KR20170129078A - Liquid crystal display and manufacturing method thereof - Google Patents

Abstract

A liquid crystal display device and a method of manufacturing the same are provided. The liquid crystal display according to an embodiment of the present invention includes a first substrate, a second substrate facing the first substrate, a liquid crystal layer interposed between the first substrate and the second substrate and including liquid crystal molecules, a first electrode disposed on the first substrate, an insulating film disposed on the first electrode, a second electrode disposed on the insulating film, and a third electrode located on the second substrate. The second electrode has a structure including a plurality of branch parts and slits between adjacent branch parts. The widths of the slits are two times to five times larger than the widths of the branch parts. Response speed can be improved.

Description

TECHNICAL FIELD [0001] The present invention relates to a liquid crystal display (LCD)

The present invention relates to a liquid crystal display device and a manufacturing method thereof.

The liquid crystal display device is one of the most widely used flat panel display devices and is composed of two display panels having an electric field generating electrode such as a pixel electrode and a common electrode and a liquid crystal layer interposed therebetween.

A voltage is applied to the electric field generating electrode 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.

Of these liquid crystal display devices, a vertically aligned mode liquid crystal display device in which the long axes of liquid crystal molecules are arranged perpendicular to the display panel in the absence of an electric field has a large contrast ratio and a wide viewing angle .

In particular, among the liquid crystal display devices of the vertical alignment type, an electrode having a fine slit structure may be formed on a lower display panel, and a bar-shaped electrode may be formed on an upper display panel to apply a voltage to each electrode. However, as the width of the fine slit is designed to be small, the distortion of the field is large, so that the degree of the liquid crystal lie is different in the portion where the electrode exists, the edge portion of the electrode and the portion where the electrode does not exist, A phenomenon such as a drop in the temperature is caused.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a liquid crystal display device with reduced distortion of an electric field and improved response speed and a method of manufacturing the same.

A liquid crystal display device according to an embodiment of the present invention includes a first substrate, a second substrate facing the first substrate, a liquid crystal layer interposed between the first substrate and the second substrate, A first electrode located on the first substrate, an insulating film located on the first electrode, a second electrode positioned on the insulating film, and a third electrode positioned on the second substrate, And a slit between the branch portions and the adjacent branch portions, wherein the width of the slit is at least two times and not more than five times the width of the branch portions.

And an alignment layer disposed on at least one of the second electrode and the third electrode.

At least one of the liquid crystal layer and the alignment layer may include an alignment assistant.

The first electrode and the third electrode may be in the form of a channel.

Wherein when a voltage applied to the first electrode is a first voltage, a voltage applied to the second electrode is a second voltage, and a voltage applied to the third electrode is a third voltage, At least one of the liquid crystal layer and the alignment layer may be exposed in a state in which the first voltage is sequentially applied to the second electrode so that the first voltage has the same value as the second voltage.

The first voltage may be higher than or at least equal to the second voltage so that the field in the liquid crystal layer may be driven in a planarized state.

The width of the slit may be greater than the height of the cell gap of the liquid crystal layer.

The portion of the liquid crystal layer corresponding to the branch of the second electrode is referred to as a first region and the portion of the liquid crystal layer corresponding to the slit of the second electrode is referred to as a second region, The orientation directions of the liquid crystal molecules in the second region may be different from each other.

Wherein when a voltage applied to the first electrode is a first voltage, a voltage applied to the second electrode is a second voltage, and a voltage applied to the third electrode is a third voltage, At least one of the liquid crystal layer and the alignment layer may be exposed in a state in which voltages are applied with different values.

A gate line disposed on the first substrate, a data line crossing the gate line, a first thin film transistor and a second thin film transistor connected to the gate line and the data line, A third thin film transistor connected to the second thin film transistor, and a reference voltage line connected to the third thin film transistor, wherein the first electrode is connected to the first thin film transistor, And may be connected to the second thin film transistor.

The first electrode and the second electrode may be electrically connected.

The second electrode may include a cross-shaped stem including a transverse stem and an intersecting longitudinal stem, and the plurality of branches extending from the cross-shaped stem.

The second electrode may include a plurality of regions from which the plurality of branch portions extend from the cruciform stem portion in different directions.

The liquid crystal molecules located in the liquid crystal layer portion corresponding to the branch portion of the second electrode may be inclined along the extending direction of the branch portions.

