JP2024139636A - Light Emitting Module - Google Patents

Abstract

[Problem] To provide a light emitting module that can easily reduce brightness unevenness. [Solution] A light emitting module comprising: a light guide member having a first surface, a second surface opposite to the first surface, and a first through hole penetrating from the first surface to the second surface, a light source unit located in the first through hole, a light adjustment member located above the light source unit, and a light-transmitting member located in the first through hole and surrounding the light source unit and the light adjustment member in a top view, the light-transmitting member including a plurality of reflective particles that are biased toward the upper side. [Selected Figure] Figure 3

Description

An embodiment of the present invention relates to a light-emitting module.

Light-emitting modules that combine a light-emitting element such as a light-emitting diode with a light-guiding member are widely used in planar light sources such as backlights for liquid crystal displays. For example, Patent Document 1 discloses a light-emitting module that includes a light source unit and a light-guiding member that includes a hole in which the light source unit is disposed.

JP 2022-056369 A

There is a demand for light-emitting modules that further reduce brightness unevenness. The object of the embodiment of the present invention is to provide a light-emitting module that can easily reduce brightness unevenness.

According to one aspect of the present invention, the light-emitting module includes a light-guiding member having a first surface, a second surface opposite to the first surface, and a first through hole penetrating from the first surface to the second surface, a light source unit located within the first through hole, a light adjustment member located above the light source unit, and a light-transmitting member located within the first through hole and surrounding the light source unit and the light adjustment member in a top view, the light-transmitting member including a plurality of reflective particles biased toward the upper side.

According to one embodiment of the light-emitting module, it is possible to provide a light-emitting module that is easy to reduce brightness unevenness.

FIG. 2 is a schematic top view of the surface light source according to the embodiment. FIG. 2 is a schematic top view of one light-emitting region of the surface light source according to the embodiment. 3 is a schematic cross-sectional view taken along line III-III in FIG. 2. FIG. 2 is a schematic cross-sectional view of a light source unit according to the embodiment. 11 is a schematic cross-sectional view of a modified example of the light source unit according to the embodiment. FIG. FIG. 3 is a schematic cross-sectional view taken along line III-III according to a modified example of the present embodiment. 13 is a schematic top view of the periphery of a light-transmitting member according to a modified example of the embodiment. FIG. 6B is a schematic cross-sectional view taken along line VIB-VIB in FIG. 6A. FIG. 2 is a schematic cross-sectional view of a light adjusting member according to the present embodiment. 5A to 5C are schematic cross-sectional views showing a method for manufacturing the surface light source according to the embodiment. 5A to 5C are schematic cross-sectional views showing a method for manufacturing the surface light source according to the embodiment. 5A to 5C are schematic cross-sectional views showing a method for manufacturing the surface light source according to the embodiment. 5A to 5C are schematic diagrams showing an example of centrifugal sedimentation in the method for manufacturing the surface light source according to the embodiment. 5A to 5C are schematic cross-sectional views showing a method for manufacturing the surface light source according to the embodiment. 5A to 5C are schematic cross-sectional views showing a method for manufacturing the surface light source according to the embodiment. 5A to 5C are schematic cross-sectional views showing a method for manufacturing the surface light source according to the embodiment.

The following describes the embodiments with reference to the drawings. Since each drawing is a schematic representation of the embodiment, the scale, spacing, or positional relationship of each component may be exaggerated, or some components may not be shown. In this specification, the direction of the Z-axis arrow is defined as upward, and the direction opposite to the direction of the Z-axis arrow is defined as downward. Viewing an object from above is called a top view, which is synonymous with a plan view. In addition, as a cross-sectional view, an end view showing only the cut surface may be shown.

In the following description, components having substantially the same functions are indicated by common reference symbols, and descriptions may be omitted. In addition, terms indicating a specific direction or position (for example, "up", "down", and other terms including these terms) may be used. However, these terms are merely used for the purpose of making the relative direction or position in the referenced drawings easier to understand. As long as the relationship of the relative direction or position by terms such as "up" and "down" in the referenced drawings is the same, the arrangement in drawings other than this disclosure, in actual products, etc., may not be the same as that in the referenced drawings. In this specification, "parallel" includes not only cases where two straight lines, sides, faces, etc. do not intersect even when extended, but also cases where the angle between the two straight lines, sides, faces, etc. is within a range of 10°. In addition, "orthogonal" means cases where two straight lines, sides, faces, etc. intersect within a range of 90°±10°, and also includes cases where the two straight lines, sides, faces, etc. do not intersect but intersect when extended. In this specification, the positional relationship expressed as "above" includes cases where the two are in contact with each other, and cases where the two are not in contact but are located above each other.

[Embodiment]
The light-emitting module 100 and the surface light source 300 of the embodiment will be described with reference to Figs. 1 to 7. Fig. 1 is a view of the surface light source 300 as viewed from the light-emitting surface side. As shown in Fig. 1, two directions that are parallel to the light-emitting surface of the surface light source 300 and perpendicular to each other are defined as the X direction and the Y direction. The direction perpendicular to the X direction and the Y direction is defined as the Z direction. In this specification, a plane parallel to the X direction and the Y direction may be referred to as the XY plane. In addition, a direction inclined from the X direction at an angle of 0° or more and less than 360° in the XY plane may be referred to as the horizontal direction, and the Z direction may be referred to as the vertical direction.

As shown in FIG. 3, the surface light source 300 includes a light emitting module 100 and a support member 200. The light emitting module 100 is located on the support member 200. The light emitting module 100 includes a light guide member 20, a light source unit 10, a light adjustment member 41, and a light-transmitting member 30. The light guide member 20 has a first surface 201, a second surface 202 opposite to the first surface 201, and a first through hole 20H penetrating from the first surface 201 to the second surface 202. The light source unit 10 is located in the first through hole 20H. The light adjustment member 41 is located above the light source unit 10. The light-transmitting member 30 is located in the first through hole 20H. The light-transmitting member 30 surrounds the light source unit 10 and the light adjustment member 41 in a top view. The light-transmitting member 30 includes a plurality of reflective particles that are biased toward the upper side.

The light-emitting module 100 can reduce the amount of light passing through the light-transmitting member 30 upwards by including a plurality of reflective particles that are biased toward the upper side of the light-transmitting member 30. This makes it easier to reduce uneven brightness of the light-emitting module 100.

The elements that make up the light-emitting module 100 and the surface light source 300 are described in detail below.

(Light source unit 10)
1, the light emitting module 100 includes a plurality of light source units 10 including a first light source 10A, a second light source 10B, a third light source 10C, and a fourth light source 10D. The number of light source units 10 included in the light emitting module 100 may be one.

As shown in FIG. 4A, the light source unit 10 includes a light emitting element 11. The light emitting element 11 includes a semiconductor laminate. The semiconductor laminate 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 semiconductor layer and the p-type semiconductor layer. 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 unit 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 unit 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 unit 10 may not include the electrode 12. When the light source unit 10 does not include a pair of positive and negative electrodes 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 unit 10. In addition, the light source unit 10 does not need to have a substrate such as sapphire or gallium nitride. This makes it easier to reduce the size of the light source unit 10 in the vertical direction.

The structure of the light emitting layer may be a structure having a single active layer such as a double heterostructure or a single quantum well structure (SQW), or a structure having a group of active layers such as a multiple quantum well structure (MQW). The light emitting layer can emit visible light or ultraviolet light. The light emitting layer can emit visible light from blue to red. An example of a semiconductor laminate including such a light emitting layer may include In _x Al _y Ga _1-x-y N (0≦x, 0≦y, x+y≦1). The semiconductor laminate may include at least one light emitting layer capable of emitting the above-mentioned light. For example, the semiconductor laminate may include one or more light emitting layers between an n-type semiconductor layer and a p-type semiconductor layer, or may include a structure in which a structure including an n-type semiconductor layer, a light emitting layer, and a p-type semiconductor layer in order is repeated multiple times. When the semiconductor laminate includes multiple light emitting layers, the semiconductor laminate may include light emitting layers having different peak wavelengths, or may include light emitting layers having the same peak wavelength. The same peak wavelength may have a variation of, for example, about several nm. Such a combination of light-emitting layers can be appropriately selected, and for example, when the semiconductor laminate includes two light-emitting layers, the light-emitting layers can be selected from combinations of 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, green light and red light, etc. Furthermore, the light-emitting layer may include a plurality of active layers having different peak wavelengths, or may include a plurality of active layers having the same peak wavelength.

