Optical film, polarizing plate with optical film, and display device

Abstract

The optical film comprises: a low refractive index layer including a plurality of lens portions; and a high refractive index layer filled between the plurality of lens portions, wherein the lens portions are columnar in shape, have flat portions at the ends, and are arranged two-dimensionally. The distance between the flat portions of the adjacent lens portions in a first direction parallel to the film surface is set to A. IN , the distance between the ends of the lens portions adjacent in the first direction on the opposite side of the flat portion is set to A EX , the pitch in the first direction between lens portions adjacent to each other in the first direction is set to P A , the distance between the flat portions of the lens portions adjacent to each other in the second direction is set to B IN , the distance between the ends of the lens portions adjacent to each other in the second direction and on the opposite side of the flat portion is set to B EX , the distance between the midpoints of the lens portions adjacent in the second direction, that is, the pitch, is set to P B , at this time, ((P A ‑((A IN +A EX ) / 2))×(P B ‑((B IN +B EX ) / 2))) / (P A ×P B ) is greater than or equal to 0.42 and less than or equal to 0.70.

Description

Technical Field

[0001] The present disclosure relates to an optical film that performs an optical effect on light emitted from a display surface of a display device, and also to a polarizing plate with an optical film and a display device including the optical film. Background Art

[0002] Liquid crystal display devices, which are an example of display devices, are used in various fields. In addition, organic LED (Organic Light Emitting Diode) display devices are also becoming popular in recent years.

[0003] In a liquid crystal display device, the color tone of an image within a viewing angle may change significantly due to changes in light intensity depending on the viewing angle, leakage of light in an oblique direction, and the like.

[0004] On the other hand, in an organic LED display device, a blue shift is likely to occur in an image viewed from an oblique direction. Blue shift refers to a phenomenon in which an image viewed from an oblique direction becomes bluer than an image viewed from the front. That is, in an image displayed by an organic LED display device, for example, there is a case where the color tone within the viewing angle changes significantly due to such a blue shift. In addition, in an organic LED display device using a microcavity structure, a blue shift is particularly likely to occur significantly.

[0005] The color change within the viewing angle as described above is the main reason that may reduce the display quality of the image. As other factors that affect the display quality, for example, the deviation of the contrast within the viewing angle can also be listed. In the past, various technologies for improving the display quality of images have been proposed. For example, JPH07-43704A, JP3272833A, JP3621959A, JP2016-126350A, JP2012-145944A, JP2011-118393A and US9507059B disclose optical films provided on the display surface of a display device in order to improve the display quality of an image. Summary of the invention

[0006] In the previous optical film, the light from, for example, a liquid crystal panel is reflected and / or refracted at the interface of two layers with a refractive index difference to diffuse the light. Such a previous optical film usually has a long strip-shaped lens portion extending between the two ends of the film. In this structure, for example, demolding becomes easy, so the production of the optical film becomes easy. However, although the improvement effect of the display quality within the viewing angle is effectively manifested in the direction orthogonal to the length direction of the lens portion, it cannot be said that it is greatly manifested in the length direction of the lens portion. Therefore, it may not be said to be good when used in a smartphone with an image rotation function.

[0007] On the other hand, US9507059B proposes an optical film having a plurality of columnar lens portions arranged in two dimensions. In this structure, it is possible to expect improvements in display quality in two directions, such as the left-right direction and the up-down direction. However, in the optical film of US9507059B, since the lens portion is small and the slope is steep, a situation may occur in which the light is not fully diffused over a wider angle range. Furthermore, the valley portion and the end between the lens portions have rounded corners, and the light parallel to the front viewing direction may be accidentally diffused, so the display quality when viewed from the front, such as the brightness level, may also be accidentally impaired.

[0008] The present disclosure is completed in consideration of the above-mentioned actual situation, and its purpose is to provide an optical film that can effectively suppress color changes within the viewing angle while maintaining good display quality when observing the display device from the front, a polarizing plate with an optical film having the optical film, and a display device.

[0009] The optical film of the present disclosure comprises: a low refractive index layer including a plurality of lens portions; and a high refractive index layer having a refractive index higher than that of the low refractive index layer, which is provided in a manner of filling between the plurality of lens portions, wherein:

[0010] The lens portion has a columnar shape that tapers toward the end on the high refractive index layer side, and has a flat portion parallel to the film surface of the optical film at the end on the high refractive index layer side.

[0011] The plurality of lens portions are two-dimensionally arranged in a first direction parallel to the film surface and in a second direction orthogonal to the first direction.

[0012] Let A be a distance in the first direction between the flat portions of the lens portions adjacent to each other in the first direction. IN ,

[0013] The distance in the first direction between the ends of the lens portions adjacent in the first direction on the opposite side to the flat portion is defined as A. EX ,

[0014] The first direction pitch, which is the distance in the first direction between the midpoints of the lens portions adjacent to each other in the first direction, is denoted by P. A ,

[0015] Let the distance in the second direction between the flat portions of the lens portions adjacent to each other in the second direction be B. IN ,

[0016] The distance in the second direction between the ends of the lens portions adjacent in the second direction on the opposite side to the flat portion is defined as B.EX ,

[0017] The distance in the second direction between the midpoints of the lens portions adjacent in the second direction, that is, the second direction pitch is denoted as P. B ,at this time,

[0018] ((P A -((A IN +A EX ) / 2))×(P B -((B IN +B EX ) / 2))) / (P A ×P B ) is greater than or equal to 0.42 and less than or equal to 0.70.

[0019] When the height of the lens portion is H, H / ((A IN +A EX ) / 2) and H / ((B IN +B EX ) / 2) can be respectively greater than or equal to 1.40 and less than or equal to 3.00.

[0020] In addition, the optical film of the present disclosure comprises: a low refractive index layer including a plurality of lens portions; and a high refractive index layer having a refractive index higher than that of the low refractive index layer, which is provided in a manner of filling between the plurality of lens portions, wherein:

[0021] The lens portion has a columnar shape that tapers toward the end on the high refractive index layer side, and has a flat portion parallel to the film surface of the optical film at the end on the high refractive index layer side.

[0022] The plurality of lens portions are two-dimensionally arranged in a first direction parallel to the film surface and in a second direction orthogonal to the first direction.

[0023] Let A be a distance in the first direction between the flat portions of the lens portions adjacent to each other in the first direction. IN , a distance in the first direction between ends of the lens portions adjacent in the first direction on the opposite side to the flat portion is defined as A EX , the distance in the second direction between the flat portions of the lens portions adjacent in the second direction is set to B IN , the distance in the second direction between the ends of the lens portions adjacent in the second direction on the opposite side to the flat portion is set to B EX , the height of the lens portion is set to H, at this time,

[0024] H / ((A IN +A EX) / 2) and H / ((B IN +B EX ) / 2) are respectively greater than or equal to 1.40 and less than or equal to 3.00.

