KR102494150B1 - Liquid crystal display device - Google Patents

Abstract

The present application is to prevent a curved polarizer from being deformed into a saddle shape by a restoring force, and includes first and second substrates bonded to each other and a liquid crystal layer interposed between the first and second substrates. panel, first and second polarizers disposed above and below the liquid crystal panel and having mutually different heat shrinkage rates in the long side direction, a backlight unit disposed below the liquid crystal panel and radiating light toward the liquid crystal panel, and the liquid crystal panel, the first polarizer , It provides a liquid crystal display device including a storage member for accommodating the second polarizing plate and the backlight unit. Here, among the first and second polarizing plates, the thermal contraction rate in the long side direction of the first polarizing plate having an absorption axis parallel to the short side direction of the liquid crystal panel is the thermal contraction rate in the long side direction of the second polarizing plate having an absorption axis parallel to the long side direction of the liquid crystal panel. It is 1/15 times to 1/3 times the shrinkage rate. Accordingly, the first polarizer may be prevented from being deformed into a saddle shape by being affected by a restoring force lower than that of the second polarizer.

Description

Liquid crystal display {LIQUID CRYSTAL DISPLAY DEVICE}

The present application relates to a liquid crystal display device that displays an image using optical anisotropy and polarization properties of liquid crystal, and more particularly, to a curved liquid crystal display device having a curved display surface.

BACKGROUND OF THE INVENTION As we enter the information age in earnest, a display field that visually displays electrical information signals is rapidly developing. Accordingly, research is being conducted to develop performance such as thinning, light weight, and low power consumption for various flat display devices.

Representative examples of such a flat panel display are a liquid crystal display device (LCD), a plasma display panel device (PDP), a field emission display device (FED), and an electroluminescent display device. (Electro Luminescence Display device: ELD), Electro-Wetting Display device (EWD), and Organic Light Emitting Display device (OLED).

Such a flat panel display device includes a flat display surface.

However, when the display surface is flat, as the distance from the display surface differs for each position of the viewing area, there is a problem in that a deviation in image display occurs. To solve this problem, a curved display device having a curved display surface has been proposed.

On the other hand, the liquid crystal display device includes a liquid crystal panel that displays an image by using the optical anisotropy and polarization properties of liquid crystal. The liquid crystal panel includes a pair of substrates and a liquid crystal layer injected therebetween, and adjusts the light transmittance of each pixel area by adjusting the arrangement direction of liquid crystals. That is, the liquid crystal panel does not generate light by itself, and displays an image by adjusting the amount of light supplied from the outside to be emitted from each pixel area. Accordingly, the liquid crystal display device further includes a backlight unit radiating light to the liquid crystal panel.

In addition, the liquid crystal display device further includes two polarizers disposed above and below the liquid crystal panel and having absorption axes perpendicular to each other in order to block external light interference and use light from the backlight unit as display light.

When such a liquid crystal display device is a curved display device, each of the liquid crystal panel and the two polarizers disposed on the top and bottom of the liquid crystal panel are provided in a flat shape, and then transformed into a curved shape in a high-temperature atmosphere by using the thermal contraction rate in the long side direction. do. Accordingly, when the curved liquid crystal display device is installed in a room temperature atmosphere for a long period of time, the curved liquid crystal panel and the two polarizers may expand or contract due to stress to gradually restore them to a flat shape, that is, a restoring force.

However, as mentioned above, the two polarizers disposed above and below the liquid crystal panel have absorption axes perpendicular to each other. That is, one of the two polarizers has an absorption axis parallel to the long-side direction, while the other polarizer has an absorption axis parallel to the short-side direction, not the long-side direction. At this time, the absorption axis of each polarizing plate corresponds to the direction in which the stretching material is stretched.

As shown in FIG. 1, in the case of a polarizer having an absorption axis parallel to the short side direction, the stretching direction interferes with the direction of the restoring force to be deformed from the curved shape to the flat shape. Accordingly, there is a problem in that the polarizer is not simply restored to a flat shape, but deformed to a saddle shape.

