Optical film including coating and backlight unit including optical film

Abstract

One embodiment of the present invention relates to an optical film for being disposed in a display device, and a backlight unit comprising the optical film, the optical film comprising a base film, a pattern layer disposed on the base film and comprising a curved portion, and a coating layer disposed on the pattern layer, the coating may include a plurality of particles disposed continuously on at least a portion of the curved portion of the pattern layer, and a filler material disposed along the curved portion of the pattern layer and filling spaces between the plurality of particles.

Description

Technical Field

[0001] Various embodiments of the present invention relate to an optical film including a coating and a backlight unit including the optical film. Background Technology

[0002] With the development of display devices, optical films are being developed to prevent the formation of images of light or objects on the display devices. For example, display devices used in electronic devices (especially small electronic devices such as smartphones) often reflect objects or light, and the image displayed from the display device cannot be accurately transmitted to the user through optical films; this problem urgently needs to be solved. In addition, besides smartphones, the application of display devices in automotive equipment and various home appliances is becoming increasingly widespread, and in order to prevent the formation of images of light or objects that are not part of the image display on the display device and to accurately transmit the information displayed on the screen, optical films that utilize optical films and coatings applied to the optical films to reduce the reflectivity of light or objects are being developed.

[0003] Optical films are typically referred to as light control films, etc. The effect of the pattern and reflectivity of optical films decreases with the change of viewing angle. Currently, the patterned surface of optical films is coated by vapor deposition. Therefore, there is an urgent need to optimize the coating process of optical films while ensuring cost and process efficiency. Summary of the Invention

[0004] To reduce the reflection of light or objects, optical films may include patterned layers and coatings. However, there are not only cost issues arising from the vapor deposition coating process, but also the possibility of cracks in curved matte patterned sections of the vapor deposition coating, which can reduce the low-reflectivity effect of the coating.

[0005] This invention implements a wet coating process through various embodiments to enable the coating of particles on the surface of a patterned layer, thereby reducing the reflection of objects or light.

[0006] This invention, through various embodiments, enables coatings to be applied to the peaks and valleys of a patterned layer using a wet coating process.

[0007] This invention utilizes a wet coating process to coat matte patterns through various embodiments, thereby preventing coating damage and maintaining a low-reflection effect. The technical problem to be solved by this invention is not limited to the aforementioned issues, and various extensions are possible without departing from the spirit and scope of this invention.

[0008] An optical film according to an embodiment of the present invention may include a base film, a patterned layer disposed on the base film and including a curved portion, and a coating disposed on the patterned layer, wherein the coating may include a plurality of particles continuously disposed on at least a portion of the curved portion of the patterned layer, and a filling material disposed along the curved portion of the patterned layer and filling the space between the plurality of particles.

[0009] According to an embodiment of the present invention, a backlight unit including an optical film may include a light source and an optical sheet for light emitted from the light source to be incident on, and at least one of the aforementioned optical films may be disposed above the optical sheet.

[0010] According to various embodiments of the present invention, optical films can maintain the effect of the patterned layer and reduce the reflection of light or objects by including a coating disposed on the patterned layer.

[0011] According to various embodiments of the present invention, the optical film may have a coating comprising multiple particles formed on the peaks and valleys of the patterned layer. By forming a coating comprising multiple particles, not only is a low reflectivity maintained, but the curved pattern shape is also maintained, thereby preventing the haze of the patterned layer from decreasing.

[0012] In addition, it can provide various effects that can be directly or indirectly confirmed through this article. Attached Figure Description

[0013] The above or other aspects, structures and / or advantages of the embodiments of the present invention will become more apparent from the following detailed description with reference to the accompanying drawings.

[0014] Figure 1 This is a schematic cross-sectional view of an optical film according to one embodiment;

[0015] Figure 2 yes Figure 1 A schematic diagram of a magnified cross-sectional view of the optical film in region S shown in the figure;

[0016] Figure 3 This is a schematic cross-sectional view of an optical film according to one embodiment;

[0017] Figure 4 This is a schematic cross-sectional view of an optical film according to one embodiment;

[0018] Figure 5 This is a schematic cross-sectional view of an optical film according to one embodiment;

[0019] Figure 6 This is an enlarged conceptual diagram of a single particle among multiple particles disposed in an optical film, according to one embodiment.

[0020] Figure 7 This is a schematic cross-sectional view of an optical film including a patterned layer according to an embodiment;

[0021] Figure 8 It is a schematic diagram of a cross-sectional view of an optical film including a conventional patterned layer and a coating layer;

[0022] Figure 9 This is a schematic diagram of a backlight unit including an optical film according to one embodiment.

[0023] Explanation of reference numerals in the attached figures

[0024] 100: Optical film; 110: Base film

[0025] 120: Pattern layer 121: Pattern surface

[0026] 122: Part One 123: Part Two

[0027] 130: Coating 131: Multiple particles

[0028] 132: Filling material; 701: Backlight unit Detailed Implementation

[0029] The various embodiments of the present invention and the terminology used therein are not intended to limit the technical features described herein to specific embodiments, but should be understood to include various modifications, equivalents, or substitutions of those embodiments. Regarding the description of the drawings, similar or related constituent elements may use similar reference numerals. Unless explicitly indicated, the singular form of a noun referring to a particular constituent may mean one or more. In describing these embodiments, the same names and symbols are used for the same constituent elements, and corresponding additional descriptions are omitted. Furthermore, in describing embodiments of the present invention, only the same names and symbols are used for constituent elements having the same function, but it should be noted beforehand that their actual structure is not entirely the same as that of the prior art.

[0030] In this invention, “A or B”, “at least one of A and B”, or substantially the same expression may mean any one or all possible combinations thereof.

[0031] In this invention, terms such as "comprising" or "having" are used to specify the presence of features, numbers, steps, actions, constituent elements, components or combinations thereof described in the specification, and should not be construed as excluding the presence or additional possibilities of one or more other features, numbers, steps, actions, constituent elements, components or combinations thereof.

