KR100710161B1 - In-Plane Switching Mode Liquid Crystal Display Device - Google Patents

Abstract

The present invention relates to a transverse electric field type liquid crystal display device which can lower the output range of the data voltage applied to each data line even if the size of the pixel voltage applied to the liquid crystal is maintained by the conventional dot inversion scheme by changing the pixel structure. A plurality of gate lines and data lines vertically intersecting to define pixel regions, a plurality of thin film transistors alternately formed in upper and lower pixel regions of the respective gate lines, and each thin film transistor formed in the same linear pixel region, respectively A plurality of storage lines formed in a zigzag shape, a plurality of pixel electrodes connected to drains of the thin film transistors, and formed in each pixel area, spaced apart from the pixel electrodes by a predetermined distance, and connected to the storage lines in the pixel areas. A plurality of common electrodes Yirueojim to have its features.

In-Plane Switching (IPS), Dot Inversion, Line Inversion

Description

In-Plane Switching Mode Liquid Crystal Display Device

1 is a schematic cross-sectional view showing a general transverse electric field type liquid crystal display device

2 is a layout diagram illustrating a pixel structure of a conventional transverse electric field type liquid crystal display device;

3 is a cross-sectional view of a structure on the line AA ′ of FIG. 2.

4 is a structural cross-sectional view taken along the line BB ′ of FIG. 2.

5 is a simplified equivalent circuit diagram of the pixel structure of FIG.

6 is a timing diagram illustrating pixel voltages of respective gate lines of FIG. 2;

FIG. 7 is a diagram illustrating polarity variation of common voltages for each pixel of a conventional transverse electric field type liquid crystal display for each odd frame / even frame. FIG.

8 is a layout diagram illustrating a pixel structure of a transverse electric field type liquid crystal display device according to a first exemplary embodiment of the present invention.

FIG. 9 is a cross-sectional view of a structure on the line C ~ C 'of FIG.

FIG. 10 is a cross-sectional view of a structure on a line D ′ D ′ of FIG. 8.

11 is a layout diagram illustrating a pixel structure of a transverse electric field type liquid crystal display device according to a second exemplary embodiment of the present invention.

FIG. 12 is a cross-sectional view of a structure on the line E-E 'of FIG.

FIG. 13 is a structural cross-sectional view taken along the line FF ′ of FIG. 11;

14 is a layout diagram illustrating a pixel structure of a transverse electric field type liquid crystal display device according to a third exemplary embodiment of the present invention.

15 is a simplified equivalent circuit diagram of a transverse electric field type liquid crystal display device of the present invention.

16 is a timing diagram illustrating pixel voltages of gate lines of FIG. 15;

FIG. 17 is a view illustrating polarity change of a common voltage for each pixel of each transverse field type liquid crystal display device according to an odd frame / even frame.

18 is a timing diagram showing a gate driver TCP structure diagram and an input / output signal change of the transverse electric field type liquid crystal display device of the present invention.

* Description of symbols on the main parts of the drawings *

200: substrate 210: gate line

215: gate insulating film 220: data line

220c: drain electrode 225: protective film

230: pixel electrode 240: common electrode

250: storage line TFT: thin film transistor

The present invention relates to a liquid crystal display device, and more particularly, to a transverse electric field type liquid crystal display device.

As the information society develops, the demand for display devices is increasing in various forms, and in recent years, liquid crystal display devices (LCDs), plasma display panels (PDPs), electro luminescent displays (ELD), and vacuum fluorescent (VFD) Various flat panel display devices such as displays have been studied, and some of them are already used as display devices in various devices.

Among them, LCD is the most widely used as the substitute for CRT (Cathode Ray Tube) for the use of mobile image display device because of the excellent image quality, light weight, thinness, and low power consumption. In addition to the use of the present invention has been developed in various ways such as a television and a computer monitor for receiving and displaying broadcast signals.

In order to use such a liquid crystal display as a general screen display device in various parts, it is a matter of how high quality images such as high definition, high brightness and large area can be realized while maintaining the characteristics of light weight, thinness and low power consumption. Can be.

Currently, an active matrix LCD, in which a thin film transistor and pixel electrodes connected to the thin film transistor are arranged in a matrix manner, is attracting the most attention due to its excellent resolution and ability to implement video.

Meanwhile, referring to the structure of a general liquid crystal display, it can be seen that the LCD is divided into a liquid crystal panel for displaying an image and a driver for applying a driving signal to the liquid crystal panel. The liquid crystal panel includes first and second substrates bonded to each other with a predetermined space, and a liquid crystal layer injected between the first and second substrates.

Here, the first substrate (first substrate) has a plurality of gate lines arranged in one direction at a predetermined interval, a plurality of data lines arranged at regular intervals in a direction perpendicular to the gate lines, and the respective gates A plurality of pixel electrodes formed in a matrix form in each pixel region defined by crossing lines and data lines and a plurality of thin film transistors that are switched by signals of the gate lines to transfer signals of the data lines to each pixel electrode are formed. do.

