KR20170002149A - Liquid Crystal Display Device - Google Patents

Abstract

The present invention provides a liquid crystal display device comprising first, second and third substrates spaced apart in parallel to each other and including a pixel region, a liquid crystal layer disposed between the first and second substrates, Second, and third polarizing plates disposed on the lower surface of the first substrate, the upper surface of the second substrate, and the lower surface of the third substrate, respectively, And a backlight unit disposed under the third substrate, the contrast ratio and sharpness of the image are improved.

Description

[0001] The present invention relates to a liquid crystal display device,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display, and more particularly, to a liquid crystal display including a shutter panel capable of blocking or transmitting light of a backlight unit by pixel regions and a display panel displaying an image.

Recently, as the age of the information society has progressed rapidly, a display field for processing and displaying a large amount of information has been developed. In order to respond to the era of thinning, lightweighting and low power consumption, a flat panel display ) Has emerged.

Accordingly, a thin film transistor liquid crystal display (TFT-LCD) having excellent color reproducibility and being thin has been developed. The liquid crystal display displays an image using the optical anisotropy and polarization properties of liquid crystal molecules.

The structure of such a liquid crystal display device will be described with reference to the drawings.

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

1, a conventional liquid crystal display device 10 includes first and second substrates 20 and 40 which are spaced apart from each other, and first and second substrates 20 and 40 formed between the first and second substrates 20 and 40 A liquid crystal layer 50, and a backlight unit 80 disposed under the first substrate 20.

Specifically, a gate electrode 22 is formed in each pixel region P on the inner surface of the first substrate 20, and a gate insulating layer 24 is formed on the gate electrode 22.

A semiconductor layer 26 is formed on the gate insulating layer 24 corresponding to the gate electrode 22 and a source electrode 28 and a drain electrode 30 are formed on the semiconductor layer 26.

The gate electrode 22, the semiconductor layer 26, the source electrode 28 and the drain electrode 30 constitute a thin film transistor (TFT) T.

A protective layer 32 is formed on the upper portion of the thin film transistor T and a pixel electrode 34 connected to the drain electrode 30 is formed on the protective layer 32.

A black matrix 42 is formed at the boundary of the pixel region P on the inner surface of the second substrate 40. A color filter layer 44 is formed in the pixel region P below the black matrix 42, And a common electrode 46 is formed under the gate electrode 44.

A liquid crystal layer 50 including a plurality of liquid crystal molecules 52 is formed between the pixel electrode 34 of the first substrate 20 and the common electrode 46 of the second substrate 40.

The first and second polarizers 36 and 48 are formed on the outer surface of the first substrate 20 and the outer surface of the second substrate 40, respectively. The first and second polarizers 36 and 48 have mutually perpendicular transmission axes .

The first and second substrates 20 and 40 and the liquid crystal layer 50 constitute a display panel for displaying an image, and the backlight unit 80 supplies light to the display panel.

In this liquid crystal display device 10, when the thin film transistor T is turned on in response to a gate signal applied to the gate electrode 22, a data signal is applied to the pixel electrode 34 so that an electric field is generated between the pixel electrode 34 and the common electrode 46.

A plurality of liquid crystal molecules 52 of the liquid crystal layer 50 are rearranged in accordance with the electric field so that the pixel region P displays a gray level corresponding to the data signal.

In this liquid crystal display device 10, since the backlight unit 80 supplies light of the same amount of light to all the pixel regions P of the display panel regardless of the gradation corresponding to the data signal, the contrast ratio of the image becomes (Light transmission and light blocking performance) of the display panel itself, and as a result, there is a problem in that the improvement of the contrast ratio is limited.

For example, an in-plane switching (IPS) liquid crystal display device in which a pixel electrode and a common electrode are formed on the same substrate has a problem that the contrast ratio is limited to 2000: 1 or less.

SUMMARY OF THE INVENTION The present invention has been made in order to solve such a problem, and it is an object of the present invention to provide a liquid crystal display device in which the contrast ratio and sharpness of an image are improved by blocking or transmitting light of a backlight unit by pixel regions using a liquid crystal capsule.

Another object of the present invention is to provide a liquid crystal display device in which the thickness and the manufacturing cost are reduced by attaching a shutter panel including a single substrate directly to a display panel.

