JP7125636B2 - light emitting device - Google Patents

Description

The present disclosure relates to light emitting devices.

2. Description of the Related Art In recent years, direct type light emitting devices using semiconductor light emitting elements have been proposed as backlights used in display devices such as liquid crystal display devices. For example, Patent Literature 1 discloses a backlight device having a plurality of LED light sources, a reflecting member, and a diffusion plate facing the LED light sources. Japanese Patent Laid-Open No. 2004-100001 proposes uniforming the luminance distribution by providing a light shielding pattern corresponding to the LED light sources on the rear surface of the diffusion plate (the surface facing the LED light sources). Patent Document 2 proposes forming a dot pattern (dot pattern) made of ink containing a white pigment on a light source side surface of a diffusion plate facing the light source.

WO2012/023459 JP 2008-282744 A

Direct type light emitting devices are required to reduce luminance unevenness of light emitted from a light source. An exemplary embodiment of the present application provides a light-emitting device with less uneven brightness.

A light emitting device of the present disclosure includes a substrate, a plurality of light sources positioned on the substrate, a light diffusion plate positioned above the plurality of light sources, and a light diffusing plate positioned above at least a portion of an emission surface of the plurality of light sources. and a light absorption layer supported by the light diffusion plate and positioned above at least the emission surfaces of the plurality of light sources, the light absorption layer absorbing at least part of the light emitted from the light sources. and the scattering reflector is closer to the light source than the light absorbing layer.

According to the embodiments of the present invention, it is possible to provide a light-emitting device that suppresses luminance unevenness.

1 is a cross-sectional view showing an example of an embodiment of a light emitting device; FIG. 2 is an enlarged cross-sectional view showing one of two regions 15r adjacent in the y-direction in FIG. 1 and its surroundings; FIG. 3 is a top view of the light source unit 10; FIG. It is a figure which shows the light distribution characteristic of the light radiate|emitted from a light source. It is a figure which shows the example of the light source which has the light reflection layer 24 in the output surface 21a. FIG. 4 is a top view showing the arrangement of the scattering reflectors of the embodiment; FIG. 10 is a top view showing another arrangement of the scattering reflectors of the embodiment; FIG. 4 is a top view showing the structure of the scattering reflector of the embodiment; FIG. 4 is a cross-sectional view showing another structure of the scattering reflector of the embodiment; 4 is a cross-sectional view showing another example of arrangement of the light absorption layer 31. FIG. FIG. 10 is a cross-sectional view showing still another arrangement of the scattering reflectors of the embodiment; FIG. 10 is a cross-sectional view showing still another arrangement of the scattering reflectors of the embodiment; FIG. 5 is a diagram showing the luminance distribution of a light-emitting device of a reference example having a light-transmitting laminate provided with a scattering reflection portion; FIG. 10 is a diagram showing the luminance distribution of a light-emitting device of a comparative example that does not have a scattering reflector;

Hereinafter, embodiments of the light emitting device of the present disclosure will be described in detail with reference to the drawings. The following embodiments are examples, and the light-emitting device of the present disclosure is not limited to the following embodiments. The following description may use terms (eg, "upper", "lower", "right", "left" and other terms that include those terms) that indicate particular directions or positions. These terms are only used to clarify relative orientations or positions in the referenced drawings. If the relative orientation or positional relationship of terms such as "upper" and "lower" in the referenced drawings is the same, then drawings other than those disclosed in this disclosure, actual products, etc., are not arranged in the same manner as the referenced drawings. may In addition, the sizes and positional relationships of components shown in the drawings may be exaggerated for the sake of clarity. May not accurately reflect relationships. In addition, in the present disclosure, “parallel” and “perpendicular” (or “perpendicular”) mean that two straight lines, sides or planes are approximately 0° to ±5° and from 90°, respectively, unless otherwise specified. Including cases in the range of about ±5°.

<First embodiment>
FIG. 1 is a cross-sectional view showing an example of the light emitting device 101 of the first embodiment. The light emitting device 101 includes a light source unit 10 and a translucent laminate 30 facing the light source unit 10 . In the configuration illustrated in FIG. 1 , the light emitting device 101 has a dividing member 15 arranged between the light source unit 10 and the translucent laminate 30 . The light emitting device 101 is used, for example, as a backlight for a display panel such as a liquid crystal display panel.

The light source unit 10 includes a substrate 11 and a plurality of light sources 20 arranged on the substrate 11 , and the translucent laminate 30 includes a light diffuser plate 33 and a scattering reflector 32 . As will be described later, the light-transmitting laminate 30 may further include a light-absorbing layer 31 . The partition member 15 includes a plurality of walls 15a and has a plurality of regions 15r defined by the walls 15a. A light source 20 is arranged inside each of the plurality of regions 15r. As will be described in detail later, the partition member 15 has a shape surrounding each of the plurality of light sources 20 on the substrate 11 . Each component will be described in detail below.

[Substrate 11]
FIG. 2 shows an enlarged view of one of the two regions 15r adjacent along the y direction in FIG. 1 and its periphery. Substrate 11 has an upper surface 11a and a lower surface 11b. The light source 20 is arranged on the upper surface 11 a side and supported by the substrate 11 . In the example shown in FIG. 1, the conductor wiring layer 13 and the metal layer 12 are provided on the upper surface 11a and the lower surface 11b of the substrate 11, respectively. Details of the conductor wiring layer 13 and the metal layer 12 will be described later.

Ceramics and resins, for example, can be used as the material of the substrate 11 . Resin may be selected as the material for the substrate 11 in terms of low cost and ease of molding. Examples of resins include phenol resin, epoxy resin, polyimide resin, BT resin, polyphthalamide (PPA), polyethylene terephthalate (PET), and the like. The substrate 11 may be a rigid substrate or a flexible substrate that can be manufactured by a roll-to-roll method. The thickness of the substrate 11 can be selected as appropriate. The rigid substrate may be a bendable thin rigid substrate.

Ceramics may also be selected as the material for the substrate 11 from the viewpoint of being excellent in heat resistance and light resistance. Ceramics include, for example, alumina, mullite, forsterite, glass ceramics, nitrides (eg, AlN), carbides (eg, SiC), LTCC, and the like.

The substrate 11 may be made of a composite material. For example, the above-described resin may be mixed with inorganic fillers such as glass fiber, SiO ₂ , TiO ₂ and Al ₂ O ₃ . This makes it possible to improve the mechanical strength of the substrate 11, reduce the coefficient of thermal expansion, improve the light reflectance, and the like. For example, a glass fiber reinforced resin (glass epoxy resin) or the like may be used as the material of the substrate 11 .

