KR20110076367A - Transverse electric field reflection type liquid crystal display device - Google Patents

Abstract

The present invention includes a first substrate and a second substrate facing each other; A gate wiring and a data wiring formed on an inner surface of the first substrate to define a pixel region having a reflection region and a transmission region crossing each other through a gate insulating film; A common wiring formed in parallel with the gate wiring; A thin film transistor connected to the gate line and the data line in the pixel area; A first passivation layer covering the data line and the thin film transistor; A reflection plate formed in the reflection area over the first protective layer; A second protective layer formed over the reflecting plate; Contacting the drain electrode through a drain contact hole exposing the drain electrode of the thin film transistor to the upper portion of the second protective layer, and is formed in a plate shape in the transmissive region, and has a long axis in a first direction in the reflective region. A pixel electrode having a plurality of first openings formed therein; A third passivation layer formed over the pixel electrode; A plurality of second openings connected to the common protective layer through the common contact hole on the third passivation layer and spaced apart from each other in the transmissive area with a long axis in a second direction perpendicular to the gate wiring; A common electrode comprising a plurality of third openings having a long axis and spaced apart in one direction; A color filter layer formed on an inner surface of the second substrate; And a liquid crystal layer interposed between the first and second substrates, wherein the first opening and the third opening are alternately arranged in a plane.

Reflective Transmissive, Liquid Crystal Display, Reflective Efficiency, Transverse Field Mode

Description

In-plane switching mode transflective type liquid crystal display device

The present invention relates to a liquid crystal display device, and more particularly, to a transverse electric field mode reflection transmission type liquid crystal display device having an improved reflectance in a reflection area region.

In general, a liquid crystal display device is a display device using characteristics of liquid crystal molecules that differ in arrangement depending on voltage application. The liquid crystal display device can be driven at a lower power than a cathode ray tube, and is advantageous in miniaturization and thinning. BACKGROUND ART There is a spotlight as a flat panel display device such as a television, and since it is easy to carry due to its lightweight and thin characteristics, it is used as a display element of a notebook or a personal portable terminal.

In the liquid crystal display, two substrates on which electrodes are formed are disposed so that the two electrodes face each other, and a liquid crystal is generated by an electric field generated by a voltage difference applied to the two electrodes through a liquid crystal between the two substrates. By controlling the movement of molecules, it is a device that expresses an image by controlling the transmittance of light that varies accordingly.

On the other hand, the liquid crystal display device is generally a passive element that does not emit light by itself, so a separate light source is required. Therefore, in addition to the liquid crystal panel (panel) consisting of the two substrates and the liquid crystal layer (backlight) for providing a light (backlight) for supplying the light emitted from the backlight to the liquid crystal panel, the amount of light according to the arrangement of the liquid crystal Display the image by adjusting.

Such a liquid crystal display device is called a transmission type liquid crystal display device. Since the liquid crystal display device uses an artificial light source such as a backlight, a bright image can be realized even in a dark external environment, but a portable device is required because power must be supplied to the backlight. When used as a display device of a relatively large power consumption (power consumption) is a disadvantage.

Therefore, a reflection type liquid crystal display device using an external light source without using a backlight has been proposed to compensate for the above disadvantage.

Since the reflective liquid crystal display device operates by using external natural light or artificial light, it significantly reduces the amount of power consumed by the backlight, so the power consumption is relatively small compared to the transmissive type, and thus it can be used in a portable state for a long time. It is mainly used as a display element of a portable device such as an assistant.

However, such a reflective liquid crystal display device has an advantage of low power consumption because it does not have a separate light source, but can not be used in a place where the external light is weak or absent.

Therefore, recently, a transflective liquid crystal display device having only the advantages of a reflective liquid crystal display device and a transmissive liquid crystal display device has been proposed. In the case of such a transflective liquid crystal display device, mainly an electrically controlled birefringence (ECB) mode or a VA (vertical alignment) mode is mainly implemented, the ECB mode has a disadvantage of low viewing angle, VA mode also requires a large number of viewing angle compensation film to be configured to improve the viewing angle, the problem of manufacturing cost increases have.

On the other hand, in the case of the liquid crystal display device, due to its lightweight and thin structure, it has recently escaped from a personal display device such as a portable notebook and is widely used as a mass media such as a TV, so that a large number of users can watch from various angles instead of only an individual. Therefore, viewing angle is becoming an important issue.

