KR20080060948A - Liquid crystal dsplay panel - Google Patents

Abstract

An LCD(Liquid Crystal Display) panel is provided to improve the brightness and image quality at a transmission mode and to implement the semi-transmission mode at an IPS(In-Plane Switching) mode. The second substrate is arranged oppositely to the first substrate. A liquid crystal layer is located between the first and second substrates. The first substrate includes the first and second gate lines(121a,121b,123a,123b) arranged in parallel to each other. The first and second data lines(161a,161b,162a,162b,163a,163b) are crossed with the first and second gate lines, arranged in parallel to each other and define four sub pixels. A reflection layer is formed to any one sub pixel among four sub pixels. The first to fourth pixel electrodes(191,192,193,194) are formed at each sub pixel. The second substrate includes a red color filter corresponding to the first pixel electrode. A green color filter corresponds to the second pixel electrode. A blue color filter corresponds to the third pixel electrode. A reflection portion color filter corresponds to the four pixel electrode.

Description

Liquid crystal panel {LIQUID CRYSTAL DSPLAY PANEL}

1A and 1B are views for explaining a pixel structure of a conventional transflective liquid crystal panel.

2 is a layout view of a thin film transistor substrate according to a first embodiment of the present invention,

3 is a cross-sectional view taken along line III-III 'of FIG. 2;

4 is a view for explaining a pixel structure of a transflective liquid crystal panel according to a first embodiment of the present invention.

5 and 6 are views for explaining a transflective liquid crystal panel according to a second embodiment of the present invention.

7 is a view for explaining a transflective liquid crystal panel according to a third embodiment of the present invention.

8 is a cross-sectional view taken along line VII-VII 'of the present invention,

9A to 9D are views for explaining a method of driving the liquid crystal panel according to the third embodiment.

* Explanation of symbols for the main parts of the drawings

10: liquid crystal panel 100: first substrate

110: first insulating substrate 121a, 123a: first gate wiring

121b, 123b: second gate wiring 130: gate insulating film

140 semiconductor layer 150 resistive contact layer

161a, 162a, and 163a: first data wires 161b, 162b, and 163b: second data wires

170: protective film 175: uneven pattern

180: reflective layer 191: first pixel electrode

192: second pixel electrode 193: third pixel electrode

194: fourth pixel electrode 200: second substrate

300: liquid crystal layer

The present invention relates to a liquid crystal panel, and more particularly, to a semi-transmissive liquid crystal panel having a quad structure in which four subpixels constitute one pixel.

In general, the liquid crystal display may be classified into a transmissive type, a transflective type, and a reflective type according to the shape of the light source. In the transmissive type, a backlight unit is disposed on a rear surface of the liquid crystal panel, and light from the backlight unit is transmitted through the liquid crystal panel. The reflection type uses natural light and can reduce power consumption by limiting the use of the backlight unit, which occupies 70% of the power consumption. The transflective liquid crystal display device utilizes the advantages of the transmissive and reflective liquid crystal display device. By using natural light and a backlight unit, the transflective liquid crystal display device can secure proper luminance regardless of the change in ambient luminance.

In general, the transflective liquid crystal display device is positioned between a thin film transistor substrate 1 on which a thin film transistor TFT is formed, a color filter substrate (not shown) disposed opposite to the thin film transistor substrate 1, and both substrates. It includes a liquid crystal layer (not shown).

Here, the thin film transistor substrate 1 covers the insulating substrate 2, the gate wiring 3 formed on the insulating substrate 2, and the gate wiring 3 as shown in Figs. 1A and 1B. In the gate insulating film 4, the data wiring 5 formed on the gate insulating film 4, the protective film 6 covering the gate wiring 3 and the data wiring 5, and in one region on the protective film 6. And a pixel electrode 8 which covers the reflective layer 7 and the reflective layer 7 and is formed on the passivation layer 6. The gate line 3 and the data line 5 are arranged to cross each other, and a thin film transistor TFT is formed at an intersection point of the gate line 3 and the data line 5. A pixel electrode 8 connected to the thin film transistor TFT is provided in the pixel region defined by the gate line 3 and the data line 5 intersecting with each other.

Here, the region in which the reflective layer 7 is formed is a reflective region R in which external light is reflected, and the other region is a transmission region T through which the light of the backlight unit passes through the liquid crystal panel. Such a transflective liquid crystal display device is driven in a transmissive mode when the external environment is dark, and is driven in a reflective mode when the external environment is bright, thereby obtaining a considerable level of luminance and color reproducibility in any environment.

However, the conventional transflective liquid crystal display has a low luminance in the transmissive mode because the reflective region R and the transmissive region T are simultaneously present in one subpixel. This is because the area of the transmission area T is relatively reduced by providing the reflection area R, and the aperture ratio is lowered due to the boundary between the transmission area T and the reflection area R. FIG. Specifically, as shown in FIGS. 1A and 1B, an uneven pattern 9 should be formed in the reflective region R for diffuse reflection of light incident from the outside, and the uneven pattern 9 performs exposure and development processes. Since it is formed through, it is difficult to be formed evenly along the boundary between the reflective region (R) and the transmission region (T). In addition, scattering of light may occur due to a step caused by the reflective layer 7 at the boundary part, and thus luminance may be lowered. In addition, in order to form a plurality of uneven patterns 9 in the reflective region R, the process margin M is set in a spatial aspect so as to cross the boundary between the reflective region R and the transmissive region T, and then the uneven pattern is formed. (9) is formed, in which case the reflective layer 7 may be formed by invading the light-transmitting region T. As a result, the luminance is lowered in the transmission mode, and the aperture ratio is lowered.

