KR20030054140A - liquid crystal display devices and manufacturing method of the same - Google Patents

Abstract

PURPOSE: A liquid crystal display device and a method for manufacturing the same are provided to reduce the thickness of the liquid crystal display device and reduce the manufacturing costs by forming a linear polarizer and a phase difference film inside liquid crystal cells. CONSTITUTION: An absorbing layer(112) is formed on a first substrate. A cholesteric liquid crystal color filter(113) is formed on the absorbing layer. A first electrode(114) is formed on the cholesteric liquid crystal color filter. A second substrate(121) is arranged on the first electrode, being separated at a certain gap. A linear polarizer(123) is formed under the second substrate. A phase difference film(124) is formed under the linear polarizer. A second electrode(122) is formed under the second substrate. A liquid crystal layer(130) is interposed between the first electrode and the second electrode.

Description

Liquid crystal display devices and manufacturing method of the same

The present invention relates to a liquid crystal display device and a manufacturing method thereof.

Recently, with the rapid development of the information society, there is a need for a flat panel display having excellent characteristics such as thinning, light weight, and low power consumption. It is excellent and is actively applied to notebooks and desktop monitors.

In general, a liquid crystal display device is formed by arranging two substrates on which electric field generating electrodes are formed so that the surfaces on which the two electrodes are formed face each other, injecting a liquid crystal material between the two substrates, and then applying a voltage to the two electrodes. By moving the liquid crystal molecules by an electric field, the device expresses an image by the transmittance of light that varies accordingly.

In this case, the liquid crystal display has polarizers that allow only light in a specific direction to pass through the outside of the two substrates, thereby enabling gray representation of transmitted light.

However, the liquid crystal display does not emit light by itself and thus requires a separate light source. Accordingly, a backlight is disposed below the liquid crystal panel and light emitted from the backlight is incident on the liquid crystal panel to display an image by adjusting the amount of light according to the arrangement of the liquid crystals, wherein the field generating electrode of the liquid crystal display is transparent. It is formed of a conductive material, and both substrates must also be made of a transparent substrate.

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 compensate for the above disadvantages, a reflection type liquid crystal display device has been proposed. The reflection type liquid crystal display device uses less power than the transmission type liquid crystal display device in the form of adjusting light transmittance according to the arrangement of liquid crystals by reflecting external natural light or artificial light. In the reflective liquid crystal display device, the lower field generation electrode is formed of a conductive material with good reflection, and the upper field generation electrode is formed of a transparent conductive material to transmit external light.

On the other hand, recently, a liquid crystal display device using a cholesteric liquid crystal color filter has been researched and developed by using the characteristics of a cholesteric liquid crystal.

The cholesteric liquid crystal color filter is made by using the selective reflection characteristic of the cholesteric liquid crystal. That is, the cholesteric liquid crystal has a selective reflection characteristic that mainly reflects only a specific wavelength according to a helical pitch, rather than reflecting all incident light. Therefore, if the rotation pitch is adjusted for each region, the color of reflected light has a color of R, G, or B. The cholesteric liquid crystal color filter also determines the polarization state of the reflected light. For example, when the liquid crystal molecules rotate counterclockwise along the axis of rotation and have a twisted structure (ie, left-handed structure), only the left circularly polarized light is reflected in the corresponding color.

The reflective liquid crystal display device using the cholesteric liquid crystal color filter has an advantage of excellent color reproduction ratio and contrast ratio compared to the reflective liquid crystal display device using the absorption color filter.

The structure of a conventional liquid crystal display using such a cholesteric liquid crystal color filter will be described with reference to the accompanying drawings.

FIG. 1 is a cross-sectional view of a conventional liquid crystal display. As shown in FIG. 1, an absorption layer 12 is formed on a transparent first substrate 11, and a cholesteric liquid crystal color filter 13 is formed thereon. Is formed, and the first electrode 14 is formed on the cholesteric liquid crystal color filter 13. Subsequently, the second substrate 21 is disposed above the first substrate 11 at a predetermined interval, and the second electrode 22 is formed below the second substrate 21. Next, the liquid crystal layer 30 is positioned between the first electrode 14 and the second electrode 22 to form a liquid crystal cell. Here, the cholesteric liquid crystal color filter 13 serves as a reflector.

Next, the phase difference plate 50 is adhered to the second substrate 21 through the adhesive layer 40 on the second substrate 21, and the linear polarizer 60 is disposed on the phase difference plate 50. .

