Light-emitting device

Abstract

To improve the accuracy of adjusting the amount of light emitted by a light-emitting device.SOLUTION: A light-emitting device according to an embodiment of the present disclosure includes: a light source; a lens which is arranged above the light source; and a light receiving element which is arranged in a position not intersecting an optical axis of the lens and which receives external light through the lens. The lens includes a light adjustment part in an area overlapping with the light receiving element in a top view for adjusting the amount of external light received by the light receiving element.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] Conventionally, there is known a light emitting device capable of adjusting the amount of light emitted by a light source according to the amount of external light received by a light receiving element. For example, Patent Document 1 discloses a light emitting device including a light source, a light receiving element, and a lens with a textured surface that is disposed on the light source and the light receiving element. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-72574 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present disclosure is to provide a light emitting device that allows for high accuracy in adjusting the amount of light emitted by the light emitting device. [Means for solving the problem]

[0005] An illumination device according to one embodiment of the present disclosure comprises a light source, a lens disposed above the light source, and a light receiving element disposed at a position not intersecting the optical axis of the lens and receiving external light through the lens, wherein the lens comprises a light adjusting section in an area overlapping with the light receiving element in a top view for adjusting the amount of external light received by the light receiving element. Effect of the Invention

[0006] According to an embodiment of the present disclosure, it is possible to improve the accuracy of adjusting the amount of light emitted by a light emitting device. [Brief description of the drawings]

[0007] [Figure 1]FIG. 2 is a schematic top view showing an example of a smartphone equipped with the light emitting device according to the first embodiment. [Diagram 2] 2 is a schematic cross-sectional view of the light-emitting device taken along line II-II in FIG. [Diagram 3] 11 is a diagram showing an example of a transition of the amount of received light depending on the angle of incidence of external light; FIG. [Figure 4] 5A to 5C are schematic diagrams illustrating the function of a light adjustment section provided on a lens of the light emitting device according to the first embodiment. [Diagram 5] 5A to 5C are schematic diagrams illustrating the function of a light adjustment section provided on a lens of the light emitting device according to the first embodiment. [Figure 6A] 5A to 5C are diagrams illustrating an example of the effect of reducing variations in the amount of received light of the light emitting device according to the first embodiment. [Figure 6B] 5A to 5C are diagrams illustrating an example of the effect of reducing variations in the amount of received light of the light emitting device according to the first embodiment. [Figure 7A] 6A to 6C are diagrams illustrating another example of the effect of reducing variations in the amount of received light of the light emitting device according to the first embodiment. [Figure 7B] 6A to 6C are diagrams illustrating another example of the effect of reducing variations in the amount of received light of the light emitting device according to the first embodiment. [Figure 8] 6 is a schematic cross-sectional view of the light emitting device according to the second embodiment taken along the XZ plane. FIG. [Figure 9A] 13A to 13C are diagrams illustrating an example of the effect of reducing variations in the amount of received light of the light emitting device according to the second embodiment. [Figure 9B] 13A to 13C are diagrams illustrating an example of the effect of reducing variations in the amount of received light of the light emitting device according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, the light-emitting device according to the embodiment of the present disclosure will be described in detail with reference to the drawings. However, the following embodiments are merely illustrative of the light-emitting device for embodying the technical ideas of the embodiments, and are not limited to the following. Furthermore, the dimensions, materials, shapes, and relative arrangements of the components described in the embodiments are merely illustrative examples, and are not intended to limit the scope of the present disclosure, unless otherwise specified. The size, positional relationship, etc. of the components shown in each drawing may be exaggerated to clarify the explanation. In the following explanation, the same names and symbols indicate the same or homogeneous components, and detailed explanations will be omitted as appropriate. An end view showing only a cut surface may be used as a cross-sectional view.

[0009] In the figures shown below, directions may be indicated by the X-axis, Y-axis, and Z-axis. The X-axis, Y-axis, and Z-axis are mutually orthogonal directions. The direction in which the arrow points in the X-axis direction is indicated as the +X direction, and the opposite direction of the +X direction is indicated as the -X direction. The direction in which the arrow points in the Y-axis direction is indicated as the +Y direction, and the opposite direction of the +Y direction is indicated as the -Y direction. The direction in which the arrow points in the Z-axis direction is indicated as the +Z direction, and the opposite direction of the +Z direction is indicated as the -Z direction. In addition, the term "top view" in the embodiments refers to viewing the object from the +Z direction. However, these do not limit the orientation of the light-emitting device when in use, and the orientation of the light-emitting device is arbitrary. In addition, in the embodiments, the surface of the object when viewed from the +Z direction is referred to as the "top surface," and the surface of the object when viewed from the -Z direction is referred to as the "bottom surface." In the embodiments shown below, "along the X-axis, Y-axis, and Z-axis" includes the object having an inclination within a range of ±10° with respect to these axes. In addition, in the embodiment, the orthogonal angle may have an error of within ±10° with respect to 90°.

[0010] Furthermore, in this disclosure, unless otherwise specified, polygons such as triangles and quadrangles are referred to as polygons, including shapes in which the corners of the polygons have been processed, such as by rounding, chamfering, removing the corners, or rounding off. Shapes in which processing has been applied not only to the corners (edges of the sides) but also to the middle parts of the sides are also referred to as polygons. In other words, shapes in which partial processing has been applied while leaving the polygon as the base are included in the interpretation of "polygon" described in this disclosure.

[0011] The same applies not only to polygons, but also to terms expressing specific shapes such as trapezoids, circles, and irregular shapes. The same also applies to terms relating to the sides that form the shapes. In other words, even if the corners or middle part of a side are processed, the interpretation of "side" includes the processed parts.

[0012] [First embodiment] <Example of overall configuration of light emitting device> The overall configuration of the light emitting device according to the first embodiment will be described with reference to Fig. 1 to Fig. 5. Fig. 1 is a schematic top view showing an example of a smartphone equipped with the light emitting device 1 according to the first embodiment. Fig. 2 is a schematic cross-sectional view of the light emitting device 1 cut along line II-II in Fig. 1. Fig. 3 is a diagram showing an example of the transition of the relative amount of received light according to the angle of incidence of external light. Figs. 4 and 5 are schematic views explaining the operation of a light adjustment unit provided in the lens 20 of the light emitting device 1 according to the first embodiment.

[0013] As an example, the light emitting device 1 is a light emitting device for a flash in an imaging device 2 provided in a smartphone. Examples of the imaging device 2 include a camera that captures still images and a camera that captures videos. The light emitting device 1 is housed in a housing 3 of the smartphone together with the imaging device 2. As shown in FIG. 1, the light emitting device 1 is disposed near the imaging device 2.

[0014] 2, the light emitting device 1 includes a light source 10, a lens 20, and a light receiving element 30. The light emitting device 1 may further include a substrate 40 on which the light source 10 and the light receiving element 30 are mounted, and a support portion 50 that supports the lens 20. The light emitting device 1 may include electronic components such as a Zener diode, a thermistor, and a capacitor. These electronic components can be mounted on the substrate 40 together with the light source 10 and the light receiving element 30 as components of the light emitting device 1.