Another method of manufacturing a liquid crystal display device according to another embodiment of the present invention includes the steps of forming a first electrode on a first substrate, forming an insulating film on the first electrode, forming a second electrode on the insulating film, Forming a third electrode on a second substrate facing the first substrate, forming an orientation film on at least one of the second electrode and the third electrode, attaching the first substrate and the second substrate, Forming a liquid crystal layer interposed between the first substrate and the second substrate and including liquid crystal molecules, applying different voltages to the first electrode and the second electrode, Applying a voltage so that the applied voltage is sequentially equal to the voltage applied to the second electrode, and applying a voltage applied to the first electrode to a voltage applied to the second electrode Wherein the second electrode is formed in a structure including a plurality of branch portions and slits between adjacent branch portions, at least one of the liquid crystal layer and the alignment layer And an orientation aid.

The voltage applied to the first electrode and the voltage applied to the third electrode may be the same in the step of applying different voltages to the first electrode and the second electrode.

The first electrode and the third electrode may be formed into a channel shape.

The width of the slit may be greater than the height of the cell gap of the liquid crystal layer.

The width of the slit may be two or more and five or less times the width of the branch portion.

The width of the branch portion may be formed to be twice or more than the width of the slit.

According to another aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device, comprising: forming a first electrode on a first substrate; forming an insulating film on the first electrode; forming a second electrode on the insulating film; Forming a third electrode on a second substrate facing the first substrate, forming an orientation film on at least one of the second electrode and the third electrode, attaching the first substrate and the second substrate together Forming a liquid crystal layer interposed between the first substrate and the second substrate and including liquid crystal molecules, applying a different voltage to the first electrode and the second electrode, And irradiating the liquid crystal layer with light in a state where different voltages are applied to the second electrode, wherein the second electrode includes a plurality of branches and a plurality of slits Is formed from a structure including, a liquid crystal layer and at least one of the alignment layer comprises an alignment aid.

The voltage applied to the first electrode and the voltage applied to the third electrode may be the same in the step of applying different voltages to the first electrode and the second electrode.

Wherein the step of irradiating light to the liquid crystal layer in a state where different voltages are applied to the first electrode and the second electrode are referred to as a first region and the liquid crystal layer portion corresponding to the branch portion of the second electrode is referred to as a first region, And a portion of the liquid crystal layer corresponding to the slit of the second electrode is referred to as a second region, light is irradiated to the liquid crystal layer in a state in which the liquid crystal molecules of the first region and the liquid crystal molecules of the second region have different alignment directions can do.

The first electrode and the third electrode may be formed into a channel shape.

The width of the slit may be greater than the height of the cell gap of the liquid crystal layer. Another liquid crystal display device according to another embodiment of the present invention includes a first substrate, a second substrate facing the first substrate, a liquid crystal layer interposed between the first substrate and the second substrate, A first electrode positioned on the first substrate, an insulating film positioned on the first electrode, a second electrode positioned on the insulating film, and a third electrode positioned on the second substrate, And the width of the branch portion is two times or more and five times or less than the width of the slit.

As described above, according to the embodiment of the present invention, the width of the branch portion of the electrode is formed to be sufficiently larger than the width of the slit, and distortion of the electric field can be reduced and the response speed can be improved by forming the pretilt.

1 is a layout diagram showing a liquid crystal display device according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along line II-II 'of FIG. 1, and FIG. 3 is a cross-sectional view taken along a line III-III' of FIG.
4 is a schematic cross-sectional view showing the electric field direction in the field exposure in the embodiment of FIG.
5 to 7 are cross-sectional views illustrating a method of forming a pre-scan square for manufacturing a liquid crystal display device according to an embodiment of the present invention.
8 is a schematic cross-sectional view showing the direction of an electric field at the time of driving the liquid crystal display device manufactured according to the embodiment of Figs. 4 to 7. Fig.
9 is an equivalent circuit diagram of one pixel of the liquid crystal display device shown in FIG.
10 is a waveform diagram of a signal applied to a pixel of the liquid crystal display device shown in FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, the embodiments disclosed herein are provided so that the disclosure can be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

In the drawings, the thicknesses of layers and regions are exaggerated for clarity. Also, when a layer is referred to as being "on" another layer or substrate, it may be formed directly on another layer or substrate, or a third layer may be interposed therebetween. Like numbers refer to like elements throughout the specification.

1 is a layout diagram showing a liquid crystal display device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line II-II 'of FIG. 1, and FIG. 3 is a cross-sectional view taken along a line III-III' of FIG.

1 to 3, the liquid crystal display according to the present embodiment includes a lower display panel 100 and an upper display panel 200 facing each other, and a liquid crystal layer 310 interposed between the two display panels 100 and 200, And a pair of polarizers (not shown) attached to the outer surfaces of the display panels 100 and 200.

