Light-emitting device

Abstract

To provide a light-emitting device that can reduce generation of a dark line due to emitted light while narrowing the angle of the emitted light.SOLUTION: The present invention includes: a substrate; a light-emitting element arranged in the upper surface of the substrate; a wavelength conversion member arranged on the light-emitting element, the wavelength conversion member having a bottom part over the upper surface of the light-emitting element and a plurality of protrusions extending upward from the bottom part and converting the wavelength of light emitted from the light-emitting element; and an optical member having a base part continuously extending over the wavelength conversion member and a plurality of lens parts in the region immediately above the protrusions of the upper surface of the base part. The protrusions include a narrowing part becoming narrower upward.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a light-emitting device using a light-emitting element.

Background Art

[0002] There is a light-emitting device that controls the emission color by passing light emitted from a light-emitting element through a phosphor. For example, Patent Document 1 discloses a light-emitting device including a semiconductor diode, a phosphor provided on the semiconductor diode and having an upper surface divided into a plurality of output sections by a reflector having a light reflection structure, and a plurality of extraction domes provided on each of the plurality of output sections.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] For example, when a light-emitting device such as that of Patent Document 1 is used as a light source for a vehicle lamp, the light emitted from the light-emitting device is preferably narrowed according to the subsequent optical system. Further, it is preferable that no dark line occurs when the emitted light of the light-emitting device is projected.

[0005] The present invention has been made in view of the above points, and an object thereof is to provide a light-emitting device capable of reducing the generation of dark lines due to the emitted light while achieving narrowing of the emitted light.

Means for Solving the Problems

[0006] The light-emitting device according to the present invention includes a substrate, a light-emitting element disposed on the upper surface of the substrate, a wavelength conversion member having a bottom portion disposed on the light-emitting element and covering the upper surface of the light-emitting element, and a plurality of protruding portions extending upward from the bottom portion, and configured to convert the wavelength of light emitted from the light-emitting element, and an optical member having a base portion continuously extending over the wavelength conversion member and a plurality of lens portions in a region directly above the plurality of protruding portions on the upper surface of the base portion, wherein the plurality of protruding portions include a narrowing portion having a shape narrowing upward.

Brief Description of Drawings

[0007]

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Embodiments for Carrying Out the Invention

[0008] Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. In the drawings, the same reference numerals are given to the same components, and the description of the overlapping components is omitted.

Example

[0009] The light-emitting device 10 of Example 1 of the present invention includes a light-emitting element 15 mounted on a support 11, a wavelength converter 17 joined to the light-emitting element 15 via an adhesive layer 34, and an optical member 23 mounted on the wavelength converter 17.

[0010] The configuration of the light-emitting device 10 according to Example 1 will be described with reference to FIGS. 1 to 3. FIG. 1 is a perspective view of the light-emitting device 10. In FIG. 1, the peripheral wall portion 13 and the second reflecting member 27 are shown as a one-dot chain line with a virtual line to avoid complication of the illustration.

[0011] The support 11 is an insulating member composed of a flat substrate 12 having a rectangular upper surface shape and a peripheral wall portion 13 having an opening 13O provided along the outer edge of the upper surface of the substrate 12. In other words, the support 11 is a member having a recess surrounded by the peripheral wall portion 13.

[0012] The substrate 12 is a member having a rectangular upper surface shape and mounting the light-emitting element 15 on the upper surface. In this embodiment, the substrate 12 is composed of an insulating substrate such as aluminum nitride (AlN), aluminum oxide (Al2O3), silicon nitride (Si3N4), etc., and a wiring pattern (not shown) formed on the substrate for supplying power to the light-emitting element 15.

[0013] The light-emitting element 15 is arranged on the substrate 12, has a light-emitting region on the upper surface, and is a light-emitting element having a rectangular upper surface shape. In this embodiment, the light-emitting element 15 is a light-emitting diode (LED) that emits blue light with a wavelength range of about 450 nm.

[0014] The wavelength converter 17 is arranged on the light-emitting element 15 and is a wavelength conversion member containing a phosphor for performing wavelength conversion of the light emitted from the light-emitting element 15. In this embodiment, the wavelength converter 17 is made of a ceramic plate (ceramic sintered body) formed by high-temperature firing of yttrium aluminum garnet (YAG) phosphor and Al2O3. The wavelength converter 17 is not limited to a ceramic sintered body, and a resin molded body in which phosphor particles are dispersed can also be used.

