Polarizing plate and optical display device including the same

Abstract

A polarizing plate and an optical display device including the same are disclosed. The polarizing plate includes a polarizer and a pattern layer disposed on the upper surface of the polarizer. The pattern layer includes a first resin layer, wherein the first resin layer has one or more gravure patterns formed on its lower surface. The gravure pattern has a side, and a first surface and a second surface having different bottom angles relative to the maximum width of the gravure pattern are continuously formed on the side. The first surface and the second surface satisfy Formula 1, and when h1 is a height projected on the first surface and h2 is a height projected on the second surface, in the maximum height of the gravure pattern, h1 and h2 satisfy Formula 2.

Description

Technical Field

[0001] The present invention relates to a polarizing plate and an optical display device including the same. More specifically, the present invention relates to a polarizing plate and an optical display device including the same, and when the polarizing plate is applied to the optical display device, the polarizing plate can significantly improve the lateral contrast, the ratio of lateral brightness to front brightness, and the lateral viewing angle. Background Art

[0002] The liquid crystal display includes an observer-side polarizing plate disposed on one surface of a liquid crystal panel and a light source-side polarizing plate disposed on the other surface thereof. The observer-side polarizing plate is formed with a pattern layer having a predetermined pattern to improve lateral contrast while expanding a viewing angle.

[0003] In this regard, there is a method of providing a pattern having a trapezoidal, rectangular or square cross-sectional shape. However, this method has limitations in improving contrast, viewing angle and brightness ratio at the lateral side.

[0004] The background art of the present invention is disclosed in Korean Patent Publication No. 10-2014-0108974. Summary of the invention

[0005] Technical issues

[0006] One embodiment of the present invention is to provide a polarizing plate that can significantly improve lateral contrast, ratio of lateral brightness to front brightness, and lateral viewing angle.

[0007] Another embodiment of the present invention is to provide a polarizing plate capable of improving the suppression of the moire phenomenon.

[0008] Technical Solution

[0009] One embodiment of the present invention relates to a polarizing plate.

[0010] 1. The polarizing plate comprises: a polarizer; and a pattern layer disposed on the upper surface of the polarizer, wherein the pattern layer comprises a first resin layer, the first resin layer having at least one engraved pattern with a lateral side formed on its lower surface, the lateral side having a first facet and a second facet continuous with the first facet, the first facet and the second facet having different bottom angles relative to the maximum width of the engraved pattern, and satisfying relations 1 and 2:

[0011] [Relation 1]

[0012] θ1>θ2,

[0013] Wherein, in Relation 1, θ1 represents the bottom angle of the first facet, θ2 represents the bottom angle of the second facet, about 70°≤θ1≤about 90°, about 0°<θ2<about 90°; and

[0014] [Relation 2]

[0015] about 0.5≤h1 / (h1+h2)<about 1.0,

[0016] In equation 2, h1 represents the projection height of the first facet projected on the maximum height of the engraved pattern, and h2 represents the projection height of the second facet projected on the maximum height of the engraved pattern.

[0017] 2. In 1, the engraved pattern may have an aspect ratio greater than about 1.0.

[0018] 3. In 1 and 2, the engraved pattern may have a (θ1-θ2) value greater than about 0° but not more than about 20°.

[0019] 4. In 1 to 3, h1 / (h1+h2) represented by Relation 2 may be in the range of about 0.5 to about 0.9.

[0020] 5. In 1 to 4, the engraved pattern may include a third facet formed at a top portion thereof and the lateral side connected to the third facet, and the third facet may be a flat surface.

[0021] 6. In 5, the first facet may be closer to the separation surface or the third facet than the second facet.

[0022] 7. In 1 to 6, the lateral surface may have no facets having the same base angle.

[0023] 8. In 1 to 7, each of the first facet and the second facet may be a flat surface or a curved surface.

[0024] 9. In 1 to 8, the maximum width of the first region of the engraved pattern having the first facets at both lateral sides thereof may be about 1.1 to about 3 times the maximum width of the second region of the engraved pattern having the second facets at both lateral sides thereof.

[0025] 10. In 1 to 9, the engraved pattern may have a longitudinal direction inclined at an angle of about -20° to about +20° with respect to an absorption axis of the polarizer.

[0026] 11. In 1 to 10, the pattern layer may further include a filling portion partially filling at least a portion of the engraved pattern, or a second resin layer on which the filling portion is formed.

[0027] 12. In 11, the first resin layer may have a smaller refractive index than the filling portion or the second resin layer.

[0028] 13. In 11, the first resin layer may have a higher refractive index than the filling portion or the second resin layer.

[0029] 14. In 11, an absolute value of a refractive index difference between the second resin layer or the filling portion and the first resin layer may be about 0.3 or less.

[0030] 15. In 11, the second resin layer may be an adhesive layer.

[0031] 16. In 5, the minimum distance between the third facet and the upper surface of the first resin layer may be in the range of about 0 micrometers to about 10 micrometers.

[0032] 17. In 1 to 16, the first resin layer may further include a separation surface between adjacent engraving patterns.

[0033] 18. In 1 to 17, the polarizing plate may further include a protective layer formed on an upper surface of the first resin layer.

[0034] 19. In 1 to 18, the engraved pattern may be composed of the first facet adjacent to the separation surface on the lower surface of the first resin layer, the second facet continuous with the first facet, and the third facet formed at its top portion continuous with the second facet.

[0035] 20. In 1 to 19, the engraved pattern may be composed of the second facet adjacent to the separation surface on the lower surface of the first resin layer, the first facet continuous with the second facet, and the third facet formed at its top portion continuous with the first facet.

[0036] An optical display device may include the polarizing plate according to the present invention.

[0037] Beneficial effects

[0038] The present invention provides a polarizing plate which can significantly improve the contrast at the lateral side, the ratio of lateral brightness to front brightness, and the lateral viewing angle.

[0039] The present invention provides a polarizing plate capable of improving the suppression of the moire phenomenon. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 FIG. 4 is a cross-sectional view of a polarizing plate according to an embodiment of the present invention.

[0041] Figure 2 for Figure 1Cross-sectional view of the engraved pattern of the polarizing plate shown.

[0042] Figure 3 FIG. 4 is a cross-sectional view of an engraved pattern of a polarizing plate according to another embodiment of the present invention.

[0043] Figure 4 is a cross-sectional view of a polarizing plate according to a further embodiment of the present invention.

[0044] Figure 5 for Figure 4 A conceptual diagram of the bottom angle of the present invention.

[0045] Figure 6 FIG. 4 is a cross-sectional view of a polarizing plate according to another embodiment of the present invention.

[0046] Figure 7 for Figure 6 Conceptual diagram of the mid-base angle (θ1, θ2). DETAILED DESCRIPTION

[0047] Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the present invention can be implemented in different ways and is not limited to the following embodiments. The following embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can thoroughly understand the present invention. Although the length, thickness or width of various components may be exaggerated in the accompanying drawings for understanding, the present invention is not limited thereto. Throughout the specification, the same components will be indicated by the same reference numerals.

[0048] In this document, spatially relative terms such as "upper" and "lower" are defined with reference to the accompanying drawings. Therefore, it should be understood that the term "upper surface" can be used interchangeably with the term "lower surface", and when an element such as a layer or film is said to be placed "on" another element, the element can be placed directly on the other element, or there can be intervening elements. On the other hand, when an element is said to be placed "directly" "on" another element, there are no intervening elements therebetween.

[0049] In this document, the terms "horizontal direction" and "vertical direction" refer to the longitudinal direction and the lateral direction of the rectangular screen of the liquid crystal display, respectively. In addition, on the screen of the liquid crystal display, the "lateral" side refers to (0°, 30°) or (0°, 60°) in a spherical coordinate system represented by (φ, θ), in which the front side is indicated by (0°, 0°), the left end point is indicated by (180°, 90°), and the right end point is indicated by (0°, 90°) with the horizontal direction as the reference.

[0050] Herein, the “bottom angle” of a first facet of an engraved pattern means an angle defined between the first facet constituting a lateral side of the engraved pattern and the maximum width of the engraved pattern or a surface of the engraved pattern parallel thereto.