In addition, in the conventional transflective liquid crystal display device, since both the reflection region R and the transmission region T exist in one subpixel at the same time, both the reflection mode and the transmission mode are driven under the same conditions regardless of the change in the external environment. There is a restriction. Due to these limitations, the image quality is deteriorated due to the poor performance of the transmissive mode in comparison with the transmissive liquid crystal display when the external environment is dark, and the reflective mode in comparison with the reflective liquid crystal display when the external environment is bright. There is a problem in that the image quality is poor because of poor performance.

In addition, such a transflective form is difficult to apply to the liquid crystal panel of the IPS mode. Specifically, the liquid crystal panel of the IPS mode has no problem in implementing the transmissive mode, but has difficulty in implementing the reflective mode. That is, in the IPS mode, a transverse electric field is formed between the two electrode layers so that the liquid crystal molecules are arranged in accordance with the transverse electric field, but some vertical electric fields are formed in the upper electrode layer, so that the liquid crystals positioned above the electrode layer are arranged in the vertical direction instead of the transverse electric field. . Accordingly, the degree of phase delay of the liquid crystal layer positioned on the electrode layer may not be controlled, and thus, the reflection mode may not be smoothly implemented.

Accordingly, an object of the present invention is to provide a liquid crystal panel in which the luminance and image quality in the transmissive mode are improved, and which can be realized in the reflective and transmissive mode in the IPS mode.

The object is, according to the present invention, a first substrate; A second substrate disposed to face the first substrate; A liquid crystal panel comprising a liquid crystal layer positioned between a first substrate and a second substrate, wherein the first substrate includes a first gate wiring and a second gate wiring arranged side by side and a first gate wiring and a second gate wiring. First data lines and second data lines arranged in parallel with each other so as to intersect the gate lines to define four subpixels, and a reflective layer and four subpixels formed in any one of the four subpixels. And a second color substrate, wherein the second substrate includes a red color filter corresponding to the first pixel electrode, a green color filter corresponding to the second pixel electrode, and a blue color corresponding to the third pixel electrode. It is achieved by a liquid crystal panel comprising a color filter and a reflector color filter corresponding to the fourth pixel electrode.

Here, the reflector color filter may be a white color filter.

The reflector color filter may be any one of a green color filter, a red color filter, and a blue color filter, and four subpixels of the first substrate are repeatedly provided in up, down, left, and right directions while forming one pixel. In the reflector color filter, a red color filter, a green color filter, and a blue color filter may be repeatedly formed for each pixel.

The first substrate may further include first to fourth thin film transistors formed at intersections of the first gate wiring and the second gate wiring and the first data wiring and the second data wiring; The protective film may further include a passivation layer covering the first to fourth thin film transistors, and a concave-convex pattern may be formed on a surface of the passivation layer disposed below the reflective layer.

The first to fourth thin film transistors may be independently driven.

The protective film is removed from regions corresponding to the first pixel electrode, the second pixel electrode, and the third pixel electrode, and the cell gap in the region where the reflective layer is provided is substantially 1/2 of the cell gap in the region where the reflective layer is not provided. It may be a boat.

In addition, the passivation layer is formed to have a substantially uniform thickness in a region corresponding to the first pixel electrode, the second pixel electrode, the third pixel electrode, and the fourth pixel electrode. It may be substantially equal to the cell gap in the non-region.

An object of the present invention, according to the present invention, the first substrate; A second substrate disposed to face the first substrate; In a liquid crystal panel including a liquid crystal layer positioned between a first substrate and a second substrate, the first substrate includes a first gate wiring and a second gate wiring arranged side by side, and a first gate wiring and a first substrate. A first data line and a second data line, which are disposed in parallel with each other to cross the two-gate line and define the first to fourth subpixels, a reflective layer formed on the fourth subpixel, a first electrode layer formed on the reflective layer, and a first And a second electrode layer and a third electrode layer which are repeatedly formed in the first to third subpixels, wherein the second substrate includes a red color filter corresponding to the first subpixel and a green color corresponding to the second subpixel. A filter, a blue color filter corresponding to the third subpixel, a reflector color filter corresponding to the fourth subpixel, and a fourth electrode layer formed on the reflector color filter. Is achieved by .

The first substrate may include first to fourth thin film transistors formed at intersections of the first gate wiring and the second gate wiring and the first data wiring and the second data wiring; The protective film may further include a passivation layer covering the first to fourth thin film transistors, and a concave-convex pattern may be formed on a surface of the passivation layer disposed below the reflective layer.

The protective layer is removed in regions corresponding to the first subpixel, the second subpixel, and the third subpixel, and the cell gap in the region where the reflective layer is provided is substantially 1/2 of the cell gap in the region where the reflective layer is not provided. It may be a boat.

The transverse electric field is formed between the second and third electrode layers repeatedly formed in the first to third subpixels, and the fourth electrode formed on the first electrode layer and the reflector color filter formed on the fourth subpixel. A vertical electric field may be formed between the electrode layers.

The first phase difference plate and the first polarizing plate may be sequentially attached to the outer surface of the first substrate, and the second phase difference plate and the second polarizing plate may be sequentially attached to the outer surface of the second substrate.

In addition, the phase delay axis of the first phase difference plate may be provided to be inclined substantially 15 degrees to the polarization axis of the first polarizing plate, and the phase delay axis of the second phase difference plate may be provided to be substantially inclined to 60 degrees to the polarization axis of the second polarization plate.

In addition, the first phase difference plate and the second phase difference plate may delay the phase of light passing through λ / 2.

In addition, the reflector color filter may be a white color filter.

