KR101982768B1 - Liquid crsytal display - Google Patents

Abstract

A liquid crystal display according to an exemplary embodiment of the present invention includes a first substrate and a second substrate facing each other, a first pixel electrode and a second pixel electrode disposed on the first substrate and including a plurality of branched electrodes, And a liquid crystal layer interposed between the first and second substrates and including liquid crystal molecules, wherein branch electrodes of the first pixel electrode and branch electrodes of the second pixel electrode are alternately arranged, and the first pixel Wherein the electrode has an enlarged portion disposed at a center portion of the first pixel electrode and the second pixel electrode and the gap between the extension portion and the branch electrode adjacent to the extension portion and the average gap between the plurality of branch electrodes is They are different.

Description

[0001] LIQUID CRYSTAL DISPLAY [0002]

The present invention relates to a liquid crystal display device.

2. Description of the Related Art A liquid crystal display device is one of the most widely used flat panel display devices and is composed of two display panels in which electric field generating electrodes such as a pixel electrode and a common electrode are formed and a liquid crystal layer interposed therebetween, To generate an electric field in the liquid crystal layer, thereby determining the orientation of the liquid crystal molecules in the liquid crystal layer and controlling the polarization of the incident light to display an image.

The liquid crystal display device further includes a switching element connected to each pixel electrode, and a plurality of signal lines such as a gate line and a data line for controlling the switching element to apply a voltage to the pixel electrode.

Such a liquid crystal display device receives an input image signal from an external graphic controller, and the input image signal contains luminance information of each pixel, and each luminance has a predetermined number. Each pixel receives a data voltage corresponding to the desired luminance information. The data voltages applied to the pixels appear as pixel voltages according to the difference of the relative voltages, and each pixel displays the brightness represented by the gray level of the video signal according to the pixel voltage. At this time, the pixel voltage range that can be used by the liquid crystal display device is determined according to the driving part.

On the other hand, in order to apply a data voltage to each pixel electrode of a liquid crystal display device, each pixel electrode is connected to a switching element, and as the number of switching elements increases because the light is not transmitted to the position where the switching element is formed, . In addition, a contact hole is formed to connect a plurality of signal transmission lines formed in different layers for transmitting signals to each pixel. In a region where the contact hole is formed, light is not transmitted, The aperture ratio of the device is reduced.

On the other hand, as the length of a signal line for transmitting a signal to each pixel electrode of a liquid crystal display device becomes longer, the resistance increases and a signal delay occurs, thereby deteriorating display quality.

On the other hand, the driving unit of the liquid crystal display device is directly mounted on a display panel in the form of a plurality of integrated circuit chips or mounted on a flexible circuit film or the like, and attached to a display panel. Such integrated circuit chips are high in the manufacturing cost of the liquid crystal display device. In particular, the greater the number of data lines to which data voltages are applied, the higher the cost of the driver of the liquid crystal display device.

Further, in order to improve the display quality of the liquid crystal display device, it is necessary to realize a liquid crystal display device having a high contrast ratio, an excellent viewing angle, and a fast response speed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to provide a liquid crystal display device capable of simultaneously ensuring a high contrast ratio and a wide viewing angle and capable of not only speeding up the response speed of liquid crystal molecules but also preventing signal delay, And to reduce the cost of the driving unit of the liquid crystal display device and at the same time to prevent the irregular behavior of the liquid crystal molecules.

A liquid crystal display according to an embodiment of the present invention includes a first substrate and a second substrate facing each other, a first pixel electrode and a second pixel electrode disposed on the first substrate and including a plurality of branched electrodes, And a liquid crystal layer interposed between the first and second substrates and including liquid crystal molecules, wherein branch electrodes of the first pixel electrode and branch electrodes of the second pixel electrode are alternately arranged, Wherein the pixel electrode has an extension disposed at a central portion of the first pixel electrode and the second pixel electrode, and the gap between the extension and the branch electrode adjacent to the extension and the average interval Are different.

The gap between the extension portion and the branch electrode adjacent to the extension portion may be narrower than the average gap between the plurality of branch electrodes.

The gap between the extension portion and the branch electrode adjacent to the extension portion may be gradually narrowed away from the central portion.

A gate line which is disposed on the first substrate and transmits a gate signal, a data line which is arranged on the first substrate, a power supply line which is arranged on the first substrate, a gate line which is connected to the gate line, And a second switching element connected to the gate line and the power line, wherein the first pixel electrode is connected to the first switching element, and the second pixel electrode is connected to the second switching element Can be connected.

When a gate-on signal is applied to the gate line, a data voltage is applied to the first pixel electrode through the data line, a first voltage is applied to the second pixel electrode through the power line, And the polarity of the first voltage may be different from each other.

The gap between the extension and the branch electrode adjacent to the extension may be wider than the average gap between the plurality of branch electrodes.

The gap between the extension and the branch electrode adjacent to the extension may gradually increase away from the central portion.

