KR20180047101A - Display device, data driver and method for driving thereof - Google Patents

Abstract

The present embodiments relate to a display device driven by a DRD (Double Rate Driving) method and a data driver included therein. When a subpixel displaying the same color repeats a strong charging and a weak charging according to a data line, Overshooting the waveform of the initial period of the data voltage to be output, thereby reducing the pre-charging delay according to the applied data voltage. By reducing the pre-charging delay of the sub-pixels of the sub-pixel where the strong charging and the weak charging are repeated, the difference between the sub-pixel charging amounts due to the pre-charging delay is reduced and the luminance difference due to the difference in charging amount and the luminance So that no abnormality occurs.

Description

DISPLAY DEVICE, DATA DRIVER AND DATA DRIVER [0001]

The present embodiments relate to a data driver included in a display device and a display device and a driving method thereof.

2. Description of the Related Art As an information society develops, various demands for a display device for displaying an image are increasing, and various types of display devices such as a liquid crystal display device, a plasma display device, and an organic light emitting display device have been utilized.

In such a display device, a plurality of gate lines and a plurality of data lines are arranged in a crossing manner on a display panel, and a plurality of sub-pixels are arranged in an area where gate lines and data lines cross each other.

Each sub-pixel is driven by a scan signal applied through a gate line, and displays an image by expressing a gray scale according to a data voltage applied through the data line according to a timing of applying the scan signal.

The data lines to which such data voltages are applied may be arranged one by one for each column of subpixels.

In recent years, in order to reduce the number of source driver integrated circuits that drive data lines, one data line is arranged for each column of two sub-pixels and a data line for driving two sub- (Double Rate Driving) scheme is applied.

In the sub-pixel structure of the DRD scheme, a data voltage for driving two sub-pixels during one horizontal period is applied through a data line.

In addition, a display device driven by the DRD scheme applies a data voltage whose polarity is inverted for each row of subpixels in order to minimize flicker and reduce power consumption.

That is, in the DRD method, two data voltages having a positive polarity (+) are applied during one horizontal period, and two data voltages having a negative polarity (-) are applied during the next horizontal period.

At this time, the data voltage applied to the subpixel may be a data voltage having the same polarity as the data voltage applied to the previous subpixel, but a data voltage having an inverted polarity may be applied.

When a data voltage of a polarity opposite to a data voltage applied to a previous subpixel is applied, a pre-charging time required to reach the level of the data voltage applied to the subpixel as the polarity is inverted It becomes longer.

Such a pre-charging delay causes a difference between a charge amount and a sub-pixel having a short pre-charging time, and there is a problem that an image abnormality such as a longitudinal diminishes in luminance between sub-pixels due to a difference in charged amount.

It is an object of the present embodiments to provide a display device, a data driver, and a driving method for preventing an image abnormality such as a longitudinal dim due to a difference in charged amount of sub pixels in a DRD (Double Rate Driving) display device.

It is an object of the present embodiments to provide a display device, a data driver, and a driving method thereof that enable a difference in charged amount of sub pixels to be easily eliminated according to the characteristics of a display panel in a DRD type display device.

In one aspect, the present embodiments are directed to a display panel in which a plurality of subpixels are arranged along a row and a column, and two subpixels disposed on both sides of the display panel, A display device including a plurality of data lines for transmitting a voltage and a data driver for driving a plurality of data lines.

The data driver of such a display device outputs two data voltages supplied to two subpixels arranged on both sides of one data line for one horizontal period and is arranged at the other side of the subpixel arranged on one side of the data line The data voltages are alternately applied to the sub-pixels.

Also, the data driver supplies a data voltage in which the polarity is inverted for each row of subpixels through a plurality of data lines, displays the same color among the plurality of subpixels, Modulates the waveform of the initial section of the data voltage applied to the display of the pixel vigilance and outputs the modulated waveform.

In one example, the data driver modulates the waveform of the initial period of the data voltage applied to the subpixel to which the data voltage applied to the previous subpixel and the inverted polarity data voltage are applied in the subpixel in which the strong charging and the weak charging are repeated, do.

At this time, the data driver can modulate and output the waveform of the initial period of the data voltage applied to the sub pixel in accordance with the timing of the source output enable signal received from the controller.

Here, the data driver can amplify and output the waveform of the initial period of the data voltage applied to the subpixel in which the strong charging and the weak charging are repeated.

Specifically, if the data voltage applied to the subpixel is positive polarity, the waveform of the initial period of the data voltage is amplified in the (+) direction. If the data voltage is in the negative polarity, Amplify the waveform of the section.

