Decorative sheets and display systems

Abstract

In decorative sheets, the design is displayed three-dimensionally, and transmitted light is displayed brightly. [Solution] The decorative sheet 10 includes a first surface 11 and a second surface 12 facing a first direction D1. The decorative sheet 10 includes a pattern layer 25 and a reflective layer 30 in that order, from the first surface 11 to the second surface 12. The reflective layer 30 includes a plurality of optical units 60 that reflect light incident on the first surface 11. Each of the plurality of optical units 60 includes a reflective surface 61 inclined with respect to the first direction D1. The total light transmittance of the decorative sheet 10 is 10% or more and 85% or less.

Description

Technical Field

[0001] The present disclosure relates to a decorative sheet and a display system.

Background Art

[0002] As disclosed in Patent Document 1, a decorative sheet overlapping a light-emitting device is known. The decorative sheet displays a design. Further, the decorative sheet transmits a part of the light emitted from the light-emitting device. The light-emitting device and the decorative sheet constitute a display system. The display system displays the design of the decorative sheet and the transmitted light from the light-emitting device.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the decorative sheet, in order to display the design three-dimensionally, a concavo-convex structure is provided on the surface. However, when a concavo-convex structure is provided on the surface of the decorative sheet, the light transmittance from the light-emitting device deteriorates, and the transmitted light cannot be displayed brightly. An object of the present disclosure is to provide a decorative sheet that displays a design three-dimensionally and displays transmitted light brightly.

Means for Solving the Problems

[0005] A decorative sheet according to an embodiment of the present disclosure includes a first surface and a second surface facing each other in a first direction, and includes a pattern layer and a reflective layer in this order from the first surface toward the second surface, the reflective layer includes a plurality of optical units that reflect light incident on the first surface, each of the plurality of optical units includes a reflective surface inclined with respect to the first direction, The total light transmittance is between 10% and 85%.

[0006] A display system according to one embodiment of this disclosure is A decorative sheet including a first surface and a second surface facing each other in the first direction, The decorative sheet comprises a light-emitting device that overlaps the second surface of the decorative sheet, The decorative sheet includes a pattern layer and a reflective layer in this order, from the first surface to the second surface. The reflective layer includes a plurality of optical units that reflect light incident on the first surface, Each of the plurality of optical units includes a reflective surface inclined with respect to the first direction. [Effects of the Invention]

[0007] According to this disclosure, a decorative sheet can display a design in three dimensions and display transmitted light brightly. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a diagram illustrating one embodiment, and is an exploded perspective view of the display system. [Figure 2] Figure 2 is a cross-sectional view of the display system shown in Figure 1. [Figure 3] Figure 3 is a plan view of the decorative sheet shown in Figure 2, showing the transparent and light-blocking portions. [Figure 4] Figure 4 is a plan view of multiple pattern units. [Figure 5] Figure 5 is a plan view of the reflective layer of the decorative sheet shown in Figure 2. [Figure 6] Figure 6 is a diagram illustrating an example of the mechanism by which a second light is observed in the decorative sheet of Figure 2 and the display system including the decorative sheet of Figure 2. [Figure 7] Figure 7 is a perspective view of the display system when the light-emitting device is emitting light. [Figure 8] Figure 8 is a cross-sectional view of a display system including a first modified example of the decorative sheet. [Figure 9]FIG. 9 is a cross-sectional view of a second modified example of the decorative sheet. [Figure 10] FIG. 10 is a cross-sectional view of a third modified example of the decorative sheet. [Figure 11] FIG. 11 is a cross-sectional view of a modified example of the display system. [Figure 12] FIG. 12 is a plan view of a fourth modified example of the decorative sheet showing a transmissive portion and a light-shielding portion.

DETAILED DESCRIPTION OF THE INVENTION

[0009] One embodiment of the present disclosure relates to the following [1] to

[21] .

[0010] [1] A decorative sheet including a first surface and a second surface facing each other in a first direction, comprising a pattern layer and a reflective layer in this order from the first surface toward the second surface, the reflective layer including a plurality of optical units that reflect light incident on the first surface, each of the plurality of optical units including a reflective surface inclined with respect to the first direction, The decorative sheet has a total light transmittance of 10% or more and 85% or less.

[0011] [2] The reflective layer includes a resin layer including a plurality of concavo-convex units, each of the plurality of optical units including any one of the plurality of concavo-convex units, the decorative sheet of [1].

[0012] [3] Each of the plurality of optical units includes a Fresnel lens structure, the decorative sheet of [1] or [2].

[0013] [4] The reflective layer includes a metal layer, the resin layer being located between the pattern layer and the metal layer, the decorative sheet of [2].

[0014] [5] The reflective layer includes a second resin layer, the metal layer being located between the resin layer and the second resin layer, the decorative sheet of [4].

[0015] [6] The decorative sheet according to [5], wherein the refractive index difference between the resin layer and the second resin layer is 0 or more and 0.5 or less.

[0016] [7] A decorative sheet comprising a base layer supporting the pattern layer and the resin layer, any of [1] to [6].

[0017] [8] A decorative sheet of any of [1] to [7], wherein the minimum pitch of the plurality of optical units is 4 mm or more and 300 mm or less.

[0018] [9] The plurality of optical units are arranged according to the pattern formed by the pattern layer, any of the decorative sheets from [1] to [8].

[0019]

[10] The pattern layer includes a plurality of pattern units, A decorative sheet [9] in which the minimum pitch of the plurality of pattern units is smaller than the minimum pitch of the plurality of optical units.

[0020]

[11] The decorative sheet according to [9] or

[10] , wherein the minimum pitch of the plurality of optical units is 2 times or more and 150 times or less the minimum pitch of the plurality of pattern units.

[0021]

[12] In observation from the first direction, the observation includes a plurality of transparent parts, A decorative sheet

[10] or

[11] wherein the minimum pitch of the plurality of transparent portions is smaller than the minimum pitch of the plurality of pattern units.

[0022]

[13] In observation from the first direction, the structure includes a transparent portion and a light-shielding portion, The patterned layer is a decorative sheet, one of [1] to

[12] , placed in the light-shielding portion.

[0023]

[14] In observation from the first direction, the maximum width of the transparent portion is 0.005% to 6% of the maximum value of the dimensions of the plurality of optical units. The minimum pitch of the transparent portion is 0.02% or more and 15% or less of the minimum pitch of the plurality of optical units, a decorative sheet of any of [1] to

[13] .

[0024]

[15] A decorative sheet having a thickness of 60 μm or more and 2000 μm or less, which is any of [1] to

[14] .

[0025]

[16] Further equipped with pattern masks, The reflective layer is a decorative sheet, one of [1] to

[15] , located between the pattern layer and the pattern mask.

[0026]

[17] One of the decorative sheets from [1] to

[16] , A display system comprising a light-emitting device that overlaps the second surface of the decorative sheet.

[0027]

[18] A decorative sheet including a first surface and a second surface facing the first direction, The decorative sheet comprises a light-emitting device that overlaps the second surface of the decorative sheet, The decorative sheet includes a pattern layer and a reflective layer in this order, from the first surface to the second surface. The reflective layer includes a plurality of optical units that reflect light incident on the first surface, A display system in which each of the plurality of optical units includes a reflective surface inclined with respect to the first direction.

[0028]

[19] The reflective layer comprises, in order from the first surface to the second surface, a resin layer containing a plurality of uneven units, a metal layer, and a second resin layer. Each of the plurality of uneven units constitutes each of the plurality of optical units, The metal layer is located between the resin layer and the second resin layer. A decorative sheet according to

[17] or

[18] , wherein the refractive index difference between the resin layer and the second resin layer is 0 or more and 0.5 or less.

[0029]

[20] The display system of

[19] wherein the second resin layer is a bonding layer for bonding the decorative sheet to the light-emitting device.

[0030]

[21] The light-emitting device includes a surface light source device and a pattern mask that overlaps the surface light source device, The pattern mask is a display system

[17] to

[20] located between the surface light source and the decorative sheet.

[0031] An embodiment of this disclosure will be described with reference to the drawings. For ease of illustration and understanding, the dimensional ratios in the drawings may differ from those of the actual object. The terms used to specify shapes, geometric conditions such as "parallel" and "orthogonal," lengths, and angle values ​​should not be interpreted strictly, but rather within a range that allows for the expectation of similar functionality.

[0032] Directions common to multiple drawings are indicated by arrows with a common reference numeral in each drawing. In each illustrated direction, the tip of the arrow is the first side, and the opposite side, i.e., the base of the arrow, is the second side. The first side in a direction perpendicular to the drawing is indicated by a symbol of a circle with a dot inside. The second side in a direction perpendicular to the drawing is indicated by a symbol of a circle with an X inside.

[0033] Multiple candidates for the lower limit of a certain parameter and multiple candidates for the upper limit of that parameter may be listed. The candidate numerical range of the parameter will be a combination of one of the multiple candidates for the lower limit and one of the multiple candidates for the upper limit. For example, B1, B2, and B3 may be listed as multiple candidates for the lower limit of parameter A. B1, B2, and B3 are all different numbers. C1, C2, and C3 may be listed as multiple candidates for the upper limit of parameter A. C1, C2, and C3 are all different numbers. In this example, the candidate numerical ranges of parameter A are B1 or greater and C1 or less, B1 or greater and C2 or less, B1 or greater and C3 or less, B2 or greater and C1 or less, B2 or greater and C2 or less, B2 or greater and C3 or less, B3 or greater and C1 or less, B3 or greater and C2 or less, B3 or greater and C3 or less.

