Display device and driving method thereof

Abstract

A display device and a driving method thereof are disclosed. The display device includes: a display panel configured to display an image based on input image data; a gate driver configured to output a gate signal to the display panel; a data driver configured to output a data voltage to the display panel; a driving controller configured to control the operation of the gate driver and the operation of the data driver, determine a normal driving mode and a low-frequency driving mode based on input image data, and determine a driving frequency of the display panel based on the input image data; and a touch driver configured to detect a touch event occurring on the display panel and output a touch interrupt signal indicating the touch event to the driving controller.

Description

Technical Field

[0001] Aspects of some example embodiments of the inventive concepts relate to a display device and a method of driving the display device. Background Art

[0002] The display device may include a display panel and a display panel driver. The display panel includes a plurality of gate lines, a plurality of data lines and a plurality of pixels. The display panel driver includes a gate driver, a data driver and a drive controller. The gate driver outputs a gate signal to the gate line. The data driver outputs a data voltage to the data line. The drive controller controls the gate driver and the data driver.

[0003] The drive controller can determine the drive frequency of the display panel based on the input image data. When an event generated at the display device in a low-frequency drive mode is not quickly transmitted to the drive controller, image transmission may be delayed. For example, when a touch event of the display panel is generated in a low-frequency drive mode, immediate image transmission may be required. When a delay in a touch event occurs under 1Hz drive, image conversion may be delayed (e.g., about one second), so that the user will perceive the image conversion as a display defect.

[0004] The above information disclosed in this background section is only for enhancement of understanding of the background technology and therefore, the information discussed in this background section does not necessarily constitute prior art. Summary of the invention

[0005] Aspects of some exemplary embodiments of the inventive concept relate to a display device and a method of driving the display device. For example, some exemplary embodiments of the inventive concept relate to a display device that quickly determines a touch event in a low-frequency driving method to prevent or reduce a delay in image conversion and a method of driving the display device.

[0006] Aspects of some example embodiments of the inventive concepts include a display device that may be able to prevent or reduce a delay in image conversion when a touch event is generated to improve display quality.

[0007] Aspects of some example embodiments of the inventive concepts may also include methods of driving the above-mentioned display device.

[0008] According to some example embodiments of the present invention, a display device includes a display panel, a gate driver, a data driver, a drive controller and a touch driver. The display panel is configured to display an image based on input image data. The gate driver is configured to output a gate signal to the display panel. The data driver is configured to output a data voltage to the display panel. The drive controller is configured to control the operation of the gate driver and the operation of the data driver, determine a normal drive mode and a low-frequency drive mode based on the input image data, and determine the drive frequency of the display panel based on the input image data. The touch driver is configured to detect a touch event occurring on the display panel and output a touch interrupt signal indicating the touch event to the drive controller.

[0009] According to some example embodiments, the drive controller may be configured to sense a touch event through a touch interrupt signal. When the display panel is driven in a low-frequency driving mode and the drive controller senses a touch event, the drive controller may be configured to drive the display panel in a normal driving mode in a frame just next to the frame when the touch event is sensed.

[0010] According to some example embodiments, the driving controller may include: a still image determiner configured to determine whether input image data is a still image or a video image, and generate a flag indicating whether the input image data is a still image or a video image; and a driving frequency determiner configured to determine a normal driving mode and a low-frequency driving mode based on the flag, and determine a driving frequency of the display panel based on a grayscale value of the input image data.

[0011] According to some example embodiments, the driving controller may further include a flicker lookup table representing a flicker degree according to a grayscale value of the input image data. The driving frequency determiner may be configured to determine the driving frequency of the display panel using the flicker lookup table.

[0012] According to some example embodiments, the driving controller may include an input port configured to receive a touch interrupt signal from the touch driver.

[0013] According to some example embodiments, the touch driver may be configured to generate a touch coordinate signal indicating a touch position. The display device may further include a host configured to output input image data to the driving controller and receive a touch interrupt signal and a touch coordinate signal from the touch driver.

[0014] According to some example embodiments, the touch driver may be configured to output a touch interrupt signal to the driving controller after a predetermined time delay.

[0015] According to some example embodiments, a display panel may include a first type of switching element and a second type of switching element different from the first type.

[0016] According to some example embodiments, in the low-frequency driving mode, the driving controller may be configured to determine the driving frequency of the first type of switching element as the first driving frequency, and determine the driving frequency of the second type of switching element as a second driving frequency that is smaller than the first driving frequency. In the normal driving mode, the driving controller may be configured to determine the driving frequency of the first type of switching element as the first driving frequency, and determine the driving frequency of the second type of switching element as the first driving frequency.

[0017] According to some example embodiments, the first type switching element may be a polysilicon thin film transistor. The second type switching element may be an oxide thin film transistor.

[0018] According to some example embodiments, the first type switching element may be a P-type transistor.The second type switching element may be an N-type transistor.

[0019] According to some example embodiments of the present invention, a display device includes a display panel, a gate driver, a data driver, a drive controller, and a button controller. The display panel is configured to display an image based on input image data. The gate driver is configured to output a gate signal to the display panel. The data driver is configured to output a data voltage to the display panel. The drive controller is configured to control the operation of the gate driver and the operation of the data driver, determine a normal drive mode and a low-frequency drive mode based on the input image data, and determine the drive frequency of the display panel based on the input image data. The button controller is configured to detect a button input event occurring at an input button, and output a button interrupt signal indicating the button input event to the drive controller.

[0020] According to some example embodiments, the drive controller may be configured to sense a button input event through a button interrupt signal. When the display panel is driven in a low-frequency driving mode and the drive controller senses the button input event, the drive controller may be configured to drive the display panel in a normal driving mode in a frame just next to the frame when the button input event is sensed.

[0021] According to some example embodiments, the display apparatus may further include a host configured to output the input image data to the driving controller and receive a button interrupt signal from the button controller.

[0022] According to some example embodiments conceived in the present invention, in a method of driving a display device, the method includes the following steps: determining a normal driving mode and a low-frequency driving mode based on input image data using a driving controller; determining a driving frequency of a display panel based on the input image data using the driving controller; outputting a gate signal to the display panel; outputting a data voltage to the display panel; and detecting a touch event occurring on the display panel and outputting a touch interrupt signal indicating the touch event to the driving controller.

[0023] According to some example embodiments, the drive controller may be configured to sense a touch event through a touch interrupt signal. When the display panel is driven in a low-frequency driving mode and the drive controller senses a touch event, the drive controller may be configured to drive the display panel in a normal driving mode in a frame just next to the frame when the touch event is sensed.

[0024] According to some example embodiments, determining the normal driving mode and the low-frequency driving mode may include the following steps: determining whether the input image data is a still image or a video image; generating a flag indicating whether the input image data is a still image or a video image; and determining the normal driving mode and the low-frequency driving mode based on the flag.

[0025] According to some example embodiments, the driving frequency of the display panel may be determined based on the grayscale value of the input image data. The driving frequency of the display panel may be determined using a flicker lookup table that represents a flicker degree according to the grayscale value of the input image data.

[0026] According to some example embodiments, the touch interrupt signal may be output to the driving controller after a predetermined time delay.

[0027] According to some example embodiments, the display panel may include a first type of switching element and a second type of switching element different from the first type. In the low-frequency driving mode, the driving controller may be configured to determine the driving frequency of the first type of switching element as the first driving frequency, and determine the driving frequency of the second type of switching element as the second driving frequency less than the first driving frequency. In the normal driving mode, the driving controller may be configured to determine the driving frequency of the first type of switching element as the first driving frequency, and determine the driving frequency of the second type of switching element as the first driving frequency.

[0028] According to some example embodiments, in a display device and a method of driving the display device, a touch driver may output a touch interrupt signal indicating the occurrence of a touch event directly to a drive controller so that the drive controller can quickly determine the touch event. In addition, a button controller may output a button interrupt signal indicating a button input event directly to the drive controller so that the drive controller can quickly determine the button input event.