In the second substrate (color filter array substrate), a black matrix layer for blocking light in portions other than the pixel region, an R, G, and B color filter layer for expressing color colors and a common color for implementing an image An electrode is formed.

The first and second substrates are bonded by a seal material having a predetermined space by a spacer and having a liquid crystal injection hole, and a liquid crystal is injected between the two substrates.

In this case, in the liquid crystal injection method, the liquid crystal is injected between the two substrates by osmotic pressure when the liquid crystal injection hole is immersed in the liquid crystal container by maintaining the vacuum state between the two substrates bonded by the reality. When the liquid crystal is injected as described above, the liquid crystal injection hole is sealed with a sealing material.

On the other hand, the driving principle of the general liquid crystal display device uses the optical anisotropy and polarization properties of the liquid crystal. Since the liquid crystal is thin and long in structure, the liquid crystal has directivity in the arrangement of molecules, and the direction of the arrangement of molecules can be controlled by artificially applying an electric field to the liquid crystal.

Therefore, when light is irradiated to the liquid crystal exhibiting polarization characteristics according to the applied state of the electric field, it is possible to arbitrarily adjust the molecular alignment direction of the liquid crystal, the amount of light passing according to the alignment state of the liquid crystal can be adjusted to represent the image information have.

As described above, a general liquid crystal display device in which a pixel electrode is formed on a first substrate and a common electrode is formed on a second substrate, and a liquid crystal is driven by an electric field applied up and down has a disadvantage in that viewing angle characteristics are not excellent. In order to overcome these disadvantages, an in-plane switching mode (IPS mode) liquid crystal display device for driving a liquid crystal by forming a horizontal electric field has been proposed.

An advantage of the transverse electric field type liquid crystal display device is that a wide viewing angle is possible. That is, when the liquid crystal display device is viewed from the front, the liquid crystal display device may be visible in the about 70 ° direction in the up / down / left / right directions. In addition, the manufacturing process is simpler than the TN mode liquid crystal display device generally used, and there is an advantage that the color shift according to the viewing angle is small.

Hereinafter, a conventional transverse electric field type liquid crystal display device will be described with reference to the accompanying drawings.

1 is a schematic cross-sectional view illustrating a general transverse electric field type liquid crystal display device.

As shown in FIG. 1, a general transverse electric field type liquid crystal display device includes a first substrate 1, a second substrate 2 opposing thereto, and a liquid crystal layer 3 filled therebetween.

Here, in the first substrate 1, a TFT (thin film transistor) array is formed in a matrix form on the substrate 10, and although not shown, the drain electrode and the pixel electrode 20 of the thin film transistor are connected to each other. The common electrode 30 is formed to be spaced apart from the pixel electrode 20 by a predetermined interval.

In addition, although not shown, a black matrix layer covering a region other than the pixel and a color filter layer implementing color colors are formed on the second substrate 2 facing the first substrate 1.

As described above, in the transverse electric field type liquid crystal display, both the pixel electrode 20 and the common electrode 30 exist on the same plane, and the liquid crystal is driven by a horizontal electric field formed between the two electrodes.

Meanwhile, a driving method of such a general transverse electric field type liquid crystal display device will be described.

A general liquid crystal display device including a transverse electric field type liquid crystal display device adopts a method in which an image signal is applied to a pixel corresponding to a line when each pixel is arranged in a matrix form and a scan signal is input to one gate line.

However, since the deterioration of characteristics occurs when the DC voltage is applied for a long time, the liquid crystal injected between the first and second substrates is driven by periodically changing the polarity of the applied voltage, and this method is called a polarity inversion method. .

The polarity inversion scheme includes frame inversion, line inversion, column inversion, and dot inversion.

In the frame inversion method, the polarity of the data voltage applied to the liquid crystal with respect to the common electrode voltage is applied in the same frame unit. That is, if a data voltage of positive polarity is applied to an even frame, a data voltage of negative polarity is applied to an odd frame. However, such a frame inversion driving method has an advantage of low current consumption during switching, but is sensitive to flicker due to asymmetry of transmittance of positive and negative polarity and is effective in crosstalk due to inter-data interference. It is very vulnerable to crosstalk.

In addition, the line inversion method is a polarity inversion driving method which is generally used for low resolution (VGA, SVGA), and the data voltage is applied so that the polarity of the data voltage applied to the liquid crystal with respect to the common electrode voltage varies in units of horizontal lines. do. That is, if a positive polarity is applied to an odd gate line and a negative polarity data voltage is applied to an odd gate line, a negative data voltage is applied to an odd gate line in a next frame. In addition, a data voltage of positive polarity is applied to the even-numbered gate line. In this line inversion method, since data voltages of opposite polarities between adjacent lines are applied, the luminance variation between lines decreases the flicker phenomenon compared to the frame inversion by spatial averaging, and voltages of opposite polarities are distributed in the vertical direction. Therefore, the coupling phenomenon between the data is canceled out so that the vertical crosstalk compared to the frame inversion is small. However, in the horizontal direction, voltages of the same polarity are distributed to generate horizontal crosstalk, and the number of switching repetitions is increased compared to frame inversion, thereby increasing current consumption.