[0015] The wavelength converter 17 is composed of a flat plate-shaped first portion 18 and a plurality of second portions 19 that extend upward in a columnar shape from the first portion 18. In other words, the wavelength converter 17 has a plurality of protrusions that extend upward on the upper surface. The first portion 18 and the second portions 19 of the wavelength converter 17 are continuously formed and configured integrally as a series.

[0016] The first reflecting member 21 is a reflecting member filled between each of the plurality of second portions 19 on the first portion 18 of the wavelength converter 17. The first reflecting member 21 is composed of a translucent member in which light-scattering particles are dispersed. In this embodiment, the first reflecting member 21 is made of a resin material in which titanium oxide (TiO2) particles are contained in a silicone resin. By providing the first reflecting member 21, the light incident from the wavelength converter 17 to the first reflecting member 21 undergoes total reflection and scattered reflection at the interface and in the vicinity of the interface between the wavelength converter 17 and the first reflecting member 21. As a result, by providing the first reflecting member 21, the light emitted from the wavelength converter 17 is determined on the upper surface of each of the second portions 19.

[0017] The optical member 23 is composed of a light-transmissive member disposed on the wavelength converter 17, and is a member that controls the light distribution by receiving the light emitted from the wavelength converter 17. The optical member 23 can be composed of a resin such as silicone resin, or a light-transmissive material such as glass. The optical member 23 is composed of a flat plate-shaped base portion 24 disposed on the wavelength converter 17 and a plurality of lens portions 25 having a dome shape that protrude upward from the base portion 24.

[0018] The lens portion 25 guides and refracts the mixed light of the light emitted from the light-emitting element 15 and wavelength-converted by the wavelength converter 17 and the light emitted from the light-emitting element 15 and passing through the wavelength converter 17 as it is, and transmits the light to the outside of the lens portion 25. In other words, the upper surface of the optical member 23 serves as the light-emitting surface of the light-emitting device 10.

[0019] Each of the plurality of lens units 25 is disposed corresponding to each of the plurality of second portions 19 of the wavelength converter 17. In the present embodiment, the centers of each of the plurality of lens units 25 and the centers of each of the plurality of second portions 19 corresponding thereto are arranged so as to overlap in the vertical direction in the drawing.

[0020] As the lens unit 25, for example, a plano-convex spherical lens, a plano-convex aspherical lens, a cylindrical lens, or the like can be used. In the present embodiment, the lens unit 25 is composed of a hemispherical convex lens, and refracts and emits the light incident from the wavelength converter 17 toward the optical axis of each of the lens units 25.

[0021] The second reflecting member 27 is a reflecting member that continuously extends on the substrate 12 so as to cover the outer surfaces of each of the above-described light-emitting element 15, the first reflecting member 21, the wavelength converter 17, and the optical member 23. Similar to the first reflecting member 21, the second reflecting member 27 can be composed of a translucent member containing light-scattering particles. In the present embodiment, the second reflecting member 27 is made of a resin material in which titanium oxide (TiO2) particles are contained in a silicone resin.

[0022] FIG. 2 is a top view of the light-emitting device 10. The wavelength converter 17 is disposed substantially at the center of the opening 13O of the peripheral wall portion 13 of the support 11, and has a first portion 18 having a rectangular upper surface shape and a plurality of second portions 19 having a rectangular upper surface shape provided on the first portion 18.

[0023] In the present embodiment, the second portions 19 are arranged in a plurality of rows on the first portion 18. Specifically, the second portions 19 are arranged in 3×3 rows as shown in FIG. 2. In the present embodiment, the second portions 19 are arranged such that the second portions 19 adjacent to each other in the vertical and horizontal directions in the drawing are at equal intervals from each other.

[0024] The optical member 23 has a base portion 24 having a rectangular upper surface shape and a plurality of lens units 25 disposed on the base portion 24. In the present embodiment, the first portion 18 of the wavelength converter 17 and the base portion 24 of the optical member 23 are substantially the same in shape and size.

[0025] In this embodiment, the lens unit 25 is arranged in a plurality of rows on the base 24, similarly to the above-described second portion 19. Specifically, as shown in FIG. 2, the lens unit 25 is arranged in 3×3 rows. In this embodiment, the lens units 25 are arranged such that the lens units 25 adjacent to each other in the vertical and horizontal directions in the figure are at equal intervals from each other.