First, the upper display panel 200 will be described.

The upper substrate 200 corresponds to the second substrate, and a light blocking member 220 is formed on the upper substrate 210 which is transparent and insulating. The light shielding member 220 is also called a black matrix and blocks light spots between the pixel electrodes 191 and 300 located on the lower panel 100 to be described later. The light shielding member 220 may be composed of a portion corresponding to the gate line 121 and the data line 171 and a portion corresponding to the thin film transistor.

The light shielding member 220 may be formed on the lower substrate 110 instead of the upper substrate 110.

An overcoat 250 is formed on the light shielding member 220. The cover film 250 can be made of an insulating material and provides a flat surface. The cover film 250 may be omitted.

A common electrode 270 corresponding to the third electrode is formed on the lid 250. Here, the common electrode 270 may be formed in a plate shape in the pixel region. The shape of a plate is the shape of a plate, which is not split.

Next, the lower panel 100 will be described.

A plurality of gate lines 121 are disposed on the lower substrate 110, which corresponds to the first substrate, and has insulation properties. The lower substrate 110 includes pixel regions. The gate line 121 transmits the gate signal and extends mainly in the horizontal direction. The gate line 121 includes a first gate electrode 124a, a second gate electrode 124b, a third gate electrode 124c, and a wide end (not shown) for connection to another layer or external drive circuit do.

 On the gate line 121, a gate insulating film 140 made of an insulating material such as silicon nitride is formed. The first semiconductor 154a, the second semiconductor 154b, and the third semiconductor 154c are positioned on the gate insulating film 140. [

A plurality of resistive contact members 163a, 165a, 163b, 165b, 163c, and 165c are disposed on the first semiconductor 154a, the second semiconductor 154b, and the third semiconductor 154c.

A plurality of data lines 171 including a first source electrode 173a and a second source electrode 173b over the resistive contact members 163a, 165a, 163b, 165b, 163c and 165c and the gate insulating film 140, The data conductors 171, 173c, 175a, and 175b including the first drain electrode 175a, the second drain electrode 175b, the third source electrode 173a, and the third drain electrode 175c and the reference voltage line 177, 175b, 175c, 177 are located.

The data conductor and the semiconductor and the resistive contact member located under the data conductor can be simultaneously formed using one mask.

The data line 171 includes a wide end portion (not shown) for connection with another layer or an external driving circuit.

The reference voltage line 177 includes two vertical portions 177a parallel to the data line 171 and a vertical portion 177b connecting the two vertical portions 177a to each other. By connecting the two vertical portions 177a of the reference voltage line 177 with the lateral portion 177b, it is possible to prevent a delay of a signal flowing through the reference voltage line 177. [

The vertical portion 177a of the reference voltage line 177 is located between the pixel electrodes 191 and 300 and the data line 171 and the reference voltage line 177 is connected to the third drain electrode 175c. The horizontal portion 177b of the reference voltage line 177 is located between the pixel electrodes 191 and 300 and the gate line 121. [ The reference voltage line 177 can reduce signal interference between the pixel electrodes 191 and 300 and the data line 171 and between the pixel electrodes 191 and 300 and the gate line 121.

The first gate electrode 124a, the first source electrode 173a and the first drain electrode 175a together with the first semiconductor 154a form a first thin film transistor Qa, Is formed in the semiconductor portion 154a between the first source electrode 173a and the first drain electrode 175a. Similarly, the second gate electrode 124b, the second source electrode 173b, and the second drain electrode 175b together with the second semiconductor 154b form a second thin film transistor Qb, The third source electrode 173c and the third drain electrode 175b are formed in the semiconductor portion 154b between the second source electrode 173b and the second drain electrode 175b. The channel portion of the thin film transistor forms a semiconductor portion 154c between the third source electrode 173c and the third drain electrode 175c, As shown in FIG.

A first passivation layer 180a is formed on the data conductors 171, 173c, 175a, 175b, 175c, and 177 and the exposed semiconductors 154a, 154b, and 154c. The first passivation film 180a may be made of an inorganic insulating material such as silicon nitride and silicon oxide.

An organic film 230 is disposed on the first passivation film 180a. The organic film 230 includes a first contact hole 185a and a second contact hole 185b. The first contact hole 185a exposes the first drain electrode 175a and the second contact hole 185b exposes the second drain electrode 175b.

