JP7266175B2 - Light-emitting module and planar light source - Google Patents

Description

The present invention relates to a light emitting module and a planar light source.

2. Description of the Related Art A light-emitting module in which a light-emitting element such as a light-emitting diode and a light guide plate are combined is widely used as a planar light source such as a backlight of a liquid crystal display. For example, Patent Literature 1 discloses a backlight device that includes an LED substrate provided with a reflective sheet and a plurality of light emitting diodes, and a diffusion plate that faces the LED substrate.

JP 2019-61929 A

SUMMARY OF THE INVENTION An object of the present invention is to provide a light-emitting module and a planar light source capable of improving the reflectance of the lower surface side of a light guide plate while reducing the thickness of the light guide plate.

According to one aspect of the present invention, a light-emitting module includes a light source, a light guide plate to which light from the light source is guided, and includes a top surface and a bottom surface opposite to the top surface, and A first light reflective member is provided, and a second light reflective member is provided below the first light reflective member. The first light reflecting member includes a first resin member and a first reflector having a lower refractive index than the first resin member. The second light reflecting member includes a second resin member and a second reflector having a higher refractive index than the second resin member. The second resin member has a lower refractive index than the first resin member.

ADVANTAGE OF THE INVENTION According to this invention, the light-emitting module and planar light source which can improve the reflectance of the lower surface side of a light-guide plate can be provided, achieving thickness reduction.

1 is a schematic plan view of a planar light source according to an embodiment of the invention; FIG. FIG. 2 is a schematic cross-sectional view taken along line II-II of FIG. 1; 1 is a schematic cross-sectional view of a first light reflective member according to one embodiment of the present invention; FIG. FIG. 4 is a schematic cross-sectional view of a second light reflective member according to one embodiment of the present invention; 1 is a schematic cross-sectional view of a light source according to one embodiment of the present invention; FIG. FIG. 5 is a schematic cross-sectional view of a light source according to another embodiment of the invention; FIG. 5 is a schematic cross-sectional view of a light source according to another embodiment of the invention; It is a schematic cross section which shows the manufacturing method of the planar light source of one Embodiment of this invention. It is a schematic cross section which shows the manufacturing method of the planar light source of one Embodiment of this invention. It is a schematic cross section which shows the manufacturing method of the planar light source of one Embodiment of this invention. It is a schematic cross section which shows the manufacturing method of the planar light source of one Embodiment of this invention. It is a schematic cross section which shows the manufacturing method of the planar light source of one Embodiment of this invention. It is a schematic cross section which shows the manufacturing method of the planar light source of one Embodiment of this invention. It is a schematic cross section which shows the manufacturing method of the planar light source of one Embodiment of this invention. It is a schematic cross section which shows the manufacturing method of the planar light source of one Embodiment of this invention. It is a schematic cross section which shows the manufacturing method of the planar light source of one Embodiment of this invention. It is a schematic cross-sectional view of part of a planar light source according to another embodiment of the present invention. It is a schematic cross-sectional view of part of a planar light source according to another embodiment of the present invention. FIG. 10 is a graph showing measurement results of reflectance versus wavelength for three test samples; FIG.

Hereinafter, embodiments will be described with reference to the drawings. Since each drawing schematically shows the embodiment, the scale, interval or positional relationship of each member may be exaggerated, illustration of a part of the member may be omitted, or an end face showing only a cut surface as a cross-sectional view. Figures may be used. In addition, the same code|symbol is attached|subjected to the same structure in each drawing.

FIG. 1 is a schematic plan view of a planar light source 300 according to one embodiment of the invention. FIG. 1 shows a planar view of a light emitting surface of a planar light source 300. FIG. In FIG. 1, two directions parallel to the light emitting surface of the planar light source 300 and perpendicular to each other are defined as the X direction and the Y direction. The planar light source 300 has, for example, a rectangular outer shape with two sides extending along the X direction and two sides extending along the Y direction.

Planar light source 300 may comprise one or more light sources 20 . When the planar light source 300 includes a plurality of light sources 20 , each light source 20 is partitioned by partition grooves 14 . A light-emitting region 301 is defined by one region defined by the dividing grooves 14 . One light emitting region 301 can be used as a driving unit for local dimming, for example. Also, a plurality of light sources 20 may be arranged in one light emitting region 301 partitioned by the partition grooves 14 .

FIG. 1 illustrates a planar light source 300 having six light emitting regions 301 partitioned into two rows and three columns. Note that the number of light emitting regions 301 forming the planar light source 300 is not limited to the number shown in FIG. Also, the planar light source 300 can include one light source 20 , and in this case, one planar light source 300 includes one light emitting region 301 . Also, by arranging a plurality of planar light sources 300, a planar light source device with a larger area can be obtained.

FIG. 2 is a schematic cross-sectional view taken along line II-II of FIG. A planar light source 300 includes a light emitting module 100 and a wiring substrate 200 .

The light emitting module 100 includes a light guide plate 10, a light source 20, a first light reflective member 41, a second light reflective member 42, a third light reflective member 43, a first translucent member 80, and a first light adjustment member 90 .

Light from the light source 20 is guided to the light guide plate 10 , and the light guide plate 10 has translucency for the light emitted by the light source 20 . The light source 20 has a light emitting element 21 . The light emitted by the light source 20 includes at least the light emitted by the light emitting element 21 . For example, when the light source 20 contains a phosphor, the light emitted by the light source 20 also includes the light emitted by the phosphor. For example, the transmittance of the light guide plate 10 with respect to the light from the light source 20 is preferably 80% or more, more preferably 90% or more.

As the material of the light guide plate 10, for example, thermoplastic resin such as acrylic, polycarbonate, cyclic polyolefin, polyethylene terephthalate, or polyester, thermosetting resin such as epoxy or silicone, glass, or the like can be used. .

The light guide plate 10 has an upper surface 11 that serves as a light emitting surface of the planar light source 300 and a lower surface 12 opposite to the upper surface 11 . Further, the light guide plate 10 has holes. In the example shown in FIG. 2 , the hole is a through hole 13 penetrating from the upper surface 11 to the lower surface 12 .

The thickness of the light guide plate 10 is preferably 200 μm or more and 800 μm or less, for example. The light guide plate 10 may be composed of a single layer or a laminate of a plurality of layers in its thickness direction. When the light guide plate 10 is composed of a laminate, a translucent adhesive member may be arranged between each layer. Each layer of the laminate may use a different type of base material. As the material of the adhesive member, for example, thermoplastic resin such as acrylic, polycarbonate, cyclic polyolefin, polyethylene terephthalate or polyester, or thermosetting resin such as epoxy or silicone can be used.

