WO2010050750A2 - Reflection polarizer, light source assembly including the same, and lcd device - Google Patents

Abstract

Provided is a reflection polarizer. The reflection polarizer comprises: a liquid crystal layer including cholesteric liquid crystals, and fillers that are dispersed in the liquid crystal layer.

Description

Reflective polarizer, light source assembly and liquid crystal display including the same

The present invention relates to a reflective polarizer, and more particularly, to a reflective polarizer applied to a display, a light source assembly including the same, and a liquid crystal display device.

A liquid crystal display (LCD) is a device that displays an image by injecting a liquid crystal between two glass plates and applying power to the upper and lower glass plate electrodes to change the liquid crystal molecular array in each pixel. Unlike cathode ray tube (CRT), plasma display panel (PDP), and the like, the display by the liquid crystal display itself is non-luminous and thus cannot be used in the absence of light. To compensate for these disadvantages, a light source assembly uniformly irradiated on the information display surface is mounted for the purpose of enabling use in a dark place.

The light source assembly used in the liquid crystal display device is largely classified into two types. The first is an edge type light source assembly that provides light at the side of the liquid crystal display, and the second is a direct type light source assembly that provides light directly at the rear of the liquid crystal display. In the case of the edge type light source assembly, a light guide plate is provided to allow the light emitted from the light source to be irradiated upward, and at least one optical film is disposed above the light guide plate to adjust optical characteristics of light passing through the light guide plate. In the case of the direct type light source assembly, a diffuser plate is provided to reduce bright lines of light emitted from the light source, and at least one optical film is provided to adjust optical characteristics of light passing through the diffuser plate. Some liquid crystal displays have reflective polarizers as one of the optical films to improve the brightness.

In general, the cholesteric liquid crystal applied to the reflective polarizer is not so wide a reflected light bandwidth, it is difficult to cover the visible light radio wave with a single cholesteric liquid crystal. Therefore, in order to cover the visible light electric wave field, a plurality of liquid crystal layers are stacked. However, when a large number of liquid crystal layers are laminated, the thickness itself becomes thick, not only the light transmittance is disadvantageous, but also the light transmittance is also lowered by the adhesive because it must interpose the liquid crystal interlayer adhesive. In addition, the adhesive generates light distortion. As a result, the brightness, light quality, and image quality of the light source assembly and the liquid crystal display device employing such reflective polarizers are reduced.

In addition, when defects are generated on the surface of the reflective polarizer, visibility and marketability may be reduced.

Furthermore, depending on the specifications applied, it is often required that the light passing through the reflective polarizer have a relatively strong color family. However, applying a new film for this purpose is disadvantageous not only in terms of brightness, but also increases manufacturing costs.

The present invention has been conceived based on these points, and the problem to be solved by the present invention is to increase the luminance and improve the visual visibility of the surface by using a single liquid crystal layer and having a predetermined reflectance for the wavelength range of visible light. It is to provide a reflective polarizer to which fine color correction is applied.

Another problem to be solved by the present invention is to provide a reflective polarizer with increased luminance, improved visual visibility, and fine color correction.

Another object of the present invention is to provide a liquid crystal display device in which luminance is increased, visual visibility is improved, and fine color correction is applied.

The objects of the present invention are not limited to the above-mentioned objects, and other objects that are not mentioned will be clearly understood by those skilled in the art from the following description.

Reflective polarizer according to an embodiment of the present invention for solving the above problems includes a liquid crystal layer comprising a cholesteric liquid crystal, and a filler dispersed in the liquid crystal layer.

Reflective polarizer according to another embodiment of the present invention for solving the above problems is a reflective polarizer comprising a liquid crystal layer comprising a cholesteric liquid crystal, and a filler dispersed in the liquid crystal layer, the surface of the reflective polarizer is flat Randomly disposed between the surface and the flat surface, and includes a protruding surface protruding from the flat surface, wherein the maximum protruding height protruding from the flat surface is 0.001㎛ to 100㎛.

The light source assembly according to an embodiment of the present invention for solving the other problem includes a reflective polarizer as described above.

The liquid crystal display according to the exemplary embodiment of the present invention for solving the another problem includes the reflective polarizer as described above.

Specific details of other embodiments are included in the detailed description and drawings.

According to embodiments of the present invention has at least the following effects.

That is, according to the reflective polarizer according to the exemplary embodiments of the present invention, the reflective polarizer may exhibit a predetermined reflectance with respect to the full-wavelength range of visible light while having a single liquid crystal layer. Thus, the thickness of the reflective polarizer is reduced, and the light transmittance can be improved. In addition, unlike the case of laminating in a multilayer, since there is no need to use an adhesive at all, it is possible to prevent the distortion of light and the decrease in light transmittance due to the interposition of the adhesive.

In addition, since the projecting surface is formed on the surface of the reflective polarizer by the filler, visual visibility can be improved. Furthermore, by finely adjusting the reflectance for each liquid crystal pitch, the color of emitted light can be finely corrected.

The effects according to the present invention are not limited by the contents exemplified above, and more various effects are included in the present specification.

1 is a cross-sectional view of a reflective polarizer according to an embodiment of the present invention.

FIG. 2 is an enlarged view of region A of FIG. 1.

FIG. 3 is a schematic diagram illustrating a traveling direction of light in the reflective polarizer of FIG. 2 of the present invention. FIG.

4 to 6 are graphs showing transmittances according to wavelengths of light incident on a liquid crystal pitch region of a reflective polarizer according to an exemplary embodiment of the present invention.

7 is a graph showing transmittance according to wavelength of light incident on a liquid crystal layer of a reflective polarizer according to an exemplary embodiment of the present invention.

8-11 are partial cross-sectional views of reflective polarizers in accordance with some embodiments of the present invention.

12 is a photograph of a reflective polarizer prepared without dispersing a filler in the liquid crystal layer.

FIG. 13 is a photograph of a reflective polarizer according to an embodiment of the present invention and is a photograph of a reflective polarizer manufactured by dispersing a filler in a liquid crystal layer. FIG.

FIG. 14 is a cross-sectional view of a reflective polarizer according to an exemplary embodiment of the present invention, in which a liquid crystal pitch region of the liquid crystal layer has substantially the same vertical arrangement as that of FIG. 2, and a filler dispersed in the liquid crystal layer is spherical.

FIG. 15 is a cross-sectional view of a reflective polarizer according to another exemplary embodiment of the present invention, in which a liquid crystal pitch region of the liquid crystal layer has substantially the same vertical arrangement as that of FIG. 2, and a cross section of fillers dispersed in the liquid crystal layer is triangular. do.

16 is a cross-sectional view of a reflective polarizer according to another embodiment of the present invention, in which the liquid crystal pitch region of the liquid crystal layer has substantially the same vertical arrangement as that of FIG. 2, and a spherical filler dispersed in the liquid crystal layer is adjacent to the substrate side. The case where only a light reflection band is located is illustrated.

17 is a cross-sectional view of a reflective polarizer according to another embodiment of the present invention.

18 to 21 are cross-sectional views illustrating various shapes of an embossed pattern.

22 is a cross-sectional view illustrating a case in which reflective polarizers are directly stacked with other optical sheets according to some embodiments of the present disclosure.

23 and 24 are bottom views for explaining an arrangement of an embossed pattern of the reflective polarizer of FIG. 22.

