KR100859522B1 - Thin Film Transistor Substrates, Color Filter Substrates, and Liquid Crystal Displays - Google Patents

Abstract

The present invention relates to a thin film transistor substrate, a color filter substrate, and a liquid crystal display device. The liquid crystal display device according to the present invention includes a red, blue, green color filter, a light shielding pattern, and a reference electrode for expressing a color on an insulating substrate. A lower substrate including a substrate, a gate wiring, a data wiring, a pixel electrode, and a thin film transistor connected thereto, and a liquid crystal filled between the upper and lower substrates, and formed on one of the upper and lower substrates. Means for forming an electric field to orientate.

LCD, electrode, liquid crystal, electric field

Description

Thin firm transistor array panels, color filter array panels and liquid crystal displays

1A is a layout view of a thin film transistor substrate according to a first exemplary embodiment of the present invention.

FIG. 1B is a cross-sectional view taken along line Ib-Ib 'of FIG. 1A.

2 is a cross-sectional view of a thin film transistor substrate according to a second exemplary embodiment of the present invention.

3A is a layout view of a thin film transistor substrate according to a third exemplary embodiment of the present invention.

3B is a cross-sectional view taken along line IIIb-IIIb 'of FIG. 3B.

4 to 8 are cross-sectional views of the thin film transistor substrate according to the fourth to eighth embodiments of the present invention.

9A is a layout view of a color filter substrate according to a ninth embodiment of the present invention.

FIG. 9B is a cross-sectional view taken along line IX-IX 'of FIG. 9B.

10 is a cross-sectional view of a color filter substrate according to a tenth embodiment of the present invention.

11A is a layout view of a color filter substrate according to an eleventh embodiment of the present invention.

FIG. 11B is a cross-sectional view taken along line XI-XI ′ of FIG. 11A.

12A to 14B are diagrams for describing an operation of the liquid crystal display according to the present invention.                 

※ Explanation of code for main part of drawing ※

95: auxiliary gate pad 97: auxiliary data pad

110: insulated substrate 121: gate line

123: gate electrode 125: gate pad

131: sustain electrode line 140: gate insulating layer

151, 153, 157, 159: semiconductor layer 161, 162, 163, 165, 169: ohmic contact layer

171: data line 173: source electrode

175: drain electrode 177: sustain electrode

179: data pad 190: pixel electrode

201a, 202a, 203a, 204a: drive electrode 201b, 202b, 203b, 204b: drive electrode line

220: shading pattern 230R: red filter

230G: Green Filter 230B: Blue Filter

270 reference electrode

The present invention relates to a thin film transistor substrate, a color filter substrate, and a liquid crystal display device for implementing a wide viewing angle.                         

The liquid crystal display includes a color filter including a black matrix (BM), an upper substrate on which a transparent reference electrode is formed on the color filter, and a switching element that transmits or blocks an image signal according to an input scan signal. It is composed of a lower substrate including a) and the liquid crystal is filled between these substrates.

Among them, the liquid crystal injected between the lower substrate and the upper substrate is generally a twisted nematic (hereinafter referred to as TN) liquid crystal. TN liquid crystal molecules have a long, thin rod shape, have a constant pitch, twist in a spiral shape, and have a twisted structure in which the long-axis alignment direction of the liquid crystal molecules is continuously changed.

In a liquid crystal display device using a TN liquid crystal, the incident polarized light exhibits different optical viewing angle characteristics according to the arrangement of the long axis and the short axis of the molecule. Since the viewing angle of the liquid crystal display device is formed along the long axis of the liquid crystal molecules of the spiral structure, the long axis of the molecule changes according to the viewing angle. Such a liquid crystal display has a symmetrical viewing angle with respect to the horizontal direction and an asymmetrical viewing angle with respect to the vertical direction. In particular, a gray level phenomenon occurs in a direction in which the liquid crystal tilt direction and the viewing angle at the center of the cell coincide with each other. Therefore, the light transmittance is distributed relatively symmetrically with respect to the horizontal viewing angle, but the light transmittance is distributed asymmetrically with respect to the up and down directions, so that an image inversion is generated at the viewing angle in the up and down directions, thereby narrowing the viewing angle.