As shown in FIG. 1, the through-hole 13 can be, for example, circular in plan view. Further, the through hole 13 can be, for example, an ellipse or a polygon such as a triangle, a quadrangle, a hexagon, or an octagon in plan view.

The light guide plate 10 is formed with a dividing groove 14 surrounding at least one light source 20 in plan view. As shown in FIG. 1, the light guide plate 10 preferably has grid-like dividing grooves 14 composed of dividing grooves 14 linearly extending in the X direction and dividing grooves 14 extending in the Y direction.

FIG. 2 illustrates the dividing groove 14 penetrating from the upper surface 11 to the lower surface 12 of the light guide plate 10 and reaching the first light reflecting member 41 . The dividing grooves 14 may be bottomed grooves that have an opening on the upper surface 11 side of the light guide plate 10 and whose bottom does not reach the lower surface 12 . In this case, it is preferable that the bottom of the dividing groove 14 is closer to the lower surface 12 . Alternatively, the dividing groove 14 may be a bottomed groove having an opening on the lower surface 12 side and having a bottom that does not reach the upper surface 11 .

A third light reflecting member 43 can be arranged in the partition groove 14 . In FIG. 2, the third light reflecting member 43 is filled in the partition groove 14 so that the upper surface thereof is flat. It may be a curved surface. Moreover, the third light reflecting member 43 may cover at least a part of the inner surface of the dividing groove 14 in a layered manner, and a space may be formed in a part of the dividing groove 14 . As such a third light reflecting member 43, for example, a resin member containing a light diffusing agent can be used. Light diffusing agents include, for example, particles of TiO ₂ . In addition, particles such as Nb ₂ O ₅ , BaTiO ₃ , Ta ₂ O ₅ , Zr ₂ O ₃ , ZnO, Y ₂ O ₃ , Al ₂ O ₃ , MgO, BaSO ₄ can be used as the light diffusing agent. Also, as the third light reflecting member 43, for example, a metal member such as Al or Ag may be used. Also, the entire partition groove 14 may be filled with air.

Further, the upper surface 11 of the light guide plate 10 may have a convex portion and/or a concave portion, for example, in a low luminance area in order to reduce luminance unevenness.

The third light reflecting member 43 suppresses light guiding between adjacent light emitting regions 301 . For example, light guiding from the light emitting region 301 in the light emitting state to the light emitting region 301 in the non-light emitting state is restricted. This enables local dimming with each light emitting region 301 as a drive unit.

A first light reflecting member 41 is arranged on the lower surface 12 side of the light guide plate 10 . The first light reflecting member 41 is adhered to the bottom surface 12 of the light guide plate 10 by, for example, an adhesive member 71 . The adhesive member 71 may be made of, for example, epoxy resin, acrylic resin, or olefin resin.

A second light reflecting member 42 is arranged on the lower surface side of the first light reflecting member 41 . For example, the second light reflecting member 42 is adhered to the bottom surface of the first light reflecting member 41 .

The first light reflecting member 41 is arranged to face the lower surface 12 of the light guide plate 10 to the lower surface of the light source 20 via the adhesive member 71 . That is, the first light reflecting member 41 closes the opening of the through hole 13 of the light guide plate 10 on the lower surface 12 side. The second light reflecting member 42 is arranged so as to face the entire lower surface of the first light reflecting member 41 . The second light reflecting member 42 may be arranged so as to face part of the lower surface of the first light reflecting member 41 . For example, the second light-reflecting member 42 may be a portion of the light-emitting region 301 that is relatively distant from the light source 20 and tends to have low luminance (for example, a corner portion of the light-emitting region 301 in plan view). part).

The first light reflecting member 41 and the second light reflecting member 42 are arranged between the wiring board 200 and the lower surface 12 of the light guide plate 10 .

The thickness of the second light reflecting member 42 can be made thinner than the thickness of the first light reflecting member 41 . For example, the thickness of the first light reflecting member 41 is 20 μm or more and 300 μm or less, preferably 40 μm or more and 250 μm or less. The thickness of the second light reflecting member 42 is 10 μm or more and 150 μm or less, preferably 20 μm or more and 100 μm or less.

3A is a schematic cross-sectional view of the first light reflecting member 41. FIG.

The first light reflecting member 41 includes a first resin member 41a and a first reflector 41b having a lower refractive index than the first resin member 41a. The first resin member 41a has translucency with respect to the light emitted from the light source 20, and is a resin member such as polyethylene terephthalate (PET) resin, olefin resin, acrylic resin, silicone resin, urethane resin, or epoxy resin, for example. The first reflector 41b is, for example, a bubble. In addition, for example, silica, hollow silica, _CaF2 , _MgF2 , or the like can be used as the first reflector 41b.

3B is a schematic cross-sectional view of the second light reflecting member 42. FIG.

The second light reflecting member 42 includes a second resin member 42a and a second reflector 42b having a higher refractive index than the second resin member 42a. The second resin member 42 a has a lower refractive index than the first resin member 41 a of the first light reflecting member 41 . The second resin member 42a has translucency with respect to the light emitted by the light source 20, and is made of resin such as acrylic resin, silicone resin, urethane resin, epoxy resin, phenol resin, BT resin, polyimide resin, or unsaturated polyester resin. It is a member. The second reflector 42b is, for example, particles of _TiO2 . In addition, particles such as Nb ₂ O ₅ , BaTiO ₃ , Ta ₂ O ₅ , Zr ₂ O ₃ , ZnO, Y ₂ O ₃ , Al ₂ O ₃ , MgO, or BaSO ₄ are used as the second reflector 42b. be able to.

Also, the second light reflecting member 42 is preferably a member whose elastic modulus changes little with respect to temperature changes from 25°C to 100°C. For example, the change in elastic modulus of the second light reflecting member 42 is preferably 60% or less at 60°C and 80% or less at 100°C with respect to the elastic modulus at 25°C. In particular, the elastic modulus of the second light reflecting member 42 at 100° C. is preferably 10000 Pa or more and 50000 Pa or less, more preferably 20000 Pa or more and 40000 Pa or less. As a result, for example, the position of the second light reflecting member 42 is shifted with respect to the first light reflecting member 41 by heating when curing the conductive paste arranged in the hole 401 as shown in FIG. Shifting can be suppressed, and cracks in the hardened conductive paste (first conductive portion 61) can be suppressed.

