KR100710176B1 - Reflective Type Liquid Crystal Display Device And Method For Fabricating The Same - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflective liquid crystal display device having excellent resolution and a method of manufacturing the same, wherein the reflective liquid crystal display device includes a thin film transistor and a pixel electrode in a unit pixel defined by gate lines and data lines formed in directions perpendicular to each other. And a first substrate, a second substrate opposed to the first substrate, a liquid crystal layer formed between the first and second substrates, a third substrate opposed to the first substrate, and the third substrate. And a color filter layer formed inside the substrate and corresponding to the unit pixel, and a color filter layer comprising a plurality of moving bodies in which a dye of an ionic material is microencapsulated on the reflective electrode.

Aperture, reflective, electrophoresis, encapsulation, resolution

Description

Reflective Liquid Crystal Display Device and Method for Manufacturing the Same {Reflective Type Liquid Crystal Display Device And Method For Fabricating The Same}

1 is a cross-sectional view of a reflective liquid crystal display device according to the prior art.

2 is a perspective view of a reflective liquid crystal display device according to the prior art.

3A and 3B are cross-sectional views of a reflective liquid crystal display device according to the present invention.

4 is a perspective view of a reflective liquid crystal display device according to a first embodiment of the present invention.

FIG. 5 is a cross-sectional view of the reflective liquid crystal display device along the line II ′ of FIG. 4. FIG.

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

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

8A to 8D are sectional views of the manufacturing process of the reflective liquid crystal display device according to the present invention.

Fig. 9 is a sectional view of a reflective liquid crystal display device showing R color in accordance with a fourth embodiment of the present invention.

Fig. 10 is a sectional view of a reflective liquid crystal display device showing color B according to the fourth embodiment of the present invention.

11A and 11B are cross-sectional views of a reflective liquid crystal display device showing G color according to the fourth embodiment of the present invention.

* Explanation of symbols on the main parts of the drawings

111: thin film array substrate 112: gate wiring

112a: gate electrode 113: gate insulating film

114: semiconductor layer 115: data wiring

115a: source electrode 115b: drain electrode

116: protective film 117: pixel electrode

118: contact hole 121: opposing substrate

122: black matrix layer 124: common electrode

125: liquid crystal layer 127: reflective electrode

150: copper 151: dye particles

211: color filter substrate

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a reflective liquid crystal display device having improved resolution and a manufacturing method thereof.

Recently, the liquid crystal display device, one of the flat panel display devices that are attracting attention, is an element that changes the optical anisotropy by applying an electric field to a liquid crystal that combines the liquidity and the optical properties of the crystal, which is applied to a conventional cathode ray tube. Compared with its low power consumption, small volume, large size, and high definition, it is widely used.

The LCD has a structure in which a color filter substrate as an upper substrate and a thin film transistor (TFT) substrate as a lower substrate are disposed to face each other, and a liquid crystal having dielectric anisotropy is formed therebetween. The TFTs are driven by switching a TFT added to hundreds of thousands of pixels through a pixel selection address wiring to apply a voltage to the corresponding pixels.

Meanwhile, the liquid crystal display device includes a transmissive liquid crystal display device using a backlight as a light source, a reflective liquid crystal display device using external natural light without using the backlight as a light source, and a transmissive liquid crystal display device with high power consumption due to the backlight. It can be classified into a semi-transmissive liquid crystal display device for overcoming the disadvantages and disadvantages of the reflective liquid crystal display device that cannot be used when the external natural light is dark.

Since the transflective liquid crystal display device has a reflective part and a transmissive part at the same time inside the unit pixel, both the transmissive type and the transmissive type can be used as necessary.

Accordingly, the pixel electrode may be formed as a transmissive electrode or a reflective electrode according to the liquid crystal display device. A transmissive electrode is formed in the transmissive portion of the transmissive liquid crystal display device and the transflective liquid crystal display device, and the reflection of the reflective liquid crystal display device and the transflective liquid crystal display device is reflected. The reflection electrode is formed in the portion.

Here, the transmissive electrodes of the transmissive and transflective liquid crystal display devices emit light from the backlight incident through the lower substrate into the liquid crystal layer to brighten the brightness, and the reflecting electrodes of the reflective and transflective liquid crystal display devices have bright external natural light. The luminance is brightened by reflecting external light incident through the upper substrate.

Hereinafter, a conventional liquid crystal display having a reflective electrode will be described with reference to the accompanying drawings.

1 is a cross-sectional view of a reflective liquid crystal display device according to the prior art, and FIG. 2 is a perspective view of a reflective liquid crystal display device according to the prior art.

In the liquid crystal display device, as shown in FIG. 1, the gate line 12 and the data line 15 are arranged to cross each other so as to define a sub-pixel on the lower substrate 11. A thin film transistor (TFT) is formed at an intersection of the wiring 12 and the data wiring 15, and a pixel electrode 17 electrically connected to the thin film transistor is formed in each unit pixel.

The thin film transistor TFT is formed of a laminated film of a gate electrode 12a, a gate insulating layer 13, a semiconductor layer 14, and source / drain electrodes 15a and 15b.

In addition, the upper substrate 21 includes a black matrix layer 22 that blocks light at an outer portion of the unit pixel, and R, G, and B (Red, Green) for implementing color in each unit pixel. And a color filter layer 23 of Blue and a common electrode 24 forming an electric field together with the pixel electrode 17 are formed.