[0032] In this invention, the "first direction" refers to the +Y direction or a direction deviating from the +Y axis to the X axis by a certain angle or more, or a "height direction," a "direction away from a constituent element," or a direction substantially the same as such. The "second direction" can refer to the -Y direction or a direction deviating from the -Y axis to the X axis by a certain angle or more, or a direction substantially the same as such. The third direction can refer to the +X direction or a direction deviating from that direction by a certain angle or more, or a direction substantially the same as such. "A certain angle" can include a range of 0 degrees or more and 45 degrees or less. The first to third directions are not limited to these and can include both "+" and "-" directions. Unless otherwise defined, the "X-axis direction" includes both the "+X" and "-X" directions. Similarly, the "Y-axis direction" includes both the "+Y" and "-Y" directions. "A certain direction" can include "a direction the same as a certain direction," "a direction substantially the same as or parallel to a certain direction," or "a direction that is parallel to a certain direction."

[0033] It should be noted that in the following description of the present invention, when referring to the overlap (or stacking) of one constituent element with another constituent element, the description of the arrangement relationship in the aforementioned height direction is applicable. However, it is not limited to this, and the description is also applicable to the arrangement relationship of one constituent element with another constituent element in a non-perpendicular oblique direction or in a substantially the same direction.

[0034] Figure 1 This is a schematic cross-sectional view of an optical film according to an embodiment of the present invention. Figure 2 yes Figure 1 The image shows a magnified cross-sectional view of the optical film in region S. (Refer to...) Figure 1 and Figure 2 The constituent elements of the optical film described can be compared with those in the reference. Figures 3 to 7 and Figure 9 The constituent elements described are essentially the same.

[0035] According to one embodiment, the optical film 100 may include a base film 110. The base film 110 may be disposed on a display device (not shown). The base film 110 may also be disposed on a substrate (not shown) constituting a cover for the display device. Although not shown, an optical sheet or other optical film, such as a diffusion layer, a light-absorbing layer, a light-shielding layer, an adhesive layer, a prism structure, or a reflective layer, may be disposed below the base film 110. The base film 110 may be formed of a material that transmits at least a portion of visible light. According to one embodiment, the base film 110 may include at least one of a polymer resin such as polycarbonate (PC), acrylate, or polyethylene terephthalate (PET). The base film 110 may include a patterned surface (e.g., Figure 2(121). The base film 110 may be provided with a patterned layer 120. It may be named the first base film coated with the coating layer 130 (e.g.: Figure 1 (110). The display device (not shown) of the present invention may be named as a constituent element including a display device cover (not shown). The display device (not shown) of the present invention may include a flexible display.

[0036] The optical film 100 may include a patterned layer 120 on the base film 110. The patterned layer 120 may be disposed on the base film 110. The patterned layer 120 may be bonded to or form a portion thereof with the base film 110. The patterned layer 120 may have a non-uniform surface roughness. The patterned layer 120 may include regular or irregular patterns. The patterned layer 120 may be a plurality of raised shapes oriented in a first direction (e.g., ...). Figure 2 The pattern layer 120 may include recessed portions (e.g., 122) arranged in a structure. Figure 2 (123). Pattern layer 120 may include protrusions (e.g.: Figure 2 (122). Pattern layer 120 may include portions extending from and protruding from recessed portions. Pattern layer 120 may include portions extending from and recessed from protruding portions. Pattern layer 120 may repeatedly include recessed portions and extended portions. Pattern layer 120 may extend in a third direction while repeatedly including recessed portions and protruding portions. Pattern layer 120 may extend in the extension direction of the base film in a pattern of repeated recessed portions and protruding portions. Pattern layer 120 may include protruding portions (e.g.: Figure 2 122) and non-protruding parts (e.g.: Figure 2 (123). Pattern layer 120 may include curved portions. Pattern layer 120 may include at least one of a matte pattern layer, a pyramidal pattern layer, an inverse pyramidal pattern layer, and a prism layer. The pattern of pattern layer 120 can reduce the amount of objects or light reflected on the display device (not shown). For example, with the protruding portions forming the matte pattern layer, the brightness can be maintained. As another example, as the haze (Hz) of the matte pattern layer decreases, the amount of total internal reflection at the interface increases, and the proportion of straight light emitted decreases, thereby creating uniformity of overall emitted light. Pattern layer 120 may refer to a portion of base film 110. Pattern layer 120 may refer to the upper layer of base film 110 facing the first direction.

[0037] Pattern layer 120 may include a patterned surface 121. Pattern layer 120 may include a first portion 122 protruding along a first direction. Patterned surface 121 may include the first portion 122 protruding along the first direction. Pattern layer 120 may include a second portion 123 recessed toward a second direction opposite to the first direction. Patterned surface 121 may include the second portion 123 recessed toward a second direction opposite to the first direction. The first portion 122 may be formed protruding toward the first direction. The first portion 122 may include a curved surface protruding toward the first direction. The first portion 122 may be formed as a conical or triangular shape protruding toward the first direction. The first portion 122 may be referred to as a peak, convexity, protrusion, or a substantially similar name. The first portion 122 may extend from the second portion 123. The second portion 123 may be formed recessed toward the second direction. The second portion 123 may include a curved surface formed recessed toward the second direction. The second portion 123 may include a non-protruding portion. The second portion 123 may be formed as a conical or triangular shape recessed toward the second direction. The second portion 123 may be referred to as a valley, recess, depression, concave portion, non-protruding portion, or substantially the same name. The second portion 123 may extend from the first portion 122. The patterned layer 120 may repeatedly include the first portion 122 and the second portion 123. The patterned layer 120 may extend along a third direction or the extension direction of the base film 110 while repeating the first portion 122 and the second portion 123. The patterned layer 120 may include a plurality of first portions 122 or a plurality of second portions 123. The patterned surface 121 may similarly include the first portions 122 and the second portions 123 included in the patterned layer 120. The patterned surface 121 may be the same as the surface of the patterned layer 120. Hereinafter, the first portion 122 of the patterned layer 120 may be substantially the same as the first portion 122 of the patterned surface 121. Hereinafter, the second portion 123 of the patterned layer 120 may be substantially the same as the second portion 123 of the patterned surface 121.