The refractive index of the first resin member 41a, the first reflector 41b, the second resin member 42a, or the second reflector 42b in the present embodiment can be measured by, for example, an Abbe refractometer or the like, or can be measured using a Fourier transform infrared ray. It can be estimated from the composition identified by external spectroscopic analysis or the like. Further, the refractive index of the first resin member 41a or the second resin member 42a is determined by, for example, placing the first resin member 41a or the second resin member 42a in a liquid having a specific refractive index (hereinafter referred to as refractive liquid). , the presence or absence of the interface between the first resin member 41a or the second resin member 42a and the refractive liquid can also be estimated by observing with an optical microscope. That is, the refractive index of the first resin member 41a or the second resin member 42a can be estimated to be close to the refractive index of the refractive liquid when the interface with the refractive liquid cannot be seen (or is difficult to see). If the first resin member 41a, the first reflector 41b, the second resin member 42a, or the second reflector 42b are commercially available products, catalog values can be used for their refractive indices.

The light source 20 is arranged on the first light reflecting member 41 in the through hole 13 of the light guide plate 10 via the adhesive member 71 .

FIG. 4A is a schematic cross-sectional view of an example of the light source 20. FIG.

The light source 20 may be a single light-emitting element, or may have a structure in which an optical member such as a wavelength conversion member is combined with a light-emitting element. In this embodiment, the light source 20 includes a light emitting element 21, an electrode 23, a covering member 24, a second translucent member 25, and a second light adjusting member 26, as shown in FIG. 4A. Also, the light source 20 may not include the second light adjustment member 26 depending on the desired light distribution. For example, the second light adjusting member 26 may not be arranged on the second translucent member 25 , in other words, the upper surface of the light source 20 may be formed by the upper surface of the second translucent member 25 .

Light emitting element 21 includes semiconductor laminate 22 . The semiconductor laminate 22 includes, for example, a support substrate such as sapphire or gallium nitride, an n-type semiconductor layer and a p-type semiconductor layer disposed on the support substrate, a light-emitting layer sandwiched therebetween, an n-type semiconductor layer and a p-type semiconductor layer. It includes an n-side electrode and a p-side electrode electrically connected to the p-type semiconductor layer. Note that the semiconductor laminate 22 from which the supporting substrate has been removed may be used. The structure of the light-emitting layer may be a structure having a single active layer such as a double hetero structure or a single quantum well structure (SQW), or a single active layer structure such as a multiple quantum well structure (MQW). A structure having layers may also be used. The light-emitting layer can emit visible light or ultraviolet light. The light-emitting layer can emit visible light from blue to red. The semiconductor laminate 22 including such a light-emitting layer can include, for example, In _x Al _y Ga _1-xy N (0≦x, 0≦y, x+y≦1). The semiconductor laminate 22 can include at least one light-emitting layer capable of emitting light as described above. For example, the semiconductor laminate 22 may have a structure including 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. may be a structure in which a structure including in order is repeated multiple times. When the semiconductor laminate 22 includes a plurality of light-emitting layers, it may include light-emitting layers with different emission peak wavelengths, or may include light-emitting layers with the same emission peak wavelength. It should be noted that the emission peak wavelength may vary by several nanometers. A combination of emission peak wavelengths can be selected as appropriate. For example, when the semiconductor stack 22 includes two light emitting layers, blue light and blue light, green light and green light, red light and red light, ultraviolet light and ultraviolet light, blue light and green light, blue light and red light. , or a combination of green light and red light, or the like. Moreover, each light-emitting layer may include a plurality of active layers with different emission peak wavelengths, or may include a plurality of active layers with the same emission peak wavelength.

The second translucent member 25 covers the top and side surfaces of the light emitting element 21 . The second translucent member 25 protects the light emitting element 20 and has functions such as wavelength conversion and light diffusion depending on the particles added to the second translucent member 25 . Specifically, the second translucent member 25 contains a translucent resin and may further contain a phosphor. As translucent resin, for example, silicone resin or epoxy resin can be used. Further, as the phosphor, yttrium-aluminum-garnet-based phosphor (e.g., _Y3 (Al, Ga) _5O12 :Ce), lutetium-aluminum-garnet- _based phosphor (e.g., _Lu3 (Al, Ga) _5O12 :Ce), terbium-aluminum- _garnet -based phosphors (e.g., _Tb3 (Al, Ga) _{5O12 :} Ce), CCA- _based phosphors (e.g., _Ca10 ( _PO4 ) _6Cl2 :Eu ), SAE phosphors (eg, Sr ₄ Al ₁₄ O ₂₅ :Eu), chlorosilicate phosphors (eg, Ca ₈ MgSi ₄ O ₁₆ Cl ₂ :Eu), β-sialon phosphors (eg, (Si, Al) ₃ (O, N) ₄ :Eu), α-sialon-based phosphor (for example, Mz(Si, Al) ₁₂ (O, N) ₁₆ :Eu (where 0 < z ≤ 2, and M is Li , Mg, Ca, Y, and lanthanide elements excluding La and Ce)), SLA-based phosphors (eg, SrLiAl ₃ N ₄ :Eu), CASN-based phosphors (eg, CaAlSiN ₃ :Eu), or SCASN-based phosphors (e.g., (Sr, Ca) AlSiN ₃ :Eu) and other nitride phosphors, KSF phosphors (e.g., K ₂ SiF ₆ :Mn), KSAF phosphors (e.g., K ₂ (Si, Al) F ₆ :Mn) or MGF-based phosphors (for example, 3.5MgO·0.5MgF ₂ ·GeO ₂ :Mn) and other fluoride-based phosphors, phosphors having a perovskite structure (for example, CsPb (F, Cl, Br, I) ₃ ), or quantum dot phosphors (eg, CdSe, InP, AgInS ₂ or AgInSe ₂ ), or the like can be used. As the phosphor added to the second translucent member 25, one kind of phosphor may be used, or plural kinds of phosphors may be used.

The KSAF-based phosphor may have a composition represented by the following formula (I).
_{M2 [ SipAlqMnrFs ]} ( _I )

In formula (I), M represents an alkali metal and may contain at least K. Mn may be a tetravalent Mn ion. p, q, r and s may satisfy 0.9≤p+q+r≤1.1, 0<q≤0.1, 0<r≤0.2, 5.9≤s≤6.1. Preferably, 0.95≦p+q+r≦1.05 or 0.97≦p+q+r≦1.03, 0<q≦0.03, 0.002≦q≦0.02 or 0.003≦q≦0.015 , 0.005≦r≦0.15, 0.01≦r≦0.12 or 0.015≦r≦0.1, 5.92≦s≦6.05 or 5.95≦s≦6.025 can be For example, _{K2 [ Si0.946Al0.005Mn0.049F5.995 ] , K2} [ _{Si0.942Al0.008Mn0.050F5.992} ] _{, K2 [ Si0 . 939} Al _0.014 Mn _0.047 F _5.986 ]. With such a KSAF-based phosphor, it is possible to obtain red light emission with high brightness and a narrow half-value width of the emission peak wavelength.