Therefore, in order to overcome the disadvantages of the low viewing angles of the above-described VA mode and ECB mode liquid crystal display devices, both the common electrode and the pixel electrode are formed on the same substrate, and are driven by the transverse electric field to improve the range of the viewing angle. The device has been proposed.

1 is a simplified cross-sectional view of a reflection area and a transmission area of a conventional transverse electric field mode reflection-transmissive liquid crystal display device. In this case, the pixel region is defined as a reflection region where a reflection plate is formed so that light does not pass from below and a transmission region in which the reflection plate is not formed.

As shown in the drawing, a gate line (not shown) and a data line (not shown) intersect with each other to define a pixel region P, and are parallel to the gate line (not shown). A common wiring (not shown) is formed to extend and penetrate the pixel region P. A thin film transistor, which is a switching element, is formed in each pixel region P. Referring to FIG.

In addition, a reflective plate 50 is formed of a metal material having good reflectance in the reflective region RA, and a pixel electrode 70 is formed in the pixel region P on the reflective plate 50.

In addition, a common electrode 80 is connected to the common wiring (not shown) through the insulating layer 72 and has a plurality of bar-shaped openings op1 and op2 over the pixel electrode 70. It is being formed. In this case, the plurality of openings op1 and op2 are divided into a plurality of first openings op1 and a plurality of second openings op2 and are provided in the transmission area TA and the reflection area RA, respectively. The first and second openings op1 and op2 are characterized by varying the directions of their major axes.

An overcoat layer 88 is formed on the front surface of the color filter layer 86 and the front surface of the color filter layer 86 so as to face the array substrate 2 having such a configuration and correspond to a black matrix (not shown) and each pixel region P at the boundary of the pixel region P. The provided color filter substrate 83 is provided, and the liquid crystal layer 90 is interposed between the array substrate 2 and the color filter substrate 83.

On the other hand, in the conventional transverse electric field mode reflection-transmissive liquid crystal display device 1 having the above-described configuration, the thickness of the liquid crystal layer 90 in the transmissive area TA (hereinafter referred to as the first cell gap d1) is a reflection area ( It is comprised so that it may double as the cell gap d2 in RA). This is to match the retardation that the light in the liquid crystal layer 90 feels. In the case of the transmission area TA, the light from the backlight unit (not shown) located under the array substrate 2 is used. Since the light passes through the liquid crystal layer 90 once, in the reflection area RA, external light is incident on the display area of the liquid crystal display device 1 and reflected by the reflection plate 50 to the outside. Since the user sees the light coming out, it passes through the liquid crystal layer 90 twice.

Therefore, in this process, the light coming out of the reflection area RA and the light coming out of the transmission area TA have different retardation values, so that the reflection area RA forms a cell of λ / 4 to match the transmission area TA. Is configured to vary the thickness of the liquid crystal layer 90 to form a cell of λ / 2.

On the other hand, the transverse electric field mode reflection-transmissive liquid crystal display having the above-described configuration forms a pixel area and a transmission area in one pixel area to simultaneously improve or improve power efficiency and external visibility by using a light source and an external light source from the backlight unit. I'm making it.

However, the conventional transverse electric field mode reflection-transmissive liquid crystal display having the above-described configuration has a problem that the reflection efficiency is relatively low in the reflection area.

FIG. 2 is a cross-sectional view of a reflection area in a conventional array substrate of a transverse electric field mode reflection-transmissive liquid crystal display device, and schematically illustrates an external light path in a common electrode, a pixel electrode, and a reflection plate and a reflection area.

As shown in the drawings, the reflection area RA of the conventional transverse electric field mode reflection-transmissive liquid crystal display device includes an insulating layer (not shown) formed on the reflective plate 50 on the array substrate. A plate-shaped pixel electrode 70 is formed on each insulating layer (not shown), and has a plurality of second openings op2 through a second insulating layer (not shown). The common electrode 80 is formed.

In this case, looking at the path in the array substrate 1 of the external light incident to the common electrode 80, the common electrode 80 passes through the common electrode 80 and is incident to the pixel electrode 70, and then enters the reflective plate 50. After reflection, the light passes through the pixel electrode 70 and the common electrode 80 and finally enters the user's eye.

