KR20090073468A - Liquid crystal display device and method for driving the same - Google Patents

Abstract

A liquid crystal display and a driving method thereof are provided to raise the satisfaction of user by improving the picture quality in the reversal drive more than 2 dot. A liquid crystal display comprises a pixel cell(PXL) and a data driver(DD). The pixel cell is connected to the data line(DL1 to DLm). A data driver outputs the positive data and the negative data in the i frame duration at least twice and supplies to the data lines. The data driver corresponds to the same polarity in the k number pixel cell of the i+1 frame duration and k-1 the pixel cell of the i frame duration. The data driver corresponds to the same polarity in the firstly driven pixel cell and the pixel cell driven the last of the i frame duration of the i+1 frame duration. The data driver shifts the polarity of data every frame and supplies to the data lines.

Description

Liquid crystal display and its driving method {LIQUID CRYSTAL DISPLAY DEVICE AND METHOD FOR DRIVING THE SAME}

The present invention relates to a liquid crystal display device and a driving method thereof, and more particularly, to a liquid crystal display device and a driving method thereof capable of improving image quality.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device capable of improving image quality by preventing a luminance difference between pixel cells.

The liquid crystal display displays an image by adjusting light transmittance of pixel cells according to a video signal. In an active matrix liquid crystal display, switching elements are formed in each pixel cell, which is advantageous for displaying a moving image. As the switching device, a thin film transistor (hereinafter referred to as "TFT") is mainly used.

Such a liquid crystal display includes a plurality of gate lines and a plurality of data lines arranged to cross each other.

1 is a view showing a waveform of a data signal supplied to a data line of a conventional liquid crystal display device.

When the data line is driven by the 2-dot driving method, as illustrated in FIG. 1, the data line Data of positive and negative data signals Data is charged alternately every 2H period. . In this case, the data line is continuously charged with the positive data signal Data over two adjacent periods, and then with the negative data signal Data over the next two consecutive periods.

In this case, referring to two adjacent periods, the first case in which the data lines are charged with opposite polarities of the data lines during the two periods, and the data lines are continuous with the same polarity data signals during the two periods. There is a second case where it is charged.

Here, if any one pixel cell is supplied with a data signal corresponding to itself from the data line in the second period, it has been charged in the data line in the first period immediately before this second period. The data signal Data affects the pixel cell.

That is, if the polarity of the data signal Data supplied to the data line in the first period and the polarity of the data signal Data supplied to the data line in the second period are the same, the pixel cell has a normal luminance. While displaying an image, if the polarity of the data signal Data supplied to the data line in the first period is different from the polarity of the data signal Data supplied to the data line in the second period, the pixel cell The charging characteristics of the deteriorate, so that the pixel cell displays an image of higher or lower luminance than normal.

Therefore, although the pixel cells displaying the same color are supplied with the same gray level data signal, the luminance difference may be displayed according to the charging condition of the data line, thereby degrading the image quality.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and provides a liquid crystal display device and a driving method thereof capable of achieving improvement in image quality in inversion driving of two dots or more by shifting the polarity of the pixel cells for each frame period. have.

According to an aspect of the present invention, there is provided a liquid crystal display device including: a plurality of pixel cells commonly connected to a first data line and sequentially driven; And alternately outputting positive data and negative data at least two periods in the i th frame period (i is a natural number) to be supplied to the first data line so that the pixel cells are sequentially supplied with data. A k-th driven pixel cell (k is a natural number of 2 or more) in a +1 frame period to have data of the same polarity as a k-1 th driven pixel cell in the i-th frame period, and the i + 1th frame The first data line is shifted by one pixel cell in every frame period such that the pixel cells driven first in the period have data having the same polarity as the pixel cells last driven in the i-th frame period. It is characterized in that it comprises a data driver to supply sequentially.

In addition, the driving method of the liquid crystal display device according to the present invention for achieving the above object, in the driving method of a liquid crystal display device comprising a plurality of pixel cells commonly connected to the data line and sequentially driven, a step of sequentially supplying data to the pixel cells by alternately outputting positive data and negative data at least two periods in an i frame period (i is a natural number); And the k-th pixel cell (k is a natural number of 2 or more) in the i + 1th frame period has the same polarity data as the k-th driving pixel cell in the i-th frame period, and The polarity of the data is shifted by one pixel cell unit every frame period such that the pixel cell driven first in the i + 1 frame period has the same polarity data as the pixel cell driven last in the i-th frame period. Its feature is that it includes a step B, which feeds the data line sequentially.

The liquid crystal display according to the present invention has the following effects.

In the present invention, the image quality can be improved during the inversion driving of 2 dots or more by sequentially shifting the polarity supplied to the pixel cells for each frame period.

2 is a view showing a liquid crystal display device according to a first embodiment of the present invention.

As shown in FIG. 2, the liquid crystal display according to the first exemplary embodiment of the present invention is formed for each pixel region defined by gate lines GL1 to GLn and data lines DL1 to DLm that cross each other. The liquid crystal panel 200 including the pixel cell PXL, the gate driver GD for inputting scan pulses to the gate lines GL1 to GLn of the liquid crystal panel 200, and the liquid crystal panel 200. A data driver DD for inputting data into the data lines DL1 to DLm, a backlight unit BU for irradiating light to the liquid crystal panel 200, and a lamp for driving the lamps of the backlight unit BU. Power required for the timing controller TC for controlling the lamp driver 600, the gate driver GD, the data driver DD, and the lamp driver 600, the liquid crystal panel 200, and the backlight unit BU. Power generation unit (PW) for supplying The.

The liquid crystal panel 200 includes a color filter array substrate and a TFT array substrate bonded to each other with a liquid crystal layer interposed therebetween. The color filter and the common electrode are formed on the color filter array substrate. In the color filter, red, green, and blue color filter layers are disposed to transmit light of a specific wavelength band, thereby enabling color display. A black matrix is formed between color filters of adjacent colors.

It includes a pixel cell formed for each pixel region defined by the data lines DL1 to DLm and the gate lines GL1 to GLn of the liquid crystal panel 200.

As illustrated in FIG. 2, the pixel cell PXL includes a liquid crystal cell 401 for displaying an image and a thin film transistor TFT for supplying a data signal to the liquid crystal cell 401.

The liquid crystal cell 401 includes a pixel electrode and a common electrode Vcom facing each other, and a liquid crystal layer formed between the pixel electrode and the common electrode Vcom. The liquid crystal layer exhibits different transmittances depending on the magnitude of the vertical electric field formed between the pixel electrode PE and the common electrode Vcom. The display device has two substrates facing each other. The common electrode Vcom is formed on the front surface of the upper substrate, and the pixel electrode PE is formed on the lower substrate.

The thin film transistor TFT inputs data on the data lines DL1 to DLm into the pixel cell PXL in response to a scan pulse from the gate driver GD. The source electrode of the thin film transistor TFT is connected to the data line, and the drain electrode is connected to the pixel electrode of the pixel cell PXL. The gate electrode of the thin film transistor TFT is connected to the gate line.

The liquid crystal cell 401 in each pixel cell PXL includes a liquid crystal capacitor Clc for holding data for one frame period and a storage capacitor Cst for stably maintaining the data for one frame period. Include.

The liquid crystal capacitor Clc includes a pixel electrode, a common electrode Vcom, and a liquid crystal layer positioned between the pixel electrode and the common electrode Vcom. That is, the pixel electrode corresponds to the first electrode of the liquid crystal capacitor Clc, and the common electrode Vcom corresponds to the second electrode of the liquid crystal capacitor Clc, and the common with the pixel electrode. The liquid crystal layer formed between the electrodes Vcom corresponds to the dielectric of the liquid crystal capacitor Clc.

The storage capacitor Cst is formed where the front gate line overlaps the pixel electrode. That is, the front gate line corresponds to the first electrode of the storage capacitor Cst, the pixel electrode corresponds to the second electrode of the storage capacitor Cst, and the front gate line and the pixel electrode. The insulating film formed therebetween corresponds to the dielectric of the storage capacitor Cst.

The timing controller TC rearranges the digital video data input from the digital video card for each of the red data R, the green data G, and the blue data B. FIG. The data R, G, and B rearranged by the timing controller TC are input to the data driver DD.

In addition, the timing controller TC generates the data control signal DCS and the gate control signal GCS using the horizontal synchronization signal Hsync, the vertical synchronization signal Vsync, and the clock signal CLK. To the data driver DD and the gate driver GD. The data control signal DCS includes a dot clock, a source shift clock, a source enable signal, a polarity inversion control signal, and the like. The gate control signal GCS is input to the gate driver GD including a gate start pulse, a gate shift clock, a gate output enable, and the like.

