WO2023013243A1

WO2023013243A1 - Light-guide plate and light-emitting module

Info

Publication number: WO2023013243A1
Application number: PCT/JP2022/023173
Authority: WO
Inventors: 翔一竹島; 挙史藤井
Original assignee: セーレン株式会社
Priority date: 2021-08-05
Filing date: 2022-06-08
Publication date: 2023-02-09
Also published as: JP2023023633A

Abstract

These light-guide plates (12, 30, 40, 52) according to an embodiment each include: a light-transmitting substrate (16) having light-transmitting properties; a plurality of light-transmitting projection layers (18) provided, in a convex shape, on the surface of the light-transmitting substrate (16), and having a light-emitting surface (18B) formed by a curved surface; and a plurality of light-scattering layers (20) composed of a resin containing light-scattering particles, and provided on the back surface of the light-transmitting substrate (16) so as to overlap the plurality of light-transmitting projection layers (18) with the light-transmitting substrate (16) interposed therebetween. A plurality of types of light-transmitting projection layers (18) with different sizes and/or heights are mixed.

Description

Light guide plate and light emitting module

An embodiment of the present invention relates to a light guide plate and a light emitting module using the light guide plate.

In order to improve the texture of vehicle interiors such as automobiles, the use of products that combine decoration and indirect lighting is increasing. For example, Patent Literature 1 discloses that, in a decorative sheet having a design with a decorative layer, the design is improved by partially causing the surface of the decorative sheet to emit light. The decorative sheet described in Patent Document 1 includes a high refractive index resin layer, a light diffusion layer provided on the back surface of the high refractive index resin layer, and a low refractive index resin layer on the surface of the high refractive index resin layer. and a decorative layer provided via.

Japanese Unexamined Patent Application Publication No. 2017-170801

　From the perspective of further improving the texture of vehicle interiors, interior parts capable of emitting crystal-like or glass-like light are being developed. However, the glint seen in real crystals and glass, that is, the effect of localized strong light and the change in luminance depending on the viewing angle is insufficient, and further improvement in texture is required.

The purpose of the present embodiment is to provide a light guide plate and a light emitting module using the light guide plate, which can express brilliance by locally increasing the brightness of light emission that varies depending on the viewing angle.

The light guide plate according to the present embodiment is composed of: a light-transmitting base material having light-transmitting properties; and a resin having light-transmitting properties. a plurality of light-transmitting convex layers each having a light exit surface formed by a curved surface; made of a resin containing light scattering particles, the plurality of light-transmitting convex layers being overlapped with the light-transmitting substrate interposed therebetween; a plurality of light-scattering layers provided on the other surface of the translucent substrate facing the one surface; In the light guide plate, a plurality of kinds of light-transmitting convex layers having different sizes and/or heights are mixed.

Schematic cross-sectional view of a light-emitting module according to the first embodiment FIG. 2 is a schematic plan view of the same light-emitting module, and (A) is an enlarged view of a part thereof; III-III line sectional view of FIG. IV-IV line sectional view of FIG. VV line sectional view of FIG. Schematic cross-sectional view showing the incident and outgoing states of light in the same light-emitting module Schematic cross-sectional view showing an example in which the light-transmitting convex layer is shifted with respect to the light-scattering layer Schematic plan view corresponding to FIG. Partial enlarged cross-sectional schematic diagram of the light guide plate according to the second embodiment Partially enlarged cross-sectional schematic diagram of the light guide plate according to the third embodiment Schematic cross-sectional view of a light-emitting module according to a fourth embodiment Schematic diagram showing a part of an arrangement example of a light-transmitting convex layer in an example A diagram showing the gradation of the light-transmitting convex layer in the arrangement example of FIG. 12A by numbers

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this specification, the surface of the light guide plate means the surface (main design surface) that is mainly visible to the human eye during use (that is, when used as a light emitting module), out of the front and back surfaces of the light guide plate. The back surface of the light guide plate means the surface opposite to the front surface. Further, the surface of the light-transmitting substrate refers to the surface of the front and back surfaces of the light-transmitting substrate that faces in the same direction as the surface of the light guide plate. The back surface of the translucent base means the surface opposite to the front surface of the translucent base.

(First embodiment)
As shown in FIGS. 1 and 2, the light emitting module 10 according to the first embodiment includes a light guide plate 12 and a light source 14. As shown in FIG.

The light guide plate 12 includes a light-transmitting base material 16 , a plurality of light-transmitting convex layers 18 and a plurality of light scattering layers 20 . In this specification, the light guide plate is not limited to a plate-like plate in the usual sense, but also includes a plate having a small thickness such as a sheet or a film.

The translucent base material 16 is a substrate forming the main body of the light guide plate 12 and has translucency. In this specification, the term “light-transmitting” refers to light-transmitting properties, that is, the ability to transmit light, and is not limited to being colorless and transparent. There may be. In one embodiment, the translucent substrate 16 is preferably colorless and transparent.

The translucent base material 16 has a surface 16A, a back surface 16B facing the surface 16A, and side surfaces 16C. The side surface 16C is a surface along the thickness direction at the edge of the translucent base material 16 . Side 16C may be perpendicular to front surface 16A and back surface 16B, but may also be slanted.

The material of the translucent base material 16 is not particularly limited, and may be resin or glass. In one embodiment, the translucent base material 16 includes, for example, polycarbonate resin (PC); polyester resin such as polyethylene terephthalate (PET); acrylic resin such as polymethyl methacrylate (PMMA); polystyrene resin, acrylonitrile-styrene Styrenic resins such as polymer resins (AS resins) and acrylonitrile-butadiene-styrene copolymers (ABS); polyolefin resins such as polyethylene and polypropylene; and resin sheets made of blends of two or more of these. As the translucent base material 16, a glass plate made of, for example, lead glass or soda-lime glass may be used. A resin sheet made of a thermoplastic resin is preferably used as the translucent base material 16 .

The translucent base material 16 serves as the main body of the light guide plate 12 to spread the light incident from the side surface 16C over the entire area. That is, the light incident from the side surface 16C of the light-transmitting base material 16 is totally reflected at the interface between the front and back surfaces of the light-transmitting base material 16, is confined in the light-transmitting base material 16, and propagates sideways. Therefore, it is preferable that the translucent base material 16 has a high refractive index. The refractive index (absolute refractive index) of the translucent base material 16 is not particularly limited, but may be, for example, 1.40 to 1.70 or 1.50 to 1.60.

In this specification, the refractive index (absolute refractive index) is the refractive index of light (D line) with a wavelength of 589 nm. Measured in °C.

The thickness of the translucent base material 16 is not particularly limited, and may be, for example, 0.1 to 3.0 mm, 0.5 to 2.5 mm, or 1.0 to 2.0 mm.