According to an aspect of the present invention, there is provided a liquid crystal display device including first, second, and third substrates spaced apart in parallel from each other and including a pixel region, a liquid crystal layer disposed between the first and second substrates, A first liquid crystal layer disposed between the first and third substrates and including a plurality of liquid crystal capsules; a first liquid crystal layer disposed on the lower surface of the first substrate, the upper surface of the second substrate, A second polarizer, a third polarizer, and a backlight unit disposed under the third substrate.

The pixel region of the third substrate may correspond to at least one pixel region of the first substrate.

The transmittance corresponding to the shutter data signal applied to the pixel region of the third substrate may be proportional to the transmittance corresponding to the data signal applied to the pixel region of the first substrate.

An adhesive layer is disposed on the front surface between the second polarizing plate and the second substrate, on the front surface between the first polarizing plate and the shutter liquid crystal layer, and on the front surface between the third polarizing plate and the third substrate, The adhesive layer may be disposed on the entire surface of the first substrate, or an adhesive layer may be disposed on the edge of the first substrate.

The plurality of liquid crystal capsules each include a plurality of shutter liquid crystal molecules, and the plurality of shutter liquid crystal molecules may be one of a nematic liquid crystal, a ferroelectric liquid crystal, and a flexo liquid crystal.

The transmission axes of the first and second polarizing plates may be perpendicular to each other, and the transmission axes of the first and third polarizing plates may be perpendicular to each other or parallel to each other.

In addition, a thin film transistor may be disposed in the pixel region on the first substrate, and first and second electrodes may be disposed in the pixel region on the third substrate.

A color filter layer is disposed in the pixel region on the first substrate or in the pixel region in the lower portion of the second substrate, and the pixel region boundary above the first substrate or the pixel region boundary under the second substrate A black matrix may be disposed.

The present invention has an effect that the contrast ratio and sharpness of an image are improved by blocking or transmitting light of a backlight unit by pixel regions using a liquid crystal capsule

Further, the present invention has the effect of reducing the thickness and manufacturing cost by attaching the shutter panel including one substrate directly to the display panel.

1 is a cross-sectional view showing a conventional liquid crystal display device.
2 is a cross-sectional view illustrating a liquid crystal display device according to a first embodiment of the present invention;
3 is a sectional view showing a method of manufacturing a shutter panel of a liquid crystal display device according to a first embodiment of the present invention.
4A and 4B are sectional views showing a shutter-on state and a shutter-off state of the shutter panel of the liquid crystal display device according to the first embodiment of the present invention, respectively.
5 is a cross-sectional view of a liquid crystal display device according to a second embodiment of the present invention.
6 is a sectional view of a liquid crystal display device according to a third embodiment of the present invention.
7 is a sectional view of a liquid crystal display device according to a fourth embodiment of the present invention;

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

2 is a cross-sectional view illustrating a liquid crystal display device according to a first embodiment of the present invention, in which a color filter layer is formed on an upper substrate and a shutter panel is in a normally white mode.

2, the liquid crystal display device 110 according to the first embodiment of the present invention includes first to third substrates 120, 140 and 160 spaced apart from each other in parallel, first and second substrates 120, A liquid crystal layer 150 formed between the first and second substrates 120 and 140, a shutter liquid crystal layer 166 formed between the first and third substrates 120 and 160, a backlight unit 180).

A gate electrode 122 is formed on each pixel region P on the upper surface of the first substrate 120 facing the second substrate 140 and a gate insulating layer 124 is formed on the gate electrode 122 .

A semiconductor layer 126 is formed on the gate insulating layer 124 corresponding to the gate electrode 122 and a source electrode 128 and a drain electrode 130 are formed on the semiconductor layer 126.

The gate electrode 122, the semiconductor layer 126, the source electrode 128, and the drain electrode 130 constitute a thin film transistor (TFT) T.

Although not shown, gate lines and data lines for defining gate lines and data signals may be formed on the upper surface of the first substrate 120 so as to intersect with the pixel regions P, May be connected to the gate electrode 122 and the source electrode 128, respectively.

A protective layer 132 is formed on the top of the thin film transistor T and a pixel electrode 134 connected to the drain electrode 130 is formed on the protective layer 132.

A black matrix 142 is formed on the lower surface of the pixel region P on the lower surface of the second substrate 140 facing the first substrate 120 and a color filter 142 is formed in the pixel region P below the black matrix 142. [ And a common electrode 146 is formed under the color filter layer 144.

A liquid crystal layer 150 including a plurality of liquid crystal molecules 152 is formed between the pixel electrode 134 of the first substrate 120 and the common electrode 146 of the second substrate 140.