[0025] In addition, the optical film of the present disclosure may be disposed so that the flat portion of the lens faces the display panel side.

[0026] The plurality of lens portions may be arranged in a matrix, and the high refractive index layer may include a tic-tac-toe shaped portion.

[0027] The lens portion may be in the shape of a quadrangular pyramid, and the flat portion may be in the shape of a square.

[0028] The lens portion may be in the shape of a quadrangular pyramid, and the flat portion may be in the shape of a rectangle.

[0029] The side surface of the lens portion may be a curved surface convex toward the high refractive index layer.

[0030] In addition, the optical film of the present disclosure comprises: a low refractive index layer including a plurality of lens portions; and a high refractive index layer having a refractive index higher than that of the low refractive index layer, which is provided in a manner of filling between the plurality of lens portions, wherein:

[0031] The lens portion is in a columnar shape that tapers toward one end in a normal direction of the film surface of the optical film, and has a flat portion parallel to the film surface at the end on the one end.

[0032] The plurality of lens portions are two-dimensionally arranged in a first direction parallel to the film surface and in a second direction orthogonal to the first direction.

[0033] Let A be a distance in the first direction between the flat portions of the lens portions adjacent to each other in the first direction. IN ,

[0034] The distance in the first direction between the ends of the lens portions adjacent in the first direction on the opposite side to the flat portion is defined as A. EX ,

[0035] The first direction pitch, which is the distance in the first direction between the midpoints of the lens portions adjacent to each other in the first direction, is denoted by P. A ,

[0036] Let the distance in the second direction between the flat portions of the lens portions adjacent to each other in the second direction be B. IN ,

[0037] The distance in the second direction between the ends of the lens portions adjacent in the second direction on the opposite side to the flat portion is defined as B. EX ,

[0038] The distance in the second direction between the midpoints of the lens portions adjacent in the second direction, that is, the second direction pitch is denoted as P. B ,at this time,

[0039] ((P A -((A IN +A EX ) / 2))×(P B -((B IN +B EX ) / 2))) / (P A ×P B ) is greater than or equal to 0.42 and less than or equal to 0.70.

[0040] In the optical film, when the height of the lens portion is defined as H, H / ((A IN +A EX ) / 2) and H / ((B IN +B EX ) / 2) can be respectively greater than or equal to 1.40 and less than or equal to 3.00.

[0041] In addition, the optical film of the present disclosure comprises: a low refractive index layer including a plurality of lens portions; and a high refractive index layer having a refractive index higher than that of the low refractive index layer, which is provided in a manner of filling between the plurality of lens portions, wherein:

[0042] The lens portion is in a columnar shape that tapers toward one end in a normal direction of the film surface of the optical film, and has a flat portion parallel to the film surface at the end on the one end.

[0043] The plurality of lens portions are two-dimensionally arranged in a first direction parallel to the film surface and in a second direction orthogonal to the first direction.

[0044] Let A be a distance in the first direction between the flat portions of the lens portions adjacent to each other in the first direction. IN , a distance in the first direction between ends of the lens portions adjacent in the first direction on the opposite side to the flat portion is defined as A EX , the distance in the second direction between the flat portions of the lens portions adjacent in the second direction is set to B IN , the distance in the second direction between the ends of the lens portions adjacent in the second direction on the opposite side to the flat portion is set to B EX , the height of the lens portion is set to H, at this time,

[0045] H / ((A IN +A EX ) / 2) and H / ((B IN +B EX ) / 2) are respectively greater than or equal to 1.40 and less than or equal to 3.00.

[0046] In addition, the display device of the present disclosure has:

[0047] The above optical film; and

[0048] The organic LED panel is provided with the optical film on the display surface of the organic LED panel.

[0049] In addition, the display device of the present disclosure has:

[0050] The above optical film; and

[0051] The optical film is arranged on the display surface of the liquid crystal panel.

[0052] In addition, the polarizing plate with an optical film of the present disclosure includes:

[0053] The above optical film; and

[0054] A polarizing plate is bonded to the optical film.

[0055] According to the present disclosure, it is possible to effectively suppress color changes within a viewing angle while maintaining good display quality of a display device when viewed from the front. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 This is a diagram schematically showing the structure of a display device including an optical film according to a first embodiment of the present disclosure.

[0057] Figure 2 is set at Figure 1 A partial perspective view of an optical film of a display device shown.

[0058] Figure 3 It is schematically shown Figure 2 A diagram showing the arrangement of lens portions in the low refractive index layer of the optical film shown.

[0059] Figure 4 It is along Figure 3 A cross-sectional view of the optical film when it is cut along the line IV-IV.

[0060] Figure 5 It is along Figure 3 A cross-sectional view of the optical film when it is cut in the direction of the VV line.

[0061] Figure 6 It is shown Figure 2 A diagram showing a modified example of the optical film shown.

[0062] Figure 7 It is shown Figure 2 A diagram showing a modified example of the optical film shown.

[0063] Figure 8 It is shown Figure 2 A diagram showing a modified example of the optical film shown.

[0064] Fig. 9 It is shown Figure 1 A diagram of a modified example of the display device shown.

[0065] Fig.10 This is a diagram schematically showing a structure of a display device including an optical film according to a second embodiment of the present disclosure.

[0066] Fig.11 The graphs are diagrams showing the relationship between the shape of the optical films of Examples and Comparative Examples and the brightness and color changes. DETAILED DESCRIPTION

[0067] Hereinafter, each embodiment of the present disclosure will be described with reference to the drawings.

[0068] It should be noted that, in this specification, the terms such as "sheet", "film", "plate" and the like are not distinguished from each other only based on the difference in name. Therefore, for example, "sheet" is a concept that also includes components that can also be called films or plates. In addition, in this specification, "sheet surface (plate surface, film surface)" refers to a surface that is consistent with the plane direction (surface direction) of the sheet component as a target when the sheet component as a target is observed as a whole and in a large area. It should be noted that "sheet surface (plate surface, film surface)" is sometimes also referred to as the main surface. Furthermore, in this specification, the normal direction of the sheet component refers to the normal direction of the sheet component as a target relative to the sheet surface.

[0069] <First Embodiment>

[0070] Figure 1 1 is a diagram schematically showing the structure of a display device 10 having an optical film 100 according to the first embodiment. The display device 10 is formed by sequentially stacking an organic LED (Organic Light Emitting Diode) panel 15, a circular polarizing plate 20, a touch panel 30, a cover glass 40, and an optical film 100. As an example, the display device 10 of this embodiment is configured as a smartphone. However, the display device 10 may also be a tablet terminal, a television, a computer display, a car navigation system, etc.