In addition, the liquid crystal panel can also be deformed by the polarizing plate deformed into the saddle shape, and as a result, the liquid crystal panel and the polarizing plate are separated from or displaced from the curved storage member, and the bezel area between the liquid crystal panel and the storage member There is a problem in that light leakage is easily generated in some areas adjacent thereto. Due to such light leakage, there are problems in that the contrast ratio of the curved liquid crystal display device is lowered, the image quality is lowered, and the lifespan is lowered.

The present application is to provide a curved liquid crystal display device capable of preventing a curved polarizer from being deformed into a saddle shape.

In order to solve this problem, the present application is a liquid crystal panel including first and second substrates bonded to each other and a liquid crystal layer interposed between the first and second substrates, disposed above and below the liquid crystal panel and mutually First and second polarizers having different heat shrinkage rates in the long side direction, a backlight unit disposed below the liquid crystal panel and irradiating light toward the liquid crystal panel, and a storage member accommodating the liquid crystal panel, the first polarizer, the second polarizer, and the backlight unit. It provides a liquid crystal display device comprising a. Here, the liquid crystal panel, the first polarizing plate and the second polarizing plate are seated on the storage member in a state of being deformed into a curved shape bent with a predetermined radius of curvature by using the respective thermal contraction rates in the longitudinal direction.

Also, the first polarizing plate has an absorption axis parallel to the direction of the short side of the liquid crystal panel, and the second polarizing plate has an absorption axis perpendicular to the absorption axis of the first polarizing plate and parallel to the direction of the long side of the liquid crystal panel. Here, the thermal contraction rate in the long side direction of the first polarizing plate is 1/15 to 1/3 times the thermal contraction rate in the long side direction of the second polarizing plate.

The liquid crystal display device according to each embodiment of the present application includes first and second polarizers disposed above and below the liquid crystal panel, but the first and second polarizers have different thermal contraction rates in the longitudinal direction. In particular, among the first and second polarizing plates, the thermal contraction rate in the long side direction of the first polarizing plate having an absorption axis parallel to the short side direction of the liquid crystal panel is the thermal contraction rate in the long side direction of the second polarizing plate having an absorption axis parallel to the long side direction of the liquid crystal panel. lower than

Accordingly, the first polarizer may be prevented from being deformed into a saddle shape by being affected by a restoring force lower than that of the second polarizer.

Therefore, deformation of the liquid crystal panel by the polarizing plate deformed into a saddle shape can be prevented, and thus, the liquid crystal panel and the polarizing plate can be prevented from being separated from or displaced from the housing member. Thus, light leakage in the bezel area and its surroundings due to a misalignment between the liquid crystal panel and the storage member can be prevented, and contrast ratio, image quality, and lifespan reduction due to light leakage can be prevented.

1 is a view showing an example in which a curved polarizer is deformed into a saddle shape.
2 is a cross-sectional view of a liquid crystal display device according to a first embodiment of the present application.
3 is a view showing a liquid crystal panel and first and second polarizers according to a first embodiment of the present application.

Hereinafter, a curved liquid crystal display device according to each embodiment of the present application will be described in detail with reference to the accompanying drawings.

First, a liquid crystal display device according to a first embodiment of the present application will be described with reference to FIGS. 2 and 3 .

2 is a cross-sectional view of a liquid crystal display device according to a first embodiment of the present application, and FIG. 3 is a view showing a liquid crystal panel and first and second polarizers according to the first embodiment of the present application.

As shown in FIG. 2, the liquid crystal display device 100 according to the first embodiment of the present application includes a liquid crystal panel 110, a first polarizing plate 121 disposed under the liquid crystal panel 110, and a liquid crystal panel 110. The second polarizing plate 122 disposed above, the backlight unit 130 disposed below the first polarizing plate 121 and radiating light toward the liquid crystal panel 110, and the liquid crystal panel 110, the first and second polarizing plates ( 121 and 122 and a storage member 140 accommodating the backlight unit 130. Here, at least the liquid crystal panel 110 and the first and second polarizers 121 and 122 are seated in the storage member 140 in a state of being deformed into a curved shape with a predetermined radius of curvature R. Here, the radius of curvature (R) is a value indicating the degree of curvature at each point of the curved surface or curve, and is the radius of the circle closest to the curve, that is, the contact circle.

