KR100806895B1 - Liquid crystal display panel - Google Patents

Abstract

The present invention discloses a liquid crystal display panel capable of eliminating horizontal stripes generated during N × 1 dot inversion driving.

According to the present invention, the pixel electrode is formed in a predetermined region between the gate electrode line for transmitting a predetermined scan signal and the first and second data electrode lines for transmitting the first and second data voltages, respectively, and the first data electrode line. And at least one of a left coupling capacitance adjusted in conjunction with and a right coupling capacitance adjusted in association with the second data electrode line. In this case, when the switching element is disposed on the right side of the pixel electrode, that is, the second data electrode line, the pixel electrode line that generates a horizontal line pattern darker than the normal shifts to the left side, and the pixel electrode line that generates a horizontal line pattern brighter than the normal It is preferable to shift to the right to compensate the gradation level.

As a result, the occurrence of horizontal streaks can be eliminated by shifting the lines of which polarity is inverted to the right on the specific column of the liquid crystal display panel and arranging pixels of the lines of which the polarity is not inverted or by arranging the pixels to the left. .

LCD, panel, shift, shift, horizontal line, compensation

Description

Liquid crystal display panel {LIQUID CRYSTAL DISPLAY PANEL}

1A to 1B are views for explaining general dot inversion driving and 2x1 dot inversion driving.

2A to 2C are views for explaining generation of horizontal stripes in a general N × 1 dot inversion driving method.

3 is a diagram for describing a general pixel equivalent circuit.

4 is a view for explaining a liquid crystal display panel according to the present invention.

5A to 5C are diagrams for describing a pixel arrangement in 2 × 1 dot inversion driving according to an embodiment of the present invention.

FIG. 6 is a diagram for describing a pixel arrangement in 3 × 1 dot inversion driving according to an embodiment of the present invention.

FIG. 7 is a diagram for describing a liquid crystal display panel in which left and right widths of pixel electrodes are adjusted according to another exemplary embodiment.

FIG. 8 is a diagram for describing a liquid crystal display panel in which a width of a data electrode line is adjusted according to another exemplary embodiment.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display panel, and more particularly, to a liquid crystal display panel that is optimal for N × 1 dot inversion driving.

In general, when the electric field in the same direction is continuously applied due to the characteristics of the liquid crystal material, there is a problem in that the liquid crystal material is deteriorated. That is, if the polarity of the applied voltage of one pixel receives the positive signal voltage, then the next frame must receive the negative signal voltage.

For this reason, the Frame Inversion Method (FIM) that inverts the polarity in units of frames to invert the TFT-LCD, the Line Inversion Method (LIM) that inverts the polarity in lines, and columns Column Inversion Method (CIM) for inverting polarity in units, Dot Inversion Method (DIM) for inverting polarity in pixels, as shown in FIG. It is becoming.

These methods use a constant luminance mean value of each dot within a certain area because the human eye recognizes several dots at the same time.

These inversion driving methods are effective in a general display and do not cause inconvenience to the user. However, if the same patterns as the inversion driving method are displayed, the flickering problem still occurs. Here, flickering is an image quality characteristic that occurs when the transmittance difference between two polarities occurs in the process of periodically inverting the charging polarity of the liquid crystal to the positive (+) and the negative (-) polarities. This is a phenomenon caused by the fact that the RC delay occurs depending on the length of the panel because the voltage is distributed and the voltage is applied in one direction only to control the dots.

That is, flicker occurs in a horizontal line pattern in line inversion, a vertical line pattern in column inversion, and a dot pattern in dot inversion. This is because the pattern is recognized by the eyes as if the frame is reversed.

However, this problem is that the horizontal line pattern, vertical line pattern, dot pattern, etc. are all included in the category of the screen used by the user.

To solve this problem, as in FIGS. 2A to 2C, an N × 1 dot inversion driving method is used. This is a way to reduce flickering by making positive and negative voltages visible in patterns that fall within the category of the screen you are using.