[0034] Figures 1 to 7 are diagrams illustrating one embodiment. Figure 1 is an exploded perspective view of the display system 1. The display system 1 includes a display surface 2. The display system 1 includes a light-emitting device 5 and a decorative sheet 10 that overlaps the light-emitting device 5. The decorative sheet 10 includes a first surface 11 and a second surface 12 that face each other in a first direction D1. In Figure 1, the first surface 11 of the decorative sheet 10 constitutes the display surface 2 of the display system 1. The decorative sheet 10 overlaps the light-emitting surface 6 of the light-emitting device 5 from the second surface 12. In Figure 1, the first direction D1 is the direction in which the light-emitting device 5 and the decorative sheet 10 overlap. In the display system 1, the light-emitting device 5 and the decorative sheet 10 are joined to each other.

[0035] The light-emitting device 5 emits light from its light-emitting surface 6. However, in Figure 1, the light-emitting device 5 has stopped emitting light. The light emitted from the light-emitting surface 6 is incident on the decorative sheet 10 on the second surface 12. At least a portion of the light emitted from the light-emitting surface 6 passes through the decorative sheet 10. The light that has passed through the decorative sheet 10 is emitted from the first surface 11, i.e., the display surface 2 of the display system 1. The decorative sheet 10 displays the design D on the first surface 11. As a result, the display system 1 in Figure 1 can display light (first light LC1) and the design D on the display surface 2. Figure 7 shows the first light LC1 and the design D displayed by the display system 1. On the first surface 11, a portion of the light emitted from the light-emitting surface 6 of the light-emitting device 5 is used as the first light LC1. The first light LC1 may be an image, as shown in Figure 7. In Figure 7, a cross-shaped image and a square image are shown as examples of images. As shown in Figure 1, the display system 1 displays the design D of the decorative sheet 10 on the display surface 2 even when the light-emitting device 5 is not emitting light. The light-emitting device 5 may be one or more of a liquid crystal display, a plasma display, or an organic EL display.

[0036] Furthermore, the display system 1 in Figure 1 can display a second light LC2 in addition to the first light LC1. The second light LC2 is displayed by the decorative sheet 10. The decorative sheet 10 and the display system 1 display the second light LC2 by the reflective layer 30 contained in the decorative sheet 10, which will be described later. The second light LC2 is observed to be separated from the first surface 11 of the decorative sheet 10 (display surface 2 of the display system 1) in a first direction D1 by a mechanism described later. Figure 7 shows, as an example, the second light LC2 which is observed to be separated from the first surface 11 in the first direction D1. In the decorative sheet 10, a portion of the light incident on the first surface 11 is used as the second light LC2.

[0037] The display system 1 in Figure 1 displays the second light LC2 whether the light-emitting device 5 is emitting light or not. When the light-emitting device 5 is emitting light, the display system 1 can display three-dimensional light by displaying the first light LC1 and the second light LC2. In particular, when the first light LC1 is an image, the display system 1 can display the image three-dimensionally by combining the first light LC1 and the second light LC2.

[0038] Display system 1 may be applied to various objects. Display system 1 may also be applied to mobile objects. Mobile objects are movable devices or equipment. Mobile objects may include vehicles such as automobiles. Mobile objects may also be unmanned machines such as drones.

[0039] In the display system 1 of Figure 1, a numerical range is provided for the total light transmittance of the decorative sheet 10. The unit of the total light transmittance of the decorative sheet 10 is %. The total light transmittance of the decorative sheet 10 may be 10% or more, 30% or more, or 50% or more. The total light transmittance of the decorative sheet 10 may be 85% or less, 70% or less, 50% or less, or 30% or less. By setting a lower limit for the total light transmittance of the decorative sheet 10 in this way, the display system 1 can display the first light LC1 brightly on the display surface 2. Furthermore, by setting an upper limit for the total light transmittance of the decorative sheet 10 in this way, the decorative sheet 10 can maintain the visibility of the design in the display system 1.

[0040] A D65 light source is used to measure total light transmittance. The D65 light source is a light source that mimics the spectrum of D65. D65 is a standard illuminant defined by the International Commission on Illumination (CIE). Before measuring the total light transmittance of the decorative sheet 10, the D65 light source is lit for 15 minutes to stabilize its output. The angle of incidence to the sample when measuring total light transmittance is set to 0°. The incident surface of the decorative sheet 10 when measuring total light transmittance is the second surface 12. The test environment when measuring total light transmittance is set to a temperature of 23°C ± 2°C and a relative humidity of 50% ± 5%. The sample is placed in the test environment for 16 hours before the start of the test. Other measurement conditions when measuring total light transmittance are in accordance with JIS K7361-1:1997.

[0041] The total light transmittance of the decorative sheet 10 is determined as the arithmetic mean of five measurements taken under the conditions described above. The five measurements are taken at five different measurement locations. The five measurement locations are 10 mm apart from each other in a direction nonparallel to the first direction D1. The direction nonparallel to the first direction D1 may also be the second direction D2 or the third direction D3. The second direction D2 is perpendicular to the first direction D1 and the third direction D3. The third direction D3 is perpendicular to the first direction D1 and the second direction D2.

[0042] Figure 2 shows a cross-sectional view of the decorative sheet 10. As shown in Figure 2, the decorative sheet 10 includes a decorative layer 20, a reflective layer 30, a base layer 40, and a bonding layer 50. The decorative sheet 10 includes the decorative layer 20 and the reflective layer 30 in that order, from the first surface 11 to the second surface 12. The decorative layer 20 constitutes the first surface 11 of the decorative sheet 10. The reflective layer 30 constitutes the second surface 12 of the decorative sheet 10. In the display system 1 of Figure 2, the reflective layer 30 is located between the decorative layer 20 and the light-emitting device 5.

[0043] The decorative layer 20 displays a design. The decorative layer 20 includes a pattern layer 25. The pattern layer 25 forms a pattern. The decorative layer 20 displays the pattern formed by the pattern layer 25 as a design. The decorative sheet 10 includes the pattern layer 25 and the reflective layer 30 in this order, from the first surface 11 to the second surface 12. Details of the pattern layer 25 will be described later.

[0044] The decorative sheet 10 may include layers other than the decorative layer 20 and the reflective layer 30, as shown in Figure 2. The decorative sheet 10 in Figure 2 includes a base layer 40 and a bonding layer 50. The decorative sheet 10 in Figure 2 includes the decorative layer 20, the base layer 40 (first base layer 41), the bonding layer 50 (first bonding layer 51), the base layer 40 (second base layer 42), and the reflective layer 30 in this order, from the first surface 11 to the second surface 12.

[0045] The decorative sheet 10 in Figure 2 includes a plurality of substrate layers 40. The plurality of substrate layers 40 include a first substrate layer 41 that supports the decorative layer 20 and a second substrate layer 42 that supports the reflective layer 30. The first substrate layer 41 and the second substrate layer 42 may have the same configuration as each other. In the display system 1 of Figure 2, light emitted from the light-emitting device 5 can pass through the plurality of substrate layers 40.

[0046] In the decorative sheet 10 of Figure 2, the base layer 40 may be transparent. The base layer 40 may be colored. The illustrated base layer 40 is a transparent resin film. The resin contained in the base layer 40 may be a thermoplastic resin. The thermoplastic resin contained in the base layer 40 may include one or more of acrylic, PET (polyethylene terephthalate), polyolefin resin, polycarbonate, and ABS (acrylonitrile-butadiene-styrene copolymer synthetic resin). The polyolefin resin may include one or more of polypropylene and polyethylene.

[0047] The term "transparent" for components such as the display system 1 and decorative sheet 10 means that the total light transmittance of the component is 70% or higher. The total light transmittance of a transparent component may be 80% or higher, or 90% or higher.

[0048] From the viewpoint of stably supporting the decorative layer 20, a lower limit may be set for the thickness of the first base layer 41. The thickness of the first base layer 41 may be 12 μm or more, or 50 μm or more. From the viewpoint of stably displaying the light transmitted through the decorative sheet 10, an upper limit may be set for the thickness of the first base layer 41. The thickness of the first base layer 41 may be 1000 μm or less, or 500 μm or less. Note that the thickness of the components of the decorative sheet 10, including the first base layer 41, is the dimension in the first direction D1.

[0049] From the viewpoint of stably supporting the reflective layer 30, a lower limit may be set for the thickness of the second substrate layer 42. The thickness of the second substrate layer 42 may be 12 μm or more, or 50 μm or more. From the viewpoint of stably displaying the light transmitted through the decorative sheet 10, an upper limit may be set for the thickness of the second substrate layer 42. The thickness of the second substrate layer 42 may be 1000 μm or less, or 500 μm or less.

[0050] A scanning transmission electron microscope (STEM) is used to determine the thickness of the decorative sheet 10 and its components. To determine the thickness of the decorative sheet 10 and its components, a cross-section of the decorative sheet 10 to be evaluated is observed using a scanning transmission electron microscope. The thickness of the decorative sheet 10 and its components is determined as the arithmetic mean of the thickness measurements taken at 10 measurement locations. These 10 measurement locations are positioned in a straight line at 10 μm intervals.