[0071] The display surface (front surface) 15A of the organic LED panel 15 is bonded to the back surface of the circular polarizer 20 via a first adhesive layer 51. The front surface of the circular polarizer 20 is bonded to the back surface of the touch panel 30 via a second adhesive layer 52. The front surface of the touch panel 30 is bonded to the back surface of the cover glass 40 via a third adhesive layer 53. Each adhesive layer 51 to 53 is a so-called OCA (Optical Clear Adhesive) having a high light transmittance.

[0072] The optical film 100 is disposed on the front surface of the cover glass 40. In this example, the optical film 100 and the cover glass 40 are not bonded together via an adhesive layer, but the optical film 100 and the cover glass 40 may be bonded together via an adhesive layer.

[0073] exist Figure 1 In the figures used in the following description, reference numeral D 1 It represents the direction parallel to the film surface of the optical film 100, that is, the first direction. 2 The direction parallel to the film surface of the optical film 100 and parallel to the first direction D 1 In addition, the symbol D 3 Indicates the first direction D 1 and the second direction D 2 The third direction is orthogonal to both sides.

[0074] The organic LED panel 15 has an organic LED panel with a microcavity structure, but may be in other forms. Generally speaking, in an organic LED panel, a blue shift is easily generated in an image observed from an oblique direction. Such a blue shift is particularly likely to be significantly apparent in an organic LED panel with a microcavity structure. Therefore, in the display device 10, the optical film 100 is used to suppress the color change within the viewing angle.

[0075] In this embodiment, a circular polarizer 20, a touch panel 30, and a cover glass 40 are arranged between the organic LED panel 15 and the optical film 100. The circular polarizer 20 has a polarizer and a phase difference plate, the phase difference plate is arranged on the side of the organic LED panel 15, and the polarizer is bonded to the surface of the phase difference plate on the side opposite to the organic LED panel 15. Specifically, the polarizer is a linear polarizer, and the phase difference plate is a λ / 4 phase difference plate. The touch panel 30 includes a transparent glass plate. The touch panel 30 preferably adopts an electrostatic capacitance method. The cover glass 40 has a protective function. However, the cover glass 40 may also have other functions such as an anti-reflection function.

[0076] The optical film 100 includes a low refractive index layer 102 and a high refractive index layer 103 bonded to each other. Although no substrate is disposed on the side of the low refractive index layer 102 opposite to the high refractive index layer 103, a substrate may be included.

[0077] Figure 2 1 is a partial stereogram of the optical film 100. Figure 2 In FIG. 1 , for convenience of explanation, the high refractive index layer 103 is indicated by a two-dot chain line. Figure 3 This is a diagram of observing the low refractive index layer 102 in the normal direction, in other words, in the third direction D 3 Observation diagram on the top. Figure 3 The arrangement of lens units 110 described later included in the low refractive index layer 102 is schematically shown. Figure 4 It is along Figure 3 This is a cross-sectional view of the optical film 100 cut along line IV-IV. Figure 5 It is along Figure 3 This is a cross-sectional view of the optical film 100 cut along the VV line.

[0078] The low refractive index layer 102 integrally includes: a film-like layer body 102A having a front surface and a back surface; and a plurality of lens portions 110 extending in the first direction D. 1 and the second direction D 2 The high refractive index layer 103 is two-dimensionally arranged on the back side of the layer body 102A. In contrast, the high refractive index layer 103 is stacked on the low refractive index layer 102 in a manner that covers the lens portion 110 and fills between the plurality of lens portions 110. Thus, in the present embodiment, the interface between the low refractive index layer 102 and the high refractive index layer 103 is formed into a concavo-convex shape. In addition, the high refractive index layer 103 is formed into a film-like shape having a plurality of holes for accommodating the plurality of lens portions 110, and more specifically, is formed into a tic-tac-toe shape or a lattice shape.

[0079] Specifically, the high refractive index layer 103 includes: a film-like layer body 103A having a front surface and a back surface; and a tic-tac-toe shaped portion 103B. The tic-tac-toe shaped portion 103B is integrated with the front surface of the layer body 103A facing the low refractive index layer 102. 3 When viewed from above, the tic-tac-toe shaped portion 103B is in a tic-tac-toe shape (grid shape, hash shape, etc.). In addition, the low refractive index layer 102 may not have the layer body 102A, but may be composed of a collection of multiple lens portions 110. In addition, the high refractive index layer 103 may not have the layer body 103A, but may be composed only of the tic-tac-toe shaped portion 103B.

[0080] like Figure 3 As shown, the lens units 110 are arranged two-dimensionally in a matrix. Specifically, in the first direction D 1 The plurality of lens portions 110 arranged at equal intervals on the upper side are arranged in a row in the second direction D 2 In this example, all of the plurality of lens portions 110 have the same shape.2 The lens portions 110 adjacent to each other are arranged in the first direction D 1 The way of not deviating in the second direction D 2 On the mutual

[0081] In addition, the lens portion 110 is located on one side of the normal direction of the film surface of the optical film 100, that is, Figure 1 The lens portion 110 has a cylindrical shape with a tapered lower end. Moreover, the lens portion 110 has a flat portion 111 at the end on the high refractive index layer 103 side as the normal direction, and the flat portion 111 extends along the surface direction of the low refractive index layer 102 and the high refractive index layer 103, that is, the film surface of the optical film 100. In detail, the lens portion 110 is a quadrangular pyramid, in detail, a regular quadrangular pyramid, and the flat portion 111 is a rectangular shape, more specifically a square. On the other hand, the lens portion 110 has four side surfaces 110S located between the flat portion 111 and the layer body 102A and connected in a rectangular shape.

[0082] like Figure 4 As shown, the flat portion 111 is interposed in the first direction D 1 The two side surfaces 110S facing each other on the upper side become thinner toward the high refractive index layer 103 side. Figure 5 As shown, the flat portion 111 is interposed in the second direction D 2 The two side surfaces 110S facing each other also taper toward the high refractive index layer 103. In addition, each of the four side surfaces 110S is a curved surface convex toward the high refractive index layer 103.

[0083] The side surface 110S may be a curved surface formed as a circular arc in the cross-sectional view and convex to the high refractive index layer 103 side, or may be a curved surface formed as an elliptical arc and convex to the high refractive index layer 103 side. In addition, the side surface 110S may also be a folded surface convex to the high refractive index layer 103 side. In addition, the side surface 110S may also be a curved surface or a folded surface recessed to the low refractive index layer 102 side, or may be a flat surface.

[0084] In addition, as can be seen from the figure, the optical film 100 in this embodiment is arranged in such a manner that the high refractive index layer 103 faces the organic LED panel 15. In other words, the optical film 100 is arranged in such a manner that the flat portion 111 of the lens portion 110 faces the organic LED panel 15. Therefore, the high refractive index layer 103 is located on the incident side of the light from the organic LED panel 15, and the low refractive index layer 102 is located on the emitting side of the light.

[0085] Figure 4 The symbol A shown IN 、Label A EX 、Label P A It means the following.