In fact, 2 × 1 dot inversion driving (shown in FIG. 2A) in which flicker appears is a method of eliminating flicker in all the use screens because it is a screen that the user rarely uses. However, in the LCD module driven by the 2 × 1 dot inversion driving method, although the flicker characteristic shows a lot of improvement, there is a problem of a weak horizontal line phenomenon.

That is, due to the coupling capacitance between the Nth line and the N + 1th line, a change occurs in the pixel voltage of the Nth line when the polarity of the pixel voltage of the N + 1th line is changed. At this time, when the polarities of the Nth line and the N + 1th line are the same, the voltage change occurs in a direction in which the Nth line becomes darker than the original brightness, and when the polarities of the Nth line and the N + 1th line are opposite, The voltage change occurs in the direction where the Nth line becomes brighter than the original brightness.

Due to this cause, a horizontal line shape occurs for each line when displaying a screen having a halftone brightness.

That is, as illustrated in FIGS. 2A to 2C, a problem in which a line hatched out darker than a gray level to be generated when a normal voltage is applied appears dark, and other lines appear brighter, and the horizontal lines have an image quality. It causes serious problems that degrade the performance.

Accordingly, the present invention has been made in an effort to solve such a conventional problem, and an object of the present invention is to compensate for distortion of a pixel voltage caused by a lower line in a liquid crystal display device employing an N × 1 dot inversion driving method. A liquid crystal display panel for removing horizontal stripes is provided.

A liquid crystal display panel according to one feature for realizing the above object of the present invention is a liquid crystal display panel employing an N × 1 dot inversion driving method.

A plurality of gate electrode lines transferring a predetermined scan signal;

A first data electrode line vertically crossing the gate electrode line to transfer a first data voltage;

A second data electrode line formed perpendicular to the gate electrode line and parallel to the first data electrode line, and configured to transfer a second data voltage;                     

It is formed in a predetermined region between the gate electrode line, the first data electrode line and the second data electrode line, and interlocked with the left coupling capacitance or the second data electrode line adjusted in conjunction with the first data electrode line. And a pixel electrode having at least one of the adjusted right coupling capacitances.

At this time, when the switching element is disposed on the right side of the pixel electrode, that is, the second data electrode line,

Pixel electrode lines that generate horizontal stripes that are darker than normal are shifted to the left, and pixel electrode lines that generate horizontal stripes that are brighter than normal are shifted to the right to compensate the gray level.

In addition, the left and right widths of the pixel electrodes generating horizontal stripes darker than normal are smaller than the reference left and right widths, and adjust the left and right widths of the pixel electrodes connected to the switching element, and the left and right widths of the pixel electrodes generating bright horizontal stripes. The width is larger than the existing left and right widths, and it is preferable to compensate the gray level by adjusting the left and right widths of the pixel electrode connected to the switching element.

In addition, the width of the data electrode line connected to the pixel electrode generating darker horizontal stripes than the normal width is preferably smaller than the reference width, and the width of the data electrode line connected to the pixel electrode generating brighter horizontal stripes than the normal width. It is desirable to have a width larger than the reference width.

On the other hand, when the switching element is disposed on the left side of the pixel electrode, that is, the first data electrode line,                     

Pixel electrode lines that generate horizontal stripes that are darker than normal are shifted to the right, and pixel electrode lines that generate horizontal stripes that are brighter than normal are shifted to the left to compensate the gray level.

In addition, the left and right widths of the pixel electrodes generating horizontal stripes darker than normal are smaller than the reference left and right widths, and adjust the left and right widths of the pixel electrodes connected to the switching element, and the left and right widths of the pixel electrodes generating bright horizontal stripes. The width is larger than the existing left and right widths, and it is preferable to compensate the gray level by adjusting the left and right widths of the pixel electrode connected to the switching element.

In addition, the width of the data electrode line connected to the pixel electrode generating darker horizontal stripes than the normal width is preferably smaller than the reference width, and the width of the data electrode line connected to the pixel electrode generating brighter horizontal stripes than the normal width. It is desirable to have a width larger than the reference width.