The thermal inversion scheme is a driving method in which the polarities of the data voltages applied to the liquid crystal with respect to the common electrode voltage are the same in the vertical direction and opposite polarities in the horizontal direction. Compared with the frame reversal method, the flicker phenomenon is smaller than the frame reversal method and the horizontal crosstalk is smaller than the frame reversal method. However, since a data voltage of opposite polarity between adjacent lines must be applied in a vertical direction with respect to the common electrode voltage, a high voltage source driver IC must be used.

Finally, the dot inversion method is a polarity inversion driving method that realizes the best image quality at present, and is applied to high resolutions (XGA, SXGA, and UXGA), and the polarities of data voltages between adjacent pixels are reversed in all directions. Therefore, the flicker phenomenon can be minimized by the spatial averaging method, but it has the disadvantage of using a high voltage source driver and having a large current consumption.

Hereinafter, the conventional transverse electric field type liquid crystal display device which takes a dot inversion drive system is demonstrated.

2 is a layout diagram illustrating a pixel structure of a conventional transverse electric field type liquid crystal display device, FIG. 3 is a cross-sectional view of a structure on a line A-A 'of FIG. 2, and FIG. 4 is a cross-sectional view of a structure on a line B-B' of FIG. 2. .

As shown in FIG. 2, a conventional transverse electric field type liquid crystal display device includes a plurality of gate lines 40 and a plurality of data lines 50 formed in a horizontal direction and a vertical direction to define a pixel area, respectively, and the plurality of gates 40. ) A plurality of storage lines 60 formed at a predetermined interval apart from each other, a plurality of thin film transistors (TFTs) formed at intersections of the plurality of gate lines 40 and the plurality of data lines 50, A pixel electrode 20 connected to a drain of each of the plurality of thin film transistors TFT and formed in a pixel area in a '|' shape, and spaced apart from the pixel electrode 20 by a predetermined interval in the pixel area, and in a '∩' shape. It includes a common electrode 30 is formed.

Hereinafter, a method of forming a conventional transverse electric field type liquid crystal display device will be described with reference to FIGS. 3 to 4.

First, the metal is entirely deposited on the substrate 10 and selectively removed, thereby horizontally separating the gate line 40 protruding from the gate electrode and a storage line spaced apart from each other in the same direction as the gate line 40. 60).

Subsequently, a gate insulating layer 25 is formed on the entire surface of the substrate 10 including the gate line 40 and the storage line 60.

Subsequently, a semiconductor layer 70 is formed on the gate insulating layer 25 to correspond to the upper portion of the gate electrode.

Subsequently, a metal is entirely deposited on a predetermined region on the gate insulating layer 25 and selectively removed to form a data line 50 and a source / drain electrode 50c in a direction perpendicular to the gate line 40. In this case, a thin film transistor TFT including the gate electrode, the semiconductor layer 70, and the source / drain electrodes 50c is formed.

Subsequently, a passivation layer 35 is formed on the entire surface of the substrate 10 including the data line 50.

Subsequently, after the metal is entirely deposited on the passivation layer 35, the storage line is spaced apart from the pixel electrode 20 and the pixel electrode 20 connected to the drain electrode 50c of the thin film transistor TFT. The common electrode 30 connected to the 60 is formed.

As such, the common electrode 30 is in contact with the storage line 60 formed at the bottom thereof to receive power, and the pixel electrode 20 applies a data voltage by an on / off operation of the thin film transistor TFT. Receive. Here, the storage lines 60 are connected to one from the outside to apply the same common voltage Vcom signal, and the common voltage Vcom signal is in a DC state.

5 is an equivalent circuit diagram of FIG. 2, and FIG. 6 is a timing diagram illustrating pixel voltages of respective gate lines of FIG. 2.

As illustrated in FIG. 5, each pixel of a conventional transverse field type liquid crystal display device includes a storage capacitor Cst formed between the drain 50c of the thin film transistor TFT and the storage line 60 and the pixel electrode 20. It can be seen that the liquid crystal capacitor Clc is formed in parallel between the and the common electrode 30.

As shown in FIG. 6, the common voltage Vcom signal is maintained at a predetermined level even when the pixel, the gate line 40, or the frame is changed. At this time, the predetermined level state is an intermediate level between voltages of two levels applied to the data line. Although not shown, voltages applied to the data lines are different for each data line. Therefore, a positive polarity voltage is applied to the odd line with respect to the common voltage, and a negative polarity voltage is applied to the even line.

The voltages applied to the data lines are alternately inputted in one horizontal period in a (+) / (-) state with respect to the common voltage.

In addition, the pixel voltage applied to the liquid crystal of each pixel is inverted in one vertical period based on the common voltage Vcom.