[0038] The optical film 100 may include a coating 130. The coating 130 may be disposed on a patterned layer 120 of the optical film 100. The coating 130 may extend along a patterned surface 121 of the patterned layer 120. The coating 130 may extend along a first portion 122 and a second portion 123 of the patterned layer 120. The coating 130 may be formed protruding in a first direction at a position corresponding to the first portion 122 of the patterned layer 120. The coating 130 may be formed recessed in a second direction at a position corresponding to the second portion 123 of the patterned layer 120. The coating 130 may be formed on the patterned surface 121 with a certain thickness. To achieve a low-reflection effect, the thickness of the coating 130 on the patterned surface 121 may be substantially equal to an odd number (2k+1) times the wavelength of the incident light divided by four times the refractive index (n) of the coating 130. For example, in the visible light region with a wavelength of approximately 550 nm, the thickness of the coating 130 may be approximately 101 nm, 303 nm, or 505 nm. However, in this invention, "substantially equal to an odd multiple" can mean "the thickness is equal to an odd (2k+1) multiple of the value obtained by dividing the average wavelength of visible light by four times the average refractive index (n) of coating 130". In this invention, "substantially equal to an odd (2k+1) multiple" means not only that the thickness must satisfy the condition that the thickness is an odd (2k+1) multiple of the value obtained by dividing the wavelength of light by four times the refractive index (n) of coating 130, but also that the difference between the optical path length of light incident on coating 130 and reflected by pattern layer 120 and the optical path length of light reflected from coating 130 results in destructive interference (i.e., optical cancellation). Optical cancellation can include not only cases where the optical path difference is a multiple of 0.5 wavelengths, but also cases where the optical path difference is in the range of 0.25 to 0.5 wavelengths. A certain thickness of coating 130 can be defined by the following Equation 1.

[0039] Formula 1:

[0040]

[0041] Where t is the thickness, m is any natural number, λ is the wavelength of light incident on the optical film, and n is the refractive index of the coating.

[0042] Coating 130 can be applied to patterned surface 121 to reduce reflectivity by coating particles onto patterned surface 121 while maintaining the patterned effect (e.g., HZ effect) of patterned layer 120. Coating 130 can have a low-reflectivity effect while maintaining the patterned effect of patterned layer 120. Coating 130 can reduce the amount of light reflected from the optical film by multiple particles 131. For example, by adjusting the thickness of coating 130 as described above, forming cavities, and filling the cavities with silica particles of air with a refractive index (n) of 1, the low-reflectivity effect can be enhanced. Coating 130 can be applied to the surface of patterned surface by a wet coating process. The wet coating can include inorganic particles and liquid filler material. Inorganic particles can be particles that form cavities internally. Inorganic particles can be silica. Liquid filler material can be resin. Liquid filler material can be cured by heat. The liquid filler material can be cured under ultraviolet light. Inorganic particles can be included in the coating liquid in multiple forms. Multiple particles 131 can be included in the liquid filler material at a content ratio of 1.95% (or wt%) or more. The content ratio can be defined as the particle volume ratio per unit volume, particle mass ratio per unit mass, or specific gravity ratio. The coating 130 may include multiple particles 131. Multiple particles 131 may be disposed at a first portion 122 of the pattern layer 120. Multiple particles 131 may be disposed at a second portion 123 of the pattern layer 120. Multiple particles 131 may be continuously disposed along the pattern surface 121 of the pattern layer 120. Multiple particles 131 may be continuously disposed along both the first portion 122 and the second portion 123 of the pattern layer 120. Multiple particles 131 may be uniformly disposed along the pattern surface 121 of the pattern layer 120. Multiple particles 131 may be uniformly disposed along the pattern surface 121 on at least a portion of the pattern surface 121. The fill rate of the multiple particles 131, defined by the proportion of the total cross-sectional area of ​​the particles disposed on the pattern surface 121 per unit area, can be 40% or more. In this invention, "uniformly disposed particles" can mean not only that they must be disposed in accordance with the overall area of ​​the pattern surface, but also that they are partially uniformly disposed. Alternatively, when disposed with a fill rate of 40% or more, an error range of about 5% is allowed.

[0043] Table 1

[0044]

[0045] Table 2

[0046]

[0047]

[0048] Table 1 shows the fill rate, reflectance, and reflectance reduction ratio of multiple particles disposed on a patterned surface according to a comparative embodiment, as the content ratio changes. Table 2 shows the fill rate, reflectance, and reflectance reduction ratio of multiple particles disposed on a patterned surface according to an embodiment of the present invention, as the content ratio changes. The reflectance reduction ratio in Tables 1 and 2 can be defined as 1 - (reflectance of each content / reflectance of the uncoated pattern). According to an embodiment of the present invention in Table 2, when the content ratio of particles included in the coating liquid is 0.95% or more, the total cross-sectional area of ​​multiple particles per unit area of ​​the patterned surface can be 40% or more. According to an embodiment of the present invention in Table 2, when the fill rate is 40.4% or more, the reflectance reduction ratio increases, showing a trend of increasing reflectance reduction effect according to the embodiment of the present invention.