The translucent convex layer 18 is a resin layer made of translucent resin, and may be colorless and transparent or colored and transparent. Examples of the resin that forms the light-transmitting convex layer 18 include acrylic resins such as polymethyl methacrylate (PMMA) and urethane acrylate resin; polystyrene resin, acrylonitrile-styrene copolymer resin (AS resin), acrylonitrile-styrene-butadiene. Styrenic resins such as copolymer resins (ABS resins); polyolefin resins such as polyethylene and polypropylene; or blends of two or more of these. The light-transmitting convex layer 18 preferably does not contain light scattering particles.

The refractive index (absolute refractive index) of the light-transmitting convex layer 18 is not particularly limited, and may be higher than that of the light-transmitting substrate 16, lower than that of the light-transmitting substrate 16, or the same value. When the light-transmitting convex layer 18 is provided in contact with the light-transmitting base material 16 and the refractive index of the light-transmitting convex layer 18 is higher than the refractive index of the light-transmitting base material 16, the light in the light-transmitting convex layer 18 The extraction effect can be enhanced. The refractive index of the translucent convex layer 18 may be, for example, 1.35 to 1.65 or 1.40 to 1.55.

The light-transmitting convex layer 18 is provided in a convex shape on either the front surface 16A or the back surface 16B of the light-transmitting substrate 16 (hereinafter referred to as the first surface). That is, the translucent convex layer 18 is provided as a convex layer that partially covers the first surface. The “convex shape” of the light-transmitting convex layer 18 means that the first surface (that is, the reference surface on which the light-transmitting convex layer 18 is provided) is raised with a bulge due to a curved surface. The height is not particularly limited as long as it is relatively high with respect to . Preferably, "convex" refers to a shape with a raised center. The light-transmitting convex layers 18 are scattered on the first surface. Dotting means that a plurality of dotted (dot-shaped) light-transmitting convex layers 18 are present. In this example, the light-transmitting convex layer 18 is provided in contact with the surface 16A of the light-transmitting substrate 16, that is, directly laminated on the surface 16A.

The light-transmitting convex layer 18 may be distributed over the entire first surface of the light-transmitting substrate 16, or may be locally disposed. By arranging a plurality of dotted light-transmitting convex layers 18 at predetermined positions on the first surface, a design consisting of a pattern, a figure, a character, a symbol, or a combination of two or more of these can be created in a crystal tone. It can be expressed by luminescence.

The light-transmitting convex layer 18 has a light emitting surface 18B for emitting light incident from its bottom surface 18A. Here, the light emitting surface 18B is the surface of the light-transmitting convex layer 18 that protrudes convexly from the first surface (surface 16A) of the light-transmitting substrate 16 and is exposed to the outside. is the surface forming the interface of The bottom surface 18A of the light-transmitting convex layer 18 is the surface facing the vertex of the light-transmitting convex layer 18, and in this example, the surface in contact with the light-transmitting base material 16 (the interface between the light-transmitting convex layer 18 and the light-transmitting base material 16). ).

Each light exit surface 18B of the plurality of light-transmitting convex layers 18 is formed by a curved surface. Here, "formed by a curved surface" includes not only a mode in which the light exit surface 18B is formed only by a curved surface, but also a mode in which a plane is partially included. It is preferable that the light exit surface 18B is mainly formed by a curved surface. As a result, the light emitted from the light emitting surface 18B is diffused, and the effect that the appearance of the emitted light differs depending on the viewing angle can be enhanced. It is preferable that the area ratio of the curved surface in the light exit surface 18B is 80% or more. That is, in one embodiment, each light exit surface 18B preferably has a curved surface area ratio of 80% or more and a flat surface area ratio of 20% or less. More preferably, the area ratio of the curved surface is 100% as shown in FIGS.

Each light exit surface 18B of the plurality of light-transmitting convex layers 18 is formed by one or more curved surfaces.

For example, the light emitting surface 18B of the translucent convex layer 18 enlarged in FIG. 3 is formed by a single curved surface. The light-transmitting convex layer 18 in FIG. 3 has a plano-convex lens shape in which the bottom surface 18A, which is one surface thereof, is flat, and the light emitting surface 18B, which is the other surface, is a curved convex surface.

The light-transmitting convex layers 18 having the light emitting surface 18B made of a single curved surface may be provided independently, but as shown in FIG. may When the distance between the light-scattering layers 20 is narrow and the light-transmitting convex layers 18 are formed larger than the light-scattering layers 20, the plurality of light-transmitting convex layers 18 may be connected in this way.

A light emitting surface 18B of the light-transmitting convex layer 18 shown enlarged in FIG. 5 is formed of a plurality of curved surfaces. The light-transmitting convex layer 18 in FIG. 5 has a shape in which a smaller plano-convex lens-like convex portion is provided on a plano-convex lens-like convex portion. Thus, the translucent convex layer 18 may have a shape in which a plurality of convex dots are superimposed.

In one embodiment, the light-transmitting convex layer 18 preferably has a curved surface shape and a convex shape that is formed high from the peripheral edge toward the center, and has a circular bottom surface 18A when viewed from above. . However, the shape is not limited to this, and may be rectangular or triangular in plan view, and various shapes can be adopted. For example, the shape in plan view may have a complicated shape in which dots formed by inkjet printing are superimposed.

The size of the translucent convex layer 18 is not particularly limited, and for example, the equivalent circle diameter of the bottom surface 18A may be 20 to 150 μm, or 30 to 100 μm. The equivalent circle diameter is the diameter of a perfect circle corresponding to the area of the bottom surface. Therefore, the area of the bottom surface 18A of the translucent convex layer 18 may be, for example, 300-18000 μm ² or 700-8000 μm ² .

The height H (see FIG. 3) of the translucent convex layer 18 is not particularly limited, and may be, for example, 1 to 30 μm or 3 to 15 μm. Here, the height H of the translucent convex layer 18 is the distance from the bottom surface 18A of the translucent convex layer 18 to the top.

The ratio of the height to the equivalent circle diameter of the translucent convex layer 18 (height/equivalent circle diameter) is not particularly limited, and may be 1/20 to 1/3 or 1/10 to 1/4.

^The arrangement density of the light-transmitting convex layers 18 is not particularly limited. It may be 1,000, 1,000 to 12,000, or 4,000 to 10,000.

Although the method for forming the light-transmitting convex layer 18 is not particularly limited, it is preferable to form the light-transmitting convex layer 18 by printing such as inkjet printing. More preferably, the plurality of light-transmitting convex layers 18 are formed by printing (preferably inkjet printing) using a photocurable resin such as an ultraviolet curable resin.

