KR20110069396A - In-plane switching mode trans-flective liquid crystal display device - Google Patents

Abstract

PURPOSE: An LCD device for reflection and transmission of in-plane switching mode is provided to prevent the deterioration of black brightness and to minimize network traffic. CONSTITUTION: A first substrate(101) and a second substrate faces with each other. A gate line and a data line are formed in a reflection area inside the first substrate. A common line is formed in the gate line. A thin film transistor is connected to the data line and the gate line. A first protection layer(136) is formed to cover the thin film transistor. A reflection plate(150) is formed on a first protection film. A second protection layer(125) is formed in the reflection area.

Description

In-plane switching mode trans-flective liquid crystal display device

The present invention relates to a liquid crystal display device, and more particularly, to an array substrate for a transverse electric field mode reflective transmission liquid crystal display device having a single cell gap and improving black luminance characteristics, and a method of manufacturing the same.

Recently, with the rapid development of the information society, the need for a flat panel display having excellent characteristics such as thinning, light weight, and low power consumption has emerged.

Such a flat panel display may be divided according to whether it emits light or not. A light emitting display is one that displays an image by emitting light by itself, and a display is performed by displaying an image using an external light source. It is called a display device. The light emitting display device includes a plasma display device, a field emission display device, an electro luminescence display device, and the like. The light receiving display device includes a liquid crystal display device ( liquid crystal display device).

Dual liquid crystal display devices are being actively applied to notebooks and desktop monitors because of their excellent resolution, color display, and image quality.

In general, a liquid crystal display device arranges two substrates on which electrodes are formed so that the surfaces on which the two electrodes are formed face each other, injects a liquid crystal between the two substrates, and applies a voltage to the two electrodes to generate an electric field. By moving the liquid crystal molecules to adjust the light transmittance of the device to represent the image.

However, the liquid crystal display device does not emit light as described above, so a separate light source is required.

Therefore, a backlight unit is formed on the rear side of the liquid crystal panel, and light emitted from the backlight unit is incident on the liquid crystal panel to display an image by adjusting the amount of light according to the arrangement of liquid crystals.

Such a liquid crystal display device is called a transmission type liquid crystal display device. Since the liquid crystal display device uses an artificial back light source such as a backlight, a bright image can be realized even in a dark external environment, but power consumption due to the backlight is consumed. There is a big disadvantage.

In order to make up for such drawbacks, reflective and reflective transmissive liquid crystal displays have been proposed.

The reflection type liquid crystal display device has less power consumption than the transmission type liquid crystal display device in the form of controlling light transmittance according to the arrangement of liquid crystals by reflecting external natural light or artificial light. In the reflective liquid crystal display, the pixel electrode formed on the lower array substrate is formed of a conductive material that reflects well, and the common electrode formed on the upper color filter substrate is formed of a transparent conductive material to transmit external light. .

In addition, the transflective liquid crystal display device has all the advantages of the transmissive and reflective liquid crystal display device, and is used in a transmissive mode using backlight light where there is no indoor or external light, and the external light where an external light source exists. It is characterized by being able to select and use a reflection mode using the light source.

Therefore, recently, a transflective liquid crystal display device that can be used in two modes has received a lot of attention, and furthermore, a transflective liquid crystal display device implemented in a transverse electric field mode having wide viewing angle characteristics has received more attention.

FIG. 1 is a cross-sectional view of a portion of a conventional transverse electric field mode reflective transmissive liquid crystal display device cut through a thin film transistor, a reflective region, and a transmissive region.

As shown in the drawing, gate wirings (not shown) extending in one direction are formed on the insulating substrate 1, and common wirings 6 are formed to be spaced apart from each other. In addition, a gate electrode 8 is formed in the switching region TrA and is connected to the gate line (not shown).

A gate insulating layer 10 is formed on the gate line and the gate electrode 8. In addition, an upper portion of the gate insulating layer 10 intersects the gate wiring (not shown) to define the pixel region P, and a data wiring 30 is formed. In the switching region TrA, pure water is sequentially formed. A semiconductor layer 20 composed of an ohmic contact layer 20b made of impurity amorphous silicon and spaced apart from the active layer 20a of amorphous silicon is formed, and source and drain electrodes 33 and 36 are formed spaced apart from each other. In this case, the source electrode 33 is connected to the data line 30.

