Controller, display device including the same, electronic device including the same, and method of driving the display device
A controller of a display device includes an input image data receiving circuit, a mode control circuit, a scan driving control circuit, and a power driving control circuit. The input image data receiving circuit receives input image data and generates a count value corresponding to the number of frames in which an image is continuously played based on a received vertical synchronization signal, memory write signal, and memory write sustain signal. The mode control circuit generates a mode indicator signal based on the count value and a luminance control signal. The scan driving control circuit outputs a gate control signal for controlling a clock based on the mode indicator signal. The power driving control circuit outputs a voltage control signal for controlling a level of a power voltage based on the mode indicator signal.
1 . A controller comprising:
an input image data receiving circuit configured to receive input image data and generate a count value corresponding to a number of frames in which an image is continuously played, the count value being generated in response to a vertical synchronization signal indicating a start of a frame among the frames, a memory write signal indicating that the input image data of a next frame has been received, and a memory write sustain signal indicating that the input image data of the next frame is continuously received;
a mode control circuit configured to generate a mode indicator signal based on the count value and a luminance control signal;
a scan driving control circuit configured to output a gate control signal including a clock signal to control driving of gate lines of a display panel, based on the mode indicator signal; and
a power driving control circuit configured to output a voltage control signal to control a level of a power voltage applied to the display panel, based on the mode indicator signal.
2 . The controller of claim 1 , wherein the input image data receiving circuit is configured to:
generate a tearing signal based on the vertical synchronization signal, and
increase the count value when the memory write signal and the memory write sustain signal are input between periods in which the tearing signal is continuously input.
3 . The controller of claim 1 , wherein the mode control circuit is configured to determine whether the received count value is greater than or equal to a preset threshold value and the luminance control signal has a value that is less than or equal to the preset threshold value.
4 . The controller of claim 3 , wherein the threshold value of the luminance control signal is a minimum value that is greater than 0 among values of the luminance control signal.
5 . The controller of claim 3 , wherein the mode control circuit is configured to:
output the mode indicator signal to have a first level when the received count value is less than the preset threshold value, or the luminance control signal has a value that is greater than the preset threshold value, and
output the mode indicator signal to have a second level when the received count value is greater than or equal to the preset threshold value and the luminance control signal has the value that is less than or equal to the preset threshold value.
6 . The controller of claim 5 , wherein:
the first level is a low level, and
the second level is a high level.
7 . The controller of claim 1 , wherein the scan driving control circuit includes a first mode circuit and a second mode circuit, and the gate control signal includes a start signal,
wherein the first mode circuit is configured to output the start signal having a first number of pulses in response to the mode indicator signal having a first level, and
the second mode circuit is configured to output the start signal having a second number of pulses that is greater than the first number in response to the mode indicator signal having a second level.
8 . The controller of claim 1 , wherein the power driving control circuit includes a first mode circuit and a second mode circuit,
wherein the first mode circuit is configured to output the voltage control signal to output the power voltage having a low voltage level in response to the mode indicator signal having a first level, and
the second mode circuit is configured to output the voltage control signal to output the power voltage having a high voltage level in response to the mode indicator signal having a second level.
9 . The controller of claim 8 , wherein the first mode circuit is configured to output a gamma voltage to output a data signal having a black gray scale and a small margin, and
the second mode circuit outputs the gamma voltage for outputting a data signal having a black gray scale and a large margin.
10 . The controller of claim 1 , further comprising:
a data driving control circuit configured to output a data control signal to control a level of a data signal applied to the display panel, based on the mode indicator signal.
11 . The controller of claim 10 , wherein:
the data driving control circuit includes a first mode circuit and a second mode circuit and is configured to receive the input image data,
the first mode circuit is configured to output image data to generate a data signal having a black gray scale and a small margin based on the mode indicator signal having a first level and the input image data, and
the second mode circuit is configured to output the image data to generate a data signal having a black gray scale and a large margin based on the mode indicator signal having a second level and the input image data.