The reflector color filter may be any one of a green color filter, a red color filter, and a blue color filter, and the first to fourth subpixels of the first substrate may be repeatedly formed in the up, down, left, and right directions while forming one pixel. The reflection part color filter may include a red color filter, a green color filter, and a blue color filter repeatedly formed for each pixel.

In addition, the first to fourth thin film transistors may be independently driven.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings. Hereinafter, a certain film (layer) is formed (prepared) on another film (layer), not only when two films (layers) are in contact but also when another film (layer) exists between the two films (layers). It also includes the case.

2 is a layout view of a thin film transistor substrate according to a first embodiment of the present invention, FIG. 3 is a cross-sectional view taken along line III-III 'of FIG. 2, and FIG. 4 is a semi-transmissive liquid crystal panel according to the first embodiment of the present invention. It is a figure for demonstrating the pixel structure of this.

In the liquid crystal display according to the exemplary embodiment of the present invention, as illustrated in FIGS. 2 and 3, a thin film transistor (TFT) is provided as a switching and driving element for controlling and driving the operation of each pixel. Liquid crystal between the thin film transistor substrate (hereinafter referred to as the first substrate 100) and the color filter substrate (hereinafter referred to as the second substrate 200) and the two substrates 100 and 200 that are bonded to the first substrate 100. The liquid crystal panel 10 in which the layer 300 is located is included.

First, the first substrate 100 will be described. The first substrate 100 includes a first insulating substrate 110, a plurality of gate wirings 121a, 121b, 123a, and 123b formed in a matrix form on the first insulating substrate 110, and a plurality of data wirings 161a, A plurality of thin film transistors, which are switching elements formed at the intersections of 161b, 162a, 162b, 163a, and 163b, the gate wirings 121a, 121b, 123a, and 123b and the data wirings 161a, 161b, 162a, 162b, 163a, and 163b. (Thin Film Transistor; Tr1, Tr2, Tr3, Tr4) and a plurality of pixel electrodes 191, 192, 193, and 194 connected to the plurality of thin film transistors Tr1, Tr2, Tr3, and Tr4. Signal voltages are applied to the liquid crystal layer 300 between the pixel electrodes 191, 192, 193, and 194 and the common electrode 250 of the second substrate 200 to be described later through the thin film transistors Tr1, Tr2, Tr3, and Tr4. When applied, the liquid crystal layer 300 is aligned according to the signal voltage to determine the light transmittance.

As the first insulating substrate 110, a substrate made of an insulating material such as glass, quartz, ceramic, or plastic may be used. When the first substrate 100 according to the present invention is used to manufacture a flexible liquid crystal display device, it is preferable to use a plastic substrate as the first insulating substrate 110. Here, the plastic type may be made of any one material selected from polycarbonate, polyimide, PNB (polynorborneen), PES, PAR, PEN (polyethylenapthanate), and PET (polyethylene terephthalate). .

A plurality of gate wires 121a, 121b, 123a, and 123b are formed on the first insulating substrate 110. The plurality of gate wires 121a, 121b, 123a, and 123b includes the first gate wires 121a and 123a and the second gate wires 121b and 123b which are arranged side by side. The plurality of gate wires 121a, 121b, 123a, and 123b may be a metal single layer or multiple layers. The gate wires 121a, 121b, 123a, and 123b are the gate lines 121a and 121a extending in the horizontal direction and the gate electrodes 123a and 123b constituting the thin film transistor TFT as part of the gate lines 121a and 121b. It includes.

On the first insulating substrate 110, a gate insulating layer 130 made of silicon nitride (SiNx), silicon oxide (SiOx), or the like covers the gate wirings 121a, 121b, 123a, and 123b. The gate insulating layer 130 is removed in the transmission region T through which the light of the backlight unit (not shown) passes through the liquid crystal panel 10.

A semiconductor layer 140 made of a semiconductor such as amorphous silicon is formed on the gate insulating layer 130 of the gate electrodes 123a and 123b, and a silicide or n-type impurity is doped at a high concentration on the semiconductor layer 140. An ohmic contact layer 150 made of a material such as n + hydrogenated amorphous silicon is formed. The ohmic contact layer 150 is removed from the channel portion between the source electrodes 162a and 162b and the drain electrodes 163a and 163b.

A plurality of data lines 161a, 161b, 162a, 162b, 163a, and 163b are formed on the ohmic contact layer 150 and the gate insulating layer 130. The plurality of data wires 161a, 161b, 162a, 162b, 163a, and 163b may also be a single layer or multiple layers of a metal layer. The plurality of data wires 161a, 161b, 162a, 162b, 163a, and 163b are formed in a vertical direction to intersect the first and second gate lines 121a and 121b to define four subpixels. First and second source electrodes 162a and 162b and first branches of the data lines 161a and 161b and the first and second data lines 161a and 161b and extending to the upper portion of the ohmic contact layer 150. And first and second drain electrodes 163a and 163b which are separated from the second source electrodes 162a and 162b and are formed on the ohmic contact layer 150 opposite to the first and second source electrodes 162a and 162b. ).

The first to fourth thin film transistors Tr1 are disposed at the intersections of the first and second gate lines 121a, 121b, 123a, and 123b and the first and second data lines 161a, 161b, 162a, 162b, 163a, and 163b. , Tr2, Tr3, Tr4) are formed. Each thin film transistor Tr1, Tr2, Tr3, Tr4 is driven independently.