Except for the insulating layer, the partial external light passes through the common electrode 80 twice and the pixel electrode 70 twice inside the array substrate 1, and in this process, light loss occurs, thereby reducing reflection efficiency. It's happening.

Therefore, the transverse electric field mode reflection-transmissive liquid crystal display device having the above-described configuration is required to further maximize the reflection efficiency in the reflection area.

The present invention has been made to solve the above problems, and provides a transverse electric field mode liquid crystal display device which can improve reflection efficiency by minimizing the number of transmission of the pixel electrode and the common electrode by the external light incident to the reflection area. It is for that purpose.

A transverse electric field mode reflective transmission liquid crystal display device according to the present invention comprises: a first substrate and a second substrate facing each other; A gate wiring and a data wiring formed on an inner surface of the first substrate to define a pixel region having a reflection region and a transmission region crossing each other through a gate insulating film; A common wiring formed in parallel with the gate wiring; A thin film transistor connected to the gate line and the data line in the pixel area; A first passivation layer covering the data line and the thin film transistor; A reflection plate formed in the reflection area over the first protective layer; A second protective layer formed over the reflecting plate; Contacting the drain electrode through a drain contact hole exposing the drain electrode of the thin film transistor to the upper portion of the second protective layer, and is formed in a plate shape in the transmissive region, and has a long axis in a first direction in the reflective region. A pixel electrode having a plurality of first openings formed therein; A third passivation layer formed over the pixel electrode; A plurality of second openings connected to the common protective layer through the common contact hole on the third passivation layer and spaced apart from each other in the transmissive area with a long axis in a second direction perpendicular to the gate wiring; A common electrode comprising a plurality of third openings having a long axis and spaced apart in one direction; A color filter layer formed on an inner surface of the second substrate; And a liquid crystal layer interposed between the first and second substrates, wherein the first opening and the third opening are alternately arranged in a plane.

In this case, a portion of the common electrode positioned between the second opening and the third opening is defined as a common electrode finger portion, the width of the first opening is a first width, the width of the common electrode finger portion is a second width, and the second When the width of the second opening or the third opening is defined as the third width, the first width is greater than or equal to 2 μm and has a size equal to or less than 1.2 times the third width, wherein The first opening may be formed to overlap the common electrode finger. In addition, when the pixel electrode portion between the first openings is defined as a pixel electrode finger portion, both ends of the pixel electrode finger portion may overlap both ends of the common electrode finger portion and less than 10% of the width of the common electrode finger portion. It is characterized by the formation.

In addition, the plate-shaped pixel electrode formed in the transmissive region has a plurality of fourth openings alternately arranged in parallel with a plurality of second openings having a long axis in the second direction and spaced apart from each other.

In addition, the thickness of the liquid crystal layer in the reflective region is characterized in that 1/2 of the thickness of the liquid crystal layer in the transmission region.

In addition, a first storage electrode branching from the common line to the reflective region and a second storage electrode branching to overlap the data line are formed, and the drain electrode extends to overlap the first storage electrode. The first storage electrode, the gate insulating layer, and the drain electrode overlapping each other form a first storage capacitor, and the second storage electrode, the gate insulating layer, and the data line overlapping each other form a second storage capacitor.

The first passivation layer is made of an organic insulating material, and in the reflective region, the surface thereof is convex and convex, and the reflecting plate formed on the first passivation layer also has convex and concave surface. .

In addition, a fourth protective layer made of an inorganic insulating material is formed between the thin film transistor and the first protective layer, and a fifth protective layer made of an inorganic insulating material is formed between the first protective layer and the reflector. In this case, a sixth passivation layer is formed between the second passivation layer and the third passivation layer to correspond to the reflective region with an organic insulating material.

In addition, a black matrix is formed between the inner surface of the second substrate and the color filter layer to correspond to the gate and data wiring, and an overcoat layer is formed on the entire surface of the second substrate to cover the color filter layer. The color filter layer is patterned and removed at a central portion of the color filter layer so as to correspond to the reflective region, thereby forming a transmission hole.

