Light-emitting module

Abstract

To provide a light emitting module capable of reducing luminance unevenness.SOLUTION: A light emitting module includes: a light guide member having a first surface, a second surface positioned on the opposite side from the first surface, a through-hole penetrating from the first surface to the second surface and a protrusion part, in which the through-hole has a first portion opening to the first surface side and a second portion which opens to the second surface side and whose width in the lateral direction is broader than the first portion, and in which the protrusion part is arranged on the second surface and has a surface continued to the second portion; a light source arranged in the through-hole; and a first translucent member arranged in the through-hole, and coming into contact with a first side surface for defining the first portion and a second side surface for defining the second portion.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] This invention relates to a light-emitting module. [Background technology]

[0002] Light-emitting modules, which combine light-emitting elements such as light-emitting diodes with light-guiding members, are widely used as planar light sources, such as backlights for liquid crystal displays. For example, Patent Document 1 discloses a backlight device comprising a reflective sheet, an LED substrate on which a plurality of light-emitting diodes are provided, and a diffuser plate facing the LED substrate. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2019-61929 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] The present invention aims to provide a light-emitting module that can reduce brightness unevenness. [Means for solving the problem]

[0005] According to one aspect of the present invention, the light-emitting module is a light-guiding member having a first surface, a second surface located opposite to the first surface, a through hole penetrating from the first surface to the second surface, and a protrusion, wherein the through hole has a first portion opening toward the first surface and a second portion opening toward the second surface and having a width in the lateral direction greater than that of the first portion, and the protrusion is positioned on the second surface and has a surface continuous with the second portion, the light-guiding member comprising a light source positioned in the through hole, and a first translucent member positioned in the through hole and in contact with a first side surface defining the first portion and a second side surface defining the second portion. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a light-emitting module that can reduce brightness unevenness. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic plan view of the light-emitting module of the embodiment. [Figure 2] This is a schematic cross-sectional view along line II-II in Figure 1. [Figure 3] This is a schematic cross-sectional view illustrating a first modified example of the light-emitting module of the embodiment. [Figure 4] This is a schematic plan view illustrating a second modified example of the light-emitting module of the embodiment. [Figure 5] This is a schematic cross-sectional view illustrating a third modified example of the light-emitting module of the embodiment. [Modes for carrying out the invention]

[0008] The light-emitting module of the embodiment will be described below with reference to the drawings. The dimensions, materials, shapes, relative arrangements, etc. of the components described in the embodiment are not intended to be the sole limiting factors unless otherwise specified, but are merely illustrative examples. The size and positional relationships of the components shown in each drawing may be exaggerated for clarity of explanation. In addition, in the following description, the same name and reference numeral indicate the same or identical components, and detailed explanations will be omitted as appropriate. In addition, in some cases, end view diagrams showing only the cut surface will be shown as cross-sectional views.

[0009] In the following description, terms indicating specific directions or positions (e.g., "up," "down," and other terms including these) may be used. However, these terms are used merely for clarity to indicate the relative directions or positions in the referenced drawings. If the relative direction or position relationship indicated by terms such as "up" and "down" in the referenced drawings is the same, the arrangement in drawings other than those disclosed, actual products, etc., does not have to be the same as in the referenced drawings. In this specification, the positional relationship expressed as "up (or down)" includes, for example, the case where two members are in contact with each other, and the case where the two members are not in contact but one member is located above (or below) the other member. Furthermore, unless otherwise specified, "a member covers an object" includes the case where the member is in contact with the object and directly covers it, and the case where the member does not contact the object and indirectly covers it.

[0010] In the diagrams shown below, directions may be indicated by the X, Y, and Z axes. The X, Y, and Z axes are orthogonal to each other. The light-emitting surface of the light-emitting module is parallel to the XY plane, and the Z axis is orthogonal to the XY plane. The direction of the arrow on the Z axis is considered upward, and the direction opposite to the direction of the arrow on the Z axis is considered downward. Furthermore, the direction that is tilted from the X direction in the XY plane at an angle of 0° or more and less than 360° is considered the lateral direction. For example, in this specification, the direction along the X axis is referred to as the first direction X, the direction along the Y axis is referred to as the second direction Y, and the direction along the Z axis is referred to as the third direction Z. In this specification, the third direction Z is also referred to as the up-down direction Z. Furthermore, in this specification, unless otherwise specified, the thickness of each member is the value at which the distance from the top surface to the bottom surface of each member is maximum in the third direction (up-down direction) Z.

[0011] The light-emitting module 100 and the planar light source 300 of the embodiment will be described with reference to Figures 1 and 2. The planar light source 300 includes the light-emitting module 100. As shown in Figure 2, the light-emitting module 100 includes at least a light guide member 50, a light source 10, and a first light-transmitting member 21. The elements constituting the light-emitting module 100 and the planar light source 300 will be described in detail below.

[0012] [Light guide member] The light guide member 50 has light transmittance with respect to the light emitted by the light source 10. The transmittance of the light guide member 50 with respect to the emission peak wavelength of the light source 10 is preferably, for example, 60% or more, and more preferably 80% or more.

[0013] As the material of the light guide member 50, for example, thermoplastic resins such as polycarbonate resin, acrylic resin, cyclic polyolefin resin, polyethylene terephthalate resin or polyester resin, or thermosetting resins such as epoxy resin or silicone resin can be used. Further, glass or the like may be used as the material of the light guide member 50. The light guide member 50 may contain a phosphor and / or light scattering particles.

[0014] As shown in FIG. 2, the light guide member 50 has a first surface 51 and a second surface 52 located on the opposite side of the first surface 51 in the vertical direction Z. Further, the light guide member 50 has a through hole 53 penetrating from the first surface 51 to the second surface 52. The light source 10 and the first light transmissive member 21 are disposed in the through hole 53.

[0015] The through hole 53 has a first portion 53a and a second portion 53b. The first portion 53a opens on the first surface 51 side of the light guide member 50. In the vertical direction Z, the second portion 53b is located above the first portion 53a. The second portion 53b opens on the second surface 52 side of the light guide member 50. The width of the second portion 53b in the lateral direction is wider than the width of the first portion 53a in the lateral direction. The second portion 53b has, in plan view, a portion overlapping the first portion 53a and a portion located outside the outer edge of the first portion 53a.

