KR20150073491A - Liquid crystal display device and method for driving the same - Google Patents

Abstract

The present invention relates to a liquid crystal display device capable of improving image quality, and to a driving method thereof. The liquid crystal display device comprises: a liquid crystal panel including a plurality of gate lines, a plurality of data lines, and a plurality of pixels arranged in a matrix form; a gate driver for applying gate signals to the gate lines; a data driver for applying data voltages to the data lines; and a timing controller for controlling the gate driver and the data driver, wherein each column of the pixels is alternately connected to the data lines disposed on both sides in a zigzag manner, and the data driver applies polarities of the data voltages in the order of positive (+), negative (-), positive (+), negative (-), negative (-), positive (+), negative (-), positive (+) polarities with respect to first to eighth data lines which are sequentially disposed and repeated. In addition, the data voltages charged in the pixels have polarities inverted every one horizontal pixel and every one vertical pixel in first to third pixel lines, and the data voltages have the same polarities in a fourth pixel line.

Description

Technical Field [0001] The present invention relates to a liquid crystal display (LCD)

The present invention relates to a liquid crystal display device capable of improving picture quality and a driving method thereof.

In general, a liquid crystal display (LCD) includes a liquid crystal panel in which a plurality of pixels are arranged in a matrix form, a driving circuit for driving the liquid crystal panel, and a backlight unit for irradiating light to the liquid crystal panel.

The applicant of the present application filed a patent application in Korean Patent Application No. 10-2003-0083310 (Oct. 30, 2003), No. 10-2003-0083313 (Oct. 30, 2003), No. 10-2004-0042143 A Z-inversion type liquid crystal display device which drives a plurality of pixels in a dot-inversion manner using a driven data driver has been proposed.

1 is a plan view of a conventional Z-inversion type liquid crystal display device.

Referring to FIG. 1, a conventional Z-inversion type liquid crystal display includes a plurality of gate lines GL, a plurality of data lines DL, and a plurality of pixels P arranged in a matrix form.

A data voltage is applied to the plurality of data lines DL from a data driver (not shown). The data voltage has positive (+) or negative (-) polarity. Data voltages of different polarities are applied to the adjacent data lines DL. For example, a positive (+) data voltage is applied to the odd data lines and a negative (-) data voltage is applied to the even data lines.

Each pixel P is connected to an adjacent gate line GL and an adjacent data line DL through a TFT. In the plurality of pixels P, each column is alternately connected in zigzag form to the data lines DL arranged on both sides. Therefore, the polarity of the data voltage supplied to the plurality of pixels P is reversed in units of one horizontal pixel and one vertical pixel.

Such a Z-inversion type liquid crystal display device has the following advantages. First, the data driver can reduce the power consumption by keeping the polarity of the output data voltage the same for one frame period. Since a large number of pixels P are driven in a dot-inversion manner, flicker can be reduced.

On the other hand, the plurality of pixels P include pixels displaying red (R), green (G), blue (B), and white (W). And pixels displaying red (R), green (G), blue (B) and white (W) are arranged in a stripe form.

In a conventional Z-inversion type liquid crystal display device, a data voltage of the same polarity is applied to a pixel column or pixel row having a specific color. For example, in the conventional Z-inversion type liquid crystal display device shown in FIG. 1, data voltages of the same polarity are applied to red pixels arranged in the horizontal direction, and green pixels arranged in the horizontal direction have the same polarity It can be seen that a data voltage is applied, a data voltage of the same polarity is applied to the blue pixels arranged in the horizontal direction, and a data voltage of the same polarity is applied to the white pixels arranged in the horizontal direction.

Thus, when a data voltage of the same polarity is applied to a pixel column or a pixel column arranged with a specific color, a dim in the horizontal or vertical direction is generated and the image quality is deteriorated.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a liquid crystal display device and a method of driving the same that can reduce dimming in a horizontal or vertical direction.