25 is a cross-sectional view illustrating a case in which reflective polarizers are spaced apart from each other by an optical sheet according to some embodiments of the present disclosure.

FIG. 26 is a bottom view illustrating an arrangement of an embossed pattern of the reflective polarizer of FIG. 25.

27 is a cross-sectional view of a reflective polarizer according to another embodiment of the present invention.

28 to 30 are cross-sectional views of reflective polarizers according to still other embodiments of the present invention.

31 is a cross-sectional view of a liquid crystal display according to an exemplary embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

10, 100: reflective polarizer 105: substrate

110: liquid crystal layer 120: embossed pattern

130: bead 140: support coating film

150: filler 160: diffusion unit

300: backlight assembly 400: liquid crystal panel assembly

500: top chassis 600: liquid crystal display

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the present embodiments are intended to complete the disclosure of the present invention, and the general knowledge in the art to which the present invention pertains. It is provided to fully convey the scope of the invention to those skilled in the art, and the present invention is defined only by the scope of the claims.

References to elements or layers "on" other elements or layers include all instances where another layer or other element is directly over or in the middle of another element. On the other hand, when a device is referred to as "directly on", it means that no device or layer is intervened in between. Like reference numerals refer to like elements throughout. "And / or" includes each and all combinations of one or more of the items mentioned.

The spatially relative terms " below ", " beneath ", " lower ", " above ", " upper " It may be used to easily describe the correlation of a device or components with other devices or components. Spatially relative terms are to be understood as including terms in different directions of the device in use or operation in addition to the directions shown in the figures. For example, when flipping a device shown in the figure, a device described as "below" or "beneath" of another device may be placed "above" of another device. Thus, the exemplary term "below" can encompass both an orientation of above and below. The device can also be oriented in other directions, so that spatially relative terms can be interpreted according to orientation.

As used herein, the term "~ film" may be used to mean "~ sheet" and "~ plate".

Hereinafter, with reference to the accompanying drawings will be described embodiments of the present invention.

1 is a cross-sectional view of a reflective polarizer according to an embodiment of the present invention. Referring to FIG. 1, a reflective polarizer 10 according to an exemplary embodiment of the present invention may include a substrate 105, a liquid crystal layer 110 formed on one surface of the substrate 105, and a filler dispersed in the liquid crystal layer 110. And 150.

The substrate 105 supports the liquid crystal layer 110. Substrate 105 is a transparent material capable of transmitting light, for example, polycarbonate (poly carbonate), poly sulfone (poly sulfone), poly acrylate (poly acrylate), poly styrene (poly styrene), polyvinyl It may comprise a chloride (poly vinyl chloride), poly vinyl alcohol (poly vinyl alcohol), poly norbornene (poly norbornene), polyester (poly ester) material. For example, the substrate 105 may be made of polyethylene terephtalate, polyethylene naphthalate, or the like.

In some embodiments, a retardation film made of polycarbonate or the like may be applied as the substrate 105. In this case, the reflective polarizer 10 serves as a composite film which integrally performs the reflective polarization and the retardation compensation. In particular, when the retardation film is used as the base material 105 to form the liquid crystal layer 110 directly on one surface thereof, since the interposition of the adhesive can be omitted, the thickness of the reflective polarizer 10 is not only reduced, but also the interposition of the adhesive. The distortion of the light can be prevented.

In some embodiments substrate 105 is applied in the form of a rectangular plate. The thickness of the substrate 105 may be, for example, about 10 to 1000 μm, more specifically 25 to 600 μm. However, of course, the thickness of the substrate 105 is not limited to the above example.

In some other embodiments, the substrate 105 may be omitted. That is, the reflective polarizer 10 may be formed of only the liquid crystal layer 110 and the filler 150 dispersed in the liquid crystal layer 110.

The liquid crystal layer 110 is formed on one surface of the substrate 105. Although FIG. 1 illustrates a case in which the liquid crystal layer 110 is directly formed on one surface of the substrate 105, the liquid crystal layer 110 may be formed on the substrate 105 through an adhesive agent. Furthermore, another layer may be interposed between the liquid crystal layer 110 and the substrate 105.

The liquid crystal layer 110 includes a cholesteric liquid crystal (or chiral nematic liquid crystal). The cholesteric liquid crystal may include a nematic liquid crystal and a chiral dopant. Cholesteric liquid crystals have a constant pitch and have a spiral structure twisted repeatedly. Repeated twisted helical structure induces Bragg reflection of light.

Cholesteric liquid crystals are classified into right-handed cholesteric liquid crystals and left-handed cholesteric liquid crystals according to their spiral directions. Preferred cholesteric liquid crystals reflect right polarized light but transmit left polarized light. In contrast, the left cholesteric liquid crystal transmits right polarized light but reflects left circular polarized light. Therefore, in theory, the cholesteric liquid crystal transmits 50% of the light included in the wavelength range reflected by the cholesteric liquid crystal and reflects the remaining 50%.

The pitch (liquid crystal pitch) of the cholesteric liquid crystal is related to the wavelength of the reflected light. The central wavelength of the reflected light reflected by the cholesteric liquid crystal is generally proportional to the liquid crystal pitch. Here, when the reflected light reflected by the cholesteric liquid crystal has a predetermined band width, the center wavelength of the reflected light may mean a wavelength that is maximum reflected within the band width or an average wavelength of the band width. In addition, the bandwidth of the reflected light may mean a range of wavelengths capable of reflecting about 30% to about 70% of the incident light, preferably reflecting about 40% to about 60% of the incident light The range of wavelengths that can be used may mean a range of wavelengths that can more preferably reflect about 50% of incident light.

The liquid crystal layer 110 may include a plurality of liquid crystal pitch regions (“112” of FIG. 2) having different pitches of the cholesteric liquid crystal. As the liquid crystal layer 110 includes more liquid crystal pitch regions 112, its reflection band increases. In a preferred embodiment, the central wavelength of the reflected light of the maximum liquid crystal pitch region of the liquid crystal layer 110 is greater than or equal to the red wavelength, the central wavelength of the reflected light of the minimum liquid crystal pitch region is smaller than or equal to the blue wavelength, and the central wavelength of the reflected light of the liquid crystal pitch regions is It is distributed between the wavelengths of blue light and red light, respectively, and reflects the whole visible light area | region.

FIG. 2 is an enlarged view of the region A of FIG. 1 and illustrates an example in which a plurality of liquid crystal pitch regions of the liquid crystal layer are vertically disposed such that the liquid crystal pitch gradually decreases from the first surface on the substrate 105 side to the surface on the second surface. do.

In the embodiment of FIG. 2, the interval from the first liquid crystal pitch region to the first liquid crystal pitch region in contact with the substrate 105 has a central wavelength of reflected light of 650 nm to 780 nm, constituting the red light reflection band RR. In the section from the (l + 1) th liquid crystal pitch region to the mth liquid crystal pitch region, the center wavelength of the reflected light is 520 nm to 650 nm, which constitutes the green light reflection band GR. The section BR from the (m + 1) th liquid crystal pitch region to the last nth liquid crystal pitch region has a center wavelength of reflected light of 380 nm to 520 nm, constituting a blue light reflection band.

