JP2024040698A - light emitting module - Google Patents

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

The present invention relates to a light emitting module.

2. Description of the Related Art Light-emitting modules that combine light-emitting elements such as light-emitting diodes and light guide members are widely used as planar light sources such as backlights for liquid crystal displays, for example. For example, Patent Document 1 discloses a backlight device including an LED board provided with a reflective sheet and a plurality of light emitting diodes, and a diffuser plate facing the LED board.

JP 2019-61929 Publication

An object of the present invention is to provide a light emitting module that can reduce uneven brightness.

According to one aspect of the present invention, the light emitting module includes a first surface, a second surface located on the opposite side of the first surface, a through hole penetrating from the first surface to the second surface, and a convex The through-hole has a first portion that opens on the first surface side, and a second portion that opens on the second surface side and has a width in the lateral direction wider than the first portion. two parts, the convex part is arranged on the second surface and has a surface that is continuous with the second part, the light guide member, the light source arranged in the through hole, and the through hole. a first translucent member disposed within the hole and in contact with a first side surface defining the first portion and a second side surface defining the second portion.

According to the present invention, it is possible to provide a light emitting module that can reduce uneven brightness.

FIG. 2 is a schematic plan view of a light emitting module according to an embodiment. FIG. 2 is a schematic cross-sectional view taken along line II-II in FIG. 1. FIG. It is a schematic cross-sectional view for explaining the 1st modification of the light emitting module of embodiment. It is a schematic plan view for demonstrating the 2nd modification of the light emitting module of embodiment. It is a schematic cross-sectional view for explaining the 3rd modification of the light emitting module of embodiment.

Hereinafter, light emitting modules according to embodiments will be described with reference to the drawings. The dimensions, materials, shapes, relative arrangements, etc. of the components described in the embodiments are not intended to be limiting unless specifically stated, and are merely illustrative examples. Note that the sizes, positional relationships, etc. of members shown in each drawing may be exaggerated for clarity of explanation. In addition, in the following description, the same names and symbols indicate the same or homogeneous members, and detailed descriptions will be omitted as appropriate. Moreover, as a sectional view, an end view showing only a cut surface may be shown.

In the following description, terms that indicate a particular direction or position (eg, "above", "below", and other terms including those terms) may be used. However, these terms are used only for clarity of relative orientation or position in the referenced drawings. If the relative directions or positional relationships using terms such as "upper" and "lower" in the referenced drawings are the same, the arrangement may not be the same in drawings other than this disclosure, actual products, etc. as in the referenced drawings. It's okay. In this specification, the positional relationship expressed as "above (or below)" means, for example, assuming that there are two members, there are cases where the two members are in contact with each other, and cases where the two members are not in contact with each other and one with the other. This includes cases where one member is located above (or below) the other member. Also, unless there is a specific description, a component covers the target to be covered, either when the component comes into contact with the target and directly covers the target, or when the component indirectly covers the target without contacting the target. including.

In the figures shown below, directions may be indicated by the X-axis, Y-axis, and Z-axis. The X-axis, Y-axis, and Z-axis 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. Further, the direction of the arrow on the Z-axis is defined as upward, and the direction opposite to the direction of the arrow on the Z-axis is defined as downward. Further, in the XY plane, a direction inclined from the X direction at an angle of 0° or more and less than 360° is defined as a lateral direction. For example, in this specification, the direction along the X axis is referred to as a first direction X, the direction along the Y axis is referred to as a second direction Y, and the direction along the Z axis is referred to as a third direction Z. In this specification, the third direction Z is also referred to as the vertical direction Z. In addition, in this specification, unless otherwise specified, the thickness of each member is the value when the distance from the top surface of each member to the bottom surface of each member in the third direction (vertical direction) Z is maximum. shall be.

A light emitting module 100 and a planar light source 300 according to an embodiment will be described with reference to FIGS. 1 and 2. The planar light source 300 includes a light emitting module 100. As shown in FIG. 2, the light emitting module 100 includes at least a light guide member 50, a light source 10, and a first translucent member 21. Each element constituting the light emitting module 100 and the planar light source 300 will be explained in detail below.

[Light guide member]
The light guide member 50 has translucency for 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 60% or more, and more preferably 80% or more, for example.

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

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 that penetrates from the first surface 51 to the second surface 52. The light source 10 and the first translucent member 21 are arranged within the through hole 53 .

The through hole 53 has a first portion 53a and a second portion 53b. The first portion 53a is open 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 is open 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 a portion overlapping the first portion 53a and a portion located outside the outer edge of the first portion 53a in plan view.

The light guide member 50 has a first side surface 50a that defines a first portion 53a and a second side surface 50b that defines a second portion 53b. The first side surface 50a is perpendicular to or inclined to the second surface 52, and the second side surface 50b is perpendicular to or inclined to the second surface 52. There is a step between the first side surface 50a and the second side surface 50b.

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

The light guide member 50 has a convex portion 55 arranged on the second surface 52. The convex portion 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.

As shown in FIG. 1, the light guide member 50 continuously surrounds the light source 10 in plan view. In FIG. 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 by, for example, a circular broken line. In FIG. 1, the convex portion 55 is represented by, for example, a double circle solid line. In FIG. 1, the outer edge of the second portion 53b coincides with the inner edge of the solid line representing the convex portion 55. In 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.

