Optical sheet, optical member and luminaire

Abstract

To provide an optical sheet capable of increasing light utilization efficiency while improving designability, an optical member and a luminaire.SOLUTION: An optical sheet 20 comprises a support part 21 having a pair of principal planes 21a and 21b, and a plurality of pattern layers 22 that is provided on the side of the one principal plane 21b of the support part 21. The support part 21 is formed with a plurality of optical extraction parts 25 that protrudes from the one principal plane 21b. In a cross-section along a normal direction N of the principal planes 21a and 21b, the pattern layer 22 and the optical extraction part 25 are alternately arranged.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an optical sheet, an optical member, and an illumination device. [Background technology]

[0002] There is known a lighting device that includes a cover member and a light irradiation unit that irradiates the cover member with light (see, for example, Patent Document 1). Patent Document 1 discloses a lighting device that can be installed on a wall surface on which a predetermined pattern is formed, without creating an unnatural look on the wall surface, and that can suppress a decrease in light utilization efficiency. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-243095 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional lighting that exhibits design value includes indirect lighting, which first shines light on a pattern and then provides indirect illumination through reflected light. However, indirect lighting can have low energy efficiency due to the influence of the light reflectance on the pattern. Furthermore, for example, lighting such as downlights can ensure energy efficiency, but the illuminated area is hole-shaped, which can reduce the design value.

[0005] The present disclosure has been made in consideration of the above points, and aims to provide an optical sheet, an optical component, and an illumination device that can improve light utilization efficiency while enhancing design. [Means for solving the problem]

[0006] The optical sheet of the present disclosure comprises: a support portion having a pair of main surfaces; a plurality of pattern layers provided on one of the main surfaces of the support portion; a plurality of light extraction portions protruding from the one of the main surfaces are formed on the support portion, In a cross section taken along the normal direction of the main surface, the pattern layers and the light extraction portions are arranged alternately. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to improve light utilization efficiency while enhancing design. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view showing a lighting device according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view showing a first modified example of the lighting device according to the first embodiment. [Figure 3] FIG. 3 is a cross-sectional view showing a second modified example of the lighting device according to the first embodiment. [Figure 4] FIG. 4 is a cross-sectional view showing a third modified example of the lighting device according to the first embodiment. [Figure 5] FIG. 5 is a cross-sectional view showing a fourth modified example of the lighting device according to the first embodiment. [Figure 6] FIG. 6 is a cross-sectional view showing a fifth modified example of the lighting device according to the first embodiment. [Figure 7] FIG. 7 is a cross-sectional view showing a lighting device according to the second embodiment. [Figure 8] FIG. 8 is a cross-sectional view showing a modified example of the lighting device according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings accompanying this specification, the scale and aspect ratios have been appropriately changed and exaggerated from those of the actual objects for the sake of ease of illustration and understanding. Configurations shown in some drawings may be omitted in other drawings.

[0010] In this specification, terms specifying shapes or geometric conditions, and the degree of shapes, etc., such as "parallel," "orthogonal," and "same," or values ​​of lengths or angles, etc., are not limited to their strict meanings but are interpreted to include a range of degrees within which similar functions can be expected.

[0011] In this specification, the normal direction of a plate-like member refers to the normal direction to the plate surface of the target plate-like member. The "plate surface" refers to the surface that coincides with the target plate-like member when the target plate-like member is viewed overall and from a global perspective.

[0012] In this specification, terms such as "sheet," "film," and "plate" are not distinguished from one another solely on the basis of differences in name. For example, a "sheet" cannot be distinguished from a member called a film or a plate solely on the basis of differences in name.

[0013] In this specification, when multiple upper limit value candidates and multiple lower limit value candidates are listed for a parameter, the parameter may be a numerical range that combines any one upper limit value candidate and any one lower limit value candidate.

[0014] An embodiment of the present disclosure relates to the following [1] to

[13] .

[0015] [1] a support portion having a pair of main surfaces; a plurality of pattern layers provided on one of the main surfaces of the support portion; a plurality of light extraction portions protruding from the one of the main surfaces are formed on the support portion, An optical sheet, wherein the pattern layers and the light extraction portions are arranged alternately in a cross section along the normal direction of the main surface.

[0016] [2] In a plan view, the areas of the respective picture layers are equal to each other, The optical sheet according to [1], wherein the pitch of the pattern layer is constant.

[0017] [3] [1] or [2], and the optical sheet according to an optical member comprising a light guide portion provided so as to face the picture layer.

[0018] [4] The optical member according to [3], wherein a gap layer is formed between the pattern layer and the light guide portion.

[0019] [5] The optical element according to [3] or [4], wherein the light extraction portion is in contact with the light guide portion.

[0020] [6] an optical sheet having a support portion having a pair of main surfaces and a plurality of pattern layers provided on one of the main surfaces of the support portion; a light guide portion provided to face the picture layer; a plurality of light extraction portions provided on the light guide portion and protruding toward the optical sheet; An optical member, wherein the pattern layers and the light extraction portions are arranged alternately in a cross section along a normal direction of the main surface.

[0021] [7] the optical sheet further includes a plurality of light deflection portions protruding from the one of the main surfaces, The optical element according to [6], wherein the pattern layers and the light deflection portions are alternately arranged in a cross section along the normal direction of the main surface.