FIG. 3 is a schematic diagram illustrating a light propagation direction in the liquid crystal layer of FIG. 2 according to the present invention. FIG. In FIG. 3, the first light includes the left circularly polarized light of the first wavelength λ1 and the right circularly polarized light of the first wavelength λ1, and the second light includes the second wavelength λ2. The left circularly polarized light of (L) and the right polarized light (R) of the second wavelength (λ2) of the third light, and the third light (L3) of the left circularly polarized light (L) of the third wavelength (λ3) It is assumed to contain unidirectional polarized light R of [lambda] 3). In addition, it is assumed that the first wavelength λ1 is a wavelength of the red band, the second wavelength λ2 is a wavelength of the green band, and the third wavelength λ3 is a wavelength of the blue band.

In addition, it is assumed that all of the liquid crystal pitch regions 112 of the liquid crystal layer 110 are made of a preferential cholesteric liquid crystal for convenience of description. Of course, this is just one exemplary assumption, where each liquid crystal pitch region consists of a left cholesteric liquid crystal, or some liquid crystal pitch region consists of a preferential cholesteric liquid crystal and some liquid crystal pitch regions comprise a left cholesteric liquid. It may be made of Trek liquid crystal. In addition, even within the same liquid crystal pitch region, both the left linear cholesteric liquid crystal and the preferential cholesteric liquid crystal may be included.

Referring to FIG. 3, under the above assumption, the first light having the first wavelength λ1 incident on the liquid crystal layer 110 includes a liquid crystal pitch region having the wavelength as the center wavelength of the reflected light in the red light reflection band RR. The left circularly polarized light is transmitted through the center, but the right circularly polarized light is reflected. The cholesteric liquid crystals of the green light reflection band GR and the blue light reflection band BR not only take priority, but if not, the first wavelength lambda 1 is the wavelength of the red band in the home. The left circularly polarized light L of (λ1) is no longer reflected in the green light reflection band GR and the blue light reflection band BR, and passes through as it is.

Similarly, since the second light, which is the second wavelength λ2, is the wavelength of the green band, the red light reflection band RR is transmitted as it is, and light reaching the green circle reflection L is transmitted through the green light reflection band GR. , The right polarized light is reflected. The left circularly polarized light L having the second wavelength λ 2 transmitted through the green light reflection band GR passes through the blue light reflection band BR as it is.

In the same way, the third light of the third wavelength λ3 transmits both the red light reflection band RR and the green light reflection band GR, and reaches the blue light reflection band BR, where the left circularly polarized light L is applied. The light is transmitted, and the circularly polarized light is reflected.

Therefore, while the first light, the second light, and the third light pass through the red light reflection band RR, the green light reflection band GR, and the blue light reflection band BR, all of the left circle polarized light L All transmitted and right polarized light R is reflected. Assuming that the light is classified into left circularly polarized light and right circularly polarized light, and that they are the same, in conclusion, the first light, the second light, and the third light incident on the liquid crystal layer 110 are concluded. Only about 50% of silver is transmitted and the remaining about 50% is reflected.

4 to 6 are graphs showing transmittances according to wavelengths of light incident on a liquid crystal pitch region of a reflective polarizer according to an exemplary embodiment of the present invention. Specifically, FIG. 4 is a graph showing transmittance according to the wavelength of light incident on the red light reflection band RR, and the red light reflection band RR has a reflectance of about 50% within a wavelength range of 650 nm to 780 nm. Show that you have FIG. 5 is a graph showing the transmittance according to the wavelength of light incident on the green light reflection band GR. The green light reflection band GR has a reflectance of about 50% within a wavelength range of 520 nm to 650 nm. 6 is a graph showing the transmittance according to the wavelength of light incident on the blue light reflection band BR, which shows that the blue light reflection band BR has a reflectance of about 50% within a wavelength range of 380 nm to 520 nm.

7 is a graph showing transmittance according to wavelength of light incident on a liquid crystal layer of a reflective polarizer according to an exemplary embodiment of the present invention. Referring to FIG. 7, while the light incident on the liquid crystal layer 110 passes through the red light reflection band RR, the green light reflection band GR, and the blue light reflection band BR_, the wavelength of visible light is 380 nm. To 780 nm) and a reflectance of 50%.

In general, cholesteric liquid crystals do not have a wide bandwidth of reflected light, and thus, it is difficult to cover visible light waves with a single cholesteric liquid crystal. However, by forming a plurality of liquid crystal pitch regions 112 in the single liquid crystal layer 110, By having different reflected light bandwidths, it is possible to implement a predetermined reflectance for the visible light wave field.

In order to form sufficiently various liquid crystal pitch regions in the single liquid crystal layer 110, the thickness of the liquid crystal layer 110 may be about 1 to 100 μm. More preferably in the range of about 2-15 μm.

2 to 7 illustrate an example in which a plurality of liquid crystal pitch regions 112 of the liquid crystal layer 110 are vertically disposed such that the liquid crystal pitch gradually decreases from the first surface on the substrate 105 side to the surface on the second surface. Although described, the present invention is not limited thereto, and the liquid crystal pitch region may be disposed such that the liquid crystal pitch is reduced in the opposite direction or is random in the vertical direction.

In addition, although the case in which the reflective polarizer 10 has a reflectance of about 30% to about 70% with respect to the full-wavelength range of the visible light has been discussed, the present invention is not limited thereto, and some wavelengths or other wavelengths of the visible light are not limited thereto. Of light, for example, infrared, ultraviolet, X-rays, or the like, or may be adjusted to have a reflectance for high frequency, medium frequency, low frequency electromagnetic waves, and the like. In addition, the reflectance is not limited to the above range, and it is apparent that other various reflectances may be employed.

The method of forming the liquid crystal layer as described above may be referred to from the disclosure of Korean Patent Application No. 2008-0102601 filed by the present applicant, and the disclosure is incorporated and incorporated as fully disclosed herein.

Referring back to FIG. 1, the filler 150 is dispersed in the liquid crystal layer 110. The filler 150 is a different material from the liquid crystal molecules and may be particles such as beads inserted between the liquid crystal molecules. In addition, the filler 150 may include a material having a refractive index different from that of the cholesteric liquid crystal. Since the refractive index is different from that of the cholesteric liquid crystal, the filler 150 may itself serve as a diffusion unit.

The filler 150 is a monomer such as acrylic, styrene, nylon, melamine formaldehyde, propylene, ethylene, silicone, urethane, polymethyl (meth) acrylate, polybutyl (meth) acrylate, polycarbonate, and the like. Organic materials such as homopolymers or copolymers obtained by use, and inorganic materials such as antimony, tin, alumina, silica, zirconia, calcium carbonate, barium sulfate, titanium oxide, and the like.

Dispersion arrangement of the filler 150 may be achieved by using a mixture of cholesteric liquid crystal and filler in a predetermined ratio in the process of forming the liquid crystal layer 110, but is not limited thereto. In this case, the filler 150 may be randomly dispersed in the liquid crystal layer 110.

The filler 150 dispersed in the liquid crystal layer 110 forms a partially convex protruding surface PS2 on the surface of the reflective polarizer 10 to thereby improve visual visibility of the reflective polarizer 10 or to reflect the reflective polarizer 10. By fine-adjusting the reflectance for each liquid crystal pitch, the emitted light color is finely corrected. Formation of the protruding surface PS2 and the reflectance adjustment for each liquid crystal pitch may be performed at the same time by the filler 150, but only one may be made.