The plurality of thin film transistors Tr1, Tr2, Tr3, and Tr4 are covered by the passivation layer 170. Specifically, the passivation layer 170 may include a plurality of thin film transistors Tr1, Tr2, Tr3, and Tr4, first and second gate wirings 121a, 121b, 123a, and 123b, and first and second data wirings 161a, 161b, 162a, 162b, 163a, and 163b and are formed in a region corresponding to the reflective layer 180, which will be described later, and removed from the region corresponding to the first to third pixel electrodes 191, 192, and 189. . That is, the protective film 170 which concerns on this invention is removed in the area | region corresponding to the transmission area | region T, and is provided in another area | region. The reason for varying the thickness of the passivation layer 170 in the transmission region T and the reflection region R is to match the light paths of the light reflected by the reflective layer 180 and the light transmitted through the liquid crystal panel 10 in the same manner. For sake. Therefore, when applying and patterning the protective film 170, it is preferable to apply and pattern to an appropriate thickness in consideration of such circumstances.

Here, the distance between the two substrates (100, 200) is defined as a cell gap, in the present invention, the height of the protective film 170 in order to match the path of light in the transmission region (T) and the reflection region (R) equally. By forming different from each other, the cell gap C1 in the region where the reflective layer 180 is provided is substantially 1/2 times as compared to the cell gap C2 in the region where the reflective layer 180 is not provided. Accordingly, the optical paths of the light in the transmission region T and the light in the reflection region R become similar to each other, thereby achieving a uniform image. And the image quality is improved.

The uneven pattern 175 is provided on the surface of the passivation layer 170 positioned in the reflective region R. That is, the protective film 170 is formed on the uneven pattern 175 in any one of the four subpixels. The uneven pattern 175 is to induce scattering of light to increase reflectance and improve front reflectivity of light. The concave-convex pattern 175 may be provided in a convex lens shape or a concave lens shape. The passivation layer 170 is provided with a drain contact hole 171 exposing the drain electrodes 163a and 163b of the thin film transistors Tr1, Tr2, Tr3, and Tr4.

The reflective layer 180 is formed on the uneven pattern 175. That is, the reflective layer 180 is formed on any one of four subpixels. Accordingly, three subpixels among the four subpixels become the transmission region T and the other subpixel becomes the reflection region R. FIG. In the transmissive region T where the reflective layer 180 is not formed, light of a backlight unit (not shown) passes through the liquid crystal panel 10 and is irradiated out of the reflective layer 180. The light from the light is reflected and irradiated out of the liquid crystal panel 10 again. Aluminum or silver is mainly used for the reflective layer 180. In some cases, a double layer of aluminum / molybdenum may be used.

First to fourth pixel electrodes 191, 192, 193, and 194 are formed in the four subpixels, respectively. Each pixel electrode 191, 192, 193, and 194 is connected to the drain electrodes 163a and 163b through the drain contact hole 171. The pixel electrodes 191, 192, 193, and 194 are generally made of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO). In the region corresponding to the reflective region R of the fourth pixel electrode 194, the uneven pattern is formed by the uneven pattern 175 on the surface of the passivation layer 170.

In the first substrate 100 configured as described above, as shown in FIG. 4, four sub pixels are repeated in the vertical direction and the left and right directions while forming one pixel. Specifically, all four subpixels are provided with the same area, and among the four subpixels, all three subpixels are composed of the transmission region T, and the other one subpixel is provided with the reflection region R. . The four subpixels driven as one pixel are referred to as quad-pixel pixels. That is, in the first substrate 100 according to the present invention, the quad pixels are repeatedly formed.

Next, the color filter substrate 200 will be described.

The black matrix 220 is formed on the second insulating substrate 210. The second insulating substrate 210 is divided into a display area where an image is formed and a peripheral area provided around the display area. In the display area, a black matrix 220 and curl filters 231 and 232 which will be described later are provided. The black matrix 220 generally distinguishes between red, green, and blue color filters, and blocks direct light irradiation to the thin film transistors Tr1, Tr2, Tr3, and Tr4 located on the first substrate 100. . The black matrix 220 is usually made of a photosensitive organic material to which black pigment is added. As the black pigment, carbon black or titanium oxide is used.

The color filters 231 and 232 are formed by repeating the red, green, blue, and white filters on the black matrix 220 as a boundary. The color filters 231 and 232 may serve to impart color to light emitted from the backlight unit (not shown) and passed through the liquid crystal layer 300. The color filters 231 and 232 are usually made of a photosensitive organic material. Although not specifically described, the color filters 231 and 232 according to the present invention have a red color filter 231 corresponding to the first pixel electrode 191 and a green color filter corresponding to the second pixel electrode 192. (Not shown), a blue color filter (not shown) corresponding to the third pixel electrode 193, and a white color filter 232 corresponding to the fourth pixel electrode 194. That is, the white color filter 232 is provided in the area corresponding to the reflection area R.

The overcoat layer 240 is formed on the black matrix 220 which is not covered by the color filters 231 and 232 and the color filters 231 and 232. The overcoat layer 240 serves to protect the color filters 231 and 232 while planarizing the color filters 231 and 232, and an acrylic epoxy material is generally used.

The common electrode 250 is formed on the overcoat layer 240. The common electrode 250 is made of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO). The common electrode 250 directly applies a voltage to the liquid crystal layer 300 along with the pixel electrodes 191, 192, 193, and 194 of the first substrate 100.

When the liquid crystal layer 300 is injected between the first substrate 100 and the second substrate 200 prepared as described above, and the two substrates 100 and 200 are bonded by a sealant (not shown), the liquid crystal panel 10 is completed. do.

Hereinafter, effects according to the first embodiment of the present invention will be described with reference to the drawings.