The organic layer 230 may serve as a planarization layer and may be a color filter. The organic film 230 used as the color filter can be elongated in the longitudinal direction along the columns of the pixel electrodes 191 and 300. Each color filter 230 may display one of the primary colors, such as the three primary colors of red, green, and blue. However, it is not limited to the three primary colors of red, green, and blue, and one of cyan, magenta, yellow, and white colors may be displayed.

A cover film 180b is placed on the organic film 230. [ The cover film 180b can be made of an insulating material, preventing the color filter 230 from being exposed and providing a flat surface. The first electrode 191 is located on the cover film 180b. The first electrode 191 may be made of a transparent conductive material such as ITO or IZO or a reflective metal such as aluminum, silver, chromium, or an alloy thereof.

A second passivation film 180c is located on the first electrode 191. [ The second passivation film 180c includes a dummy hole 183 for exposing the first electrode 191. [ The dummy pattern 83 and the second electrode 300 are located on the second passivation film 180c. The dummy pattern 83 is formed to fill the first contact hole 185a and the dummy hole 183 to electrically connect the first drain electrode 175a and the first electrode 191. [

One end of the vertical stripe portion 330 of the second electrode 300 is elongated and electrically connected to the second drain electrode 175b through the second contact hole 185b.

The second electrode 300 is located in most of the unit pixel region and has a slit structure. The overall shape of the second electrode 300 formed by the slit structure is a quadrangle and includes a cruciform stem comprising a transverse stem 320 and an intersecting stem 330. In addition, the sub-regions are divided into four sub-regions by the transverse stem 320 and the longitudinal stem 330, and each sub-region includes a plurality of branches 340. The portion where the second electrode 300 is not present between the neighboring branch portions 340 corresponds to the slit.

The width d2 of the slit corresponding to the interval between the branches 340 as shown in Fig. 3 may be 2 times or more and 5 times or less as large as the width d1 of the branch 340. The width d2 of the slit may be larger than the height of the cell gap of the liquid crystal layer 3. [

The electrode formed by the conventional fine slit structure is required to be designed so that the width of the branch portions is as small as possible and a force is required to strongly push the liquid crystal molecules on the branch portions from both edges of the branch portions. In addition, the width of the slit is designed to be sufficiently small so that a sufficient force is required to move the liquid crystal molecules on the slit, which is a part where no electrode exists, by the elastic force of the liquid crystal molecules moving on the branch. However, in such a case, due to the fine electrode pattern, the distortion of the field is so severe that the degree of the liquid crystal molecules lie down on the electrode, the edge portion of the electrode, and the slit, resulting in a decrease in transmittance and a decrease in response time . Further, in the case of a fine slit structure, it is difficult to pattern and there is a high possibility that a short circuit occurs between neighboring electrodes.

However, according to the present embodiment, the width d1 of the branch 340 is formed to be sufficiently larger than the width d2 of the slit corresponding to the gap between the adjacent branch portions 340, . Also, since the width d2 of the slit is relatively large, it is relatively easy to pattern and the probability of occurrence of a short circuit between neighboring electrodes is also reduced.

As the width d2 of the slit becomes larger, the force for moving the liquid crystal molecules on the portion where the electrode is not present becomes insufficient. In order to solve this problem, according to the present embodiment, the voltage applied to the first electrode 191 and the voltage applied to the second electrode 300 are initially applied so as to have different values, and then sequentially applied to the first electrode 191 The liquid crystal layer 3 or the alignment films 11 and 21 are exposed in a state in which a voltage is applied so that the voltage applied to the liquid crystal layer 3 becomes equal to the voltage applied to the second electrode 300. [ The voltage of the first electrode 191 is higher than or at least equal to the voltage of the second electrode 300 so that the field in the liquid crystal layer 3 is driven in a substantially planarized state. This will be described in detail later.

The width d1 of the branch 340 may be two times larger than the width d2 of the slit, unlike the structure of the second electrode 300 described above.

The second electrode 300 having a slit structure will be described in detail.

The branches 340 of the second electrode 300 can have a total of four populations, one of which extends obliquely from the transverse stem 320 or the stem 37 to the upper left, The other group extends obliquely from the transverse stem 320 or the stem base 330 in the upper right direction. Another group further extends from the transverse stem 320 or the stem stem 330 in the lower left direction and the other group extends from the stem stem 320 or the stem stem 330 in the lower right direction It extends obliquely. The branches 340 of the two adjacent sub-regions may be orthogonal to each other. Although not shown, the width of the branches 340 may gradually increase.

The first electrode 191 may be in the shape of a plate having a rectangular shape in the unit pixel region. The shape of a plate is the shape of a plate, which is not split.

