KR20110070475A - Liquid crystal display - Google Patents

Abstract

PURPOSE: A liquid crystal display device is provided to reduce the parasitic capacitance between an electric filed generating electrode and a data line and to prevent the reduction of transmittance of the liquid crystal display device. CONSTITUTION: A gate line(121) and a data line(171) are located on an insulating substrate. A thin film transistor is connected to the gate line and the data line and includes a source electrode(173) and a drain electrode. A pixel electrode contacts a part of the drain electrode. A protective film is located on the pixel electrode and the thin film transistor.

Description

[0001] LIQUID CRYSTAL DISPLAY [0002]

The present invention relates to a liquid crystal display device.

Liquid Crystal Display (Liquid Crystal Display) is one of the most widely used flat panel display (Flat Panel Display), a display that controls the amount of light transmitted by rearranging the liquid crystal molecules of the liquid crystal layer by applying a voltage to the electrode Device. Although the liquid crystal display device has an advantage of easy thinning, there are disadvantages in that the side visibility is inferior to the front visibility, and various methods of arranging and driving liquid crystals have been developed to overcome this problem. As a method of implementing such a wide viewing angle, a liquid crystal display device in which a pixel electrode and a common electrode are formed on one substrate has been attracting attention.

However, in the liquid crystal display, since the pixel electrode and the reference electrode are formed on one substrate, the parasitic capacitance between the two electrodes and the data line may increase. In order to reduce the parasitic capacitance, when the distance between the two electrodes and the data line is widened, the transmittance may decrease.

Accordingly, an object of the present invention is to provide a liquid crystal display device capable of reducing the parasitic capacitance between the field generating electrode and the data line without reducing the transmittance of the liquid crystal display device.

The pixel electrode of the liquid crystal display according to the exemplary embodiment of the present invention is disposed between the gate insulating film and the passivation layer, and directly covers a part of the drain electrode, so that the pixel electrode is directly physically and electrically connected to the liquid crystal display device. Compared with the opening ratio.

In addition, the liquid crystal display according to the exemplary embodiment of the present invention includes a source electrode positioned on the same line as the data line and a drain electrode extending in parallel with a part of the data line, thereby increasing the width of the thin film transistor without increasing the area occupied by the data conductor. In this case, the aperture ratio of the liquid crystal display device can be increased.

In addition, in the liquid crystal display according to the exemplary embodiment of the present invention, the reference electrode disposed on the passivation layer may include an opening that exposes a gate electrode, an island semiconductor, a portion of the data line and a drain electrode, which form a thin film transistor, and a portion of the reference voltage line. By having, the parasitic capacitance between the data line and the reference electrode can be reduced.

According to the exemplary embodiment of the present invention, the parasitic capacitance between the field generating electrode and the data line can be reduced without reducing the transmittance of the liquid crystal display.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement 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 of layers, films, panels, regions, etc., are exaggerated for clarity. Like parts are designated by like reference numerals throughout the specification. Whenever a portion of a layer, film, region, plate, or the like is referred to as being "on" another portion, it includes not only the case where it is "directly on" another portion, but also the case where there is another portion in between. On the contrary, when a part is "just above" another part, there is no other part in the middle.

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

FIG. 1 is a layout view of a liquid crystal display according to an exemplary embodiment of the present invention, FIG. 2A is a cross-sectional view of the liquid crystal display of FIG. 1 taken along the line IIA-IIA, and FIG. 2B is a liquid crystal display of FIG. Sectional drawing of the apparatus cut along the line IIB-IIB.

1 and 2, a liquid crystal display according to an exemplary embodiment includes a lower panel 100 and an upper panel 200 facing each other and a liquid crystal layer 3 injected therebetween.

First, the lower panel 100 will be described.

A gate conductor including a gate line 121 and a reference voltage line 131 is formed on an insulating substrate 100 made of transparent glass or plastic. The gate line 121 includes a wide end portion (not shown) for connection with the gate electrode 124 and another layer or an external driving circuit. The gate line 121 may be formed of aluminum-based metal such as aluminum (Al) or aluminum alloy, silver-based metal such as silver (Ag) or silver alloy, copper-based metal such as copper (Cu) or copper alloy, molybdenum (Mo) or molybdenum alloy, etc. It may be made of molybdenum-based metal, chromium (Cr), tantalum (Ta) and titanium (Ti). However, the gate line 121 may have a multi-layer structure including at least two conductive layers having different physical properties.