The first and second electrodes 162 and 164 are formed in each pixel region P on the upper surface of the third substrate 160 facing the first substrate 120.

Although not shown, on the upper surface of the third substrate 160, a pixel region P is defined to intersect with each other, a shutter gate wiring and a shutter data wiring for transferring a shutter gate signal and a shutter data signal are formed, A shutter thin film transistor may be formed in the pixel region P.

In addition, the shutter gate wiring and the shutter data wiring may be connected to the shutter thin film transistor, respectively, and the first electrode 162 may be connected to the shutter thin film transistor and the second electrode 164 may be connected to the common voltage terminal.

A shutter liquid crystal layer 166 including a plurality of liquid crystal capsules 168 is formed between the lower surface of the first substrate 120 and the first and second electrodes 162 and 164 of the third substrate 160, Each of the liquid crystal capsules 168 includes a plurality of shutter liquid crystal molecules 170.

Here, each of the plurality of liquid crystal capsules 168 is a polymer capsule having a diameter of several nanometers to several hundred nanometers, and may be formed of a positive or negative nematic liquid crystal, and a plurality of shutter liquid crystal molecules (170) may be a nematic LC, a ferroelectric liquid crystal (FLC), or a flexo electric LC.

The first, second, and third polarizers 136, 148, and 172 are formed on the upper surface of the second substrate 140 and the lower surface of the third substrate 160, respectively. The second polarizing plates 136 and 148 may have mutually perpendicular transmission axes, and the first and third polarizing plates 136 and 172 may have transmission axes parallel to each other.

For example, the first and third polarizing plates 136 and 172 may have a transmission axis perpendicular to the paper plane, and the second polarizing plate 148 may have a transmission axis parallel to the paper plane.

The first and second substrates 120 and 140 and the liquid crystal layer 150 constitute a display panel for displaying an image. The backlight unit 180 supplies light to the display panel, And the shutter liquid crystal layer 166 constitute a shutter panel that blocks or transmits light of the backlight unit 180 for each pixel region P. Since the shutter panel simply blocks or transmits light, Is omitted.

Since the shutter panel can be formed of only the third substrate 160 and the shutter liquid crystal layer 166 instead of the two substrates, the thickness of the liquid crystal display device 110 can be minimized, and the contrast ratio and sharpness can be improved.

Although not shown, a front surface between the first polarizer 136 and the first substrate 120, a front surface between the second polarizer 148 and the second substrate 140, a front surface between the first polarizer 136 and the shutter liquid crystal layer 166 The first to third substrates 120, 140, and 160 and the first to third polarizers 136, 148, and 144 are formed on the front surface, between the third polarizer 172 and the third substrate 160, 172, the display panel and the shutter panel can be bonded together.

An adhesive layer is formed on the edge portion between the first polarizer 136 and the first substrate 120 and the front surface between the second polarizer 148 and the second substrate 140 and between the first polarizer 136 and the shutter liquid crystal layer 140. [ The first to third substrates 120, 140 and 160 and the first to third polarizing plates 172 and 176 are formed on the front surface of the first polarizer 172 and between the third polarizer 172 and the third substrate 160, 136, 148, and 172, the display panel and the shutter panel can be bonded together.

In the first embodiment, it is exemplified that the display panel is a twist nematic (TN) type in which the pixel electrode 134 and the common electrode 146 are formed on the first and second substrates 120 and 140, respectively In another embodiment, the display panel may be a vertical alignment (VA) structure, or may be an in-plane switching (FFS) structure in which a pixel electrode and a common electrode are formed on the same substrate .

In the first embodiment, it is assumed that the shutter panel is a horizontal electric field system (IPS), but in other embodiments, the shutter panel may be TN, VA, FFS.

In particular, when the shutter panel is IPS or FFS in which the pixel electrode and the common electrode are formed on the same substrate, the thickness of the liquid crystal display device 110 can be reduced and the manufacturing process can be simplified by forming a shutter panel with one substrate .

Meanwhile, the shutter liquid crystal layer 166 of the shutter panel can be formed by a coating method, which will be described with reference to the drawings.

3 is a sectional view showing a method of manufacturing a shutter panel of a liquid crystal display device according to a first embodiment of the present invention, which will be described with reference to FIG.

3, a plurality of first and second electrodes 162 and 164 are formed on the upper surface and a plurality of nozzles 176 are formed on the upper surface of the third substrate 160 having the third polarizer 172 formed on the lower surface thereof, The liquid crystal capsule material layer 174 is formed by applying a solution containing the liquid crystal capsule 168 of the liquid crystal material layer 174 and then the liquid crystal capsule material layer 174 is dried or cured to form a shutter liquid crystal layer 166 may be formed.