When the light-transmitting convex layer 18 is formed by inkjet printing, by adjusting the viscosity of the ink, the light-transmitting convex layer 18 having the light emitting surface 18B having the curved surface as described above can be formed. For example, the higher the viscosity of the ink, the easier it is to maintain a large contact angle of the droplets ejected onto the substrate surface and form the light-transmitting convex layer 18 in the shape of a convex lens. The viscosity of the ink in that case is not particularly limited, and may be, for example, 13 to 20 mPa·s or 15 to 18 mPa·s. Here, the viscosity is a measured value at 25° C. measured by a cone-plate type viscometer RE105H (manufactured by Toki Sangyo Co., Ltd.).

The light scattering layer 20 is a resin layer made of resin containing light scattering particles. A plurality of light scattering layers 20 are provided on the other surface (hereinafter referred to as the second surface) facing the one surface (first surface) of the translucent base material 16 . That is, a plurality of light scattering layers 20 are provided as layers that partially cover the second surface. The light scattering layers 20 are scattered on the second surface in the same manner as the light-transmitting convex layer 18 on the first surface side.

The light scattering layer 20 is provided in partial contact with the second surface. As a result, the light confined within the translucent base material 16 by total reflection and propagating is scattered by the light scattering particles. That is, the light is diffusely reflected and emitted at various angles, and the light travels at an angle (less than the critical angle) that is nearly perpendicular to the first surface facing the second surface. Since such light is not totally reflected, it is emitted from the first surface and thus can be extracted from the light guide plate 12 .

In this example, the light scattering layer 20 is provided in contact with the back surface 16B of the translucent substrate 16, that is, directly laminated on the back surface 16B. Therefore, the light traveling through the translucent base material 16 is scattered by the light scattering particles of the light scattering layer 20 on the back surface 16B side. As a result, light traveling at an angle less than the critical angle with respect to the surface 16A is generated, and at least part of it enters the translucent convex layer 18 provided on the surface 16A side.

The shape of each light scattering layer 20 is not particularly limited. It may have a complex shape that is superimposed. The surface of the light scattering layer 20 may be formed with a curved surface, similar to the light-transmitting convex layer 18 . However, it does not have to be formed by a curved surface, and may have a flat cross-sectional shape with a constant thickness (height), for example. Here, the bottom surface of the light scattering layer 20 is the surface in contact with the translucent base material 16 (the interface between the light scattering layer 20 and the translucent base material 16).

The size of the light scattering layer 20 is not particularly limited. For example, the equivalent circle diameter of the bottom surface may be 20 to 150 μm, or 30 to 100 μm. The thickness (height) of the light scattering layer 20 is not particularly limited, and may be, for example, 0.5 to 15 μm or 1 to 10 μm. The equivalent circle diameter is the diameter of a perfect circle corresponding to the area of the bottom surface.

The arrangement density of the light scattering layers 20 is not particularly limited. For example, in a design area expressing a design composed of crystal tone or glass tone light emission, the number of light scattering layers 20 per 1 cm ² is 800 to 15,000. , 1,000 to 12,000, or 4,000 to 10,000.

As the light scattering particles contained in the light scattering layer 20, various fine particles having the effect of scattering light can be used. Specific examples of the light-scattering particles include titanium oxide, calcium carbonate, glass beads, and aluminum powder, and any one of these may be used alone or in combination of two or more. Among these, titanium oxide has a high refractive index and is therefore excellent in the effect of improving luminance. In addition, if it is scaly titanium oxide, it diffusely reflects light on the reflecting surface, so that it is possible to locally enhance the luminescence effect of high brightness and glitter.

Although the refractive index of the light scattering particles is not particularly limited, it is preferably higher than the light refractive index of the matrix resin forming the light scattering layer 20. For example, it may be 1.5 to 2.8, or 2.0 to 2.0. 7 is fine.

The particle size of the light scattering particles is not particularly limited, and for example, the 50% volume particle size (D50) may be 100 to 4000 nm or 200 to 800 nm.

The resin (matrix resin) forming the light scattering layer 20 is not particularly limited, and examples include acrylic resins such as polymethyl methacrylate (PMMA) and urethane acrylate resins; resins), acrylonitrile-styrene-butadiene copolymer resins (ABS resins); polyolefin resins such as polyethylene and polypropylene; or blends of two or more of these. As the matrix resin, it is preferable to use a translucent resin, which may be colorless and transparent, or may be colored and transparent.

The method of forming the light scattering layer 20 is not particularly limited, and the light scattering layer 20 may be formed by printing such as inkjet printing, for example. Preferably, the plurality of light scattering layers 20 are formed by printing (preferably inkjet printing) using a photocurable resin such as an ultraviolet curable resin. When the light scattering layer 20 is formed by inkjet printing, the viscosity of the ink is not particularly limited, and may be, for example, 7 to 13 mPa·s or 10 to 13 mPa·s. Here, the viscosity is a measured value at 25° C. measured by a cone-plate type viscometer RE105H (manufactured by Toki Sangyo Co., Ltd.).

The plurality of light scattering layers 20 are provided so as to overlap with the plurality of light-transmitting convex layers 18 with the light-transmitting substrate 16 interposed therebetween. In this example, the light scattering layer 20 overlaps the light-transmitting convex layers 18 corresponding to each of the plurality of light-transmitting convex layers 18 provided on the surface 16A of the light-transmitting substrate 16 (that is, in one-to-one correspondence). is provided on the rear surface 16B of the translucent base material 16 . As a result, the light scattered by the light scattering layer 20 is transmitted through the light-transmitting substrate 16 in the thickness direction and enters the light-transmitting convex layer 18 from the bottom surface 18A of the light-transmitting convex layer 18. there is

As shown in an enlarged view in FIG. 3, the light-transmitting convex layer 18 may be provided so as to entirely overlap the corresponding light-scattering layer 20 with the light-transmitting substrate 16 interposed therebetween. That is, the amount of overlap between the light-transmitting convex layer 18 and the light scattering layer 20 corresponding to the light-transmitting convex layer 18 is 100% of the area of the light scattering layer 20 when viewed from the direction perpendicular to the surface 16A of the light-transmitting substrate 16. It's okay. However, it is not necessary to overlap the whole like this, and the light-transmitting convex layer 18 may at least partially overlap the corresponding light-scattering layer 20 .

FIG. 7 is a schematic cross-sectional view of an embodiment in which the light-transmitting convex layers 18 overlap the corresponding light-scattering layers 20 so that their positions are shifted from each other. FIG. 8 is a schematic plan view thereof. By displacing them in this manner, the amount of overlap varies greatly depending on the viewing angle from the front side, and the sparkling effect can be enhanced. A mixture of a light-transmitting convex layer 18 provided so as to overlap the light scattering layer 20 in its entirety and a light-transmitting convex layer 18 provided so as to partially overlap the light scattering layer 20 It is possible to further enhance the sparkling effect.