[0051] Herein, the “bottom angle” of the second facet of the engraved pattern means an angle defined between the second facet constituting a lateral side of the engraved pattern and the maximum width of the engraved pattern or a surface of the engraved pattern parallel thereto.

[0052] Herein, a "base angle" is defined as an angle of 90° or less.

[0053] Herein, "top portion" refers to the highest point of the engraved pattern.

[0054] Herein, "aspect ratio" refers to the ratio of the maximum height of a pattern to its maximum width (maximum height / maximum width).

[0055] Herein, "pitch" means the sum of distances between adjacent engraved patterns, for example, the sum of the maximum width of one engraved pattern and the maximum width of a separation surface.

[0056] Herein, "in-plane retardation (Re)" is a value measured at a wavelength of 550 nanometers and is represented by Equation A:

[0057] [Formula A]

[0058] Re=(nx-ny)×d,

[0059] In equation A, nx and ny are the refractive indices of the corresponding protective layer on the slow axis and the fast axis at a wavelength of 550 nanometers, respectively, and d is the thickness of the protective layer (unit: nanometer).

[0060] Herein, the term "(meth)acrylic group" refers to acrylic group and / or methacrylic group.

[0061] The expression "X to Y" used herein to express a specific numerical range means "X ≤ and ≤ Y".

[0062] The polarizing plate according to the present invention comprises: a polarizer; and a pattern layer arranged on the upper surface of the polarizer, wherein the pattern layer comprises a first resin layer, and the first resin layer is formed with at least one engraved pattern having a lateral side on its lower surface, the lateral side having a first facet and a second facet continuous with the first facet, the first facet and the second facet have different bottom angles relative to the maximum width of the engraved pattern or a plane parallel thereto, and satisfy relations 1 and 2:

[0063] [Relation 1]

[0064] θ1>θ2,

[0065] Wherein in relation 1, θ1 represents the bottom angle of the first facet, θ2 represents the bottom angle of the second facet,

[0066] About 70°≤θ1≤about 90°, and about 0°<θ2<about 90°.

[0067] [Relation 2]

[0068] About 0.5≤h1 / (h1+h2)<about 1.0.

[0069] In equation 2, h1 represents the projection height of the first facet projected on the maximum height of the engraved pattern, and h2 represents the projection height of the second facet projected on the maximum height of the engraved pattern.

[0070] In the polarizing plate according to the present invention, the lateral side of the engraved pattern includes a first facet and a second facet that are continuous with each other and have different bottom angles, which is different from the typical engraved pattern having a completely flat lateral side or a curved lateral side in the related art. In addition, among the first facet and the second facet of the polarizing plate according to the present invention, the facet having a larger bottom angle than the other facet has a projection height that is the same as or larger than the other facet having a smaller bottom angle at the maximum height of the engraved pattern. With such a structure, the polarizing plate according to the present invention can significantly improve the viewing angle and contrast at its lateral side and the ratio of the lateral brightness to the front brightness on the screen of the liquid crystal display.

[0071] Preferably, in the first facet and the second facet, the projection height of the facet having a larger bottom angle than another facet at the maximum height of the engraved pattern may be greater than the projection height of another facet having a smaller bottom angle. That is, the first facet and the second facet satisfy the relationship 2: about 0.5

[0072] Below, we will refer to Figure 1 A polarizing plate according to an embodiment of the present invention will be described.

[0073] refer to Figure 1 The polarizing plate includes a polarizer 400 , a second resin layer 200 , a first resin layer 100 and a protective layer 500 .

[0074] In the polarizing plate, the second resin layer 200, the first resin layer 100, and the protective layer 500 are sequentially stacked on the upper surface of the polarizer 400. The first resin layer 100 and the second resin layer 200 constitute the pattern layer 300.

[0075] The upper surface of the polarizer 400 may be a light incident surface or a light emitting surface of the polarizer, preferably a light emitting surface of the polarizer.

[0076] First resin layer

[0077] The first resin layer 100 is formed on the light exiting surface of the polarizer 400 , and allows the light having passed through the polarizer to exit therethrough. ​

[0078] The first resin layer 100 is formed with at least one engraved pattern 110 and a separation surface 120 disposed between adjacent engraved patterns on its lower surface. With the engraved pattern described below, the first resin layer 100 can significantly improve the viewing angle and contrast on the screen of the liquid crystal display at the lateral side of the polarizing plate. "Engraved pattern" means a convex pattern formed on the lower surface of the pattern layer 300 and protruding toward the protective layer 500.

[0079] refer to Figure 2 , the engraving pattern will be elaborated in detail.

[0080] The engraved pattern 110 is composed of a third facet 115 formed at a top portion thereof and a lateral side connected to the third facet 115. For ease of explanation, the surface formed at the top portion of the engraved pattern 110 is referred to as a third facet. The "lateral side" means the entire surface portion of the engraved pattern disposed between the top portion (specifically, the third facet) and the separation surface to connect the top portion to the separation surface.

[0081] The engraved pattern may have an aspect ratio of about 1.0 or greater than about 1.0. Preferably, the engraved pattern has an aspect ratio greater than about 1.0. Within this range, the engraved pattern can significantly improve the viewing angle and contrast on the screen of the liquid crystal display at the lateral side of the polarizing plate. Preferably, the engraved pattern has an aspect ratio of about 1.5 or greater than about 1.5, more preferably about 1.5 to about 3.0, about 2.0 to about 3.0, thereby significantly improving the viewing angle and contrast at the lateral side of the polarizing plate. For example, the engraved pattern may have an aspect ratio of about 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, or 3.0.

[0082] The lateral side of the engraved pattern may include a first facet 111 and a second facet 112 continuous with the first facet 111. Each of the first facet and the second facet may be a flat surface or a curved surface. Figure 1 The first facet and the second facet are both flat surfaces. The curved surface may be Figure 4 The convex surface shown or Figure 6 Concave surface shown.

[0083] In one embodiment, the lateral side of the engraved pattern may consist of a first facet and a second facet. In this embodiment, the first facet 111 may be directly connected to the separation surface 120 , and the second facet 112 may be directly connected to the third facet 115 .

[0084] In another embodiment, the lateral side of the engraved pattern includes a first facet, a second facet, and a connecting facet, wherein the connecting facet connects the first facet or the second facet to the separation surface or the third facet. The connecting surface may be a curved surface or a flat surface, but is not limited thereto. In one embodiment, the lateral side of the engraved pattern may not have facets with the same bottom angle.

[0085] The first facet 111 and the second facet 112 have different bottom angles relative to the maximum width W1 of the engraved pattern or a plane parallel thereto, and satisfy relations 1 and 2:

[0086] [Relation 1]

[0087] θ1>θ2,

[0088] Wherein in Relation 1, θ1 represents the bottom angle of the first facet, θ2 represents the bottom angle of the second facet, about 70°≤θ1≤about 90°, and about 0°<θ2<about 90°; and

[0089] [Relation 2]

[0090] about 0.5≤h1 / (h1+h2)<about 1.0,

[0091] In relational expression 2, h1 represents the projection height of the first facet 111 projected on the maximum height H of the engraved pattern 110 , and h2 represents the projection height of the second facet 112 projected on the maximum height H thereof.

[0092] Herein, "projection height" means the height of the projection, e.g. Figure 2 The height of the first facet 111 corresponds to the height of the maximum height H of the engraved pattern.

[0093] The first facet and the second facet having different bottom angles are continuously formed on the lateral side of the engraved pattern. When the bottom angle of the first facet is greater than the bottom angle of the second facet, the bottom angle θ1 of the first facet is within the range of about 70°≤θ1≤about 90°, and the projection height of the first facet projected on the maximum height of the engraved pattern can be about 0.5 times to less than about 1.0 times the entire projection height (of the first facet and the second facet) on the maximum height of the engraved pattern, thereby significantly improving the viewing angle and contrast at the lateral side of the engraved pattern.