The reference voltage line 131 transmits a constant reference voltage and includes an extension 135 for connection with the reference electrode 270, which will be described later. The reference voltage line 131 is connected to the reference electrode 270 to be described later to transfer the reference voltage to the reference electrode 270. The reference voltage line 131 may be parallel to the gate line 121 and may be made of the same material as the gate line 121.

A gate insulating layer 140 made of silicon nitride (SiNx), silicon oxide (SiOx), or the like is formed on the gate conductors 121 and 131. The gate insulating layer 140 may have a multilayer structure including at least two insulating layers having different physical properties.

An island semiconductor 154 made of amorphous silicon, polycrystalline silicon, or the like is formed on the gate insulating layer 140. The island semiconductor 154 at least partially overlaps the gate electrode 124.

Ohmic contacts 163 and 165 are formed on the island-like semiconductor 154. The resistance contact members 163 and 165 may be made of a material such as n + hydrogenated amorphous silicon doped with a high concentration of n-type impurities such as phosphorus or made of silicide. The ohmic contacts 163 and 165 may be paired and disposed on the island-like semiconductor 154.

A data conductor including a data line 171 including a source electrode 173 and a drain electrode 175 is formed on the ohmic contacts 163 and 165 and the gate insulating layer 140.

The data line 171 includes a wide end portion (not shown) for connection with another layer or an external driving circuit. The data line 171 transmits a data signal and mainly extends in the vertical direction to cross the gate line 121 and the reference voltage line 131. The data line 171 together with the gate line 121 forms a pixel area. In this case, the data line 171 may have a first curved portion having a curved shape in order to obtain a maximum transmittance of the liquid crystal display, and the curved portions may meet each other in an intermediate region of the pixel area to form a V shape. The middle region of the pixel region may further include a second curved portion bent to form a predetermined angle with the first curved portion.

The first curved portion of the data line 171 may be bent at about 7 ° with the rubbing direction of the alignment layer to be described. The second curved portion disposed in the middle region of the pixel area may be further curved to form about 7 ° to about 15 ° with the first curved portion.

The source electrode 173 is a part of the data line 171 and is disposed on the same line as the data line 171. The drain electrode 175 is formed to extend in parallel with the source electrode 173. Therefore, the drain electrode 175 is parallel with a part of the data line 171.

The gate electrode 124, the source electrode 173, and the drain electrode 175 together with the island-like semiconductor 154 form one thin film transistor (TFT), and a channel of the thin film transistor is a source electrode ( It is formed in the semiconductor 154 between the 173 and the drain electrode 175.

The liquid crystal display according to the exemplary embodiment of the present invention includes a source electrode 173 positioned on the same line as the data line 171 and a drain electrode 175 extending parallel to the data line 171, thereby providing a data conductor. It is possible to widen the width of the thin film transistor without increasing the area to occupy, thereby increasing the aperture ratio of the liquid crystal display.

The data line 171 and the drain electrode 175 are preferably made of a refractory metal such as molybdenum, chromium, tantalum, and titanium, or an alloy thereof, and include a refractory metal film (not shown) and a low resistance conductive film. It may have a multilayer structure including (not shown). Examples of the multilayer structure include a double layer of chromium or molybdenum (alloy) lower layer and an aluminum (alloy) upper layer, and a triple layer of molybdenum (alloy) lower layer and aluminum (alloy) interlayer and molybdenum (alloy) upper layer. However, the data line 171 and the drain electrode 175 may be made of various metals or conductors. The width of the data line 171 may be about 3.5 μm ± 0.75.

The pixel electrode 191 is formed on a part of the drain electrode 175 and the gate insulating layer 140.

The pixel electrode 191 includes a pair of curved edges substantially parallel to the first curved portion and the second curved portion of the data line 171.

The pixel electrode 191 covers a portion of the drain electrode 175 and is disposed thereon to be directly and physically connected to the drain electrode 175.

The pixel electrode 191 may be made of a transparent conductive material such as polycrystalline, single crystal or amorphous indium tin oxide (ITO), or indium zinc oxide (IZO).