After the data driver DD samples the data according to the data control signal DCS from the timing controller TC, the data driver DD latches the sampled data for each horizontal period (Horizontal Time: 1H, 2H, ...). The latched data is supplied to the data lines DL1 to DLm. That is, the data driver DD converts the data R, G, and B from the timing controller TC into analog pixel signals using the gamma voltages GMA1 to 6 input from the power generator PW. Supply to the data lines DL1 to DLm. This data driver will be described in more detail later.

The gate driver GD drives a shift register that sequentially generates scan pulses in response to a gate start pulse among the gate control signals GCS from the timing controller TC, and drives the voltage of the scan pulses of the pixel cell PXL. And a level shifter for shifting to a voltage level suitable for. The gate driver GD sequentially supplies a gate high voltage to the gate lines GL1 to GLn in response to the gate control signal GCS.

The power generator PW supplies the common electrode voltage Vcom to the liquid crystal panel 200, the gamma voltages GMA1 to 6 to the data driver DD, and the lamp driving voltage Vinv to the backlight unit BU.

3 is a diagram illustrating a configuration of the liquid crystal panel 200 of FIG. 2.

As shown in FIG. 3, the liquid crystal panel 200 includes a plurality of gate lines GL1 to GLn arranged in one direction and a plurality of data arranged in one direction to intersect the gate lines GL1 to GLn. Lines DL1 to DLm.

A pixel cell PXL is formed in each pixel area defined by the gate lines GL1 to GLn and the data lines DL1 to DLm. These pixel cells PXL are disposed in each pixel area to form a matrix.

A plurality of pixel cells PXL is arranged in the length direction of the gate line in each of the pixel rows HL1 to HLn positioned above the gate lines GL1 to GLn. The pixel cells PXL in one pixel row are commonly connected to gate lines located below them. In addition, each of the pixel cells PXL in the one pixel row is individually connected to each of the data lines DL1 to DLm located on its left side.

For example, the pixel cells PXL provided in the first pixel row HL1 are commonly connected to the first gate line GL1 and individually connected to the first to mth data lines DL1 to DLm. do.

In this case, the pixel electrode in each pixel cell PXL is connected to the corresponding gate line and the corresponding data line through the thin film transistor TFT.

The pixel cells PXL connected to the 3k + 1th data line are electrodes for displaying an image for red, and the pixel cells PXL connected to the 3k + 2th data line are electrodes for displaying an image for green. And the pixel cells PXL connected to the 3k + 3th data line are electrodes for displaying an image for blue color.

The data driver DD alternately outputs positive data and negative data. The data of the positive polarity and the data of the negative polarity may be analog signals or digital signals as data for displaying an image. The positive data means data having a value greater than the common voltage, and the negative data is data having a value smaller than the common voltage.

The data driver DD alternately outputs positive data and negative data in at least two periods in an i th frame period (i is a natural number). This period may be set to two or more periods. In the present invention, for example, the data driver DD alternately outputs the positive data and the negative data every two or three periods. Let's do it.

In this one period, one gate line is driven so that one pixel row of pixel cells PXL connected to the gate line receive data from the corresponding data line, that is, one horizontal time (1H time). : 1 Horizontal time). In addition, one frame period is a time when all periods are collected, and all pixel cells PXL of the liquid crystal panel 200 are sequentially supplied with data in pixel row units during one frame period.

The data driver DD alternately outputs the positive data and the negative data twice in the i-th frame period. For example, the data driver DD continuously outputs the positive data twice in succession for the first and second consecutive periods, and then outputs the data twice in succession for the third and fourth successive periods. . Subsequently, the data of the positive polarity is output twice again in the fifth and sixth consecutive periods, and the data of the negative polarity is output twice again in the seventh and eighth periods.

Accordingly, as illustrated in FIG. 3, the pixel cells PXL connected to one data line alternately have two positive polarity and a negative polarity.

The data driver DD supplies positive data to the odd data line and negative data first to the even data line in the i-th frame period. Accordingly, in the i-th frame period, as illustrated in FIG. 3, the pixel cell PXL connected to the odd data line and the pixel cell PXL connected to the odd data line corresponding thereto are opposite to each other. The pixel cells PXL for one horizontal line connected to one gate line alternately exhibit positive polarity and negative polarity by alternating one pixel cell PXL.

On the other hand, the data driver DD includes a pixel cell PXL (k is a natural number of two or more) driven k-th in the i + 1th frame period (k-1 th driving period of the i-th frame period). The pixel cells PXL that are driven to have the same polarity data as PXL and that are driven first in the i + 1 frame period are the same polarities as the pixel cells PXL that are driven last in the i-th frame period. The polarities of the data are shifted by one pixel cell every frame period so as to be sequentially supplied to one data line.

If this is explained in more detail as follows.

FIG. 4 is a diagram for describing polarity change of each pixel period of the pixel cells PXL connected to the first data line DL1 of FIG. 3.

The data driver DD alternately outputs positive data and negative data on the first data line DL1 alternately for two periods during the first frame period. Then, as shown in FIG. 4A, two pixel cells PXL adjacent to each other in turn have positive and negative polarities. In this case, the data driver DD supplies the positive data to the first data line DL1 before the negative data.

That is, the data driver DD supplies positive data to the 4a + 1 and 4a + 2 pixel cells (a is a natural number including 0) in the first frame period through the first data line DL1. Then, negative data is supplied to the fourth a + 3 and fourth a + 4 pixel cells.

Thereafter, the data driver DD shifts the polarity of the data to be supplied during the second frame period by one period, thereby driving the k-th pixel cell in the second frame period, as shown in FIG. The pixel PXL has the same polarity as the pixel cell PXL driven k-th in the first frame period.

For example, as shown in FIGS. 4A and 4B, the second pixel cell PXL2 driven second in the second frame period is first driven in the first frame period. It has the same polarity as the pixel cell PXL1.

That is, the data driver DD supplies negative data to a 4q + 1 pixel cell in a second frame period through the first data line DL1, and supplies 4a + 2 and 4a + 3 pixels. Positive data is supplied to a cell, and negative data is supplied to a 4a + 4 pixel cell.

Meanwhile, the first pixel cell PXL1 first driven in the second frame period has the same polarity as the nth pixel cell PXLn last driven in the first frame period.

Accordingly, the pixel cells PXL in the second frame period are shifted down one space from the polarity of the pixel cells PXL in the first frame period, as shown in FIG. 4B. It shows polarity.

In the same manner, the pixel cells PXL in the third frame period are shifted down one space from the polarity of the pixel cells PXL in the second frame period, as shown in FIG. 4C. Polarity.

That is, the data driver DD supplies negative data to the 4a + 1 and 4a + 2 pixel cells in the third frame period through the first data line DL1, and supplies the 4a + 3 and Positive data is supplied to the fourth a + 4 pixel cell.

The pixel cells PXL in the fourth frame period have a polarity shifted downward by one space from the polarity of the pixel cells PXL in the third frame period, as shown in FIG. 4D. Indicates.

That is, the data driver DD supplies positive data to a 4a + 1 pixel cell in a fourth frame period through the first data line DL1, and controls the 4a + 2 and 4a + 3 pixel cells. The data of negative polarity is supplied to, and the data of positive polarity is supplied to the fourth a + 4 pixel cell.

Although not shown in the drawings, the polarities of the pixel cells PXL in the fifth frame period are the same as the polarities of the pixel cells PXL in the first frame period.

In general, the polar pattern of the pixel cells PXL in the fourth p + 1 frame period is the same as the polar pattern of the pixel cells PXL in the first frame period, and the pixel cell in the fourth p + 2 frame period. The polar pattern of the PXLs is the same as the polar pattern of the pixel cells PXL in the second frame period, and the polar pattern of the pixel cells PXL in the fourth p + 3 frame period is the pixel in the third frame period. The polarity pattern of the cells PXL is the same, and the polarity pattern of the pixel cells PXL in the fourth p + 4 frame period is the same as the polarity pattern of the pixel cells PXL in the fourth frame period.

The polarity change of each pixel period of the pixel cells PXL connected to the odd data line among the second to mth data lines DL2 to DLm is the pixel cell PXL connected to the first data line DL1. Is the same as the polarity change of each frame period.

FIG. 5 is a diagram for describing polarity change of each pixel period of the pixel cells PXL connected to the second data line DL2 of FIG. 3.

The data driver DD alternately outputs the positive data and the negative data to the second data line DL2 alternately for two periods during the first frame period. Then, as illustrated in FIG. 5A, two pixel cells PXL adjacent to each other in turn have positive and negative polarities. In this case, the data driver DD supplies the negative data before the positive data to the second data line DL2.