[0029] According to some example embodiments, the driving controller can quickly determine touch events and button input events, so that display defects caused by delays in image conversion in a low-frequency driving mode can be prevented or reduced. Therefore, the display quality of the display panel can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The above and other features and aspects of the inventive concept will become more apparent by describing in detail aspects of some example embodiments of the inventive concept with reference to the accompanying drawings, in which:

[0031] Figure 1 is a block diagram illustrating a display device according to some example embodiments of the inventive concept;

[0032] Figure 2 It shows Figure 1 The block diagram of the drive controller;

[0033] Figure 3 It shows Figure 2 An example of a flashing lookup table;

[0034] Figure 4 is a timing chart showing input signals and output signals of a display device according to a comparative embodiment;

[0035] Figure 5 is a timing chart showing input signals and output signals of a display device according to a comparative embodiment;

[0036] Figure 6 It shows Figure 1 A timing diagram of input signals and output signals of a display device;

[0037] Figure 7 is a timing diagram illustrating input signals and output signals of a display device according to some example embodiments of the inventive concept;

[0038] Figure 8 is a block diagram illustrating a display device according to some example embodiments of the inventive concept;

[0039] Fig. 9 is a block diagram illustrating a display device according to some example embodiments of the inventive concept;

[0040] Fig.10 It shows Fig. 9 A circuit diagram of a pixel of a display panel;

[0041] Fig.11 is shown applied to Fig.10 A timing diagram of signals of pixels of a display panel; and

[0042] Fig.12 is shown in the low frequency drive mode applied to Fig.10 A timing diagram of signals of pixels of a display panel. DETAILED DESCRIPTION

[0043] Hereinafter, aspects of some example embodiments of the inventive concept will be explained in more detail with reference to the accompanying drawings.

[0044] Figure 1 is a block diagram illustrating a display device according to some example embodiments of the inventive concept.

[0045] Reference Figure 1 The display device includes a display panel 100 and a display panel driver. The display panel driver includes a driving controller 200, a gate driver 300, a gamma reference voltage generator 400 and a data driver 500. The display device may further include a touch driver 600. The display device may further include a host 700.

[0046] For example, the driving controller 200 and the data driver 500 may be integrally formed. For example, the driving controller 200, the gamma reference voltage generator 400 and the data driver 500 may be integrally formed. A driving module including at least the driving controller 200 and the data driver 500 may be referred to as a data driver embedded with a timing controller (TED).

[0047] The display panel 100 includes a display area and a peripheral area adjacent to the display area.

[0048] For example, the display panel 100 may be an organic light emitting diode display panel including organic light emitting diodes. Alternatively, the display panel 100 may be a liquid crystal display panel including liquid crystal molecules.

[0049] The display panel 100 includes a plurality of gate lines GL, a plurality of data lines DL, and a plurality of pixels electrically connected to the gate lines GL and the data lines DL. The gate lines GL extend in a first direction D1, and the data lines DL extend in a second direction D2 crossing the first direction D1.

[0050] According to some example embodiments, the display panel 100 may be a touch screen panel that senses a touch event.

[0051] The driving controller 200 receives input image data IMG and input control signal CONT from the host 700. The input image data IMG may include red image data, green image data and blue image data. The input image data IMG may include white image data. The input image data IMG may include magenta image data, yellow image data and cyan image data. The input control signal CONT may include a main clock signal and a data enable signal. The input control signal CONT may also include a vertical synchronization signal and a horizontal synchronization signal.

[0052] The driving controller 200 generates a first control signal CONT1 , a second control signal CONT2 , a third control signal CONT3 , and a data signal DATA based on input image data IMG and an input control signal CONT.

[0053] The driving controller 200 generates a first control signal CONT1 for controlling the operation of the gate driver 300 based on the input control signal CONT, and outputs the first control signal CONT1 to the gate driver 300. The first control signal CONT1 may include a vertical start signal and a gate clock signal.

[0054] The driving controller 200 generates a second control signal CONT2 for controlling the operation of the data driver 500 based on the input control signal CONT, and outputs the second control signal CONT2 to the data driver 500. The second control signal CONT2 may include a horizontal start signal and a load signal.

[0055] The driving controller 200 generates a data signal DATA based on the input image data IMG. The driving controller 200 outputs the data signal DATA to the data driver 500. According to some example embodiments, the driving controller 200 may compensate for the input image data IMG to generate the data signal DATA.

[0056] The driving controller 200 generates a third control signal CONT3 for controlling the operation of the gamma reference voltage generator 400 based on the input control signal CONT, and outputs the third control signal CONT3 to the gamma reference voltage generator 400 .

[0057] The gate driver 300 generates a gate signal for driving the gate line GL in response to the first control signal CONT1 received from the driving controller 200. The gate driver 300 outputs the gate signal to the gate line GL. For example, the gate driver 300 may sequentially output the gate signal to the gate line GL. For example, the gate driver 300 may be mounted on the display panel 100. For example, the gate driver 300 may be integrated on the display panel 100.

[0058] The gamma reference voltage generator 400 generates a gamma reference voltage VGREF in response to the third control signal CONT3 received from the driving controller 200. The gamma reference voltage generator 400 provides the gamma reference voltage VGREF to the data driver 500. The gamma reference voltage VGREF has a value corresponding to a level of the data signal DATA.

[0059] According to some example embodiments, the gamma reference voltage generator 400 may be located in the driving controller 200 or in the data driver 500 .

[0060] The data driver 500 receives the second control signal CONT2 and the data signal DATA from the driving controller 200, and receives the gamma reference voltage VGREF from the gamma reference voltage generator 400. The data driver 500 converts the data signal DATA into a data voltage of an analog type using the gamma reference voltage VGREF. The data driver 500 outputs the data voltage to the data line DL.

[0061] The touch driver 600 may determine a touch event of the display panel 100. The touch driver 600 may generate a touch interrupt signal TINT indicating the occurrence of a touch event and a touch coordinate signal TC indicating the coordinates of a touch position. The touch driver 600 may output the touch interrupt signal TINT and the touch coordinate signal TC to the host 700. In addition, the touch driver 600 may output the touch interrupt signal TINT to the driving controller 200. Therefore, according to some example embodiments, the driving controller 200 may include an input port for receiving the touch interrupt signal TINT from the touch driver 600.

[0062] The host 700 outputs input image data IMG and an input control signal CONT to the driving controller 200 .

[0063] The host 700 may receive a touch interrupt signal TINT and a touch coordinate signal TC from the touch driver 600. The host 700 may change the input image data IMG to change a display image of the display panel 100 in response to the touch interrupt signal TINT and the touch coordinate signal TC.

[0064] Figure 2 It shows Figure 1 1 is a block diagram of a driving controller 200 . Figure 3 It shows Figure 2 An example flash lookup table 260 is shown.

[0065] Reference Figures 1 to 3 , the display panel 100 can be driven in a normal driving mode and a low-frequency driving mode. In the normal driving mode, the display panel 100 can be driven at a normal driving frequency. In the low-frequency driving mode, the display panel 100 can be driven at a driving frequency lower than the normal driving frequency.

[0066] For example, when the input image data represents a video image, the display panel 100 may be driven in a normal driving mode. For example, when the input image data represents a still image, the display panel 100 may be driven in a low-frequency driving mode. For example, when the display device operates in an always-on mode, the display panel 100 may be driven in a low-frequency driving mode.

[0067] The driving controller 200 may include a still image determiner 220 , a driving frequency determiner 240 , and a flicker lookup table 260 .

[0068] The still image determiner 220 may determine whether the input image data IMG is a still image or a video image. The still image determiner 220 may output a flag SF indicating whether the input image data IMG is a still image or a video image to the driving frequency determiner 240. For example, when the input image data IMG is a still image, the still image determiner 220 may output a flag SF of 1 to the driving frequency determiner 240. When the input image data IMG is a video image, the still image determiner 220 may output a flag SF of 0 to the driving frequency determiner 240. When the display panel 100 operates in the normally-on mode, the still image determiner 220 may output a flag SF of 1 to the driving frequency determiner 240.