[0026] Each of the plurality of lens units 25 is arranged at the same position as each position of the second portion 19 of the wavelength converter 17 in a top view, and is arranged so as to surround the upper surface 19T of each of the second portions 19.

[0027] The second reflecting member 27 has a frame shape with a rectangular outer shape on the upper surface, and continuously extends along the outer edge of the first portion 18 and the outer edge of the base 24 so as to surround the first portion 18 and the base 24 within the opening 13O. In other words, the second reflecting member 27 is surrounded by the peripheral wall portion 13 of the support 11 along the outer edge of the second reflecting member 27. The second reflecting member 27 is filled between the peripheral wall portion 13 and the light emitting element 15, and between the peripheral wall portion 13 and the wavelength converter 17.

[0028] FIG. 3 is a cross-sectional view taken along line 3-3 of the top view of the light emitting device 10 in FIG. 2. As described above, the support 11 is composed of a flat substrate 12 and a peripheral wall portion 13 continuously arranged along the outer edge of the upper surface of the substrate 12. The substrate 12 has a mounting surface on which a light emitting element such as an LED can be mounted.

[0029] In this embodiment, the substrate 12 and the peripheral wall portion 13 are integrally formed. For example, the support 11 can be formed by laminating and firing a frame-shaped ceramic green sheet serving as the peripheral wall portion 13 on a flat ceramic green sheet serving as the substrate 12.

[0030] The light emitting element 15 is mounted at the center of the upper surface of the substrate 12, and includes a support substrate 31 and a semiconductor layer 32 arranged on the support substrate 31.

[0031] The support substrate 31 is a flat substrate with a rectangular upper surface shape arranged on the upper surface of the substrate 12. The support substrate 31 is made of a semiconductor material such as silicon (Si) or silicon carbide (SiC), for example.

[0032] The semiconductor layer 32 is a flat semiconductor layer with a rectangular upper surface shape formed on the upper surface of the support substrate 31. The semiconductor layer 32 is made of a nitride semiconductor such as gallium nitride (GaN), for example, and a p-type semiconductor layer, a light-emitting layer (active layer), and an n-type semiconductor layer are laminated in this order on the support substrate 31. In this embodiment, blue light having a wavelength of about 450 nm is emitted from the light-emitting layer of the semiconductor layer 32.

[0033] The semiconductor layer 32 is bonded to the support substrate 31 via a bonding layer (not shown) made of, for example, a conductive metal, and the upper surface serves as a light-emitting surface. That is, the light-emitting element 15 is a light-emitting element having a light-emitting surface on the upper surface. Note that the light-emitting element 15 can also have a configuration including a semiconductor layer 32 epitaxially grown directly on the support substrate 31.

[0034] In this embodiment, the semiconductor layer 32 is formed so as not to reach the outer edge of the support substrate 31. Therefore, the upper surface of the support substrate 31 is formed to be slightly larger than the upper surface of the semiconductor layer 32. In other words, when viewed from above, the upper surface of the support substrate 31 is exposed so as to surround the outer edge of the semiconductor layer 32.

[0035] A plurality of element electrodes (not shown) made of a conductive metal such as gold (Au) electrically connected to the n-type semiconductor layer or the p-type semiconductor layer, respectively, are formed on the light-emitting element 15, and the element electrodes are electrically connected to a wiring (not shown) made of a conductive metal formed on the substrate 12.

[0036] Also, the wiring on the substrate 12 is connected to a terminal (not shown) of an external power source, for example, via a conductive through-via or the like that penetrates the substrate 12 in the vertical direction. That is, the light-emitting device 10 is configured such that power can be supplied to the light-emitting element 15 from outside the light-emitting device 10.

[0037] The adhesive layer 34 is a resin adhesive layer formed to cover the upper surface and the side surfaces of the semiconductor layer 32 and to cover the upper surface of the support substrate 31 exposed outside the semiconductor layer 32. In the present embodiment, the adhesive layer 34 is made of a transparent silicone resin having translucency with respect to the light emitted from the light-emitting element 15.

[0038] The wavelength converter 17 has a first portion 18 which is a flat bottom joined onto the light-emitting element 15 via the adhesive layer 34, and a plurality of second portions 19 extending upward from the first portion 18. In the present embodiment, the first portion 18 and the second portions 19 are integrally formed.