[0051] The decorative sheet 10 in Figure 2 includes a plurality of bonding layers 50. The plurality of 50 in the decorative sheet 10 includes a first bonding layer 51 and a second bonding layer 52. The first bonding layer 51 and the second bonding layer 52 may have the same configuration as each other. In the display system 1 of Figure 2, the light emitted from the light-emitting device 5 can pass through the plurality of 50.

[0052] The first bonding layer 51 in Figure 2 bonds the first base material layer 41 and the second base material layer 42. By bonding the first base material layer 41 and the second base material layer 42, the first bonding layer 51 bonds the decorative layer 20 supported on the first base material layer 41 and the reflective layer 30 supported on the second base material layer 42. The second bonding layer 52 in Figure 2 also bonds the decorative sheet 10 to the light-emitting device 5. The illustrated second bonding layer 52 is a component of the reflective layer 30, as will be described later.

[0053] The bonding layer 50 may contain an optically transparent resin. The optically transparent resin is a transparent material. The bonding layer 50 may contain OCR (Optical Clear Resin) or OCA (Optical Clear Adhesive) as the optically transparent resin. The bonding layer 50 may be transparent. The first bonding layer 51 and the second bonding layer 52 may have the same composition as each other. Whether the bonding layer 50 contains a transparent material is determined from the total light transmittance of the bonding layer 50. The total light transmittance of the bonding layer 50 is determined by the method described above using the bonding layer 50 peeled off from the decorative sheet 10.

[0054] The decorative layer 20 in Figure 1 includes a first surface 21 and a second surface 22 facing the first direction D1. The first surface 21 of the decorative layer 20 constitutes the first surface 11 of the decorative sheet 10. The decorative layer 20 is in contact with the base layer 40 (first base layer 41) at the second surface 22.

[0055] As shown in Figures 2 and 3, the decorative sheet 10 includes a transparent portion 13 and a light-shielding portion 14. Figure 3 is an enlarged view of the decorative sheet 10 observed from the first side in the first direction D1. The transparent portion 13 and the light-shielding portion 14 shown in Figures 2 and 3 are adjacent to each other in a direction nonparallel to the first direction D1. The transparent portion 13 is the transparent part of the decorative sheet 10. The "transparent portion" of the decorative sheet 10 is a portion of the decorative sheet 10 that transmits light to a degree that is distinguishable from the light-shielding portion 14. The light-shielding portion 14 is a portion that absorbs at least a portion of the light incident on the decorative sheet 10 from the first surface 11. When light passes through the decorative sheet 10, the amount of light transmitted in the transparent portion 13 is greater than the amount of light transmitted in the light-shielding portion 14. In other words, when light passes through the decorative sheet 10, the amount of light transmitted through the light-shielding portion 14 is less than the amount of light transmitted through the light-transmitting portion 13.

[0056] The "plan view" of the decorative sheet 10 and its components is a view of the object as it is observed from the first or second side in the first direction D1. The "cross-sectional view" of the display system 1 and the decorative sheet 10 is a view of the object as it is cut by the first direction D1 and the planes extending in the direction perpendicular to the first direction D1.

[0057] The decorative sheet 10 in Figure 3 includes a plurality of transparent portions 13. In Figure 3, the plurality of transparent portions 13 are arranged in a two-dimensional array. In other words, the plurality of transparent portions 13 are regularly arranged in two directions that are not parallel to each other. Specifically, the plurality of transparent portions 13 are regularly arranged with spacing in the second direction D2 and the third direction D3. In the decorative sheet 10 in Figure 3, the light-shielding portions 14 are the portions other than the plurality of transparent portions 13. Note that, unlike the example shown in Figure 3, the transparent portions 13 and light-shielding portions 14 do not have to be arranged in a two-dimensional array. As shown in Figure 12, the light-shielding portions 14 arranged between the transparent portions 13 may extend linearly.

[0058] The decorative layer 20 in Figure 2 includes a surface protection layer 26 in the transparent portion 13 of the decorative sheet 10, extending from the first surface 21 to the second surface 22. In the transparent portion 13, the surface protection layer 26 constitutes the first surface 21 and the second surface 22 of the decorative layer 20. In the light-shielding portion 14 of the decorative sheet 10, the decorative layer 20 includes the surface protection layer 26, the pattern layer 25, and the light-shielding layer 24 in this order, extending from the first surface 21 to the second surface 22. As shown in Figures 2 and 3, the pattern layer 25 is located in the light-shielding portion 14 of the decorative sheet 10. As a result, the decorative sheet 10 displays the design in the light-shielding portion 14. The illustrated pattern layer 25 is not located in the transparent portion 13 of the decorative sheet 10.

[0059] By arranging the pattern layer 25 on the light-shielding portion 14, the decorative sheet 10 can suppress the transmission of light incident from the second surface 12 through the pattern layer 25. The decorative sheet 10 including the light-shielding portion 14 can stably display the design on the light-shielding portion 14 even when light incident from the second surface 12 is emitted from the first surface 11. Furthermore, when the decorative sheet 10 including the light-shielding portion 14 is applied to the display system 1, it can suppress the observation of the light-emitting device 5 by light incident from the display surface 2. In particular, such a display system 1 can conceal the light-emitting device 5 with the decorative sheet 10 when the light-emitting device 5 is not emitting light.

[0060] In Figure 3, each of the multiple translucent sections 13 is observed to be circular. From the viewpoint of stably displaying the light from the light-emitting device 5, a lower limit may be set for the maximum width LM of the multiple translucent sections 13. The maximum width LM of the multiple translucent sections 13 may be 24 μm or more, or 48 μm or more. Furthermore, from the viewpoint of stably displaying the design of the decorative sheet 10, an upper limit may be set for the maximum width LM of the multiple translucent sections 13. The maximum width LM of the multiple translucent sections 13 may be 240 μm or less, or 95 μm or less.

[0061] The maximum width LM of the transparent portion 13 is the maximum width of the transparent portion 13. The width of the transparent portion 13 is the dimension of the portion of the normal of the contour of the transparent portion 13 in the decorative sheet 10, as observed from the first direction D1, that is located on the transparent portion 13. In other words, the width of the transparent portion 13 is the dimension of the transparent portion 13 as observed from the first direction D1, in the direction of the normal parallel to the contour normal. The contour of the transparent portion 13 is located at the boundary between the transparent portion 13 and the light-shielding portion 14. In other words, the normal of the contour of the transparent portion 13 is the line segment perpendicular to the tangent to the contour of the transparent portion 13.

[0062] Figure 3 shows the normal vector N1 at point P1 of the contour of the transparent portion 131, the normal vector N2 at point P2 of the contour of the transparent portion 132, the normal vector N3 at point P3 of the transparent portion 133, and the normal vector N4 at point P4 of the transparent portion 134. The width L1 of the transparent portion 131 is the dimension of the portion of the normal vector N1 that lies on the transparent portion 131. The width L2 of the transparent portion 132 is the dimension of the portion of the normal vector N2 that lies on the transparent portion 132. The width L3 of the transparent portion 133 is the dimension of the portion of the normal vector N3 that lies on the transparent portion 133. The width L4 of the transparent portion 134 is the dimension of the portion of the normal vector N4 that lies on the transparent portion 134. Normal vectors N1 and N2 extend in the normal direction DN1. Normal vectors N3 and N4 extend in the normal direction DN2. The normal direction DN1 is parallel to the second direction D2. The normal direction DN2 is parallel to the third direction D3. Therefore, widths L1 and L2 are the dimensions of the transparent sections 131 and 132 in the second direction D2. Widths L3 and L4 are the dimensions of the transparent sections 133 and 134 in the third direction D3. In Figure 3, each of the normals N1, N2, N3, and N4 passes through the center MM of the circular transparent sections 131, 132, 133, and 134. As a result, each of the widths L1, L2, L3, and L4 is the maximum width LM of the transparent section 13.

[0063] Figure 12 shows the normal vector NA at point PX of the permeable section 13A. The width LA of the permeable section 13A is the dimension of the portion of the normal vector NA located on the permeable section 13A. The normal vector NA extends in the direction of normal DNA. The direction of normal DNA is the direction that extends between the second direction D2 and the third direction D3 in the circumferential direction centered on the first direction D1. The width LA is the dimension of the permeable section 13A in the direction of normal DNA. The width LA is the maximum width LM of the permeable section 13 shown in Figure 12.

[0064] The maximum width LM of the multiple translucent portions 13 is determined from a microscopic image of the decorative sheet 10 observed from a first direction D1. The microscopic image is acquired at a magnification that allows observation of 10 to 20 translucent portions 13. When determining the maximum width LM of the multiple translucent portions 13, the maximum dimension in a direction nonparallel to the first direction D1 is measured for five different translucent portions 13 of the decorative sheet 10. The maximum width LM of the multiple translucent portions 13 is the average of the five measurements taken from the five different translucent portions 13. The five different translucent portions 13 may be selected from one microscopic image of the decorative sheet 10, or from multiple microscopic images of the decorative sheet 10.

[0065] The multiple transparent sections 13 shown in Figure 3 are arranged at equal intervals in the second direction D2 and the third direction D3. In Figure 3, the pitch between two adjacent transparent sections 13 in the second direction D2 is equal. In Figure 3, the pitch between two adjacent transparent sections 13 in the third direction D3 is also equal. Furthermore, in Figure 3, the pitch between two adjacent transparent sections 13 in the second direction D2 is equal to the pitch between two adjacent transparent sections 13 in the third direction D3. In other words, the multiple transparent sections 13 shown in Figure 3 are arranged in a square.