Accordingly, as shown in FIG. 5, the polarity change of each pixel period of the pixel cells PXL connected to the second data line DL2 is a frame of the pixel cells PXL connected to the first data line DL1. It is the same as the change in polarity for each period, and only the polarity between two pixel cells PXL corresponding to each other is reversed. For example, the polarity of the first pixel cell PXL1 shown in FIG. 4B and the polarity of the first pixel cell PXL1 shown in FIG. 5B are opposite to each other.

The polarity change of each pixel period of the pixel cells PXL connected to the even-numbered data line among the second to m-th data lines DL2 to DLm is the pixel cell PXL connected to the second data line DL2. Is the same as the polarity change of each frame period.

The pixel cells PXL connected to the data lines may be divided into a plurality of pixel cell groups including first to fourth pixel cells PXL1 to PXL4.

The pixel cell groups are sequentially driven, and the first to fourth pixel cells PXL1 to PXL4 in each pixel cell group are sequentially driven from the first pixel cell PXL1 to the fourth pixel cell PXL4.

For example, the first to n th pixel cells PXL1 to PXLn connected to the first data line DL1 are the first pixel cell PXL1 group including the first to fourth pixel cells PXL1 to PXL4. , A second pixel cell PXL2 group including fifth to eighth pixel cells PXL5 to PXL8, a third pixel cell PXL3 group including ninth to twelfth pixel cells PXL9 to PXL12. .., may be defined as an n / 4 pixel cell group including n-3 th to n th pixel cells PXLn-3 to PXLn, and the first to n th pixel cells PXL1 to PXLn are first pixels The cell PXL1 is sequentially driven from the nth pixel cell PXLn.

The fourth f + 2 pixel cell driven second in the j th pixel cell group in the i + 1 th frame period has the same polarity as the fourth f + 1 pixel cell driven first in the j th pixel cell group in the i th frame period. Have On the other hand, a fourth f + 1 pixel cell driven first in the j th pixel cell group in the i + 1th frame period is a fourth f + 4 pixel driven last in the j th pixel cell group in the i th frame period. It has the same polarity as the cell. An example of this is as follows.

FIG. 6 is a diagram illustrating polarity change for each frame period of the first to fourth pixel cells PXL1 to PXL4 connected to the first data line DL1 and included in the first pixel cell PXL1 group.

The data driver DD alternately outputs positive data and negative data on the first data line DL1 alternately for two periods during the first frame period. Then, as illustrated in FIG. 6A, two pixel cells PXL adjacent to each other have positive and negative polarities in turn. In this case, the data driver DD supplies the positive data to the first data line DL1 before the negative data.

That is, the data driver DD has a positive polarity for the first and second pixel cells PXL2 included in the first pixel cell PXL1 group in the first frame period through the first data line DL1. Data is supplied, and negative data is supplied to the third and fourth pixel cells PXL4.

Thereafter, the data driver DD shifts the polarity of the data to be supplied during the second frame period by one period, so that the first pixel cell PXL1 is displayed in the second frame period as shown in FIG. The second pixel cell PXL2 driven second in the) group has the same polarity as the first pixel cell PXL1 driven first in the first pixel cell PXL1 in the first frame period.

Meanwhile, the first pixel cell PXL1 driven first in the first pixel cell PXL1 group in the second frame period has the same polarity as the fourth pixel cell PXL4 driven last in the first frame period. Has

Accordingly, the first to fourth pixel cells PXL1 to PXL4 of the first pixel cell PXL1 group during the second frame period, as shown in FIG. 6B, have the first frame. The polarity is shifted downward by one space from the polarity of the first to fourth pixel cells PXL1 to PXL4 during the period.

In the same manner, the first to fourth pixel cells PXL1 to PXL4 of the first pixel cell PXL1 group during the third frame period are as shown in FIG. 6C. The polarity shifted downward by one column from the polarity of the first to fourth pixel cells PXL1 to PXL4 during the frame period.

In addition, the first to fourth pixel cells PXL1 to PXL4 of the first pixel cell PXL1 group during the fourth frame period are, as shown in FIG. 6D, during the third frame period. The polarity is shifted downward by one column from the polarity of the first to fourth pixel cells PXL1 to PXL4 of the first pixel cell PXL1.

On the other hand, the change in polarity of each of the four pixel cells in the remaining second to n / 4 pixel cell groups connected to the first data line DL1 according to the frame period is performed by the first pixel connected to the first data line DL1. The change in polarity of each of the first to fourth pixel cells PXL1 to PXL4 in the cell PXL1 group for each frame period is the same.

In addition, the change in polarity of each pixel period of the pixel cells PXL connected to the odd data line is the same as the change of polarity of each pixel period of the pixel cells PXL connected to the first data line DL1.

FIG. 7 is a view illustrating polarity change for each frame period of the first to fourth pixel cells PXL1 to PXL4 connected to the second data line DL2 and included in the first pixel cell PXL1 group.

The data driver DD alternately outputs the positive data and the negative data to the second data line DL2 alternately for two periods during the first frame period. Then, as shown in (a) of FIG. 7, two pixel cells PXL adjacent to each other in turn have a positive polarity and a negative polarity. In this case, the data driver DD supplies the positive data to the second data line DL2 before the negative data.

Accordingly, as shown in FIG. 7, the polarity change for each frame period of the first to fourth pixel cells PXL1 to PXL4 connected to the second data line DL2 and included in the first pixel cell PXL1 group , Two pixel cells that are connected to the first data line DL1 and that are identical to the polarity change of each of the first to fourth pixel cells PXL1 to PXL4 included in the first pixel cell PXL1 by frame periods, and correspond to each other only. The polarity between (PXL) is reversed. For example, the polarity of the first pixel cell PXL1 shown in FIG. 6B and the polarity of the first pixel cell PXL1 shown in FIG. 7B are opposite to each other.

On the other hand, the polarity change in each frame period of each of the four pixel cells PXL in the remaining second to n / 4 pixel cell groups connected to the second data line DL2 is connected to the second data line DL2. The polarity of each of the first to fourth pixel cells PXL1 to PXL4 in the first pixel cell PXL1 is changed according to the frame period.

In addition, the change in polarity of each pixel period of the pixel cells PXL connected to the even-numbered data line is the same as the change of polarity of each pixel period of the pixel cells PXL connected to the second data line DL2.

FIG. 8 is a diagram illustrating a polarity control unit PC according to the present invention, and FIG. 9 is a diagram illustrating a change in each frame period of the polarity inversion control signal Pol output from the polarity control unit PC of FIG. 8.

In the liquid crystal display according to the present invention, as illustrated in FIG. 8, a polarity control unit PC which provides a polarity control signal to the data driver DD so that the data driver DD may impart the polarity of the data. More).

The polarity inversion control signal Pol, as shown in FIG. 8, includes a plurality of positive polarity sections (hatched portions) that remain high for two periods and a plurality of negative polarities that remain low for two periods. Have a section.

As shown in FIG. 9, the polarity inversion control signal Pol is shifted and output by a time corresponding to one period in every frame period. Specifically, the polarity control unit PC shifts and outputs the polarity inversion control signal Pol for a period of time each time a vertical synchronization signal Vsync indicating the start of one frame is output. Accordingly, the polarity of the data Data is also shifted by a time corresponding to one period.

The polarity inversion control signal Pol shown in FIG. 9 is a signal supplied to one channel portion of the data driver DD, that is, the first channel portion connected to the first data line DL1. The first channel unit changes the polarity of data Data according to the polarity inversion control signal Pol. The polarity inversion control signal Pol shown in FIG. 9 is also supplied to the odd channel portion connected to the odd data line. Meanwhile, the polarity inversion control signal Pol having a phase inversion of 180 degrees with respect to the polarity inversion control signal Pol shown in FIG. 9 is supplied to the even-numbered channel portion including the second channel portion.

10 is a diagram illustrating a change in polarity of data supplied to the first data line DL1 for each frame period.

As described above, when the data line is driven by the 2-dot driving method, as shown in FIG. 1, the data line of the positive data and the data of the negative data has a 2H period. Charging alternately in cycles. In this case, the data line is continuously charged with the positive data signal Data over two adjacent periods, and then with the negative data signal Data over the next two consecutive periods.

In this case, referring to two adjacent periods, the first case in which the data lines are charged with opposite polarities of the data lines during the two periods, and the data lines with the same polarity data signals during the two periods There is a second case where it is continuously charged.

Here, if any one pixel cell is supplied with a data signal Data corresponding to itself from the data line in the second period, in the second period T2 which is just before the third period T3, The data signal Data charged in the data line affects the pixel cell PXL.