According to another aspect of the present invention, there is provided a liquid crystal display device including a first substrate and a second substrate facing each other, a first pixel electrode and a second pixel electrode disposed on the first substrate, And a liquid crystal layer interposed between the first and second substrates and including liquid crystal molecules, wherein branch electrodes of the first pixel electrode and the branch electrodes of the second pixel electrode are alternately arranged, Wherein the edges of the first pixel electrode and the second pixel electrode are spaced apart from each other, and the edge portions of the first pixel electrode and the second pixel electrode are spaced apart from the center of the first pixel electrode and the second pixel electrode, . ≪ / RTI >

According to another aspect of the present invention, there is provided a liquid crystal display device including a first substrate and a second substrate facing each other, a first pixel electrode and a second pixel electrode disposed on the first substrate, And a liquid crystal layer interposed between the first and second substrates and including liquid crystal molecules, wherein branch electrodes of the first pixel electrode and the branch electrodes of the second pixel electrode are alternately arranged, Wherein the edge of the first pixel electrode and the edge of the second pixel electrode are spaced apart from each other, and a spacing distance between edges of the first pixel electrode and the second pixel electrode is different from a distance between the first pixel electrode and the second pixel electrode, May be wider than the spacing between the branch electrodes.

According to another aspect of the present invention, there is provided a liquid crystal display device including a first substrate and a second substrate facing each other, a first pixel electrode and a second pixel electrode disposed on the first substrate, And a liquid crystal layer interposed between the first and second substrates and including liquid crystal molecules, wherein branch electrodes of the first pixel electrode and the branch electrodes of the second pixel electrode are alternately arranged, One pixel electrode includes an extension portion disposed at a center portion of the first pixel electrode and the second pixel electrode, and an additional branch portion extending from the extension portion.

The additional prongs may have an edge-surrounding shape of the extension.

The spacing between the extension and the additional branch may be different from the average spacing between the plurality of branch electrodes.

The spacing between the extension and the additional branch may be wider than the average spacing between the branch electrodes.

According to the embodiment of the present invention, a high contrast ratio and a wide viewing angle of a liquid crystal display can be secured at the same time, a response speed of liquid crystal molecules can be increased, a signal delay can be prevented, The cost of the driving unit of the liquid crystal display device can be reduced, and irregular behavior of the liquid crystal molecules can be prevented.

1 is a block diagram of a liquid crystal display device according to an embodiment of the present invention.
2 is an equivalent circuit diagram showing a pixel together with the structure of a liquid crystal display device according to an embodiment of the present invention.
3 is a schematic cross-sectional view of a liquid crystal display device according to an embodiment of the present invention.
4 is an equivalent circuit diagram of four pixels of a liquid crystal display according to an embodiment of the present invention.
5 is an equivalent circuit diagram of four pixels of the liquid crystal display device shown in Fig.
6 is a layout diagram showing the shape of a pixel of a liquid crystal display device according to an embodiment of the present invention.
7 is a layout diagram showing the shape of a pixel of a liquid crystal display device according to an embodiment of the present invention.
8 is a layout diagram showing the shape of a pixel of a liquid crystal display device according to an embodiment of the present invention.
9 is a layout diagram showing the shape of a pixel of a liquid crystal display device according to an embodiment of the present invention.
10 is a layout diagram showing the shape of a pixel of a liquid crystal display device according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

In the drawings, the thickness is enlarged to clearly represent the layers and regions. Like parts are designated with like reference numerals throughout the specification. It will be understood that when an element such as a layer, film, region, plate, or the like is referred to as being "on" another portion, it includes not only the element directly over another element, Conversely, when a part is "directly over" another part, it means that there is no other part in the middle.

Now, a liquid crystal display according to an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of a liquid crystal display device according to an embodiment of the present invention, and FIG. 2 is an equivalent circuit diagram illustrating a pixel together with the structure of a liquid crystal display device according to an embodiment of the present invention.

1, a liquid crystal display according to an exemplary embodiment of the present invention includes a liquid crystal panel assembly 300, a gate driver 400, a data driver 500, A gray voltage generator 800, and a signal controller 600.

Referring to FIG. 2, the liquid crystal panel assembly 300 includes lower and upper display panels 100 and 200 facing each other and a liquid crystal layer 3 interposed therebetween.

The liquid crystal capacitor Clc has the first pixel electrode PEa and the second pixel electrode PEb of the lower panel 100 as two terminals and the liquid crystal layer 3 between the first and second pixel electrodes PEa and PEb ) Function as a dielectric. The first pixel electrode PEa is connected to a first switching element (not shown), and the second pixel electrode PEb is connected to a second switching element (not shown). The first switching element and the second switching element are connected to corresponding gate lines (not shown) and data lines (not shown).

The liquid crystal layer 3 may have a dielectric anisotropy and the liquid crystal molecules of the liquid crystal layer 3 may be oriented so that their long axes are perpendicular to the surface of the two display plates in the absence of an electric field.

The first pixel electrode PEa and the second pixel electrode PEb may be formed on different layers or on the same layer. The first and second storage capacitors (not shown), which serve as auxiliary capacitors of the liquid crystal capacitors Clc, are connected to the first and second pixel electrodes PEa , And PEb, and an insulator.

On the other hand, in order to implement color display, each pixel PX uniquely displays one of primary colors (space division), or each pixel PX alternately displays a basic color (time division) So that the desired color is recognized by the spatial and temporal sum of these basic colors. Examples of basic colors include red, green, and blue. 2 shows an example of space division in which each pixel PX has a color filter CF representing one of the basic colors in an area of the upper panel 200 corresponding to the first and second pixel electrodes PEa and PEb Respectively. 2, the color filter CF may be placed above or below the first and second pixel electrodes PEa and PEb of the lower panel 100. [

The liquid crystal panel assembly 300 is provided with at least one polarizer (not shown).

1 and 2 together with FIG. 3, the operation of the liquid crystal display according to an embodiment of the present invention will be described.

3 is a schematic cross-sectional view of a liquid crystal display device according to an embodiment of the present invention.