As described above, in the conventional liquid crystal display, the linear polarizer and the retardation plate are formed through separate manufacturing processes and then attached to the liquid crystal cell. However, in general, as the linear polarizer includes a protective layer, a polarizer, a transparent film supporting the same, and several layers such as an adhesive layer, the linear polarizer and the retarder include a plurality of layers, and thus the thickness of the linear polarizer and the retarder Becomes about 100-200 micrometers. Therefore, there is a disadvantage in that the thickness of the liquid crystal display device becomes thick, and the manufacturing process and the cost increase.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a liquid crystal display device and a method of manufacturing the same, which reduce the manufacturing cost by reducing the thickness.

1 is a cross-sectional view of a conventional liquid crystal display device.

2 is a cross-sectional view of a liquid crystal display device according to a first embodiment of the present invention.

3A to 3C are cross-sectional views illustrating a manufacturing process of an upper substrate of a liquid crystal display according to the present invention.

4 is a sectional view showing an example of a color filter according to the present invention;

5a to 5e are sectional views showing the manufacturing process of the color filter according to the present invention.

6 is a cross-sectional view of a liquid crystal display according to a second embodiment of the present invention.

7 is a cross-sectional view of a liquid crystal display according to a third embodiment of the present invention.

8 is a cross-sectional view of a liquid crystal display according to a fourth embodiment of the present invention.

9 is a cross-sectional view of a liquid crystal display according to a fifth embodiment of the present invention.

10 is a cross-sectional view of a liquid crystal display according to a sixth embodiment of the present invention.

<Description of Symbols for Main Parts of Drawings>

111: first substrate 112: absorber layer

113: cholesteric liquid crystal color filter 114: first electrode

121: second substrate 122: second electrode

123: linear polarizer 124: retardation film

130: liquid crystal layer

In the liquid crystal display according to the present invention for achieving the above object, an absorption layer is formed on the first substrate, and the cholesteric liquid crystal color filter and the first electrode are sequentially formed thereon. A second substrate is disposed above the first electrode at regular intervals, and a linear polarizer is formed below the second substrate. A retardation film is formed under the linear polarizer, and a second electrode is formed under the linear polarizer. The liquid crystal layer is positioned between the first and second electrodes.

Here, it is preferable that the upper surface of the second substrate is subjected to antiglare treatment or antireflection treatment.

In another liquid crystal display according to the present invention, a reflecting plate is formed on the first substrate, and an absorption type color filter and a first electrode are formed on the first substrate. The second substrate is disposed above the first electrode at regular intervals, and a linear polarizer is formed below the first electrode. A retardation film is formed under the linear polarizer, and a second electrode is formed under the linear polarizer. The liquid crystal layer is positioned between the first and second electrodes.

In the liquid crystal display according to the present invention, the second electrode may be positioned between the second substrate and the linear polarizer, or may be positioned below the retardation film.

In another liquid crystal display according to the present invention, a first electrode is formed on an upper portion of the first substrate, and a second substrate is disposed on the first electrode at a predetermined interval. The linear polarizer and the retardation film are sequentially formed under the second substrate, and the absorption type color filter is formed under the retardation film. A second electrode is formed below the absorption type color filter, and a liquid crystal layer is positioned between the first and second electrodes.

Here, the backlight may further include a lower portion of the first substrate.

In another liquid crystal display according to the present invention, a color filter is formed on the first substrate, and a first electrode is formed thereon. The second substrate is disposed above the first electrode at regular intervals, and a linear polarizer is formed below the first electrode. A second electrode is formed below the linear polarizer, and a liquid crystal layer is positioned between the first and second electrodes. The backlight is disposed under the first substrate.

Here, the color filter may be made of cholesteric liquid crystal, or may be made of an absorption type color filter.

On the other hand, the present invention may further include a protective film made of tetraacetyl cellulose on the second substrate, the protective film may be bonded to the second substrate and the adhesive layer. At this time, the upper surface of the protective film may be antiglare treatment or anti-reflection treatment.

In the method of manufacturing a liquid crystal display according to the present invention, an absorption layer is formed on the first substrate, a cholesteric liquid crystal color filter is formed thereon, and then a first electrode is formed on the cholesteric liquid crystal color filter. Next, a linear polarizer is formed on the second substrate, and a retardation film and a second electrode are formed thereon. Subsequently, after disposing the first substrate and the second substrate so that the first and second electrodes face each other, the liquid crystal is injected between the disposed first and second substrates.