And, as shown in FIG. 2 , the backlight unit 130 may also be seated in the housing member 140 in a state of being deformed into a curved shape bent with a radius of curvature R. Alternatively, unlike shown in FIG. 2, the liquid crystal display device 100 further includes a curved liquid crystal panel 110 and a guide member (not shown) accommodating the first and second polarizers 121 and 122. Including, the accommodating member 140 may be to accommodate the guide member and the backlight unit 130.

Also, the liquid crystal display device 100 may further include a reinforcing plate 150 disposed on the second polarizing plate 122 and protecting the first polarizing plate 121 and the liquid crystal panel 110 from an external force. In this case, the reinforcing plate 150 may be seated in the accommodating member 140 while being attached to the second polarizing plate 122 . Alternatively, although not shown in FIG. 2 , the reinforcing plate 150 may be attached on the receiving member 140 .

The liquid crystal panel 110 includes first and second substrates 111 and 112 bonded to each other, a liquid crystal layer 113 interposed between the first and second substrates 111 and 112, and the first and second substrates. It includes a sealing layer 114 disposed in the edge region between 111 and 112 and bonding the first and second substrates 111 and 112 together.

Although not shown in detail in FIG. 2 , when the liquid crystal panel 110 is of an active matrix driving type, the first substrate 111 disposed below among the first and second substrates 111 and 112 defines a plurality of pixel areas. and a thin film transistor array for driving each pixel area.

The thin film transistor array includes a gate line and a data line that cross each other to define a plurality of pixel areas in a display area, a thin film transistor corresponding to each pixel area and disposed in an intersection area between the gate line and the data line, and corresponding to each pixel area. and a pixel electrode connected to each thin film transistor.

The liquid crystal panel 110 of the active matrix driving method further includes a common electrode disposed on one of the first and second substrates 111 and 112 and generating a predetermined electric field together with the pixel electrode. At this time, the arrangement direction of the liquid crystals of the liquid crystal layer 113 is changed by the electric field between the pixel electrode and the common electrode, so that the light transmittance of each pixel area is adjusted.

In addition, although not shown in detail in FIG. 2 , when the liquid crystal panel 110 displays a color image, the liquid crystal panel 110 further includes a color filter disposed on either one of the first and second substrates 111 and 112 . can include

The first polarizing plate 121 is disposed below the first substrate 111 , and the second polarizing plate 122 is disposed above the second substrate 112 . The first and second polarizers 121 and 122 have absorption axes orthogonal to each other.

The first polarizer 121 polarizes light incident from the backlight unit 130 to the liquid crystal panel 110 along a first polarization axis. And, the second polarizer 122 emits light polarized by the liquid crystal panel 110 with a second polarization axis perpendicular to the first polarization axis as display light.

Although not shown in detail in FIG. 2 , the backlight unit 130 includes a light guide plate facing the liquid crystal panel 110, a light source facing at least one side of the light guide plate, a reflective sheet disposed under the light guide plate, and disposed on the light guide plate and scattering or dispersing light. It includes at least one optical sheet for diffusion. The backlight unit 130 may further include a guide member disposed in the storage member 140 and supporting the light guide plate, the light source, the reflective sheet, and at least one optical sheet, and between the at least one optical sheet and the guide member. It may further include a light-shielding tape disposed over the spaced portion of the. In addition, the at least one optical sheet may include a diffusion sheet for diffusing or scattering light emitted from an upper surface of the light guide plate and a prism sheet for condensing the light.

As shown in FIG. 3, the first and second polarizers 121 and 122 have absorption axes perpendicular to each other. Specifically, one of the first and second polarizers 121 and 122 has an absorption axis parallel to the long side direction of the liquid crystal panel 110, that is, a corner bent to be deformed into a curved shape. And, the other one has an absorption axis parallel to the direction of the short side of the liquid crystal panel 110, that is, a corner maintaining a straight line without being bent.

For example, as shown in FIG. 3 , the first polarizing plate 121 disposed under the first substrate 111 of the liquid crystal panel 110 has an absorption axis parallel to the direction of the short side of the liquid crystal panel 110, and the liquid crystal panel ( The second polarizing plate 122 disposed on the second substrate 112 of 110 may have an absorption axis parallel to the long side direction of the liquid crystal panel 110 . In the following description, it is assumed that the absorption axis of the first polarizing plate 121 is parallel to the short side direction of the liquid crystal panel 110, and the absorption axis of the second polarizing plate 122 is parallel to the long side direction of the liquid crystal panel 110. . However, this is just an example, and according to the intention of the designer, the absorption axis of the first polarizing plate 121 is parallel to the long side direction of the liquid crystal panel 110, and the absorption axis of the second polarizing plate 122 is parallel to the liquid crystal panel 110. It goes without saying that may be parallel to the direction of the short side of .