In addition, the first and second polarizing plates which are respectively formed on the outer surface of the first and second substrates and disposed so that their polarization axes are perpendicular to each other; A first alignment layer covering the common electrode; And a second alignment layer formed to cover the color filter layer.

According to an embodiment of the present invention, a plurality of first openings and a plurality of third openings are formed in a planar alternating manner to correspond to the pixel electrode and the common electrode provided in the reflective area, respectively. Reducing the number of times has the effect of improving the reflection efficiency in the reflection area.

Furthermore, the light emitted from the backlight unit passes through the plurality of second openings and the plurality of fourth openings in the form of alternating planes corresponding to the pixel electrode and the common electrode in the same manner as the reflective area. There is an effect of improving the transmission efficiency in the transmission area by reducing the number of pixel electrodes and the common electrode.

Hereinafter, with reference to the accompanying drawings will be described in detail with respect to the reflective liquid crystal display device according to the present invention.

3 is a cross-sectional view of one pixel area of a transverse electric field mode reflective transmissive liquid crystal display according to an exemplary embodiment of the present invention. For convenience of description, a region in which the thin film transistor Tr, which is a switching element, is formed in the pixel region P is defined as a switching region TrA, and at the same time, a portion where the reflector 150 is formed in the pixel region P is reflected. The area RA and other areas are defined as the transmission area TA.

As shown in the drawing, the gate wiring 103 and the data wiring 125 intersect with each other to define the pixel region P, and extend in parallel with the gate wiring 103. The common wiring 109 penetrating the pixel region P is formed.

In this case, a first storage electrode 110 is formed in the reflective region RA by branching from the common wiring 109, and a second storage branch is branched from the common wiring 109 on the data line 125. The electrode 111 is formed.

In addition, each pixel region P is connected to the gate wiring 103 and the data wiring 125 and has a gate electrode 106, a gate insulating film 115, an active layer 120a of pure amorphous silicon, and an impurity amorphous material. The semiconductor layer 120 including the ohmic contact layer 120b of silicon and the thin film transistor Tr including the source and drain electrodes 130 and 133 spaced apart from each other are formed.

In addition, the drain electrode 133 is formed to overlap with the first storage electrode 110 and the gate insulating layer 115 therebetween, and the first storage electrode 110 and the drain electrode overlapping each other ( 133 includes a gate insulating film 115 interposed between the two electrodes 110 and 133 to form a first storage capacitor StgC1.

In addition, the second storage electrode 111 and the data line 125 overlapping each other with the gate insulating layer 115 interposed therebetween to form a second storage capacitor StgC2.

The first protective layer 136 is formed as an inorganic insulating material and covers the thin film transistor Tr and the data line 125, and a second protective layer as the organic insulating material is formed on the first protective layer 136. 140 is formed on the front side. At this time, the second protective layer 140 is characterized in that the concave-convex irregularities are formed on the surface of the reflective region (RA).

A third passivation layer 142 is formed on the second passivation layer 140 as an inorganic insulating material, and a reflecting plate as a metal material having good reflectance on the reflecting region RA. 150) is formed. At this time, the third protective layer 142 and the reflective plate 150 is characterized in that the surface of the convex concave-convex shape due to the influence of the second protective layer 140 formed on the bottom.

In the exemplary embodiment of the present invention, the first to third protective layers 136, 140, and 142 are formed as an example, but the first and third protective layers 136 and 142 may be omitted. Since the first protective layer 136 made of an inorganic insulating material is in contact with the active layer 120a, characteristics of channel contamination and thin film transistor (Tr) that may occur when the organic insulating material is in contact with the active layer 120a The third protective layer 142 may be formed to prevent degradation, and the third protective layer 142 may be formed of a reflective plate 150 made of a metal material and the third made of an organic insulating material to solve the problem of weakening of adhesion between the organic insulating material and the metal material. It is formed between the protective layer 142.

Next, a fourth passivation layer 152 is formed on the reflective plate 150 to correspond to the reflective region RA as an organic insulating material. The fourth passivation layer 152 forms a step difference with the transmission area TA to form the double cell gaps d3 and d4 in the reflection area RA and the transmission area TA.

In addition, a fifth passivation layer 155 is formed on the entire surface of the fourth passivation layer 152 and the third passivation layer 142 as an inorganic insulating material. At this time, the fifth passivation layer 155 and the third passivation layer 142, the second and the first passivation layer (below) outside the end of the fourth passivation layer 152 in the pixel region P. 140 and 136 are patterned to have drain contact holes 158 exposing the drain electrode 133.