[0086] ·A IN: In the first direction D 1 The distance between the flat portions 111 of the lens portions 110 adjacent to each other in the first direction D 1 The distance on the first direction, that is, the incident width on the high refractive index side.

[0087] ·A EX : In the first direction D 1 The distance between the ends of the lens portions 110 on the opposite side to the flat portion 111 is in the first direction D. 1 The distance on the high refractive index side, that is, the emission width in the first direction.

[0088] ·P A : In the first direction D 1 The first direction D of the lens portions 110 adjacent to each other 1 In the first direction D 1 The distance on is the first direction spacing.

[0089] Figure 5 The number B shown IN 、Label B EX 、Label P B It means the following.

[0090] ·B IN : In the second direction D 2 The distance between the flat portions 111 of the lens portions 110 adjacent to each other in the second direction D 2 The distance on the side, that is, the incident width on the high refractive index side in the second direction.

[0091] ·B EX : In the second direction D 2 The distance between the ends of the lens portions 110 on the opposite side to the flat portion 111 is in the second direction D. 2 The distance on the high refractive index side in the second direction.

[0092] ·P B : In the second direction D 2 The second direction D of the lens portions 110 adjacent to each other 2 The midpoints between the 2 The distance on is the second direction spacing.

[0093] in addition, Figure 4 and Figure 5 The symbol H in denoted by FIG. 1 represents the height of the lens portion 110 .

[0094] Here, the optical film 100 of the present embodiment satisfies the relationship between the following conditions (1) and (2).

[0095] Condition (1): ((P A -((AIN +A EX ) / 2))×(P B -((B IN +B EX ) / 2))) / (P A ×P B ) is greater than or equal to 0.42 and less than or equal to 0.70.

[0096] ·Condition (2): H / ((A IN +A EX ) / 2) and H / ((B IN +B EX ) / 2) are respectively greater than or equal to 1.40 and less than or equal to 3.00.

[0097] In addition, in the following, ((P A -((A IN +A EX ) / 2))×(P B -((B IN +B EX ) / 2))) / (P A ×P B ) is called the slope ratio.

[0098] In addition, H / ((A IN +A EX ) / 2) is called the average aspect ratio when viewed in the first direction, and H / ((B IN +B EX ) / 2) is called the average aspect ratio when viewed in the second direction.

[0099] The inventors of the present application have found that when the above-mentioned condition (1) or (2) is satisfied, the color change within the viewing angle can be effectively suppressed while maintaining the good display quality when the display device 10 is observed from the front. The inventors of the present application have also found that when both condition (1) and condition (2) are satisfied, this effect can be further improved.

[0100] The optical film 100 allows the organic LED panel 15 to emit light, such as Figure 4The light L1 to L3 shown in the figure is totally reflected on the side surface 110S of the lens portion 110, and the totally reflected light is diffused to a wide angle range on the high-angle side. Here, if the lens portion 110 is relatively small, the amount of light that can be totally reflected on the side surface 110S is reduced. In addition, if the lens portion 110 is small and the side surface 110S is steeply sloped, it may not be possible to diffuse the light to a wide range. In addition, if the side surface 110S is steeply sloped and the end of the lens portion 110 is sharp or rounded, the light parallel to the front viewing direction may be diffused unexpectedly. The inventors of the present application conducted an in-depth study on the shape, size, etc. of the lens portion 110 while taking these matters into consideration, and as a result, discovered the above-mentioned conditions (1) and (2).

[0101] More specifically, it was found that: for the light emitted from the organic LED panel 15 to the outside through the optical film 100, in the direction from the third direction D 3 The front viewing direction of the display device 10 is parallel to the front viewing direction of the display device 10, and the first direction D includes the front viewing direction and the first direction D. 1 When the light is observed in a direction 45 degrees relative to the front observation direction in a plane and the color change Δu'v' of the light emitted in the direction 45 degrees relative to the color of the light emitted in the front observation direction is calculated, it can be predicted that the color change Δu'v' in the case of having the optical film 100 is less than 75% of the color change in the case of not having the optical film 100.

[0102] Similarly, it was found that the light emitted from the organic LED panel 15 to the outside through the optical film 100 is emitted in the direction corresponding to the third direction D. 3 The front viewing direction of the display device 10 is parallel to the front viewing direction of the display device 10, and the second direction D includes the front viewing direction and the second direction D 2 When the light is observed in a direction 45 degrees relative to the front observation direction in a plane and the color change Δu'v' of the light emitted in the direction 45 degrees relative to the color of the light emitted in the front observation direction is calculated, it can be predicted that the color change Δu'v' in the case of having the optical film 100 is less than 75% of the color change in the case of not having the optical film 100.

[0103] In addition, the color change Δu'v' represents the color difference. In the present embodiment, the smaller the value, the smaller the color difference relative to the light emitted in the front observation direction. The color change Δu'v' is calculated based on the color specified by u' and v' in the uniform color space. The value of Δu'v' at an angle θ in a certain viewing angle is expressed by the following formula (1). By substituting the value of 45 degrees into θ in formula (1), the color change when the observation angle is 45 degrees can be calculated.

[0104] [Number 1]

[0105]

[0106] The color coordinates u' and v' in the uniform color space in equation (1) are expressed by the following equations (2-1) and (2-2), respectively.

[0107] [Number 2]

[0108]

[0109]

[0110] Here, in each of the above equations, x and y are color coordinates defined by the CIE1931 color space (CIExy Y color space).

[0111] in addition, Figure 4 The symbol θ in A The straight line passing through the end point on the high refractive index layer 103 side of the side surface 110S and the end point on the opposite side and the third direction D 3 The angle of one side of the acute angle. Figure 5 The symbol θ in B The straight line passing through the end point on the high refractive index layer 103 side of the side surface 110S and the end point on the opposite side and the third direction D 3 The angle of the acute angle formed by these angles θ A and θ B The angle θ is determined within the range of greater than 0 degrees and less than or equal to 15 degrees under the conditions of satisfying the above conditions (1) and (2). A and θ B It is preferably greater than 0 degrees and less than 10 degrees, and more preferably greater than 5 degrees and less than 10 degrees. If it is less than 0 degrees, it may be difficult to release the mold. In addition, if it is greater than 15 degrees, there is a situation where the light totally reflected on the side surface 110S travels too obliquely, which may cause the unfavorable situation of reduced front brightness. In addition, the angle θ A and θ B This corresponds to the “average slope angle” shown in Table 1 etc. described later.