The forming of the cholesteric liquid crystal color filter may include forming a first alignment layer on the first substrate, forming a first cholesteric liquid crystal layer on the alignment layer, and forming the first cholesteric liquid crystal layer. Color patterning the pixel to have a different pitch for each pixel, curing the color patterned first cholesteric liquid crystal color filter with ultraviolet light, exposing the cured first cholesteric liquid crystal color filter to plasma, Forming a second alignment layer on the plasma treated first cholesteric liquid crystal color filter, forming a second cholesteric liquid crystal layer on the second alignment layer, and coloring the second cholesteric liquid crystal layer Patterning, curing the color patterned second cholesteric liquid crystal color filter with ultraviolet light, the ultraviolet cured first and second cholesters And thermosetting the liquid crystal layer.

In this case, the plasma treatment may use any one of oxygen, hydrogen, and argon.

In another method of manufacturing a liquid crystal display according to the present invention, a reflective plate is formed on the first substrate and an absorption type color filter is formed thereon, and then a first electrode is formed on the absorption type color filter. Subsequently, a linear polarizer is formed on the second substrate and a retardation film is formed on the linear polarizer. Next, after the second electrode is formed on the retardation film, the first and second substrates are disposed to face the first and second electrodes. Next, the liquid crystal is injected between the disposed first and second substrates.

In another method of manufacturing a liquid crystal display according to the present invention, a first electrode is formed on the first substrate. Next, a linear polarizer is formed on the second substrate and a retardation film is formed thereon, and then an absorption type color filter is formed on the retardation film. Next, a second electrode is formed on the absorption type color filter, and the first and second substrates are disposed to face the first and second electrodes. Next, the liquid crystal is injected between the first and second substrates arranged.

In the present invention, the method may further include disposing a backlight under the first substrate after injecting the liquid crystal.

In another method of manufacturing a liquid crystal display according to the present invention, a color filter is formed on the first substrate, and a first electrode is formed thereon. Next, a linear polarizer is formed on the second substrate, a retardation film is formed on the linear polarizer, and a second electrode is formed thereon. Subsequently, the first and second substrates are disposed so that the first and second electrodes face each other, and the liquid crystal is injected between the disposed first and second substrates. Next, the backlight is disposed below the first substrate.

In this case, the color filter may be made of cholesteric liquid crystal, or may be made of an absorption type color filter.

In the manufacturing method according to the present invention may further comprise the step of adhering a protective film made of tetraacetyl cellulose to the upper portion of the second substrate as an adhesive layer.

As described above, in the liquid crystal display and the manufacturing method thereof according to the present invention, the linear polarizer and the retardation film may be formed inside the liquid crystal cell to reduce the thickness of the liquid crystal display and reduce the manufacturing cost. In this case, the liquid crystal display may further improve luminance when the external light source is bright due to the reflection type or the transflective type. When the color filter is formed of the cholesteric liquid crystal color filter, the color change according to the viewing angle may be displayed.

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

First, FIG. 2 is a cross-sectional view of a liquid crystal display according to a first embodiment of the present invention.

As shown, an absorbing layer 112 is formed on the first substrate 111, a cholesteric liquid crystal color filter 113 is formed thereon, and a first portion is disposed on the cholesteric liquid crystal color filter 113. The electrode 114 is formed. The first substrate 111 may be made of a transparent insulating substrate, or may be made of a opaque or low transparency substrate. On the other hand, the first electrode 114 is made of a transparent conductive material such as indium-tin-oxide (hereinafter referred to as ITO). Here, the cholesteric liquid crystal color filter 113 reflects only a specific wavelength according to the rotational pitch of the incident light, and thus serves as a reflection plate, and thus does not require a separate reflection plate. In this case, light that is not reflected by the cholesteric liquid crystal color filter 113 and is transmitted through the cholesteric liquid crystal color filter 113 among the incident light is absorbed by the absorbing layer 112.

Next, the second substrate 121 is disposed above the first electrode 114 at regular intervals, and a transparent second electrode 122 is formed below the second substrate 121. Here, the second substrate 121 is made of a transparent substrate such as glass, and the second electrode 122 is made of a transparent conductive material such as ITO. Subsequently, the linear polarizer 123 and the retardation film 124 are formed under the second electrode 122, respectively. In this case, the linear polarizer 123 and the retardation film 124 are made of only a film having a thickness of several μm or less.