Alternatively, the data driver may set an initial period of a data voltage applied to a subpixel in which strong and weak charges are repeatedly set as a part of a period in which the data voltage is applied, and set the initial period of the data voltage in the initial period of the data voltage The voltage level to be amplified may be determined.

The data driver includes a data voltage generator for generating a data voltage by converting a video data signal received from the controller and a data voltage generator for generating a data voltage at an initial period of a data voltage applied at a timing of polarity reversal A data modulation waveform generator for modulating the waveform and a data voltage output for outputting the modulated data voltage through a specific data line.

The data modulated waveform generator of the data driver may include a delay circuit for adjusting the initial period of the data voltage and a voltage amplifier for amplifying the voltage level of the initial period of the data voltage.

The data driver includes a step of converting a video data signal received from the controller to generate a data voltage and a waveform of an initial period of a data voltage supplied to a specific data line in accordance with the timing of the source output enable signal received from the controller And outputting a data voltage having a modulated waveform.

According to the present embodiments, by amplifying the waveform of the initial period of the data voltage applied to the sub-pixels of the sub-pixel in which strong charging and weak charging are repeated in the DRD (Double Rate Driving) display device, So that the delay can be reduced.

According to the embodiments, the pre-charging delay of the data voltage applied to the vampire lamp is reduced, so that the case of strong charging and the difference in charging amount are reduced so that the vertical dimming due to the difference in charging amount is prevented.

According to the embodiments, by improving the longitudinal dimming by waveform modulation of the initial period of the data voltage applied to the vampire display, the improvement method can be easily applied according to the characteristics of the display panel.

1 is a diagram showing a schematic configuration of a display device according to the present embodiments.
2 is a diagram showing an example of the sub-pixel structure of the display device according to the present embodiments.
3 is a diagram illustrating an example of a sub-pixel driving method of the display device according to the present embodiments.
4 is a diagram illustrating an example of a waveform of a scan signal and a data voltage applied in driving a sub-pixel of a display device according to the present embodiments.
FIG. 5 is a diagram showing an example of a data voltage charging state of a subpixel when driven according to the method of FIGS.
6 is a diagram showing an example of modulation of a data voltage in a display device according to the present embodiments.
7 is a diagram illustrating a method of modulating a data voltage in a display device according to the present embodiments.
8 is a view showing an example of a waveform of a data voltage applied to each data line in the display device according to the present embodiments.
9 is a diagram showing an example of driving states of subpixels for each data line in the display device according to the present embodiments.
10 is a diagram showing a schematic configuration of a data driver in a display device according to the present embodiments.
11 is a flowchart illustrating a method of driving a data driver according to the present embodiments.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In the drawings, like reference numerals are used to denote like elements throughout the drawings, even if they are shown on different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In describing the components of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are intended to distinguish the components from other components, and the terms do not limit the nature, order, order, or number of the components. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected or connected to the other component, Quot; intervening " or that each component may be " connected, " " coupled, " or " connected " through other components.

Fig. 1 shows a schematic configuration of a display device 100 according to the present embodiments.

Referring to FIG. 1, a display device 100 according to the present embodiment includes a plurality of gate lines GL and a plurality of data lines DL, a gate line GL and a data line DL, A gate driver 120 for driving the plurality of gate lines GL, and a data driver 110 for supplying data voltages to the plurality of data lines DL. The display panel 110 includes a plurality of sub- A driver 130 and a controller 140 for controlling driving of the gate driver 120 and the data driver 130.

The gate driver 120 sequentially drives the plurality of gate lines GL by sequentially supplying scan signals (gate signals) to the plurality of gate lines GL.

The gate driver 120 sequentially supplies gate signals of an ON voltage or an OFF voltage to the plurality of gate lines GL under the control of the controller 140 to sequentially supply a plurality of gate lines GL And sequentially driven.

The gate driver 120 may be located on only one side of the display panel 110 or on both sides of the display panel 110 according to the driving method.

In addition, the gate driver 120 may include one or more gate driver integrated circuits.

Each gate driver integrated circuit may be connected to a bonding pad of the display panel 110 by a tape automated bonding (TAB) method or a chip on glass (COG) method, or may be connected to a GIP Gate In Panel) type and can be disposed directly on the display panel 110. [

In addition, they may be integrated on the display panel 110, or may be implemented by a chip on film (COF) method, which is mounted on a film connected to the display panel 110.

The data driver 130 drives the plurality of data lines DL by supplying data voltages to the plurality of data lines DL.

The data driver 130 converts image data received from the controller 140 into analog data voltages and supplies the image data to the plurality of data lines DL so that a plurality of data lines DL are formed. .