The gate driver (not shown) applies a selection pulse through the gate line to drive the pixels corresponding to the same line, and the source driver (not shown) applies an image signal to the thin film transistor turned on through the signal line. When a data voltage is applied through the turned on thin film transistor, the liquid crystal capacitor Clc and the storage capacitor Cst connected between the drain and the storage line of the thin film transistor are charged while the thin film transistor is turned on. Is turned off to maintain charge charge until the thin film transistor is subsequently turned on.

Referring to FIG. 6, the pixel voltage decreases at a feed-through voltage ΔVp when the thin film transistor is turned off. The feed-through voltage ΔVp is a gate electrode and a source of the thin film transistor. This is caused by a parasitic capacitor Cgs or the like formed between the electrodes. Here, the pixel voltage Vp is induced by the parasitic capacitor Cgs of the thin film transistor at the falling edge of the scan signal applied to the gate line by the feed through voltage ΔVp and is induced in the liquid crystal.

FIG. 7 is a view illustrating polarity change of common voltage for each pixel of each conventional transverse electric field type liquid crystal display for each odd frame / even frame.

As illustrated in FIG. 7, a conventional transverse electric field type liquid crystal display device driven by a dot inversion method has different polarities (data voltages for common voltages) in adjacent pixels, and each time the frame is changed, the polarity of each pixel is inverted. do.

In this case, the polarities of the charges charged to the adjacent pixels are different from each other by (+), (-), ..., etc. of the polarities of the charges charged to each pixel, so that a high quality image can be obtained at high speed. Can be.

However, the conventional transverse electric field type liquid crystal display device has the following problems.

When driving the conventional transverse type liquid crystal display device by the dot inversion method, a common voltage signal is applied with a constant value of DC, and the data voltage applied to the data line has polarities (+) and (−) based on the common voltage signal. ) Alternately to apply voltage.

Since the pixel voltage applied to the liquid crystal has a polarity depending on the data voltage, a source driver having a high output voltage difference must be used in order to form a high voltage in the liquid crystal.

A source driver of a transverse field type liquid crystal display device which is generally applied at present has an output range using a VDD power supply of about 15V.

In this case, the pixel voltage actually applied to the liquid crystal is about (−) 6V to (+) 6V.

However, since the cost is higher for the source driver of the high output range, efforts have been made to reduce the cost by inducing low power consumption to lower the output range.

On the other hand, in the transverse type liquid crystal display, the liquid crystal is driven by a horizontal fringe field formed between the common electrode and the pixel electrode. Therefore, the gap between the pixel electrode and the common electrode is narrowed between the two electrodes for smooth driving of the liquid crystal. The induced horizontal field must be formed with a large value.

In order to narrow the gap between the pixel electrode and the common electrode, when forming a pattern of the pixel electrode and the common electrode, a single line-type pixel electrode and a common electrode are not formed, but fingers that intersect and intersect at a predetermined interval apart from each other. The pixel electrode and the common electrode pattern having a fin form are formed. In this case, the gap between the pixel electrode and the common electrode is narrowed, but the aperture ratio of the pixel is lowered.

Of course, although the ITO or the like of the transparent material is mainly used as the pattern of the pixel electrode or the common electrode, various shapes of patterns are formed in the pixel area, thereby preventing light from being evenly transmitted.

In this case, when the distance between the pixel electrode and the common electrode is increased for the high opening ratio, the horizontal electric field formed between the two electrodes becomes small, so that a data voltage of a high output range is required to obtain the required luminance.

The present invention has been made to solve the above problems, and by changing the pixel structure, the output range of the data voltage applied to each data line is reduced even if the magnitude of the pixel voltage applied to the liquid crystal is maintained in the conventional dot inversion method. It is an object of the present invention to provide a transverse electric field type liquid crystal display device.

In an aspect of the present invention, a transverse electric field type liquid crystal display device includes a plurality of gate lines and data lines vertically intersecting to define a pixel region, and a plurality of gate lines and data lines alternately formed in upper and lower pixel regions of each gate line. A thin film transistor, a plurality of storage lines each formed in a zigzag shape along each thin film transistor formed in the same linear pixel region, a plurality of pixel electrodes connected to a drain of each thin film transistor and formed in each pixel region; And a plurality of common electrodes spaced apart from the pixel electrode by a predetermined distance and connected to the storage line in each pixel area.

In the storage line, first and second common voltages having a high level and a low level are applied to each adjacent line.

In the storage line, when the frame is changed, first and second common voltages for inverting the state of the previous frame are applied to each line.

Preferably, the dummy lines are further configured to be spaced apart from each other at a top end and a bottom end where the gate lines are formed.

Preferably, a storage capacitor is formed by overlapping a drain electrode of the thin film transistor and the storage line.

The storage line may be formed at an edge of the pixel area and formed parallel to an adjacent gate line or data line.

The storage line is preferably formed by a pattern parallel to the gate line along the thin film transistor and connected to the front and rear pixel areas to cross the data line on one side.

Each common electrode may be formed to overlap a portion of the storage line.

The overlap between the common electrode and the storage line may be performed at a common electrode portion adjacent to one data line in the pixel area.