The amount of overlap between each light-transmitting convex layer 18 of the plurality of light-transmitting convex layers 18 and the light scattering layer 20 corresponding to the light-transmitting convex layer 18 is set as follows. That is, the overlapping amount is preferably 30% or more, more preferably 50% or more, and still more preferably 70% of the area of the light scattering layer 20 when viewed from the direction perpendicular to the surface 16A of the translucent substrate 16. % or more. As a result, the light scattered by the light scattering layer 20 can effectively enter the translucent convex layer 18 . Here, the amount of overlap between the light-transmitting convex layer 18 and the light scattering layer 20 is the overlapping portion between the solid-line circle indicated by reference numeral 18 and the dotted-line circle indicated by reference numeral 20 in the example shown in FIG. Therefore, it is preferable that this overlapped portion is 30% or more, 50% or more, or 70% or more, assuming that the area of the dotted circle indicated by reference numeral 20 is 100%.

The size ratio of the light-transmitting convex layer 18 to the light-scattering layer 20 is not particularly limited, but the bottom area of the light-transmitting convex layer 18 is preferably 40 to 200% of the bottom area of the light scattering layer 20. , more preferably 70 to 150%. The light-transmitting convex layer 18 may be larger than the light scattering layer 20, so that the light-transmitting convex layer 18 protrudes from the light scattering layer 20 in plan view. In this case, the light scattered by the light scattering layer 20 can enter the translucent convex layer 18 in a wider range. Conversely, the light-scattering layer 20 may be larger than the light-transmitting convex layer 18, so that the light-scattering layer 20 protrudes from the light-transmitting convex layer 18 in plan view. In this case, the light emitted through the light-transmitting convex layer 18 and the light emitted directly from the light-transmitting substrate 16 without passing through the light-transmitting convex layer 18 are mixed. can make a change.

In this embodiment, the plurality of light-transmitting convex layers 18 are formed so that a plurality of types with different sizes (that is, equivalent circle diameters) and/or heights are mixed. That is, as an example is shown in FIG. 2, a plurality of types of light-transmitting projections having different sizes and heights are provided on the first surface (the surface 16A in this example) of the light-transmitting base material 16. Layers 18 are provided and intermingled. For this reason, light-transmitting convex layers having the same size and height are arranged in a plurality of rows over the entire surface of the light-transmitting substrate, and light-transmitting convex layers whose size gradually increases with increasing distance from the light source are used in the light-transmitting substrate. A mode of arranging them in a plurality of rows over the entire surface cannot be said to be "mixed" and is not included in the present embodiment. In other words, a mixture of multiple types means that multiple types of light-transmitting convex layers 18 having different sizes and/or heights are intermingled and arranged regardless of the distance from the light source. However, the light-transmitting convex layers 18 do not necessarily have to be arranged randomly. subsumed.

As a mode of providing a plurality of types of light-transmitting convex layers 18, for example, light-transmitting convex layers 18 of multiple gradations are set according to the size and / or height, and these multi-gradation light-transmitting convex layers 18 are set. A mode in which they are provided in a mixed manner is exemplified. As an example, when the light-transmitting convex layer 18 is formed by inkjet printing, a plurality of gradations may be set according to the number of droplets (ink particles) ejected from the nozzles (the number of drops). A plurality of droplets ejected from the nozzles become one droplet in the air and land on the translucent substrate 16 , or combine to form one droplet on the translucent substrate 16 . Therefore, a light-transmitting convex layer 18 having a size and/or height corresponding to the number of ejected droplets is formed. At that time, the degree of spread of the droplets may vary depending on the viscosity of the ink and the surface condition of the light-transmitting substrate 16. and/or a multi-gradation translucent convex layer 18 having a height is formed. Therefore, the light-transmitting convex layers 18 having a plurality of gradations may be mixed and formed. The number of gradations is not particularly limited, and may be, for example, 3-20 or 5-15.

The light scattering layer 20 is provided so as to correspond to the light-transmitting convex layer 18 and overlap each other as described above. Therefore, as with the light-transmitting convex layer 18, a plurality of types of light-scattering layers 20 having different sizes and/or heights may be provided in a mixed manner. For this purpose, for example, the light scattering layer 20 having a plurality of gradations is set according to the size, and the light scattering layers 20 having a plurality of gradations are provided in a mixed manner. As an example, when the light scattering layer 20 is formed by inkjet printing, multiple gradations may be set according to the number of droplets (ink particles) ejected from the nozzles (the number of drops). The number of gradations is not particularly limited, and may be, for example, 3-20 or 5-15.

In one embodiment, the light-transmitting convex layers 18 and the light-scattering layers 20 are set to the same number of gradations, and the light-scattering It is preferable to arrange the light-transmitting convex layer 18 and the light-scattering layer 20 so that the layer 20 has the same gradation.

As shown in FIGS. 1 and 2, the light emitting module 10 according to the first embodiment includes a light guide plate 12 and a light source . The light source 14 can enter light into a side surface (light incident end surface) 16</b>C of the translucent base material 16 . As the light source 14, for example, a light emitting diode (LED) can be used.

The light source 14 is provided on at least a part of the periphery of the light guide plate 12 . The light source 14 is arranged so as to irradiate the side surface 16C of the translucent base material 16 with light at the edge. For example, one light source 14 may be provided on one side of the translucent base material 16 having a polygonal shape, or a plurality of light sources 14 may be provided side by side along the side. The light source 14 is attached to a portion of the edge of the light guide plate 12 with a holder (not shown).

In one embodiment, the light emitting module 10 includes a moving device 22 that moves the light source 14 along the side surface 16C of the translucent substrate 16. The moving device 22 is not particularly limited as long as it can move the light source 14, and can be configured using a gear, a belt drive, or the like.

The moving device 22 may be configured to move the light source 14 in the thickness direction of the translucent base material 16, as indicated by the arrow X in FIG. The moving device 22 may also be configured to move the light source 14 laterally along the one side of the translucent substrate 16, as indicated by arrow Y in FIG. Alternatively, the moving device 22 moves the light source 14 obliquely with respect to the side surface 16C of the translucent base material 16, that is, moves it in the lateral direction Y while moving it in the thickness direction X. It may be configured as

Although not shown, the light emitting module 10 may be configured to include electrical components such as wiring to the light source 14, a power supply, and a control device, as well as other components such as a frame.