[0039] The first portion 18 faces the semiconductor layer 32 of the light-emitting element 15 and has a bottom surface 18B covering the entire upper surface of the semiconductor layer 32. That is, the bottom surface 18B of the first portion 18 faces the light-emitting surface on the upper surface of the light-emitting element 15 and serves as a light-incident surface for the light emitted from the light-emitting element 15. In the present embodiment, the bottom surface 18B and the upper surface of the support substrate 31 are substantially the same in shape and size.

[0040] The second portion 19 is a protruding portion extending upward from the upper surface 18T of the first portion 18. The second portion 19 has a frustum-shaped narrowing portion 35 that narrows upward from the lower end of the second portion 19. In other words, the second portion 19 has side surfaces 35S that incline inward upward.

[0041] Thus, it is preferable that the second portion 19 has a narrowing portion 35. This is because, by the second portion 19 having the narrowing portion 35, that is, by providing inclined side surfaces, incident light from the light-emitting element 15 can be efficiently guided to the upper surface 19T of the second portion 19 as compared with the case where the second portion 19 does not have inclined side surfaces. The side surface 35S of the second portion 19 may be a flat surface or a curved surface, but when it is a curved surface, it is preferably a convex inclined curved surface inward of each of the second portions 19.

[0042] The second portion 19 has a columnar portion 36 having a quadrangular prism shape that extends vertically and upward with respect to the upper surface of the narrowing portion 35. In other words, the second portion 19 has a side surface 36S perpendicular to the upper surface of the narrowing portion 35. The bottom surface of the columnar portion 36 is substantially the same in shape and size as the upper surface of the narrowing portion 35.

[0043] The first portion 18 of the wavelength converter 17 receives light emitted from the light-emitting element 15 from its bottom surface and guides the light to the second portion 19. The light guided to the second portion 19 is guided to the upper surface of the second portion 19 and exits from the upper surface of the second portion 19. At this time, the light traveling on the side surface 35S of the second portion 19 is reflected inward and upward on the side surface 35S. Specifically, for example, the light traveling on the side surface 35S is reflected by the side surface 35S and travels toward the upper surface 19T of the second portion 19.

[0044] In this embodiment, the upper surface 19T of the second portion 19 is a light-emitting surface from which light incident from the bottom surface 18B of the first portion 18 exits. The light exiting from the upper surface 19T of the second portion 19 is incident on an optical member 23 disposed on the second portion 19. That is, the light emitted from the light-emitting element 15 is incident on the optical member 23 via the upper surfaces 19T of the plurality of second portions 19 of the wavelength converter 17.

[0045] As described above, in this embodiment, the wavelength converter 17 contains a YAG phosphor, and the YAG phosphor is excited by the blue light emitted from the light emitting element 15 to generate yellow fluorescence. The blue light emitted from the light emitting element 15 and incident on the wavelength converter 17 partly excites the YAG phosphor and partly travels upward without exciting the YAG phosphor.

[0046] From the upper surface 19T of the second portion 19, the blue light that has passed through the wavelength converter 17 and the yellow fluorescence generated by exciting the YAG phosphor are emitted. That is, white light in which blue light and yellow fluorescence are mixed is emitted from the upper surface 19T.

[0047] In this embodiment, the side surfaces 35S and 36S of the second portion 19 and the upper surface 18T of the first portion 18 are smoother than the upper surface 19T of the second portion 19. In other words, the upper surface 19T of the second portion 19 has a larger surface roughness than the side surfaces 35S and 36S and the upper surface 18T of the first portion 18.

[0048] Specifically, the upper surface 19T of the second portion 19 has the surface roughness as it is after firing of the ceramic sintered body, for example, has irregularities with a height of about 1 to 3 μm, and the ratio of the surface area to the cross-sectional area (the area when the target surface is a flat surface without irregularities) is 1.2 to 1.3. On the other hand, the side surfaces 35S and 36S of the second portion 19 and the upper surface 18T of the first portion 18 have a ratio of the surface area to the cross-sectional area of 1.0 to 1.1, which is a smaller value compared to the upper surface 19T of the second portion 19.