The covering member 24 is arranged at least on the lower surface of the light emitting element 21 . Covering member 24 is arranged such that the surface (lower surface in FIG. 4A) of electrode 23 electrically connected to light emitting element 21 is exposed from covering member 24 . The covering member 24 is also arranged on the lower surface of the second translucent member 25 that covers the side surface of the light emitting element 21 .

The covering member 24 has reflectivity with respect to the light emitted by the light source 20 . The covering member 24 is, for example, a resin member containing a light diffusing agent. Specifically, the covering member 24 is silicone resin, epoxy resin, or acrylic resin containing a light diffusing agent made of particles such as TiO ₂ , SiO ₂ , Al ₂ O ₃ , ZnO, or glass. Also, the covering member 24 may be an inorganic member.

The second light adjusting member 26 is arranged on the upper surface of the second translucent member 25 and controls the amount and direction of light emitted from the upper surface of the second translucent member 25 . The second light adjusting member 26 has reflectivity and translucency with respect to the light emitted by the light source 20 . Part of the light emitted from the upper surface of the second translucent member 25 is reflected by the second light adjustment member 26 and the other part is transmitted through the second light adjustment member 26 . For example, the transmittance of the second light adjusting member 26 is preferably 1% or more and 50% or less, and more preferably 3% or more and 30% or less. As a result, the luminance immediately above the light source 20 is reduced, and the in-plane variation in the luminance of the planar light source 300 is reduced. The second light adjusting member 26 can be made of translucent resin and a light diffusing agent or the like contained in the translucent resin. Translucent resins are, for example, silicone resins, epoxy resins, or acrylic resins. Light diffusing agents include particles such as TiO ₂ , SiO ₂ , Al ₂ O ₃ , ZnO, or glass. The second light adjusting member 26 may be, for example, a metal member such as Al or Ag, or a dielectric multilayer film. Also, the second light adjusting member 26 may be an inorganic member.

Further, a sheet-like wavelength conversion member (hereinafter referred to as a wavelength conversion sheet) containing the above phosphor may be arranged on the planar light source 300 . The wavelength conversion sheet can be used as a planar light source that absorbs part of the blue light from the light source 20, emits yellow light, green light and/or red light, and emits white light. For example, white light can be obtained by combining a light source capable of emitting blue light and a wavelength conversion sheet containing a phosphor capable of emitting yellow light. Alternatively, a light source capable of emitting blue light may be combined with a wavelength conversion sheet containing a red phosphor and a green phosphor. Also, a light source 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. Also, a light source having a light emitting element capable of emitting blue light, a translucent member containing a phosphor capable of emitting red light, and a wavelength conversion sheet containing a phosphor capable of emitting green light are combined. may

As shown in FIG. 2 , a first translucent member 80 is arranged inside the through hole 13 of the light guide plate 10 . The first translucent member 80 has translucency with respect to the light emitted by the light source 20. For example, the same resin as the material of the light guide plate 10 or a resin having a small refractive index difference with the material of the light guide plate 10 is used. can be done.

The first translucent member 80 is arranged between the side surface of the light source 20 and the side surface of the through hole 13 . At this time, a space such as an air layer is not formed between the side surface of the light source 20 and the first translucent member 80 and between the side surface of the through hole 13 and the first translucent member 80. It is preferable to dispose a translucent member 80 . Thereby, the light from the light source 20 can be easily guided into the light guide plate 10 .

The first translucent member 80 covers the top surface of the light source 20 (the top surface of the second light adjustment member 26 in this example). The upper surface of the first translucent member 80 can be a flat surface. Also, the upper surface of the first translucent member 80 can be a concave or convex curved surface.

The wiring board 200 includes an insulating base material 50, a first wiring layer 53 arranged on one surface of the insulating base material 50, a second wiring layer 54 arranged on the other surface of the insulating base material 50, and a conductive material. a member 60;

The wiring board 200 may further include a first insulating layer 52 and a second insulating layer 51 . The first insulating layer 52 covers part of the surface of the insulating base material 50 on which the first wiring layer 53 is arranged and part of the first wiring layer 53 . The second insulating layer 51 covers the surface of the insulating base material 50 on which the second wiring layer 54 is arranged and the second wiring layer 54 . The second light reflecting member 42 is arranged on the second insulating layer 51 .

Conductive member 60 includes a first conductive portion 61 and a second conductive portion 62 . The first conductive portion 61 penetrates the adhesive member 71 , the first light reflecting member 41 , the second light reflecting member 42 , the second insulating layer 51 and the insulating base material 50 . The first conductive portion 61 is located under the electrode 23 of the light source 20 in the thickness direction of the planar light source 300 and is connected to the electrode 23 .

The second conductive portion 62 is arranged on the surface of the insulating base material 50 exposed from the first insulating layer 52 and covers part of the first wiring layer 53 . The second conductive portion 62 is connected to the first conductive portion 61 and the first wiring layer 53 . Therefore, the electrode 23 of the light source 20 is electrically connected to the second wiring layer 53 via the first conductive portion 61 and the second conductive portion 62 of the conductive member 60 .

The first wiring layer 53 and the second wiring layer 54 are electrically connected to each other at a portion of the planar light source 300 other than the cross-sectional portion shown in FIG. For example, the first wiring layer 53 and the second wiring layer 54 are connected by wiring penetrating the insulating base material 50 .

The insulating base material 50, the first insulating layer 52, and the second insulating layer 51 can contain resin such as polyimide, polyethylene naphthalate, or polyethylene terephthalate, for example. The first wiring layer 53 and the second wiring layer 54 can contain metal such as copper or aluminum, for example. The conductive member 60 is, for example, a conductive paste in which a conductive filler is dispersed in a binder resin. The conductive member 60 can contain a metal such as copper or silver as a filler. The filler is particulate or flaky.

The first light adjusting member 90 is arranged at least on the first translucent member 80 . The first light adjustment member 90 has reflectivity and translucency with respect to the light emitted by the light source 20 . The first light adjusting member 90 can be made of translucent resin and a light diffusing agent or the like dispersed in the translucent resin. Translucent resins are, for example, silicone resins, epoxy resins, or acrylic resins. Light diffusing agents include particles such as TiO ₂ , SiO ₂ , Al ₂ O ₃ , ZnO, or glass. Also, the first light adjusting member 90 may be an inorganic member. Also, the first light adjusting member 90 can be arranged so as to cover all or part of the upper surface of the first translucent member 80 .