The liquid crystal display device 110 can be completed by attaching the third substrate 160 on which the shutter liquid crystal layer 166 is formed to the lower surface of the first polarizer 136. [

By thus forming the shutter liquid crystal layer 166 in a coating manner, the manufacturing process of the shutter panel can be simplified.

In addition, when a flexible substrate such as a plastic substrate is used as the third substrate 160, the entire shutter panel can be formed in a film form and attached to the display panel. As a result, the manufacturing process of the liquid crystal display device 110 can be simplified .

In this liquid crystal display device 110, when the thin film transistor T is turned on in response to a gate signal applied to the gate electrode 122, An electric field is generated between the pixel electrode 134 and the common electrode 146. The liquid crystal molecules 152 of the liquid crystal layer 150 are rearranged in accordance with the electric field, (P) indicates a gray level corresponding to the data signal.

At this time, when the shutter thin film transistor is turned on according to the shutter gate signal, a shutter data signal is applied to the first electrode 162 through the shutter thin film transistor to form a horizontal (horizontal) signal between the first electrode 162 and the second electrode 164 An electric field is generated and a plurality of shutter liquid crystal molecules 170 inside the plurality of liquid crystal capsules 168 of the shutter liquid crystal layer 166 are rearranged in accordance with the horizontal electric field so that the pixel region P of the shutter panel is aligned with the backlight unit 180 ) To block or transmit light.

At this time, by making the transmittance corresponding to the shutter data signal proportional to the transmittance corresponding to the data signal, the contrast ratio and sharpness of the liquid crystal display device 110 can be improved.

For example, when a data signal applied to a specific pixel area P of the display panel corresponds to a high gradation, the shutter data signal applied to the corresponding pixel area P of the shutter panel is made to correspond to a relatively high transmittance And the data signal applied to the specific pixel area P of the display panel corresponds to a low gradation, the shutter data signal applied to the corresponding pixel area P of the shutter panel can be made to correspond to a relatively low transmittance have.

Accordingly, light of a higher light amount is supplied to the image of higher gradation displayed by each pixel region P to further increase the luminance, and light of a lower light amount is emitted to the image of lower gradation displayed by each pixel region (P) The contrast ratio and sharpness of the image displayed by the liquid crystal display device 110 can be improved.

In the first embodiment, the pixel area P of the display panel and the pixel area P of the shutter panel are matched one by one (that is, the resolution of the display panel is equal to the resolution of the shutter panel) The brightness of the displayed image is adjusted for each pixel region P, but in another embodiment, one pixel region P of the shutter panel corresponds to many of the pixel regions P of the display panel The brightness of the image displayed by the display panel may be adjusted on a block-by-block basis including a plurality of pixel regions P, such that the resolution of the shutter panel is smaller than the resolution of the panel. In this case, margin can be sufficiently ensured to improve process reliability and yield.

The operation of such a shutter panel will be described with reference to the drawings.

4A and 4B are cross-sectional views showing the shutter-on state and the shutter-off state of the shutter panel of the liquid crystal display device according to the first embodiment of the present invention, respectively, and will be described with reference to FIG.

As shown in FIG. 4A, when no voltage is applied between the first and second electrodes 162 and 164 (OFF), a horizontal electric field is not generated between the first and second electrodes 162 and 164 As a result, the plurality of shutter liquid crystal molecules 170 inside the plurality of liquid crystal capsules 168 of the shutter liquid crystal layer 166 are randomly arranged.

Accordingly, the light supplied from the backlight unit 180 passes through the third polarizer 172 having the transmission axis perpendicular to the paper surface, changes to polarized light in a direction perpendicular to the paper surface, and thereafter, 166), and then passes through the first polarizer 136 having a transmission axis perpendicular to the paper surface, and is supplied to the display panel.

That is, when no voltage is applied between the first and second electrodes 162 and 164 (OFF), the shutter panel has a shutter-on state for supplying light of the backlight unit 180 to the display panel (normally white) .

As shown in FIG. 4B, when a voltage is applied between the first and second electrodes 162 and 164 (ON), a horizontal electric field is generated between the first and second electrodes 162 and 164, As a result, the plurality of shutter liquid crystal molecules 170 in the plurality of liquid crystal capsules 168 of the shutter liquid crystal layer 166 are rearranged in accordance with the horizontal electric field.