The upper and lower substrates 11 and 21 are bonded to each other with a predetermined gap, and a liquid crystal layer 25 is formed therebetween.

When the liquid crystal display device as described above is a reflective liquid crystal display device, the pixel electrode 17 is formed of aluminum, copper, or the like, for example, a metal having high reflectance.

In the case of a semi-transmissive liquid crystal display device, the reflective electrode and the transmissive part are defined, and then the reflective part is formed with a metal having high reflectance, and the transmissive part is formed with a transparent electrode of transparent conductive material connected to the reflective electrode. .

The retardation plate 54 and the polarizing plate 55 are further disposed on the upper surface of the upper substrate 21 of the liquid crystal display device as described above.

The manufacturing method of the liquid crystal display device is as follows.

First, a low resistance conductive metal is deposited on the lower substrate 11 by a sputtering method, and then a gate wiring 12 (see FIG. 2) and a gate electrode 12a are formed through a photoetch process.

Next, the gate insulating layer 13 is formed on the entire surface including the gate electrode 12a, and the semiconductor layer 14 is formed on the gate insulating layer 13 on the gate electrode 12a.

A low resistance metal is further deposited on the entire surface including the gate insulating layer 13 to form a data line (15 in FIG. 2) and a source / drain electrode 15a / 15b through a photoetch process.

In this case, the data line 15 is formed to cross the gate line 12 to define a unit pixel, and the source / drain electrodes 15a / 15b are formed on the semiconductor layer 14 to form a thin film transistor. Complete (TFT).

Subsequently, a protective film 16 is formed by depositing an organic insulating material or an inorganic insulating material to a predetermined thickness on the entire surface including the thin film transistor TFT and exposes a predetermined portion of the drain electrode 15b of the thin film transistor. The pixel electrode 17 is formed in each unit pixel so as to be connected to the drain electrode 15b on the protective layer 16. In the case of the reflective liquid crystal display device, the pixel electrode 17 is a reflective electrode which is a metal film having a high reflectance.

Thereafter, a metal film having a high reflectance is deposited on the upper substrate 21 and patterned so as to remain only at the edge of the unit pixel, thereby forming a black matrix 22. In the unit pixel between the black matrix, red, The color filter layer 23 having a predetermined order of green and blue is formed.

There are various methods for forming the color filter layer, such as dyeing, dispersion, coating, and electrodeposition, but are the most common pigment dispersion methods.

Specifically, the first color resist with red color is applied so as to completely cover the black matrix 22, the mask is disposed and exposed, and then the first uncolored portion is removed to remove the first color resist. Form a layer pattern.

Subsequently, the above processes are repeatedly performed to form second and third colored layer patterns in which green and blue colors are colored, respectively, to form color filter layers 23 of R, G, and B. As shown in FIG. 2, the color filter layer 23 is formed in a predetermined order of R, G, and B.

In this structure, three unit pixels composed of R, G, and B implement one pixel to express color.

In this case, the color resist is used as having a negative resist property so that the unexposed part is removed, and the mask is used by shifting the same mask used when exposing the first color resist. .

A common electrode 24 for applying a voltage to the liquid crystal cell together with the reflective electrode 17 is formed on the entire surface including the color filter layer 23.

Next, a seal pattern (not shown) is formed at the edge of the upper substrate 21 or the lower substrate 11 on which various elements are formed, and the upper and lower substrates 11 and 21 are bonded to face each other, and then the two substrates are bonded to each other. The liquid crystal layer 25 is formed in this.

Next, a retardation film 54 having a function of changing a polarization state of light is disposed on the upper surface of the upper substrate 21. The retardation plate 54 uses a quarter wave plate (QWP) having a phase difference corresponding to λ / 4 to change the incident linearly flattened light into circularly polarized light or circularly polarized light into linearly polarized light.

A polarizer 55 is disposed outside the retardation plate 54 to convert natural light into linearly polarized light by passing only light in a direction parallel to the light transmission axis.

When external natural light is incident on the liquid crystal display device, the incident natural light is converted into linearly polarized light through the polarizing plate 55, and the converted linearly polarized light is converted into circularly polarized light while passing through the phase difference plate 54.

Next, the circularly polarized light passes through the upper substrate 21, the color filter layer 23 and the common electrode 24, which have no effect on the phase of the circularly polarized light.

Subsequently, circularly polarized light passes through the liquid crystal layer 25. When the liquid crystal layer 25 is formed to have a phase difference value of λ / 4, the circularly polarized light is converted into linearly polarized light. The linearly polarized light is reflected by the reflective electrode 17 to be circularly polarized again through the liquid crystal layer 25, and then linearly polarized while passing through the phase difference plate 54, and then passes through the polarizing plate 55. At this time, when the polarized direction of the linearly polarized light coincides with the light transmission axis of the polarizing plate 55, all the light is transmitted, and when the light polarization is perpendicular to the light transmission axis, no light is output.

However, when light is output, all colors other than the desired color in the color filter layer are absorbed by the color filter layer, so only specific colors of R, G, and B are emitted.

For reference, a backlight (not shown) is disposed on the rear surface of the liquid crystal display, and may be used as a light source in the transmission mode.

