Light-emitting device and surface light source

Abstract

To provide a light emitting device capable of emitting light with a wide distribution, and a surface light source including the light emitting device.SOLUTION: A light emitting device includes a substrate, a light emitting element mounted on the substrate, a light-transmitting member arranged to cover the light emitting element, and a light-shielding member arranged on the light-transmitting member to block at least a portion of the light emitted from the light emitting element. The light-transmitting member includes an upper surface on which the light-shielding member is arranged and a side surface having an inclined portion continuing to the upper surface. The substrate is provided with a wall portion located to the side of the light emitting element and having an upper end located below the upper surface of the light emitting element.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a light emitting device and a surface light source. [Background technology]

[0002] Technologies relating to the light distribution of light emitted from a light emitting device have been developed. For example, Patent Document 1 discloses a light emitting device with improved directivity. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-50468 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of an embodiment of the present disclosure is to provide a light emitting device capable of emitting light with a wide distribution, and a surface light source including the light emitting device. [Means for solving the problem]

[0005] In one aspect of the present disclosure, a light-emitting device includes a substrate, a light-emitting element mounted on the substrate, a light-transmitting member arranged to cover the light-emitting element, and a light-shielding member arranged on the light-transmitting member to block at least a portion of light emitted from the light-emitting element. The light-transmitting member includes an upper surface on which the light-shielding member is arranged and a side surface having an inclined portion continuous with the upper surface. The substrate is provided with a wall portion located to the side of the light-emitting element and having an upper end located below the upper surface of the light-emitting element. [Effects of the Invention]

[0006] According to an embodiment of the present disclosure, it is possible to provide a light emitting device capable of emitting light with a wide distribution, and a surface light source using the light emitting device. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a schematic perspective view of a light emitting device according to a first embodiment. [Figure 2] FIG. 2 is a schematic cross-sectional view taken along line II-II in FIG. [Figure 3] 10 is a schematic cross-sectional view of a light emitting device according to Modification 1 taken along the XZ plane. FIG. [Figure 4] FIG. 10 is a schematic cross-sectional view of a light emitting device according to Modification 2 taken along the XZ plane. [Figure 5] FIG. 10 is a schematic perspective view of a light emitting device according to a second embodiment. [Figure 6] FIG. 10 is a schematic perspective view of a light emitting device according to a second embodiment. [Figure 7] FIG. 10 is a schematic plan view of a surface light source according to a third embodiment. [Figure 8] FIG. 8 is a schematic cross-sectional view taken along line VIII-VIII in FIG. 7. [Figure 9] FIG. 8 is a schematic cross-sectional view taken along line IX-IX in FIG. 7. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, a light-emitting device according to an embodiment of the present disclosure will be described with reference to the drawings. The following embodiments are illustrative of light-emitting devices for embodying the technical concept of the present embodiment, and are not limited thereto. Furthermore, unless otherwise specified, the dimensions, materials, shapes, relative arrangements, etc. of the components described in the embodiments are not intended to limit the scope of the present disclosure, but are merely illustrative examples. Note that the size, positional relationship, etc. of components shown in each drawing may be exaggerated for clarity. Furthermore, in the following description, the same names and symbols indicate the same or similar components, and detailed description will be omitted as appropriate. Furthermore, as cross-sectional views, end views showing only the cut surface may be used.

[0009] In the following description, terms indicating specific directions or positions (e.g., "above," "below," and other terms including these terms) may be used. However, these terms are used merely to facilitate understanding of relative directions or positions in the referenced drawings. As long as the relative direction or position relationship indicated by terms such as "above" and "below" in the referenced drawings is the same, the arrangement in drawings other than those disclosed herein, actual products, etc., does not need to be the same as in the referenced drawings. In this specification, the positional relationship expressed as "above (or below)" includes, for example, when two components are assumed to exist, a case in which the two components are in contact with each other, and a case in which the two components are not in contact with each other and one component is located above (or below) the other component. Furthermore, a planar view refers to a view from above (i.e., the positive side of the Z axis) or below (i.e., the negative side of the Z axis), either directly or through a perspective view. Furthermore, in this specification, unless otherwise specified, a component covering an object to be covered includes a case in which the component is in contact with the object to be covered directly and a case in which the component is not in contact with the object to be covered indirectly. In this specification, the term "area" means the area in a plan view unless otherwise specified.

[0010] In the diagrams below, directions may be indicated by the X, Y, and Z directions. The X, Y, and Z directions are perpendicular to one another. If the plane containing the X and Y directions is the XY plane, the Z direction is perpendicular to the XY plane. For example, one side of a substrate is parallel to the X direction, and the other side is parallel to the Y direction.

[0011] 1. First Embodiment (1.1. Overall structure) The overall configuration of a light emitting device 100 according to the first embodiment will be described with reference to FIGS. FIG. 1 is a schematic perspective view of the light emitting device according to the first embodiment. FIG. 2 is a schematic cross-sectional view taken along line II-II in FIG.

[0012] 1, the light emitting device 100 has a rectangular shape in a plan view. As shown in FIG. 1, the light emitting device 100 includes a substrate 20, a light emitting element 30 mounted on the substrate, a light-transmitting member 10 arranged to cover the light emitting element 30, and a light-shielding member 40 on the light-transmitting member 10 that blocks at least a portion of the light emitted from the light emitting element 30.

