Formed film, laminate, laminate with light guide layer, lighting device, and mold

Abstract

The present invention reduces luminance unevenness. This formed film is an optical formed film having a main surface. The main surface is provided with a plurality of recesses arranged in a forming direction with a first period P1, and a plurality of projections arranged in the forming direction with a second period P2. The greatest depth of the depths of the recesses is greater than the greatest height of the heights of the projections. When n is a positive integer, either n - 0.05 ≤ P1 / P2 ≤ n + 0.05 or n - 0.05 ≤ P2 / P1 ≤ n + 0.05 is satisfied.

Description

Shaped film, laminate, laminate with light guide layer, lighting device, and mold

[0001] The present invention relates to a shaped film, a laminate, a laminate with a light guide layer, a lighting device, and a mold.

[0002] For example, Patent Document 1 discloses a transparent substrate having a plurality of recesses or protrusions formed on one of its main surfaces.

[0003] International Publication No. 2019 / 102959

[0004] However, when light is incident inside a shape-imparting film such as the transparent substrate described in Patent Document 1, uneven brightness may occur in the light extracted from the main surface of the shape-imparting film.

[0005] An object of the present invention is to reduce brightness unevenness.

[0006] A shaped film according to one embodiment of the present invention is an optical shaped film having a main surface, wherein the main surface is provided with a plurality of recesses arranged in a formation direction with a first period P1 and a plurality of protrusions arranged in the formation direction with a second period P2, the maximum depth of the recesses is greater than the maximum height of the protrusions, and where n is a positive integer, either n-0.05≦P1 / P2≦n+0.05 or n-0.05≦P2 / P1≦n+0.05 is satisfied.

[0007] According to the present invention, it is possible to reduce brightness unevenness.

[0008] 1 is a schematic plan view showing a first example of a lighting device including a shaped-transfer film according to an embodiment. A schematic cross-sectional view of line II-II in FIG. 1. A schematic cross-sectional view of a shaped-transfer film corresponding to line III-III in FIG. 1. A schematic cross-sectional view of a mold for explaining a method for manufacturing a shaped-transfer film. A schematic cross-sectional view of a mold used for manufacturing a shaped-transfer film. A schematic cross-sectional view of a cavity provided in a shaped-transfer film according to an embodiment. A schematic plan view showing a first example of a cavity provided in a shaped-transfer film according to an embodiment. A schematic plan view showing a second example of a cavity provided in a shaped-transfer film according to an embodiment. A schematic plan view of a shaped-transfer film according to another embodiment, showing evaluation results of brightness unevenness. A view showing the brightness distribution of light extracted from the main surface of a shaped-transfer film according to Example 1. A view showing the brightness distribution of light extracted from the main surface of a shaped-transfer film according to Example 3. A schematic cross-sectional view showing a second example of a shaped-transfer film according to an embodiment. A schematic cross-sectional view showing a third example of a shaped-transfer film according to an embodiment. A schematic cross-sectional view showing a fourth example of a shaped-transfer film according to an embodiment. A schematic cross-sectional view showing a second example of a lighting device including a shaped-transfer film according to an embodiment.

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same components are given the same reference numerals, and duplicated descriptions will be omitted as appropriate.

[0010] The embodiments shown below exemplify a shaped film, a laminate, a laminate with a light guide layer, a lighting device, and a mold for embodying the technical concept of the present invention, and the present invention is not limited to the embodiments shown below. The dimensions, materials, shapes, relative positions, etc. of the components described below are intended to be illustrative and not to limit the scope of the present invention, unless otherwise specified to limit it to a specific embodiment. Furthermore, the sizes and positional relationships of the components shown in the drawings may be exaggerated for clarity of explanation.

[0011] In the drawings shown below, directions are expressed using a Cartesian coordinate system having an X-axis, a Y-axis, and a Z-axis. The X-axis, the Y-axis, and the Z-axis are approximately perpendicular to one another. The direction in which the arrow representing the X-axis points is referred to as the +X direction or +X side, and the direction opposite to the +X direction is referred to as the -X direction or -X side. The direction in which the arrow representing the Y-axis points is referred to as the +Y direction or +Y side, and the direction opposite to the +Y direction is referred to as the -Y direction or -Y side. The direction in which the arrow representing the Z-axis points is referred to as the +Z direction or +Z side, and the direction opposite to the +Z direction is referred to as the -Z direction or -Z side.

[0012] The X direction along the X axis corresponds to the forming direction in which the plurality of recesses provided in the shaped film according to the embodiment are arranged at a first period P1. In the description of the embodiment, the above-mentioned forming direction is referred to as the forming direction X. The Z direction along the Z axis indicates the direction along the normal to the main surface of the shaped film according to the embodiment. In this specification, "planar view" refers to viewing an object from the +Z direction. The +Z direction is referred to as "up" and the -Z direction is referred to as "down." However, the above directional expressions merely represent relative positional relationships for the purpose of explanation and do not limit the directions in the embodiment. In Figures 1 and 9, the X direction is the forming direction.

[0013] In this specification and claims, "substantially parallel" means that the absolute value of the angular deviation from the parallel state is between 0 and 10 degrees. Furthermore, "substantially perpendicular" means that the absolute value of the angular deviation from the perpendicular state is between 0 and 10 degrees. "Arranged" does not necessarily mean direct contact, but also includes indirect arrangement, for example, via another member. Furthermore, in this specification, "thickness" refers to the length of the object in the Z direction. Furthermore, in this specification, cross-sectional views may be shown as end views showing only the cross section.