[0049] Multiple particles 131 can be arranged in a manner that allows them to contact each other. The multiple particles 131 can be arranged along the patterned surface 121 of the patterned layer 120, corresponding to at least a portion of the first portion 122 or the second portion 123. Each particle of the multiple particles 131 may include a cavity (e.g., ...). Figure 6 As shown in 13110). Cavity (e.g.: Figure 6 The 13110 shown may be referred to as a hollow portion or a substantially similar name. Multiple particles 131 may be deposited on the pattern layer 120 using a wet coating process. The multiple particles 131 may be deposited on the pattern layer 120 in liquid form for the wet coating process. The multiple particles 131 may be disposed on the patterned surface 121 of the pattern layer 120 to reduce the reflectivity of the optical film 100. This reduction in reflectivity reduces the effect of light or objects reflecting off the display device, thereby clearly conveying the information displayed on the screen to the user. The multiple particles 131 may be referred to as "nano particles," "spherical particles," or a substantially similar name. The multiple particles 131 may include at least one of silicon dioxide (SiO2), titanium dioxide (TiO2), zirconium dioxide (ZrO2), aluminum oxide (Al2O3), magnesium fluoride (MgF2), and tantalum dioxide (TaO2).

[0050] The coating 130 may include a filler material 132. The coating 130 may include the gaps between the particles constituting the plurality of particles 131. The filler material 132 may be disposed along the patterned surface 121 of the patterned layer 120. The filler material 132 may be disposed along a first portion 122 and a second portion 123 of the patterned layer 120. The filler material 132 may protrude in a first direction corresponding to the first portion 122. The filler material 132 may include a protruding portion 1321 corresponding to the first portion 122. The filler material 132 may be recessed in a second direction corresponding to the second portion 123. The filler material 132 may include a recessed portion 1322 corresponding to the second portion 123. The filler material 132 may be disposed in the gaps between the plurality of particles 131. The filler material 132 may completely fill the gaps between the particles constituting the plurality of particles 131. The filler material 132 may constitute the surface of the coating 130. The filler material 132 may include a first surface 133. When the display panel incorporating the flexible display moves, the filler material 132 can flow and move along with the plurality of particles 131. Due to the function of the filler material 132, the coating 130 can prevent damage to the flexible display during movement. The filler material 132 can support the plurality of particles 131 disposed on the patterned surface 121 of the patterned layer 120. The filler material 132 may include resin.

[0051] Coating 130 can be achieved by applying multiple nanoparticles (e.g., composed of at least one material selected from TiO2, SiO2, ZrO2, Al2O3) to the coating. Figure 1 The particles (131) are dispersed in a low-reflectivity coating liquid and applied to the patterned surface 121 of the patterned layer 120 by a wet coating process. The surface of the optical film 100 achieved by the wet coating process can provide a reflectivity reduction effect. The particles may include other spherical particles. For example, hollow spherical particles can be dispersed in a wet coating liquid on the patterned surface 121 of the patterned layer 120, and the coating liquid can be applied to the patterned surface 121 by a wet coating process to achieve the coating 130.

[0052] Figure 3 This is a schematic cross-sectional view of an optical film 200 according to an embodiment of the present invention. (Refer to...) Figure 3 The constituent elements of the optical film 200 described herein can be compared with those in the reference. Figure 1 and Figure 2 The constituent elements described are essentially the same. (See reference...) Figure 3 The constituent elements of the optical film 200 described herein can be used with Figures 4 to 7 and Figure 9The constituent elements described herein are substantially the same. Constituent elements not described below may be referenced elsewhere. Figure 1 and Figure 2 The constituent elements described are essentially the same.

[0053] Reference Figure 3 According to one embodiment, the optical film 200 may include a plurality of coatings 230. The plurality of coatings 230 may be disposed on a patterned layer 120. The plurality of coatings 230 may extend along a patterned surface 121 of the patterned layer 120. The plurality of coatings 230 may include portions corresponding to at least one of a first portion 122 and a second portion 123 of the patterned layer 120. The plurality of coatings 230 may be stacked in a direction away from the patterned layer 120. The plurality of coatings 230 may be stacked in a first direction. The plurality of coatings 230 may include a plurality of particles 241, 251 and filler materials 242, 252. Each coating 240, 250 constituting the plurality of coatings 230 may be referenced. Figure 1 and Figure 2 The coating described (e.g.: Figure 1 The 130) are essentially the same.

[0054] Multiple coatings 230 may include a first coating 240 and a second coating 250. The first coating 240 may be disposed along the patterned surface 121 of the patterned layer 120. The first coating 240 may include multiple particles 241 and a filler material 242. The first coating 240 may include a first surface 243. The filler material 242 of the first coating 240 may include the first surface 243. The first surface 243 of the first coating 240 may be substantially the same as the first surface 243 of the filler material 242. The second coating 250 may be disposed on the first coating 240. The second coating 250 may be disposed on the first surface 243 of the first coating 240. The second coating 250 may extend along the first coating 240. The second coating 250 may be stacked on the first coating 240. The second coating 250 may include multiple particles 251 and a filler material 252. The filler material 252 of the second coating 250 may include a second surface 253. The second surface 253 of the filler material 252 may be the same as the second surface 253 of the second coating 250.

[0055] Each of the multiple coatings 230 (e.g., Figure 3 The first coating 240 may be composed of different refractive indices. The first coating 240 disposed on the pattern surface 121 may be composed of a higher refractive index than the second coating 250. For example, when the refractive index (n) of the first coating 240 disposed near the pattern surface 121 is 1.4 to 1.7, the refractive index (n) of the second coating 250 disposed away from the pattern surface 121 may be about 1.2 to 1.4. The coatings of the plurality of coatings 230 exposed to air (e.g.: Figure 3 The refractive index of the second coating (250) can be higher than that of the unexposed coating (e.g., ). Figure 3 The first coating 240 has a low refractive index. The coating disposed on the patterned surface 121 (e.g., ...) Figure 3 The 240) may include particles of titanium dioxide (TiO2). Coatings exposed to air (e.g.: Figure 3 (250) may include particles of silicon dioxide (SiO2). See reference. Figure 3 The coatings exposed to air (e.g.: Figure 3 250) may refer to the upper coating of a plurality of stacked coatings 230. The coating disposed on the patterned surface 121 (e.g.: Figure 3 (240) can refer to a coating that is not exposed to air, or a coating located at the bottom of a plurality of coatings. See reference. Figure 3 The first coating 240 and the second coating 250 described herein can be respectively compared with the reference. Figure 1 and Figure 2 The coating described (e.g.: Figure 1 The 130) is substantially the same. The plurality of particles 241, 251 and filler materials 242, 252 included in each of the first coating 240 and the second coating 250 are comparable to those in reference. Figure 1 and Figure 2 Multiple particles described (e.g.: Figure 1 131) and filler materials (e.g.: Figure 1 (132) is the same.