According to an aspect of the present invention, there is provided a liquid crystal display comprising: a liquid crystal panel including a plurality of gate lines, a plurality of data lines, and a plurality of pixels arranged in a matrix; A gate driver for applying a gate signal to the plurality of gate lines; A data driver for applying a data voltage to the plurality of data lines; And a timing controller for controlling the gate driver and the data driver; Wherein each column of the plurality of pixels is alternately connected in zigzag form to data lines disposed on both sides; The data driver includes positive, negative, positive, negative, negative, positive and negative polarities of the data voltage for the first through eighth data lines sequentially arranged and repeated. Apply in positive (+), negative (-), positive (+) order; The data voltages charged in the plurality of pixels are polarized in units of horizontal one pixel and vertical one pixel in the first through third pixel columns and have the same polarity in the fourth pixel column.

And the fourth pixel column is disposed between the fourth and fifth data lines neighboring to each other and between the eighth and first data lines neighboring to each other.

The plurality of pixels including pixels displaying red, green, blue, and white; The fourth pixel column may display any one color selected from red, blue, and white, or may display at least two colors selected from red, blue, and white.

Wherein the first pixel column displays red, the second pixel column displays green, the third column displays blue, and the fourth column displays white.

Wherein the first column is arranged with pixels alternately displaying white and green, the second column alternatingly displaying pixels displaying red and blue, and the third column alternatingly displaying pixels displaying green and white And the fourth column is characterized in that pixels displaying blue and red are arranged alternately.

According to another aspect of the present invention, there is provided a method of driving a liquid crystal display including a plurality of gate lines, a plurality of gate lines, and a plurality of pixels arranged in a matrix, A driving method of a liquid crystal display device in which each column of a plurality of pixels is alternately connected in a staggered manner to data lines arranged on both sides, the driving method comprising the steps of: Applying the polarity of the data voltage in the order of positive (+), negative (-), positive (+), negative (-), negative (+), negative ; The data voltages charged in the plurality of pixels are polarized in units of horizontal one pixel and vertical one pixel in the first through third pixel columns and have the same polarity in the fourth pixel column.

And the fourth pixel column is disposed between the fourth and fifth data lines neighboring to each other and between the eighth and first data lines neighboring to each other.

The plurality of pixels including pixels displaying red, green, blue, and white; The fourth pixel column may display any one color selected from red, blue, and white, or may display at least two colors selected from red, blue, and white.

Wherein the first pixel column displays red, the second pixel column displays green, the third column displays blue, and the fourth column displays white.

Wherein the first column is arranged with pixels alternately displaying white and green, the second column alternatingly displaying pixels displaying red and blue, and the third column alternatingly displaying pixels displaying green and white And the fourth column is characterized in that pixels displaying blue and red are arranged alternately.

(+), Negative (+), negative (-), positive (+), negative (-) and negative (-) polarities of a data voltage for successive data lines, And positive (+). Then, the polarity of the data voltage charged in the plurality of pixels is inverted in units of horizontal one pixel and vertical one pixel, except for a part of the column, so that flicker and horizontal dimming can be reduced. In some of the columns, pixels of a color having a relatively low visibility of the dim can be arranged to minimize dim in the vertical direction.

1 is a plan view of a conventional Z-inversion type liquid crystal display device.
2 is a configuration diagram of a liquid crystal display device according to an embodiment of the present invention.
3 is a schematic plan view of the liquid crystal panel 2 shown in Fig.
4A and 4B are plan views showing an array of pixels having a plurality of colors according to the present invention.
5 is a plan view of a liquid crystal panel in which pixels for displaying white are arranged in a fourth pixel column C4.
6 is a plan view of a liquid crystal panel in which pixels for displaying blue are arranged in a fourth pixel column C4.
7 is a plan view of a liquid crystal panel in which pixels for displaying red are arranged in a fourth pixel column C4.
8 is a plan view showing an array of pixels having a plurality of colors according to another embodiment of the present invention.
9 is a plan view of a liquid crystal panel in which blue and red pixels are arranged in a fourth pixel column C4.

Hereinafter, a liquid crystal display device and a driving method thereof according to embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a configuration diagram of a liquid crystal display device according to an embodiment of the present invention.

The liquid crystal display device shown in Fig. 2 includes a liquid crystal panel 2, a timing controller 8, a data driver 6, and a gate driver 4.