In this case, the viewing angle may be improved by applying a discotic-based compensation plate, but it is difficult to improve the gray level reversal.                         

The liquid crystal mode having a wide viewing angle characteristic includes an in-plane-switching (hereinafter referred to as IPS) mode and a vertically aligned mode (hereinafter referred to as VA) mode.

The IPS mode is a structure in which the common electrode and the pixel electrode are spaced apart from each other on the same substrate by a predetermined interval, and the change of the refractive index of the liquid crystal molecules is small depending on the direction viewed by the transverse electric field distributed between the pixel electrode and the reference electrode, thereby improving the viewing angle. . However, in the transverse electric field mode, since the reference electrode and the pixel electrode are simultaneously formed on a single pixel, the aperture ratio of the liquid crystal panel is reduced, the luminance characteristic is poor, and the response speed is slow.

VA mode facilitates symmetrical arrangement of liquid crystals, and has a wide viewing angle and fast response characteristics. Such a vertical alignment mode can be used to form a multi-domain such as patterned vertical alignment (PVA) to improve the wide viewing angle characteristics, but the process for forming the domain is complicated and the pixel structure is complicated. In addition, since the use of negative liquid crystals requires high voltage driving, the aperture ratio is low, and the resiliency of the liquid crystal itself is used even at the response speed, thereby limiting the response speed.

For this reason, as the liquid crystal display becomes larger, a wide viewing angle and a quick response characteristic of the liquid crystal display are required.

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid crystal display device having a wide viewing angle and a quick response characteristic and a method of manufacturing the same.

The present invention relates to a thin film transistor substrate, a color filter, and a liquid crystal display device for implementing a wide viewing angle.

A thin film transistor substrate according to the present invention includes a gate line formed on an insulating substrate, a gate electrode which is a part of the gate line, a gate wiring including a gate pad connected to one end of the gate line, a gate insulating layer formed on the substrate, and gate insulation A semiconductor layer formed in a predetermined region of the layer, an ohmic contact layer formed to be spaced apart from each other by a predetermined distance on the semiconductor layer, and a data line and a data line formed on the gate insulating layer and defining a pixel region crossing the gate line. A source electrode connected to one side of the ohmic contact layer, a drain electrode facing the source electrode and formed on the other side of the ohmic contact layer, a data line including a data pad connected to one end of the data line, and formed on the data line. Including a first contact hole A protective layer, which is formed on the protective layer, is connected to the drain electrode through the first contact hole and includes a pixel electrode having an exposure hole, and is formed on the same layer as the gate wiring or data wiring and disposed at a position corresponding to the exposure hole. And a driving electrode line connected to one end of the driving electrode for applying power to the driving electrode.

In this case, the driving electrode is a regular polygon having a vertex of at least three points or more, and is preferably formed to correspond to the center of the pixel area or the edge of the pixel area.

In addition, the color substrate according to the present invention includes a light shielding pattern formed in a matrix shape on an insulating substrate, a red, blue, green color filter formed on the light shielding pattern, a first interlayer insulating layer and a first interlayer formed on the color filter. A driving electrode line formed in a predetermined region on the insulating layer and a driving electrode line connected to one end of the driving electrode to apply power to the driving electrode, a second interlayer insulating layer formed on the driving electrode, and a second interlayer insulating layer And a reference electrode.

Here, the driving electrode is a regular polygon having a vertex of at least three points or more, and is preferably formed to correspond to the center or edge of the color filter.

In addition, the liquid crystal display according to the present invention includes red, blue, and green color filters, light blocking patterns, upper substrates including reference electrodes, gate wirings, data wirings, pixel electrodes, and the like, for expressing colors on an insulating substrate. And a means for forming an electric field including a liquid crystal filled between the lower substrate, the upper substrate, and the lower substrate including the thin film transistor, and formed on one of the upper substrate and the lower substrate.

The means for forming the electric field is preferably formed between the reference electrode and the color filter so as to be insulated from the reference electrode, or is formed on the same layer as the data wiring or the gate wiring.