Preferably, the storage line is formed on the same layer as the gate line, and the storage line is formed of the same material as the gate line.

Preferably, the pixel electrode is formed at the center of the pixel area, and the common electrode is formed at the edge of the pixel area at a predetermined distance from the pixel area.

In addition, the horizontal field type liquid crystal display device of the present invention for achieving the above object is a plurality of vertically intersecting gate lines and data lines, a storage line formed between the first gate line and the second gate line, A first thin film transistor formed in connection with a second gate line and a first data line, a first storage capacitor and a first liquid crystal capacitor formed in parallel between a drain electrode of the first thin film transistor and the storage line, and the first thin film transistor A second thin film transistor formed at an intersection of the gate line and the second data line, a second storage capacitor and a second liquid crystal capacitor formed in parallel between the drain electrode of the second thin film transistor and the storage line. It has its features.

In the storage line, a common voltage signal having a different level may be applied to odd-numbered lines and even-numbered lines, respectively.

Each of the common voltage signals having different levels is preferably a high level first common voltage and a low level second common voltage.

In the storage line, when the frame is changed, first and second common voltages for inverting the state of the previous frame are applied to each line.

Preferably, the dummy lines are further configured to be spaced apart from each other by a predetermined interval in parallel with the plurality of gate lines.

Preferably, the gate line receives a pulse signal in one vertical period.

Preferably, the data line is applied with a voltage having a different level in one horizontal period.

Hereinafter, the transverse electric field type liquid crystal display of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 8 is a layout diagram illustrating a pixel structure of a transverse electric field type liquid crystal display device according to a first exemplary embodiment of the present invention, FIG. 9 is a cross-sectional view of the structure on the line C ′ of FIG. 8, and FIG. It is a structural cross section on the D 'line.

As illustrated in FIG. 8, the transverse electric field type liquid crystal display according to the present invention has a plurality of gate lines 210 and a plurality of data lines 220 which are formed in a horizontal direction and a vertical direction to define a pixel area, respectively, and gates of adjacent pixels. A plurality of thin film transistors TFT alternately formed up and down the line 210, a pixel electrode 230 formed in a pixel region by being connected to a drain of the thin film transistor TFT, and the pixel electrode 230. A common electrode 240 spaced apart from each other and spaced apart from each other, and a storage line 250 formed in a zigzag shape with respect to pixel areas formed on the same line along a portion where the plurality of thin film transistors TFTs are formed. It is done by

Here, a storage capacitor is formed by overlapping the drain electrode 220c of the thin film transistor TFT and the storage line 250.

In addition, the storage line is formed at the edge of the pixel area and is formed parallel to the adjacent gate line or data line.

That is, each of the storage lines is formed in a direction parallel to the gate line along the thin film transistor formed in the corresponding pixel region, and connected to and overlapped with the common electrode adjacent to the right data line in the same pixel region, and connected thereto. The storage line may be formed in a pattern parallel to the gate line along the thin film transistor formed in the next pixel area, so that each of the storage lines crosses one side of the data line and is connected to the front and rear pixel areas.

In this case, each of the common electrodes may be formed to overlap a part of the storage line, and a contact may be formed in a predetermined region of a portion where the common electrode overlaps with the storage line so that the voltage applied to the storage line is a common electrode. To be authorized.

That is, the transverse field type liquid crystal display according to the first exemplary embodiment of the present invention includes a thin film transistor formed by alternating up and down, and a storage line in which a continuous pattern of a '' 'pattern lying along the thin film transistor in the same linear pixel area is continuously connected. It is characterized by the formation.

Hereinafter, a method of forming a transverse electric field type liquid crystal display device according to a first embodiment of the present invention will be described in detail with reference to FIGS. 9 to 10.

First, the entire surface of the metal is deposited on the substrate 200 and selectively removed to form the storage line 250 by being spaced apart from the gate line 210 of FIG. 8 by a predetermined interval. In this case, the gate electrodes of the gate lines 210 are formed in different directions up and down with respect to adjacent pixel areas. In addition, the storage line 250 formed at this time is formed in a zigzag manner so as to overlap the portion where the drain electrode and the common electrode formed in a later process are spaced apart from the gate line 210 by a predetermined interval. do.

Subsequently, a gate insulating layer 215 is formed on the entire surface of the substrate 200 including the gate line 210 and the storage line 250.

Subsequently, a semiconductor layer 270 is formed on the gate insulating layer 215 to correspond to the gate electrode.

Subsequently, metal is entirely deposited on a predetermined region on the gate insulating layer 215 and selectively removed to form a data line 220 and a source / drain electrode 220c in a direction perpendicular to the gate line 210. In this case, a thin film transistor TFT including the gate electrode, the semiconductor layer 270, and the source / drain electrodes 220c is formed.

Subsequently, a passivation layer 225 is formed on the entire surface of the substrate 200 including the data line 220.