Next, a first passivation layer 40 is formed on the data line 30 and the thin film transistor Tr, and the surface of the reflective area RA is convex on the first passivation layer 40. A second protective layer 43 having an uneven structure and having a flat surface is formed in the transmission area TA.

In addition, a reflective plate having a concave-convex structure on the surface of the second passivation layer 43 reflecting the concave-convex structure of the surface of the second passivation layer 43 as a metal material having excellent reflectivity in the reflective region RA. 50) is formed.

Next, in the reflective region RA, a third protective layer 55 having a flat surface is formed on the reflective plate 50. In this case, the third passivation layer 55 forms a step with the transmissive area TA, so that the liquid crystals of the reflective area RA and the transmissive area TA may be implemented when a transverse electric field mode reflective transmissive liquid crystal display (not shown) is implemented. This is to change the thickness of the layer (not shown), and also to prevent the concave-convex structure implemented in the reflecting plate 50 located below it from being applied to the components constituted thereon. In the reflective area RA, since the user sees the light reflected by the reflector 50 when external light is incident, the user passes through the liquid crystal layer twice (not shown), while in the transmission area TA, Since the user sees the light emitted from the backlight unit (not shown) once passed through the liquid crystal layer (not shown), the user feels a phase difference in the two areas TA and RA.

Therefore, in order to overcome the phase difference problem in the reflection area RA and the transmission area TA, the thickness of the liquid crystal layer (not shown) of the transmission area TA is 2 than that of the liquid crystal layer of the reflection area RA. The third protective layer 55 is further formed in the reflective region RA in order to realize the thickness difference of the liquid crystal layer (not shown).

In this case, the third protective layer 55 and the second protective layer 43 disposed below the drain contact hole exposing the drain electrode 36 overlapping with the portion where the common wiring 6 is formed. 58 is provided.

Next, an upper portion of the third passivation layer 55 of the reflective area RA and the second passivation layer 43 of the transmission area TA is separated for each pixel area P, and the drain contact hole 58 is formed. In contact with the drain electrode 36, a plate-shaped pixel electrode 62 is formed.

Next, a fourth passivation layer 65 is formed on the entire surface of the pixel electrode 62, and each pixel corresponds to the transmissive area TA as a transparent conductive material on the entire surface of the fourth passivation layer 65. A plurality of first openings op1 having a bar shape having a long axis parallel to the data line 30 is provided in an area P, and corresponding to the reflective area RA, the data line 30 is provided in the data line 30. A common electrode 70 having a plurality of second openings op2 having a long axis arranged at a predetermined angle with respect to the second electrode is formed.

Although not shown in the drawing, the common electrode 70 formed on the entire surface of the substrate 1 has the common wiring 6 exposed through a common contact hole (not shown) provided in a plurality of protective layers formed below the common electrode 70. Is electrically connected by contacting

However, the conventional transverse electric field mode transflective liquid crystal display device (not shown) having the array substrate 1 having the stepped structure in the transmission area TA and the reflection area RA described above realizes a double cell gap when black luminance is realized. Light leakage occurs on the third passivation layer 55 formed for the purpose of the black luminance characteristic is deteriorated because of this.

This is because the cell gap (thickness of the liquid crystal layer) in the reflection area RA is lower than the cell gap in the transmission area TA, and in the upper part of the third protective layer 55 formed in the reflection area RA to realize such a double cell gap. Due to the cell gap decrease, a portion in which the alignment of liquid crystals is reduced (particularly, a boundary between the reflective area TA and the transmission area RA) is generated, and a polarizing plate is disposed so that polarization axes intersect the upper and lower portions of the liquid crystal panel. This is because light leakage occurs in a portion where the arrangement alignment of the liquid crystal is lowered, thereby increasing black luminance when black is implemented.