The data driver 130 may include at least one source driver integrated circuit to drive a plurality of data lines DL.

Each source driver integrated circuit may be connected to a bonding pad of the display panel 110 by a tape automated bonding (TAB) method or a chip on glass (COG) method, The display panel 110 may be directly disposed on the display panel 110 or integrated on the display panel 110.

In addition, each source driver integrated circuit may be implemented by a chip on film (COF) method. In this case, one end of each source driver integrated circuit is bonded to at least one source printed circuit board, and the other end is bonded to the display panel 110.

The controller 140 supplies various control signals to the gate driver 120 and the data driver 130 to control the gate driver 120 and the data driver 130.

The controller 140 starts scanning according to the timing implemented in each frame, switches the input image data input from the outside according to the data signal format used by the data driver 130, and outputs the converted image data , And controls the data driving at a proper time according to the scan.

The controller 140 outputs various timing signals including a vertical synchronization signal Vsync, a horizontal synchronization signal Hsync, an input data enable (DE) signal, and a clock signal (CLK) From an external (e.g., host system).

The controller 140 outputs the switched image data by switching the input image data inputted from the outside according to the data signal format used by the data driver 130 and outputs the converted image data to the gate driver 120 and the data driver 130, A timing signal such as a vertical synchronization signal Vsync, a horizontal synchronization signal Hsync, an input data enable signal DE and a clock signal CLK to generate various control signals, 120, and the data driver 130, respectively.

For example, to control the gate driver 120, the controller 140 may include a gate start pulse (GSP), a gate shift clock (GSC), a gate output enable signal GOE Gate Output Enable), and the like.

Here, the gate start pulse GSP controls the operation start timing of one or more gate driver integrated circuits constituting the gate driver 120. The gate shift clock GSC is a clock signal commonly input to one or more gate driver integrated circuits, and controls the shift timing of the gate signal. The gate output enable signal GOE specifies the timing information of one or more gate driver ICs.

In order to control the data driver 130, the controller 140 may further include a source start pulse (SSP), a source sampling clock (SSC), and a source output enable signal (SOE) And outputs various data control signals (DCS: Data Control Signals).

Here, the source start pulse SSP controls the data sampling start timing of one or more source driver integrated circuits constituting the data driver 130. The source sampling clock SSC is a clock signal for controlling sampling timing of data in each of the source driver integrated circuits. The source output enable signal SOE controls the output timing of the data driver 130.

The controller 140 is connected to a source printed circuit board to which a source driver integrated circuit is bonded and a control printed circuit board (not shown) connected via a connection medium such as a flexible flat cable (FFC) or a flexible printed circuit (Control Printed Circuit Board).

A power controller (not shown) for controlling various voltages or currents to supply or supply various voltages or currents to the display panel 110, the gate driver 120, the data driver 130, . These power controllers are also referred to as power management ICs.

The subpixel is arranged in an area where the gate line GL and the data line DL intersect in the display panel 110. [

The subpixel is driven by a scan signal applied by the gate driver 120 and displays an image by expressing the gray scale according to the data voltage applied from the data driver 130 in accordance with the timing of applying the scan signal.

Such a subpixel may be composed of a circuit element such as a transistor, a capacitor, or the like, and may be designed variously according to the characteristics of the display apparatus 100. [

FIG. 2 illustrates an example of a sub-pixel structure in the display device 100 according to the present embodiments, and shows an example of a sub-pixel structure in the liquid crystal display device.

Referring to FIG. 2, the subpixels of the display device 100 according to the present embodiment are defined in a region where the gate line GL and the data line DL cross each other, and the transistor TR, the liquid crystal capacitor Clc, , A storage capacitor (Cst), and the like.

The transistor TR is controlled by a signal electrically connected between the data line DL and the pixel electrode and applied to the gate line GL.

The transistor TR is turned on when a scan signal is applied through the gate line GL to apply a data voltage supplied through the data line DL to the pixel electrode.

The liquid crystal capacitor Clc is electrically connected between the pixel electrode and the common electrode to be charged by the voltage difference between the data voltage applied to the pixel electrode and the common voltage applied to the common electrode when the transistor TR is turned on .

The storage capacitor Cst is charged at the same time as the liquid crystal capacitor Clc and functions to reduce the voltage drop of the liquid crystal capacitor Clc due to the leakage current when the transistor TR is turned off so that the gray- .

The data lines DL for transmitting the data voltages to the subpixels are arranged for each column of one subpixel to transfer the data voltage to one subpixel during one horizontal period.