The liquid crystal panel 2 includes an upper substrate and a lower substrate facing each other, and a liquid crystal layer formed between the upper substrate and the lower substrate. The upper substrate has a color filter, a black matrix, and a common electrode. The common electrode may be formed on the lower substrate. The lower substrate has a plurality of gate lines GL and a plurality of data lines DL. In this liquid crystal panel 2, a plurality of pixels P are provided in a matrix form by intersection of a plurality of gate lines GL and a plurality of data lines DL.

Each pixel P includes a thin film transistor (TFT) connected to the gate line GL and the data line DL, a liquid crystal capacitor Clc connected to the thin film transistor TFT, and a storage capacitor Cst ). The liquid crystal capacitor Clc includes a pixel electrode connected to the thin film transistor TFT and a common electrode which is spaced apart from the pixel electrode and applies an electric field to the liquid crystal. The storage capacitor Cst stores the voltage applied from the thin film transistor TFT to the pixel electrode. In the plurality of pixels P, each column is alternately connected in zigzag form to the data lines DL arranged on both sides.

Unlike the conventional Z-inversion type liquid crystal display device, the polarity of the data voltage is positive, negative, positive, negative, and negative polarity with respect to the consecutive data lines DL. , Negative (-), positive (+), negative (-), and positive (+). Then, the polarity of the data voltage charged in the plurality of pixels P is inverted in units of one horizontal pixel and one vertical pixel, except for some columns, so that flicker and horizontal dimming can be reduced. In addition, dimming can be minimized by disposing pixels of a color having a relatively low visibility in a part of the columns. The related features will be described later in detail with reference to Figs. 3 to 9.

The timing controller 8 includes a data control signal DCS for controlling the operation timing of the data driver 6 using the synchronization signals SYNC supplied from the system (not shown) And outputs a gate control signal GCS for controlling the gate control signal GCS. The synchronizing signal SYNC includes a horizontal synchronizing signal Hsync, a vertical synchronizing signal Vsync, a data enable signal DE and a dot clock DCLK. The timing controller 8 rearranges the digital video data RGB supplied from the system in accordance with the resolution of the liquid crystal panel 2 and supplies the data to the data driver 6. [ The data control signal DCS includes a source start pulse SSP indicating a sampling start point of digital video data RGB and a source sampling clock SSC indicating a latch operation of digital video data RGB, And a polarity control signal POL indicative of the polarity of the data voltage applied to the plurality of data lines DL, and the like. The gate control signal GCS includes a gate start pulse GSP for instructing the start of the scan drive of the gate driver 4, a gate shift clock signal GSC input to the shift register of the gate driver 4, And a gate output enable signal GOE for indicating the output of the comparator 4 and the like.

The data driver 6 latches digital video data (RGB). The data driver 6 converts the digital video data RGB according to the polarity control signal POL into an analog gamma voltage having a positive polarity or a negative polarity and outputs a positive polarity positive polarity signal or a negative polarity negative polarity signal, (-) data voltage. This data driver 6 can control the polarity of the data voltage to the positive polarity, negative polarity, positive polarity, negative polarity, and negative polarity with respect to the consecutive data lines DL for one frame period. (+), Negative (-), and positive (+), and the polarity of the data voltage applied to each data line DL is changed every frame period. Specifically, the data driver 6 can control the polarity of the data voltage with respect to the first to eighth data lines DL1 to DL8 (see FIG. 3) arranged and repeated sequentially, (+), Negative (-), negative (-), positive (+), negative (-) and positive (+) in this order.

The gate driver 4 generates a scan pulse for selecting a pixel line to which the analog data voltage is supplied from the data line DL. The gate driver 4 sequentially supplies the scan pulses to the plurality of gate lines GL.

3 is a schematic plan view of the liquid crystal panel 2 shown in Fig.

For reference, the plurality of data lines DL may start to be arranged from any one of the first to eighth data lines DL1 to DL8. That is, the first data line among the plurality of data lines DL may be any one of the first to eighth data lines DL1 to DL8. In FIG. 3, the positive data voltage is denoted by '+' and the negative data voltage is denoted by '-'. In the following description, the polarities of the data voltages sequentially applied to the first to eighth data lines DL1 to DL8 are positive, negative, positive, negative, negative, A specific frame period of positive (+), negative (-) and positive (+) will be described as an example.