 Next, on the fifth passivation layer 155, a plate-shaped pixel electrode 160 is formed for each pixel region P using a transparent conductive material. At this time, as a most characteristic configuration in the present invention, the inside of the plate-shaped pixel electrode 160 is spaced apart in a bar shape at a portion corresponding to the reflective area RA, and a plurality of first openings op1 are formed. It is characterized by being. That is, in the reflective region RA, a plurality of first openings op1 having their long axes arranged in the first direction are formed at regular intervals.

In the exemplary embodiment of the present invention, the pixel electrode 160 is formed in the transmissive area TA so that the first opening op1 is not formed therein and maintains a plate shape.

The pixel electrode 160 having the above-described shape is in contact with the drain electrode 133 of the thin film transistor Tr through the drain contact hole 158.

Meanwhile, the fifth protective layer 155 made of an inorganic insulating material is also formed to improve adhesion between the fourth protective layer 152 made of an organic insulating material and the pixel electrode 160 made of a transparent conductive material. Can be.

In addition, a sixth protective layer 163 is formed on the pixel electrode 160 having the plurality of first openings op1 as an inorganic insulating material, and a transparent conductive material is formed on the sixth protective layer 163. The common electrode 170 is formed for each pixel area P or over the display area of the array substrate 102. In the drawing, the common electrode 170 is formed on the entire display area. In this case, although not shown, the common electrode 170 is in contact with the common wire 109 through a common contact hole (not shown).

Meanwhile, in the common electrode 170, a plurality of second openings op2 disposed with a second axis different from the first direction in the common electrode 170 are spaced apart at regular intervals. In response to the reflection area RA, a plurality of third openings op3 having the long axis having the first direction are spaced apart from each other by a predetermined interval.

In this case, as a characteristic configuration according to the exemplary embodiment of the present invention, a plurality of first openings op1 and the common electrode 170 provided in the pixel electrode 160 may be planar in the reflective region RA. The plurality of third openings op3 formed are arranged to alternate with each other.

That is, the common electrode finger portions 170a formed between the third openings op3 of the common electrode 170 correspond to the plurality of first openings op1 provided in the pixel electrode 160. The pixel electrode finger 160a between the first opening op1 of the pixel electrode 160 corresponds to the third opening op3 of the common electrode 170.

A first alignment layer (not shown) is provided on the common electrode 170 having the plurality of second and third openings op2 and op3.

The color filter substrate 181 is provided corresponding to the array substrate 102 having the above-described configuration.

On the inner surface of the color filter substrate 181 facing the array substrate 102, a black matrix 183 is formed to correspond to the boundary of each pixel region P, that is, the gate and data lines 103 and 125. And a color filter layer 185 formed of red, green, and blue color filter patterns (R, G, not shown) that cover the black matrix 183 and are sequentially repeated corresponding to each pixel region (P). It is. In this case, the color filter layer 185 is patterned and removed to correspond to the central portion of the reflection area RA in each pixel area P, so that the color filter layer 185 includes a transmission hole TH. The configuration of the transmission hole TH in the reflection area RA may be omitted to improve luminance in the reflection area RA.

An overcoat layer 187 is formed on the entire surface of the color filter substrate 181, covering the color filter layer 185 having the transmission hole TH, and covering the overcoat layer 187. ) Is provided.

In addition, first and second polarizing plates 193 and 195 having polarization axes orthogonal to each other are provided on the outer surfaces of each of the array substrate 102 and the color filter substrate 181.

Meanwhile, a second thickness between the first and second alignment layers (not shown) has a first thickness d1 corresponding to the transmission area TA, and a second thickness thinner than the first thickness d1 in the reflection area RA. The liquid crystal layer 190 having (d2) is provided. In this case, the second thickness d2 is 1/2 of the first thickness d1.

On the other hand, although not shown in the drawing, the second direction, which is the major axis direction of the second opening op2 in the transmission area TA, is parallel to the direction in which the data line 125 extends, that is, the data line 125. It is preferred that the direction is, wherein the second direction, which is the major axis direction of the first and third openings op1 and op3 in the reflection area RA, is formed so as to be orthogonal to the data line 125 (not shown). It is characterized by forming an angle of about 30 to 60 degrees in the clockwise or counterclockwise direction with respect to).