In addition, each of the first and second polarizers 121 and 122 includes polarizers 211 and 212 made of an elongated material and a pair of protective substrates 221a and 221b facing each other with the polarizers 211 and 212 interposed therebetween. ) (222a, 222b). Here, the stretching material may have a polarization function through a stretching process in which it is stretched in a direction corresponding to the absorption axis. Illustratively, the stretching material may be polyvinyl alcohol (PVA).

Specifically, the first polarizing plate 121 includes a first polarizing element 211 that polarizes with an absorption axis parallel to the direction of the short side of the liquid crystal panel 110 (up and down arrows in FIG. 3), and a first polarizing element 211. It may be a structure including a pair of protective substrates (221a, 221b) facing each other with a in-between.

Further, the second polarizer 122 includes a second polarizer 212 that polarizes with an absorption axis parallel to the long side direction of the liquid crystal panel 110 (left and right arrows in FIG. 3), and the second polarizer 212. It may be a structure including a pair of protective substrates (222a, 222b) facing each other placed in between.

Meanwhile, as mentioned above, the liquid crystal panel 110 and the first and second polarizers 121 and 122 are stored in a state in which they are deformed into a curved shape rather than a flat shape in a high-temperature atmosphere using respective thermal contraction rates. It settles at (140).

Accordingly, when the liquid crystal display device 100 is exposed to a room temperature atmosphere for a critical period or more, at least one of the liquid crystal panel 110 and the first and second polarizers 121 and 122 is gradually restored to a flat shape, that is, the restoring force. It can be expanded or contracted in a predetermined direction by

In particular, in the case of the first polarizing plate 121, the first polarizing element 211 is stretched to have an absorption axis that does not coincide with the direction of the long side bent to be deformed into a curved surface. Accordingly, the restoring force of the first polarizing plate 121 is not generated in the direction in which the bending process is performed, but in a direction in which the direction in which the stretching process is performed interferes with the direction in which the bending process is performed. Due to this restoring force, the first polarizer 121 may be deformed into a saddle shape. Like the first polarizer 121 deformed into a saddle shape, the liquid crystal panel 110 and the second polarizer 122 disposed on the first polarizer 121 may also be deformed into a saddle shape. As a result, the liquid crystal panel 110 and the first and second polarizers 121 and 122 do not maintain the curved shape of a predetermined radius of curvature R, so that they may be separated from or twisted from the storage member 140. There is a problem. At this time, there is a problem in that a light leakage defect occurs due to a gap generated between the liquid crystal panel 110 and the housing member 140, and as a result, a decrease in contrast ratio, image quality, and lifespan are accelerated.

In order to solve this problem, the first polarizing plate 121 according to the first embodiment of the present application has a different thermal contraction rate than the second polarizing plate 122 . That is, since the first and second polarizers 121 and 122 have different thermal contraction rates, they are affected by different restoring forces.

In particular, since the first polarizer 121 has an absorption axis that does not coincide with the direction of the long side of the liquid crystal panel 110, it can be deformed into a saddle shape by restoring force. Accordingly, the first polarizing plate 121 has a thermal contraction rate in the long side direction lower than that of the second polarizing plate 122 in the long side direction so that the first polarizing plate 121 has a smaller restoring force than the second polarizing plate 122 .

Illustratively, the thermal contraction rate of the first polarizing plate 121 in the long side direction may be 1/15 to 1/3 times the thermal contraction rate of the second polarizing plate 122 in the long side direction. The thermal contraction rate in the longitudinal direction of each of the first and second polarizers 121 and 122 may be adjusted by at least one of a thickness and a material.

According to the first embodiment, the first and second polarizers 121 and 122 include polarizers 211 and 212 having different thicknesses, so that they have different thermal contraction rates in the longitudinal direction.