In the present invention, as each pixel cell PXL is periodically supplied with data under the charging condition according to the first case and the charging condition according to the second case, the charging state of each pixel cell PXL is improved.

That is, as shown in Fig. 10A, when any pixel cell is supplied with second data (hatched portion) in the third period of the first frame period, the arbitrary pixel cell is in the second period. Since the second data is supplied under the first charging condition in which the polarities of the data of T2 and the third period T3 are different from each other, the state of charge is reduced.

However, as shown in Fig. 10B, when the arbitrary pixel cell PXL is supplied with the second data (hatched portion) in the third period T3 of the next second frame period, Since the pixel cell PXL receives the second data under the second charging condition in which the data of the second period T2 and the third period T3 have the same polarity, the state of charge becomes good.

Subsequently, as shown in FIG. 10C, when any pixel cell PXL receives second data (hatched portion) in the third period T3 of the third frame period, the pixel cell is provided. In the PXL, since the second data is supplied under the first charging condition in which the polarities of the data of the second period T2 and the third period T3 are different from each other, the state of charge decreases again.

However, as shown in Fig. 10D, when the arbitrary pixel cell PXL is supplied with the second data (hatched portion) in the third period T3 of the next second frame period, Since the pixel cell PXL receives the second data under the first charging condition in which the data of the second period T2 and the third period T3 have the same polarity, the state of charge becomes good.

As described above, the arbitrary state of the pixel cells is degraded as they are charged under the first charging condition in the odd-numbered frame period, but the degraded state of charge is compensated as they are charged under the second charging condition in the even-numbered period. Is improved.

The remaining pixel cells PXL also have different frame periods for charging compensation, and thus the charging characteristics of the other pixel cells PXL are improved by receiving data in the same manner as any of the pixel cells.

11 is a view showing a liquid crystal display device according to a second embodiment of the present invention.

The liquid crystal display device according to the second embodiment of the present invention is almost the same as that of the first embodiment described above, and as shown in FIG. 11, the pixel cells PXL connected to one data line have three positive polarities. Have alternating data and negative data.

To this end, the data driver DD included in the liquid crystal display according to the second exemplary embodiment of the present invention alternately outputs the positive data and the negative data three times in the i-th frame period. For example, the data driver DD consecutively outputs positive data three times in successive first to third periods, and then sequentially outputs negative data three times in successive fourth and sixth periods. . Thereafter, the data of the positive polarity is sequentially output three times in the seventh and ninth consecutive periods, and the data of the negative polarity is output three times in the tenth and twelfth periods.

In addition, the data driver DD includes a pixel cell PXL (k is a natural number of two or more) driven k-th in the i + 1th frame period (k-1) of the i-th frame period. The pixel cells PXL that are driven to have the same polarity data as PXL and that are driven first in the i + 1 frame period are the same polarities as the pixel cells PXL that are driven last in the i-th frame period. The polarities of the data are shifted by one pixel cell every frame period so as to be sequentially supplied to one data line.

If this is explained in more detail as follows.

FIG. 12 is a diagram for describing polarity change of each pixel period of the pixel cells PXL connected to the first data line DL1 of FIG. 10.

The data driver DD alternately outputs the positive data and the negative data to the first data line DL1 alternately for three periods during the first frame period. Then, as illustrated in FIG. 12A, three pixel cells PXL adjacent to each other have positive and negative polarities in turn. In this case, the data driver DD supplies the positive data to the first data line DL1 before the negative data.

That is, the data driver DD transmits to the 6q + 1, 6q + 2 and 6q + 3 pixel cells (q is a natural number including 0) in the first frame period through the first data line DL1. Positive data is supplied, and negative data is supplied to the 6q + 4, 6q + 5, and 6q + 6 pixel cells.

Thereafter, the data driver DD shifts the polarity of the data to be supplied during the second frame period by one period, thereby driving the k-th pixel cell in the second frame period, as shown in FIG. The pixel PXL has the same polarity as the pixel cell PXL driven k-th in the first frame period.

For example, as shown in FIGS. 12A and 12B, the second pixel cell PXL2 driven second in the second frame period is first driven in the first frame period. It has the same polarity as the pixel cell PXL1.

That is, the data driver DD supplies negative data to the sixth q + 1 pixel cell in the second frame period through the first data line DL1, and generates the sixth q + 2, the sixth q3, and the third data period. Positive data is supplied to the sixth q + 4 pixel cell, and negative data is supplied to the sixth q + 5 and 6q + 6 pixel cells.

Meanwhile, the first pixel cell PXL1 first driven in the second frame period has the same polarity as the nth pixel cell PXLn last driven in the first frame period.

Accordingly, the pixel cells PXL in the second frame period are shifted down by one space from the polarity of the pixel cells PXL in the first frame period, as shown in FIG. 12B. It shows polarity.

In the same manner, the pixel cells PXL in the third frame period are shifted down one space from the polarity of the pixel cells PXL in the second frame period, as shown in FIG. 12C. Polarity.

That is, the data driver DD supplies negative data to the 6q + 1 and 6q + 2 pixel cells in the third frame period through the first data line DL1, and supplies the 6q + 3, Positive data is supplied to the sixth q + 4 and 6q + 5 pixel cells, and negative data is supplied to the sixth q + 6 pixel cells.

Next, the pixel cells PXL in the fourth frame period have a polarity shifted downward one by one from the polarity of the pixel cells PXL in the third frame period, as shown in FIG. 12D. Indicates.

That is, the data driver DD supplies negative data to the sixth q + 1, the sixth q + 2 and the sixth q + 3 pixel cells through the first data line DL1, and the sixth q + 4, Positive data is supplied to the sixth q + 5 and the sixth q + 6 pixel cells.

Subsequently, the pixel cells PXL in the fifth frame period have a polarity shifted downward by one space from the polarity of the pixel cells PXL in the fourth frame period, as shown in FIG. 12E. Indicates.

That is, the data driver DD supplies positive data to the sixth q + 1 pixel cell through the first data line DL1, and the sixth q + 2, sixth q + 3 and sixth q4 fourth pixel cells. The data of negative polarity is supplied to, and the data of positive polarity is supplied to the sixth q + 5 and sixth q + 6 pixel cells.

Next, the pixel cells PXL in the sixth frame period have a polarity shifted downward by one space from the polarity of the pixel cells PXL in the fifth frame period, as illustrated in FIG. 12F. Indicates.

That is, the data driver DD supplies positive data to the sixth q + 1 and the sixth q + 2 pixel cells through the first data line DL1, and the sixth q + 3, the sixth q4 and the fourth data. Negative data is supplied to the 6q + 5 pixel cell, and positive data is supplied to the 6q + 6 pixel cell.

Although not shown in the drawings, the polarities of the pixel cells PXL in the fifth frame period are the same as the polarities of the pixel cells PXL in the first frame period.

In general, the polar pattern of the pixel cells PXL in the 6p + 1 frame period is the same as the polar pattern of the pixel cells PXL in the first frame period, and the pixel cell (in the 6p + 2 frame period). The polar pattern of the PXLs is the same as the polar pattern of the pixel cells PXL in the second frame period, and the polar pattern of the pixel cells PXL in the 6p + 3 frame period is the pixel in the third frame period. The polarity pattern of the pixel cells PXL in the sixth p + 4 frame period is the same as the polarity pattern of the cells PXL, and the polarity pattern of the pixel cells PXL in the fourth frame period is the same as the sixth p +. The polar pattern of the pixel cells PXL in the fifth frame period is the same as the polar pattern of the pixel cells PXL in the fifth frame period, and the polar pattern of the pixel cells PXL in the sixth p + 6 frame period. Is the same as the polar pattern of the pixel cells PXL in the sixth frame period. work.

The polarity change of each pixel period of the pixel cells PXL connected to the odd data line among the second to mth data lines DL2 to DLm is the pixel cell PXL connected to the first data line DL1. Are the same as the polarity change of each frame period.

FIG. 13 is a diagram for describing polarity change of each pixel period of the pixel cells PXL connected to the second data line DL2 of FIG. 10.

The data driver DD outputs the positive data and the negative data to the second data line DL2 alternately for two periods during the first frame period. Then, as shown in FIG. 13A, two pixel cells PXL adjacent to each other in turn have positive and negative polarities. In this case, the data driver DD supplies the negative data before the positive data to the second data line DL2.

Accordingly, as shown in FIG. 12, the polarity change of each pixel period of the pixel cells PXL connected to the second data line DL2 is performed by the frame of the pixel cells PXL connected to the first data line DL1. It is the same as the change in polarity for each period, and only the polarity between two pixel cells PXL corresponding to each other is reversed. For example, the polarity of the first pixel cell PXL1 shown in FIG. 12B and the polarity of the first pixel cell PXL1 shown in FIG. 13B are opposite to each other.