The unit pixel region may be an area formed by intersecting the gate line 121 and the data line 171, but is not limited thereto.

On the inner surface of each of the display panels 100 and 200, alignment films 11 and 21 are disposed, and they may be vertical alignment films.

A polarizer (not shown) is provided on the outer surface of the display panels 100 and 200. The polarizing axes of the two polarizers are orthogonal and one of the polarizing axes is parallel to the gate line 121. In the case of a reflection type liquid crystal display device, one of the two polarizers may be omitted.

The liquid crystal layer 3 is contained between the two display panels 100 and 200 and the liquid crystal molecules 310 included in the liquid crystal layer 3 may have a negative dielectric anisotropy. The liquid crystal molecules 310 of the liquid crystal layer 3 have a linear gradient along the direction substantially parallel to the longitudinal direction of the branches 340 of the second electrode 300 and the electric field is not applied And may be oriented so as to be perpendicular to the surfaces of the two display panels 100 and 200. The liquid crystal layer 3 further includes an alignment assistant 50 including a reactive mesogen such that the liquid crystal molecules 310 are aligned with the long axis of the second electrode 300 may have a line inclination along a direction substantially parallel to the longitudinal direction of the fine branch portion 340.

In the other embodiment of the present invention, the above-described alignment aid may be included in the alignment films 11 and 21 instead of the liquid crystal layer 3. [ At this time, the alignment layers 11 and 21 include a main-chain and a side-chain, and the alignment-assisting agent may be connected to the side chain and may be electrically-negative.

Hereinafter, a method of manufacturing a liquid crystal display device according to another embodiment of the present invention will be described with reference to FIGS. 1 to 7. FIG. 4 is a schematic cross-sectional view showing the electric field direction in the field exposure in the embodiment of FIG. 5 to 7 are cross-sectional views illustrating a method of forming a pre-scan square for manufacturing a liquid crystal display device according to an embodiment of the present invention. The lines shown in Figs. 5 to 7 correspond to an equipotential line.

1 to 3, the first display panel 100 and the second display panel 200 are manufactured first.

The upper display panel 200 is manufactured in the following manner.

A light shielding member 220 is formed on the upper substrate 210, and a cover film 250 is formed thereon. A common electrode 270 is formed on the cover film 250. An alignment film 21 is formed on the common electrode 270.

The lower panel 100 is manufactured in the following manner.

A plurality of thin films are stacked and patterned on the lower substrate 110 to form gate lines 121, a gate insulating film 140, semiconductor layers 151, 154a, 154b, and 154c including gate electrodes 124a, 124b, and 124c, The data line 171 including the source electrodes 173a, 173b and 173c, the drain electrodes 175a, 175b and 175c and the first passivation film 180a are formed in this order.

An organic film 230 is formed on the first passivation film 180a.

A cover film 180b is formed on the organic film 230 and a conductive layer such as ITO or IZO is laminated on the cover film 180b and patterned to form a first electrode 191, . Next, a second passivation film 180c is formed on the first electrode 191.

The second passivation film 180c is patterned to form a first contact hole 185a for exposing the first drain electrode 175a, a second contact hole 185b for exposing the second drain electrode 175b, Thereby forming a dummy hole 183 which exposes the opening 191.

A dummy pattern 83 for electrically connecting the first drain electrode 175a and the first electrode 191 and the second electrode 300 for electrically connecting the conductive layer such as ITO or IZO on the second passivation film 180c, ). Then, the alignment layer 11 is coated on the second electrode 300.

Next, the lower panel 100 and the upper panel 200 manufactured as described above are assembled, and a mixture of the liquid crystal molecules 310 and the alignment aid 50 is injected therebetween to form a liquid crystal layer 3). However, the liquid crystal layer 3 may be formed by dropping a mixture of the liquid crystal molecules 310 and the alignment assistant 50 on the lower panel 100 or the upper panel 200. The alignment assistant 50 is included in the liquid crystal layer 3 but may be formed so as to include the alignment assistant 50 in the alignment layers 11 and 21 instead of the liquid crystal layer 3 in another embodiment .

Next, referring to FIG. 4, a voltage is applied to the first electrode 191 and the second electrode 300. A voltage applied to the first electrode 191 is referred to as a first voltage V1, a voltage applied to the second electrode 300 is referred to as a second voltage V2, and a voltage applied to the common electrode 270 The voltage is applied to the first electrode 191 and the second electrode 300 such that the first voltage V1 has a lower voltage than the second voltage V2. The first voltage V1 and the third voltage V3 may be the same. Specifically, the first voltage V1 and the third voltage V3 may be 0, and the second voltage V2 may be 7V.