In this case, a source driver integrated circuit driving the data line DL is required by the number of columns of subpixels.

In order to reduce the number of such source driver integrated circuits, one data line (DL) is arranged for each column of two subpixels and a data voltage is applied to two subpixels disposed on both sides of one data line (DL) DRD (Double Rate Driving) scheme can be utilized.

FIG. 3 illustrates a structure and a driving method in the case where the display device 100 according to the present embodiments is driven by the DRD method.

3, a display device 100 according to the present embodiment is a liquid crystal display device, and a subpixel is composed of red (R), green (G), and blue (B) .

The display device 100 driven by the DRD method has a structure in which one data line DL is arranged for each of two sub pixel columns in the display panel 110 and two gate lines GL .

A data voltage applied to two subpixels is supplied through one data line DL during one horizontal period, and the gate line GL is driven at twice the frequency as the normal driving, Signal.

In order to minimize the occurrence of flicker and reduce power consumption, a data voltage is alternately applied to the subpixels disposed on both sides of one data line DL, and a data voltage in which the polarity is inverted for each subpixel row .

For example, in the case where the first data line DL1 shown in FIG. 3 is driven, two data voltages having positive polarity for one horizontal period are applied to the red (R) and green (G) Respectively.

During the next horizontal period, two data voltages having a (-) polarity are sequentially applied to the red (R) subpixel and the green (G) subpixel.

Similarly, two data voltages are sequentially applied to the subpixels disposed on both sides of the data line DL during one horizontal period through the second data line DL2 and the third data line DL3, A data voltage whose polarity is inverted is applied to each row.

At this time, the sub-pixel to which the data voltage is applied at the timing when the polarity of the data voltage is inverted is in a relatively charged state due to the pre-charging delay.

For example, a green (G) subpixel driven by the first data line DL1 is applied with a data voltage having the same polarity as that of the red (R) subpixel to which the data voltage is previously applied, The time required is short and the pre-charging delay does not occur, resulting in a strong charging state.

On the other hand, a red (R) subpixel driven by the first data line DL1 is applied with a data voltage having a polarity opposite to that of the green (G) subpixel to which the data voltage is previously applied, So that it is in a charged state.

The strong charging and weak charging of each subpixel can be clearly identified through the waveform of the data voltage applied to the data line DL.

FIG. 4 shows waveforms of a scan signal and a data voltage applied when the display device 100 according to the present embodiments is driven by the DRD method.

Referring to FIG. 4, scan signals are sequentially applied to the first to fourth gate lines GL1 to GL4, and two data voltages are applied to the first data line DL1 during one horizontal period .

During the first horizontal period, two data voltages having a (+) polarity are applied and two data voltages having a (-) polarity are applied during a second horizontal period.

The first data voltage applied during the first horizontal period is applied to the red (R) sub-pixel driven by the first gate line GL1 and the second data voltage is applied to the green (G) sub-pixel.

Therefore, in the red (R) subpixel to which the data voltage is applied at the timing when the polarity is inverted, the green (G) subpixel to which the data voltage of the same polarity is applied becomes a charged state due to the pre- Delay is not generated and the battery is charged.

The first data voltage applied during the second horizontal period is applied to the red (R) sub-pixel driven by the third gate line GL3 and the second data voltage is applied to the green (G) sub-pixel.

Likewise, the red (R) subpixel is applied with the data voltage at the timing when the polarity is inverted to become the approximately charge state due to the pre-charging delay, and the green (G) subpixel is applied with the data voltage of the same polarity, Delay is not generated and the battery is charged.

Accordingly, a strong charging state and a weak charging state relative to each column of the subpixel driven by the data line DL appear.

FIG. 5 shows an example in which a strong charging state and a weak charging state occur in the above-described sub-pixel structure.

Referring to FIG. 5, the row of the red (R) subpixel driven by the first data line DL1 is in the approximately charged state, and the row of the green (G) subpixel is in the strongly charged state.

Then, the row of the blue (B) sub-pixel driven by the second data line DL2 becomes a strong-charged state, and the row of the red (R) sub-pixel becomes the approximately charged state.

Also, the green (G) subpixel column driven by the third data line DL3 is in a strongly charged state and the blue (B) subpixel column is in a substantially charged state.

Therefore, when the subpixels are composed of red (R), green (G) and blue (B) and driven by the DRD scheme described above, all the rows of the red (R) All the columns of the subpixels are in the state of a strongly charged state. On the other hand, the columns of blue (B) subpixels are repeatedly charged and charged in accordance with the data lines DL.