2 and 3, when the voltages V _CH and V _CL are applied to the data lines or the power source lines connected to the respective pixels, the voltages V _CH and V _CL are applied to the corresponding pixels through the first and second switching elements turned on by the gate signal, (PX). That is, the first data voltage or the first voltage is applied to the first pixel electrode PEa through the first switching element, and the second data voltage or the second voltage . The difference between the voltages applied to the first pixel electrode PEa and the second pixel electrode PEb is a voltage corresponding to the luminance to be displayed by the pixel PX, The voltage applied to the electrode PEb may be opposite in polarity to the reference voltage Vref.

The difference between the two voltages having different polarities applied to the first pixel electrode PEa and the second pixel electrode PEb appears as a charging voltage of the liquid crystal capacitor Clc, that is, a pixel voltage. An electric field parallel to the surfaces of the display panels 100 and 200 is applied to the liquid crystal layer 3 between the first and second pixel electrodes PEa and PEb when a potential difference is generated at both ends of the liquid crystal capacitor Clc, . When the liquid crystal molecules 31 have a positive dielectric anisotropy, the liquid crystal molecules 31 are tilted such that their long axes are parallel to the direction of the electric field, and the degree of tilt depends on the magnitude of the pixel voltage. This liquid crystal layer 3 is referred to as an EOC (electrically-induced optical compensation) mode. The degree of polarization of the light passing through the liquid crystal layer 3 varies depending on the degree of tilting of the liquid crystal molecules 31. This change in polarization is caused by a change in transmittance of light by the polarizer, whereby the pixel PX displays a desired predetermined brightness.

By applying two voltages having different polarities to the reference voltage Vref to the pixel PX, the driving voltage can be increased, the response speed of the liquid crystal molecules can be increased, and the transmissivity of the liquid crystal display device can be increased. In addition, since the polarities of the two voltages applied to one pixel PX are opposite to each other, even when the inverted mode in the data driver 500 is column inversion or row inversion, the image deterioration due to the flicker is prevented .

Also, when the first and second switching elements are turned off in one pixel PX, since the voltages applied to the first and second pixel electrodes PEa and PEb are all lowered by the respective kickback voltages, There is almost no change in the charging voltage of the PX. Therefore, the display characteristics of the liquid crystal display device can be improved.

The arrangement of the signal lines and the pixels of the liquid crystal display device and the driving method thereof according to an embodiment of the present invention will be described with reference to FIG. 2 together with FIG. 4 is an equivalent circuit diagram of four pixels of a liquid crystal display according to an embodiment of the present invention.

2 and 4, the liquid crystal display according to the present embodiment includes a plurality of first pixels PX (i, j) and a plurality of second pixels PX (i + 1, j) and a plurality of second pixels PX (i, j) adjacent to each other in the pixel row direction and a plurality of second pixels PX (i, j) , j + 1), a plurality of fourth pixels PX (i + 1, j + 1), and a plurality of signal lines Gni, Gni + 1, Dj, Dj ', Dj + +1 ', Chigh, Clow). The signal lines Gni, Gni + 1, Dj, Dj ', Dj + 1, Dj + 1', Chj and Clow transfer the data voltage to the gate line Gn, which carries a gate signal And a plurality of pairs of power supply lines (Chigh, Clow) for transferring a predetermined constant voltage to the plurality of data lines Dj and Dj ', Dj + 1 and Dj + 1' The first gate line Gni and the second gate line Gni + 1 are divided into a first gate line Gni and a second gate line Gni + 1 arranged above and below in the pixel column direction, A gate-on signal or a gate-off signal is applied.

The first pixel PX (i, j) (i = 1, 2, ..., n, j = 1, 2, ..., m) includes a pair of gate lines Gni, Gni + A first data line Dj (j is an arbitrary integer) and a power supply line (Chigh, Clow), a first switching element Qaj and a second switching element Qbj, and a liquid crystal capacitor Clc connected thereto. The first switching device Qaj and the second switching device Qbj are three terminal devices such as a thin film transistor. The control terminal of the first switching device Qaj is connected to the first gate line Gni, Is input to the first data line Dj, and the output terminal is connected to the liquid crystal capacitor Clc. The control terminal of the second switching element Qbj is connected to the first gate line Gni and the input terminal thereof is connected to the first power supply line Chigh of the pair of power supply lines Chigh and Clow, Terminal is connected to the liquid crystal capacitor Clc.

The second pixel PX (i + 1, j) adjacent to the first pixel PX (i, j) in the pixel column direction is connected to the second gate line Gn of the pair of gate lines Gn, Gni + (Gni + 1), a second data line (Dj '), a power supply line (Chigh, Clow), a third switching device (Qcj) and a liquid crystal capacitor Clc connected thereto. The third switching element Qcj is a three terminal element such as a thin film transistor and the control terminal of the third switching element Qcj is connected to the second gate line Gni + 1 of the pair of gate lines Gni, Gni + An input terminal is connected to the second data line Dj ', and an output terminal is connected to one terminal of the liquid crystal capacitor Clc. The other terminal of the liquid crystal capacitor Clc of the second pixel PX (i + 1, j) is connected to the second switching element Qbj of the first pixel PX (i, j).