[0016] The light guide member 50 has a first side surface 50a defining the first portion 53a and a second side surface 50b defining the second portion 53b. The first side surface 50a is perpendicular or inclined with respect to the second surface 52, and the second side surface 50b is perpendicular or inclined with respect to the second surface 52. There is a step between the first side surface 50a and the second side surface 50b.

[0017] In the example shown in Figure 2, the light guide member 50 has a surface 50c that is continuous with the first side surface 50a and the second side surface 50b and defines the second portion 53b. The surface 50c is perpendicular or inclined with respect to the first side surface 50a and perpendicular or inclined with respect to the second side surface 50b.

[0018] The light guide member 50 has a protrusion 55 positioned on the second surface 52. The protrusion 55 has a surface that is continuous with the second side surface 50b that defines the second portion 53b of the light guide member 50.

[0019] As shown in Figure 1, in a plan view, the light guide member 50 continuously surrounds the light source 10. In Figure 1, the first side surface 50a of the light guide member 50 that defines the first portion 53a of the through hole 53 is represented, for example, by a circular dashed line. In Figure 1, the convex portion 55 is represented, for example, by a double circle solid line. In Figure 1, the outer edge of the second portion 53b coincides with the inner edge of the solid line representing the convex portion 55. In a plan view, the outer edges of the convex portion 55 and the second portion 53b continuously surround the outer edge of the first portion 53a.

[0020] In a plan view, the convex portion 55, the outer edge of the second portion 53b, and the outer edge of the first portion 53a may be elliptical, or polygonal in shape such as a triangle, quadrilateral, hexagon, or octagon.

[0021] The thickness between the first surface 51 and the second surface 52 of the light guide member 50 is preferably, for example, 150 μm or more and 800 μm or less. The light guide member 50 may be composed of a single layer in the vertical direction Z, or it may be composed of a laminate of multiple layers. When the light guide member 50 is composed of a laminate, a light-transmitting adhesive may be placed between each layer. However, it is not necessary to place an adhesive between each layer. Each layer of the laminate may use different types of main materials, or it may use the same type of main material.

[0022] In the light-emitting module 100 of this embodiment, as shown in Figure 1, the light guide member 50 is divided into a plurality of light-emitting regions 50A by partition grooves 54 extending in a first direction X and a second direction Y. One light-emitting region 50A can be used as a driving unit for local dimming. Figure 1 shows a portion of the light-emitting surface of the light-emitting module 100 where, for example, four light-emitting regions 50A are arranged. Note that the light-emitting module 100 is not limited to a plurality of light-emitting regions 50A, but may also have a configuration with one light-emitting region 50A. Furthermore, having partition grooves 54 in the light guide member 50 makes it easier to improve the contrast between a light-emitting region 50A that is emitting light and a light-emitting region 50A that is not emitting light. For example, a portion of the light from the light source 10 propagating laterally within the light guide member 50 is reflected or refracted by the surface of the light guide member 50 that defines the partition grooves 54. Therefore, it is easier to reduce the incidence of light from the light source 10 propagating laterally within the light guide member 50 onto the light guide member 50 of an adjacent light-emitting region. This makes it easier to improve the contrast between the light-emitting region 50A in the light-emitting state and the light-emitting region 50A in the non-light-emitting state.

[0023] Preferably, the partition groove 54 penetrates from the first surface 51 to the second surface 52 of the light guide member 50. This allows the light guide member 50 to be separated into multiple parts, thereby reducing the warping of the support member 200 caused by the difference in thermal expansion coefficients between the light guide member 50 and the support member 200, which will be described later and supports the light guide member 50. Reducing the warping of the support member 200 reduces the likelihood of cracks occurring in the conductive member 67, which will be described later. The partition groove 54 may also be a recess that opens only on the second surface 52 side of the light guide member 50, or a recess that opens only on the first surface 51 side of the light guide member 50. If the partition groove 54 is a recess, the partition groove 54 has a bottom surface defined by the light guide member 50.

[0024] A component that is reflective to the light emitted by the light source 10 may be placed within the partition groove 54. This improves the contrast between the light-emitting region 50A in the illuminated state and the light-emitting region 50A in the non-illuminated state. However, a component that is reflective to the light emitted by the light source 10 does not necessarily have to be placed within the partition groove 54.

[0025] [light source] As shown in Figure 1, the light-emitting module 100 of the embodiment comprises a plurality of light sources 10. Alternatively, the light-emitting module 100 may comprise a single light source 10. As shown in Figure 2, the light source 10 includes a light-emitting element 11. The light-emitting element 11 includes a semiconductor structure. The semiconductor structure includes, for example, a substrate such as sapphire or gallium nitride, an n-type semiconductor layer disposed on the substrate, a p-type semiconductor layer, and a light-emitting layer sandwiched between the n-type and p-type semiconductor layers. The light-emitting element 11 also includes an n-side electrode electrically connected to the n-type semiconductor layer and a p-side electrode electrically connected to the p-type semiconductor layer. The n-side electrode and the p-side electrode constitute a part of the lower surface of the light-emitting element 11. Furthermore, the light source 10 includes a pair of positive and negative electrodes 12. The pair of positive and negative electrodes 12 constitute a part of the lower surface of the light source 10. One of the pair of electrodes 12 is electrically connected to the p-side electrode, and the other is electrically connected to the n-side electrode. Note that the light source 10 does not necessarily include electrodes 12. If the light source 10 does not include electrodes 12, the n-side electrode and p-side electrode of the light-emitting element 11 constitute a part of the lower surface of the light source 10. Furthermore, the light source 10 does not need to have a substrate such as sapphire or gallium nitride. This makes it easier to miniaturize the light source 10 in the vertical Z direction.