According to such a liquid crystal display panel, a line in which polarity is inverted is shifted to the right to arrange pixels on a specific column of the liquid crystal display panel, and a line in which polarity is not inverted is arranged as it is or to the left, thereby generating horizontal streaks. Can be removed

In addition, the horizontal stripes can be eliminated by adjusting the horizontal widths of the pixel electrodes present in the line in which the polarity is inverted and the pixel electrodes present in the line in which the polarity is inverted on a specific column of the liquid crystal display panel.

In addition, by adjusting the widths of the data electrode lines present in the lines in which the polarities are reversed and the data electrode lines present in the lines in which the polarities are inverted on a specific column of the liquid crystal display panel, generation of horizontal stripes may be eliminated.

3 is a diagram for describing an equivalent circuit of a general liquid crystal display panel.

Referring to FIG. 3, a pixel formed in a predetermined region between a data line and a gate line is inverted in polarity, and a vertical coupling capacitance C _{pp ′} is generated between the upper and lower pixels, and a left and right coupling capacitance C _{d1 is formed} between the left and right pixels. , C _d2 ) occurs to generate a voltage change.

)가 하기 하는 수학식 1과 같이 발생한다.That is, in the upper pixel p, the voltage change due to the vertical coupling capacitance C _{pp '} between the two pixels p and p' while the polarity of the lower pixel p 'is inverted (

) Is generated as in Equation 1 below.

)가 발생한다. In addition, in the upper pixel p, the pixel voltage also changes due to the left coupling capacitance C _d1 and the right coupling capacitance C _{d2 which} exist between the left and right data lines D _k and D _{k + 1} . When the signal applied to the line is inverted, for example, if the inversion from the first data voltage (-Vd) to the second data voltage (+ Vd) changes in voltage (Equation 2)

) Occurs.

If the signal is inverted again in the next frame, for example, if the signal is inverted from the second data voltage (+ Vd) to the first data voltage (-Vd), the pixel voltage is returned to its original state, and such a voltage change is caused by the data line. Since the repetition period is repeated in the same manner as in, the arithmetic mean must be taken to produce a voltage change in consideration of the practical effect.

)는 하기 하는 수학식 3과 같다.That is, the voltage change applied to the actual brightness change (

) Is shown in Equation 3 below.

)는 하기 하는 수학식 4와 같이 정리할 수 있다.Therefore, the change in voltage at a particular pixel (

) Can be summarized as in Equation 4 below.

)과 우변의 3항(

)을 조절하여 보상할 수 있고, 특히, 본 발명의 일 실시예에서는 우변의 3번째 항을 조절하기 위해 라인별로 좌측 커플링 커패시턴스(C_d1)와 우측 커 플링 커패시턴스(C_d2)를 다르게 설계한다.According to the above equation (4), two terms of the right side causing the horizontal stripes (

) And the right side term 3

), And in particular, in an embodiment of the present invention, the left coupling capacitance (C _d1 ) and the right coupling capacitance (C _d2 ) are designed differently for each line to adjust the third term of the right side. .

Then, various embodiments of the present invention will be described with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention.

4 is a view for explaining an embodiment of a liquid crystal display panel according to the present invention. In particular, a liquid crystal display panel which is optimal for 2x1 dot inversion driving by shifting pixel electrodes will be described as an example.

In general, when 2x1 dot inversion driving is used, as shown in FIG. 2A, odd lines, that is, N, N + 2th lines, etc., appear brighter than normal brightness, and even lines, that is, N + 1, The cause of the horizontal stripes is that the N + 3th line, etc. appears darker than the normal brightness. Where N is a natural number greater than one.

이고, 유전율(ε)과 도전체의 두께(d)는 상수로 가정할 수 있으므로 도전체의 면적(A)을 조절하므로써, 좌우측 커플링 커패시턴스를 조절한다.With this in mind, in the exemplary embodiment of the present invention shown in FIG. 4, the right coupling capacitance C _d2 is shifted by shifting pixel electrodes of odd lines to a right length, preferably about 0.5 μm, from the even lines. Implement greater than the left coupling capacitance (C _d1 ). That is, capacitance

Since the dielectric constant epsilon and the thickness d of the conductor can be assumed to be constant, the left and right coupling capacitances are adjusted by adjusting the area A of the conductor.