[0013] The substrate 20 has a rectangular shape in a plan view. The substrate 20 includes a base 21 having a mounting surface 21a on which the light-emitting element 30 is mounted, and a wall 22 on the base 21 that surrounds the periphery of the light-emitting element 30. In this embodiment, the wall 22 is a single wall 22 whose outer surface is flush with the outer surface of the base 21, and is provided to surround the light-emitting element 30 and beside the light-emitting element 30 mounted in the center of the mounting surface 21a. The wall 22 has an upper end 22a that is located below the upper surface 30a of the light-emitting element 30. Specifically, the height H1 of the upper surface 30a of the light-emitting element 30 relative to the mounting surface 21a is higher than the height H2 of the wall 22 relative to the mounting surface 21a. For example, the height H1 of the upper surface 30a of the light-emitting element 30 relative to the mounting surface 21a is preferably 120 μm or more and 250 μm or less, and specifically 200 μm. For example, the height H2 of the wall portion 22 relative to the mounting surface 21a is preferably 70 μm or more and 200 μm or less, specifically 100 μm. By making the height H1 of the upper surface 30a of the light-emitting element 30 relative to the mounting surface 21a higher than the height H2 of the wall portion 22 relative to the mounting surface 21a, a portion of the light traveling from the light-emitting element in a direction parallel to the XY plane can be diffusely reflected by the wall portion. Furthermore, the amount of light traveling toward the surface on which the light-emitting device is mounted, such as a base, can be reduced.

[0014] The wall portion 22 has an inner surface 22b facing the light emitting element 30 and an outer surface 22c opposite the inner surface 22b and forming a side surface of the substrate 20. The inner surface 22b of the wall portion 22 is inclined so that its height increases with increasing distance from the light emitting element 30. The angle formed between the mounting surface 21a and the inner surface 22b is preferably 135° or more and 175° or less, and can be, for example, 150°. The angle formed between the inner surface 22b of the wall portion 22 and the mounting surface 21a may also be 90°.

[0015] The light-transmitting member 10 is provided so as to cover the upper surface 30a and the side surface 30b of the light-emitting element 30. The light-transmitting member 10 has an upper surface 11 on which the light-blocking member 40 is disposed, and side surfaces 12. The upper surface 11 is a surface that is continuous with the side surfaces 12 and is, for example, flat. The upper surface 11 may have a recess. The upper surface 11 may be entirely concave, or may have a flat surface and a recess surrounded by the flat surface. The side surface 12 has an inclined portion 12a that is continuous with the upper surface 11, and a side portion 12b that is continuous with the inclined portion 12a and has a larger inclination angle than the inclined portion 12a. As an example, the side portion 12b may be a surface parallel to the vertical direction (i.e., the Z direction). In this case, the light-transmitting member 10 has a lower portion shaped like a quadrangular prism and an upper portion shaped like a truncated quadrangular pyramid, with the side surface of the upper portion corresponding to the inclined portion 12a and the side surface of the lower portion corresponding to the side portion 12b. Instead of the truncated quadrangular pyramid-shaped upper portion, the side portion 12b may be continuous with the quadrangular prism-shaped lower portion, and the corners may be gradually rounded toward the light-blocking member 40, resulting in a circular upper surface. It is preferable that the height of the boundary between the lower and upper portions of the light-transmitting member 10 from the mounting surface 21a is at least higher than the height of the upper surface of the light-emitting element 30.

[0016] The light-shielding member 40 is disposed on the upper surface 11 of the light-transmitting member 10. In a plan view, the area of ​​the lower surface 41 of the light-shielding member 40 is approximately equal to the area of ​​the upper surface 11 of the light-transmitting member. As an example, the light-shielding member 40 has a rectangular plate shape in a plan view, and includes side surfaces 42 that are perpendicular or inclined to the lower surface 41. The thickness of the light-shielding member 40 is preferably, for example, 100 μm or more and 600 μm or less, and specifically, 400 μm.

[0017] A protection element 50 is disposed on the mounting surface 21a of the substrate 20. An upper surface 51 of the protection element 50 is located below an upper end 22a of the wall portion 22. Specifically, a height H3 of the upper surface of the protection element 50 relative to the mounting surface 21a is lower than a height H2 of the wall portion 22 relative to the mounting surface 21a. The height H3 of the upper surface of the protection element 50 relative to the mounting surface 21a is preferably 50 μm or more and 150 μm or less, and specifically 100 μm.

[0018] The substrate 20 includes a conductive member 32 disposed on the upper surface of the base 21. The conductive member 32 is electrically connected to the light-emitting element 30 and supplies power to the light-emitting element 30. The base 21 and the wall 22 may be made of any material that can insulate and separate at least one pair of conductive members 32, such as ceramics, resin, and composite materials. Examples of resins include phenolic resin, epoxy resin, polyimide resin, BT resin, polyphthalamide (PPA), and polyethylene terephthalate (PET). Examples of composite materials include a mixture of the above-mentioned resins with inorganic fillers such as glass fiber, silicon oxide, titanium oxide, and aluminum oxide; glass fiber reinforced resin (glass epoxy); and a metal substrate in which a metal member is coated with an insulating layer.

[0019] (1.2. Translucent member 10) The light-transmitting member 10 is made of or contains a light-transmitting base material. In the present disclosure, "light-transmitting" means that the transmittance for the peak wavelength of the light-emitting element is 50% or more. When the light-emitting device 100 includes multiple light-emitting elements, it is sufficient that at least one of the light-emitting elements has a transmittance for the peak wavelength of 50% or more.

[0020] The base material of the light-transmitting member 10 can be, for example, a resin material. The resin used for the base material of the light-transmitting member 10 is preferably a thermosetting resin. Examples of thermosetting resins include epoxy resin, modified epoxy resin, silicone resin, modified silicone resin, acrylate resin, urethane resin, and fluorine-based resin. Among these, silicone resin and modified silicone resin are preferred because of their excellent heat resistance and light resistance. The base material of the light-transmitting member 10 can be, for example, a phenyl silicone resin or a dimethyl silicone resin.