[0026] The structure of the light-emitting layer may be a double heterostructure, a single quantum well structure (SQW) with a single active layer, or a multiple quantum well structure (MQW) with a group of active layers. The light-emitting layer is capable of emitting visible light or ultraviolet light. The light-emitting layer is capable of emitting visible light from blue to red. An example of a semiconductor structure containing such a light-emitting layer is In x Al y Ga 1-x-yN(0≦x, 0≦y, x+y≦1) can be included. The semiconductor structure may include at least one light-emitting layer capable of the light emission described above. For example, the semiconductor structure may have a structure that includes one or more light-emitting layers between an n-type semiconductor layer and a p-type semiconductor layer, or it may have a structure in which a structure containing an n-type semiconductor layer, a light-emitting layer, and a p-type semiconductor layer in sequence is repeated multiple times. When the semiconductor structure includes multiple light-emitting layers, it may include light-emitting layers with different emission peak wavelengths, or it may include light-emitting layers with the same emission peak wavelength. Note that the emission peak wavelengths may be the same, for example, with variations of a few nanometers. Such combinations of light-emitting layers can be selected as appropriate. For example, when the semiconductor structure includes two light-emitting layers, the light-emitting layers can be selected in combinations such as blue light and blue light, green light and green light, red light and red light, ultraviolet light and ultraviolet light, blue light and green light, blue light and red light, or green light and red light. Furthermore, the light-emitting layer may include multiple active layers with different emission peak wavelengths, or it may include multiple active layers with the same emission peak wavelength.

[0027] A single light source 10 includes one light-emitting element 11. A single light source 10 may include multiple light-emitting elements 11. The emission peak wavelengths of the multiple light-emitting elements 11 included in a single light source 10 may be the same or different. For example, if a single light source 10 includes two light-emitting elements 11, the emission peak wavelengths of the light-emitting elements can be selected from combinations such as blue light and green light, blue light and red light, ultraviolet light and blue light, ultraviolet light and green light, ultraviolet light and red light, or green light and red light. For example, if a single light source 10 includes three light-emitting elements 11, the emission peak wavelengths of the light-emitting elements can be selected from combinations such as blue light and green light and red light, ultraviolet light and green light and red light, ultraviolet light and blue light and green light, ultraviolet light and blue light and red light, or ultraviolet light and green light and red light.

[0028] In the example shown in FIG. 2, the light source 10 can further include a third light-transmissive member 14. The third light-transmissive member 14 covers the upper surface and the side surfaces of the light-emitting element 11. The third light-transmissive member 14 can protect the light-emitting element 11. The third light-transmissive member 14 may be arranged so as to expose at least a part of the upper surface of the light-emitting element 11. Thereby, it becomes easy to miniaturize the light source 10 in the vertical direction Z.

[0029] The third light-transmissive member 14 has light-transmittance with respect to the light emitted by the light-emitting element 11. For example, the third light-transmissive member 14 may include a light-transmissive resin and may further include a phosphor. As the light-transmissive resin, for example, a silicone resin or an epoxy resin can be used. As the phosphor, yttrium aluminum garnet-based phosphors (for example, (Y,Gd)3(Al,Ga)5O 12 :Ce), lutetium aluminum garnet-based phosphors (for example, Lu3(Al,Ga)5O 12 :Ce), terbium aluminum garnet-based phosphors (for example, Tb3(Al,Ga)5O 12 :Ce), CCA-based phosphors (for example, Ca 10 (PO4)6Cl2:Eu), SAE-based phosphors (for example, Sr4Al 14 O 25 :Eu), chlorosilicate-based phosphors (for example, Ca8MgSi4O 16 Cl2:Eu), silicate-based phosphors (for example, (Ba,Sr,Ca,Mg)2SiO4:Eu), β-sialon-based phosphors (for example, (Si,Al)3(O,N)4:Eu) or α-sialon-based phosphors (for example, Ca(Si,Al) 12 (O,N) 16 :Eu) and other oxynitride-based phosphors, LSN-based phosphors (for example, (La,Y)3Si6N 11:Ce), BSESN-based phosphors (e.g., (Ba,Sr)2Si5N8:Eu), SLA-based phosphors (e.g., SrLiAl3N4:Eu), CASN-based phosphors (e.g., CaAlSiN3:Eu), or SCASN-based phosphors (e.g., (Sr,Ca)AlSiN3:Eu), etc. nitride-based phosphors, KSF-based phosphors (e.g., K2SiF6:Mn), KSAF-based phosphors (e.g., K2(Si 1-x Al x )F 6-x :Mn where x satisfies 0 < x < 1), or fluoride-based phosphors such as MGF-based phosphors (e.g., 3.5MgO·0.5MgF2·GeO2:Mn), quantum dots having a perovskite structure (e.g., (Cs,FA,MA)(Pb,Sn)(F,Cl,Br,I)3 where FA and MA represent formamidinium and methylammonium, respectively), II-VI group quantum dots (e.g., CdSe), III-V group quantum dots (e.g., InP), or quantum dots having a chalcopyrite structure (e.g., (Ag,Cu)(In,Ga)(S,Se)2), etc. can be used. As the phosphor added to the third light-transmissive member 14, one type of phosphor may be used, or a plurality of types of phosphors may be used.

[0030] Furthermore, a wavelength conversion sheet containing the aforementioned phosphor may be placed on the light-emitting module 100. The wavelength conversion sheet absorbs a portion of the blue light from the light source 10 and emits yellow light, green light, and / or red light, and the planar light source 300 can emit white light. For example, white light can be obtained by combining a light source 10 capable of emitting blue light with a wavelength conversion sheet containing a phosphor capable of emitting yellow light. Alternatively, a light source 10 capable of emitting blue light may be combined with a wavelength conversion sheet containing a red phosphor and a green phosphor. Furthermore, a light source 10 capable of emitting blue light may be combined with multiple wavelength conversion sheets. As for the multiple wavelength conversion sheets, for example, a wavelength conversion sheet containing a phosphor capable of emitting red light and a wavelength conversion sheet containing a phosphor capable of emitting green light can be selected. Alternatively, a light source 10 having a light-emitting element 11 capable of emitting blue light and a third translucent member 14 containing a phosphor capable of emitting red light may be combined with a wavelength conversion sheet containing a phosphor capable of emitting green light.

[0031] For the phosphor capable of emitting yellow light used in the wavelength conversion sheet, it is preferable to use, for example, the yttrium-aluminum-garnet phosphor described above. For the phosphor capable of emitting green light used in the wavelength conversion sheet, it is preferable to use, for example, quantum dots having a perovskite structure, III-V quantum dots, or quantum dots having a chalcopyrite structure, which have a narrow full width at half maximum of the emission peak wavelength, as described above. For the phosphor capable of emitting red light used in the wavelength conversion sheet, it is preferable to use, similar to the phosphor capable of emitting green light, quantum dots having a narrow full width at half maximum of the emission peak wavelength, such as, for example, the KSF phosphor, KSAF phosphor, III-V quantum dots, or quantum dots having a chalcopyrite structure, as described above.