When the liquid crystal display panel is implemented by shifting the pixel electrode lines as described above, the gray scale changes in the direction of brightening, thereby compensating the gray scale change by line by 2 × 1 dot inversion driving, thereby eliminating the occurrence of horizontal lines that appear relatively dark for each line. can do.

On the contrary, the pixel electrodes of the even lines are shifted to the left of the predetermined reference line and the pixel electrodes of the odd lines are shifted to the right of the reference line, and the difference between the left coupling capacitance and the right coupling capacitance according to the shift distance (C _d1 −) The liquid crystal display panel is designed such that C _d2 is close to the following equation (5).

In the above-described embodiment of the present invention, it is assumed that the voltage applied to the pixel is transmitted through the switching element TFT through the right data line of the pixel, but is transmitted through the switching element through the left data line of the pixel. In this case, the shift direction of the pixel electrode described above is reversed.

5A to 5C are diagrams for describing a pixel arrangement in 2 × 1 dot inversion driving according to an embodiment of the present invention. In particular, FIG. 5A illustrates an arrangement in which odd lines are shifted to the left in comparison to even lines. FIG. 5C is a diagram for explaining an arrangement in which the even lines are shifted to the right, and the odd lines are shifted to the right and the even lines are shifted to the left.

As shown in Figs. 5A to 5C, the polarity-inverted lines are shifted to the right to arrange the pixels, and the non-inverted lines to the left are arranged as they are or to the left. Can be removed                     

In the above, when implementing a liquid crystal display panel having a 2 × 1 dot inversion driving, odd lines (ie, N, N + 1 th lines) are inverted to pixel polarities of the previous column, and even lines (ie, N + 1, N + Since the third line) maintains the pixel polarity of the previous column, the arrangement structure of shifting the odd lines to the right with respect to the even lines has been described.

Similarly, an embodiment of the present invention may be similarly applied to a liquid crystal display panel having 3x1 dot inversion driving, 4x1 dot inversion driving, or the like.

FIG. 6 is a diagram for describing a pixel arrangement in 3 × 1 dot inversion driving according to an embodiment of the present invention.

Referring to FIG. 6, in the case of 3x1 dot inversion driving, the polarity is inverted in the 3n-th line, and in the 3n + 1 and 3n + 2th lines, the 3n-th line is shifted to the left because the polarity maintains the polarity of the previous pixel electrode. To form a liquid crystal display panel.

That is, by generating shifted lines on a specific column of the liquid crystal display panel to the right, the pixels are arranged, and lines having non-inverted polarities are arranged as they are or to the left, thereby eliminating the occurrence of horizontal stripes.

In the above, shifting the pixel electrode line to remove the horizontal streaks generated in the liquid crystal display panel having the N × 1 dot inversion driving has been described as an embodiment.

However, by adjusting the left and right width of the pixel electrode, the left and right coupling capacitance between the pixel electrode line and both data lines may be adjusted.

FIG. 7 is a view for explaining an equivalent circuit of a liquid crystal display panel according to another exemplary embodiment of the present invention. In particular, FIG. 7 illustrates a liquid crystal display panel in which left and right widths of pixel electrodes are adjusted.

FIG. 7 illustrates an example of a liquid crystal display panel that is optimal for driving a 2 × 1 dot inversion, and assumes that a voltage applied to a pixel is input via a switching element TFT through a right data line. .

Referring to FIG. 7, pixel electrodes included in a line in which polarity is inverted on a specific column are arranged to have left and right widths larger than the normal width, and pixel electrodes included in a line in which polarity is not inverted are left or right width intact or smaller than the normal width. Arrangement can eliminate the occurrence of horizontal stripes.

More specifically, since the switching element is disposed between the right data line of the pixel electrode and the pixel electrode, the right coupling capacitance can be increased by maintaining the left area of the pixel electrode and reducing the right area of the pixel electrode. The line is displayed close to the normal gradation level.

In another embodiment of the present invention, it is assumed that the data voltage applied to the pixel is transmitted through the right data line of the pixel (that is, the switching element TFT is connected to the right side of the pixel electrode). It can also be implemented to transmit via (i.e., the switching element (TFT) is connected to the left side of the pixel electrode).