[0014] [Embodiment] <Overall configuration of lighting device including shaped-transfer film according to embodiment> The overall configuration of a lighting device including a shaped-transfer film according to an embodiment will be described with reference to Figures 1 to 5. Figure 1 is a schematic plan view showing a first example of a lighting device 100 including a shaped-transfer film 62 according to an embodiment. Figure 2 is a schematic cross-sectional view taken along line II-II in Figure 1. Figure 3 is a schematic cross-sectional view showing an example of a shaped-transfer film 62 corresponding to line III-III in Figure 1. Figure 4 is a schematic cross-sectional view showing an example of a method for manufacturing the shaped-transfer film 62. Figure 5 is a schematic cross-sectional view explaining an example of a mold used in manufacturing the shaped-transfer film 62.

[0015] 1 and 2, the lighting device 100 includes a laminate 80 with a light guide layer, and a light source LS disposed near an end surface 81 of the laminate 80 with a light guide layer. The light source LS shown in Fig. 2 is disposed at a position where it can emit light toward the end surface 81 of the laminate 80 with a light guide layer. In the example shown in Fig. 2, part of the light Lr emitted from the light source LS is indicated by a dashed arrow.

[0016] The laminate 80 with a light guide layer includes a light guide layer 10, a laminate 70, and a first adhesive layer 52. The first adhesive layer 52 is disposed between the light guide layer 10 and the laminate 70, and is a layer that bonds the light guide layer 10 and the laminate 70 together. The laminate 70 includes a substrate 30 and a direction changing layer 60. The direction changing layer 60 includes a shaped film 62 and a second adhesive layer 54. The second adhesive layer 54 is disposed between the shaped film 62 and the substrate 30, and is a layer that bonds the shaped film 62 and the substrate 30 together. The substrate 30 is disposed opposite a main surface 621 of the shaped film 62. The light guide layer 10 is disposed opposite the shaped film 62. The shaped film 62 is a film manufactured without cutting the material.

[0017] A plurality of cavities 64 are provided inside the direction-changing layer 60. Each of the plurality of cavities 64 has a first inclined surface ISa and a second inclined surface ISb arranged on the opposite side of the first inclined surface ISa in the Y direction. For example, air is present inside the cavities 64. A plurality of recesses 622 are provided on the main surface 621 of the shaped film 62. The open portions of each of the plurality of recesses 622 are blocked by the substrate 30 arranged on the main surface 621 via the second adhesive layer 54, thereby forming the cavities 64. The cavities 64 may also be referred to as internal spaces or air cavities.

[0018] The lighting device 100 is used, for example, with the light guide layer-equipped laminate 80 disposed on an adherend such as glass, a window, a wall, a floor, or a ceiling. Light Lr emitted from the light source LS of the lighting device 100 enters the inside of the light guide layer-equipped laminate 80 from an end surface 81 and is guided inside the light guide layer-equipped laminate 80. A portion of the light Lr guided inside the light guide layer-equipped laminate 80 is reflected toward the −Z side by either the first inclined surface ISa or the second inclined surface ISb of the cavity 64, passes through an exit surface 82 of the light guide layer-equipped laminate 80 that intersects with the end surface 81, and is emitted in the −Z direction that intersects with the main surface 621 of the shaping film 62. The lighting device 100 can illuminate an indoor space in which the light guide layer-equipped laminate 80 is disposed, using light Lr emitted from substantially the entire exit surface 82 of the light guide layer-equipped laminate 80.

[0019] As shown in FIG. 3, the shaped film 62 according to this embodiment is an optical shaped film having a main surface 621. The main surface 621 is provided with a plurality of recesses 622 arranged in the forming direction X at a first period P1 and a plurality of protrusions 65 arranged in the forming direction X at a second period P2. The maximum depth Dx1 of the recesses 622 is greater than the maximum height Hx1 of the protrusions 65. In the shaped film 62, where n is a positive integer, either n-0.05≦P1 / P2≦n+0.05 or n-0.05≦P2 / P1≦n+0.05 is satisfied. Ideally, the protrusions 65 are not present, but as described below, they are irregularities generated by the molding process of the shaped film 62. Note that n may be any value as long as it is a positive integer. Furthermore, the condition "where n is a positive integer, either n-0.05≦P1 / P2≦n+0.05 or n-0.05≦P2 / P1≦n+0.05" is synonymous with the condition "either the absolute value of the value obtained by subtracting the value of P1 / P2 without a decimal from the value of P1 / P2 with a decimal is ±0.05 or less, or the absolute value of the value obtained by subtracting the value of P2 / P1 without a decimal from the value of P2 / P1 with a decimal is ±0.05 or less."

[0020] The first period P1 corresponds to the center-to-center distance between adjacent recesses 622 in the forming direction X. In the example shown in Fig. 3 , the center-to-center distance is the distance in the forming direction X between the center C11 and the center C12 of adjacent recesses 622 in the forming direction X. From another perspective, the first period P1 may be the distance between the lowest positions of adjacent recesses 622 in the forming direction X.