Accordingly, the light supplied from the backlight unit 180 passes through the third polarizer 172 having the transmission axis perpendicular to the plane of the paper, changes to polarized light in a direction perpendicular to the paper surface, passes through the shutter liquid crystal layer 166 Polarized light in the direction parallel to the paper surface by the plurality of rearranged shutter liquid crystal molecules 170 and then blocked by the first polarizing plate 136 having the transmission axis perpendicular to the plane of the paper and is not supplied to the display panel.

That is, when a voltage is applied between the first and second electrodes 162 and 164 (ON), the shutter panel has a shutter-off state for shutting off the light of the backlight unit 180 without supplying it to the display panel.

Here, the amount of light blocked by the shutter panel (or the amount of light supplied to the display panel through the shutter panel) can be adjusted by adjusting the magnitude of the voltage applied between the first and second electrodes 162 and 164, The contrast ratio and sharpness can be improved by supplying the display panel with light of a light quantity proportional to the gradation of the image displayed by the result display panel.

The liquid crystal display 110 includes a timing controller for converting an image signal provided from the outside into image data and shutter data, a data driver for converting the image data into a data signal and supplying the data signal to the display panel, And a shutter data driver for converting the data signal into a data signal and supplying the data signal to the shutter panel.

At this time, the shutter data of the specific pixel area P of the shutter panel can be set to have a gradation proportional to the image data of the corresponding pixel area P of the display panel.

In addition, since the shutter panel serves primarily to cut off the light, and the display panel serves to cut off the light secondarily, the shutter panel driven in the normally white mode has a voltage lower than the maximum driving voltage, So that the increase in power consumption can be minimized.

As described above, in the liquid crystal display device 110 according to the first embodiment of the present invention, the shutter liquid crystal layer 166 of the plurality of liquid crystal capsules 168 is formed on the third substrate 160 to constitute a shutter panel, The contrast ratio and sharpness of the image can be improved by transmitting or blocking the light of the backlight unit 180 using the shutter panel for each pixel region P and supplying it to the display panel.

In addition, by attaching the shutter liquid crystal layer 166 formed on the third substrate 160 to the display panel using an adhesive layer or an adhesive without any additional substrate, the thickness and weight can be reduced and the manufacturing cost can be reduced.

Further, by forming the shutter panel in the form of a film using the third substrate 160 of a flexible material, the manufacturing process can be simplified.

Meanwhile, in another embodiment, the transmission axes of the first and third polarizing plates 136 and 172 may be perpendicular to each other, or the color filter layer 144 may be formed on the first substrate 120, .

5 is a cross-sectional view of a liquid crystal display device according to a second embodiment of the present invention, showing a liquid crystal display device in which a color filter layer is formed on an upper substrate and a shutter panel is in a normally black mode, The description of the same portions as those of FIG.

5, the liquid crystal display device 210 according to the second embodiment of the present invention includes first to third substrates 220, 240 and 260 spaced apart from each other in parallel, first and second substrates 220, A liquid crystal layer 250 formed between the first and second substrates 220 and 240, a shutter liquid crystal layer 266 formed between the first and third substrates 220 and 260, a backlight unit 280).

Specifically, a thin film transistor (TFT) T and a pixel electrode 234 are formed in each pixel region P on the upper surface of the first substrate 220 facing the second substrate 240, A black matrix 242 is formed at the boundary of the pixel region P on the lower surface of the second substrate 240 facing the first substrate 220 and a color filter layer 244 is formed in the pixel region P below the black matrix 242. [ And the common electrode 246 are formed.

The first and second electrodes 262 and 264 are formed in the pixel region P on the upper surface of the third substrate 260 facing the first substrate 220.

The first, second, and third polarizers 236, 248, and 272 are formed on the upper surface of the second substrate 240 and the lower surface of the third substrate 260, respectively. The second polarizing plates 236 and 248 may have mutually perpendicular transmission axes, and the first and third polarizing plates 236 and 272 may have mutually perpendicular transmission axes.

For example, the first polarizing plate 236 may have a transmission axis perpendicular to the paper plane, and the second and third polarizing plates 248 and 272 may have a transmission axis parallel to the paper plane.

In this liquid crystal display device 210, when no voltage is applied between the first and second electrodes 262 and 264 (OFF), a horizontal electric field is not generated between the first and second electrodes 262 and 264 And as a result, the plurality of shutter liquid crystal molecules 270 inside the plurality of liquid crystal capsules 268 of the shutter liquid crystal layer 266 are randomly arranged.