In the first embodiment as described above, when light is incident from the side surface 16C of the light-transmitting base material 16 forming the main body of the light guide plate 12, the light is confined in the light-transmitting base material 16 by total reflection and It spreads out within the material 16 . At that time, as shown in FIG. 6, the light is scattered by the light scattering particles in the light scattering layer 20, and light is incident on the surface 16A of the translucent base material 16 at an angle close to perpendicular (less than the critical angle). . The light enters the light-transmitting convex layer 18 from the bottom surface 18A of the light-transmitting convex layer 18 provided facing the light scattering layer 20 . The light incident on the translucent convex layer 18 is emitted to the outside through the light emitting surface 18B. At that time, since the light exit surface 18B is formed by a curved surface, the light is diffused by the lens effect. Therefore, angle dependence is obtained in which the appearance of light emission differs depending on the viewing angle. In addition, as the light-transmitting convex layer 18 for emitting light, a plurality of types with different sizes and/or heights are mixed, so that it is possible to express locally high brightness and sparkle. Therefore, it is possible to achieve crystal-like sparkle similar to that of real crystals and movement of light due to angle dependence, thereby imparting a sense of quality.

In the first embodiment, the direction of light emission can be changed by moving the light source 14 with the moving device 22 . Therefore, it is possible to make the light move without changing the viewing angle, and in combination with changing the viewing angle, the movement of the light can be emphasized. Also, by moving the light source 14, it is possible to realize an illumination effect as if light were flowing.

In the first embodiment, light is scattered by the light scattering layer 20 and light is reflected by the light-transmitting convex layer 18, so that part of the light is emitted from the back side of the light guide plate 12 as well. Sometimes. That is, while the front side of the light guide plate 12 provided with the light-transmitting convex layer 18 is used as the main light output surface, the back side of the light guide plate 12 provided with the light scattering layer 20 is set to have a higher light quantity than the main light output surface. Fewer secondary light exit surfaces can be provided. Therefore, the light guide plate 12 can also be used as a partition (partition) from which light can be emitted from both the front and back surfaces.

(Second embodiment)
FIG. 9 is an enlarged cross-sectional view of a main part showing the light guide plate 30 of the light emitting module according to the second embodiment. The light guide plate 30 of the second embodiment differs from the light guide plate 12 of the first embodiment in that a light-transmitting resin layer 32 is provided as a protective layer on the first surface (surface 16A in this example) of the light-transmitting base material 16. different.

The translucent resin layer 32 is a translucent resin layer provided to protect the translucent base material 16, which is a high refractive index layer. In this example, the translucent resin layer 32 is made of resin having a lower refractive index than the translucent base material 16 . The refractive index (absolute refractive index) of the translucent resin layer 32 is not particularly limited as long as it is lower than that of the translucent base material 16, and may be, for example, 1.35 to 1.65 or 1.40 to 1.55.

The translucent resin layer 32 may be colorless and transparent, or may be colored and transparent. Examples of the resin that forms the translucent resin layer 32 include acrylic resins such as polymethyl methacrylate (PMMA) and urethane acrylate resin; polystyrene resin, acrylonitrile-styrene copolymer resin (AS resin), acrylonitrile-styrene-butadiene. Styrenic resins such as copolymer resins (ABS resins); polyolefin resins such as polyethylene and polypropylene; or blends of two or more of these.

The thickness of the translucent resin layer 32 is not particularly limited, and may be, for example, 10 to 100 μm or 20 to 50 μm.

In the second embodiment, the translucent resin layer 32 is provided over the entire surface 16A of the translucent base material 16 so as to be in contact with the surface 16A. A plurality of light-transmitting convex layers 18 are provided on the light-transmitting resin layer 32 so as to be in contact with the surface of the light-transmitting resin layer 32 . That is, in the second embodiment, the plurality of light-transmitting convex layers 18 are provided on the first surface (surface 16A) of the light-transmitting base material 16 via the light-transmitting resin layer 32 . Therefore, in this case, the surface of the light-transmitting resin layer 32 is the reference surface on which the light-transmitting convex layer 18 is provided.

The method of forming the translucent resin layer 32 is not particularly limited, and examples thereof include known coating methods such as spraying, dipping, spin coating and bar coating, and printing methods such as inkjet printing and screen printing.

In the second embodiment, the light-transmitting convex layer 18 is provided not directly on the light-transmitting base material 16 but via the light-transmitting resin layer 32 . The light-transmitting resin layer 32 has a smaller refractive index than the light-transmitting base material 16, but the light emitted to the outside through the light-transmitting convex layer 18 is less than the critical angle scattered by the light scattering layer 20 on the back side. is directed toward surface 16A at an angle of . Therefore, the decrease in luminance due to the provision of the translucent resin layer 32 is small. Moreover, if the surface 16A of the light-transmitting base material 16 is scratched without the light-transmitting resin layer 32, light may leak from that portion. However, by providing the translucent resin layer 32 with a small refractive index, even if there is a scratch, it is difficult for light to leak from that portion.

The rest of the configuration and operational effects of the second embodiment are the same as those of the first embodiment, and descriptions thereof will be omitted.

(Third embodiment)
FIG. 10 is an enlarged cross-sectional view of a main part showing the light guide plate 40 of the light emitting module according to the third embodiment. A light guide plate 40 of the third embodiment differs from that of the second embodiment in the configuration of a light-transmitting resin layer 42 as a protective layer provided on the surface 16A of the light-transmitting base material 16 .

In the third embodiment, as in the first embodiment, the light-transmitting convex layer 18 is directly provided on the surface 16A of the light-transmitting base material 16, and then the part other than the light-transmitting convex layer 18 on the surface 16A is covered with a light-transmitting resin. A layer 42 is provided. By directly providing the light-transmitting convex layer 18 on the surface 16A of the light-transmitting base material 16 in this way, it is possible to eliminate the possibility of lowering the brightness due to interposition of the light-transmitting resin layer 32 as in the second embodiment. . However, the second embodiment is preferable in terms of ease of manufacture.

The rest of the configuration and operational effects of the third embodiment are the same as those of the second embodiment, and description thereof will be omitted.

(Fourth embodiment)
FIG. 11 is a schematic cross-sectional view of a light emitting module 50 according to the fourth embodiment. The light emitting module 50 according to the fourth embodiment differs from the light emitting module 10 according to the first embodiment in that the light guide plate 52 includes a coating resin layer 54 that covers the light scattering layer 20 .

A light guide plate 52 of the fourth embodiment has a light-transmitting base material 16, a plurality of light-transmitting convex layers 18, and a plurality of light scattering layers 20 similar to the light guide plate 12 of the first embodiment. Further, a plurality of coating resin layers 54 are provided to cover the plurality of light scattering layers 20 respectively.