[0022] [8] In a plan view, the areas of the respective picture layers are equal to each other, The optical element according to [6] or [7], wherein the pitch of the pattern layer is constant.

[0023] [9] [3] to [8], and the optical member according to any one of [3] to [8]. a light source provided to the side of the light guide portion.

[0024]

[10] The lighting device according to [9], wherein the light extraction portion has an inclined surface facing away from the light source.

[0025]

[11] the light extraction portion has a curved surface facing away from the light source, The lighting device according to [9], wherein in a cross section along a normal direction of the main surface, the curved surface is convex toward the light-guiding section.

[0026]

[12] The lighting device according to any one of [9] to

[11] , wherein the shape of the light extraction portion changes based on the distance from the light source.

[0027]

[13] [5] The optical member according to [5], a light source provided on a side of the light guide portion, a contact area between the light extraction portion and the light guide portion that increases with increasing distance from the light source.

[0028] (First embodiment) A first embodiment of the present disclosure will be described below with reference to Fig. 1. An optical sheet 20, an optical member 10, and an illumination device 1 according to this embodiment can be installed and used on, for example, a wall surface on which a predetermined pattern is formed.

[0029] 1, the lighting device 1 includes an optical member 10 and a light source 50 provided on the side of a light guide section 30 (described later) of the optical member 10. Of these, the optical member 10 includes an optical sheet 20 and the light guide section 30 provided so as to face a pattern layer 22 (described later) of the optical sheet 20.

[0030] The optical sheet 20 of the optical member 10 includes a support portion 21 having a pair of main surfaces 21a, 21b, and a plurality of pattern layers 22 provided on the main surface 21b side of the support portion 21.

[0031] The support section 21 is a member that constitutes the light-emitting surface of the lighting device 1. The support section 21 also plays a role in changing the traveling direction of light from the light source 50 and adjusting the angular distribution of brightness. As a result, the lighting device 1 is configured to achieve lighting with a desired light distribution characteristic that is expected in advance.

[0032] As described above, the support portion 21 has a pair of main surfaces 21a, 21b. Of these, the main surface 21a is a surface located on the side that is viewed by a user of the lighting device 1, that is, on the so-called observation side, and is the light-emitting surface of the lighting device 1. On the other hand, the main surface 21b is a surface located on the side where light from the light source 50 is incident, that is, on the so-called light source side. In this embodiment, the main surfaces 21a and 21b are parallel to each other. Note that the main surfaces 21a, 21b refer to surfaces that coincide with the planar direction of the support portion 21 when the support portion 21 is viewed overall and from a global perspective.

[0033] In the example shown in FIG. 1 , the support portion 21 has a base material 23 and a high-refractive index resin layer 24 laminated on the base material 23. The base material 23 supports the high-refractive index resin layer 24 and the pattern layer 22, and also has the function of transmitting light from the light source 50. The base material 23 may be a transparent resin film. A material that sufficiently transmits light and has appropriate strength is used as a material for forming the base material 23. As an example, a transparent resin containing one or more of acrylic, styrene, polycarbonate, polyethylene terephthalate, acrylonitrile, etc. as a main component can be used as a material for forming the base material 23.

[0034] The thickness of the substrate 23 can be appropriately set based on the transmittance, diffusion performance, strength, and the like required for the substrate 23 .

[0035] The high-refractive index resin layer 24 supports the pattern layer 22 and transmits light from the light source 50. A material that sufficiently transmits light and has an appropriate refractive index is used as the material for the high-refractive index resin layer 24. For example, a transparent resin containing one or more of a UV-curable resin, a thermoplastic resin, a thermosetting resin, or a two-component curable resin as its main component may be used as the material for the high-refractive index resin layer 24. The high-refractive index resin layer 24 may be formed by various known forming methods. For example, the high-refractive index resin layer 24 may be formed on the substrate 23 by a molding method, or by injection molding or extrusion molding. Furthermore, post-processing such as grinding may be performed to obtain a desired shape.

[0036] Such support section 21 has a plurality of light extraction sections 25 formed therein, protruding from one main surface 21b. These light extraction sections 25 serve to reflect light incident from light guide section 30, thereby allowing the light to be emitted to the outside from main surface 21a. In this embodiment, light extraction sections 25 protrude from high-refractive-index resin layer 24. These light extraction sections 25 may be formed integrally with high-refractive-index resin layer 24.

[0037] The light extraction portion 25 may have an inclined surface 25a facing away from the light source 50. This allows incident light to be reflected (particularly, totally reflected) at the inclined surface 25a, thereby deflecting the light. In the illustrated example, the shape of the light extraction portion 25 is a substantially inverted trapezoid in a cross section taken along the normal direction N (hereinafter simply referred to as the normal direction N) of the main surfaces 21a and 21b. With such a light extraction portion 25, light incident from the surface forming the upper base of the inverted trapezoid can be deflected by being reflected (particularly, totally reflected) at the surfaces forming the legs of the trapezoid. In the illustrated example, the multiple light extraction portions 25 are configured identically to one another. Although not illustrated, for example, the cross-sectional shape of the light extraction portion 25 may be a shape different from the substantially inverted trapezoid shown in FIG. 1. Furthermore, the shape of some of the light extraction portions 25 may be different from the shape of the other light extraction portions 25.