Referring to FIG. 3, the liquid crystal panel 2 includes a plurality of data lines DL arranged in the longitudinal direction and a plurality of gate lines GL arranged in the horizontal direction. Pixels P are arranged at intersections of the data lines DL and the gate lines DL. The TFT provided in each pixel P is connected to the adjacent gate line GL and is also connected to any one of the data lines provided on both sides. Each pixel column is alternately connected in zigzag form to the data lines DL arranged on both sides. For example, among the plurality of pixels, the hole performance may be connected to the left data line among the adjacent two data lines, and the even-numbered performance among the plurality of pixels may be connected to the right data line among the adjacent two data lines. 3, the pixel rows connected to the k-th gate line GLk and the (k + 2) -th gate line GLk + 2 are connected to the left data line, and the k + ) Is connected to the right data line.

The plurality of pixels P include the first to fourth pixel columns C1 to C4. The first to fourth pixel columns (C1 to C4) are sequentially arranged and repeated. Specifically, the first pixel column C1 is disposed between the adjacent first and second data lines DL1 and DL2 or between the neighboring fifth and sixth data lines DL5 and DL6 . The second pixel column C2 is disposed between the adjacent second and third data lines DL1 and DL2 or between the neighboring sixth and seventh data lines DL6 and DL7. The third pixel column C3 is disposed between the neighboring third and fourth data lines DL1 and DL2 or between the neighboring seventh and eighth data lines DL7 and DL8. The fourth pixel column C4 is disposed between the neighboring fourth and fifth data lines DL1 and DL2 or between the neighboring eighth and first data lines DL8 and DL1.

The data voltage of positive polarity is applied to the first data line DL1 and the data voltage of negative polarity is applied to the second data line DL2. A negative data voltage is applied to the fourth data line DL4 and a negative data voltage is applied to the fifth data line DL5, The positive data voltage is applied to the sixth data line DL6 and the negative data voltage is applied to the seventh data line DL7 and the positive data voltage is applied to the eighth data line DL8. (+) Data voltage is applied.

Then, the data voltages applied to the pixel rows connected to the k-th gate line GLk are positive, negative, positive, negative, negative, positive, Negative (+) polarity, and is repeated. The data voltages applied to the pixel rows connected to the (k + 1) -th gate line GLk + 1 are negative, positive, negative, positive, positive, -), positive (+), negative (-) polarity, and is repeated. The data voltages applied to the pixel rows connected to the (k + 2) -th gate line GLk + 2 are positive, negative, positive, negative, +), Negative (-), positive (+) polarity, and is repeated. Accordingly, the polarities of the data voltages charged in the plurality of pixels P are inverted in the first to third pixel columns C1 to C3 in units of horizontal one pixel and vertical one pixel, and in the fourth pixel column C4 The polarities become equal. As described above, since the polarity of the data voltage is inverted in units of horizontal one pixel and vertical one pixel except for the fourth pixel lines C4, the flicker and the horizontal dimming can be reduced.

4A and 4B are plan views showing an array of pixels having a plurality of colors according to the present invention. 5 is a plan view of a liquid crystal panel in which pixels for displaying white are arranged in a fourth pixel column C4. 6 is a plan view of a liquid crystal panel in which pixels for displaying blue are arranged in a fourth pixel column C4. 7 is a plan view of a liquid crystal panel in which pixels for displaying red are arranged in a fourth pixel column C4.

As shown in Figs. 4A and 4B, the plurality of pixels P include pixels displaying red, green, blue, and white. The red pixel R, the green pixel G, the blue pixel B, and the white pixel W are arranged in a stripe form.

In this case, as shown in FIG. 4A, four pixels including a red pixel R, a green pixel G, a blue pixel B, and a white pixel W are gathered to form a unit pixel ). Further, as shown in Fig. 4B, three pixels selected from a red pixel R, a green pixel G, a blue pixel B and a white pixel W may be gathered to constitute a unit pixel .