The reflective liquid crystal display device thus formed is displayed by external light incident through the upper substrate, thereby reducing power consumption by using a backlight.

In the conventional reflective liquid crystal display device as described above, since three unit pixels form one pixel, there is a limit in increasing the resolution.

The present invention has been made to solve the above problems, and an object thereof is to provide a reflective liquid crystal display device having high resolution and a method of manufacturing the same by expressing two colors in one unit pixel.

According to an aspect of the present invention, a reflective liquid crystal display device includes a first substrate having a thin film transistor and a pixel electrode formed in a unit pixel defined by a gate line and a data line formed in a direction perpendicular to each other; A second substrate opposed to the first substrate, a liquid crystal layer formed between the first and second substrates, a third substrate opposed to the first substrate, and formed inside the third substrate, And a color filter layer comprising a corresponding reflecting electrode and a plurality of moving bodies in which a dye of an ionic material is microencapsulated on the reflecting electrode.

In addition, a method of manufacturing a reflective liquid crystal display device according to the present invention for achieving the above object is to form a gate wiring and a data wiring on a first substrate to define a unit pixel, the gate wiring and data wiring Forming a thin film transistor at an intersection point, forming a pixel electrode connected to the thin film transistor, bonding a second substrate to face the first substrate, and between the first and second substrates; Forming a color filter layer; forming a color electrode on the third substrate; forming a color filter layer comprising a plurality of moving bodies on which the dye of the ionic material is microencapsulated; And opposing the third substrate to each other.

At this time, the electrophores are composed of dyes of R, G, and B which are ionic materials. Specifically, the electrophores are R dyes and G dyes, R dyes and B dyes, and G dyes and B dyes, respectively. It consists of a first, a second, a third constituting body, characterized in that the dye of different colors in the first, second, third primer is charged with different electrodes.

The dyes of different colors inside such a moving body are moved to different areas, that is, the upper or lower side, and separated into two colors by voltages of (+) or (-) polarity applied to the reflecting electrode.

Since the reflective liquid crystal display device configured as described above can implement two colors in one unit pixel, the reflective liquid crystal display device exhibits twice the resolution of the conventional unit pixel of the same size.

That is, in the related art, one pixel is formed of three R, G, and B unit pixels, but in the present invention, two pixels may be formed of three unit pixels. In addition, since two pixels may be formed of three unit pixels, double the size of each unit pixel to have the same resolution as before. At this time, since the size of the unit pixel is increased, the aperture ratio is increased and the process error can be reduced.

On the other hand, the electrophoretic body is composed of a first electrophoretic body composed of R, G dye particles and a second electrophoretic body composed of B, G dye particles, formed on each unit pixel, and the liquid crystal layer on the first and second electrophoretic bodies is selectively selected. R, G, and B colors can be expressed sequentially within a predetermined time by turning on and off. In this case, two unit pixels can express the colors of R, G, and B, so that the resolution can be increased.

In this case, when two unit pixels are formed with the size corresponding to three unit pixels to implement the same resolution as before, the aperture ratio may be improved by increasing the size of the unit pixel.

Hereinafter, a liquid crystal display and a manufacturing method thereof according to the present invention will be described with reference to the accompanying drawings.

3A and 3B are cross-sectional views of a reflective liquid crystal display device according to the present invention, FIG. 4 is a perspective view of a reflective liquid crystal display device according to a first embodiment of the present invention, and FIG. 5 is a line II ′ of FIG. 4. It is sectional drawing of the linear reflection liquid crystal display element.

6 is a cross-sectional view of a reflective liquid crystal display device according to a second embodiment of the present invention, and FIG. 7 is a cross-sectional view of a reflective liquid crystal display device according to a third embodiment of the present invention.

As shown in FIGS. 3A and 3B, the reflective LCD according to the present invention has a thin film array substrate 111 on which a plurality of wirings and thin film transistors are formed, and faces the thin film array substrate 111. The liquid crystal layer 125 encapsulated between the substrate 121, the thin film array substrate 111 and the counter substrate 121, and a dye charged to face the outer circumferential surface of the thin film array substrate 111 are charged to the microcapsule. A color in which a copper body 150 is encapsulated to realize color, and a reflective electrode 127 is formed to apply an electric field to charged particles of the copper body 150 and to reflect external natural light introduced into the liquid crystal panel to the outside. It consists of the filter substrate 211.

In this case, the thin film array substrate 111 includes a gate wiring 112 (see FIG. 4) and a data wiring (115 of FIG. 4) arranged in a direction perpendicular to each other to define a unit pixel, and the gate wiring 112 and data. A thin film transistor TFT formed at an intersection of the wiring 115 and a pixel electrode 117 connected to the thin film transistor are formed.

The TFT may include a gate electrode 112a branched from the gate line, a gate insulating layer 113 stacked on the gate electrode 112a, and an island shape on the gate electrode 112a. And a source / drain electrodes 116a and 116b branched from the data line and formed on the semiconductor layer 114.

The counter substrate 121 includes a black matrix layer 122 serving as a light shielding layer, and a common electrode 124 forming an electric field together with the pixel electrode 117 to control an arrangement of liquid crystals. The black matrix layer 122 is formed in an area where an electric field is unstable so that the liquid crystal cannot be accurately controlled, typically, an area corresponding to an edge of a unit pixel and a thin film transistor.