[0112] In addition, when the above conditions (1) and (2) are satisfied, the first direction high refractive index side incident width A IN and the first direction high refractive index side emission width A EX Preferably formed as: ((A IN -A EX )×2) / P A The relationship of being 0.2 or more and 0.5 or less (in the case of percentage, being 20% ​​or more and 50% or less) holds. IN and the second direction high refractive index side emission width B EXPreferably formed as: ((B IN -B EX )×2) / P B The relationship of being 0.2 or more and 0.5 or less (in the case of percentage, being 20% ​​or more and 50% or less) holds true. IN -A EX )×2) / P A or ((B IN -B EX )×2) / P B Less than 0.2, the color change suppression effect may not be effectively obtained. IN -A EX )×2) / P A or ((B IN -B EX )×2) / P B If it is greater than 0.5, the front brightness may decrease.

[0113] In addition, in the present embodiment, the low refractive index layer 102 and the high refractive index layer 103 are selected so that the difference between the refractive index of the low refractive index layer 102 and the refractive index of the high refractive index layer 103 is within the range of 0.05 or more and 0.60 or less. When the optical film 100 is combined with the organic LED panel 15, the difference between the refractive index of the low refractive index layer 102 and the refractive index of the high refractive index layer 103 is preferably 0.05 or more and 0.50 or less, and more preferably 0.10 or more and 0.20 or less. In addition, when the optical film 100 is combined with a liquid crystal panel instead of the organic LED panel 15, the difference between the refractive index of the low refractive index layer 102 and the refractive index of the high refractive index layer 103 is also preferably 0.05 or more and 0.50 or less, and more preferably 0.10 or more and 0.20 or less.

[0114] The refractive index of the low refractive index layer 102 is, for example, 1.40 or more and 1.55 or less, and the refractive index of the high refractive index layer 103 is, for example, 1.55 or more and 1.90 or less, which is larger than the refractive index of the low refractive index layer 102 .

[0115] In addition, as described above, the optical film 100 is configured such that the high refractive index layer 103 is located on the incident side of the light from the organic LED panel 15, and the low refractive index layer 102 is located on the exit side of the light. In the present embodiment, by satisfying the above-mentioned conditions (1) and (2), the following effect is achieved: the amount of light that is directed from the high refractive index layer 103 toward the side surface 110S of the lens portion 110 that is a part of the low refractive index layer 102 and is totally reflected by the side surface 110S can be ensured to a large extent. Here, assuming that the low refractive index layer 102 is located on the incident side of the light from the organic LED panel 15, and the portion corresponding to the lens portion 110 is formed on the high refractive index layer 103, it is difficult to ensure a large amount of totally reflected light. Therefore, in the optical film 100, the high refractive index layer 103 is configured on the organic LED panel 15 side.

[0116] However, the inventors of the present application have confirmed that when the low refractive index layer 102 is located on the incident side of light from the organic LED panel 15 and the low refractive index layer 102 has the lens portion 110 , advantageous optical performance can be obtained.

[0117] It should be noted that the low refractive index layer 102 can be formed by curing, for example, an ultraviolet curing resin, an electron beam curing resin, or a thermosetting resin. When the low refractive index layer 102 is formed by curing an ultraviolet curing resin, the ultraviolet curing resin can include an acrylic resin or an epoxy resin.

[0118] High refractive index layer 103 can also be formed by, for example, curing ultraviolet curing resin, electron beam curing resin, or thermosetting resin. When high refractive index layer 103 is formed by curing ultraviolet curing resin, the ultraviolet curing resin can include acrylic resin or epoxy resin. In addition, when high refractive index layer 103 is formed as an adhesive layer, high refractive index layer 103 can be formed by an acrylic resin adhesive.

[0119] In addition, the layer body 102A in the low refractive index layer 102 is oriented in the third direction D 3 The thickness of the lens portion 110 is, for example, 0.5 μm or more and 30 μm or less. In addition, the height of the lens portion 110 is, for example, 1.0 μm or more and 30 μm or less. On the other hand, the thickness of the high refractive index layer 103 is 5 μm or more and 100 μm or less. In addition, the thickness of the high refractive index layer 103 is the distance from the end point of the low refractive index layer 102 side of the cross-shaped portion 103B to the surface of the layer body 103A on the opposite side of the low refractive index layer 102 side.

[0120] Next, the operation of this embodiment will be described.

[0121] When light for forming an image is emitted from the organic LED panel 15, the light is incident on the optical film 100 through the circular polarizer 20, the touch panel 30, and the cover glass 40. Of the light incident on the optical film 100, light that is incident on the flat portion 111 or the flat portion of the layer body 102A between adjacent lens portions 110 along the front viewing direction is Figure 4 As shown by the reference numerals L4 and L5, the light is emitted from the low refractive index layer 102 without changing the angle of the traveling direction or with almost no change in the angle of the traveling direction, thereby contributing to the formation of an image when observed from the front.

[0122] On the other hand, among the light incident on the optical film 100, the light that is directed toward the side surface 110S of the lens portion 110 along the front viewing direction or in a direction inclined at a relatively small angle relative to the front viewing direction is totally reflected by the side surface 110S. Figure 4 As shown by the reference numerals L1 to L3, the light changes its traveling direction to the high angle side and is emitted from the low refractive index layer 102. That is, the light in a direction inclined at a relatively small angle relative to the front viewing direction is totally reflected by the side surface 110S and travels to the high angle side compared to the initial direction. Thus, a large amount of light can be avoided from being concentrated in the front viewing direction, thereby forming a high-quality image when viewed obliquely.

[0123] Here, in this embodiment, the optical film 100 is formed in a manner that satisfies the above-mentioned conditions (1) and (2), whereby the lens portion 110 is elongated in the height direction, which can ensure that the area of ​​the side surface 110S is large, and thus it is easy to guide light from between adjacent lens portions 110 to the side surface 110S of the lens portion 110, thereby making it possible to diffuse the light within a relatively light range. In addition, by providing a flat portion 111 at the end of the lens portion 110, it is possible to avoid accidental diffusion of light traveling in the front viewing direction, thereby suppressing the reduction in image quality when viewed from the front. Moreover, the lens portion 110 is in the shape of a column that tapers toward the high refractive index layer 103 side, thereby making it possible to provide a flat portion 111 at the end of the lens portion 110, thereby preventing the light traveling in the front viewing direction from being accidentally diffused, thereby suppressing the reduction in image quality when viewed from the front. In addition, the lens portion 110 is in the shape of a column that tapers toward the high refractive index layer 103 side, thereby making it possible to provide a flat portion 111 at the end of the lens portion 110, thereby preventing the light traveling in the front viewing direction from being accidentally diffused, thereby suppressing the reduction in image quality when viewed from the front. 1 A direction inclined relative to the front viewing direction in the plane of 2 Color changes are suppressed in two directions: in the plane tilted relative to the front viewing direction.

[0124] As described above, in this embodiment, it is possible to effectively suppress color changes within a viewing angle while maintaining good display quality when the display device is viewed from the front.

[0125] Hereinafter, a modification of the above-mentioned embodiment will be described. Figures 6 to 9Modifications of the above-described embodiment are shown in . Among the components of each modification, the same components as those described in the above-described embodiment are denoted by the same reference numerals, and descriptions other than the differences are omitted.