That is, since the red (R) subpixel or the green (G) subpixel repeats the same charging state, the image abnormality such as vertical dimming is not well recognized. However, There is a problem that an image abnormality such as a vertical dim is recognized.

The display device 100 according to the present embodiments reduces the pre-charging delay of the columns of the sub-pixels in which the strong charging and the weak charging are repeated in the DRD method, So that the dimming can be improved.

6 shows an example of a modulated waveform of the data voltage when the display device 100 according to the present embodiments is driven in the DRD method.

Referring to FIG. 6, the data driver 130 at the time of normal driving outputs the waveform of the data voltage generated by converting the image data signal to the data line DL as it is.

Even if the data driver 130 generates and outputs the waveform of the data voltage according to the gradation of the image data, the time required for pre-charging becomes longer when the polarity of the data voltage applied to the previous sub pixel is reversed .

Therefore, as shown in the normal driving of FIG. 6, the pre-charging time at which the voltage charged in the sub-pixel reaches the level of the data voltage applied through the data line DL becomes longer.

This pre-charging delay causes the data voltage charge amount of the subpixel to be reduced and the difference between the subpixel luminance difference due to the difference from the data voltage charge amount of the subpixel in which the pre-charging delay has not occurred.

The display device 100 according to the present embodiment modulates the waveform of the initial period of the data voltage applied to the specific data line DL to thereby reduce the time required for pre-charging so that the charge amount due to the pre- So that the reduction does not occur.

Referring to the overshooting driving shown in FIG. 6, the data driver 130 generates a data voltage according to an image data signal, modulates a waveform of an initial period of the generated data voltage, and outputs the modulated waveform.

The waveform of the initial period of the data voltage may be a waveform amplified from the level of the generated data voltage.

By amplifying the waveform of the initial period of the data voltage by a predetermined level, time required for pre-charging is reduced and charge amount reduction due to pre-charging delay does not occur.

That is, by modulating only the initial period of the data voltage waveform, the pre-charging delay is reduced and the gradation according to the level of the data voltage can be expressed as it is.

The initial period in which the waveform of the data voltage is modulated can be set based on the time at which the pre-charging delay of the data voltage occurs and the voltage level amplified in the initial period of the data voltage can be set according to the length of the initial period .

In one example, the initial period in which the waveform of the data voltage is modulated may be set to a time equal to the time required for pre-charging at the other data voltage in which the waveform of the data voltage is not modulated.

The voltage level amplified in the initial period of the data voltage can be set so that the voltage charged at the end of the initial period where the waveform of the data voltage is modulated can reach the level of the data voltage.

Therefore, it is possible to control the pre-charging time of the data voltage applied to the data line DL through the waveform modulation of the initial period of the data voltage, adjust the voltage level amplified in the initial period and the initial period, So that it is possible to prevent a difference in charging amount due to a difference in pre-charging time.

By preventing the difference in the charged amount of the data voltage between the subpixels, it is possible to prevent an image abnormality such as luminance unevenness and longitudinal dimming caused by the difference in charge amount due to the pre-charging delay.

7 shows an example of a method of modulating the waveform of the data voltage in the display device 100 according to the present embodiments.

7, the data driver 130 receives a source output enable signal SOE, which is a signal for controlling the operation of the data driver 130, from the controller 140, and outputs a video data signal for displaying an image .

The data driver 130 converts the image data signals to generate data voltages and supplies them to the respective data lines DL in accordance with the timing of the source output enable signal SOE.

The data driver 130 may output the waveform of the data voltage generated by converting the video data signal as it is (Vdata in FIG. 7).

Alternatively, the data voltage applied to the specific data line DL may be modulated to output the waveform of the initial period of the data voltage applied at the timing at which the polarity is inverted (Vdata 'in FIG. 7).

Here, the specific data line DL includes a data line DL for transferring a data voltage to sub-pixels of a sub-pixel in which strong charging and weak charging are repeated in a row of sub-pixels displaying the same color, it means.

In other words, when all columns of subpixels displaying the same color are only in the strongly charged state or only in the substantially charged state, the luminance difference between the subpixels does not occur, so that the image abnormality such as the vertical dimmability is not well recognized.

On the other hand, when the columns of subpixels displaying the same color are repeatedly charged and charged according to the data lines DL, the luminance difference between the subpixels is generated due to the difference in the charged amount, .

Accordingly, when the column of subpixels displaying the same color is only a strong charge or only a charge, the data driver 130 outputs a data voltage waveform such as Vdata to the data line DL.

When a row of subpixels representing the same color is repeatedly charged and charged according to the data line DL, a data voltage waveform such as Vdata is also output to the columns of the subpixels to be strongly charged, .