FIG. 4 is a cross-sectional view schematically illustrating only a pixel electrode, a common electrode, and a reflecting plate configured in a reflective region of an array substrate in a transverse electric field mode liquid crystal display according to an exemplary embodiment of the present invention.

As illustrated, in the array substrate 102 of the transverse electric field mode liquid crystal display device having the above-described configuration, most of the external light passes through the common electrode 170 only once and the pixel electrode 160 once. As a result, the reflection efficiency is improved compared to the conventional transverse electric field type liquid crystal display (see FIG. 1) which passes through the pixel electrode 160 and the common electrode 170 twice.

The common electrode 170 and the pixel electrode 160 are generally made of indium tin oxide (ITO) or indium zinc oxide (IZO), which are transparent conductive materials. When the thickness passes, for example, 1000 mm to 3000 mm, a light loss of 7% to 11% occurs.

Accordingly, in the conventional transverse electric field mode reflective transmission liquid crystal display device (see FIG. 1), since the external light passes through the common electrode and the pixel electrode twice, the optical loss is relatively large, but according to an embodiment of the present invention, In the transverse electric field mode reflection type liquid crystal display device, a plurality of first openings alternate with a third opening op3 provided in the common electrode 170 in the pixel electrode 160 in response to the reflection area RA. (op1) is provided so that most of the external light passes through the common electrode 170 and the pixel electrode 160 only once, thereby minimizing the light loss generated by passing through the transparent conductive material layer, thereby reducing the reflection efficiency by about 17%. Could improve.

FIG. 5 is a cross-sectional view schematically illustrating only a pixel electrode, a common electrode, and a reflecting plate configured in a reflective region of an array substrate in a transverse electric field mode liquid crystal display according to an exemplary embodiment of the present invention. FIG. 5 is a width of a first opening width and a third opening. And a relationship between the widths of the common electrode finger portions. In this case, the dotted line shows a case where both ends of the pixel electrode finger portion overlap the common electrode finger portion at the maximum.

As illustrated, the plurality of first openings op1 provided in the pixel electrode 160 have a width w3 equal to 1.2 times the width w1 of the common electrode finger portion 170a corresponding to the upper portion. It is characterized in that it is formed to be smaller or smaller and to have a value equal to or larger than the patterning limit of 2 μm (2 μm ≦ w 3 ≦ w 1 * 1.2).

In this case, when the width w3 of the plurality of first openings op1 provided in the pixel area is larger than 1.2 times the width w1 of the common electrode finger portion 170a positioned above the common electrode 170. Experimentally it can be seen that the larger the driving voltage is required by affecting the intensity and shape of the fringe field generated between the third opening (op3) and the pixel electrode 160 of the (), and thus the fringe field strength and shape It was found that the width w3 of the first opening op1 that has no influence is 1 to 1.2 times the width w1 of the common electrode finger portion 170a positioned above the first opening op1.

If the width w3 of the first opening op1 is smaller than the width w1 of the common electrode finger portion 170a positioned above it, the same fringe field intensity as that of forming a plate-shaped pixel electrode for the fringe field; It does not matter because it has a form.

However, the larger the width w3 of the plurality of first openings op1 formed in the pixel electrode 160 increases the reflection efficiency of external light, the width w1 of the common electrode finger portion 170a is increased. It is preferable to form large in proportion to).

Accordingly, from this point of view, the common electrode finger portion adjacent to each of both ends of the pixel electrode finger portion 160a positioned between both ends of the width w3 of the first opening op1 more precisely between the first opening op1 The overlap width w4 of both ends is preferably formed to overlap (w4 <w1 * 0.1) in a range smaller than 10% of the width w1 of the common electrode finger portion 170a. In the present technology stage, the width w3 of the first opening op1 may be larger than 2 μm because the process feature is about 2 μm.