[0032] The light source 10 may further include a second covering member 15. The second covering member 15 is positioned on the lower surface of the light-emitting element 11. The second covering member 15 is positioned such that the lower surface of the electrode 12 of the light source 10 is exposed from the second covering member 15. The second covering member 15 is also positioned on the lower surface of a third translucent member 14 that covers the side surface of the light-emitting element 11.

[0033] The second coating member 15 is reflective to the light emitted by the light-emitting element 11. The second coating member 15 can be made of, for example, a resin material containing a gas such as nitrogen and / or oxygen, or a resin material containing light-scattering particles. The material of the resin material of the second coating member 15 can be the same material as the resin used for the light guide member 50. As the light-scattering particles of the second coating member 15, for example, titania, silica, alumina, zinc oxide, magnesium oxide, zirconia, yttria, calcium fluoride, magnesium fluoride, niobium pentoxide, barium titanate, tantalum pentoxide, barium sulfate, or glass particles can be used. The second coating member 15 may contain both a gas and light-scattering particles.

[0034] The light source 10 may further include a first covering member 13 located on the upper surface of the light-emitting element 11. The first covering member 13 constitutes at least a portion of the upper surface of the light source 10. In a plan view, the first covering member 13 and the light-emitting element 11 overlap, and in the overlapping portion, the first covering member 13 is located above the light-emitting element 11. The first covering member 13 is positioned above the third translucent member 14 and adjusts the amount and / or direction of light emitted from the upper surface of the third translucent member 14. The first covering member 13 has reflectivity and translucency to the light emitted by the light-emitting element 11. A portion of the light emitted from the upper surface of the third translucent member 14 is reflected by the first covering member 13, and the other portion is transmitted through the first covering member 13. The transmittance of the first covering member 13 with respect to the peak wavelength of the light-emitting element 11 is preferably, for example, 1% or more and 50%, and more preferably 3% or more and 30%. By including the first covering member 13 in the light source 10, it is possible to reduce the excessive brightness in the area directly above the light source 10. This reduces the brightness unevenness of the light-emitting module 100.

[0035] The first coating member 13 can be made of, for example, a resin member containing light-scattering particles. The resin member of the first coating member 13 can be the same material as the resin used for the light guide member 50. The light-scattering particles of the first coating member 13 can be the same material as the light-scattering particles of the second coating member 15. Alternatively, the first coating member 13 may be a metal member such as aluminum or silver, or a dielectric multilayer film.

[0036] The light source 10 is not limited to the form shown in Figure 2. Other forms of the light source 10 are described below.

[0037] The light source 10 does not necessarily have to include the first covering member 13. This makes it easier to miniaturize the light source 10 in the vertical Z direction compared to when the light source 10 includes the first covering member 13 which is positioned above the light-emitting element 11.

[0038] The light source 10 does not necessarily have to include the second covering member 15. For example, the lower surface of the light source 10 may be formed by the lower surface of the light-emitting element 11, the lower surfaces of the pair of electrodes 12, and the lower surface of the third light-transmitting member 14.

[0039] The light source 10 may consist of only the light-emitting element 11.

[0040] The light source 10 may not include the second covering member 15 and the third light-transmitting member 14, and the first covering member 13 may be arranged on the upper surface of the light-emitting element 11.

[0041] The light source 10 may not include the third light-transmitting member 14, and may have a configuration in which the first covering member 13 is placed on the upper surface of the light-emitting element 11 and the second covering member 15 is placed on the lower surface of the light-emitting element 11.

[0042] The shape of the light source 10 in plan view is not particularly limited. The shape of the light source 10 in plan view can be, for example, a circle, a triangle, a square, a hexagon, or an octagon. If the shape of the light source 10 in plan view is a square, the pair of parallel outer edges of the light source 10 may be parallel to the first direction X, or they may be inclined with respect to the first direction X. In this embodiment, as shown in Figure 1, the pair of parallel outer edges of the light source 10 are inclined at 45° with respect to the first direction X.

[0043] [First translucent member] The first light-transmitting member 21 is light-transmitting to light emitted by the light source 10. The transmittance of the first light-transmitting member 21 with respect to the emission peak wavelength of the light source 10 is preferably 60% or more, and more preferably 80% or more.

[0044] The first light-transmitting member 21 is in contact with the side surface of the light source 10. This makes it easier for light from the light source 10 to enter the first light-transmitting member 21. The light from the light source 10 that enters the first light-transmitting member 21 propagates within the first light-transmitting member 21.

[0045] In a plan view, the first translucent member 21 continuously surrounds the light source 10. This makes it easier for light from the light source 10 to enter the first translucent member 21 in a 360° direction around the light source 10.

[0046] It is preferable that the first light-transmitting member 21 is positioned so as to expose at least a portion of the upper surface of the light source 10. This makes it easier to miniaturize the light-emitting module 100 in the vertical direction Z compared to when the first light-transmitting member 21 covers the entire upper surface of the light source 10. The first light-transmitting member 21 may also be positioned so as to expose the entire upper surface of the light source 10.

[0047] The first light-transmitting member 21 may cover the entire upper surface of the light source 10. By covering the entire upper surface of the light source 10 with the first light-transmitting member 21, it becomes easier to adjust the brightness in the region directly above the light source 10. For example, the brightness in the region directly above the light source 10 can be adjusted by changing the thickness of the portion of the first light-transmitting member 21 that covers the upper surface of the light source 10. By making it easier to adjust the brightness in the region directly above the light source 10, it becomes easier to reduce brightness unevenness in the light-emitting module 100.

[0048] The first light-transmitting member 21 may be composed of a single layer or a laminate of multiple layers in the vertical direction Z. The first light-transmitting member 21 may also contain a phosphor and / or light-scattering particles. If the first light-transmitting member 21 is a laminate, each layer may or may not contain a phosphor and / or light-scattering particles. For example, the first light-transmitting member 21 may consist of a layer containing a phosphor and a layer not containing a phosphor. As the material for the first light-transmitting member 21, for example, a material similar to the resin used for the light-guiding member 50 can be used.