As shown in FIG. 1, the first light adjustment member 90 is arranged at a position overlapping the light source 20 in plan view. In the example shown in FIG. 1 , the first light adjustment member 90 has a rectangular shape that is larger than the rectangular light source 20 in a plan view. The first light adjustment member 90 can be circular, triangular, hexagonal, octagonal, or the like in plan view. As shown in FIG. 2, the first light adjusting member 90 may extend over the upper surface of the first translucent member 80 and the upper surface 11 of the light guide plate 10 therearound.

Further, the first light adjustment member 90 may be arranged in a high luminance area on the upper surface 11 of the light guide plate 10 to reduce luminance unevenness, instead of being arranged at a position overlapping the light source 20 in plan view. For example, the first light adjustment members 90 can be scattered near the dividing grooves 14 , more specifically along the dividing grooves 14 .

A portion of the first translucent member 80 is arranged between the first light adjusting member 90 and the second light adjusting member 26 of the light source 20 . The first translucent member 80 has a higher transmittance for the light emitted by the light source 20 than the second light adjusting member 26 and the first light adjusting member 90 . The transmittance of the first translucent member 80 with respect to the light emitted by the light source 20 is 2 to 100 times the transmittance of the second light adjusting member 26 and the transmittance of the first light adjusting member 90 within the range of 100% or less. can be:

The second light adjusting member 26 reflects part of the light emitted directly above the light source 20 and transmits the other part. As a result, in each light emitting region 301 of the planar light source 300, it is possible to prevent the brightness of the region immediately above the light source 20 from becoming extremely higher than the brightness of other regions. That is, it is possible to reduce uneven brightness of light emitted from one light emitting region 301 partitioned by the partition groove 14 . The thickness of the first light adjusting member 90 is preferably 0.005 mm or more and 0.2 mm or less, more preferably 0.01 mm or more and 0.075 mm or less. In addition, the reflectance of the first light adjustment member 90 is preferably set lower than the reflectance of the second light adjustment member 26 of the light source 20. For example, 20% to 90% of the light from the light source 20 The following is preferable, and more preferably 30% or more and 85% or less.

In addition, in the example shown in FIG. 2 , a first transparent member having a higher transmittance than the second light adjustment member 26 and the first light adjustment member 90 is provided between the second light adjustment member 26 and the first light adjustment member 90 . A part of the optical member 80 is interposed. The first translucent member 80 between the second light adjusting member 26 and the first light adjusting member 90 receives the light emitted from the light source 20 and the light reflected by the first light reflecting member 41 around the light source 20. Light or the like is guided. As a result, the area immediately above the light source 20 does not become too bright or too dark, and as a result, uneven brightness in the light emitting surface of the light emitting area 301 can be reduced.

The first light reflecting member 41 arranged on the lower surface 12 side of the light guide plate 10 directs the light guided in the light guide plate 10 toward the lower surface 12 side to the upper surface 11 side, which is the light emitting surface of the planar light source 300 . to improve the brightness of the light extracted from the upper surface 11 .

In the region between the first light reflective member 41 and the top surface 11 , the light from the light source 20 is guided toward the dividing groove 14 while total reflection is repeated between the first light reflective member 41 and the top surface 11 . The light is guided through the light plate 10 . A part of the light directed toward the upper surface 11 is extracted from the upper surface 11 to the outside of the light guide plate 10 .

As described above with reference to FIG. 3A, the first light reflecting member 41 includes a translucent first resin member 41a and a first reflector 41b having a lower refractive index than the first resin member 41a. . Therefore, the light incident on the first resin member 41a is likely to be totally reflected at the interface between the first resin member 41a and the first reflector 41b. By utilizing such total reflection in the first light reflecting member 41 , light can be easily guided to a region farther from the light source 20 . Even if the distance between the light source 20 and the end (dividing groove 14) of each light emitting region 301 is long, the light can be easily guided to the entire light emitting region 301 . This can reduce luminance unevenness in the light emitting surface (upper surface 11). In addition, the number of light sources 20 arranged on the light guide plate 10 can be reduced.

It is preferable that the refractive index difference between the first resin member 41a and the first reflector 41b is large, and bubbles (air) are particularly preferable as the first reflector 41b.

As the thickness of the first light reflecting member 41 increases, the effect of suppressing the light that passes through the first light reflecting member 41 and escapes downward from the light emitting module 100 increases. Light passing through the light emitting module 100 downward is not extracted from the upper surface 11 and becomes a loss. However, thickening the first light reflecting member 41 hinders thinning of the light emitting module 100 .

Therefore, in this embodiment, the second light reflecting member 42 is arranged on the lower surface side of the first light reflecting member 41 . As described above with reference to FIG. 3B, the second light reflecting member 42 includes a translucent second resin member 42a and a second reflector 42b having a higher refractive index than the second resin member 42a. . The light incident on the second resin member 42 a is scattered and reflected by the second reflector 42 b , thereby suppressing the escape of light downward from the light emitting module 100 . That is, by combining the first light-reflecting member 41 and the second light-reflecting member 42 having different reflection characteristics, the light guiding property in the light guide plate 10 is ensured while suppressing the light passing below the light-emitting module 100. As a result, the light extraction efficiency from the upper surface 11 can be improved.

In addition, deterioration of the wiring board 200 can be suppressed by suppressing the light passing through the light emitting module 100 below.

A larger difference in refractive index between the second resin member 42a and the second reflector 42b is preferable, and titanium oxide is particularly preferable as the second reflector 42b.

Moreover, the refractive index of the second resin member 42 a of the second light reflecting member 42 is preferably lower than the refractive index of the first resin member 41 a of the first light reflecting member 41 . As a result, when light is incident on the second resin member 42a from the first resin member 41a, it is more likely to be totally reflected at the interface between the first resin member 41a and the second resin member 42a, and the light passes through the light emitting module 100 below. Light can be suppressed more. In addition, when the refractive index of the second resin member 42a is low, the difference in refractive index from the second reflector 42b, which has a higher refractive index, becomes greater, making it easier to scatter and reflect light.

Light guiding in the light guide plate 10 is mainly performed by the first light reflective member 41, and the second light reflective member 42 only needs to suppress the light from escaping downward. may be thinner than the thickness of the first light reflecting member 41 .

FIG. 16 is a graph showing measurement results of reflectance versus wavelength for three test samples.