[0021] The light-transmitting member 10 may contain a light-reflecting material. This makes it easier to adjust the light distribution of the light-emitting device 100. As the light-reflecting material, it is preferable to use a material that does not easily absorb light from the light-emitting element 30 and has a large refractive index difference with respect to the base material. Examples of such light-reflecting materials include titanium oxide, zinc oxide, silicon oxide, zirconium oxide, aluminum oxide, and aluminum nitride.

[0022] Furthermore, the light-transmitting member 10 may contain a wavelength conversion material. This facilitates color adjustment of the light from the light emitting device 100. The light-transmitting member 10 may contain one type of wavelength conversion material or multiple types of wavelength conversion materials. The phosphor contained in the light-transmitting member 10 may be dispersed or unevenly distributed.

[0023] A known phosphor can be used for the wavelength conversion material contained in the light-transmitting member 10. The phosphor can be an yttrium-aluminum-garnet phosphor (for example, Y3(Al,Ga)5O 12 :Ce), lutetium aluminum garnet phosphors (e.g., Lu3(Al,Ga)5O 12 :Ce), terbium aluminum garnet phosphors (e.g., Tb3(Al,Ga)5O 12 :Ce), CCA-based phosphors (e.g., Ca 10 (PO4)6Cl2:Eu), SAE-based phosphors (e.g., Sr4Al 14 O 25 :Eu), chlorosilicate phosphors (e.g., Ca8MgSiO 16 C l2 :Eu), β-sialon phosphors (e.g., (Si,Al)3(O,N)4:Eu), α-sialon phosphors (e.g., Ca(Si,Al) 12 (O,N) 16:Eu), SLA-based phosphors (e.g., SrLiAlN:Eu), CASN-based phosphors (e.g., CaAlSiN:Eu), or SCASN-based phosphors (e.g., (Sr,Ca)AlSiN:Eu); fluoride-based phosphors such as KSF-based phosphors (e.g., KSiF:Mn), KSAF-based phosphors (e.g., K(Si,Al)F:Mn), or MGF-based phosphors (e.g., 3.5MgO·0.5MgF·GeO:Mn); phosphors having a perovskite structure (e.g., CsPb(F,Cl,Br,I)); or quantum dot phosphors (e.g., CdSe, InP, AgInS, or AgInSe).

[0024] (1.3. Light-emitting element 30) The light emitting element 30 is a semiconductor element that emits light by itself when a voltage is applied, and known semiconductor elements made of nitride semiconductors or the like can be used for the light emitting element 30. An example of the light emitting element 30 is an LED chip. The light emitting element 30 includes a semiconductor laminate. The semiconductor laminate includes an n-type semiconductor layer, a p-type semiconductor layer, and a light emitting layer sandwiched between them. The light emitting layer may have a structure such as a double heterojunction or a single quantum well (SQW), or may have a structure with a group of active layers such as a multiple quantum well (MQW). The semiconductor laminate is configured to be able to emit visible light or ultraviolet light. A semiconductor laminate including such a light emitting layer can be formed using, for example, In x Al y Ga 1-x-y N (0≦x, 0≦y, x+y≦1).

[0025] The semiconductor stack 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 have a structure in which a structure including an n-type semiconductor layer, a light-emitting layer, and a p-type semiconductor layer in that order is repeated multiple times. When the semiconductor stack includes multiple light-emitting layers, the multiple light-emitting layers may include light-emitting layers with different emission peak wavelengths or light-emitting layers with the same emission peak wavelength. Note that "same emission peak wavelength" also includes cases where the emission peak wavelengths vary within ±10 nm. The combination of emission peak wavelengths between the multiple light-emitting layers can be selected appropriately. For example, when the semiconductor stack includes two light-emitting layers, the light-emitting layers can be selected from combinations such as blue light and blue light, green light and green light, red light and red light, ultraviolet light and ultraviolet light, blue light and green light, blue light and red light, or green light and red light. Each light-emitting layer may include multiple active layers with different emission peak wavelengths or multiple active layers with the same emission peak wavelength.

[0026] Only one light-emitting element 30 may be mounted in one light-emitting device 100, or multiple light-emitting elements 30 may be mounted. When one light-emitting device 100 includes multiple light-emitting elements 30, multiple light-emitting elements having the same peak emission wavelength may be combined to improve the luminous intensity of the light-emitting device as a whole. Furthermore, by combining multiple light-emitting elements 30 having different peak emission wavelengths to correspond to, for example, red, green, and blue, the color gamut as a backlight light source can be broadened.

[0027] When the light emitting device 100 includes a plurality of light emitting elements 30, the light emitting elements may all be connected in series, in parallel, or in a combination of series and parallel connections. The light emitting elements 30 may be mounted with the surface on which the electrodes are formed facing up, or may be flip-chip mounted with the surface on which the electrodes are formed facing down. The light emitting elements 30 of the light emitting device 100 are mounted with the surface on which the electrodes are formed facing up, and are electrically connected to the conductive member 32 of the substrate via wires 31.

[0028] The light emitting element 30 has a quadrilateral shape such as a square or a rectangle in plan view, and one side of the quadrilateral may be parallel to the X direction or the Y direction. Alternatively, the light emitting element 30 may be mounted on the mounting surface 21a of the substrate 20 with one side of the quadrilateral tilted relative to the X and Y directions. By mounting the light emitting element 30 on the mounting surface 21a of the substrate 20 with one side of the quadrilateral tilted relative to the X and Y directions in plan view, the light distribution characteristics of the light emitting device 100 can be changed compared to when one side of the quadrilateral is parallel to the X or Y direction. For example, one side of the quadrilateral shape of the light emitting element 30 in plan view may be tilted at an angle of 35° to 60° relative to the X direction. The light emitting device 100 may include two or more light emitting elements 30, each of which has a rectangular shape in plan view.

