Lighting device

Abstract

An illumination device (100A) is provided with: a first illumination member (110A1) having a first light source (LS1) and a first light guide member (10A1), the first light guide member (10A1) having a first light guide layer (10A1) and a first light distribution control structure capable of causing a part of first light propagating through the first light guide layer to face at least the front surface side; a second illumination member (110A2) having a second light source (LS2) and a second light guide member (10A2) disposed on the front surface side of the first light guide member, the second light guide member having a second light guide layer (10A2) and a second light distribution control structure capable of causing a portion of second light propagating through the second light guide layer to face at least the front surface side; and a low refractive index layer (20) disposed between the first light guide member and the second light guide member and having a refractive index lower than that of either the first light guide layer or the second light guide layer.

Description

Technical Field

[0001] The present invention relates to a lighting device, and more particularly to a sheet-like lighting device having a light source and a light guide layer. Here, "sheet-like" means a plate-like or film-like shape, regardless of the rigidity (flexibility) and thickness of the sheet. In addition, the sheet-like lighting device can be used in various forms such as a roll. Background Art

[0002] Sheet-shaped lighting devices with a light source and a light guide layer are used, for example, as backlights or frontlights for liquid crystal display devices. In addition, in recent years, the use of a new generation of semiconductor lighting (Solid State Lighting: SSL) represented by LED lighting has been promoted. For example, architectural lighting, which is a combination of architectural components and lighting devices to create a design or entertainment effect, is being proposed.

[0003] For example, Patent Document 1 discloses a single-sided illumination and dual-purpose window, which has a light source at the end of a plate-shaped transparent substrate, and functions as a lighting device that causes light emitted from the light source and guided within the transparent substrate to be emitted from a single side of the transparent substrate during lighting such as nighttime, and functions as a transparent window during non-lighting such as daytime. In addition, Patent Documents 2 to 5 disclose a sheet-shaped lighting device having a light distribution structure using total reflection based on an interface of an air cavity (internal space). The entire disclosure of Patent Documents 2 to 5 is incorporated into this specification by reference.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: International Publication No. 2019 / 102959

[0007] Patent Document 2: International Publication No. 2019 / 182091

[0008] Patent Document 3: International Publication No. 2019 / 146628

[0009] Patent Document 4: International Publication No. 2011 / 124765

[0010] Patent Document 5: International Publication No. 2019 / 087118 Summary of the invention

[0011] Technical problem to be solved by the invention

[0012] As various lighting devices are developed, the scenes where lighting devices are used are also diversified. However, conventional lighting devices can generally only emit light having a predetermined light distribution.

[0013] Therefore, an object of the present invention is to provide a lighting device configured to emit two or more types of light having mutually different light distributions.

[0014] Technical solutions for solving technical problems

[0015] According to the embodiment of the present invention, the solving means described in the following items are provided.

[0016] [Project 1]

[0017] A lighting device configured to emit light having a first light distribution and light having a second light distribution different from the first light distribution from a front side, the lighting device comprising: a first lighting component having a first light source and a first light guide component, the first light guide component having: a first light guide layer having a first light receiving side surface for receiving first light emitted from the first light source; and a first light distribution control structure capable of directing at least a portion of the first light propagating in the first light guide layer toward the front side;

[0018] a second lighting component having a second light source and a second light guide component disposed on the front side of the first light guide component, the second light guide component having: a second light guide layer having a second light receiving side surface for receiving second light emitted from the second light source; and a second light distribution control structure capable of directing at least a portion of the second light propagating in the second light guide layer toward the front side; and

[0019] a low refractive index layer disposed between the first light guide member and the second light guide member and having a refractive index lower than that of either the first light guide layer or the second light guide layer;

[0020] The lighting device is configured to emit light having the first light distribution toward the front side when the first light source is turned on, and to emit light having the second light distribution toward the front side when the second light source is turned on.

[0021] [Project 2]

[0022] The lighting device according to item 1,

[0023] The first light guide member, the low refractive index layer, and the second light guide member are stacked using an adhesive.

[0024] [Item 3]

[0025] The lighting device according to item 1 or 2,

[0026] The first light distribution control structure has multiple first internal spaces, each of which has a first front inclined surface that directs light toward the front side through total internal reflection. The second light distribution control structure has multiple second internal spaces, each of which has a second front inclined surface that directs light toward the front side through total internal reflection. The inclination angle θa1 of the first front inclined surface is different from the inclination angle θa2 of the second front inclined surface.

[0027] [Item 4]

[0028] The lighting device according to item 3,

[0029] An inclination angle θa1 of the first front inclined surface is greater than an inclination angle θa2 of the second front inclined surface.

[0030] [Item 5]

[0031] The lighting device according to item 3 or 4,

[0032] The first light distribution control structure is formed on a first direction changing layer disposed on the front side or the back side of the first light guide layer.

[0033] The second light distribution control structure is formed on a second direction changing layer disposed on the front side or the back side of the second light guide layer.

[0034] [Item 6]

[0035] The lighting device according to any one of items 1 to 5,

[0036] The visible light transmittance of the first light guide member and the second light guide member is greater than 60%, and the haze value is less than 10%.

[0037] Effects of the Invention

[0038] According to an embodiment of the present invention, there is provided a lighting device configured to emit light having two or more different light distributions. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1A It is a schematic cross-sectional view of the lighting device 100A according to the embodiment of the present invention (the first light source LS1 is in the on state and the second light source LS2 is in the off state).

[0040] Figure 1B 1 is a schematic cross-sectional view of the lighting device 100A (the first light source LS1 is in an OFF state and the second light source LS2 is in an ON state).

[0041] Figure 2 It is a schematic plan view of the first lighting component 110A1 included in the lighting device 100A.

[0042] Figure 3A It is a schematic cross-sectional view of an internal space 14A that may be included in the first light introducing member 10A1 and the second light introducing member 10A2 .

[0043] Figure 3B It is a schematic top view of the internal space 14A.

[0044] Figure 3C It is a schematic plan view showing a modification of the internal space 14A.

[0045] Figure 4A It is a schematic cross-sectional view of the lighting device 100B according to the embodiment of the present invention (the first light source LS1 is in the on state and the second light source LS2 is in the off state).

[0046] Figure 4B 1 is a schematic cross-sectional view of the lighting device 100B (the first light source LS1 is in an OFF state and the second light source LS2 is in an ON state).

[0047] Figure 5A It is a schematic cross-sectional view of the lighting device 100C according to the embodiment of the present invention (the first light source LS1 is in the on state and the second light source LS2 is in the off state).

[0048] Figure 5B 1 is a schematic cross-sectional view of the lighting device 100C (the first light source LS1 is in an OFF state and the second light source LS2 is in an ON state).

[0049] Figure 6 It is a schematic cross-sectional view of a lighting device 100D according to an embodiment of the present invention.