Disclosure of Invention The present invention has been made to solve the above-described problem, and an object of the present invention is to provide a transverse electric field mode reflection-transmissive liquid crystal display device capable of preventing black luminance degradation caused by the implementation of a double cell gap in a reflection area and a transmission area. do.

       In order to achieve the above object, a transverse electric field mode reflective transmission liquid crystal display device according to an embodiment of 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 orthogonal to each other via 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 having a flat surface over the reflective plate and formed over the entire display area; A pixel electrode in contact with the drain electrode through a drain contact hole exposing the drain electrode of the thin film transistor on the second passivation layer and formed in a plate shape for each pixel region; A third passivation layer formed over an entire surface of the display area above the pixel electrode; A plurality of first openings connected to the third protective layer through the common wiring and the common contact hole and having a long axis spaced apart from each other in the first direction in parallel with the data wiring; A common electrode formed with a plurality of second openings having a long axis and spaced apart from each other in a second direction forming a first angle with one direction; A first alignment layer formed over the common electrode; A color filter layer formed on an inner surface of the second substrate; A second alignment layer covering the color filter layer; A liquid crystal layer interposed between the first and second alignment layers and having the same first thickness in the reflective and transmissive regions; A first polarizing plate having a first polarization axis on an outer surface of the first substrate; And a second polarizing plate having a second polarization axis orthogonal to the first polarization axis on an outer side surface of the second substrate, wherein the liquid crystal director in the liquid crystal layer is arranged to be twisted at a second angle in the reflection area. It is done.

In this case, the first angle is 95 degrees in a clockwise or counterclockwise direction, and the second angle is 63 degrees.

In addition, the first and second alignment layers facing each other corresponding to the transmissive region are oriented in a first alignment direction having a third angle with the data line, and the first alignment layer corresponding to the reflective region is the first alignment layer. The substrate is oriented in a second alignment direction perpendicular to the alignment direction, and the second alignment layer corresponding to the reflective region is oriented in a third alignment direction having a fourth angle with the second alignment direction. In this case, the third angle is 5 degrees, and the fourth angle is 63 degrees.

In addition, the second polarization axis is characterized by coinciding with the first alignment direction, characterized in that the first thickness is 4.3㎛.

In addition, a first storage electrode branching from the common wiring to the reflective region is formed, and the drain electrode extends to overlap the first storage electrode so that the first storage electrode, the gate insulating layer, and the drain overlap each other. The electrode is characterized by forming a storage capacitor.

In addition, the first protective layer is made of an organic insulating material, the surface of the reflective embossed embossed form, the reflective plate formed on the first protective layer is also characterized in that the surface of the embossed form. to be.

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. It is characteristic.

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 between the color filter layer and the second alignment layer.

As described above, the transverse electric field mode reflection-transmissive liquid crystal display device according to the present invention has an effect of preventing black luminance reduction due to light leakage caused by having a conventional double cell gap by implementing a single cell gap.

In addition, since the insulating layer formed only in the reflective region can be omitted to form a step with the transmissive region, the material cost can be reduced.

Hereinafter, with reference to the accompanying drawings will be described in detail an embodiment of the present invention.

2 is a plan view of one pixel area of a reflective 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 is formed in each pixel region P is defined as an element region.

As shown, the reflective transmissive liquid crystal display device 100 according to the present invention is largely a liquid crystal layer interposed between an array substrate 101, a color filter substrate (not shown), and these two substrates 101 (not shown). (Not shown).

First, in the array substrate 101, the pixel regions P are defined to be orthogonal to each other, and gates and data lines 103 and 125 are formed, and pass through the pixel regions P to be parallel to the gate lines 103. Common wiring 109 is formed. In this case, the pixel area P is further divided into a transmission area TA and a reflection area RA by the common wiring 109. In addition, the first storage electrode 110 is formed in the reflection area in each pixel area by branching from the common wiring.

On the other hand, the reflective region RA in each pixel region P is connected to the gate wiring 103 and the data wiring 125, and as a switching element, the gate electrode 106, the gate insulating film (not shown), and the semiconductor layer ( A thin film transistor Tr including source and drain electrodes 130 and 133 spaced apart from each other is formed. In this case, the drain electrode 133 is formed to overlap with the first storage electrode 110, so that the first storage electrode 110, the drain electrode 133, and the two electrodes 110 and 133 overlap each other. The interposed gate insulating layer (not shown) forms a first storage capacitor StgC1.