[0094] Therefore, according to the present invention, instead of the first facet and the second facet having the same bottom angle and being arranged parallel to each other to form a plane, facets with different bottom angles are formed on the lateral sides of the engraved pattern to affect the traveling direction of the light emitted from the engraved pattern passing through the polarizer, and to control all the bottom angles, the projection heights and the aspect ratios of the facets with different bottom angles to achieve the advantageous effects of the present invention.

[0095] Each of the first facet 111 and the second facet 112 may be a flat surface, which facilitates the formation of an engraved pattern. However, at least one of the first facet and the second facet may be a curved surface or a flat surface having a curved surface formed on at least a portion thereof. This structure will be described in detail.

[0096] The first facet 111 may be closer to the separation surface 120 than the second facet 112 .

[0097] The first facet 111 may have a base angle (angle θ1) of about 70° to about 90°, more preferably about 75° to about 90°, or about 80° to about 85°. Within this range, the engraved pattern can help improve contrast and viewing angle and can be easily formed. For example, the first facet 111 may have a base angle θ1 of about 70°, 71°, 72°, 73°, 74°, 75°, 76°, 77°, 78°, 79°, 80°, 81°, 82°, 83°, 84°, 85°, 86°, 87°, 88°, 89°, or 90°.

[0098] The second facet 112 may have a bottom angle θ2 greater than about 0° to less than about 90° (about 0°<θ2<about 90°), more preferably about 60° to about 80°, about 70° to about 80°, or about 70° to about 75°. Within this range, the engraved pattern may help improve contrast and viewing angle, and may be easily formed. For example, the second facet 112 may have a depth of about 0.01°, 0.1°, 0.5°, 1°, 2°, 3°, 4°, 5°, 6°, 7°, 8°, 9°, 10°, 11°, 12°, 13°, 14°, 15°, 16°, 17°, 18°, 19°, 20°, 21°, 22°, 23°, 24°, 25°, 26°, 27°, 28°, 29°, 30°, 31°, 32°, 33°, 34°, 35°, 36°, 37°, 38°, 39°, 40°, 41°, 42°, 43°, 44°, 45°, 46°, 47°, 48°, 49°, 50°, 51°, 52°, 53°, 54°, 55°, 56°, 57°, 58°, 59°, 60°, 61°, 62°, 63°, 64°, 65°, 66°, 67°, 68°, 69°, 70°, 71°, 72°, 73°, 74°, 75°, 76°, 77°, 78°, 79°, 80°, 81°, 82°, 83°, 84°, 85°, 86°, 87°, 88°, 89°, 90°, 91°, 92°, 93°, 94°, 95°, 96° , 46°, 47°, 48°, 49°, 50°, 51°, 52°, 53°, 54°, 55°, 56°, 57°, 58°, 59°, 60°, 61°, 62°, 63°, 64°, 65°, 66°, 67°, 68°, 69°, 70°, 71°, 72°, 73°, 74°, 75°, 76°, 77°, 78°, 79°, 80°, 81°, 82°, 83°, 84°, 85°, 86°, 87°, 88°, 89°, 89.5°, 89.9° or 89.99° of the base angle θ2.

[0099] In the engraved pattern, θ1-θ2 may be greater than about 0° but not more than about 20° (about 0°<θ1-θ2≤about 20°), specifically about 5° to about 15°. Within this range, the engraved pattern can improve the contrast at the lateral side of the polarizing plate. For example, θ1-θ2 may be about 0.1°, 0.5°, 1°, 2°, 3°, 4°, 5°, 6°, 7°, 8°, 9°, 10°, 11°, 12°, 13°, 14°, 15°, 16°, 17°, 18°, 19° or 20°.

[0100] In the engraved pattern, h1 / (h1+h2) represented by relation 2 may be in the range of about 0.5 to less than about 1.0, thereby helping to improve the contrast and viewing angle on the screen of the liquid crystal display. Preferably, h1 / (h1+h2) is in the range of about 0.5 to about 0.9, about 0.6 to about 0.8, or about 0.7 to about 0.8, thereby being able to easily adjust the thickness of the pattern layer while improving the suppression of the moire phenomenon.

[0101] For example, h1 / (h1+h2) may be approximately 0.5, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.60, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67, 0.68, 0.69, 0.70, 0.71, 0.72, 0. 73, 0.74, 0.75, 0.76, 0.77, 0.78, 0.79, 0.80, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98 or 0.99.

[0102] In Relation 2, h1 may be in the range of about 5 microns to about 20 microns, preferably about 10 microns to about 20 microns, and h2 may be in the range of about 1 micron to about 10 microns, preferably about 4 microns to about 8 microns. Within this range, the engraved pattern can satisfy Relation 2 and can be easily formed. For example, in Relation 2, h1 may be about 5 microns, 6 microns, 7 microns, 8 microns, 9 microns, 10 microns, 11 microns, 12 microns, 13 microns, 14 microns, 15 microns, 16 microns, 17 microns, 18 microns, 19 microns, or 20 microns. For example, in Relation 2, h2 may be about 1 micron, 2 microns, 3 microns, 4 microns, 5 microns, 6 microns, 7 microns, 8 microns, 9 microns, or 10 microns.

[0103] The engraved pattern may have a maximum height H of about 5 microns to about 25 microns, preferably about 10 microns to about 20 microns. Within this range, the engraved pattern can easily achieve the aspect ratio according to the present invention, and can easily satisfy Relation 2. For example, the engraved pattern may have a maximum height H of about 5 microns, 6 microns, 7 microns, 8 microns, 9 microns, 10 microns, 11 microns, 12 microns, 13 microns, 14 microns, 15 microns, 16 microns, 17 microns, 18 microns, 19 microns, 20 microns, 21 microns, 22 microns, 23 microns, 24 microns, or 25 microns.

[0104] The ratio ((h1+h2) / H) of (h1+h2) to the maximum height H of the engraved pattern may be in the range of about 0.5 to about 1.0, preferably about 0.6 to about 1.0, and more preferably about 0.9 to about 1.0. Within this range, the polarizing plate can achieve a reduction in the thickness of the pattern layer while improving its contrast and viewing angle. For example, ((h1+h2) / H) may be about 0.5, 0.6, 0.7, 0.8, 0.9 or 1.0.

[0105] The engraved pattern may have a maximum width W1 of about 5 microns to about 20 microns, preferably about 8 microns to about 15 microns. Within this range, the engraved pattern can easily achieve the aspect ratio according to the present invention. For example, the engraved pattern may have a maximum width W1 of about 5 microns, 6 microns, 7 microns, 8 microns, 9 microns, 10 microns, 11 microns, 12 microns, 13 microns, 14 microns, 15 microns, 16 microns, 17 microns, 18 microns, 19 microns or 20 microns.

[0106] The engraved pattern may have a bi-symmetrical structure, but is not limited thereto, and both the first facet and the second facet may be formed on each of both lateral sides of the engraved pattern.

[0107] The engraved pattern may include a first region 113 and a second region 114 adjoining each other on each of its two lateral sides, wherein the first region 113 includes a first facet and the second region 114 includes a second facet.

[0108] The first region 113 may have a maximum width W1 that is the same as the maximum width W1 of the engraved pattern 110, and the second region 114 may have a maximum width W2 of about 3 microns to about 15 microns, preferably about 4 microns to about 15 microns. Within this range, the engraved pattern can easily achieve the aspect ratio according to the present invention. For example, the second region 114 may have a maximum width W2 of about 3 microns, 4 microns, 5 microns, 6 microns, 7 microns, 8 microns, 9 microns, 10 microns, 11 microns, 12 microns, 13 microns, 14 microns, or 15 microns.

[0109] The ratio (h1 / W1) of the projection height h1 to the maximum width W1 of the first region 113, i.e., the aspect ratio of the first region 113, can be in the range of about 1 to about 3, specifically about 1.1 to about 3, about 1.1 to about 2, and the ratio (h2 / W2) of the projection height h2 to the maximum width W2 of the second region 114, i.e., the aspect ratio of the second region 114, can be in the range of about 0.1 to about 1, specifically about 0.3 to about 1, more specifically about 0.3 to about 0.9. Within this range, the engraved pattern can improve the contrast at the lateral side of the polarizing plate.