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 an ellipse or a polygonal shape such as a triangle, quadrilateral, hexagon, or octagon.

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

In the light emitting module 100 of the embodiment, as shown in FIG. 1, the light guide member 50 is partitioned into a plurality of light emitting regions 50A by partition grooves 54 extending in the first direction X and the second direction Y. One light emitting region 50A can be used as a drive unit for local dimming. FIG. 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 having a plurality of light emitting regions 50A, but may have a configuration including one light emitting region 50A. Moreover, by having the dividing groove 54 of the light guide member 50, it becomes 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. For example, a portion of the light from the light source 10 that propagates laterally within the light guide member 50 is reflected or refracted by the surface of the light guide member 50 that defines the partition groove 54 . Therefore, the light from the light source 10 that propagates laterally within the light guide member 50 is easily prevented from entering the light guide member 50 in the 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.

It is preferable that the partition groove 54 penetrates from the first surface 51 to the second surface 52 of the light guide member 50. As a result, the light guide member 50 can be separated into a plurality of parts, so that, for example, the support member 200 may warp due to a difference in thermal expansion coefficient between the light guide member 50 and a support member 200, which will be described later, that supports the light guide member 50. can be reduced. By reducing the warpage of the support member 200, it is possible to reduce the occurrence of cracks in the conductive member 67, which will be described later. Further, the partition groove 54 may be a recess that opens only on the second surface 52 side of the light guide member 50, or may be a recess that opens only on the first surface 51 side of the light guide member 50. When the division groove 54 is a recess, the division groove 54 has a bottom surface defined by the light guide member 50.

A member having a reflective property for the light emitted by the light source 10 may be arranged in the partition groove 54 . Thereby, 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 can be improved. Note that a member having a reflective property for the light emitted by the light source 10 does not have to be arranged in the partition groove 54 .

[light source]
As shown in FIG. 1, the light emitting module 100 of the embodiment includes a plurality of light sources 10. Further, the light emitting module 100 may include one light source 10. As shown in FIG. 2, the light source 10 includes a light emitting element 11. Light emitting element 11 includes a semiconductor structure. The semiconductor structure includes, for example, a substrate made of 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 semiconductor layer and the p-type semiconductor layer. including. Furthermore, the light emitting element 11 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 need to include the electrode 12. When the light source 10 does not include the electrode 12, the n-side electrode and the p-side electrode of the light emitting element 11 constitute a part of the lower surface of the light source 10. Further, the light source 10 does not need to include a substrate such as sapphire or gallium nitride. This makes it easier to downsize the light source 10 in the vertical direction Z.

The structure of the light emitting layer may be a structure with a single active layer such as a double heterostructure or a single quantum well structure (SQW), or a structure with a group of active layers such as a multiple quantum well structure (MQW). A structure with . The light emitting layer is capable of emitting visible light or ultraviolet light. The light emitting layer is capable of emitting visible light ranging from blue to red. A semiconductor structure including such a light emitting layer can include, for example, In _x Al _y Ga _1-x-y N (0≦x, 0≦y, x+y≦1). The semiconductor structure can include at least one light-emitting layer capable of emitting light as described above. For example, the semiconductor structure may include one or more light-emitting layers between an n-type semiconductor layer and a p-type semiconductor layer, or may include an n-type semiconductor layer, a light-emitting layer, and a p-type semiconductor layer. It may be a structure in which the structures included in this order are repeated multiple times. When the semiconductor structure includes a plurality of light-emitting layers, the semiconductor structure may include light-emitting layers with different light-emitting peak wavelengths, or may contain light-emitting layers with the same light-emitting peak wavelength. Note that the same emission peak wavelength may mean, for example, a variation of several nanometers. Such combinations of light-emitting layers can be selected as appropriate. For example, when the semiconductor structure includes two light-emitting layers, combinations of blue light and blue light, green light and green light, red light and red light, and ultraviolet light and The light-emitting layer can be selected using a combination of ultraviolet light, blue light and green light, blue light and red light, or green light and red light. Further, the light emitting layer may include a plurality of active layers having different emission peak wavelengths, or may include a plurality of active layers having the same emission peak wavelength.

One light source 10 includes one light emitting element 11. One light source 10 may include a plurality of light emitting elements 11. The light emission peak wavelengths of the plurality of light emitting elements 11 included in one light source 10 may be the same or different. For example, when one light source 10 includes two light emitting elements 11, 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 The emission peak wavelength of the light emitting element can be selected by combining red light and the like. For example, when one light source 10 includes three light emitting elements 11, blue light, green light, and red light, ultraviolet light, green light, and red light, ultraviolet light, blue light, and green light, ultraviolet light, blue light, and red light, The light emission peak wavelength of the light emitting element can be selected by combining light, ultraviolet light, green light, red light, etc.

In the example shown in FIG. 2, the light source 10 can further include a third translucent member 14. The third translucent member 14 covers the top and side surfaces of the light emitting element 11. The light emitting element 11 can be protected by the third translucent member 14. The third translucent member 14 may be arranged to expose at least a portion of the upper surface of the light emitting element 11. This makes it easier to downsize the light source 10 in the vertical direction Z.