[0029] (1.4. Light-blocking member 40) The light-shielding member 40 blocks at least a portion of the light emitted from the light-emitting element 30. The light-shielding member 40 has a lower transmittance for the peak wavelength of the light-emitting element 30 than the light-transmitting member 10. The light-shielding member 40 has, for example, a transmittance of 40% or less for the peak wavelength of the light-emitting element 30. The light-shielding member 40 covers the upper surface 30a of the light-emitting element 30 via the light-transmitting member 10. As a result, part of the light traveling upward from the light-emitting element 30 is blocked by the light-shielding member 40, and the light emitted from the light-emitting device 100 tends to have a larger lateral (X-direction and / or Y-direction) component than an upward (Z-direction) component.

[0030] In a plan view, at least a portion of the light-emitting element 30 overlaps with the light-blocking member 40. In a plan view, it is preferable that the entirety of each light-emitting element 30 included in the light-emitting device 100 overlaps with the light-blocking member 40. This makes it easier to block a portion of the light traveling upward from the light-emitting element 30. As a result, the light emitted from the light-emitting device 100 tends to have a large lateral component. The light-blocking member 40 may transmit a portion of the light. Furthermore, the light-blocking member 40 may reflect or absorb light from the light-emitting element 30. It is preferable that the light-blocking member 40 has reflectivity. In this way, light from the light-emitting element 30 is less likely to be absorbed by the light-blocking member 40, thereby improving the light extraction efficiency of the light-emitting device 100.

[0031] The light-shielding member 40 may be made of a metal or a resin material containing a light-reflecting substance. When the light-shielding member 40 is made of a metal, aluminum or the like can be used. When a resin material is used as the base material of the light-shielding member 40, the same resin material as that of the light-transmitting member 10 can be used. Similarly to the light-transmitting member 10, titanium oxide, zinc oxide, silicon oxide, zirconium oxide, aluminum oxide, aluminum nitride, or the like can be used as the light-reflecting substance. The light-reflecting substance can be contained in a proportion of, for example, 10% by weight to 90% by weight of the resin material. The resin member may also include a reflector. In this case, examples of the resin member include polyethylene terephthalate (PET) resin, olefin resin, acrylic resin, silicone resin, urethane resin, and epoxy resin. Examples of the reflector include gases such as air. Other reflector materials include particles of silicon dioxide, calcium fluoride, magnesium fluoride, or the like.

[0032] The difference between the linear expansion coefficient of the base material of the light-transmitting member 10 and the linear expansion coefficient of the base material of the light-blocking member 40 is not particularly limited, but is preferably within 30 ppm / °C. This makes it possible to prevent the light-blocking member 40 from peeling off from the light-transmitting member 10. For example, when a phenyl silicone resin is used as the base material of the light-transmitting member 10, a phenyl silicone resin may also be used as the base material of the light-blocking member 40. The light-transmitting member 10 and the light-blocking member 40 may be in contact with each other, or a known adhesive member may be located between the light-transmitting member 10 and the light-blocking member 40.

[0033] (1.5. Protective element 50) The light emitting device 100 includes a protective element 50. The protective element 50 includes, for example, an element portion and a pair of positive and negative electrodes arranged on the underside of the element portion, and is connected in parallel to the light emitting element 30. In the case of a protective element 50 with polarity such as a Zener diode, it is connected in the reverse direction to the light emitting element 30. In the case of a protective element 50 without polarity such as a varistor, it is connected in the forward or reverse direction to the light emitting element 30. The element portion of the protective element 50 has a rectangular parallelepiped shape, and the pair of electrodes can be arranged on one surface of the element portion. Examples of protective elements 50 with electrodes of this shape include Zener diodes and varistors.

[0034] The role of the protective element 50 is to reduce the voltage load between the positive and negative electrodes of the light-emitting element 30 when an excessive voltage load is applied to the light-emitting device 100 by reducing the resistance of the parallel circuit formed by the protective element 50 and bypassing the current. For example, the light-emitting element 30 and the protective element 50 are connected in parallel in reverse direction to form a drive circuit including the light-emitting element 30 and a bypass circuit including the protective element 50. When the protective element 50 is operating, a smaller resistance in the bypass circuit can reduce the current shunted to the light-emitting element 30 connected in parallel to the protective element 50. For example, when the light-emitting device 100 is mounted on a wiring board, the resistance of the bypass circuit can be reduced by reducing the distance between the wiring on the wiring board and the protective element 50, i.e., by shortening the path of the bypass circuit. This reduces the load on the light-emitting element 30 and further enhances the protection effect of the light-emitting element 30.

[0035] (1.6.Summary) As described above, the light-emitting device 100 of this embodiment includes a substrate 20, a light-emitting element 30 mounted on the substrate 20, a light-transmitting member 10 arranged to cover the light-emitting element 30, and a light-shielding member 40 on the light-transmitting member 10 that blocks at least a portion of the light emitted from the light-emitting element 30. The light-transmitting member 10 includes an upper surface 11 on which the light-shielding member 40 is arranged and a side surface 12 having an inclined portion 12a continuing from the upper surface 11. The substrate 20 is provided with a wall portion 22 located to the side of the light-emitting element 30 and having an upper end 22a located below the upper surface 30a of the light-emitting element 30. With this configuration, a portion of the light emitted from the light-emitting element 30 and exiting from the upper surface 11 of the light-transmitting member 10 is blocked by the light-shielding member 40 and exits from the inclined portion 12a of the light-transmitting member 10, thereby achieving a light-emitting device 100 with a wide light distribution. Here, wide light distribution refers to a light distribution characteristic having a luminous intensity peak that is greater than the luminous intensity when the light distribution angle is 0°, within a range of 0° to ±90°.

[0036] In the light emitting device 100, the area of ​​the lower surface 41 of the light-blocking member 40 may be approximately equal to the area of ​​the upper surface 11 of the light-transmitting member 10 in a plan view. With this configuration, the light emitted from the light emitting element 30 and exiting from the inclined portion 12a of the light-transmitting member 10 can be extracted at a desired angle, and all of the light exiting from the upper surface 11 of the light-transmitting member 10 can be directed onto the light-blocking member 40.