[0050] Figure 7 It is a schematic cross-sectional view of a lighting device 100E according to an embodiment of the present invention.

[0051] Figure 8 It is a schematic cross-sectional view of a lighting device 100F according to an embodiment of the present invention.

[0052] Fig. 9 It is a schematic cross-sectional view of a lighting device 100G according to an embodiment of the present invention.

[0053] Fig.10 It is a schematic top view of a prototype lighting device 100D_S.

[0054] Fig.11 1 is a schematic diagram showing a measurement system of the light distribution of the lighting device 100D_S.

[0055] Fig.12: is a graph showing the luminance distribution on the front side of the lighting device 100D_S.

[0056] Fig.13 : is a graph showing the brightness distribution on the back side of the lighting device 100D_S.

[0057] Fig.14 It is a schematic top view of a prototype lighting device 100F_S.

[0058] Fig.15 1 is a schematic diagram showing a measurement system of the light distribution of the lighting device 100F_S.

[0059] Fig.16 It is a graph showing the brightness distribution on the front side of the lighting device 100F_S.

[0060] Fig.17 It is a graph showing the brightness distribution on the back side of the lighting device 100F_S. DETAILED DESCRIPTION

[0061] Hereinafter, the lighting device according to the embodiment of the present invention will be described with reference to the drawings. The lighting device according to the embodiment of the present invention is not limited to the following examples.

[0062] Reference Figure 1A and Figure 1B , the structure and operation of the lighting device 100A according to the embodiment of the present invention are described. The lighting device 100A includes two lighting components (a first lighting component 110A1 and a second lighting component 110A2), Figure 1A A schematic cross-sectional view showing the lighting device 100A in which the first lighting component 110A1 is turned on, Figure 1B A schematic cross-sectional view showing the lighting device 100A in which the second lighting component 110A2 is turned on. The dashed arrows in the figure represent examples of light rays.

[0063] The lighting device 100A is configured to emit light LRf1 having a first light distribution toward the front side (upper side in the figure, z direction) (see Figure 1A ) and light LRf2 having a second light distribution different from the first light distribution (refer to Figure 1B ).

[0064] The first lighting component 110A1 has a first light source LS1 and a first light guide component 10A1. The first light guide component 10A1 has: a first light guide layer 10A1 (herein, represented by the same reference figure mark as the first light guide component), which has a first light receiving side surface that receives the first light emitted from the first light source LS1; and a first light distribution control structure, which can direct at least a portion of the first light propagating in the first light guide layer 10A1 (y direction) toward the front side. The first light distribution control structure illustrated here has a plurality of first internal spaces 14A1, and the plurality of first internal spaces 14A1 have a first front inclined surface ISa1 that directs light toward the front side by total internal reflection (TIR). The "front" of the "front inclined surface" possessed by the internal space refers to the inclined side surface possessed by the internal space that is located on the light receiving side surface side (close to the light receiving side surface). In addition, the inclined surface on the side opposite to the light receiving side surface (away from the light receiving side surface) in the inclined side surface possessed by the internal space is referred to as a "rear inclined surface".

[0065] The first light guide component 10A1 has a first light distribution control structure in the first light guide layer 10A1, but is not limited thereto. As exemplified below, the first light guide component may also have a direction conversion layer (sometimes also referred to as a "light extraction layer"), and the direction conversion layer has the first light distribution control structure. This is also the same for the second light guide component 10A2 described below.

[0066] The second lighting component 110A2 has a second light source LS2 and a second light guide component 10A2. The second light guide component 10A2 has: a second light guide layer 10A2 (herein, represented by the same reference numeral as the second light guide component) having a second light receiving side surface that receives the second light emitted from the second light source LS2; and a second light distribution control structure that can direct at least a portion of the second light propagating in the second light guide layer 10A2 toward the front side. The second light distribution control structure illustrated here has a plurality of second internal spaces 14A2, and the plurality of second internal spaces 14A2 have a second front inclined surface ISa2 that directs light toward the front side by total internal reflection.

[0067] The lighting device 100A has a low refractive index layer 20, which is arranged between the first light guide member 10A1 and the second light guide member 10A2 and has a refractive index lower than both the first light guide layer 10A1 and the second light guide layer 10A2. The low refractive index layer 20 causes light incident at an angle greater than the critical angle on the interface between the low refractive index layer 20 and the first light guide member 10A1 and the interface between the low refractive index layer 20 and the second light guide member 10A2 to be totally reflected toward the first light guide member 10A1 side or the second light guide member 10A2 side.

[0068] The low refractive index layer 20 is, for example, a solid, and the first light guide component 10A1, the low refractive index layer 20 and the second light guide component 10A2 are stacked using an adhesive (not shown). If the low refractive index layer 20 is solid, it is possible to prevent foreign matter from being present between the first light guide component 10A1 and the second light guide component 10A2. If there is foreign matter between the first light guide component 10A1 and the second light guide component 10A2, there is a concern that the light distribution may be disturbed, the light utilization efficiency may be reduced, or the appearance may be deteriorated due to light scattering. In addition, in order to provide a gap between the first light guide component 10A1 and the second light guide component 10A2, for example, an air layer may be used as the low refractive index layer 20, and a spacer needs to be configured, which may result in problems such as difficulty in ensuring the uniformity of the gap and / or the gap becoming larger.

[0069] The lighting device 100A is as follows Figure 1A As shown, when only the first light source LS1 is turned on (the second light source LS2 is turned off), that is, the first lighting component 110A1 is turned on, the light LRf1 having the first light distribution can be emitted to the front side, as shown in FIG. Figure 1B As shown, when only the second light source LS2 is turned on (the first light source LS1 is in the off state), that is, the second lighting component 110A2 is in the on state, the light LRf2 having the second light distribution can be emitted to the front side. For example, by making the inclination angle θa1 of the first front inclined surface ISa1 different from the inclination angle θa2 of the second front inclined surface ISa2, the first light distribution can be different from the second light distribution. For example, the inclination angle θa1 is larger than the inclination angle θa2. According to experiments, for example, the difference between the inclination angle θa1 and the inclination angle θa2 is preferably greater than 6°, and more preferably greater than 20°. For example, θa1 is greater than 49° and less than 64°, and θa2 is greater than 29° and less than 58°. θb1 and θb2 may be the same or different. In addition, the inclination angle is represented by an angle relative to the plane of the light guide layers 10A1 and 10A2, that is, the xy plane).

[0070] In addition, the light distribution of a lighting device refers to the distribution of luminous intensity (intensity) relative to an angle, and has nothing to do with the wavelength of light emitted from the lighting device. The light distribution of a lighting device is measured, for example, by a method in accordance with JIS C8105-5. For example, if the direction (for example, more than 5°) of the light with the highest luminous intensity (intensity) in the light distribution (hereinafter referred to as the "principal light") is different, it can be said that the light distribution is different.