The third translucent member 14 has translucency to light emitted by the light emitting element 11. For example, the third translucent member 14 may contain a translucent resin and may further contain a phosphor. As the transparent resin, for example, silicone resin or epoxy resin can be used. Further, as the phosphor, yttrium-aluminum-garnet-based phosphor (for example, (Y,Gd) ₃ (Al, Ga) ₅ O ₁₂ :Ce), lutetium-aluminum-garnet-based phosphor (for example, Lu ₃ ( Al, Ga) ₅ O ₁₂ :Ce), terbium aluminum garnet phosphor (e.g. Tb ₃ (Al, Ga) ₅ O ₁₂ :Ce), CCA phosphor (e.g. Ca ₁₀ (PO ₄ ) ₆ Cl ₂ :Eu), SAE phosphor (e.g. Sr ₄ Al ₁₄ O ₂₅ :Eu), chlorosilicate phosphor (e.g. Ca ₈ MgSi ₄ O ₁₆ Cl ₂ :Eu), silicate phosphor (e.g. (Ba, Sr, Ca, Mg) ₂ SiO ₄ :Eu), β-sialon phosphor (e.g. (Si, Al) ₃ (O,N) ₄ :Eu) or α-sialon phosphor (e.g. Ca( Oxynitride-based phosphors such as Si, Al) ₁₂ (O, N) ₁₆ :Eu), LSN-based phosphors (e.g., (La, Y) ₃ Si ₆ N ₁₁ :Ce), BSESN-based phosphors (e.g. , (Ba,Sr) ₂ Si ₅ N ₈ :Eu), SLA-based phosphor (e.g., SrLiAl ₃ N ₄ :Eu), CASN-based phosphor (e.g., CaAlSiN ₃ :Eu), or SCASN-based phosphor (e.g., Nitride-based phosphors such as (Sr,Ca)AlSiN ₃ :Eu), KSF-based phosphors (e.g., K ₂ SiF ₆ :Mn), KSAF-based phosphors (e.g., K ₂ (Si _1-x Al _x )) F _6-x :Mn (where x satisfies 0<x<1) or a fluoride-based phosphor such as MGF-based phosphor (for example, 3.5MgO・0.5MgF ₂・GeO ₂ :Mn) , a quantum dot with a perovskite structure (for example, (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 with a chalcopyrite structure (e.g. (Ag,Cu)(In,Ga)(S, Se) ₂ ) etc. can be used. As the phosphor added to the third light-transmitting member 14, one type of phosphor may be used, or multiple types of phosphor may be used.

Further, a wavelength conversion sheet containing the above-mentioned phosphor may be placed on the light emitting module 100. The wavelength conversion sheet absorbs a part of the blue light from the light source 10 and emits yellow light, green light, and/or red light, and can emit white light as the planar light source 300. For example, white light can be obtained by combining the light source 10 capable of emitting blue light and a wavelength conversion sheet containing a phosphor capable of emitting yellow light. Alternatively, the light source 10 capable of emitting blue light and a wavelength conversion sheet containing a red phosphor and a green phosphor may be combined. Further, the light source 10 capable of emitting blue light may be combined with a plurality of wavelength conversion sheets. As the plurality of 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. Further, the light source 10 includes a light emitting element 11 capable of emitting blue light, a third translucent member 14 containing a phosphor capable of emitting red light, and a wavelength converter containing a phosphor capable of emitting green light. You may also combine the sheets.

As the phosphor capable of emitting yellow light used in the wavelength conversion sheet, it is preferable to use, for example, the above-mentioned yttrium-aluminum-garnet-based phosphor. Further, as the phosphor capable of emitting green light and used in the wavelength conversion sheet, examples of the phosphor having a narrow half-width of the emission peak wavelength, such as the above-mentioned quantum dots having a perovskite structure, III-V quantum dots, or chalcopyrite, can be used. Preferably, quantum dots having a structure are used. In addition, as for the phosphor capable of emitting red light used in the wavelength conversion sheet, similar to the phosphor capable of emitting green light, the half width of the emission peak wavelength is narrow, such as the above-mentioned KSF-based phosphor, KSAF-based phosphor, etc. It is preferable to use a phosphor, a III-V group quantum dot, or a quantum dot having a chalcopyrite structure.

The light source 10 can further include a second covering member 15. The second covering member 15 is arranged on the lower surface of the light emitting element 11. The second covering member 15 is arranged 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 arranged on the lower surface of the third translucent member 14 that covers the side surface of the light emitting element 11 .

The second covering member 15 has reflectivity for light emitted by the light emitting element 11. For the second covering member 15, for example, a resin member containing gas such as nitrogen and/or oxygen, a resin member containing light scattering particles, or the like can be used. As the material of the resin member of the second covering member 15, the same material as the resin used for the light guide member 50 can be used. Examples of the light scattering particles of the second coating member 15 include titania, silica, alumina, zinc oxide, magnesium oxide, zirconia, yttria, calcium fluoride, magnesium fluoride, niobium pentoxide, barium titanate, tantalum pentoxide, Particles of barium sulfate or glass can be used. The second covering member 15 may contain both gas and light scattering particles.