[0037] In the light-emitting device 100, the side surface 12 of the light-transmitting member 10 may have an inclined portion 12a continuing from the upper surface 11 of the light-transmitting member 10, and a side portion 12b having a larger inclination angle than the inclined portion 12a or being vertical. With this configuration, the angle of the inclined portion 12a of the light-emitting device 100 can be adjusted, and the light distribution of the light emitted from the inclined portion 12a can be adjusted.

[0038] In the light-emitting device 100, the wall 22 has an inner surface 22b facing the light-emitting element 30 and an outer surface 22c opposite the inner surface 22b and serving as a side surface of the substrate 20. The inner surface 22b of the wall 22 may be inclined so that its height increases with increasing distance from the light-emitting element 30. With this configuration, light emitted from the light-emitting element 30 is diffusely reflected by the inner surface 22b of the wall 22 and travels toward the light-blocking member 40. A portion of the diffusely reflected light is further diffusely reflected by the light-blocking member. The light further diffusely reflected by the light-blocking member is emitted from the side of the translucent member, thereby achieving a light-emitting device 100 with a wide light distribution. Furthermore, compared to a light-emitting device without the wall 22, the proportion of light emitted from the inclined portion of the side and inclined portion of the translucent member can be increased.

[0039] In the light emitting device 100, the wall portion 22 may be disposed so as to surround the light emitting element 30. With this configuration, the light emitted from the light emitting element 30 can be diffused and reflected by the inner surface 22b of the wall portion 22.

[0040] In the light emitting device 100, a protective element 50 is disposed on the substrate 20, and an upper surface 50a of the protective element 50 may be located below an upper end 22a of the wall portion 22. With this configuration, the light emitting device 100 including the protective element 50 can also achieve a wide light distribution.

[0041] (1.7. Variations) A modification of the first embodiment will be described with reference to FIGS. FIG. 3 is a schematic cross-sectional view of the light emitting device according to the first modification taken along the XZ plane. FIG. 4 is a schematic cross-sectional view of a light emitting device according to the second modification taken along the XZ plane.

[0042] As shown in FIG. 3 , in the light-emitting device 100 according to the first modification, the area of ​​the lower surface 41 of the light-blocking member 40 is larger than the area of ​​the upper surface 11 of the light-transmitting member 10 in a plan view. Preferably, the area of ​​the lower surface 41 of the light-blocking member 40 in a plan view is equal to the area of ​​the boundary between the side portion 12 b and the inclined portion 12 a of the light-transmitting member 10. Also, preferably, in a plan view, the shape of the lower surface 41 of the light-blocking member 40 is similar to the shape of the upper surface 11 of the light-transmitting member 10, and the length of the periphery of the lower surface 41 of the light-blocking member 40 is longer than the length of the outline of the upper surface 11 of the light-transmitting member 10. By adopting such an embodiment, a portion of the light emitted from the light-emitting element 30 and exiting from the inclined portion 12 a of the light-transmitting member 10 can be directed onto the light-blocking member 40, thereby changing the direction in which the light travels.

[0043] As shown in FIG. 4 , in the light-emitting device 100 according to the second modification, the area of ​​the lower surface 41 of the light-shielding member 40 is smaller than the area of ​​the upper surface 11 of the light-transmitting member 10 in a plan view. Preferably, in a plan view, the shape of the lower surface 41 of the light-shielding member 40 is similar to the shape of the upper surface 11 of the light-transmitting member 10, and the length of the periphery of the lower surface 41 of the light-shielding member 40 is shorter than the length of the outline of the upper surface 11 of the light-transmitting member 10. By adopting such an embodiment, a portion of the light emitted from the light-emitting element 30 and passing through the upper surface 11 of the light-transmitting member 10 can be directed to the light-shielding member 40, while the remaining portion can be transmitted, thereby adjusting the light distribution characteristics. Note that, in a plan view, the area of ​​the lower surface 41 of the light-shielding member 40 is preferably larger than the area of ​​the upper surface 30 a of the light-emitting element 30.

[0044] 2. Second Embodiment In the first embodiment described above, the substrate 20 has a wall portion 22 consisting of a single wall portion 22, the outer surface of which is flush with the outer surface of the base, and is arranged to surround the light-emitting element 30, but is not limited to this form. FIG. 5 is a schematic perspective view of the light emitting device according to the second embodiment. For example, as shown in FIG. 5, wall portions 22 may be provided only at the four corners of the substrate 20. Even in this embodiment, the same effects as those of the above embodiment can be obtained. Furthermore, a portion of the light traveling in a direction parallel to the XY plane from the light-emitting element can be diffusely reflected at the corners of the substrate. When comparing the light emitted from the corners of the substrate with the light emitted from between two adjacent corners, the light emitted from between each of the two adjacent corners can be propagated farther in a direction parallel to the XY plane. Furthermore, apart from FIG. 5, a light-emitting device can be provided in which, for example, wall portions 22 are provided between each of the two adjacent corners of the substrate 20, but no wall portions are provided at the four corners. In this case, the light emitted from the four corners can be propagated farther in a direction parallel to the XY plane.

[0045] 3. Third Embodiment FIG. 6 is a schematic perspective view of a light emitting device according to another embodiment. 6, the wall portion 22 may be provided along the outer periphery of the substrate 20, further inward than the outer periphery. This makes it possible to adjust the distribution of light emitted from the light-emitting element 30. Furthermore, the contact area between the light-transmitting member and the substrate can be increased, improving the adhesion between the substrate and the light-transmitting member.