In this case, of course, the right area of the pixel electrode is maintained as it is, and the occurrence of horizontal stripes can be reduced by reducing the left area of the pixel electrode.

In addition, although not shown, the generation of horizontal stripes may be reduced by adjusting the coupling capacitance of the line appearing brighter than the normal gray level. That is, in the liquid crystal display panel having the 2 * 1 dot inversion driving, the left and right widths of pixel electrodes belonging to a line brighter than normal gray scale are adjusted.

On the other hand, the coupling capacitance can be adjusted by adjusting the width of the data electrode line.

FIG. 8 is a diagram for describing an equivalent circuit of a liquid crystal display panel according to another exemplary embodiment of the present invention. In particular, the liquid crystal display panel in which the width of the data electrode line is adjusted will be described.

FIG. 8 illustrates, as an example, a liquid crystal display panel that is optimal for 2x1 dot inversion driving, and assumes that a voltage applied to a pixel is input via a switching element TFT through a right data line. .

Referring to FIG. 8, a data electrode line belonging to a line whose polarity is inverted on a specific column increases its width, and a data electrode line belonging to a line whose polarity is non-inverted is arranged intact or small so that the width of the horizontal line pattern is reduced. Occurrences can be eliminated.

More specifically, since the switching element is disposed between the right data line of the pixel electrode and the pixel electrode, the right coupling capacitance can be increased by making the width of the right data line smaller than the width of the normal data line, thereby making it darker than the normal gray scale. The corresponding line that appears is displayed close to the normal gradation level.

In another embodiment of the present invention, it is assumed that the voltage applied to the pixel is transmitted through the right data line of the pixel (that is, the switching element TFT is connected to the right side of the pixel electrode). It may be implemented to transmit via a line (that is, the switching element TFT is connected to the left side of the pixel electrode). In this case, the width of the left data electrode line rather than the right data electrode line is reduced.

In addition, although not shown, the generation of horizontal stripes may be reduced by adjusting the coupling capacitance of the line appearing brighter than the normal gray level. That is, in the liquid crystal display panel having the 2 * 1 dot inversion driving, the width of the data electrode line belonging to the line brighter than the normal gray scale is adjusted.

In the above, the liquid crystal display panel that is optimal for N * 1 dot inversion driving has been described. However, it is obvious to those skilled in the art that the present invention can be applied to the liquid crystal display device including the liquid crystal display panel.

Although the above has been described with reference to a preferred embodiment of the present invention, those skilled in the art will be able to variously modify and change the present invention without departing from the spirit and scope of the invention as set forth in the claims below. It will be appreciated.

As described above, according to the present invention, a line in which polarity is inverted is arranged on a specific column of a liquid crystal display panel adapted to the N × 1 dot inversion driving method to shift pixels to the right, and a line in which polarity is not inverted is left or By arranging the pixels to the left, the occurrence of horizontal stripes can be eliminated.                     

In addition, the horizontal stripes are adjusted by adjusting the left and right widths of the pixel electrode present in the line of which polarity is inverted and the pixel electrode present in the line of non-inverting polarity on a specific column of the liquid crystal display panel adapted to the N × 1 dot inversion driving method. The occurrence of can be eliminated.

In addition, the horizontal lines are adjusted by adjusting the widths of the data electrode lines present in the line in which the polarity is inverted and the data electrode lines present in the line in which the polarity is not inverted on a specific column of the liquid crystal display panel adapted to the N × 1 dot inversion driving method. The occurrence of fringes can be eliminated.