[0066] From the viewpoint of stably displaying the design of the decorative sheet 10, a lower limit may be set for the minimum pitch PM of the multiple translucent parts 13. The minimum pitch PM of the multiple translucent parts 13 may be 30 μm or more, or 50 μm or more. From the viewpoint of stably displaying the light from the light-emitting device 5, an upper limit may be set for the minimum pitch PM of the multiple translucent parts 13. The minimum pitch PM of the multiple translucent parts 13 may be 300 μm or less, or 120 μm or less.

[0067] The minimum pitch PM of the multiple transparent sections 13 is the minimum pitch of the multiple transparent sections 13. The pitch of the multiple transparent sections 13 is the distance between the ends of the portions located on the transparent section 13 between two adjacent transparent sections 13 in the normal direction described above. More specifically, the distance between the ends of the portions located on the transparent section 13 is the distance between the first ends in the normal direction of the portions located on the transparent section 13, or the distance between the second ends in the normal direction. Figure 3 shows the pitches PT1, PT2, PT3, and PT4 of the multiple transparent sections 13. In Figure 3, pitches PT1, PT2, PT3, and PT4 are the minimum pitch PM. Figure 12 shows the pitches PTX and PTY of the multiple transparent sections 13. In Figure 12, pitches PTX and PTY are the minimum pitch PM. In the transparent section 13, the minimum pitch PM may be greater than the maximum width LM. In the examples in Figures 3 and 12, the minimum pitch PM of the transparent section 13 is greater than the maximum width LM of the transparent section 13.

[0068] In Figure 3, pitch PT1 is an index between two adjacent transparent sections 131 and 135 in the normal direction DN1. Pitch PT1 is the distance between points P1 and P5. Point P1 is the first end of the portion of the normal N1 located on the transparent section 131 in the normal direction DN1. Point P5 is the first end of the portion of the normal N1 located on the transparent section 135 in the normal direction DN1. Therefore, pitch PT1 is the distance between the first ends of the portions of the normal N1 located on the transparent sections 131 and 135 in the normal direction DN1.

[0069] In Figure 3, pitch PT2 is an index between two adjacent transparent sections 132 and 136 in the normal direction DN1. Pitch PT2 is the distance between points P2 and P6. Point P2 is the second end of the portion of the normal N2 located on the transparent section 132 in the normal direction DN1. Point P6 is the second end of the portion of the normal N2 located on the transparent section 136 in the normal direction DN1. Therefore, pitch PT2 is the distance between the second ends of the portions of the normal N2 located on the transparent sections 132 and 136 in the normal direction DN1.

[0070] In Figure 3, pitch PT3 is an index between two adjacent transparent sections 133 and 137 in the normal direction DN2. Pitch PT3 is the distance between points P3 and P7. Point P3 is the first end in the normal direction DN2 of the portion of the normal N3 located on the transparent section 133. Point P7 is the first end in the normal direction DN2 of the portion of the normal N3 located on the transparent section 135. Therefore, pitch PT3 is the distance between the first ends in the normal direction DN2 of the portions of the normal N3 located on the transparent sections 133 and 137.

[0071] In Figure 3, pitch PT4 is an index between two adjacent transparent sections 134 and 138 in the normal direction DN2. Pitch PT4 is the distance between points P4 and P8. Point P4 is the second end of the portion of the normal N4 located on the transparent section 134 in the normal direction DN2. Point P8 is the second end of the portion of the normal N4 located on the transparent section 135 in the normal direction DN2. Therefore, pitch PT4 is the distance between the second ends of the portions of the normal N4 located on the transparent sections 134 and 138 in the normal direction DN2.

[0072] The pitch PTX in Figure 12 is an index of the distance between two adjacent permeable regions 13A and 13B in the normal DNA. Pitch PTX is the distance between points PX and PY. Point PX is the second end of the normal DNA portion of the normal NA located on permeable region 13A. Point PY is the second end of the normal DNA portion of the normal NA located on permeable region 13B. Therefore, pitch PTX is the distance between the second ends of the normal DNA portions of the normal NA located on permeable regions 13A and 13B.

[0073] The pitch PTY in Figure 12 is an index of the distance between two adjacent permeable regions 13A and 13C in the normal DNA. Pitch PTY is the distance between points PZ and PW. Point PZ is the first end of the normal DNA portion of the normal NA located on permeable region 13A. Point PW is the first end of the normal DNA portion of the normal NA located on permeable region 13C. Therefore, pitch PTY is the distance between the first ends of the normal DNA portions of the normal NA located on permeable regions 13A and 13C.

[0074] The minimum pitch PM of the multiple translucent areas 13 is determined from a microscopic image of the decorative sheet 10 observed from a first direction D1. The microscopic image is acquired at a magnification that allows observation of 10 to 20 translucent areas 13. When determining the minimum pitch PM of the multiple translucent areas 13, the minimum pitch value described above is measured in 5 different sets, i.e., 10 translucent areas 13, of the decorative sheet 10. The minimum pitch PM of the multiple translucent areas 13 is the average value of the 5 pitch measurements in the 5 different sets of translucent areas 13. The 5 different sets of translucent areas 13 may be selected from one microscopic image of the decorative sheet 10, or from multiple microscopic images of the decorative sheet 10.

[0075] The light-shielding layer 24 in Figure 2 is positioned in the light-shielding portion 14 of the decorative sheet 10. The light-shielding layer 24 is located between the pattern layer 25 and the first base material layer 41 in the first direction D1. The light-shielding layer 24 has visible light-shielding properties. Because the light-shielding layer 24 has visible light-shielding properties, the decorative sheet 10 absorbs light in the light-shielding portion 14.

[0076] "Visible light shielding" means that the visible light transmittance is 1% or less, preferably 0.2% or less. Visible light transmittance is determined as the average value of the total light transmittance at each wavelength when measured every 1 nm within the range of measurement wavelengths from 380 nm to 780 nm using a haze meter conforming to JIS K 7361-1:1997. The angle of incidence when measuring visible light transmittance is set to 0° unless the transmission direction is specifically defined. The angle of incidence is the angle that the direction of propagation of incident light makes with the direction normal to the incident surface, and is a value less than 90°.

[0077] The light-shielding layer 24 may contain a binder resin and light-absorbing particles dispersed in the binder resin. The light-absorbing particles may include black pigments such as carbon black and titanium black. The light-shielding layer 24 may also contain light-interference pigments instead of light-absorbing particles. For example, the light-interference pigment may be an aluminum pigment.

[0078] From the viewpoint of ensuring sufficient visible light shielding, a lower limit may be set for the thickness of the light-shielding layer 24. The thickness of the light-shielding layer 24 may be 1 μm or more, or 5 μm or more. From the viewpoint of suppressing an increase in the thickness of the decorative sheet 10 and stably displaying the light from the light-emitting device 5, an upper limit may be set for the thickness of the light-shielding layer 24. The thickness of the light-shielding layer 24 may be 20 μm or less, or 10 μm or less.

[0079] The pattern layer 25 in Figure 2 is located in the light-shielding section 14. The pattern layer 25 displays a pattern. The pattern displayed by the pattern layer 25 may be any of the following: a figure, design, picture, photograph, character, mark, pictogram, letter, or number. The pattern layer 25 may contain a binder resin and a colorant dispersed within the binder resin. The colorant may be a dye, a pigment, or a combination of dye and pigment. The pattern layer 25 may display a pattern. The pattern displayed by the pattern layer 25 may be any of the following: wood grain, stone pattern, hairline, or carbon fiber.

[0080] The pattern layer 25 may include a plurality of pattern units 250, as shown in Figure 4. The illustrated pattern layer 25 includes a first pattern unit 250A and a second pattern unit 250B as the plurality of pattern units 250. The first pattern unit 250A and the second pattern unit 250B have the same shape as each other. The first pattern unit 250A and the second pattern unit 250B are colored in different colors. The pattern units 250 may be colored in chromatic colors or in achromatic colors.

[0081] The pattern units 250 in Figure 4 are arranged in two dimensions in the first pattern direction DD1 and the second pattern direction DD2. The illustrated first pattern direction DD1 and second pattern direction DD2 are directions in which adjacent pattern units 250 are in line contact with each other. In addition, in the illustrated pattern layer 25, the pitch of two adjacent pattern units 250 in the third direction D3 is the minimum pitch PD of the multiple pattern units 250. The minimum pitch PD of the multiple pattern units 250 means the minimum distance MD between the centroids MD of two adjacent pattern units 250 in a direction nonparallel to the first direction D1 when the decorative sheet 10 is observed from the first direction D1. The minimum pitch PD of the multiple pattern units 250 may be 1.0 mm or more, or 2.5 mm or more. The minimum pitch of the multiple pattern units 250 may be 50 mm or less, or 25 mm or less.

[0082] Each of the multiple pattern units 250 shown in Figure 4 is observed to be a parallelogram, or even a rhombus. By making the pattern units 250 parallelograms, the pattern units can be arranged efficiently. The maximum value LD of each of the multiple pattern units 250 is not particularly limited. The maximum value LD of each of the multiple pattern units 250 may be 2 mm or more, or 5 mm or more. The maximum value LD of each of the multiple pattern units 250 may be 100 mm or less, or 50 mm or less.