[0015] The light source 10 emits light in synchronization with, for example, the timing at which the imaging device 2 captures an image of a subject. The lens 20 transmits the light emitted by the light source 10 and emits the light to the outside of the light-emitting device 1. The light-receiving element 30 receives external light from the sun, various lighting fixtures, etc. through the lens 20. The light-emitting device 1 adjusts the amount of light emitted by the light source 10 according to the amount of external light received by the light-receiving element 30.

[0016] The light emitting device 1 has an upper surface, a lower surface, and one or more side surfaces connecting the upper surface and the lower surface. As shown in Fig. 2, the upper surface of the light emitting device 1 corresponds to the upper surface of the lens 20 and the upper surface of the support part 50. The lower surface of the light emitting device 1 corresponds to the lower surface of the substrate 40. The side surfaces of the light emitting device 1 correspond to the outer surfaces of the support part 50.

[0017] The lens 20 is fixed above the light source 10 by being supported by the support portion 50. As a result, a hollow space S surrounded by the support portion 50 is formed inside the light emitting device 1 as shown in Fig. 2. The light source 10 and the light receiving element 30 are housed in the space S while being placed at different positions on the upper surface of the substrate 40. By housing the light source 10 and the light receiving element 30 in the same space S, the light emitting device 1 can be made compact. In addition, since the light source 10 and the light receiving element 30 are not exposed to the outside of the light emitting device 1, the design freedom of a smartphone or the like incorporating the light emitting device 1 can be increased.

[0018] The lens 20 is disposed above the light source 10 and the light receiving element 30. A light extraction surface corresponding to the upper surface of the light source 10 faces the lower surface of the lens 20. Light emitted by the light source 10 enters the lower surface of the lens 20 and exits from the upper surface of the lens 20. In contrast, external light enters the upper surface of the lens 20 and exits from the lower surface of the lens 20. When the external light exiting from the lower surface of the lens 20 reaches the light receiving element 30, the light receiving element 30 detects the external light.

[0019] The substrate 40 is a member on which the light source 10 and the light receiving element 30 are disposed. The substrate 40 includes wiring and a base that supports the wiring. The substrate 40 is a plate-like member having a substantially rectangular outer shape when viewed from above. However, the substrate 40 may have other outer shapes, such as a substantially circular shape, a substantially elliptical shape, or a substantially polygonal shape, when viewed from above.

[0020] The wiring is connected to an external power source and supplies power to the light source 10. The wiring includes, for example, upper surface wiring provided on the upper surface of the substrate 40, relay wiring such as via wiring penetrating the substrate 40, and lower surface wiring provided on the lower surface of the substrate 40. The light source 10 and the light receiving element 30 are connected to the upper surface wiring. The wiring can be made of a metal material, and for example, a simple metal such as gold (Au), silver (Ag), aluminum (Al), nickel (Ni), rhodium (Rh), copper (Cu), titanium (Ti), platinum (Pt), palladium (Pd), molybdenum (Mo), chromium (Cr), tungsten (W), or an alloy containing these metals can be suitably used. Examples of a substrate supporting the wiring include ceramic substrates such as aluminum nitride, aluminum oxide, and silicon nitride, and resin substrates such as glass epoxy. However, the substrate 40 is not limited to these.

[0021] The support portion 50 supports the lens 20. The light emitting device 1 can be disposed above the light source 10 by the support portion 50, with the lens 20 spaced apart from the light source 10. The support portion 50 has a substantially rectangular outer shape when viewed from above. However, the support portion 50 may have other outer shapes, such as a substantially circular shape, a substantially elliptical shape, or a substantially polygonal shape, when viewed from above.

[0022] The support portion 50 is attached to the upper surface of the substrate 40. The support portion 50 surrounds the light source 10 and the light receiving element 30 in a top view. The support portion 50 has a through hole 51, and the lens 20 is supported by the support portion 50 in a state where it is fitted into the through hole 51. The support portion 50 is preferably a light blocking member. By using the support portion 50 as a light blocking member, it is possible to reduce the amount of light emitted from the light source 10 passing through the support portion 50 and emitting to the outside of the light emitting device 1.

[0023] When the light emitting device 1 is used as a flash light source for a smartphone, the light emitting device 1 is disposed such that the support 50 overlaps the housing 3 of the smartphone in a top view. The lens 20 is disposed such that the lens 20 overlaps the cover glass 4 disposed in the opening of the housing 3 in a top view. However, if the cover glass 4 is not provided on the housing 3, the upper surface of the lens 20 may be exposed to the outside through the opening. It is preferable that the through hole 51 of the support 50 overlaps with the opening of the housing 3 or includes the opening of the housing 3 in a top view. This makes it difficult for the support 50 to be seen from outside the smartphone.

[0024] <Light source 10> Next, the configuration of the light source 10 will be described. As shown in Fig. 2, the light source 10 is disposed on the upper surface of the substrate 40 so as to intersect with the optical axis OA of the lens 20. In the light emitting device 1, the light source 10 and the lens 20 are preferably disposed so that the center of the light source 10 intersects with the optical axis OA of the lens 20.

[0025] The light source 10 has an upper surface, a lower surface, and one or more side surfaces connecting the outer edges of the upper surface and the lower surface. The light source 10 has a substantially rectangular outer shape when viewed from above. However, the light source 10 may have other outer shapes, such as a substantially circular shape, a substantially elliptical shape, or a substantially polygonal shape, when viewed from above.

[0026] 2, the light source 10 includes a light emitting element 11, a wavelength conversion member 12, and a light blocking member 13. The light source 10 emits white light. However, the light emitted by the light source 10 is not limited to white light, and may be light having a specific wavelength, such as blue light. The wavelength and chromaticity of the light emitted by the light source 10 may be appropriately selected depending on the intended use of the light emitting device 1.

[0027] The light emitting element 11 is placed on the upper surface of the substrate 40. The light emitting element 11 has positive and negative electrodes connected to the wiring of the substrate 40. This allows power from an external power source to be supplied to the light emitting element 11. The light emitting element 11 has a rectangular outer shape when viewed from above. However, the light emitting element 11 may have other outer shapes, such as a substantially circular, substantially elliptical, or substantially polygonal shape, when viewed from above.

[0028] The light emitting element 11 is a semiconductor light emitting element such as an LED (Light Emitting Diode) or an LD (Laser Diode). The light emitting element 11 is preferably made of a semiconductor such as a III-V group compound semiconductor or a II-VI group compound semiconductor. Examples of the semiconductor that constitutes the light emitting element 11 include In. X Al Y Ga 1-X-Y Examples of nitride semiconductors include nitride semiconductors such as N(0≦X, 0≦Y, X+Y≦1).

[0029] From the viewpoints of luminous efficiency and excitation of the wavelength conversion material, the emission peak wavelength of the light emitting element 11 is preferably from 400 nm to 530 nm, more preferably from 420 nm to 490 nm, and even more preferably from 450 nm to 475 nm. The light emitting element 11 emits blue light belonging to these wavelength ranges.

[0030] The wavelength conversion member 12 is disposed on the light emitting element 11. The wavelength conversion member 12 is a plate-like member having a rectangular outer shape in a top view. However, the wavelength conversion member 12 may have other outer shapes such as a substantially circular shape, a substantially elliptical shape, or a substantially polygonal shape.