[0056] Figure 4 This is a schematic cross-sectional view of an optical film 300 according to an embodiment of the present invention. (Refer to...) Figure 4 The constituent elements of the optical film 300 described herein can be compared with those in the reference. Figures 1 to 3 The constituent elements described are essentially the same. (See reference...) Figure 4 The constituent elements described can be compared with those in the reference. Figures 5 to 7 and Figure 9 The constituent elements described are essentially the same. Constituent elements not described below may be related to... Figures 1 to 3 The constituent elements described in the text are essentially the same.

[0057] Reference Figure 4 An optical film 300 according to one embodiment may include a coating 330. The coating 330 may include a plurality of particles 331 and a filler material 332. The plurality of particles 331 may be disposed on a pattern layer 120. Each particle constituting the plurality of particles 331 may be stacked along a first direction. Each particle constituting the plurality of particles 331 may be stacked along a direction away from the pattern layer 120. The particles constituting the plurality of particles 331 may be stacked irregularly along a direction away from the pattern layer 120. The plurality of particles 331 may include a first particle, a second particle, and a third particle. The third particle may be stacked on at least a portion of the first particle and at least a portion of the second particle along a direction away from the pattern layer 120. The coating 330 not described below may be related to the referenced material. Figures 1 to 3 The coating described (e.g.: Figure 1 The coating 130 is substantially the same. The plurality of particles 331 and filler material 332 of coating 330, not described below, may be compared with those in reference. Figures 1 to 3 Multiple particles described (e.g.: Figure 1 131) and filler materials (e.g.: Figure 1 (132) is the same.

[0058] Figure 5 This is a cross-sectional view of an optical film according to an embodiment of the present invention. (Refer to...) Figure 5 The particles described can be compared with the reference. Figures 1 to 4 The particles that constitute multiple particles are essentially the same. (See reference...) Figure 5 The particles described can be compared with the reference. Figure 6 , Figure 7 and Figure 9 The particles that constitute multiple particles are substantially the same. The constituent elements of particles not described below can be compared with those in the reference section. Figures 1 to 4 The particles that constitute multiple particles are essentially the same.

[0059] Reference Figure 5 According to one embodiment, the optical film 400 may include a plurality of coatings 430. The plurality of coatings 430 may be disposed on a patterned layer 120. The plurality of coatings 430 may extend along a patterned surface 121 of the patterned layer 120. The plurality of coatings 430 may include portions corresponding to at least one of a first portion 122 and a second portion 123 of the patterned layer 120. The plurality of coatings 430 may be stacked in a direction away from the patterned layer 120. The plurality of coatings 430 may be stacked in a first direction. The plurality of coatings 430 may include a plurality of particles (441; 451) and a filler material (442; 452). The plurality of particles (e.g.: Figure 5 The particles shown in 451) may include cavities (or pores) 4511 within the particles. The individual coatings (440; 450) constituting the plurality of coatings 430 may be related to a reference. Figure 1 and Figure 2 The coating described (e.g.: Figure 1 The 130) are essentially the same.

[0060] Multiple coatings 430 may include a first coating 440 and a second coating 450. A first filler material 442 of the first coating 440 may include a first surface 443. The first surface 443 of the first coating may be substantially the same as the first surface 443 of the first filler material 442. The first coating 440 may be referenced... Figure 3The first coating 240 described is substantially the same. A second coating 450 may be disposed on the first coating 440. The second coating 450 may be disposed on a first surface 443 of the first coating 440. The second coating 450 may extend along the first coating 440. The second coating 450 may be stacked on the first coating 440. The second coating 450 may include a plurality of particles 451 and a filler material 452. The plurality of particles 451 of the second coating 450 may include cavities (or pores) 4511 within the particles. (See reference...) Figure 5 The arrangement of the first coating 440 and the second coating 450 described herein is not limited to this. For example, multiple particles 451, each including a cavity (or pore) 4511 within the particle, may be included in the first coating 440. (See reference...) Figure 5 The first coating 240 and the second coating 250 described herein can be respectively compared with the reference. Figure 1 and Figure 4 The coating described (e.g.: Figure 1 The 130) is substantially the same. The plurality of particles 241, 251 and filler materials 242, 252 included in each of the first coating 240 and the second coating 250 are comparable to those in reference. Figure 1 and Figure 4 Multiple particles described (e.g.: Figure 1 131) and filler materials (e.g.: Figure 1 The same as 132). The cavities (or pores) formed inside the particles 4511 can be compared with the reference. Figure 6 The hollow portion (or pore) 13110 described is essentially the same.

[0061] Figure 6 This is a magnified conceptual diagram of a single particle according to one embodiment of the present invention, which is disposed among multiple particles in an optical film. (See also...) Figure 6 The particles described can be compared with the reference. Figures 1 to 5 The particles that constitute multiple particles are essentially the same. (See reference...) Figure 6 The particles described can be compared with the reference. Figure 7 and Figure 9 The particles that constitute multiple particles are substantially the same. The constituent elements of particles not described below can be compared with those in the reference section. Figures 1 to 5 The particles that constitute multiple particles are essentially the same.