According to the pixel structure according to the present invention, luminance and image quality are improved in the transmission mode of the transmission region T as compared with the conventional pixel structure. Specifically, when driven in the transmission mode, the brightness is increased in the transmission mode by the light reflected from the reflection area (R). In addition, when the pixel is manufactured under the same conditions and the constraints of the same area, the area of the transmission region T of the quad structure pixel according to the present invention is larger than that of the transmission region of the pixel structure according to the prior art. Accordingly, luminance and image quality are improved in the transmission mode.

In addition, according to the present invention, three subpixels of four subpixels are independently driven in the transmissive mode, and one subpixel is independently driven in the reflective mode. That is, four subpixels are driven independently by each thin film transistor. Accordingly, when it is recognized that the light amount of the external environment is small by using the optical sensor, it is possible to control to improve the luminance of the subpixels of the three transmission modes and to implement a high quality image. When it is recognized that the external light amount is large, the black and white screen can be easily implemented by controlling to reduce the luminance of the three subpixels in three transmission modes and controlling the luminance of one subpixel in the reflection form. That is, the luminance of each subpixel can be controlled in response to the external environment, thereby improving the image quality.

Hereinafter, a transflective liquid crystal panel according to a second embodiment of the present invention will be described with reference to FIGS. 5 and 6.

In the second embodiment, only characteristic parts distinguished from the first embodiment will be described and described, and descriptions omitted or summarized will be in accordance with the first embodiment. In addition, for the convenience of description, the same reference numerals are assigned to the same components to be described.

First, the first substrate 100 will be described. In the first substrate 100 according to the second embodiment, unlike the first embodiment, the protective film 170 is formed on the entire surface of the first substrate material 110. That is, unlike the first embodiment, the passivation layer 170 is coated on the transmission region T. The uneven pattern 175 is formed only in the reflective region R. As shown in FIG. In addition, the first to third pixel electrodes 191, 192, and 193 are formed on the passivation layer 170 of each subpixel, and the fourth pixel electrode 194 is formed on the reflective layer 180.

Next, the second substrate 200 will be described. Although not specifically illustrated, the color filters 231a, 231b, 231c, and 231d are red color filters 231a corresponding to the first pixel electrode 191 and green color filters corresponding to the second pixel electrode 192. 231b, a blue color filter 231c corresponding to the third pixel electrode 193, and a reflector color filter 231d corresponding to the fourth pixel electrode 194. The reflector color filter 231d may be any one of a green color filter, a blue color filter, and a red color filter. That is, in the reflector color filter 231d, a green color filter, a red color filter, and a blue color filter are repeatedly formed for each pixel of a quad structure, as shown in FIG.

In the liquid crystal panel 10 according to the second embodiment, the cell gaps C3 defined as the distances between the two substrates 100 and 200 are substantially the same. That is, unlike the first embodiment, in the second embodiment, the protective film 170 is uniformly coated on the entire surface of the first substrate material 110, so that the cell gap C3 is transparent in the transmission region T and the reflection region R. FIG. Is the same.

As described above, when the cell gap C3 is the same in the transmission region T and the reflection region R, as described in the first embodiment, the optical path of the light passing through the transmission region T and the reflection region R There is a problem of being different. That is, the light in the reflective region R passes through the liquid crystal layer 300 twice, and the light in the transmission region T passes through the liquid crystal layer 300 once. As a result, unevenness in luminance may occur.

The problem is that three subpixels of four subpixels are independently driven in a transmission mode, and one subpixel is driven in a reflection mode. That is, the four subpixels are solved by the structure of the present invention in which each of the thin film transistors is driven independently. That is, the fourth pixel electrode corresponding to the reflective region R, considering that each pixel electrode 191, 192, 193, and 194 is connected to each of the thin film transistors Tr1, Tr2, Tr3, and Tr4. Different voltages may be applied to the first to third pixel electrodes 191, 192, and 193 corresponding to the first and second pixels 194 and T to set the luminance to be uniform. That is, by adjusting the arrangement of the liquid crystal layer 300 corresponding to the reflective region (R) to increase the transmittance, the same luminance as in the transmission region (T) is controlled.

In addition, if the amount of light in the external environment is recognized by using an optical sensor, the control is performed to improve the luminance of the subpixels in the three transmissive modes. If the amount of the external light is recognized, the luminance of the subpixels in the three transmissive modes is controlled. At the same time, the luminance of one sub-pixel in the form of reflection can be improved while controlling to reduce. That is, the luminance of each subpixel can be controlled in response to the external environment, thereby improving the image quality.

On the other hand, as compared with the prior art, the reflection area is reduced, and as the characteristics of the reflection mode are degraded, the resolution may be reduced in the reflection mode. As described above, the problem of deterioration in the reflection mode may be compensated by applying a known sub pixel rendering technique when implementing an image through the reflection mode. Here, the sub pixel rendering technique sums up a plurality of data signals to be input to the reflection areas of adjacent pixels when the reflection mode is implemented, and then inputs the averaged data signals to the reflection areas of the pixels as a whole. It is a technique to improve the resolution. In this case, the weights may be set to be the same between adjacent pixels, or a subpixel rendering technique may be applied by setting weights differently.

7 and 8, a transflective liquid crystal panel according to a third embodiment of the present invention will be described.

In the third embodiment, only the characteristic parts distinguished from the first embodiment will be described and described, and the description thereof will be omitted or summarized according to the first embodiment. In addition, for the convenience of description, the same reference numerals are assigned to the same components to be described.

First, the first substrate 100 will be described with a characteristic partial center distinguished from the above-described first embodiment.