The third pixel PX (i, j + 1) adjacent to the first pixel PX (i, j) in the pixel row direction is connected to the first gate line GND of the pair of gate lines Gni, Gni + And a liquid crystal capacitor Clc connected to the third data line Dj + 1 and the third data line Dj + 1 and the power supply lines Chigh and Clow, the fourth switching device Qaj + 1 and the fifth switching device Qbj + . The fourth switching element Qaj + 1 and the fifth switching element Qbj + 1 are three-terminal elements such as a thin film transistor and the control terminal of the fourth switching element Qaj + 1 is connected to the first gate line Gni The input terminal is connected to the third data line Dj + 1, and the output terminal is connected to the liquid crystal capacitor Clc. The control terminal of the fifth switching element Qbj + 1 is connected to the first gate line Gni and the input terminal is connected to the second power line Clow of the pair of power lines Chigh and Clow , And the output terminal is connected to the liquid crystal capacitor Clc.

The fourth pixel PX (i + 1, j + 1) adjacent to the second pixel PX (i + 1, j) in the pixel row direction is connected to one of the pair of gate lines Gn and Gni + And a liquid crystal capacitor Clc connected to the second gate line Gni + 1, the fourth data line Dj + 1 ', the power source line Chigh and Clow, the sixth switching device Qcj + 1, . The sixth switching element Qcj + 1 is a three-terminal element such as a thin film transistor and the control terminal of the sixth switching element Qcj + 1 is connected to the second gate line GND of the pair of gate lines Gni and Gni + Gni + 1, an input terminal connected to the fourth data line Dj + 1 ', and an output terminal connected to one terminal of the liquid crystal capacitor Clc. The other terminal of the liquid crystal capacitor Clc of the fourth pixel PX (i + 1, j + 1) is connected to the second switching element Qbj + 1 of the third pixel PX (i, j + It is connected.

The liquid crystal display according to this embodiment is connected to the first pixel electrode PEa of the second pixel PX (i + 1, j), the first power line Chigh and the second power line Clow And the second pixel electrode PEb of the fourth pixel PX (i + 1, j + 1) and the first power line Chigh and the second pixel electrode PEb of the fourth pixel PX And two storage capacitors Cstb1 and Cstb2 having two terminals connected to two power lines Clow. (I + 1, j) and the fourth pixel PX (i + 1, j + 1) can be maintained by including the storage capacitors Cstb1 and Cstb2, It is possible to prevent the light leakage generated in the lower portion of the light guide plate.

Although not shown, the first power supply line (Chigh) of the plurality of power supply lines (Chigh, Clow) is connected to the same first voltage, and the second power supply line Clow are connected to each other and the same second voltage is applied. The polarities of the first voltage and the second voltage applied to the first power supply line Chigh and the second power supply line Clow are different from each other with respect to the reference voltage Vref. For example, when the reference voltage Vref is 7.5 V, the first voltage may be about 15 V or more, the second voltage may be about 0 V or less, and vice versa.

An example of a method of driving the liquid crystal display device according to the present embodiment will now be described in detail. When a gate-on voltage is applied to the gate line Gn, the first data voltage is applied to the first pixel PX (i, j) through the turned-on first switching device Qaj, The first voltage is applied to the first pixel PX (i, j) and the second pixel PX (i + 1, j) through the first switching element Qbj and the third switching element Qcj through the turned- 2 data voltage is applied to the second pixel PX (i + 1, j). The third data voltage is applied to the third pixel PX (i, j + 1) through the turned-on fourth switching element Qaj + 1, and the fifth switching element Qbj + The second voltage is applied to the third pixel PX (i, j + 1) and the fourth pixel PX (i + 1, j + 1), and the sixth switching element Qcj + And the fourth data voltage is applied to the fourth pixel PX (i + 1, j + 1).

That is, the first data voltage flowing through the first data line Dj is applied to the first pixel electrode PEa of the first pixel PX (i, j) through the first switching device Qaj, A first voltage that flows to the first power supply line (Chigh) is applied to the pixel electrode (PEb) through the second switching device (Qbj). The voltage difference between the first pixel electrode PEa and the second pixel electrode PEb to which the first data voltage and the first voltage are respectively applied is charged to the liquid crystal capacitor Clc of the first pixel PX (i, j) Voltage. The first data voltage and the first voltage applied to the first pixel electrode PEa and the second pixel electrode PEb of the first pixel PX (i, j) are applied to the first pixel PX (i, j) ) Is the voltage corresponding to the luminance to be displayed and the polarities are opposite to each other with respect to the reference voltage Vref.

A first voltage is applied to the first pixel electrode PEa of the second pixel PX (i + 1, j) through the second switching element Qbj to the first power line Chigh, The second data voltage flowing through the second data line Dj 'is applied to the two pixel electrodes PEb through the third switching device Qci. At this time, the first voltage and the second data voltage applied to the first pixel electrode PEa and the second pixel electrode PEb of the second pixel PX (i + 1, j) , j + 1) is a voltage corresponding to the luminance to be displayed, and the polarities are opposite to each other with respect to the reference voltage Vref. Therefore, the polarities of the first data voltage and the second data voltage may be equal to each other with respect to the reference voltage Vref.

The third data voltage (Vth) flowing through the third data line (Dj + 1) through the fourth switching element (Qaj + 1) is applied to the first pixel electrode PEa of the third pixel PX And a second voltage is applied to the second pixel electrode PEb through the fifth switching device Qbj + 1 to the second power line Clow. A voltage difference between the first pixel electrode PEa and the second pixel electrode PEb to which the third data voltage and the second voltage are applied is applied to the liquid crystal capacitor Clc of the third pixel PX (i, j + 1) The charging voltage of At this time, the third data voltage and the second voltage applied to the first pixel electrode PEa and the second pixel electrode PEb of the third pixel PX (i, j + 1) , j + 1) is a voltage corresponding to the luminance to be displayed, and the polarities are opposite to each other with respect to the reference voltage Vref.