[0031] The wavelength conversion member 12 includes a wavelength conversion layer that converts the wavelength of light emitted by the light emitting element 11, and a light diffusion layer disposed on the wavelength conversion layer. The upper surface of the light diffusion layer corresponds to the upper surface of the light source 10. In other words, the upper surface of the light diffusion layer corresponds to the light extraction surface of the light source 10.

[0032] The wavelength conversion layer of the wavelength conversion member 12 includes a base material containing a light-transmitting material and a wavelength conversion material disposed in the base material. Here, "light-transmitting" means that 60% or more of the light emitted by the light-emitting element 11 is transmitted. Examples of the light-transmitting material include resin materials, ceramics, and glass. In this embodiment, the light-transmitting material constituting the base material of the wavelength conversion layer includes a resin material. Examples of the resin material include silicone resin, silicone-modified resin, epoxy resin, epoxy-modified resin, and phenol resin. In particular, silicone resin or modified resin thereof, which has excellent light resistance and heat resistance, is preferable. However, the light-transmitting material is not limited to these.

[0033] The wavelength conversion material contained in the wavelength conversion layer is an yttrium-aluminum-garnet phosphor (e.g., (Y,Gd)3(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 phosphors (e.g., Ca 10 (PO4)6Cl2:Eu), SAE phosphors (e.g., Sr4Al 14 O 25 :Eu), chlorosilicate phosphors (e.g., Ca8MgSi4O 16 Cl2:Eu), silicate phosphors (e.g., (Ba,Sr,Ca,Mg)2SiO4:Eu), β-sialon phosphors (e.g., (Si,Al)3(O,N)4:Eu) or α-sialon phosphors (e.g., Ca(Si,Al) 12 (O,N) 16 :Eu) and other oxynitride phosphors, LSN phosphors (e.g., (La,Y)3Si6N 11:(Ce), BSESN-based phosphors (e.g., (Ba,Sr)2Si5N8:Eu), SLA-based phosphors (e.g., SrLiAl3N4:Eu), CASN-based phosphors (e.g., CaAlSiN3:Eu), or SCASN-based phosphors (e.g., (Sr,Ca)AlSiN3:Eu), etc., nitride-based phosphors, KSF-based phosphors (e.g., K2SiF6:Mn), KSAF-based phosphors (e.g., K2(Si 1-x Al x )F 6-x :Mn where x satisfies 0 < x < 1), or fluoride-based phosphors such as MGF-based phosphors (e.g., 3.5MgO·0.5MgF2·GeO2:Mn), quantum dots having a perovskite structure (e.g., (Cs,FA,MA)(Pb,Sn)(F,Cl,Br,I)3 where FA and MA represent formamidinium and methylammonium, respectively), II-VI group quantum dots (e.g., CdSe), III-V group quantum dots (e.g., InP), or quantum dots having a chalcopyrite structure (e.g., (Ag,Cu)(In,Ga)(S,Se)2), etc. can be used. The wavelength conversion material of the present embodiment includes a YAG (yttrium aluminum garnet)-based phosphor having excellent heat resistance. A part of the blue light emitted from the light emitting element 11 is converted into yellow light by the YAG-based phosphor. Thereby, white light is emitted from the light extraction surface of the light source 10.

[0034] The light diffusion layer of the wavelength conversion member 12 is disposed on the wavelength conversion member 12. The light diffusion layer includes a base material containing a light transmissive material and a light diffusion material dispersed in the base material. The light transmissive material constituting the base material of the light diffusion layer may be the same kind of material as the light transmissive material constituting the base material of the wavelength conversion layer, or may be a different kind of material. In the present embodiment, the light transmissive material constituting the base material of the light diffusion layer includes a silicone resin. However, the light transmissive material is not limited thereto.

[0035] The light diffusion material of the light diffusion layer diffuses the light emitted from the wavelength conversion layer. Examples of the light diffusion material include titanium oxide, barium titanate, aluminum oxide, and silicon oxide. However, the light diffusion material is not limited to these.

[0036] The light shielding member 13 covers the side surface of the light emitting element 11. The light shielding member 13 may also cover the side surface of the wavelength conversion member 12. The outer edge of the light shielding member 13 has a substantially rectangular shape when viewed from above. However, the outer edge of the light shielding member 13 may have other outer shapes, such as a substantially circular shape, a substantially elliptical shape, or a substantially polygonal shape, when viewed from above.

[0037] The light shielding member 13 preferably has light reflectivity in order to improve the light extraction efficiency of the light source 10. For example, the light shielding member 13 is made of a resin material containing a light reflecting substance. Examples of the light reflecting substance include titanium oxide, zinc oxide, magnesium oxide, magnesium carbonate, magnesium hydroxide, calcium carbonate, calcium hydroxide, calcium silicate, magnesium silicate, barium titanate, barium sulfate, aluminum hydroxide, aluminum oxide, zirconium oxide, and silicon oxide. It is preferable to use one of these alone or two or more of these in combination. In addition, examples of the resin material include resin materials mainly composed of thermosetting resins such as epoxy resins, epoxy-modified resins, silicone resins, silicone-modified resins, and phenolic resins.

[0038] <Lens 20> Next, the configuration of the lens 20 will be described. The lens 20 is disposed above the light source 10. The lens 20 is optically transparent to light emitted by the light source 10 and external light reaching the light emitting device 1. Examples of materials constituting the lens 20 include resin materials such as polycarbonate resin, acrylic resin, silicone resin, and epoxy resin, and glass materials. The optical transparency of the lens 20 refers to the property of transmitting 60% or more of the light incident on the lens 20.

[0039] The lens 20 has an upper surface, a lower surface, and one or more side surfaces connecting the outer edges of the upper surface and the lower surface. The lens 20 has a substantially circular outer shape when viewed from above. However, the lens 20 may have an outer shape such as a substantially rectangular, substantially elliptical, or substantially polygonal shape when viewed from above.

[0040] A Fresnel lens is an example of the lens 20. As shown in Fig. 2, the lens 20 has a plurality of protrusions 21 on its lower surface. Each of the plurality of protrusions 21 is arranged concentrically around the optical axis OA of the lens 20. Each of the plurality of protrusions 21 has an annular outer shape arranged concentrically around the optical axis OA when viewed from above.

[0041] The multiple convex portions 21 have one or more first convex portions 211 arranged at a position overlapping the light source 10 in a top view, and one or more second convex portions 212 arranged at a position overlapping the light receiving element 30. The second convex portions 212 are arranged on the outer side of the lens 20 (i.e., on the side farther from the optical axis OA of the lens 20) than the first convex portions 211. The first convex portions 211 and the second convex portions 212 each correspond to a multiple unit lenses that constitute the Fresnel lens structure.

[0042] Each of the one or more first convex portions 211 includes an apex 211B located at the lowest position (-Z direction side), a first surface 211F disposed on the inner side of the lens 20 in top view, and a second surface 211S disposed on the outer side of the lens 20. The second surface 211S is continuous with the first surface 211F via the apex 211B. The second surface 211S of the first convex portion 211 corresponds to the lens surface of the Fresnel lens. The first surface 211F of the first convex portion 211 corresponds to a rise surface connecting the lens surfaces of the Fresnel lens.