In addition, the thin film transistor Tr is in direct contact with the drain electrode 133 and has a plate shape. The pixel electrode 160 is formed for each pixel region P. Referring to FIG.

On the other hand, the common wiring 109 and the common contact hole 157 are connected to correspond to the pixel electrode 160 formed for each pixel region P, and the display of the substrate 101 without the division of the pixel region P is performed. A common electrode (not shown) is formed to correspond to the entire area of the region and a portion of the non-display region. In this case, although the common contact hole 157 is formed in each pixel area P, this shows an example, and the common contact hole 157 has an end of the common wiring 109. It may be formed in a non-display area (not shown) located.

The pixel electrode 160 and the common electrode (not shown) overlapping each other through the protective layer (not shown) form a second storage capacitor.

In addition, a plurality of first openings op1 are formed in the common electrode (not shown) in parallel with the data line 125 to correspond to the transmission area TA of each pixel area P. The first opening op1 of the first and second openings op1 is formed so that the ends thereof overlap the gate wiring 103 and the common wiring 109, respectively.

In addition, in the common electrode (not shown) corresponding to the reflective region RA, a plurality of second openings op2 are formed at a predetermined angle with the gate wiring 103 at an angle of 5 degrees in a clockwise or counterclockwise direction. The slant is forming. In this case, each of the plurality of second openings op2 may have a straight bar shape and may be extended or may have a bar shape for each pixel area irrespective of the left and right neighboring pixel areas P. It is being formed. In the drawing, the plurality of second openings op2 are positioned on the common line 109 at which one end thereof is a boundary between the transmission area TA and the reflection area RA, and the other end thereof is a pixel ( It is shown as being connected to the adjacent pixel area P regardless of the area P).

On the other hand, in the reflection area RA, in order to improve reflection efficiency, the reflection plate 150 having an embossed structure whose surface is randomly convex is provided.

On the color filter substrate (not shown) facing the array substrate 101 having the above-described configuration, a black matrix (not shown) is formed corresponding to the boundary of each pixel region P. The black matrix (not shown) ), A color filter layer (not shown) having a red, green, and blue color filter pattern (not shown) is formed in the region enclosed by (), that is, the pixel region (P), and covers the color filter layer (not shown). An overcoat layer (not shown) having a flat surface is formed.

In addition, a liquid crystal layer (not shown) is interposed between the array substrate 101 and the color filter substrate (not shown) having the above-described configuration, and although not shown in the drawing, the liquid crystal layer (not shown) maintains a constant thickness. A spacer (not shown) is provided, and a seal pattern (not shown) is formed at an edge of the array substrate 101 and the color filter substrate (not shown) to prevent leakage of the liquid crystal layer (not shown). The two substrates 101 (not shown) are maintained in a bonded state.

Although not shown in the drawings, first and second polarizing plates (not shown) are attached to outer surfaces of the array substrate 101 and the color filter substrate (not shown) so that the polarization axes are orthogonal to each other.

In the transverse electric field mode reflection-transmissive liquid crystal display device 100 having the above-described configuration, the first openings op1 provided in the transmission area TA of the array substrate 101 are the most characteristic configurations. The second polarization axis pol2 of the second polarizing plate (not shown) formed on the outer surface of the color filter substrate (not shown) is disposed to have a difference of about 5 degrees in a clockwise or counterclockwise direction.

Although not shown in the drawings, a first alignment layer (not shown) is disposed on the common electrode (not shown) having the plurality of first and second openings op1 and op2 in the array substrate 101. A second alignment layer (not shown) is provided to cover the overcoat layer (not shown) of the color filter substrate (not shown).