First, the visual visibility improvement of the reflective polarizer by the filler will be described with reference to FIGS. 8 to 13.

8-11 are partial cross-sectional views of reflective polarizers in accordance with some embodiments of the present invention. 12 is a photograph of a reflective polarizer prepared without dispersing a filler in the liquid crystal layer. FIG. 13 is a photograph of a reflective polarizer according to an embodiment of the present invention and is a photograph of a reflective polarizer manufactured by dispersing a filler in a liquid crystal layer. FIG.

8 to 11, in some embodiments, the surface of the reflective polarizer 10 may include a flat surface PS1 and a protruding surface PS2 that protrudes finely from the flat surface PS1. The protruding surface PS2 is formed by the filler 150.

For example, as shown in FIGS. 8 and 9, when the filler 150 is exposed from the surface of the liquid crystal layer 110, the surface of the liquid crystal layer 110 may be a flat surface (eg, the reflective polarizer 10). PS1, the surface of the exposed filler 150 constitutes the protruding surface PS2 of the reflective polarizer 10. As another example, as shown in FIGS. 10 and 11, although the filler 150 is surrounded by the liquid crystal layer 110, the area of the liquid crystal layer 110 surrounding the filler 150 is the filler 150. In the case of having a conformal structure, the surface of the liquid crystal layer 110 which is separated from the filler 150 constitutes the flat surface PS1 of the reflective polarizer 10, but the liquid crystal layer 110 around the filler 150 is formed. ) Forms a convex surface, thereby constituting the fine projecting surface PS2 of the reflective polarizer 10. In any case, the protruding surface PS2 of the reflective polarizer 10 is formed in the region where the filler 10 is located. Therefore, when the filler 150 is randomly disposed in the liquid crystal layer 110, the protruding surface PS2 of the reflective polarizer 10 is also randomly disposed between the flat surfaces PS1.

Theoretically, if the surface of the reflective polarizer 10 consists of only a single complete flat surface, no abnormal visual recognition phenomenon appears when viewed from the outside. However, in the actual manufacturing process, it is almost impossible to realize a complete single flat surface. When following a conventional manufacturing process, the surface of the reflective polarizer will comprise a plurality of flat surfaces, which are distinguished by rather fine steps. If the area of each of the flat surfaces divided by the steps is rather large and large enough to be visually discernible, these various flat surfaces are perceived as uneven spots. That is, the rainbow spot defect appears as shown in FIG.

Referring to FIG. 13, the filler 150 having a size of 100 μm or less is dispersed in the liquid crystal layer 110 to partially form the protruding surface PS2 on the surface of the reflective polarizer 10, even under the same process conditions. It was confirmed that the rainbow stain defect was not recognized. This is presumably because partial light scattering or light diffusion by the filler 150 or the protruding surface PS2 suppresses the visibility of the rainbow stain. That is, even in this case, although the surface of the reflective polarizer is not a complete single flat surface, but may be composed of a plurality of flat surfaces which are distinguished by fine steps, nevertheless, as a light scattering or light diffusing effect by the protruding surface PS2 Rainbow stains are presumed not to be visualized. In addition, since the filler 150 having a thickness of 100 μm or less was used, the height and size of the protruding surface PS2 were also small, so that the protruding surface PS2 was hardly visually recognized by the naked eye, and was recognized as a perfect flat surface.

In view of the above, the size of the filler 150 is preferably 100 μm or less. Since the nanoparticles may also be applied to the filler 150, the lower limit of the size of the filler 150 may be 0.001 μm. In some embodiments, nanoparticles applied as the filler 150 may aggregate together to form larger chunks as a whole.

More preferably, the size of the filler 150 may be 0.1 to 50 μm. More preferably, it may be 1 to 10㎛. The maximum height of the protruding surface PS2 from the flat surface PS1 will be generally smaller than the size of the pillar 150. In exemplary embodiments, the maximum protrusion height of the protruding surface PS2 may range from 0.001 μm to 100 μm. More preferably, the maximum protrusion height of the protruding surface PS2 may range from 0.1 μm to 50 μm.

In order to stably disperse the filler 150 in the liquid crystal layer 110, the size of the filler 150 may be 10 times or less than the thickness of the liquid crystal layer 110.

In addition, the size of the filler 150 for forming the protruding surface PS2 is preferably 0.0001 times or more relative to the thickness of the liquid crystal layer 110. More preferably, the size of the filler 150 may be 0.1 to 4 times the thickness of the liquid crystal layer 110.

The shape of the filler 150 for forming the protruding surface PS2 on the surface of the reflective polarizer 10 may be a spherical shape, an ellipsoid, a tetrahedron, a hexahedron, or a polygonal column such as a triangular pillar, a square pillar, a cylinder, an elliptical pillar, or the like. . However, the present invention is not limited thereto, and may be star-shaped, dumbbell-shaped or other amorphous form.

The content of the filler 150 dispersed in the liquid crystal layer 110, that is, the weight ratio of the filler to the cholesteric liquid crystal may be 0.1 to 20% by weight, preferably 0.5 to 10% by weight.

On the other hand, if the area where the protruding surface PS2 is formed is too large, the protruding surface PS2 itself may be visually recognized. Therefore, it is preferable to control the total area of the protruding surface PS2. In general, the total area of the protruding surface PS2 is controlled by the content of the filler 150. The total area of the exemplary protruding surface PS2 of the reflective polarizer 10 may be 0.01% to 10% of the total area of the flat surface PS1 of the reflective polarizer 10.

Subsequently, fine color correction of the reflective polarizer 10 by the filler 150 will be described.

The space occupied by the filler 150 in the liquid crystal layer 110 is a space in which the cholesteric liquid crystal is not arranged and is excluded from the liquid crystal pitch region 112 and does not reflect circularly polarized light. Therefore, as the dispersed filler 150 occupies each liquid crystal pitch region 112, the reflectance of the wavelength decreases. However, depending on the size, shape, and arrangement of the filler 150, the volume of the space occupied by the filler 150 for each liquid crystal pitch region of the liquid crystal layer 110 may be different, and thus, reflectance of a specific wavelength may be selectively selected. Can be reduced. Hereinafter, it will be described in more detail with a specific example.

FIG. 14 is a cross-sectional view of a reflective polarizer according to an exemplary embodiment of the present invention, in which a liquid crystal pitch region of the liquid crystal layer has substantially the same vertical arrangement as that of FIG. 2, and a filler dispersed in the liquid crystal layer is spherical.

In FIG. 14, the space in which the filler 150 occupies the liquid crystal pitch area of the red light reflection band RR adjacent to the substrate 105 is defined as the liquid crystal pitch area of the first space S1 and the green light reflection band GR. If the space occupying the second space S2 and the space occupying the liquid crystal pitch area of the blue light reflection band BR adjacent to the surface are defined as the third space S3, the size of the second space S2 among them is defined. Is maximum, and the first space S1 is minimum. Compared with the case where the filler 150 is not dispersed, although the volume of each reflection band RR, GR, BR is reduced, the red light reflection in which the filler 150 occupies the smallest first space S1 is relatively small. The band RR is reduced the least, and the green light reflection band GR is reduced the most. Accordingly, the reflective polarizer of FIG. 14 emits light having a relatively small green wavelength and a large red wavelength. That is, the light emitted by the reflective polarizer is finely adjusted so that the red system has a strong color as compared with the case where the filler 150 is not dispersed.