The substrate 11 may have a laminated structure as long as at least the upper surface 11a has electrical insulation. For example, the substrate 11 may be a metal plate having an insulating layer on its surface.

[Conductor wiring layer 13]
In the configuration illustrated in FIG. 2 , the light source unit 10 includes a conductor wiring layer 13 provided on the upper surface 11 a of the substrate 11 . The conductor wiring layer 13 has a wiring pattern for supplying electric power to each light source 20 from the outside. Here, the light sources 20 are electrically connected to and fixed to the conductor wiring layer 13 by a joint member 23, which will be described later. there is

The material of the conductor wiring layer 13 can be appropriately selected according to the material of the substrate 11, the manufacturing method, and the like. When ceramics, for example, is used as the material of the substrate 11 , a high melting point metal that can be co-fired with the ceramics of the substrate 11 can be used as the material of the conductor wiring layer 13 . For example, the conductor wiring layer 13 can be formed from a refractory metal such as tungsten or molybdenum. If, for example, glass epoxy resin is used as the material of the substrate 11, it is beneficial to select a material that is easy to process as the material of the conductor wiring layer 13. FIG. For example, a metal layer of copper, nickel, or the like formed by plating, sputtering, vapor deposition, or pressing can be used as the conductor wiring layer 13 . A metal layer having a predetermined wiring pattern can be formed by applying printing, photolithography, or the like.

The conductor wiring layer 13 may have a multilayer structure. For example, the conductor wiring layer 13 includes a refractory metal pattern formed by the method described above and a metal layer containing other metals such as nickel, gold, and silver formed on this pattern by plating, sputtering, vapor deposition, or the like. and

[Insulating member 14]
In this example, an insulating member 14 is provided on the conductor wiring layer 13 . The insulating member 14 is provided with a through hole 14e, and the insulating member 14 covers the area of the conductor wiring layer 13 other than the area electrically connected to the light source 20 and other elements. The insulating member 14 functions as a resist that imparts insulation to regions of the conductor wiring layer 13 where the light source 20 and other elements are not arranged.

The insulating member 14 can be formed using a resin material such as epoxy resin, urethane resin, acrylic resin, polycarbonate resin, polyimide resin, oxetane resin, silicone resin, modified silicone resin, or the like. The insulating member 14 may be made of a material in which a reflecting material made of oxide particles such as titanium oxide, aluminum oxide, or silicon oxide is dispersed in a resin material. By using such a material and providing the insulating member 14 having light reflectivity on the conductor wiring layer 13, the light from the light source 20 is reflected on the upper surface 11a side of the substrate 11, and the light on the substrate 11 side is reflected. Leakage and absorption can be prevented to improve the light extraction efficiency of the light emitting device.

From the viewpoint of enhancing the light utilization efficiency by reflecting the light incident on the insulating member 14 having light reflectivity toward the upper side of the light source 20, the light generated between the outer edge of the through hole 14e and the light source 20 when viewed from the top. A narrow gap is advantageous. However, if the gap between the outer edge of the through-hole 14e and the light source 20 is made smaller, the proportion of the light reflected directly above the light emitting surface of the light source 20 increases, and uneven brightness tends to occur. As will be described later, in the present embodiment, above the light source 20, a scattering reflector 32 is provided that includes a first region R1 including a portion directly above the emission surface of the light source 20. As shown in FIG. Since the light directly above and in the vicinity of the emission surface of the light source 20 can be scattered and reflected by the scattering reflection portion 32, even if the gap between the through-hole 14e and the light source 20 is made small, the light source 20 can be reflected. It is possible to suppress luminance unevenness by reducing the luminance directly above the exit surface.

[Metal layer 12]
In this example, the light source unit 10 further has a metal layer 12 on the bottom surface 11 b of the substrate 11 . The metal layer 12 may be provided on the entire lower surface 11b for heat radiation, or may have a wiring pattern. For example, metal layer 12 may have a circuit pattern of a driver circuit for driving light source 20 . Components constituting the drive circuit may be mounted on the circuit pattern of the metal layer 12 .

[Light source 20]
FIG. 3 is a top view of the light source unit 10. FIG. A plurality of light sources 20 are arranged on the upper surface 11 a side of the substrate 11 . The plurality of light sources 20 are arranged one-dimensionally or two-dimensionally on the upper surface 11 a of the substrate 11 . In this embodiment, the plurality of light sources 20 are two-dimensionally arranged along two orthogonal directions, that is, the x-direction and the y-direction. In FIG. 3, the array pitch px in the x direction of the plurality of light sources 20 matches the array pitch py in the y direction. However, the arrangement of the plurality of light sources 20 is not limited to the illustrated example, and the pitch may differ between the x-direction and the y-direction, and the two directions of arrangement may not be orthogonal. Also, the arrangement pitch is not limited to equal intervals, and may be irregular intervals. For example, the light sources 20 may be arranged so that the distance between them increases from the center to the periphery of the substrate 11 . The pitch between the light sources 20 is the distance between the optical axes L of the light sources 20 (see FIG. 1).

Refer to FIG. 2 again. Each light source 20 includes at least a light emitting element 21 having an exit surface 21a. As the light emitting element 21, known semiconductor light emitting elements such as semiconductor lasers and light emitting diodes can be used. In this embodiment, a light emitting diode is exemplified as the light emitting element 21 . The light source 20 may include a covering member 22 that covers the emission surface 21a. When the light source 20 includes the covering member 22 , the surface 22 a of the covering member 22 is the emission surface of the light source 20 . When the light source 20 does not include the covering member 22 , the emission surface 21 a of the light emitting element 21 is also the emission surface of the light source 20 .

The light source 20 emits blue light, for example. A light source that emits white light may be used as the light source 20 . In this case, the light emitting element 21 itself may emit white light, or the light emitted from the light emitting element 21 may be transmitted through the covering member 22 to emit white light. In other words, the light source 20 as a whole should emit white light. The number and type of elements included in each light source 20 are not limited to one, and each light source 20 may have multiple or multiple types of light emitting elements 21 . For example, the light source 20 includes a light-emitting element including three light-emitting portions that emit red, blue, and green light, or includes three light-emitting elements that emit red, blue, and green light, respectively. may be mixed to emit white light. Light source 20 may include light emitting elements that emit white light and light emitting elements that emit other colors. By using a light-emitting element that emits white light and a light-emitting element that emits other colors as the light source 20, the color rendering of the light emitted from the light source 20 can be improved.