[0069] When the flag SF is 1, the driving frequency determiner 240 may drive the display panel 100 in the low frequency driving mode. When the flag SF is 0, the driving frequency determiner 240 may drive the display panel 100 in the normal driving mode.

[0070] The driving frequency determiner 240 may refer to the flicker lookup table 260 to determine the low driving frequency. The flicker lookup table 260 may include flicker values ​​according to the grayscale value of the input image data IMG. For example, the flicker lookup table 260 may store the minimum driving frequency under the condition that the difference between the brightness of the write frame and the brightness of the hold frame does not exceed the just noticeable difference for the grayscale value of the input image data IMG.

[0071] exist Figure 3 In FIG. 2 , for grayscale values ​​of 0, 1, and 2, the flicker lookup table 260 may have a value of 0. Here, a value of 0 of the flicker lookup table 260 may represent a driving frequency of 1 Hz. Figure 3 In FIG. 1 , the flicker lookup table 260 may have a value of 1 for grayscale values ​​of 15, 16, and 17. Here, the value of 1 of the flicker lookup table 260 may represent a driving frequency of 30 Hz. Figure 3 In FIG. 1 , for grayscale values ​​of 18 to 22, the flicker lookup table 260 may have a value of 2. Here, the value of 2 of the flicker lookup table 260 may represent a driving frequency of 10 Hz. Figure 3 In FIG. 2 , for grayscale values ​​of 23 to 27, the flicker lookup table 260 may have a value of 3. Here, the value of 3 of the flicker lookup table 260 may represent a driving frequency of 5 Hz. Figure 3 In the example, for grayscale values ​​of 254 to 255, the flicker lookup table 260 may have a value of 0.

[0072] Figure 4is a timing chart showing input signals and output signals of a display device according to a comparative embodiment.

[0073] Reference Figures 1 to 4 , the driving controller 200 may generate a data signal DATA (OUTPUT IMAGE) based on the input image data IMG (INPUT IMAGE).

[0074] The input image data IMG (INPUT IMAGE) may include an input frame image, and the data signal DATA (OUTPUT IMAGE) may include an output frame image.

[0075] The frame can be defined by the vertical synchronization signal VSYNC. Figure 4 In , a frame is defined by the duration between adjacent rising edges of the vertical synchronization signal VSYNC.

[0076] When the input data enable signal IDE has a valid level, the input image data INPUT IMAGE may be input, and when the output data enable signal ODE has a valid level, the data signal OUTPUT IMAGE may be output.

[0077] The input data enable signal IDE can be Figure 4 In contrast, the output data enable signal ODE may not be Figure 4 The output data enable signal ODE may be activated in the write frame of the low frequency driving mode and deactivated in the hold frame of the low frequency driving mode.

[0078] The input image data INPUT IMAGE during the first frame F1 to the third frame F3 may be A, B, and C, respectively. The input image data INPUT IMAGE during the first frame F1 to the third frame F3 are different from each other, so that the driving controller 200 can determine the input image data INPUT IMAGE during the first frame F1 to the third frame F3 as a moving image. Therefore, during the first frame F1 to the third frame F3, the data signal OUTPUT IMAGE is driven at a relatively high frequency (e.g., 60 Hz).

[0079] The input image data INPUT IMAGE of the fourth frame F4 is identical to the input image data INPUT IMAGE of the third frame F3 , so that the driving controller 200 may determine the input image data INPUT IMAGE of the fourth frame F4 as a still image.

[0080] The input image data INPUT IMAGE during the fifth to seventh frames F5 to F7 are identical to the input image data INPUT IMAGE of the fourth frame F4 , so that the driving controller 200 may determine the input image data INPUT IMAGE during the fifth to seventh frames F5 to F7 as a still image.

[0081] When the input image data INPUT IMAGE represents a moving image, the display panel 100 is driven in a normal driving mode. When the input image data INPUT IMAGE represents a still image, the display panel 100 is driven in a low-frequency driving mode.

[0082] According to some example embodiments, the driving frequency (eg, 30 Hz) in the low frequency driving mode may be half the driving frequency (eg, 60 Hz) in the normal driving mode. Thus, the write frame and the hold frame may be alternately arranged in the low frequency driving mode.

[0083] exist Figure 4 In the seventh frame F7, a touch event occurs on the display panel 100. The sensing clock signal SENSINGCLOCK is a signal for sensing a touch event. The frequency of the sensing clock signal SENSING CLOCK may be different from the frequency of the vertical synchronization signal VSYNC. Figure 4 For example, the frequency of the sensing clock signal SENSING CLOCK may be three or more times the frequency of the vertical synchronization signal VSYNC.

[0084] The touch driver 600 detects the touch event when a touch event occurs on the display panel 100. The related art touch driver 600 may output a touch interrupt signal TINT and a touch coordinate signal TC to the host 700 when a touch event occurs.

[0085] The host 700 may change the input image data INPUT IMAGE in response to a touch event. The host 700 may change the input image data INPUT IMAGE based on the touch interrupt signal TINT and the touch coordinate signal TC, and output the input image data INPUT IMAGE to the driving controller 200.

[0086] The first delay DY1 is generated from the time point when the touch event is detected to the time point when the touch interrupt signal TINT is generated. The second delay DY2 is generated from the time point when the touch interrupt signal TINT is generated to the time point when the touch coordinate signal TC is generated. The third delay DY3 is generated from the time point when the touch coordinate signal TC is generated to the time point when the touch coordinate signal TC is completely sent to the host 700.

[0087] In the related art display device, the driving controller 200 may receive a touch event from the host 700 , so that the driving controller 200 senses the touch event after a first delay DY1 , a second delay DY2 , and a third delay DY3 .

[0088] exist Figure 4 In the embodiment, the touch event may occur at an early time point of the seventh frame F7, and the host 700 may sense the touch event at a late time point of the seventh frame F7 due to a delay.

[0089] When the host 700 senses a touch event in a late time point of the seventh frame F7, the host 700 may change the input image data of the eighth frame F8 to "D". Because the input image data (D) of the eighth frame F8 is different from the input image data (C) of the seventh frame F7, the driving controller 200 determines the input image data in the eighth frame F8 as a motion image, and the driving controller 200 drives the display device in a normal driving mode (high-frequency driving mode) from the ninth frame F9. Therefore, although the touch event occurs in the seventh frame F7, the display panel 100 is driven in a low-frequency driving mode until the eighth frame F8. In the eighth frame F8, the output image is output at the driving frequency of the low-frequency driving mode, so that the output image of the eighth frame F8 is not D but C due to the data delay.

[0090] In the low-frequency driving mode, the period of refreshing the image may be long. Therefore, when the touch event occurs in the seventh frame F7 and the changed image E is displayed in the ninth frame F9, the user may perceive a delay in the image conversion.

[0091] Figure 5 is a timing chart showing input signals and output signals of a display device according to a comparative embodiment. Figure 5 Indicates ratio Figure 4 The situation is worse.

[0092] Reference Figures 1 to 5 , the input image data INPUT IMAGE during the first frame F1 to the third frame F3 may be A, B, and C, respectively. The input image data INPUT IMAGE during the first frame F1 to the third frame F3 are different from each other, so that the driving controller 200 can determine the input image data INPUT IMAGE during the first frame F1 to the third frame F3 as a moving image. Therefore, during the first frame F1 to the third frame F3, the data signal OUTPUT IMAGE is driven at a relatively high frequency (e.g., 60 Hz).

[0093] The input image data INPUT IMAGE of the fourth frame F4 is identical to the input image data INPUT IMAGE of the third frame F3 , so that the driving controller 200 may determine the input image data INPUT IMAGE of the fourth frame F4 as a still image.

[0094] The input image data INPUT IMAGE during the fifth to seventh frames F5 to F7 are identical to the input image data INPUT IMAGE of the fourth frame F4 , so that the driving controller 200 may determine the input image data INPUT IMAGE during the fifth to seventh frames F5 to F7 as a still image.