FIG. 15 is a cross-sectional view of a reflective polarizer according to another exemplary embodiment of the present invention, in which a liquid crystal pitch region of the liquid crystal layer has substantially the same vertical arrangement as that of FIG. 2, and a cross section of fillers dispersed in the liquid crystal layer is triangular. do. The filler having a triangular cross section may be, for example, a tetrahedral or triangular pillar-shaped filler.

In the same manner as in FIG. 14, when the space occupied by the fillers 150 for each reflection band (RR, GR, BR) in FIG. 15 is compared, the size of the first space S1 is the largest and the third space. The size of S3 becomes minimum. Therefore, in the present embodiment, the red light reflection band RR is reduced the most, and the blue light reflection band BR is reduced the least. Accordingly, the reflective polarizer of FIG. 15 emits light of a strong blue color, which has a relatively low red wavelength and a large blue wavelength, as compared with the case where the filler 150 is not dispersed.

16 is a cross-sectional view of a reflective polarizer according to another embodiment of the present invention, in which the liquid crystal pitch region of the liquid crystal layer has substantially the same vertical arrangement as that of FIG. 2, and the spherical filler dispersed in the liquid crystal layer is adjacent to the substrate side. The case where only a light reflection band is located is illustrated. Such a structure can be easily implemented by applying a spherical filler 150 having a smaller size than the size of the red light reflection band RR and having a specific gravity greater than that of the liquid crystal layer 110. However, it is not limited thereto.

Referring to FIG. 16, since the spherical filler 150 is located only in the red light reflection band RR, the actual size of the red light reflection band RR decreases, but the green light reflection band GR or the blue light reflection band. (BR) does not decrease in size. Therefore, only the red wavelength reflectivity is selectively reduced as compared with the case where the filler 150 is not dispersed, and the green or blue system emits light of strong color.

From the above embodiments, if the shape and arrangement of the filler 150 and the vertical arrangement of the liquid crystal pitch region 112 are modified, it may be understood that color fine correction by the filler 150 may be performed in various ways. . As described above, when the content of the filler 150 is 20% by weight or less of the cholesteric liquid crystal, overall decrease in luminance due to the dispersion of the filler 150 may be minimized.

On the other hand, the above embodiments mainly described the fine correction of the color for the light passing through the reflective polarizer 10 in the vertical direction, but in the same way of the off axis color (OAC) of the color viewed from the inclined angle Of course, fine correction is also possible. Depending on the shape or arrangement of the filler 150, it will be readily understood that the degree of fine correction in the vertical direction and the degree of fine correction in the inclined direction, wavelength, etc. may be different. When the off-axis color is selectively corrected, there is an advantage that the color correction film can be omitted.

As described above, the reflective polarizer 10 according to the exemplary embodiment of the present invention exhibits a predetermined reflectance for the full-wavelength range of the visible light even with a single liquid crystal layer 110, thereby reducing the thickness of the reflective polarizer, and thus the light transmittance. This can be improved. In addition, unlike the case of laminating in a multilayer, since there is no need to use an adhesive at all, it is possible to prevent the distortion of light and the decrease in light transmittance due to the interposition of the adhesive. In addition, the reflective polarizer 10 according to the exemplary embodiment of the present invention includes the filler 150 in the liquid crystal layer 110, whereby visual visibility is improved and color fine adjustment is possible.

17 is a cross-sectional view of a reflective polarizer according to another embodiment of the present invention.

Referring to FIG. 17, the reflective polarizer 100 according to the present exemplary embodiment includes a substrate 105, a liquid crystal layer 110 formed on one surface of the substrate 105, a filler 150 dispersed in the liquid crystal layer 110, And a plurality of embossed patterns 120 and diffusion units 160 formed on the other surface of the substrate 105.

Since the substrate 105, the liquid crystal layer 110, and the filler 150 are the same as those described with reference to FIGS. 1 to 16, redundant descriptions are omitted.

The embossed pattern 120 is close to or in close contact with another optical sheet (not shown), an optical plate (not shown), or a liquid crystal panel (not shown) to which the other surface of the reflective polarizer 100 substrate 105 is adjacent. When the friction occurs due to flow or the occurrence of friction, scratches are prevented from occurring on the other surface of the substrate 105 and / or other optical sheets, optical plates, liquid crystal panels, and the like. A more detailed description thereof will be described later.

The diffusion unit 160 is disposed in the interior of the embossed pattern 120. As the diffusion unit, for example, a homopolymer obtained by using monomers such as acrylic, styrene, melamine formaldehyde, propylene, ethylene, silicone, urethane, polymethyl (meth) acrylate, polybutyl (meth) acrylate, polycarbonate, etc. At least one of an organic material such as a polymer or a copolymer, or an inorganic material such as silica, zirconia, calcium carbonate, barium sulfate, titanium oxide, or the like may be applied.

In some exemplary embodiments, each emboss pattern 120 is independently formed in an island shape, and the neighboring emboss patterns 120 are spaced a predetermined distance D from each other.

18 to 21 are cross-sectional views illustrating various shapes of an embossed pattern. 18 to 21, the embossed pattern 120 may have a three-dimensional shape whose cross section is a semicircle (FIG. 18), a trapezoid (FIG. 19), and a triangle (FIG. 20). In some embodiments, as shown in FIG. 21, it may be formed in an amorphous three-dimensional shape. Irrespective of the specific shape of the embossed pattern 120, the width of the surface in which the embossed pattern 120 is in contact with the other surface of the base 105 is defined as the diameter R of the embossed pattern, and the embossed pattern 120 is referred to as the base 105. When the maximum protruding distance from the other surface of) is defined as the height h of the embossed pattern, the diameter R of the embossed pattern 120 is about 0.1 μm to 100 μm, and the height h of the embossed pattern 120 is About 0.05 μm to 50 μm.

The embossing pattern 120 may be formed of a transparent material, and may be advantageous in terms of light transmittance of the reflective polarizer 100.

In some embodiments of the present invention, the emboss pattern 120 has the same or similar hardness as other adjacent optical sheets, optical plates or liquid crystal panels to reduce scratching of other adjacent optical sheets, optical plates, liquid crystal panels, and the like. It may be made of a material having a. Here, having similar hardness includes, for example, a case where the difference in MOS hardness is within 1 range. Within this range of similar hardness, the scratch can be minimized even if the tip of the embossed pattern 120 is in contact with another adjacent optical sheet, optical plate, liquid crystal panel, or the like.

In some other embodiments, the embossed pattern 120 may be made of a material having a lower hardness than other adjacent optical sheets, optical plates, and liquid crystal panels. For example, when the reflective polarizer 100 is adjacent to another optical sheet, when the embossed pattern 120 of the reflective polarizer 100 is lower in hardness than other adjacent optical sheets, mutual friction occurs between the two sheets. Even if the contact surface of the embossed pattern 120 is to be ground, the surface of another adjacent optical sheet hardly scratches. Until the embossed pattern 120 is ground and all removed, the surface of the substrate 105 of the reflective polarizer 100 continues to be protected from scratches. In view of the above, the embossed pattern 120 may be made of a material having a MOS hardness of at least one lower than that of an adjacent optical sheet, preferably, a material having a low 1.5 or more, and more preferably a material having a low 2.0 or more.