[0021] The second period P2 corresponds to the center-to-center distance between adjacent convex portions 65 in the forming direction X. In the example shown in Fig. 3, the center-to-center distance is the distance in the forming direction X between the centers C21 and C22 of adjacent convex portions 65 in the forming direction X. From another perspective, the second period P2 may be the distance between the highest points of adjacent convex portions 65 in the forming direction X. In the example shown in Fig. 3, the first period P1 is approximately twice the second period P2, and therefore P1 / P2 is approximately 2.0.

[0022] Here, in a shaped film having either a plurality of recesses or a first protrusion, when the shaped film is applied to a lighting device, etc., brightness unevenness may occur in the light extracted from the lighting device through the shaped film. Below, the cause of this brightness unevenness will be described together with an example of a manufacturing method of the shaped film.

[0023] The shaped film having a plurality of recesses is manufactured by molding a resin material using a mold. In the manufacturing method of the shaped film, first, a roll member made of a metal material or the like and serving as a material for the mold is prepared.

[0024] Next, the outer peripheral surface of the roll member is mirror-finished by cutting, grinding, or the like, to form a roll-shaped mold having a prepared base for forming a plurality of recesses on the outer peripheral surface.

[0025] Next, a plurality of recesses are formed on the outer peripheral surface of the roll-shaped mold by cutting or grinding, etc. In forming the recesses, a different machining tool from that used for mirror finishing is used, and the outer peripheral surface of the roll-shaped mold after mirror finishing is continuously or intermittently cut or ground by FTS (Fast tool servo) drive. This forms a plurality of recesses on the outer peripheral surface of the mold.

[0026] Next, a sheet-like resin substrate for the intermediate transfer member, made of a resin material or the like, is wound around a portion of a roll-shaped mold, an active energy ray-curable resin is disposed between the resin substrate for the intermediate transfer member and the roll-shaped mold, and active energy rays are irradiated to cure the active energy ray-curable resin. By curing the active energy ray-curable resin, an intermediate transfer member composed of the resin substrate for the intermediate transfer member and the active energy ray-curable resin is obtained. An inverted shape of either a plurality of recesses or protrusions on the mold is formed on the surface of the intermediate transfer member. When recesses are formed on the mold, the inverted shape formed on the intermediate transfer member will be protrusions. On the other hand, when protrusions are formed on the mold, the inverted shape formed on the intermediate transfer member will be recesses.

[0027] Next, the sheet-like intermediate transfer member on which the reversed shape is formed is arranged on the outer circumferential surface of a roller member other than the roll-like mold so as to be wound around the roller member, thereby forming a transfer roller.

[0028] Next, a sheet-like resin substrate for a shape-transfer film made of a resin material or the like is wound around a part of the transfer roller, a releasable active energy ray-curable resin is placed between the transfer roller and the resin substrate for the shape-transfer film, and the active energy ray is irradiated to cure the active energy ray-curable resin. By curing the active energy ray-curable resin, a shape-transfer film composed of the resin substrate for the shape-transfer film and the active energy ray-curable resin is obtained. The shape-transfer film is peeled off from the transfer roller.

[0029] By the above process, the shape of either the plurality of recesses or the plurality of protrusions on the transfer roller is reversed, and either the plurality of recesses or the plurality of protrusions formed on the roll-shaped mold are transferred to the shape-transfer film via the intermediate transfer member.

[0030] Here, even when the outer peripheral surface of the roll-shaped die is mirror-finished, either concave or convex portions depending on the performance of the processing equipment may remain as processing marks, as shown in Figures 4 and 5. Figure 4 shows how mirror finishing is performed on the outer peripheral surface 310 of a roll-shaped die 300 that rotates around a rotation axis parallel to the X axis while feeding the processing tool 200 at a predetermined feed rate in the +X direction. Note that Figure 4 shows an enlarged view of the vicinity of the outer peripheral surface 310 of the die 300.

[0031] The tip 200a of the machining tool 200 that contacts the mold 300 is determined in terms of its shape, taking into consideration the characteristics (material) of the mold to be machined, the desired height of the irregularities, and the machinability during machining. It is typically an arc. Therefore, after mirror-finishing, the outer peripheral surface 310 of the roll-shaped mold 300 is left with either multiple recesses or multiple protrusions corresponding to the shape of the tip 200a of the machining tool 200, aligned in the forming direction X at a second period P2 corresponding to the feed rate of the machining tool 200. In the example shown in FIG. 4 , multiple mold protrusions 302 corresponding to the shape of the tip 200a of the machining tool 200 remain on the outer peripheral surface 310 of the mold 300. Furthermore, even if the tip 200a of the machining tool 200 is manufactured to be sharp, it will have a somewhat rounded shape microscopically.

[0032] On the other hand, Figure 5 shows how a plurality of mold recesses 301 corresponding to a plurality of recesses to be provided in the shaped film are processed on the outer peripheral surface 310 of a roll-shaped mold 300 rotating around a rotation axis parallel to the X axis. Figure 5 also shows an enlarged view of the vicinity of the outer peripheral surface 310 of the mold 300. A plurality of mold recesses 301 are formed on the outer peripheral surface 310 of the roll-shaped mold 300 in the forming direction X so as to overlap a plurality of mold protrusions 302 at a period substantially the same as the first period P1 of the plurality of recesses to be provided in the shaped film.