[0095] When the input image data INPUT IMAGE represents a moving image, the display panel 100 is driven in a normal driving mode. When the input image data INPUT IMAGE represents a still image, the display panel 100 is driven in a low-frequency driving mode.

[0096] exist Figure 5 In the seventh frame F7, a touch event occurs on the display panel 100.

[0097] The touch driver 600 detects the touch event when a touch event occurs on the display panel 100. The related art touch driver 600 may output a touch interrupt signal TINT and a touch coordinate signal TC to the host 700 when a touch event occurs.

[0098] The host 700 may change the input image data INPUT IMAGE in response to a touch event. The host 700 may change the input image data INPUT IMAGE based on the touch interrupt signal TINT and the touch coordinate signal TC, and output the input image data INPUT IMAGE to the driving controller 200.

[0099] In the related art display device, the driving controller 200 may receive a touch event from the host 700 , so that the driving controller 200 senses the touch event after a first delay DY1 , a second delay DY2 , and a third delay DY3 .

[0100] exist Figure 5 In the embodiment, the touch event may occur at a middle time point of the seventh frame F7, and the host 700 may sense the touch event at an early time point of the eighth frame F8 due to the delay.

[0101] When the host 700 senses a touch event in an early time point of the eighth frame F8, the host 700 may change the input image data of the ninth frame F9 to "D". Because the input image data (C) of the eighth frame F8 is the same as the input image data (C) of the seventh frame F7, the drive controller 200 determines the input image data in the eighth frame F8 as a still image, and the drive controller 200 drives the display device in a low-frequency driving mode in the eighth frame F8. Because the input image data (D) of the ninth frame F9 is different from the input image data (C) of the eighth frame F8, the drive controller 200 determines the input image data in the ninth frame F9 as a moving image, and the drive controller 200 drives the display device in a normal driving mode (high-frequency driving mode) from the tenth frame F10. Therefore, although the touch event occurs in the seventh frame F7, the display panel 100 is driven in a low-frequency driving mode until the ninth frame F9.

[0102] In the low-frequency driving mode, the period of refreshing the image may be long. Therefore, when the touch event occurs in the seventh frame F7 and the changed image E is displayed in the tenth frame F10, the user will perceive the delay of the image conversion. Figure 5 The delay of image conversion in Figure 4 The delay in image conversion is long.

[0103] Figure 6 It shows Figure 1 The timing diagram of the input and output signals of the display device. Figure 6 In, with Figure 4 and Figure 5 Different from the comparative embodiment in FIG. 1 , the touch driver 600 directly outputs the touch interrupt signal TINT to the driving controller 200 .

[0104] Reference Figures 1 to 6 , the input image data INPUT IMAGE during the first frame F1 to the third frame F3 may be A, B, and C, respectively. The input image data INPUT IMAGE during the first frame F1 to the third frame F3 are different from each other, so that the driving controller 200 can determine the input image data INPUT IMAGE during the first frame F1 to the third frame F3 as a moving image. Therefore, during the first frame F1 to the third frame F3, the data signal OUTPUT IMAGE is driven at a relatively high frequency (e.g., 60 Hz).

[0105] The input image data INPUT IMAGE of the fourth frame F4 is identical to the input image data INPUT IMAGE of the third frame F3 , so that the driving controller 200 may determine the input image data INPUT IMAGE of the fourth frame F4 as a still image.

[0106] The input image data INPUT IMAGE during the fifth to seventh frames F5 to F7 are identical to the input image data INPUT IMAGE of the fourth frame F4 , so that the driving controller 200 may determine the input image data INPUT IMAGE during the fifth to seventh frames F5 to F7 as a still image.

[0107] When the input image data INPUT IMAGE represents a moving image, the display panel 100 is driven in a normal driving mode. When the input image data INPUT IMAGE represents a still image, the display panel 100 is driven in a low-frequency driving mode.

[0108] exist Figure 6 In the seventh frame F7, a touch event occurs on the display panel 100.

[0109] When a touch event occurs on the display panel 100, the touch driver 600 detects the touch event. When a touch event occurs, the touch driver 600 of the related art may output the touch interrupt signal TINT and the touch coordinate signal TC only to the host 700. In contrast, when a touch event occurs, the touch driver 600 according to some example embodiments outputs the touch interrupt signal TINT to the host 700 and the driving controller 200.

[0110] The host 700 may change the input image data INPUT IMAGE in response to a touch event. The host 700 may change the input image data INPUT IMAGE based on the touch interrupt signal TINT and the touch coordinate signal TC, and output the input image data INPUT IMAGE to the driving controller 200.

[0111] According to some example embodiments, the driving controller 200 receives a touch event from the touch driver 600 before receiving the touch event from the host 700 , so that the driving controller 200 senses the touch event only after the first delay DY1 .

[0112] exist Figure 6 In the embodiment, the touch event may occur in an early time point of the seventh frame F7, and due to the delay, the host 700 may sense the touch event in a late time point of the seventh frame F7, and the driving controller 200 may sense the touch event in a middle time point of the seventh frame F7.

[0113] When the host 700 senses a touch event at a late time point of the seventh frame F7, Figure 4The host 700 may change the input image data of the eighth frame F8 to "D" as in the comparative embodiment. Since the driving controller 200 of the prior art may not receive a touch event in advance, the driving controller 200 of the prior art compares the input image data of the eighth frame F8 with the input image data of the seventh frame F7 and determines the input image data in the eighth frame F8 as a moving image. The driving controller 200 of the prior art drives the display panel 100 in a normal driving mode from the ninth frame F9.

[0114] However, according to some example embodiments, since the driving controller 200 receives a touch event from the touch driver 600 in advance, the driving controller 200 may drive the display panel 100 in the normal driving mode from the eighth frame F8. Figure 4 In the comparative embodiment of FIG. 1 , an output image (C) of the eighth frame F8 different from the input image data (D) of the eighth frame F8 is output. Figure 6 In the present exemplary embodiment, the output image (D) of the eighth frame F8 which is the same as the input image data (D) of the eighth frame F8 is output, so that the delay of the image conversion can be prevented or reduced.

[0115] When the display panel 100 is driven in the low frequency driving mode and a touch event is sensed by the driving controller 200 , the driving controller 200 drives the display panel 100 in the normal driving mode in the frame just next to the frame when the touch event is sensed.

[0116] According to some example embodiments, the touch driver 600 directly outputs a touch interrupt signal TINT indicating the occurrence of a touch event to the driving controller 200 so that the driving controller 200 may immediately sense the touch event.

[0117] The driving controller 200 can immediately determine a touch event, thereby preventing or reducing display defects caused by a delay in image conversion in a low-frequency driving mode. Therefore, the display quality of the display panel 100 can be improved.

[0118] Figure 7 2 is a timing diagram illustrating input signals and output signals of a display device according to some example embodiments of the inventive concept.

[0119] The display device and the method of driving the display device according to the present exemplary embodiment are different from those of the reference numerals except for the output timing of the touch interrupt signal TINT. Figures 1 to 3 and Figure 6 The display device and the method of driving the display device of the previously described exemplary embodiments are substantially the same. Therefore, the same reference numerals will be used to represent the same Figures 1 to 3 and Figure 6The present invention relates to components that are the same as or similar to those described in the previous example embodiments, and any repeated explanation regarding the above elements will be omitted.

[0120] Reference Figures 1 to 3 and Figure 7 The display device includes a display panel 100 and a display panel driver. The display panel driver includes a driving controller 200, a gate driver 300, a gamma reference voltage generator 400 and a data driver 500. The display device may further include a touch driver 600. The display device may further include a host 700.

[0121] The touch driver 600 may determine a touch event of the display panel 100. The touch driver 600 may generate a touch interrupt signal TINT indicating the occurrence of a touch event and a touch coordinate signal TC indicating the coordinates of a touch position. The touch driver 600 may output the touch interrupt signal TINT and the touch coordinate signal TC to the host 700. In addition, the touch driver 600 may output the touch interrupt signal TINT to the driving controller 200. Therefore, according to some example embodiments, the driving controller 200 may include an input port for receiving the touch interrupt signal TINT from the touch driver 600.