[0062] For ease of explanation, refer to Figure 6 The description consists of multiple particles (e.g.: Figure 1The particle 13100 (131) is shown as circular, but is not limited to this, and may include elliptical, irregular circular, or other shapes. The particle 13100 may include an internal cavity (or hollow portion) 13110. The particle 13100 may include an outer shell (outermost layer) 13120 enclosing the internal cavity (or hollow portion) 13110. The particle 13100 may be made of silicon dioxide (SiO2). The internal cavity 13110 of the particle 13100 may be filled with air. The refractive index (n) of the particle 13100 may be set to approximately 1.45. The air (n) filled in the internal cavity 13110 of the particle 13100, with a refractive index (n) of 1, reduces the overall average refractive index (n) of the particle 13100 because its refractive index (n) is lower than that of the material constituting the particle 13100 (e.g., silicon dioxide (SiO2)). The average refractive index (n) of particles 13100 can be reduced by adjusting the ratio of air occupying the internal cavity 13110 to particles 13100. For example, when the refractive index of silica (SiO2) of particles 13100 is about 1.45, by adjusting the proportion of air, particles 13100 with an average refractive index (n) of about 1.36 can be formed. By filling the internal cavity 13110 with air of relatively low refractive index, particles 13100 reduce the average refractive index (n) while light passes through by changing the light path and repeatedly passing between air and particles 13100.

[0063] For the description of particle 13100 not mentioned below, please refer to [reference needed]. Figures 1 to 5 The particles that make up the multiple particles are the same.

[0064] Figure 7 This is a schematic cross-sectional view of an optical film including a patterned layer according to an embodiment of the present invention. (Refer to...) Figure 7 The constituent elements of the optical film described can be compared with those in the reference. Figures 1 to 6 The constituent elements described are essentially the same. (See reference...) Figure 7 The constituent elements of the optical film described can be compared with those in the reference. Figure 9 The constituent elements described are essentially the same. The constituent elements of optical films not described below can be compared with those in the reference section. Figures 1 to 6 The constituent elements described are essentially the same.

[0065] Reference Figure 7The pattern layer 520 of the optical film 500 may be disposed on the base film 510. The pattern layer 520 may include at least one of a pyramid, an inverted pyramid, a matte pattern, and a prism pattern. The pattern layer 520 may include a patterned surface 521. The pattern layer 520 may include a protrusion 522 protruding along a first direction. The patterned surface 521 may include a protrusion 522 protruding along the first direction. The protrusion 522 of the patterned surface 521 may be the same as the protrusion 522 of the patterned layer 520. The pattern layer 520 may include a recessed portion 523 recessed along a second direction. The patterned surface 521 may include a recessed portion 523 recessed along the second direction. The recessed portion 523 of the patterned surface 521 may be the same as the recessed portion 523 of the patterned layer 520. The coating 530 may include a plurality of particles 531 and a filler material 532. The coating 530 may include a coating surface 533. The filler material 532 may form the coating surface 533 of the coating. The optical film 500 may include a coating 530 on the patterned layer 520. The constituent elements of the optical film 500 not described below may be referenced. Figures 1 to 5 The constituent elements described are essentially the same. The constituent elements of the optical film 500 not described below can be compared with those in the reference section. Figures 1 to 5 The constituent elements described are essentially the same.

[0066] Figure 8 This is a schematic cross-sectional view of an optical film 600 including a conventional patterned layer 620 and a coating 630. The conventional patterned layer 620 may include a patterned surface 621. The conventional patterned layer 620 may include peaks (or protrusions) 622 protruding along a first direction. The conventional patterned layer 620 may include valleys (or recesses) 623 recessed along a second direction. The peaks (or protrusions) 622 and valleys (or recesses) 623 may be repeatedly extended to form the patterned layer 620. The valleys (or recesses) 623 may form recesses 624 on the patterned layer 620. The coating 630 may be disposed on the patterned layer 620. The coating 630 may be applied to the patterned layer 620 using a wet coating process. The coating 630 may include a plurality of particles 631. In a conventional optical film 600, multiple particles 631 may aggregate at the recesses 624 of the pattern layer 620. This aggregation of particles 631 can reduce the haze effect of the pattern layer 620 of the optical film 600. Consequently, it may make it difficult for users to accurately identify information displayed on a display device (not shown).

[0067] Unlike conventional optical films 600, the optical films according to embodiments of the present invention (e.g.: Figure 1 The 100 shown can be in the pattern layer (e.g.: Figure 1 Multiple particles (e.g., on the 120 shown) are uniformly arranged on the surface. Figure 1 As shown in 131). And including Figure 8 The backlight unit shown includes an optical film 600, which differs from the backlight unit of an embodiment of the present invention (e.g., according to another embodiment: Figure 9 The 701 shown can be used in a pattern layer (e.g.: Figure 1 Multiple particles (e.g., on the 120 shown) are uniformly arranged on the surface. Figure 1 (See 131). Therefore, the optical film or backlight unit according to an embodiment of the present invention can effectively reduce the amount of reflection of objects or light on the display device. Thus, the image information displayed on the display device can be accurately conveyed to the user. (Refer to...) Figures 1 to 8 The optical film described in an embodiment of the present invention may include, as referenced... Figure 9 The description illustrates different coatings of the optical film (e.g.: Figure 1 (of 130).

[0068] Figure 9 This is an exploded view of a backlight unit including an optical film according to one embodiment. (Refer to...) Figure 9 The constituent elements of the optical film constituting the backlight unit described herein can be compared with those in the reference. Figures 1 to 7 The constituent elements described are essentially the same. The constituent elements of optical films not described below can be compared with those in the reference section. Figures 1 to 7 The constituent elements described are the same.