A passivation layer 180 is formed on the data conductors 171 and 175, the exposed semiconductor 154, and the pixel electrode 191. The passivation layer 180 is made of an inorganic insulator such as silicon nitride and silicon oxide. However, the passivation layer 180 may be made of an organic insulator and may have a flat surface. The organic insulator may have photosensitivity and its dielectric constant may be about 4.0 or less. The passivation layer 180 may also have a double layer structure of the lower inorganic layer and the upper organic layer so as not to damage the exposed portion of the semiconductor 154 while maintaining excellent insulating properties of the organic layer. The passivation layer 180 may have a thickness of about 5000 kPa or more and about 6000 kPa to about 8000 kPa.

A passivation hole (not shown) is formed in the passivation layer 180 to expose an end portion of the data line 171, and a connection portion of the reference voltage line 131 is formed in the passivation layer 180 and the gate insulating layer 140. A contact hole 183 exposing the 135 and a contact hole (not shown) exposing an end portion of the gate line 121 are formed.

The reference electrode 270 is formed on the passivation layer 180. The reference electrode 270 overlaps the pixel electrode 191, and includes a horizontal connector 272 connecting the plurality of branch electrodes 271 and the branch electrodes 271, and a vertical connector connecting the horizontal connector 272. 273). The reference electrode 270 is made of a transparent conductive material such as polycrystalline, monocrystalline or amorphous indium tin oxide (ITO), or indium zinc oxide (IZO). The reference electrodes 270 disposed in adjacent pixels are connected to each other.

The branch electrode 271 of the reference electrode 270 includes the first portion 271a (see A) and the second portion 271b (A ′) which are respectively parallel to the first curved portion and the second curved portion of the data line 171 described above. Reference). The first portion 271a is about 5 ° to 10 °, more specifically about 7 °, with the rubbing direction of the alignment layer, which will be described later, and the second portion 271b is about 7 ° to the first portion 271a. It may be further bent to achieve about 15 °.

The horizontal connecting portion 272 of the reference electrode 270 is substantially parallel with the gate line 121, and connects the branch electrodes 271 with each other from above and below. The horizontal connection portion 272 of the reference electrode 270 disposed under the pixel region may include a gate electrode 124 constituting a thin film transistor, an island semiconductor 154, a data line 171 constituting a source electrode 173, and a drain. The electrode 175 has a first opening 274 exposing a portion of the reference voltage line 131. The horizontal connection 272 of the reference electrode 270 has a reference electrode extension 275 extending toward the extension 135 of the reference voltage line 131. The reference electrodes 270 disposed in the neighboring pixels are connected to each other.

The branch electrode 271 of the reference electrode 270 further includes a third portion 271c (see A ″) bent at an angle to a portion connected to the horizontal connection portion 272 of the reference electrode 270. The three portions 271c may be further bent to form about 7 ° to about 15 ° with the first portion 271a, that is, the first portion 271a of the branch electrode 271 of the reference electrode 270 is transverse to the first portion 271a. The acute angle formed by the connecting portion 272 is about 7 ° to the acute angle formed by the second portion 271b with the horizontal connecting portion 272 or the acute angle formed by the horizontal portion 272 with the third portion 271c. About 15 ° larger.

The vertical connection portion 273 of the reference electrode 270 extends over the data line 171 disposed between two neighboring pixels, and has a first opening 274 disposed over a portion of the data line 171. .

The first opening 274 of the reference electrode 270 completely exposes the data line 171 forming the source electrode 173 and may have a vertical width of about 30 μm to about 60 μm.

The extension 275 of the reference electrode 270 is physically connected to the reference voltage line 131 through the contact hole 183 formed in the passivation layer 180 and the gate insulating layer 140.

Although not illustrated, an alignment layer is coated on the reference electrode 270 and the passivation layer 180, and the alignment layer may be a horizontal alignment layer and may be rubbed in a predetermined direction. The rubbing direction of the alignment layer may be about 5 ° to about 10 °, more specifically about 7 ° to the direction in which the first portion 271a of the branch electrode of the reference electrode 270 extends.

Next, the upper panel 200 will be described.

A light blocking member 220 is formed on an insulating substrate 210 made of transparent glass or plastic. The light blocking member 220 is also called a black matrix and prevents light leakage.

A plurality of color filters 230 is also formed on the substrate 210. The color filter 230 is mostly present in an area surrounded by the light blocking member 220, and may extend in the vertical direction along the column of the pixel electrodes 191. Each color filter 230 may display one of primary colors such as three primary colors of red, green, and blue.