[0038] The light extraction portion 25 is in contact with the light guide portion 30. The light extraction portion 25 is optically integrated with the light guide portion 30. This makes it easier for light traveling through the light guide portion 30 to enter the light extraction portion 25. The refractive index of the light extraction portion 25 and the refractive index of the light guide portion 30 may be equal to each other.

[0039] The width W of the light extraction portion 25 may be 0.1 mm or more and 10 mm or less. When the width W is in this range, the light utilization efficiency can be further improved and the light extraction portion 25 can be easily formed. Furthermore, the height H of the light extraction portion 25 may be 0.05 mm or more and 10 mm or less. When the height H is in the above range, the light utilization efficiency can be further improved and the light extraction portion 25 can be easily formed.

[0040] Next, the pattern layer 22 will be described. The pattern layer 22 is provided to harmonize the design of the optical sheet 20 of the lighting device 1 with the surrounding design, such as the design of the wall on which the lighting device 1 is installed. As shown in FIG. 1 , the pattern layer 22 is partially disposed on the main surface 21b of the support portion 21. For example, the pattern layer 22 may be formed with the same or similar pitch and color as the pattern on the wall. Specifically, the pattern layer 22 may be formed with a striped pattern or a checkered pattern. Note that, in this specification, the term "pattern" is not limited to a pattern that indicates or signifies specific information. In this specification, the term "pattern" refers to, but is not limited to, a figure, letter, design, pattern, symbol, pattern, mark, color, or the like.

[0041] 1, in a cross section taken along the normal direction N of the main surfaces 21a and 21b, the pattern layers 22 and the light extraction portions 25 are alternately arranged. This allows light to be selectively extracted from the intermittently arranged light extraction portions 25. Furthermore, by arranging the pattern layers 22 in areas where no light extraction portions 25 are provided, it is possible to improve the design, improve the light utilization efficiency, and simplify the configuration.

[0042] Furthermore, in a planar view, the areas of the individual pattern layers 22 may be equal to one another. Furthermore, the pitch of the pattern layers 22 may be constant. This allows light to be emitted uniformly from the light extraction sections 25 arranged alternately with the pattern layers 22. The area of ​​the pattern layers 22 in a planar view may be 1 to 10 times the area of ​​the light extraction sections 25 in a planar view. This allows the pattern of the pattern layers 22 to be clearly visible, while preventing a decrease in the lighting effect. Furthermore, by keeping the above numerical range, it is possible to prevent the portion from which light is emitted to the outside from the main surface 21a and the pattern layers 22 from being perceived separately.

[0043] The material for the pattern layer 22 is appropriately selected in consideration of the pattern formed on the surrounding wall surface or affinity with the support part 21. For example, the material for the pattern layer 22 may be an ink containing a dye or pigment that reproduces a color corresponding to the pattern of the pattern on the wall surface.

[0044] In some cases, the picture pattern on the surrounding wall surface is expressed by recesses or protrusions formed on the surrounding wall surface. In this case, in order to further enhance harmony with the surrounding design, recesses or protrusions may be formed on the picture layer 22 made of ink or the like. Such recesses or protrusions can be formed, for example, by embossing the ink or the like that constitutes the picture layer 22.

[0045] Such a design layer 22 may be formed by various known methods. For example, the design layer 22 may be formed by a transfer method or printing using an inkjet printer or the like.

[0046] Next, the light guide section 30 will be described.

[0047] The light guide section 30 is configured to guide the light emitted from the light source 50 in the arrangement direction (light guide direction) of the light extraction sections 25. For this reason, it is preferable that the light guide section 30 has excellent visible light transmittance. As an example, a transparent resin containing one or more of acrylic, styrene, polycarbonate, polyethylene terephthalate, acrylonitrile, etc. as a main component can be suitably used as a material for the light guide section 30. The thickness of the light guide section 30 may be, for example, 1 mm or more and 10 mm or less.

[0048] Furthermore, a gap layer G is formed between the pattern layer 22 and the light guide 30. The gap layer G is a layer made of air. This allows the light in the light guide 30 to be totally reflected at the interface between the light guide 30 and the gap layer G. This prevents the light in the light guide 30 from being absorbed by the pattern layer 22. As a result, a decrease in light utilization efficiency can be prevented.

[0049] Such light guide section 30 may be formed with an inclined surface (reflecting surface (not shown)) for changing the traveling direction of light. Furthermore, a diffusing component (not shown) for diffusing incident light may be dispersed within light guide section 30. The diffusing component may be, for example, a metal compound, a porous substance containing gas, resin beads surrounding a metal compound, white fine particles, air bubbles, particles with a refractive index different from that of the surroundings, or the like.

[0050] Next, the light source 50 will be described. The light source 50 is configured to irradiate light onto the light-guiding section 30. The light source 50 may be configured in various forms, such as a linear fluorescent lamp such as a cold cathode fluorescent lamp, a large number of point-like LEDs (light-emitting diodes), or an incandescent lamp.

[0051] The light guide section 30 and the light source 50 may be housed in a case (not shown).

[0052] Next, the functions of the lighting device 1, the optical member 10, and the optical sheet 20 configured as above will be described.