[0049] The first light-transmitting member 21 is positioned between the side surface of the light source 10 and the light guide member 50. The light guide member 50 facilitates the propagation of light from the light source 10 to a wider area in the lateral direction.

[0050] The first light-transmitting member 21 is in contact with the surface that defines the through-hole 53 in the light guide member 50. This makes it easier for light from the light source 10 to propagate through the first light-transmitting member 21 and enter the light guide member 50. In the example shown in Figure 2, the first light-transmitting member 21 is in contact with the first side surface 50a, the second side surface 50b, and the surface 50c.

[0051] At the interface between the first light-transmitting member 21 and the light-guiding member 50, light tends to be directed upward due to refraction or reflection. Therefore, on the light-emitting surface of the light-emitting module 100, the area near the upper end of the interface between the first light-transmitting member 21 and the light-guiding member 50 may tend to be brighter.

[0052] According to this embodiment, at least a portion of the interface between the first light-transmitting member 21 and the light-guiding member 50 is composed of a first side surface 50a and a second side surface 50b. The first side surface 50a and the second side surface 50b, which tend to direct light upward due to refraction or reflection, do not overlap in a plan view. This reduces the likelihood of the interface between the first light-transmitting member 21 and the light-guiding member 50 becoming too bright on the light-emitting surface of the light-emitting module 100, and makes it easier to reduce brightness unevenness on the light-emitting surface.

[0053] Furthermore, in a plan view, the brightness on the light-emitting surface of the light-emitting module 100 can be adjusted by the size and / or position of the protrusion 55 located at the boundary between the second surface 52 and the outer edge of the second portion 53b of the through hole 53. This makes it easier to reduce brightness unevenness on the light-emitting surface of the light-emitting module 100.

[0054] In the vertical direction Z, it is preferable that the second portion 53b of the through hole 53 is located above the height of the upper surface 11a of the light-emitting element 11. This reduces the excessive brightness at the boundary between the second surface 52 and the outer edge of the second portion 53b caused by light emitted from the upper surface 11a of the light-emitting element 11, making it easier to reduce brightness unevenness on the light-emitting surface of the light-emitting module 100.

[0055] Furthermore, in the vertical direction Z, it is preferable that a portion of the second part 53b of the through hole 53 is located below the height of the upper surface 13a of the first covering member 13 of the light source 10. This reduces the excessive brightness at the boundary between the second surface 52 and the outer edge of the second part 53b caused by light emitted laterally from the side surface of the first covering member 13, making it easier to reduce brightness unevenness on the light-emitting surface of the light-emitting module 100.

[0056] As shown in Figure 3, in a cross-sectional view, at least a portion of the second side surface 50b of the light guide member 50 may be inclined with respect to the second surface 52. The second side surface 50b includes, for example, a curved surface that is concave downward. It is continuous from the surface of the convex portion 55 through the second side surface 50b to the first side surface 50a.

[0057] The inclination of the second side surface 50b relative to the second surface 52 makes it easier to reduce brightness unevenness on the light-emitting surface compared to the case where the second side surface 50b is perpendicular to the second surface 52. For example, the inclination of the second side surface 50b relative to the second surface 52 allows for a larger area of ​​the second side surface 50b in a plan view compared to the case where the second side surface 50b is perpendicular to the second surface 52. By extracting light from the light source 10 from the second side surface 50b, which has a larger area in a plan view, it is possible to reduce excessive brightness above the second side surface 50b. This makes it easier to reduce brightness unevenness on the light-emitting surface of the light-emitting module 100.

[0058] The first side surface 50a may be perpendicular to the second surface 52 or inclined. The first side surface 50a may also include a recess that is recessed toward the light guide member 50. Furthermore, a protrusion may be arranged on the first side surface 50a toward the light source 10.

[0059] As shown in Figure 4, multiple second parts 53b located outside the first part 53a in a plan view may be arranged to surround the light source 10. This allows the first light-transmitting member 21 and the light-guiding member 50, which are arranged in the second parts 53b, to be mixed around the light source 10 in a plan view, making the boundary between the first light-transmitting member 21 and the light-guiding member 50 less noticeable and making it easier to reduce brightness unevenness on the light-emitting surface.

[0060] In Figure 4, the outer edge of the first portion 53a is represented by, for example, a circular dashed line. In Figure 4, the convex portion 55 is represented by a solid line. In Figure 4, the outer edge of the second portion 53b coincides with the inner edge of the solid line representing the convex portion 55. In a plan view, the outer edges of the convex portion 55 and the second portion 53b include portions that coincide with the outer edge of the first portion 53a.

[0061] For example, in a plan view, along a virtual closed curve surrounding the light source 10, the distance D between adjacent second portions 53b is preferably shorter than the length L of the outer edge of the second portion 53b. A shorter distance D than length L makes it easier to increase the proportion of the through-hole 53 in which the second portion 53b is located. This makes the boundary between the first light-transmitting member 21 and the light-guiding member 50 less noticeable and makes it easier to reduce brightness unevenness on the light-emitting surface of the light-emitting module 100. In this specification, the length L of the outer edge of the second portion 53b is the length of the line segment connecting one end and the other end at the point where the first portion 53a and the second portion 53b are in contact in a plan view.

[0062] The length L of the outer edge of the second portion 53b is, for example, 0.2 times or more and 2 times the thickness of the light guide member 50. The length L of the outer edge of the second portion 53b is, for example, 100 μm or more and 1000 μm or less.

[0063] In a plan view, if there is an angle at the outer edge of the second portion 53b, the direction in which the outer edge of the second portion 53b extends changes abruptly. That is, the orientation of the interface between the second side surface 50b of the light guide member 50 and the first translucent member 21 (the direction of the normal vector) changes abruptly. Due to the abrupt change in the orientation of the interface between the light guide member 50 and the first translucent member 21, brightness unevenness, such as localized brightness, is likely to occur. Therefore, as shown in Figures 1 and 4, it is preferable that at least a part of the outer edge of the second portion 53b is curved in a plan view.