[0110] For example, the ratio (h1 / W1) can be about 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.8, 2.8, 2.9, or 3.0. For example, the ratio (h2 / W2) can be about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.0.

[0111] The maximum width W1 of the first region 113 can be about 1.1 times to about 3 times, specifically about 1.3 times to about 3 times, the maximum width W2 of the second region 114. Within this range, the engraved pattern can further improve the contrast on the screen of the liquid crystal display at its lateral side. For example, the maximum width W1 of the first region 113 can be about 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, or 3.0 times the maximum width W2 of the second region 114.

[0112] The third facet 115 formed at the top portion of the engraved pattern allows the vertical component of the light that has passed through the polarizer to pass through it, thereby improving the front contrast and brightness. The third facet can be parallel to the maximum width of the engraved pattern or the separation surface and can be a flat surface. As another option, the third facet can have roughness formed on its surface.

[0113] The third facet 115 can have a width W3 greater than about 0 microns but not exceeding about 10 microns (about 0 microns < W3 ≤ about 10 microns), preferably about 2 microns to about 8 microns. Within this range, the third facet can improve the front contrast and brightness of the polarizing plate. For example, the third facet 115 can have a width W3 of about 0.1 microns, 0.5 microns, 1 micron, 2 microns, 3 microns, 4 microns, 5 microns, 6 microns, 7 microns, 8 microns, 9 microns, or 10 microns.

[0114] The engraved pattern may be composed of the third facet, the first facet, and the second facet to have a bisymmetrical hexagonal cross-sectional shape. However, it should be understood that the engraved pattern may have any cross-sectional shape as long as the engraved pattern includes the first facet and the second facet. For example, the engraved pattern may have an N-gonal shape (N is an integer of 6 to 20), such as an octagonal shape, a decagonal shape, etc.

[0115] In one embodiment, the engraved pattern is composed of a first facet 111 adjacent to the separation surface 120 on the lower surface of the first resin layer, a second facet 112 continuous with the first facet 111, and a third facet 115 formed at its top portion continuous with the second facet 112.

[0116] Reference again Figure 1 The first resin layer may include one or more engraved patterns formed on its lower surface. The engraved patterns may have the same or different bottom angles, maximum heights, shapes, etc.

[0117] although Figure 1 Although not shown in the figure, the engraved pattern may have a strip shape extending in its longitudinal direction. Herein, the "longitudinal direction of the engraved pattern" means a vertical direction relative to the maximum width direction of the engraved pattern. However, the engraved pattern may be arranged in a dot shape. The "dot" shape means that the engraved pattern is dispersed.

[0118] The longitudinal direction of the engraved pattern 110 may be inclined at an angle of about -20° to about +20°, for example, at an angle of about -5° to about +5°, or at an angle of about 0° relative to the absorption axis (0°) of the polarizer 400 (machine direction (MD) of the polarizer). Within this range, the engraved pattern 110 can improve the suppression of the moire phenomenon. For example, the longitudinal direction of the engraved pattern 110 may be inclined at an angle of approximately -20°, -19°, -18°, -17°, -16°, -15°, -14°, -13°, -12°, -11°, -10°, -9°, -8°, -7°, -6°, -5°, -4°, -3°, -2°, -1°, 0°, +1°, +2°, +3°, +4°, +5°, +6°, +7°, +8°, ​​+9°, +10°, +11°, +12°, +13°, +14°, +15°, +16°, +17°, +18°, +19° or +20° relative to the absorption axis (0°) of the polarizer.

[0119] The first resin layer 100 includes a separation surface 120. The separation surface 120 is used to spread the light reaching the separation surface while maintaining the front contrast and brightness. The separation surface can be a flat surface, a curved surface or a rough surface. Preferably, the separation surface is a flat surface to allow easy patterning.

[0120] The separation surface 120 may have a width L of about 1 micrometer to about 300 micrometers, specifically about 3 micrometers to about 50 micrometers. Within this range, the separation surface may improve front brightness.

[0121] The ratio of the maximum width W1 of the engraved pattern 110 to the width L of the separation surface 120 may be about 9 or less, preferably about 0.1 to about 5, and more preferably about 0.1 to about 3. Within this range, the engraved pattern can improve the front brightness while reducing the difference between the front contrast and the lateral contrast. For example, the ratio of the maximum width W1 of the engraved pattern to the width L of the separation surface may be about 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5 or 9.

[0122] The first resin layer 100 may have a pitch P of about 5 micrometers to about 500 micrometers, specifically about 10 micrometers to about 50 micrometers. Within this range, the first resin layer may improve brightness and contrast of the polarizing plate while improving suppression of a moire phenomenon.

[0123] The first resin layer 100 has a higher refractive index than the second resin layer 200. With this structure, the polarizing plate according to the present invention can have various effects. The refractive index difference between the second resin layer and the first resin layer can be about 0.3 or less, specifically about 0.2 or less, preferably greater than about 0 but not more than about 0.2, more preferably about 0.05 to about 0.2. Within this range, the polarizing plate can achieve improvements in contrast and viewing angle. For example, the refractive index difference therebetween may be about 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.2, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.3.

[0124] The first resin layer 100 may have a refractive index of about 1.55 or more, specifically about 1.58 to about 1.70, and more specifically about 1.60 to about 1.68. Within this range, the polarizing plate according to the present invention may have various effects. For example, the first resin layer 100 may have a refractive index of about 1.55, 1.56, 1.57, 1.58, 1.59, 1.60, 1.61, 1.62, 1.63, 1.64, 1.65, 1.66, 1.67, 1.68, 1.69 or 1.70.

[0125] The first resin layer 100 may be formed of a composition including at least one of an ultraviolet (UV) curable resin and a heat curable resin, which can ensure the aforementioned refractive index and transparency. For example, the resin may include at least one selected from the group consisting of (meth) acrylic resin, polycarbonate resin, silicone resin and epoxy resin, but is not limited thereto. The first resin layer may further include a photoinitiator, a thermal initiator or various additives.

[0126] Second resin layer

[0127] The second resin layer 200 is formed on the lower surface of the first resin layer 100 to constitute the pattern layer 300. The second resin layer 200 is formed on the light exiting surface of the polarizer and serves to spread light by refraction of light having passed through the polarizer in various directions depending on its light incident position.

[0128] The second resin layer 200 is formed with a filling portion 210 that fills at least a portion of the engraved pattern. Herein, "filling at least a portion of the engraved pattern" includes filling the engraved pattern completely or partially. In a structure in which the engraved pattern is partially filled, the remaining portion of the engraved pattern may be filled with air.

[0129] The second resin layer 200 may directly contact the engraved pattern 111 and the separation surface 120. The second resin layer may be formed between the separation surface and the polarizer to facilitate uniform diffusion of light by allowing light having passed through the polarizer to pass therethrough instead of directly passing through the first resin layer.

[0130] According to other embodiments, the second resin layer may consist of only a filling portion that fills at least a portion of the engraved pattern.

[0131] The second resin layer 200 may have a refractive index of about 1.55 or less, specifically about 1.4 to about 1.55, and more specifically about 1.42 to about 1.52. Within this range, the second resin layer can ensure a good light dispersion effect while improving contrast. For example, the second resin layer 200 may have a refractive index of about 1.4, 1.41, 1.42, 1.43, 1.44, 1.45, 1.46, 1.47, 1.48, 1.49, 1.5, 1.51, 1.52, 1.53, 1.54, or 1.55.

[0132] The second resin layer may be formed of a composition including at least one of a UV-curable resin and a heat-curable resin, which can ensure the aforementioned refractive index and transparency. For example, the resin may include at least one selected from the group consisting of (meth) acrylic resin, polycarbonate resin, silicone resin and epoxy resin, but is not limited thereto. The second resin layer may further include a photoinitiator, a thermal initiator or various additives.

[0133] In one embodiment, the second resin layer may be a non-adhesive layer.