[0049] The above-mentioned smoothing is achieved, for example, by performing mirror processing on the side surfaces 35S and 36S of the second portion 19 and the upper surface 18T of the first portion 18 using a mirror processing device. That is, in this embodiment, the side surfaces 35S and 36S and the upper surface 18T are processed to be in a state close to a mirror surface.

[0050] In this embodiment, the side surfaces 35S and 36S of the second portion 19 and the upper surface 18T of the first portion 18 are smooth, so that the total reflection component of light can be increased at the interface between each of the side surfaces 35S, 36S and the upper surface 18T and the first reflecting member 21. This is because an interface is formed between each of the side surfaces 35S, 36S and the upper surface 18T and the light-transmissive member constituting the first reflecting member 21.

[0051] In particular, when the second portion 19 has the narrowing portion 35, the inclined side surface 35S can direct more of the total reflection component of light at the interface with the first reflecting member 21 toward the upper surface 19T than when the side surface is not inclined.

[0052] For example, part of the light incident on the wavelength converter 17 and traveling to the side surface 35S of the second portion 19 is totally reflected at the interface between the side surface 35S and the light-transmissive member constituting the first reflecting member 21, and travels toward the upper surface 19T of the second portion 19. Therefore, by increasing the total reflection component of light at the interface, the light traveling toward the upper surface 19T can be increased.

[0053] As described above, the upper surface 19T of the second portion 19 has a larger surface roughness than the side surfaces 35S and 36S and the upper surface 18T of the first portion 18. Since the upper surface 19T has a large surface roughness, total reflection is less likely to occur on its surface. Therefore, the light traveling to the upper surface 19T is less likely to be reflected toward the light-emitting element 15 side at the upper surface 19T, and is incident on the optical member 23 bonded on the upper surface 19T.

[0054] In this embodiment, the corner C at the lower end of the second portion 19 has a rounded shape. In other words, the portion where the second portion 19 rises from the upper surface 18T of the first portion 18 may be rounded.

[0055] For example, when the corner C is configured to be a right angle, when the light-emitting device 10 receives an external force or the like, stress is generated in the wavelength converter 17, and the stress concentrates on the corner C, and cracks or fractures may occur. According to the present embodiment, since the corner C has a rounded shape, it is difficult for stress to concentrate on the corner C, and the occurrence of cracks and fractures can be prevented.

[0056] As described above, the first reflecting member 21 is filled between each of the plurality of second portions 19 of the wavelength converter 17. That is, the bottom surface of the first reflecting member 21 is in contact with the upper surface 18T of the first portion 18 of the wavelength converter 17.

[0057] The upper surface of the first reflecting member 21 coincides with the upper surface 19T of the second portion 19. Further, the outer edge of the first reflecting member 21 coincides with the outer edge of the first portion 18. That is, the wavelength converter 17 filled with the first reflecting member 21 has a rectangular cross section.

[0058] Of the light emitted from the light-emitting element 15 and incident on the wavelength converter 17, for example, the first reflecting member 21 reflects the light traveling on the side surfaces 35S and 36S of the second portion 19 inward and upward at the interface between the side surfaces 35S and 36S and the first reflecting member 21. That is, the first reflecting member 21 reflects the light toward the wavelength converter 17 without allowing the light traveling from the wavelength converter 17 toward itself to be incident thereon.

[0059] As described above, the optical member 23 has a flat base portion 24 disposed on the wavelength converter 17 and a plurality of hemispherical lens portions 25 protruding upward from the base portion 24.

[0060] The base portion 24 has a bottom surface 24B that continuously extends across the upper surface 19T of the second portion 19 of the wavelength converter 17 and the upper surface of the first reflecting member 21 via a light-transmissive adhesive layer for optical members (not shown). In other words, the base portion 24 is a continuous portion that continuously extends across the upper surface 19T of the second portion 19 and the upper surface of the first reflecting member 21.

[0061] The base 24 propagates the light emitted from the upper surface 19T of the second portion 19. Specifically, the base 24 propagates the light emitted from the upper surface 19T of the second portion 19 in the left - right direction in the figure, spreads the light between each of the adjacent lens portions 25, that is, up to the upper surface 24T of the base 24, and condenses the light onto the lens portions 25.

[0062] Each of the lens portions 25 is disposed directly above each of the upper surfaces 19T of the second portion 19, and transmits the light that is emitted from the upper surface 19T of the second portion 19, travels through the base 24, and proceeds to the lens portions 25, outward. That is, the surface of the lens portion 25 is the light extraction surface of the light - emitting device 10. In this embodiment, the above - described white light is extracted from the light - emitting device 10.