For reference, as described above, when a data voltage of the same polarity is applied to a pixel column or a pixel row having a specific color, a dim in the horizontal or vertical direction is generated and the image quality is deteriorated. The present invention is applicable to a white pixel W having a relatively low visibility to a dim among the red pixel R, the green pixel G, the blue pixel B and the white pixel W, The pixel B and the red pixel R are arranged in the fourth pixel train C4 to minimize the dim.

5, the red pixels R are arranged in the first pixel columns C1, the green pixels G are arranged in the second pixel columns C2, The blue pixels B are arranged in the columns C3 and the white pixels W are arranged in the fourth pixel columns C4. Then, the polarities of the data voltages charged in the red pixels R, green pixels G, and blue pixels B are inverted in units of horizontal one pixel and vertical one pixel. The white pixels W are charged with data voltages of the same polarity in the vertical direction. Although the white pixels W are charged with the data voltages of the same polarity in the vertical direction, the white pixels W have lower visibility with respect to the dim pixels G than the green pixels G, Dim is not visible.

Hereinafter, an example in which pixels of different colors other than the white pixels W are arranged in the fourth pixel column C4 will be described.

6, the white pixels W are arranged in the first pixel columns C1, the red pixels R are arranged in the second pixel columns C2, Green pixels G are arranged in the third pixel rows C3 and blue pixels B are arranged in the fourth pixel rows C4. Then, the polarities of the data voltages charged in the red pixels R, the green pixels G, and the white pixels W are inverted in units of horizontal one pixel and vertical one pixel. The blue pixels B are charged with data voltages of the same polarity in the vertical direction. Although the blue pixels B are charged with the data voltages of the same polarity in the vertical direction, the blue pixels B have lower visibility with respect to the dim pixels G than the green pixels G, Dim is not visible.

Referring to FIG. 7, green pixels G are arranged in the first pixel columns C1, blue pixels B are arranged in the second pixel columns C2, C3 are arranged with white pixels W and the fourth pixel columns C4 with red pixels R are arranged. Then, the polarities of the data voltages charged in the blue pixels B, the green pixels G and the white pixels W are reversed in units of horizontal one pixel and vertical one pixel. And a data voltage of the same polarity is applied to the red pixels R in the vertical direction. Although the data voltages of the same polarity are applied to the red pixels R in the vertical direction, since the red pixels R have a lower visibility with respect to the dim pixels G than the green pixels G, Dim is not visible.

As described above, the present invention is applicable to the fourth pixel array C4 configured to apply the data voltage of the same polarity to the white pixels W having low dim visibility compared to the green pixels G, (B), and red pixels (R) are disposed, thereby minimizing dimming in the vertical direction. Particularly, visibility to the dim is known to be lowest in the white pixel W or blue pixel B, and it is best to arrange the white pixels W or the blue pixels B in the fourth pixel line C4 desirable.

The present invention is not limited to the arrangement in which the red pixel R, the green pixel G, the blue pixel B and the white pixel W are arranged in a stripe form. .

8 is a plan view showing an array of pixels having a plurality of colors according to another embodiment of the present invention. 9 is a plan view of a liquid crystal panel in which blue and red pixels are arranged in a fourth pixel column C4.

8 and 9, a plurality of pixels are arranged in such a manner that a red pixel R, a green pixel G, a blue pixel B, and a white pixel W are sequentially repeated in a horizontal direction. The red pixel R and the blue pixel B are arranged adjacent to each other in the vertical direction and the green pixel G and the white pixel W are arranged adjacent to each other in the vertical direction.

In this case, the present invention alternately arranges the blue pixels B and the red pixels R in the fourth pixel column C4. Then, a data voltage (Vth) charged in the red pixel R, the green pixel G, the blue pixel B and the white pixels W arranged in the first to third pixel columns C1 to C3 Is inverted in units of horizontal one pixel and vertical one pixel. The blue pixels B arranged in the fourth pixel columns C4 and the red pixels R are charged with data voltages of the same polarity in the vertical direction. The blue pixels B and the red pixels R are supplied with the data voltages of the same polarity in the vertical direction to the blue pixels B and the red pixels R, Since the visibility to the dim is low, the dim in the vertical direction is not visible.