[0043] Each of the one or more second convex portions 212 includes an apex 212B located at the lowest position (-Z direction side), a first surface 212F disposed on the inner side of the lens 20 in a top view, and a second surface 212S disposed on the outer side of the lens 20. The second surface 212S is continuous with the first surface 212F via the apex 212B. The second surface 212S of the second convex portion 212 corresponds to the lens surface of the Fresnel lens. The first surface 212F of the second convex portion 212 corresponds to a rise surface connecting the lens surfaces of the Fresnel lens.

[0044] When the light source 10 is disposed in the center of the substrate 40 so as to intersect with the optical axis OA of the lens 20, the light receiving element 30 is disposed outside the substrate 40 with respect to the light source 10 and does not intersect with the optical axis OA of the lens 20. In other words, the optical design regarding the shape, etc. of the lens 20 is adapted to the light source 10, but is often not adapted to the light receiving element 30.

[0045] 3, the transition of the amount of received light according to the incident angle of external light by a light receiving element arranged at a position intersecting the optical axis OA, and the transition of the amount of received light according to the incident angle of external light by a light receiving element arranged at a position not intersecting the optical axis OA (hereinafter referred to as a conventional light receiving element) will be described. Note that the conventional light receiving element is disposed closer to the -X direction with respect to the optical axis OA, similar to the light receiving element 30 of this embodiment.

[0046] The horizontal axis of the graph on the left side of FIG. 3 indicates the angle of incidence of external light with respect to the lens 20 (hereinafter referred to as the "angle of incidence of external light"). The angle of incidence of external light is based on the optical axis OA. The angle of incidence of external light that is incident on the lens 20 in a direction parallel to the optical axis OA is "0°". The vertical axis of FIG. 3 indicates the relative amount of light received by the light receiving element 30. The lines S11 and S12 indicate the relative amount of light received when the amount of light received when the angle of incidence is 0° is set to 100%. In FIG. 3, the line S11 indicates the transition of the relative amount of light received by the light receiving element arranged at a position intersecting with the optical axis OA. The line S12 indicates the transition of the relative amount of light received by a conventional light receiving element arranged at a position not intersecting with the optical axis OA. In the following description, the relative amount of light received may be simply referred to as the "amount of light received". Also, the angle of incidence of external light that enters the lens 20 from the +X direction of the optical axis OA (hereinafter referred to as "external light entering from the +X side"), such as external light L14 and L15 shown in FIG. 2, is defined as a "positive incident angle." For example, the incident angle "+θ" shown in the illustration on the right side of FIG. 3 is an example of a "positive incident angle." In contrast, the angle of incidence of external light that enters the lens 20 from the -X direction of the optical axis OA (hereinafter referred to as "external light entering from the -X side"), such as external light L11 and L12 shown in FIG. 2, is defined as a "negative incident angle." The incident angle "-θ" shown in the illustration on the right side of FIG. 3 is an example of a "negative incident angle."

[0047] As shown by line S11 in Fig. 3, the amount of light received by the light receiving element arranged at the intersection with the optical axis OA is the largest when the incident angle of the external light is 0°. In contrast, as the incident angle of the external light increases, the amount of light received by the light receiving element arranged at the intersection with the optical axis OA decreases. In other words, line S11 in Fig. 3 has a shape that is approximately line symmetrical.

[0048] On the other hand, in the transition of the amount of light received by the conventional light receiving element shown by line S12 in FIG. 3, the amount of received light of external light incident at a positive incident angle is greater than the amount of received light of external light incident at a negative incident angle. Specifically, external light incident from the -X side such as external light L11 and external light L12 in FIG. 2 is difficult to reach the conventional light receiving element because the conventional light receiving element is closer to the -X direction. Therefore, the amount of received light of external light incident from the -X side decreases. In contrast, external light incident from the +X side such as external light L14 and external light L15 is easy to reach the conventional light receiving element because the conventional light receiving element is closer to the -X direction. Therefore, the amount of received light of external light incident from the +X side increases. That is, line S12 in FIG. 3 has an asymmetric shape.

[0049] In this way, in the conventional light receiving element, there may be variation in the amount of received light according to the angle of incidence of the external light with respect to the lens 20 (hereinafter referred to as "variation in the amount of received light"). Therefore, there is a risk that the conventional light receiving element may not be able to properly detect the amount of external light according to the angle of incidence.

[0050] Therefore, in order to reduce the variation in the amount of received light, the lens 20 includes a light adjusting section for adjusting the amount of external light received by the light receiving element 30. The light adjusting section is provided in at least a region of the lens 20 that overlaps with the light receiving element 30 in a top view.

[0051] The light adjustment unit 212R of this embodiment is a rough surface provided on at least the second surface 212S of the second convex portion 212 in the lens 20 (see FIG. 2, FIG. 4, and FIG. 5). The light adjustment unit 212R is preferably provided on the entire area of ​​the second surface 212S of the second convex portion 212. That is, the light adjustment unit 212R is continuously arranged in an annular area centered on the optical axis OA. This can improve the aesthetics of the light emitting device 1 due to the geometric symmetry when the light emitting device 1 is viewed from the outside. For example, when the first surface 212F and the second surface 212S (see FIG. 2) of the second convex portion 212 are rough surfaces, the light adjustment unit 212R corresponds to the first surface 212F and the second surface 212S of the second convex portion 212. Also, when only the second surface 212S of the second convex portion 212 is rough, the light adjustment unit 212R corresponds to the second surface 212S of the second convex portion 212.

[0052] The rough surface of the light adjusting portion 212R is preferably a textured surface. By forming the light adjusting portion 212R as a textured surface, fine irregularities for roughening the second surface 212S of the second convex portion 212 can be easily formed. The rough surface of the light adjusting portion 212R may be provided on the first surface 212F of the second convex portion 212. However, the light adjusting portion 212R is not limited to being a textured surface.

[0053] The light adjusting portion 212R may have a configuration other than a rough surface. Other light adjusting portions include a light diffusing material contained inside the second convex portion 212. Examples of the light diffusing material include titanium oxide, barium titanate, aluminum oxide, and silicon oxide. However, the light diffusing material may be a material other than these.

[0054] The second convex portion 212 on which the light adjustment portion 212R is provided is disposed outside the light source 10 in a top view. That is, the light adjustment portion 212R is disposed at a position that does not intersect with the optical path of the light incident on the lens 20 from the light source 10. Therefore, the light adjustment portion 212R can reduce the influence of the light adjustment portion 212R on the lens design related to the lens 20.

[0055] By providing the light adjustment section 212R on the second convex section 212 of the lens 20, it is possible to scatter the external light emitted from the lower surface of the lens 20. Specifically, as shown in FIG. 4, when the external light, such as external light L11 and L12, incident from the -X side is emitted from the lower surface of the lens 20, it collides with the unevenness of the light adjustment section 212R and is scattered. As a result, the external light incident from the -X side is diffused in a random direction, and the amount of external light reaching the light receiving element 30 can be increased. Also, as shown in FIG. 5, when the external light, such as external light L13 and L14, incident from the +X side is emitted from the lower surface of the lens 20, it collides with the unevenness of the light adjustment section 212R and is scattered. As a result, the external light incident from the +X side is diffused in a random direction, and the amount of external light reaching the light receiving element 30 can be reduced. As a result, it is possible to reduce the variation in the amount of received light. Also, the light receiving signal output from the light receiving element 30 appropriately reflects the amount of external light. This makes it possible to improve the accuracy of adjusting the amount of light emitted by the light source 10.