[0053] As shown in FIG. 1, light L1 and L2 emitted from light source 50 enters light guide section 30. As shown in FIG.

[0054] The light L1 and L2 incident on the light-guiding section 30 travels in the light-guiding direction (leftward in Figure 1) while repeatedly undergoing reflection, particularly total reflection due to the difference between the refractive index of the light-guiding section 30 and the refractive index outside the light-guiding section 30.

[0055] Here, a gap layer G is formed between the picture layer 22 and the light guide section 30. This makes it easier for light L1 that reaches the interface between the light guide section 30 and the gap layer G to be totally reflected at the interface. This prevents light L1 emitted from the light source 50 from reaching the picture layer 22. As a result, absorption of light L1 by the picture layer 22 can be effectively prevented.

[0056] On the other hand, as shown in FIG. 1 , light L2 emitted from the light guide 30 and incident on the light extraction portion 25 travels in a direction significantly inclined from the normal direction N of the principal surfaces 21a and 21b. The light L2 incident on the light extraction portion 25 is reflected, particularly totally reflected, by the inclined surface 25a of the light extraction portion 25 due to the difference in refractive index between the light extraction portion 25 and the air gap layer G. This reflection bends the traveling direction of the light L2 so that the angle with respect to the normal direction N is smaller than the traveling direction of the light when it enters the light extraction portion 25. Due to this action, the light extraction portion 25 deflects the traveling direction of the transmitted light toward the normal direction N. The light L2 is then emitted relatively uniformly from each light extraction portion 25 arranged along the light guide direction of the light emitted from the light guide 30. In this manner, the light L2 is emitted to the outside from the principal surface 21a.

[0057] As described above, according to the present embodiment, the optical sheet 20 includes a support portion 21 having a pair of principal surfaces 21a, 21b, and a plurality of pattern layers 22 provided on one principal surface 21b of the support portion 21. The support portion 21 also has a plurality of light extraction portions 25 protruding from the one principal surface 21b. The pattern layers 22 and the light extraction portions 25 are alternately arranged in a cross section taken along the normal direction N of the principal surfaces 21a, 21b. This allows light to be selectively extracted from the intermittently arranged light extraction portions 25. By arranging the pattern layers 22 in areas where no light extraction portions 25 are provided, it is possible to improve the design, improve light utilization efficiency, and simplify the configuration.

[0058] As described above, the pattern layer 22 and the light extraction portions 25 are arranged alternately in the cross section along the normal direction N. In this way, the pattern layer 22 is arranged partially in the cross section along the normal direction N, so that when the optical sheet 20 is installed on a wall surface on which a predetermined pattern is formed, it is less likely to look out of place on the wall surface.

[0059] Furthermore, since the pattern layer 22 and the light extraction portion 25 are alternately arranged in the cross section along the normal direction N, alignment of the pattern layer and the prism can be omitted, for example, compared to an optical element (lighting device) in which a light-directing prism is provided so as to overlap with the pattern layer in the normal direction N. Also, according to this embodiment, a decrease in light utilization efficiency caused by misalignment between the pattern layer and the prism can be suppressed. Furthermore, in an optical element provided with a light-directing prism, thickness variations can occur due to the thickness of the prism. In contrast, according to this embodiment, thickness variations caused by the light-directing prism can be suppressed. Therefore, a decrease in light utilization efficiency caused by thickness variations can be suppressed.

[0060] Furthermore, according to this embodiment, in a plan view, the areas of the respective pattern layers 22 are equal to each other, and the pitch of the pattern layers 22 is constant. This allows light to be emitted uniformly from the light extraction portions 25 that are arranged alternately with the pattern layers 22.

[0061] Furthermore, according to this embodiment, an air gap layer G is formed between the pattern layer 22 and the light guide 30. This allows the light in the light guide 30 to be totally reflected at the interface between the light guide 30 and the air gap layer G. This effectively prevents the light in the light guide 30 from being absorbed by the pattern layer 22, thereby preventing a decrease in light utilization efficiency.

[0062] Furthermore, according to the present embodiment, the light extraction portion 25 is in contact with the light guide portion 30. This makes it easier for light traveling through the light guide portion 30 to enter the light extraction portion 25. This improves the light utilization efficiency.

[0063] In the above-described embodiment, the optical member 10 and the optical sheet 20 are used as a lighting device, but the present invention is not limited to this. The use of the optical member 10 and the optical sheet 20 is not particularly limited as long as they transmit light and blend in with the surrounding pattern. For example, the optical member 10 and the optical sheet 20 may be used as a light-emitting wall material, ceiling material, or floor material, or a display device for displaying information.

[0064] Next, a modification of the lighting device 1 will be described.

[0065] Fig. 2 shows a first modified example of the lighting device 1. The modified example shown in Fig. 2 differs in that the support portion 21 does not have the high-refractive-index resin layer 24, but other configurations are substantially the same as the embodiment shown in Fig. 1 described above. In Fig. 2, the same parts as those in the embodiment shown in Fig. 1 are given the same reference numerals, and detailed description thereof will be omitted.

[0066] 2, the support portion 21 does not have the high-refractive-index resin layer 24. That is, the support portion 21 is made of the base material 23. In this modification, the light extraction portion 25 protrudes from the base material 23.