The coating resin layer 54 is made of a translucent resin, and may be colorless and transparent, or may be colored and transparent. The coating resin layer 54 is a resin layer containing no light scattering particles. Examples of the resin forming the coating resin layer 54 include resins similar to those of the light-transmitting convex layer 18, that is, the acrylic resins, styrene resins, polyolefin resins, or a blend of two or more of these.

The refractive index (absolute refractive index) of the coating resin layer 54 is not particularly limited, and may be higher than that of the translucent base material 16, lower than that of the translucent base material 16, or the same value. The refractive index of the coating resin layer 54 may be, for example, 1.35 to 1.65 or 1.40 to 1.55.

A plurality of coating resin layers 54 are provided so as to cover only the respective light scattering layers 20 of the plurality of light scattering layers 20 provided on the second surface (back surface 16B) of the translucent base material 16 . However, the coating resin layer 54 is formed so as to cover the entire surface of each light scattering layer 20 so as to surround each light scattering layer 20 and have a portion in contact with the translucent base material 16 . Since the coating resin layer 54 is formed to be larger than the light scattering layer 20 in this way, when the distance between the light scattering layers 20 is narrow as shown in FIG. may

A surface 54A of the coating resin layer 54 is formed by a curved surface as shown in FIG. A surface 54A of the coating resin layer 54 is a surface forming an interface between the coating resin layer 54 and air. The surface 54A may be formed only of curved surfaces, but may partially include flat surfaces. Preferably, the surface 54A is mainly formed of a curved surface, and more preferably, the curved surface accounts for 80% or more of the surface 54A.

The surface 54A of the coating resin layer 54 is formed of one or more curved surfaces, similar to the translucent convex layer 18, and may be formed into a convex lens shape composed of a single curved convex surface as shown in FIG. The coating resin layers 54 each having a surface 54A composed of such a single curved convex surface may be provided independently, or may be formed by connecting a plurality of coating resin layers 54 as described above. In addition, the surface 54A having a plurality of curved surfaces may be formed by arranging plano-convex lens-shaped convex portions in two stages in the same manner as the translucent convex layer 18 shown in FIG.

It is preferable that the coating resin layer 54 is formed in a convex shape that has a curved surface shape and is formed high from the peripheral edge toward the center. Although it is preferable that the coating resin layer 54 is circular in plan view, it is not limited to this, and may be rectangular or triangular in plan view, and various shapes can be adopted.

The coating resin layer 54 can be formed, for example, by inkjet printing. By adjusting the viscosity of the ink, it is possible to form the coating resin layer 54 having the curved surface 54A as described above.

Since the coating resin layer 54 is provided so as to cover each light scattering layer 20, a plurality of types of coating resin layers 54 having different sizes and/or heights are provided in a mixed manner in the same manner as the light scattering layer 20. may For this purpose, for example, the coating resin layers 54 of multiple gradations are set according to the size, and the coating resin layers 54 of these multiple gradations are provided in a mixed manner. As an example, when the coating resin layer 54 is formed by inkjet printing, multiple gradations may be set according to the number of droplets (ink particles) ejected from the nozzles (the number of drops).

According to the fourth embodiment, the coating resin layer 54 that covers the light scattering layer 20 is provided, and its surface 54A is formed with a curved surface. Thereby, the light scattered by the light scattering layer 20 can be diffused by the lens effect of the coating resin layer 54 . Therefore, it is possible to further increase the difference in brightness on the front surface side of the light guide plate 52, thereby expanding the range of design expression. In addition, it is possible to emit glittering light from the back side of the light guide plate 52 as well. Therefore, for example, when the light guide plate 52 is used as a partition, it is possible to obtain a light design expression with a sparkling effect on both the front and back surfaces.

The rest of the configuration and operational effects of the fourth embodiment are the same as those of the first embodiment, and description thereof will be omitted.

(Other embodiments)
Additional layers may be formed in the

light guide plates

12, 30, 40, 52 in the above embodiments. For example, a resin layer having an extremely low refractive index may be provided on the rear surface side of the

light guide plates

12, 30, 40, 52. FIG. Also, a specular layer may be provided on the rear surface side by applying a paint that provides a metallic specular surface.

In the above embodiment, for each light scattering layer 20 provided on the back surface 16B side of the translucent substrate 16, the light-transmitting convex layer 18 having the light exit surface 18B formed by a curved surface is provided on the front surface 16A side. ing. However, it is not necessary to form the curved light-transmitting convex layers 18 corresponding to all the light scattering layers 20 . That is, the light-transmitting convex layer 18 may be provided so as to correspond to at least a part of the light-scattering layer 20 . For example, for some of the light scattering layers 20, a translucent resin layer having a flat cross-sectional light exit surface that is not formed by a curved surface may be provided on the surface 16A side. Alternatively, for some of the light scattering layers 20, the corresponding translucent resin layer may not be provided on the surface 16A side.

Each configuration in the above embodiments can be appropriately combined. good too. In addition, it is preferable that the light emitting surface 18B of the light-transmitting convex layer 18 on the surface side is not covered with another resin layer.

[Example 1]
As the substrate, "Technoloy (registered trademark) C003" manufactured by Sumika Acrylic Co., Ltd. was used (rectangular sheet with a short side length of 180 mm and a long side length of 400 mm). The substrate consists of a surface 16A of a polycarbonate layer (thickness: 1.97 mm, refractive index: 1.587) corresponding to the translucent substrate 16, and a PMMA layer (thickness: 0.03 mm, refractive index 1.49).

The formulations of the light-scattering layer ink and the light-transmitting convex layer ink are shown in Tables 1 and 2 below.

A light scattering layer ink was applied to the back surface of the substrate (back surface 16B of the translucent substrate 16) using a serial inkjet printer. After that, an ultraviolet lamp was used to immediately irradiate the ink with ultraviolet rays, and the ink was cured to form a plurality of light scattering layers 20 circular in plan view. The viscosity of the ink (25° C.) was 12.2 mPa·s. The printing conditions were head heating temperature: 35° C., nozzle diameter: 20 μm, applied voltage: 21 V, pulse width: 15 μs, resolution: 300 dpi. The ultraviolet irradiation conditions were as follows: lamp type: metal halide lamp, lamp output: 100 W, irradiation time: 0.5 s, irradiation times: 4 times, irradiation distance: 5 mm, and integrated light quantity: 200 mJ/cm ² .