[0126] exist Figure 6 In the illustrated modification, the side surface 110S is a folded surface and has three element surfaces, namely, a first element surface 131, a second element surface 132, and a third element surface 133, each of which is formed as a plane. Figure 7 In the illustrated variation, the side surface 110S includes: a curved surface 134; and a folded surface having two element surfaces 135 and 136 that are configured as planes. Figure 8 In the illustrated variation, the side surface 110S includes a curved surface 137 and a flat surface 138 .

[0127] Fig. 9 The display device 10' of the modified example shown is composed of an organic LED panel 15, an optical film 100, a circular polarizing plate 20, a touch panel 30 and a cover glass 40 stacked in sequence. The optical film 100 is arranged on the display surface (front) 15A of the organic LED panel 15. The front of the optical film 100 and the back of the circular polarizing plate 20 are bonded by an adhesive layer 510. The front of the circular polarizing plate 20 and the back of the touch panel 30 are bonded by an adhesive layer 520. The front of the touch panel 30 and the back of the cover glass 40 are bonded by an adhesive layer 530. Each adhesive layer 510, 520, 530 is a so-called OCA (Optical Clear Adhesive) having a high light transmittance. In this example, the organic LED panel 15 and the optical film 100 are not bonded by an adhesive layer, but the organic LED panel 15 and the optical film 100 may also be bonded by an adhesive layer.

[0128] In the display device 10' of the modified example, the circular polarizing plate 20 is arranged at a position closer to the external light incident side (cover glass 40 side) than the optical film 100. Therefore, when external light is incident from the cover glass 40 toward the organic LED panel 15, the circular polarizing plate 20 makes it difficult for the external light to be incident on the optical film 100, thereby suppressing multiple reflections in the optical film 100. As a result, the occurrence of visual recognition obstruction phenomena such as rainbow unevenness and interference fringes can be suppressed, and good visual recognition of the image can be ensured.

[0129] In the above embodiment, the lens portion 110 in the low refractive index layer 102 is a quadrangular pyramid, but may be a cone, a hexagonal pyramid, or an octagonal pyramid. In addition, the arrangement of the lens portion 110 is not limited to a matrix, and may be, for example, a staggered grid.

[0130] In addition, when the lens portion 110 is viewed in the normal direction of the low refractive index layer 102, in the above embodiment, the flat portion 111 and the base end portion are in a square shape. Figure 3 As shown, when the lens portion 110 is observed in the normal direction of the low refractive index layer 102, the aspect ratio (first maximum width W1: second maximum width W2 in a direction perpendicular to the direction defining the first maximum width W) of the lens portion 110 (flat portion 111 and base end portion) is 1:1. However, the shape of the lens portion 110 is not limited thereto, and for example, W1:W2 may be approximately 1:3 to 3:1. The direction defining the first maximum width W1 or the direction defining the second maximum width W2 may be perpendicular to the first direction D. 1 If the difference between the first maximum width W1 and the second maximum width W2 is greater than three times, mold release becomes difficult, which leads to a decrease in productivity and a high risk of collapse of the lens portion 110 .

[0131] Furthermore, the above-described display devices 10 and 10 ′ include a combination of the organic LED panel 15 and the optical film 100 in which the lens portions 110 are two-dimensionally arranged, but a liquid crystal panel and the optical film 100 may also be combined.

[0132] In addition, during assembly Fig. 9 In the case of the display device 10 ′ shown, a polarizing plate with an optical film may be prepared in advance by integrating the optical film 100 and the circular polarizing plate 20 . In this case, the low refractive index layer 102 of the optical film 100 and the phase difference plate of the circular polarizing plate 20 are bonded together.

[0133] <Second Embodiment>

[0134] Fig.10 1 is a diagram schematically showing the structure of a display device 10 ″ including an optical film 200 according to a second embodiment. The same reference numerals are used for the same components of this embodiment as those of the first embodiment, and description thereof is omitted.

[0135] In the optical film 200 of the display device 10 ″ of the second embodiment, the orientation of the low refractive index layer 102 and the high refractive index layer 103 is opposite to that of the optical film 100 of the first embodiment. The other structures are the same as those of the first embodiment.

[0136] That is, in the optical film 200 of the display device 10 ″ of the second embodiment, the low refractive index layer 102 is located on the incident side of light from the organic LED panel 15 , and the low refractive index layer 102 has the lens portion 110 .

[0137] In such an optical film 200 , by satisfying the following conditions (1) and / or (2) described in the first embodiment, it is possible to effectively suppress color changes within a viewing angle while maintaining good display quality when the display device is viewed from the front.

[0138] Condition (1): ((P A -((A IN +A EX ) / 2))×(P B -((B IN +B EX ) / 2))) / (P A ×P B ) is greater than or equal to 0.42 and less than or equal to 0.70.

[0139] ·Condition (2): H / ((A IN +A EX ) / 2) and H / ((B IN +B EX ) / 2) are respectively greater than or equal to 1.40 and less than or equal to 3.00.

[0140] [Example]

[0141] Hereinafter, examples and comparative examples thereof will be described.

[0142] The optical films of Examples 1 to 4 have the same shape as that described in the first embodiment, and have a first direction D 1 and the second direction D 2 On both of them, quadrangular pyramid-shaped lens portions 110 are arranged in a matrix at an equal pitch of 8.6 μm. The lens portions 110 are regular quadrangular pyramid-shaped, and the flat portions 111 are square-shaped.

[0143] The low refractive index layer 102 is formed of a resin having a refractive index of 1.48, and the high refractive index layer 103 is formed of a resin having a refractive index of 1.65.

[0144] Furthermore, the optical films of Examples 1 to 4 are formed by: A -((A IN +A EX ) / 2))×(P B -((B IN +B EX ) / 2))) / (P A ×P B ) is greater than or equal to 0.42 and less than or equal to 0.70, and the slope ratio determined by H / ((A IN +A EX ) / 2) and the average aspect ratio in the first direction section as determined by H / ((B IN +B EX) / 2) and the average aspect ratio of the cross section in the second direction determined is 1.40 or more and 3.00 or less.

[0145] In addition, since the lens portion 110 is a regular tetrahedral pyramid, the average aspect ratio when viewed in the first direction and the average aspect ratio when viewed in the second direction are the same value. Hereinafter, when simply referred to as the "average aspect ratio", this refers to both the average aspect ratio when viewed in the first direction and the average aspect ratio when viewed in the second direction.

[0146] The optical film of Example 5 has the same shape as that described in the second embodiment, and has a 1 and the second direction D 2 The lens portions 110 are arranged in a matrix at an equal pitch of 8.6 μm in these two directions. The lens portions 110 are regular quadrangular pyramids, and the flat portions 111 are square.