The first gate wiring 121a and 123a and the second gate wiring 121b and 123b intersect the first data wiring 161a, 162a and 163a and the second data wiring 161b, 162b and 163b to form a first subpixel. (I), the second subpixel (II), the third subpixel (III) and the fourth subpixel (IV) are defined. Four subpixels I, II, III, and IV constitute one pixel.

The first to the first gate wiring 121a, 123a, the second gate wiring 121b, 123b, the first data wiring 161a, 162a, 163a, and the second data wiring 161b, 162b, 163b at the intersections of the first through Fourth thin film transistors Tr1, Tr2, Tr3, and Tr4 are formed. The first to fourth thin film transistors Tr1, Tr2, Tr3, and Tr4 are driven independently. A plurality of common voltage lines 125 are formed on the first insulating substrate 110 in parallel with the first gate lines 121a and 123a and the second gate lines 121b and 123b. The common voltage line 125 is connected to the third electrode layer 190c to be described later through the common voltage contact hole 173, and applies the common voltage Vcom to the third electrode layer 190c.

A passivation layer 170 is formed on the first to fourth thin film transistors Tr1, Tr2, Tr3, and Tr4 and on the fourth subpixel IV. In other words, the passivation layer 170 is removed in areas corresponding to the first subpixel I, the second subpixel II, and the third subpixel III. Accordingly, the cell gap C1 of the fourth subpixel IV is 1/2 times the cell gap C2 of the first subpixel I, the second subpixel II, and the third subpixel III. It is about. An uneven pattern 175 is formed on the surface of the passivation layer 170 corresponding to the fourth subpixel IV. The drain contact holes 171 exposing the drain electrodes 163a and 163b of the first to fourth thin film transistors Tr1, Tr2, Tr3, and Tr4 are formed.

The reflective layer 180 is formed on the uneven pattern 175 of the fourth subpixel IV. Accordingly, the fourth subpixel IV becomes the reflection area R, and the first subpixel I, the second subpixel II, and the third subpixel III become the transmission area T. .

The first electrode layer 190a is formed on the reflective layer 180. Specifically, the fourth subpixel IV is filled by the first electrode layer 190a. The first electrode layer 190a is connected to the fourth thin film transistor Tr4 through the drain contact hole 171. On the contrary, in the first subpixel I, the second subpixel II, and the third subpixel III, the second electrode layer 190b and the third electrode layer 190c are repeatedly formed. The second electrode layer 190b is connected to the first thin film transistor Tr1, the second thin film transistor Tr2, and the third thin film transistor Tr3 through the drain contact hole 171, and the third electrode layer 190c is connected to the first thin film transistor Tr1. The common voltage contact 125 is connected to the common voltage line 125. Accordingly, the pixel voltage is charged in the first electrode layer 190a and the second electrode layer 190b, and the common voltage is charged in the third electrode layer 190c. In addition, a transverse electric field is formed between the second electrode layer 190b and the third electrode layer 190c to implement an IPS mode.

Hereinafter, the second substrate 200 will be described with a characteristic partial center distinguished from the above-described first embodiment.

The second substrate 200 may include a red color filter 231 corresponding to the first subpixel (I), a green color filter (not shown) corresponding to the second subpixel (II), and a third subpixel ( A blue color filter (not shown) corresponding to III) and a fourth electrode layer 250 formed on the reflector color filter 232 and the reflector color filter 232 corresponding to the fourth subpixel (IV). ). The fourth electrode layer 250 formed on the reflector color filter 232 forms a vertical electric field together with the first electrode layer 190a formed on the fourth subpixel IV.

Here, the reflector color filter 232 may be provided as a white color filter as in the first embodiment, and may be any one of a green color filter, a red color filter, and a blue color filter as in the second embodiment. Can be. That is, in the reflector color filter 232, a red color filter, a green color filter, and a blue color filter may be repeatedly formed for each pixel of one quad structure as in the second embodiment.

As shown in FIG. 8, the first phase difference plate 410 and the first polarizing plate 420 are sequentially attached to the outer surface of the first insulating substrate 110 and the outside of the second insulating substrate 210. The second phase difference plate 430 and the second polarizing plate 440 are sequentially attached to the surface. Here, the first phase difference plate 410 and the second phase difference plate 430 are films that delay the phase of light passing by λ / 2, and the first phase difference plate 410 and the second phase difference plate 430 have a predetermined direction. A phase delay axis formed by The phase delay axis of the first phase difference plate 410 is provided to be inclined substantially 15 degrees to the polarization axis of the first polarization plate 420, and the phase delay axis of the second phase difference plate 430 is the polarization axis of the second polarization plate 440. It is provided to be inclined at substantially 60 degrees.

Hereinafter, the optical operation of the transflective liquid crystal panel according to the third embodiment will be described with reference to FIGS. 9A to 9D.

9A and 9B are views for explaining the optical operation in the IPS mode in the transmission region T. FIG.

First, an optical operation of implementing a black screen in a state in which no voltage is applied to the electrode layers 190b and 190c will be described with reference to FIG. 9A. Light transmitted through the first polarizing plate 420 attached to the outer surface of the first insulating substrate 110 is formed at 15 degrees with a slow axis (SA) of the first phase difference plate 410. The incident light passes through the first phase difference plate 410 and is symmetrically moved 15 degrees with respect to the slow axis (SA) (②). Here, the light passing through the first flat plate 410 is changed from circularly polarized light to linearly polarized light, and the linearly polarized light passes through the first phase difference plate 410 and is delayed in phase by λ / 2 (180 degrees) so that the phase delay axis ( Slow axis, SA) will be symmetrical movement.