On the other hand, the present invention is characterized by adding a color filter substrate 211 is formed on the moving body 150 and the reflecting electrode 127, the moving body 150 serves as a color filter layer and the reflecting electrode ( 127 serves to control the position of the dye particles 151 of different colors inside the moving body 150.

In this case, an opposite electrode 190 may be further provided on an outer surface of the thin film array substrate 111 to face the reflective electrode 127 with the moving body 150 interposed therebetween. 3A may have a size corresponding to the reflective electrode 127 to apply a voltage having a polarity opposite to that of the reflective electrode 127, or may be integrally formed as shown in FIG. 3B. And apply a voltage of a constant value such as ground voltage. Since the counter electrode 190 must transmit light, the counter electrode 190 is formed of a transparent conductive material.

Further, a partition wall 191 is further provided between the reflective electrodes 127 to separate the moving bodies 150 between the unit pixels, and the partition wall 191 includes the thin film array substrate 111 and the color filter substrate. Also serves as a spacer for maintaining the gap of (211).

Specifically, the moving body 150 is a microcapsule having a size of about 100 μm or less in diameter, and a polymer material that serves as a solvent is further added to the inside of the moving body 150 in addition to charged dye grains. About 3 to 5 pieces of the moving object 150 are arranged in one unit pixel, but the number of the moving bodies 150 may vary depending on the unit pixel size.

Such a carrier 150 is formed by mixing and encapsulating dyes of ionic materials having R, G, and B colors, and as shown in FIG. 5, positively charged B dyes, and ( The dyes of any two colors, R dye charged with-) and G dye charged with negative, are encapsulated in one homologue.

That is, the blue (B) dye particles 151 positively charged and the red (R) fine particles 151 charged negatively are mixed and encapsulated on the first reflective electrode 127a. On the second reflective electrode 127b, positively charged blue (B) dye particles 151 and negatively charged green (G) dye particles 151 are mixed and encapsulated. On the third reflective electrode 127c, the positively charged red (R) dye particles 151 and the negatively charged green (G) dye particles 151 are mixed and encapsulated. .

When an electric field is applied to the moving object 150 having such a configuration, the dye particles having different colors move in opposite directions, so that the inside of one moving object 150 is divided into two areas having different colors. That is, when a positive (+) or a negative (-) electric field is applied to the reflective electrode 127, dye particles 151 of R, G, and B colors are gathered on the surface of the moving body 150 to form colors of R, G, and B. Display.

Specifically, as shown in FIG. 5, a positive polarity voltage is applied to the first reflective electrode 127a and the third reflective electrode 127c, and a negative polarity is applied to the second reflective electrode 127b. When voltage is applied, the negatively charged red (R) moves downward on the first reflective electrode 127a and the positively charged blue (B) moves upward, thereby moving a single moving object ( 150) is divided into two areas to implement two colors.

Similarly, on the negative second reflecting electrode 127b, negatively charged green G moves upward, positively charged blue B moves downward, and positive ( On the third reflective electrode 127c of +), negatively-charged green G moves downward and positively-charged red R moves upward.

Accordingly, the colors B, G, and R are displayed on the images corresponding to the first, second, and third reflective electrodes 127a, 127b, and 127c, respectively. Here, when the opposite polarity is applied to each of the reflective electrodes 127a, 127b, and 127c, the colors of R, B, and G are displayed on the image.

On the other hand, unlike the above, as shown in Figure 6, the dye of any two colors of negatively-charged B dye, positively-charged R dye, G dye may be encapsulated in one homologue. have.

That is, on the first reflective electrode 127a, negatively charged blue (B) dye particles 151 and positively charged red (R) dye particles 151 are mixed and encapsulated. On the second reflective electrode 127b, negatively charged blue (B) dye particles 151 and positively charged green (G) dye particles 151 are mixed and encapsulated. On the third reflective electrode 127c, the negatively charged red (R) dye particles 151 and the positively charged green (G) dye particles 151 are mixed and encapsulated. have.

When an electric field is applied to the moving object 150 having such a configuration, as shown in FIG. 6, the positively charged red R moves upward on the positive first reflecting electrode 127a. The negatively charged blue B moves downward, and the negatively charged blue B moves upward and positively on the second reflective electrode 127b. Charged green (G) moves downward, and positively charged green (G) moves upward and negatively charged on the third reflective electrode (127c). The red (R) is moved downwards and the dye particles 151 having different colors are moved in opposite directions so that the inside of one of the moving bodies 150 is divided into two regions of different colors.

On the other hand, a positive electric field may be applied to the reflective electrode collectively.

That is, as shown in FIG. 7, the dye particles 151 of blue (B) charged negatively and the dye particles of red (R) charged positively (+) on the first reflective electrode 127a. 151 are mixed with each other and encapsulated, and blue (B) dye particles 151 charged negatively and green (G) charged particles positively (+) on the second reflective electrode 127b. 151 are mixed with each other and encapsulated. On the third reflective electrode 127c, negatively charged red (R) dye particles 151 and positively charged green (G) dye particles are provided. 151 is mixed with each other encapsulated.