[0056] Furthermore, by providing the light adjustment section 212R on the second convex section 212 of the lens 20, the light incident on the lens 20 from the light source 10 can be diffused by the light adjustment section 212R and emitted from the upper surface of the lens 20. This allows emitted light with reduced directivity to be emitted from the light emitting device 1. Furthermore, by providing the light adjustment section 212R, the uniformity of the illuminance of the emitted light from the light emitting device 1 can be improved.

[0057] <Photodetector 30> Next, the configuration of the light receiving element 30 will be described. As shown in Fig. 2, the light receiving element 30 is disposed at a position that does not intersect with the optical axis OA of the lens 20. Specifically, the light receiving element 30 is disposed closer to the -X direction with respect to the optical axis OA. However, the light receiving element 30 may be disposed closer to the +X direction, +Y direction, or -Y direction with respect to the optical axis OA.

[0058] The light receiving element 30 includes an element housing 31 placed on a substrate 40, a light receiving unit 32 arranged on the element housing 31, and a light-transmitting covering member 33 that covers the element housing 31 and the light receiving unit 32. The light receiving element 30 is connected to wiring on the substrate 40 through, for example, metallic wiring such as wire. This allows power from an external power source to be supplied to the light receiving element 30. In addition, an electrical signal indicating the amount of light received by the light receiving element 30 is transmitted to, for example, a signal processing unit provided in a smartphone.

[0059] In the light receiving element 30, the light receiving section 32 is a component that receives external light. The light receiving section 32 is disposed on the upper surface of the light receiving element 30. The light receiving section 32 has a substantially rectangular outer shape when viewed from above. However, the light receiving section 32 may have other outer shapes, such as a substantially circular shape, a substantially elliptical shape, or a substantially polygonal shape, when viewed from above.

[0060] Examples of the light receiving element 30 include photoelectric conversion elements such as photodiodes and phototransistors. As shown in Fig. 2, the light receiving section 32 is disposed closer to the +X direction side on the upper surface of the light receiving element 30. However, the position of the light receiving section 32 is not limited thereto.

[0061] <Example of reduction in variation in received light amount due to difference in spread angle σ of external light> Next, with reference to FIGS. 6A and 6B, an example of the effect of reducing variations in the amount of received light due to differences in the spread angle σ of external light diffused by the light adjustment portion 212R of the lens 20 (hereinafter referred to as "spread angle σ") will be described.

[0062] A simulation was performed to show an example of the effect of reducing the variation in the amount of received light. In this simulation, Examples 1 to 3 having different divergence angles σ and Comparative Example 1 not having the light adjustment section 212R were used. In each of Examples 1 to 3, the first surface 212F and the second surface 212S of the second convex portion 212 are roughened. That is, the light adjustment section 212R of Examples 1 to 3 corresponds to the first surface 212F and the second surface 212S of the second convex portion 212.

[0063] The divergence angle σ in the first to third embodiments is as follows: (1) Example 1: σ=3.0° (2) Example 2: σ=17.0° (3) Example 3: σ=33.0° It should be noted that the external light emitted from the lower surface of the lens in Comparative Example 1 is not diffused. That is, the spread angle σ in Comparative Example 1 is "0°."

[0064] The spread angle σ corresponds to the surface roughness of the light adjusting portion 212R. As the spread angle σ increases, the surface roughness of the light adjusting portion 212R increases. The surface roughness of Example 1 is the smallest, and the surface roughness of Example 3 is the largest. The surface roughness of Example 2 is a value between the surface roughness of Example 1 and Example 3.

[0065] Specifically, the surface roughness Ra of Examples 1 to 3 corresponding to the above-mentioned spread angle σ is as follows: (1) Example 1: Ra=0.6 μm (2) Example 2: Ra=2.2 μm (3) Example 3: Ra=6.3 μm The surface roughness Ra of Comparative Example 1 corresponds to "0.0 μm."

[0066] FIG. 6A is a graph showing the transition of the amount of light received by the light receiving element 30 depending on the incident angle of external light in this simulation. The horizontal axis of FIG. 6A shows the incident angle of external light. The vertical axis of FIG. 6A shows the relative amount of light received based on the amount of light received at an incident angle of 0° in Comparative Example 1. In FIG. 6A, line R11 shows the transition of the amount of light received depending on the incident angle of external light in Example 1. Line R12 shows the transition of the amount of light received depending on the incident angle of external light in Example 2. Line R13 shows the transition of the amount of light received depending on the incident angle of external light in Example 3. Line R14 shows the transition of the amount of light received depending on the incident angle of external light in Comparative Example 1.

[0067] As shown in FIG. 6A, in Comparative Example 1 not having the light adjustment unit 212R, the difference between the amount of received external light incident from the +X side and the amount of received external light incident from the -X side is large. That is, the variation in the amount of received light is large. In contrast, in Examples 1 to 3, as the spread angle σ increases, the difference between the amount of received external light incident from the +X side and the amount of received external light incident from the -X side becomes smaller. As an example, in Examples 1 to 3, the relative amount of received light at -30° is relatively increased compared to the comparative example, and the relative amount of received light at +30° is relatively decreased compared to the comparative example. That is, it was shown that the variation in the amount of received light is reduced as the surface roughness of the light adjustment unit 212R increases.

[0068] Next, Fig. 6B is a graph in which the difference in the relative amount of received light for two types of external light having the same magnitude of incident angle is plotted for each of Examples 1 to 3 and Comparative Example 1. Here, "two types of external light having the same magnitude of incident angle" refers to a pair of two types of external light having the same angle "θ" indicating the magnitude of angle, for example, external light having an incident angle of +θ and external light having an incident angle of -θ shown in Fig. 3. Examples of two types of external light with the same incidence angle include a pair of external light with an incidence angle of +15° and an external light with an incidence angle of -15° (hereinafter referred to as "external light of Δ15°"), a pair of external light with an incidence angle of +30° and an incidence angle of -30° (hereinafter referred to as "external light of Δ30°"), a pair of external light with an incidence angle of +45° and an incidence angle of -45° (hereinafter referred to as "external light of Δ45°"), a pair of external light with an incidence angle of +60° and an incidence angle of -60° (hereinafter referred to as "external light of Δ60°"), and a pair of external light with an incidence angle of +75° and an incidence angle of -75° (hereinafter referred to as "external light of Δ75°").

[0069] The points on line R15 in FIG. 6B show the difference in the relative amount of received external light at Δ15° in each of Examples 1 to 3 and Comparative Example 1. The points on line R16 show the difference in the relative amount of received external light at Δ30° in each of Examples 1 to 3 and Comparative Example 1. The points on line R17 show the difference in the relative amount of received external light at Δ45° in each of Examples 1 to 3 and Comparative Example 1. The points on line R18 show the difference in the relative amount of received external light at Δ60°. The points on line R19 show the difference in the relative amount of received external light at Δ75°.