[0083] The minimum pitch PD of multiple pattern units 250 is determined from an image of the first surface 11 of the decorative sheet 10 as observed from a first direction D1. When determining the minimum pitch PD of multiple pattern units 250, the minimum distance between adjacent pattern units 250 in a direction nonparallel to the first direction D1 is measured for five different sets, i.e., 10 pattern units 250, of the decorative sheet 10. The minimum pitch PD of multiple pattern units 250 is the average of five measurements taken from five different sets of pattern units 250. The five different sets of pattern units 250 may be selected from one image of the decorative sheet 10, or they may be selected from multiple images of the decorative sheet 10.

[0084] The maximum value LD of the dimensions of multiple pattern units 250 is determined from an image of the first surface 11 of the decorative sheet 10 as observed from a first direction D1. When determining the maximum value LD of the dimensions of multiple pattern units 250, the maximum value of the dimensions in a direction non-parallel to the first direction D1 is measured for five different pattern units 250 of the decorative sheet 10. The maximum value LD of the dimensions of multiple pattern units 250 is the average value of five measurements in five different pattern units 250. The five different pattern units 250 may be selected from one image of the first surface 11, or from multiple images of the first surface 11.

[0085] In the decorative sheet 10 shown in Figure 2, the minimum pitch PM of the multiple transparent areas 13 may be smaller than the minimum pitch PD of the multiple pattern units 250. As described above, the illustrated pattern layer 25 is not placed on the transparent areas 13. By arranging the multiple transparent areas 13 with a minimum pitch PM smaller than the minimum pitch PD of the multiple pattern units 250, the pattern layer 25 can stably display the pattern even when the decorative sheet 10 includes multiple transparent areas 13.

[0086] In Figure 2, the surface protection layer 26 is positioned on the transparent portion 13 and the light-shielding portion 14 of the decorative sheet 10. The surface protection layer 26 constitutes the first surface 21 of the decorative layer 20. The surface protection layer 26 constitutes the first surface 11 of the decorative sheet 10. The surface protection layer 26 constitutes the display surface 2 of the display system 1. The surface protection layer 26 may also be a hard coat layer. In the display system 1 of Figure 2, light emitted from the light-emitting device 5 passes through the surface protection layer 26 and is then emitted from the display surface 2. The surface protection layer 26 may be transparent. The surface protection layer 26 may contain a cured resin.

[0087] The cured resin product is a cured product of a thermosetting resin composition or a cured product of an ionizing radiation-curable resin composition. The thermosetting resin composition contains a thermosetting resin. The thermosetting resin is usually a resin that crosslinks upon heating. The thermosetting resin composition hardens by crosslinking of the thermosetting resin. The thermosetting resin composition may further contain a curing agent. The curing agent may function as a catalyst to accelerate the hardening of the thermosetting resin, or it may react with the thermosetting resin. The thermosetting resin may crosslink upon reaction with the curing agent. The curing agent may be included in the cured product of the thermosetting resin composition. In a thermosetting resin composition, the thermosetting resin may be referred to as the main component.

[0088] The thermosetting resin contained in the thermosetting resin composition may include one or more of the following: phenolic resin, urea resin, diallyl phthalate resin, melamine resin, guanamine resin, unsaturated polyester resin, polyurethane resin, epoxy resin, amino alkyd resin, melamine-urea cocondensation resin, and silicon resin. The curing agent contained in the thermosetting resin composition may be an isocyanate compound. The isocyanate compound is a compound containing an isocyanate group. The isocyanate compound may also be a polyisocyanate containing multiple isocyanate groups.

[0089] An ionizing radiation-curable resin composition contains an ionizing radiation-curable resin. An ionizing radiation-curable resin is a resin that crosslinks upon irradiation with ionizing radiation. Ionizing radiation means electromagnetic waves or charged particle beams that have energy quanta capable of polymerizing or crosslinking molecules. Electromagnetic waves may be ultraviolet (UV), X-rays, or gamma rays. Charged particle beams may be electron beams (EB), alpha rays, or ion beams. Among ionizing radiation-curable resins, those that crosslink upon irradiation with ultraviolet radiation may be referred to as ultraviolet-curable resins. Among ionizing radiation-curable resins, those that crosslink upon irradiation with electron beams may be referred to as electron-beam-curable resins.

[0090] In an ionizing radiation-curable resin composition, the ionizing radiation-curable resin may contain functional groups having ethylenically double bonds, such as (meth)acryloyl groups, vinyl groups, and allyl groups. The ionizing radiation-curable resin may also contain one or more epoxy groups and oxetanyl groups. The ionizing radiation-curable resin may also contain ethylenically unsaturated bonding groups. The ionizing radiation-curable resin may also contain siloxane bonds.

[0091] The reflective layer 30 in Figure 2 includes a first surface 31 and a second surface 32. The first surface 31 and the second surface 32 face each other in a first direction D1. The second surface 32 constitutes the second surface 12 of the decorative sheet 10. The reflective layer 30 in Figure 2 includes a first resin layer 33, a metal layer 35, and a second resin layer 34 in that order, from the first surface 31 to the second surface 32.

[0092] The reflective layer 30 in Figures 2 and 5 includes a plurality of optical units 60 that reflect light incident on the first surface 11. Figure 5 is a view of the optical units 60 from the second side in the first direction D1. Figure 5 shows a plurality of optical units 60 arranged in two dimensions in the first arrangement direction DR1 and the second arrangement direction DR2. The first arrangement direction DR1 and the second arrangement direction DR2 are non-parallel to each other. Each of the first arrangement direction DR1 and the second arrangement direction DR2 is perpendicular to the first direction D1. The first arrangement direction DR1 and the second arrangement direction DR2 are directions in which adjacent optical units 60 are in line contact with each other.

[0093] In the multiple optical units 60 shown in Figure 5, the pitch between two adjacent optical units 60 in the third direction D3 is the minimum pitch PN of the multiple optical units 60. The minimum pitch PN of the multiple optical units 60 refers to the minimum distance MN between the centroids MN of two adjacent optical units 60 in a direction nonparallel to the first direction D1 when the reflective layer 30 is observed from the first direction D1. The minimum pitch PN of the multiple optical units 60 may be 2 mm or more, or 55 mm or more. The minimum pitch of the multiple optical units 60 may be 150 mm or less, or 75 mm or less.

[0094] Each of the multiple optical units 60 shown in Figure 5 is observed as a parallelogram. In particular, each of the illustrated multiple optical units 60 is observed as a rhombus. The maximum value LN of each of the multiple optical units 60 is not particularly limited. The maximum value LN of each of the multiple optical units 60 may be 4 mm or more, or 10 mm or more. The maximum value LN of each of the multiple optical units 60 may be 300 mm or less, or 150 mm or less.

[0095] The minimum pitch PN of multiple optical units 60 is determined from an image of the second surface 12 of the decorative sheet 10 observed from a first direction D1. When determining the minimum pitch PN of multiple optical units 60, the minimum distance between adjacent optical units 60 in a direction nonparallel to the first direction D1 is measured for five different sets of optical units 60, i.e., 10 optical units 60 of the reflective layer 30. The minimum pitch PN of multiple optical units 60 is the average of five measurements taken from five different sets of optical units 60. The five different sets of optical units 60 may be selected from one image of the second surface 12, or from multiple images of the second surface 12.

[0096] The maximum value LN of the dimensions of multiple optical units 60 is determined from an image of the second surface 12 of the decorative sheet 10 when observed from a first direction D1. When determining the maximum value LN of the dimensions of multiple optical units 60, the maximum value of the dimensions in a direction nonparallel to the first direction D1 is measured for five different optical units 60 of the reflective layer 30. The maximum value LN of the dimensions of multiple optical units 60 is the average of the five measurements taken for the five different optical units 60. The five different optical units 60 may be selected from one image of the second surface 12, or from multiple images of the second surface 12.

[0097] The optical unit 60 in Figures 2 and 5 includes a reflective surface 61. The illustrated reflective surface 61 is formed by the interface between the first resin layer 33 and the metal layer 35. As shown in Figures 2 and 5, the optical unit 60 may include a plurality of reflective surfaces 61 and a plurality of connecting surfaces 62 that connect adjacent reflective surfaces 61. The optical unit 60 reflects light incident on the first surface 11 at the reflective surfaces 61. In the optical unit 60 shown in Figure 5, each of the plurality of reflective surfaces 61 is rotationally symmetric about the axis Ax. Each of the plurality of reflective surfaces 61 extends in the circumferential direction about the axis Ax. The illustrated plurality of reflective surfaces 61 are arranged concentrically about the axis Ax. The axis Ax in Figure 5 is located at the centroid when the optical unit 60 is observed from the first direction D1.

[0098] Each of the multiple reflective surfaces 61 shown in Figure 2 is at least partially inclined with respect to a first direction D1. The inclined reflective surfaces 61 approach the first surface 31 as they move away from the axis Ax in a direction perpendicular to the first direction D1. In Figure 2, the inclined reflective surfaces 61 approach the first surface 31 as they move away from the axis Ax in a second direction D2. The illustrated optical units 60 may have the function of focusing reflected light from the reflective surfaces 61 due to the inclined reflective surfaces 61. In the reflective layer 30, each of the multiple optical units 60 may have the function of focusing reflected light from the reflective surfaces 61. Each of the multiple connecting surfaces 62 shown in Figure 2 extends in the first direction D1.