The solid line represents the measurement results for the first test sample. The first test sample has a structure in which a PET resin layer containing air bubbles is laminated on a glass substrate via an acrylic resin layer containing TiO ₂ particles. The first test sample is a three-layer laminate including a glass substrate, an acrylic resin layer containing _TiO2 particles, and a PET resin layer containing air bubbles. The PET resin layer containing air bubbles corresponds to the first light reflecting member of this embodiment, and the acrylic resin layer containing TiO ₂ particles corresponds to the second light reflecting member of this embodiment. The thickness of the PET resin layer containing air bubbles is 50 μm and the thickness of the acrylic resin layer containing TiO ₂ particles is 40 μm.

The dashed line represents the measurement results for the second test sample. The second test sample has a structure in which a PET resin layer containing air bubbles is laminated on a glass substrate via an acrylic resin layer that does not contain a light diffusing agent such as TiO ₂ particles. A second test sample is a three-layer laminate including a glass substrate, an acrylic resin layer containing no light diffusing agent, and a PET resin layer containing air bubbles. The thickness of the PET resin layer containing air bubbles in the second test sample is 188 μm, which is thicker than the thickness of the PET resin layer containing air bubbles in the first test sample. The thickness of the acrylic resin layer containing no light diffusing agent in the second test sample is 25 μm.

The dotted line represents the measurement results for the third test sample. The third test sample is the same three-layer laminate as the second test sample, and differs from the second test sample only in the thickness of the PET resin layer containing air bubbles. The thickness of the bubble-containing PET resin layer of the third test sample is 50 μm, which is the same as the thickness of the bubble-containing PET resin layer of the first test sample.

The total thickness of the two layers on the glass substrate of the first test sample is less than the total thickness of the two layers on the glass substrate of the second test sample. Furthermore, the total thickness of the two layers on the glass substrate of the first test sample is less than the thickness of one layer of the bubble-containing PET resin layer of the second test sample. The thickness of the glass substrate is the same in the first, second and third test samples. For the first, second, and third test samples, a high-speed spectrophotometer CMS-35SP (Murakami Color Research Laboratory) was used to measure the reflectance for each wavelength from the side of the PET resin layer containing bubbles. .

From the measurement results of FIG. 16, in the first test sample corresponding to the configuration of the present embodiment, although the thickness of the PET resin layer containing air bubbles is thinner than that of the second test sample, air bubbles By forming an acrylic resin layer containing TiO ₂ particles under the containing PET resin layer, the reflectance is equal to or higher than that of the second test sample in the wavelength band of about 430 nm or more and 650 nm or less. is obtained.
The reflectance of the third test sample decreases as the wavelength of the light increases, whereas the decrease of the reflectance of the first test sample is small even on the long wavelength side.
For example, when trying to obtain a light source capable of emitting white light by combining a light emitting element capable of emitting blue light, a yellow phosphor, and a red phosphor, the first test sample reflects more yellow light than the third test sample. Light and red light can be increased. For this reason, in the first test sample, the same amount of white light as in the third test sample can be obtained with a smaller amount of phosphor than in the third test sample, so the cost of the phosphor can be reduced. Further, for example, when one light-emitting element including a light-emitting layer capable of emitting blue light and a light-emitting layer capable of emitting green light having a longer wavelength than this is used as a light source, the first One test sample can reflect more green light than the third test sample. Therefore, in the first test sample, it is possible to prevent the amount of green light from becoming smaller than that of blue light.

Assuming that the X direction is the row direction and the Y direction is the column direction in FIG. 1, the planar light source 300 shown in FIG. A planar light source having 25 light-emitting regions partitioned into 5 rows and 5 columns, which was prototyped under the conditions of the first test sample, and a planar light source having 25 light-emitting regions, which were also partitioned into 5 rows and 5 columns, prototyped under the conditions of the third test sample. Luminance was measured and compared with a planar light source having 25 light emitting regions. As a result, the luminance of the planar light source prototyped under the conditions of the first test sample was about 7.7% higher than the luminance of the planar light source prototyped under the conditions of the third test sample. From the reflectance measurement results shown in FIG. 16, the difference in reflectance between the first test sample and the third test sample is about 1 to 2%. It can be seen that there is a large difference in luminance.

According to this embodiment, it is possible to improve the reflectance of the lower surface 12 side of the light guide plate 10 while reducing the thickness of the light emitting module 100 . Thereby, the light extraction efficiency from the upper surface 11 of the light guide plate 10 can be improved.

The first light reflecting member 41 is arranged to face the lower surface 12 of the light guide plate 10 to the lower surface of the light source 20 , and the second light reflecting member 42 faces the entire lower surface of the first light reflecting member 41 . are arranged as That is, the first light reflecting member 41 and the second light reflecting member 42 are also arranged on the bottom surface of the through hole 13 where the light source 20 is arranged. This can reduce light absorption in areas under and near the light source 20 .

Next, a method for manufacturing the planar light source 300 will be described with reference to FIGS. 5 to 13. FIG.

The manufacturing method of the planar light source 300 of the embodiment has a step of preparing a structure 200' shown in FIG. A structure 200 ′ is a structure before forming the conductive member 60 on the wiring substrate 200 described above.

Laminate sheet 40 is placed on structure 200' to form structure 400, as shown in FIG. The laminated sheet 40 includes a second light reflective member 42 arranged on the second insulating layer 51 of the structure 200', a first light reflective member 41 arranged on the second light reflective member 42, and an adhesive member 71 disposed on the first light reflecting member 41 .

As shown in FIG. 7, holes 401 are formed in structure 400 . The hole 401 penetrates the adhesive member 71 , the first light reflecting member 41 , the second light reflecting member 42 , the second insulating layer 51 and the insulating base material 50 . For example, a hole 401 is formed with a drill. Alternatively, the holes 401 may be formed by punching or laser processing. Further, the adhesive member 71, the first light reflecting member 41, the second light reflecting member 42, the second insulating layer 51, and the insulating base material 50 (the insulating base material 50 includes the first insulating material) are provided. layer 52, the first wiring layer 53, and the second wiring layer 54) are purchased, and by bonding them together, the adhesive member 71, the first light reflective member 41, and the second light reflective member 42, the second insulating layer 51, and the insulating substrate 50, a hole 401 may be formed continuously. Alternatively, the structure 400 in which the holes 401 are formed in advance may be purchased and prepared.

As shown in FIG. 8, the light guide plate 10 is arranged on the structure 400 in which the holes 401 are formed. The lower surface 12 of the light guide plate 10 is adhered to the adhesive member 71 . A through hole 13 is formed in the light guide plate 10 and positioned so as to overlap the hole 401 .