[0134] In another embodiment, the second resin layer may be an adhesive layer and may be directly stacked on an adherend such as a polarizer, thereby being able to reduce the thickness of the polarizing plate.

[0135] Pattern layer

[0136] The entirety of the first resin layer 100 and the second resin layer 200 forms a pattern layer 300 .

[0137] In the pattern layer 300, the minimum distance between the third facet 115 of the engraved pattern 110 and the uppermost surface of the pattern layer 300 or the minimum distance S between the third facet and the upper surface of the first resin layer may be in the range of about 0 micrometers to about 10 micrometers, specifically greater than about 0 micrometers to but not more than about 10 micrometers, more specifically about 1 micrometer to about 5 micrometers. Within this range, the pattern layer 300 can improve the suppression of the moire phenomenon. For example, the minimum distance therebetween may be about 0 micrometers, 1 micrometer, 2 micrometers, 3 micrometers, 4 micrometers, 5 micrometers, 6 micrometers, 7 micrometers, 8 micrometers, 9 micrometers, or 10 micrometers.

[0138] The pattern layer 300 may have a thickness of about 10 micrometers to about 50 micrometers, specifically about 20 micrometers to about 40 micrometers. Within this range, the pattern layer 300 may improve suppression of the moire phenomenon.

[0139] Protective layer

[0140] The protective layer 500 may be formed on the first resin layer 100 to support the first resin layer and the second resin layer. The protective layer is a light-transmitting layer and allows light emitted from the optical display device and having spread through the first resin layer and the second resin layer to pass therethrough. The protective layer 500 may be formed directly on the first resin layer 100.

[0141] The protective layer 500 may be integrally formed with the first resin layer 100. Herein, "integrally" means that the protective layer is not independently separated from the first resin layer.

[0142] The protective layer may be a retardation film or an isotropic optical film having a predetermined retardation range. In one embodiment, the protective layer may have an Re of about 6,000 nanometers or greater, about 8,000 nanometers or greater, specifically about 10,000 nanometers or greater, more specifically greater than about 10,000 nanometers, more specifically about 10,100 nanometers to about 15,000 nanometers. Within this range, the protective layer can prevent rainbow spots from being visible and can promote the diffusion of light that spreads through the first resin layer. In another embodiment, the protective layer may be an isotropic optical film having an Re of about 60 nanometers or less, specifically about 0 nanometers to about 60 nanometers, more specifically about 40 nanometers to about 60 nanometers. Within this range, the protective layer can compensate for viewing angles to improve image quality. "Isotropic optical film" means an optical film having substantially the same nx, ny, and nz values. Here, the expression "substantially the same" includes not only the case where nx, ny, and nz are completely the same but also the case where there is an acceptable tolerance.

[0143] The protective layer 500 may have a thickness of about 30 micrometers to about 120 micrometers, specifically about 55 micrometers to about 105 micrometers. Within this range, the protective layer can be used in an optical display device. The protective layer may have a light transmittance of about 80% or more, specifically about 85% to about 95%, in the visible spectrum. The protective layer may include a film formed by uniaxially or biaxially stretching an optically transparent resin. Specifically, the resin may include at least one selected from the following: polyester resins, including polyethylene terephthalate (PET), polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, etc.; acrylic resins; cyclic olefin polymer (COP) resins; cellulose ester resins, including triacetylcellulose (TAC); polyvinyl acetate; polyvinyl chloride (PVC); polynorbornene; polycarbonate (PC); polyamide; polyacetal; polyphenylene ether; polyphenylene sulfide; polysulfone; polyether sulfone; polyarylate; and polyimide resin. The protective layer may include a film manufactured after the resin is modified. The modification may include copolymerization, branching, crosslinking or modification of terminal molecules.

[0144] although Figure 1Although not shown in the figure, the functional layer may be formed on the other surface of the protective layer. The functional layer may be a separate layer independent of the protective layer, or may be formed integrally with the protective layer. The functional layer may provide at least one of an anti-reflection function, a low-reflection function, a hard coating function, an anti-glare function, an anti-fingerprint function, an anti-pollution function, a diffusion function, and a refraction function.

[0145] polarizer

[0146] Polarizer 400 is used to polarize incident light, and may include a typical polarizer known to those skilled in the art. Specifically, the polarizer may include a polyvinyl alcohol-based polarizer formed by uniaxially stretching a polyvinyl alcohol film, or a polyene-based polarizer formed by dehydrating a polyvinyl alcohol film. The polarizer may have a thickness of about 5 microns to about 40 microns. Within this range, the polarizer may be used in an optical display device.

[0147] although Figure 1 Although not shown in the figure, the aforementioned protective layer may be further formed on the upper surface or the lower surface of the polarizer.

[0148] Next, we will refer to Figure 3 A polarizing plate according to another embodiment will be described.

[0149] refer to Figure 3 ,Apart from Figure 3 The engraved pattern 130 shown replaces Figure 2 In addition to the engraved pattern shown, the polarizing plate according to this embodiment is Figure 1 The polarizing plates shown are substantially identical.

[0150] refer to Figure 3 , the engraved pattern 130 is composed of a third facet 135 formed at a top portion thereof and a lateral side connected to the third facet 135 .

[0151] The engraved pattern 130 may have an aspect ratio of about 1.0 or greater, specifically greater than about 1.0. Within this range, the engraved pattern may help improve the viewing angle and contrast at the lateral side of the polarizing plate. Preferably, the engraved pattern has an aspect ratio of about 1.5 or greater, more preferably about 1.5 to about 3.0, and still more preferably about 2.0 to about 3.0, to achieve a significant improvement in lateral contrast and viewing angle, while further improving visibility at the lateral side.

[0152] For example, the engraved pattern 130 may have an aspect ratio of approximately 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, or 3.0.

[0153] The engraved pattern 130 includes a lateral side on which a first facet 131 and a second facet 132 continuous with the first facet 131 are formed. The first facet 131 is closer to the third facet 135 than the second facet 132.

[0154] The first facet 131 and the second facet 132 have different bottom angles relative to the maximum width W1 of the engraved pattern or a plane parallel thereto, and satisfy relations 1 and 2:

[0155] [Relation 1]

[0156] θ1>θ2,

[0157] Wherein in Relation 1, θ1 represents the bottom angle of the first facet, θ2 represents the bottom angle of the second facet, about 70°≤θ1≤about 90°, and about 0°<θ2<about 90°; and

[0158] [Relation 2]

[0159] about 0.5≤h1 / (h1+h2)<about 1.0,

[0160] In Relationship 2, h1 represents the projection height of the first facet 131 projected on the maximum height H of the engraved pattern 130, and h2 represents the projection height of the second facet 132 projected on the maximum height H thereof.

[0161] The first facet 131 and the second facet 132 having different bottom angles are continuously formed on the lateral side of the engraved pattern 130. When the bottom angle of the first facet is greater than the bottom angle of the second facet, the bottom angle θ1 of the first facet is within the range of about 70°≤θ1≤about 90°, and the projection height of the first facet projected on the maximum height of the engraved pattern can be about 0.5 times to less than about 1.0 times the entire projection height (of the first facet and the second facet) on the maximum height of the engraved pattern, thereby significantly improving the viewing angle and contrast on the lateral side of the engraved pattern. Therefore, according to the present invention, instead of the first facet and the second facet having the same bottom angle and arranged parallel to each other, facets with different bottom angles are formed on the engraved pattern to affect the traveling direction of the light emitted from the engraved pattern through the polarizer, and control all the bottom angles, the projection heights and aspect ratios of the facets with different bottom angles to achieve the advantageous effects of the present invention.

[0162] Each of the first facet 131 and the second facet 132 may be a flat surface, which facilitates the formation of an engraved pattern. However, at least one of the first facet and the second facet may be a curved surface or a flat surface having a curved surface formed on at least a portion thereof.