The light source unit 10 shown in FIG. 4A includes one light-emitting element 11. Each of the light source units 10 of the first light source 10A, the second light source 10B, the third light source 10C, and the fourth light source 10D may include multiple light-emitting elements 11. The peak wavelengths of the multiple light-emitting elements included in each light source unit 10 may be the same or different. For example, when each light source unit 10 includes two light-emitting elements, the 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, when each light source unit 10 includes three light-emitting elements, the 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, ultraviolet light and green light and red light.

As shown in FIG. 4A, the light source unit 10 can further include a translucent member (hereinafter referred to as the light source translucent member 13). The light source translucent member 13 covers the upper surface and side surfaces of the light emitting element 11. The light source translucent member 13 can protect the light emitting element 11. The light source translucent member 13 may be arranged so as to expose at least a portion of the upper surface of the light emitting element 11. This makes it easier to miniaturize the light source unit 10 in the vertical direction.

In a cross-sectional view, the side surface of the light-source translucent member 13 may be parallel to the Z direction, or may be inclined relative to the Z direction. When the side surface of the light-source translucent member 13 is inclined relative to the Z direction in a cross-sectional view, the lateral length of the light-source translucent member 13 in the cross-sectional view may be inclined so that it becomes longer in the downward direction, or may be inclined so that it becomes shorter in the downward direction. In addition, a pair of side surfaces of the light-source translucent member 13 in the cross-sectional view may be inclined at the same angle relative to the Z direction. In a cross-sectional view, the side surface of the light-source translucent member 13 may have a step.

For example, the light source translucent member 13 has translucency to the light emitted by the light emitting element 11. The light source translucent member 13 includes a translucent resin and may further include a phosphor. As the translucent resin, for example, a silicone resin, an epoxy resin, or the like can be used. Examples of phosphors include yttrium aluminum garnet phosphors (e.g., (Y,Gd) ₃ (Al,Ga) _5O12 :Ce), lutetium aluminum garnet phosphors (e.g., _Lu3 (Al,Ga) _5O12 :Ce), terbium aluminum garnet phosphors (e.g., _Tb3 (Al, _Ga ) _5O12 :Ce), CCA phosphors (e.g. _{, Ca10 (PO4 ) 6Cl2 :} Eu), SAE phosphors ( _e.g. , _{Sr4Al14O25 :} Eu), _{chlorosilicate} phosphors (e.g., _{Ca8MgSi4O16Cl2} :Eu), silicate phosphors (e.g. _, (Ba, _Sr ,Ca,Mg) _{2SiO 4} :Eu), β-sialon phosphor (for example, (Si,Al) ₃ (O,N) ₄ :Eu) or α-sialon phosphor (for example, Ca(Si,Al) ₁₂ (O,N) ₁₆ :Eu), nitride phosphors such as LSN phosphor (for example, ( _La , _{Y)3Si6N11 :} Ce), BSESN phosphor (for example, (Ba,Sr) _2Si5N8 :Eu ₎ , SLA phosphor (for example, _SrLiAl3N4 : _Eu ), _CASN phosphor (for example, _CaAlSiN3 :Eu) or SCASN phosphor (for example, (Sr,Ca) _AlSiN3 :Eu), KSF _phosphor (for example, _K2SiF6 Fluoride-based phosphors such as KSAF-based phosphors (e.g., _K2 (Si1 _{-xAlx ) F6-x} :Mn, where x satisfies 0<x< ₁ ) or 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 quantum dots (e.g., CdSe), III-V 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. The phosphor added to the light source transmissive member 13 may be one type of phosphor or a plurality of types of phosphors.

The wavelength conversion sheet containing the phosphor described above may be placed on the upper side of the planar light source 300. The wavelength conversion sheet can be a planar light source that absorbs a part of the blue light from the light source unit 10, emits yellow light, green light and/or red light, and emits white light. For example, white light can be obtained by combining the light source unit 10 capable of emitting blue light with a wavelength conversion sheet containing a phosphor capable of emitting yellow light. Alternatively, the light source unit 10 capable of emitting blue light may be combined with a wavelength conversion sheet containing a red phosphor and a green phosphor. The light source unit 10 capable of emitting blue light may be combined with multiple wavelength conversion sheets. As 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. Also, a light source unit 10 having a light emitting element 11 capable of emitting blue light and a light source translucent member 13 containing a phosphor capable of emitting red light may be combined with a wavelength conversion sheet containing a phosphor capable of emitting green light.

As the phosphor capable of emitting yellow light used in the wavelength conversion sheet, for example, the above-mentioned yttrium aluminum garnet phosphor is preferably used. As the phosphor capable of emitting green light used in the wavelength conversion sheet, it is preferable to use quantum dots having a narrow half-width of the emission peak wavelength, for example, quantum dots having a perovskite structure, III-V group quantum dots, or quantum dots having a chalcopyrite structure, as the above-mentioned. As the phosphor capable of emitting red light used in the wavelength conversion sheet, it is preferable to use quantum dots having a narrow half-width of the emission peak wavelength, for example, the above-mentioned KSF phosphor, KSAF phosphor, III-V group quantum dots, or quantum dots having a chalcopyrite structure, as the same as the phosphor capable of emitting green light.

A bandpass filter that transmits light in a specific wavelength region and reflects light in other wavelength regions may be disposed between the wavelength conversion sheet and the light source unit 10. For example, a dichroic sheet is used as the bandpass filter. It is preferable that the bandpass filter transmits only blue light and reflects light of other colors (green light and red light). This allows only blue light from the light source unit 10 to be incident on the wavelength conversion sheet, so that the wavelength conversion sheet can easily emit white light by using it in combination with a wavelength conversion sheet that absorbs a portion of the blue light from the light source unit 10 and emits white light. In addition, it is possible to reduce the return of light other than blue light (e.g., green light, red light, etc.) that passes through the bandpass filter and is reflected by the wavelength conversion sheet to the light source unit 10 side. This reduces the luminance unevenness of the light emitting module 100.

A diffusion sheet may be disposed between the bandpass filter and the light source unit 10. The diffusion sheet transmits light from the light source unit 10 and can diffuse the transmitted light when it is emitted from the diffusion sheet to the bandpass filter side. This can reduce the luminance unevenness of the light-emitting module 100. The diffusion sheet faces the first surface 201 of the light-guiding member 20, the translucent member 30, and the upper surface of the light adjustment member 41. The diffusion sheet may be in contact with the first surface 201 of the light-guiding member 20, the translucent member 30, and/or the upper surface of the light adjustment member 41, or may be separated from them. The diffusion sheet is preferably made of a material that has low absorption of light emitted by the light-emitting element 11. Examples of the diffusion sheet include polycarbonate, polystyrene, acrylic, and polyethylene. The diffusion sheet may include minute irregularities on the emission surface, or may include an optical film having light diffusion properties. The diffusion sheet may be composed of a single layer, or may be composed of a laminate of multiple layers.

A prism sheet may be disposed so as to face the surface of the wavelength conversion sheet opposite the light source unit 10. A plurality of prisms extending in one direction are arranged on the surface of the prism sheet. A single prism sheet may be used, or a plurality of prism sheets may be stacked. When a plurality of prism sheets are stacked, for example, one of the prism sheets may be a prism extending in the X direction and the other may be a prism extending in the Y direction. This allows the light emitted from the prism sheet to be aligned in a direction perpendicular to the exit surface of the prism sheet, thereby increasing the brightness of the light-emitting module 100 when viewed from above.

The light source unit 10 may further include a covering member (hereinafter referred to as light source covering member 14). The light source covering member 14 is disposed on the underside of the light emitting element 11. The light source covering member 14 is disposed so that the underside of the electrode 12 of the light source unit 10 is exposed from the light source covering member 14. The light source covering member 14 is also disposed on the underside of the light source translucent member 13 that covers the side surface of the light emitting element 11.