[0071] In addition, if Figure 1A as well as Figure 1BAs shown, the lighting device 100A emits light LRr1 to the back side (lower side in the figure, -z direction) when the first lighting component 110A1 is turned on, and emits light LRr2 to the back side (lower side in the figure) when the second lighting component 110A2 is turned on. The light distribution of light LRr1 and light LRr2 may be different from each other.

[0072] The first light guide component 10A1 and the second light guide component 10A2 have a visible light transmittance of, for example, 60% or more. In addition, the first light guide component 10A1 and the second light guide component 10A2 have a haze value of less than 10%. The visible light transmittance of the first light guide component 10A1 and the second light guide component 10A2 is preferably 70% or more, and more preferably 80% or more. The haze value of the first light guide component 10A1 and the second light guide component 10A2 is preferably 5% or less. Here, light with a wavelength of 380nm to 780nm is considered as visible light. The visible light transmittance and the haze value can be measured, for example, using a haze meter (manufactured by Murakami Color Technology Laboratory: trade name HM-150).

[0073] The first light source LS1 and the second light source LS are, for example, LED devices, and a plurality of LED devices may be arranged for use. In addition, a coupling optical system may be provided between the light source LS and the light guide layer 10A for effectively guiding the light emitted from the light source LS to the light guide layer 10A. The following shows an example in which the first light source LS1 and the second light source LS2 emit light of the same wavelength band, but they may also be different.

[0074] The first light distribution and the second light distribution can be controlled by adjusting the cross-sectional shape, planar shape, size, arrangement density, and distribution of the internal spaces 14A1 and 14A2, for example. Figure 3A As described later, the inclination angle θa of the front inclined surface ISa is, for example, greater than 10° and less than 70°. In addition, the inclination angle θb of the rear inclined surface ISb is, for example, greater than 50° and less than 100°. The inclination angle θa1 of the first front inclined surface ISa1 and the inclination angle θa2 of the second front inclined surface ISa2 may be independently within the above-mentioned range of the inclination angle θa of the front inclined surface ISa, and the inclination angle θb1 of the first rear inclined surface ISb1 and the inclination angle θb1 of the second rear inclined surface ISb2 may be independently within the above-mentioned range of the inclination angle θb of the rear inclined surface ISb. As described above, for example, by making the inclination angle θa1 of the first front inclined surface ISa1 different from the inclination angle θa2 of the second front inclined surface ISa2, the first light distribution and the second light distribution can be made different. For example, the inclination angle θa1 is larger than the inclination angle θa2. Although the cross-sectional shapes of the internal spaces 14A1 and 14A2 are triangular as illustrated here, the cross-sectional shapes are not limited thereto and may be trapezoidal or the like, respectively and independently.

[0075] As the multiple internal spaces 14A1 and 14A2 of the light distribution control structure, when the light guide layers 10A1 and 10A2 are observed from the normal direction of the main surface, the proportion of the area of ​​the multiple internal spaces 14A1 and 14A2 in the area of ​​the light guide layers 10A1 and 10A2 (occupancy rate) is preferably 1% or more and 80% or less, and the upper limit is more preferably 50% or less, and further preferably 45% or less. In order to obtain high transmittance and / or low haze value, it is preferably 30% or less, more preferably 10% or less, and further preferably 5% or less. For example, when the occupancy rate of the internal space is 50%, a haze value of 30% can be obtained. In addition, the occupancy rate of the internal spaces 14A1 and 14A2 can be uniform, or the occupancy rate can be increased as the distance increases, so that even if the distance from the light sources LS1 and LS2 increases, the brightness will not decrease. In order to mass-produce by roll-to-roll or roll-to-sheet method, the occupancy rate of the internal spaces 14A1 and 14A2 is preferably uniform.

[0076] Next, refer to Figure 2 An example of the planar shape and arrangement of the internal space 14A will be described. Figure 2 A schematic top view of the lighting component 110A is shown. Figure 3A , Figure 3B as well as Figure 3C , the shape of the internal space 14A is described. Figure 3A is a schematic cross-sectional view of the internal space 14A, Figure 3B is a schematic top view of the internal space 14A, Figure 3C Schematic top views showing variations of the internal space 14A. The lighting component 110A, light guide layer 10A, internal space 14A, front inclined surface ISa (inclination angle θa), rear inclined surface ISb (inclination angle θb), and light source LS in these figures may respectively be the lighting component 110A1 or 110A2, light guide layer 10A1 or 10A2, internal space 14A1 or 14A2, front inclined surface ISa1 (inclination angle θa1) or ISa2 (inclination angle θa2), rear inclined surface ISb1 (inclination angle θb1) or ISb2 (inclination angle θb2), and light source LS1 or LS2. In addition, an example is described below in which the first light distribution is made different from the second light distribution by making the inclination angle θa1 of the first front inclined surface ISa1 and the inclination angle θa2 of the second front inclined surface ISa2 different. Figure 2 As shown, the plurality of internal spaces 14A are discretely arranged in the light guiding direction (y direction) of the light guiding layer 10A and in a direction orthogonal to the light guiding direction (x direction). The size of the internal space 14A (length L, width W: see Figure 3A , Figure 3B) For example, the length L is preferably 10 μm or more and 500 μm or less, and the width W is preferably 1 μm or more and 100 μm or less. In addition, from the viewpoint of light extraction efficiency, the height H (see Figure 3A ) is preferably greater than or equal to 1 μm and less than or equal to 100 μm.

[0077] Here, an example is shown in which a plurality of internal spaces 14A are discretely arranged in the light guiding direction (y direction) of the light guiding layer 10A and in a direction (x direction) perpendicular to the light guiding direction, but the present invention is not limited thereto, and a plurality of internal spaces 14A can be discretely arranged in the light guiding direction (y direction) of the light guiding layer 10A and in a direction intersecting the light guiding direction. The discrete arrangement of the internal spaces 14A can be appropriately set according to the shape of the light guiding layer 10A or the obtained light distribution, etc. In addition, light propagates in various directions in the light guiding layer 10A, but the y direction can also be used as the light guiding direction, and light having a Y direction component (not zero) propagates in the Y direction. In addition, the same is true for other directions. That is, all light propagating in the -y direction includes light having a -y direction component (not zero).