An overcoat 250 is formed on the color filter 230 and the light blocking member 220. The overcoat 250 may be made of an (organic) insulator, which prevents the color filter 230 from being exposed and provides a flat surface. The overcoat 250 may be omitted.

The liquid crystal layer 3 comprises a nematic liquid crystal material having positive dielectric anisotropy. The liquid crystal molecules of the liquid crystal layer 3 have their long axis directions arranged in parallel to the display panels 100 and 200, and the directions thereof are in a spiral shape from the rubbing direction of the alignment layer of the lower display panel 100 to the upper display panel 200. It has a 90 ° twisted structure.

The pixel electrode 191 receives a data voltage from the drain electrode 175, and the reference electrode 270 receives a reference voltage having a predetermined magnitude from the reference voltage line 131. The reference electrodes 270 are connected to each other and receive a reference voltage from a reference voltage applying unit disposed outside the display area, but in order to prevent a voltage drop in the display area, a reference voltage having the same size from the reference voltage line 131 is provided. The voltage is applied.

The pixel electrode 191 to which the data voltage is applied generates an electric field together with the reference electrode 270 to which the data voltage is applied, so that the liquid crystal molecules of the liquid crystal layer 3 positioned on the two electrodes 191 and 270 are aligned with the direction of the electric field. Rotate in parallel direction. The polarization of light passing through the liquid crystal layer varies according to the rotation direction of the liquid crystal molecules determined as described above.

As described above, the liquid crystal molecules 31 of the liquid crystal layer 3 of the liquid crystal display 3 rotate by the electric field formed between the sides of the branch portions 271 of the reference electrode 270 and the pixel electrode 191. In this case, in the liquid crystal display according to the exemplary embodiment of the present invention, the alignment layer is rubbed such that the liquid crystal molecules 31 of the liquid crystal layer 3 are pretilted at a predetermined angle, and the rubbing angle is a branch portion of the reference electrode 270. 271) and about 5 ° to 10 °, more specifically about 7 °, the liquid crystal molecules 31 can be rotated quickly in the pretilted direction.

Since the pixel electrode 191 of the liquid crystal display according to the exemplary embodiment of the present invention is disposed between the gate insulating layer 140 and the passivation layer 180, the pixel electrode 191 covers a part of the drain electrode 175 and is directly physically connected to each other. The aperture ratio is increased compared to the conventional liquid crystal display device connected through the contact hole.

In addition, the liquid crystal display according to the exemplary embodiment of the present invention includes a source electrode 173 positioned on the same line as the data line 171 and a drain electrode 175 extending in parallel with a portion of the data line 171. As a result, the width of the thin film transistor can be widened without increasing the area occupied by the data conductor, thereby increasing the aperture ratio of the liquid crystal display.

In the liquid crystal display according to the exemplary embodiment of the present invention, the reference electrode 270 disposed on the passivation layer 180 may include the gate electrode 124, the island-type semiconductor 154, and the source electrode 173 forming the thin film transistor. By having an opening 274 exposing a part of the data line 171 and the drain electrode 175, the parasitic capacitance between the data line 171 and the reference electrode 270 can be reduced.

A parasitic capacitance between the data line 171 and the reference electrode 270 of the liquid crystal display according to an exemplary embodiment of the present invention will be described. Table 1 is a result of comparing the parasitic capacitance between the data line 171 and the reference electrode 270 of the liquid crystal display according to an experimental example of the present invention. In the present experimental example, the shape of the data line 171 and the drain electrode 175 forming the thin film transistor of the liquid crystal display device, the opening of the reference electrode 270, the line width of the data line 171 and the thickness of the passivation layer 180 are determined. While changing, the parasitic capacitance between the data line 191 and the reference electrode 270 was compared.

TABLE 1

A 71.0% B 62.1% C 49.6%

Table 1 shows a parasitic between the reference electrode 270 and the data line 171 of a typical liquid crystal display including a conventional U-shaped drain electrode and including an organic insulating layer between the reference electrode 270 and the data line 171. It is the result of calculating the ratio of parasitic dose in each case based on dose. In the case (A), as in the liquid crystal display according to the exemplary embodiment of the present invention, the source electrode 173 and the drain electrode 175 extending in parallel with the data line 171 are located on the same line as the data line 171. A portion of the data line 171 constituting the gate electrode 124, the island-shaped semiconductor 154, the source electrode 173, and the reference electrode 270 in which the reference electrode 270 forms a thin film transistor, and a reference voltage line. This is the case with the opening 274 exposing a part of 131. In the case (B), the line width of the data line was formed to be about 3.5 μm in addition to the case (A), and in the case (C), the thickness of the protective film 180 was formed to be about 8000 Å in addition to the case (B). to be.