Next, the liquid crystal layer 130 is positioned between the first electrode 114 on the first substrate 111 and the retardation film 124 under the second substrate 121 to form a liquid crystal cell. Although not shown, an alignment layer for arranging the liquid crystal molecules of the liquid crystal layer 130 is disposed on the upper portion of the first electrode 114 and the lower phase retardation film 124, and the liquid crystal molecules are formed of the first electrode 114 and the second electrode ( When a voltage is applied to 122, the arrangement state is changed by the electric field generated between the two electrodes 114 and 122.

The liquid crystal display according to the present invention is a reflective liquid crystal display, which reflects the light of an external light source to represent an image. In this case, the external light source may be seen depending on the viewing angle, so that the second substrate 121 may be prevented. An antiglare treatment for dispersing light diffused on the outer surface 121a of the anti-reflection treatment or an antireflection treatment for preventing reflection of light at an angle is performed.

In addition, by attaching a scattering film on the surface of the cholesteric liquid crystal color filter 113 or by providing a scattering function through surface treatment, the viewing angle effect can be improved, and the formation conditions of the materials forming the first and second electrodes can be controlled. Scattering functions can also be imparted to the first and second electrodes.

In the liquid crystal display according to the present invention, the second electrode 122 is positioned between the second substrate 121 and the linear polarizer 123, and the second electrode 122 is the linear polarizer 123 and the retardation film 124. It may be located between or may be located below the retardation film 124.

In the present invention, the retardation film 124 may be formed on the cholesteric liquid crystal color filter. In this case, the liquid crystal mode should be changed, and an alignment layer may be added between the retardation film and the cholesteric liquid crystal color filter.

On the other hand, the cholesteric liquid crystal color filter 113 of the present invention is formed of monochrome (monochrome), at this time may be reflected to the light of the wavelength band corresponding to any color of red, green, blue. In this case, the manufacturing cost and the process can be further reduced, and since the pitch experienced by the light varies according to the angle reflected by the cholesteric liquid crystal color filter, the color may be different depending on the viewing angle.

Since the liquid crystal display device according to the present invention is a reflective liquid crystal display device, power consumption can be reduced, and as the illuminance of the external light source is increased, a clearer and brighter screen can be seen.

3A to 3C illustrate a process of forming an upper substrate of a liquid crystal cell in the liquid crystal display according to the present invention. In the liquid crystal display of the present invention, the lower substrate is the same as the manufacturing process of a general liquid crystal display.

First, as shown in FIG. 3A, a transparent conductive material such as ITO is deposited on the substrate 121 to form a second electrode 122. Here, ITO can be deposited by the same method as sputtering.

Next, as illustrated in FIG. 3B, the linear polarizer 123 is formed on the second electrode 122. The linear polarizer 123 may be formed by coating a lyotropic liquid crystal in an aqueous solution and then drying it.

Next, as illustrated in FIG. 3C, the retardation film 124 is formed on the linear polarizer 123. An overcoat layer 124a may be further formed below the retardation film 124, as shown, or the overcoat layer may be formed. The retardation film 124 may be formed directly on the linear polarizer 123 by omitting 124a. Here, the retardation film 124 is formed to a thickness of several μm or less, in order to have a phase difference of λ / 4, it is preferable to use a liquid crystal material having a large birefringence, and preferably curable. In this case, an alignment layer may be further formed below the retardation film 124.

In the present invention, the cholesteric liquid crystal color filter is formed in monochrome, but the color may be represented by realizing the colors of red, green, and blue by patterning the cholesteric liquid crystal color filter. In this case, it is preferable to form the cholesteric liquid crystal color filter in a double layer in order to increase the reflectance.

4 is a cross-sectional view of the cholesteric liquid crystal color filter.

As shown in FIG. 4, in the cholesteric liquid crystal color filter, first cholesteric liquid crystal color filters 161, 162, and 163 are formed on the first alignment layer 150, and the second alignment layer 170 is formed thereon. ) Is formed, and second cholesteric liquid crystal color filters 181, 182, and 183 are formed on the second alignment layer 170. As mentioned above, the cholesteric liquid crystal color filters 161, 162, 163, 181, 182, and 183 cause selective reflection of incident light, which is determined by the rotational pitch of the cholesteric liquid crystal molecules. For each pixel, the pitch of rotation is different so that the reflected light has red, green, and blue colors. In this case, the second cholesteric liquid crystal color filters 181, 182, and 183 reflect light of a different wavelength band from the first cholesteric liquid crystal color filters 161, 162, and 163, but the reflected light has the same color. do. Therefore, the luminance of the reflected light can be increased.