The polarity change of each pixel period of the pixel cells PXL connected to the even-numbered data line among the second to m-th data lines DL2 to DLm is the pixel cell PXL connected to the second data line DL2. Is the same as the polarity change of each frame period.

The pixel cells PXL connected to the data lines may be divided into a plurality of pixel cell groups including first to sixth pixel cells PXL1 to PXL6.

The pixel cell groups are sequentially driven, and the first to sixth pixel cells PXL1 to PXL6 in each pixel cell group are sequentially driven from the first pixel cell PXL1 to the sixth pixel cell PXL6.

For example, the first to nth pixel cells PXLn connected to the first data line DL1 may include a first group of pixel cells PXL1 including first to sixth pixel cells PXL1 to PXL6. Second pixel cell PXL2 group including seventh to twelfth pixel cells PXL, third pixel cell PXL3 group including thirteenth to eighteenth pixel cells PXL, ..., n- N-th pixel cell group including fifth pixel cells PXL to n-th pixel cells PXLn, and the first to n-th pixel cells PXLn are the first to n-th pixel cells PXL1 to nth. The pixel cells PXLn are sequentially driven.

The sixth f + 2 pixel cell driven second in the j th pixel cell group in the i + 1 th frame period has the same polarity as the sixth f + 1 pixel cell driven first in the j th pixel cell group in the i th frame period. Have Meanwhile, the sixth f + 1 pixel cell which is driven first in the j-th pixel cell group in the i + 1th frame period is the sixth f + 6 pixel that is driven last in the j-th pixel cell group in the i-th frame period. It has the same polarity as the cell. An example of this is as follows.

FIG. 14 is a view illustrating polarity change for each frame period of the first to sixth pixel cells PXL1 to PXL6 connected to the first data line DL1 and included in the first pixel cell PXL1 group.

The data driver DD outputs the positive data and the negative data to the first data line DL1 alternately for two periods during the first frame period. Then, as illustrated in FIG. 14A, three pixel cells PXL adjacent to each other in turn have positive and negative polarities. In this case, the data driver DD supplies the positive data to the first data line DL1 before the negative data.

That is, the data driver DD transmits positive polarity data to the first to third pixel cells PXL3 included in the first pixel cell PXL1 group in the first frame period through the first data line DL1. Is supplied, and negative data is supplied to the fourth to sixth pixel cells PXL6.

Thereafter, the data driver DD shifts the polarity of the data to be supplied during the second frame period by one period, so that the first pixel cell PXL1 is displayed in the second frame period as shown in FIG. The second pixel cell PXL2 driven second in the) group has the same polarity as the first pixel cell PXL1 driven first in the first pixel cell PXL1 in the first frame period.

Meanwhile, the first pixel cell PXL1 driven first in the first pixel cell PXL1 group in the second frame period has the same polarity as the sixth pixel cell PXL6 driven last in the first frame period. Has

Accordingly, the first to sixth pixel cells PXL1 to PXL6 of the first pixel cell PXL1 group during the second frame period are, as shown in FIG. 12B, the first frame. The polarity is shifted down by one space from the polarity of the first to sixth pixel cells PXL1 to PXL6 during the period.

In the same manner, the first to sixth pixel cells PXL1 to PXL6 of the first pixel cell PXL1 group during the third frame period are as shown in FIG. 12C. Polarities shifted downward by one column from the polarities of the first to sixth pixel cells PXL1 to PXL6 during the frame period.

Then, the first to sixth pixel cells PXL1 to PXL6 of the first pixel cell PXL1 group during the fourth frame period, as shown in (d) of FIG. 12, during the third frame period. The polarity is shifted downward one by one from the polarities of the first to sixth pixel cells PXL1 to PXL6 of the first pixel cell PXL1.

The first to sixth pixel cells PXL1 to PXL6 of the first pixel cell PXL1 group during the fifth frame period are, as shown in FIG. 12E, during the fourth frame period. The polarity is shifted downward one by one from the polarities of the first to sixth pixel cells PXL1 to PXL6 of the first pixel cell PXL1.

Then, the first to sixth pixel cells PXL1 to PXL6 of the first pixel cell PXL1 group during the sixth frame period, as shown in FIG. 12 (f), during the fifth frame period. The polarity is shifted downward one by one from the polarities of the first to sixth pixel cells PXL1 to PXL6 of the first pixel cell PXL1.

On the other hand, the polarity change of each six pixel cells PXL in the remaining second to n / 6 pixel cell groups connected to the first data line DL1 is changed for each frame period, and is connected to the first data line DL1. The change in polarity of each of the first to sixth pixel cells PXL1 to PXL6 in the first pixel cell PXL1 in each frame period is the same.

In addition, the change in polarity of each pixel period of the pixel cells PXL connected to the odd data line is the same as the change of polarity of each pixel period of the pixel cells PXL connected to the first data line DL1.

FIG. 15 is a view illustrating polarity change for each frame period of the first to sixth pixel cells PXL1 to PXL6 connected to the second data line DL2 and included in the first pixel cell PXL1 group.

The data driver DD outputs the positive data and the negative data to the second data line DL2 alternately for three periods during the first frame period. Then, as illustrated in FIG. 15A, two pixel cells PXL adjacent to each other in turn have positive and negative polarities. In this case, the data driver DD supplies the positive data to the second data line DL2 before the negative data.

Accordingly, as illustrated in FIG. 15, the polarity change of each of the first to sixth pixel cells PXL1 to PXL6 connected to the second data line DL2 and included in the first pixel cell PXL1 group may vary. , Two pixel cells connected to the first data line DL1 and corresponding to the polarity change of each of the first to sixth pixel cells PXL1 to PXL6 included in the first pixel cell PXL1 for each frame period, and corresponding to each other. Polarity between PXL) is reversed. For example, the polarity of the first pixel cell PXL1 shown in FIG. 14B and the polarity of the first pixel cell PXL1 shown in FIG. 15B are opposite to each other.

On the other hand, the polarity change of each six pixel cells PXL in the remaining second to n / 6 pixel cell groups connected to the second data line DL2 by frame period is connected to the second data line DL2. The change in polarity of each of the first to sixth pixel cells PXL1 to PXL6 in the first pixel cell PXL1 is changed according to the frame period.

In addition, the change in polarity of each pixel period of the pixel cells PXL connected to the even-numbered data line is the same as the change of polarity of each pixel period of the pixel cells PXL connected to the second data line DL2.

FIG. 16 illustrates a frame period change of the polarity inversion control signal Pol from the polarity controller PC included in the liquid crystal display according to the second exemplary embodiment of the present invention.

The polarity inversion control signal Pol may include a plurality of positive polarity sections (hatched portions) that remain high for three periods and a plurality of negative polarities that remain low for three periods, as shown in FIG. Has a section.

As shown in FIG. 16, the polarity inversion control signal Pol is shifted and output by a time corresponding to one period every frame period. Specifically, the polarity control unit PC shifts and outputs the polarity inversion control signal Pol for a period of time each time a vertical synchronization signal Vsync indicating the start of one frame is output. Accordingly, the polarity of the data is also shifted for a time corresponding to one period.

The polarity inversion control signal Pol shown in FIG. 16 is a signal supplied to one channel portion of the data driver DD, that is, the first channel portion connected to the first data line DL1. The first channel unit changes the polarity of data Data according to the polarity inversion control signal Pol. The polarity inversion control signal Pol shown in FIG. 10 is also supplied to the odd channel portion connected to the odd data line. Meanwhile, the polarity inversion control signal Pol having a phase inversion of 180 degrees with respect to the polarity inversion control signal Pol shown in FIG. 9 is supplied to the even-numbered channel portion including the second channel portion.

17 illustrates a liquid crystal display according to a third exemplary embodiment of the present invention.

As shown in FIG. 17, the pixel cells PXL adjacent to each other in the vertical direction are supplied with data having different polarities in units of one pixel cell to display an image, and the pixel cells PXL adjacent to each other in the horizontal direction are represented by two. An image is displayed by receiving data having different polarities in units of pixel cells. To this end, the data driver DD alternately supplies positive data and negative data to each of the data lines DL1 to DLm in units of two periods, and supplies data having opposite polarities to the data lines adjacent to each other. That is, the data driver DD outputs data in a 2-dot manner.

As shown in FIG. 17, pixel cells PXL of the same polarity are positioned to face each other on each side of each of the data lines DL1 to DLm, and the pixel cells PXL are common to the data lines located between them. Is connected.