[0064] [Light adjustment component] As shown in Figure 2, the light-emitting module 100 of the embodiment may further include a light-adjusting member 30. The light-adjusting member 30 has reflectivity and light transmission properties to the light emitted from the light source 10. A portion of the light emitted from the light source 10 is reflected by the light-adjusting member 30, and another portion is transmitted through the light-adjusting member 30. The transmittance of the light-adjusting member 30 with respect to the peak wavelength of the light source 10 is preferably, for example, 1% or more and 50%, and more preferably 3% or more and 30%. The upper surface of the light-adjusting member 30, together with the second surface 52 of the light guide member 50, constitutes the light-emitting surface of the light-emitting module 100.

[0065] The light-adjusting member 30 can be composed of, for example, a resin member (hereinafter referred to as the light-adjusting resin member) and a reflector contained in the light-adjusting resin member (hereinafter referred to as the light-adjusting reflector). The material of the light-adjusting resin member can be the same as the resin used for the light guide member 50. The material of the light-adjusting reflector can be the same as the material of the light-scattering particles of the second coating member 15. A gas such as nitrogen and / or oxygen may be used as the light-adjusting reflector. The light-adjusting member 30 may contain both light-scattering particles and a gas. The light-adjusting member 30 may be composed of a single layer or a laminate of multiple layers.

[0066] The light adjustment member 30 is positioned above the light source 10. In a plan view, the light adjustment member 30 and the light source 10 overlap. By positioning the light adjustment member 30 above the light source 10, it is possible to reduce excessive brightness in the area directly above the light source 10, and to reduce brightness unevenness on the light-emitting surface of the light-emitting module 100.

[0067] Furthermore, the light adjustment member 30 is positioned above the first portion 53a of the through hole 53. That is, the light adjustment member 30 is positioned above the first translucent member 21 which is positioned above the first portion 53a. In a plan view, at least a portion of the light adjustment member 30 overlaps with the first portion 53a and the first translucent member 21. By positioning the light adjustment member 30 above the first translucent member 21, it is possible to reduce the area directly above the first translucent member 21 (the area surrounding the light source 10) from becoming too bright, and it is possible to reduce brightness unevenness on the light-emitting surface of the light-emitting module 100.

[0068] Furthermore, it is preferable that the light adjusting member 30 extends from the upper position of the first portion 53a of the through hole 53 to the upper position of the second portion 53b, so as to straddle the first side surface 50a in a plan view. That is, the light adjusting member 30 covers the upper part of the first side surface 50a. This reduces the problem of the upper part of the first side surface 50a, which is the boundary between the light guide member 50 and the first light-transmitting member 21, becoming too bright, and makes it easier to reduce brightness unevenness on the light-emitting surface of the light-emitting module 100.

[0069] [Second translucent member] The light-emitting module 100 of the embodiment may further include a second light-transmitting member 22. The second light-transmitting member 22 is light-transmitting to light emitted by the light source 10. The transmittance of the second light-transmitting member 22 with respect to the emission peak wavelength of the light source 10 is preferably 60% or more, and more preferably 80% or more.

[0070] The second light-transmitting member 22 is positioned between the light source 10 and the light-adjusting member 30, and between the first light-transmitting member 21 and the light-adjusting member 30, in a cross-sectional view. The second light-transmitting member 22 adheres the light source 10 and the light-adjusting member 30, and adheres the first light-transmitting member 21 and the light-adjusting member 30. The maximum thickness of the second light-transmitting member 22 in the vertical Z direction is smaller than the maximum thickness of the first light-transmitting member 21 in the vertical Z direction.

[0071] The first translucent member 21 is formed, for example, by supplying a fluid resin into the through hole 53 and then heat-curing it. When forming the first translucent member 21, the upper surface of the first translucent member 21 may become concave due to resin shrinkage. In this case, the second translucent member 22 makes it easier to flatten the surface on which the light-adjusting member 30 is placed (the upper surface of the second translucent member 22). For example, if the light-adjusting member 30 is in the form of a sheet, the flatness of the upper surface of the second translucent member 22 makes it easier to place the light-adjusting member 30 on the upper surface of the second translucent member 22.

[0072] As the material for the second translucent member 22, for example, the same material as the resin member of the first translucent member 21 can be used. In this case, the refractive index difference between the first translucent member 21 and the second translucent member 22 can be reduced. This reduces the reflection of light at the interface between the first translucent member 21 and the second translucent member 22, making it easier to improve the amount of light extracted upward. The second translucent member 22 may contain a phosphor and / or light scattering particles.

[0073] After supplying the fluid second translucent member 22 onto the first translucent member 21 and the light source 10, a light adjusting member 30, for example, in the form of a sheet, is placed on the second translucent member 22. After placing the light adjusting member 30 on the second translucent member 22, the second translucent member 22 is, for example, heat-cured. When the fluid second translucent member 22 is supplied onto the first translucent member 21, the second translucent member 22 comes into contact with the protrusion 55, and the protrusion 55 makes it difficult for the second translucent member 22 to flow out onto the second surface 52. This makes it easier to adjust the brightness on the second surface 52.

[0074] The light-adjusting member 30 is not limited to a sheet; it may also be supplied onto the second translucent member 22 in a fluid state and then heat-cured. In this case, the fluid light-adjusting member 30 comes into contact with the protrusions 55, and the protrusions 55 make it difficult for the light-adjusting member 30 to flow out onto the second surface 52. This makes it easier to adjust the brightness on the second surface 52. Furthermore, the positional accuracy of the light-adjusting member 30 can be improved, making it easier to adjust the brightness on the light-emitting surface of the light-emitting module 100. In addition, variations in the shape and / or thickness of the light-adjusting member 30 can be reduced, making it easier to adjust the brightness in the area where the light-adjusting member 30 is placed.

[0075] Furthermore, the second side surface 50b of the light guide member 50, which defines the second portion 53b of the through hole 53, makes it difficult for the second light-transmitting member 22 and the light-adjusting member 30 to flow out onto the second surface 52.

[0076] As shown in Figure 5, the protrusion 56 may be placed on the second surface 52 at a position away from the through hole 53. The second surface 52 is continuous between the surface of the protrusion 56 and the second side surface 50b that defines the second portion 53b of the through hole 53. This protrusion 56 makes it difficult for the second light-transmitting member 22 and the light-adjusting member 30 to flow out onto the second surface 52 which is located outside the protrusion 56 in a plan view.