[0069] The backlight unit 701 may include a light source 702. The backlight unit 701 may include an optical sheet 703. The backlight unit 701 may include an optical film 700. The optical film 700 may include a base film 710. The optical film 700 may include a pattern layer 720. The pattern layer 720 may include a first portion 722 protruding in a first direction and a second portion 723 recessed in a second direction. The pattern layer 720 may include a pattern surface 721. The pattern layer 720 may include a plurality of first portions 722 and a plurality of second portions 723. The pattern surface 721 may include a plurality of first portions 722 and a plurality of second portions 723. The optical film 700 may include a coating 730. The coating 730 may be disposed on the pattern layer 720. The coating 730 may include a plurality of particles 731. The coating 730 may include a filler material 732. Light emitted from the light source 702 of the backlight unit 701 can be emitted to the outside through the optical sheet 703 and the optical film.

[0070] The optical films involved in the embodiments of the present invention (e.g.: Figure 1 The 100 can be used not only with flat panel displays (FPDs) but also with flexible displays.

[0071] Optical films according to embodiments of the present invention (e.g.: Figure 1 When used in conjunction with a flexible display, the reflectivity can also be reduced without compromising fluidity.

[0072] Optical films according to embodiments of the present invention (e.g.: Figure 1 (100) may include a coating having a uniform thickness along the patterned surface 121 of the patterned layer 120. Optical films according to embodiments of the present invention (e.g.: Figure 1 The 100) may include a coating comprising a plurality of particles that are at least partially uniformly disposed on the pattern layer 120.

[0073] Optical films according to embodiments of the present invention (e.g.: Figure 1 The 100) may include a coating containing multiple particles, some of which are also uniformly disposed in the peaks of the curved portion of the pattern layer 120.

[0074] According to an embodiment of the present invention, an optical film (e.g., disposed in a display device) is used. Figures 1 to 9 The 100; 200; 300; 400; 500; 700) may include a base film (e.g.: Figures 1 to 9 (of 110).

[0075] According to one embodiment of the present invention, an optical film (e.g.: Figures 1 to 9 (100; 200; 300; 400; 500; 700) can be disposed on the base film and include a patterned layer containing curved portions (e.g.: Figures 1 to 9 (of 120).

[0076] An optical film according to an embodiment of the present invention (e.g.: Figures 1 to 9 The 100; 200; 300; 400; 500; 700) may include a coating disposed on the patterned layer (e.g.: Figures 1 to 9 (of 130).

[0077] An optical film according to an embodiment of the present invention (e.g.: Figures 1 to 9 The coating of 100; 200; 300; 400; 500; 700) may include a plurality of particles (e.g., 100; 200; 300; 400; 500; 700) continuously disposed on at least a portion of the curved portion of the patterned layer. Figures 1 to 9 (131).

[0078] An optical film according to an embodiment of the present invention (e.g.: Figures 1 to 9 The coating of (100; 200; 300; 400; 500; 700) may include a filler material (e.g., 100; 200; 300; 400; 500; 700) disposed along the curved portion of the patterned layer and filling the spaces between the plurality of particles. Figures 1 to 9 (132).

[0079] An optical film according to an embodiment of the present invention (e.g.: Figures 1 to 9The coating of 100; 200; 300; 400; 500; 700) may include multiple coatings (e.g.: Figures 1 to 9 230; 430).

[0080] An optical film according to an embodiment of the present invention (e.g.: Figures 1 to 9 The plurality of coatings (e.g., 100; 200; 300; 400; 500; 700) Figures 1 to 9 (230; 430) can be stacked in a direction away from the pattern layer.

[0081] An optical film according to an embodiment of the present invention (e.g.: Figures 1 to 9 The coating of 100; 200; 300; 400; 500; 700) may include a first coating (e.g.: Figures 1 to 9 240; 440) and the second coating (e.g.: Figures 1 to 9 250; 450).

[0082] An optical film according to an embodiment of the present invention (e.g.: Figures 1 to 9 The first coating (100; 200; 300; 400; 500; 700) may be disposed along the curved portion of the patterned layer, and the second coating may be disposed on the first coating.

[0083] An optical film according to an embodiment of the present invention (e.g.: Figures 1 to 9 The plurality of particles (e.g., 100) of the second coating of the second coating Figures 1 to 9 451) may include cavities inside the particle (e.g.: Figures 1 to 9 (4511).

[0084] An optical film according to an embodiment of the present invention (e.g.: Figures 1 to 9 The individual particles included in the plurality of particles of (100) may include cavities within the particles (e.g.: Figures 1 to 9 (13110).

[0085] An optical film according to an embodiment of the present invention (e.g.: Figures 1 to 9 The plurality of particles (e.g., 100) Figures 1 to 9 331) can be irregularly formed inside the coating.

[0086] An optical film according to an embodiment of the present invention (e.g.: Figures 1 to 9 The patterned layer of (100) may include an irregular matte layer (e.g.: Figures 1 to 9 120), pyramidal patterns (e.g.: Figures 1 to 9 420), inverted pyramidal pattern (e.g.: Figures 1 to 9 520) and prism patterns (e.g.: Figures 1 to 9At least one of (420).

[0087] An optical film according to an embodiment of the present invention (e.g.: Figures 1 to 9 The plurality of particles of 100) can be set along the pattern surface (121; 521; 721) of the pattern layer to have a fill rate of 40% or more, defined by the cross-sectional area of ​​the particles per unit area of ​​the pattern surface.

[0088] An optical film according to an embodiment of the present invention (e.g.: Figures 1 to 9 The coating of 100) (e.g.: Figures 1 to 9 130) can be along the pattern surface of the pattern layer (e.g.: Figures 1 to 9 (121; 521; 721) are set with uniform thickness extension.

[0089] An optical film according to an embodiment of the present invention (e.g.: Figures 1 to 9 The pattern layer of 100) (e.g.: Figures 1 to 9 The curved portion of (e.g., 120) Figures 1 to 9 122) may consist of a first portion protruding along a first direction and a second portion recessed along a second direction opposite to the first portion (e.g.: Figures 1 to 9 (123) is repeatedly extended.