[0078] The plurality of internal spaces 14A are discretely arranged, for example, in the light guiding direction and in the direction intersecting the light guiding direction. The discrete arrangement may have periodicity (regularity) in at least one direction, or may have no regularity. From the perspective of mass production, it is preferred that the plurality of internal spaces 14A are arranged in the same manner. For example, Figure 2 In the example shown, a plurality of internal spaces 14A having curved surfaces convex in substantially the same shape in the same direction are discretely, periodically, and fully arranged in the light guiding direction (y direction) of the light guiding layer 10A and in the direction orthogonal to the light guiding direction (x direction). In this case, the pitch Px is preferably, for example, greater than 10 μm and less than 500 μm, and the pitch Py is preferably, for example, greater than 10 μm and less than 500 μm. Figure 2 In the example shown, there is also an internal space arranged to be offset by half the pitch in the y direction and the x direction.

[0079] like Figure 2As shown, when observed from the normal direction relative to the main surface of the light guide layer 10A, the front inclined surface ISa forms a curved surface convex to the light source LS side. The light source LS is, for example, an LED device, and a plurality of LED devices are arranged in the x direction. Because the light emitted from each of the plurality of LED devices is diffusive with respect to the y direction, although the front inclined surface ISa has a curved surface convex to the light source LS side, the front inclined surface ISa acts uniformly with respect to the light. In addition, a coupling optical system is provided between the light source LS and the light receiving side of the light guide layer 10A, and when light with high parallelism (light with small diffusion relative to the y direction) is incident, the front inclined surface ISa may also be parallel to the x direction. In addition, instead of the discrete internal space 14A, an internal space such as a groove extending in the x direction (such as a triangular prism) may be used.

[0080] like Figure 3A As shown, the cross-sectional shape of the internal space 14A is, for example, a triangle. The inclination angle θa of the front inclined surface ISa on the light source LS side is, for example, greater than 10° and less than 70°. When the inclination angle θa is smaller than 10°, the controllability of the light distribution is sometimes reduced, and the light extraction efficiency is also reduced. On the other hand, if the inclination angle θa exceeds 70°, for example, manufacturing may become difficult. In addition, the inclination angle θb of the rear inclined surface ISb is, for example, greater than 50° and less than 100°. When the inclination angle θb is smaller than 50°, astigmatism may occur in unintentional directions. On the other hand, if the inclination angle θb exceeds 100°, for example, manufacturing may become difficult. As Figure 3B as well as Figure 3C As shown, the length L of the internal space 14A is preferably 10 μm or more and 500 μm or less, and the width W is preferably 1 μm or more and 100 μm or less. The length L is, for example, at least twice the width W. The height H (see Figure 3A ) is preferably 1 μm or more and 100 μm or less. Figure 3B The machining accuracy of the concave portion in the plane shape shown in the figure is sometimes formed with Figure 3C Even in such a case, the planar shape of the internal space can be characterized by the length L and the width W. The shape of the curved surface of the front inclined surface ISa convex toward the light source LS side when viewed from the normal direction of the main surface of the light guide layer 10A can be represented by a quadratic curve, for example. The internal space 14A can be composed of a shaped film having a concave portion on the surface and an adhesive layer, as described later.

[0081] The low refractive index layer 20 has a refractive index n higher than that of the first light guide layer 10A1. GP1 and the refractive index n of the second light guide layer 10A2 GP2 Small refractive index n L The refractive index n of the low refractive index layer 20 is LFor example, it is preferably 1.30 or less, more preferably 1.20 or less, and further preferably 1.15 or less. The low refractive index layer 20 is preferably solid, and the refractive index is preferably, for example, 1.05 or more. The refractive index n of the first light guide layer 10A1 is preferably 1.30 or less, more preferably 1.20 or less, and further preferably 1.15 or less. GP1 and the refractive index n of the second light guide layer 10A2 GP2 The refractive index n of the low refractive index layer 20 is L The difference is preferably 0.20 or more, more preferably 0.23 or more, and further preferably 0.25 or more. The low refractive index layer 20 having a refractive index of 1.30 or less can be formed using, for example, a porous material. The thickness of the low refractive index layer 20 is, for example, 0.3 μm or more and 5 μm or less.

[0082] When low-refractive index layer 20 is a porous material with a void inside, its void ratio is preferably more than 35 volume %, more preferably more than 38 volume %, and particularly preferably more than 40 volume %. If such a scope, a low-refractive index layer with a particularly low refractive index can be formed. The upper limit of the void ratio of low-refractive index layer is, for example, below 90 volume %, preferably below 75 volume %. If such a scope, a low-refractive index layer with excellent intensity can be formed. The void ratio is the value of the refractive index measured according to the ellipsometer, the value calculated by Lorentz-Lorenz's formula (the formula of Lorentz-Lorenz).

[0083] About low refractive index layer 20, for example, the low refractive index layer with voids disclosed in patent document 3 can be used.By reference, the entire disclosure of patent document 3 is cited to the specification of the present application.Specifically, the low refractive index layer with voids includes roughly spherical particles such as silica particles, silica particles with micropores, hollow silica nanoparticles, cellulose nanofibers, alumina nanofibers, fibrous particles such as silica nanofibers, and nanoclays composed of bentonite.In one embodiment, the low refractive index layer with voids is a porous body composed of particles (such as microporous particles) directly chemically combined with each other.In addition, among the particles constituting the low refractive index layer with voids, at least a portion thereof can also be combined via a small amount (for example, less than the mass of the particles) of the adhesive component.The voidage and refractive index of the low refractive index layer can be adjusted according to the particle size, particle size distribution, etc. of the particles constituting the low refractive index layer.

[0084] As the method for obtaining the low refractive index layer with space, for example, can enumerate the method that is recorded in (Japan) Unexamined Patent Publication No. 2010-189212, (Japan) Unexamined Patent Publication No. 2008-040171, (Japan) Unexamined Patent Publication No. 2006-011175, International Publication No. 2004 / 113966 and these references.By reference to the whole disclosure of Unexamined Patent Publication No. 2010-189212, (Japan) Unexamined Patent Publication No. 2008-040171, (Japan) Unexamined Patent Publication No. 2006-011175, International Publication No. 2004 / 113966, is quoted in this specification.

[0085] As a low refractive index layer with voids, a porous silica body can be appropriately used. The porous silica body is manufactured, for example, by the following method. Silicon compounds can be listed; a method of hydrolyzing and polycondensing at least any one of hydrolyzable silanes and / or silsesquioxanes, and partial hydrolyzates and dehydrated condensates thereof; a method of using porous particles and / or hollow microparticles; and a method of generating an aerogel layer using a rebound phenomenon; a method of using a crushed gel-like silicon compound obtained by a sol-gel method and chemically bonding the obtained crushed body, i.e., microporous particles, to each other by catalysis, etc. Among them, the low refractive index layer is not limited to a porous silica body, and the manufacturing method is not limited to the manufacturing method shown as an example, and any manufacturing method can be used for manufacturing. Among them, the porous layer is not limited to a porous silica body, and the manufacturing method is not limited to the manufacturing method shown as an example, and any manufacturing method can be used for manufacturing. In addition, silsesquioxane is (RSiO 1.5 , R is a hydrocarbon group) as a basic constituent unit is strictly different from silicon dioxide with SiO2 as a basic constituent unit, but has the same network structure cross-linked by siloxane bonds as silicon dioxide. Therefore, the porous body containing silsesquioxane as a basic constituent unit is also referred to as a silica porous body or a silica-based porous body.