An element that emits light of any wavelength can be selected as the light emitting element 21 . For example, a light-emitting device using ZnSe, a nitride-based semiconductor ( _{InxAlyGa1 - xyN} , 0≤X, 0≤Y, X+Y≤1) or GaP as a device that emits blue and green light. can be used. A light-emitting element containing a semiconductor such as GaAlAs or AlInGaP can be used as the element that emits red light. Furthermore, semiconductor light-emitting elements made of materials other than these can also be used. Various emission wavelengths can be selected depending on the material of the semiconductor layer and its crystallinity. The composition, emission color, size, number, and the like of the light-emitting elements to be used may be appropriately selected according to the purpose. Here, an element that emits blue light is used as the light emitting element 21, and a light source that emits blue light is exemplified as the light source 20. FIG.

The light emitting element 21 has, for example, a translucent substrate and a semiconductor lamination structure laminated on the substrate. The semiconductor laminated structure includes an active layer, and an n-type semiconductor layer and a p-type semiconductor layer sandwiching the active layer, and an n-side electrode and a p-side electrode are electrically connected to the n-type semiconductor layer and the p-type semiconductor layer, respectively. be. In this embodiment, the n-side electrode and the p-side electrode are located on the surface opposite to the emission surface 21a. The n-side electrode and the p-side electrode are electrically connected to and fixed to the conductor wiring layer 13 provided on the upper surface 11 a of the substrate 11 by the bonding member 23 . That is, here, the light emitting element 21 is mounted on the substrate 11 by flip chip bonding. The n-side electrode and the p-side electrode may be arranged on the same plane side as in this example, or may be arranged on different planes. The light emitting element 21 may be a bare chip, or may be provided with a package having a reflector on the side surface. Further, the light emitting element 21 may include a lens or the like for widening the range of the emission angle of the light emitted from the emission surface 21a.

[Coating member 22]
The covering member 22 covers at least the emission surface 21 a of the light emitting element 21 and is supported by the upper surface 11 a of the substrate 11 . The covering member 22 suppresses damage to the light emitting element 21 due to exposure of the emission surface 21a to the external environment. As a material of the covering member 22, an epoxy resin, a silicone resin, a mixed resin of these, or a translucent material such as glass can be used. From the viewpoint of light resistance and moldability of the covering member 22, it is beneficial to select a silicone resin as the covering member 22.

The covering member 22 may contain a diffusing member, a wavelength converting member, a coloring agent, and the like. For example, the light source 20 may include a semiconductor light emitting element that emits blue light and a wavelength conversion member that converts blue light into yellow light. That is, white light may be emitted from the light source 20 by combining blue light and yellow light. Alternatively, the light source 20 includes a semiconductor light-emitting element that emits blue light, a wavelength conversion member that converts blue light into green light, and a wavelength conversion member that converts blue light into red light. White light may be emitted in combination with red light. It is also possible to use a light source that includes a semiconductor light emitting element that emits blue light, a semiconductor light emitting element that emits green light, and a wavelength conversion member that converts blue light or green light into red light.

Examples of wavelength conversion members that convert blue light into green light include β-sialon phosphors, and examples of wavelength conversion members that convert blue light into red light include fluoride-based phosphors such as KSF-based phosphors. . By including a β-sialon phosphor and a fluoride-based phosphor such as a KSF-based phosphor as wavelength conversion members in the covering member 22, the color reproduction range of the light-emitting device can be widened. When the coating member 22 includes a wavelength conversion member, the light emitting element 21 is made of a nitride semiconductor (In _x Aly Ga _{1-xy N} ,
0≤X, 0≤Y, X+Y≤1).

The covering member 22 can be formed by compression molding or injection molding so as to cover the emission surface 21 a of the light emitting element 21 . In addition, by optimizing the viscosity of the material of the covering member 22, it is also possible to drop or draw on the light emitting element 21 and control the shape of the covering member 22 using the surface tension of the material itself. . According to the latter forming method, the covering member 22 can be formed by a simpler method without requiring a mold. When such a forming method is applied, as a method of adjusting the viscosity of the material of the covering member 22, in addition to the inherent viscosity of the material, a desired light diffusing agent, a wavelength converting member, and a coloring agent are added as described above. Viscosity may be obtained.

[Joining member 23]
The joining member 23 fixes the light emitting element 21 to the conductor wiring layer 13 . Here, the joining member 23 also has a function of electrically connecting the light emitting element 21 to the conductor wiring layer 13 . The joining member 23 is made of Au-containing alloy, Ag-containing alloy, Pd-containing alloy, In-containing alloy, Pb--Pd-containing alloy, Au--Ga-containing alloy, Au--Sn-containing alloy, Sn-containing alloy, Sn--Cu-containing alloy, Sn -Cu-Ag containing alloys, Au-Ge containing alloys, Au-Si containing alloys, Al containing alloys, Cu-In containing alloys, or mixtures of metals and fluxes. When the p-side electrode and the n-side electrode are electrically connected to the conductor wiring layer 13 by wires or the like, the bonding member 23 is used to connect the light-emitting element 21 except for the p-side electrode and the n-side electrode. As long as it can be fixed to the upper surface 11 a of the substrate 11 , the light emitting element 21 and the conductor wiring layer 13 do not have to be electrically connected.

As the bonding member 23, a liquid, paste, or solid (sheet-like, block-like, powder-like, wire-like) member can be used. It can be selected as appropriate. The joining member 23 may be composed of a single member, or may be used as the joining member 23 by combining several kinds of members.

FIG. 4 shows an example of light distribution characteristics of light emitted from the light source 20. As shown in FIG. The light source 20 may have a batwing-type light distribution characteristic. When the light source 20 has a batwing-type light distribution characteristic, the amount of light directly above the light source 20 can be suppressed, the light distribution of each light source can be widened, and luminance unevenness can be further improved. In a broad sense, the batwing type light distribution characteristic is defined as an angle where the absolute value of the light distribution angle (φ in FIG. 2) is larger than 0°, with the optical axis L (see FIG. 2) of the light source 20 being 0°. It is defined by an emission intensity distribution with a high emission intensity. In particular, in a narrow sense, it is defined by the luminous intensity distribution in which the luminous intensity is highest in the vicinity of 45° to 90°. In other words, in the batwing type light distribution characteristics, the central portion is darker than the outer peripheral portion.

FIG. 5 shows an example of a light source having a light reflecting layer 24 on the exit surface 21a. As in the light source 20 ′ shown in FIG. 5 , batwing type light distribution characteristics may be imparted to the light source by, for example, providing a light reflection layer 24 on the emission surface 21 a of the light emitting element 21 . The light reflecting layer 24 may be a metal film or a dielectric multilayer film. By providing the light reflecting layer 24 on the exit surface 21a, the light directed upward from the light emitting element 21 is reflected by the light reflecting layer 24, the amount of light directly above the light emitting element 21 is suppressed, and batwing type light distribution characteristics are realized. realizable. With such a configuration, it is possible to omit a lens for imparting a batwing type light distribution characteristic, which is advantageous in reducing the thickness of the light source. Of course, by adjusting the outer shape of the covering member 22, the light source 20 may be provided with a batwing-type light distribution characteristic.