For example, the thickness of the first polarizing element 211 of the first polarizing plate 121 may be 1/10 to 1/2 times the thickness of the second polarizing element 212 of the second polarizing plate 122 . In this case, the second polarizer 212 of the second polarizer 122 may have a thickness of 3 μm to 30 μm.

If the thickness of the second polarizing element 212 is less than 3 μm, there is a problem in that the polarizing element 212 may be torn during a stretching process for forming an absorption axis. And, if the thickness of the second polarizing element 212 is greater than 30 μm, there are problems in that light efficiency may be lowered by the polarizing plate 122 and resilience increases.

Tables 1 and 2 below show the results of experiments on whether or not there is a light leakage defect according to the example according to the prior art, the first to sixth examples according to the first embodiment of the present application, and the defective example, respectively.

In Tables 1 and 2, common experimental conditions for each example are that the bending process of the polarizer was performed for about 75 hours or more in an atmosphere of 75 degrees Celsius and a structure including a curved backlight unit. And, in Tables 1 and 2, when HVC (Human Visual Contrast) of black gradation was 11 or more, it was classified as poor light leakage. HVC is a parameter representing visibility of luminance according to a predetermined formula.

prior art Example 1 Example 2 Example 3 Thickness of the second polarizer 25㎛ 12㎛ 18㎛ 18㎛ Thickness of the first polarizer 25㎛ 5㎛ 5㎛ 7㎛ radius of curvature 1.8 2.5 2.8 2.7 HVC 30 8 6 7 Poor light leakage NG OK OK OK

Example 4 Example 5 Example 6 bad example Thickness of the second polarizer 25㎛ 25㎛ 25㎛ 25㎛ Thickness of the first polarizer 5㎛ 7㎛ 12㎛ 18㎛ radius of curvature 3.1 3.0 2.4 2.2 HVC 2 3 11 25 Poor light leakage OK OK OK NG

As in the prior art shown in Table 1, when the first and second polarizers have the same thickness of 25 μm, even if they are bent with a relatively small radius of curvature of 1.8, it can be confirmed that light leakage occurs.

In contrast, as in the first to sixth examples shown in Table 1, the thickness of the second polarizing element 212 is any one of 12 μm, 18 μm, and 25 μm, and the thickness of the first polarizing element 211 is In the case of 1/5 to 1/2 times the thickness of the 2-polarizer 212, it can be seen that no light leakage occurs even when the film is bent with a radius of curvature of 2.4 to 3.1, which is greater than that of the prior art. At this time, although the restoring force increases as the radius of curvature increases, in the first to sixth examples according to the first embodiment of the present application, light leakage in the bezel area due to deformation of the polarizer does not occur.

In addition, as shown in the defective examples of Table 2, the thickness of the second polarizing element 122 is 25 μm, and the thickness of the first polarizing element 211 is smaller than the thickness of the second polarizing element 212, and the second polarizing element ( 212), it can be confirmed that light leakage occurs even when bent with a radius of curvature of 2.2, which is smaller than that of the first to sixth examples.

As such, when the thickness of the first polarizing element 211 is 1/5 to 1/2 times smaller than the thickness of the second polarizing element 212, the restoring force of the first polarizing plate 121 is reduced to the saddle shape. small enough not to deform. In addition, since the restoring force of the second polarizing plate 122 is greater than that of the first polarizing plate 121, even if the shape of the first polarizing plate 121 is deformed by the restoring force, the shape of the second polarizing plate 122 is maintained. It can be. Therefore, even if the first and second polarizers 121 and 122 are deformed into a curved shape having a radius of curvature greater than that of the prior art example, light leakage in the bezel area due to the first polarizer 121 deformed into a saddle shape is reduced. It can easily be predicted that it will be prevented.

Meanwhile, unlike the first embodiment, since the first and second polarizers 121 and 122 include the polarizers 211 and 212 made of different materials, they may have different thermal contraction rates in the longitudinal direction.

That is, in the liquid crystal display device according to the second embodiment of the present application, the second polarizing element 212 of the second polarizing plate 122 is made of an elongating material having a polarization function through an elongating process, whereas the first polarizing plate 121 The first polarizer 211 of is the same as the first embodiment of FIG. 3 except that it is made of a non-stretchable material having a polarization function without a stretching process, so redundant description is omitted.