[0067] In this modification, light can also be selectively extracted from the intermittently provided light extraction portions 25. Furthermore, by arranging the pattern layer 22 in the portion where no light extraction portions 25 are provided, it is possible to improve the design, improve the light utilization efficiency, and simplify the configuration.

[0068] Fig. 3 shows a second modified example of the lighting device 1. The modified example shown in Fig. 3 differs in that the support portion 21 does not have the base material 23, but other configurations are substantially the same as the embodiment shown in Figs. 1 and 2 described above. In Fig. 3, the same parts as those in the embodiment shown in Figs. 1 and 2 are given the same reference numerals, and detailed description thereof will be omitted.

[0069] 3, the support section 21 does not have a base material 23. That is, the support section 21 is composed of a high-refractive index resin layer 24. On the other hand, the optical sheet 20 further has a support layer 26 provided on the main surface 21b side, and a low-refractive index resin layer 27 provided between the design layer 22 and the support layer 26.

[0070] Of these, the support layer 26 supports the high-refractive index resin layer 24, the pattern layer 22, the light extraction portion 25, and the low-refractive index resin layer 27, and also has the function of transmitting light from the light source 50. The support layer 26 may be a transparent resin film. A material that allows sufficient light transmission and has appropriate strength is used as the material for the support layer 26. As an example, the material for the support layer 26 may be a transparent resin whose main component is one or more of acrylic, styrene, polycarbonate, polyethylene terephthalate, acrylonitrile, etc.

[0071] The thickness of the support layer 26 can be appropriately set based on the transmittance, diffusion performance, strength, and the like required for the support layer 26 .

[0072] The low-refractive index resin layer 27 supports the design layer 22 and transmits light from the light source 50. The low-refractive index resin layer 27 has a lower refractive index than the high-refractive index resin layer 24. The low-refractive index resin layer 27 is made of a material that sufficiently transmits light and has an appropriate refractive index. For example, the low-refractive index resin layer 27 may be made of a transparent resin primarily composed of one or more of a UV-curable resin, a thermoplastic resin, a thermosetting resin, or a two-component curable resin. The low-refractive index resin layer 27 may be formed by various known forming methods. For example, the low-refractive index resin layer 27 may be formed on the support layer 26 by a molding method, or by injection molding or extrusion molding. Furthermore, post-processing such as grinding may be performed to obtain a desired shape.

[0073] Next, the functions of the lighting device 1, the optical member 10, and the optical sheet 20 according to this modified example will be described.

[0074] 3, light L3 and L4 emitted from light source 50 enters light guiding section 30. Light L3 and L4 that has entered light guiding section 30 travels in the light guiding direction (leftward in FIG. 3) while repeatedly being reflected in light guiding section 30.

[0075] Here, a low-refractive index resin layer 27 is provided between the pattern layer 22 and the support layer 26. As a result, light L3 that reaches the interface between the support layer 26 and the low-refractive index resin layer 27 is totally reflected at the interface. This prevents light L3 emitted from the light source 50 from reaching the pattern layer 22. As a result, absorption of light L3 by the pattern layer 22 can be effectively prevented.

[0076] 3, light L4 emitted from the light guide 30 and incident on the light extraction portion 25 is reflected, particularly totally reflected, by the inclined surface 25a of the light extraction portion 25 due to the difference in refractive index between the light extraction portion 25 and the low-refractive-index resin layer 27. Then, the light L4 is emitted somewhat uniformly from each light extraction portion 25. In this way, the light L4 is emitted to the outside from the main surface 21a.

[0077] In this modification, light can also be selectively extracted from the intermittently provided light extraction portions 25. Furthermore, by arranging the pattern layer 22 in the portion where no light extraction portions 25 are provided, it is possible to improve the design, improve the light utilization efficiency, and simplify the configuration.

[0078] Fig. 4 shows a third modified example of the lighting device 1. The modified example shown in Fig. 4 differs in that the support portion 21 does not have the high-refractive index resin layer 24 and that a low-refractive index resin layer 27 is provided between the base material 23 and the picture layer 22, but the other configurations are substantially the same as those of the embodiment shown in Figs. 1 to 3 described above. In Fig. 4, the same parts as those of the embodiment shown in Figs. 1 to 3 are designated by the same reference numerals and detailed description thereof will be omitted.

[0079] 4, the support portion 21 does not have the high-refractive index resin layer 24. That is, the support portion 21 is made of the base material 23. In this modification, the light extraction portion 25 protrudes from the base material 23.

[0080] In this modification, the optical sheet 20 further includes a low-refractive index resin layer 27 provided between the support portion 21 (base material 23) and the pattern layer 22, and a protective portion 28 covering the low-refractive index resin layer 27 and the pattern layer 22. An air gap layer G is formed between the support portion 21 (base material 23), the protective portion 28, and the light guide portion 30.

[0081] The protective portion 28 of the optical sheet 20 is a layer for protecting the pattern layer 22. A material that allows sufficient light transmission and has an appropriate refractive index is used as the material for the protective portion 28. As an example, the material for the protective portion 28 may be the same as the material for the high refractive index resin layer 24 described above. The protective portion 28 may be formed by various known forming methods. As an example, the protective portion 28 may be formed on the substrate 23 by a molding method, or may be formed by injection molding or extrusion molding.