The light source covering member 14 has reflectivity to the light emitted by the light emitting element 11. For example, a resin member containing a gas such as nitrogen and/or oxygen, or a resin member containing light scattering particles can be used for the light source covering member 14. For example, a thermoplastic resin such as an acrylic resin, a polycarbonate resin, a cyclic polyolefin resin, a polyethylene terephthalate resin, or a polyester resin, or a thermosetting resin such as an epoxy resin or a silicone resin can be used for the resin member of the light source covering member 14. For example, particles of titania, silica, alumina, zinc oxide, magnesium oxide, zirconia, yttria, calcium fluoride, magnesium fluoride, niobium pentoxide, barium titanate, tantalum pentoxide, barium sulfate, or glass can be used for the light source covering member 14. The light source covering member 14 may contain both a gas and light scattering particles.

As shown in FIG. 4B, the light source unit 10 may include a light adjustment member (hereinafter referred to as the light source light adjustment member 15). The light source light adjustment member 15 constitutes at least a part of the upper surface of the light source unit 10. The light source light adjustment member 15 is located above the light emitting element 11. When viewed from above, the light source light adjustment member 15 and the light emitting element 11 overlap, and the light source light adjustment member 15 is located above the light emitting element 11 at the overlapping portion. The light source light adjustment member 15 is located above the light source translucent member 13 and adjusts the amount and/or emission direction of light emitted from the upper surface of the light source translucent member 13. The light source light adjustment member 15 has reflectivity and translucency for the light emitted by the light emitting element 11. A part of the light emitted from the upper surface of the light source translucent member 13 is reflected by the light source light adjustment member 15, and the other part passes through the light source light adjustment member 15. The transmittance of the light source light adjustment member 15 for the peak wavelength of the light emitting element 11 is, for example, preferably 1% to 50%, and more preferably 3% to 30%. By including the light source light adjustment member 15 in the light source unit 10, it is possible to prevent the area directly above the light source unit 10 from becoming too bright. This reduces the brightness unevenness of the light emitting module 100.

The light source light adjustment member 15 can be made of, for example, a resin member containing light scattering particles. The resin member of the light source light adjustment member 15 can be made of the same material as the resin member of the light source covering member 14. The light scattering particles of the light source light adjustment member 15 can be made of the same material as the light scattering particles of the light source covering member 14. The light source light adjustment member 15 can also be made of, for example, a metal member such as aluminum or silver, or a dielectric multilayer film.

As shown in FIG. 4A, the light source unit 10 may not include the light source light adjustment member 15. In this way, the light source unit 10 can be made smaller in size in the vertical direction than when the light source unit 10 includes the light source light adjustment member 15 located above the light emitting element 11. In another embodiment of the light source unit 10, the light source unit 10 may not include the light source cover member 14. For example, the lower surface of the light source unit may be formed by the lower surface of the light emitting element, the lower surfaces of the pair of electrodes 12, and the lower surface of the light source translucent member. In another embodiment of the light source unit 10, the light source unit 10 may be only the light emitting element 11 alone. In another embodiment of the light source unit 10, the light source unit 10 may not include the light source cover member 14 and the light source translucent member 13, and the light source light adjustment member 15 may be located on the upper surface of the light emitting element 11. In another embodiment of the light source unit 10, the light source unit 10 may not include the light source translucent member 13, the light source light adjustment member 15 may be located on the upper surface of the light emitting element 11, and the light source cover member 14 may be located on the lower surface of the light emitting element 11.

The shape of the light source unit 10 when viewed from above is not particularly limited. The shape of the light source unit 10 when viewed from above can be, for example, a circle, a triangle, a rectangle, a hexagon, or an octagon. When the shape of the light source unit 10 when viewed from above is a rectangle, a pair of outer edges of the light source unit 10 may be parallel to the X direction or may be inclined with respect to the X direction. In this embodiment, a pair of outer edges of the light source unit 10 are inclined at 45° with respect to the X direction.

(Light guiding member 20)
The light guide member 20 is a member having translucency for the light emitted by the light source unit 10. The transmittance of the light guide member 20 for the peak wavelength of the light source unit 10 is, for example, preferably 60% or more, more preferably 80% or more. As shown in FIG. 3, the light emitting module 100 has a first surface 201 which is a light emitting surface, and a second surface 202 located on the opposite side of the first surface 201. The light guide member 20 has a first through hole 20H penetrating from the first surface 201 to the second surface 202. As shown in FIG. 1, the light source unit 10 is located in the first through hole 20H of the light guide member 20. As a result, the light guide member 20 surrounds the light source unit 10 in a top view. The first through hole 20H in this embodiment is circular in a top view. The first through hole 20H may be an ellipse or a polygon such as a triangle, a rectangle, a hexagon, or an octagon in a top view.

In a cross-sectional view, the horizontal length of the first through hole 20H may be the same from the first surface 201 to the second surface 202, or may be different between the upper side and the lower side as shown in FIG. 5. By making the horizontal length of the first through hole 20H different between the upper side and the lower side, the area of the interface between the light guide member 20 and the light-transmissive member 30 in a top view can be increased. The interface between the light guide member 20 and the light-transmissive member 30 tends to have high brightness due to the difference between the refractive index of the light guide member 20 and the refractive index of the light-transmissive member 30, but by increasing the area of the interface between the light guide member 20 and the light-transmissive member 30 in a top view, it becomes easier to reduce the brightness unevenness of the light-emitting module 100. In this case, in a cross-sectional view, the horizontal length of the upper end of the first through hole 20H may be longer than the horizontal length of the lower end of the first through hole 20H. Furthermore, when viewed in cross section, if the lateral length of the first through hole 20H differs between the upper and lower sides, the side surface of the first through hole 20H may be inclined with respect to the Z direction, or may have a step that includes a surface parallel to the XY plane.

The number of light guide members 20 included in the light emitting module 100 may be one or more. In this embodiment, the light emitting module 100 includes a plurality of light guide members 20 including a first light guide section 20A, a second light guide section 20B, a third light guide section 20C, and a fourth light guide section 20D. As shown in FIG. 1, the first light guide section 20A and the second light guide section 20B are adjacent to each other in the X direction. The third light guide section 20C and the fourth light guide section 20D are adjacent to each other in the X direction. The first light guide section 20A and the third light guide section 20C are adjacent to each other in the Y direction. The second light guide section 20B and the fourth light guide section 20D are adjacent to each other in the Y direction. The first light source 10A is located in the first through hole 20H of the first light guide section 20A. The second light source 10B is located in the first through hole 20H of the second light guide section 20B. The third light source 10C is located in the first through hole 20H of the third light guiding section 20C. The fourth light source 10D is located in the first through hole 20H of the fourth light guiding section 20D.

The light guide member 20 is partitioned by partitioning grooves 20G. One area partitioned by the partitioning grooves 20G is the light emitting area 300A. In this embodiment, the first light guide section 20A, the second light guide section 20B, the third light guide section 20C, and the fourth light guide section 20D partitioned by the partitioning grooves 20G are different light emitting areas 300A. One light emitting area 300A can be a driving unit for local dimming. The number of light emitting areas 300A constituting the surface light source 300 is not particularly limited. For example, the surface light source 300 may have one light emitting area 300A, or the surface light source 300 may have multiple light emitting areas 300A. In addition, a surface light source device with a larger area may be formed by arranging multiple surface light sources 300. A member having reflectivity to the light emitted by the light source section 10 may be arranged in the partitioning groove 20G. This can improve the contrast between the light emitting area in the light emitting state and the light emitting area in the non-light emitting state. In addition, the light-emitting module does not need to have a member that is reflective to the light emitted by the light source unit 10 disposed within the partition groove 20G.

In this embodiment, the light guide member 20 has a lattice-shaped partition groove 20G consisting of a first partition groove 21G extending in the Y direction and a second partition groove 22G extending in the X direction. Between the first light guide section 20A and the second light guide section 20B, there is a first partition groove 21G extending in the Y direction. Between the first light guide section 20A and the third light guide section 20C, there is a second partition groove 22G extending in the X direction. It is preferable that the partition groove 20G penetrates from the first surface 201 to the second surface 202 of the light guide member 20. In this way, the light guide member 20 can be separated into multiple parts, so that, for example, warping of the support member 200 caused by the difference in thermal expansion coefficient between the light guide member 20 and the support member 200 can be reduced. This can reduce cracks in the conductive member 80 described later. Furthermore, the partitioning groove 20G may be a recess that is open only on the first surface 201 side of the light-guiding member 20, or may be a recess that is open only on the second surface 202 side of the light-guiding member 20. When the partitioning groove 20G is a recess, the partitioning groove 20G has a bottom surface formed by the light-guiding member 20.