A second voltage flowing to the second power line Clow through the fifth switching element Qbj + 1 is applied to the first pixel electrode PEa of the fourth pixel PX (i + 1, j + 1) And the fourth data voltage flowing through the fourth data line Dj + 1 'is applied to the second pixel electrode PEb through the sixth switching element Qcj + 1. At this time, the second voltage and the fourth data voltage applied to the first pixel electrode PEa and the second pixel electrode PEb of the fourth pixel PX (i + 1, j + 1) (i + 1, j + 1)) is a voltage corresponding to the luminance to be displayed, and polarities of the reference voltage Vref are opposite to each other.

In general, two pixels adjacent in the column direction are divided into two pixel electrodes PEa and PEb, and voltages having different polarities are applied using different switching elements to charge a voltage of a desired magnitude to the liquid crystal capacitor Clc Two pixels are connected to two gate lines to which gate-on voltages are applied at different times and two different data lines, or one data line to which a gate-on voltage is applied at the same time and four data lines Lt; / RTI > That is, when two adjacent pixels in the column direction are connected to different gate lines, the data voltages are applied to the first pixel electrode and the second pixel electrode of the two pixels through two data lines during different gate-on times , Since the gate-on signals are sequentially applied in this way, the driving speed is slow. Alternatively, when two pixels adjacent in the column direction are connected to a gate line to which the same gate-on voltage is applied, since two data voltages must be simultaneously applied to the first pixel electrode and the second pixel electrode of the two pixels, In this case, the number of data lines is increased and the cost of the driving unit of the liquid crystal display device is increased.

However, the first pixel PX (i) and the second pixel PX (i + 1), which are adjacent to each other in the pixel column direction of the liquid crystal display device according to the present embodiment, 1 are connected to the first gate line Gni and the second gate line Gni + 1, respectively, and the gate on / off voltage is applied through one gate line Gn. Therefore, the driving speed can be increased.

In addition, since one of the two pixel electrodes PEa and PEb of two adjacent pixels in the column direction is connected to one of the first power source line (Chigh) and the second power source line (Clow), not the data line, The cost of the driving unit of the liquid crystal display device can be reduced.

The two pixel electrodes connected to either the first power supply line Chigh or the second power supply line Clow receive the first voltage or the second voltage through one switching element Qbj and Qbj + , An additional switching element is not required, thereby increasing the aperture ratio of the liquid crystal display device.

As described above, two pixels adjacent to each other in the pixel column direction of the liquid crystal display device according to the present embodiment are connected to two gate lines, two data lines, and one power line, which are simultaneously connected to gate on / off voltage. Therefore, the driving speed is increased, the number of data lines is reduced, the cost of the driving unit of the liquid crystal display device can be reduced, and the aperture ratio of the liquid crystal display device is increased. According to the signal line and pixel arrangement of the liquid crystal display device according to the present embodiment, two power supply lines are added as compared with a general arrangement of signal lines and pixels. However, since a voltage of the same magnitude is always applied to each power supply line, It is only necessary to add a simple driving unit for applying a voltage, and therefore, the driving method is simple and the manufacturing cost is low.

The arrangement and driving method of the signal lines and the pixels of the liquid crystal display according to the above-described embodiments include all pixel structures including at least a first pixel electrode and a second pixel electrode which are formed on the same layer and are alternately arranged Can be applied.

An example of the pixel structure of the liquid crystal display device shown in Fig. 4 will now be described with reference to Fig. Fig. 5 shows an example of the pixel structure of the liquid crystal display device shown in Fig.

Referring to FIG. 4, the liquid crystal display according to the present embodiment includes a first pixel PX (i, j) and a second pixel PX (i + 1, j) PX (i, j + 1) and the fourth pixel PX (i, j) adjacent to each other in the pixel row direction with the first pixel PX (i, j) and the second pixel PX the data lines 171a1, 171b1, 171a2 and 171b2, the first power line 131a and the second power line 131b connected to the gate lines 121a and 121b, i + 1 and j + And a third power line 173. The first power line 131a and the second power line 131b may be formed of the same layer as the gate lines 121a and 121b and the third power line 173 may be formed of the data lines 171a1, 171b1, 171a2, and 171b2, As shown in FIG.

The first pixel PX (i, j) includes a first pixel electrode 191a and a second pixel electrode 191b connected to the first switching device Qaj and the second switching device Qbj. The first switching element and the second switching element are three-terminal elements such as a thin film transistor. Each of the control electrodes is a first gate electrode 124a and a second gate electrode 124b. Each input electrode is connected to a first source electrode 173a And a second source electrode 173b, and each of the output electrodes is a first drain electrode 175a and a second drain electrode 175b. The first source electrode 173a is connected to the data line 171a1 and the second source electrode 173b is connected to the first power line 131a. The second pixel PX (i + 1, j) includes a first pixel electrode 191a connected to the second switching device Qbj and a second pixel electrode 191b connected to the third switching device Qcj. The third switching element is also a three terminal element such as a thin film transistor, the control electrode is a third gate electrode 124c, the input electrode is a third source electrode 173c, and the output electrode is a third drain electrode 175c.