The light source 10 may further include a first covering member 13 located on the top 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 . The first covering member 13 and the light emitting element 11 overlap in plan view, and the first covering member 13 is located above the light emitting element 11 in the overlapping portion. The first covering member 13 is arranged above the third transparent member 14 and adjusts the amount and/or direction of light emitted from the upper surface of the third transparent member 14 . The first covering member 13 has a reflective property and a translucent property for the light emitted by the light emitting element 11 . A part of the light emitted from the upper surface of the third transparent member 14 is reflected by the first covering member 13, and the other part 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, for example, preferably 1% or more and 50% or less, and more preferably 3% or more and 30% or less. By including the first covering member 13 in the light source 10, it is possible to prevent the area immediately above the light source 10 from becoming too bright. This reduces uneven brightness of the light emitting module 100.

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

The light source 10 is not limited to the form shown in FIG. Other forms of the light source 10 will be described below.

The light source 10 may not include the first covering member 13. This makes it easier to downsize the light source 10 in the vertical direction Z than when the light source 10 includes the first covering member 13 disposed above the light emitting element 11.

The light source 10 may not include the second covering member 15. For example, the lower surface of the light source 10 may be configured by the lower surface of the light emitting element 11, the lower surface of the pair of electrodes 12, and the lower surface of the third transparent member 14.

The light source 10 may include only the light emitting element 11 alone.

The light source 10 may have a configuration in which the first covering member 13 is disposed on the upper surface of the light emitting element 11 without including the second covering member 15 and the third translucent member 14.

Even if the light source 10 does not include the third transparent member 14, the first covering member 13 is arranged on the upper surface of the light emitting element 11, and the second covering member 15 is arranged on the lower surface of the light emitting element 11. good.

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, circular, triangular, quadrangular, hexagonal, or octagonal. When the shape of the light source 10 in plan view is a quadrilateral, a pair of mutually parallel outer edges of the light source 10 may be parallel to the first direction X, or may be inclined with respect to the first direction X. In this embodiment, a pair of mutually parallel outer edges of the light source 10 are inclined at 45 degrees with respect to the first direction X, as shown in FIG.

[First translucent member]
The first translucent member 21 has translucency to the light emitted by the light source 10. The transmittance of the first transparent 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, for example.

The first translucent 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 translucent member 21. The light from the light source 10 that has entered the first transparent member 21 propagates within the first transparent member 21 .

In 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 360° directions around the light source 10.

It is preferable that the first translucent member 21 is arranged so as to expose at least a portion of the upper surface of the light source 10. This makes it easier to downsize the light emitting module 100 in the vertical direction Z than when the first translucent member 21 covers the entire upper surface of the light source 10. The first translucent member 21 may be arranged so as to expose the entire upper surface of the light source 10.

The first translucent 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 translucent member 21, it becomes easy to adjust the brightness in the area directly above the light source 10. For example, by changing the thickness of the portion of the first translucent member 21 that covers the upper surface of the light source 10, the brightness in the area directly above the light source 10 can be adjusted. By making it easier to adjust the brightness in the area directly above the light source 10, it becomes easier to reduce uneven brightness of the light emitting module 100.

The first translucent member 21 may be composed of a single layer in the vertical direction Z, or may be composed of a laminate of a plurality of layers. Further, the first light-transmitting member 21 may contain a fluorescent substance and/or light-scattering particles. When the first translucent member 21 is a laminate, each layer may or may not contain phosphor and/or light scattering particles. For example, the first light-transmitting member 21 may be composed of a layer containing a phosphor and a layer not containing a phosphor. As the material of the first translucent member 21, for example, the same material as the resin used for the light guide member 50 can be used.

The first translucent member 21 is located between the side surface of the light source 10 and the light guide member 50. The light guide member 50 makes it easier to propagate the light from the light source 10 over a wider area in the lateral direction.

The first translucent member 21 is in contact with a surface of the light guide member 50 that defines the through hole 53 . Thereby, the light from the light source 10 propagates within the first translucent member 21 and becomes easier to enter the light guide member 50. In the example shown in FIG. 2, the first translucent member 21 is in contact with the first side surface 50a, the second side surface 50b, and the surface 50c.

At the interface between the first light-transmitting member 21 and the light guide member 50, light tends to head upward due to refraction or reflection. Therefore, on the light emitting surface of the light emitting module 100, the vicinity of the upper end of the interface between the first light transmitting member 21 and the light guide member 50 may easily become bright.

According to this embodiment, at least a portion of the interface between the first transparent member 21 and the light guide member 50 is configured by the first side surface 50a and the second side surface 50b. The first side surface 50a and the second side surface 50b, on which light tends to head upward due to refraction or reflection, do not overlap in plan view. Thereby, on the light emitting surface of the light emitting module 100, it is possible to prevent the interface between the first translucent member 21 and the light guide member 50 from becoming too bright, and it becomes easier to reduce brightness unevenness on the light emitting surface.

In addition, the brightness on the light emitting surface of the light emitting module 100 is adjusted by the size and/or position of the convex portion 55 located at the boundary between the second surface 52 and the outer edge of the second portion 53b of the through hole 53 in plan view. can. This makes it easier to reduce brightness unevenness on the light emitting surface of the light emitting module 100.