The side of the partition groove 20G may be a surface parallel to the Z direction, or may be a surface inclined with respect to the Z direction. When the side of the partition groove 20G is a surface inclined with respect to the Z direction, the distance between opposing side surfaces in the partition groove 20G may become shorter or longer as it goes downward.

As shown in FIG. 1, the light guide member 20 preferably has a hole portion (hereinafter referred to as the first light guide hole portion 21) that opens on the first surface 201 and/or the second surface 202 of the light guide member 20. In a top view, the first light guide hole portion 21 is located between the first through hole 20H and the partition groove 20G. In this embodiment, the first light guide hole portion 21 is a recess that opens only on the first surface 201 side. The first light guide hole portion 21 may be a recess that opens only on the second surface 202 side, or may be a through hole that penetrates from the first surface 201 to the second surface 202 of the light guide member 20. By including the first light guide hole portion 21 in the light guide member 20, the surface area of the light guide member 20 can be increased. In this way, the amount of light extracted from the surface of the light guide member 20 to the outside of the light guide member 20 can be increased. This makes it easier to adjust the brightness of the light emitting module 100, making it easier to reduce brightness unevenness of the light emitting module 100. The depth of the recess in the Z direction is, for example, 0.1 times or more the thickness of the light-guiding member 20.

The shape of the first light guiding hole 21 when viewed from above is not particularly limited. As shown in FIG. 1, the shape of the first light guiding hole 21 in this embodiment includes a linear portion. In this specification, linear includes a straight line, a curved line, or a bent line. The shape of the first light guiding hole 21 when viewed from above may be a V-shape or an L-shape extending in two directions. In addition, the shape of the first light guiding hole 21 when viewed from above may be a circle, an ellipse, or a polygon such as a triangle, a rectangle, a hexagon, or an octagon.

In this specification, as shown in FIG. 2, the point on the outer edge of the first light guiding section 20A located on the first surface 201 that is farthest from the center of the first light source 10A is referred to as the first point P1, and the point on the outer edge of the first light guiding section 20A located on the first surface 201 that is closest to the center of the first light source 10A is referred to as the second point P2. In this embodiment, the first point P1 is located at each corner of the first light guiding section 20A, and the second point P2 is located at the center of each side of the first light guiding section 20A. There may be one each of the first point P1 and the second point P2, or there may be multiple points.

As shown in FIG. 2, in a top view, it is preferable that at least one of the first light guide holes 21 is located on the first imaginary straight line IL connecting the center of the first light source 10A and the first point P1. In this way, the brightness unevenness of the light emitting module 100 is reduced. The first point P1, which is far from the first light source 10A, tends to have a lower brightness than the second point P2, which is closer to the first light source 10A. However, by positioning the first light guide hole 21 on the first imaginary straight line IL, it becomes easier to increase the amount of light extracted from the light guide member 20 to the outside in the vicinity of the first point P1. This makes it possible to reduce the difference between the brightness at the first point P1 and the brightness at the second point P2, thereby reducing the brightness unevenness of the light emitting module 100.

It is also preferable that a plurality of first light guide holes 21 are located on the first imaginary straight line IL connecting the center of the first light source 10A and the first point P1. This makes it easier to adjust the brightness in the vicinity of the first point P1, making it easier to reduce the brightness unevenness of the light emitting module 100. It is preferable that the number of first light guide holes 21 located on the first imaginary straight line IL is greater than the number of first light guide holes 21 located on the second imaginary straight line IIL connecting the center of the first light source 10A and the second point P2. This makes it easier to reduce the difference between the brightness at the first point P1 and the brightness at the second point P2. As shown in FIG. 2, there may be no first light guide holes 21 located on the second imaginary straight line IIL.

When viewed from above, it is preferable that at least one of the first light guiding holes 21 extends from an end of the first light guiding hole 21 closest to the center of the first light source 10A at an angle in the X and Y directions away from the first light source 10A. In this way, a portion of the light from the first light source 10A can be guided in the direction in which the first light guiding hole 21 extends. This can reduce uneven brightness of the light emitting module 100.

The shape of the first light guide hole 21 provided in the first light guide section 20A and the shape of the first light guide hole 21 provided in the second light guide section 20B may be the same or different. In addition, the number of first light guide holes 21 provided in the first light guide section 20A and the number of first light guide holes 21 provided in the second light guide section 20B may be the same or different. For example, before forming the first light guide hole 21 in the light guide member 20, the luminance unevenness of the first light guide section 20A and the luminance unevenness of the second light guide section 20B are confirmed. After confirming the luminance unevenness of the first light guide section 20A and the luminance unevenness of the second light guide section 20B, the first light guide hole 21 suitable for each of the first light guide section 20A and the second light guide section 20B is formed in the light guide member 20. In this way, the luminance unevenness of the light emitting module 100 can be reduced. For example, if the luminance unevenness is suppressed to a desired range before forming the first light guiding hole 21 in the light guiding member 20, the first light guiding hole 21 does not need to be provided in the light guiding member 20. The luminance unevenness of the first light guiding section 20A and the luminance unevenness of the second light guiding section 20B can be confirmed, for example, by measuring the luminance with a two-dimensional color luminance meter (CA-2500 manufactured by Konica Minolta).

The light-guiding member 20 may include one or more first light-guiding holes 21. As shown in FIG. 2, it is preferable that the multiple first light-guiding holes 21 surround the light source unit 10 in a top view. In this way, the multiple first light-guiding holes 21 make it easier to extract light traveling laterally from the light source unit 10 to the outside of the light-guiding member 20. Note that, in a top view, one first light-guiding hole 21 may surround the light source unit 10 without any breaks.

The light guide member 20 may be made of the same material as the resin member of the light source cover member 14. The light guide member 20 may also be made of glass or the like. The light guide member 20 may contain phosphors and/or light scattering particles.

The thickness of the light-guiding member 20 is preferably, for example, 150 μm or more and 800 μm or less. In this specification, unless otherwise specified, the thickness of each member is the value when the distance from the upper surface of each member to the lower surface of each member in the vertical direction is maximum. The light-guiding member 20 may be composed of a single layer in the vertical direction, or may be composed of a laminate of multiple layers. When the light-guiding member 20 is composed of a laminate, a translucent adhesive may be disposed between each layer. Each layer of the laminate may use a different type of main material.

The method for forming the first light guiding hole 21 in the light guiding member 20 is not particularly limited. For example, the first light guiding hole 21 can be formed in the light guiding member 20 by laser processing. The first light guiding hole 21 can be formed by heat generated by laser irradiation. Note that the light guiding member including the first light guiding hole 21 may be formed by a method such as injection molding, transfer molding, or compression molding using a mold or the like.

(Light-transmitting member 30)
As shown in FIG. 3, the light emitting module 100 includes a light-transmitting member 30. The light-transmitting member 30 has light transmissivity with respect to the light emitted by the light source unit 10. As shown in FIG. 2, in a top view, the light-transmitting member 30 surrounds the light source unit 10. At least a part of the light-transmitting member 30 is located in the first through hole 20H. It is preferable that the entire light-transmitting member 30 is located in the first through hole 20H. For example, a resin member containing a plurality of reflective particles can be used for the light-transmitting member 30. The resin member of the light-transmitting member 30 can be made of the same material as the resin member of the light source covering member 14. The reflective particles of the light-transmitting member 30 can be made of the same material as the light scattering particles of the light source covering member 14.

As shown in FIG. 3, in a cross-sectional view, the light-transmitting member 30 has a light-transmitting portion 31 and a reflecting portion 32 located above the light-transmitting portion 31. The reflecting portion 32 is a portion in the light-transmitting member 30 where a plurality of reflective particles are located unevenly. The reflecting portion 32 adjusts the amount and/or emission direction of light passing through the light-transmitting portion 31 and exiting the reflecting portion 32. The reflecting portion 32 of the light-transmitting member 30 has reflective particles located at a higher density than the light-transmitting portion 31 of the light-transmitting member 30. When the light-transmitting member 30 is a resin member containing a plurality of reflective particles, the reflecting portion 32 has a higher ratio of the area of the reflective particles to the area of the resin member in a cross-sectional view than the light-transmitting portion 31. The ratio of the area of the reflective particles to the area of the resin member in a cross-sectional view of the reflecting portion 32 is not particularly limited, but is preferably 10 times or more the ratio of the area of the reflective particles to the area of the resin member in a cross-sectional view of the light-transmitting portion 31. This reduces the amount of light escaping upward from the reflective portion 32, which reduces the amount of light that becomes too bright in the area directly above the reflective portion 32. The translucent portion 31 may or may not contain reflective particles.