A method of manufacturing the cholesteric liquid crystal color filter is illustrated in FIGS. 5A to 5E.

As shown in FIG. 5A, after forming the first alignment layer 150 on the substrate 140 and orienting the surface of the first alignment layer 150 in a predetermined direction by using a rubbing or photoalignment method, the first alignment layer ( The cholesteric liquid crystal is coated on the 150 to form the first cholesteric liquid crystal layer 160. Here, the substrate 140 becomes the first substrate 111 having the absorption layer 112 formed on the upper surface of FIG. 2.

Next, as shown in FIG. 5B, color patterning is performed to irradiate a first cholesteric liquid crystal layer (160 of FIG. 5A) with ultraviolet rays (hereinafter referred to as UV) to have different pitches for each pixel region. ), And the first cholesteric liquid crystal color filters 161, 162, and 163 are formed by curing the first cholesteric liquid crystal layer (160 in FIG. 5A) using UV light.

Next, as shown in FIG. 5C, the surfaces of the first cholesteric liquid crystal color filters 161, 162, and 163 are plasma treated. Here, the plasma treatment is to increase the surface tension of the first cholesteric liquid crystal color filters 161, 162, and 163 so that the coating of the alignment layer is uniform. The gas may be a gas such as oxygen, hydrogen, argon, or a mixture thereof. Can be used. Among them, plasma using hydrogen or a gas having a high hydrogen content does not affect the first cholesteric liquid crystal color filters 161, 162, and 163, and it is preferable to use the plasma because it improves the coating state of the alignment layer.

Next, as shown in FIG. 5D, a second alignment layer 170 is formed on the plasma treated first cholesteric liquid crystal color filters 161, 162, and 163, and the second alignment layer 170 is formed by rubbing or photoalignment. After orienting the surface, the cholesteric liquid crystal is coated thereon to form the second cholesteric liquid crystal layer 180.

Subsequently, as shown in FIG. 5E, the second cholesteric liquid crystal layer (180 of FIG. 5E) is irradiated with UV to perform color patterning to have a different pitch for each pixel region, and the second cholester using UV. The second cholesteric liquid crystal color filters 181, 182, and 183 are formed by curing the lick liquid crystal layer (180 of FIG. 5E). As mentioned above, the rotation pitch of each pixel region of the second cholesteric liquid crystal color filter 181, 182, and 183 is applied to each pixel region of the first cholesteric liquid crystal color filter 161, 162, and 163. The pitch is different from the rotation pitch, but the reflected light should have the same color.

Next, heat treatment is performed to completely cure the first cholesteric liquid crystal color filters 161, 162, and 163 and the second cholesteric liquid crystal color filters 181, 182, and 183.

As described above, in the present invention, the linear polarizer and the retardation film are formed inside the liquid crystal cell, thereby reducing the manufacturing process and cost of the liquid crystal display and reducing the thickness thereof. In addition, when the reflective cholesteric liquid crystal color filter is used, different colors can be displayed according to the viewing angle, and the power consumption can be reduced by using an external light source, and in the case of a bright external light source, the brightness of the liquid crystal display device can be increased. have. Therefore, the present invention can be applied to a device such as a watch or a portable display.

In the liquid crystal display according to the present invention, when the second substrate is formed of a glass substrate, a separate film may be attached to prevent the glass substrate from being broken.

6 is a cross-sectional view of the liquid crystal display according to the second exemplary embodiment of the present invention. Since the liquid crystal display according to the second exemplary embodiment of the present invention has substantially the same structure as the first exemplary embodiment, the same parts will be briefly described.

As shown, the absorption layer 212 is formed on the first substrate 211, the cholesteric liquid crystal color filter 213 is formed thereon, and the first cholesteric liquid crystal color filter 213 is formed on the first substrate 211. The electrode 214 is formed. Here, the cholesteric liquid crystal color filter 213 may be monochrome or may be patterned to implement red, green, and blue colors, respectively.

Next, the second substrate 221 is disposed above the first electrode 214 at regular intervals, and a transparent second electrode 222 is formed below the second substrate 221. Next, a linear polarizer 223 and a retardation film 224 are formed below the second electrode 222.

Subsequently, the liquid crystal layer 230 is positioned between the first electrode 214 on the first substrate 211 and the retardation film 224 under the second substrate 221 to form a liquid crystal cell. Although not shown, an alignment layer for arranging the liquid crystal molecules of the liquid crystal layer 230 is positioned above the first electrode 214 and below the retardation film 224.