The first drain electrode 175a is connected to the first pixel electrode 191a of the first pixel PX (i, j) through the contact hole 185a and the second drain electrode 175b is connected to the contact hole 185b Is connected to the first pixel electrode 191a of the second pixel PX (i + 1, j) through the second pixel electrode 191b of the first pixel PX (i, j) The drain electrode 175c is connected to the second pixel electrode 191b of the second pixel PX (i + 1, j) through the contact hole 185c. The second source electrode 173b and the first power source line 131a are electrically connected to the second source electrode 173b exposed through the contact holes 186a and 186b and the connecting member 196 covering the first power source line 131a ), As shown in Fig. The connection member 196 may be formed of the same layer as the first pixel electrode 191a or the second pixel electrode 191b. The first power source line 131a and the third power source line 173 are electrically connected to the first power source line 131a and the third power source line 173 which are exposed through the contact holes 187a and 187b, (Not shown). The first pixel electrode 191a and the second pixel electrode 191b of each pixel are formed in the same layer and are alternately arranged.

The first power source line 131a and the second power source line 131b disposed below the second pixel PX (i + 1, j) are connected to the first pixel electrode 191a through the contact hole 188 And the storage capacitor 177 overlaps the storage conductive line 177. The storage conductive line 177 may be formed of the same layer as the data lines 171a1, 171b1, 171a2, and 171b2.

The first power source line 131a and the second power source line 131b disposed below the second pixel PX (i + 1, j) Can be prevented.

6, the shape of the first and second pixel electrodes PEa and PEb of one pixel PX of the liquid crystal panel assembly according to an embodiment of the present invention will be described. 6 is a layout diagram showing the shape of a pixel of a liquid crystal display device according to an embodiment of the present invention.

Referring to FIG. 6, the liquid crystal display according to the present embodiment includes a basic electrode 199. The overall shape of the basic electrode 199 is rectangular and the first pixel electrode PEa and the second pixel electrode PEb include a plurality of branches 91a and 91b and the branch of the first pixel electrode PEa And the branch portions 91b of the second pixel electrode PEb are engaged with each other. The first pixel electrode PEa and the second pixel electrode PEb are disposed outside the pixel region and include connecting portions 93a and 93b connecting the plurality of branch portions 91a and 91b to each other.

The branch portions 91a of the first pixel electrode PEa and the branch portions 91b of the second pixel electrode PEb extend diagonally from the connecting portions 93a and 93b in the lower left or upper left direction, It extends diagonally upward. An angle formed by the branch portions 91a and 91b with an arbitrary horizontal center line crossing the central portion of the pixel region may be approximately 45 degrees.

Referring to part A1 of FIG. 6, at the edge of the central portion of the base electrode 199, the branch portions 91a and 91b of the first pixel electrode PEb and the second pixel electrode PEb face each other, The portion has an enlarged portion 92. The gap between the extension portions 92 and the branch portions adjacent to the extension portion 92 may be narrower than the average gap between the branch portions of the first pixel electrode PEb and the second pixel electrode PEb interlocked with each other, May gradually become narrower away from the central portion of the pixel region. The edge of the extension 92 is not parallel to the branch adjacent to the extension 92 and the edge of the extension 92 forms an arbitrary horizontal center line across the center of the pixel area, Can be small.

As described above, the base electrode 199 of the liquid crystal display according to the present embodiment has the enlarged portion 92 at the central portion of the pixel region, and the gap between the extended portion 92 and the adjacent branch portions gradually changes. The formation of the extension portion 92 of this type allows the diffusion of the irregular behavior of the liquid crystal which starts from the edge of the pixel region and propagates into the pixel region, as compared with the case of having the extension portion 92 parallel to the adjacent branch portions. Can be prevented.

The intensity of the horizontal electric field applied to the liquid crystal is determined by the interval between the adjacent two sub-pixel electrodes PEa and PEb. In the liquid crystal display device according to the present embodiment, the gap between the extension portion 92 and the adjacent branch portions gradually The irregular behavior of the liquid crystal started at the edge of the pixel region becomes more difficult to propagate along the branch portions of the pixel electrode than in the case where a constant electric field is applied since the intensity of the electric field applied to the liquid crystal is changed. Therefore, it is possible to prevent the deterioration of the display quality, which starts from the edge of the pixel and diffuses in a certain direction.

In general, the irregular behavior of the liquid crystals starting from the edge region of the pixel is diffused to the central portion of the pixel through the gap between the two sub-pixel electrodes PEa and PEb arranged at regular intervals, resulting in deterioration of display quality. In the case of the liquid crystal display device according to the example, the base electrode 199 of the pixel electrode has the enlarged portion 92 at the center portion of the pixel region, and the gap between the extended portion 92 and the adjacent branch portions gradually changes, It is possible to prevent such irregular diffusion of the behavior of the liquid crystal.

Now, referring to FIG. 7, the first and second pixel electrodes PEa and PEb of one pixel PX of the liquid crystal panel assembly according to another embodiment of the present invention will be described. 7 is a layout diagram showing the shape of a pixel of a liquid crystal display device according to another embodiment of the present invention.

Referring to FIG. 7, the basic electrode 199 of the liquid crystal display device according to the present embodiment is similar to the basic electrode 199 of the liquid crystal display device according to the embodiment shown in FIG.

The overall shape of the basic electrode 199 is rectangular and the first pixel electrode PEa and the second pixel electrode PEb include a plurality of branches 91a and 91b and the branch of the first pixel electrode PEa And the branch portions 91b of the second pixel electrode PEb are engaged with each other. The first pixel electrode PEa and the second pixel electrode PEb are disposed outside the pixel region and include connecting portions 93a and 93b connecting the plurality of branch portions 91a and 91b to each other.