[0163] The first facet 131 may have a bottom angle θ1 of about 70° to about 90°, more preferably about 75° to about 90°, about 85° to about 90°, or about 80° to about 85°. Within this range, the engraved pattern can help improve contrast and viewing angle and can be easily formed. For example, the first facet 131 may have a bottom angle θ1 of about 70°, 71°, 72°, 73°, 74°, 75°, 76°, 77°, 78°, 79°, 80°, 81°, 82°, 83°, 84°, 85°, 86°, 87°, 88°, 89°, or 90°.

[0164] The second facet 132 may have a bottom angle θ2 greater than about 0° to less than about 90° (about 0°<θ2<about 90°), more preferably about 60° to about 80°, about 70° to about 80°, or about 70° to about 75°. Within this range, the engraved pattern may help improve contrast and viewing angle, and may be easily formed. For example, the second facet 132 may have a depth of about 0.01°, 0.1°, 0.5°, 1°, 2°, 3°, 4°, 5°, 6°, 7°, 8°, 9°, 10°, 11°, 12°, 13°, 14°, 15°, 16°, 17°, 18°, 19°, 20°, 21°, 22°, 23°, 24°, 25°, 26°, 27°, 28°, 29°, 30°, 31°, 32°, 33°, 34°, 35°, 36°, 37°, 38°, 39°, 40°, 41°, 42°, 43°, 44°, 45°, 46°, 47°, 48°, 49°, 50°, 51°, 52°, 53°, 54°, 55°, 56°, 57°, 58°, 59°, 60°, 61°, 62°, 63°, 64°, 65°, 66°, 67°, 68°, 69°, 70°, 71°, 72°, 73°, 74°, 75°, 76°, 77°, 78°, 79°, 80°, 81°, 82°, 83°, 84°, 85°, 86°, 87°, 88°, 89°, 90°, 91°, 92°, 93°, 94°, 95°, 96° , 46°, 47°, 48°, 49°, 50°, 51°, 52°, 53°, 54°, 55°, 56°, 57°, 58°, 59°, 60°, 61°, 62°, 63°, 64°, 65°, 66°, 67°, 68°, 69°, 70°, 71°, 72°, 73°, 74°, 75°, 76°, 77°, 78°, 79°, 80°, 81°, 82°, 83°, 84°, 85°, 86°, 87°, 88°, 89°, 89.5°, 89.9° or 89.99° of the base angle θ2.

[0165] In the engraved pattern, θ1-θ2 may be greater than about 0° but not more than about 20°, specifically about 5° to about 15°. Within this range, the engraved pattern can improve the lateral contrast. θ1-θ2 may be about 0.01°, 0.1°, 0.5°, 1°, 2°, 3°, 4°, 5°, 6°, 7°, 8°, 9°, 10°, 11°, 12°, 13°, 14°, 15°, 16°, 17°, 18°, 19° or 20°.

[0166] In the engraved pattern 130, h1 / (h1+h2) represented by the relationship 2 may be in the range of about 0.5 to less than about 1.0, thereby helping to improve contrast and viewing angle. Preferably, h1 / (h1+h2) is in the range of about 0.5 to about 0.9, about 0.5 to about 0.8, or about 0.5 to about 0.7, thereby being able to easily adjust the thickness of the pattern layer while improving the suppression of the moire phenomenon. For example, h1 / (h1+h2) may be about 0.5, 0.6, 0.7, 0.8, 0.9, or 0.99.

[0167] In Relation 2, h1 may be in the range of about 5 micrometers to about 20 micrometers, preferably about 10 micrometers to about 20 micrometers, and h2 may be in the range of about 1 micrometer to about 10 micrometers, preferably about 4 micrometers to about 8 micrometers. Within this range, the engraved pattern can satisfy Relation 2 and can be easily formed. For example, in Relation 2, h1 may be about 5 micrometers, 6 micrometers, 7 micrometers, 8 micrometers, 9 micrometers, 10 micrometers, 11 micrometers, 12 micrometers, 13 micrometers, 14 micrometers, 15 micrometers, 16 micrometers, 17 micrometers, 18 micrometers, 19 micrometers, or 20 micrometers, and h2 may be 1 micrometer, 2 micrometers, 3 micrometers, 4 micrometers, 5 micrometers, 6 micrometers, 7 micrometers, 8 micrometers, 9 micrometers, or 10 micrometers.

[0168] The engraved pattern 130 may have a maximum height H of about 5 micrometers to about 25 micrometers, preferably about 10 micrometers to about 20 micrometers. Within this range, the engraved pattern can easily achieve the aspect ratio according to the present invention and can easily satisfy Relation 2.

[0169] The ratio ((h1+h2) / H) of (h1+h2) to the maximum height H of the engraved pattern 130 may be in the range of about 0.5 to about 1.0, preferably about 0.6 to about 1.0, and more preferably about 0.9 to about 1.0. Within this range, a reduction in the thickness of the pattern layer can be achieved while improving contrast and viewing angle. For example, ((h1+h2) / H) may be about 0.5, 0.6, 0.7, 0.8, 0.9, or 1.0.

[0170] The engraved pattern 130 may have a maximum width W1 of about 5 microns to about 20 microns, preferably about 8 microns to about 15 microns. Within this range, the engraved pattern can easily achieve the aspect ratio according to the present invention. For example, the engraved pattern 130 may have a maximum width W1 of about 5 microns, 6 microns, 7 microns, 8 microns, 9 microns, 10 microns, 11 microns, 12 microns, 13 microns, 14 microns, 15 microns, 16 microns, 17 microns, 18 microns, 19 microns or 20 microns.

[0171] The engraved pattern 130 may have a bisymmetrical structure, but is not limited thereto, and both the first facet and the second facet may be formed on each of the two lateral sides of the engraved pattern. The engraved pattern may include a first region 133 and a second region 134 adjacent to each other on each of its two lateral sides, wherein the first region 133 includes the first facet 131, and the second region 134 includes the second facet 132.

[0172] The second region 134 may have a maximum width that is the same as the maximum width W1 of the above-mentioned engraved pattern. The first region 133 may have a maximum width W2 of about 3 microns to about 15 microns, preferably about 8 microns to about 15 microns. Within this range, the engraved pattern can easily achieve the aspect ratio according to the present invention. For example, the first region may have a maximum width W2 of about 3 microns, 4 microns, 5 microns, 6 microns, 7 microns, 8 microns, 9 microns, 10 microns, 11 microns, 12 microns, 13 microns, 14 microns, or 15 microns.

[0173] The ratio (h1 / W1) of the projection height h1 to the maximum width W2 of the first region 133, that is, the aspect ratio of the first region 133, may be in the range of about 1 to about 3, specifically about 1.1 to about 3. Within this range, the engraved pattern can improve the contrast of the polarizing plate at its lateral side. For example, the ratio (h1 / W1) may be about 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9 or 3.

[0174] The ratio (h2 / W2) of the projection height h2 to the maximum width W1 of the second region 134, that is, the aspect ratio of the second region 134 may be in the range of about 0.1 to about 1, specifically about 0.3 to about 1, and more specifically about 0.3 to about 0.9. For example, the ratio (h2 / W2) of the projection height h2 to the maximum width W1 in the second region may be about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1.0.

[0175] The maximum width of the second region 134 may be about 1.1 to about 3 times, specifically about 1.3 to about 3 times, the maximum width of the first region 133 of the engraved pattern. Within this range, the engraved pattern may further improve the lateral contrast on the screen of the liquid crystal display.

[0176] The third facet 135 formed at the top portion of the engraved pattern allows the vertical component of the light that has passed through the polarizer to pass through it, thereby improving the front contrast and brightness. The third facet 135 can be parallel to the maximum width of the engraved pattern or the separation surface, and can be a flat surface. As another option, the third facet 135 can have a roughness formed on its surface. The third facet can have a width of about 1 micron to about 10 microns, preferably about 3 microns to about 6 microns. For example, the third facet 135 can have a width W3 of about 1 micron, 2 microns, 3 microns, 4 microns, 5 microns, 6 microns, 7 microns, 8 microns, 9 microns or 10 microns.