Thus, the light supplied from the backlight unit 280 passes through the third polarizing plate 272 having the transmission axis parallel to the paper surface and changes to polarized light in a direction parallel to the paper surface. Thereafter, the light from the shutter liquid crystal layer 266, and is then blocked by the first polarizer 236 having a transmission axis perpendicular to the paper surface, and is not supplied to the display panel.

That is, when no voltage is applied between the first and second electrodes 262 and 264 (OFF), the shutter panel has a shutter-off state in which the light of the backlight unit 280 is not supplied to the display panel ).

When a voltage is applied between the first and second electrodes 262 and 264, a horizontal electric field is generated between the first and second electrodes 262 and 264. As a result, the shutter liquid crystal layer 266 The plurality of shutter liquid crystal molecules 270 inside the plurality of liquid crystal capsules 268 of the liquid crystal cell array 260 are rearranged in accordance with the horizontal electric field.

Accordingly, the light supplied from the backlight unit 280 passes through the third polarizing plate 272 having the transmission axis parallel to the paper, changes to polarized light in a direction parallel to the paper surface, passes through the shutter liquid crystal layer 266 Is changed to polarized light in a direction perpendicular to the paper surface by a plurality of rearranged shutter liquid crystal molecules 270 and then supplied to the display panel through a first polarizer plate 236 having a transmission axis perpendicular to the paper surface.

That is, when a voltage is applied between the first and second electrodes 262 and 264 (ON), the shutter panel has a shutter-on state for supplying the light from the backlight unit 280 to the display panel.

As described above, in the liquid crystal display device 210 according to the second embodiment of the present invention, the shutter liquid crystal layer 266 of the plurality of liquid crystal capsules 268 is formed on the third substrate 260 to constitute a shutter panel, The contrast ratio and sharpness of the image can be improved by transmitting or blocking the light of the backlight unit 280 using the shutter panel for each pixel region P and supplying it to the display panel.

By attaching the shutter liquid crystal layer 266 formed on the third substrate 260 without a separate substrate to the display panel using an adhesive layer or an adhesive, the thickness and weight can be reduced and the manufacturing cost can be reduced.

Further, by forming the shutter panel in the form of a film using the third substrate 260 of a flexible material, the manufacturing process can be simplified.

6 is a cross-sectional view of a liquid crystal display device according to a third embodiment of the present invention, in which a color filter layer is formed on a lower substrate and a shutter panel is in a normally white mode, The description of the same portions as those of FIG.

6, the liquid crystal display device 310 according to the third exemplary embodiment of the present invention includes first to third substrates 320, 340, and 360 that are spaced apart from each other in parallel, first and second substrates 320, A liquid crystal layer 350 formed between the first and second substrates 320 and 340, a shutter liquid crystal layer 366 formed between the first and third substrates 320 and 360, a backlight unit 380).

A thin film transistor (TFT) T, a pixel electrode 334, and a color filter layer 344 are formed in each pixel region P on the upper surface of the first substrate 320 facing the second substrate 340. [ A black matrix 342 is formed on the boundary of the pixel region P on the color filter layer 344 and a pixel region P on the lower surface of the second substrate 340 facing the first substrate 320 is formed. A common electrode 346 is formed.

In another embodiment, the black matrix 342 may be formed on the pixel electrode 334 and the color filter layer 344 may be formed on the black matrix 342. In this case, May be formed.

The first and second electrodes 362 and 364 are formed in the pixel regions P on the upper surface of the third substrate 360 facing the first substrate 320.

The first, second, and third polarizing plates 336, 348, and 372 are formed on the upper surface of the second substrate 340 and the lower surface of the third substrate 360, respectively. The second polarizing plates 336 and 348 may have mutually perpendicular transmission axes, and the first and third polarizing plates 336 and 372 may have transmission axes parallel to each other.

For example, the first and third polarizing plates 336 and 372 may have a transmission axis perpendicular to the paper plane, and the second polarizing plate 348 may have a transmission axis parallel to the paper plane.

In this liquid crystal display device 310, when no voltage is applied between the first and second electrodes 362 and 364 (OFF), a horizontal electric field is not generated between the first and second electrodes 362 and 364 And as a result, the plurality of shutter liquid crystal molecules 370 in the plurality of liquid crystal capsules 368 of the shutter liquid crystal layer 366 are randomly arranged.