[Partition member 15]
Please refer to FIG. The dividing member 15 includes a wall portion 15ax extending in the x direction between two light sources 20 adjacent in the y direction, a wall portion 15ay extending in the y direction between the two light sources 20 adjacent in the x direction, and a bottom portion 15b. including. The bottom portion 15b is located in a region 15r surrounded by two wall portions 15ax and two wall portions 15ay. As shown, each light source 20 is surrounded by two walls 15ax extending in the x direction and two walls 15ay extending in the y direction. In this embodiment, since the light sources 20 are arranged at the same pitch in the x and y directions, the bottom 15
The outline of b is square.

A through hole 15e is provided in the center of the bottom portion 15b, and the bottom portion 15b is positioned on the insulating member 14 so that the light source 20 is positioned within the through hole 15e. The shape and size of the through-hole 15e are not particularly limited as long as the shape and size allow the light source 20 to be positioned therein. The outer edge of the through-hole 15e is positioned near the light source 20 so that the light from the light source 20 can be reflected by the bottom portion 15b, that is, the gap between the through-hole 15e and the light source 20 when viewed from above. Narrower is preferable.

The wall portion 15ax includes a pair of inclined surfaces 15s extending in the x direction. Each of the pair of inclined surfaces 15s is connected to one of two sides extending in the x-direction to form a top portion 15c. The other of the two sides extending in the x direction is connected to the bottom portion 15b. Similarly, the wall portion 15ay extending in the y direction includes a pair of inclined surfaces 15t extending in the y direction. Each of the pair of inclined surfaces 15t is connected to one of two sides extending in the y-direction to form a top portion 15c. The other of the two sides extending in the y direction is connected to the bottom portion 15b. A light emitting space 17 having an opening 17a is formed by the bottom portion 15b, the two wall portions 15ax and the two wall portions 15ay. FIG. 3 shows the luminous spaces 17 arranged in 3 rows and 3 columns.

The luminous space 17 partitioned by the partitioning member 15 is the minimum unit of the luminous area when the plurality of light sources 20 are independently driven. Therefore, when the plurality of light sources 20 are driven independently, the light emitting space 17 becomes the minimum unit of local dimming when the light emitting device 101 as a surface emitting light source is viewed from the upper surface 30a side of the translucent laminate 30. If the light sources 20 are independently driven, a light-emitting device capable of local dimming drive in minimum units is realized. By simultaneously driving a plurality of adjacent light sources 20 and driving them so as to synchronize their ON/OFF timings, driving by local dimming in a larger unit becomes possible.

Please refer to FIG. The pair of inclined surfaces 15s face the opening 17a of the light emitting space 17 in the yz cross section. Similarly, the pair of inclined surfaces 15t also face the opening 17a of the light emitting space 17 in the zx section (not shown). The partitioning member 15 has light reflectivity, and reflects the light emitted from the light source 20 toward the opening 17a of the light emitting space 17 by the inclined surface 15s of the wall portion 15ax and the inclined surface 15t of the wall portion 15ay. In addition, the light incident on the bottom portion 15b is also reflected toward the opening 17a of the light emitting space 17. As shown in FIG. This allows the light emitted from the light source 20 to enter the light-transmitting laminate 30 efficiently.

The dividing member 15 may be molded using a resin containing a reflecting material made of oxide particles such as titanium oxide, aluminum oxide, or silicon oxide, or may be molded using a resin containing no reflecting material. , a reflective material may be provided on the surface. It is preferable that the reflectance of the dividing member 15 with respect to the light emitted from the light source 20 is, for example, 70% or more.

The dividing member 15 can be formed by molding using a mold or stereolithography. As a molding method using a mold, molding methods such as injection molding, extrusion molding, compression molding, vacuum molding, air pressure molding, and press molding can be used. For example, by vacuum forming a reflecting sheet made of PET or the like, it is possible to obtain the dividing member 15 in which the bottom portion 15b and the wall portions 15ax and 15ay are integrally formed. The thickness of the reflective sheet is, for example, 100-500 μm.

The lower surface of the bottom portion 15b of the dividing member 15 is fixed to the upper surface of the insulating member 14 by an adhesive member or the like. If the insulating member 14 exposed from the through hole 15e has light reflectivity, it is beneficial because the light extraction efficiency is improved. When the adhesive member is arranged around the through hole 15e, the insulating member 14
and the division member 15, the incident light from the light source 20 can be suppressed. For example, it is beneficial to arrange the adhesive member in a ring shape along the outer edge of the through hole 15e. The adhesive member may be a double-sided tape, a hot-melt adhesive sheet, or a thermosetting resin or thermoplastic resin adhesive. Advantageously, these adhesive members have high flame retardancy. The partitioning member 15 may be fixed to the insulating member 14 by other connecting members such as screws and pins instead of the adhesive member.

A translucent laminate 30 is arranged above the light source 20 so as to cover the opening 17 a of the light emitting space 17 . The translucent laminate 30 is supported at a predetermined distance from the light source unit 10 by, for example, a support (not shown). The lower surface of the translucent laminate 30 may or may not be in contact with the top portion 15c of the partition member 15 . When the lower surface of the translucent laminate 30 is in contact with the top portion 15c, the light emitted from the light source 20 in one light emitting space 17 can be prevented from entering the adjacent light emitting space 17. FIG.

[Light diffusion plate 33]
The light diffusing plate 33 has an upper surface 33 a and a lower surface 33 b , and is arranged so that the lower surface 33 b faces the light source unit 10 . The light diffusion plate 33 diffuses and transmits incident light. The light diffusion plate 33 is made of a material that absorbs less visible light, such as polycarbonate resin, polystyrene resin, acrylic resin, or polyethylene resin. A structure for diffusing light is provided on the light diffusion plate 33 by providing unevenness on the surface of the light diffusion plate 33 or by dispersing materials having different refractive indices in the light diffusion plate 33 . As the light diffusing plate 33, a member commercially available under the name of a light diffusing sheet, a diffuser film, or the like can be used.

[Scattering reflection part 32]
The scattering reflector 32 is supported by the light diffuser plate 33 . In the configuration illustrated in FIG. 2 , the scattering reflector 32 is provided on the lower surface 33 b of the light diffusion plate 33 . The scattering reflection part 32 scatters and reflects incident light. As can be seen from FIG. 1 , the scattering reflectors 32 are arranged at a plurality of locations on the light diffusion plate 33 corresponding to the plurality of light sources 20 .