At that time, the following 1 to 7 gradations were set for the multiple types of light scattering layers 20 according to the number of droplets ejected from the nozzle.
・1 gradation: 1 drop, diameter 20 to 25 μm
・2 gradations: 2 drops, diameter 25-30 μm
・3 gradations: 3 drops, diameter 30-35 μm
・4 gradations: 4 drops, diameter 40-50 μm
・5 gradations: 5 drops, diameter 55-65 μm
・6 gradations: 6 drops, diameter 70-80 μm
・7 gradations: 7 drops, diameter 80-100 μm

Next, the light-transmitting convex layer ink was applied to the surface of the substrate (the surface of the light-transmitting resin layer 32) using a serial inkjet printer. After that, the ink was immediately irradiated with ultraviolet rays using an ultraviolet lamp to cure the ink, thereby forming a plurality of light-transmitting convex layers 18 in the shape of plano-convex lenses circular in plan view. The light-transmitting convex layer 18 was provided at the same position as the light-scattering layer 20 so as to overlap with the light-scattering layer 20 provided on the back side with the base material interposed therebetween. The viscosity of the ink (25° C.) was 15.0 mPa·s. The printing conditions were head heating temperature: 35° C., nozzle diameter: 20 μm, applied voltage: 22 V, pulse width: 15 μs, resolution: 300 dpi. The ultraviolet irradiation conditions were as follows: lamp type: metal halide lamp, lamp output: 160 W, irradiation time: 0.5 s, number of times of irradiation: 8 times, irradiation distance: 40 mm, integrated light quantity: 640 mJ/cm ² . The refractive index of the translucent convex layer 18 was 1.458.

At that time, the following 1 to 7 gradations were set for the plurality of types of translucent convex layers 18 according to the number of droplets ejected from the nozzles.
・1 gradation: 1 drop, diameter 20-25 μm, height 1-2 μm
・2 gradations: 2 drops, diameter 25-30 μm, height 3-4 μm
・3 gradations: 3 drops, diameter 30-35 μm, height 5-6 μm
・4 gradations: 4 drops, diameter 40-45 μm, height 7-8 μm
・5 gradations: 5 drops, diameter 45-50 μm, height 9-10 μm
・6 gradations: 6 drops, diameter 55-65 μm, height 11-13 μm
・7 gradations: 7 drops, diameter 70-90 μm, height 14-17 μm

In this way, the light-transmitting convex layer 18 and the light-scattering layer 20 are set to have the same number of gradations. Further, each light-transmitting convex layer 18 of the plurality of light-transmitting convex layers 18 and the light scattering layer 20 corresponding to the light-transmitting convex layer 18 are arranged so as to have the same gradation. That is, for example, the light-scattering layer 20 of "3 gradations" was provided at the position where the light-transmitting convex layer 18 of "3 gradations" overlaps with the light-transmitting substrate 16 interposed therebetween.

FIG. 12A shows a part of an arrangement example of the plurality of types of light-transmitting convex layers 18 described above. In FIG. 12A, one side of the grid is about 85 μm, and the arrangement pattern of the light-transmitting convex layer 18 in a square area with one side of about 0.85 mm is shown as a plan view of the light-transmitting convex layer 18 . In FIG. 12B, the gradation is indicated by numbers. The arrangement examples of the plurality of types of light scattering layers 20 are the same as the arrangement examples of the light-transmitting convex layers 18, and are in one-to-one correspondence. In addition, the blank square means the part of 0 gradation where the light-transmitting convex layer 18 is not provided.

The light guide plate obtained as described above corresponds to the light guide plate 30 of the second embodiment shown in FIG. An LED was attached to a side surface on the short side of the light guide plate, and the LED was turned on to allow light to enter from the side surface. Then, light was emitted from the light-transmitting convex layer 18 on the surface side, and there were locally high-brightness spots and sparkles. In addition, there was an angle dependence in which the appearance of light emission differs depending on the viewing angle. Therefore, it was possible to realize crystal-like sparkle and movement of light due to angle dependence, and a high-class design was obtained.

[Example 2]
In the light guide plate obtained in Example 1, a plurality of coating resin layers 54 were provided to cover the plurality of light scattering layers 20 respectively. Specifically, the ink for the light-transmitting convex layer of Example 1 was applied to the surface of the light-scattering layer 20 using a serial inkjet printer. After that, the coating resin layer 54 was formed by immediately irradiating ultraviolet rays using an ultraviolet lamp to cure the ink. The printing conditions, ultraviolet irradiation conditions, and gradation settings for the coating resin layer 54 were the same as those for the light-transmitting convex layer 18 of the first embodiment. The coating resin layer 54 had a circular convex lens-like surface in plan view, which was the same as the translucent convex layer 18 on the surface side.

The resulting light guide plate has a configuration in which the fourth embodiment and the second embodiment are combined. An LED was attached to a side surface on the short side of the light guide plate, and the LED was turned on to allow light to enter from the side surface. Then, light was emitted from the light-transmitting convex layer 18 on the surface side, and there were locally high-brightness spots and sparkles. In addition, there was an angle dependence in which the appearance of light emission differs depending on the viewing angle. Compared with the light guide plate of Example 1, the difference in luminance depending on the part was further emphasized, and the design effect on the surface side was excellent. In addition, emission of light with a sparkling effect was observed on the back side as well. Therefore, a design expression of light with a sparkling effect was obtained not only on the front side of the light guide plate but also on the back side.