The data voltage applied to the column of the subpixel to be charged in the column of the subpixel in which the strong charging and the weak charging are repeated is output to the data voltage waveform such as Vdata 'so that the time required for the precharging can be reduced .

The data voltage waveform such as Vdata 'can be generated by amplifying the waveform of the initial period of the data voltage according to the timing of the source output enable signal SOE in the waveform of the data voltage generated by converting the image data signal.

Vdata 'is overshooting the initial period of the data voltage, thereby reducing the time required for pre-charging, thereby preventing the data voltage charge amount of the corresponding subpixel from being reduced, causing luminance unevenness due to the difference in charge amount, Do not occur.

Hereinafter, a specific example of the above-described data voltage modulation waveform and a phenomenon of improvement of the longitudinal dimming will be described in detail with reference to FIGS. 8 and 9. FIG.

8 shows a data voltage waveform applied to each data line DL when the display device 100 according to the present embodiment is driven by the DRD method. In the subpixel structure shown in FIG. 3, And the data voltage waveform applied to the line DL.

Referring to FIG. 8, the data voltage Vdata_DL1 applied to the first data line DL1 is applied to the data voltage waveform at the time of normal driving.

The red (R) subpixel to which the data voltage is applied by the first data line DL1 is a subpixel which is charged approximately for every data line DL, and the green (G) Since it is the subpixel to be charged, the longitudinal dim is not well recognized.

Accordingly, the data voltage Vdata_DL1 applied to the first data line DL1 is applied to the data voltage waveform at the time of normal driving without waveform modulation.

The data voltage Vdata_DL2 applied to the second data line DL2 is also applied to the data voltage waveform at the time of normal driving.

The red (R) subpixel among the subpixels to which the data voltage is applied by the second data line DL2 is a subpixel that is approximately charged in all the data lines DL, so that it is not necessary to modulate the waveform of the data voltage.

The blue (B) sub-pixel among the sub-pixels to which the data voltage is applied by the second data line DL2 is charged and charged repeatedly according to the data line DL, The data voltage of the same polarity as that of the previous sub-pixel is applied, and thus the data is in a strongly charged state.

Therefore, since the waveform modulation of the data voltage applied to the blue (B) sub-pixel is not necessary, the data voltage Vdata_DL2 applied to the second data line DL2 is applied to the waveform at the time of normal driving.

The data voltage Vdata_DL3 applied to the third data line DL3 is applied to the data voltage waveform during overshooting driving.

The green (G) subpixel among the subpixels to which the data voltage is applied by the third data line DL3 is a subpixel that is strongly charged in all the data lines DL, so that waveform modulation of the data voltage is not required.

On the other hand, the blue (B) sub-pixel to which the data voltage is applied by the third data line DL3 repeats the strong charging and weak charging according to the data line DL, and the data voltage applied to the previous sub- Polarity data voltage is applied, and therefore, the charge state is caused by the pre-charging delay.

Therefore, the blue (B) subpixel to which the data voltage is applied by the second data line DL2 is in a strongly charged state and the blue (B) subpixel to which the data voltage is applied by the third data line DL3 So that a longitudinal dim phenomenon due to a luminance difference may occur.

Therefore, the data voltage applied to the third data line DL3 amplifies and outputs the polarity reversal timing, i.e., the initial period of the data voltage applied to the blue (B) subpixel.

Due to this overshooting driving, the pre-charging delay of the blue (B) sub-pixel driven by the third data line DL3 is reduced, and the pre-charging delay of the blue (B) (B) subpixel driven by the blue subpixel DL2.

Since the blue (B) subpixel driven by the third data line DL3 is not in the approximately charge state, the luminance difference from the blue (B) subpixel driven by the second data line DL2 is reduced, Make sure that the car is not recognized as a vertical dim.

FIG. 9 shows driving states of respective subpixels driven according to the data voltage waveform of FIG.

9, the red (R) subpixel driven by the first data line DL1 and the red (R) subpixel driven by the second data line DL2 all have the polarities of the data voltages inverted The data voltage is applied at the timing and the battery is charged to a substantially charged state.

The green (G) subpixel driven by the first data line DL1 and the green (G) subpixel driven by the third data line DL3 are all applied with the data voltages of the same polarity, The battery is in a charged state.

Therefore, the red (R) subpixel is in the approximately charged state for each data line DL, and the green (G) subpixel is in the strongly charged state for each data line DL, and the longitudinal dim due to the luminance difference is not well recognized. And is driven by a normal driving method in which the data voltage waveform is not driven.