The branch portions 91a of the first pixel electrode PEa and the branch portions 91b of the second pixel electrode PEb extend diagonally from the connecting portions 93a and 93b in the lower left or upper left direction, It extends diagonally upward. An angle formed by the branch portions 91a and 91b with an arbitrary horizontal center line crossing the central portion of the pixel region may be approximately 45 degrees.

7, in the portion where the branches of the first pixel electrode PEb and the second pixel electrode PEb face each other at the edge of the central portion of the base electrode 199, . The interval between the extension portions 93 and the branch portions adjacent to the extension portion 93 may be wider than the average interval between the branch portions of the first pixel electrode PEb and the second pixel electrode PEb which are interlocked with each other, Can be gradually widened away from the central portion of the pixel region. The edge of the extension portion 93 is not parallel to the branch portion adjacent to the extension portion 93 but the edge portion of the extension portion 93 forms an arbitrary horizontal center line crossing the central portion of the pixel region at an angle of 45 degrees It can be big.

As described above, the base electrode 199 of the liquid crystal display according to the present embodiment has the enlarged portion 93 at the central portion of the pixel region, and the gap between the extended portion 93 and the adjacent branch portions gradually changes. The formation of the extension portion 93 of this type allows the diffusion of the irregular behavior of the liquid crystal which starts from the edge of the pixel region and can propagate into the pixel region compared with the case where the extension portion 93 has the extension portion 93 parallel to the adjacent branch portions. Can be prevented.

In general, the irregular behavior of the liquid crystals starting from the edge region of the pixel is diffused to the central portion of the pixel through the gap between the two sub-pixel electrodes PEa and PEb arranged at regular intervals, resulting in deterioration of display quality. In the case of the liquid crystal display device according to the example, the base electrode 199 of the pixel electrode has the enlarged portion 93 at the central portion of the pixel region, and the gap between the extended portion 93 and the adjacent branch portions gradually changes, It is possible to prevent such irregular diffusion of the behavior of the liquid crystal.

Referring to FIG. 8, the first and second pixel electrodes PEa and PEb of one pixel PX of the liquid crystal panel assembly according to another embodiment of the present invention will be described. 8 is a layout diagram showing the shape of a pixel of a liquid crystal display device according to another embodiment of the present invention.

Referring to FIG. 8, the basic electrode 199 of the liquid crystal display device according to the present embodiment is similar to the basic electrode 199 of the liquid crystal display device according to the embodiment shown in FIG. 6 and FIG.

The overall shape of the basic electrode 199 is rectangular and the first pixel electrode PEa and the second pixel electrode PEb include a plurality of branches 91a and 91b and the branch of the first pixel electrode PEa And the branch portions 91b of the second pixel electrode PEb are engaged with each other. The first pixel electrode PEa and the second pixel electrode PEb are disposed outside the pixel region and include connecting portions 93a and 93b connecting the plurality of branch portions 91a and 19b to each other.

The branch portions 91a of the first pixel electrode PEa and the branch portions 91b of the second pixel electrode PEb extend diagonally from the connecting portions 93a and 93b in the lower left or upper left direction, It extends diagonally upward. An angle formed by the branch portions 91a and 91b with an arbitrary horizontal center line crossing the central portion of the pixel region may be approximately 45 degrees.

Referring to A3 of FIG. 8, the connecting portions of the first pixel electrode PEa and the second pixel electrode PEb are spaced apart from each other and arranged at the center portion of the base electrode 199, The spacing portions where the connection portions of the pixel electrode PEa and the second pixel electrode PEb face each other are apart from the central portion of the pixel region. Since the spaced portion between the first pixel electrode PEa and the second pixel electrode PEb is disposed apart from the central portion of the pixel region, it is possible to start from the edge of the central portion of the pixel region, It is possible to prevent the diffusion of the irregular behavior of the liquid crystal molecules.

Next, referring to FIG. 9, the first and second pixel electrodes PEa and PEb of one pixel PX of the liquid crystal panel assembly according to another embodiment of the present invention will be described. 9 is a layout diagram showing the shape of a pixel of a liquid crystal display device according to another embodiment of the present invention.

Referring to FIG. 9, the basic electrode 199 of the liquid crystal display device according to the present embodiment is similar to the basic electrode 199 of the liquid crystal display device according to the embodiment shown in FIGS. 6 to 8.

The overall shape of the basic electrode 199 is rectangular and the first pixel electrode PEa and the second pixel electrode PEb include a plurality of branches 91a and 91b and the branch of the first pixel electrode PEa And the branch portions 91b of the second pixel electrode PEb are engaged with each other. The first pixel electrode PEa and the second pixel electrode PEb are disposed outside the pixel region and include connections 93a and 93b connecting the plurality of branch portions 91a and 91b to each other.

The branch portions 91a of the first pixel electrode PEa and the branch portions 91b of the second pixel electrode PEb extend diagonally from the connecting portions 93a and 93b in the lower left or upper left direction, It extends diagonally upward. An angle formed by the branch portions 91a and 91b with an arbitrary horizontal center line crossing the central portion of the pixel region may be approximately 45 degrees.

9, the interval between the first pixel electrode PEa and the second pixel electrode PEb, which are spaced apart from each other at a central portion of the base electrode 199, is wide. More specifically, the interval between the connection portions of the first pixel electrode PEa and the second pixel electrode PEb which are spaced apart from each other is equal to the distance between the branch portions 91a and 91b of the first pixel electrode PEa and the second pixel electrode PEb ). Since the spacing between the first pixel electrode PEa and the second pixel electrode PEb is very large at the central portion of the pixel region, the distance between the two sub-pixel electrodes PEa and PEb at the center of the pixel region The irregular behavior of the liquid crystal molecules generated in the pixel region can be prevented and diffusion of the liquid crystal molecules diffused in the pixel region starting from the central portion of the pixel region can be prevented.