[0033] By manufacturing a shaped film using a mold 300 formed by superimposing multiple mold recesses 301 and multiple mold protrusions 302, shapes corresponding to the multiple mold recesses 301 and multiple mold protrusions 302 are superimposed on the shaped film. However, for example, if the relative position of the mold recesses 301 with respect to the mold protrusions 302 changes depending on the position within the main surface of the shaped film, the reflection area of ​​the mold protrusions 302 changes depending on the relative position of the mold recesses 301 with respect to the mold protrusions 302. This change in reflection area causes the brightness of the light extracted from the main surface of the shaped film to change depending on the position within the main surface of the shaped film, which can result in brightness unevenness in the light extracted from the main surface of the shaped film. Such brightness unevenness reduces the quality of lighting devices equipped with shaped films.

[0034] In the shape-transfer film 62 according to this embodiment, when n is a positive integer, either n-0.05≦P1 / P2≦n+0.05 or n-0.05≦P2 / P1≦n+0.05 is satisfied, so that the first period P1 is approximately an integer multiple of the second period P2. As a result, the relative position of the recess 622 with respect to the convex portion 65 is approximately constant regardless of the position within the main surface 621 of the shape-transfer film 62. The reflection area of ​​the convex portion 65 is also approximately constant regardless of the position within the main surface 621 of the shape-transfer film 62. Since the reflection area of ​​the convex portion 65 is approximately constant, the brightness of the light extracted from the shape-transfer film 62 is approximately constant regardless of the position within the main surface 621 of the shape-transfer film 62. Since the brightness of the light extracted from the main surface 621 of the shape-transfer film 62 is approximately constant, in this embodiment, brightness unevenness can be reduced.

[0035] 1, a plurality of recesses 622 are further arranged in a line in the Y direction intersecting with the forming direction X on the main surface 621 of the shaped film 62. This makes it possible to reduce the uneven brightness of the light extracted from the main surface 621 of the shaped film 62 even in the shaped film 62 extending in a two-dimensional direction.

[0036] 2, the laminate 70 includes a shaped film 62 and a substrate 30 disposed opposite a main surface 621 of the shaped film 62. This makes it possible to reduce uneven brightness of light extracted from the laminate 70 through the shaped film 62.

[0037] The laminate 80 with a light guide layer includes the laminate 70 and the light guide layer 10 disposed opposite the shaping film 62. This reduces uneven brightness of the light extracted from the laminate 80 with a light guide layer via the shaping film 62. The light guide layer 10 may be disposed opposite the substrate 30.

[0038] The lighting device 100 includes a laminate 80 with a light guide layer and a light source LS disposed near an end surface 81 of the laminate 80 with a light guide layer. This makes it possible to reduce uneven brightness of the light extracted from the lighting device 100 via the shaping film 62.

[0039] In the lighting device 100, light Lr emitted from the light source LS enters the inside of the laminate with a light guide layer 80 from the end face 81 and the end face 81 of the laminate with a light guide layer 80, is guided inside the laminate with a light guide layer 80, and then exits from the laminate with a light guide layer 80 through the exit surface 82. This makes it possible to provide a surface-illumination type lighting device 100 that can illuminate with light Lr extracted from almost the entire exit surface 82. The light source LS may be disposed on at least one of the end face 81 and the exit surface 82.

[0040] Furthermore, in this embodiment, as shown in FIG. 5 , the mold 300 has an outer peripheral surface 310 provided with a plurality of mold recesses 301 arranged in the forming direction X at a first period P1 and a plurality of mold protrusions 302 arranged in the forming direction X at a second period P2. The maximum depth Dx2 of the mold recesses 301 is greater than the maximum height Hx2 of the mold protrusions 302. When n is a positive integer, either n-0.05≦P1 / P2≦n+0.05 or n-0.05≦P2 / P1≦n+0.05 is satisfied. As a result, in the shaped film 62 manufactured using the mold 300, the relative position of the recess 622 corresponding to the mold recess 301 with respect to the protrusion 65 corresponding to the mold protrusion 302 is substantially constant regardless of the position within the main surface 621 of the shaped film 62. As a result, this embodiment can provide a shaped film 62 capable of reducing brightness unevenness. Furthermore, in this embodiment, it is possible to provide a mold 300 for manufacturing a shaped film 62 capable of reducing brightness unevenness. Note that the mold 300 satisfying the above conditions can be manufactured by controlling an FTS processing device that processes the mold 300, for example.

[0041] <Details of the Configuration of the Illumination Device 100> The following describes the details of the configuration of the illumination device 100. The illumination device 100 has a light distribution control structure having a plurality of cavities 64. The first inclined surface ISa in each of the plurality of cavities 64 directs a portion of the light Lr guided within the laminate 80 with a light-guiding layer toward the exit surface 82 by total internal reflection (TIR). Note that when the light Lr passes through an interface, it may be refracted according to the refractive index of the material that constitutes the interface.

[0042] The laminate 80 with a light guide layer is configured, by the light distribution control structure, to emit light Lr having a desired light distribution from the exit surface 82. The light distribution can be controlled by adjusting, for example, the cross-sectional shape, planar shape, size, arrangement density, distribution, etc. of the cavities 64.