Further, in some embodiments embossed pattern 120 may comprise a material having a friction coefficient of 0.35 or less. If the friction coefficient of the embossing pattern 120 is 0.35 or less, even if the tip of the embossing pattern 120 comes into contact with another adjacent optical sheet, optical plate, liquid crystal panel, or the like, when pressure is applied from the outside, it easily slips on the contact surface. Therefore, the occurrence of scratches can be minimized. As an example of satisfying the condition of the friction coefficient, the embossed pattern 120 may include a UV curable material and an additive.

Examples of applicable UV curable materials include reactive oligomers such as acrylics, urethanes, polyesters, silicones, esters, and the like, and monofunctional (meth) acrylate monomers or polyfunctional (di, tri) (meth) acrylate monomers. do. As said monofunctional (meth) acrylate or polyfunctional (meth) acrylate monomer, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, tetrahydrofurfuryl (meth), for example Acrylate, butoxy ethyl (meth) acrylate, ethyl diethylene glycol (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, phenoxyethyl (meth) acrylate, di Cyclopentadiene (meth) acrylate, polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, methyl triethylene diglycol (meth) acrylate, isobornyl (meth) acrylate, N-vinylpyrroli Don, N-vinyl caprolactam, diacetone acrylamide, isobutoxymethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, t-octyl (meth) acrylamide, di Methylaminoethyl (meth) acrylate, acryloylmorpholine, dicyclopentenyl (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) ) Acrylate, ethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,4-butanedioldi (meth) acrylate, 1,6-hexanediol Di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane trioxyethyl (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, dicyclodecane dimethanol di (meth) Acrylate, tripropylene glycol di (meth) acrylate, dicyclopentanedi (meth) acrylate, dicyclopentadienedi (meth) acrylate, and the like, It may be used alone or in mixture of the listed substances.

As the additive, a material having high lubricity may be applied. For example, at least one of a silicon based additive and a fluorine based additive may be applied. Specifically, a reactive monomer or a reactive oligomer having a silicone group (for example, a silicone group-containing vinyl compound, a silicone group-containing (meth) acrylate compound, a (meth) acryloxy group-containing organosiloxane, silicone polyacrylate) Etc.), a reactive monomer or reactive oligomer having a fluorine group (e.g., a fluoroalkyl group-containing vinyl compound, a fluoroalkyl group-containing (meth) acrylate compound, fluorine polyacrylate, etc.), a silicone group or a fluorine group A resin (for example, polydimethylsiloxane, a fluoropolymer, etc.), a surfactant having a silicone group or a fluorine group, an oil (for example, dimethyl silicone oil, etc.) may be applied alone or in combination.

The content ratio of the UV curable material and the additive may range from 100 parts by weight: 0.001 parts by weight to 100 parts by weight: 10 parts by weight, preferably 100 parts by weight: 0.01 parts by weight to 100 parts by weight: 5 parts by weight. .

The embossing pattern 120 may further include a photoinitiator in addition to the UV curable material and the additive. The photoinitiator is one or more free radical initiators selected from benzyl ketals, benzoin ethers, acetophenone derivatives, ketoxime ethers, benzophenones, benzo or thioxanthone compounds, onium salts, ferrocenium salts ( ferrocenium salts, and one or more cationic initiators selected from diazonium salts, or mixtures thereof.

Securing the light transmittance of the reflective polarizer 100, and the degree of adhesion prevention, antistatic and scratch prevention with other adjacent optical sheets, optical plates, and liquid crystal panels may be embossed with the constituent materials of the embossed pattern 120 described above. It depends on the shape, arrangement and the like of 120. Reference is made to FIGS. 22 to 26 for a more detailed description. For convenience of description, the illustration of the filler is omitted in FIGS. 22 to 26.

22 is a cross-sectional view illustrating a case in which reflective polarizers are directly stacked with other optical sheets according to some embodiments of the present disclosure. That is, FIG. 22 illustrates a case where another optical sheet is seated on the first seating end 81 of the mold frame 50 and the reflective polarizer 100 is directly stacked thereon.

When a plurality of embossed patterns 120 having appropriate heights are disposed at appropriate intervals on the lower surface of the substrate 105 of the reflective polarizer 100, as shown in FIG. 22, the upper surface of the other optical sheet 70 is flat. However, the optical sheet 70 and the reflective polarizer 100 only contact the embossed pattern 120 of the reflective polarizer 100, and the top surface of the optical sheet 70 and the substrate 105 of the reflective polarizer 100 are directly It does not contact and is spaced a predetermined distance apart. Therefore, although the optical sheet 70 and the reflective polarizer 100 are laminated sequentially, the whole surface does not adhere closely. As a result, static electricity between the optical sheet 70 and the reflective polarizer 100 can be prevented, and scratches on the surface of the reflective polarizer 100 substrate 105 can be prevented. In addition, as described above, when the embossed pattern 120 in contact with the top surface of the optical sheet 70 is made of a material having a friction coefficient of 0.35 or less, scratches of other adjacent optical sheets 70 may be reduced. In addition, if the area occupied by the embossed pattern 120 in the reflective polarizer 100 is minimized, a decrease in light transmittance may be minimized.

When the embossed pattern 120 is formed in the reflective polarizer 100, it is obvious that the face adhesion with the other optical sheet 70 is deteriorated. However, in order to sufficiently secure the anti-adherence reliability therebetween, the height and arrangement of the embossed pattern 120 Is preferably controlled appropriately. For example, when the reflective polarizer 100 and the optical sheet 70 have a large area in the example of FIG. 22, if the height of the embossed pattern 120 is too low, the top surface of the optical sheet 70 The likelihood that the substrate 105 of the reflective polarizer 100 is in close contact with each other will increase, and the anti-contact reliability will be lowered. Therefore, as described above, when the height h of the embossed pattern 120 is set within the range of about 0.05 μm to 50 μm, a high level of semi-adhesion reliability can be ensured. In some embodiments, the height h of the embossed pattern 120 is set in proportion to the thickness of the substrate 105. For example, the height h of the embossed pattern 120 may have a range of 0.0001 to 0.5 times the thickness of the substrate 105.

On the other hand, if the height h of the embossed pattern 120 is larger than the diameter R of the embossed pattern 120, there is a problem in the stability of the embossed pattern 120 itself, and the height h of the embossed pattern 120 In contrast, if the diameter R of the embossed pattern 120 is too large, the occupied area of the embossed pattern 120 with respect to the entire area of the substrate 105 is unnecessarily widened, thereby deteriorating light transmission characteristics. In consideration of these points, the ratio of the diameter R of the embossed pattern 120 to the height h of the embossed pattern 120 may be adjusted in a range of about 10: 1 to 1:10.

23 and 24 are bottom views for explaining an arrangement of an embossed pattern of the reflective polarizer of FIG. 22. In the embodiment of FIG. 23, the plurality of embossed patterns 120 are arranged at equal intervals at positions of a predetermined matrix. That is, FIG. 23 illustrates an example in which embossed patterns 120 are arranged on vertices of squares repeatedly arranged. In some other embodiments of the present invention, the plurality of embossed patterns 120 may be arranged in random order, as shown in FIG. 24.