Referring to Table 1, it can be seen that the parasitic capacitance of the reference electrode 270 and the data line 171 is reduced to about 71.0% in the case of the liquid crystal display according to the exemplary embodiment of the present invention. By decreasing the line width of the data line 171, the decrease was about 62.1%, and by adjusting the thickness of the passivation layer 180, the decrease was about 49.6%.

As such, the liquid crystal display according to the exemplary embodiment of the present invention reduces the parasitic capacitance between the data line 171 and the reference electrode 270 and reduces parasitics without reducing the aperture ratio of the liquid crystal display or complicating manufacturing steps. It was found that the deterioration in image quality due to the capacity can be reduced.

Next, the shape of the branch electrode 271 of the reference electrode 270 of the liquid crystal display according to the exemplary embodiment of the present invention will be described with reference to FIG. 3. 3 is an enlarged view illustrating a portion of the liquid crystal display of FIG. 1.

First, referring to FIG. 3A, the first portion 271a of the branch electrode 271 of the reference electrode 270 has a rubbing direction and a first angle θ1 of the alignment layer disposed on the lower panel 100. Tilt to achieve As described above, the first angle θ1 may be about 5 ° to about 10 °, more specifically about 7 °. Referring to FIG. 3B, the second portion 271a of the branch electrode 271 of the reference electrode 270 is bent to form a second angle θ2 with the first portion 271a. ), The third portion 271c of the reference electrode 270 is bent to form a second angle θ2 with the first portion 271a. The second angle θ2 may be about 7 ° to about 15 °.

As such, the branch electrode 271 of the reference electrode 270 is formed by dividing the branch electrode 271 into the first portion 271a, the second portion 271b, and the third portion 271c, so that the electric field of the center portion and the edge portion of the pixel region is formed. You can change the direction of production. In general, the end portion of the branch electrode 271 is different from the center of the branch electrode 271 in the direction of the electric field. When the electric field is applied to the liquid crystal layer 3, the rotation direction of the liquid crystal becomes irregular, so that texture may occur. have. However, the liquid crystal display according to the exemplary embodiment of the present invention is disposed at the end of the first portion 271a of the branch electrode 271, and the second portion 271b is bent at a larger angle than the first portion 271a. And the third portion 271c, it is possible to change the direction of the electric field applied to the liquid crystal layer 3, so that the liquid crystal molecules of the liquid crystal layer 3 can rotate in a constant direction. In addition, by including the second portion 271b and the third portion 271c that are bent at an angle larger than the first portion 271a, the rotation direction of the liquid crystal molecules 31 may be determined. Therefore, the texture due to the irregular rotation of the liquid crystal molecules 31 at the central portion or the upper and lower boundary portions of the pixel area can be prevented. In addition, the branch electrodes 271 of the reference electrode 270 are formed by dividing the first electrode 271a, the second portion 271b, and the third portion 271c, thereby rotating the angles of rotation of the liquid crystal molecules 31 to each other. Since it can be set differently, the viewing angle of a liquid crystal display device can be raised and a color tone can be compensated.

Next, a liquid crystal display according to another exemplary embodiment of the present invention will be described with reference to FIG. 4. 4 is a layout view of a liquid crystal display according to another exemplary embodiment, and illustrates a plurality of pixels.

The layer structure of the liquid crystal display device shown in FIG. 4 is almost the same as the liquid crystal display device shown in FIGS. 1 and 2. Therefore, detailed description is omitted.

Referring to FIG. 4, the liquid crystal display according to the present exemplary embodiment includes at least three pixels neighboring each other, and a spacer 325 is formed in at least one pixel among the three neighboring pixels. The spacer 325 may be disposed on the extension 135 of the reference voltage line 131, and the spacer 325 may be disposed in contact with the contact hole 183 for connecting the reference voltage line 131 and the reference electrode 270. Bigger

A contact hole 183 for connecting the reference voltage line 131 and the reference electrode 270 may not be formed in a pixel in which the spacer 325 is disposed among three pixels adjacent to each other, and only the remaining pixels are contact holes. 183 may be formed. Therefore, the reference voltage line 131 and the reference electrode 270 may be connected to each other through the contact hole 183 only in the pixel area where the spacer 325 is not disposed.