Subsequently, a metal is entirely deposited on the passivation layer 225 and selectively removed, and the pixel electrode 230 and the pixel electrode 230 connected to the drain electrode 220c of the TFT in each pixel area are predetermined. The common electrode 240 connected to the storage line 250 is spaced apart from each other.

In this case, a gate insulating film is interposed between the drain electrode 220c and the storage line 250 of the thin film transistor TFT to form a storage capacitor Cst (not shown).

The common electrode 240 and the storage line 250 are formed to have a contact in a predetermined region of the overlapped portion.

FIG. 11 is a layout diagram illustrating a pixel structure of a transverse electric field type liquid crystal display device according to a second exemplary embodiment of the present invention, FIG. 12 is a cross-sectional view of a structure on the line E-E 'of FIG. 11, and FIG. It is a structural cross section on the F 'line.

As illustrated in FIG. 11, in the transverse field type liquid crystal display according to the second exemplary embodiment of the present invention, a storage line overlaps a common electrode adjacent to a left data line in a pixel area, and is connected to form a thin film transistor in the pixel area. Except for the same as in the first embodiment, the same number is given.

In the transverse field type liquid crystal display of the second embodiment, as shown in FIG. 12, an overlapping portion of the common electrode and the storage line is formed at a portion adjacent to the left data line of the pixel region, and as shown in FIG. 13, along the thin film transistor of the pixel region. The formed storage line is connected to the next pixel area.

That is, the transverse electric field type liquid crystal display according to the second exemplary embodiment of the present invention has a thin film transistor formed by alternating up and down, and a storage in which a 'd' type inversion pattern lying in the same linear pixel area along the thin film transistor is continuously connected. Line is formed.

The embodiments described above show that two windows are formed between the common electrode and the pixel electrode formed in the pixel area.

However, the storage line overlaps the common electrode adjacent to one data line and is connected to the thin film transistor of the corresponding pixel region, and is continuously connected to the next pixel region by crossing the other data line of the same pixel region. The spirit of the present invention in that it is connected to form can be extended to the structure of 4 windows, 6 windows or more in the following embodiments.

14 is a layout diagram illustrating a pixel structure of a transverse electric field type liquid crystal display device according to a third exemplary embodiment of the present invention.

The transverse electric field type liquid crystal display device according to the third embodiment of the present invention is the same as the first embodiment except that four windows are formed between the pattern between the common electrode and the pixel electrode, and are therefore given the same number. .

As illustrated in FIG. 14, in the transverse field type liquid crystal display according to the third exemplary embodiment, the pixel electrode is connected to the drain electrode 220c to have a '∩' shape, and the common electrode is spaced apart from the pixel electrode 240 by a predetermined interval. 230 is formed. The storage line is formed in a direction parallel to the gate line along the portion where the thin film transistor of the pixel region is formed, overlaps with the common electrode adjacent to one data line, and is continuously connected to the portion where the thin film transistor of the next pixel region is formed. It is formed along the parallel to the gate line.

As described above, in the case of the third embodiment, the 'L'-shaped pattern, which is laid down, is formed in a continuous form in the pixel area on the same line.

Next, the signal application of the transverse electric field type liquid crystal display device having the above configuration will be described with reference to FIGS. 15 and 16.

FIG. 15 is a simplified equivalent circuit diagram of a transverse electric field type liquid crystal display device of the present invention, and FIG. 16 is a timing diagram showing pixel voltages of respective gate lines of FIG. 15.

As shown in FIG. 15, when the pixel structure of FIG. 8, 11, or 14 is represented by an equivalent circuit, each storage line may be illustrated as being located between adjacent gate lines.

That is, the pixel structure of the transverse field type liquid crystal display device according to the present invention includes a plurality of gate lines and a plurality of data lines that vertically intersect. And an nth storage line formed between the nth (n ≧ 1) gate line and the n + 1th gate line, a first thin film transistor connected to the nth + 1th gate line and the mth data line, A second thin film formed at an intersection of the first storage capacitor and the first liquid crystal capacitor formed in parallel between the drain electrode of the first thin film transistor and the nth storage line, and the nth gate line and the m + 1th data line And a second storage capacitor and a second liquid crystal capacitor formed in parallel between the transistor, the drain electrode of the second thin film transistor, and the storage line.

In this case, the odd-numbered storage lines are applied with the first common voltage (or the second common voltage) among the odd-numbered storage lines, and the even-numbered storage lines are provided with the second common voltage (or first) with the even-numbered storage lines. Common voltage). In this case, pixel voltages having the same polarity are applied to pixels connected to the same storage line.

In the transverse electric field type liquid crystal display of the present invention, a signal is applied to the liquid crystal panel side in a dot reversal method from a gate driver and a general source driver applying different levels of common voltage, respectively, to maintain fast signal response characteristics, and also to a storage line. As a result, the driving is performed by the line inversion method, so that the distortion of the electric field of the adjacent pixels is less affected. In particular, the electro-optical characteristics such as black luminance are good.