In this case, the first and second alignment layers (not shown) facing each other in the transmission area TA are aligned in the same direction as the extension direction of the second polarization axis pol2, that is, in the first alignment direction Ad1. The first alignment layer (not shown) may correspond to the reflective region RA, and the second alignment direction Ad2 may have an angle of 90 degrees in the clockwise or counterclockwise direction with the second polarization axis pol2. The second alignment layer (not shown) corresponding to the reflective region RA is aligned to have a third alignment direction Ad3 having an angle of 27 degrees clockwise or counterclockwise with the second polarization axis pol2. It is characterized by being.

In this case, the thickness of the cell gap, that is, the liquid crystal layer (not shown) in the transmission area TA and the reflection area RA is equal to 4.3 μm.

This condition uses a twisted structure of the liquid crystal layer (not shown) of the reflection area RA to select a condition that matches the transmission area TA among relatively large cell gap conditions, and simulates the black and white optimum conditions. Could get through.

That is, the transverse electric field mode reflection-transmissive liquid crystal display device 100 according to the present invention performs UV division alignment to form different orientations of the transmission area TA and the reflection area RA, and at this time, the reflection area RA In this case, the liquid crystal director 191 is twist-driven in the liquid crystal layer (not shown) by changing the alignment directions Ad2 and Ad3 in the first and second alignment layers (not shown), and when forming a large cell gap. It is characterized by lowering the effective phase difference.

Also, by acquiring the same black condition as the cell gap of the transmission area TA and optimizing the arrangement of the second openings op2 accordingly, the transmission curve in the transmission area TA coincides with the reflection curve in the reflection area RA. It is characterized by being driven to drive. Thus, the liquid crystal director 191 is twist-driven in the reflection area RA so that there is almost no phase difference between the transmission area TA and the reflection area RA even when the double cell gap is not implemented.

On the other hand, the simulation conditions are the twist angle of the liquid crystal director 191 in the reflection region (RA) 20 to 80 degrees, the cell gap of 3.2 ㎛ to 4.6 ㎛, the second polarization axis (pol2) and the reflection region (of the array substrate 101) When the angles of the alignment directions in the RA), that is, the angles of the second and third alignment directions Ad2 and Ad3 are 0 degrees to 180 degrees, and these conditions are optimized through simulation, the cell gap, that is, the liquid crystal layer (not shown) ) And the lowest black luminance in the reflective region RA when the liquid crystal director 191 is twisted by 63 degrees, that is, the second and third alignment angles Ad2 and Ad3 may have a 63 degree difference. I knew it was time.

3 is a cross-sectional view of an alignment direction of a color filter substrate and an array substrate and a direction of a polarization axis of a first polarizing plate and a second polarizing plate in a transmissive region and a reflective region of a transverse electric field mode reflective transmissive liquid crystal display device according to the present invention. It is a coordinate system showing the direction of the major axis of the opening. In this case, for convenience of description, the coordinate system uses the extension direction of the data line as the x-axis of the gate wiring and the long axis direction of the first opening as the y-axis.

As shown, the reflective transmissive liquid crystal display (not shown) according to the embodiment of the present invention has a second polarization axis of the second polarizing plate (not shown) with respect to the first opening op1 in the transmission region (not shown). (pol2) is disposed to be inclined 5 degrees in the clockwise direction, in which the first and second alignment layers (not shown) are oriented in the first alignment direction Ad1 in the transmission region (not shown), and the first alignment is performed. The direction Ad1 and the second polarization axis pol2 coincide.

In addition, the second opening op2 in the reflective region (not shown) is disposed to form an angle of 95 degrees with the first opening op1 in a clockwise direction, and a second alignment layer corresponding to the reflective region (not shown) is provided. (Not shown) is oriented in a third alignment direction Ad3 having an angle of 27 degrees clockwise with the second polarization axis pol2, and the first alignment layer (not shown) corresponding to the reflection area (not shown). Is oriented in the second alignment direction Ad2 forming an angle of 63 degrees clockwise with the third alignment direction Ad3.

Meanwhile, in the illustrated coordinate system, all the components are arranged to be inclined in the clockwise direction with respect to the first opening op1, which is the coordinate reference axis, but all are inclined at the same angle as described above in the counterclockwise direction. It is obvious that it can be arranged.

Hereinafter, the cross-sectional structure of the reflective liquid crystal display device according to the present invention will be described.