Some embodiments are listed below, but are not limited thereto.
[1] A light-transmitting substrate having a light-transmitting property, the light-transmitting substrate having a first surface that is one of the front surface and the back surface of the light-transmitting substrate and a second surface that is the other surface; a plurality of light-transmitting convex layers made of a translucent resin, provided in a convex shape on the first surface and provided with a light exit surface formed by a curved surface; and made of a resin containing light scattering particles, the a plurality of light scattering layers provided on the second surface so as to overlap with the plurality of light-transmitting convex layers with the light-transmitting substrate interposed therebetween; A light guide plate in which a plurality of types of the light-transmitting convex layers with different values are mixed.
[2] The light guide plate according to [1], wherein the curved surface accounts for 80% or more of the light exit surface of each of the plurality of light-transmitting convex layers.
[3] The light guide plate according to [1] or [2], wherein the light scattering layers of different sizes and/or heights are mixed.
[4] [1] to [3], wherein the plurality of light-transmitting convex layers are scattered on the first surface, and the plurality of light-scattering layers are scattered on the second surface; The light guide plate according to any one of .
[5] The light guide plate according to any one of [1] to [4], wherein each light exit surface of the plurality of light-transmitting convex layers is formed by one or more curved surfaces.
[6] The equivalent circle diameter of the bottom surfaces of the plurality of light-transmitting convex layers is 20 to 150 μm, more preferably 30 to 100 μm, and the equivalent circle diameter of the bottom surfaces of the plurality of light scattering layers is 20 to 150 μm, more preferably. The light guide plate according to any one of [1] to [5], which is 30 to 100 μm.
[7] The amount of overlap between each light-transmitting convex layer of the plurality of light-transmitting convex layers and the light scattering layer corresponding to the light-transmitting convex layer is the above when viewed from the direction perpendicular to the surface of the light-transmitting base material. The light guide plate according to any one of [1] to [6], wherein the area of the light scattering layer is 30% or more, more preferably 50% or more, and still more preferably 70% or more.
[8] The light guide plate according to any one of [1] to [7], wherein the plurality of light-transmitting convex layers include a light-transmitting convex layer provided so as to entirely overlap the corresponding light scattering layer. .
[9] Any one of [1] to [8], wherein the plurality of light-transmitting convex layers include light-transmitting convex layers that are displaced so as to partially overlap the corresponding light scattering layers. 1. The light guide plate according to 1.
[10] The bottom surface area of each light-transmitting convex layer of the plurality of light-transmitting convex layers is 40 to 200%, more preferably 70 to 150% of the bottom surface area of each light-scattering layer of the plurality of light-scattering layers. The light guide plate according to any one of [1] to [9].
[11] Any one of [1] to [10], wherein the plurality of light-transmitting convex layers include light-transmitting convex layers that are larger than the corresponding light-scattering layers and protrude from the light-scattering layers in plan view. light guide plate.
[12] The plurality of light-scattering layers according to any one of [1] to [11], wherein the plurality of light-scattering layers include light-scattering layers that are larger than the corresponding light-transmitting convex layers and protrude from the light-transmitting convex layers in plan view. light guide plate.
[13] Any one of [1] to [12], wherein the plurality of types of light-transmitting convex layers are light-transmitting convex layers with multiple gradations set according to size and/or height. Light guide plate as described.
[14] The light scattering layer according to any one of [3] to [13], wherein the plurality of types of light scattering layers are light scattering layers with multiple gradations set according to size and/or height. Light guide plate.
[15] Further comprising a light-transmitting resin layer having light-transmitting properties provided on the first surface of the light-transmitting substrate, wherein the plurality of light-transmitting convex layers extend to the light-transmitting substrate via the light-transmitting resin layer. The light guide plate according to any one of [1] to [14], provided on the first surface of the material.
[16] The plurality of light-transmitting convex layers are directly provided on the first surface of the light-transmitting substrate, and a light-transmitting resin layer having a light-transmitting property is provided on the first surface other than the light-transmitting convex layers. provided, the light guide plate according to any one of [1] to [14].
[17] Any one of [1] to [16], further comprising a plurality of translucent coating resin layers respectively coating the plurality of light scattering layers, wherein the surface of each coating resin layer is formed by a curved surface. 1. The light guide plate according to 1.
[18] A light-emitting module comprising the light guide plate according to any one of [1] to [17] and a light source capable of injecting light into the side surface of the translucent base.
[19] The light-emitting module according to [18], further comprising a moving device configured to move the light source along the side surface of the translucent base.
[20] The light emission according to [19], wherein the moving device can move the light source in the thickness direction of the light-transmitting substrate, in a lateral direction along the edge of the light-transmitting substrate, or in an oblique direction. module.

In the drawings, the thickness of each layer including the light-transmitting base material 16, and the dimensional relationships such as the size and height of the light-transmitting convex layer 18 and the light scattering layer 20 are only conceptually shown. Yes, not based on actual dimensions.

For the various numerical ranges described in the specification, the upper and lower limits thereof can be arbitrarily combined, and all combinations thereof are described herein as preferred numerical ranges. Further, the description of the numerical range "X to Y" means X or more and Y or less.

Although several embodiments have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, as well as the scope of the invention described in the claims and equivalents thereof.

The applications of the light guide plate and the light emitting module according to this embodiment are not particularly limited. For example, it can be used for various vehicle interior parts including automotive interior materials such as automotive instrument panels and door inner materials, and housings for various electrical products such as home appliances and communication equipment.

DESCRIPTION OF

SYMBOLS

10, 50...

Light emitting module

12, 30, 40, 52... Light guide plate 14... Light source 16... Translucent base material 18... Translucent convex layer 20...

Light scattering layer

32, 42... Translucent resin layer , 54 ... Coating resin layer

Claims

a light-transmitting substrate having a light-transmitting property, the light-transmitting substrate having a first surface that is either one of the front surface or the back surface of the light-transmitting substrate and a second surface that is the other;
a plurality of light-transmitting convex layers made of a resin having a light-transmitting property, provided in a convex shape on the first surface, and having a light exit surface formed by a curved surface;
a plurality of light scattering layers made of a resin containing light scattering particles and provided on the second surface so as to overlap the plurality of light-transmitting convex layers with the light-transmitting substrate interposed therebetween;
A light guide plate comprising
A light guide plate comprising a mixture of a plurality of types of light-transmitting convex layers having different sizes and/or heights.
The light guide plate according to claim 1, wherein the curved surface accounts for 80% or more of the light exit surface of each of the plurality of light-transmitting convex layers.
The light guide plate according to claim 1 or 2, wherein a plurality of types of said light scattering layers having different sizes and/or heights are mixed.
The amount of overlap between each light-transmitting convex layer of the plurality of light-transmitting convex layers and the light scattering layer corresponding to the light-transmitting convex layer is the light scattering layer when viewed from a direction perpendicular to the surface of the light-transmitting base material. 4. The light guide plate according to any one of claims 1 to 3, which is 30% or more of the area of .
5. The light-transmitting convex layers according to any one of claims 1 to 4, wherein the plurality of light-transmitting convex layers include light-transmitting convex layers provided so as to partially overlap the corresponding light scattering layers. light guide plate.
A light-transmitting resin layer having a light-transmitting property provided on the first surface of the light-transmitting substrate is further provided, and the plurality of light-transmitting convex layers are arranged on the light-transmitting substrate via the light-transmitting resin layer. The light guide plate according to any one of claims 1 to 5, provided on the first surface.
The plurality of light-transmitting convex layers are directly provided on the first surface of the light-transmitting substrate, and a light-transmitting resin layer having a light-transmitting property is provided on a portion of the first surface other than the light-transmitting convex layers. The light guide plate according to any one of claims 1 to 5.
8. The method according to any one of claims 1 to 7, further comprising a plurality of translucent coating resin layers respectively coating the plurality of light scattering layers, wherein the surface of each coating resin layer is formed by a curved surface. light guide plate.
A light-emitting module comprising the light guide plate according to any one of claims 1 to 8 and a light source capable of injecting light into the side surface of the translucent base material.
10. The light emitting module of Claim 9, further comprising a moving device configured to move the light source along the side of the translucent substrate.