[0099] The reflective surface 61 may be a curved surface. In other words, the inclination angle between the reflective surface 61 and the first direction D1 may change continuously. In Figure 2, the reflective surface 61 where the axis Ax is located is a curved surface. At the reflective surface 61 where the axis Ax is located, the inclination angle between the reflective surface 61 and the first direction D1 decreases continuously as it moves away from the axis Ax.

[0100] As shown in Figures 2 and 5, the multiple reflective surfaces 61 and the multiple connecting surfaces 62 may constitute a Fresnel lens structure 63. Each of the multiple optical units 60 may include a Fresnel lens structure 63. When the multiple reflective surfaces 61, together with the multiple connecting surfaces 62, constitute a Fresnel lens structure 63, they may be arranged concentrically as described above. That is, the Fresnel lens structure 63 may be a circular Fresnel lens structure. Contrary to the figures, the Fresnel lens structure 63 may be a linear Fresnel lens structure. By including a Fresnel lens structure 63 in the optical unit 60, the thickness of the reflective layer 30 and the decorative sheet 10 can be reduced.

[0101] The multiple reflective surfaces 61 shown in Figure 2 are part of the Fresnel lens structure 63. The multiple reflective surfaces 61 constitute a divided concave surface. The divided concave surface is concave towards the second surface 32 as it approaches the axis Ax.

[0102] The first resin layer 33 in Figure 2 is located between the second substrate layer 42 and the metal layer 35. The first resin layer 33 includes an uneven surface 71 facing the second surface 12. The uneven surface 71 contains a plurality of uneven units 70. The first resin layer 33, together with the metal layer 35, constitutes a reflective surface 61 on the uneven surface 71. Each of the plurality of optical units 60 contains one of the plurality of uneven units 70.

[0103] The first resin layer 33 may contain a cured resin product. In particular, the first resin layer 33 may contain a cured product of an ionizing radiation-curable resin composition as the cured resin product. The ionizing radiation-curable resin composition forming the first resin layer 33 may contain the above-mentioned ultraviolet-curable resin, or it may contain the above-mentioned electron beam-curable resin. The first resin layer 33 may be formed by pressing a shaping plate onto a curable resin composition containing a curable resin before curing.

[0104] The metal layer 35 in Figure 2 is located between the first resin layer 33 and the second resin layer 34. The interface between the metal layer 35 and the first resin layer 33 constitutes a reflective surface 61. In the metal layer 35, the surface that, together with the first resin layer 33, constitutes the reflective surface 61 has a shape complementary to the uneven surface 71. The illustrated metal layer 35 also has an uneven structure on the surface opposite to the surface that constitutes the reflective surface 61.

[0105] The metal layer 35 is a layer for promoting reflection on the reflective surface 61. The metal layer 35 covers the first resin layer 33 from the second side in the first direction D1. The metal layer 35 may be formed by vapor deposition of a metal material. In forming the metal layer 35, the metal material may be deposited by various methods such as sputtering and vacuum deposition.

[0106] The second resin layer 34 in Figure 2 constitutes the second surface 12 of the decorative sheet 10. The second resin layer 34 fills the aforementioned uneven structure of the metal layer 35. By filling the uneven structure of the metal layer 35, the second resin layer 34 includes a second uneven surface 81. The second uneven surface 81 is the surface opposite to the surface that constitutes the second surface 12. The metal layer 35 is located between the uneven surface 71 and the second uneven surface 81. The second uneven surface 81 contains a plurality of second uneven units 80.

[0107] The second resin layer 34 flattens the second surface 32 of the reflective layer 30. Furthermore, by positioning the metal layer 35 between the first resin layer 33 and the second resin layer 34, it is possible to suppress the peeling of the metal layer 35 from the reflective layer 30 when the decorative sheet 10 and the light-emitting device 5 are joined together.

[0108] The second resin layer 34 in Figure 2 is a bonding layer 50 (second bonding layer 52) that bonds the decorative sheet 10 to the light-emitting device 5. As described above, the second bonding layer 52 may also contain an optically transparent resin. The second bonding layer 52 may have the same configuration as the first bonding layer 51.

[0109] The decorative sheet 10 in Figure 2 may be manufactured by joining a first sheet 15 and a second sheet 16 via a bonding layer 50 (first bonding layer 51). The first sheet 15 includes a first base layer 41 and a decorative layer 20. When manufacturing the first sheet 15, the light-shielding layer 24 and the pattern layer 25 may be formed on the base layer 40 (first base layer 41) by printing. When manufacturing the first sheet 15, a resin composition that forms the surface protective layer 26 may be applied to the base layer 40 (first base layer 41). The second sheet 16 includes a second base layer 42 and a reflective layer 30. The first sheet 15 and the second sheet 16 may be manufactured separately.

[0110] The operation of the decorative sheet 10 shown in Figures 1 to 5 and Figure 4 will be explained. Specifically, the operation of the illustrated display system 1 will be explained.

[0111] In the illustrated display system 1, ambient light is incident on the display surface 2 regardless of the state of the light-emitting device 5. The ambient light is incident on the first surface 11 of the decorative sheet 10. The light incident on the first surface 11 reaches the light-shielding layer 24 or the pattern layer 25 at the light-shielding portion 14. The light that reaches the light-shielding layer 24 is absorbed. The light that reaches the pattern layer 25 is reflected back towards the first surface 11 according to the pattern and emitted from the display surface 2. The observer observes the design D of the decorative sheet 10 by observing the reflected light from the pattern layer 25. As shown in Figure 7, the decorative sheet 10 can conceal the light-emitting device 5 with its design D. By concealing the light-emitting device 5, the display system 1, including the light-emitting device 5, can be harmonized with the surrounding environment.

[0112] Light incident on the first surface 11 passes through the surface protective layer 26, the first substrate layer 41, the first bonding layer 51, and the second substrate layer 42 in that order in the transmission section 13, and reaches the reflective layer 30. The light that reaches the reflective layer 30 is reflected by the reflective surface 61. The reflected light from the reflective surface 61 is emitted from the first surface 11 in the transmission section 13. As a result, the display system 1 including the illustrated decorative sheet 10 displays the second light LC2 on the display surface 2 by the reflected light from the reflective surface 61.

[0113] Figures 6 and 7 illustrate an example of the mechanism by which the second light LC2 is observed in the decorative sheet 10 and the display system 1 including the decorative sheet 10. Figures 6 and 7 schematically show the display system 1 illuminated by light from a light source on the display surface 2. In Figure 6, components other than the optical units 60 of the decorative sheet 10 are omitted. Light from the light source is incident on the first surface 11 of the decorative sheet 10. As described above, the multiple optical units 60 reflect the light incident on the first surface 11 in the transmissive portion 13 of the decorative sheet 10. In Figures 6 and 7, the light from the light source is reflected on the reflective surface 61 which is inclined with respect to the first direction D1. The multiple reflective surfaces 61 shown in Figures 2 and 5 function as concave mirrors. In Figure 6, the multiple reflective surfaces 61 are schematically connected to each other. The observer observes the light reflected on the reflective surface 61. The observer is positioned between the light source and the reflective surface 61.

[0114] Parallax occurs when an observer observes a light source on a reflective surface 61 tilted with respect to a first direction D1. This parallax may be motion parallax or binocular parallax. Due to the parallax, the light source on the reflective surface 61 may be observed in a position different from its actual position, as shown in Figure 6. Figure 6 shows a state in which the light reflected on the reflective surface 61 is observed to be located on the axis Ax. As shown in Figure 6, the light on the reflective surface 61 is observed to be floating above the reflective surface 61 and the first surface 11 of the decorative sheet 10. When light from the light source illuminates the first surface 11 of the decorative sheet 10, parallax occurs in each of the multiple optical units 60. As a result, as shown in Figure 7, the multiple lights are observed as multiple second light LC2s floating above the first surface 11. The multiple second light LC2s are observed as planar surfaces, as shown in Figure 7. The multiple second light LC2s are observed as surfaces floating above the first surface 11 in the first direction D1. Furthermore, the mechanism by which the second optical LC2 is observed in display system 1 is not limited to the above description.

[0115] As a result, the illustrated display system 1 displays the design D and the second light LC2 regardless of the state of the light-emitting device 5. The combination of design D and the multiple second light LC2s allows the decorative sheet 10 and the display system 1 including the decorative sheet 10 to display design D in three dimensions.

[0116] In the illustrated decorative sheet 10, in order to more effectively display the design D in three dimensions, a plurality of optical units 60 may be arranged according to the pattern formed by the pattern layer 25. For example, the pattern layer 25 may include a plurality of pattern units 250, similar to the plurality of optical units 60. The plurality of optical units 60 may be arranged two-dimensionally in a direction perpendicular to the first direction D1 as shown in Figure 5, and the plurality of pattern units 250 may be arranged two-dimensionally in a direction perpendicular to the first direction D1 as shown in Figure 4.

[0117] When multiple optical units 60 are arranged according to a pattern, a lower limit may be set for the angle between the arrangement directions DD1, DD2 of the multiple pattern units 250 and the arrangement directions DR1, DR2 of the multiple optical units 60. Specifically, either the angle between the first pattern direction DD1 and the first arrangement direction DR1, or the angle between the first pattern direction DD1 and the second arrangement direction DR2, may be 45° or less, or 10° or less. Similarly, either the angle between the second pattern direction DD2 and the first arrangement direction DR1, or the angle between the second pattern direction DD2 and the second arrangement direction DR2, may be 45° or less, or 10° or less.