4 is a cross-sectional view of a portion taken along the cutting line IV-IV of FIG. 2. For convenience of description, a portion in which the thin film transistor Tr, which is a switching element, is formed in each pixel region P is defined as an element region TrA.

As shown in the drawing, the gate wiring 103 and the data wiring 125 intersect with each other with the gate insulating film 115 interposed therebetween to define the pixel region P. The gate wiring 103 is formed on the array substrate 101. A common wiring 109 is formed to extend parallel to the 103 and penetrate the pixel region P. In this case, the first storage electrode 110 is formed in the reflective region RA by branching from the common wiring 109.

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 this case, the drain electrode 133 is formed to overlap with the first storage electrode 110 and the gate insulating layer 115 interposed 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 StgC.

In addition, a first protective layer 136 is formed as an inorganic insulating material covering the thin film transistor Tr and the data line 125, and a second protective layer as an organic insulating material on the first protective layer 136. 140 is formed on the front surface. At this time, the second protective layer 140 is characterized in that the surface of the reflective area (RA) has a convex embossed form.

In addition, a third protective layer 142 is formed on the second protective layer 140 as an inorganic insulating material, and a metal material having excellent reflection performance in the reflective region RA over the third protective layer 142. For example, the reflector plate 150 is formed of aluminum (Al) or aluminum alloy (AlNd). At this time, the third protective layer 142 and the reflective plate 150 is characterized in that the surface of the embossed convex surface is formed by the influence of the second protective layer 125 formed below.

Meanwhile, in the embodiment of the present invention, although the first to third protective layers 136, 125, and 142 are formed as an example, the first and third protective layers 136 and 142 made of an inorganic insulating material are shown. ) 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 include the reflective plate 150 made of a metallic material and the second 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, the reflective plate 150 is a reflective structure RA and a transmissive area on the reflective plate 150 so as to have a flat state as an organic insulating material in order to eliminate a step caused by the reflective plate 150 having the embossed structure as a characteristic configuration of the present invention. The fourth passivation layer 152 is formed over the entire display area without being classified as TA. In this case, when the reflective plate 150 does not have an embossing structure, the fourth protective layer 152 may be omitted or formed of an inorganic insulating material.

Meanwhile, the fourth protective layer 152 and the third, second, and first protective layers 142, 140, and 136 below are patterned to provide a drain contact hole 158 exposing the drain electrode 133. It is becoming.

 Next, on the fourth passivation layer 152, a plate-shaped pixel electrode 160 is formed for each pixel region P using a transparent conductive material. In this case, the pixel electrode 160 is in contact with the drain electrode 133 of the thin film transistor Tr through the drain contact hole 158.

In addition, a fifth passivation layer 163 is formed on the pixel electrode 160 as an inorganic insulating material, and a transparent conductive material is formed on the fifth passivation layer 163 by each pixel region P or the array. The common electrode 170 is formed on the entire display area of the substrate 102. 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).

In this case, the common electrode 170 is patterned so that the plurality of first openings op1 having a bar shape extending in parallel with the data line 125 with respect to the transmission area TA are formed in each pixel area ( P is formed at regular intervals, and the plurality of second openings having a bar shape with an angle of 95 degrees in the clockwise or counterclockwise direction with respect to the reflective region RA. (op2) is formed at regular intervals apart.

Next, a first alignment layer 172 is formed on the entire display area over the common electrode 170 having the plurality of first and second openings op1 and op2. In this case, the first alignment layer 172 has a first alignment direction (5) with an angle of 5 degrees clockwise or counterclockwise with the first opening op1 or the data line 125 in the transmission area TA. It is characterized in that the UV alignment process to form the Ad1 of Fig. 2, in the reflection area (RA) to have a second alignment direction (Ad2 of Fig. 2) perpendicular to the first alignment direction (Ad1 of Fig. 2). It is characterized by UV alignment treatment.

A color filter substrate 181 is provided opposite to and facing the array substrate 101 having the above-described configuration.