However, in the above embodiment, the negatively charged red dye and the positively charged red dye should be provided, respectively, so that the process is cumbersome.

After all, the photoconductor consists of a first dye, a second dye, a third dye composed of a R dye and a G dye, a R dye and a B dye, and a G dye and a B dye, respectively. The dyes of different colors in the three carriers are characterized by being charged with different electrodes.

As shown in FIG. 4, the reflective liquid crystal display device configured as described above can display two times the resolution of unit pixels having the same size because two colors can be implemented in one unit pixel.

That is, in the related art, one pixel is formed of three R, G, and B unit pixels, but in the present invention, two pixels may be formed of three unit pixels. In addition, since two pixels may be formed of three unit pixels, double the size of each unit pixel to have the same resolution as before. At this time, since the size of the unit pixel is increased, the aperture ratio is increased and the process error can be reduced.

On the other hand, the reflective electrode 127 may be formed in a unit pixel size, as shown in Figure 4, may be formed in a pixel-by-pixel size. The reflective electrode 127 receives a voltage from the outside to have a positive polarity or a negative polarity.

For reference, in the reflective liquid crystal display device, since external natural light is incident to the reflector 150 or the reflecting electrode 127, the light is emitted to the outside, and thus, the thin film array substrate 111 and the pixel electrode 117. Must have a light transmitting characteristic.

Referring to the method of manufacturing a reflective liquid crystal display device according to the present invention as follows.

8A to 8D are cross-sectional views of the manufacturing process of the reflective liquid crystal display device according to the present invention.

First, as shown in FIG. 8A, copper (Cu), aluminum (Al), aluminum alloy (AlNd), tin (Sn), molybdenum (Mo), and chromium (Cu) on a transparent thin film array substrate 111 having excellent insulating properties. Low resistance conductive materials such as Cr), titanium (Ti), tantalum (Ta), and molybdenum-tungsten (MoW) are deposited by a sputtering method and then patterned to form a plurality of gate wirings (112 in FIG. 4) and gate electrodes 112a. To form.

A gate insulating layer 113 is formed by depositing an inorganic insulating layer such as silicon nitride (SiNx) or silicon oxide (SiOx) having excellent dielectric breakdown voltage on the entire surface including the gate electrode 112a by PECVD.

Next, an amorphous silicon is deposited on the gate insulating layer 113 on the gate electrode 112a and patterned into islands to form a semiconductor layer 114. In this case, although not shown, an ohmic contact layer may be formed by depositing amorphous silicon implanted with impurity ions on the semiconductor layer.

The ohmic contact layer is for forming ohmic contact with a source / drain electrode to be formed through a later process.

Subsequently, a plurality of data lines (115 in FIG. 4) are formed to intersect the gate lines to form pixel regions, and at the same time, source electrodes 115a and drain electrodes 115b are formed at both ends of the semiconductor layer to form gate electrodes. A thin film transistor (TFT) including a 112a, a gate insulating film 113, a semiconductor layer 114, and source / drain electrodes 115a and 115b is completed.

In this case, the data line and the source / drain electrodes may also include copper (Cu), aluminum (Al), aluminum alloy (AlNd), tin (Sn), molybdenum (Mo), chromium (Cr), titanium (Ti), and tantalum ( A low resistance conductive material such as Ta) and molybdenum-tungsten (MoW) is formed by depositing and patterning by a sputtering method.

Subsequently, as shown in FIG. 8B, a protective film 116 is formed by coating an organic insulating film such as benzocyclobutene (BCB), polyimide, or acrylic resin to a predetermined thickness on the entire surface of the thin film transistor (TFT). A contact hole 118 through which the drain electrode 115b of the thin film transistor is exposed is formed.

The pixel electrode 117 is formed on the passivation layer 116 to be electrically connected to the drain electrode 115b through the contact hole 118.

The pixel electrode 117 is formed to be electrically connected to the drain electrode 115b through the contact hole 118 by depositing and patterning a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO). .

Subsequently, as illustrated in FIG. 8C, chromium (Cr), in order to block light leakage at the point where the edge of the unit pixel and the thin film transistor are formed on the opposing substrate 121 facing the thin film array substrate 111, The black matrix layer 122 is formed using chromium oxide (CrOx) and the like, and an indium tin oxide (ITO) or indium zinc oxide (IZO), which is a transparent conductive material on the entire surface including the black matrix layer 122, is formed. : Indium Zinc Oxide) is deposited to form a common electrode 124.

Subsequently, a seal pattern (not shown) is formed at the edge of the thin film array substrate 111 or the opposing substrate 121 to bond the two substrates 111 and 121 to face each other, and then liquid crystal is injected between the two substrates. The liquid crystal layer 125 is formed.

Next, as shown in FIG. 8D, a separate color filter substrate 211 is prepared, and a high reflectance metal, for example, aluminum, aluminum alloy, to reflect external natural light well on the color filter substrate 211. Titanium or the like is deposited and patterned to form the reflective electrode 127.

The reflective electrode 127 is formed to have a size corresponding to each unit pixel or to a size corresponding to each unit pixel line, and each reflective electrode is applied with a specific voltage from the outside (+) or (-) It has the polarity of.

At this time, before or after forming the reflective electrode, partitions 191 may be formed between the reflective electrodes to separate the moving bodies having different colors.