[0090] A backlight unit according to an embodiment of the present invention (e.g.: Figures 1 to 9 701) may include a light source (e.g.: Figures 1 to 9 702).

[0091] A backlight unit according to an embodiment of the present invention (e.g.: Figures 1 to 9 701) may include an optical sheet (e.g., for incident light emitted from the light source) Figures 1 to 9 703).

[0092] A backlight unit according to an embodiment of the present invention (e.g.: Figures 1 to 9 701) may include at least one optical film disposed on the optical sheet (e.g.: Figures 1 to 9 (100; 200; 300; 400; 500; 700).

[0093] A backlight unit according to an embodiment of the present invention (e.g.: Figures 1 to 9 Optical films of type 701 (e.g.: Figures 1 to 9 The 100; 200; 300; 400; 500; 700) may include a base film (e.g.: Figures 1 to 9 710), a patterned layer disposed on the base film (e.g.: Figures 1 to 9 720), and multiple particles disposed on the pattern layer (e.g.: Figures 1 to 9 (of 731).

[0094] A backlight unit according to an embodiment of the present invention (e.g.: Figures 1 to 9 Optical films of type 701 (e.g.: Figures 1 to 9 The 100; 200; 300; 400; 500; 700) may include a filling material (e.g., in the space between the plurality of particles) disposed in the space between the plurality of particles. Figures 1 to 9 (732).

[0095] A backlight unit according to an embodiment of the present invention (e.g.: Figures 1 to 9 Optical films of type 701 (e.g.: Figures 1 to 9 The 100; 200; 300; 400; 500; 700) may include a coating comprising the plurality of particles and the filler material (e.g.: Figures 1 to 9 (of 230).

[0096] A backlight unit according to an embodiment of the present invention (e.g.: Figures 1 to 9 The coating 230 of (701) may include a first coating (e.g.: Figures 1 to 9 240) and the second coating (e.g.: Figures 1 to 9 (of 250).

[0097] A backlight unit according to an embodiment of the present invention (e.g.: Figures 1 to 9 701) coating (e.g.: Figures 1 to 9 230) may include a filler material formed at a uniform thickness (e.g.: Figures 1 to 9 (242), and the filler material of the first coating may include the first surface (e.g.: Figures 1 to 9 (of 243).

[0098] A backlight unit according to an embodiment of the present invention (e.g.: Figures 1 to 9 The second coating of (e.g., 701) Figures 1 to 9 (250) can be disposed on the first surface of the first coating.

[0099] A backlight unit according to an embodiment of the present invention (e.g.: Figures 1 to 9 The second coating of (701) may include a plurality of particles (e.g.: Figures 1 to 9 (251; 451).

[0100] A backlight unit according to an embodiment of the present invention (e.g.: Figures 1 to 9 The second coating of 701) contains multiple particles (e.g.: Figures 1 to 9 251; 451) can include a cavity 4511 inside the particle.

[0101] A backlight unit according to an embodiment of the present invention (e.g.: Figures 1 to 9 The individual particles included in the plurality of particles of (701) Figures 1 to 9 The 13100 can include cavities inside the particle (e.g.: Figures 1 to 9 (13110).

[0102] While specific embodiments have been described above in the detailed description of the present invention, it will be apparent to those skilled in the art that various modifications can be made without departing from the scope of the present invention.

Claims

1. An optical film (100; 200;) for use in a display device. 300; 400; 500; 700), characterized in that, include: Base film (110); A patterned layer (120) disposed on the base film and including curved portions; as well as A coating (130) is disposed on the pattern layer (120); The coating (130) includes: A plurality of particles (131) are continuously disposed on at least a portion of the curved portion of the patterned layer; as well as A filling material (132) is disposed along the curved portion of the patterned layer and fills the space between the plurality of particles.

2. The optical film according to claim 1, characterized in that: The coating comprises multiple coatings (230; 430). The multiple coatings are stacked in a direction away from the pattern layer.

3. The optical film according to claim 2, characterized in that: The refractive index of the coating exposed to air among the plurality of coatings is less than that of the coating disposed on the pattern layer.

4. The optical film according to claim 1, characterized in that: The coating comprises a first coating (240; 440) and a second coating (250; 450). The first coating is disposed along the curved portion of the patterned layer. The second coating is applied over the first coating.

5. The optical film according to claim 3, characterized in that: The plurality of particles (251; 451) of the second coating include cavities (4511) inside the particles.

6. The optical film according to claim 4, characterized in that: The refractive index of the second coating is less than that of the first coating.

7. The optical film according to claim 1, characterized in that: The plurality of particles include cavities (13110) inside the particles.

8. The optical film according to claim 1, characterized in that: The plurality of particles (331) are irregularly formed inside the coating.

9. The optical film according to claim 1, characterized in that: The patterned layer includes at least one of an irregular matte layer, a pyramidal pattern, an inverted pyramidal pattern, and a prism pattern.

10. The optical film according to claim 1, characterized in that: The plurality of particles are arranged along the pattern planes (121; 521; 721) of the pattern layer. The fill rate, defined by the cross-sectional area of ​​the particles per unit area of ​​the patterned surface, is 40% or higher.

11. The optical film according to claim 1, characterized in that: The coating (130) extends with a uniform thickness along the patterned surfaces (121; 521; 721) of the patterned layer.

12. The optical film according to claim 1, characterized in that: The curved portion of the patterned layer is repeatedly extended by a first portion that protrudes along a first direction and a second portion that is recessed along a second direction opposite to the first portion.

13. A backlight unit comprising the optical film according to claim 1, characterized in that, include: Light source (702); An optical sheet (703) for incident light emitted from the light source; as well as At least one optical film (100; 200; 300; 400; 500; 700) is disposed on the optical sheet.

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