That is, a fringe field E is formed by applying a larger voltage to the second voltage V2 than the first voltage V1 based on the third voltage V3. The liquid crystal molecules 310 are tilted by the generated fringe field. At this time, the liquid crystal molecules 310 located on the branches 340 and the liquid crystal molecules 310 located at the edges of the branches 340 may be inclined by the vertical electric field and the fringe field, The liquid crystal molecules 310 are difficult to have directionality because the first voltage V1 and the third voltage V3 are the same. 5, since the width d2 of the slit widens and the elastic force of the liquid crystal molecules 310 lying down at the edges of the branch portions 340 is weak, the liquid crystal molecules 340 are deformed with respect to the display plates 100 and 200 And maintains the vertically aligned state. The liquid crystal molecules 310 located at the portions of the liquid crystal layer 3 corresponding to the branches 340 of the second electrode 300 may be inclined along the extending direction of the branches 340. [

Thereafter, the first voltage V1 may be sequentially increased to be equal to the second voltage V2. Alternatively, a voltage smaller than the second voltage V2 may be applied to the first electrode 191, which is larger than the first voltage V1 initially applied discontinuously. 6, the liquid crystal molecules 310 located on the slit are subjected to a force that can be tilted by the electric field between the first electrode 191 and the third electrode 270, and the branches 340 The liquid crystal molecules 310 located at the edges of the liquid crystal molecules 310 are slightly inclined along the tilted direction.

7, when the first voltage V1 is increased to be equal to the second voltage V2, the liquid crystal molecules 310 located at the slits are separated from the liquid crystal molecules 310 located at the edges of the branches 340 So that it lies almost in the same direction as the tilting direction. In this state, the liquid crystal layer 3 is exposed. Accordingly, the liquid crystal molecules 310 may have a pretilt.

8 is a schematic cross-sectional view showing the direction of an electric field at the time of driving the liquid crystal display device manufactured according to the embodiment of Figs. 4 to 7. Fig.

Referring to FIG. 8, the liquid crystal display manufactured according to the embodiment shown in FIGS. 4 to 7 may be driven under the following conditions. The first voltage V1 applied to the first electrode 191 is higher than or at least equal to the second voltage V2 applied to the second electrode 300 so that an electric field existing in the liquid crystal layer 3 Is substantially planarized, the liquid crystal display device according to the present embodiment is driven. As a result of applying the differential voltage in this manner, the data voltage is applied to the first electrode 191 through the data line 171 as in the structure of the liquid crystal display device according to this embodiment described with reference to FIGS. 1 to 3 A reduced voltage may be applied to the second electrode 300 through a resistance distribution. A common voltage, which is a voltage having a predetermined magnitude, is applied to the common electrode 270. Therefore, most of the liquid crystal molecules 310 are driven by the vertical electric field E generated between the common electrode 270 and the first electrode 191 at the time of driving the liquid crystal display device, thereby minimizing the reduction of the transmittance by the horizontal electric field , A high-speed response can be realized.

Hereinafter, a liquid crystal display device and a method of manufacturing the same according to another embodiment of the present invention will be described.

In this embodiment, the liquid crystal layer 3 is exposed in a state where different voltages are applied to the first electrode 191 and the second electrode 300, unlike the above-described exposure method. 6, the liquid crystal molecules 310 of the slit portion between the liquid crystal molecules 310 and the branches 340 in the branch 340 can be oriented at different inclination angles and azimuth angles. And is exposed in the liquid crystal alignment state shown in FIG. 6 to form regions having different pretilt angles and azimuth angles.

The portion of the liquid crystal layer 3 corresponding to the branch 340 of the second electrode 300 is referred to as a first region and the portion of the liquid crystal layer 3 corresponding to the slit of the second electrode 300 is referred to as a second region The alignment direction of the liquid crystal molecules 310 of the first region and the alignment direction of the liquid crystal molecules 310 of the second region are different from each other at the time of driving the liquid crystal display device according to the present embodiment. Therefore, visibility can be improved by exhibiting the same effect as when the pixels are divided.

Except for the differences described above, most of the explanations of the embodiments of Figs. 1 to 7 can be applied to this embodiment as well.

Now, referring to FIG. 9 and FIG. 10, one example of the arrangement of the signal lines and pixels and the driving method thereof in the liquid crystal display device according to the embodiment of the present invention will be described. 9 is an equivalent circuit diagram of one pixel of the liquid crystal display device shown in FIG. 10 is a waveform diagram of a signal applied to a pixel of the liquid crystal display device shown in FIG.