The inner surface of the color filter substrate 181 is provided with a black matrix 183 corresponding to the boundary of each pixel region P, and sequentially and repeatedly corresponding to the pixel region P surrounded by the black matrix 183. As a result, a color filter layer 185 including red, green, and blue color filter patterns 185a, 185b (not shown) is formed, and an overcoat layer 187 covering the color filter layer 185 and having a flat surface is formed. It is.

In addition, a second alignment layer 189 is formed to cover the overcoat layer 187. In this case, the second alignment layer 189 has the same orientation as that of the first alignment layer 189 provided in the transmission area TA corresponding to the transmission area TA of the array substrate 101 located below. UV alignment is performed to have a direction (Ad1 in FIG. 2), and the reflection area RA is inclined 32 degrees clockwise or counterclockwise with the first opening op1 or the data line 125. It is characterized by being UV-oriented in three orientation directions (Ad3 of FIG. 2). Therefore, when the driving voltage is not applied by this configuration, the liquid crystal director (not shown) adjacent to the array substrate 101 in the reflection area RA is arranged in the second alignment direction (Ad2 in FIG. 2). The liquid crystal director (not shown) adjacent to the color filter substrate 181 is arranged in the third alignment direction (Ad3 of FIG. 2), thereby making a twisted arrangement of 63 degrees from the bottom to the top. In the transmissive area TA, since the first and second alignment layers 172 and 189 are all UV-oriented in the first alignment direction (Ad1 in FIG. 2), the liquid crystal director (not shown) is not twisted, and thus the first alignment is performed. The arrangement is made in the direction (Ad1 of FIG. 2).

On the other hand, between the first alignment layer 172 of the array substrate and the second alignment layer 189 of the color filter substrate 181 has the same thickness of about 4.3㎛ in both the reflection area (RA) and the transmission area (TA). It is a feature that the liquid crystal layer 190 is provided.

In the conventional transverse electric field mode reflection-transmissive liquid crystal display device, a liquid crystal layer is formed to have a different thickness in the reflection region and the transmissive region, that is, to form a double cell gap, but the transverse electric field mode reflection transmissive liquid crystal display according to an embodiment of the present invention. The device 100 is arranged such that the liquid crystal director (not shown) is twisted in the reflection area RA so that the phases of the reflection area RA and the transmission area TA coincide with each other without implementing a double cell gap. It is a feature that the liquid crystal layer 190 is provided to have.

  In addition, a first polarizing plate 193 having a first polarization axis (pol1 in FIG. 2) is attached to an outer surface of the array substrate 101, and a first polarization axis () is formed on an outer surface of the color filter substrate 181. The 2nd polarizing plate 195 which has the 2nd polarization axis (pol2 of FIG. 2) orthogonal to pol1 of FIG. 2 is attached. In this case, the second polarization axis (pol2 in FIG. 2) is arranged in parallel with the first alignment direction (Ad1 in FIG. 2).

As described above, the transverse electric field mode reflection-transmissive liquid crystal display device 100 according to the exemplary embodiment of the present invention has a liquid crystal layer 190 having the same thickness in both the reflection area RA and the transmission area TA to reflect the light. Light leakage caused by an abnormal arrangement of the liquid crystal director (not shown) due to the generation of steps in the area RA and the transmission area TA can be prevented. Therefore, it has the effect of improving the black luminance characteristic.

On the other hand, it can be seen that the white luminance, ie, the highest reflectance, in the reflection region of the transverse electric field mode reflection-transmissive liquid crystal display device according to the embodiment of the present invention is at the same level.

5A and 5B illustrate changes in reflectance of a transverse electric field mode reflection-transmissive liquid crystal display having a double cell gap and a transverse field-mode reflection transmissive liquid crystal display according to an exemplary embodiment of the present invention, according to a time course in the reflection region. It is a graph measured.

In the conventional case (see FIG. 5A), when the driving voltage is applied to display white, the lowest luminance shows a transmittance of about 0.004. The reflectance at a specific time, for example, 450 ms is about 0.75, and the maximum transmittance is about 0.87. In the case of the embodiment of the present invention, the transmittance of about 0.002 is shown for the first time, and the reflectance of the reflecting area is about 0.74 about 450 ms, and the maximum transmittance is about 0.97.