[0147] The low refractive index layer 102 is formed of a resin having a refractive index of 1.48, and the high refractive index layer 103 is formed of a resin having a refractive index of 1.65.

[0148] The difference between Example 5 and Examples 1 to 4 is that in Examples 1 to 4, the high refractive index layer 103 is located on the light source (display panel) side, whereas in Example 5, the low refractive index layer 102 is located on the light source (display panel) side.

[0149] Moreover, although the slope ratio of the optical film of Example 5 was within the range of 0.42 to 0.70, the average aspect ratio was outside the range of 1.40 to 3.00.

[0150] Comparative Examples 1 to 4 have a regular quadrangular pyramid-shaped lens portion, and the lens portion is oriented in the first direction D 1 and the second direction D 2 In these two directions, they are arranged in a matrix at an equal interval of 8.6 μm. However, the slope ratio deviates from the range of 0.42 to 0.70, and the average aspect ratio deviates from the range of 1.40 to 3.00. It should be noted that the forming material is the same as that of the embodiment. That is, the basic shape of Comparative Examples 1 to 4 is the same as that of Embodiments 1 to 4, but the slope ratio deviates from the range of 0.42 to 0.70, and the average aspect ratio deviates from the range of 1.40 to 3.00.

[0151] In addition, Comparative Examples 5 and 6 have a regular quadrangular pyramid-shaped lens portion, and in the first direction D 1 and the second direction D 2These two directions are arranged in a matrix at an equal interval of 8.6 μm. However, the slope ratio deviates from the range of more than 0.42 and less than 0.70, and the average aspect ratio deviates from the range of more than 1.40 and less than 3.00. Moreover, the configuration positions of the low refractive index layer and the high refractive index layer are opposite to those of Examples 1 to 4. In detail, the low refractive index layer has a lens portion. That is, Comparative Examples 5 and 6 are structures in which they are arranged in the order of low refractive index layer and high refractive index layer from the light source side (the "L low high" in Table 1 shown below means that they are arranged in the order of low refractive index layer and high refractive index layer from the light source side). It should be noted that the forming material is the same as that of Examples 1 to 5. In detail, the basic shape of Comparative Examples 5 and 6 is the same as that of Example 5, but the slope ratio deviates from the range of more than 0.42 and less than 0.70, and the average aspect ratio deviates from the range of more than 1.40 and less than 3.00.

[0152] The examples and comparative examples were evaluated from the viewpoints of brightness and color change. The brightness was evaluated as follows: the brightness of the image displayed by the organic LED display panel with the optical film installed in the front viewing direction (front brightness) was compared with the front brightness of the same image displayed by the organic LED display panel without the optical film installed, and the ratio of the former to the latter was calculated.

[0153] The color change is evaluated as follows: the color change Δu'v' when an image displayed by an organic LED display panel without an optical film is observed from a direction tilted 45 degrees relative to the front observation direction is compared with the color change Δu'v' when the same image displayed by an organic LED display panel with an optical film is observed from a direction tilted 45 degrees relative to the front observation direction.

[0154] When evaluating the brightness and color changes, a full-screen white image was displayed on the organic LED display panel.

[0155] As a measuring device for brightness and color change, CS-1000 manufactured by Konica Minolta Inc. was used.

[0156] The dimensional conditions, slope ratio, average aspect ratio, ratio (%) of front brightness with / without optical film, and color change values ​​of the embodiments and comparative examples are shown in Table 1 below. In addition, the slope in the display corresponds to the side surface. The lens portion is a regular quadrangular pyramid, but the side surface is a curved surface with a fixed curvature. In addition, Fig.11 It is a graph showing the ratio of front brightness and the value of color change when there is / is not an optical film. The horizontal axis represents the ratio of front brightness, and the vertical axis represents the value of color change.

[0157] In addition, the "high refractive index side emission width" in the table related to Example 5 corresponds to Fig.10 The label AIN (B IN ), the "high refractive index side incident width" in the table related to Example 5 corresponds to Fig.10 The label A EX (B EX ). That is, the "high refractive index side exit width" and "high refractive index side incident width" in the table related to Example 5 are determined according to the definitions described in the first embodiment. It should be noted that the "high refractive index side exit width" and "high refractive index side incident width" in the table related to Comparative Examples 5 and 6 are also determined in the same manner as in Example 5.

[0158] [Table 1]

[0159]

[0160] In Examples 1 to 4, as shown by the color change suppression rate, the color change Δu'v' when observed from a direction inclined 45 degrees relative to the front observation direction can be suppressed to less than 75% relative to the color change in the case without the optical film. In addition, the brightness at this time is also more than 90% of the brightness when there is no optical film, and the decrease in brightness when observed from the front is suppressed. The results of such examples also confirm the effect of the present disclosure.

[0161] In addition, in Example 5, the color change Δu'v' when observed from a direction inclined 45 degrees relative to the front observation direction can be suppressed to less than 75% relative to the color change in the absence of an optical film. It should be noted that the bevel ratio in Example 5 is 0.51, but it can be inferred that: in the bevel ratio of 0.42 to 0.70 spanning Examples 1 to 4, an appropriate color change suppression effect can also be exerted. In addition, the average aspect ratio of Example 5 is 1.22, which deviates from the range of 1.40 to 3.00, but in the range of 1.40 to 3.00, by ensuring that the area of ​​the side 110S is large while making the lens portion 110 not too sharp, it is inferred that the effect of suppressing color changes and suppressing the reduction in front brightness can be improved.

[0162] in addition, Fig.11 The straight line L in is a straight line indicating the tendency of the optical films of Comparative Examples 5 and 6, which are low refractive index layers and high refractive index layers in order from the light source side. Examples 1 to 4 are located below the straight line L, and can suppress color change compared with the optical films of Example 5, Comparative Example 5 and Comparative Example 6, which are low refractive index layers and high refractive index layers in order from the light source side. Based on this result, it is inferred that when the high refractive index layer 103 is located on the light source (display panel) side, a higher color change suppression effect can be obtained compared with the case where the low refractive index layer 102 is located on the light source (display panel) side.

[0163] (simulation)

[0164] In the optical film 100 of the first embodiment, the high refractive index layer 103 on the light source side has a cross-shaped portion 103B, and the low refractive index layer 102 has a lens portion 110. In the simulation described below, the effectiveness of the form of the first embodiment is verified by comparison with the simulation comparative example X. The simulation comparative example X is an optical film in which a lens portion is provided on the high refractive index layer on the light source side, and the low refractive index layer stacked on the lens portion is in a cross-shaped shape.

[0165] The following dimensional conditions were set for the lens portion 110 of the optical film 100 of the first embodiment as the simulation object. In addition, the high refractive index side emission width and the high refractive index side incident width in the first direction D 1 and the second direction D 2 The same value in both directions.

[0166] The lens portion is in the shape of a regular quadrangular pyramid.