[0086] The porous silica body can be composed of microporous particles of a gel-like silicon compound bonded to each other. As the microporous particles of the gel-like silicon compound, a pulverized body of the gel-like silicon compound can be cited. The porous silica body can be formed, for example, by applying a coating liquid containing a pulverized body of the gel-like silicon compound to a substrate. The pulverized body of the gel-like silicon compound can be chemically bonded (for example, siloxane bonding) by catalysis, light irradiation, heating, etc.

[0087] Next, refer to Figure 4A , Figure 4B , Figure 5A as well as Figure 5B, the lighting device of other embodiments of the present invention is described. In the lighting device exemplified below, the first light distribution control structure is formed on the first direction conversion layer arranged on the front side or the back side of the first light guide layer, and the second light distribution control structure is formed on the second direction conversion layer arranged on the front side or the back side of the second light guide layer.

[0088] First, refer to Figure 4A and Figure 4B , the structure and operation of a lighting device 100B according to another embodiment of the present invention will be described. The lighting device 100B has two lighting components (a first lighting component 110B1 and a second lighting component 110B2), Figure 4A A schematic cross-sectional view showing the lighting device 100B in which the first lighting component 110B1 is turned on, Figure 4B A schematic cross-sectional view of the lighting device 100B showing the second lighting component 110B2 in the on state. The dashed arrows in the figure represent examples of light rays.

[0089] The first lighting component 110B1 has a first light source LS1 and a first light guide component 110B1 (G). The first light guide component 110B1 (G) has: a first light guide layer 10B1 having a first light receiving side surface for receiving the first light emitted from the first light source LS1; and a first direction conversion layer 60B1, which is arranged on the front side of the first light guide layer 10B1. The first direction conversion layer 60B1 has a first light distribution control structure capable of directing at least a portion of the first light propagating in the first light guide layer 10B1 (y direction) toward the front side. The first light distribution control structure illustrated here has a plurality of first internal spaces 64BA1, and the plurality of first internal spaces 64BA1 have a first front inclined surface that directs light toward the front side by total internal reflection. The direction conversion layer 60B1 having a plurality of first internal spaces 64BA1 is composed of a shaping film 64B1 having a recess 64BA1 (indicated by the same reference figure mark as the internal space 64BA1) on the surface and an adhesive layer 54B1.

[0090] The second lighting component 110B2 has a second light source LS2 and a second light guide component 110B2 (G). The second light guide component 110B2 (G) has: a second light guide layer 10B2, which has a second light receiving side surface for receiving the second light emitted from the second light source LS2; and a second direction conversion layer 60B2, which is arranged on the front side of the second light guide layer 10B2. The second direction conversion layer 60B2 has a second light distribution control structure that can make at least a part of the second light propagating in the second light guide layer 10B2 (y direction) toward the front side. The second light distribution control structure illustrated here has a plurality of second internal spaces 64BA2, and the plurality of second internal spaces 64BA2 have a second front inclined surface that directs light toward the front side by total internal reflection. The direction conversion layer 60B2 having a plurality of second internal spaces 64BA2 is composed of a shaping film 64B2 having a recessed portion 64BA2 (indicated by the same reference figure mark as the internal space 64BA2) on the surface and an adhesive layer 54B2. The lighting device 100B has a low refractive index layer 20, which is arranged between the first light guide member 110B1 (G) and the second light guide member 110B2 (G) and has a refractive index lower than that of the first light guide layer 10B1 and the second light guide layer 10B2. The low refractive index layer 20 causes light incident at an angle greater than the critical angle to the interface between the low refractive index layer 20 and the first light guide member 110B1 (G) and the interface between the low refractive index layer 20 and the second light guide member 110B2 (G) to be totally reflected toward the first light guide member 110B1 (G) side or the second light guide member 110B2 (G) side.

[0091] The lighting device 100B is as follows Figure 4A As shown, when only the first light source LS1 is turned on (the second light source LS2 is turned off), that is, the first lighting component 110B1 is turned on, the light LRf1 having the first light distribution can be emitted to the front side, as shown in FIG. Figure 4B As shown, when only the second light source LS2 is turned on (the first light source LS1 is turned off), that is, the second lighting component 110B2 is turned on, the light LRf2 having the second light distribution can be emitted to the front side. For example, by making the inclination angle θa1 of the first front inclined surface different from the inclination angle θa2 of the second front inclined surface, the first light distribution can be different from the second light distribution.

[0092] Next, refer to Figure 5A as well as Figure 5B , the structure and operation of a lighting device 100C according to another embodiment of the present invention will be described. The lighting device 100C includes two lighting components (a first lighting component 110C1 and a second lighting component 110C2). Figure 5A A schematic cross-sectional view of the lighting device 100C showing the first lighting component 110C1 in the on state, Figure 5BA schematic cross-sectional view of the lighting device 100C showing the second lighting component 110C2 in the on state. The dashed arrows in the figure represent examples of light rays.

[0093] The first lighting component 110C1 has a first light source LS1 and a first light guide component 110C1 (G). The first light guide component 110C1 (G) has: a first light guide layer 10C1 having a first light receiving side surface for receiving the first light emitted from the first light source LS1; and a first direction conversion layer 60C1, which is arranged on the back side of the first light guide layer 10C1 via an adhesive layer 52C1. The first direction conversion layer 60C1 has a first light distribution control structure capable of directing at least a portion of the first light propagating in the first light guide layer 10C1 (y direction) toward the front side. The first light distribution control structure illustrated here has a plurality of first internal spaces 64CA1, and the plurality of first internal spaces 64CA1 have a first front inclined surface that directs light toward the front side by total internal reflection. The direction conversion layer 60C1 having a plurality of first internal spaces 64CA1 is composed of a shaping film 64C1 having a concave portion 64CA1 (indicated by the same reference figure mark as the internal space 64CA1) on the surface, and an adhesive layer 54C1. Furthermore, the shaping film 64C1 and the base material layer 30C1 are bonded to each other via the adhesive layer 54C1.