[0046] In the first to third embodiments, the light-shielding member 40 is rectangular and plate-like in plan view, but is not limited to this. For example, the light-shielding member 40 may be formed in a frustum shape. In this case, the side surface 42 of the light-shielding member 40 and the inclined portion 12a of the light-transmitting member 10 may be formed to be flush with each other.

[0047] In the first to third embodiments, the inclined portion 12a of the light-transmitting member 10 is a flat surface, but is not limited to this. For example, the inclined portion 12a may be a curved surface having a convex portion facing outward from the light-transmitting member 10, or a curved surface having a convex portion facing inward from the light-transmitting member 10.

[0048] 4. Fourth Embodiment A fourth embodiment of the present disclosure will be described with reference to FIGS. FIG. 7 is a plan view illustrating a surface light source according to the fourth embodiment. FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. FIG. 9 is a cross-sectional view taken along line IX-IX in FIG.

[0049] 7 and 8, the surface light source 200 has a base 201, a covering member 202, a partitioning member 1, and a plurality of light emitting devices 100. The partitioning member 1 is disposed on the base 201. The covering member 202 covers at least a portion of the upper surface of the base 201. The covering member 202 is provided as needed.

[0050] The partitioning member 1 has a plurality of first wall portions 60, a plurality of second wall portions 70, and a plurality of partition regions 80. The plurality of first wall portions 60 are, for example, arranged parallel to one another. The plurality of second wall portions 70 are, for example, arranged parallel to one another. The partitioning member 1 may have a plurality of bottom portions 90 as necessary. The first wall portion 60 has a first ridge line 61 extending in a first direction, a first side wall 62, and a second side wall 63. The first side wall 62 and the second side wall 63 are arranged on either side of the first ridge line 61 in a plan view. The upper end of the first side wall 62 and the upper end of the second side wall 63 are continuous. There is a space between the first side wall 62 and the second side wall 63.

[0051] The second wall portion 70 of the partition member 1 has a second ridge line 71 extending in the second direction, a third side wall 72, and a fourth side wall 73. The third side wall 72 and the fourth side wall 73 are arranged on either side of the second ridge line 71 in a plan view. The upper ends of the third side wall 72 and the fourth side wall 73 are continuous. There is a space between the third side wall 72 and the fourth side wall 73.

[0052] 9, the partition member 1 has cut portions 55 partially on the first ridge line 61 and the second ridge line 71. The cut portions 55 may be provided as appropriate, but as shown in FIG. 9, the cut portions 55 parallel to the X direction and the cut portions 55 parallel to the Y direction may be provided alternately.

[0053] In the surface light source 200, the lower surface of the bottom 90 of the partitioning member 1 is disposed on a covering member 202 disposed on a base 201. That is, the lower surface of the bottom 90 of the partitioning member 1 is indirectly disposed on the base 201 via the covering member 202. In addition, in the surface light source 200, the light emitting device 100 is disposed on the base 201 exposed within the opening 91 of the bottom 90. The components included in the surface light source 200 will be described in detail below.

[0054] (2.1.Base 201) The base 201 is a member for mounting a plurality of light emitting devices 100. A conductive member 32 for supplying power to the light emitting devices 100 is disposed on the upper surface of the base 201. It is preferable that a covering member 202 covers a part of the region of the conductive member 32 that is not electrically connected to the light emitting elements.

[0055] The material of the base 201 may be any material that can insulate and separate at least the conductive member 32, and examples thereof include ceramics, resin, composite materials, etc. Examples of resins include phenolic resin, epoxy resin, polyimide resin, BT resin, polyphthalamide (PPA), polyethylene terephthalate (PET), etc. Examples of composite materials include the above-mentioned resins mixed with inorganic fillers such as glass fiber, silicon oxide, titanium oxide, and aluminum oxide, glass fiber reinforced resin (glass epoxy resin), and metal substrates in which a metal member is coated with an insulating layer.

[0056] The thickness of the substrate 201 can be selected appropriately. The substrate 201 may be either a flexible substrate or a rigid substrate that can be manufactured by a roll-to-roll method. The rigid substrate may be a thin rigid substrate that can be bent. The material of the conductive member 32 is not particularly limited as long as it is a conductive member, and materials that are normally used as wiring layers for circuit boards and the like can be used.

[0057] The covering member 202 is preferably made of an insulating material. Examples of materials for the covering member 202 include the same materials as those exemplified as materials for the base 201. By using the above-mentioned resin containing an inorganic filler such as titanium oxide, aluminum oxide, or silicon oxide as the covering member 202, the light emitted from the light emitting device 100 is reflected, thereby improving the light extraction efficiency of the surface light source 200.

[0058] (2.2. Light-emitting device 100) As the light emitting device, for example, the light emitting device 100 described in the first embodiment is used. The light emitting device 100 may use one light emitting element 30, or may use a plurality of light emitting elements to form one light emitting device 100. The light emitting device 100 may be one that emits white light, for example.

[0059] By using a light emitting device 100 that can obtain a wide light distribution, the amount of light emitted directly above the light emitting device 100 is reduced, the light distribution of each light emitting device 100 is widened, and the widened light is irradiated onto the first side wall 62, the second side wall 63, the third side wall 72, the fourth side wall 73, and the bottom 90, thereby reducing brightness unevenness in each partitioned area 80.

[0060] The plurality of light emitting devices 100 can be driven independently of one another, and are preferably wired on the base 201 so that dimming control (for example, local dimming or high dynamic range) for each light emitting device 100 is possible.

[0061] (2.3. Compartment member 1) The partition member 1 is disposed on a base 201. A space is provided between the lower surfaces of the first side wall 62 and the second side wall 63 and the upper surface of the base 201 or the upper surface of the covering member 202. In addition, a space is provided between the lower surfaces of the third side wall 72 and the fourth side wall 73 and the upper surface of the base 201 or the upper surface of the covering member 202.