On the other hand, the common electrode finger portion 170a has a width w1 of about 2 μm to about 10 μm, and the common electrode finger portion when the width w1 of the common electrode finger portion 170a is about 2 μm to about 10 μm. The width w3 of the third opening op3 positioned between the 170a and the finger portion 170a may be about 1.5 to 2.5 times the width w1 of the common electrode finger portion 170a. Therefore, in the embodiment of the present invention, the width w2 of the third opening op3 is about 3 µm to about 25 µm.

For example, when the width w1 of the common electrode finger portion 170a is 2 μm, the width w2 of the third opening op3 may be 4 μm, which is double, and the pixel electrode 160 The first opening op1 provided therein may be formed such that its width w3 is about 2 μm to about 2.4 μm.

6 is a cross-sectional view of one pixel area of a transverse electric field mode reflective transmissive liquid crystal display according to a modification of the exemplary embodiment of the present invention. In this case, for the convenience of description, the same reference numerals are given to the same constituents as the exemplary embodiment, and the description will be given focusing on parts having a difference.

In the modified example of the embodiment of the present invention, a part different from the embodiment is in the form of the pixel electrode 160 formed in the transmission area TA. In the exemplary embodiment, a plate-shaped pixel electrode was formed to correspond to the transmissive region. However, in the modified example, the transmissive region TA corresponds to the common electrode finger portion 170a positioned above the pixel region P. Therefore, a plurality of fourth openings op4 having a long axis in a second direction parallel to the plurality of second openings op2 provided in the common electrode 170 is configured. In this case, the width of the fourth opening op4 has the same range as the width of the first opening described above, and other components are the same as in the above-described embodiment, and thus description thereof is omitted.

In the modification of the embodiment of the present invention having the above-described configuration, the reflection efficiency can be improved in the reflection area RA as in the embodiment, and the common electrode 170 and the pixel electrode also exist in the transmission area TA. Since only the light emitted from the backlight unit (not shown) passes through only one of the electrodes 160, the transmission efficiency can be improved.

When the pixel electrode is formed in a plate shape, the pixel electrode and the common electrode finger portion are formed to completely overlap, so that light from the backlight unit passes through both the pixel electrode and the common electrode in a portion corresponding to the common electrode finger portion. In a modified example of the embodiment, most of the light emitted to the backlight unit (not shown) is formed by the fourth opening op4 formed in the pixel electrode 160 corresponding to the common electrode finger portion 170a. Alternatively, since only one electrode of the common electrode 170 passes therethrough, light loss generated by passing through the transparent conductive material layer may be minimized.

 The present invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit of the present invention.

1 is a simplified cross-sectional view of a reflection area and a transmission area of a conventional transverse electric field mode reflection type liquid crystal display device.

FIG. 2 is a cross-sectional view of a reflection area in a conventional array substrate of a transverse electric field mode reflection-transmissive liquid crystal display device, and schematically illustrates an external light path in a common electrode, a pixel electrode, and a reflection plate and a reflection area; FIG.

3 is a cross-sectional view of one pixel area of a transverse electric field mode reflective transmissive liquid crystal display device according to an exemplary embodiment of the present invention.

FIG. 4 is a cross-sectional view schematically illustrating only a pixel electrode, a common electrode, and a reflecting plate configured in the reflecting region of the array substrate in the transverse electric field mode liquid crystal display according to the exemplary embodiment of the present invention.

FIG. 5 is a cross-sectional view schematically illustrating only a pixel electrode, a common electrode, and a reflecting plate configured in a reflective region of an array substrate in a transverse electric field mode liquid crystal display according to an exemplary embodiment of the present invention. A diagram showing the relationship between the widths of electrode fingers.

6 is a cross-sectional view of one pixel area of a transverse electric field mode reflective transmissive liquid crystal display device according to a modification of the embodiment of the present invention;

<Description of Symbols for Main Parts of Drawings>

101: transverse electric field mode reflection transmission type liquid crystal display device

102 array substrate 106 gate electrode

110: first storage electrode 115: gate insulating film

120: semiconductor layer 120a: active layer

120b: ohmic contact layer 125: data wiring

130: source electrode 133: drain electrode

136: first protective layer 140: second protective layer

142: third protective layer 150: reflecting plate

152: fourth protective layer 160: pixel electrode

160a: pixel electrode finger portion 163: fifth protective layer

170: common electrode 170: common electrode finger portion

181: color filter substrate 183: black matrix

185: color filter layer 187: overcoat layer

190: liquid crystal layer 193: first polarizing plate

195: second polarizing plate

d1, d2: first and second cell gaps

op1, op2, op3: first, second and third opening

P: pixel area RA: reflection area

TA: Transmission Area Tr: Thin Film Transistor

TrA: device area

Claims (13)