FIG. 6 shows the positional relationship between the scattering reflector 32 and the emission surface of the light source 20 (the surface 22a of the covering member 22 or the emission surface 21a) in the top view of the light emitting device 101. FIG. Typically, the scattering reflectors 32 are provided at a plurality of locations corresponding to each light source 20 . In this example, each scattering reflector 32 is located above the emission surface of each light source 20 , that is, the light from the light source 20 . It is located on the axis L. The scattering reflector 32 is located in a first region R1 and a second region R2 including a portion located outside the first region R1 (see FIGS. 1 and 2). The light emitted from the light sources 20 has a high emission intensity on the optical axis L, and when the optical axis L of each light source 20 is 0°, the emission intensity is relatively high at angles where the absolute value of the light distribution angle is larger than 0°. becomes lower. Therefore, by providing the scattering reflection portion 32 to scatter and reflect the light directed directly above the light source 20 , uneven brightness on the upper surface 30 a of the light-transmitting laminate 30 can be suppressed.

In FIG. 6, the scattering reflection portion 32 has a circular shape centered on the optical axis of each light source 20 in a top view, but the shape of the scattering reflection portion 32 is not limited to a circle. Depending on the light distribution characteristics of the light source 20, the shape of the scattering/reflecting portion 32, such as an ellipse or a rectangle, can be appropriately determined so that the light can be scattered more uniformly. Further, when the light emission intensity on the optical axis of the light source 20 is weaker than that around the optical axis due to the reason that the light source 20 has a batwing type light distribution characteristic, the scattering reflection part 32 For example, it may have a ring shape when viewed from above. In other words, the scattering reflector 32 may be positioned above at least a portion of the exit surface of each light source 20 .

Since the light emission intensity is relatively low at an angle where the absolute value of the light distribution angle is relatively large, there is little need to scatter the light above the top portion 15c of the partition member 15, which is the boundary of the light emission space 17. . Therefore, the scattering reflector 32 may not be provided above the top 15 c of the partition member 15 . In the present embodiment, the scattering reflection portion 32 is not provided on the light diffusion plate 33 above the portion of the dividing member 15 that protrudes toward the light diffusion plate 33 . In other words, the scattering reflection part 32 is not arranged in the region overlapping the wall part 15a (especially the top part 15c) of the dividing member 15 when viewed from above. For example, when the top portion 15c and the light diffusion plate 33 are separated from each other, the distance between the light diffusion plate 33 and the wall portion 15ax or the wall portion 15ay increases, and the light is reflected by the light diffusion plate 33 to cause the wall portions 15ax and The amount of light that irradiates 15ay may decrease, and the region near the top 15c may become dark. In such a case, if the scattering reflection portion 32 is provided in the region overlapping the top portion 15c of the dividing member 15, the light from the light diffusion plate 33 is scattered by the scattering reflection portion 32, and the amount of light applied to the wall portions 15ax and 15ay is reduced. decrease and the area near the top 15c may become darker. Therefore, in such a case, by not arranging the scattering reflection portion 32 above the wall portions 15ax and 15ay, a decrease in brightness in the region near the top portion 15c is suppressed, and a decrease in brightness in the region near the top portion 15c is suppressed. It is possible to suppress luminance unevenness caused by

It is not essential not to provide the scattering reflection portion 32 in the region overlapping the top portion 15c of the partitioning member 15 . From the viewpoint of reducing luminance unevenness, it may be advantageous to provide the scattering reflection portion 32 in the region overlapping the top portion 15c of the dividing member 15 . For example, when the top portion 15 c and the light diffusion plate 33 are in contact with each other, if the scattering reflection portion 32 is provided in the region overlapping the top portion 15 c of the dividing member 15 , the light reflected by the light diffusion plate 33 is scattered by the scattering reflection portion 32 . , and the amount of light applied to the wall portions 15ax and 15ay (which may also be referred to as the inclined surfaces 15s and 15t inside the region 15r) can be increased. As a result, the area near the top 15c becomes bright, the brightness above the top 15c is improved, and uneven brightness is suppressed.

The scattering reflector 32 includes a resin and oxide particles such as titanium oxide, aluminum oxide, and silicon oxide, which are particles of a reflector dispersed in the resin. The average particle size of the oxide particles is, for example, about 0.05 μm or more and 30 μm or less. If a photocurable resin containing acrylate, epoxy, or the like as a main component is used as the resin for dispersing the particles of the reflective material, the uncured resin containing the reflective material is applied to the light diffusion plate 33, and then irradiated with, for example, ultraviolet rays. The scattering reflection portion 32 can be formed by. The resin may be photo-cured with light emitted from the light source 20 . The uncured resin in which the particles of the reflector are dispersed can be applied onto the light diffusion plate 33 by, for example, a printing method using a plate or an inkjet method.

The particles of the reflective material that scatters the light in the scattering reflection portion 32 may be uniformly distributed, and the light distribution angle of the light source 20 has a smaller absolute value in a region than a region in which the light distribution angle has a large absolute value. They may be arranged in high density. The scattering reflector 32' shown in FIG. 7A includes a first portion 32a and a second portion 32b. The first portion 32a and the second portion 32b can be arranged in the above-described first region R1 and second region R2 (see, eg, FIG. 2), respectively. In other words, for example, the first portion 32a is located directly above the exit surface 21a, and the second portion 32b is located around the first portion.

The density of the particles of the reflector in the first portion 32a is greater than the density of the particles of the reflector in the second portion 32b. Here, the density of particles is represented by, for example, the number density indicated by the number of particles per unit area on a plane viewed from the top, that is, on the xy plane. By arranging the first portion 32a having a relatively high density of reflective particles like the scattering reflection portion 32' in a region with a higher illuminance, the uniformity of light on the light emitting surface of the light emitting device can be effectively improved. can be increased to

For example, as shown in FIG. 7B, the scattering reflection part 32′ is formed by densely arranging minute areas 32c of uncured resin in which particles of the reflecting material are dispersed in the first part 32a by a printing method or an inkjet method, It can be formed by arranging the second portion 32b with a lower density than the first portion 32a. Further, as shown in FIG. 7C, a first layer 32d made of uncured resin in which reflective material particles are dispersed is formed on the first portion 32a and the second portion 32b, and the first layer 32d is formed only on the first portion 32a. A second layer 32e may be formed over layer 32d. In the scattering reflector 32' having the structure shown in FIG. 7B or 7C, the density of the particles of the reflector in the scattering reflector 32' in the xy plane satisfies the above-described relationship.