[0122] The input image data INPUT IMAGE during the first frame F1 to the third frame F3 may be A, B, and C, respectively. The input image data INPUT IMAGE during the first frame F1 to the third frame F3 are different from each other, so that the driving controller 200 can determine the input image data INPUT IMAGE during the first frame F1 to the third frame F3 as a moving image. Therefore, during the first frame F1 to the third frame F3, the data signal OUTPUT IMAGE is driven at a relatively high frequency (e.g., 60 Hz).

[0123] The input image data INPUT IMAGE of the fourth frame F4 is identical to the input image data INPUT IMAGE of the third frame F3 , so that the driving controller 200 may determine the input image data INPUT IMAGE of the fourth frame F4 as a still image.

[0124] The input image data INPUT IMAGE during the fifth to seventh frames F5 to F7 are identical to the input image data INPUT IMAGE of the fourth frame F4 , so that the driving controller 200 may determine the input image data INPUT IMAGE during the fifth to seventh frames F5 to F7 as a still image.

[0125] When the input image data INPUT IMAGE represents a moving image, the display panel 100 is driven in a normal driving mode. When the input image data INPUT IMAGE represents a still image, the display panel 100 is driven in a low-frequency driving mode.

[0126] exist Figure 7 In the seventh frame F7, a touch event occurs on the display panel 100.

[0127] When a touch event occurs on the display panel 100, the touch driver 600 detects the touch event. When a touch event occurs, the touch driver 600 of the related art may output the touch interrupt signal TINT and the touch coordinate signal TC only to the host 700. In contrast, when a touch event occurs, the touch driver 600 according to some example embodiments outputs the touch interrupt signal TINT to the host 700 and the driving controller 200.

[0128] According to some example embodiments, the touch driver 600 may output the touch interrupt signal TINT to the drive controller 200 after a predetermined time delay DYT. When the touch driver 600 immediately outputs the touch interrupt signal TINT to the drive controller 200, the drive controller 200 senses the occurrence of a touch event before the host 700. Therefore, when the drive controller 200 senses the occurrence of a touch event before the host 700, an unexpected display defect of a display image of the display panel 100 may be generated, or the drive mode of the display panel 100 may be converted to a normal drive mode earlier than a desired frame, thereby possibly increasing the power consumption of the display device. Therefore, the touch driver 600 may output the touch interrupt signal TINT to the drive controller 200 after a predetermined time delay DYT, and the predetermined time delay DYT may be appropriately adjusted in consideration of the display defect and the power consumption of the display device.

[0129] For example, the predetermined time delay DYT may adjust the timing of the touch interrupt signal TINT so that the touch interrupt signal TINT is simultaneously transmitted to the driving controller 200 and the host 700 .

[0130] For example, the predetermined time delay DYT may adjust the timing of the touch interrupt signal TINT so that the touch interrupt signal TINT is output to the driving controller 200 at a falling edge of the touch coordinate signal TC.

[0131] The host 700 may change the input image data INPUT IMAGE in response to the touch event. The host 700 may change the input image data INPUT IMAGE based on the touch interrupt signal TINT and the touch coordinate signal TC, and output the changed input image data INPUT IMAGE to the driving controller 200.

[0132] exist Figure 7 In the embodiment, the touch event may occur in an early time point of the seventh frame F7, and due to the delay, the host 700 may sense the touch event in a late time point of the seventh frame F7, and the driving controller 200 may sense the touch event in a late time point of the seventh frame F7.

[0133] When the host 700 senses a touch event at a late time point of the seventh frame F7, Figure 4 The host 700 may change the input image data of the eighth frame F8 to "D" as in the comparative embodiment. Since the driving controller 200 of the prior art may not receive a touch event in advance, the driving controller 200 of the prior art compares the input image data of the eighth frame F8 with the input image data of the seventh frame F7 and determines the input image data in the eighth frame F8 as a moving image. The driving controller 200 of the prior art drives the display panel 100 in a normal driving mode from the ninth frame F9.

[0134] However, according to some example embodiments, since the driving controller 200 receives a touch event from the touch driver 600 in advance, the driving controller 200 may drive the display panel 100 in the normal driving mode from the eighth frame F8. Figure 4 In the comparative embodiment of FIG. 1 , an output image (C) of the eighth frame F8 different from the input image data (D) of the eighth frame F8 is output. Figure 7 In the present exemplary embodiment, the output image (D) of the eighth frame F8 which is the same as the input image data (D) of the eighth frame F8 is output, so that the delay of the image conversion can be prevented or reduced.

[0135] According to some example embodiments, the touch driver 600 directly outputs a touch interrupt signal TINT indicating the occurrence of a touch event to the driving controller 200 so that the driving controller 200 may immediately sense the touch event.

[0136] The driving controller 200 can immediately determine a touch event, thereby preventing or reducing display defects caused by a delay in image conversion in a low-frequency driving mode. Therefore, the display quality of the display panel 100 can be improved.

[0137] Figure 8 is a block diagram illustrating a display device according to some example embodiments of the inventive concept.

[0138] The display device and the method of driving the display device according to the present exemplary embodiment are similar to those of the reference numerals except that the display device includes a button controller. Figures 1 to 3 and Figure 6 The display device and the method of driving the display device of the previously described exemplary embodiments are substantially the same. Therefore, the same reference numerals will be used to represent the same Figures 1 to 3 and Figure 6 The present invention relates to components that are the same as or similar to those described in the previous example embodiments, and any repeated explanation regarding the above elements will be omitted.

[0139] Reference Figure 2 , Figure 3 , Figure 6 and Figure 8 The display device includes a display panel 100 and a display panel driver. The display panel driver includes a driving controller 200, a gate driver 300, a gamma reference voltage generator 400 and a data driver 500. The display device may further include a host 700. The display device may further include a button controller 800. Although not shown in the figure, the display device may further include Figure 1 The touch driver 600 is provided. Optionally, the display device may not include Figure 1 A touch driver 600 is provided.

[0140] The button controller 800 may determine a button input event of the display device. The button controller 800 may generate a button interrupt signal BINT indicating the occurrence of a button input event at an input button of the display device. The button controller 800 may output the button interrupt signal BINT to the host 700. In addition, the button controller 800 may output the button interrupt signal BINT to the drive controller 200. Therefore, according to some example embodiments, the drive controller 200 may include an input port that receives the button interrupt signal BINT from the button controller 800.

[0141] The host 700 outputs input image data IMG and an input control signal CONT to the driving controller 200 .

[0142] The host 700 may receive the button interrupt signal BINT from the button controller 800. The host 700 may change the input image data IMG to change the display image of the display panel 100 in response to the button interrupt signal BINT.

[0143] The display panel 100 may be driven in a normal driving mode and a low frequency driving mode. In the normal driving mode, the display panel 100 may be driven at a normal driving frequency. In the low frequency driving mode, the display panel 100 may be driven at a driving frequency lower than the normal driving frequency.

[0144] For example, when the input image data represents a video image, the display panel 100 may be driven in a normal driving mode. For example, when the input image data represents a still image, the display panel 100 may be driven in a low-frequency driving mode. For example, when the display device operates in a normally-on mode, the display panel 100 may be driven in a low-frequency driving mode.

[0145] When a button input event occurs, the button controller 800 detects the button input event. When a button input event occurs, the button controller of the prior art outputs the button interrupt signal BINT only to the host 700. In contrast, when a button input event occurs, the button controller 800 according to some example embodiments outputs the button interrupt signal BINT to the host 700 and the drive controller 200.

[0146] According to some example embodiments, the driving controller 200 receives a button input event from the button controller 800 before receiving the button input event from the host 700, so that the driving controller 200 receives the button input event only in Figure 6 The button input event is sensed after the first delay DY1.