However, if the distance D of the embossed pattern 120 is too large, the possibility that the upper surface of the adjacent optical sheet 70 and the substrate 105 of the reflective polarizer 100 is in close contact with each other increases, and thus the neighboring embossed pattern 120 The maximum spacing D of is preferably about 1000 µm or less. In addition, if the spacing D of the embossed pattern 120 is too narrow, the number of embossed patterns 120 per unit area increases, and thus the area occupied by the embossed pattern 120 becomes wide, thereby deteriorating light transmission characteristics. Therefore, the minimum spacing D of the embossed pattern 120 is preferably about 1 μm or more.

In addition, in consideration of light transmission characteristics, the area occupied by the embossed pattern 120 is preferably adjusted in the range of 0.001% to 95% of the total substrate 105 area, more preferably in the range of 0.01% to 10%. It is better to adjust at. Here, the occupied area of the embossed pattern 120 may be adjusted by the diameter of each embossed pattern, the number of embossed patterns, the spacing of the embossed patterns, the density of the embossed pattern, and the like.

On the other hand, in consideration of both the semi-adhesiveness and the light transmission characteristics, the average spacing (D) between the neighboring embossing pattern may be, for example, about 5㎛ to 500㎛.

25 is a cross-sectional view illustrating a case in which reflective polarizers are spaced apart from each other by an optical sheet according to some embodiments of the present disclosure. That is, in FIG. 25, another optical sheet 70 is seated on the first seating end 81 of the mold frame 80, and the reflective polarizer 100 is mounted on the second seating end 82 of the mold frame 80. The case where it is seated is illustrated.

Referring to FIG. 25, the optical sheet 70 and the reflective polarizer 100 have spaced apart from each other at approximately the thickness of the second seating end 82 at both sides. However, when the reflective polarizer 100 and the optical sheet 70 have a large area or when pressure in the horizontal direction is applied from the outside, the central portion of the optical sheet 70 and / or the reflective polarizer 100 may often be bent. As such, when the optical sheet 70 and / or the reflective polarizer 100 are bent, complete separation between the optical sheet 70 and the reflective polarizer 100 is difficult to ensure. For example, as shown in FIG. 14, the optical sheet 70 is normally kept flat, but the reflective polarizer 100 is convexly curved downward, so that the optical sheet 70 and the reflective polarizer 100 are in contact with each other at the center portion. This may occur. That is, even if the two sides are spaced apart and secured to different seating ends 81 and 82, such a seating mode does not cover even the center part.

An example of an embossed pattern 120 arrangement applicable to the seating aspect of FIG. 25 is shown in FIG. 26. Referring to FIG. 26, the embossed pattern 120 is disposed at different densities according to the center portion CP and both side portions SP that divide the substrate into 1/3. Since the center portion CP has a high possibility of contacting the neighboring optical sheet 70, the density of the embossed pattern 120 is high, while the side portions SP are spaced apart by the second seating end 82. Therefore, the density of the embossed pattern 120 may be relatively low. Although the density of the embossed pattern 120 may be constant within the same central portion CP, the density of the embossed pattern 120 may be increased toward the center line as shown in FIG. 25. In addition, in the case of both side portions SP, the closer to the center portion CP, the greater the density of the embossed pattern 120 may be disposed. In general, the embossed pattern 120 may be disposed to have a higher density as the center line is closer to the center line. In some other embodiments of the present invention, the embossed pattern 120 of both side portions SP may be omitted. Although the arrangement of the embossed pattern as in FIGS. 23 and 24 may also be applied to the seating aspect of FIG. 25, applying the arrangement of FIG. 26 may be advantageous in view of the overall light transmission characteristics of the reflective polarizer 100.

27 is a cross-sectional view of a reflective polarizer according to another embodiment of the present invention.

Referring to FIG. 27, in the present exemplary embodiment, the reflective polarizer 101 includes a substrate 105, a liquid crystal layer 110 formed on one surface of the substrate 105, fillers dispersed in the liquid crystal layer, and the other surface of the substrate 105. The adhesion preventing layer 125 formed in the contact unit, and the diffusion unit 160 dispersed in the adhesion preventing layer 125 is included. The substrate 105 and the liquid crystal layer 110 are the same as in the above-described embodiment, except that the diffusion unit 160 may also be dispersedly disposed in the adhesion preventing layer 125 instead of the emboss pattern 120. Therefore, duplicate description thereof will be omitted.

The other surface of the adhesion preventing layer 125 includes a reference surface 121 and a plurality of embossed pattern surfaces 122 protruding from the reference surface 121. The embossed pattern surface 122 of the adhesion preventing layer 125 has substantially the same function as the embossed pattern 120 described in the embodiments of FIGS. 17 to 26. Therefore, the shape of the embossed pattern surface 125, the protruding height of the embossed pattern surface 122 with respect to the reference plane 121 of the adhesion preventing layer 125, the arrangement of the embossed pattern surface 122, and the like are described above. The shape of the, the height of the embossed pattern 120 with respect to the substrate 105, the arrangement of the embossed pattern 120 is substantially the same. In addition, the adhesion preventing layer 125 including the embossed pattern surface 122 is made of a material substantially the same as the material of the embossed pattern 120.

28 to 30 are cross-sectional views of reflective polarizers according to still other embodiments of the present invention.

The reflective polarizers 103_1, 103_2, and 103_3 according to still another embodiment of the present invention employ the bead 130 instead of the emboss pattern 120 described with reference to FIGS. 17 to 26. That is, a plurality of beads 130 are formed on the other surface of the substrate 105 instead of the plurality of emboss patterns 120. Bead 130 may include, for example, at least one of organic beads and inorganic beads. Examples of the organic beads include homopolymers or copolymers obtained by using monomers such as acrylic, styrene, melamine formaldehyde, propylene, ethylene, silicone, urethane, methyl (meth) acrylate, polycarbonate, and the like. Examples of the inorganic beads include silica, zirconia, calcium carbonate, barium sulfate, titanium oxide, and the like. Since the beads 130 replace the role of the emboss pattern 120, the shape or arrangement of the beads 130 is substantially the same as that of the emboss pattern 120 described above.

The plurality of beads 130 are supported by the substrate 105 by the support coating film 140 of the substrate 105. The support coating layer 140 is formed on the other surface of the substrate 105 of the reflective polarizers 103_1, 103_2, and 103_3 to at least partially surround the beads 130. For example, the support coating layer 140 may be formed to surround the entire bead 130 as shown in FIG. 28, or may be formed to surround only a portion of the bead 130 as shown in FIG. 29. In addition, the support coating film 140 may be formed in a pattern shape to surround the bead 130, as shown in FIG.

The support coating film 140 may be, for example, a thermosetting resin or an epoxy acrylate resin, a urethane acrylate resin, a silicone acrylate resin, an acrylic acrylate and an ester acrylate such as an acrylic resin, a urethane resin, a polyester resin, or the like. It may be made by including an ultraviolet curable resin such as.

The diffusion unit 160 is substantially the same as the above-described embodiments except that the diffusion unit 160 is distributed and disposed inside the support coating layer 140.

As described above, the reflective polarizers according to the embodiments of the present invention may have a single liquid crystal layer and exhibit a predetermined reflectance with respect to the full-wavelength range of visible light. Thus, the thickness of the reflective polarizer is reduced, and the light transmittance can be improved. In addition, unlike the case of laminating in a multilayer, since there is no need to use an adhesive at all, it is possible to prevent the distortion of light and the decrease in light transmittance due to the interposition of the adhesive.