As described above, according to the present invention, any one selected from the red pixel, the blue pixel, and the white pixel is arranged in the fourth pixel columns (c) configured to be charged with the data voltage of the same polarity, or the red pixel, At least two pixels are arranged. Thus, flicker and dimming in the horizontal and vertical directions can be minimized.

As described above, according to the present invention, the polarity of the data voltage is divided into positive (+), negative (-), positive (+), negative (-), negative Apply in positive (+), negative (-), and positive (+) order. Then, the polarity of the data voltage charged in the plurality of pixels P is inverted in units of one horizontal pixel and one vertical pixel, except for some columns, so that flicker and horizontal dimming can be reduced. In some of the columns, pixels of a color having a relatively low visibility of the dim can be arranged to minimize dim in the vertical direction.

Meanwhile, the present invention described above is merely an example, and the present invention can be applied to RGBW color arrangements having colors other than RGBW combinations or not described herein. That is, the present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes may be made without departing from the technical spirit of the present invention. Will be apparent to those of ordinary skill in the art.

C1: first pixel column C2: second pixel column
C3: third pixel column C4: fourth pixel column
2: liquid crystal panel 4: gate driver
6: Data driver 8: Timing controller

Claims (10)

A liquid crystal panel including a plurality of gate lines, a plurality of data lines, and a plurality of pixels arranged in a matrix form;
A gate driver for applying a gate signal to the plurality of gate lines;
A data driver for applying a data voltage to the plurality of data lines;
And a timing controller for controlling the gate driver and the data driver;
Wherein each column of the plurality of pixels is alternately connected in zigzag form to data lines disposed on both sides;
The data driver includes positive, negative, positive, negative, negative, positive and negative polarities of the data voltage for the first through eighth data lines sequentially arranged and repeated. Apply in positive (+), negative (-), positive (+) order;
Wherein the data voltages charged in the plurality of pixels are polarized in units of horizontal one pixel and vertical one pixel in the first through third pixel columns and have the same polarity in the fourth pixel column. The method according to claim 1,
The fourth pixel column
Wherein the second data line is disposed between the fourth and fifth data lines adjacent to each other and between the eighth and first data lines adjacent to each other. The method of claim 2,
The plurality of pixels including pixels displaying red, green, blue, and white;
Wherein the fourth pixel column displays any one color selected from red, blue, and white, or displays at least two colors selected from among red, blue, and white. The method of claim 3,
Wherein the first pixel column displays red, the second pixel column displays green, the third column displays blue, and the fourth column displays white. The method of claim 3,
Wherein the first column is arranged with pixels alternately displaying white and green, the second column alternatingly displaying pixels displaying red and blue, and the third column alternatingly displaying pixels displaying green and white And the fourth row is arranged such that pixels displaying blue and red are alternately arranged. A liquid crystal display device comprising: a plurality of gate lines; a plurality of gate lines; and a plurality of pixels arranged in a matrix, wherein each column of the plurality of pixels includes a liquid crystal display A method of driving an apparatus,
(+), Negative (+), negative (-), negative (-), and positive (-) polarities of the data voltages for the first to eighth data lines in which the data drivers are sequentially arranged and repeated +), Negative (-), and positive (+);
Wherein the data voltages charged in the plurality of pixels are polarized in units of horizontal one pixel and vertical one pixel in the first through third pixel columns and have the same polarity in the fourth pixel column. Way. The method of claim 6,
The fourth pixel column
Wherein the second data line is disposed between the fourth and fifth data lines adjacent to each other and between the eighth and first data lines adjacent to each other. The method of claim 7,
The plurality of pixels including pixels displaying red, green, blue, and white;
Wherein the fourth pixel column displays any one color selected from among red, blue, and white, or displays at least two colors selected from among red, blue, and white. The method of claim 8,
Wherein the first column displays red, the second column displays green, the third column displays blue, and the fourth column displays white. The liquid crystal display device according to claim 1, Way. The method of claim 8,
Wherein the first column is arranged with pixels alternately displaying white and green, the second column alternatingly displaying pixels displaying red and blue, and the third column alternatingly displaying pixels displaying green and white And the fourth row is arranged with the pixels displaying blue and red alternating with each other.

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