The means for forming the electric field may include a driving electrode formed of a conductive metal and a driving electrode line for applying power to the driving electrode, and the driving electrode may be formed to correspond to the center or the edge of the pixel electrode or the color filter.

In addition, an exposure opening is formed in the pixel electrode or the reference electrode corresponding to the driving electrode, and an electric field formed between the pixel electrode and the reference electrode is larger than an electric field formed between the driving electrode and the reference electrode, and the driving electrode is a circle or It is preferable that it is formed in the regular polygon which has three or more vertices.

Embodiments according to the present invention will now be described in detail with the accompanying drawings.

[First Embodiment]

 1A is a layout view illustrating a thin film transistor substrate according to a first exemplary embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along line Ib-Ib ′ of FIG. 1A.

As illustrated in FIGS. 1A to 1B, gate wirings 121, 123, and 125, a driving electrode 201a, and a driving electrode line 201b are formed on the transparent insulating substrate 110.

The gate wires 121, 123, and 125 are connected to one end of the gate line 121 and the gate line 121 that are formed to extend in the horizontal direction, and receive a gate signal from the outside and transfer the gate signal to the gate line 121. The pad 125 includes a gate electrode 123 that is a part of the gate line 121.

The driving electrode 201a is a branch of the driving electrode line 201b formed in parallel with the gate line and is formed in the pixel region defined by the gate line 121 and the data line to be described later, so that a uniform electric field is formed in the entire pixel region. . The electrode is a regular polygon with a circle or three or more vertices, and is formed to be completely coincident when the polygon is folded in half.

The gate insulating layer 140 is formed on the entire surface of the substrate including the gate wirings 121, 123, and 125.                     

On the gate insulating layer 140 corresponding to the gate electrode 123, a semiconductor layer 151 formed of a semiconductor material such as amorphous silicon and a semiconductor material such as amorphous silicon are doped with high concentration of n-type impurities. The ohmic contacts 161, 163, and 165 are formed.

The data lines 171, 173, 175, and 179 and the storage electrode 177 are formed on the ohmic contacts 161, 163, and 165 and the gate insulating layer 140.

The data wires 171, 173, 175, and 179 are perpendicular to the gate line 121 to branch to the data line 171 and the data line 171 to define a pixel area, and are also connected to the ohmic contact layer 163. It is connected to one end of the source electrode 173 and the data line 171, and is separated from the data pad 179 and the source electrode 173 to which an image signal from an external source is applied. A drain electrode 175 formed on the opposite ohmic contact layer 165 of 173, and a storage electrode 177 overlapping the gate line 121 to improve the storage capacitance.

A first contact hole 181 exposing the drain electrode 175 on the substrate, a second contact hole 182 exposing the gate pad 125, a third contact hole 183 exposing the data pad 125, The protective layer 180 having the fourth contact hole 184 exposing the sustain electrode 177 is formed.

The pixel electrode 190 and the second contact hole 182 connected to the drain electrode 175 and the storage electrode 177 are respectively formed on the passivation layer 180 through the first and fourth contact holes 181 and 184. An auxiliary gate pad 95 connected to the gate pad 125 and an auxiliary data pad 97 connected to the data pad 179 through the third contact hole 183 are formed. The pixel electrode 190 may partially overlap the gate line 121 and the data line 171 to increase the aperture ratio, but may also be formed so as not to overlap (not shown). When the pixel electrode 190 is formed to overlap the data line 171, the protective layer 180 is made of a low dielectric constant material to reduce the coupling between the data line 171 and the pixel electrode 190. It is preferable to form. In addition, the exposure holes 191 and 192 are formed at portions of the pixel electrode 190 corresponding to the driving electrode 201a so that the electric field of the driving electrode 201a flows out into the liquid crystal layer.

Second Embodiment

2 is a cross-sectional view of a thin film transistor substrate according to a second exemplary embodiment of the present invention. As shown in FIG. 2, unlike the first embodiment, the opening 185 exposing the driving electrode 201a is further formed in the protective layer 180 in the second embodiment.