Therefore, in the case of white luminance, the conventional embodiment having the double cell gap and the embodiment of the present invention having the single cell gap are almost the same level, and furthermore, the maximum transmittance was found to be superior to the embodiment of the present invention having the single cell gap.

1 is a cross-sectional view of a portion of a conventional transverse electric field mode reflective transmissive liquid crystal display device cut through a thin film transistor, a reflective region, and a transmissive region;

2 is a plan view of one pixel area of a reflective liquid crystal display according to an exemplary embodiment of the present invention.

3 is a cross-sectional view of an alignment direction of a color filter substrate and an array substrate and a direction of a polarization axis of a first polarizing plate and a second polarizing plate in a transmissive region and a reflective region of a transverse electric field mode reflective transmissive liquid crystal display device according to the present invention. Coordinate system showing the direction of the major axis of the opening.

4 is a cross-sectional view of a portion taken along the line IV-IV of FIG. 2.

5A and 5B illustrate changes in reflectance of a transverse field mode reflective transmission liquid crystal display having a double cell gap and a transverse field mode reflective transmission liquid crystal display according to an exemplary embodiment of the present invention, according to a time course in the reflection region. Measured graph.

<Description of Symbols for Main Parts of Drawings>

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

101: 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

163: fifth protective layer 170: common electrode

172: first alignment layer 181: color filter substrate

183: Black matrix 185: color filter layer

187: overcoat layer 189: second alignment layer

190: liquid crystal layer 193: first polarizing plate

195: second polarizing plate

op1, op2: first and second openings P: pixel area

RA: reflection area TA: transmission area

Tr: Thin Film Transistor TrA: Device Area

Claims (10)

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 orthogonal to each other via 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 having a flat surface over the reflective plate and formed over the entire display area; A pixel electrode in contact with the drain electrode through a drain contact hole exposing the drain electrode of the thin film transistor on the second passivation layer and formed in a plate shape for each pixel region; A third passivation layer formed over an entire surface of the display area above the pixel electrode; A plurality of first openings connected to the third protective layer through the common wiring and the common contact hole and having a long axis spaced apart from each other in the first direction in parallel with the data wiring; A common electrode formed with a plurality of second openings having a long axis and spaced apart from each other in a second direction forming a first angle with one direction; A first alignment layer formed over the common electrode; A color filter layer formed on an inner surface of the second substrate; A second alignment layer covering the color filter layer; A liquid crystal layer interposed between the first and second alignment layers and having the same first thickness in the reflective and transmissive regions; A first polarizing plate having a first polarization axis on an outer surface of the first substrate; A second polarizing plate having a second polarization axis orthogonal to the first polarization axis on an outer surface of the second substrate; And the liquid crystal director in the liquid crystal layer is arranged to be twisted at a second angle in the reflective region. The method of claim 1, The first angle is 95 degrees clockwise or counterclockwise; And the second angle is 63 degrees. The method according to claim 1 or 2, The first and second alignment layers facing each other corresponding to the transmission region are oriented in a first alignment direction having a third angle with the data line, The first alignment layer corresponding to the reflective region is oriented in a second alignment direction perpendicular to the first alignment direction, And a second alignment layer corresponding to the reflective region is oriented in a third alignment direction having a fourth angle with the second alignment direction. The method of claim 3, wherein And the third angle is 5 degrees, and the fourth angle is 63 degrees. The method of claim 3, wherein And the second polarization axis coincides with the first alignment direction. The method of claim 5, And the first thickness is 4.3 [mu] m. The method of claim 1, A first storage electrode branching from the common wiring to the reflective region is formed, And wherein the drain electrode extends to overlap the first storage electrode, wherein the first storage electrode, the gate insulating layer, and the drain electrode overlap each other to form a storage capacitor. The method of claim 1, The first protective layer is made of an organic insulating material and the reflective region has a convex embossed surface, and the reflective plate formed on the first protective layer also has a convex embossed surface. 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 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. And a overcoat layer formed between the color filter layer and the second alignment layer.

Images