The storage line Storage n is the first common voltage Vcom in synchronization with a scan signal applied to a gate line corresponding to each storage line between odd-numbered lines and odd-numbered lines and even-numbered lines. (-)) The same common voltage is applied to the second common voltage Vcom (+). The applied first common voltage Vcom (−) and the second common voltage Vcom (+) are converted to the second common voltage Vcom (+) and the first common voltage Vcom (−) during frame conversion. Level translation.

The signal applied to the storage line Storage n is alternately inputted to the first and second common voltage signals Vcom (−) and Vcom (+) by a data voltage applied from a source driver (not shown). Since the liquid crystal capacitors Clc and the storage capacitors Cst, which are arranged in parallel in the lower and upper pixel regions in alternate pixel regions in the adjacent pixel regions, are disposed, the pixel voltages applied to the liquid crystals. The same value is applied to the vertical crossings in the adjacent pixel areas of the same storage line.

Accordingly, in the transverse electric field type liquid crystal display of the present invention, a common voltage signal Vcom (-) / Vcom (+) is applied to each storage line by a line inversion method, but dot inversion in which pixel voltages have different polarities for each pixel. Driven in a manner.

As shown in FIG. 15, if an equivalent circuit is shown such that the storage line Storage n shown in zigzag form in FIG. 8, 11, or 14 is parallel to each gate line Gn, the thin film transistor may be formed in relation to the gate line Gn. It can be seen that the TFTs are alternately arranged up and down, and the liquid crystal capacitor Clc and the storage capacitor Cst are formed in parallel between the drain electrode and the storage line Storage n of each thin film transistor TFT.

At this time, as shown in FIG. 15, when a data voltage having a positive polarity is applied to an arbitrary pixel, a first common voltage Vcom (−) is applied to a corresponding storage line, and a common electrode connected to the storage line. The first common voltage Vcom (−) is derived.

When a negative data voltage is applied to an arbitrary pixel, a second common voltage Vcom (+) is applied to a corresponding storage line, and a second common voltage Vcom is applied to a common electrode connected to the storage line. (-)) Is derived.

That is, the low-level first common voltage Vcom (n) is applied to the (n-1) (n> 1, n is a positive integer) th storage line (n-1) of the cell to which a positive data voltage is applied. The second common voltage Vcom (+) of the high level is applied to the n-th storage line of the cell to which the negative polarity data signal is applied.

Therefore, the voltage difference between the pixel electrode and the common electrode increases.

FIG. 17 is a diagram illustrating polarity change of a common voltage for each pixel of each transverse field type liquid crystal display device according to an odd frame / even frame.

As shown in FIG. 17, a conventional transverse electric field type liquid crystal display device driven by a dot inversion method has different polarities (data voltages for common voltages) in each adjacent pixel, and each time the frame is changed, the polarity of each pixel is inverted. do.

In this case, the polarities of the charges charged to the adjacent pixels are different from each other by (+), (-), ..., etc. of the polarities of the charges charged to each pixel, so that a high quality image can be obtained at high speed. have.

18 is a timing diagram showing a gate driver TCP structure diagram and a change in an input / output signal of the transverse electric field type liquid crystal display device of the present invention.

As shown in FIG. 18, the gate driver receives a gate shift clock (GSC) and gate start pulse (GSP) signals from a microcomputer (not shown), and outputs a scan signal Gout n applied to each gate line. In this case, an output pin for a gate line and a storage line is disposed on an output pin of the gate driver.

That is, the gate driver receives the GSP signal from the microcomputer, outputs the scan signal Gout n in synchronization with the signal of the GSC, and then scans the high level VGH scan signal Gout n by shifting the GSP signal. Output sequentially.

At this time, when the shift register value is set low by a gate output enable (GOE) signal, the scan signal Gout n is output at a low level VGL voltage.

The storage line signals Sout output from adjacent output line output pins output first and second common voltages (high level and low level) having different levels. Simultaneously with the output of the scan signal Gout, the level of the storage line signal Sout is changed and output.

Although not shown, the source driver required by the transverse field type liquid crystal display device of the present invention can be configured to have a lower output range of the data voltage applied to the data line than the conventional transverse field type liquid crystal display device.

That is, the pixel voltage applied to the liquid crystal is applied with a difference value between the data voltage and the common voltage, which is achieved by setting the common voltage value to two levels.

In detail, in the present invention, the difference between the high level data voltage and the low level common voltage (first common voltage) or the low level data voltage and the high level common voltage (second common voltage) is defined as the pixel voltage. In the related art, a margin is generated by a difference between a common voltage of a predetermined level and a first or second common voltage.

Thus, the source driver can implement low power consumption. Thus, the output of the source driver in which the pixel voltage for any (+) field may be lower than the pixel voltage for any (-) field, and the pixel voltage for the (-) field may be higher than the pixel voltage for the (+) field. Will have

In the transverse electric field type liquid crystal display of the present invention, the screen configuration is expressed in a horizontal line inverted visual form while using a conventional driver (source driver, gate driver) as it is. Therefore, the actual pixel voltage is output at the same time (+) field voltage and (-) field voltage can be implemented to implement a high-quality screen.