The light blocking member 220 formed in the pixel in which the spacer 325 is disposed among three neighboring pixels may partially extend in a portion corresponding to the spacer 325 to cover all of the spacer 325. have. Therefore, the aperture ratio of the pixel on which the spacer 325 is disposed can be somewhat smaller than that of the remaining pixels.

The three neighboring pixels may display different colors, and the pixel having the smallest aperture ratio may be the green pixel because the spacer 325 is disposed.

Many of the features of the liquid crystal display described above with reference to FIGS. 1 and 2 may be applicable to the embodiment shown in FIG. 4.

Next, a liquid crystal display according to another exemplary embodiment of the present invention will be described with reference to FIG. 5. 5 is a layout view of a liquid crystal display according to another exemplary embodiment, and illustrates a plurality of pixels.

The layer structure of the liquid crystal display device shown in FIG. 5 is almost the same as the liquid crystal display device shown in FIGS. 1 and 2. Therefore, detailed description is omitted.

However, in the liquid crystal display according to the exemplary embodiment illustrated in FIG. 5, unlike the liquid crystal display illustrated in FIGS. 1 and 2, the reference voltage line 131 is disposed at the center of the pixel area. In addition, the extension 135 of the reference voltage line 131 is also disposed at the center of the pixel area, and the reference electrode extension 275 is also disposed at the center of the pixel area.

A contact hole 183 for connecting the reference voltage line 131 and the reference electrode 270 to only one of three neighboring pixels, an extension 135 of the reference voltage line 131, and a reference electrode 270. The extended portion 275 may be formed, and the contact hole 183 may not be formed in the remaining pixels. Therefore, the reference voltage line 131 and the reference electrode 270 may be connected to each other through the contact hole 183 only in one pixel area among three pixels adjacent to each other. The contact portion of the reference voltage line 131 and the reference electrode 270 may be disposed in an area adjacent to the data line 171 of the pixel area.

Of the three pixels adjacent to each other, in the pixel in which the reference voltage line 131 and the reference electrode 270 are connected to each other through the contact hole 183, the pixel electrode 191 is an extension portion of the reference voltage line 131 ( 135, and the contact hole 183 and the extension 275 of the reference electrode 270 are removed at a position so that one of the edges of the pixel electrode 191 adjacent to the data line 171 is a reference voltage line. It may have a recess 192 surrounding the contact portion of the 131 and the reference electrode 270. As a result, the pixel electrode 191 disposed between the reference voltage line 131 and the reference electrode 270 is removed from the contact portion between the reference voltage line 131 and the reference electrode 270, thereby removing the reference electrode 270 and the pixel electrode. A short of 191 may be prevented.

A contact hole 183 for connecting the reference voltage line 131 and the reference electrode 270 to only one of three neighboring pixels, an extension 135 of the reference voltage line 131, and a reference electrode 270. Since the extension portion 275 is formed, the aperture ratio of the pixel to which the reference voltage line 131 and the reference electrode 270 are physically and electrically connected may be slightly smaller than the remaining pixels.

Three neighboring pixels may display different colors, and the reference voltage line 131 and the reference electrode 270 are physically connected to each other so that the pixel having the smallest aperture ratio may be a green pixel.

As such, by connecting the reference voltage line 131 and the reference electrode 270 to only some of the pixels, the aperture ratio of the remaining pixels may be increased, thereby increasing the overall aperture ratio of the liquid crystal display.

Many of the features of the liquid crystal display described with reference to FIGS. 1, 2, and 4 can be applied to the embodiment shown in FIG. 5.

Next, a liquid crystal display according to another exemplary embodiment of the present invention will be described with reference to FIGS. 6A and 6B. 6A is a layout view of a portion of a liquid crystal display according to another exemplary embodiment. FIG. 6B is a cross-sectional view of the liquid crystal display of FIG. 6A taken along a line VIB-VIB.

The layer structure of the liquid crystal display device shown in Figs. 6A and 6B is almost the same as the liquid crystal display device shown in Figs. Detailed description will be omitted.