Gate lines are provided above and below each of the pixel rows HL1 to HLn, and the odd pixel cells PXL in each of the pixel rows HL1 to HLn are positioned above the pixel rows HL1 to HLn. Commonly connected to the gate lines, even-numbered pixel cells PXL in each of the pixel rows HL1 to HLn are commonly connected to gate lines located below each of the pixel rows HL1 to HLn. For example, the odd-numbered pixel cells PXL of the pixel cells PXL in the first pixel row are commonly connected to the first gate line GL1, and the even-numbered pixel cells PXL are connected to the second gate line ( Commonly connected to GL2).

As the first to nth gate lines GL1 to GLn are sequentially driven from the first gate line GL1 to the nth gate line GLn, two first pixel lines GL1 to GLn are positioned in the same pixel row and connected to the same data line. The pixel cell PXL located on the left side of the pixel cells PXL is driven first, and then the pixel cell PXL located on the right side is driven.

Accordingly, the pixel cell PXL positioned in the first pixel row HL1 and located on the opposite side of the first data line DL1 is driven first of one frame period, and the n / 2 pixel row HL (n / 2)) and the pixel cell PXL connected to the right side of the first data line DL1 is driven at the end of one frame period. The pixel cells PXL connected to the second to m th data lines DL2 to DLm are also driven in the same order as the pixel cells PXL connected to the first data line DL1.

 The data driver DD alternately outputs the positive data and the negative data twice in an i frame period. For example, the data driver DD continuously outputs the positive data twice in succession for the first and second consecutive periods, and then outputs the data twice in succession for the third and fourth successive periods. . Subsequently, the data of the positive polarity is output twice again in the fifth and sixth consecutive periods, and the data of the negative polarity is output twice again in the seventh and eighth periods.

Accordingly, as illustrated in FIG. 17, the pixel cells PXL connected to one data line alternately display the positive and negative polarities of the two pixel cells PXL.

The data driver DD supplies positive data to the odd data line and negative data first to the even data line in the i frame period. Accordingly, in the i frame period, as illustrated in FIG. 17, the pixel cells PXL connected to the odd data lines and the pixel cells PXL connected to the odd data lines corresponding thereto have opposite polarities. In addition, the pixel cells PXL for one horizontal line connected to one gate line alternately have one positive polarity and one negative polarity.

On the other hand, the data driver DD includes a pixel cell PXL (k is a natural number of two or more) driven k-th in the i + 1th frame period (k-1 th driving period of the i-th frame period). The pixel cells PXL that are driven to have the same polarity data as PXL and that are driven first in the i + 1 frame period are the same polarities as the pixel cells PXL that are driven last in the i-th frame period. The polarities of the data are shifted by one pixel cell every frame period so as to be sequentially supplied to one data line.

If this is explained in more detail as follows.

FIG. 18 is a diagram for describing polarity change of each pixel period of the pixel cells PXL connected to the first data line DL1 of FIG. 17.

The data driver DD outputs the data of the positive polarity and the data of the negative polarity alternately for two periods to the first data line DL1 during the first frame period. Then, as illustrated in FIG. 18A, two pixel cells PXL adjacent to each other in turn have positive and negative polarities. In this case, the data driver DD supplies the positive data to the first data line DL1 before the negative data.

That is, the data driver DD supplies positive data to the 4a + 1 and 4a + 2 pixel cells (a is a natural number including 0) in the first frame period through the first data line DL1. Then, negative data is supplied to the fourth a + 3 and fourth a + 4 pixel cells.

Thereafter, the data driver DD shifts the polarity of the data to be supplied during the second frame period by one period, thereby driving the k-th pixel cell in the second frame period as shown in FIG. 18B. The pixel PXL has the same polarity as the pixel cell PXL driven k-th in the first frame period.

For example, as shown in FIGS. 18A and 18B, the second pixel cell PXL2 driven second in the second frame period is first driven in the first frame period. It has the same polarity as the pixel cell PXL1.

That is, the data driver DD supplies negative data to a 4q + 1 pixel cell in a second frame period through the first data line DL1, and supplies 4a + 2 and 4a + 3 pixels. Positive data is supplied to a cell, and negative data is supplied to a 4a + 4 pixel cell.

Meanwhile, the first pixel cell PXL1 first driven in the second frame period has the same polarity as the nth pixel cell PXLn last driven in the first frame period.

Accordingly, the pixel cells PXL in the second frame period are shifted down one space from the polarity of the pixel cells PXL in the first frame period, as shown in FIG. 18B. It shows polarity.

In the same manner, the pixel cells PXL in the third frame period are shifted down one space from the polarity of the pixel cells PXL in the second frame period, as shown in FIG. 18C. Polarity.

That is, the data driver DD supplies negative data to the 4a + 1 and 4a + 2 pixel cells in the third frame period through the first data line DL1, and supplies the fourth 4a + 3 data. And positive data is supplied to the fourth a + 4 pixel cell.

The pixel cells PXL in the fourth frame period have a polarity shifted downward by one space from the polarity of the pixel cells PXL in the third frame period, as shown in FIG. 18D. Indicates.

That is, the data driver DD supplies positive data to a 4a + 1 pixel cell in a fourth frame period through the first data line DL1, and controls the 4a + 2 and 4a + 3 pixels. Negative data is supplied to the cell, and positive data is supplied to the fourth a + 4 pixel cell.

Although not shown in the drawings, the polarities of the pixel cells PXL in the fifth frame period are the same as the polarities of the pixel cells PXL in the first frame period.

In general, the polar pattern of the pixel cells PXL in the fourth p + 1 frame period is the same as the polar pattern of the pixel cells PXL in the first frame period, and the pixel cell in the fourth p + 2 frame period. The polar pattern of the PXLs is the same as the polar pattern of the pixel cells PXL in the second frame period, and the polar pattern of the pixel cells PXL in the fourth p + 3 frame period is the pixel in the third frame period. The polarity pattern of the cells PXL is the same, and the polarity pattern of the pixel cells PXL in the fourth p + 4 frame period is the same as the polarity pattern of the pixel cells PXL in the fourth frame period.

The polarity change of each pixel period of the pixel cells PXL connected to the odd data line among the second to mth data lines DL2 to DLm is the pixel cell PXL connected to the first data line DL1. Is the same as the polarity change of each frame period.

FIG. 19 is a diagram for describing polarity change of each pixel period of the pixel cells PXL connected to the second data line DL2 of FIG. 17.

The data driver DD outputs the positive data and the negative data to the second data line DL2 alternately for two periods during the first frame period. Then, as shown in (a) of FIG. 19, two pixel cells PXL adjacent to each other in turn have a positive polarity and a negative polarity. In this case, the data driver DD supplies the negative data before the positive data to the second data line DL2.

Accordingly, as illustrated in FIG. 19, the polarity change of each pixel period of the pixel cells PXL connected to the second data line DL2 is a frame of the pixel cells PXL connected to the first data line DL1. It is the same as the change in polarity for each period, and only the polarity between two pixel cells PXL corresponding to each other is reversed. For example, the polarity of the first pixel cell PXL1 shown in FIG. 4B and the polarity of the first pixel cell PXL1 shown in FIG. 19B are opposite to each other.

The polarity change of each pixel period of the pixel cells PXL connected to the even-numbered data line among the second to m-th data lines DL2 to DLm is the pixel cell PXL connected to the second data line DL2. Is the same as the polarity change of each frame period.

The pixel cells PXL connected to each of the data lines DL1 to DLm may be divided into a plurality of pixel cell groups including first to fourth pixel cells PXL1 to PXL4.

The pixel cell groups are sequentially driven, and the first to fourth pixel cells PXL1 to PXL4 in each pixel cell group are sequentially driven from the first pixel cell PXL1 to the fourth pixel cell PXL4.

For example, the first to n th pixel cells PXL1 to PXLn connected to the first data line DL1 are the first pixel cell PXL1 group including the first to fourth pixel cells PXL1 to PXL4. , A second pixel cell PXL2 group including fifth to eighth pixel cells PXL5 to PXL8, a third pixel cell PXL3 group including ninth to twelfth pixel cells PXL9 to PXL12. .., May be defined as an n / 2 pixel cell group including n-3 th to n th pixel cells PXLn-3 to PXLn, and the first to n th pixel cells PXLn may be defined as a first pixel cell. The driving is sequentially performed from PXL1 to the nth pixel cell PXLn.

The fourth f + 2 pixel cell driven second in the j th pixel cell group in the i + 1 th frame period has the same polarity as the fourth f + 1 pixel cell driven first in the j th pixel cell group in the i th frame period. Have On the other hand, a fourth f + 1 pixel cell driven first in the j th pixel cell group in the i + 1th frame period is a fourth f + 4 pixel driven last in the j th pixel cell group in the i th frame period. It has the same polarity as the cell. An example of this is as follows.