[0043] The laminate 80 with a light guide layer has a visible light transmittance of 60% or more and a haze value of less than 30%. The visible light transmittance is preferably 70% or more, and more preferably 80% or more. The haze value is preferably less than 10%, and more preferably 5% or less. Since the laminate 80 with a light guide layer has a high visible light transmittance and a low haze value, objects (displays) can be seen through the laminate 80 with a light guide layer. Visible light is light with a wavelength of 380 nm or more and 780 nm or less. The visible light transmittance and haze value can be measured using a haze meter (manufactured by Murakami Color Research Laboratory: product name HM-150) or the like.

[0044] The ratio of the area of ​​the plurality of cavities 64 to the area of ​​the light guide layer 10 (occupancy rate) is preferably 1% or more and 80% or less when the light guide layer 10 is viewed from the normal direction of the light exit surface 82. The upper limit of the occupation rate is more preferably 50% or less, and even more preferably 45% or less, and in order to obtain at least one of high transmittance and low haze value, it is preferably 30% or less, more preferably 10% or less, and even more preferably 5% or less.

[0045] For example, when the cavity occupancy rate is 50%, a haze value of 30% can be obtained. The cavity occupancy rate may be uniform, or may increase with increasing distance from the light source LS so that brightness does not decrease even when the distance from the light source LS increases. For mass production using a roll-to-roll method or a roll-to-sheet method, it is preferable that the cavity occupancy rate be uniform.

[0046] In the laminate 80 with a light guide layer, the light guide layer 10 and the shaped film 62 are bonded together by a first adhesive layer 52. The substrate 30 and the shaped film 62 are bonded together by a second adhesive layer 54 that constitutes the shaped film 62 and the direction changing layer 60. The light guide layer 10 and the substrate 30 may be transparent substrates or films.

[0047] 1, the cavities 64 are discretely arranged in the X and Y directions of the light guide layer 10. However, the discrete arrangement of the cavities 64 may be appropriately set depending on the shape of the light guide layer 10, the desired light distribution, etc.

[0048] 1, a plurality of cavities 64 having substantially the same shape and curved surfaces convex in the same direction are discretely and periodically arranged over the entire region in the X and Y directions. In this case, the first period P1 is preferably, for example, 10 μm or more and 500 μm or less, and the pitch Py is preferably, for example, 10 μm or more and 500 μm or less. In the example shown in FIG. 1, the laminate 80 with a light guide layer further includes cavities 64 that are shifted from one another by half the first period P1 in the X direction and half the pitch Py in the Y direction.

[0049] The light source LS is, for example, an LED (Light Emitting Diode) device. A plurality of LED devices are arranged in a line in the X direction. There are no particular limitations on the number and arrangement of the LEDs. Note that the light source LS is not limited to an LED device and may be a halogen lamp or the like.

[0050] The detailed configuration of the cavity 64 will be described with reference to Figures 6 to 8. Figure 6 is a schematic cross-sectional view showing an example of the cavity 64. Figure 7 is a schematic plan view showing a first example of the cavity 64. Figure 8 is a schematic plan view showing a second example of the cavity 64.

[0051] The cross-sectional shape of the cavity 64 shown in Fig. 6 is substantially triangular. However, the cross-sectional shape of the cavity 64 is not limited to a substantially triangular shape and may be a substantially trapezoid, etc. In the example shown in Fig. 6, the inclination angle θa of the first inclined surface ISa is larger than the inclination angle θb of the second inclined surface ISb.

[0052] The inclination angle θa of the first inclined surface ISa on the light source LS side is, for example, 10° or more and 70° or less. If the inclination angle θa is smaller than 10°, the controllability of the light distribution may decrease and the light extraction efficiency may also decrease. On the other hand, if the inclination angle θa exceeds 70°, it may become difficult to process the shaped film 62. By setting the inclination angle θa to 10° or more and 70° or less, the light extraction efficiency can be increased and the processing of the shaped film 62 can be made easier.

[0053] The inclination angle θb of the second inclined surface ISb is, for example, 50° or more and 100° or less. If the inclination angle θb is less than 50°, stray light may be generated in an unintended direction. On the other hand, if the inclination angle θb exceeds 100°, it may become difficult to process the shaping film 62. By setting the inclination angle θba to 50° or more and 100° or less, the light extraction efficiency can be increased and the shaping film 62 can be easily processed.

[0054] 7 is a curved surface convex toward the light source LS in a plan view. Here, the light emitted from each of the plurality of LED devices constituting the light source LS has a spread in the Y direction. Therefore, the first inclined surface ISa acts uniformly on the light when the first inclined surface ISa has a curved surface convex toward the light source LS. Note that if a coupling optical system is provided between the light source LS and the end surface 81 of the laminate 80 with a light guide layer to allow highly parallel light (light with a small spread in the Y direction) to be incident, the first inclined surface ISa may be parallel to the X direction.

[0055] As shown in Figures 7 and 8, the length L of the cavity 64 is preferably 10 µm or more and 500 µm or less, and the width W is preferably 1 µm or more and 100 µm or less. The length L is preferably, for example, at least twice the width W. The height H is preferably 1 µm or more and 100 µm or less. Depending on the processing accuracy when forming the shaped film 62 including the recess 622 having the shape shown in Figure 7 in plan view, the recess 622 may have the shape shown in Figure 8 in plan view. Even in such a case, the shape of the cavity 64 in plan view can be specified by the length L and the width W.