[0167] · Pitch: 8.6μm (1st direction D 1 and the second direction D 2 Both)

[0168] Average bevel angle: 12.1 (°)

[0169] Inclined surface curvature radius: 15 (μm)

[0170] ·High refractive index side emission width: 1.8 (μm)

[0171] ·High refractive index side incident width: 3.1 (μm)

[0172] Height: 3 (μm)

[0173] ·Slope ratio: 51(%)

[0174] Average aspect ratio 1.22

[0175] The following dimensional conditions were set for the lens portion of the simulation comparative example X. The high refractive index side emission width and the high refractive index side incident width in the first direction D 1 and the second direction D 2 The same value in both directions.

[0176] The lens portion is in the shape of a regular quadrangular pyramid.

[0177] · Pitch: 8.6μm (1st direction D 1 and the second direction D 2 Both)

[0178] Average bevel angle: 12.1 (°)

[0179] Inclined surface curvature radius: 15 (μm)

[0180] ·High refractive index side emission width: 5.5 (μm)

[0181] ·High refractive index side incident width: 6.8 (μm)

[0182] Height: 3 (μm)

[0183] ·Slope ratio: 8(%)

[0184] Average aspect ratio 0.48

[0185] * In addition, regarding the “high refractive index side emission width side” of the simulation comparative example X, according to the definition described in the first embodiment above, by 1 (2nd direction D 2 ) between the flat portions 111 of the adjacent lens portions 110 in the first direction D 1 (2nd direction D 2 ) is calculated based on the distance on the

[0186] Similarly, regarding the “high refractive index side incident width side” of the simulation comparative example X, according to the definition described in the first embodiment, by 1 (2nd direction D 2 ) between the ends of the lens portions 110 on the opposite side to the flat portion 111 in the first direction D 1 (2nd direction D 2 ) is calculated based on the distance on the

[0187] In the simulation results, the color change Δu'v' with respect to the front observation at multiple observation angles (45°, 30°, and 15°) tilted with respect to the front observation was calculated. The following Table 2 shows the simulation results.

[0188] [Table 2]

[0189] First Embodiment Simulation Comparison Example x Color change (observation angle: 45°) 0.0110 0.0139 Color change (observation angle: 30°) 0.0066 0.0069 Color change (observation angle: 15°) 0.0018 0.0019

[0190] According to the above simulation results, in the first embodiment, at any observation angle, the degree of color change is smaller than that of the simulation comparative example X, and the color change can be effectively suppressed. According to such simulation results, it is confirmed that the suppression of color change is also effective for the cross-shaped portion 103B of the high refractive index layer 103 facing the light source side and the lens portion 110 of the low refractive index layer 102, compared with the case where the lens portion is arranged in the high refractive index layer.

[0191] Description of symbols

[0192] 10: display device;

[0193] 15: Organic LED panel;

[0194] 15A: display surface;

[0195] 20: Circular polarizer;

[0196] 30: Touch panel;

[0197] 40: cover glass;

[0198] 51: first adhesive layer;

[0199] 52: second adhesive layer;

[0200] 53: the third adhesive layer;

[0201] 100: optical film;

[0202] 102: low refractive index layer;

[0203] 102A: layer body;

[0204] 103: high refractive index layer;

[0205] 103A: layer body;

[0206] 103B: Tic-tac-toe shape portion;

[0207] 110: lens portion;

[0208] 110S: Side;

[0209] 111: flat part;

[0210] 131: The first element surface;

[0211] 132: The second element surface;

[0212] 133: The third element surface;

[0213] 134: Surface;

[0214] 135, 136: element surface;

[0215] 137: Surface;

[0216] 138: Plane.

Claims

1. An optical film comprising: a low refractive index layer including a plurality of lens portions; and a high refractive index layer having a refractive index higher than that of the low refractive index layer, the high refractive index layer being arranged so as to fill between the plurality of lens portions, wherein: The lens portion has a columnar shape that tapers toward the end on the high refractive index layer side, and has a flat portion parallel to the film surface of the optical film at the end on the high refractive index layer side. The plurality of lens portions are two-dimensionally arranged in a matrix in a first direction parallel to the film surface and in a second direction orthogonal to the first direction. The flat portion is rectangular, and the lens portion has two side surfaces that are opposite to each other in the first direction and two side surfaces that are opposite to each other in the second direction. The high refractive index layer includes a tic-tac-toe shaped portion, An acute angle formed by a straight line passing through an endpoint on the high refractive index layer side of each of the side surfaces and an endpoint on the opposite side thereof and a third direction is 5 degrees or more and 10 degrees or less, wherein the third direction is orthogonal to both the first direction and the second direction, The flat portion of the lens portion is arranged to face the display panel side. Let A be a distance in the first direction between the flat portions of the lens portions adjacent to each other in the first direction. IN , The distance in the first direction between the ends of the lens portions adjacent in the first direction on the opposite side to the flat portion is defined as A. EX , The first direction pitch, which is the distance in the first direction between the midpoints of the lens portions adjacent in the first direction, is denoted by P. A , Let the distance between the flat portions of the lens portions adjacent to each other in the second direction in the second direction be B. IN , The distance in the second direction between the ends of the lens portions adjacent in the second direction on the opposite side to the flat portion is defined as B. EX , The distance in the second direction between the midpoints of the lens portions adjacent in the second direction, that is, the second direction pitch is denoted as P. B ,at this time, ((P A -((A IN +A EX ) / 2))×(P B -((B IN +B EX ) / 2))) / (P A ×P B ) is 0.42 or more and 0.55 or less, and ((A IN -A EX )×2) / P A is 0.2 or more and 0.5 or less, and ((B IN -B EX )×2) / P B is 0.2 or more and 0.5 or less, When the height of the lens portion is set to H, H / ((A IN +A EX ) / 2) and H / ((B IN +B EX ) / 2) are respectively greater than or equal to 1.40 and less than or equal to 1.

91.

2. The optical film according to claim 1, wherein: The lens portion is in the shape of a quadrangular pyramid, and the flat portion is in the shape of a square.

3. The optical film according to claim 1, wherein The lens portion is in the shape of a quadrangular pyramid, and the flat portion is in the shape of a rectangle.

4. The optical film according to any one of claims 1 to 3, wherein: The side surface of the lens portion is a curved surface that is convex toward the high refractive index layer.

5. A display device, wherein: The display device comprises: The optical film according to any one of claims 1 to 4; and The organic LED panel is provided with the optical film on the display surface of the organic LED panel.

6. A display device, wherein: The display device comprises: The optical film according to any one of claims 1 to 4; and The optical film is arranged on the display surface of the liquid crystal panel.

7. A polarizing plate with an optical film, wherein: The polarizing plate with an optical film comprises: The optical film according to any one of claims 1 to 4; and A polarizing plate is bonded to the optical film.

Images