claim 16 , wherein the gray data enable signal is generated using the data enable signal and the sensing data enable signal.