Thereafter, the movable body 150 is formed on the reflective electrode 127. In this case, the thin film may be formed using a spin coating method, a dipping method, a dispensing method, a printing method, an ink jet method, a screen coating method, or the like. Could be.

For example, the screen coating method is as follows.

That is, the first reflective electrode 150 is prepared by encapsulation with a gel type material having excellent light permeability, and then the first reflective electrode 127a of FIG. 4. ) Is coated to expose a first moving body on the first reflective electrode. Thereafter, the second and third moving bodies are coated on the second and third reflecting electrodes 127b and 127c in the same manner.

Here, the gel-type material for encapsulation includes a fluid encapsulation material serving as a solvent, an ionic material colored with R, G, and B dyes, and the like.

The ionic material colored with the R, G, and B dyes is specifically, positively charged (+) and dye particles 151 colored blue (B), negatively charged (-) and red (R). As the colored dye particles 151 and the negatively charged dye particles 151, which are negatively charged and colored green (G), any two of them are selectively taken and microencapsulated to form the copper body 150. .

Specifically, as shown in FIG. 5, the photoreceptor 150 is positively (+) charged and dyes colored blue (B) and negatively charged (-) colored dye (R). A first moving body composed of particles, and a second moving body consisting of dye particles charged positively (+) and colored blue (B) and dye particles charged negatively (-) and colored green (G) And a third electrophoretic body consisting of dye particles positively charged and colored red (R) and dye particles negatively charged and colored green (G).

At this time, the moving body may be configured as shown in Fig. 6 or 7, as described above. However, it is important to include two-color dye particles inside one of the moving bodies, and to charge the included two-color dye particles in different states.

Thereafter, the color filter substrate 211 having the reflective electrode 127 and the moving body 150 formed thereon is bonded to face the thin film array substrate 111. At this time, the opposing bonding while pressing the substrate to reduce the empty space between the moving body 150.

For reference, on the upper surface of the counter substrate 121, a retardation plate having a function of converting incident linear flat light into circularly polarized light and linearly polarized light into linearly polarized light, and converting natural light into linearly polarized light by passing only light in a direction parallel to the light transmission axis. The polarizing plate can be further arranged.

When external natural light is incident on the reflective liquid crystal display device formed as described above, the external light passes through the counter substrate 121, the liquid crystal layer 125, the pixel electrode 117, and the thin film array substrate 111 in order. Thereafter, the light is reflected by the moving body 150 or the reflecting electrode 127 and output to the outside to display images of R, G, and B.

As the reflective liquid crystal display device formed as described above, two colors are implemented in one unit pixel, an excellent image quality can be obtained.

Meanwhile, in the first, second, and third embodiments, the electrophores of each pixel are simultaneously driven to express an image. In the fourth embodiment, hereinafter, R, G, and B colors are sequentially ordered within a predetermined time. It is a method of expressing an image by driving to be expressed and mixing colors.

Hereinafter, the fourth embodiment will be described in detail with reference to FIGS. 9 through 11B.

9 is a sectional view of a reflective liquid crystal display device showing R color according to the fourth embodiment of the present invention, and FIG. 10 is a sectional view of a reflective liquid crystal display device showing B color according to the fourth embodiment of the present invention. 11A and 11B are cross-sectional views of a reflective liquid crystal display device showing G color according to the fourth embodiment of the present invention.

The liquid crystal display device according to the fourth embodiment of the present invention includes a thin film array substrate 511 on which a plurality of wirings and thin film transistors are formed, an opposing substrate 521 facing the thin film array substrate 511, and the thin film. The color filter comprises a liquid crystal layer 525 encapsulated between the array substrate 511 and the counter substrate 521 and a color filter substrate 611 opposed to the outer circumferential surface of the thin film array substrate 511. On the substrate 611, charged dye particles are encapsulated in a microcapsule to implement color, and an external natural light introduced into the liquid crystal panel while applying an electric field to the dye particles of the movable body 550 Reflecting electrodes 527a and 527b are formed to reflect the light.

At this time, the fluorophore 550 is divided into first and second fluorophores 550a and 550b, and the first electrophoretic 550a is negatively charged with green (G) dye particles 551 and Positive (+) charged dye particles of red (R) are mixed with each other and encapsulated, and charged with negative (+) charged green (G) dye particles in the second carrier 550b. The blue (B) dye particles are mixed and encapsulated. The first moving body 550a is formed on the first reflecting electrode 127a and the second moving body 550b is formed on the second reflecting electrode 127b.

The outer surface of the thin film array substrate 511 may further include counter electrodes 590a and 590b facing the reflective electrodes 527a and 527b with the moving body 550 interposed therebetween. Is formed in a size corresponding to the reflective electrode 527 to apply a voltage having a polarity opposite to that of the reflective electrode 527 or integrally formed to apply a voltage having a constant value such as a ground voltage.

In order to express the R color in the liquid crystal display device, as shown in FIG. 9, a positive electric field is applied to the first reflective electrode 527a and a negative polarity is applied to the first counter electrode 590a. The positive red dye particles (R) in the first carrier 550a are raised by applying an electric field, and the negative green dye particles (G) are lowered so that the R color is displayed on the opposite substrate 521 side. Let this be observed.