3, in the present embodiment, in the cross-sectional view, one lateral end of the translucent member 30 contacts the light source unit 10, and the other end contacts the side of the light-guiding member that defines the first through hole 20H of the light-guiding member 20. In this specification, the side of the light-guiding member that defines the first through hole 20H may be referred to as the side of the first through hole 20H. In the cross-sectional view, it is preferable that the number of reflective particles at the end of the translucent member 30 on the side surface side of the first through hole 20H of the light-guiding member 20 is greater than the number of reflective particles at the end of the translucent member 30 on the light source unit 10 side. In the present embodiment, in the cross-sectional view, the thickness of the reflective portion 32 becomes thicker as it approaches the side surface of the first through hole 20H from the light source unit 10. It is preferable that the maximum thickness of the reflective portion 32 is 10 μm or more and 200 μm or less. In a cross-sectional view, the number of reflective particles at the end of the light-transmissive member 30 on the side surface side of the first through hole 20H of the light-guiding member 20 can be increased, which can prevent the brightness from becoming too high near the interface between the light-guiding member 20 and the light-transmissive member 30. This makes it easier to reduce brightness unevenness in the light-emitting module 100.

As shown in FIG. 5, the thickness of the end of the reflecting portion 32 on the first through hole 20H side can be adjusted by inclining the side of the first through hole 20H with respect to the Z direction. As shown in FIG. 5, it is preferable that the horizontal length of the upper end of the first through hole 20H is longer than the horizontal length of the lower end of the first through hole 20H. In this way, the thickness of the reflecting portion 32 at the portion where the reflecting portion 32 and the side of the first through hole 20H contact each other can be made thinner as it moves away from the light source unit 10. Since the brightness tends to be low at a position away from the light source unit 10, the thickness of the reflecting portion 32 of the translucent member 30 becomes thinner as it moves away from the light source unit 10, making it easier to extract light from the light source unit 10 at a position away from the light source unit 10. This makes it easier to reduce the brightness unevenness of the light-emitting module 100. For example, in a cross-sectional view, the thickness of the end of the reflecting portion 32 on the first through hole 20H side can be made thicker by increasing the angle between the side of the first through hole 20H and the Z direction.

When viewed from above, the reflective portion 32 overlaps the translucent portion 31. A portion of the light passing through the translucent portion 31 is reflected by the reflective portion 32, and the other portion is transmitted through the reflective portion 32. The transmittance of the reflective portion 32 for the peak wavelength of the light-emitting element 11 is preferably, for example, 1% to 70%, and more preferably 3% to 50%. In addition, the transmittance of light incident on the lower surface of the translucent portion 31 and exiting from the upper surface of the reflective portion 32 (hereinafter referred to as the light transmittance of the translucent member 30) is preferably 1% to 70%, and more preferably 3% to 50%, for the peak wavelength of the light-emitting element 11.

As shown in FIG. 3, the light-transmitting portion 31 is preferably in contact with the side surface of the light source unit 10. This allows light from the light source unit 10 to easily enter the light-transmitting portion 31. The light-transmitting portion 31 is preferably in contact with the light-guiding member 20. This allows light from the light source unit 10 to easily enter the light-guiding member 20.

It is preferable that the upper surface of the light-transmitting member 30 and the upper surface of the light adjustment member 41 are flush. It is also preferable that the upper surface of the light-transmitting member 30 and the first surface 201 of the light-guiding member 20 are flush. When the light-transmitting member 30 and the light adjustment member 41 are flush, and the light-transmitting member 30 and the light-guiding member 20 are flush, the light-emitting module 100 can be easily miniaturized in the vertical direction. In this specification, "flush" means that there is no step between the surfaces of adjacent members. The step here means a step in which the difference in height of the surfaces of adjacent members exceeds 10 μm, and if the difference in height of the surfaces of adjacent members is within 10 μm, it is included in "flush". It is preferable that the entire upper surface of the light-transmitting member 30 is a plane, and in this case, it is preferable that it is located on the same plane as the first surface 201 of the light-guiding member 20 and the upper surface of the light adjustment member 41. In this way, it is easier to miniaturize the light-emitting module 100 in the vertical direction. In a cross-sectional view, if the upper surface of one lateral end of the light-transmitting member 30 is flush with the upper surface of the light-guiding member 20, and the upper surface of the other lateral end of the light-transmitting member 30 is flush with the upper surface of the light-adjusting member 41, the portion between both ends of the light-transmitting member 30 does not have to be located on the same plane, and may be uneven, recessed downward, or bulged upward. Also, the upper surfaces of the light-guiding member 20 and the light-adjusting member 41 do not have to be located on the same plane, and in this case, the upper surface of the light-transmitting member 30 may include a portion that is inclined with respect to the XY plane.

The light-transmitting member 30 may be composed of a single layer in the vertical direction, or may be composed of a laminate of multiple layers. When the light-transmitting member 30 is a laminate, it may be composed of a single layer of light-transmitting section 31 and a single layer of reflective section 32, or may be composed of multiple layers of light-transmitting section 31 and a single layer of reflective section 32. For example, the same material as the resin member of the light source covering member 14 can be used as the material of the light-transmitting member 30. In addition, the same material as the light-scattering particles of the light source covering member 14 can be used as the material of the reflective particles.

As shown in FIG. 3, the lower surface of the light-transmitting member 30 preferably has a recess (hereinafter referred to as the first light-transmitting recess 33). The first light-transmitting recess 33 is in contact with a covering member (hereinafter referred to as the light-transmitting portion covering member 62A) that covers the lower surface of the light-transmitting member 30. The refractive index of the light-transmitting portion covering member 62A is preferably different from the refractive index of the light-transmitting member 30, and is more preferably lower than the refractive index of the light-transmitting member 30. In this way, a part of the light from the light source unit 10 that is incident on the light-transmitting portion covering member 62A is easily totally reflected at the interface between the light-transmitting portion covering member 62A and the light-transmitting member 30. This makes it possible to reduce the light that passes downward from the light-emitting module 100, thereby improving the light extraction efficiency of the light-emitting module 100. In this embodiment, the light-transmitting portion covering member 62A is the second adhesive layer 62 described later. The light-transmitting portion covering member 62A is not limited to the second adhesive layer 62, and may be provided separately from the second adhesive layer 62 as long as it covers at least the lower surface of the light-transmitting member 30. The light-transmitting portion covering member 62A may be a gas such as nitrogen and/or oxygen. The first light-transmitting recess 33 is in contact with the light-transmitting portion covering member 62A, so that the light traveling in the lateral direction from the light source unit 10 can be reflected upward at the interface between the first light-transmitting recess 33 and the light-transmitting portion covering member 62A. This reduces the light that escapes downward from the light-emitting module 100, improving the light extraction efficiency of the light-emitting module 100.

As shown in Figures 6A and 6B, the upper surface of the light-transmitting member 30 preferably has a plurality of recesses (hereinafter referred to as second light-transmitting recesses 34) recessed downward. This makes it easier to adjust the thickness of the reflecting portion 32, and therefore makes it easier to adjust the brightness in the area directly above the light-transmitting member 30. The second light-transmitting recess 34 extends downward from the upper surface of the reflecting portion 32. At least a portion of the light-transmitting portion 31 may be exposed from the reflecting portion 32 in the second light-transmitting recess 34. This improves the light extraction efficiency of the light-emitting module 100. Note that the light-transmitting portion 31 does not have to be exposed from the reflecting portion 32 in the second light-transmitting recess 34.

(Light adjustment member 41)
The light adjustment member 41 has reflectivity and translucency for the light emitted by the light source unit 10. A part of the light emitted from the light source unit 10 is reflected by the light adjustment member 41, and the other part is transmitted through the light adjustment member 41. The transmittance of the light adjustment member 41 for the peak wavelength of the light source unit 10 is lower than the transmittance of the light guide member 20 for the peak wavelength of the light source unit 10. The transmittance of the light adjustment member 41 for the peak wavelength of the light source unit 10 is preferably, for example, 1% or more and 50% or less, and more preferably 3% or more and 30% or less. The light transmittance of the light adjustment member 41 for one peak wavelength of the light source unit 10 is preferably lower than the light transmittance of the translucent member 30. In this way, it is possible to reduce the amount of light passing upward from the light adjustment member 41, and therefore it is possible to reduce the area directly above the periphery of the light source unit 10 from becoming too bright, thereby reducing the brightness unevenness of the light emitting module 100.