In the vertical direction Z, the second portion 53b of the through hole 53 is preferably located above the height at which the upper surface 11a of the light emitting element 11 is located. This can prevent the boundary between the second surface 52 and the outer edge of the second portion 53b from becoming too bright due to light emitted from the upper surface 11a of the light emitting element 11, and reduce uneven brightness on the light emitting surface of the light emitting module 100. It becomes easier.

Further, in the vertical direction Z, a part of the second portion 53b of the through hole 53 is preferably located below the height at which the upper surface 13a of the first covering member 13 of the light source 10 is located. As a result, the boundary between the second surface 52 and the outer edge of the second portion 53b can be prevented from becoming too bright due to light emitted laterally from the side surface of the first covering member 13, and the luminance on the light emitting surface of the light emitting module 100 can be reduced. It becomes easier to reduce unevenness.

As shown in FIG. 3, 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 in a cross-sectional view. The second side surface 50b includes, for example, a downwardly recessed curved surface. It continues from the surface of the convex portion 55 to the first side surface 50a via the second side surface 50b.

Since the second side surface 50b is inclined with respect to the second surface 52, uneven brightness on the light emitting surface can be reduced more easily than when the second side surface 50b is perpendicular to the second surface 52. For example, since the second side surface 50b is inclined with respect to the second surface 52, the area of the second side surface 50b in plan view is reduced compared to the case where the second side surface 50b is perpendicular to the second surface 52. Can be made larger. By extracting the light from the light source 10 from the second side surface 50b, which has a large area in plan view, it is possible to prevent the upper part of the second side surface 50b from becoming too bright. This makes it easier to reduce brightness unevenness on the light emitting surface of the light emitting module 100.

The first side surface 50a may be perpendicular to the second surface 52 or may be inclined. Further, the first side surface 50a may include a recessed portion recessed toward the light guide member 50 side. Further, a convex portion may be arranged on the first side surface 50a toward the light source 10 side.

As shown in FIG. 4, a plurality of second portions 53b located outside the first portion 53a in plan view may be arranged to surround the light source 10. As a result, the first light-transmitting member 21 disposed in the second portion 53b and the light guide member 50 coexist around the light source 10 in a plan view, and the first light-transmitting member 21 and the light guide member 50 This makes the boundary between the two surfaces less noticeable, making it easier to reduce uneven brightness on the light emitting surface.

In FIG. 4, the outer edge of the first portion 53a is represented by, for example, a circular broken line. In FIG. 4, the convex portion 55 is represented by a solid line. In FIG. 4, the outer edge of the second portion 53b coincides with the inner edge of the solid line representing the convex portion 55. In FIG. In plan view, the outer edges of the convex portion 55 and the second portion 53b include a portion that coincides with the outer edge of the first portion 53a.

For example, in a direction along a virtual closed curve surrounding the light source 10 in plan view, the distance D between adjacent second portions 53b is preferably shorter than the length L of the outer edge of the second portions 53b. Since the distance D is shorter than the length L, it becomes easier to increase the proportion of the portion of the through hole 53 where the second portion 53b is arranged. This makes the boundary between the first light-transmitting member 21 and the light guide member 50 less noticeable, and makes it easier to reduce uneven brightness 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 refers to a line segment connecting one end and the other end of the portion where the first portion 53a and the second portion 53b touch in plan view. It is the length.

The length L of the outer edge of the second portion 53b is, for example, not less than 0.2 times and not more than twice 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.

In plan view, if the outer edge of the second portion 53b has a corner, the direction in which the outer edge of the second portion 53b extends changes abruptly. That is, the direction of the interface between the second side surface 50b of the light guide member 50 and the first light-transmitting member 21 (the direction of the normal vector) changes rapidly. Due to a sudden change in the direction of the interface between the light guide member 50 and the first light-transmitting member 21, uneven brightness such as local brightness is likely to occur. Therefore, as shown in FIGS. 1 and 4, it is preferable that at least a portion of the outer edge of the second portion 53b is curved in plan view.

[Light adjustment member]
As shown in FIG. 2, the light emitting module 100 of the embodiment can further include a light adjustment member 30. The light adjustment member 30 has reflective properties and translucency for the light emitted by the light source 10. Part of the light emitted from the light source 10 is reflected by the light adjustment member 30, and the other part is transmitted through the light adjustment member 30. The transmittance of the light adjustment member 30 with respect to the peak wavelength of the light source 10 is, for example, preferably 1% or more and 50% or less, and more preferably 3% or more and 30% or less. The upper surface of the light adjusting member 30 constitutes the light emitting surface of the light emitting module 100 together with the second surface 52 of the light guiding member 50 .

The light adjustment member 30 can be configured by, for example, a resin member (hereinafter referred to as a light adjustment resin member) and a reflector included in the light adjustment resin member (hereinafter referred to as a light adjustment reflector). As the material of the light adjustment resin member, the same material as the resin used for the light guide member 50 can be used. As the material of the light adjustment reflector, the same material as the light scattering particles of the second covering member 15 can be used. Gases such as nitrogen and/or oxygen may also be used as light regulating reflectors. The light adjustment member 30 may include both light scattering particles and gas. The light adjustment member 30 may be composed of a single layer or a laminate of a plurality of layers.