FIG. 20 is a view illustrating polarity change of each of the first to fourth pixel cells PXL1 to PXL4 connected to the first data line DL1 and included in the first pixel cell PXL1.

The data driver DD outputs the data of the positive polarity and the data of the negative polarity alternately for two periods to the first data line DL1 during the first frame period. Then, as shown in FIG. 20A, two adjacent pixel cells PXL have positive and negative polarities in turn. In this case, the data driver DD supplies the positive data to the first data line DL1 before the negative data.

That is, the data driver DD has a positive electrode in the first and second pixel cells PXL1 and PXL2 included in the first pixel cell PXL1 group in the first frame period through the first data line DL1. Last data is supplied, and negative data is supplied to the third and fourth pixel cells PXL3 and PXL4.

Thereafter, the data driver DD shifts the polarity of the data to be supplied during the second frame period by one period, so that the first pixel cell PXL1 is displayed in the second frame period as shown in FIG. The second pixel cell PXL2 driven second in the) group has the same polarity as the first pixel cell PXL1 driven first in the first pixel cell PXL1 in the first frame period.

Meanwhile, the first pixel cell PXL1 driven first in the first pixel cell PXL1 group in the second frame period has the same polarity as the fourth pixel cell PXL4 driven last in the first frame period. Has

Accordingly, the first to fourth pixel cells PXL1 to PXL4 of the first pixel cell PXL1 group during the second frame period, as shown in FIG. 20B, have the first frame. The polarity is shifted downward by one space from the polarity of the first to fourth pixel cells PXL1 to PXL4 during the period.

In the same manner, the first to fourth pixel cells PXL1 to PXL4 of the first pixel cell PXL1 group during the third frame period are as shown in FIG. 20C. The polarity shifted downward by one column from the polarity of the first to fourth pixel cells PXL1 to PXL4 during the frame period.

The first to fourth pixel cells PXL1 to PXL4 of the first pixel cell PXL1 group during the fourth frame period are, as shown in FIG. 20D, during the third frame period. The polarity is shifted downward one by one from the polarities of the first to fourth pixel cells PXL1 to PXL4 of the first pixel cell PXL1.

On the other hand, the polarity change of each of the four pixel cells PXL in the remaining second to n / 2 pixel cell groups connected to the first data line DL1 is changed for each frame period and is connected to the first data line DL1. The polarity of each of the first to fourth pixel cells PXL1 to PXL4 in the first pixel cell PXL1 is changed according to the frame period.

In addition, the change in polarity of each pixel period of the pixel cells PXL connected to the odd data line is the same as the change of polarity of each pixel period of the pixel cells PXL connected to the first data line DL1.

FIG. 21 is a view illustrating a polarity change for each frame period of the first to fourth pixel cells PXL1 to PXL4 connected to the second data line DL2 and included in the first pixel cell PXL1 group.

The data driver DD outputs the positive data and the negative data to the second data line DL2 alternately for two periods during the first frame period. Then, as shown in (a) of FIG. 21, two adjacent pixel cells PXL have positive and negative polarities in turn. In this case, the data driver DD supplies the positive data to the second data line DL2 before the negative data.

Accordingly, as illustrated in FIG. 21, the polarity change of each of the first to fourth pixel cells PXL1 to PXL4 connected to the second data line DL2 and included in the first pixel cell PXL1 group may vary. , Two pixel cells connected to the first data line DL1 and corresponding to the polarity change of each of the first to fourth pixel cells PXL1 to PXL4 included in the first pixel cell PXL1 for each frame period, and corresponding to each other. Polarity between PXL) is reversed. For example, the polarity of the first pixel cell PXL1 shown in FIG. 20B and the polarity of the first pixel cell PXL1 shown in FIG. 21B are opposite to each other.

On the other hand, the change in polarity of each of the four pixel cells PXL in the remaining second to n / 2 pixel cell groups connected to the second data line DL2 by frame period is connected to the second data line DL2. The polarity of each of the first to fourth pixel cells PXL1 to PXL4 in the first pixel cell PXL1 is changed according to the frame period.

In addition, the change in polarity of each pixel period of the pixel cells PXL connected to the even-numbered data line is the same as the change of polarity of each pixel period of the pixel cells PXL connected to the second data line DL2.

FIG. 22 is a diagram illustrating a liquid crystal display device having a vertical R / G / B pixel cell structure.

Referring to FIG. 22, a red pixel cell R, a green pixel cell G, and a blue pixel cell B are commonly connected to one data line.

The data driver DD according to the present invention can also be used in a liquid crystal display device having a structure as shown in FIG.

FIG. 23 is a view showing a liquid crystal display device having another vertical R / G / B pixel cell structure.

Referring to FIG. 23, a red pixel cell R, a green pixel cell G, and a blue pixel cell B are divided and connected to two adjacent data lines.

The data driver DD according to the present invention can also be used in a liquid crystal display device having a structure as shown in FIG.

On the other hand, the first pixel cell of the i + 1 frame period may have the same polarity data as any one of the pixel cells (A pixel cell) of the pixel cells of the i-th frame period, the i + The second pixel cell of one frame period may have data of the same polarity as any one of the pixel cells (B pixel cell) except for the A pixel cell among the pixel cells of the i frame period, and the i + 1 The third pixel cell of the frame period may have the same polarity data as any one of the pixel cells (C pixel cell) except the A and B pixel cells of the i-th frame period, and the i + The fourth pixel cell in one frame period may have data of the same polarity as any one pixel cell (D pixel cell) except for the A, B, and C pixel cells of the i-th frame period. The fifth pixel cell of the i + 1 frame period includes the i th frame. The pixel cells of the period may have the same polarity data as any one of the pixel cells (E pixel cells) except for the A, B, C, and D pixel cells, and the i + 1 frame period. The n-th pixel cell of the pixel cell of the i-th frame period may be any one of the pixel cells except the pixel cells (selected pixel cells of the pixel cells of the i-frame period). May have data of the same polarity as any of the pixel cells (not selected).

The present invention described above is not limited to the above-described embodiment and the accompanying drawings, and it is common in the art that various substitutions, modifications, and changes can be made without departing from the technical spirit of the present invention. It will be evident to those who have knowledge of.

1 is a view showing a waveform of a data signal supplied to a data line of a conventional liquid crystal display device.

2 is a view showing a liquid crystal display device according to a first embodiment of the present invention.

3 is a view illustrating a configuration of a liquid crystal panel of FIG. 2.

4 is a diagram illustrating polarity change of each pixel period connected to pixel cells connected to a first data line of FIG. 3;

FIG. 5 is a diagram illustrating polarity change of each pixel period connected to pixel cells connected to the second data line of FIG. 3; FIG.

FIG. 6 is a view illustrating polarity change for each frame period of first to fourth pixel cells connected to a first data line and included in a first pixel cell group; FIG.

FIG. 7 is a view illustrating polarity change for each frame period of first to fourth pixel cells connected to a second data line and included in a first pixel cell group; FIG.

8 is a view showing a polarity control unit according to the present invention

FIG. 9 is a view illustrating a change in each frame period of a polarity inversion control signal output from the polarity controller of FIG. 8; FIG.

10 is a diagram illustrating a change in polarity of data supplied for each frame period to a first data line;

11 is a view showing a liquid crystal display device according to a second embodiment of the present invention.

FIG. 12 is a diagram for describing polarity change for each frame period of pixel cells connected to a first data line of FIG. 10. FIG.

FIG. 13 is a diagram for describing polarity change of each pixel period connected to pixel cells connected to the second data line of FIG. 10; FIG.

FIG. 14 is a view illustrating polarity change for each frame period of first to sixth pixel cells connected to a first data line and included in a first pixel cell group; FIG.

FIG. 15 is a view illustrating polarity change for each frame period of first to sixth pixel cells connected to a second data line and included in a first pixel cell group; FIG.

FIG. 16 is a view illustrating a frame period change of a polarity inversion control signal from a polarity controller provided in a liquid crystal display according to a second exemplary embodiment of the present invention.

17 illustrates a liquid crystal display according to a third embodiment of the present invention.

FIG. 18 is a diagram illustrating polarity change for each frame period of pixel cells connected to a first data line of FIG. 17; FIG.

FIG. 19 is a diagram for describing polarity change of each pixel period connected to pixel cells connected to the second data line of FIG. 17. FIG.

FIG. 20 is a view illustrating polarity change for each frame period of first to fourth pixel cells connected to a first data line and included in a first pixel cell group; FIG.