[0056] The shaping film 62 can be manufactured using, for example, polymethyl methacrylate (PMMA). The total thickness of the shaping film 62 is, for example, 200 μm or less, 150 μm or less, with a lower limit of 20 μm or more. The visible light transmittance of the shaping film 62 is 60% or more, and the haze value is less than 30%. The visible light transmittance is preferably 70% or more, and more preferably 80% or more. The haze value is preferably less than 10%, and more preferably 5% or less. Visible light can be measured by the above-mentioned method.

[0057] The light guide layer 10 is formed of a known material with high transmittance to visible light. The light guide layer 10 is formed, for example, of an acrylic resin such as polymethyl methacrylate (PMMA), a polycarbonate (PC) resin, a cycloolefin resin, or glass (quartz glass, alkali-free glass, borosilicate glass, etc.). The refractive index nGP of the light guide layer 10 is, for example, 1.40 or more and 1.80 or less. Unless otherwise specified, the refractive index refers to the refractive index measured with an ellipsometer at a wavelength of 550 nm. The thickness of the light guide layer 10 can be appropriately set depending on the application. The thickness of the light guide layer 10 is, for example, 0.05 mm or more and 50 mm or less.

[0058] The thickness of the substrate 30 is, for example, 1 μm to 1000 μm, preferably 10 μm to 100 μm, and more preferably 20 μm to 80 μm. The refractive index of the substrate 30 is independently preferably 1.40 to 1.70, and more preferably 1.43 to 1.65.

[0059] The thicknesses of the first adhesive layer 52 and the second adhesive layer 54 are each independently, for example, from 0.1 μm to 100 μm, preferably from 0.3 μm to 100 μm, and more preferably from 0.5 μm to 50 μm. The refractive indexes of the first adhesive layer 52 and the second adhesive layer 54 are each independently preferably from 1.42 to 1.60, and more preferably from 1.47 to 1.58. The refractive indexes of the first adhesive layer 52 and the second adhesive layer 54 are preferably close to the refractive index of the light guide layer 10 or the shaping film 62 to which they are in contact, and the absolute value of the difference in refractive index is preferably 0.2 or less.

[0060] The second adhesive layer 54 can preferably be bonded without filling the recesses 622 of the shaped film 62. Suitable adhesives for forming the second adhesive layer 54 include those described in International Application PCT / JP2021 / 006452, International Application PCT / JP2021 / 006453, or Japanese Patent Application No. 2021-025496 filed by the present applicant. The entire disclosures of these applications are incorporated herein by reference. In particular, the polyester-based adhesive described in Japanese Patent Application No. 2021-025496 is preferred.

[0061] <Evaluation Results of Brightness Unevenness> Next, the evaluation results of brightness unevenness in the shaped film 62 will be described with reference to FIGS. 9 to 11. FIG. 9 is a diagram showing an example of the evaluation results of brightness unevenness in the shaped film 62. Like FIG. 1, FIG. 9 shows an example in which the recesses 622 of the shaped film 62 have a longitudinal direction. FIG. 9 shows an example in which the longitudinal direction of the recesses 622 is different from that shown in FIG. 1. In FIG. 1, the longitudinal direction of the recesses 622 coincides with the formation direction. In FIG. 9, the direction perpendicular to the longitudinal direction of the recesses 622 in plan view coincides with the formation direction. FIG. 10 is a diagram showing an example of the brightness distribution of light extracted from the main surface 621 of the shaped film 62 according to Example 1. FIG. 11 is a diagram showing an example of the brightness distribution of light extracted from the main surface of the shaped film according to Example 3.

[0062] In FIG. 9, Examples 1 and 2 are working examples, and Example 3 is a comparative example. The "image" in FIG. 9 is a schematic perspective view showing a portion of a shaped film to illustrate the positional relationship between the recesses and protrusions in the shaped film. In the brightness unevenness evaluation method shown in FIG. 9, first, a substrate 30 (PMMA: 40 μm) was bonded to the main surface 621 of the shaped film 62 via a second adhesive layer 54 (polyester adhesive). Then, the surface opposite the main surface 621 of the shaped film 62 was bonded to a translucent substrate 401. For the translucent substrate 401, Acrylite EX manufactured by Mitsubishi Chemical Corporation, measuring 145 mm in length, 1000 mm in width, and 5 mm in thickness, was used. For the adhesive, CS9862 manufactured by Nitto Denko Corporation was used. After the shaping film 62 was adhered to the light-transmitting substrate 401, the shaping film 62 was autoclaved under the conditions of a temperature of 50° C., a pressure of 0.5 MPa, and 15 minutes, to prepare an evaluation sample 400.

[0063] The shape-transfer film 62 used had the following specifications: Thickness: 130 μm Pitch in the direction perpendicular to the first period (Y direction in FIG. 9): 140 μm Inclination angle θa of the first inclined surface ISa: 49° Area ratio of the plurality of recesses 622 to the area of ​​the shape-transfer film 62: 3.7% Shape of the recesses 622: Shape shown in FIG. 8. Width W is 20 μm, length L is 80 μm. First period P1: As shown in Table 1 described later Second period P2: As shown in Table 1 described later

[0064] The image shown in Fig. 10 is an image of a part of the exit surface of the lighting device 100 equipped with the shaped film according to Example 1, photographed from the normal direction of the exit surface. The image shown in Fig. 11 is an image of a part of the exit surface of the lighting device equipped with the shaped film according to Example 2, photographed from the normal direction of the exit surface. In the evaluation of brightness unevenness, the image photographed from the normal direction of the exit surface was visually inspected to determine and evaluate the presence or absence of brightness unevenness.