However, in the case of the liquid crystal display shown in FIGS. 6A and 6B, unlike the liquid crystal display shown in FIGS. 1 and 2, a shielding electrode 88 is formed below the data line 171, and the data line is formed. The vertical connection portion 273 of the reference electrode 270 extending above 171 has a second opening 276 disposed on the data line 171. The shielding electrode 88 may be formed of the same layer as the gate conductor and may be floated. The shielding electrode 88 can prevent light leakage. The second opening 276 of the reference electrode 270 disposed on the data line 171 may be about 50% or more of the vertical length of the data line 171 disposed in one pixel area. As described above, the parasitic capacitance between the data line 171 and the reference electrode 270 may be further reduced by forming and removing the second opening 276 in the reference electrode 270 disposed on the data line 171.

Many features of the embodiment shown in FIGS. 1 and 2, 4, and 5 are all applicable to the embodiment shown in FIG. 6.

Next, a liquid crystal display according to another exemplary embodiment of the present invention will be described with reference to FIGS. 7A and 7B. FIG. 7A is a layout view of a portion of a liquid crystal display according to another exemplary embodiment. FIG. 7B is a cross-sectional view of the liquid crystal display of FIG. 7A taken along the line VIIB-VIIB.

The layer structure of the liquid crystal display device shown in Figs. 7A and 7B is almost the same as that of the liquid crystal display device shown in Figs.

The gate line 121 and the reference voltage line 131 including the gate electrode 124 are formed on the substrate 110, and the gate insulating layer 140 is formed on the gate line 121 and the reference voltage line 131. The semiconductor line 154 and the ohmic contacts 163 and 165 are formed on the gate insulating layer 140, and the data line includes the source electrode 173 on the gate insulating layer 140 and the ohmic contacts 163 and 165. 171 and a drain electrode 175 are formed. A pixel electrode 191 is formed on a portion of the gate insulating layer 140 and the drain electrode 175, and a contact is formed on the pixel electrode 191, the data line 171, the drain electrode 175, and the exposed semiconductor 154. A protective film 180 having a hole 183 is formed. The reference electrode 270 overlapping the pixel electrode 191 and having the branch electrode 271 is formed on the passivation layer 180.

However, unlike the liquid crystal display illustrated in FIGS. 1 and 2, the reference electrode 270 of the liquid crystal display according to the present exemplary embodiment overlaps the pixel electrode 191, and the plurality of branch electrodes 271 and the plurality of branch electrodes 271. The first connector 272 connects the branch electrodes 271 of the second electrode 271, and the second connector 273 connects the reference electrodes 270 of the neighboring pixel regions with each other.

The branch electrode 271 of the reference electrode 270 extends in a direction substantially parallel to the gate line 121, and may be inclined to form an angle of about 5 ° to about 20 ° with the gate line 121. In addition, the branch electrode 271 of the reference electrode 270 may be inclined to form an angle of about 7 ° to 13 °, more specifically about 10 ° with the rubbing direction of the alignment layer.

The branch electrode 271 of the reference electrode 270 is disposed at a portion adjacent to the first portion 271a and the first connection portion 272 extending in a predetermined direction, and is disposed at both ends of the first portion 271a. Second portion 271b.

The first portion 271a of the branch electrode 271 of the reference electrode 270 forms about 10 ° with the rubbing direction of the alignment layer, which will be described later, and the second portion 271b is about 7 ° with the first portion 271a. To bend to about 15 °.

Many of the features of the embodiments shown in FIGS. 1 and 2, 4, 5, and 6A and 6B are applicable to all of the embodiments shown in FIGS. 7A and 7B.

In the above embodiment, the pixel electrode has a surface shape without a separate pattern in the pixel region, and the reference electrode is formed of a plurality of linear branch electrodes and branch electrode connecting portions connecting them, but the present invention is limited thereto. It doesn't happen. That is, the reference electrode may have a surface shape without a separate pattern in the pixel area, and the pixel electrode may be formed of a plurality of linear branch electrodes and branch electrode connecting parts connecting them. Further, the present invention is applicable not only to the case where the color filter and the light blocking film are formed on the upper substrate, but also to all the cases where the color filter and the light blocking film are positioned on the insulating substrate.

1 is a layout view illustrating a liquid crystal display according to an exemplary embodiment of the present invention.

FIG. 2A is a cross-sectional view of the liquid crystal display of FIG. 1 taken along the line IIA-IIA.

FIG. 2B is a cross-sectional view of the liquid crystal display of FIG. 1 taken along the line IIB-IIB. FIG.

3 is an enlarged view illustrating a portion of the liquid crystal display of FIG. 1.