[0077] The planar light source 300 of the embodiment further comprises a support member 200 that supports the light-emitting module 100. The light guide member 50 is positioned on the support member 200 with its first surface 51 facing the upper surface of the support member 200. Within the through hole 53, the light source 10 and the first light-transmitting member 21 are located on the support member 200.

[0078] The support member 200 has a wiring board 60. The wiring board 60 has an insulating substrate 61 and at least one wiring layer 62 disposed on at least one surface of the insulating substrate 61. The insulating substrate 61 may be a rigid substrate or a flexible substrate. To make the planar light source 300 thinner, it is preferable that the insulating substrate 61 be a flexible substrate. The insulating substrate 61 may be composed of a single layer in the vertical direction Z, or it may be composed of a laminate of multiple layers. For example, the insulating substrate 61 may be composed of a single-layer flexible substrate, or it may be composed of a laminate of multiple rigid substrates. As the material for the insulating substrate 61, for example, a resin such as polyimide can be used. The wiring layer 62 is a metal film, for example, a copper film.

[0079] The support member 200 further comprises a first adhesive layer 63 disposed on the wiring board 60, a reflective member 64 disposed on the first adhesive layer 63, and a second adhesive layer 65 disposed on the reflective member 64.

[0080] The first adhesive layer 63 is positioned between the wiring board 60 and the reflective member 64, and adheres the wiring board 60 and the reflective member 64 together. The first adhesive layer 63 can be made of, for example, a resin member containing light-scattering particles. As the resin member of the first adhesive layer 63, for example, a material similar to the resin used for the light guide member 50 can be used. As the light-scattering particles of the first adhesive layer 63, for example, a material similar to the light-scattering particles of the second coating member 15 can be used. A sheet-like optical transparent adhesive may be used as the first adhesive layer 63.

[0081] The refractive index of the resin member of the first adhesive layer 63 is preferably lower than that of the resin member of the reflective member 64. In this specification, the refractive index is defined as the refractive index at the emission peak wavelength of the light source 10. By making the refractive index of the resin member of the first adhesive layer 63 lower than that of the resin member of the reflective member 64, some of the light traveling from the reflective member 64 to the first adhesive layer 63 is more likely to undergo total internal reflection at the interface between the reflective member 64 and the first adhesive layer 63. This reduces the amount of light that escapes downward from the light-emitting module 100, thus improving the light extraction efficiency of the light-emitting module 100.

[0082] The reflective member 64 is positioned below the light guide member 50, below the light source 10, below the first light-transmitting member 21, and below the partition groove 54. The reflective member 64 is reflective to the light emitted by the light source 10. The reflective member 64 can be composed of a resin member and a reflector contained within the resin member. As the resin member of the reflective member 64, for example, a material similar to the resin used in the light guide member 50 can be used. As the material of the reflector of the reflective member 64, a material similar to the light-scattering particles of the second coating member 15 can be used. A gas such as nitrogen and / or oxygen may be used as the reflector of the reflective member 64. Furthermore, the reflective member 64 may contain both light-scattering particles and a gas as the reflector.

[0083] It is preferable that the refractive index of the reflector of the reflective member 64 is lower than the refractive index of the resin member of the reflective member 64. By making the refractive index of the reflector of the reflective member 64 lower than that of the resin member of the reflective member 64, a portion of the light from the light source 10 incident on the reflective member 64 is more likely to undergo total internal reflection at the interface between the resin member of the reflective member 64 and the reflector of the reflective member 64. As a result, the amount of light that escapes downward from the reflective member 64 is reduced, which improves the light extraction efficiency of the light-emitting module 100.

[0084] When the refractive index of the reflector of the reflective member 64 is lower than the refractive index of the resin member of the reflective member 64, it is preferable that the refractive index of the resin member of the reflective member 64 is higher than the refractive index of the light guide member 50. This makes it easier to increase the refractive index difference between the resin member of the reflective member 64 and the reflector of the reflective member 64, making it easier for a portion of the light from the light source 10 incident on the reflective member 64 to undergo total internal reflection at the interface between the resin member of the reflective member 64 and the reflector of the reflective member 64.

[0085] The second adhesive layer 65 is positioned between the reflective member 64 and the second surface 52 of the light guide member 50, and adheres the reflective member 64 and the light guide member 50. The light source 10 is positioned on the second adhesive layer 65 within the through hole 53 of the light guide member 50. The second adhesive layer 65 can be made of, for example, a resin member containing light scattering particles. As the resin member of the second adhesive layer 65, for example, a material similar to the resin used for the light guide member 50 can be used. As the light scattering particles of the second adhesive layer 65, for example, a material similar to the light scattering particles of the second coating member 15 can be used. A sheet-like optical transparent adhesive may be used as the second adhesive layer 65.

[0086] The refractive index of the resin component of the second adhesive layer 65 is preferably lower than that of the light guide member 50. By making the refractive index of the resin component of the second adhesive layer 65 lower than that of the light guide member 50, some of the light traveling from the light guide member 50 to the second adhesive layer 65 is more likely to undergo total internal reflection at the interface between the light guide member 50 and the second adhesive layer 65. This reduces the amount of light that escapes downward from the light-emitting module 100, thereby improving the light extraction efficiency of the light-emitting module 100.

[0087] The refractive index of the resin component of the second adhesive layer 65 is preferably lower than that of the first light-transmitting component 21. By making the refractive index of the resin component of the second adhesive layer 65 lower than that of the first light-transmitting component 21, some of the light traveling from the first light-transmitting component 21 to the second adhesive layer 65 is more likely to undergo total internal reflection at the interface between the first light-transmitting component 21 and the second adhesive layer 65. This reduces the amount of light that escapes downward from the light-emitting module 100, thus improving the light extraction efficiency of the light-emitting module 100.

[0088] The support member 200 further comprises a conductive member 67. The conductive member 67 includes, for example, a resin and metal particles contained in the resin. As the resin of the conductive member 67, for example, epoxy resin or phenolic resin can be used. As the metal particles of the conductive member 67, for example, copper or silver particles can be used.