[0094] The second lighting component 110C2 has a second light source LS2 and a second light guide component 110C2 (G). The second light guide component 110C2 (G) has: a second light guide layer 10C2, which has a second light receiving side surface for receiving the second light emitted from the second light source LS2; and a second direction conversion layer 60C2, which is arranged on the back side of the second light guide layer 10C2 via an adhesive layer 52C2. The second direction conversion layer 60C2 has a second light distribution control structure that can make at least a part of the second light propagating in the second light guide layer 10C2 (y direction) toward the front side. The second light distribution control structure illustrated here has a plurality of second internal spaces 64CA2, and the plurality of second internal spaces 64CA2 have a second front inclined surface that directs light toward the front side by total internal reflection. The direction conversion layer 60C2 having a plurality of second internal spaces 64CA2 is composed of a shaping film 64C2 having a recess 64CA2 (indicated by the same reference figure mark as the internal space 64CA2) on the surface and an adhesive layer 54C2. Furthermore, the shaping film 64C2 is bonded to the base material layer 30C2 via the adhesive layer 54C2.

[0095] The lighting device 100C has a low refractive index layer 20, which is arranged between the first light guide member 110C1 (G) and the second light guide member 110C2 (G) and has a refractive index lower than that of either the first light guide layer 10C1 or the second light guide layer 10C2. The low refractive index layer 20 causes light incident at an angle greater than the critical angle to the interface between the low refractive index layer 20 and the first light guide member 110C1 (G) and the interface between the low refractive index layer 20 and the second light guide member 110C2 (G) to be totally reflected toward the first light guide member 110C1 (G) side or the second light guide member 110C2 (G) side.

[0096] The lighting device 100C is as follows Figure 5A As shown, when only the first light source LS1 is turned on (the second light source LS2 is turned off), that is, the first lighting component 110C1 is turned on, the light LRf1 having the first light distribution can be emitted to the front side, as shown in FIG. Figure 5B As shown, when only the second light source LS2 is turned on (the first light source LS1 is turned off), that is, the second lighting component 110C2 is turned on, the light LRf2 having the second light distribution can be emitted to the front side. For example, by making the inclination angle θa1 of the first front inclined surface different from the inclination angle θa2 of the second front inclined surface, the first light distribution can be different from the second light distribution.

[0097] Next, refer to Figure 6 to Figure 9 , lighting devices 100D to 100G according to other embodiments of the present invention will be described.

[0098] Figure 6 A schematic cross-sectional view of a lighting device 100D according to an embodiment of the present invention is shown. The lighting device 100D includes a first lighting component 110D1 and a second lighting component 110D2. The lighting device 100D can operate in the same manner as the lighting device 100C according to the above-described embodiment.

[0099] The first lighting component 110D1 has a first light source LS1 and a first light guide component 110D1 (G). The first light guide component 110D1 (G) has: a first light guide layer 10D1 having a first light receiving side surface for receiving the first light emitted from the first light source LS1; and a first direction conversion layer 60D1, which is arranged on the back side of the first light guide layer 10D1 via an adhesive layer 52D1. The first direction conversion layer 60D1 has a first light distribution control structure capable of directing at least a portion of the first light propagating in the first light guide layer 10D1 (y direction) toward the front side. The first light distribution control structure illustrated here has a plurality of first internal spaces 64DA1, and the plurality of first internal spaces 64DA1 have a first front inclined surface that directs light toward the front side by total internal reflection. The direction conversion layer 60D1 having a plurality of first internal spaces 64DA1 is composed of a shaping film 64D1 having a recess 64DA1 (indicated by the same reference figure mark as the internal space 64DA1) on the surface, and an adhesive layer 54D1. Furthermore, the shaping film 64D1 is bonded to the base material layer 30D1 via the adhesive layer 54D1.

[0100] The second lighting component 110D2 has a second light source LS2 and a second light guide component 110D2 (G). The second light guide component 110D2 (G) has: a second light guide layer 10D2, which has a second light receiving side surface for receiving the second light emitted from the second light source LS2; and a second direction conversion layer 60D2, which is arranged on the back side of the second light guide layer 10D2 via an adhesive layer 52D2. The second direction conversion layer 60D2 has a second light distribution control structure that can make at least a part of the second light propagating in the second light guide layer 10D2 (y direction) toward the front side. The second light distribution control structure illustrated here has a plurality of second internal spaces 64DA2, and the plurality of second internal spaces 64DA2 have a second front inclined surface that directs light toward the front side by total internal reflection. The direction conversion layer 60D2 having a plurality of second internal spaces 64DA2 is composed of a shaping film 64D2 having a recess 64DA2 (indicated by the same reference figure mark as the internal space 64DA2) on the surface and an adhesive layer 54D2. Furthermore, the shaping film 64D2 and the base material layer 30D2 are bonded to each other via the adhesive layer 54D2.

[0101] The lighting device 100D has a low refractive index layer 20, which is arranged between the first light guide member 110D1 (G) and the second light guide member 110D2 (G) and has a refractive index lower than that of the first light guide layer 10D1 and the second light guide layer 10D2. The low refractive index layer 20 causes light incident at an angle greater than the critical angle to the interface between the low refractive index layer 20 and the first light guide member 110D1 (G) and the interface between the low refractive index layer 20 and the second light guide member 110D2 (G) to be totally reflected toward the first light guide member 110D1 (G) side or the second light guide member 110D2 (G) side.

[0102] The low refractive index layer 20 is supported by the base layer 32D2. The base layer 32D2 is bonded to the first light guide layer 10D1 via the adhesive layer 56D1, and the low refractive index layer 20 is bonded to the base layer 30D2 via the adhesive layer 58D2. When the low refractive index layer 20 is formed using a porous material, it is preferred that the low refractive index layer 20 is formed on the base layer 32D2.

[0103] Figure 7 A schematic cross-sectional view of a lighting device 100E according to an embodiment of the present invention is shown. The lighting device 100E includes a first lighting component 110E1 and a second lighting component 110E2. The lighting device 100E can operate in the same manner as the lighting device 100B according to the above embodiment.

[0104] The first lighting component 110E1 has a first light source LS1 and a first light guide component 110E1 (G). The first light guide component 110E1 (G) has: a first light guide layer 10E1 having a first light receiving side surface for receiving the first light emitted from the first light source LS1; and a first direction conversion layer 60E1, which is arranged on the front side of the first light guide layer 10E1 via an adhesive layer 54E1. The first direction conversion layer 60E1 has a first light distribution control structure that can direct at least a portion of the first light propagating in the first light guide layer 10E1 (y direction) toward the front side. The first light distribution control structure illustrated here has a plurality of first internal spaces 64EA1, and the plurality of first internal spaces 64EA1 have a first front inclined surface that directs light toward the front side by total internal reflection. The direction conversion layer 60E1 having a plurality of first internal spaces 64EA1 is composed of a shaping film 64E1 having a recess 64EA1 (indicated by the same reference figure mark as the internal space 64EA1) on the surface, and an adhesive layer 54E1. Furthermore, the shaping film 64E1 and the base material layer 30E1 are bonded to each other via the adhesive layer 52E1.