9, a pixel PX of the liquid crystal display according to an exemplary embodiment of the present invention includes a gate line GL for transmitting a gate signal and a data line DL for transmitting a data signal, A first switching device Qa, a second switching device Qb, and a third switching device Qc, which are connected to the plurality of signal lines, and a plurality of signal lines including a reference voltage line RL, (Clca) and a second liquid crystal capacitor (Clcb).

The first switching device Qa and the second switching device Qb are connected to the gate line GL and the data line DL respectively and the third switching device Qc is connected to the output of the second switching device Qb Terminal and the reference voltage line RL.

The first switching element Qa and the second switching element Qb are three terminal elements such as a thin film transistor and the control terminal thereof is connected to the gate line GL and the input terminal thereof is connected to the data line DL The output terminal of the first switching device Qa is connected to the first liquid crystal capacitor Clca and the output terminal of the second switching device Qb is connected to the second liquid crystal capacitor Clcb and the third switching device Qc As shown in Fig.

The third switching element Qc is also a three terminal element such as a thin film transistor. The control terminal is connected to the gate line GL. The input terminal is connected to the second liquid crystal capacitor Clcb. (RL).

10, when a gate signal Von is applied to the gate line GL, the first switching device Qa, the second switching device Qb, and the third switching device Qc connected thereto are turned on Is turned on. The data voltage applied to the data line DL is applied to the first electrode PEa and the second electrode PEb through the turned-on first switching device Qa and the second switching device Qb, respectively . At this time, the data voltages applied to the first electrode PEa and the second electrode PEb may be charged to the same value. However, according to the embodiment of the present invention, the voltage applied to the second electrode PEb becomes a partial pressure through the third switching element Qc connected in series with the second switching element Qb. Therefore, the voltage Vb applied to the second electrode PEb becomes smaller than the voltage Va applied to the first electrode PEa.

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.

121 gate line 171 data line
180a First passivation film 180b Cover film
180c Second passivation film 230 Organic film
191 First electrode 270 Common electrode
280 insulating film 300 second electrode

Claims (28)