[0062] In the partitioning member 1, each opening 91 is disposed in the center of each partitioned region 80. The shape and size of each opening 91 may be any shape and size that allows the entire light emitting device 100 to be exposed, and it is preferable that the outer edge of each opening 91 is positioned only in the vicinity of the light emitting device 100. This makes it possible for the light from the light emitting device 100 to be reflected by each bottom 90 as well, improving the light extraction efficiency, when the partitioning member 1 has light reflectivity.

[0063] 8, the angle α formed by the adjacent third side wall 72 and fourth side wall 73 is preferably set to, for example, 60 degrees to 90 degrees. By setting the angle α in this range, the space and area occupied by the partitioning member 1 can be reduced, the height of the partitioning member 1 can be reduced, and a thinner surface light source 200 can be achieved. The same applies to the angle formed by the adjacent first side wall 62 and second side wall 63.

[0064] The pitch between adjacent first ridge lines 61 and the pitch between adjacent second ridge lines 71 can be adjusted appropriately depending on the size of the light source used, the size of the intended planar light source, etc. The pitch between adjacent first ridge lines 61 and the pitch between adjacent second ridge lines 71 are, for example, 1 mm to 50 mm, preferably 5 mm to 20 mm, and more preferably 6 mm to 15 mm.

[0065] Furthermore, the height H of the partition member 1 itself, i.e., the length in the Z direction from the underside of each bottom 90 of the partition member 1 to the first ridge 61 or the second ridge 71, is preferably 8 mm or less, and in the case of a thinner surface light source, it is preferably approximately 1 mm to 4 mm.

[0066] The partitioning member 1 is preferably bonded to the base 201 or the covering member on the upper surface of the base 201 using an adhesive. This prevents the partitioning member 1 from shrinking due to heat because the partitioning member 1 is bonded to the base 201 via the adhesive. The partitioning member 1 can be bonded around each opening 91 using a light-reflective adhesive to prevent light emitted from the light-emitting device 100 from entering between the base 201 and the partitioning member 1. For example, it is more preferable to arrange a light-reflective adhesive in a ring shape along the outer edge of each opening 91. The adhesive may be, for example, a double-sided tape with an acrylic resin-based adhesive applied to both sides of a PET substrate, a hot-melt adhesive sheet, or a resin-based adhesive such as a thermosetting resin or a thermoplastic resin. These adhesives preferably have high flame retardancy.

[0067] As described above, it is preferable that the partition member 1 has light reflectivity, so that the light emitted from the light emitting device 100 can be efficiently reflected upward by the first side wall 62, the second side wall 63, the third side wall 72, the fourth side wall 73, and the bottom 90.

[0068] The partitioning member 1 may be made of a resin containing a reflective material made of particles of titanium oxide, aluminum oxide, silicon oxide, or the like, or may be made of a resin that does not contain a reflective material and has a reflective material applied to its surface. Alternatively, a resin containing a plurality of fine bubbles may be used. In this case, light is reflected at the interface between the bubbles and the resin. Examples of resins used for the partitioning member 1 include thermoplastic resins such as acrylic resin, polycarbonate resin, cyclic polyolefin resin, polyethylene terephthalate, polyethylene naphthalate, and polyester, and thermosetting resins such as epoxy resin and silicone resin. The partitioning member 1 is preferably designed to have a reflectance of 70% or more for light emitted from the light-emitting device 100.

[0069] The compartment member 1 may be formed by a molding method using a mold, a molding method using stereolithography, or the like, or the compartment member 1 having the first wall portions 60, the second wall portions 70, and the bottom portions 90 may be purchased. As a molding method using a mold, injection molding, extrusion molding, compression molding, vacuum molding, press molding, and other molding methods can be applied. For example, by vacuum molding using a reflective sheet made of PET or the like, a compartment member 1 in which the first wall portions 60, the second wall portions 70, and the bottom portions 90 are integrally molded can be obtained.

[0070] The surface light source 200 may include a diffusion sheet as an optical member disposed above the light emitting device 100 with the partition member 1 sandwiched therebetween. Furthermore, when a light emitting device that emits, for example, blue light is used instead of a light emitting device that emits white light, an optical sheet including a wavelength conversion member may be further provided on the diffusion sheet. The wavelength conversion member used here may be the material described for the wavelength conversion member contained in the light-transmitting member 10.

[0071] The surface light source 200 may be parallel to the XY plane, or curved toward the Z+ side or Z- side with respect to the XY plane. For example, the surface light source 200 may be curved such that the center of the surface light source 200 is recessed toward the Z- side in the X direction.