As shown in FIG. 9, the light source 20 is arranged inside the through hole 13 . The lower surface of the covering member 24 , which is the lower surface of the light source 20 , is adhered to the upper surface of the first light reflecting member 41 exposed inside the through hole 13 . Electrode 23 of light source 20 is positioned in hole 401 . At least part of the lower surface of the electrode 23 is exposed through the hole 401 .

After arranging the light source 20, a translucent member 81 is formed in the through hole 13 as shown in FIG. Translucent member 81 is formed between the side surface of light source 20 and the inner side surface of through hole 13 . For example, the translucent member 81 is formed by supplying a liquid translucent resin into the through holes 13 and then curing the resin. The temperature at which the translucent resin is cured is preferably 30° C. or higher and 150° C. or lower, more preferably 40° C. or higher and 130° C. or lower. The side surface of the light source 20 is covered with the translucent member 81 , and the upper surface of the light source 20 is exposed from the translucent member 81 within the through hole 13 .

After forming the translucent member 81 in the through-hole 13, the dividing groove 14 is formed in the light guide plate 10 as shown in FIG. In the example shown in FIG. 11 , the dividing groove 14 penetrates the light guide plate 10 and reaches part of the structure 400 . For example, the dividing grooves 14 are formed by cutting. Since the gap between the side surface of the light source 20 and the inner side surface of the through hole 13 is filled with the translucent member 81, it is possible to prevent cutting waste from the dividing groove 14 from entering the gap.

After forming the dividing grooves 14 , the first conductive portions 61 are formed in the holes 401 . As shown in FIG. 12 , conductive paste, for example, is supplied into the holes 401 while the structure 400 is positioned above the light guide plate 10 and the light sources 20 . By curing the conductive paste, the first conductive portion 61 connected to the electrode 23 of the light source 20 is formed. Further, a second conductive portion 62 is formed on the surface of the insulating base material 50 on which the first wiring layer 53 is formed so as to connect the first wiring layer 53 and the first conductive portion 61 . For example, the second conductive portion 62 is formed by supplying a conductive paste onto the surface of the insulating base material 50 and then curing the paste. For example, the first conductive portion 61 and the second conductive portion 62 are integrally formed in the same process. At this time, since the light source 20 is already adhered to the adhesive member 71 , the conductive paste does not enter between the lower surface of the light source 20 and the adhesive member 71 . Thereby, a short circuit between the electrodes 23 through the conductive paste can be prevented.

After forming the conductive member 60 , the translucent member 82 shown in FIG. 13 is formed on the light source 20 and the translucent member 81 in the through hole 13 . As a result, the through hole 13 is filled with the first translucent member 80 composed of the translucent member 81 and the translucent member 82 .

For example, the translucent member 82 is formed by supplying a liquid translucent resin into the through holes 13 and then curing the resin. At this time, it is possible to correct the color tone by dispersing the phosphor 83 in the translucent resin.

For example, in the state of FIG. 12, a current is supplied to the light emitting element 21 through the conductive member 60 to cause the light emitting element 21 to emit light. The light emitted by the light emitting element 21 excites the phosphor contained in the second translucent member 25 to emit light. That is, the color of the light emitted by the light source 20 is a mixture of the color of the light emitted by the light emitting element 21 and the color of the light emitted by the phosphor, and the chromaticity of the light emitted by the light source 20 is measured. By mixing an appropriate amount of the phosphor 83 into the translucent member 82 according to the result of the chromaticity measurement, it is possible to correct the chromaticity to the target. 10, a phosphor for chromaticity correction may be mixed into the translucent member 81 when forming the translucent member 81 in the through hole 13. As shown in FIG.

After filling the through hole 13 with the first translucent member 80, the third light reflective member 43 is formed in the partition groove 14 as shown in FIG. Furthermore, the first light adjusting member 90 is formed on the first translucent member 80 . The third light reflecting member 43 and the first light adjusting member 90 can be made of the same material at the same time. The third light reflecting member 43 and the first light adjusting member 90 can be formed by printing or inkjet, for example.

FIG. 4B is a schematic cross-sectional view of another example of the light source.

A covering member 24 covers the side and bottom surfaces of the semiconductor laminate 22 of the light emitting element 21 . A second translucent member 25 is arranged on the upper surface of the semiconductor laminate 22 . A second translucent member 25 is also arranged on the covering member 24 that covers the side surface of the semiconductor laminate 22 . A second light adjusting member 26 is arranged on the second translucent member 25 . The second light adjusting member 26 may not be arranged on the second translucent member 25 depending on desired light distribution.

FIG. 4C is a schematic cross-sectional view of still another example of the light source.

The light source shown in FIG. 4C does not include the second translucent member 25 and the covering member 24 described above, but includes the light emitting element 21 and the second light adjusting member 26 arranged on the top surface of the light emitting element 21 . Note that the second light adjustment member 26 may not be arranged on the upper surface of the light emitting element 21 depending on desired light distribution.

FIG. 14 is a schematic cross-sectional view of part of a planar light source according to another embodiment of the invention. FIG. 14 shows a cross section of a portion of the planar light source where the light source 20 is arranged and its peripheral portion.

The light guide plate 10 includes a bottomed hole portion 15 having a concave cross section and opening toward the lower surface 12 side. The hole portion 15 is a truncated conical space in the present embodiment, and may be, for example, a truncated polypyramidal space such as a quadrangular truncated pyramid or a hexagonal truncated pyramid. The light source 20 is arranged within such a hole 15 . A light reflecting member 45 is arranged between the inner side surface of the hole 15 and the side surface of the light source 20 . The light reflective member 45 is, for example, a resin member containing a light diffusing agent.

A concave portion 16 is formed at a position facing the hole portion 15 on the upper surface 11 side of the light guide plate 10 . The concave portion 16 includes, for example, a concave portion having a polygonal pyramid shape such as a conical shape, a square pyramid shape, and a hexagonal pyramid shape, and a polygonal pyramid shape such as a truncated cone shape, a square pyramid shape, and a hexagonal pyramid shape. be done. A first light adjustment member 46 is arranged in the recess 16 . The first light adjustment member 46 is configured similarly to the first light adjustment member 90 described above.

The first light reflecting member 41 is arranged on the lower surface 12 side of the light guide plate 10, and the second light reflecting member 42 is arranged on the lower surface side of the first light reflecting member 41, as in the above-described embodiment.