The light is symmetrically moved relative to the liquid crystal director while passing through the liquid crystal layer 300 (③). Here, the liquid crystal layer 300 is set to have a phase delay value of λ / 2 (180 degrees) when no voltage is applied to the electrode layers 190b and 190c. The phase delay axis of the first phase difference plate 410 is arranged to form 60 degrees. Specifically, since the phase difference value of the liquid crystal layer 300 is a relation of δ =? N × d, the phase delay value of the liquid crystal layer 300 may be set to be λ / 2 (180 degrees). . Is the phase difference value,? N is the refractive index of the liquid crystal layer, and d is the cell gap. That is, the liquid crystal layer 300 acts like a phase delay plate to delay the phase of linearly polarized light by λ / 2 (180 degrees). Accordingly, the linearly polarized light is symmetrically shifted by 45 degrees with respect to the liquid crystal director.

The light passes again through the second phase delay plate 430 and symmetrically moves about the phase delay axis (Slow Axis, SA) of the second phase delay plate 430 to be 90 degrees with the polarization axis of the second polarizing plate 440. (④). That is, the light passing through the second phase delay plate 430 is symmetrically moved 30 degrees with respect to the phase delay axis to form 90 degrees with the polarization axis of the second polarizing plate 440. Accordingly, light does not pass through the second polarizing plate 440, thereby implementing a black screen. That is, the black screen is normally black when the voltage is not applied to the electrode layers 190b and 190c.

Next, an optical operation of implementing a white screen when a voltage is applied to the electrode layers 190b and 190c will be described with reference to FIG. 9B.

Light transmitted through the first polarizing plate 420 attached to the outer surface of the first insulating substrate 110 is formed at 15 degrees with a slow axis (SA) of the first phase difference plate 410. The incident light passes through the first phase difference plate 410 and is symmetrically moved 15 degrees with respect to the slow axis (SA) (②). Here, the light passing through the first flat plate 410 is changed from circularly polarized light to linearly polarized light, and the linearly polarized light passes through the first phase difference plate 410 and is delayed in phase by λ / 2 (180 degrees) so that the phase delay axis ( Slow axis, SA) will be symmetrical movement.

When voltage is applied to the electrode layers 190b and 190c, the liquid crystal molecules forming the liquid crystal layer 300 rotate 45 degrees, and the liquid crystal director also rotates 45 degrees in the initial state. The liquid crystal director rotated 45 degrees coincides with the phase delay axis of the first phase difference plate 410, so that the light passing through the first phase difference plate 410 does not generate phase delay by the liquid crystal layer 300 (③ ). That is, the light ③ passing through the liquid crystal layer 300 has the same angle as the light ② passing through the first phase difference plate 410.

The light ③ passes through the second phase difference plate 430 and is symmetrically moved based on the phase delay axis (④). Specifically, since the light (③) passing through the liquid crystal layer 300 forms 60 degrees with respect to the phase delay axis, it becomes the same as the polarization axis of the second polarizing plate 440, and white passes through the second polarizing plate 440. do.

9C and 9D are views for explaining the optical operation in the IPS mode in the reflection region R. FIG.

First, an optical operation of implementing a black screen in a state in which no voltage is applied to the electrode layers 190a and 250 will be described with reference to FIG. 9C.

In the reflective mode, external light passes through the second polarizing plate 440 first (①). The light passing through the second polarizing plate 440 is converted from circularly polarized light to linearly polarized light, and the light (①) converted into linearly polarized light passes through the second phase difference plate 430 and is λ / 2 (180 degrees) based on the phase delay axis. As a result, the phase is delayed so as to symmetrically move about the phase delay axis (Slow Axis, SA). Specifically, since the light ① passing through the second polarizing plate 440 forms 60 degrees with the phase delay axis of the second phase difference plate 430, the light 1 is moved symmetrically with respect to the phase delay axis to become a light state such as ②. .

This light (2) forms 45 degrees with the liquid crystal director of the liquid crystal layer 300, so that the phase is delayed. Here, since the cell gap of the reflective region R is 1/2 of the transmission region T, the reflected light feels (λ / 4) × 2 = λ / 2 as a result. That is, the cell gap is 1/2, but light passes through the liquid crystal layer 300 twice. Therefore, this light ② moves symmetrically with respect to the liquid crystal director and becomes a state like ③.

The reflected light ③ passes through the second phase difference plate 430 again, and since the reflected light ③ forms 30 degrees with the phase delay axis of the second phase difference plate 430, the second phase difference plate 430. The light passing through) moves symmetrically with respect to the phase delay axis and becomes the light in the same state as ④. Since the light ④ forms 90 degrees with the polarization axis of the second polarizing plate 440, a black screen is realized.

Next, an optical operation of implementing a white screen in a state where voltage is applied to the electrode layers 190a and 250 will be described with reference to FIG. 9D.

In the reflective mode, external light passes through the second polarizing plate 440 first (①). The light passing through the second polarizing plate 440 is converted from circularly polarized light to linearly polarized light, and the light (①) converted into linearly polarized light passes through the second phase difference plate 430 and is λ / 2 (180 degrees) based on the phase delay axis. As a result, the phase is delayed so as to symmetrically move about the phase delay axis (Slow Axis, SA). Specifically, since the light ① passing through the second polarizing plate 440 forms 60 degrees with the phase delay axis of the second phase difference plate 430, the light 1 is moved symmetrically with respect to the phase delay axis to become a light state such as ②. .