The light adjustment member 41 is located above the light source unit 10. When viewed from above, the light adjustment member 41 and the light source unit 10 overlap, and the light adjustment member 41 is located above the light source unit 10 at the overlapping portion. By positioning the light adjustment member 41 above the light source unit 10, it is possible to reduce the area directly above the light source unit 10 from becoming too bright.

The lateral end face of the light adjustment member 41 is preferably in contact with the reflecting portion 32 of the light-transmitting member 30. The thickness of the light adjustment member 41 may be the same as the minimum thickness of the reflecting portion 32, may be thinner than the minimum thickness of the reflecting portion 32, or may be thicker than the minimum thickness of the reflecting portion 32. The thickness of the light adjustment member 41 is preferably thinner than the maximum thickness of the reflecting portion 32. This makes it easier to miniaturize the light-emitting module 100 in the vertical direction. The light adjustment member 41 may be composed of a single layer, or may be composed of a laminate of multiple layers.

The size of the light adjustment member 41 in top view may be the same as that of the light source unit 10 as shown in FIG. 2, or may be larger than that of the light source unit 10 as shown in FIG. 5. When the size of the light adjustment member 41 in top view is the same as that of the light source unit 10, it is preferable that the outer edge of the light adjustment member 41 coincides with the outer edge of the light source unit 10. When the size of the light adjustment member 41 in top view is larger than that of the light source unit 10, it is preferable that the entire outer edge of the light adjustment member 41 is located outside the outer edge of the light source unit 10. Note that, in top view, a part of the outer edge of the light adjustment member 41 may be located inside the outer edge of the light source unit 10. By making the size of the light adjustment member 41 larger than that of the light source unit 10 in top view, it is possible to reduce the area directly above the light source unit 10 from becoming too bright, and to reduce the luminance unevenness between the inside and outside of the light source unit 10 in top view.

The light adjustment member 41 has at least one second through hole 41H. By having the light adjustment member 41 have the second through hole 41H, it becomes easier to adjust the brightness in the area directly above the light adjustment member 41. For example, by changing the size and position of the second through hole 41H, it is possible to adjust the light from the light source unit 10 that is blocked by the light adjustment member 41. This makes it easier to adjust the brightness in the area directly above the light adjustment member 41, making it easier to reduce brightness unevenness in the light-emitting module 100. When viewed from above, the second through hole 41H is located away from the outer edge of the light adjustment member 41.

The shape of the second through hole 41H when viewed from above is not particularly limited. As shown in FIG. 2, in this embodiment, the shape of the second through hole 41H when viewed from above is circular. The shape of the second through hole 41H when viewed from above may be an ellipse or a polygon such as a triangle, a rectangle, a hexagon, or an octagon. The shape of the second through hole 41H when viewed from above may include a linear portion. For example, the shape of the second through hole 41H when viewed from above may include a V-shaped or L-shaped portion extending in two directions.

As shown in FIG. 2, in a top view, the light adjustment member 41 preferably has a plurality of recesses (hereinafter referred to as first recesses 41C) that are recessed in the horizontal direction. The first recesses 41C are provided on the outer edge of the light adjustment member 41. By having the light adjustment member 41 have the first recesses 41C, it becomes easy to adjust the brightness around the light adjustment member 41. For example, by changing the size and/or position of the first recesses 41C, it is possible to adjust the light from the light source unit 10 that is blocked by the light adjustment member 41. This makes it easy to adjust the brightness around the light adjustment member 41, making it easier to reduce the brightness unevenness of the light-emitting module 100. In addition, by having the plurality of first recesses 41C in the light adjustment member 41, it becomes easy to mix a portion with high brightness and a portion with low brightness near the outer edge of the light adjustment member 41. As a result, it is possible to make the boundary between the brightness of the portion located inside the outer edge of the light adjustment member 41 and the brightness of the portion located outside the outer edge of the light adjustment member 41 less noticeable near the outer edge of the light adjustment member 41. The size of the first recess 41C is not particularly limited. The maximum length of the first recess 41C in the X direction may be shorter than the maximum length of the second through hole 41H in the X direction. The maximum length of the first recess 41C in the Y direction may be shorter than the maximum length of the second through hole 41H in the Y direction.

As shown in FIG. 7, the light adjustment member 41 can be composed of a resin member (hereinafter referred to as the light adjustment resin member 41A) and a plurality of reflectors (hereinafter referred to as the light adjustment reflectors 41B) contained in the light adjustment resin member 41A. The material of the light adjustment resin member 41A can be the same as that of the resin member of the light source covering member 14. The material of the light adjustment reflectors 41B can be the same as that of the light scattering particles of the light source covering member 14. Gases such as nitrogen and/or oxygen may be used as the light adjustment reflectors 41B. The light adjustment member 41 may also contain both light scattering particles and gas.

The refractive index of the light adjusting reflector 41B is preferably lower than that of the light adjusting resin member 41A. This makes it easier for a portion of the light from the light source unit 10 that is incident on the light adjusting resin member 41A to be totally reflected at the interface between the light adjusting resin member 41A and the light adjusting reflector 41B. This reduces the amount of light that escapes above the light source unit 10, thereby reducing the amount of the area directly above the light source unit 10 that becomes too bright. In this specification, the refractive index refers to the refractive index at the peak wavelength of the light source unit 10.

When the refractive index of the light adjusting reflector 41B is lower than that of the light adjusting resin member 41A, it is preferable that the refractive index of the light adjusting resin member 41A is higher than that of the base material of the light guide member 20. This makes it easier to increase the refractive index difference between the light adjusting resin member 41A and the light adjusting reflector 41B. This makes it easier for a portion of the light traveling from the light adjusting resin member 41A to the light adjusting reflector 41B to be totally reflected at the interface between the light adjusting resin member 41A and the light adjusting reflector 41B. This reduces the amount of light escaping above the light source unit 10, thereby reducing the area directly above the light source unit 10 from becoming too bright.

7, it is preferable that the maximum length L1 of the light adjustment reflector 41B in the horizontal direction is longer than the maximum length L2 in the vertical direction in a cross-sectional view. In this way, it is easier to make the surface of the light adjustment reflector 41B facing the light source unit 10 closer to a flat surface than when the light adjustment reflector 41B is spherical. As a result, when the light emitted from the light source unit 10 is reflected by a part of the light adjustment member 41 located around the light source unit 10 in a top view, it is easier to reflect in a direction away from the light source unit 10. In other words, it is possible to reduce the light emitted from the light source unit 10 being reflected by a part of the light adjustment member 41 and returning to the light source unit 10. As a result, it is possible to reduce the absorption of the light emitted from the light source unit 10 by the light source unit 10, thereby improving the light extraction efficiency of the light emitting module 100. For example, when the light source translucent member 13 of the light source unit 10 contains a phosphor, the light emitted from the light source unit 10 can be reduced from being reflected by the light adjustment member 41 and returning to the light source unit 10, thereby reducing the wavelength of the light from the light source unit 10 from being excessively converted by the phosphor contained in the light source translucent member 13. The maximum length L1 of the light adjustment reflector 41B in the horizontal direction is not particularly limited. For example, the maximum length L1 of the light adjustment reflector 41B in the horizontal direction is at least twice the maximum length L2 of the light adjustment reflector 41B in the vertical direction.

(Support member 200)
3 , the support member 200 is a member on which the light emitting module 100 is disposed. The light guide member 20 is disposed on the support member 200 with the second surface 202 facing the upper surface of the support member 200.

The support member 200 has a wiring board 50. The wiring board 50 has an insulating base material 51 and at least one wiring layer 52 arranged on at least one surface of the insulating base material 51. The insulating base material 51 may be a rigid board or a flexible board. In order to make the surface light source 300 thinner, it is preferable that the insulating base material 51 is a flexible board. The insulating base material 51 may be composed of a single layer in the vertical direction, or may be composed of a laminate of multiple layers. For example, the insulating base material 51 may be composed of a single layer flexible board, or may be composed of a laminate of multiple rigid boards. For example, a resin such as polyimide can be used as the material of the insulating base material 51. The wiring layer 52 is a metal film, for example, a copper film.