Embodiments having emboss patterns, beads, etc. on the other side of the substrate, in addition to the effects described above, may further be in close proximity or in close contact with neighboring optical sheets to generate static electricity, or may be applied to reflective polarizers or other optical sheets by friction caused by flow. It is effective in preventing scratches from occurring.

The reflective polarizer described above may be employed in a light source assembly or a liquid crystal display including the same, and used to enhance light efficiency. The light source assembly is classified into a direct type light source assembly in which the lamp is located at the bottom, an edge type light source assembly in which the lamp is located at the side, and the like. The reflective polarizer according to embodiments of the present invention may be employed in any kind of light source assembly. The present invention is also applicable to a back light assembly disposed below the liquid crystal panel or a front light assembly disposed above the liquid crystal panel. Hereinafter, as an example of various applications, a case in which a reflective polarizer according to an embodiment of the present invention is applied to a liquid crystal display including a direct type backlight assembly is illustrated.

31 is a cross-sectional view of a liquid crystal display according to an exemplary embodiment of the present invention.

Referring to FIG. 31, the liquid crystal display 600 includes a backlight assembly 300, a liquid crystal panel assembly 400, and a top chassis 500.

The backlight assembly 300 includes a lamp 310, a reflective film 315 that reflects light emitted from the lamp 310, and a diffuser plate 320 and optical films 330 that adjust optical characteristics of the emitted light. It includes.

The lamp 310 may be, for example, a Cold Cathode Fluorescent Lamp (CCFL), a Hot Cathode Fluorescent Lamp (HCFL), an External Electrode Fluorescent Lamp (EEFL), or the like.

A reflective film 315 is disposed below the lamp 310 to reflect light emitted downward from the lamp 310 upward.

The diffusion plate 320 and the optical films 230 are disposed on the lamp 310. The diffusion plate 320 diffuses the light incident from the lamp 310. Optical films 330 include a diffuser film that diffuses incident light, a prism sheet that collects incident light, a reflective polarizer that partially reflects incident circularly polarized light, a retardation film that converts circularly polarized light into linearly polarized light, and / Or a protective film. As the reflective polarizer, the reflective polarizer according to the embodiments of the present invention described above is applied. Accordingly, light utilization is maximized, visibility is improved, and color fine correction is possible. Further, when the reflective polarizer according to the embodiments of the present invention having the embossed pattern or the bead is applied, the adhesion and the proximity of neighboring optical sheets may be prevented, thereby reducing the static electricity or the scratch.

The lamp 310, the reflective film 315, the diffuser plate 320, and the optical films 330 are received by the bottom chassis 340 and the mold frame 350. The bottom chassis 340 forms the bottom surface of the backlight assembly 300, and a mold frame 350 having a window frame shape is disposed on the bottom chassis 340, and the light diffuser plate is disposed at a seating end provided in the mold frame 350. 320, the optical films 330 and the liquid crystal panel 410 are seated.

The liquid crystal panel assembly 400 includes a liquid crystal panel 410 including a first display panel 411, a second display panel 412, and a liquid crystal layer (not shown) interposed therebetween, the first display panel 411, and the second display panel 411. The polarizing plate 420 attached to the surface of the display panel 412, the data TCP (Tape Carrier Package) 430 attached to one side of the liquid crystal panel 310, and the printed circuit board 440 attached to the data TCP 430. ). On the data TCP 430, a data driver integrated circuit (IC) 431 is mounted. A gate TCP (not shown) is attached to the other side of the liquid crystal panel 410 adjacent to an attachment side of the data TCP 430, and a gate driver IC (not shown) is mounted on the gate TCP.

The top chassis 500 covers an edge of the liquid crystal panel 410 and surrounds side surfaces of the liquid crystal panel 410 and the backlight assembly 300. The data TCP 430, the printed circuit board 440, and the like are bent and received in a space between the side wall of the bottom chassis 340 and the side wall of the top chassis 500.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains may be embodied in other specific forms without changing the technical spirit or essential features of the present invention. I can understand that. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

The present invention is applicable to the display industry. However, it is not limited thereto.

Claims (18)

1. A liquid crystal layer comprising a cholesteric liquid crystal; And

   A reflective polarizer comprising a filler dispersed in the liquid crystal layer.
2. According to claim 1,

   And a surface of the reflective polarizer includes a flat surface and a projecting surface protruding from the flat surface.
3. The method of claim 2,

   The projecting surface is a reflective polarizer disposed randomly between the flat surface.
4. According to claim 1,

   The liquid crystal layer may include a plurality of liquid crystal pitch regions having different pitches of the cholesteric liquid crystal.
5. According to claim 1,

   The fillers are acrylic, styrene, nylon, melamine formaldehyde, propylene, ethylene, silicone, urethane, polymethyl (meth) acrylate, polybutyl (meth) acrylate, polycarbonate, antimony, tin, alumina, silica, zirconia, A reflective polarizer comprising at least one of calcium carbonate, barium sulfate, and titanium oxide.
6. According to claim 1,

   The filler is a reflective polarizer having a spherical shape, an ellipsoid, a tetrahedron, a hexahedron, a triangular pole, a square pole, a cylinder, an ellipse pole, a polygonal pole, or an amorphous shape.
7. According to claim 1,

   The size of the filler is a reflective polarizer of 0.0001 times to 10 times the thickness of the liquid crystal layer.
8. According to claim 1,

   The size of the filler is a reflective polarizer of 0.1 to 4 times the thickness of the liquid crystal layer.
9. According to claim 1,

   The filler is a reflective polarizer which is dispersed in an amount of 0.1 to 20% by weight relative to the liquid crystal layer.
10. According to claim 1,

    The liquid crystal layer includes a first liquid crystal pitch region having a first liquid crystal pitch and a second liquid crystal pitch region having a second liquid crystal pitch different from the first liquid crystal pitch,

    And a total volume of the filler occupying the first liquid crystal pitch region is greater than a total volume of the filler occupying the second liquid crystal pitch region.
11. According to claim 1,

    The liquid crystal layer is a single film,

    A reflective polarizer that reflects 30% to 70% of incident light at 380-780 nm.
12. According to claim 1,

    A reflective polarizer further comprising a transparent substrate on which one side of the liquid crystal layer is formed.
13. The method of claim 12,

    Reflective polarizer further comprises a bead supported by an embossed pattern or a support coating film formed on the other surface of the substrate.
14. The method of claim 13,

    The embossed pattern or the support coating film is a reflective polarizer comprising a diffusion unit.
15. The method of claim 12,

    The substrate is a reflective polarizer which is a retardation film.
16. A liquid crystal layer comprising a cholesteric liquid crystal; And

    As a reflective polarizer comprising a filler dispersed in the liquid crystal layer,

    The surface of the reflective polarizer is randomly disposed between the flat surface and the flat surface, and includes a protruding surface protruding from the flat surface,

    And a maximum projecting height from which the projecting surface protrudes from the flat surface is 0.001 µm to 100 µm.
17. A light source assembly comprising a reflective polarizer according to any one of claims 1 to 16.
18. A liquid crystal display device comprising the reflective polarizer according to any one of claims 1 to 16.

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