[0177] The longitudinal direction of the engraved pattern may be inclined at an angle of about -20° to about +20°, for example, at an angle of about -5° to about +5°, or at about 0° relative to the absorption axis (0°) (machine direction (MD) of the polarizer). Within this range, the engraved pattern 110 can achieve suppression of the moire phenomenon. For example, the longitudinal direction of the engraved pattern may be inclined at an angle of about -20°, -19°, -18°, -17°, -16°, -15°, -14°, -13°, -12°, -11°, -10°, -9°, -8°, -7°, -6°, -5°, -4°, -3°, -2°, -1°, 0°, +1°, +2°, +3°, +4°, +5°, +6°, +7°, +8°, ​​+9°, +10°, +11°, +12°, +13°, +14°, +15°, +16°, +17°, +18°, +19° or +20° relative to the absorption axis (0°).

[0178] The first resin layer includes a separation surface 120. The separation surface 120 is used to spread the light reaching the separation surface while maintaining the front contrast and brightness. The separation surface can be a flat surface, a curved surface or a rough surface. Preferably, the separation surface is a flat surface to allow easy patterning.

[0179] The separation surface 120 may have a width L of about 1 micrometer to about 300 micrometers, specifically about 3 micrometers to about 50 micrometers. Within this range, the separation surface may improve front brightness.

[0180] The ratio of the maximum width W1 of the engraved pattern to the width of the separation surface 120 may be about 9 or less, preferably about 0.1 to about 5, and more preferably about 0.1 to about 3. Within this range, the engraved pattern can improve the front brightness while reducing the difference between the front contrast and the lateral contrast. For example, the ratio of the maximum width W1 of the engraved pattern to the width of the separation surface may be about 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5 or 9.

[0181] The first resin layer 100 may have a pitch P of about 5 micrometers to about 500 micrometers, specifically about 10 micrometers to about 50 micrometers. Within this range, the first resin layer may improve brightness and contrast of the polarizing plate while improving suppression of a moire phenomenon.

[0182] In one embodiment, the engraved pattern is composed of a second facet 132 adjacent to the separation surface 120 on the lower surface of the first resin layer, a first facet 131 continuous with the second facet 132, and a third facet 135 formed at its top portion continuous with the first facet 131.

[0183] Next, we will refer to Figure 4 A polarizing plate according to a further embodiment will be described.

[0184] refer to Figure 4 The polarizing plate according to this embodiment includes a polarizer 400, a first resin layer 100' having an engraved pattern 140 thereon, a second resin layer 200' and a protective layer 500. In addition to the engraved pattern 140, the polarizing plate according to this embodiment is Figure 1 The polarizing plates shown are substantially identical.

[0185] The engraving pattern 140 according to this embodiment is Figure 1 The engraving pattern 110 shown is substantially the same, except that the engraving pattern 140 according to this embodiment includes a first facet 141 and a second facet 142, the first facet 141 and the second facet 142 having different bottom angles (θ1, θ2) relative to their maximum widths and being continuous with each other, wherein the first facet 141 is a curved surface and the second facet 142 is a flat surface.

[0186] refer to Figure 5 , the bottom angle θ1 of the curved first facet 141 is defined as the angle between the tangent line T at the most convex portion of the curved surface of the bottom angle and the extension line of the maximum width W1 of the engraved pattern 140. As another option, the second facet 142 of the engraved pattern may be a curved surface, and the bottom angle θ2 of the curved second facet may be as follows: Figure 5 It is defined like the first facet in .

[0187] refer to Figure 6 , a polarizing plate according to still another embodiment of the present invention will be described.

[0188] refer to Figure 6 The polarizing plate includes a polarizer 400, a first resin layer 100" having an engraved pattern 150 thereon, a second resin layer 200" and a protective layer 500. The polarizing plate according to this embodiment is similar to the polarizer 400, except that the engraved pattern 150 replaces the engraved pattern 110. Figure 3 The polarizing plates shown are substantially the same. A separation surface 120 is formed between the engraved patterns 150.

[0189] The engraved pattern 150 is composed of a third facet 155 formed at a top portion thereof and a lateral side connected to the third facet 155. In addition to the engraved pattern 150 being formed with the first facet 151 and the second facet 152 having different bottom angles (θ1, θ2) relative to the maximum width of the engraved pattern 150 and being continuous with each other on the lateral side thereof, the engraved pattern 150 is Figure 3 The engraved patterns 130 are substantially the same.

[0190] refer to Figure 7 , the bottom angle θ1 of the curved first facet 151 is defined as the minimum angle among the angles between the tangent line T on the first facet 151 and the second facet 152 and the extension line of the maximum width W1 of the engraved pattern 150, wherein the angles satisfy Equation 2. The bottom angle θ2 of the second facet 152 is defined as the angle between the second facet 152 and the extension line of the maximum width W1 of the engraved pattern 150.

[0191] Preferably, the bottom angle θ1 of the first facet 151 is in the range of about 70° to about 85°, more preferably about 70° to about 80°. Within this range, the engraved pattern can help improve contrast and viewing angle, and can be easily formed. Preferably, the bottom angle θ2 of the second facet 152 is in the range of about 60° to about 80° or about 70° to about 80°. Within this range, the engraved pattern can help improve contrast and viewing angle, and can be easily formed. In the engraved pattern, θ1-θ2 may be greater than about 0° but not more than about 20°, specifically about 5° to about 15°. Within this range, the engraved pattern can improve lateral contrast.

[0192] The polarizing plate according to still another embodiment may be substantially the same as the polarizing plate according to the above embodiment, except that the first resin layer has a lower refractive index than the second resin layer.

[0193] Here, the absolute value of the refractive index difference between the first resin layer and the second resin layer is about 0.3 or less than about 0.3, specifically about 0.2 or less than about 0.2, greater than about 0 but not more than about 0.2, and more preferably about 0.05 to about 0.2. Within this range, the polarizing plate can achieve further improvement in contrast and viewing angle. The first resin layer may have a refractive index of about 1.55 or less than about 1.55, specifically about 1.4 to about 1.55, and more specifically about 1.42 to about 1.52. Within this range, the first resin layer can easily achieve the effect of the present invention. The second resin layer may have a refractive index of about 1.55 or greater than about 1.55, specifically about 1.58 to about 1.70, and more specifically about 1.60 to about 1.68. Within this range, the second resin layer can ensure a good light scattering effect while improving contrast.

[0194] A polarizing plate according to still another embodiment may be substantially the same as the polarizing plate according to the above-described embodiment, except that engraved patterns are continuously formed without a separation surface.

[0195] The optical display device according to the present invention may include the polarizing plate according to the present invention. For example, the optical display device may include a liquid crystal display, etc. The polarizing plate according to the present invention may be provided as an observer-side polarizing plate.

[0196] Invention Mode

[0197] Next, the present invention will be described in more detail with reference to examples. However, it should be noted that these examples are provided for illustration only and should not be construed as limiting the present invention in any way.

[0198] Example 1

[0199] A coating layer was formed on one surface of a PEM membrane (thickness: 80 μm, Re=14,000 nm at 550 nm, Toyobo Co., Ltd.) serving as a protective layer by coating an ultraviolet curable resin (SSC-SP4620M8, Shina T&C) thereon. From a film having a pattern portion including engraved patterns and separation surfaces alternately arranged thereon, the engraved patterns and separation surfaces were transferred to the coating layer and cured to form a first resin layer (refractive index: 1.50) on which a film having a pattern portion including engraved patterns and separation surfaces alternately arranged thereon was formed. Figure 2 The engraved pattern and separation surface (width: 10 μm) of the shape and specifications shown in Table 1 are coated on the first resin layer to form a protective layer and a Figure 1 A stack of pattern layers of the shape shown, in which a second resin layer (refractive index: 1.62) having a filling portion that completely fills the engraved pattern is formed on the first resin layer.

[0200] The polarizer was manufactured by stretching a polyvinyl alcohol film to 3 times its original length at 60°C, dyeing the stretched film with iodine, and then stretching the dyed film to 2.5 times in a boric acid aqueous solution at 40°C.