[Light absorbing layer 31]
Refer to FIG. 2 again. As illustrated in FIG. 2 , a light absorption layer 31 may be further provided on the light diffusion plate 33 . The light absorption layer 31 is positioned at least above the emission surface of the light source 20 and absorbs at least part of the light emitted from the light source 20 . The light absorption layer 31 has an arrangement such that the scattering reflection portion 32 is closer to the light source 20 than the light absorption layer 31 is.

As shown in FIG. 2, by providing the light absorption layer 31 on the light diffusion plate 33 so as to be positioned above the emission surface of the light source 20, blue light emitted at a light distribution angle close to 0° is absorbed. It can be absorbed into layer 31 . In this case, the light absorption layer 31 may be an optical filter that selectively transmits yellow light, for example. Such an optical filter can be obtained, for example, by applying a material obtained by dispersing a pigment (or dye) in a resin onto the light diffusion plate 33 by applying a printing method or an ink-jet method, similar to a known color filter. can be formed. By causing the light absorption layer 31 to absorb the blue light emitted at a light distribution angle close to 0°, it is possible to suppress the occurrence of bluishness directly above the light source 20 .

When white light is obtained by combining a semiconductor light emitting element and a covering member containing a wavelength conversion member, light is emitted in a region where the absolute value of the light distribution angle is close to 0 compared to a region where the absolute value of the light distribution angle is larger. In some cases, the intensity is high and the wavelength conversion by the wavelength conversion member in the covering member is not sufficient. For example, when using a light source having a semiconductor light-emitting element that emits blue light and a covering member that includes a wavelength conversion member that converts blue light into yellow light, the area immediately above each light source appears bluish on the display surface. There is That is, color unevenness may occur. In such a light source configuration as well, by arranging the light absorption layer 31 above the light emitting surface of the light source, the blue light emitted at a light distribution angle close to 0° is selectively absorbed by the light absorption layer 31. be able to. Therefore, it is possible to suppress color unevenness.

As will be described later, the light-transmitting laminate 30 may further include a wavelength conversion layer 34, prism array layers 35 and 36, a reflective polarizing layer 37, and the like. For example, the wavelength conversion layer 34 is arranged above the light diffusion plate 33 , absorbs part of the light emitted from the light source 20 and emits light with a wavelength different from the wavelength of the light emitted from the light source 20 . In such a configuration, the light absorption layer 31 may have a reflection characteristic of high reflectance at the wavelength of the light emitted from the wavelength conversion layer 34 . In this case, the light absorption layer 31 absorbs the blue light emitted from the light source 20 at a light distribution angle close to 0°, and the light traveling from the wavelength conversion layer 34 toward the light absorption layer 31 (and the wavelength Light emitted from the conversion layer 34 and reflected by other members such as, for example, a prism array layer) can be reflected away from the light source 20 . Thereby, the uniformity of the light emitted from the upper surface 30a of the translucent laminate 30 can be further improved.

The light absorption layer 31 itself may be a layer that absorbs part of the light emitted from the light source 20 and emits light with a wavelength different from the wavelength of the light emitted from the light source 20 . For example, the light absorption layer 31 may contain a wavelength conversion member. The phosphor, pigment, etc. dispersed in the resin can be appropriately selected according to the spectral characteristics of the light source 20 . For example, when using a light source that emits blue light, a wavelength conversion member that converts blue light into yellow light can be used. This allows the light absorption layer 31 to absorb blue light and emit yellow light from the light absorption layer 31, thereby more efficiently suppressing color unevenness.

As shown in FIG. 2, the light absorption layer 31 may be formed so that the thickness decreases as the distance from the optical axis L increases. By increasing the thickness of the light absorption layer 31 closer to the optical axis L, color unevenness can be suppressed more efficiently. Alternatively, in the same manner as the example of the scattering reflection portion 32' described with reference to FIGS. 7A to 7C, for example, the arrangement density of the minute regions made of uncured resin in which particles such as pigments and phosphors are dispersed is changed. may Of course, the light absorption layer 31 may be flat.

[Wavelength conversion layer 34]
The light-emitting device 101 may further have a wavelength conversion layer 34 in the translucent laminate 30 . The wavelength conversion layer 34 is located on the side of the light diffusion plate 33 opposite to the side where the substrate 11 is located, that is, on the side of the upper surface 33a. As can be seen from FIG. 2 , when using the wavelength conversion layer 34 , the light absorption layer 31 is positioned between the wavelength conversion layer 34 and the scattering reflector 32 .

The wavelength conversion layer 34 absorbs part of the light emitted from the light source 20 and emits light with a wavelength different from the wavelength of the emitted light from the light source 20 . For example, the wavelength conversion layer 34 absorbs some of the blue light from the light source 20 and emits yellow light. Alternatively, wavelength conversion layer 34 may absorb some of the blue light from light source 20 and emit green and red light. Since the wavelength conversion layer 34 is separated from the light emitting element 21 of the light source 20, the wavelength conversion layer 34 may contain a wavelength converting material that is difficult to use in the vicinity of the light emitting element 21 and has poor resistance to heat or light intensity. It is possible to use This makes it possible to improve the performance of the light emitting device 101 as a backlight. The wavelength conversion layer 34 has a sheet shape or a layer shape and contains the wavelength conversion material described above.

[Prism array layers 35 and 36, reflective polarizing layer 37]
The light-emitting device 101 may further include prism array layers 35 and 36 and a reflective polarizing layer 37 in the translucent laminate 30 . The prism array layers 35 and 36 have a shape in which a plurality of prisms extending in a predetermined direction are arranged. For example, the prism array layer 35 has a plurality of prisms extending in the y direction in FIG. 2, and the prism array layer 36 has a plurality of prisms extending in the x direction. The prism array layers 35 and 36 refract light incident from various directions toward the display panel facing the light emitting device (in this case, the positive direction of z). As a result, the light emitted from the upper surface 30a of the light-transmitting laminate 30, which is the light emitting surface of the light emitting device 101, mainly includes components perpendicular to the upper surface 30a (parallel to the z-axis). direction).