[0105] The second lighting component 110E2 has a second light source LS2 and a second light guide component 110E2 (G). The second light guide component 110E2 (G) has: a second light guide layer 10E2, which has a second light receiving side surface for receiving the second light emitted from the second light source LS2; and a second direction conversion layer 60E2, which is arranged on the front side of the second light guide layer 10E2 via an adhesive layer 54E2. The second direction conversion layer 60E2 has a second light distribution control structure that can make at least a part of the second light propagating in the second light guide layer 10E2 (y direction) toward the front side. The second light distribution control structure illustrated here has a plurality of second internal spaces 64EA2, and the plurality of second internal spaces 64EA2 have a second front inclined surface that directs light toward the front side by total internal reflection. The direction conversion layer 60E2 having a plurality of second internal spaces 64EA2 is composed of a shaped film 64E2 having a recess 64EA2 (indicated by the same reference figure mark as the internal space 64EA2) on the surface and an adhesive layer 54E2. Furthermore, the shaping film 64E2 and the base material layer 34E2 are bonded to each other via the adhesive layer 58E2.

[0106] The lighting device 100E has a low refractive index layer 20, which is arranged between the first light guide member 110E1 (G) and the second light guide member 110E2 (G) and has a refractive index lower than that of the first light guide layer 10E1 and the second light guide layer 10E2. The low refractive index layer 20 causes light incident at an angle greater than the critical angle to the interface between the low refractive index layer 20 and the first light guide member 110E1 (G) and the interface between the low refractive index layer 20 and the second light guide member 110E2 (G) to be totally reflected toward the first light guide member 110E1 (G) side or the second light guide member 110E2 (G) side.

[0107] The low refractive index layer 20 is supported by the base layer 32E2. The base layer 32E2 is bonded to the second light guide layer 10E2 via an adhesive layer 52E2, and the low refractive index layer 20 is bonded to the base layer 30E1 via an adhesive layer 58E1. When the low refractive index layer 20 is formed using a porous material, it is preferred that the low refractive index layer 20 is formed on the base layer 32E2.

[0108] Figure 8 A schematic cross-sectional view of a lighting device 100F according to an embodiment of the present invention is shown. The lighting device 100F includes a first lighting component 110F1 and a second lighting component 110F2. The first lighting component 110F1 and the second lighting component 110F2 are respectively configured as follows: Figure 6 The first lighting component 110D1 and the second lighting component 110D2 included in the lighting device 100D shown are identical, and the components are denoted by common reference numerals, and detailed descriptions thereof are omitted.

[0109] In the lighting device 100F, the light guiding direction (y direction) of the first light in the light guiding layer 10D1 of the first lighting component 110F1 is antiparallel to the light guiding direction (-y direction) of the second light in the light guiding layer 10D2 of the second lighting component 110F2. In the lighting device 100D, the light guiding direction of the first light in the light guiding layer of the first lighting component is parallel to the light guiding direction of the second light in the light guiding layer of the second lighting component (y direction), but they may be set to be antiparallel as in the lighting device 100F. Of course, the combination of the light guiding direction of the first lighting component and the light guiding direction of the second lighting component may also be opposite.

[0110] Fig. 9 A schematic cross-sectional view of a lighting device 100G according to an embodiment of the present invention is shown. The lighting device 100G includes a first lighting component 110G1 and a second lighting component 110G2. The first lighting component 110G1 and the second lighting component 110G2 are respectively configured as follows: Figure 7 The first lighting component 110E1 and the second lighting component 110E2 included in the lighting device 100E shown are identical, and the components are denoted by common reference numerals, and detailed descriptions thereof are omitted.

[0111] In the lighting device 100G, the light guiding direction (y direction) of the first light in the light guiding layer 10E1 of the first lighting component 110G1 is antiparallel to the light guiding direction (-y direction) of the second light in the light guiding layer 10E2 of the second lighting component 110G2. In the lighting device 100E, the light guiding direction of the first light in the light guiding layer of the first lighting component is parallel to the light guiding direction of the second light in the light guiding layer of the second lighting component (y direction), but they may be set to be antiparallel as in the lighting device 100G. Of course, the combination of the light guiding direction of the first lighting component and the light guiding direction of the second lighting component may also be opposite.

[0112] In the other lighting devices mentioned above, the light guiding direction of the first light in the light guiding layer of the first lighting component is also parallel to the light guiding direction of the second light in the light guiding layer of the second lighting component (y direction), but it can also be set to be anti-parallel as in lighting devices 100F and 100G. Of course, the combination of the light guiding direction of the first lighting component and the light guiding direction of the second lighting component can also be opposite. Preferred examples of the various components of the lighting device of the embodiment of the present invention are described. The shaped film for forming the internal space can be manufactured as follows, for example. The concave-convex shaped film is manufactured according to the method described in the gazette of Special Table No. 2013-524288. Specifically, the surface of a polymethyl methacrylate (PMMA) film is coated with a spray paint (finecure RM-64 manufactured by Sanyo Chemical Industries, Ltd.), an optical pattern is embossed on the surface of the film containing the spray paint, and then the target concave-convex shaped film is manufactured by curing the spray paint. The total thickness of the concave-convex shaped film is 130μm.

[0113] The light guide layer is formed of a known material with high transmittance to visible light. For example, the light guide layer is formed of acrylic resins such as polymethyl methacrylate (PMMA), polycarbonate (PC) resins, cycloolefin resins, and glass (for example, quartz glass, alkali-free glass, borosilicate glass). The refractive index of the light guide layer is n GP For example, it is greater than 1.40 and less than 1.80. In addition, unless otherwise specified, the refractive index refers to the refractive index measured by an ellipsometer at a wavelength of 550 nm. The thickness of the light-guiding layer can be appropriately set according to the purpose. The thickness of the light-guiding layer is, for example, greater than 0.05 mm and less than 50 mm.

[0114] The thickness of the substrate layer is, for example, 1 μm to 1000 μm, preferably 10 μm to 100 μm, and more preferably 20 μm to 80 μm. The refractive index of the substrate layer is independently preferably 1.40 to 1.70, and more preferably 1.43 to 1.65.

[0115] The thickness of the adhesive layer is independently, for example, 0.1 μm or more and 100 μm or less, preferably 0.3 μm or more and 100 μm or less, and more preferably 0.5 μm or more and 50 μm or less. The refractive index of the adhesive layer is independently preferably 1.42 or more and 1.60 or less, and more preferably 1.47 or more and 1.58 or less. In addition, the refractive index of the adhesive layer is preferably close to the refractive index of the light-guiding layer, the shaping film or the substrate layer connected thereto, and the absolute value of the difference in refractive index is preferably 0.2 or less.