The opening 185 is for forming a stronger electric field than in the first embodiment, so that a sufficiently strong electric field can be applied to the liquid crystal when driving the liquid crystal layer using the thin film transistor according to the present invention. That is, in the case where the opening 185 is not present, the electric field is weakened due to the plurality of dielectric layers (gate insulating layer and protective layer) formed on the driving electrode 201a, so that it is difficult to obtain a sufficiently strong electric field.

 [Third to eighth embodiments]

3A is a layout view illustrating a thin film transistor substrate according to a third exemplary embodiment of the present invention, and FIG. 3B is a cross-sectional view taken along line IIIb-IIIb ′ of FIG. 3A.

As shown in Figs. 3A and 3B, a driving electrode line 201b for supplying power and a driving electrode 202a connected to the driving electrode line 201b are formed. The driving electrode 202a is a regular polygon having a circle or three or more vertices. The driving electrode 202a corresponds to the pixel area and is formed along an edge inside the pixel area so that the liquid crystal is positioned in an area surrounded by the driving electrode 202a. The pixel electrode 190 has an exposure hole 193 in an area corresponding to the driving electrode 202a.

The drive electrode 201a of the first embodiment is a circle having a predetermined radius, and the linear wiring is connected to the drive electrode line 201b. However, the drive electrode 202a of the third embodiment has a drive electrode along an edge in the pixel region. Since 201a is formed, the vertices are only connected by a line having a certain width. The electrode was formed in the same structure as in the first embodiment except that the shape of the electrode was different. Of course, as shown in Fig. 4, the openings 186 formed in the second embodiment can be formed.

In all the embodiments described above, the electrodes are formed on the same layer as the gate wiring, but as shown in FIGS. 5 to 8, the electrodes according to the present invention are formed on the same layer as the data wiring (Fifth to Eighth Embodiments). Can be

 [Example 9, Example 10]

FIG. 9A is a layout view of a color filter substrate according to a ninth embodiment of the present invention, and FIG. 9B is a cross-sectional view taken along line IX-IX ′ of FIG. 9A.

9A and 9B, a black matrix 220 is formed in a matrix shape in order to prevent light leakage on the insulating substrate. A color filter of red 230R, green 230G, and blue 230B colors is formed in a region defined by the light shielding pattern, and a first interlayer insulating layer 801 is formed on the color filters 230R, 230G, and 230B. Formed. A driving electrode 203a for forming an electric field in the liquid crystal and a driving electrode line 203b for applying power to the driving electrode 203a are formed on the first interlayer insulating layer 801. The driving electrode 203a is a regular polygon consisting of a circle or three or more vertices, and is formed to correspond to the center of each color filter. In addition, a second interlayer insulating layer 802 is formed on the driving electrode 203a and a reference electrode 270 made of a transparent conductive material such as indium tin oxide (ITO) or indiumzinc oxide (IZO) on the second interlayer insulating layer 802. ) Is formed. Of course, like the pixel electrode 190 of the thin film transistor described above, the reference electrode 270 is not formed in the region 271 corresponding to the driving electrode 203a.

As shown in Fig. 10, a stronger electric field can be formed by forming the openings 187 formed in the thin film transistor substrate according to the present invention.

11A to 11B, a drive electrode 204a having the same shape as the drive electrode 202a formed in the third embodiment can be formed on the color filters 230R, 230G, and 230B. Eleventh Embodiment Of course, an opening 187 may be formed on the driving electrode 204a to form a stronger electric field (not shown).

When the liquid crystal display device using the thin film transistor and the color filter substrate described above are manufactured, their operation is as follows. 12 to 15 are schematic diagrams for explaining the operation of the liquid crystal display according to the present invention, which may be equally applied to various liquid crystal display devices using the thin film transistor substrate and the color filter substrate according to the above-described embodiments. Can be.

The operation of the liquid crystal display according to the present invention will now be described using white and black states as an example.