[0118] Furthermore, when multiple optical units 60 are arranged according to the pattern, the minimum pitch PD of the multiple pattern units 250 may be smaller than the minimum pitch PN of the multiple optical units 60. By arranging the multiple pattern units 250 with a minimum pitch PD smaller than the minimum pitch PN of the multiple optical units 60, interference between the multiple second optical LC2s and the pattern can be suppressed, which would otherwise make it difficult to observe the pattern. As a result, even when the display system 1 is displaying the second optical LC2s, the pattern formed by the design D can be clearly observed.

[0119] From the viewpoint of ensuring stable visibility of the pattern, a numerical range may be provided between the minimum pitch PD of the multiple pattern units 250 and the minimum pitch PN of the multiple optical units 60. The minimum pitch PN of the multiple optical units 60 may be 2 times or more, 3 times or more, 5 times or more, 10 times or more, or 20 times or more than the minimum pitch PD of the multiple pattern units 250. The minimum pitch PN of the multiple optical units 60 may be 150 times or less, 100 times or less, or 50 times or less than the minimum pitch PD of the multiple pattern units 250.

[0120] From the viewpoint of suppressing the absorption of reflected light from the reflective surface 61 at the light-shielding portion 14 and stably displaying the second light LC2, a lower limit may be set for the ratio of the maximum width LM of the multiple transmission portions 13 to the maximum value LN of the dimensions of the multiple optical units 60. From a similar viewpoint, a lower limit may be set for the ratio of the minimum pitch PM of the multiple transmission portions 13 to the minimum pitch PN of the dimensions of the multiple optical units 60. When observed from the first direction D1, the maximum width LM of the multiple transmission portions 13 may be 0.005% or more, 0.1% or more, 0.5% or more, or 1% or more of the maximum value LN of the dimensions of the multiple optical units 60. When observed from the first direction D1, the minimum pitch PM of the multiple transmission portions 13 may be 0.02% or more, 0.03% or more, 0.05% or more, or 0.1% or more of the minimum pitch PN of the multiple optical units 60.

[0121] From the viewpoint of stably displaying the design by the pattern layer 25 arranged in the light-shielding portion 14, an upper limit may be set on the ratio of the maximum width LM of the multiple transmission portions 13 to the maximum value LN of the dimensions of the multiple optical units 60. From a similar viewpoint, an upper limit may be set on the ratio of the minimum pitch PM of the multiple transmission portions 13 to the minimum pitch PN of the dimensions of the multiple optical units 60. When observed from the first direction D1, the maximum width LM of the multiple transmission portions 13 may be 6% or less, 4% or less, or 3% or less of the maximum value LN of the dimensions of the multiple optical units 60. When observed from the first direction D1, the minimum pitch PM of the multiple transmission portions 13 may be 15% or less, 10% or less, 5% or less, or 1% or less of the minimum pitch PN of the multiple optical units 60.

[0122] When the light-emitting device 5 emits light from the light-emitting surface 6, the light is incident on the second surface 12 of the decorative sheet 10. The light incident on the second surface 12 is transmitted through the decorative sheet 10 in the light-transmitting portion 13. The light incident on the second surface 12 is absorbed in the light-shielding portion 14. The light transmitted through the decorative sheet 10 passes through each layer of the decorative sheet 10 in the following order: second resin layer 34, metal layer 35, first resin layer 33, second substrate layer 42, first bonding layer 51, first substrate layer 41, and surface protection layer 26. The light transmitted through the decorative sheet 10 is emitted from the display surface 2. As shown in Figure 7, the display system 1 displays the light emitted from the display surface 2 as the first light LC1.

[0123] In the illustrated display system 1, an upper limit may be set for the thickness of the decorative sheet 10 from the viewpoint of suppressing the diffusion of light emitted from the light-emitting device 5 and efficiently displaying the first light LC1 brightly. The thickness of the decorative sheet 10 may be 2000 μm or less, or 1000 μm or less. The lower limit for the thickness of the decorative sheet 10 is not particularly limited as long as the design D and the second light LC2 can be displayed. The thickness of the decorative sheet 10 may be 60 μm or more, 200 μm or more, or 500 μm or more.

[0124] Conventional decorative sheets that display designs and transmitted light from light-emitting devices include a layer that provides tactile sensation and texture for the three-dimensional representation of the design, as described in JP2018-163341A. Such a layer is superimposed on the pattern layer that forms the design. Conventional decorative sheets may have an uneven surface structure. However, decorative sheets with an uneven surface structure may have reduced light transmittance from light-emitting devices. This reduced light transmittance from light-emitting devices can lead to a problem in conventional decorative sheets where it is not possible to achieve both a three-dimensional display of the design and a bright display of transmitted light.

[0125] In contrast, in the display system 1 shown in Figures 1 and 8, the decorative sheet 10 includes a pattern layer 25 and a reflective layer 30. As described above, the decorative sheet 10 can display the design D three-dimensionally through a combination of the design D and a plurality of second light LC2s. Furthermore, in the illustrated display system 1, a numerical range is provided for the total light transmittance of the decorative sheet 10. The total light transmittance of the decorative sheet 10 may be 10% or more, 30% or more, or 50% or more. The total light transmittance of the decorative sheet 10 may be 85% or less, 70% or less, or 60% or less. By providing a numerical range for the total light transmittance of the decorative sheet 10, particularly the lower limit, the deterioration of the transmittance of the first light LC1 is suppressed in the display system 1. The display system 1 can display the first light LC1 brightly. Therefore, in the illustrated display system 1, the decorative sheet 10 can display the design D three-dimensionally and display the transmitted light brightly.

[0126] Furthermore, the illustrated display system 1 can also display an image three-dimensionally by combining the first light LC1 and a plurality of second light LC2s when the light-emitting device 5 is emitting light. The illustrated display system 1 can display an image three-dimensionally with a simple configuration of the light-emitting device 5 and the decorative sheet 10.

[0127] In the illustrated display system 1, in order to display the first light LC1 brightly, an upper limit may be set on the refractive index difference between the first resin layer 33 and the second resin layer 34 in the reflective layer 30. The refractive index difference between the first resin layer 33 and the second resin layer 34 may be 0.5 or less, or 0.1 or less. By setting an upper limit on the refractive index between the first resin layer 33 and the second resin layer 34, the deviation between the direction of propagation in the second resin layer 34 and the direction of propagation in the first resin layer 33 can be reduced for light traveling from the second surface 32 toward the first surface 31. This suppresses the bending of light emitted from the light-emitting device 5 in an unintended direction in the reflective layer 30. As a result, the illustrated decorative sheet 10 and the display system 1 including the decorative sheet 10 can display the first light LC1 brightly. The lower limit of the refractive index difference between the first resin layer 33 and the second resin layer 34 is not particularly limited. The refractive index difference between the first resin layer 33 and the second resin layer 34 may be 0 or greater, or 0.1 or greater.

[0128] The refractive index difference between the first resin layer 33 and the second resin layer 34 is defined as the absolute value of the difference between the refractive index of the first resin layer 33 and the refractive index of the second resin layer 34. The refractive index of the first resin layer 33 and the refractive index of the second resin layer 34 are measured by Method A as specified in JIS K7142:2014.

[0129] For the measurement of the refractive index, samples of the first resin layer 33 and the second resin layer 34 are obtained. Each sample has a width of at least 8 mm, a length of 20 mm, and a thickness of 2 μm to 50 μm. The sample of the first resin layer 33 is cut from the reflective layer 30. The sample of the second resin layer 34 is cut from the reflective layer 30.

[0130] For measuring the refractive index, an Abbe refractometer, a multi-wavelength Abbe refractometer, or a refractometer with equivalent performance is used. The refractometer measures the refractive index of the sample to be measured, which is placed on the main prism. When measuring the refractive index of the first resin layer 33, a contact solution is placed between the sample of the first resin layer 33 and the main prism. When measuring the refractive index of the second resin layer 34, a contact solution is placed between the second resin layer 34 and the main prism. 1-Bromonaphthalene is used as the contact solution. The test environment for measuring the refractive index is a temperature of 23°C ± 2°C and a relative humidity of 50% ± 5%. Other conditions for measuring the refractive index follow the provisions for Method A of JIS K7142:2014.

[0131] The refractive index of the first resin layer 33 and the refractive index of the second resin layer 34 are determined as the arithmetic mean of five measurements taken under the conditions described above. The five measurements are taken using five different samples.

[0132] In the embodiment described above, the decorative sheet 10 includes a first surface 11 and a second surface 12 facing a first direction D1. The decorative sheet 10 includes a pattern layer 25 and a reflective layer 30 in that order, from the first surface 11 to the second surface 12. The reflective layer 30 includes a plurality of optical units 60 that reflect light incident on the first surface 11. Each of the plurality of optical units 60 includes a reflective surface 61 inclined with respect to the first direction D1. The total light transmittance of the decorative sheet 10 is 10% or more and 85% or less.

[0133] Furthermore, in the embodiment described above, the display system 1 includes a decorative sheet 10 including a first surface 11 and a second surface 12 facing a first direction D1, and a light-emitting device 5 that overlaps the second surface 12 of the decorative sheet 10. The decorative sheet 10 includes a pattern layer 25 and a reflective layer 30 in that order, from the first surface 11 to the second surface 12. The reflective layer 30 includes a plurality of optical units 60 that reflect light incident on the first surface 11. Each of the plurality of optical units 60 includes a reflective surface 61 inclined with respect to the first direction D1.