[0116] The adhesive layer that is in contact with the concave portion on the surface of the excipient film and constitutes the internal space is preferably capable of bonding without filling the concave portion on the surface of the excipient film. As an adhesive suitable for forming such an adhesive layer, the adhesive described in International Publication No. 2021 / 167090, International Publication No. 2021 / 167091 or International Publication No. 2022 / 176658 of the applicant can be suitably used. The entire disclosure of these applications is cited in this specification. The polyester adhesive described in International Publication No. 2022 / 176658 is particularly preferred.

[0117] Furthermore, a hard coating layer, an antireflection layer, an antifouling layer, etc. may be provided on the front surface of the lighting device, for example. These may be formed using known materials.

[0118] Below, refer to Figure 10 to Figure 16 An experimental example will be described.

[0119] Fig.10 FIG. 1 is a schematic top view of a prototype lighting device 100D_S. The device region 100D_DA of the lighting device 100D_S has Figure 6The first light guide layer 10D1 and the second light guide layer 10D2 use an acrylic plate with a thickness of 5 mm. Table 1 below shows parameters that characterize the arrangement and structure of the internal spaces 64DA1 and 64DA2 of the first lighting component 100D1 and the second lighting component 100D2 of the lighting device 100D (see Figure 2 , Figure 3A to Figure 3C The low refractive index layer 20 is formed using the above-mentioned porous silica body, and has a refractive index of 1.20 and a thickness of about 0.9 μm.

[0120] [Table 1]

[0121]

[0122] Fig.11 Schematic diagram of a measurement system for the light distribution of the lighting device 100D_S. The light distribution is measured using a measurement device CS with a conoscope (Radiant's Prometric IC-PM16 luminance meter). The light distribution is measured in a state where only the first light source is turned on (front emission mode) and in a state where only the second light source is turned on (oblique emission mode). In each lighting state, the polar angle distribution of the luminance on the front side and the back side is measured.

[0123] Fig.12 A graph showing the brightness distribution of the front side of the lighting device 100D_S is shown. Fig.13 A graph showing the brightness distribution of the back side of the lighting device 100D_S is shown. In any of the graphs, the solid line represents the light distribution when only the first light source is turned on (the first light distribution), and the dotted line represents the light distribution when only the second light source is turned on (the second light distribution). Fig.12 It can be seen that on the front side, the first light distribution is greatly different from the second light distribution (the main light direction is -3° in the first light distribution and -42° in the second light distribution). Fig.13 and Fig.12 It can be seen that the difference in light distribution on the back side is smaller than that on the front side (direction of principal light: -66° in the first light distribution and -70° in the second light distribution).

[0124] Fig.14 FIG. 1 is a schematic top view of a prototype lighting device 100F_S. The device region 100F_DA of the lighting device 100F_S has Figure 8 The structure is the same as that of the lighting device 100F shown in the figure. The inclination angle θa1 of the first front inclined surface ISa1 is set to 49°, and the inclination angle θa2 of the second front inclined surface ISa2 is set to 30°. The other structures are also the same as those of the lighting device 100F.

[0125] Fig.15 1 is a schematic diagram showing a measurement system of the light distribution of the lighting device 100F_S. The light distribution is measured in the same manner as the light distribution of the lighting device 100D_S.

[0126] Fig.16 A graph showing the brightness distribution of the front side of the lighting device 100F_S is shown. Fig.17 A graph showing the brightness distribution of the back side of the lighting device 100F_S is shown. In any of the graphs, the solid line represents the light distribution when only the first light source is turned on (the first light distribution), and the dotted line represents the light distribution when only the second light source is turned on (the second light distribution). Fig.16 It can be seen that on the front side, the asymmetry between the first light distribution and the second light distribution is large (the direction of the main light beam is -3° in the first light distribution and -31° in the second light distribution). Fig.17 and Fig.16 It can be seen that the asymmetry of the light distribution on the back side is smaller than that on the front side (direction of the main light ray: 68° in the first light distribution and -69° in the second light distribution).

[0127] In this way, by making the inclination angle θa1 of the first front inclined surface ISa1 and the inclination angle θa2 of the second front inclined surface ISa2 different from each other, the first light distribution and the second light distribution can be made different from each other.

[0128] [Industrial Applicability]

[0129] The lighting device according to the embodiment of the present invention can emit light having two or more different light distributions. Therefore, for example, the light distribution of the emitted light can be selected according to the scene in which the lighting device is used.

[0130] Description of Reference Numerals

[0131] 10A1: first light guide component (first light guide layer), 10A2: second light guide component (second light guide layer), 14A1: first internal space, 14A2: second internal space, 20: low refractive index layer, 100A: lighting device, 110A1: first lighting component, 110A2: second lighting component, ISa1: first front inclined surface, ISa2: second front inclined surface, LRf1: light, LRf2: light, LS1: first light source, LS2: second light source

Claims

1. A lighting device configured to emit light having a first light distribution and light having a second light distribution different from the first light distribution from a front side, characterized in that: The lighting device comprises: A first lighting component comprises a first light source and a first light guide component, wherein the first light guide component comprises: a first light guide layer having a first light receiving side surface receiving the first light emitted from the first light source; and a first light distribution control structure capable of directing at least a portion of the first light propagating in the first light guide layer toward the front side; a second lighting member having a second light source and a second light guide member disposed on the front side of the first light guide member, the second light guide member having: a second light guide layer having a second light receiving side surface receiving second light emitted from the second light source; and a second light distribution control structure capable of directing a portion of the second light propagating in the second light guide layer toward at least the front side; as well as a low refractive index layer disposed between the first light guide member and the second light guide member and having a refractive index lower than that of either the first light guide layer or the second light guide layer; The lighting device is configured to emit light having the first light distribution toward the front side when the first light source is turned on, and to emit light having the second light distribution toward the front side when the second light source is turned on.

2. The lighting device according to claim 1, characterized in that: The first light guide member, the low refractive index layer, and the second light guide member are stacked using an adhesive.

3. The lighting device according to claim 1, characterized in that: The first light distribution control structure has a plurality of first internal spaces, each of which has a first front inclined surface that directs light toward the front side by total internal reflection. The second light distribution control structure has a plurality of second internal spaces, each of which has a second front inclined surface that directs light toward the front side by total internal reflection. An inclination angle θa1 of the first front inclined surface is different from an inclination angle θa2 of the second front inclined surface.

4. The lighting device according to claim 3, characterized in that: An inclination angle θa1 of the first front inclined surface is greater than an inclination angle θa2 of the second front inclined surface.

5. The lighting device according to claim 3, characterized in that: The first light distribution control structure is formed on a first direction changing layer disposed on the front side or the back side of the first light guide layer. The second light distribution control structure is formed on a second direction changing layer disposed on the front side or the back side of the second light guide layer.

6. The lighting device according to any one of claims 1 to 5, characterized in that: The visible light transmittance of the first light guide member and the second light guide member is greater than 60%, and the haze value is less than 10%.

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