The light adjustment member 30 is arranged above the light source 10. In plan view, the light adjustment member 30 and the light source 10 overlap. By locating the light adjustment member 30 above the light source 10, it is possible to prevent the area immediately above the light source 10 from becoming too bright, and it is possible to easily reduce brightness unevenness on the light emitting surface of the light emitting module 100.

Further, the light adjustment member 30 is arranged above the first portion 53a of the through hole 53. That is, the light adjustment member 30 is arranged above the first translucent member 21 arranged in the first portion 53a. In 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 locating the light adjustment member 30 above the first light-transmitting member 21 , it is possible to prevent the area directly above the first light-transmitting member 21 (the area around the light source 10 ) from becoming too bright, and to improve the brightness of the light-emitting module 100 . Luminance unevenness on the light emitting surface can be easily reduced.

Further, it is preferable that the light adjustment member 30 extends from a position above the first portion 53a of the through hole 53 to a position above the second portion 53b so as to straddle the first side surface 50a in a plan view. That is, the light adjustment member 30 covers the upper side of the first side surface 50a. Thereby, it is possible to prevent 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, from becoming too bright, and it is possible to easily reduce brightness unevenness on the light emitting surface of the light emitting module 100.

[Second translucent member]
The light emitting module 100 of the embodiment can further include a second light-transmitting member 22. The second translucent member 22 has translucency to the light emitted by the light source 10. The transmittance of the second transparent 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, for example.

The second translucent member 22 is arranged between the light source 10 and the light adjustment member 30 and between the first translucent member 21 and the light adjustment member 30 in cross-sectional view. The second light-transmitting member 22 bonds the light source 10 and the light adjustment member 30 together, and bonds the first light-transmission member 21 and the light adjustment member 30 together. The maximum thickness of the second transparent member 22 in the vertical direction Z is smaller than the maximum thickness of the first transparent member 21 in the vertical direction Z.

The first translucent member 21 is formed, for example, by supplying a fluid resin into the through hole 53 and then thermally curing the resin. When forming the first light-transmitting member 21, the upper surface of the first light-transmitting member 21 may become a concave surface due to contraction of the resin. In this case, the second light-transmitting member 22 can easily make the surface on which the light adjustment member 30 is arranged (the upper surface of the second light-transmitting member 22) flat. For example, when the light adjustment member 30 is sheet-shaped, the flat upper surface of the second light-transmitting member 22 makes it easier to arrange the light adjustment member 30 on the upper surface of the second light-transmitting member 22. .

As the material of 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 difference in refractive index between the first light-transmitting member 21 and the second light-transmitting member 22 can be reduced. Thereby, reflection of light at the interface between the first light-transmitting member 21 and the second light-transmitting member 22 can be reduced, and the amount of light extracted upward can be easily increased. The second light-transmitting member 22 may contain phosphor and/or light-scattering particles.

After supplying the second light-transmitting member 22 having fluidity onto the first light-transmitting member 21 and the light source 10, a light adjusting member 30 in the form of a sheet, for example, is arranged on the second light-transmitting member 22. . After the light adjustment member 30 is placed on the second light-transmitting member 22, the second light-transmitting member 22 is cured, for example, by heat. When the second translucent member 22 having fluidity is supplied onto the first translucent member 21 , the second translucent member 22 comes into contact with the convex portion 55 , and the convex portion 55 causes the second translucent member 22 to This makes it difficult for the liquid to flow out onto the second surface 52. This facilitates brightness adjustment on the second surface 52.

The light adjustment member 30 is not limited to a sheet shape, and may be supplied onto the second light-transmitting member 22 in a fluid state and then thermally cured. At this time, the light adjusting member 30 having fluidity comes into contact with the convex portion 55, and the convex portion 55 makes it difficult for the light adjusting member 30 to flow out to the second surface 52. This facilitates brightness adjustment on the second surface 52. Furthermore, the positional accuracy of the light adjustment member 30 can be improved, and brightness adjustment on the light emitting surface of the light emitting module 100 can be easily performed. Moreover, variations in the shape and/or thickness of the light adjustment member 30 can be reduced, and brightness adjustment in the area where the light adjustment member 30 is arranged becomes easy.

Further, the second side surface 50b of the light guide member 50 that defines the second portion 53b of the through hole 53 can also make it difficult for the second light-transmitting member 22 and the light adjustment member 30 to flow out to the second surface 52.

As shown in FIG. 5, a convex portion 56 may be arranged on the second surface 52 at a position away from the through hole 53. A second surface 52 is continuous between the surface of the convex portion 56 and the second side surface 50b defining the second portion 53b of the through hole 53. The convex portion 56 makes it difficult for the second light-transmitting member 22 and the light adjustment member 30 to flow out to the second surface 52 located outside the convex portion 56 in plan view.

The planar light source 300 of the embodiment further includes a support member 200 that supports the light emitting module 100. The light guide member 50 is arranged on the support member 200 with the first surface 51 facing the upper surface of the support member 200. Inside the through hole 53, the light source 10 and the first translucent member 21 are located on the support member 200.