[0072] The present disclosure includes the following aspects. (Appendix 1) A substrate; a light-emitting element mounted on the substrate; a light-transmitting member disposed to cover the light-emitting element; a light-shielding member on the light-transmitting member that blocks at least a part of the light emitted from the light-emitting element, The light-transmitting member is an upper surface on which the light-blocking member is disposed; a side surface having an inclined portion continuing to the upper surface, The substrate is provided with a wall portion that is located to the side of the light-emitting element and has an upper end that is located below an upper surface of the light-emitting element. (Appendix 2) 2. The light emitting device according to claim 1, wherein, in a plan view, the area of ​​the lower surface of the light blocking member is larger than the area of ​​the upper surface of the light transmitting member. (Appendix 3) 2. The light emitting device according to claim 1, wherein, in a plan view, the area of ​​the lower surface of the light blocking member is approximately equal to the area of ​​the upper surface of the light transmitting member. (Appendix 4) 2. The light emitting device according to claim 1, wherein, in a plan view, the area of ​​the lower surface of the light blocking member is smaller than the area of ​​the upper surface of the light transmitting member. (Appendix 5) 5. The light emitting device according to any one of claims 1 to 4, wherein the side surface of the translucent member has the inclined portion continuing from the upper surface of the translucent member and a side portion having a larger inclination angle than the inclined portion or being vertical. (Appendix 6) The light-emitting device according to any one of claims 1 to 5, wherein the wall portion has an inner surface facing the light-emitting element and an outer surface opposite the inner surface that forms a side surface of the substrate, and the inner surface of the wall portion is inclined so that its height increases as it moves away from the light-emitting element. (Appendix 7) 7. The light emitting device according to claim 1, wherein the wall portion is disposed so as to surround the light emitting element. (Appendix 8) a protection element is disposed on the substrate; 8. The light emitting device according to claim 1, wherein an upper surface of the protective element is located below an upper end of the wall portion. (Appendix 9) A substrate; a plurality of light emitting devices disposed on the substrate; At least one partition member disposed on the substrate, The partition member is a plurality of first wall portions each having a first ridge line extending in a first direction; a plurality of second wall portions each having a second ridge line extending in a second direction intersecting the first direction; a partitioned area including two opposing first wall portions and two opposing second wall portions, the partitioned area being surrounded by the first ridge line and the second ridge line in a plan view, a plurality of the partitioned regions are arranged in the first direction and the second direction, and at least one first notch portion is provided on at least one of the first ridge lines; Each of the plurality of light emitting devices Located within the partitioned area, a light-emitting element mounted on the substrate; a light-transmitting member disposed to cover the light-emitting element; a light-shielding member on the light-transmitting member that blocks at least a part of the light emitted from the light-emitting element, The light-transmitting member is an upper surface on which the light-blocking member is disposed; a side surface having an inclined portion continuing to the upper surface, The substrate is provided with a wall portion located on a side of the light-emitting element and having an upper end located below an upper surface of the light-emitting element, in a surface light source.

[0073] The embodiments of the present disclosure have been described above with reference to specific examples. However, the present disclosure is not limited to these specific examples. All forms that can be implemented by a person skilled in the art through appropriate design modifications based on the above-described embodiments of the present disclosure also fall within the scope of the present disclosure, as long as they include the gist of the present disclosure. In addition, within the scope of the concept of the present disclosure, a person skilled in the art may come up with various modified examples and examples of alterations, and these modified examples and examples of alterations also fall within the scope of the present disclosure. [Explanation of symbols]

[0074] 1: partition member, 10: light-transmitting member, 11: upper surface, 12: side surface, 12a: inclined portion, 12b: side portion, 20: substrate, 21: base portion, 21a: mounting surface, 22: wall portion, 22a: upper end, 22b: inner surface, 22c: outer surface, 30: light-emitting element, 30a: upper surface, 31: wire, 32: conductive member, 40: light-shielding member, 41: lower surface, 42: side surface, 50: protective element , 50a: upper surface, 51: upper surface, 55: notch, 60: first wall, 61: first ridge, 62: first side wall, 63: second side wall, 63b: sealing member, 70: second wall, 71: second ridge, 72: third side wall, 73: fourth side wall, 80: partitioned area, 90: bottom, 91: opening, 100: light emitting device, 200: surface light source, 201: base, 202: covering member

Claims

1. A substrate; a light-emitting element mounted on the substrate; a light-transmitting member disposed to cover the light-emitting element; a light-shielding member on the light-transmitting member that blocks at least a part of the light emitted from the light-emitting element, The light-transmitting member is an upper surface on which the light-blocking member is disposed; a side surface having an inclined portion continuing to the upper surface, The substrate is provided with a wall portion that is located to the side of the light-emitting element and has an upper end that is located below an upper surface of the light-emitting element.

2. The light emitting device according to claim 1 , wherein, in a plan view, an area of ​​a lower surface of the light blocking member is larger than an area of ​​an upper surface of the light transmitting member.

3. The light emitting device according to claim 1 , wherein, in a plan view, the area of ​​the lower surface of said light blocking member is substantially equal to the area of ​​the upper surface of said light transmitting member.

4. The light emitting device according to claim 1 , wherein, in a plan view, the area of ​​the lower surface of the light blocking member is smaller than the area of ​​the upper surface of the light transmitting member.

5. The light-emitting device according to any one of claims 1 to 4, wherein the side surface of the translucent member has the inclined portion continuing from the upper surface of the translucent member and a side portion having a larger inclination angle than the inclined portion or being vertical.

6. The wall portion has an inner surface facing the light-emitting element and an outer surface opposite the inner surface, which is the side surface of the substrate, and the inner surface of the wall portion is inclined so that its height increases as it moves away from the light-emitting element.

7. 5. The light emitting device according to claim 1, wherein the wall portion is disposed so as to surround the light emitting element.

8. a protection element is disposed on the substrate; 5. The light emitting device according to claim 1, wherein an upper surface of said protective element is located below an upper end of said wall portion.

9. A substrate; a plurality of light emitting devices disposed on the substrate; At least one partition member disposed on the substrate, The partition member is a plurality of first wall portions each having a first ridge line extending in a first direction; a plurality of second wall portions each having a second ridge line extending in a second direction intersecting the first direction; a partitioned area including two opposing first wall portions and two opposing second wall portions, the partitioned area being surrounded by the first ridge line and the second ridge line in a plan view, a plurality of the partitioned regions are arranged in the first direction and the second direction, and at least one first notch portion is provided on at least one of the first ridge lines; Each of the plurality of light emitting devices Located within the partitioned area, a light-emitting element mounted on the substrate; a light-transmitting member disposed to cover the light-emitting element; a light-shielding member on the light-transmitting member that blocks at least a part of the light emitted from the light-emitting element, The light-transmitting member is an upper surface on which the light-blocking member is disposed; a side surface having an inclined portion continuing to the upper surface, The substrate is provided with a wall portion located on a side of the light-emitting element and having an upper end located below an upper surface of the light-emitting element, in a surface light source.

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