The support member 200 further includes a first adhesive layer 61 disposed on the wiring board 50, a reflective member 70 disposed on the first adhesive layer 61, and a second adhesive layer 62 disposed on the reflective member 70.

The first adhesive layer 61 is disposed between the wiring board 50 and the reflective member 70, and bonds the wiring board 50 and the reflective member 70. The first adhesive layer 61 can be made of, for example, a resin member containing light scattering particles. For example, the same material as the resin member of the light source covering member 14 can be used as the resin member of the first adhesive layer 61. For example, the same material as the light scattering particles of the light source covering member 14 can be used as the light scattering particles of the first adhesive layer 61. A sheet-shaped optical transparent adhesive can be used as the first adhesive layer 61.

The refractive index of the resin material of the first adhesive layer 61 is preferably lower than the refractive index of the resin material of the reflective member 70. By doing so, a portion of the light traveling from the reflective member 70 to the first adhesive layer 61 is more likely to be totally reflected at the interface between the reflective member 70 and the first adhesive layer 61. This reduces the amount of light that escapes downward from the light-emitting module 100, improving the light extraction efficiency of the light-emitting module 100.

The reflective member 70 is disposed below the light guide member 20, below the light source unit 10, and below the light-transmitting member 30. The reflective member 70 is reflective to the light emitted by the light source unit 10. The reflective member 70 can be composed of a resin member and a reflector contained in the resin member. For example, the same material as the resin member of the light source covering member 14 can be used as the resin member of the reflective member 70. The same material as the light scattering particles of the light source covering member 14 can be used as the material of the reflector of the reflective member 70. A gas such as nitrogen and/or oxygen may be used as the reflector of the reflective member 70. The reflective member 70 may also contain both light scattering particles and a gas as the reflector.

The refractive index of the reflector of the reflector member 70 is preferably lower than the refractive index of the resin member of the reflector member 70. In this way, a portion of the light from the light source unit 10 that is incident on the reflector member 70 is more likely to be totally reflected at the interface between the resin member of the reflector member 70 and the reflector of the reflector member 70. This reduces the amount of light that escapes downward from the reflector member 70, improving the light extraction efficiency of the light-emitting module 100.

When the refractive index of the reflector of the reflecting member 70 is lower than the refractive index of the resin member of the reflecting member 70, it is preferable that the refractive index of the resin member of the reflecting member 70 is higher than the refractive index of the base material of the light-guiding member 20. By doing so, it becomes easier to increase the refractive index difference between the resin member of the reflecting member 70 and the reflector of the reflecting member 70. As a result, a part of the light from the light source unit 10 that is incident on the reflecting member 70 is easily totally reflected at the interface between the resin member of the reflecting member 70 and the reflector of the reflecting member 70.

The second adhesive layer 62 is disposed between the reflecting member 70 and the second surface 202 of the light guide member 20, and bonds the reflecting member 70 and the light guide member 20. The light source unit 10 is disposed on the second adhesive layer 62 in the first through hole 20H of the light guide member 20. The second adhesive layer 62 can be formed, for example, of a resin member containing light scattering particles. For example, the same material as the resin member of the light source covering member 14 can be used as the resin member of the second adhesive layer 62. For example, the same material as the light scattering particles of the light source covering member 14 can be used as the light scattering particles of the second adhesive layer 62. For example, a sheet-shaped optical transparent adhesive can be used as the second adhesive layer 62.

The refractive index of the resin member of the second adhesive layer 62 is preferably lower than the refractive index of the base material of the light guide member 20. In this way, a part of the light traveling from the light guide member 20 to the second adhesive layer 62 is more likely to be totally reflected at the interface between the light guide member 20 and the second adhesive layer 62. This makes it possible to reduce the light that escapes downward from the light emitting module 100, thereby improving the light extraction efficiency of the light emitting module 100. The refractive index of the resin member of the second adhesive layer 62 is preferably lower than the refractive index of the base material of the light transmitting section 31. In this way, a part of the light traveling from the light transmitting section 31 to the second adhesive layer 62 is more likely to be totally reflected at the interface between the light transmitting section 31 and the second adhesive layer 62. This makes it possible to reduce the light that escapes downward from the light emitting module 100, thereby improving the light extraction efficiency of the light emitting module 100.

The support member 200 further includes a conductive member 80. The conductive member 80 includes, for example, a resin and metal particles contained in the resin. For example, an epoxy resin or a phenolic resin can be used as the resin of the conductive member 80. For example, copper or silver particles can be used as the metal particles.

The conductive member 80 has a connection portion 81 and a wiring portion 82. The connection portion 81 penetrates the second adhesive layer 62, the reflective member 70, the first adhesive layer 61, and the insulating base material 51 in the vertical direction. The wiring portion 82 is disposed on the surface of the wiring board 50 on which the wiring layer 52 is disposed, and is connected to the connection portion 81. The connection portion 81 and the wiring portion 82 can be integrally formed from the same material. A portion of the wiring portion 82 is connected to the wiring layer 52.

A pair of conductive members 80 are arranged apart from each other in correspondence with the pair of positive and negative electrodes 12 of the light source unit 10. The connection portion 81 of one conductive member 80 is connected to the positive electrode 12 below the light source unit 10, and the connection portion 81 of the other conductive member 80 is connected to the negative electrode 12 below the light source unit 10. The electrodes 12 of the light source unit 10 are electrically connected to the conductive members 80 and the wiring layer 52.

The support member 200 further includes an insulating layer 90. The insulating layer 90 is disposed on the lower surface of the wiring substrate 50 and covers the wiring layer 52. The insulating layer 90 may be made of, for example, epoxy resin, urethane resin, or acrylic resin.

(Production method)
Next, an example of a manufacturing method of the light emitting module 100 and the surface light source 300 will be described with reference to Figs. 8A to 10C. The manufacturing method according to this embodiment includes a step of arranging the light guide member 20, the light source unit 10, and the light adjustment member 41 on the holding member 91, a step of filling the first through hole 20H with the uncured light-transmitting member 30, a step of biasing a plurality of reflective particles in the light-transmitting member 30 to the upper side (the first surface 201 side), a step of forming the cured light-transmitting member 30, and a step of attaching the light emitting module 100 to the support member 200. Note that the members in the middle of each step may be prepared by manufacturing or by transfer, including purchase. In addition, in the following description of the manufacturing method, the light emitting module 100 and the surface light source 300 are manufactured in a state in which they are upside down, so that unless otherwise specified, the "upper" and "lower" in the above embodiment will be described in reverse. For example, the first surface 201 side of the light guide member 20 will be described as the lower side, and the second surface 202 side will be described as the upper side.

As shown in FIG. 8A, a sheet-like holding member 91 is prepared, and a light guide member 20 having a first through hole 20H is placed on the holding member 91. The first surface 201 of the light guide member 20 is placed so as to face the holding member 91. In addition, in the first through hole 20H of the light guide member 20, a light adjustment member 41 is placed on the holding member 91, and a light source unit 10 is placed on the light adjustment member 41. A translucent adhesive may be placed between the light adjustment member 41 and the light source unit 10. On the holding member 91, the light guide member 20 may be placed first and then the light adjustment member 41 and the light source unit 10, or the light guide member 20 may be placed first and then the light adjustment member 41 and the light source unit 10.

The holding member 91 preferably holds the light guide member 20 and the light adjustment member 41. The upper surface of the holding member 91 may be adhesive, or an adhesive may be disposed between the holding member 91 and the light guide member 20.

As shown in FIG. 8B, the first through-hole 20H of the light-guiding member 20 arranged on the holding member 91 is filled with an uncured light-transmitting member 30 (hereinafter referred to as light-transmitting resin 301). The light-transmitting resin 301 contains a plurality of reflective particles dispersed therein. The light-transmitting resin 301 has fluidity.