A first substrate and a second substrate facing each other; A gate wiring and a data wiring formed on an inner surface of the first substrate to define a pixel region having a reflection region and a transmission region crossing each other through a gate insulating film; A common wiring formed in parallel with the gate wiring; A thin film transistor connected to the gate line and the data line in the pixel area; A first passivation layer covering the data line and the thin film transistor; A reflection plate formed in the reflection area over the first protective layer; A second protective layer formed over the reflecting plate; Contacting the drain electrode through a drain contact hole exposing the drain electrode of the thin film transistor to the upper portion of the second protective layer, and is formed in a plate shape in the transmissive region, and has a long axis in a first direction in the reflective region. A pixel electrode having a plurality of first openings formed therein; A third passivation layer formed over the pixel electrode; A plurality of second openings connected to the common protective layer through the common contact hole on the third passivation layer and spaced apart from each other in the transmissive area with a long axis in a second direction perpendicular to the gate wiring; A common electrode comprising a plurality of third openings having a long axis and spaced apart in one direction; A color filter layer formed on an inner surface of the second substrate; Liquid crystal layer interposed between the first and second substrate And wherein the first opening and the third opening are alternately arranged in a planar manner. The method of claim 1, The common electrode portion positioned between the second opening and the third opening is defined as a common electrode finger portion, the width of the first opening is a first width, the width of the common electrode finger portion is a second width, and the second opening is defined. Or when defining the width of the third opening as the third width, And wherein the first width is greater than or equal to 2 μm and has a size equal to or less than 1.2 times the third width. The method of claim 2, And the first opening is formed to overlap the common electrode finger. The method of claim 3, wherein When the pixel electrode portion between the first openings is defined as a pixel electrode finger portion, both ends of the pixel electrode finger portion are formed to overlap both ends of the common electrode finger portion and less than 10% of the width of the common electrode finger portion. Characteristic transverse electric field reflection type liquid crystal display device. The method of claim 1, The plate-shaped pixel electrode formed in the transmissive region has a plurality of fourth openings alternately arranged in parallel with a plurality of second openings having a long axis in the second direction and spaced apart from each other. Reflective type liquid crystal display device. The method of claim 1, And a thickness of the liquid crystal layer in the reflective region is 1/2 of the thickness of the liquid crystal layer in the transmissive region. The method of claim 1, A first storage electrode branching from the common line to the reflective region, and a second storage electrode branching to overlap the data line; The drain electrode extends to overlap the first storage electrode, such that the first storage electrode, the gate insulating layer, and the drain electrode overlap each other to form a first storage capacitor. And the second storage electrode, the gate insulating layer, and the data line overlap each other to form a second storage capacitor. The method of claim 1, The first protective layer is made of an organic insulating material, and in the reflective region, the surface thereof is convex and convex, and the reflecting plate formed on the first protective layer is also characterized in that the surface is convex and concave and convex. Field mode reflective transmission liquid crystal display device. The method of claim 1, A fourth protective layer made of an inorganic insulating material is formed between the thin film transistor and the first protective layer. And a fifth protective layer formed of an inorganic insulating material between the first protective layer and the reflecting plate. The method of claim 9, And a sixth passivation layer formed of an organic insulating material between the second passivation layer and the third passivation layer to correspond to the reflecting region. The method of claim 1, A black matrix is formed between the inner surface of the second substrate and the color filter layer to correspond to the gate and data wirings. A transverse electric field mode transmissive liquid crystal display device covering the color filter layer and having an overcoat layer formed on the entire surface of the second substrate. The method of claim 11, And wherein the color filter layer is patterned and removed at a central portion of the color filter layer to form a transmission hole. The method of claim 1, First and second polarizing plates respectively disposed on the outer surfaces of the first and second substrates and arranged such that their polarization axes are perpendicular to each other; A first alignment layer covering the common electrode; A second alignment layer formed covering the color filter layer Transverse electric field mode reflective transmission liquid crystal display device comprising a.

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