12A and 12B are diagrams for describing a white state. A voltage is applied only between the driving electrode 201a and the reference electrode 270, and a voltage is applied between the pixel electrode 190 and the reference electrode 270. It is not. Therefore, as shown, the direction of the liquid crystal is arranged concentrically around the electrode to display white.

In this case, the pixel electrode 190 may be in a floating state or maintained at an equipotential with the reference electrode 270.

Next, FIGS. 13A and 13B are diagrams for describing a black state. A voltage is applied only between the pixel electrode 190 and the reference electrode 270 without applying a voltage between the driving electrode 201a and the reference electrode 270. It is authorized. In this case, since the liquid crystal 3 is aligned with the driving electrode 201a, the liquid crystal 3 has a pretilt PRE PILT and is forced by the electric field formed between the pixel electrode 190 and the reference electrode 270. 3) is reordered so that it responds very quickly and achieves a complete black state like the vertical orientation of the PVA.

As another method for displaying the black state, as shown in FIGS. 14A and 14B, a voltage is applied between the driving electrode 201a and the reference electrode 270 as well as between the pixel electrode 190 and the reference electrode 270. It is authorized. In this case, the electric field applied between the pixel electrode 190 and the reference electrode 270 should be much stronger than the electric field applied between the driving electrode 201a and the reference electrode 270. At this time, the light may be slightly leaked from the front, but by blocking the light blocking pattern 220, an excellent black state may be obtained.

As described above, in the present invention, since the driving electrode is formed separately from the pixel electrode and the liquid crystal is driven using the driving electrode and the pixel electrode, the change in the alignment of the liquid crystal is always forced by an electric field, and the response speed is high. An alignment film forming process and a rubbing process for aligning the liquid crystal may be omitted. In addition, since the liquid crystals are aligned so as to be symmetrical with respect to the driving electrode, the viewing angle and gray level inversion are improved.

Claims (14)

A gate wiring formed on an insulating substrate, A data line insulated from and intersecting the gate line, A thin film transistor connected to the gate line and the data line, A pixel electrode connected to the thin film transistor and having an exposure hole; A driving electrode formed on the same layer as the gate wiring or data wiring and disposed at a position corresponding to the exposure opening; A driving electrode line connected to one end of the driving electrode to apply power to the driving electrode; Including, The exposure opening is a thin film transistor substrate positioned in the center of the pixel electrode. delete In claim 1, The driving electrode may be a regular polygon having a circle or three or more vertices. A light shielding pattern formed in a matrix on an insulating substrate, A red, blue, and green color filter formed on the light blocking pattern; A first interlayer insulating layer formed on the color filter, A driving electrode corresponding to a center of an area surrounded by the light blocking pattern formed on the first interlayer insulating layer and surrounded by a light blocking pattern, and a driving electrode line connected to one end of the driving electrode to apply power to the driving electrode; A second interlayer insulating layer formed on the driving electrode; And a reference electrode formed on the second interlayer insulating layer and formed on the entire surface of the substrate. delete In claim 4, The driving electrode may be a regular polygon having a circle or three or more vertices. An upper substrate including red, blue, and green color filters, a light shielding pattern, and a reference electrode for expressing colors on the insulating substrate; A lower substrate including a gate wiring, a data wiring, a pixel electrode, and a thin film transistor connected thereto; A liquid crystal filled between the upper and lower substrates, A driving electrode formed on one of the upper substrate and the lower substrate and overlapping the center of the pixel electrode; One of the reference electrode and the pixel electrode has an exposed hole corresponding to the driving electrode Including, And the driving electrode is positioned at the center of the pixel electrode. In claim 7, And the driving electrode is insulated from the reference electrode between the reference electrode and the color filter. In claim 7, And the driving electrode is formed on the same layer as the data line or the gate line. The method according to any one of claims 7 to 9, The driving electrode crosses the pixel electrode and includes a driving electrode line for applying power to the driving electrode. The driving electrode is symmetrical about the driving electrode line. delete delete In claim 10, And an electric field formed between the pixel electrode and the reference electrode is larger than an electric field formed between the driving electrode and the reference electrode. In claim 10, And the driving electrode is formed in a regular polygon having a circle or three or more vertices.

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