[0082] The thickness of the protective portion 28 can be appropriately set based on the transmittance, diffusion performance, strength, and the like required for the protective portion 28 .

[0083] Next, the functions of the lighting device 1, the optical member 10, and the optical sheet 20 according to this modified example will be described.

[0084] 4, light L5 to L7 emitted from light source 50 enters light guiding section 30. Light L5 to L7 that has entered light guiding section 30 travels in the light guiding direction (leftward in FIG. 4) while repeatedly being reflected in light guiding section 30.

[0085] Here, a gap layer G is formed between the protective section 28 and the light-guiding section 30. As a result, light L5 that reaches the interface between the light-guiding section 30 and the gap layer G is likely to be totally reflected at the interface. This makes it possible to prevent light L5 irradiated from the light source 50 from reaching the pattern layer 22. In addition, the pattern layer 22 is covered with the protective section 28. As a result, even when light L6 is incident on the gap layer G, light L6 that reaches the interface between the gap layer G and the protective section 28 is likely to be totally reflected at the interface. This makes it possible to prevent light L6 irradiated from the light source 50 from reaching the pattern layer 22.

[0086] 4, the light L7 emitted from the light guide 30 and incident on the light extraction portion 25 is reflected, particularly totally reflected, by the inclined surface 25a of the light extraction portion 25 due to the difference in refractive index between the light extraction portion 25 and the air gap layer G. Then, the light L7 is emitted somewhat uniformly from each light extraction portion 25. In this way, the light L7 is emitted to the outside from the main surface 21a.

[0087] In this modification, light can also be selectively extracted from the intermittently provided light extraction portions 25. Furthermore, by arranging the pattern layer 22 in the portion where no light extraction portions 25 are provided, it is possible to improve the design, improve the light utilization efficiency, and simplify the configuration.

[0088] Fig. 5 shows a fourth modified example of the lighting device 1. The modified example shown in Fig. 5 differs in that the shape of the light extraction portion 25 changes based on the distance from the light source 50, but other configurations are substantially the same as the embodiment shown in Figs. 1 to 4 described above. In Fig. 5, the same parts as those in the embodiment shown in Figs. 1 to 4 are given the same reference numerals, and detailed description thereof will be omitted.

[0089] In the lighting device 1 shown in FIG. 5 , the shape of the light extraction portion 25 changes based on the distance from the light source 50. In this modification, the contact area of ​​the light extraction portion 25 with the light guide 30 increases with increasing distance from the light source 50. Generally, the amount of light emitted from the light extraction portion 25 may decrease with increasing distance from the light source 50. Furthermore, when the contact area of ​​the light extraction portion 25 with the light guide 30 is large, the amount of light emitted from the light extraction portion 25 increases. Therefore, because the contact area of ​​the light extraction portion 25 with the light guide 30 increases with increasing distance from the light source 50, the amount of light emitted from the light extraction portion 25 can be increased even at locations far from the light source 50. Therefore, according to this modification, the lighting device 1 can emit light more uniformly.

[0090] Fig. 6 shows a fifth modified example of the lighting device 1. The modified example shown in Fig. 6 differs in that the light extraction portion 25 has a curved surface 25b facing away from the light source 50, but other configurations are substantially the same as the embodiment shown in Figs. 1 to 5 described above. In Fig. 6, the same parts as those in the embodiment shown in Figs. 1 to 5 are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0091] 6, the light extraction portion 25 has a curved surface 25b facing away from the light source 50. In addition, in a cross section taken along the normal direction N of the main surfaces 21a and 21b, the curved surface 25b is convex toward the light guide portion 30. In this case, the convergence of the light L8 extracted from the light extraction portion 25 can be improved.

[0092] (Second embodiment) Next, a second embodiment of the present disclosure will be described with reference to Fig. 7. Fig. 7 is a cross-sectional view showing an illumination device according to the second embodiment of the present disclosure. The second embodiment shown in Fig. 7 is different in that the optical member 10 includes a plurality of light extraction portions 40 provided on the light guide portion 30, but other configurations are substantially the same as those of the first embodiment described above. In Fig. 7, the same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0093] The optical member 10 according to this embodiment includes a plurality of light extraction portions 40 provided on the light guide portion 30. In this embodiment, the light extraction portions 40 protrude from a base portion 41 that is laminated on the light guide portion 30. A gap layer G is formed between the optical sheet 20 and the light extraction portions 40 and the base portion 41.

[0094] The base 41 has a function of supporting the light extraction portion 40 and transmitting light from the light source 50. The material constituting the base 41 may be the same as the material constituting the light extraction portion 40. The base 41 and the light extraction portion 40 may be formed integrally.

[0095] The thickness of the base 41 can be appropriately set based on the transmittance, diffusion performance, strength, and the like required for the base 41 .

[0096] Next, the light extraction portion 40 will be described in detail.

[0097] The light extraction section 40 serves to reflect the light incident from the light guide section 30, thereby causing the light to be emitted to the outside from the main surface 21a. The light extraction section 40 protrudes toward the optical sheet 20 and is in contact with the optical sheet 20. The light extraction section 40 may have an inclined surface 40a facing the opposite side to the light source 50. This allows the incident light to be refracted and deflected at the inclined surface 40a.