Next, a protective film 250 such as triacetylcellulose (hereinafter referred to as TAC) that does not change the polarization state of light is formed on the second substrate 221 by the adhesive layer 240. It is bonded with. Here, the outer surface of the protective film 250 is subjected to the anti-glare treatment or anti-reflection treatment, the adhesive layer 240 may have a diffusion function.

The protective film 250 prevents the fragments from being thrown out even if the glass substrate is broken, and even though the protective film 250 is attached, its thickness is increased by about 40 μm or less compared to the liquid crystal display of the first embodiment. The thickness can be reduced as compared with the liquid crystal display device.

As described above, in the second embodiment of the present invention, a linear polarizer and a retardation film are formed inside the liquid crystal cell to reduce the thickness of the liquid crystal display, and attach a protective film on the second substrate to not change the polarization state of light. Damage to the substrate and damage by the substrate can be prevented.

Meanwhile, although the cholesteric liquid crystal color filter is used in the first and second embodiments, the absorption type color filter may be used.

FIG. 7 is a cross-sectional view of the liquid crystal display according to the third exemplary embodiment of the present invention. As illustrated, a reflecting plate 312 is formed on the first substrate 311, and the absorption type color filter 313 is formed thereon. The first electrode 314 is formed on the absorption type color filter 313. Here, the reflective plate 312 may be made of a material such as a metal, and the absorption type color filter 313 may represent colors by sequentially forming red, green, and blue colors for each pixel area. In this case, the first electrode 314 is made of a transparent conductive material such as ITO.

Next, the second substrate 321 is disposed above the first electrode 314 at regular intervals, and the linear polarizer 322 and the retardation film 323 are formed below the second substrate 321, respectively. A second electrode 324 made of a transparent conductive material is formed under the retardation film 323.

Subsequently, the liquid crystal layer 330 is positioned between the first electrode 314 on the first substrate 311 and the second electrode 324 on the lower portion of the second substrate 321 to form a liquid crystal cell. Although not shown, an alignment layer for arranging the liquid crystal molecules of the liquid crystal layer 330 is positioned above the first electrode 314 and below the second electrode 324.

Next, the polarizing state of light is not changed on the second substrate 321, and a protective film 350 such as an anti-reflection treatment or an antiglare TAC is coated on the outer surface of the second substrate 321 by the adhesive layer 340. ) Is adhered to.

Meanwhile, in the above embodiment, the color filter is formed on the lower substrate. When the absorption type color filter is used, the color filter may be formed on the upper second substrate. This fourth embodiment is shown in FIG.

As shown in FIG. 8, a first electrode 412 is formed on the first substrate 411. The first electrode 412 preferably has a reflective function, and may be made of a metal such as aluminum or an aluminum alloy having a relatively low specific resistance and high reflectivity.

Next, the second substrate 421 is disposed above the first electrode 412 at regular intervals, and the linear polarizer 422 and the retardation film 423 are formed under the second substrate 421. An absorption type color filter 424 is formed under the retardation film 423, and a second electrode 425 made of a transparent conductive material is formed under the retardation film 423.

Subsequently, the liquid crystal layer 430 is positioned between the first electrode 412 on the first substrate 411 and the second electrode 425 under the second substrate 421 to form a liquid crystal cell. Although not shown, an alignment layer for arranging the liquid crystal molecules of the liquid crystal layer 430 is positioned above the first electrode 412 and below the second electrode 425.

Next, the polarization state of the light is not changed on the second substrate 421, and a protective film 450, such as an anti-reflection or antiglare TAC, is formed on the second substrate 421 by the adhesive layer 440. It is glued.

In the foregoing first to fourth embodiments, the reflection type liquid crystal display device has been described. Recently, a semi-transmissive liquid crystal display device in which a reflection part and a transmission part are formed in one pixel area and used as necessary is proposed.

9 is a cross-sectional view of a liquid crystal display according to a fifth exemplary embodiment of the present invention, and relates to a transflective liquid crystal display.

As shown in FIG. 9, the color filter 512 is formed on the first substrate 511, and the first electrode 513 is formed thereon. Here, the color filter 512 may be an absorption type color filter or a cholesteric liquid crystal color filter. In the case of the cholesteric liquid crystal color filter, the color filter 512 may be formed of a double layer reflecting wavelength bands corresponding to different colors. .