At this time, the liquid crystal layer 525 on the second moving body 550b is completely turned off to prevent light from being transmitted to prevent any color of G and B from appearing. Accordingly, no voltage is required to be applied to the second reflective electrode 527b and the second counter electrode 590b, and for convenience of driving, as shown in FIG. 9, the first reflective electrode 527b and the first counter electrode are illustrated. You may apply an electric field of the same polarity as (527a).

In order to express B color, as shown in FIG. 10, a positive electric field is applied to the second reflection electrode 527b and a negative electric field is applied to the second counter electrode 590b. Thus, positive (+) blue dye particles (B) inside the second carrier (550b) are raised and negative (-) green dye particles (G) are lowered so that the B color can be observed on the side of the counter substrate 521. do. At this time, the liquid crystal layer 525 on the first moving body 550a is completely turned off to prevent light from being transmitted.

Next, to express the G color, as shown in FIG. 11A, a negative electric field is applied to the first and second reflective electrodes 527a and 527b and the first and second counter electrodes 590a and 590b. Negative polar dye is applied to the positive and negative red dye particles (R) by applying a positive polarity field to the first and second copper bodies (550a, 550b). And the blue dye particles B are lowered so that the G color is observed on the side of the counter substrate 521. At this time, the liquid crystal layer 525 is turned on so that light is transmitted in all regions.

On the other hand, as shown in Figure 11b, one of the first liquid crystal layer 525 of any one of the first and second moving body (550a, 550b) may be turned off completely to prevent light transmission.

However, since the luminance contribution to the green element is the highest among R, G, and B, it is common to form a large green area in the case of a reflective liquid crystal display device. Therefore, in order to increase the luminance of the element, the latter (Fig. It is more preferable to take the structure of Fig. 11B).

As described above, R, G, and B are sequentially displayed according to the image data by applying a method of expressing the colors of R, G, and B. At this time, R, G, and B correspond to one frame (17.6 ms). ), R, G, and B may be mixed to represent a desired image.

As such, since the colors of R, G, and B can be expressed by two unit pixels, the resolution can be increased, or when two unit pixels are formed with the size corresponding to three unit pixels to realize the same resolution as the conventional unit pixel The opening ratio can be improved by increasing the size of.

In order to express the gray of the reflective liquid crystal display device according to the present invention, the rotation angle of the liquid crystal may be used as in the general liquid crystal display device. In this case, only a positive or negative electric field is applied to the reflective electrode. In addition to the positive and negative electric fields, a medium value electric field may be applied to the reflecting electrode to adjust the distribution of the dye particles in the electrophoretic body to control color, but the former method is more preferable.

On the other hand, the present invention described above is not limited to the above-described embodiment and the accompanying drawings, it is possible that various substitutions, modifications and changes within the scope without departing from the technical spirit of the present invention. It will be apparent to those of ordinary skill in Esau.

Reflective liquid crystal display device and a method of manufacturing the same according to the present invention as described above has the following effects.

First, a first unit pixel comprising a first moving body composed of R, G dye particles, a second unit pixel including a second moving body composed of G and B dye particles, and a first unit pixel consisting of R and B dye particles In the case of simultaneously driving the third unit pixel including the three moving bodies, two colors can be implemented in each unit pixel (the first, the second, and the third unit pixel), thereby doubling the existing unit pixel of the same size. Will indicate the resolution of.
That is, when the pixel according to the present invention is increased to a conventional size, a larger number of unit pixels may be included in the pixel than in the prior art, and thus the present invention may exhibit higher resolution in the same area as compared with the conventional art.

In this case, since two pixels are formed of three unit pixels, when the size of each unit pixel is doubled, it has the same resolution as before. At this time, since the size of the unit pixel is doubled, the aperture ratio is increased and the process error is reduced.

Second, a first moving body composed of R and G dye particles and a second moving body composed of B and G dye particles are formed in each unit pixel, and the liquid crystal layer on the first and second moving bodies is selectively turned on / off. When the R, G, and B colors are sequentially expressed within a predetermined time, the colors of R, G, and B may be represented by two unit pixels, thereby increasing the resolution.

In this case, when two unit pixels are formed with a size corresponding to three unit pixels to implement the same resolution as before, the aperture ratio may be improved by increasing the size of the unit pixel.

Claims (34)