Accordingly, the light supplied from the backlight unit 380 passes through the third polarizing plate 372 having the transmission axis perpendicular to the paper surface and is changed to the polarized light in the direction perpendicular to the paper surface. Thereafter, the light from the shutter liquid crystal layer 366, and then passes through the first polarizer 336 having a transmission axis perpendicular to the paper surface, and is supplied to the display panel.

That is, when no voltage is applied between the first and second electrodes 362 and 364 (OFF), the shutter panel has a shutter-on state for supplying light of the backlight unit 380 to the display panel (normally white) .

When a voltage is applied between the first and second electrodes 362 and 364, a horizontal electric field is generated between the first and second electrodes 362 and 364. As a result, the shutter liquid crystal layer 366 The plurality of shutter liquid crystal molecules 370 in the plurality of liquid crystal capsules 368 of the liquid crystal cell array 368 are rearranged in accordance with the horizontal electric field.

Accordingly, the light supplied to the backlight unit 380 passes through the third polarizing plate 372 having the transmission axis perpendicular to the paper surface, changes to polarized light in a direction perpendicular to the paper surface, passes through the shutter liquid crystal layer 366 Polarized light in a direction parallel to the plane of the drawing by a plurality of rearranged shutter liquid crystal molecules 370 and then blocked by the first polarizing plate 336 having a transmission axis perpendicular to the plane of the drawing and is not supplied to the display panel.

That is, when a voltage is applied between the first and second electrodes 362 and 364 (ON), the shutter panel has a shutter-off state for shutting off the light from the backlight unit 380 without supplying it to the display panel.

As described above, in the liquid crystal display device 310 according to the third embodiment of the present invention, the shutter liquid crystal layer 366 of the plurality of liquid crystal capsules 368 is formed on the third substrate 360 to constitute a shutter panel, The contrast ratio and sharpness of the image can be improved by transmitting or blocking the light of the backlight unit 380 by using the shutter panel for each pixel region P and supplying it to the display panel.

By attaching the shutter liquid crystal layer 366 formed on the third substrate 360 without using a separate substrate to the display panel using an adhesive layer or an adhesive, the thickness and weight can be reduced and the manufacturing cost can be reduced.

Further, by forming the shutter panel in the form of a film using the third substrate 360 of a flexible material, the manufacturing process can be simplified.

7 is a cross-sectional view of a liquid crystal display device according to a fourth embodiment of the present invention, in which a color filter layer is formed on a lower substrate and a shutter panel is in a normally black mode, The description of the same portions as those of FIG.

7, the liquid crystal display device 410 according to the fourth embodiment of the present invention includes first to third substrates 420, 440 and 460 spaced apart from each other in parallel, first and second substrates 420, A liquid crystal layer 450 formed between the first and second substrates 420 and 440, a shutter liquid crystal layer 466 formed between the first and third substrates 420 and 460, a backlight unit 480).

A thin film transistor (TFT) T, a pixel electrode 434, and a color filter layer 444 are formed in the pixel region P on the upper surface of the first substrate 420 facing the second substrate 440. [ A black matrix 442 is formed on the boundary of the pixel region P above the color filter layer 444 and a black matrix 442 is formed on the pixel region P on the lower surface of the second substrate 440 facing the first substrate 420. [ A common electrode 446 is formed.

In another embodiment, a black matrix 442 is formed on the pixel electrode 434 and a color filter layer 444 is formed on the black matrix 442. In this case, May be formed.

The first and second electrodes 462 and 464 are formed in the pixel region P on the upper surface of the third substrate 460 facing the first substrate 420.

The first, second, and third polarizers 436, 448, and 472 are formed on the upper surface of the second substrate 440 and the lower surface of the third substrate 460, respectively. The second polarizing plates 436 and 448 may have mutually perpendicular transmission axes, and the first and third polarizing plates 436 and 472 may have mutually perpendicular transmission axes.

For example, the first polarizing plate 436 may have a transmission axis perpendicular to the paper plane, and the second and third polarizing plates 448 and 472 may have a transmission axis parallel to the paper plane.

In this liquid crystal display device 410, when no voltage is applied between the first and second electrodes 462 and 464 (OFF), a horizontal electric field is not generated between the first and second electrodes 462 and 464 And as a result, the plurality of shutter liquid crystal molecules 470 in the plurality of liquid crystal capsules 468 of the shutter liquid crystal layer 466 are randomly arranged.