[0201] An adhesive for polarizing plates (Z-200, Nippon Goshei Co., Ltd.) was deposited on the lower surface of the polarizer, and a COP film (Zeon Co., Ltd.) was bonded thereto. The polarizing plate was manufactured by bonding the laminated second resin layer to the upper surface of the polarizer.

[0202] Example 2 to Example 4

[0203] Each of the polarizing plates was manufactured in the same manner as in Example 1, except that the shape of the engraved pattern was changed as listed in Table 1.

[0204] Example 5

[0205] A polarizing plate was manufactured in the same manner as in Example 1, except that the first resin layer (refractive index: 1.62) was formed of an ultraviolet curable resin (SSC-6000M4, Shiner T&C Co., Ltd.) and the second resin layer (refractive index: 1.50) was formed of an ultraviolet curable resin (SSC-SP4620M8, Shiner T&C Co., Ltd.).

[0206] Examples 6 to 9

[0207] Each of the polarizing plates was manufactured in the same manner as in Example 5, except that the shape of the engraved pattern was changed as listed in Table 1.

[0208] Comparative Example 1

[0209] A polarizing plate having a PET film as a protective layer, a polarizer, and a COP film sequentially stacked thereon was manufactured in the same manner as in Example 1, except that the pattern layer was not formed.

[0210] Comparative Example 2 to Example 7

[0211] Each of the polarizing plates was manufactured in the same manner as in Example 1, except that the shape of the engraved pattern was changed as listed in Table 2.

[0212] Each of the polarizing plates manufactured in Examples and Comparative Examples was evaluated for the following properties shown in Tables 1 and 2.

[0213] <Manufacturing of light source side polarizing plate>

[0214] The polarizer was manufactured by stretching a polyvinyl alcohol film to 3 times its original length at 60° C., dyeing the stretched film with iodine, and then stretching the dyed film to 2.5 times in a boric acid aqueous solution at 40° C. The polarizer was manufactured by bonding a triacetyl cellulose film (thickness: 80 μm) to both surfaces of the polarizer using a binder for polarizing plates (Z-200, Japan Koshi Co., Ltd.).

[0215] <Manufacturing of Liquid Crystal Display Modules>

[0216] A liquid crystal display module was manufactured by sequentially assembling a light source side polarizing plate, a liquid crystal panel (PVA mode), and each of the polarizing plates manufactured in Examples and Comparative Examples. A pattern layer and a protective layer were disposed on the light exiting surface of the polarizer.

[0217] (1) L value: The front luminance in the spherical coordinate system (0°, 0°) was obtained by measuring the luminance in the white mode using EZCONTRAST X88RC (EZXL-176R-F422A4, ELDIM Co., Ltd.).

[0218] (2) Ratio of lateral brightness (at 30° or 60°) to front brightness: A liquid crystal display (having the same configuration as a Samsung LED TV (UN32H5500) including a side edge type LED light source, except for the liquid crystal display modules of the example and the comparative example) was manufactured by assembling a light-emitting diode (LED) light source, a light guide plate, and a liquid crystal display module. The front brightness (0°, 0°), lateral side (0°, 30°), and lateral side (0°, 60°) in the spherical coordinate system were measured in the white mode using an EZ contrast X88RC (EZXL-176R-F422A4, Eldim Co., Ltd.). The ratio of lateral brightness to front brightness was calculated.

[0219] (3) Horizontal contrast: A module was manufactured in the same manner as (2). The lateral brightness (0°, 60°) was measured in the white mode and the black mode. The lateral contrast was calculated based on the ratio of the brightness in the white mode to the brightness in the black mode. When the lateral contrast was 280 or more, the improvement in the lateral contrast was confirmed when the polarizing plate was applied to an optical display device.

[0220] [Table 1]

[0221]

[0222] [Table 2]

[0223]

[0224] As shown in Table 1, the polarizing plate according to the present invention can significantly improve brightness and contrast. The polarizing plate according to the present invention can increase the ratio (%) of the brightness at 30° to the brightness at the front side and the ratio (%) of the brightness at 60° to the brightness at the front side, and the lateral contrast is significantly increased.

[0225] On the contrary, as shown in Table 2, the polarizing plates of the comparative examples that do not satisfy the pattern layer according to the present invention may not achieve the advantageous effects of the present invention.

[0226] Although some embodiments have been described herein, it should be understood that various modifications, changes, variations, and equivalent embodiments may be made by those skilled in the art without departing from the spirit and scope of the invention.

Claims

1. A polarizing plate, comprising: polarizer; as well as a pattern layer disposed on the upper surface of the polarizer, The pattern layer includes a first resin layer, the first resin layer has at least one engraved pattern with a lateral side formed on its lower surface, the lateral side has a first facet and a second facet continuous with the first facet, the first facet and the second facet have different bottom angles relative to the maximum width of the engraved pattern, and satisfy relations 1 and 2, wherein each of the first facet and the second facet is a flat surface or a concave surface: [Relation 1] θ1>θ2, Wherein, in relation 1, θ1 represents the bottom angle of the first facet, θ2 represents the bottom angle of the second facet, 70°≤θ1≤90°, 0°<θ2<90°; and [Relation 2] 0.5≤h1 / (h1+h2)<1.0, In relation 2, h1 represents the projection height of the first facet projected on the maximum height of the engraved pattern, and h2 represents the projection height of the second facet projected on the maximum height of the engraved pattern. 2 . The polarizing plate of claim 1 , wherein the engraved pattern has an aspect ratio greater than 1.

0. 3 . The polarizing plate according to claim 1 , wherein the engraved pattern has a θ1-θ2 value greater than 0° but not more than 20°. The polarizing plate according to claim 1 , wherein h1 / (h1+h2) is in the range of 0.5 to 0.

9. 5 . The polarizing plate of claim 1 , wherein the engraved pattern includes a third facet formed at a top portion thereof, the lateral side is connected to the third facet, and the third facet is a flat surface. 6 . The polarizing plate according to claim 5 , wherein the first facet is closer to a separation surface or the third facet than the second facet. The polarizing plate according to claim 1 , wherein the lateral sides have no facets having the same base angle. 8 . The polarizing plate according to claim 1 , wherein a maximum width of a first region of the engraved pattern having the first facets at both lateral sides thereof is 1.1 to 3 times a maximum width of a second region of the engraved pattern having the second facets at both lateral sides thereof. 9 . The polarizing plate of claim 1 , wherein the engraved pattern has a longitudinal direction inclined at an angle of −20° to +20° with respect to an absorption axis of the polarizer. 10 . The polarizing plate according to claim 1 , wherein the pattern layer further comprises a filling portion partially filling at least a portion of the engraved pattern, or a second resin layer having the filling portion formed thereon. 11 . The polarizing plate according to claim 10 , wherein the first resin layer has a smaller refractive index than the filling portion or the second resin layer. 12 . The polarizing plate according to claim 10 , wherein the first resin layer has a higher refractive index than the filling portion or the second resin layer. 13 . The polarizing plate according to claim 10 , wherein an absolute value of a refractive index difference between the second resin layer or the filling portion and the first resin layer is 0.3 or less. The polarizing plate according to claim 10 , wherein the second resin layer is an adhesive layer. 15 . The polarizing plate according to claim 5 , wherein a minimum distance between the third facet and an upper surface of the first resin layer is in a range from 0 μm to 10 μm. 16 . The polarizing plate according to claim 1 , wherein the first resin layer further comprises a separation surface between adjacent engraved patterns.

17. The polarizing plate according to claim 1, further comprising: A protective layer is formed on an upper surface of the first resin layer.

18. The polarizing plate according to claim 1, wherein the engraved pattern is composed of the first facet adjacent to the separation surface on the lower surface of the first resin layer, the second facet continuous with the first facet, and the third facet formed at its top portion continuous with the second facet.

19. The polarizing plate according to claim 1, wherein the engraved pattern is composed of the second facet adjacent to the separation surface on the lower surface of the first resin layer, the first facet continuous with the second facet, and a third facet formed at a top portion thereof continuous with the first facet.

20. An optical display device comprising the polarizing plate according to any one of claims 1 to 19.

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