The reflective polarizing layer 37 selectively transmits light with a polarization direction that matches the polarization direction of a polarizing plate arranged on the backlight side of a display panel, for example, a liquid crystal display panel, and transmits polarized light in a direction perpendicular to the polarization direction. is reflected toward the prism array layers 35 and 36 . A portion of the polarized light returning from the reflective polarizing layer 37 is reflected again by the prism array layers 35 and 36, the wavelength conversion layer 34, and the light diffusion plate 33. FIG. At this time, the polarization direction changes, the light is converted into polarized light having the polarization direction of the polarizing plate of the liquid crystal display panel, enters the reflective polarizing layer 37 again, and exits to the display panel. As a result, the polarization directions of the light emitted from the light emitting device 101 can be aligned, and the light with the polarization direction effective for improving the luminance of the display panel can be emitted with high efficiency. As the reflective polarizing layer 37 and the prism array layers 35 and 36 described above, commercially available optical members for backlight can be used.

The light-transmitting laminate 30 is formed by stacking the above-described scattering/reflection section 32, light absorption layer 31, light diffusion plate 33, wavelength conversion layer 34, prism array layers 35 and 36, and reflective polarizing layer 37. can be done. At least one interface of these layers may be spaced without contact with each other. However, from the viewpoint of minimizing the thickness of the light-emitting device 101, it is beneficial if two layers adjacent to each other are laminated so as to be in contact with each other without providing a space.

The light-emitting device 101 can be assembled by producing the light source unit 10 and the light-transmitting laminate 30 respectively, and supporting the light-transmitting laminate 30 with respect to the light source unit 10 with the support described above.

(Operation and Effects of Light Emitting Device 101)
The reason why the operation of the light emitting device 101, particularly the uneven brightness of the light emitted from the light source 20 is suppressed will be described. When the light-emitting device 101 is used as a surface-emitting device such as a backlight, it is preferable that the luminance unevenness on the upper surface 30a of the light-transmitting laminate 30, which is the emission surface from the light-emitting device 101, is as small as possible.

However, the light source 20 is a point light source, and the illuminance of the surface illuminated by the light emitted from the light source 20 is inversely proportional to the square of the distance. Therefore, the illuminance of light incident on the lower surface of the light-transmitting laminate 30 is higher in the first region R1 in the vicinity directly above the light source 20 than in the second region R2 located around the first region R1 when viewed from above. high. This is because the distance between the light source 20 and the top surface 30a in the first region R1 is shorter than the distance between the light source 20 and the top surface 30a in the second region R2.

On the other hand, when the light-emitting device 101 is used as a backlight, the thickness of the display device is required to be small from the viewpoint of the design, beauty, or functionality of the display device. height) is requested to be reduced. Therefore, it is preferable that the distance OD (see FIG. 2) between the light source unit 10 and the translucent laminate 30 is small. As the distance OD becomes smaller, more light directly enters the light-transmitting laminate 30 from the light sources 20, so unless the distance between the light sources 20 is made as small as possible, the unevenness in brightness on the upper surface 30a increases.

The light emitting device 101 of this embodiment includes a scattering reflector 32 . The scattering reflector 32 is positioned above at least a portion of the emission surface of the light source 20 and contains resin and particles dispersed in the resin. The scattering reflector 32 scatters and reflects light directly above and in the vicinity of, for example, the exit surface of the light source 20 . Therefore, the light having a high luminous flux density in the vicinity of the optical axis L of the light source 20 is selectively diffused, so that uneven brightness can be reduced.

The light emitting device 101 of this embodiment further includes a light absorption layer 31 . The light absorption layer 31 is positioned above the emission surface of the light source 20 and absorbs at least part of the light emitted from the light source 20 . The scattering reflection portion 32 and the light absorption layer 31 described above are arranged in the light emitting device 101 such that the scattering reflection portion 32 is closer to the light source 20 than the light absorption layer 31 is.

If the scattering reflection portion 32 and the light absorption layer 31 are arranged so that the light absorption layer 31 is closer to the light source 20 than the scattering reflection portion 32 is, the light emitted from the light source 20 is absorbed by the light absorption layer 31 . The light that has not been reflected enters the scattering reflection portion 32 and is extracted to the outside of the light emitting device. In other words, not all of the light emitted from the light source 20 can enter the scattering reflection portion 32, and the light extraction efficiency is lowered. By arranging at least a part of the scattering reflection part 32 closer to the light source 20 than the light absorption layer 31, the light emitted from the light emitting element 21 is scattered and reflected on the side closer to the light source 20, and is reflected along the optical axis L. It is possible to cause the light absorption layer 31 to absorb light of a specific wavelength range (eg, blue light) traveling along the line. That is, it is possible to reduce color unevenness while suppressing a decrease in light extraction efficiency.

A wavelength conversion layer 34 that absorbs part of the light emitted from the light source 20 and emits light in a wavelength band different from the emitted light from the light source 20 may be arranged above the light absorption layer 31 . In this case, if the light absorption layer 31 has a reflection characteristic of reflecting the light emitted by the wavelength conversion layer 34, the light absorption layer 31 will reflect the light emitted from the light source 20 at a light distribution angle close to 0°. It is possible to absorb light in the wavelength range and reflect the light traveling from the wavelength conversion layer 34 toward the light absorption layer 31 toward the side opposite to the light source 20 . That is, the uniformity of light emitted from the upper surface 30a of the translucent laminate 30 can be further improved.

The light absorption layer 31 itself may be a layer that absorbs part of the light emitted from the light source 20 and emits light in a wavelength band different from the emitted light from the light source 20. In this case, the emission surface of the light source 20 make the light absorption layer 31 absorb light in a specific wavelength range (e.g., blue light) strongly emitted upward from the light absorption layer 31, and emit light in other wavelength ranges (e.g., yellow light) from the light absorption layer 31 It is possible to suppress color unevenness more efficiently.

Furthermore, since the light source 20 has a batwing type light distribution characteristic, the illuminance in the first region R1 in FIG. 2 can be reduced. The luminance unevenness in 30a can be suppressed. In particular, if the light source 20 has a light distribution characteristic in which the amount of light at an elevation angle of less than 20° with respect to the horizontal direction is 30% or more of the total amount of light, unevenness in brightness can be further suppressed.

<Second embodiment>
FIG. 8 shows another example of the arrangement of the light absorption layer 31. In FIG. A light absorbing layer 31 may be provided on the lower surface 33b of the light diffusing plate 33 as in a light-transmitting laminate 30' shown in FIG. Also in this case, the scattering reflection part 32 and the light absorption layer 31 are arranged so that the scattering reflection part 32 is closer to the light source 20 than the light absorption layer 31 is. In other words, at least part of the scattering reflector 32 is located closer to the light source 20 than the light absorption layer 31 is. This point is common to the configuration described with reference to FIG. With this arrangement, even when white light is obtained by combining, for example, a semiconductor light emitting element that emits blue light and a covering member that includes a wavelength conversion member, the light emitted from the semiconductor light emitting element is directed to the light source 20. Blue light traveling along the optical axis L can be absorbed by the light absorption layer 31 while being scattered and reflected on the near side, and color unevenness can be reduced while suppressing a decrease in light extraction efficiency.