A first substrate on which a thin film transistor and a pixel electrode are formed in a unit pixel defined by gate lines and data lines formed in directions perpendicular to each other; A second substrate opposed to the first substrate; A liquid crystal layer formed between the first and second substrates; A third substrate opposed to the first substrate; A reflective electrode formed inside the third substrate and corresponding to the unit pixel; Reflective liquid crystal display device comprising a color filter layer consisting of a plurality of electrophores microencapsulated ionic dye on the reflective electrode. The reflective liquid crystal display of claim 1, further comprising a black matrix layer and a common electrode inside the second substrate. The reflective liquid crystal display of claim 1, wherein the dye implements colors of R, G, and B. The reflective liquid crystal display device according to claim 1, wherein the diameter of the moving body has a size of 0 to 100 µm or less. The method of claim 1, wherein the reflector is a reflector, characterized in that the first, second and third primers composed of R dye and G dye, R dye and B dye, G dye and B dye, respectively Liquid crystal display device. 6. The reflective liquid crystal display device according to claim 5, wherein the dyes of different colors in the first, second and third carriers are charged with different electrodes. The method of claim 1, wherein the moving body, A first copper body comprising dye particles positively charged and colored with B dye and negatively charged dye particles with R dye, A second electrophore composed of dye particles positively charged and colored with B dye and negatively charged dye particles with G dye, A reflective liquid crystal display device comprising a third electrophoretic body comprising dye particles positively charged and colored with R dye and dye particles negatively charged and colored with G dye. The method of claim 1, wherein the moving body, A first copper body comprising dye particles positively charged and colored with R dye and dye particles negatively charged and colored with B dye, A second conductor composed of dye particles negatively charged and colored with B dye and positively charged dye particles with G dye, A reflective liquid crystal display device comprising a third electrophoretic body consisting of dye particles negatively charged and colored with R dye and dye particles positively charged and colored with G dye. The method of claim 1, wherein the moving body, A first copper body comprising dye particles positively charged and colored with R dye and dye particles negatively charged and colored with B dye, A second electrophore composed of dye particles positively charged and colored with G dye and negatively charged dye particles with B dye, A reflective liquid crystal display device comprising a third electrophoretic body consisting of dye particles positively charged and colored with G dye and dye particles negatively charged and colored with R dye. The reflective liquid crystal display device according to claim 1, wherein the reflective electrode is formed in a unit pixel size, and each moving body is provided on each reflective electrode. The reflective liquid crystal display device according to claim 1, wherein the reflective electrode is formed in a size for each pixel line, and each moving body is provided on each reflective electrode line. The reflective liquid crystal display device according to claim 1, wherein dyes having different polarities in each of the moving bodies move upward or downward by a voltage applied to the reflective electrode. The liquid crystal display of claim 5, wherein two pixels of R, G, and B are formed in the three unit pixel regions. The reflective liquid crystal display device according to claim 1, wherein the pixel electrode is a transmissive electrode. The reflective liquid crystal display device of claim 1, wherein the first and second substrates are transparent substrates. The method of claim 1, A reflective liquid crystal display device further comprising a partition wall between the reflective electrodes. The method of claim 1, A reflective liquid crystal display device, characterized in that the partition also serves as a spacer. 2. The reflective liquid crystal display device according to claim 1, wherein the moving body comprises a first moving body composed of R dye particles and G dye particles, and a second moving body composed of B dye particles and G dye particles. . 19. The method of claim 18, wherein the liquid crystals on the first fluorophore are completely turned off to realize B or G colors, and the liquid crystals on the second fluorophores are completely off to implement R or G colors. Type liquid crystal display device. 20. The reflective liquid crystal display of claim 19, wherein the R, G, and B colors are driven to be sequentially expressed within one frame time. 19. The reflective liquid crystal display device according to claim 18, wherein the dye particles of different colors in the first and second moving bodies are charged with different electrodes. 19. The reflective liquid crystal display device according to claim 18, wherein one pixel of R, G, and B is formed in the two unit pixel regions. The method of claim 1, wherein the moving body, A first copper body comprising a dye particle positively charged and colored with an R dye and a dye particle negatively charged and colored with a G dye, A reflective liquid crystal display device comprising a second electrophore composed of dye particles positively charged and colored with B dye and negatively charged dye particles with G dye. The method of claim 1, wherein the moving body, A first moving body comprising a dye particle positively charged and colored with a G dye and a dye particle negatively charged and colored with a R dye, A reflective liquid crystal display device comprising a second electrophoretic body consisting of dye particles positively charged and colored with G dye and dye particles negatively charged and colored with B dye. Forming a unit pixel by forming a gate line and a data line on the first substrate; Forming a thin film transistor at an intersection point of the gate line and the data line; Forming a pixel electrode connected to the thin film transistor; Bonding a second substrate to face the first substrate, and forming a liquid crystal layer between the first and second substrates; Forming a reflective electrode on the third substrate; Forming a color filter layer comprising a plurality of moving bodies on which the dye of the ionic material is microencapsulated on the reflective electrode; And opposingly bonding the third substrate to the first substrate. 26. The method of claim 25, wherein the electrophoretic body is formed by encapsulating an ionic material in which dyes of different colors are colored and charged with different electrodes. The method of claim 25, wherein the moving body is formed by a spin coating method, a dipping method, a dispensing method, a printing method, an ink jet method, or a screen coating method. A method of manufacturing a reflective liquid crystal display device, characterized in that. The method of claim 25, wherein the reflective electrode is formed to have a size corresponding to each unit pixel or to a size corresponding to each unit pixel line. 29. The method of claim 28, wherein a positive voltage or a negative voltage is applied to each of the reflective electrodes. 29. The method of claim 28, wherein the moving body encapsulates at least two dyes of R, G, and B dyes and forms them on each of the reflective electrodes. 26. The method of claim 25, further comprising forming partitions between the reflective electrodes. 27. The method of claim 25, wherein the reflective electrode is formed of aluminum, aluminum alloy, or titanium. 26. The method of claim 25, wherein the pixel electrode is formed of indium tin oxide (ITO) or indium zinc oxide (IZO). 26. The method of claim 25, wherein the pressing is performed at the step of opposing the third substrate to the first substrate.

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