A light reflecting member 44 is arranged in the area around the light source 20 on the lower surface 12 of the light guide plate 10 and on the lower surface of the light reflecting member 45 . The light reflective member 44 is, for example, a resin member containing a light diffusing agent.

Electrode 23 of light source 20 is connected to wiring layer 56 of wiring substrate 210 . The wiring board 210 includes an insulating base material 55 and a wiring layer 56 formed on the insulating base material 55 . The first light reflecting member 41 and the second light reflecting member 42 are arranged between the wiring board 210 and the lower surface 12 of the light guide plate 10 .

In the planar light source shown in FIG. 14 as well, by combining the first light-reflecting member 41 and the second light-reflecting member 42 having different reflection characteristics, the light guiding property in the light guide plate 10 is ensured and the light guide plate It is possible to suppress the light passing through to the lower side of 10 and improve the light extraction efficiency from the upper surface 11 .

FIG. 15 is a schematic cross-sectional view of part of a planar light source according to still another embodiment of the invention.

This planar light source is an edge-type planar light source, and the light source 20 is arranged to face the end surface 17 of the light guide plate 10 . An end surface 17 of the light guide plate 10 is a light incident surface into which light from the light source 20 is incident, and a light exit surface 20 a of the light source 20 faces the end surface 17 of the light guide plate 10 .

The light source 20 and the light guide plate 10 are arranged inside the case 500 . A wiring board 220 is arranged between the light source 20 and the bottom wall 501 of the case 500 , and the light source 20 is mounted on the wiring board 220 .

The lower surface 12 of the light guide plate 10 faces the bottom wall 501 of the case 500 , and the first light reflecting member 41 and the second light reflecting member 41 are disposed between the lower surface 12 of the light guide plate 10 and the bottom wall 501 of the case 500 . A member 42 is arranged. A first light reflecting member 41 is arranged on the lower surface 12 side of the light guide plate 10 , and a second light reflecting member 42 is arranged on the lower surface side of the first light reflecting member 41 .

In the planar light source shown in FIG. 15 as well, by combining the first light-reflecting member 41 and the second light-reflecting member 42 having different reflection characteristics, the light guiding property in the light guide plate 10 is ensured and the light guide plate It is possible to suppress the light passing through to the lower side of 10 and improve the light extraction efficiency from the upper surface 11 .

In each embodiment described above, the second light reflective member 42 having a higher reflectance than the first light reflective member 41 can be arranged on the lower surface side of the first light reflective member 41. For example, a metal film , a dielectric multilayer film, or the like can also be used as the second light reflecting member 42 .

An air layer can also be used as a light guide member corresponding to the light guide plate 10 .

In the manufacturing method of the planar light source 300 described above, after forming the first conductive portion 61 in the hole 401 of the structure 400 shown in FIG. A light source 20 may be arranged in the through hole 13 . After that, the process of forming the translucent member 81 in the through hole 13, the process of forming the dividing groove 14 in the light guide plate 10, the process of forming the second conductive portion 62, and the like are continued.

Further, in the manufacturing method of the planar light source 300 described above, after forming the first conductive portion 61 in the hole 401 of the structure 400 shown in FIG. An elastic member 80 may be arranged. In this case, the step of forming the dividing grooves 14 in the light guide plate 10 is performed, for example, after the light guide plate is arranged on the structure 400 shown in FIG. It can be done before placing the light source 20 . The first translucent member 80 may be composed of a plurality of translucent members 81 and 82, or may be composed of a single-layer translucent member. Note that the single-layer translucent member can contain, for example, the above-described phosphor, light diffusing agent, and the like.

The embodiments of the present invention have been described above with reference to specific examples. However, the invention is not limited to these specific examples. Based on the above-described embodiment of the present invention, all forms that can be implemented by those skilled in the art by appropriately designing and changing are also included in the scope of the present invention as long as they include the gist of the present invention. In addition, within the scope of the idea of the present invention, those skilled in the art can conceive of various modifications and modifications, and these modifications and modifications also belong to the scope of the present invention.

DESCRIPTION OF SYMBOLS 10... Light-guide plate 13... Through-hole 14... Division groove 20... Light source 21... Light emitting element 24... Covering member 25... 2nd translucent member 26... 2nd light adjustment member 41... 1st Light reflecting member 41a First resin member 41b First reflector 42 Second light reflecting member 42a Second resin member 42b Second reflector 43 Third light reflecting member , 50... Insulating base material 53... First wiring layer 54... Second wiring layer 60... Conductive member 71... Adhesive member 80... First translucent member 90... First light adjusting member 100... Light-emitting module 200 Wiring board 300 Planar light source 301 Light-emitting region

Claims (12)

a light source;
a light guide plate through which light from the light source is guided, the light guide plate including an upper surface and a lower surface opposite to the upper surface;
a first light reflective member disposed on the lower surface side of the light guide plate;
a second light reflective member disposed on the lower surface side of the first light reflective member;
with
The first light reflecting member includes a first resin member and a first reflector having a lower refractive index than the first resin member,
The second light reflecting member includes a second resin member and a second reflector having a higher refractive index than the second resin member,
A said 2nd resin member is a light emitting module with a refractive index lower than a said 1st resin member . The light emitting module of claim 1, wherein the first reflector is a bubble. 3. The light emitting module according to claim 1, wherein said second reflector is titanium oxide. The light emitting module according to any one of claims 1 to 3 , wherein the first resin member is polyethylene terephthalate resin, olefin resin, acrylic resin, silicone resin, urethane resin, or epoxy resin. The light emitting module according to any one of claims 1 to 4, wherein the second resin member is acrylic resin, silicone resin, urethane resin or epoxy resin. The light emitting module according to any one of claims 1 to 5 , wherein the thickness of the second light reflecting member is thinner than the thickness of the first light reflecting member. The light emitting module according to any one of claims 1 to 6 , wherein the first light reflecting member is arranged to face the lower surface of the light guide plate and the lower surface of the light source. 8. The light emitting module according to claim 7 , wherein the second light reflecting member is arranged to face the entire lower surface of the first light reflecting member. The light guide plate has a hole,
The light emitting module according to any one of claims 1 to 8 , wherein the light source is arranged inside the hole. 10. The light emitting module according to claim 9 , wherein the hole is a bottomed hole that opens to the lower surface side of the light guide plate. 10. The light-emitting module according to claim 9 , wherein the hole is a through-hole penetrating from the upper surface to the lower surface of the light guide plate. a light-emitting module according to any one of claims 1 to 11 ;
a wiring board;
with
The first light reflecting member and the second light reflecting member are arranged between the wiring board and the lower surface of the light guide plate.

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