[0070] 6B, it was confirmed that the difference in the relative amount of received light was small for external light at Δ30°, external light at Δ45°, external light at Δ60°, and external light at Δ75° in Example 1. It was confirmed that the difference in the relative amount of received light was small for external light at Δ15°, external light at Δ30°, external light at Δ45°, external light at Δ60°, and external light at Δ75° in Example 2 and Example 3.

[0071] 6B, for external light of Δ15°, the difference in the relative amount of received light decreased in the order of the spreading angle σ of Example 1, Example 2, and Example 3. Similarly, for external light of Δ30°, external light of Δ45°, external light of Δ60°, and external light of Δ75°, the difference in the relative amount of received light decreased in the order of the spreading angle σ of Example 1, Example 2, and Example 3. That is, as the surface roughness of the light adjustment section 212R increased, the difference in the amount of received light between the external light incident from the +X side and the external light incident from the -X side decreased.

[0072] <Another example of the effect of reducing the variation in the amount of received light due to differences in the spread angle σ of external light> Next, with reference to Figures 7A and 7B, another example of the effect of reducing the variation in the amount of received light due to the difference in the spread angle σ of the light diffused by the light adjustment unit 212R of the lens 20 will be described. For the following Examples 4 to 6, a simulation similar to the simulation shown in Figures 6A and 6B was performed. Note that Figures 7A and 7B exemplify the effect of reducing the variation in the amount of received light, and the effect of reducing the variation in the amount of received light of this embodiment is not limited to the results of this simulation.

[0073] 6A and 6B in that only the second surface 212S of the second convex portion 212 in Examples 4 to 6 is roughened. Other points are the same as those in the simulations shown in Figures 6A and 6B. The light adjustment portion 212R in Examples 4 to 6 corresponds to the second surface 212S of the second convex portion 212.

[0074] The divergence angles σ in the fourth to sixth embodiments are as follows: (4) Example 4: σ=3.0° (corresponding to Ra=0.6 μm) (5) Example 5: σ=17.0° (corresponding to Ra=2.2 μm) (6) Example 6: σ=33.0° (corresponding to Ra=6.3 μm)

[0075] FIG. 7A is a graph showing the transition of the amount of received light according to the incident angle of external light in this simulation. The horizontal axis of FIG. 7A shows the incident angle of external light. The vertical axis of FIG. 7A shows the relative amount of received light based on the amount of received light at an incident angle of 0° in Comparative Example 1. In FIG. 7A, line R21 shows the transition of the amount of received light according to the incident angle of external light in Example 4. Line R22 shows the transition of the amount of received light according to the incident angle of external light in Example 5. Line R23 shows the transition of the amount of received light according to the incident angle of external light in Example 6. Line R14 shows the transition of the amount of received light according to the incident angle of external light in Comparative Example 1.

[0076] 7B, it was confirmed that the difference in the relative amount of received light was small for external light of Δ60° and external light of Δ75° in Example 4. It was confirmed that the difference in the relative amount of received light was small for external light of Δ15°, external light of Δ30°, external light of Δ45°, external light of Δ60°, and external light of Δ75° in Example 5 and Example 6.

[0077] As shown in FIG. 7A, in Examples 4 to 6, as the spread angle σ increases, the difference between the amount of received external light incident from the +X side and the amount of received external light incident from the -X side decreases. That is, as the surface roughness of the light adjustment section 212R increases, the variation in the amount of received light is reduced. As an example, in Examples 4 to 6, the relative amount of received light at -30° is relatively increased compared to the comparative example, and the relative amount of received light at +30° is relatively decreased compared to the comparative example. It was shown that by roughening the second surface 212S of the second convex portion 212, the directivity of external light incident from the +X side that easily reaches the light receiving element 30 can be reduced, and the variation in the amount of received light can be reduced.

[0078] Next, FIG. 7B is a graph in which the difference in the relative amount of received light for two types of external light having the same incident angle is plotted for each of Examples 4 to 6 and Comparative Example 1. The points on line R25 in FIG. 7B indicate the difference in the relative amount of received light of Δ15° of external light in each of Examples 4 to 6 and Comparative Example 1. The points on line R26 indicate the difference in the relative amount of received light of Δ30° of external light in each of Examples 4 to 6 and Comparative Example 1. The points on line R27 indicate the difference in the relative amount of received light of Δ45° of external light in each of Examples 4 to 6 and Comparative Example 1. The points on line R28 indicate the difference in the relative amount of received light of Δ60° of external light in each of Examples 4 to 6 and Comparative Example 1. The line R29 indicates the difference in the relative amount of received light of Δ75° of external light in each of Examples 4 to 6 and Comparative Example 1.

[0079] 7B, the difference in the relative amount of received light of external light at Δ15° became smaller in the order of Example 4, Example 5, and Example 6, in which the spread angle σ increased. Similarly, the difference in the relative amount of received light of external light at Δ30°, the difference in the relative amount of received light of external light at Δ45°, the difference in the relative amount of received light of external light at Δ60°, and the difference in the relative amount of received light of external light at Δ75° also became smaller in the order of Example 4, Example 5, and Example 6, in which the spread angle σ increased. It was shown that by roughening the second surface 212S of the second convex portion 212, the directivity of external light incident from the +X side, which is likely to reach the light receiving element 30, can be reduced, and the variation in the amount of received light can be reduced.

[0080] [Second embodiment] A light emitting device 1A according to a second embodiment will be described with reference to Fig. 8. Fig. 8 is a schematic cross-sectional view of the light emitting device 1A cut along the XZ plane. The light emitting device 1A according to the second embodiment differs from the first embodiment in the structure of a light adjustment unit provided in the lens 20A.

[0081] The light emitting device 1A according to this embodiment includes a light source 10, a lens 20A, and a light receiving element 30. The light emitting device 1A further includes a substrate 40 on which the light source 10 and the light receiving element 30 are mounted, and a support 50 that supports the lens 20A. In the light emitting device 1A shown in Fig. 8, the light receiving portion 32 of the light receiving element 30 is disposed on the upper surface of the light receiving element 30, closer to the +X direction side.

[0082] An example of the lens 20A is a Fresnel lens. The lens 20A has a plurality of protrusions 25 on its lower surface. Each of the plurality of protrusions 25 is arranged concentrically around the optical axis OA of the lens 20A. As shown in Fig. 8, each of the plurality of protrusions 25 has an annular outer shape arranged concentrically around the optical axis OA in a top view.

[0083] The multiple convex portions 25 have one or more first convex portions 251 arranged at a position overlapping the light source 10, and one or more second convex portions 252 arranged at a position overlapping the light receiving element 30, in a top view. The second convex portions 252 are arranged on the outer side of the lens 20A than the first convex portions 251. The first convex portions 251 and the second convex portions 252 each correspond to a multiple unit lenses in the Fresnel lens structure.

[0084] Each of the one or more first convex portions 251 includes an apex 251B located at the lowest position (-Z direction side), a first surface 251F arranged on the inner side of the lens 20A in a top view, and a second surface 251S arranged on the outer side of the lens 20A. The second surface 251S is continuous with the first surface 251F via the apex 251B. The second surface 251S of the first convex portion 251 corresponds to the lens surface of the Fresnel lens. The first surface 251F of the first convex portion 251 corresponds to a rise surface connecting the lens surfaces of the Fresnel lens.