[0147] When the display panel 100 is driven in the low frequency driving mode and a button input event is sensed by the driving controller 200 , the driving controller 200 drives the display panel 100 in the normal driving mode in the frame just next to the frame when the button input event is sensed.

[0148] According to some example embodiments, the button controller 800 outputs a button interrupt signal BINT indicating the occurrence of a button input event directly to the driving controller 200 so that the driving controller 200 can immediately perceive the button input event.

[0149] The driving controller 200 can immediately determine the button input event, so that display defects caused by delay of image conversion in the low-frequency driving mode can be prevented or reduced. Therefore, the display quality of the display panel 100 can be improved.

[0150] Fig. 9 is a block diagram illustrating a display device according to some example embodiments of the inventive concept. Fig.10 It shows Fig. 9 Circuit diagram of a pixel of a display panel. Fig.11 is shown applied to Fig.10 A timing diagram of signals of pixels of a display panel. Fig.12 is shown in the low frequency drive mode applied to Fig.10 A timing diagram of signals of pixels of a display panel.

[0151] Except for the structures of the display panel and the emission driver, the display device and the method of driving the display device according to the present exemplary embodiment are similar to those of the reference Figures 1 to 3 and Figure 6 The display device and the method of driving the display device of the previously described exemplary embodiments are substantially the same. Therefore, the same reference numerals will be used to represent the same Figures 1 to 3 and Figure 6 The present invention relates to components that are the same as or similar to those described in the previous example embodiments, and any repeated explanation regarding the above elements will be omitted.

[0152] Reference Figure 2 , Figure 3 , Figure 6 and Figures 9 to 12 , the display device includes a display panel 100 and a display panel driver. The display panel driver includes a driving controller 200, a gate driver 300, a gamma reference voltage generator 400 and a data driver 500. The display device may further include an emission driver 650. The display device may further include a touch driver 600. The display device may further include a host 700.

[0153] The display panel 100 includes a plurality of gate lines GWPL, GWNL, GIL, and GBL, a plurality of data lines DL, a plurality of emission lines EL, and a plurality of pixels electrically connected to the gate lines GWPL, GWNL, GIL, and GBL, the data lines DL, and the emission lines EL. The gate lines GWPL, GWNL, GIL, and GBL may extend in a first direction D1, the data lines DL may extend in a second direction D2 crossing the first direction D1, and the emission lines EL may extend in the first direction D1.

[0154] The driving controller 200 generates a first control signal CONT1 , a second control signal CONT2 , a third control signal CONT3 , a fourth control signal CONT4 , and a data signal DATA based on input image data IMG and an input control signal CONT.

[0155] The emission driver 650 generates an emission signal to drive the emission line EL in response to the fourth control signal CONT4 received from the driving controller 200. The emission driver 650 may output the emission signal to the emission line EL.

[0156] The touch driver 600 may determine a touch event of the display panel 100. The touch driver 600 may generate a touch interrupt signal TINT indicating the occurrence of a touch event and a touch coordinate signal TC indicating the coordinates of a touch position. The touch driver 600 may output the touch interrupt signal TINT and the touch coordinate signal TC to the host 700. In addition, the touch driver 600 may output the touch interrupt signal TINT to the driving controller 200. Therefore, according to some example embodiments, the driving controller 200 may include an input port for receiving the touch interrupt signal TINT from the touch driver 600.

[0157] The host 700 outputs input image data IMG and an input control signal CONT to the driving controller 200 .

[0158] The host 700 may receive a touch interrupt signal TINT and a touch coordinate signal TC from the touch driver 600. The host 700 may change the input image data IMG to change a display image of the display panel 100 in response to the touch interrupt signal TINT and the touch coordinate signal TC.

[0159] The display panel 100 includes a plurality of pixels, and each pixel includes an organic light emitting element OLED.

[0160] The pixel receives data writing gate signals GWP and GWN, data initialization gate signal GI, organic light emitting element initialization signal GB, data voltage VDATA and emission signal EM, and the organic light emitting element OLED of the pixel emits light corresponding to the level of data voltage VDATA to display an image.

[0161] According to some example embodiments, a pixel may include a first type of switching element and a second type of switching element different from the first type. For example, the first type of switching element may be a polysilicon thin film transistor. For example, the first type of switching element may be a low temperature polysilicon (LTPS) thin film transistor. For example, the second type of switching element may be an oxide thin film transistor. For example, the first type of switching element may be a P-type transistor, and the second type of switching element may be an N-type transistor.

[0162] For example, the data write gate signal may include a first data write gate signal GWP and a second data write gate signal GWN. The first data write gate signal GWP may be applied to a P-type transistor so that the first data write gate signal GWP has a valid signal at a low level corresponding to the data write timing. The second data write gate signal GWN may be applied to an N-type transistor so that the second data write gate signal GWN has a valid signal at a high level corresponding to the data write timing.

[0163] At least one of the pixels may include first to seventh pixel switching elements T1 to T7 , a storage capacitor CST, and an organic light emitting element OLED.

[0164] The first pixel switch element T1 includes a control electrode connected to the first node N1, an input electrode connected to the second node N2, and an output electrode connected to the third node N3. For example, the first pixel switch element T1 may be a polysilicon thin film transistor. For example, the first pixel switch element T1 may be a P-type thin film transistor.

[0165] The second pixel switch element T2 includes a control electrode to which a first data write gate signal GWP is applied, an input electrode to which a data voltage VDATA is applied, and an output electrode connected to the second node N2. For example, the second pixel switch element T2 may be a polysilicon thin film transistor. For example, the second pixel switch element T2 may be a P-type thin film transistor.

[0166] The third pixel switch element T3 includes a control electrode to which the second data write gate signal GWN is applied, an input electrode connected to the first node N1, and an output electrode connected to the third node N3. For example, the third pixel switch element T3 may be an oxide thin film transistor. For example, the third pixel switch element T3 may be an N-type thin film transistor.

[0167] The fourth pixel switching element T4 includes a control electrode to which a data initialization gate signal GI is applied, an input electrode to which an initialization voltage VI is applied, and an output electrode connected to the first node N1. For example, the fourth pixel switching element T4 may be an oxide thin film transistor. For example, the fourth pixel switching element T4 may be an N-type thin film transistor.

[0168] The fifth pixel switching element T5 includes a control electrode to which an emission signal EM is applied, an input electrode to which a high power supply voltage ELVDD is applied, and an output electrode connected to the second node N2. For example, the fifth pixel switching element T5 may be a polysilicon thin film transistor. For example, the fifth pixel switching element T5 may be a P-type thin film transistor.

[0169] The sixth pixel switch element T6 includes a control electrode to which an emission signal EM is applied, an input electrode connected to the third node N3, and an output electrode connected to the anode electrode of the organic light emitting element OLED. For example, the sixth pixel switch element T6 may be a polysilicon thin film transistor. For example, the sixth pixel switch element T6 may be a P-type thin film transistor. The control electrode of the sixth pixel switch element T6 may be a gate electrode, the input electrode of the sixth pixel switch element T6 may be a source electrode, and the output electrode of the sixth pixel switch element T6 may be a drain electrode.

[0170] The seventh pixel switch element T7 includes a control electrode to which an organic light emitting element initialization gate signal GB is applied, an input electrode to which an initialization voltage VI is applied, and an output electrode connected to the anode electrode of the organic light emitting element OLED. For example, the seventh pixel switch element T7 may be an oxide thin film transistor. For example, the seventh pixel switch element T7 may be an N-type thin film transistor. Alternatively, the seventh pixel switch element T7 may be a polysilicon thin film transistor. For example, the seventh pixel switch element T7 may be a P-type thin film transistor. When the seventh pixel switch element T7 is a P-type thin film transistor, the organic light emitting element initialization gate signal GB may have the same Fig.11 and Fig.12 Different low level active signals.

[0171] The storage capacitor CST includes a first electrode to which the high power voltage ELVDD is applied and a second electrode connected to the first node N1.

[0172] The organic light emitting element OLED includes an anode electrode and a cathode electrode to which a low power voltage ELVSS is applied.