[0098] The light extraction portion 40 has a shape obtained by joining a pair of trapezoids together so as to be line-symmetrical in a cross section taken along the normal direction N. In other words, the light extraction portion 40 has a shape obtained by cutting out a part of a rectangle by an inverted isosceles triangle in a cross section taken along the normal direction N. In the illustrated example, the multiple light extraction portions 40 are configured identically to one another. Although not shown, for example, the cross-sectional shape of the light extraction portions 40 may be different from the shape shown in FIG. 7. Furthermore, the shape of some of the light extraction portions 40 may be different from the shape of the other light extraction portions 40.

[0099] Furthermore, the light extraction portion 40 is optically integrated with the light guide portion 30. This makes it easier for light traveling through the light guide portion 30 to enter the light extraction portion 40.

[0100] In this embodiment, the pattern layers 22 and the light extraction portions 40 are alternately arranged in a cross section along the normal direction N of the main surfaces 21a, 21b. This allows light to be selectively extracted from the intermittently arranged light extraction portions 40. Furthermore, by arranging the pattern layers 22 in areas where no light extraction portions 40 are provided, it is possible to improve the design, improve the light utilization efficiency, and simplify the configuration.

[0101] Other configurations of the light extraction section 40 may be similar to those of the light extraction section 25 described above.

[0102] In this embodiment, the optical sheet 20 does not have a light extraction portion 25. Furthermore, the support portion 21 does not have a high-refractive index resin layer 24. That is, the support portion 21 is formed of a base material 23. In this embodiment, the optical sheet 20 has a support portion 21 (base material 23) having a pair of main surfaces 21a and 21b, and a plurality of pattern layers 22 provided on the one main surface 21b side of the support portion 21. Furthermore, the optical sheet 20 may further have a plurality of light deflection portions 29 protruding from the one main surface 21b. Furthermore, the optical sheet 20 may further have a low-refractive index resin layer 27 provided between the base material 23 and the pattern layer 22.

[0103] The light deflection portion 29 of the optical sheet 20 has a function of transmitting and deflecting the light emitted from the light extraction portion 40. In the present embodiment, the light deflection portion 29 protrudes from the base material 23.

[0104] In the illustrated example, the shape of the light deflection unit 29 is an inverted isosceles triangle in a cross section taken along the normal direction N. Such a light deflection unit 29 can deflect light incident from one equilateral surface by reflecting (particularly total reflection) the light from the other equilateral surface. In the illustrated example, the multiple light deflection units 29 are configured identically to one another. Although not shown, for example, the cross-sectional shape of the light deflection units 29 may be a shape different from the inverted isosceles triangle shown in FIG. 7. Furthermore, the shape of some of the light deflection units 29 may be different from the shape of the other light deflection units 29.

[0105] Furthermore, in a cross section taken along the normal direction N of the main surfaces 21a and 21b, the pattern layers 22 and the light deflection sections 29 are arranged alternately. This allows light to be selectively extracted from the intermittently arranged light deflection sections 29. Furthermore, by arranging the pattern layers 22 in areas where no light deflection sections 29 are provided, it is possible to improve the design, while simultaneously improving the light utilization efficiency and simplifying the configuration.

[0106] The material constituting the light deflection section 29 is a material that transmits light sufficiently and has an appropriate refractive index. As an example, the material constituting the light deflection section 29 may be the same as the material constituting the low refractive index resin layer 27. The light deflection section 29 may be formed by various known forming methods. As an example, the light deflection section 29 may be formed by a molding method on the base material 23, or may be formed by injection molding or extrusion molding.

[0107] Next, the functions of the lighting device 1, the optical member 10, and the optical sheet 20 configured as above will be described.

[0108] As shown in FIG. 7, light L9 and L10 emitted from light source 50 enters light guide section 30. Light L9 and L10 are incident on light guide section 30. As shown in FIG.

[0109] The light L9 and L10 incident on the light-guiding section 30 travels in the light-guiding direction (leftward in Figure 7) while repeatedly undergoing reflection, particularly total reflection due to the difference between the refractive index of the light-guiding section 30 and the refractive index outside the light-guiding section 30.

[0110] Here, a gap layer G is formed between the base 41 and the optical sheet 20. This makes it easier for light L9 that reaches the interface between the light guide 30 and the gap layer G to be totally reflected at the interface. This prevents light L9 emitted from the light source 50 from reaching the pattern layer 22. As a result, absorption of light L9 by the pattern layer 22 can be effectively prevented.

[0111] 7, light L10 that has exited the light guide 30 and entered the light extraction section 40 is refracted when it leaves the light extraction section 40, and travels toward the light deflection section 29. Due to this action, the light extraction section 40 deflects the traveling direction of the transmitted light.

[0112] The light L10 emitted from the light extraction portion 40 and incident on the light deflection portion 29 is reflected, particularly totally reflected, on the surface of the light deflection portion 29 due to the difference in refractive index between the light deflection portion 29 and the air gap layer G. Then, the light L10 is emitted relatively uniformly from each light deflection portion 29. In this way, the light L10 is emitted to the outside from the main surface 21a.