[0085] Each of the one or more second convex portions 252 includes an apex 252B located at the lowest position (-Z direction side), a first surface 252F arranged on the inner side of the lens 20A in a top view, and a second surface 252S arranged on the outer side of the lens 20A. The second surface 252S is connected to the first surface 252F via the apex 252B. The second surface 252S of the second convex portion 252 corresponds to the lens surface of the Fresnel lens. The first surface 252F of the second convex portion 252 corresponds to a rise surface connecting the lens surfaces of the Fresnel lens.

[0086] As shown in FIG. 8, the first surface 252F of at least one second convex portion 252 has an inclined surface with a larger inclination angle with respect to the optical axis OA of the lens 20A than the first surface 251F of the first convex portion 251. That is, the inclination angle φ1 with respect to the optical axis OA of the lens 20 at the first surface 252F of the second convex portion 252 is smaller than the inclination angle φ2 with respect to the optical axis OA of the lens 20 at the first surface 251F of the first convex portion 251. The inclined surface of the first surface 252F corresponds to the light adjustment portion of the lens 20A. The inclined surface of the first surface 252F is provided at least in the area overlapping with the light receiving element 30 in the top view. In this embodiment, the inclined surface of the first surface 252F is provided in the entire area of ​​the first surface 252F. That is, the light adjustment portion is continuously arranged in an annular area centered on the optical axis OA. This can improve the aesthetics of the light emitting device 1A due to the geometric symmetry when the light emitting device 1A is viewed from the outside.

[0087] 8, in the radial direction of the lens 20A (direction from the optical axis OA toward the outside in the XY plane), the width of at least one second convex portion 252 is preferably greater than the width of the first convex portion 251. Furthermore, in the height direction of the lens 20A (direction along the Z direction), it is preferable that the apex 252B of at least one second convex portion 252 is located above (on the +Z direction side) the position of the apex 251B of the first convex portion 251.

[0088] According to lens 20A, by making the inclination angle φ1 of first surface 252F of second convex portion 252 with respect to the optical axis OA larger than the inclination angle φ2 of first surface 251F of first convex portion 251, the difference between the amount of external light on the +X side and the amount of external light on the -X side reaching light receiving element 30 can be reduced.

[0089] The shape of the first surface 252F overlapping with the light receiving element 30 in top view is determined so as to guide the external light incident on the first surface 252F to the light receiving element 30. Since the light receiving element 30 is disposed closer to the -X side than the optical axis OA, the amount of external light entering from the -X side is reduced due to obstruction by the housing 3 and the like. For this reason, in order to facilitate guiding the external light entering from the -X side to the light receiving element 30, the first surface 252F of the second convex portion 252 located on the +X side is made to have an inclined surface having a larger inclination angle with respect to the optical axis OA of the lens 20A than the first surface 251F of the first convex portion 251 as a light adjustment portion. This can reduce the difference between the amount of external light on the +X side that reaches the light receiving element 30 and the amount of external light on the -X side, and can reduce the variation in the amount of received light. In addition, the light receiving signal output from the light receiving element 30 appropriately reflects the amount of external light. As a result, the adjustment accuracy of the light emission amount of the light source 10 can be improved.

[0090] Moreover, by making the width of the second convex portion 252 larger than the width of the first convex portion 251, the second convex portion 252 can be made closer to a flat state than the first convex portion 251. This makes it easier to design the second convex portion 252. Furthermore, by positioning the apex 252B of the second convex portion 252 higher than the position of the apex 251B of the first convex portion 251, the second convex portion 252 can be made closer to a flat state than the first convex portion 251. This makes it easier to design the second convex portion 252. Furthermore, as shown in FIG. 8, the apex 252B is closer to the outside than the center of the width of the second convex portion 252 in the second convex portion 252. Furthermore, the second surface 252S of the second convex portion 252 is an inclined surface with a smaller inclination angle with respect to the optical axis OA of the lens 20A than the second surface 251S of the first convex portion 251. That is, the inclination angle φ3 of the second surface 252S of the second convex portion 252 with respect to the optical axis OA of the lens 20 is smaller than the inclination angle φ4 of the second surface 251S of the first convex portion 251 with respect to the optical axis OA of the lens 20. The shape of the second surface 252S may be determined so as to guide external light incident on the second surface 252S to the outside of the light receiving element 30.

[0091] <An example of the effect of reducing the variation in the amount of received light with or without a light adjustment unit> Next, an example of the effect of reducing the variation in the amount of received light depending on the presence or absence of the light adjustment unit will be described with reference to Figs. 9A and 9B. A simulation was performed to show an example of the effect of reducing the variation in the amount of received light. Example 7 used in this simulation includes the light adjustment unit described with reference to Fig. 8. That is, in Example 7, the inclination angle φ1 of the first surface 252F of the second convex portion 252 with respect to the optical axis OA is larger than the inclination angle φ2 of the first surface 251F of the first convex portion 251 with respect to the optical axis OA. Also, the width of the second convex portion 252 of Example 7 is larger than the width of the first convex portion 251. Also, the apex 252B of the second convex portion 252 of Example 7 is located above the position of the apex 251B of the first convex portion 251. In contrast, the Fresnel lens of Comparative Example 2 does not have a shape feature such as the light adjustment unit of Example 7 in the multiple convex portions provided on the lower surface. 9A and 9B are illustrative diagrams showing the effect of reducing the variation in the amount of received light, and the effect of reducing the variation in the amount of received light in this embodiment is not limited to the results of this simulation.

[0092] Fig. 9A is a graph showing the transition of the amount of light received by the light receiving element 30 depending on the incident angle of external light in this simulation. The horizontal axis of Fig. 9A shows the incident angle of external light. The vertical axis of Fig. 9A shows the relative amount of light received based on the amount of light received at an incident angle of 0° in Comparative Example 2. In Fig. 9A, line R31 shows the transition of the amount of light received depending on the incident angle of external light in Example 7. Line R32 shows the transition of the amount of light received depending on the incident angle of external light in Comparative Example 1.

[0093] As shown in Fig. 9A, the line R31 corresponding to Example 7 has a shape close to line symmetry, in which the amount of received light decreases as the incident angle of external light increases, with the boundary being the amount of received light of external light at an incident angle of 0°. The light adjustment unit of this embodiment can reduce the difference between the amount of external light on the +X side and the amount of external light on the -X side that reaches the light receiving element 30. This shows that the provision of the light adjustment unit of this embodiment can reduce the variation in the amount of received light.

[0094] Next, FIG. 9B is a graph showing the difference in the relative amount of received light for two types of external light having the same incident angle for Example 7 and Comparative Example 2. The difference in the relative amount of received light at "15°" on the horizontal axis of FIG. 9B corresponds to the difference in the relative amount of received light of external light at Δ15°. The difference in the relative amount of received light at "30°" on the horizontal axis of FIG. 9B corresponds to the difference in the relative amount of received light of external light at Δ30°. The difference in the relative amount of received light at "45°" on the horizontal axis of FIG. 9B corresponds to the difference in the relative amount of received light of external light at Δ45°. The difference in the relative amount of received light at "60°" on the horizontal axis of FIG. 9B corresponds to the difference in the relative amount of received light of external light at Δ60°. The difference in the relative amount of received light at "75°" on the horizontal axis of FIG. 9B corresponds to the difference in the relative amount of received light of external light at Δ75°.