After filling the first through-hole 20H of the light-guiding member 20 with the translucent resin 301, a plurality of reflective particles can be allowed to settle on the holding member 91 side before the translucent resin 301 hardens, and the translucent resin 301 can be hardened to form the translucent member 30, as shown in FIG. 8C. The plurality of reflective particles can be allowed to settle on the holding member 91 side by natural settling or centrifugal settling. Centrifugal settling is performed, for example, using a centrifuge. As shown in FIG. 9, the centrifuge can rotate the light-guiding member 20 (hereinafter, referred to as the workpiece W1) in which the first through-hole 20H is filled with the translucent resin 301, about the first rotation axis R1. The centrifuge can also rotate the workpiece W1 about the second rotation axis R2. The second rotation axis R2 is perpendicular to the first rotation axis R1. The second rotation axis R2 passes through the center of the first through-hole 20H in the Z direction. In the centrifuge, the workpiece W1 is placed so that the second surface 202 of the light-guiding member 20 faces the first rotation axis R1, and is rotated around the first rotation axis R1 while being rotated around the second rotation axis R2. This causes the multiple reflective particles in the light-transmitting resin 301 to be biased toward the holding member 91, and the thickness of the reflective portion 32 can be increased in the lateral direction as it approaches the side of the first through hole 20H. If it is only necessary to bias the multiple reflective particles in the light-transmitting member 30 toward the holding member 91, the centrifuge does not need to rotate the workpiece around the second rotation axis R2.

As shown in FIG. 8C, in the light-transmitting resin 301, the reflective particles are allowed to settle on the holding member 91 side, and then the light-transmitting resin 301 is cured to form the light-transmitting member 30. Note that the light-transmitting member 30 may be formed by curing the light-transmitting resin 301 while allowing a plurality of reflective particles to settle on the holding member 91 side using a centrifuge or the like. For example, the liquid light-transmitting resin can be cured by heating. For example, the light-transmitting member 30 shrinks when the light-transmitting resin 301 hardens, forming a first light-transmitting recess 33 on the upper surface of the light-transmitting member 30.

When forming a light-emitting module 100 that does not have a first light-transmitting recess 33, for example, a part of the second surface 202 of the light-guiding member 20, a part of the light-transmitting member 30, a part of the light source cover member 14 of the light source unit 10, and a part of the electrode 12 may be cut to make the surface of the light-emitting module 100 on the support member 200 side flush. In addition, when filling the first through-hole 20H with the light-transmitting resin 301, the light-transmitting resin 301 may be filled so as to rise above the second surface 202 of the light-guiding member 20, and after hardening, the light-transmitting member 30 may be cut to the height of the second surface 202 of the light-guiding member 20.

After the light-emitting module 100 is completed, the holding member 91 is peeled off from the light-emitting module 100. Then, as shown in FIG. 10A, the laminated member 200A is arranged on the plurality of light-emitting modules 100. The laminated member 200A includes a second adhesive layer 62, a reflective member 70, a first adhesive layer 61, and a wiring board 50. The laminated member 200A has a through hole 203 that penetrates the second adhesive layer 62, the reflective member 70, the first adhesive layer 61, and the wiring board 50. The through hole 203 is formed, for example, by punching, drilling, or laser processing. The shape of the through hole 203 when viewed from above is circular. The shape of the through hole when viewed from above may be an ellipse or a polygon other than a circle.

The laminated member 200A is placed on the multiple light-emitting modules 100. For example, the upper surface of the light source unit 10 and the lower surface of the second adhesive layer 62 are bonded together. When viewed from above, the electrodes 12 of the light source unit 10 and the through holes 203 formed in the laminated member 200A are arranged to overlap. Of the pair of positive and negative electrodes 12 of the light source unit 10, one through hole 203 faces one electrode (e.g., the positive electrode), and one through hole 203 faces the other electrode 12 (e.g., the negative electrode).

As shown in FIG. 10B, a conductive member 80 is formed in the through-hole 203 of the laminate member 200A. For example, a conductive paste is placed in the through-hole 203, and then cured to form the conductive member 80 connected to the electrode 12 of the light source unit 10. The conductive member 80 is also formed on the upper surface of the wiring board 50, and is connected to the wiring layer 52 of the wiring board 50.

After forming the conductive member 80, an insulating layer 90 is formed to cover the conductive member 80, as shown in FIG. 10C. The insulating layer 90 can be formed by a method such as printing, potting, spraying, inkjet printing, or laminating a resin sheet.

The above steps allow the manufacture of the light emitting module 100 and the surface light source 300. The above-described manufacturing method for the light emitting module 100 and the surface light source 300 is an example, and various modifications are possible as long as no technical contradictions arise.

This specification includes the following embodiments.
Item 1. A light-emitting module including a light-guiding member having a first surface, a second surface opposite to the first surface, and a first through hole penetrating from the first surface to the second surface, a light source unit located in the first through hole, a light adjustment member located above the light source unit, and a light-transmitting member located in the first through hole and surrounding the light source unit and the light adjustment member in a top view, wherein the light-transmitting member includes a plurality of reflective particles biased toward the upper side.
Item 2. The light emitting module according to item 1, wherein an upper surface of the light-transmitting member and an upper surface of the light adjusting member are flush with each other, and an upper surface of the light-transmitting member and an upper surface of the light guiding member are flush with each other.
Item 3. The light emitting module according to item 1 or 2, wherein the light adjusting member has a light transmittance lower than the light transmitting member.
Item 4. The light emitting module according to any one of items 1 to 3, wherein the light-transmitting member has a recess on a lower surface thereof, and further includes a covering member having a refractive index different from that of the light-transmitting member and in contact with the recess.
Item 5. The light emitting module according to any one of items 1 to 4, wherein, in a cross-sectional view, the number of the reflective particles at an end of the light-transmissive member on the light guide member side is greater than the number of the reflective particles at an end of the light-transmissive member on the light source side.
Item 6. The light emitting module according to any one of items 1 to 5, wherein the light adjustment member is larger than the light source unit when viewed from above.
Item 7. The light emitting module according to any one of items 1 to 6, wherein the light adjustment member has a plurality of first recesses recessed in a lateral direction.
Item 8. The light emitting module according to any one of items 1 to 7, wherein the light adjustment member has a plurality of second through holes.
Item 9. The light-emitting module according to any one of items 1 to 8, wherein the light-transmitting member has a plurality of recesses recessed downward on an upper surface thereof.
Item 10. The light emitting module according to item 9, wherein bottom surfaces of the plurality of recesses in the upper surface of the light-transmitting member are located in portions of the light-transmitting member where the plurality of reflective particles are not present.

The above describes the embodiments of the present invention 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 as long as they include the gist of the present invention. In addition, a person skilled in the art can come up with various modifications and alterations within the scope of the concept of the present invention, and these modifications and alterations also fall within the scope of the present invention.

REFERENCE SIGNS LIST 10 light source section 20 light guide member 30 light-transmitting member 31 light-transmitting section 32 reflecting section 41 light adjustment member 50 wiring substrate 61 first adhesive layer 62 second adhesive layer 70 reflecting member 80 conductive member 90 insulating layer 100 light-emitting module 200 support member 300 surface light source

Claims (10)

a light guiding member having a first surface, a second surface opposite to the first surface, and a first through hole penetrating from the first surface to the second surface;
a light source portion located within the first through hole;
a light adjustment member located above the light source unit;
a light-transmitting member located in the first through hole and surrounding the light source unit and the light adjustment member in a top view,
The light-emitting module includes a plurality of reflective particles, the transparent member being biased toward an upper side. The light-emitting module according to claim 1, wherein the upper surface of the translucent member is flush with the upper surface of the light adjustment member, and the upper surface of the translucent member is flush with the upper surface of the light-guiding member. The light emitting module according to claim 1 or 2, wherein the light transmittance of the light adjusting member is lower than the light transmittance of the translucent member. the light-transmitting member has a recess on a lower surface thereof,
The light emitting module according to claim 1 , further comprising a covering member having a refractive index different from that of the translucent member and in contact with the recess. The light-emitting module according to claim 1 or 2, wherein, in a cross-sectional view, the number of the reflective particles at the end of the translucent member facing the light guide member is greater than the number of the reflective particles at the end of the translucent member facing the light source unit. The light-emitting module according to claim 1 or 2, in which the light adjustment member is larger than the light source unit when viewed from above. The light-emitting module according to claim 1 or 2, wherein the light adjustment member has a plurality of first recesses recessed in the lateral direction. The light-emitting module according to claim 1 or 2, wherein the light adjustment member has a plurality of second through holes. The light-emitting module according to claim 1 or 2, wherein the light-transmitting member has a plurality of recesses on the upper surface that are recessed downward. The light-emitting module according to claim 9, wherein the bottom surfaces of the recesses on the upper surface of the translucent member are located in a portion of the translucent member where the plurality of reflective particles are not present.

Images