[0173] exist Fig.11 During the first duration DU1, the first node N1 and the storage capacitor CST are initialized in response to the data initialization gate signal GI. During the second duration DU2, in response to the first data write gate signal GWP and the second data write gate signal GWN, the threshold voltage |VTH| of the first pixel switch element T1 is compensated, and the data voltage VDATA compensating the threshold voltage |VTH| is written to the first node N1. During the third duration DU3, the anode electrode of the organic light emitting element OLED is initialized in response to the organic light emitting element initialization gate signal GB. During the fourth duration DU4, the organic light emitting element OLED emits light in response to the emission signal EM, so that the display panel 100 displays an image.

[0174] During the first duration DU1, the data initialization gate signal GI may have an effective level. For example, the effective level of the data initialization gate signal GI may be a high level. When the data initialization gate signal GI has an effective level, the fourth pixel switching element T4 is turned on, so that the initialization voltage VI can be applied to the first node N1. The data initialization gate signal GI[N] of the current stage can be generated based on the scan signal SCAN[N-1] of the previous stage.

[0175] During the second duration DU2, the first data write gate signal GWP and the second data write gate signal GWN may have an effective level. For example, the effective level of the first data write gate signal GWP may be a low level, and the effective level of the second data write gate signal GWN may be a high level. When the first data write gate signal GWP and the second data write gate signal GWN have an effective level, the second pixel switch element T2 and the third pixel switch element T3 are turned on. In addition, the first pixel switch element T1 is turned on in response to the initialization voltage VI. The first data write gate signal GWP[N] of the current level may be generated based on the scan signal SCAN[N] of the current level. The second data write gate signal GWN[N] of the current level may be generated based on the scan signal SCAN[N] of the current level.

[0176] A voltage obtained by subtracting an absolute value |VTH| of a threshold voltage of the first pixel switching element T1 from the data voltage VDATA may be charged at the first node N1 along a path generated by the first to third pixel switching elements T1 to T3 .

[0177] During the third duration DU3, the organic light emitting element initialization signal GB may have an effective level. For example, the effective level of the organic light emitting element initialization signal GB may be a high level. When the organic light emitting element initialization signal GB has an effective level, the seventh pixel switch element T7 is turned on, so that the initialization voltage V1 may be applied to the anode electrode of the organic light emitting element OLED. The organic light emitting element initialization signal GB[N] of the current stage may be generated based on the scan signal SCAN[N+1] of the next stage.

[0178] During the fourth duration DU4, the emission signal EM may have an effective level. The effective level of the emission signal EM may be a low level. When the emission signal EM has an effective level, the fifth pixel switch element T5 and the sixth pixel switch element T6 are turned on. In addition, the first pixel switch element T1 is turned on by the data voltage VDATA.

[0179] The driving current flows through the fifth pixel switching element T5, the first pixel switching element T1 and the sixth pixel switching element T6 to drive the organic light emitting element OLED. The intensity of the driving current can be determined by the level of the data voltage VDATA. The brightness of the organic light emitting element OLED is determined by the intensity of the driving current. The driving current ISD flowing through the path from the input electrode to the output electrode of the first pixel switching element T1 is determined by the following formula 1.

[0180] [Formula 1]

[0181]

[0182] In Formula 1, μ is the mobility of the first pixel switch element T1. Cox is the capacitance per unit area of ​​the first pixel switch element T1. W / L is the width-to-length ratio of the first pixel switch element T1. VSG is the voltage between the input electrode of the first pixel switch element T1 (i.e., the second node N2) and the control electrode of the first pixel switch element T1 (i.e., the first node N1). |VTH| is the threshold voltage of the first pixel switch element T1.

[0183] The voltage VG of the first node N1 may be expressed as the following Equation 2 after compensation of the threshold voltage |VTH| during the second duration DU2.

[0184] [Formula 2]

[0185] VG=VDATA-|VTH|

[0186] When the organic light emitting element OLED emits light during the fourth duration DU4, the driving voltage VOV and the driving current ISD may be expressed as the following Formula 3 and Formula 4. In Formula 3, VS is the voltage of the second node N2.

[0187] [Formula 3]

[0188] VOV=VS-VG-|VTH|=ELVDD-(VDATA-|VTH|)-|VTH|=ELVDD-VDATA

[0189] [Formula 4]

[0190]

[0191] The threshold voltage |VTH| is compensated during the second duration DU2 , so that when the organic light emitting element OLED emits light during the fourth duration DU4 , the driving current ISD may be determined regardless of the threshold voltage |VTH| of the first pixel switching element T1 .

[0192] According to some example embodiments, when the image displayed on the display panel 100 is a still image or the display panel 100 is operated in a normally open mode, the driving frequency of the display panel 100 can be reduced to reduce power consumption. When all of the switching elements of the pixels of the display panel 100 are polysilicon thin film transistors, flickering may occur due to the leakage current of the pixel switching elements in the low-frequency driving mode. Therefore, some of the pixel switching elements can be designed using oxide thin film transistors. According to some example embodiments, the third pixel switching element T3, the fourth pixel switching element T4, and the seventh pixel switching element T7 can be oxide thin film transistors. The first pixel switching element T1, the second pixel switching element T2, the fifth pixel switching element T5, and the sixth pixel switching element T6 can be polysilicon thin film transistors.

[0193] The display panel 100 may be driven in a normal driving mode in which the display panel 100 is driven at a normal driving frequency and a low-frequency driving mode in which the display panel 100 is driven at a driving frequency lower than the normal driving frequency.

[0194] For example, when the input image data represents a video image, the display panel 100 may be driven in a normal driving mode. For example, when the input image data represents a still image, the display panel 100 may be driven in a low-frequency driving mode. For example, when the display device operates in a normally-on mode, the display panel 100 may be driven in a low-frequency driving mode.

[0195] The display panel 100 may be driven in units of frames. The display panel 100 may be refreshed in each frame in a normal driving mode. Therefore, the normal driving mode includes only a writing frame in which data is written in pixels.

[0196] The display panel 100 may be refreshed at a frequency of the low frequency driving mode in the low frequency driving mode. Therefore, the low frequency driving mode includes a writing frame in which data is written in a pixel and a holding frame in which the written data is maintained without writing data in the pixel.

[0197] For example, when the frequency of the normal driving mode is 60 Hz and the frequency of the low-frequency driving mode is 1 Hz, the low-frequency driving mode includes 1 write frame WRITE and 59 hold frames HOLD in one second. Here, the length of the write frame WRITE can be substantially the same as the length of the hold frame HOLD. For example, when the frequency of the normal driving mode is 60 Hz and the frequency of the low-frequency driving mode is 1 Hz, 59 consecutive hold frames HOLD are located between 2 adjacent write frames WRITE.

[0198] For example, when the frequency of the normal driving mode is 60 Hz and the frequency of the low-frequency driving mode is 10 Hz, the low-frequency driving mode includes 10 write frames WRITE and 50 hold frames HOLD in one second. Here, the length of the write frame WRITE can be substantially the same as the length of the hold frame HOLD. For example, when the frequency of the normal driving mode is 60 Hz and the frequency of the low-frequency driving mode is 10 Hz, 5 consecutive hold frames HOLD are located between 2 adjacent write frames WRITE.

[0199] According to some example embodiments, the second data write gate signal GWN and the data initialization gate signal GI may have a first frequency in the low frequency driving mode. The first frequency may be the frequency of the low frequency driving mode. Conversely, the first data write gate signal GWP, the emission signal EM, and the organic light emitting element initialization gate signal GB may have a second frequency greater than the first frequency. The second frequency may be a normal frequency of the normal driving mode. Fig.12 For example, the first frequency is 1 Hz and the second frequency is 60 Hz.

[0200] The transmission signal EM in a frame may include a transmission-off duration OD when the transmission signal EM has an inactive level and a transmission-on duration OD when the transmission signal EM has an active level.