[0089] The conductive member 67 has a connecting portion 67a and a wiring portion 67b. The connecting portion 67a penetrates the second adhesive layer 65, the reflective member 64, the first adhesive layer 63, and the insulating substrate 61 in the vertical direction Z. The wiring portion 67b is located on the surface of the wiring board 60 on which the wiring layer 62 is arranged, and is connected to the connecting portion 67a. The connecting portion 67a and the wiring portion 67b can be integrally formed from the same material. A portion of the wiring portion 67b is connected to the wiring layer 62.

[0090] A pair of conductive members 67 are arranged laterally, separated from each other, corresponding to the positive and negative electrodes 12 of the light source 10. Of the pair of conductive members 67, the connection portion 67a of one conductive member 67 is connected to the positive electrode 12 below the light source 10, and the connection portion 67a of the other conductive member 67 is connected to the negative electrode 12 below the light source 10. The electrodes 12 of the light source 10 are electrically connected to the wiring layer 62 via the conductive members 67.

[0091] The support member 200 further has an insulating layer 66. The insulating layer 66 is located on the lower surface of the wiring board 60 and covers the wiring layer 62. As the material for the insulating layer 66, for example, epoxy resin, urethane resin, or acrylic resin can be used.

[0092] Embodiments of the present invention include the following light-emitting module.

[0093] [Section 1] A light guide member having a first surface, a second surface located opposite the first surface, a through hole penetrating from the first surface to the second surface, and a protrusion, wherein the through hole has a first portion opening toward the first surface and a second portion opening toward the second surface and having a width in the lateral direction that is wider than the first portion, and the protrusion is positioned on the second surface and has a surface continuous with the second portion, A light source placed inside the through hole, A first translucent member is disposed within the through-hole and is in contact with the first side surface defining the first portion and the second side surface defining the second portion, A light-emitting module equipped with the following features. [Section 2] A light adjusting member is positioned above the light source and above the first portion, The light-emitting module described in item 1 above, comprising: [Section 3] The system includes a second light-transmitting member located between the light-adjusting member and the first light-transmitting member, The light-emitting module according to item 2, wherein the second light-transmitting member is in contact with the protrusion. [Section 4] The light-emitting module according to item 1 or 2, wherein the light-adjusting member is in contact with the protrusion. [Section 5] The light-emitting module according to any one of items 1 to 4 above, wherein, in a cross-sectional view, at least a portion of the second side surface is inclined with respect to the second surface. [Section 6] The light source has a light-emitting element, The light-emitting module according to any one of items 1 to 5 above, wherein in the vertical direction, the second portion is located above the height at which the upper surface of the light-emitting element is located. [Section 7] The light source has a first covering member located on the upper surface of the light-emitting element, The light-emitting module according to item 6, wherein in the vertical direction, a portion of the second part is located below the height at which the upper surface of the first covering member is located. [Section 8] The light-emitting module according to any one of items 1 to 7, wherein, in a plan view, a plurality of the second parts are arranged to surround the light source. [Section 9] The light-emitting module according to item 8, wherein, in a plan view, the distance between adjacent second parts is less than the length of the outer edge of the second part. [Section 10] The light-emitting module according to any one of items 1 to 9 above, wherein, in a plan view, at least a portion of the outer edge of the second part is curved.

[0094] The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. All forms that a person skilled in the art can implement by appropriately modifying the design based on the above-described embodiments of the present invention also fall within the scope of the present invention, insofar as they encompass the gist of the present invention. Furthermore, within the scope of the idea of ​​the present invention, a person skilled in the art can conceive of various modifications and alterations, and these modifications and alterations also fall within the scope of the present invention. [Explanation of Symbols]

[0095] 10...Light source, 11...Light-emitting element, 13...First covering member, 14...Third light-transmitting member, 15...Second covering member, 21...First light-transmitting member, 22...Second light-transmitting member, 30...Light adjusting member, 50...Light guide member, 50A...Light-emitting region, 50a...First side surface, 50b...Second side surface, 51...First surface, 52...Second surface, 53...Through hole, 53a...First part, 53b...Second part, 54...Partition groove, 55...Protrusion, 56...Protrusion, 60...Wiring board, 61...Insulating substrate, 62...Wiring layer, 63...First adhesive layer, 64...Reflective member, 65...Second adhesive layer, 66...Insulating layer, 67...Conductive member, 100...Light-emitting module, 200...Support member, 300...Planar light source

Claims

1. A light guide member having a first surface, a second surface located opposite the first surface, a through hole penetrating from the first surface to the second surface, and a protrusion, wherein the through hole has a first portion opening toward the first surface and a second portion opening toward the second surface and having a width in the lateral direction that is wider than the first portion, and the protrusion is positioned on the second surface and has a surface continuous with the second portion, A light source placed inside the through hole, A first translucent member is disposed within the through-hole and is in contact with the first side surface defining the first portion and the second side surface defining the second portion, A light-emitting module equipped with the following features.

2. A light adjusting member is positioned above the light source and above the first portion, The light-emitting module according to claim 1, comprising:

3. The light-adjusting member and the first light-transmitting member are provided together, and the second light-transmitting member is located between them. The light-emitting module according to claim 2, wherein the second light-transmitting member is in contact with the protrusion.

4. The light-emitting module according to claim 2, wherein the light-adjusting member is in contact with the protrusion.

5. The light-emitting module according to any one of claims 1 to 4, wherein, in a cross-sectional view, at least a portion of the second side surface is inclined with respect to the second surface.

6. The light source has a light-emitting element, The light-emitting module according to any one of claims 1 to 4, wherein in the vertical direction, the second portion is located above the height at which the upper surface of the light-emitting element is located.

7. The light source has a first covering member located on the upper surface of the light-emitting element, The light-emitting module according to claim 6, wherein in the vertical direction, a portion of the second part is located below the height at which the upper surface of the first covering member is located.

8. The light-emitting module according to any one of claims 1 to 4, wherein, in a plan view, a plurality of the second parts are arranged to surround the light source.

9. The light-emitting module according to claim 8, wherein, in a plan view, the distance between adjacent second parts is less than the length of the outer edge of the second part.

10. The light-emitting module according to any one of claims 1 to 4, wherein, in a plan view, at least a portion of the outer edge of the second part is curved.

Images