Illustratively, the first polarizer 211 of the first polarizer 121 may be made of a patterned non-stretched material. At this time, the non-stretching material may be any one of a dye (DYE), a reactive liquid crystal, and a metal.

Table 3 below shows the results of testing whether or not there is light leakage according to the example according to the prior art and the seventh and eighth examples according to the second embodiment of the present application.

prior art Example 7 Example 8 Thickness of the second polarizer 25㎛ 25㎛ 18㎛ 1st polarizer 25㎛ unstretched unstretched HVC 30 2 3 Poor light leakage NG OK OK

As in the seventh and eighth examples shown in Table 3, when the thickness of the second polarizing element 212 is any one of 25 μm and 18 μm, and the first polarizing element 211 is made of a non-stretched material, light leakage is poor. You can confirm that this does not happen.

That is, when the first polarizing element 211 is made of a non-stretching material as in the second embodiment, the direction in which the restoring force is generated in the first polarizing plate 121 is affected only by the bending direction, so that the first polarizing plate 121 ) can be prevented from being deformed into a saddle shape.

Alternatively, unlike the first and second embodiments, the first and second polarizers 121 and 122 may have different thermal contraction rates in the longitudinal direction by including protective materials made of different materials.

That is, in the liquid crystal display device according to the third exemplary embodiment of the present application, the protective materials 221a and 221b of the first polarizing plate 121 have lower rows in the long side direction than the protective materials 222a and 222b of the second polarizing plate 122 Except that it is made of a material having a shrinkage rate, it is the same as the first embodiment of FIG. 3, so redundant description will be omitted. Here, the heat shrinkage of the protective materials 221a and 221b of the first polarizing plate 121 in the long side direction is 1/50 to 1 of the heat shrinkage of the protective materials 222a and 222b of the second polarizing plate 122 in the long side direction. / can be 15 times.

Illustratively, the protective materials 221a and 221b (222a and 222b) of the first and second polarizers 121 and 122 may include a tri-acetyl-cellulose (TAC) film, a polyester (PET) film, and a cyclo olefin (COP) film. Polymer) may be made of any of the films. Here, the thermal contraction rate of the TAC film in the long side direction is 0.1, and the thermal shrinkage rate of the PET film in the long side direction is 2.5.

Therefore, according to the third embodiment, the protective substrates 222a and 222b of the second polarizing plate 122 having an absorption axis parallel to the long side direction may be made of a PET film having a relatively high heat shrinkage rate in the long side direction. In addition, the protective materials 221a and 221b of the first polarizing plate 121 having absorption axes that do not coincide in the long side direction have a heat shrinkage rate in the long side direction of about 1/1 of that of the protective materials 222a and 222b of the second polarizing plate 122. It can be made of a PET film that is 50 times larger.

Meanwhile, deformation of the first and second polarizers 121 and 122 is relatively greatly affected by moisture.

Thus, according to the fourth embodiment, the protective materials 221a and 221b of the first polarizing plate 121 are made of a material having lower moisture permeability than the protective materials 222a and 222b of the second polarizing plate 122 . For example, the moisture permeability of the protective materials 221a and 221b of the first polarizing plate 121 may be 0 to 1/20 times the moisture permeability of the protective materials 222a and 222b of the second polarizing plate 122 .

As a result, the degree to which the restoring force of the first polarizing plate 121 is expressed is lower than the degree to which the restoring force of the second polarizing plate 122 is expressed, further preventing the first polarizing plate 121 from being deformed into a saddle shape by the restoring force. can do.

As mentioned above, materials that can be provided as the protective substrates 221a and 221b (222a and 222b) include a TAC film, a PET film, and a COP film.

Here, the TAC film has a water vapor transmission rate of about 400 G/m ² -day, the PET film has a water vapor transmission rate of about 9 G/m ² -day, and the COP film has a water vapor transmission rate of about 0.5 G/m ² -day.

Accordingly, according to the fourth embodiment, the protective substrates 222a and 222b of the second polarizing plate 122 having an absorption axis parallel to the long side direction may be formed of a TAC film having a relatively high moisture permeability. In addition, the protective materials 221a and 221b of the first polarizing plate 121 having absorption axes that do not coincide in the long side direction may be formed of a PET film or a COP film.