Accordingly, the light supplied from the backlight unit 480 passes through the third polarizing plate 472 having the transmission axis parallel to the paper surface, and is changed into the polarized light in the direction parallel to the paper surface. Thereafter, the light from the shutter liquid crystal layer 466, and is then blocked by the first polarizer 436 having a transmission axis perpendicular to the paper surface, and is not supplied to the display panel.

That is, when no voltage is applied between the first and second electrodes 462 and 464 (OFF), the shutter panel has a shutter-off state in which the light from the backlight unit 480 is not supplied to the display panel ).

When a voltage is applied between the first and second electrodes 462 and 464, a horizontal electric field is generated between the first and second electrodes 462 and 464. As a result, the shutter liquid crystal layer 466 The plurality of shutter liquid crystal molecules 470 in the plurality of liquid crystal capsules 468 of the liquid crystal display panel 480 are rearranged in accordance with the horizontal electric field.

Accordingly, the light supplied from the backlight unit 480 passes through the third polarizing plate 472 having a transmission axis parallel to the paper surface, changes to polarized light in a direction parallel to the paper surface, passes through the shutter liquid crystal layer 466 Is changed to polarized light in a direction perpendicular to the paper surface by a plurality of rearranged shutter liquid crystal molecules 470 and then supplied to the display panel through the first polarizing plate 436 having a transmission axis perpendicular to the paper surface.

That is, when a voltage is applied between the first and second electrodes 462 and 464 (ON), the shutter panel has a shutter-on state to supply the light from the backlight unit 480 to the display panel.

As described above, in the liquid crystal display device 410 according to the fourth embodiment of the present invention, the shutter liquid crystal layer 466 of the plurality of liquid crystal capsules 468 is formed on the third substrate 460 to constitute a shutter panel, It is possible to improve the contrast ratio and sharpness of the image by transmitting or blocking the light of the backlight unit 480 by using the shutter panel for each pixel region P and supplying it to the display panel.

In addition, by attaching the shutter liquid crystal layer 466 formed on the third substrate 460 to the display panel using an adhesive layer or an adhesive without a separate substrate, the thickness and weight can be reduced and the manufacturing cost can be reduced.

Further, by forming the shutter panel in the form of a film using the third substrate 460 made of a flexible material, the manufacturing process can be simplified.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. It can be understood that

110: liquid crystal display device 120: first substrate
140: second substrate 150: liquid crystal layer
160: third substrate 166: shutter liquid crystal layer
168: liquid crystal capsule 170: shutter liquid crystal molecule

Claims (8)

First, second and third substrates spaced apart from each other in parallel and including pixel regions;
A liquid crystal layer disposed between the first and second substrates;
A shutter liquid crystal layer disposed between the first and third substrates, the shutter liquid crystal layer including a plurality of liquid crystal capsules;
First, second, and third polarizers respectively disposed on the lower surface of the first substrate, the upper surface of the second substrate, and the lower surface of the third substrate;
And a backlight unit
And the liquid crystal display device.
The method according to claim 1,
And the pixel region of the third substrate corresponds to at least one pixel region of the first substrate.
The method according to claim 1,
Wherein a transmittance corresponding to a shutter data signal applied to the pixel region of the third substrate is proportional to a transmittance corresponding to a data signal applied to the pixel region of the first substrate.
The method according to claim 1,
An adhesive layer is disposed on the front surface between the second polarizing plate and the second substrate, on the front surface between the first polarizing plate and the shutter liquid crystal layer, and on the front surface between the third polarizing plate and the third substrate,
Wherein the adhesive layer is disposed on the entire surface between the first polarizer plate and the first substrate or an adhesive layer is disposed on the edge.
The method according to claim 1,
Wherein the plurality of liquid crystal capsules each include a plurality of shutter liquid crystal molecules,
Wherein the plurality of shutter liquid crystal molecules are one of a nematic liquid crystal, a ferroelectric liquid crystal, and a flexo liquid crystal.
The method according to claim 1,
Wherein the transmission axes of the first and second polarizing plates are perpendicular to each other,
Wherein the transmission axes of the first and third polarizing plates are perpendicular to each other or parallel to each other.
The method according to claim 1,
A thin film transistor is disposed in the pixel region above the first substrate,
And the first and second electrodes are disposed in the pixel region on the third substrate.
8. The method of claim 7,
A color filter layer is disposed in the pixel region above the first substrate or in the pixel region below the second substrate,
And a black matrix is disposed on the pixel region boundary above the first substrate or the pixel region boundary below the second substrate.

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