[0065] 9, Example 1 is a case where recesses 622 are arranged only at positions that overlap with protrusions 65. In Example 1, as shown in the "conceptual diagram," the multiple recesses 622 are all located only near the apexes of the protrusions 65, and are not located between adjacent protrusions 65. Example 1 satisfies either the condition n-0.05≦P1 / P2≦n+0.05 or n-0.05≦P2 / P1≦n+0.05, where n is a positive integer.

[0066] Example 2 is a case where recesses 622 are arranged only between adjacent protrusions 65. In Example 2, as shown in the "conceptual diagram," all of the recesses 622 are located only between adjacent protrusions 65, and are not located near the apexes of the protrusions 65. Example 2 satisfies either the condition n-0.05≦P1 / P2≦n+0.05 or n-0.05≦P2 / P1≦n+0.05, where n is a positive integer.

[0067] Example 3 is a case where recesses 622 are mixed and arranged at positions overlapping with the protrusions 65 and between adjacent protrusions 65. In Example 3, as shown in the "conceptual diagram," some of the multiple recesses 622 are located near the apexes of the protrusions 65, and others are located between adjacent protrusions 65. Example 3 does not satisfy either of the conditions n-0.05≦P1 / P2≦n+0.05 and n-0.05≦P2 / P1≦n+0.05, where n is a positive integer.

[0068] 10, no luminance unevenness was visually observed in Example 1. The same was true for Example 2. Therefore, in both Examples 1 and 2, the "luminance unevenness" was "absent" and the "evaluation" was "good."

[0069] On the other hand, as shown in Fig. 11, in Example 3, streak-like brightness unevenness S extending in the Y direction was visible. In the image shown in Fig. 11, high-brightness streaks (white portions) extending in the Y direction and low-brightness streaks (black portions) extending in the Y direction were observed. Therefore, in Example 3, the "brightness unevenness" was "present" and the "evaluation" was "×".

[0070] Table 1 below shows the evaluation results of Examples 1 to 3, Comparative Examples 1 and 2, other than Examples 1 to 3 shown in FIG. 9 . In both Examples 1 and 2, P1 / P2 = 2.00, and assuming n = 2, the condition P1 / P2 ≦ n + 0.05 is satisfied. In Example 3, P1 / P2 = 3.00, and assuming n = 3, the condition P1 / P2 ≦ n + 0.05 is satisfied. In Comparative Example 1, P1 / P2 = 2.06, and assuming n is a positive integer, the conditions n - 0.05 ≦ P1 / P2 ≦ n + 0.05 and n - 0.05 ≦ P2 / P1 ≦ n + 0.05 are not satisfied. In Comparative Example 2, P1 / P2=1.50, and neither of the conditions n-0.05≦P1 / P2≦n+0.05 nor n-0.05≦P2 / P1≦n+0.05, where n is a positive integer, is satisfied.

[0071] As shown in Table 1, in Examples 1 to 3, the "evaluation" was "good", and in Comparative Examples 1 and 2, the "evaluation" was "poor".

[0072] From the above, it was found that the shaping films 62 according to Examples 1, 2, and Examples 1 to 3 were evaluated as "good" and that brightness unevenness could be reduced.

[0073] [Other Preferred Modifications] Figure 12 is a schematic cross-sectional view showing a second example of the shape-transfer film 62 according to the embodiment. Figure 12 shows a cross-section of the second example of the shape-transfer film 62 corresponding to line III-III in Figure 1. This also applies to Figures 13 and 14 shown below. In the second example of the shape-transfer film 62 shown in Figure 12, each of the multiple recesses 622 is arranged only near the vertices of the multiple protrusions 65. P1 / P2 is approximately 3.00.

[0074] 13 is a schematic cross-sectional view showing a third example of the shaped film 62 according to the embodiment. In the third example of the shaped film 62 shown in FIG. 13, each of the plurality of recesses 622 is arranged only between adjacent convex portions 65 among the plurality of convex portions 65. P1 / P2 is approximately 3.00.

[0075] 14 is a schematic cross-sectional view showing a fourth example of the shaped film 62 according to the embodiment. In the fourth example of the shaped film 62 shown in FIG. 14, each of the plurality of recesses 622 is arranged only near the vertices of the plurality of protrusions 65. P1 / P2 is approximately 4.00.

[0076] In any of the second example shown in FIG. 12, the third example shown in FIG. 13, and the fourth example shown in FIG. 14, the same effects as those of the embodiment can be obtained.

[0077] Fig. 15 is a schematic cross-sectional view showing a second example of the lighting device 100 including the shaped film according to the embodiment. Fig. 15 shows a part of the cross section corresponding to the line II-II in Fig. 1 in the second example of the lighting device 100.

[0078] In the second example of the lighting device 100 shown in Fig. 15 , the light guide layer 10 is disposed opposite the substrate 30. Light incident from the light source LS into the laminate 80 with a light guide layer is emitted from an exit surface 82 located on the opposite side to the light guide layer 10. The second example of the lighting device 100 is mainly different from the first example of the lighting device 100 shown in Fig. 2 in these points.