As described above, according to each embodiment of the present application, in each of the first and second polarizers 121 and 122 having absorption axes perpendicular to each other, the thickness of the polarizers 211 and 212, the polarizers 211 and 212 At least one of the material of the material and the material of the protective substrates 221a and 221b is different from each other. Therefore, the first polarizing plate 121 having an absorption axis that does not coincide with the long side direction of the liquid crystal panel 110 has a lower long side direction than the second polarizing plate 122 having an absorption axis that coincides with the long side direction of the liquid crystal panel 110. has a thermal shrinkage of Accordingly, the first polarizer 121 is affected by a smaller restoring force than the second polarizer 122, and thus can be prevented from being deformed into a saddle shape. Therefore, since the liquid crystal panel 110 can be prevented from being deformed by the first polarizing plate 121 deformed into a saddle shape, light leakage and resulting degradation of contrast ratio and image quality can be prevented.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible within the scope of the technical spirit of the present invention. Conventionally in the art to which the present invention belongs It will be clear to those who have knowledge of

100: liquid crystal display device 110: liquid crystal panel
121: first polarizing plate 122: second polarizing plate
130: backlight unit 140: storage member
150: reinforced plate
211: first polarizer 212: second polarizer
221a, 221b, 222a, 222b: protective material

Claims (14)

a liquid crystal panel including first and second substrates bonded to each other and a liquid crystal layer interposed between the first and second substrates;
a first polarizer disposed below the liquid crystal panel and having an absorption axis parallel to a direction of a short side of the liquid crystal panel;
a second polarizer disposed on the liquid crystal panel and having an absorption axis parallel to a long side direction of the liquid crystal panel;
a backlight unit disposed below the liquid crystal panel and irradiating light toward the liquid crystal panel; and
A storage member accommodating the liquid crystal panel, the first polarizing plate, the second polarizing plate, and the backlight unit;
The first polarizing plate has a smaller thermal contraction rate in the long side direction than the second polarizing plate,
The liquid crystal panel, the first polarizing plate, and the second polarizing plate are seated on the housing member in a state in which the liquid crystal panel, the first polarizing plate, and the second polarizing plate are deformed into a curved shape bent to a predetermined radius of curvature using the respective thermal contraction rates in the longitudinal direction. According to claim 1,
Absorption axes of the first and second polarizers are perpendicular to each other. According to claim 2,
The thermal contraction rate in the long side direction of the first polarizing plate is 1/15 to 1/3 times the thermal contraction rate in the long side direction of the second polarizing plate. According to claim 2,
Each of the first and second polarizers is
a polarizing element made of an elongated material; and
A liquid crystal display device comprising a pair of protective substrates facing each other with the polarizing element interposed therebetween. According to claim 4,
The polarizing elements of each of the first and second polarizing plates have different thicknesses from each other. According to claim 5,
The thickness of the polarizing element of the first polarizing plate is 1/10 to 1/2 times the thickness of the polarizing element of the second polarizing plate. According to claim 6,
The thickness of the polarizing element of the second polarizing plate is 3㎛ to 30㎛ liquid crystal display. According to claim 2,
The first polarizing plate may include a first polarizing element made of a non-stretched material; and a pair of protective materials facing each other with the first polarizing element interposed therebetween;
The second polarizing plate may include a second polarizing element made of an elongated material; and a pair of protective materials facing each other with the second polarizer interposed therebetween. According to claim 8,
The non-stretching material is any one of a dye (DYE), a reactive liquid crystal and a metal liquid crystal display device. According to any one of claims 4 to 9,
The protective material of each of the first and second polarizers is a liquid crystal display device made of any one of a tri-acetyl-cellulose (TAC) film, a polyester (PET) film, and a cyclo olefin polymer (COP) film. According to claim 10,
The protective substrate of each of the first and second polarizing plates is a liquid crystal display device made of a material having a different thermal contraction rate in a long side direction. According to claim 11,
The protective material of the first polarizing plate is made of a TAC film, and the protective material of the second polarizing plate is made of a PET film. According to claim 10,
The liquid crystal display device wherein the protective substrate of each of the first and second polarizing plates is made of a material having different moisture permeability. According to claim 13,
The protective material of the first polarizing plate is made of a TAC film, and the protective material of the second polarizing plate is made of a PET film or a COP film.

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