When the blue (B) sub-pixel is driven by the second data line DL2, the polarity of the data voltage is applied in the same state and becomes a charged state. Then, when driven by the third data line DL3, the polarity of the data voltage is applied at the inverted timing to be in the approximately charged state.

Since the blue (B) subpixel repeats the strong charging and the weak charging for each data line DL, the vertical dim due to the luminance difference can be recognized.

Therefore, the data voltage applied to the blue (B) sub-pixel driven by the third data line DL3 to be charged in the blue (B) sub-pixel in which the strong charging and the weak charging are repeated is overshooting driving, To reduce the pre-charging delay.

As the pre-charging time of the blue (B) subpixel driven by the third data line DL3 decreases, the difference in charge amount with the blue (B) subpixel driven by the second data line DL2 decreases And it is possible to prevent an image abnormality such as the longitudinal dim due to the difference in the charged amount.

10 shows a configuration of a data driver 130 that outputs a data voltage waveform of normal driving and a data voltage modulation waveform of overshooting driving in the display device 100 according to the present embodiments will be.

10, the data driver 130 according to the present embodiment includes a data voltage generation section 131, a data modulation waveform generation section 132, and a data voltage output 133.

The data modulation waveform generation unit 132 may include a voltage amplifier 132a and a delay circuit 132b.

The data voltage generator 131 receives the video data signal from the controller 140, and converts the received video data signal to generate an analog data voltage.

The data-modulated waveform generating section 132 outputs the data voltage generated by the data voltage generating section 131 as it is or modulates the waveform of the generated data voltage and outputs the modulated waveform.

The data modulation waveform generation section 132 can modulate and output the waveform of the initial period of the data voltage applied to the specific data line DL.

For example, a waveform of an initial period of a data voltage applied to a subpixel in which a strong charge and a weak charge are repeated due to a pre-charging delay is repeated according to a data voltage applied to a subpixel displaying the same color, .

The data-modulated waveform generating unit 132 generates a data-modulated waveform of the initial period of the data voltage applied to the sub-pixel in which the strong charging and the weak charging are repeated in accordance with the timing of the source output enable signal SOE received from the controller 140 Modulate the waveform.

The waveform modulation of the data voltage can be performed by the voltage amplifier 132a and the delay circuit 132b included in the data modulation waveform generation section 132. [

The voltage amplifier 132a amplifies the voltage level of the initial period of the data voltage generated by the data voltage generator 131 and the delay circuit 132b adjusts the initial period of the data voltage to which the voltage level is amplified.

The initial period of the data voltage may be set to the same time as the pre-charging time of the data voltage applied to the sub-pixel where the pre-charging delay does not occur, in order to reduce the pre-charging delay.

The voltage level amplified in the initial period of the data voltage may be set according to the length of the initial period set for pre-charging delay reduction.

That is, as the length of the initial section where the waveform is modulated is shortened, the voltage level to be amplified is set to be large, and if the length of the initial section is long, the amplified voltage level can be set relatively small.

The data voltage of the waveform modulated by the data modulation waveform generation section 132 is transferred to the data voltage output section 133. [

The data voltage output section 133 outputs the data voltage received from the data modulation waveform generation section 132 to each data line DL.

Accordingly, when the subpixels displaying the same color are only charged with a strong charge or only with a charge, a data voltage whose waveform is not modulated is applied.

The data voltage in which the waveform of the initial period of the data voltage is amplified by the sub-pixel to be charged is applied to the sub-pixel which is strongly charged among the sub-pixels in which the strong charging and the weak charging are repeated. So that the vertical dimming due to the difference in the charged amount in the sub pixels displaying the same color is prevented.

11 shows a process of driving the data driver 130 according to the present embodiments.

Referring to FIG. 11, the data driver 130 according to the present embodiment receives a source output enable signal SOE and a video data signal from the controller 140 (S1100).

The data driver 130 converts the received video data signal to generate an analog data voltage waveform (S1110).

The data driver 130 checks whether the generated data voltage is a data voltage applied to the specific data line DL (S1120).

Here, the specific data line DL refers to a data line DL that applies a data voltage to a sub-pixel that is approximately charged in a sub-pixel in which strong charging and weak charging are repeated among sub-pixels that display the same color.

The data driver 130 amplifies and modulates the data voltage applied to the sub-pixels of the sub-pixel in which the strong charging and the weak charging are repeated, according to the timing of the source output enable signal SOE (S1130).

The data driver 130 outputs a data voltage whose waveform is not modulated and a data voltage whose waveform is modulated to each data line DL (S1140).