12 . A display device comprising:
a display panel which includes a plurality of subpixels and a power line connected to the plurality of subpixels;
a data driver configured to supply a data signal to the plurality of subpixels based on a data control signal and image data;
a gate driving circuit configured to supply a scan signal to the plurality of subpixels based on a gate control signal;
a voltage generator configured to supply a gamma voltage to the data driver and an initialization voltage to the power line based on a voltage control signal; and
a controller configured to receive input image data and change at least one of the gate control signal, the voltage control signal, or the image data based on a count value corresponding to a number of frames in which an image is continuously played and a luminance control signal to control luminance of an image displayed on the display panel,
wherein the count value is generated in response to a memory write signal indicating that the input image data of a next frame among the frames has been received, and a memory write sustain signal indicating that the input image data of the next frame is continuously received.
13 . The display device of claim 12 , wherein at least one of the plurality of subpixels includes:
a pixel driving circuit to which a first power voltage is applied, and
a light-emitting element including an anode connected to the pixel driving circuit and a cathode to which a second power voltage, and
wherein the initialization voltage is applied to the anode through the pixel driving circuit.
14 . The display device of claim 13 , wherein the controller is configured to:
generate a tearing signal based on a vertical synchronization signal, and
increase the count value when the memory write signal and the memory write sustain signal are received during a period corresponding to one frame period during which the tearing signal is continuously input.
15 . The display device of claim 14 , wherein the controller is configured to:
generate a mode indicator signal having a first level when the count value is greater than or equal to a preset threshold value and the received luminance control signal has a value that is less than or equal to the preset threshold value, and
generate the mode indicator signal having a second level when the count value is less than or equal to the preset threshold value or the luminance control signal has the value that is greater than or equal to the preset threshold value.
16 . The display device of claim 15 , wherein the controller is configured to:
output the voltage control signal to control a level of the initialization voltage to be lower than a level of the second power voltage based on the mode indicator signal with the first level, and
output the voltage control signal to control the level of the initialization voltage to be higher than the level of the second power voltage based on the mode indicator signal with the second level.
17 . A method of driving a display device including a controller, the method comprising:
determining, by the controller, whether display luminance of an image is less than or equal to a preset threshold value and the image is played for a preset threshold period or more by generating a count value in response to a vertical synchronization signal indicating a start of a frame, a memory write signal indicating that input image data of a next frame has been received, and a memory write sustain signal indicating that the input image data of the next frame is continuously received;
displaying the image in a first mode when the display luminance of the image is greater than the preset threshold value, or the image is played for a period that is less than the preset threshold period; and
displaying the image in a second mode when the display luminance of the image is lower than or equal to the preset threshold value and the image is played for the preset threshold period or more.
18 . The method of claim 17 , wherein, in displaying the image in the first mode:
in the display device, an initialization voltage applied to an anode of a light-emitting element included in the display device is applied at a first level that is lower than that of a power voltage applied to a cathode of the light-emitting element,
in the display device, a data signal for displaying a black gray scale is applied with a small margin, and
in the display device, an on-bias voltage is applied to a driving transistor, which is for supplying a driving current to the light-emitting element, a first number of times, and
wherein in displaying the image in the second mode:
in the display device, the initialization voltage applied to the anode of the light-emitting element included in the display device is applied at a second level that is higher than that of the power voltage applied to the cathode of the light-emitting element,
in the display device, the data signal for displaying the black gray scale is applied with a large margin, and
in the display device, the on-bias voltage is applied to the driving transistor a second number of times that is greater than the first number of times.
19 . An electronic device comprising:
a display panel which includes a plurality of subpixels and a power line connected to the plurality of subpixels;
a data driver configured to supply a data signal to the plurality of subpixels based on a data control signal and image data;
a gate driving circuit configured to supply a scan signal to the plurality of subpixels based on a gate control signal;
a voltage generator configured to supply a gamma voltage to the data driver and an initialization voltage to the power line based on a voltage control signal;
a main processor configured to output a luminance control signal to control luminance of an image displayed on the display panel; and
a controller configured to receive input image data and change at least one of the gate control signal, the voltage control signal, or the image data based on a count value corresponding to a number of frames in which an image is continuously played and the luminance control signal,
wherein the count value is generated in response to a memory write signal indicating that the input image data of a next frame among the frames has been received, and a memory write sustain signal indicating that the input image data of the next frame is continuously received.