[0113] As described above, according to the present embodiment, the optical element 10 includes a support portion 21 having a pair of principal surfaces 21a and 21b, an optical sheet 20 having a plurality of pattern layers 22 provided on one principal surface 21b of the support portion 21, a light guide portion 30 provided to face the pattern layer 22, and a plurality of light extraction portions 40 provided on the light guide portion 30 and protruding toward the optical sheet 20. The pattern layers 22 and the light extraction portions 40 are alternately arranged in a cross section taken along the normal direction N of the principal surfaces 21a and 21b. Even in this case, light can be selectively extracted from the intermittently arranged light extraction portions 40. Furthermore, by arranging the pattern layers 22 in areas where no light extraction portions 40 are provided, it is possible to improve the design, improve light utilization efficiency, and simplify the configuration.

[0114] Furthermore, according to this embodiment, the optical sheet 20 further has a plurality of light deflection portions 29 protruding from one of the principal surfaces 21b. In addition, in a cross section taken along the normal direction N of the principal surfaces 21a, 21b, the pattern layer 22 and the light deflection portions 29 are arranged alternately. This allows light to be selectively extracted from the intermittently arranged light deflection portions 29. Furthermore, by arranging the pattern layer 22 in areas where no light deflection portions 29 are provided, it is possible to improve the design, while simultaneously improving light utilization efficiency and simplifying the configuration.

[0115] Next, a modification of the lighting device 1 will be described.

[0116] Fig. 8 shows a modified example of the lighting device 1. The modified example shown in Fig. 8 differs in the shapes of the light extraction portion 40 and the light deflection portion 29, but other configurations are substantially the same as the embodiment shown in Fig. 7 described above. In Fig. 8, the same parts as those in the embodiment shown in Fig. 7 are given the same reference numerals, and detailed description thereof will be omitted.

[0117] In the lighting device 1 shown in Fig. 8, the shape of the light extraction unit 40 is a trapezoid in a cross section taken along the normal direction N. In this case, as shown in Fig. 8, light L11 emitted from the light source 50 is deflected by being reflected (total reflected) on the inclined surface 40a of the light extraction unit 40. Furthermore, the shape of the light deflection unit 29 in a cross section taken along the normal direction N is a right-angled isosceles triangle whose base faces away from the light source 50.

[0118] 8, in this modification, light L11 can be selectively extracted from the light extraction portions 40 and light deflection portions 29 that are provided at intervals. In addition, by arranging the pattern layer 22 in the portion where the light extraction portions 40 are not provided, it is possible to improve the design, improve the light utilization efficiency, and simplify the configuration.

[0119] It is also possible to combine the multiple components disclosed in the above-described embodiments and modifications as needed, or to delete some of the components disclosed in the above-described embodiments and modifications. [Explanation of symbols]

[0120] 1. Lighting equipment 10 Optical components 20 Optical Sheet 21 Support part 21a Main surface 21b Main surface 22 Picture layer 25 Light extraction part 25a Slope 25b Curved surface 29 Light deflection section 30 Light guide section 40 Light extraction part 50 light source G void layer

Claims

1. a support portion having a pair of main surfaces; a plurality of pattern layers provided on one of the main surfaces of the support portion; a plurality of light extraction portions protruding from the one of the main surfaces are formed on the support portion, An optical sheet, wherein the pattern layers and the light extraction portions are arranged alternately in a cross section along the normal direction of the main surface.

2. In a plan view, the areas of the respective picture layers are equal to each other, The optical sheet according to claim 1 , wherein the pattern layer has a constant pitch.

3. The optical sheet according to claim 1; an optical member comprising a light guide portion provided so as to face the picture layer.

4. The optical member according to claim 3 , wherein a gap layer is formed between the pattern layer and the light guide portion.

5. The optical member according to claim 3 , wherein the light extraction portion is in contact with the light guide portion.

6. an optical sheet having a support portion having a pair of main surfaces and a plurality of pattern layers provided on one of the main surfaces of the support portion; a light guide portion provided to face the picture layer; a plurality of light extraction portions provided on the light guide portion and protruding toward the optical sheet; An optical member, wherein the pattern layers and the light extraction portions are arranged alternately in a cross section along a normal direction of the main surface.

7. the optical sheet further includes a plurality of light deflection portions protruding from the one of the main surfaces, The optical member according to claim 6 , wherein the pattern layers and the light deflection portions are alternately arranged in a cross section along a normal direction of the main surface.

8. In a plan view, the areas of the respective picture layers are equal to each other, The optical member according to claim 6 , wherein the pattern layer has a constant pitch.

9. The optical member according to any one of claims 3 to 8; a light source provided to the side of the light guide portion.

10. The lighting device according to claim 9 , wherein the light extraction portion has an inclined surface facing away from the light source.

11. the light extraction portion has a curved surface facing away from the light source, The lighting device according to claim 9 , wherein the curved surface is convex toward the light guiding section in a cross section along a normal direction of the main surface.

12. The lighting device according to claim 9 , wherein the shape of the light extraction portion varies based on the distance from the light source.

13. The optical member according to claim 5 ; a light source provided on a side of the light guide portion, a contact area between the light extraction portion and the light guide portion that increases with increasing distance from the light source.

Images