Therefore, according to the present embodiments, by pre-modulating and applying the waveform of the initial period of the data voltage applied to the subpixel in which the strong and weak charges are repeated, the precharging delay of the subpixel to be charged is reduced .

By reducing the pre-charging delay of the subpixel to be charged, the difference between the charged amount of the subpixel to be strongly charged and the relative charge amount is reduced, so that the luminance difference and the image abnormality such as the vertical dimming due to the difference of the charged amount are prevented.

In addition, by reducing the pre-charging delay by waveform modulation of the initial period of the data voltage, it is possible to easily reduce the pre-charging delay according to the characteristics of the display panel 110, So that it is possible to express the gray level according to the gray level.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. In addition, the embodiments disclosed in the present invention are not intended to limit the scope of the present invention but to limit the scope of the technical idea of the present invention. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

100: display device 110: display panel
120: gate driver 130: data driver
131: Data voltage generation unit 132: Data modulation waveform generation unit
132a: voltage amplifier 132b: delay circuit
133: Data voltage output section 140: Controller

Claims (16)

A display panel in which a plurality of subpixels are arranged along rows and columns;
A plurality of data lines arranged for each column of two subpixels arranged on the display panel and transferring data voltages to two subpixels arranged on both sides; And
A data driver for supplying the data voltage of which the polarity is inverted for each row of the subpixels through the plurality of data lines and for displaying the same color among the plurality of subpixels, And a data driver for modulating and outputting a waveform of an initial section of the data voltage,
.
The method according to claim 1,
The data driver includes:
The waveform of the initial period of the data voltage applied to the subpixel to which the data voltage of the polarity opposite to the data voltage applied to the previous subpixel in the subpixel in which the strong charging and the weak charging are repeated is applied Display device.
The method according to claim 1,
The data driver includes:
And modulates and outputs a waveform of an initial period of the data voltage applied to the subpixel in accordance with the timing of the source output enable signal received from the controller.
The method according to claim 1,
The data driver includes:
And amplifying and outputting a waveform of an initial period of the data voltage applied to the subpixel in which the strong charging and the weak charging are repeated.
5. The method of claim 4,
The data driver includes:
(+) Polarity of the data voltage applied to the subpixel and amplifying the waveform of the initial period of the data voltage in the (+) direction, and if the data voltage is the negative polarity, And amplifies the waveform of the initial section of the display device.
The method according to claim 1,
The data driver includes:
And an initial period of the data voltage applied to the subpixel in which the strong charging and the weak charging are repeated is set as a part of a period during which the data voltage is applied and an initial period of the data voltage The voltage level to be amplified is determined.
The method according to claim 1,
The data driver includes:
Wherein the data voltage is alternately applied to the subpixel arranged on one side of the data line and the subpixel arranged on the other side.
The method according to claim 1,
The data driver includes:
And outputs two data voltages supplied to two subpixels disposed on both sides of one data line during one horizontal period.
The method according to claim 1,
Wherein all the subpixels displaying the first color in the plurality of subpixels are strongly charged during driving and all subpixels displaying the second color are charged during driving.
A data voltage generator for converting a video data signal received from the controller to generate a data voltage;
A data modulation waveform generator for modulating a waveform of an initial period of a data voltage applied at a timing at which polarity is inverted among data voltages supplied to a specific data line; And
A data voltage output unit for outputting the modulated data voltage through the specific data line,
/ RTI >
11. The method of claim 10,
Wherein the data modulation waveform generator comprises:
A delay circuit for adjusting an initial period of the data voltage; And
And a voltage amplifier for amplifying a voltage level of an initial period of the data voltage.
11. The method of claim 10,
Wherein the data modulation waveform generator comprises:
And modulates the waveform of the initial period of the data voltage in accordance with the timing of the source output enable signal received from the controller.
11. The method of claim 10,
Wherein the specific data line is a data line for displaying the same color and applied with a phantom display data voltage of a sub pixel in which strong charging and weak charging are repeated by a data voltage applied through the data line.
Generating a data voltage by converting a video data signal received from the controller;
Modulating a waveform of an initial period of the data voltage supplied to a specific data line in accordance with a timing of a source output enable signal received from the controller; And
Outputting a data voltage having the modulated waveform
And a data driver for driving the data driver.
15. The method of claim 14,
Wherein modulating the waveform of the initial period of the data voltage comprises:
And amplifying a voltage level of an initial period of a data voltage applied at a timing at which the polarity of the data voltage applied to the specific data line is inverted.
15. The method of claim 14,
Wherein the specific data line is a data line for displaying the same color and applied with a phantom display data voltage of a subpixel in which strong charging and weak charging are repeated by a data voltage applied through the data line.

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