The support member 200 has a wiring board 60. The wiring board 60 includes an insulating base material 61 and at least one wiring layer 62 disposed on at least one surface of the insulating base material 61. The insulating base material 61 may be a rigid substrate or a flexible substrate. In order to reduce the thickness of the planar light source 300, the insulating base material 61 is preferably a flexible substrate. The insulating base material 61 may be composed of a single layer in the vertical direction Z, or may be composed of a laminate of a plurality of layers. For example, the insulating base material 61 may be composed of a single-layer flexible substrate, or may be composed of a laminate of a plurality of rigid substrates. As the material of the insulating base material 61, for example, resin such as polyimide can be used. The wiring layer 62 is a metal film, for example, a copper film.

The support member 200 includes a first adhesive layer 63 disposed on the wiring board 60, a reflective member 64 disposed on the first adhesive layer 63, a second adhesive layer 65 disposed on the reflective member 64, It further has.

The first adhesive layer 63 is disposed between the wiring board 60 and the reflective member 64 and bonds 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, the same material as 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, the same material as the light scattering particles of the second covering member 15 can be used. As the first adhesive layer 63, a sheet-shaped optical transparent adhesive may be used.

The refractive index of the resin member of the first adhesive layer 63 is preferably lower than the refractive index of the resin member of the reflective member 64. In this specification, the refractive index is 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 the refractive index of the resin member of the reflective member 64, a part of the light that travels from the reflective member 64 to the first adhesive layer 63 is transmitted to the reflective member 64. Total reflection is likely to occur at the interface with the first adhesive layer 63. This makes it possible to reduce the amount of light that passes through the light emitting module 100 downward, thereby making it easier to improve the light extraction efficiency of the light emitting module 100.

The reflective member 64 is arranged below the light guide member 50, below the light source 10, below the first translucent member 21, and below the partition groove 54. The reflective member 64 has reflectivity for the light emitted by the light source 10. The reflective member 64 can be configured by a resin member and a reflector contained in the resin member. As the resin member of the reflective member 64, for example, the same material as the resin used for the light guide member 50 can be used. As the material of the reflector of the reflective member 64, the same material as the light scattering particles of the second covering member 15 can be used. A gas such as nitrogen and/or oxygen may be used as the reflector of the reflective member 64. Further, the reflecting member 64 may include both light scattering particles and gas as a reflector.

The refractive index of the reflector of the reflective member 64 is preferably lower than the refractive index of the resin member of the reflective member 64. By setting the refractive index of the reflector of the reflective member 64 to be lower than the refractive index of the resin member of the reflective member 64, a part of the light from the light source 10 that is incident on the reflective member 64 is transmitted to the resin member of the reflective member 64. Total reflection is likely to occur at the interface between the reflective member 64 and the reflector. This can reduce the amount of light passing downward from the reflective member 64, making it easier to improve the light extraction efficiency of the light emitting module 100.

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 difference in refractive index between the resin member of the reflective member 64 and the reflector of the reflective member 64, so that a part of the light from the light source 10 that has entered the reflective member 64 is reflected by the resin member of the reflective member 64. Total reflection is likely to occur at the interface between the member 64 and the reflector.

The second adhesive layer 65 is disposed between the reflective member 64 and the second surface 52 of the light guide member 50 and bonds the reflective member 64 and the light guide member 50 together. The light source 10 is arranged 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, the same material as 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, the same material as the light scattering particles of the second covering member 15 can be used. As the second adhesive layer 65, a sheet-shaped optical transparent adhesive may be used.

The refractive index of the resin member of the second adhesive layer 65 is preferably lower than the refractive index of the light guide member 50. By making the refractive index of the resin member of the second adhesive layer 65 lower than the refractive index of the light guide member 50, a part of the light that travels from the light guide member 50 to the second adhesive layer 65 is transferred to the light guide member 50. Total reflection is likely to occur at the interface with the second adhesive layer 65. This makes it possible to reduce the amount of light that passes through the light emitting module 100 downward, thereby making it easier to improve the light extraction efficiency of the light emitting module 100.

The refractive index of the resin member of the second adhesive layer 65 is preferably lower than the refractive index of the first translucent member 21 . By making the refractive index of the resin member of the second adhesive layer 65 lower than the refractive index of the first transparent member 21, a portion of the light that travels from the first transparent member 21 to the second adhesive layer 65 is , total reflection is likely to occur at the interface between the first transparent member 21 and the second adhesive layer 65. This makes it possible to reduce the amount of light that passes through the light emitting module 100 downward, thereby making it easier to improve the light extraction efficiency of the light emitting module 100.

Support member 200 further includes a conductive member 67. The conductive member 67 includes, for example, resin and metal particles contained in the resin. As the resin for the conductive member 67, for example, epoxy resin or phenol resin can be used. As the metal particles of the conductive member 67, for example, copper or silver particles can be used.

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 base material 61 in the vertical direction Z. The wiring section 67b is arranged on the surface of the wiring board 60 on which the wiring layer 62 is arranged, and is connected to the connection section 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.

A pair of conductive members 67 are arranged apart from each other in the lateral direction, corresponding to the pair of positive and negative electrodes 12 of the light source 10 . Among the pair of conductive members 67, the connecting portion 67a of one conductive member 67 is connected to the positive electrode 12 below the light source 10, and the connecting portion 67a of the other conductive member 67 is connected to the negative electrode 12 below the light source 10. It is connected to the side electrode 12. The electrode 12 of the light source 10 is electrically connected to the wiring layer 62 via a conductive member 67.