When voltage is applied to the electrode layers 190a and 250, the liquid crystal molecules constituting the liquid crystal layer 300 are vertically aligned according to the formed vertical electric field. That is, liquid crystal molecules are vertically arranged between the first polarizing plate 410 and the second polarizing plate 440. According to this arrangement, since the phase delay by the liquid crystal layer 300 does not occur, the light ② passing through the second phase difference plate 430 does not change and is reflected as it is to face the second phase difference plate 430. (③).

The light ③ again passes through the second phase difference plate 430 and is symmetrically moved again based on the phase delay axis to become light in the state of ④. This light ④ is the light in the same state as the light ① passing through the second polarizing plate 440. Accordingly, the light ④ passes through the polarization axis of the second polarizing plate 440 to realize a white screen.

Accordingly, a black screen and a white screen can be driven in both the transmission region T and the reflection region R, thereby providing a liquid crystal panel capable of implementing reflection and transmission modes.

As described above, according to the present invention, there is provided a liquid crystal panel capable of improving luminance and image quality in a transmission mode, and implementing reflection and transmission modes in an IPS mode.

Claims (19)

A first substrate; A second substrate disposed to face the first substrate; In the liquid crystal panel comprising a liquid crystal layer positioned between the first substrate and the second substrate, The first substrate may include first and second gate interconnections arranged side by side, and first data defining four subpixels arranged in parallel to intersect the first gate interconnection and the second gate interconnection. A wiring layer, a second data wiring line, a reflective layer formed on any one of the four subpixels, and first to fourth pixel electrodes formed on each of the four subpixels; The second substrate may include a red color filter corresponding to the first pixel electrode, a green color filter corresponding to the second pixel electrode, a blue color filter corresponding to the third pixel electrode, and the fourth pixel electrode. And a reflector color filter corresponding to the liquid crystal panel. The method of claim 1, The reflective part color filter is a liquid crystal panel, characterized in that the white color filter. The method of claim 1, The reflector color filter is any one of the green color filter, the red color filter and the blue color filter. The method of claim 3, wherein The four subpixels of the first substrate are repeatedly provided in up, down, left and right directions while forming one pixel. And the red color filter, the green color filter, and the blue color filter are repeatedly formed in each of the pixels in the reflector color filter. The method of claim 1, The first substrate, First to fourth thin film transistors formed at intersections of the first gate line, the second gate line, the first data line, and the second data line;  Further comprising a passivation layer covering the first to fourth thin film transistor, And a concave-convex pattern is formed on a surface of the passivation layer under the reflective layer. The method of claim 5, The first to fourth thin film transistors are driven independently. The method of claim 5, The passivation layer is removed in regions corresponding to the first pixel electrode, the second pixel electrode, and the third pixel electrode. The cell gap in the region where the reflective layer is provided is substantially 1/2 times the cell gap in the region where the reflective layer is not provided. The method of claim 5, The passivation layer is formed to have a substantially uniform thickness in a region corresponding to the first pixel electrode, the second pixel electrode, the third pixel electrode, and the fourth pixel electrode. The cell gap in the region where the reflective layer is provided is substantially the same as the cell gap in the region where the reflective layer is not provided. A first substrate; A second substrate disposed to face the first substrate; In the liquid crystal panel comprising a liquid crystal layer positioned between the first substrate and the second substrate, The first substrate may be arranged in parallel with each other to intersect the first gate wiring and the second gate wiring and the first gate wiring and the second gate wiring, and define first to fourth subpixels. A first data line and a second data line, a reflective layer formed on the fourth subpixel, a first electrode layer formed on the reflective layer, a second electrode layer repeatedly formed on the first to third subpixels, and A third electrode layer, The second substrate may include a red color filter corresponding to the first subpixel, a green color filter corresponding to the second subpixel, a blue color filter corresponding to the third subpixel, and the fourth subpixel. And a fourth electrode layer formed on the reflector color filter corresponding to the reflector color filter. The method of claim 1, The first substrate, First to fourth thin film transistors formed at intersections of the first gate line, the second gate line, the first data line, and the second data line;  Further comprising a passivation layer covering the first to fourth thin film transistor, And a concave-convex pattern is formed on a surface of the passivation layer under the reflective layer. The method of claim 10, The passivation layer is removed in areas corresponding to the first subpixel, the second subpixel, and the third subpixel. The cell gap in the region where the reflective layer is provided is substantially 1/2 times the cell gap in the region where the reflective layer is not provided. The method of claim 11, A transverse electric field is formed between the second and third electrode layers repeatedly formed in the first to third subpixels. And a vertical electric field is formed between the first electrode layer formed on the fourth subpixel and the fourth electrode layer formed on the reflector color filter. The method of claim 11, The first phase difference plate and the first polarizing plate are sequentially attached to the outer surface of the first substrate, And a second phase difference plate and a second polarizing plate are sequentially attached to the outer surface of the second substrate. The method of claim 13, The phase delay axis of the first phase difference plate is provided to be inclined substantially 15 degrees to the polarization axis of the first polarizing plate, And a phase delay axis of the second phase difference plate is substantially inclined at an angle of 60 degrees to the polarization axis of the second polarizing plate. The method of claim 13, And the first phase difference plate and the second phase difference plate delay the phase of light passing by λ / 2. The method of claim 9, The reflective part color filter is a liquid crystal panel, characterized in that the white color filter. The method of claim 9, The reflector color filter is any one of the green color filter, the red color filter and the blue color filter. The method of claim 17, The first to fourth subpixels of the first substrate are repeatedly provided in up, down, left and right directions while forming one pixel. And the red color filter, the green color filter, and the blue color filter are repeatedly formed in each of the pixels in the reflector color filter. The method of claim 9, The first to fourth thin film transistors are driven independently.

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