FIG. 21 is a view illustrating polarity change for each frame period of first to fourth pixel cells connected to a second data line and included in a first pixel cell group; FIG.

22 illustrates a liquid crystal display device having a vertical R / G / B pixel cell structure.

FIG. 23 is a view showing a liquid crystal display device having another vertical R / G / B pixel cell structure

* Description of the main parts of the drawings

PXL1 to PXLn: first to nth pixel cells

Claims (10)

A plurality of pixel cells commonly connected to the first data line and sequentially driven; And, In the i-frame period (i is a natural number), the positive data and the negative data are alternately outputted and supplied to the first data line so that the pixel cells are sequentially supplied with data. A k-th pixel cell (k is a natural number of two or more) in the frame period has the same polarity data as the k-th driving pixel cell in the i-th frame period, and in the i + 1th frame period. The polarities of the data are shifted by one pixel cell in every frame period so that the first pixel cell has the same polarity data as the pixel cell last driven in the i-th frame period, and is sequentially sequenced to the first data line. Liquid crystal display comprising a data driver for supplying. The method of claim 1, Pixel cells connected to the first data line are divided into a plurality of pixel cell groups including first to fourth pixel cells; The pixel cell groups are sequentially driven, and the first to fourth pixel cells in each pixel group are sequentially driven from the first pixel cell to the fourth pixel cell; The data driver through the first data line, In the fourth p + 1 frame period (p is a natural number including 0), positive data is supplied to the first and second pixel cells in each pixel cell group, and negative data is supplied to the third and fourth pixel cells. To; In the 4p + 2 frame period, the negative data is supplied to the first pixel cells in each pixel cell group, the positive data is supplied to the second and third pixel cells, and the negative data is supplied to the fourth pixel cells. Supplying; In the fourth p + 3 frame period, negative data is supplied to the first and second pixel cells in each pixel cell group, and positive data is supplied to the third and fourth pixel cells; And, In the fourth p + 4 frame period, the positive data is supplied to the first pixel cells in each pixel cell group, the negative data is supplied to the second and third pixel cells, and the positive data is supplied to the fourth pixel cells. Liquid crystal display device characterized in that the supply. The method of claim 1, The pixel cells connected to the first data line are divided into a plurality of pixel cell groups including first to sixth pixel cells; The pixel cell groups are sequentially driven, and the first to sixth pixel cells in each pixel group are sequentially driven from the first pixel cell to the sixth pixel cell; The data driver through the first data line, In the sixth p + 1 frame period (p is a natural number including 0), positive data is supplied to the first, second, and third pixel cells in each pixel cell group, and the fourth, fifth, and sixth pixel cells are supplied. Supply negative polarity data; In the sixth p + 2 frame period, each pixel cell group My Supplying negative data to one pixel cell, supplying positive data to the second, third and fourth pixel cells, and supplying negative data to the fifth and sixth pixel cells; In the 6p + 3 frame period, the negative data is supplied to the first and second pixel cells in each pixel cell group, the positive data is supplied to the third, fourth and fifth pixel cells, and the sixth pixel is provided. Supply negative data to the cell; In the 6p + 4 frame period, negative data is supplied to the first, second, and third pixel cells in each pixel cell group, and positive data is supplied to the fourth, fifth, and sixth pixel cells; In the sixth p + 5 frame period, the positive data is supplied to the first pixel cells in each pixel cell group, the negative data is supplied to the second, third and fourth pixel cells, and the fifth and sixth pixels are supplied. Supply positive data to the cell; And, In the sixth p + 6 frame period, the positive data is supplied to the first and second pixel cells in each pixel cell group, the negative data is supplied to the third, fourth and fifth pixel cells, and the sixth pixel is provided. A liquid crystal display device comprising supplying positive polarity data to a cell. The method of claim 1, A polarity control unit for providing a polarity control signal to the data driver so that the data driver can impart polarity of the data; The polarity inversion control signal is defined as a plurality of positive polarity sections that remain high for at least two periods and a plurality of negative polarity sections that remain low for at least two periods; And, And in each frame period, the polarity inversion control signal is shifted and output by a time corresponding to one period. The method of claim 4, wherein And the polarity control unit shifts and outputs the polarity inversion control signal by a time corresponding to one period according to the vertical synchronization signal indicating the start of one frame. The method of claim 1, A second data line located at one side of the first data line; And, A plurality of pixel cells commonly connected to the second data line; The data driver alternately outputs negative data and positive data in at least two periods in the i-frame period to supply the second data line to the pixel data so that the pixel cells may receive data sequentially. The pixel cells driven in the k-th period in the period have the same polarity as the k-1th driven pixel cells in the i-th frame period, and the pixel cells driven first in the i + 1th frame period are The polarities of the data are shifted by one pixel cell in every frame period so as to have data of the same polarity as the pixel cells last driven in the i frame period, and are sequentially supplied to the second data line; And, And the data driver is configured to supply positive data first to the first data line and to supply negative data first to the second data line in the i-th period. The method of claim 6, Third to qth data lines sequentially arranged on one side of the second data line (q is a natural number of 4 or more); And, A plurality of pixel cells connected to each of the third to qth data lines; Pixel cells connected to each of the odd data lines including the third data line receive data having the same polarity as those of the pixel cells connected to the first data line; And, And pixel cells connected to each of the even-numbered data lines including the fourth data line receive data having the same polarity as those of the pixel cells connected to the second data line. A driving method of a liquid crystal display device including a plurality of pixel cells commonly connected to data lines and sequentially driven, A step of sequentially supplying data to the pixel cells by alternately outputting positive data and negative data at least two periods in an i th frame period (i is a natural number); And, The k-th pixel cell (k is a natural number of two or more) in the i-th frame period has the same polarity data as the k-th-driven pixel cell in the i-th frame period, and the i + The polarity of the data is shifted by one pixel cell every frame period so that the pixel cell driven first in one frame period has the same polarity as the pixel cell driven last in the i-th frame period. And a step B of sequentially supplying the same to the liquid crystal display device. The method of claim 8, The pixel cells connected to the data line are divided into a plurality of pixel cell groups including first to fourth pixel cells, and the pixel cell groups are sequentially driven, and the first to fourth pixel cells in each pixel group are driven. Sequentially driven from the first pixel cell to the fourth pixel cell; Step A, In the fourth p + 1 frame period (p is a natural number including 0), positive data is supplied to the first and second pixel cells in each pixel cell group through the data line, and negative data is supplied to the third and fourth pixel cells. Supplying data of polarity; Step B, In the fourth p + 2 frame period, the negative data is supplied to the first pixel cells in each pixel cell group through the data line, the positive data is supplied to the second and third pixel cells, and the fourth pixel cell is supplied. Supplying negative data to the device; Supplying negative data to first and second pixel cells in each pixel cell group through the data line in a fourth p + 3 frame period, and supplying positive data to third and fourth pixel cells; And, In a 4p + 4 frame period, the positive data is supplied to the first pixel cells in each pixel cell group through the data line, the negative data is supplied to the second and third pixel cells, and the fourth pixel cell is supplied. And supplying positive polarity data to the liquid crystal display device. The method of claim 8, The pixel cells connected to the data line are divided into a plurality of pixel cell groups including first to sixth pixel cells, and the pixel cell groups are sequentially driven and the first to sixth pixel cells in each pixel group are driven. Sequentially driven from the first pixel cell to the sixth pixel cell; Step A, In the 6p + 1 frame period (p is a natural number including 0), positive data is supplied to the first, second and third pixel cells in each pixel cell group through the data line, and the fourth, fifth and Supplying negative data to the sixth pixel cell; Step B, In the 6p + 2 frame period, the negative data is supplied to the first pixel cells in each pixel cell group through the data line, and the positive data is supplied to the second, third and fourth pixel cells. Supplying negative data to the fifth and sixth pixel cells In the 6p + 3 frame period, the negative data is supplied to the first and second pixel cells in each pixel cell group through the data line, and the positive data is supplied to the third, fourth and fifth pixel cells. Supplying negative data to the sixth pixel cell; In the 6p + 4 frame period, the negative data is supplied to the first, second, and third pixel cells in each pixel cell group through the data line, and the positive is supplied to the fourth, fifth, and sixth pixel cells. Supplying data; In the 6p + 5 frame period, the positive data is supplied to the first pixel cells in each pixel cell group through the data lines, and the negative data is supplied to the second, third and fourth pixel cells. Supplying positive polarity data to the fifth and sixth pixel cells; And, In the 6p + 6 frame period, the positive data is supplied to the first and second pixel cells in each pixel cell group through the data line, and the negative data is supplied to the third, fourth and fifth pixel cells. And supplying positive polarity data to the sixth pixel cell.

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