[0095] Line R41 in FIG. 9B shows the difference in the relative amount of received light for two types of external light having the same incident angle in Example 7. Line R42 in FIG. 9B shows the difference in the relative amount of received light for two types of external light having the same incident angle in Comparative Example 2. As shown in FIG. 9B, the difference in the relative amount of received light for external light at Δ15°, the difference in the relative amount of received light for external light at Δ30°, the difference in the relative amount of received light for external light at Δ45°, the difference in the relative amount of received light for external light at Δ60°, and the difference in the relative amount of received light for external light at Δ75° in Example 7 were all reduced compared to Comparative Example 2. That is, from this viewpoint as well, the effect of reducing the variation in the amount of received light by the light adjustment unit of this embodiment was demonstrated.

[0096] Although the preferred embodiments have been described above in detail, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the claims. For example, in the second embodiment, the first surface 252F and the second surface 252S of the second convex portion 252 may be roughened like the light adjustment portion 212R in the first embodiment.

[0097] Aspects of the present disclosure are, for example, as follows. <Item 1> A light source, a lens disposed above the light source; a light receiving element that is disposed at a position not intersecting an optical axis of the lens and receives external light via the lens; Equipped with the lens includes a light adjusting portion in a region overlapping with the light receiving element in a top view, the light adjusting portion adjusting an amount of external light received by the light receiving element; Light emitting device. <Item 2> The lens has a plurality of convex portions arranged concentrically around the optical axis on a lower surface facing the light source, the plurality of convex portions include one or more first convex portions overlapping with the light source in a top view, and one or more second convex portions arranged outside the first convex portions and overlapping with the light receiving element, Each of the first convex portion and the second convex portion is A lowest apex; A first surface is disposed on an inner side of the lens when viewed from above; a second surface that is disposed outside the lens when viewed from above and that is continuous with the first surface via the apex; Equipped with The light emitting device according to <Item 1>, wherein the light adjustment section is disposed on the second surface. <Item 3> The light emitting device according to <Item 1> or <Item 2>, wherein the light adjustment section has a rough surface. <Item 4> The light emitting device according to <Item 3>, wherein the rough surface is a textured surface. <Item 5> The lens has a plurality of convex portions arranged concentrically around the optical axis on a lower surface facing the light source, the plurality of convex portions include one or more first convex portions overlapping with the light source in a top view, and one or more second convex portions arranged outside the first convex portions and overlapping with the light receiving element, Each of the first convex portion and the second convex portion is A lowest apex; A first surface is disposed on an inner side of the lens when viewed from above; a second surface that is disposed outside the lens when viewed from above and that is continuous with the first surface via the apex; Equipped with The light emitting device according to <Item 1>, wherein the light adjustment section is disposed on the first surface. <Item 6> The light emitting device according to <Item 5>, wherein a first surface of the second convex portion has, as the light adjustment portion, an inclined surface having a larger inclination angle with respect to the optical axis of the lens than the first surface of the first convex portion. <Item 7> The light emitting device according to <Item 5> or <Item 6>, wherein a width of the second convex portion in a radial direction of the lens is greater than a width of the first convex portion. <Item 8> The light emitting device according to any one of <Item 5> to <Item 7>, wherein, in a height direction of the lens, an apex of the second convex portion is positioned higher than the position of an apex of the first convex portion. <Item 9> The light emitting device according to any one of <Item 1> to <Item 8>, wherein the light adjustment portion is disposed continuously in an annular area of ​​the lens centered on the optical axis. <Item 10> The light emitting device according to any one of <Item 1> to <Item 9>, wherein the light adjustment section is disposed outside the light source in a top view. <Item 11> The light emitting device according to any one of <Item 1> to <Item 10>, wherein the light source includes a light emitting element and a wavelength conversion member disposed on the light emitting element. [Explanation of symbols]

[0098] 1,1A Light Emitting Device 10 light source 11 Light emitting element 12 Wavelength conversion material 13 Light-shielding material 20 Lenses 21 Convex 211,251 First convex part 211F, 251F 1st surface of 1st convex part Second surface of the first convex part of 211S and 251S 211B, 251B Top of the first convex part 212,252 Second convex part 212F, 252F 1st surface of the 2nd convex part 212S, 252S 2nd surface of 2nd convex part 212B, 252B Top of the second convex part 212R Light adjustment section 30 Photodetector 31 Element housing 32 Light receiving part 33 Covering materials 40 Substrate 50 Support part

Claims

1. A light source; a lens disposed above the light source; a light receiving element that is disposed at a position not intersecting an optical axis of the lens and receives external light via the lens; Equipped with the lens includes a light adjusting portion in a region overlapping with the light receiving element in a top view, the light adjusting portion adjusting an amount of external light received by the light receiving element; Light emitting device.

2. the lens has a plurality of convex portions arranged concentrically about the optical axis on a lower surface facing the light source, the plurality of convex portions include one or more first convex portions overlapping with the light source in a top view, and one or more second convex portions arranged outside the first convex portions and overlapping with the light receiving element, Each of the first convex portion and the second convex portion is A lowest apex; A first surface is disposed on an inner side of the lens when viewed from above; a second surface that is disposed outside the lens when viewed from above and that is continuous with the first surface via the apex; Equipped with The light emitting device according to claim 1 , wherein the light adjusting portion is disposed on the second surface.

3. The light emitting device according to claim 1 , wherein the light adjusting portion has a rough surface.

4. The light emitting device of claim 3 , wherein the rough surface is a textured surface.

5. the lens has a plurality of convex portions arranged concentrically about the optical axis on a lower surface facing the light source, the plurality of convex portions include one or more first convex portions overlapping with the light source in a top view, and one or more second convex portions arranged outside the first convex portions and overlapping with the light receiving element, Each of the first convex portion and the second convex portion is A lowest apex; A first surface is disposed on an inner side of the lens when viewed from above; a second surface that is disposed outside the lens when viewed from above and that is continuous with the first surface via the apex; Equipped with The light emitting device according to claim 1 , wherein the light adjusting portion is disposed on the first surface.

6. The light emitting device according to claim 5 , wherein the first surface of the second convex portion has, as the light adjusting portion, an inclined surface having a larger inclination angle with respect to the optical axis of the lens than the first surface of the first convex portion.

7. 7. The light emitting device according to claim 5, wherein a width of the second convex portion is greater than a width of the first convex portion in a radial direction of the lens.

8. The light emitting device according to claim 7 , wherein an apex of the second convex portion is located higher than an apex of the first convex portion in a height direction of the lens.

9. The light emitting device according to claim 2 , wherein the light adjusting portion is disposed continuously in an annular region of the lens centered on the optical axis.

10. The light emitting device according to claim 2 , wherein the light adjustment section is disposed outside the light source when viewed from above.

11. The light emitting device according to claim 1 , wherein the light source comprises a light emitting element and a wavelength conversion member disposed on the light emitting element.

Images