Support member 200 further includes an insulating layer 66. The insulating layer 66 is disposed on the lower surface of the wiring board 60 and covers the wiring layer 62. As a material for the insulating layer 66, for example, epoxy resin, urethane resin, or acrylic resin can be used.

Embodiments of the present invention include the following light emitting modules.

[Section 1]
A light guide member having a first surface, a second surface located on the opposite side of the first surface, a through hole penetrating from the first surface to the second surface, and a convex part, The hole has a first portion that opens toward the first surface, and a second portion that opens toward the second surface and has a width wider than the first portion in the lateral direction, and the convex portion has a second portion that opens toward the second surface and has a width wider than the first portion. the light guide member having a surface disposed on a second surface and continuous with the second portion;
a light source disposed within the through hole;
a first translucent member disposed within the through hole and in contact with a first side surface defining the first portion and a second side surface defining the second portion;
A light emitting module.
[Section 2]
a light adjustment member disposed above the light source and above the first portion;
The light emitting module according to item 1 above, comprising:
[Section 3]
a second light-transmitting member located between the light adjustment member and the first light-transmitting member;
3. The light emitting module according to item 2, wherein the second light-transmitting member is in contact with the convex portion.
[Section 4]
3. The light emitting module according to item 1 or 2 above, wherein the light adjustment member is in contact with the convex portion.
[Section 5]
5. The light emitting module according to any one of items 1 to 4 above, wherein at least a portion of the second side surface is inclined with respect to the second surface when viewed in cross section.
[Section 6]
The light source has a light emitting element,
6. The light emitting module according to any one of items 1 to 5 above, wherein the second portion is located above a height at which the top surface of the light emitting element is located in the vertical direction.
[Section 7]
The light source includes a first covering member located on the top surface of the light emitting element,
7. The light emitting module according to item 6, wherein in the vertical direction, a part of the second portion is located below a height at which the upper surface of the first covering member is located.
[Section 8]
8. The light emitting module according to any one of items 1 to 7 above, wherein the plurality of second portions are arranged so as to surround the light source in plan view.
[Section 9]
9. The light emitting module according to item 8, wherein the distance between the adjacent second portions is smaller than the length of the outer edge of the second portion in plan view.
[Section 10]
10. The light emitting module according to any one of items 1 to 9 above, wherein at least a part of the outer edge of the second portion is a curved line when viewed in plan.

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 can be implemented by appropriately modifying the design based on the above-described embodiments of the present invention by those skilled in the art also belong to the scope of the present invention as long as they encompass the gist of the present invention. In addition, within the scope of the idea of the present invention, those skilled in the art will be able to come up with various changes and modifications, and these changes and modifications also belong to the scope of the present invention.

DESCRIPTION OF SYMBOLS 10... Light source, 11... Light emitting element, 13... First covering member, 14... Third translucent member, 15... Second covering member, 21... First translucent member, 22... Second translucent member, 30... Light adjusting member, 50... Light guiding 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 portion, 54...Dividing groove, 55...Protrusion, 56...Protrusion, 60...Wiring board, 61...Insulating base material, 62...Wiring layer, 63...First adhesive layer, 64...Reflection member , 65... Second adhesive layer, 66... Insulating layer, 67... Conductive member, 100... Light emitting module, 200... Supporting member, 300... Planar light source

Claims (10)

A light guide member having a first surface, a second surface located on the opposite side of the first surface, a through hole penetrating from the first surface to the second surface, and a convex part, The hole has a first portion that opens toward the first surface, and a second portion that opens toward the second surface and has a width wider than the first portion in the lateral direction, and the convex portion has a second portion that opens toward the second surface and has a width wider than the first portion. the light guide member having a surface disposed on a second surface and continuous with the second portion;
a light source disposed within the through hole;
a first translucent member disposed within the through hole and in contact with a first side surface defining the first portion and a second side surface defining the second portion;
A light emitting module. a light adjustment member disposed above the light source and above the first portion;
The light emitting module according to claim 1, comprising: a second light-transmitting member located between the light adjustment member and the first light-transmitting member;
The light emitting module according to claim 2, wherein the second translucent member is in contact with the convex portion. The light emitting module according to claim 2, wherein the light adjustment member is in contact with the convex portion. The light emitting module according to any one of claims 1 to 4, wherein at least a portion of the second side surface is inclined with respect to the second surface when viewed in cross section. The light source has a light emitting element,
5. The light emitting module according to claim 1, wherein the second portion is located above a height at which an upper surface of the light emitting element is located in the vertical direction. The light source includes a first covering member located on the top surface of the light emitting element,
The light emitting module according to claim 6, wherein in the vertical direction, a part of the second portion is located below a height at which an upper surface of the first covering member is located. The light emitting module according to any one of claims 1 to 4, wherein the plurality of second portions are arranged so as to surround the light source in plan view. The light emitting module according to claim 8, wherein a distance between adjacent second portions is smaller than a length of an outer edge of the second portion when viewed in plan. The light emitting module according to any one of claims 1 to 4, wherein at least a part of the outer edge of the second portion is a curved line when viewed in plan.

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