[0201] When a touch event occurs on the display panel 100, the touch driver 600 detects the touch event. When a touch event occurs, the touch driver 600 of the related art may output the touch interrupt signal TINT and the touch coordinate signal TC only to the host 700. In contrast, when a touch event occurs, the touch driver 600 according to some example embodiments outputs the touch interrupt signal TINT to the host 700 and the driving controller 200.

[0202] According to some example embodiments, the driving controller 200 receives a touch event from the touch driver 600 before receiving the touch event from the host 700 , so that the driving controller 200 senses the touch event only after the first delay DY1 .

[0203] When the display panel 100 is driven in the low frequency driving mode and a touch event is sensed by the driving controller 200 , the driving controller 200 drives the display panel 100 in the normal driving mode in the frame just next to the frame when the touch event is sensed.

[0204] According to some example embodiments, in the low-frequency driving mode, the driving controller 200 determines the driving frequency of the first type of switching element as a first driving frequency (e.g., a normal driving frequency), and determines the driving frequency of the second type of switching element as a second driving frequency (e.g., a low driving frequency) that is smaller than the first driving frequency.

[0205] In the normal driving mode, the driving controller 200 determines the driving frequency of the first type switching element as the first driving frequency (eg, normal driving frequency), and determines the driving frequency of the second type switching element as the first driving frequency (eg, normal driving frequency).

[0206] According to some example embodiments, the touch driver 600 directly outputs a touch interrupt signal TINT indicating the occurrence of a touch event to the driving controller 200 so that the driving controller 200 may immediately sense the touch event.

[0207] The driving controller 200 can immediately determine a touch event, thereby preventing or reducing display defects caused by a delay in image conversion in a low-frequency driving mode. Therefore, the display quality of the display panel 100 can be improved.

[0208] According to some example embodiments of a display device and a method of driving the same, display quality in a low-frequency driving mode may be improved.

[0209] The foregoing is an illustration of the inventive concept and will not be construed as a limitation of the inventive concept. Although some example embodiments of the inventive concept have been described, it will be readily understood by those skilled in the art that many modifications may be made in the example embodiments without substantially departing from the novel teachings and features of the inventive concept. Therefore, all such modifications are intended to be included within the scope of the inventive concept as defined in the claims. In the claims, the method-plus-function statement is intended to cover structures that perform the functions described herein, and not only structural equivalents but also equivalent structures. Therefore, it will be understood that the foregoing is an illustration of the inventive concept and will not be construed as being limited to the specific example embodiments disclosed, and modifications to the disclosed example embodiments and other example embodiments are intended to be included within the scope of the appended claims. The inventive concept is defined by the claims and the equivalents of the claims included therein.

Claims

1. A display device, comprising: a display panel configured to display an image based on input image data; a gate driver configured to output a gate signal to the display panel; a data driver configured to output a data voltage to the display panel; a driving controller configured to control an operation of the gate driver and an operation of the data driver, determine a normal driving mode and a low-frequency driving mode based on the input image data, and determine a driving frequency of the display panel based on the input image data; as well as a touch driver configured to detect a touch event occurring on the display panel and output a touch interrupt signal indicating the touch event to the drive controller, The driving controller is configured to sense the touch event through the touch interrupt signal, and Wherein, when the display panel is driven in the low-frequency driving mode and the driving controller senses the touch event, the driving controller is configured to drive the display panel in the normal driving mode in a frame just next to the frame when the touch event is sensed.

2. The display device according to claim 1, wherein: The drive controller comprises: a still image determiner configured to determine whether the input image data is a still image or a video image, and to generate a flag indicating whether the input image data is the still image or the video image; and A driving frequency determiner is configured to determine the normal driving mode and the low-frequency driving mode based on the flag, and determine the driving frequency of the display panel based on a grayscale value of the input image data.

3. The display device according to claim 2, wherein: The drive controller further includes a flicker lookup table representing the degree of flicker according to the grayscale value of the input image data, and The driving frequency determiner is configured to determine the driving frequency of the display panel using the flicker lookup table.

4. The display device according to claim 1, wherein: The driving controller includes an input port configured to receive the touch interrupt signal from the touch driver.

5. The display device according to claim 1, wherein: The touch driver is configured to generate a touch coordinate signal indicating a touch position. The display device further includes a host configured to output the input image data to the driving controller and receive the touch interrupt signal and the touch coordinate signal from the touch driver.

6. The display device according to claim 1, wherein: The touch driver is configured to output the touch interrupt signal to the driving controller after a predetermined time delay.

7. The display device according to claim 1, wherein: The display panel includes switching elements of a first type and switching elements of a second type different from the first type.

8. The display device according to claim 7, wherein: In the low-frequency driving mode, the driving controller is configured to determine the driving frequency of the first type of the switching element as a first driving frequency, and determine the driving frequency of the second type of the switching element as a second driving frequency smaller than the first driving frequency, and Wherein, in the normal driving mode, the driving controller is configured to determine the driving frequency of the first type of the switching element as the first driving frequency, and to determine the driving frequency of the second type of the switching element as the first driving frequency.

9. The display device according to claim 7, wherein: The switching element of the first type is a polysilicon thin film transistor, and Wherein, the second type of switching element is an oxide thin film transistor.

10. The display device according to claim 9, wherein: The switching element of the first type is a P-type transistor, and Wherein, the second type of switch element is an N-type transistor.

11. A display device, comprising: a display panel configured to display an image based on input image data; a gate driver configured to output a gate signal to the display panel; a data driver configured to output a data voltage to the display panel; a driving controller configured to control an operation of the gate driver and an operation of the data driver, determine a normal driving mode and a low-frequency driving mode based on the input image data, and determine a driving frequency of the display panel based on the input image data; as well as a button controller configured to detect a button input event occurring at an input button and output a button interrupt signal indicating the button input event to the drive controller, The drive controller is configured to sense the button input event through the button interrupt signal, and Wherein, when the display panel is driven in the low-frequency driving mode and the driving controller senses the button input event, the driving controller is configured to drive the display panel in the normal driving mode in a frame just next to the frame when the button input event is sensed.

12. The display device according to claim 11, further comprising: The host is configured to output the input image data to the driving controller and receive the button interrupt signal from the button controller.

13. A method for driving a display device, the method comprising the following steps: determining a normal driving mode and a low frequency driving mode based on input image data using a driving controller; determining a driving frequency of a display panel based on the input image data using the driving controller; Outputting a gate signal to the display panel; outputting a data voltage to the display panel; detecting a touch event occurring on the display panel, and outputting a touch interrupt signal indicating the touch event to the drive controller using a touch driver; as well as outputting a touch coordinate signal indicating a touch position and the touch interrupt signal to a host, The driving controller is configured to sense the touch event through the touch interrupt signal, and Wherein, when the display panel is driven in the low-frequency driving mode and the driving controller senses the touch event, the driving controller is configured to drive the display panel in the normal driving mode in a frame just next to the frame when the touch event is sensed.

14. The method according to claim 13, wherein: Determining the normal driving mode and the low-frequency driving mode comprises the following steps: Determining whether the input image data is a still image or a video image; generating a flag indicating whether the input image data is the still image or the video image; and The normal driving mode and the low-frequency driving mode are determined based on the flag.

15. The method according to claim 14, wherein: determining the driving frequency of the display panel based on the grayscale value of the input image data, and The driving frequency of the display panel is determined using a flicker lookup table, and the flicker lookup table represents the flicker degree according to the grayscale value of the input image data.

16. The method according to claim 13, wherein: The touch interrupt signal is output to the driving controller after a predetermined time delay.

17. The method according to claim 13, wherein: The display panel includes a first type of switching elements and a second type of switching elements different from the first type, and wherein, in the low-frequency driving mode, the driving controller is configured to determine the driving frequency of the first type of the switching element as a first driving frequency, and to determine the driving frequency of the second type of the switching element as a second driving frequency that is smaller than the first driving frequency, and Wherein, in the normal driving mode, the driving controller is configured to determine the driving frequency of the first type of the switching element as the first driving frequency, and to determine the driving frequency of the second type of the switching element as the first driving frequency.

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