<Other Modifications>
It is not essential that the first portion 32 a and the second portion 32 b be arranged on the same surface of the light diffusion plate 33 . The first portion 32a may be positioned on one of the upper surface 33a and the lower surface 33b of the light diffusion plate 33, and the second portion 32b may be positioned on the other of the upper surface 33a and the lower surface 33b. For example, as shown in FIG. 9, in a translucent laminate 30'', the first portion 32a is arranged on the upper surface 33a of the light diffusion plate 33, and the second portion 32b is arranged on the lower surface 33b of the light diffusion plate 33. You may In particular, arranging the first portion 32a on the side of the light diffusion plate 33 opposite to the light sources 20 facilitates alignment between the light sources 20 on the light source unit 10 and the corresponding scattering reflectors 32'. Therefore, it is easier to more reliably arrange the first portion 32 a having a relatively high density of the particles of the reflective material directly above the light source 20 . In addition, since the uniformity of light can be improved by the light diffuser plate 33 and then scattered reflection can be caused by the first portion 32a, compared with the case where the first portion 32a is arranged on the side facing the light source 20, the light uniformity can be improved. , may reduce the density of the reflective particles in the first portion 32a. That is, it is possible to improve the utilization efficiency of light. As shown in FIG. 9, the light absorption layer 31 may be omitted. As in this example, a portion of the first portion 32a and a portion of the second portion 32b may overlap when viewed from above.

FIG. 10 shows another arrangement of the scattering reflectors 32 . As shown in FIG. 10 , the scattering reflector 32 may be arranged on the upper surface 33 a side of the light diffusion plate 33 in the light-transmitting laminate 30 ′″. In this case, the light absorbing layer 31 is typically omitted. According to such an arrangement, the light diffusion plate 3
3, the scattering reflection portion 32 is provided on the side opposite to the light source 20, so the alignment between the light source 20 and the corresponding scattering reflection portion 32 is easy. In addition, the light whose uniformity is improved by the light diffuser plate 33 can be scattered and reflected, and the effect of improving the utilization efficiency of light can be obtained. The scattering reflection part 32 may be arranged on the lower surface 33b side of the light diffusion plate 33, and the light absorption layer 31 may be omitted.

FIG. 11 shows the luminance distribution of a light-emitting device of a reference example having a light-transmitting laminate provided with a scattering reflection portion, and FIG. 12 shows the luminance distribution of a light-emitting device of a comparative example having no scattering reflection portion.

11 and 12 show the results of photographing the light-emitting surface, here showing the results regarding the configuration without the light absorption layer. Both of the light emitting devices of the reference example and the comparative example use a light source unit in which the light sources are arranged in 5 rows and 5 columns at a pitch of 18.8 mm, and above the light source unit, a green phosphor and a red phosphor are contained. A phosphor sheet, two prism sheets arranged so that the prisms extend perpendicular to each other, and a reflective polarizing film are arranged in this order from the side closer to the light source unit. The light source includes a nitride-based blue light-emitting element and a covering member, and has a batwing-type light distribution characteristic. In the light-emitting device of the reference example, white ink, in which titanium oxide particles are dispersed in resin, is printed on the upper surface of the light diffusion plate (the surface opposite to the surface facing the light source) using an inkjet printer to form the scattering reflection portion. ing. Further, here, the distance OD between the substrate and the light diffusion plate was set to 2.8 mm for the light emitting device of the reference example, and the distance OD between the substrate and the light diffusion plate was set to 2.8 mm for the light emitting device of the comparative example (see FIG. 2). is set to 3.8 mm.

In the light-emitting device of the comparative example (FIG. 12), some luminance unevenness was observed. Almost no unevenness was observed. In addition, in the average luminance in the area including the light sources of 3 rows and 3 columns in the central portion of the light source unit, the luminance of the light emitting device of the reference example was 2.3% higher than that of the light emitting device of the comparative example.

From the results described with reference to FIGS. 11 and 12, by providing the scattering reflection portion located on the optical axis of the light source, the luminance distribution is equal to or greater than that of the comparative example while the distance between the light sources is the same. It can be seen that a uniform light emitting device can be realized. In addition, it can be seen that the thickness of the light-emitting device can be reduced while suppressing luminance unevenness.

The light emitting device of the present disclosure can be used as a backlight source for liquid crystal displays, various lighting fixtures, and the like.

10 light source unit 11 substrate 11a upper surface 11b lower surface 12 metal layer 13 conductor wiring layer 14 insulating member 14e through hole 15 partitioning member 15ax, 15ay wall portion 15b bottom portion 15c top portion 15e through hole 15r region 15s, 15t inclined surface 17 light emitting space 17a opening 20 , 20′ light source 21 light emitting element 21a emitting surface 22 coating member 22a surface 23 joining member 24 light reflecting layer 30, 30′, 30″, 30′″ translucent laminate 30a, 33a upper surface 30b, 33b lower surface 31 light absorption Layers 32, 32' scattering reflector 32a first portion 32b second portion 32c minute region 32d first layer 32e second layer 33 light diffusion plate 34 wavelength conversion layers 35, 36 prism array layer 37 reflective polarizing layer 101 light emission Device

Claims (6)

a substrate;
a plurality of light sources located on the substrate;
a light diffusion plate positioned above the plurality of light sources;
a scattering reflector positioned above at least a portion of the emission surfaces of the plurality of light sources;
a light absorption layer supported by the light diffusion plate and positioned above at least the emission surfaces of the plurality of light sources, the light absorption layer absorbing at least part of the light emitted from the light sources;
a wavelength conversion layer located on the opposite side of the light diffusion plate to the side on which the substrate is located, absorbing light from the light source and emitting light of a wavelength different from that of the light from the light source;
with
The light-emitting device, wherein the scattering reflector is closer to the light source than the light-absorbing layer. 2. The light-emitting device of claim 1, further comprising a partition member having a plurality of regions formed by walls having a top and surrounding each of the plurality of light sources on the substrate. 3. The light-emitting device according to claim 2, wherein said scattering reflector is not positioned above said partition member. 4. The light-emitting device according to claim 1 , wherein said light absorption layer has a reflective property of reflecting light emitted by said wavelength conversion layer. 5. The light emitting device according to claim 1 , wherein said light absorbing layer absorbs light from said light source and emits light having a wavelength different from that of light from said light source. The light emitting device according to any one of claims 1 to 5 , wherein the scattering/reflecting portion includes a resin and particles dispersed in the resin.

Images