Claims (15)

In a liquid crystal display panel employing an N × 1 dot inversion driving method, A plurality of gate electrode lines transferring a predetermined scan signal; A plurality of first and second data electrode lines respectively perpendicular to the plurality of gate electrode lines and configured to transfer first and second data voltages; And A plurality of pixel electrodes formed between the plurality of gate electrode lines, the plurality of first data electrode lines, and the plurality of second data electrode lines to form a plurality of pixel electrode lines in a row direction; The plurality of pixel electrode lines include a first pixel line of which polarity is inverted and a second pixel line of which polarity is not inverted among the plurality of pixel electrode lines. The first and second pixel lines, A method of shifting the second pixel electrode line to the left based on the first pixel electrode line, a method of shifting the first pixel electrode line to the right based on the second pixel electrode line, and a reference to the first reference line And the first pixel electrode line is shifted to the right, and the second pixel electrode line is shifted to the left. In a liquid crystal display panel employing an N × 1 dot inversion driving method, A plurality of gate electrode lines transferring a predetermined scan signal; A plurality of first and second data electrode lines respectively perpendicular to the plurality of gate electrode lines and configured to transfer first and second data voltages; And A plurality of pixel electrodes formed between the plurality of gate electrode lines, the plurality of first data electrode lines, and the plurality of second data electrode lines to form a plurality of pixel electrode lines in a row direction; The plurality of pixel electrode lines include a first pixel line of which polarity is inverted and a second pixel line of which polarity is not inverted among the plurality of pixel electrode lines. The first and second pixel lines, A method of shifting the second pixel electrode line to the right based on the first pixel electrode line, a method of shifting the first pixel electrode line to the left based on the second pixel electrode line, and a reference to the first reference line And the first pixel electrode line is shifted to the left, and the second pixel electrode line is shifted to the right. The method according to claim 1 or 2, A first end is connected to the second data electrode line, a second end is connected to the gate electrode line, and is turned on / off according to the scan signal to transfer the second data voltage to the pixel electrode through a third end. A liquid crystal display panel further comprising a switching element to output. The method according to claim 1 or 2, A first end is connected to the first data electrode line, a second end is connected to the gate electrode line, and is turned on / off according to the scan signal to transfer the first data voltage to the pixel electrode through a third end. A liquid crystal display panel further comprising a switching element to output. In a liquid crystal display panel employing an N × 1 dot inversion driving method, A plurality of gate electrode lines transferring a predetermined scan signal; A plurality of first and second data electrode lines respectively perpendicular to the plurality of gate electrode lines and configured to transfer first and second data voltages; A first end is connected to the second data electrode line, a second end is connected to the gate electrode line, and is turned on / off according to the scan signal to transfer the second data voltage to the pixel electrode through a third end. An output switching element; And A plurality of pixel electrodes formed between the plurality of gate electrode lines, the plurality of first data electrode lines, and the plurality of second data electrode lines, Among the plurality of pixel electrodes, The first pixel electrode of which polarity is inverted is disposed to be spaced apart from the switching element by a first length, and has a first width to the left and right, and the second pixel electrode of which the polarity is not reversed to the first pixel electrode. The liquid crystal display panel, characterized in that formed differently. The method of claim 5, The second pixel electrode, And the switching element is disposed farther from the first length, and the length of the left and right widths is shorter than the second length. The method of claim 5, The second pixel electrode, And the switching element is disposed closer than the first length, and the length of the left and right widths is wider than the second width. In a liquid crystal display panel employing an N × 1 dot inversion driving method, A plurality of gate electrode lines transferring a predetermined scan signal; A plurality of first and second data electrode lines respectively perpendicular to the plurality of gate electrode lines and configured to transfer first and second data voltages; A first end is connected to the second data electrode line, a second end is connected to the gate electrode line, and is turned on / off according to the scan signal to transfer the second data voltage to the pixel electrode through a third end. An output switching element; And A plurality of pixel electrodes formed between the plurality of gate electrode lines, the plurality of first data electrode lines, and the plurality of second data electrode lines, Among the plurality of first and second data electrode lines, The widths of the first and second data electrode lines corresponding to pixel electrodes whose polarities are not inverted are formed to have a first length, The width of the first and second data electrode lines corresponding to the pixel electrodes whose polarities are inverted is formed differently from the first length. The method of claim 8, The length of the width of the first and second data electrode lines corresponding to the pixel electrodes of which the polarity is inverted is shorter than the first length. The method of claim 8, The length of the width of the first and second data electrode lines corresponding to the pixel electrodes of which the polarity is inverted is longer than the first length. delete delete delete delete delete

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