Data output is performed using a line memory for outputting data on zigzag positions. Further, compensation data for no signal use is formed at the top and bottom of the horizontal direction. That is, the dummy line is further configured to store the compensation data.

The above-described transverse electric field type liquid crystal display of the present invention has the following effects.

First, when a positive data voltage is applied to an arbitrary pixel, a first common voltage Vcom (−) is applied to the corresponding storage line and the common electrode, and a negative polarity is applied to an arbitrary pixel. When the data voltage is applied, the second common voltage Vcom (+) is applied to the storage line and the common electrode. That is, a low level first common voltage Vcom (−) is applied to a corresponding storage line Storage n of a cell to which a positive data voltage is applied, and a cell to which a negative data signal is applied. The second common voltage Vcom (+) of a high level is applied to the corresponding storage line Storage n of. Accordingly, the voltage difference between the pixel electrode and the common electrode increases, thereby reducing power consumption by reducing the variation range of the output voltage of the source driver.

Second, the pixel voltage value can be increased compared to the output voltage of the same source driver as compared with the related art, thereby enabling a high-aperture structure to increase the distance between the pixel electrode and the common electrode, and improve luminance.

Third, the output voltage of the source driver is simultaneously outputted with the opposite polarity in the same way as the general dot inversion method, whereas the pixel voltages of the same polarity are arranged in the actual gate line direction, so that electric fields of adjacent pixels are arranged. The distortion is less affected by the electro-optical properties, especially black brightness.

Fourth, since a source driver / gate driver of a general dot inversion driving method is used as it is, high quality with small vertical and horizontal crosstalks can be realized as compared with other inversion methods.

Claims (19)

A plurality of gate lines and data lines that vertically intersect to define pixel regions at each intersection region; A plurality of thin film transistors alternately formed in adjacent upper and lower pixel regions in the same line pixel areas adjacent to the gate lines; A plurality of storage lines each formed in a zigzag form to pass through each of the thin film transistors alternately formed in the upper and lower pixel regions of the same line pixel regions adjacent to the gate lines; A plurality of pixel electrodes connected to the drains of the thin film transistors and formed in each pixel area; And a plurality of common electrodes spaced apart from the pixel electrode by a predetermined distance and connected to the storage line in each pixel area. The method of claim 1, And each of the storage lines alternately apply first and second common voltages having a high level and a low level for each adjacent line. The method of claim 2, The storage line type horizontal liquid crystal display device, characterized in that the first and second common voltage for inverting the state of the previous frame is applied to each line when the frame is changed. The method of claim 1, And a dummy line further spaced apart from each other by a predetermined interval at an uppermost end and a lowermost end of the gate line. The method of claim 1, And a storage capacitor is formed by overlapping a drain electrode of the thin film transistor and the storage line. The method of claim 1, And the storage line is formed at an edge of the pixel area and is formed parallel to an adjacent gate line or data line. The method of claim 6, And wherein the storage line is formed by a pattern parallel to the gate line along the thin film transistor and intersecting with one side data line in the front and rear pixel areas. The method of claim 1, Each common electrode is formed to overlap a portion of the storage line, transverse field type liquid crystal display device. The method of claim 8, The overlap of the common electrode and the storage line is formed in the common electrode portion adjacent to one data line in the pixel area. The method of claim 1, And the storage line is formed on the same layer as the gate line. The method of claim 10, And the storage line is formed of the same material as the gate line. The method of claim 1, And the pixel electrode is formed at the center of the pixel area, and the common electrode is formed at the edge of the pixel area at a predetermined distance from the pixel area. In a transverse field type liquid crystal display device having a plurality of gate lines and data lines crossing each other vertically and defining a unit pixel area in each crossing area, A storage line formed between the adjacent first gate line and the second gate line; A first thin film transistor formed at an intersection of the second gate line and the first data line; A first storage capacitor and a first liquid crystal capacitor defined in parallel between the drain electrode of the first thin film transistor and the storage line; A second thin film transistor formed at an intersection of the first gate line and the second data line; And a second storage capacitor and a second liquid crystal capacitor defined in parallel between the drain electrode of the second thin film transistor and the storage line. The method of claim 13, The storage line is a transverse electric field type liquid crystal display device characterized in that the common voltage signal of different levels are applied to the odd line and the even line. The method of claim 14, The common voltage signal having different levels may be a first common voltage having a high level and a second common voltage having a low level. The method of claim 13, The storage line is a transverse electric field type liquid crystal display device characterized in that the first and second common voltage for inverting the state of the previous frame is applied to each line when the frame is changed. The method of claim 13, And a dummy line further disposed at upper and lower ends thereof in parallel with the plurality of gate lines and spaced apart from each other by a predetermined interval. The method of claim 13, And the gate line receives a pulse signal at one vertical period. The method of claim 13, The data line has a horizontal electric field type liquid crystal display, characterized in that the voltage is applied at a different level in one horizontal period.

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