The first substrate,
A second substrate facing the first substrate,
A liquid crystal layer interposed between the first substrate and the second substrate, the liquid crystal layer including liquid crystal molecules,
A gate line and a data line intersecting and insulated on the first substrate,
A first thin film transistor and a second thin film transistor connected to the gate line and the data line,
A third thin film transistor connected to the gate line and the second thin film transistor,
A first electrode located on the first substrate and connected to the first thin film transistor,
An insulating film disposed on the first electrode,
A second electrode located on the insulating film and connected to the second thin film transistor,
And a third electrode located on the second substrate,
Wherein the second electrode has a structure including a plurality of branches and a slit between neighboring branches, and the width of the slits is at least two times and not more than five times the width of the branches.
The method of claim 1,
And an alignment layer disposed on at least one of the second electrode and the third electrode.
3. The method of claim 2,
Wherein at least one of the liquid crystal layer and the alignment layer comprises an alignment assisting agent.
4. The method of claim 3,
Wherein the first electrode and the third electrode are in the shape of a channel.
5. The method of claim 4,
Wherein when a voltage applied to the first electrode is a first voltage, a voltage applied to the second electrode is a second voltage, and a voltage applied to the third electrode is a third voltage, Wherein at least one of the liquid crystal layer and the alignment layer is exposed in a state in which the first voltage is sequentially applied to the second electrode so that the first voltage is equal to the second voltage.
The method of claim 5,
Wherein the first voltage is higher than or at least equal to the second voltage so that the field in the liquid crystal layer is driven in a planarized state.
The method of claim 6,
Wherein a width of the slit is greater than a height of a cell gap of the liquid crystal layer.
4. The method of claim 3,
The portion of the liquid crystal layer corresponding to the branch of the second electrode is referred to as a first region and the portion of the liquid crystal layer corresponding to the slit of the second electrode is referred to as a second region, And the liquid crystal molecules of the second region have different alignment directions.
9. The method of claim 8,
Wherein the first electrode and the third electrode are in the shape of a channel.
The method of claim 9,
Wherein when a voltage applied to the first electrode is a first voltage, a voltage applied to the second electrode is a second voltage, and a voltage applied to the third electrode is a third voltage, Wherein at least one of the liquid crystal layer and the alignment layer is exposed in a state in which voltages are applied with different values.
11. The method of claim 10,
Wherein a width of the slit is greater than a height of a cell gap of the liquid crystal layer.
The method of claim 1,
And a reference voltage line connected to the third thin film transistor.
The method of claim 12,
Wherein the first electrode and the second electrode are electrically connected to each other.
The method of claim 1,
Wherein the second electrode comprises a cross-shaped stem portion including a transverse stem portion and an intersecting longitudinal stem portion,
And the plurality of branch portions extending from the cruciform stem portion.
The method of claim 14,
And the second electrode includes a plurality of regions from which the plurality of branch portions extend from the cruciform stem portion in different directions.
The method of claim 1,
And the liquid crystal molecules located in the liquid crystal layer portion corresponding to the branch portions of the second electrode are inclined along the extending direction of the branch portions.
Forming a first electrode on the first substrate,
Forming an insulating film on the first electrode,
Forming a second electrode on the insulating film,
Forming a third electrode on a second substrate facing the first substrate,
Forming an orientation film on at least one of the second electrode and the third electrode,
Attaching the first substrate and the second substrate together,
Forming a liquid crystal layer interposed between the first substrate and the second substrate, the liquid crystal layer including liquid crystal molecules,
Applying different voltages to the first electrode and the second electrode,
Applying a voltage applied to the first electrode so as to be sequentially equal to a voltage applied to the second electrode, and
And irradiating the liquid crystal layer with light in a state where a voltage applied to the first electrode and a voltage applied to the second electrode are equal to each other,
The second electrode is formed in a structure including a plurality of branch portions and slits between neighboring branch portions,
Wherein at least one of the liquid crystal layer and the alignment layer comprises an alignment assistant.
The method of claim 17,
Wherein a voltage applied to the first electrode and a voltage applied to the third electrode are different from each other in the step of applying different voltages to the first electrode and the second electrode.
The method of claim 18,
Wherein the first electrode and the third electrode are formed in a shape of a channel.
20. The method of claim 19,
Wherein a width of the slit is larger than a height of a cell gap of the liquid crystal layer.
20. The method of claim 20,
Wherein a width of the slit is formed to be two times or more and five times or less than a width of the branch portion.
20. The method of claim 20,
And the width of the branch portion is formed to be twice or more than the width of the slit.
Forming a first electrode on the first substrate,
Forming an insulating film on the first electrode,
Forming a second electrode on the insulating film,
Forming a third electrode on a second substrate facing the first substrate,
Forming an orientation film on at least one of the second electrode and the third electrode,
Attaching the first substrate and the second substrate together,
Forming a liquid crystal layer interposed between the first substrate and the second substrate, the liquid crystal layer including liquid crystal molecules,
Applying different voltages to the first electrode and the second electrode, and
And irradiating the liquid crystal layer with light in a state where different voltages are applied to the first electrode and the second electrode,
The second electrode is formed in a structure including a plurality of branch portions and slits between neighboring branch portions,
Wherein at least one of the liquid crystal layer and the alignment layer comprises an alignment assistant.
24. The method of claim 23,
Wherein a voltage applied to the first electrode and a voltage applied to the third electrode are different from each other in the step of applying different voltages to the first electrode and the second electrode.
25. The method of claim 24,
The step of irradiating the liquid crystal layer with light in a state where different voltages are applied to the first electrode and the second electrode
The portion of the liquid crystal layer corresponding to the branch of the second electrode is referred to as a first region and the portion of the liquid crystal layer corresponding to the slit of the second electrode is referred to as a second region, And irradiating the liquid crystal layer with light in a state where alignment directions of liquid crystal molecules in the second region are different from each other.
26. The method of claim 25,
Wherein the first electrode and the third electrode are formed in a shape of a channel.
26. The method of claim 26,
Wherein a width of the slit is larger than a height of a cell gap of the liquid crystal layer.
The first substrate,
A second substrate facing the first substrate,
A liquid crystal layer interposed between the first substrate and the second substrate, the liquid crystal layer including liquid crystal molecules,
A gate line and a data line intersecting and insulated on the first substrate,
A first thin film transistor and a second thin film transistor connected to the gate line and the data line,
A third thin film transistor connected to the gate line and the second thin film transistor,
A first electrode located on the first substrate and connected to the first thin film transistor,
An insulating film disposed on the first electrode,
A second electrode located on the insulating film and connected to the second thin film transistor,
And a third electrode located on the second substrate,
Wherein the second electrode has a structure including a plurality of branches and a slit between neighboring branches, and the width of the branches is two times or more and five times or less than the width of the slit.

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