[0134] According to these embodiments, the decorative sheet 10 can display the first light LC1 by transmitting light emitted from the light-emitting device 5. The decorative sheet 10 can also display the second light LC2 at a position separate from the first surface 11 by utilizing the reflected light on the reflective surface 61. The decorative sheet 10 can display the design D three-dimensionally through a combination of the design D and the second light LC2. Therefore, the decorative sheet 10 can display the design D three-dimensionally and also display the transmitted light brightly.

[0135] While one embodiment has been described with reference to specific examples, the above-mentioned example does not limit this embodiment. The above-described embodiment can be implemented in various other examples, and various omissions, substitutions, modifications, and additions can be made without departing from its essence.

[0136] An example of modification will be described below with reference to the drawings. In the following explanation and the drawings used therein, parts that can be configured in the same way as in the specific example described above will be given the same reference numerals as those used for the corresponding parts in the specific example described above, and redundant explanations will be omitted.

[0137] In the decorative sheet 10 described above, the multiple reflective surfaces 61 constituted part of the Fresnel lens structure 63. The multiple reflective surfaces 61 constituted divided concave surfaces. The divided concave surfaces were recessed toward the second surface 32 as they approached the axis Ax. As shown in Figure 8, the multiple reflective surfaces 61 may also constitute divided convex surfaces. The illustrated convex surfaces protrude toward the first surface 31 as they approach the axis Ax.

[0138] The decorative sheet 10 described above included multiple base material layers 40. The decorative sheet 10 included a first base material layer 41 that supports the pattern layer 25 and a second base material layer 42 that supports the components of the reflective layer 30. The decorative sheet 10 may also include a single base material layer 40, as shown in Figure 9. The decorative sheet 10 may also include a base material layer 40 that supports the pattern layer 25 and the reflective layer 30. On one side of the base material layer 40 in Figure 9, a light-shielding layer 24, a pattern layer 25, and a surface protection layer 26 are superimposed. On the other side of the base material layer 40, a first resin layer 33, a metal layer 35, and a second resin layer 34 are superimposed. The decorative sheet 10 in Figure 9 can reduce the thickness of the base material layer 40 compared to the decorative sheet 10 described above. This reduces the thickness of the decorative sheet 10 and allows for stable display of light from the light-emitting device 5.

[0139] The decorative sheet 10 described above included a transparent portion 13 and a light-shielding portion 14 when observed from a first direction D1. The decorative sheet 10 included a light-shielding layer 24 having visible light-shielding properties. The decorative sheet 10 does not necessarily have to include the light-shielding portion 14, as shown in Figure 10. The light-shielding layer 24 may be omitted in the decorative sheet 10. The display system 1 may display the first light LC1 by light transmitted through the pattern layer 25.

[0140] As shown in Figure 11, the light-emitting device 5 may include a surface light source device 7 and a pattern mask 8 that overlaps the surface light source device 7. The pattern mask 8 in Figure 11 is located between the surface light source device 7 and the decorative sheet 10. The pattern mask 8 shapes the light emitted from the surface light source device 7. The illustrated pattern mask 8 includes a light-transmitting region 8A and a light-shielding region 8B.

[0141] The pattern mask 8 is capable of transmitting light emitted from the surface light source device 7 in the transparent region 8A. The transparent region 8A has the same shape as the first light LC1. Depending on the shape of the first light LC1 to be displayed, the transparent region 8A may have the shape of a figure, mark, pictogram, etc.

[0142] The pattern mask 8 has visible light shielding properties in the light-shielding region 8B. In the display system 1 of Figure 11, light emitted from the surface light source device 7 can be absorbed in the light-shielding region 8B of the pattern mask 8. The pattern mask 8 may contain a binder resin and light-absorbing particles dispersed in the binder resin in the light-shielding region 8B. The light-absorbing particles may include black pigments such as carbon black and titanium black. The pattern mask 8 may also contain an optical interference pigment in place of the light-absorbing particles in the light-shielding region 8B. An example of an optical interference pigment is an aluminum pigment.

[0143] The pattern mask 8 may be included in the decorative sheet 10. In the decorative sheet 10 including the pattern mask 8, the reflective layer 30 may be located between the pattern layer 25 and the pattern mask 8.

[0144] In the decorative sheet 10 described above, the multiple reflective surfaces 61 were part of the Fresnel lens structure 63. The multiple reflective surfaces 61 may also be part of a hologram structure instead of the Fresnel lens structure 63. Each of the multiple optical units 60 may also include a hologram structure. The decorative sheet 10 may use holography to display a second light LC2 at a position away from the display surface 2 in the first direction D1. The hologram structure may also be a relief hologram. [Explanation of Symbols]

[0145] 1: Display system, 2: Display surface, 5: Light-emitting device, 6: Light-emitting surface, 7: Surface light source device, 8: Pattern mask, 10: Decorative sheet, 11: First surface, 12: Second surface, 13: Transmitting part, 14: Light-shielding part, 24: Light-shielding layer, 25: Pattern layer, 30: Reflective layer, 33: First resin layer, 34: Second resin layer, 35: Metal layer, 40: Substrate layer, 41: First substrate layer, 42: Second substrate layer, 50: Bonding layer, 51: First bonding layer, 52: Second bonding layer, 60: Optical unit, 61: Reflective surface, 62: Connecting surface, 63: Fresnel lens structure, 70: Concave / concave unit, 71: Concave / concave surface, 81: Second concave / concave surface, D1: First direction

Claims

1. Including a first surface and a second surface facing the first direction, From the first surface to the second surface, the pattern layer and the reflective layer are provided in this order. The reflective layer includes a plurality of optical units that reflect light incident on the first surface, Each of the plurality of optical units includes a reflective surface inclined with respect to the first direction, A decorative sheet with a total light transmittance of 10% to 85%.

2. The reflective layer includes a resin layer containing a plurality of uneven units, The decorative sheet according to claim 1, wherein each of the plurality of optical units includes any of the plurality of uneven units.

3. The decorative sheet according to claim 2, wherein each of the plurality of optical units includes a Fresnel lens structure.

4. The aforementioned reflective layer includes a metal layer, The decorative sheet according to claim 2, wherein the resin layer is located between the pattern layer and the metal layer.

5. The reflective layer includes a second resin layer, The decorative sheet according to claim 4, wherein the metal layer is located between the resin layer and the second resin layer.

6. The decorative sheet according to claim 5, wherein the refractive index difference between the resin layer and the second resin layer is 0 or more and 0.5 or less.

7. The decorative sheet according to claim 2, comprising a base layer that supports the pattern layer and the resin layer.

8. The decorative sheet according to claim 1, wherein the minimum pitch of the plurality of optical units is 4 mm or more and 300 mm or less.

9. The decorative sheet according to claim 1, wherein the plurality of optical units are arranged according to the pattern formed by the pattern layer.

10. The aforementioned pattern layer includes multiple pattern units, The decorative sheet according to claim 9, wherein the minimum pitch of the plurality of pattern units is smaller than the minimum pitch of the plurality of optical units.

11. The decorative sheet according to claim 10, wherein the minimum pitch of the plurality of optical units is 2 times or more and 150 times or less the minimum pitch of the plurality of pattern units.

12. Observation from the first direction includes a plurality of transparent parts, The decorative sheet according to claim 10, wherein the minimum pitch of the plurality of transparent portions is smaller than the minimum pitch of the plurality of pattern units.

13. In the observation from the first direction, it includes a transparent portion and a light-shielding portion, The decorative sheet according to claim 1, wherein the patterned layer is arranged in the light-shielding portion.

14. In observation from the first direction, the maximum width of the transmitted portion is 0.005% to 6% of the maximum value of the dimensions of the plurality of optical units. The decorative sheet according to claim 13, wherein the minimum pitch of the transparent portion is 0.02% or more and 15% or less of the minimum pitch of the plurality of optical units.

15. The decorative sheet according to claim 1, having a thickness of 60 μm or more and 2000 μm or less.

16. With additional pattern masks, The decorative sheet according to claim 1, wherein the reflective layer is located between the pattern layer and the pattern mask.

17. The decorative sheet according to claim 1, A display system comprising a light-emitting device that overlaps the second surface of the decorative sheet.

18. A decorative sheet including a first surface and a second surface facing each other in the first direction, The decorative sheet comprises a light-emitting device that overlaps the second surface of the decorative sheet, The decorative sheet includes a pattern layer and a reflective layer in this order, from the first surface to the second surface. The reflective layer includes a plurality of optical units that reflect light incident on the first surface, A display system in which each of the plurality of optical units includes a reflective surface inclined with respect to the first direction.

19. The reflective layer includes, in this order, a resin layer containing a plurality of uneven units, a metal layer, and a second resin layer, from the first surface toward the second surface. Each of the plurality of uneven units constitutes each of the plurality of optical units, The metal layer is located between the resin layer and the second resin layer. The display system according to claim 17 or 18, wherein the refractive index difference between the resin layer and the second resin layer is 0 or more and 0.5 or less.

20. The display system according to claim 19, wherein the second resin layer is a bonding layer for bonding the decorative sheet to the light-emitting device.

21. The light-emitting device includes a surface light source device and a pattern mask that overlaps the surface light source device. The display system according to claim 17 or 18, wherein the pattern mask is located between the surface light source device and the decorative sheet.

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