4 is a layout view of a liquid crystal display according to another exemplary embodiment, and illustrates a plurality of pixels.

5 is a layout view of a liquid crystal display according to another exemplary embodiment, and illustrates a plurality of pixels.

6A is a layout view of a portion of a liquid crystal display according to another exemplary embodiment of the present invention.

FIG. 6B is a cross-sectional view of the liquid crystal display of FIG. 6A taken along the line VIB-VIB.

7A is a layout view illustrating a portion of a liquid crystal display according to another exemplary embodiment of the present invention.

FIG. 7B is a cross-sectional view of the liquid crystal display of FIG. 7A taken along the line VIIB-VIIB. FIG.

Claims (27)

Insulation board, A gate line and a data line on the insulating substrate; A thin film transistor connected to the gate line and the data line and including a source electrode and a drain electrode, A pixel electrode in contact with a portion of the drain electrode, A passivation layer on the pixel electrode and the thin film transistor, and A reference electrode positioned on the passivation layer and overlapping the pixel electrode; The reference electrode includes a plurality of branch electrodes. In claim 1, The data line may include a first curved portion disposed in an intermediate region of the pixel region; And a second curved portion bent to form a predetermined angle with the first curved portion. 3. The method of claim 2, And the pixel electrode includes a pair of curved edges substantially parallel to the first curved portion and the second curved portion of the data line. 3. The method of claim 2, The branch electrode of the reference electrode includes a first portion and a second portion parallel to the first curved portion and the second curved portion of the data line. In claim 4, Further comprising an alignment film disposed on the insulating substrate, The alignment layer is a horizontal alignment layer, And the first portion of the branch electrode of the reference electrode is in a range of 5 ° to 10 ° with a rubbing direction of the alignment layer. The method of claim 5, And the second portion of the branch electrode of the reference electrode forms an angle of 7 ° to 15 ° with the first portion. In claim 6, And the first portion of the branch electrode of the reference electrode is 7 ° to the rubbing direction of the alignment layer. In claim 1, The reference electrode further includes a horizontal connecting portion connecting the branch electrode to each other from above and below, The horizontal connection part is substantially parallel with the gate line. In claim 8, The branch electrode of the reference electrode may further include a third portion bent at a predetermined angle to a portion where the horizontal connection portion and the branch electrode are connected. The method of claim 9, And the third portion of the reference electrode forms a 7 ° to 15 ° angle with the branch electrode. In claim 1, The reference electrode has a first opening that exposes a portion of the thin film transistor and the data line. The method of claim 12, The first opening has a vertical width of about 30 μm to about 60 μm. In claim 1, Further comprising a reference voltage line disposed on the substrate, And the reference voltage line is physically and electrically connected to the reference electrode through a contact hole formed in the passivation layer. The method of claim 13, And the reference voltage line is disposed at a central portion of the pixel area. The method of claim 14, And a contact portion of the reference voltage line and the reference voltage is disposed in at least one pixel among three adjacent pixels. 16. The method of claim 15, And the pixel electrode is removed from a portion corresponding to a contact portion between the reference voltage line and the reference voltage. 16. The method of claim 15, A spacer is disposed in at least one of the adjacent pixels in which the contact portion of the reference voltage line and the reference voltage is not disposed. 16. The method of claim 15, The pixel in which the spacer is disposed among the three adjacent pixels is a green pixel. 16. The method of claim 15, The pixel in which the contact portion of the reference voltage line and the reference voltage is disposed among the three adjacent pixels is a green pixel. In claim 1, And the reference electrodes arranged on neighboring pixels are connected to each other. In claim 1, The source electrode is positioned on the same line as the data line; The drain electrode extends in parallel with the drain electrode. In claim 1, Further comprising a reference voltage line disposed on the substrate, The reference voltage line is physically and electrically connected to the reference electrode through a contact hole formed in the passivation layer. And the reference voltage line is disposed at a portion adjacent to the gate line. In claim 1, The width of the data line is about 3.5 μm ± 0.75. In claim 1, The pixel electrode covers a portion of the drain electrode, and is directly connected to the drain electrode. In claim 1, The protective film has a thickness of about 5000 kPa or more. In claim 1, The protective film has a thickness of about 6000 kPa to about 8000 kPa. In claim 1, An opposite substrate facing the insulating substrate, And a liquid crystal layer positioned between the insulating substrate and the opposite side and having a positive dielectric anisotropy value.

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