Next, the second substrate 521 is disposed above the first electrode 513 at regular intervals, and the linear polarizer 522 and the retardation film 523 are formed below the second substrate 521, respectively. A second electrode 524 made of a transparent conductive material is formed under the retardation film 523.

Next, the liquid crystal layer 530 is positioned between the first electrode 513 on the first substrate 511 and the second electrode 524 under the second substrate 521 to form a liquid crystal cell. Although not shown, an alignment layer for arranging the liquid crystal molecules of the liquid crystal layer 530 is disposed above the first electrode 513 and below the second electrode 524.

Subsequently, the polarizing state of light is not changed on the second substrate 521, and a protective film 550 such as a TAC having an antireflection treatment or an antiglare treatment is formed on the outer surface by the adhesive layer 540. 521).

Next, a backlight 560 is disposed below the first substrate 511 to be used as a light source in a transmissive mode. The backlight 560 is a light source of one side of the light guide plate 561 and one side of the light guide plate 561. Lamp 562 and lamp housing 563 surrounding lamp 562.

Meanwhile, in the transflective liquid crystal display according to the present invention, the color filter may be formed on the upper substrate. The liquid crystal display according to the sixth embodiment of the present invention is illustrated in FIG.

As illustrated, a first electrode 612 is formed on the first substrate 611, and a second substrate 621 is disposed above the first electrode 612 at regular intervals, and the second substrate ( The linear polarizer 622 and the retardation film 623 are formed under the 621. A color filter 624 is formed below the retardation film 623. The color filter 624 is preferably an absorption type color filter. Next, a second electrode 625 is formed under the color filter 624.

Subsequently, the liquid crystal layer 630 is positioned between the first electrode 612 on the first substrate 611 and the second electrode 625 under the second substrate 621 to form a liquid crystal cell. Although not illustrated, an alignment layer for arranging liquid crystal molecules of the liquid crystal layer 630 is disposed above the first electrode 612 and below the second electrode 625.

Next, the polarizing state of light is not changed on the second substrate 621, and a protective film 650 such as a TAC having antireflection or antiglare treatment is formed on the outer surface by the adhesive layer 640. 621).

Next, a backlight 660 is disposed below the first substrate 611 to be used as a light source in a transmissive mode. The backlight 660 is a light source of one side of the light guide plate 661 and one side of the light guide plate 661. Lamp 662 and lamp housing 663 surrounding lamp 662.

As described above, in the fifth and sixth exemplary embodiments of the present invention, the linear polarizer and the retardation plate may be formed in the liquid crystal cell to reduce the thickness of the liquid crystal display and reduce the manufacturing cost. The power consumption can be reduced, and in a dark external environment, the transmission mode can be used selectively as needed.

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

In the present invention, the linear polarizer and the retardation film of the reflective or transflective liquid crystal display device are formed inside the liquid crystal cell, thereby reducing the thickness of the liquid crystal display device and reducing the manufacturing cost. In this case, when the external light source is bright, the luminance may be further improved, and when the color filter is formed of the cholesteric liquid crystal color filter, the color change may be displayed according to the viewing angle.

Claims (25)