10, the shapes of the first and second pixel electrodes PEa and PEb of one pixel PX of the liquid crystal panel assembly according to another embodiment of the present invention will be described. 10 is a layout diagram showing the shape of a pixel of a liquid crystal display device according to another embodiment of the present invention.

Referring to FIG. 10, the basic electrode 199 of the liquid crystal display device according to the present embodiment is similar to the basic electrode 199 of the liquid crystal display device according to the embodiment shown in FIGS.

The first pixel electrode PEa includes a plurality of first branch portions 91a and the second pixel electrode PEb includes a plurality of second branch portions 91b. And the first branch portion 91a of the first pixel electrode PEa and the second branch portion 91b of the second pixel electrode PEb are engaged with each other. The first pixel electrode PEa and the second pixel electrode PEb are disposed outside the pixel region and include connecting portions 93a and 93b connecting the plurality of branch portions 91a and 91b to each other.

The first branch portion 91a of the first pixel electrode PEa and the second branch portion 91b of the second pixel electrode PEb extend obliquely from the connecting portions 93a and 93b in the lower left or upper left direction, It extends diagonally in the lower right or upper right direction. An angle formed by the branch portions 91a and 91b with an arbitrary horizontal center line crossing the central portion of the pixel region may be approximately 45 degrees.

Referring to A5 of FIG. 10, at the edge of the central portion of the base electrode 199, the connection portions 93a and 93b of the first pixel electrode PEb and the second pixel electrode PEb face each other, 93a has an extension 94 and includes an additional edge 95 extending from the extension 94 and surrounding the edge of the extension 94. The edge 94 of the extension 93 is shown in Fig. Accordingly, the extension 94 is surrounded by the additional branch 95 extending from the extension 94, not directly adjacent to the second branch 91b of the adjacent second sub-pixel electrode PEb. The interval between the additional branch portions 95 of the extension portion 94 is different from the average interval between the branch portions 91a of the first pixel electrode PEa and the branch portions 91a of the second pixel electrode PEb Can be, and can be wider.

As such, by forming the extension portion 94 disposed at the center portion of the pixel region so as to surround the additional branch portion 95 extending therefrom, it is possible to prevent the irregular behavior of the liquid crystal from further expanding in the additional branch portion have. Accordingly, it is possible to prevent the diffusion of the irregular behavior of the liquid crystal molecules starting from the edge of the central portion of the pixel region and diffused inward of the pixel region.

As described above, according to the liquid crystal display device according to the embodiment of the present invention, a high contrast ratio and a wide viewing angle of a liquid crystal display device can be secured at the same time, a response speed of liquid crystal molecules can be increased, Therefore, the number of data lines can be reduced and the cost of the driving unit of the liquid crystal display can be reduced. By forming the shape of the center portion of the pixel electrode in various ways, it is possible to prevent the irregular behavior of the liquid crystal molecules that can start at the edge of the pixel region.

The arrangement and driving method of the signal lines and the pixels of the liquid crystal display according to the above-described embodiments include all pixel structures including at least a first pixel electrode and a second pixel electrode which are formed on the same layer and are alternately arranged Can be applied.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of the right.

Claims (9)

A first substrate and a second substrate facing each other,
A first pixel electrode and a second pixel electrode disposed on the first substrate and including a plurality of branched electrodes,
And a liquid crystal layer interposed between the first and second substrates and including liquid crystal molecules,
The branch electrode of the first pixel electrode and the branch electrode of the second pixel electrode are alternately arranged,
The first pixel electrode includes an extension disposed at a center portion of the first pixel electrode and the second pixel electrode,
An additional branch extending from the extension,
Wherein the additional prongs have a shape that surrounds the edge of the extension.
delete The method of claim 1,
Wherein an interval between the extension portion and the additional branch portion is different from an average interval between the plurality of branch electrodes.
4. The method of claim 3,
Wherein an interval between the extension portion and the additional branch portion is larger than an average interval between the branch electrodes.
5. The method of claim 4,
A gate line disposed on the first substrate and transmitting a gate signal,
A data line disposed on the first substrate,
A power supply line disposed on the first substrate,
A first switching element connected to the gate line and the data line, and
And a second switching element connected to the gate line and the power line,
Wherein the first pixel electrode is connected to the first switching element and the second pixel electrode is connected to the second switching element.
The method of claim 5,
When a gate-on signal is applied to the gate line,
A data voltage is applied to the first pixel electrode through the data line, a first voltage is applied to the second pixel electrode through the power line,
Wherein the polarity of the data voltage and the polarity of the first voltage are different from each other. The method of claim 1,
Wherein an interval between the extension portion and the additional branch portion is larger than an average interval between the branch electrodes.
8. The method of claim 7,
A gate line disposed on the first substrate and transmitting a gate signal,
A data line disposed on the first substrate,
A power supply line disposed on the first substrate,
A first switching element connected to the gate line and the data line, and
And a second switching element connected to the gate line and the power line,
Wherein the first pixel electrode is connected to the first switching element and the second pixel electrode is connected to the second switching element.
9. The method of claim 8,
When a gate-on signal is applied to the gate line,
A data voltage is applied to the first pixel electrode through the data line, a first voltage is applied to the second pixel electrode through the power line,
Wherein the polarity of the data voltage and the polarity of the first voltage are different from each other.

Images