[0079] 15 also provides the same effects as those of the embodiment. The light exit surface from which light exits the light-guiding layer-equipped laminate 80 may be at least one of the upper surface (the surface on the +Z side) and the lower surface (the surface on the −Z side) of the light-guiding layer-equipped laminate 80.

[0080] The laminate 80 with a light guide layer may have a low refractive index layer disposed on one side of the laminate 80 with a light guide layer and having a refractive index lower than that of the light guide layer 10 or the shaping film 62. The laminate 80 with a light guide layer may also have a low refractive index layer between the shaping film 62 and the substrate 30. The low refractive index layer preferably has a refractive index of 1.30 or less. The laminate 80 with a light guide layer may also have a hard coat layer or an anti-reflection layer.

[0081] The adherend on which the laminate 80 with a light guide layer is placed is not limited to glass, but may also be an electronic substrate such as a liquid crystal cell, or a non-light-transmitting member such as a ceiling, wall, or floor. The shaping film 62 is not limited to extracting light to the side opposite to the side on which the adherend is located, but may extract light to the side on which the adherend is located. In this case, if the adherend has high light transmittance, the extracted light may pass through the adherend, and if the adherend has low light transmittance, the adherend may reflect the light.

[0082] Although the preferred embodiments have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the claims.

[0083] The ordinal numbers, quantities, and other figures used in the description of the embodiments are all provided as examples to specifically explain the technology of the present invention, and the present invention is not limited to the illustrated figures. Furthermore, the connection relationships between the components are provided as examples to specifically explain the technology of the present invention, and do not limit the connection relationships that realize the functions of the present invention.

[0084] The shaped film, the laminate, and the laminate with a light guide layer according to the embodiments can reduce brightness unevenness, and therefore, by combining them with a light source and placing them on building components such as glass, windows, walls, floors, and ceilings, it is possible to brightly illuminate the interior or exterior space of a building with reduced brightness unevenness. The same applies to the lighting device according to the embodiments.

[0085] Furthermore, the lighting device according to the embodiment can be used as a partition to suitably partition a room or conceal a desired space. Furthermore, by arranging the shape-transfer film, laminate, and laminate with a light guide layer according to the embodiment on a glass substrate of a display device such as a liquid crystal panel or an organic EL (Electro Luminescence) display panel, it is possible to brighten backlight illumination in the display device. In addition, the shape-transfer film, laminate, laminate with a light guide layer, and lighting device according to the embodiment can provide new uses other than those described above.

[0086] This application claims priority based on Japanese Patent Application No. 2024-055496 filed with the Japan Patent Office on March 29, 2024, and includes the entire contents of this Japanese patent application.

[0087] 10 Light guide layer 30 Substrate 52 First adhesive layer 54 Second adhesive layer 60 Direction conversion layer 62 Shape-transferring film 621 Main surface 622 Recess 64 Cavity 65 Convex portion 70 Laminate 80 Laminate with light guide layer 81 End surface 82 Emission surface 100 Lighting device 200 Processing tool 300 Mold 301 Mold recess 302 Mold protrusion 310 Outer circumferential surface C11, C12, C21, C22 Center Dx1 Maximum depth of recess Dx2 Maximum depth of mold recess H Height Hx1 Maximum depth of protrusion Hx2 Maximum depth of mold protrusion ISa First inclined surface ISb Second inclined surface L Length Lr Light LS Light source P1 First period P2 Second period Py Pitch S Luminance unevenness W Width θa, θb Inclination angle

Claims

1. An optical shaped film having a main surface, wherein the main surface is provided with a plurality of recesses arranged in a forming direction with a first period P1 and a plurality of protrusions arranged in the forming direction with a second period P2, wherein the maximum depth of the recesses is greater than the maximum height of the protrusions, and wherein, where n is a positive integer, either n-0.05≦P1 / P2≦n+0.05 or n-0.05≦P2 / P1≦n+0.05 is satisfied.

2. A shaped film as described in claim 1, wherein the main surface further has a plurality of recesses arranged in a direction intersecting the forming direction.

3. A laminate comprising the shaped film according to claim 1 or claim 2 and a substrate arranged opposite the main surface of the shaped film.

4. A laminate with a light guide layer, comprising the laminate according to claim 3 and a light guide layer disposed opposite either the shaping film or the substrate.

5. A lighting device comprising: a laminate with a light guide layer according to claim 4; and a light source disposed in the vicinity of an end face of the laminate with a light guide layer.

6. The lighting device according to claim 5, wherein light emitted from the light source enters the interior of the laminate with a light guide layer from at least one of the end face and an exit surface of the laminate with a light guide layer that intersects with the end face of the laminate with a light guide layer, is guided inside the laminate with a light guide layer, and then exits through the exit surface.

7. A mold having an outer peripheral surface provided with a plurality of mold recesses arranged in the forming direction at a first period P1 and a plurality of mold protrusions arranged in the forming direction at a second period P2, wherein the maximum depth of the mold recesses is greater than the maximum height of the mold protrusions, and wherein, where n is a positive integer, either n-0.05≦P1 / P2≦n+0.05 or n-0.05≦P2 / P1≦n+0.05 is satisfied.

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