A first substrate; An absorption layer formed on the first substrate; A cholesteric liquid crystal color filter formed on the absorption layer; A first electrode formed on the cholesteric liquid crystal color filter; A second substrate disposed above the first electrode at predetermined intervals; A linear polarizer formed under the second substrate; A retardation film formed under the linear polarizer; A second electrode formed under the second substrate; Liquid crystal layer positioned between the first and second electrode Liquid crystal display comprising a. The method of claim 1, The upper surface of the second substrate is an antiglare liquid crystal display device. The method of claim 1, The upper surface of the second substrate is an anti-reflection treatment. A first substrate; A reflector formed on the first substrate; An absorption type color filter formed on the reflective plate; A first electrode formed on the absorption type color filter; A second substrate disposed above the first electrode at predetermined intervals; A linear polarizer formed under the second substrate; A retardation film formed under the linear polarizer; A second electrode formed under the second substrate; Liquid crystal layer positioned between the first and second electrode Liquid crystal display comprising a. The method according to claim 1 or 4, And the second electrode is positioned between the second substrate and the linear polarizer. The method according to claim 1 or 4, And the second electrode is formed under the retardation film. A first substrate; A first electrode formed on the first substrate; A second substrate disposed above the first electrode at predetermined intervals; A linear polarizer formed under the second substrate; A retardation film formed under the linear polarizer; An absorption type color filter formed under the retardation film; A second electrode formed under the absorption type color filter; Liquid crystal layer positioned between the first and second electrode Liquid crystal display comprising a. The method of claim 7, wherein The liquid crystal display device further comprising a backlight under the first substrate. A first substrate; A color filter formed on the first substrate; A first electrode formed on the color filter; A second substrate disposed above the first electrode at predetermined intervals; A linear polarizer formed under the second substrate; A retardation film formed under the linear polarizer; A second electrode formed under the second substrate; A liquid crystal layer positioned between the first and second electrodes; A backlight disposed under the first substrate Liquid crystal display comprising a. The method of claim 9, The color filter is a liquid crystal display device made of cholesteric liquid crystal. The method of claim 9, And the color filter is an absorption type color filter. The method according to any one of claims 4 and 7 to 11, The liquid crystal display further comprises a protective film made of tetraacetyl cellulose on the second substrate. The method of claim 12, The protective film is a liquid crystal display device is bonded to the second substrate and the adhesive layer The method of claim 12, The upper surface of the protective film is an anti-glare liquid crystal display device. The method of claim 12, The upper surface of the protective film is an anti-reflection treatment liquid crystal display device. Forming an absorbing layer over the first substrate; Forming a cholesteric liquid crystal color filter on the absorption layer; Forming a first electrode on the cholesteric liquid crystal color filter; Forming a linear polarizer on the second substrate; Forming a retardation film on the linear polarizer; Forming a second electrode on the retardation film; Disposing a first substrate on which the first electrode is formed and a second substrate on which the second electrode is formed such that the first and second electrodes face each other; Injecting liquid crystal between the disposed first and second substrates Method of manufacturing a liquid crystal display comprising a. The method of claim 16, The forming of the cholesteric liquid crystal color filter may include forming a first alignment layer on the first substrate; Forming a first cholesteric liquid crystal layer on the alignment layer; Color patterning the first cholesteric liquid crystal layer to have a different pitch for each pixel; Curing the color patterned first cholesteric liquid crystal color filter with ultraviolet light; Exposing the cured first cholesteric liquid crystal color filter to a plasma; Forming a second alignment layer on the plasma treated first cholesteric liquid crystal color filter; Forming a second cholesteric liquid crystal layer on the second alignment layer; Color patterning the second cholesteric liquid crystal layer; Curing the color patterned second cholesteric liquid crystal color filter with ultraviolet light; And thermosetting the ultraviolet cured first and second cholesteric liquid crystal layers. The method of claim 17, The plasma process is a method of manufacturing a liquid crystal display device using any one of oxygen, hydrogen and argon gas. Forming a reflector on the first substrate; Forming an absorption type color filter on the reflective plate; Forming a first electrode on the absorption type color filter; Forming a linear polarizer on the second substrate; Forming a retardation film on the linear polarizer; Forming a second electrode on the retardation film; Disposing a first substrate on which the first electrode is formed and a second substrate on which the second electrode is formed such that the first and second electrodes face each other; Injecting liquid crystal between the disposed first and second substrates Method of manufacturing a liquid crystal display comprising a. Forming a first electrode on the first substrate; Forming a linear polarizer on the second substrate; Forming a retardation film on the linear polarizer; Forming an absorption type color filter on the retardation film; Forming a second electrode on the absorption type color filter; Disposing a first substrate on which the first electrode is formed and a second substrate on which the second electrode is formed such that the first and second electrodes face each other; Injecting liquid crystal between the disposed first and second substrates Method of manufacturing a liquid crystal display comprising a. The method of claim 20, And disposing a backlight under the first substrate after injecting the liquid crystal. Forming a color filter on the first substrate; Forming a first electrode on the color filter; Forming a linear polarizer on the second substrate; Forming a retardation film on the linear polarizer; Forming a second electrode on the retardation film; Disposing the first substrate on which the first electrode is formed and the second substrate on which the second electrode is formed such that the first and second electrodes face each other; Injecting liquid crystal between the disposed first and second substrates; Placing a backlight under the first substrate after the liquid crystal injection Method of manufacturing a liquid crystal display comprising a. The method of claim 22, And the color filter comprises a cholesteric liquid crystal. The method of claim 22, And the color filter comprises an absorption type color filter. The method according to any one of claims 16 to 24, A method of manufacturing a liquid crystal display device further comprising the step of adhering a protective film made of tetraacetylcellulose to the upper portion of the second substrate using an adhesive layer.