[0063] As described above, the second reflecting member 27 is filled in the portion surrounded by the peripheral wall portion 13 on the substrate 12 of the support 11. Specifically, the inner surface of the second reflecting member 27 extends upward from the substrate 12 while covering the side surface of the light - emitting element 15 including the adhesive layer 34, the side surface of the wavelength - converting body 17 including the first reflecting member 21, and the side surface of the base 24 of the optical member 23.

[0064] The height from the upper surface of the substrate 12 to the upper surface 27T of the second reflecting member 27 (hereinafter referred to as the height of the upper surface 27T) is formed higher than the bottom surface 24B of the base 24 of the optical member 23. In this embodiment, the height of the upper surface 27T is formed substantially the same as the height of the base 24 of the optical member 23, that is, the height of the bottom surface of the lens portion 25.

[0065] For example, when the height of the upper surface 27T of the second reflecting member 27 is the same as the height of the bottom surface 24B of the base 24, when light is emitted from the light - emitting element 15, there is a risk that leakage light will be generated from the lower end of the base 24. Therefore, it is preferable that the height of the upper surface 27T is higher than the bottom surface 24B of the base 24.

[0066] The second reflecting member 27 reflects, at the interface between the side surface 18S and the second reflecting member 27, the light that has traveled from the light-emitting element 15, entered the wavelength converter 17, and traveled, for example, to the side surface 18S of the first portion 18, inward and upward.

[0067] Further, the second reflecting member 27 reflects, at the interface between the first reflecting member 21 and the second reflecting member 27, the light that has entered the first reflecting member 21 via the wavelength converter 17 and then traveled to the inner surface of the second reflecting member 27 without entering the wavelength converter 17, inward and upward.

[0068] In the light-emitting device 10 of the present embodiment, each of the light-emitting element 15, the wavelength converter 17, and the optical member 23 has an upper surface dimension of approximately 1 mm square. The wavelength converter 17 has a first portion 18 with a thickness of 0.05 mm, a second portion with a thickness of 0.17 mm, and an upper surface dimension of each of the second portions of 0.18 mm square. The optical member 23 has a base portion 24 with a thickness of 0.165 mm, a lens portion 25 with a height of 0.33 mm, and a diameter of the lens portion 25 of 0.33 mm.

[0069] [Narrowing of the emitted light from the light-emitting device] Here, the narrowing of the emitted light in the light-emitting device 10 will be described with reference to FIG. 4. FIG. 4 is an enlarged cross-sectional view of the light-emitting device 10 in FIG. 3. In FIG. 4, the light EL indicated by the arrow is the light emitted from the light-emitting element 15 and incident on the wavelength converter 17.

[0070] In the present embodiment, as described above, the second portion 19 of the wavelength converter 17 has a tapered narrowing portion 35 in the shape of a frustum of a square pyramid. In other words, the second portion 19 of the wavelength converter 17 has a side surface 35S that slopes inward. According to the present embodiment, when the light EL is incident on the second portion 19, the light EL is reflected upward by the side surface 35S, and thus the light is collected on the upper surface 19T.

[0071] That is, according to the present embodiment, the light emitted from the light-emitting element 15 and incident on the wavelength converter 17 is emitted from the wavelength converter 17 with its emission range restricted and is incident on the base 24 of the optical member 23. In other words, only the light emitted from a partial region on the upper surface of the wavelength converter 17 is incident on the base 24 of the optical member 23.

[0072] Also, in the present embodiment, as described above, the side surfaces 35S and 36S of the second portion 19 of the wavelength converter 17 and the upper surface 18T of the first portion 18 are smoother than the upper surface 19T. As a result, the components of the light incident on the side surfaces 35S and 36S of the second portion 19 and the upper surface 18T of the first portion 18 that are emitted outward from the wavelength converter 17 are reduced, and the components that are reflected to the first portion 18 or the second portion 19 are increased.

[0073] In particular, the light reflected by the side surface 35S of the second portion 19 travels toward the upper surface 19T. That is, when light EL is incident on the second portion 19, the light EL is reflected upward by the side surface 35S, so that the light is collected on the upper surface 19T. Therefore, the light emitted from the light-emitting element 15 and incident on the wavelength converter 17 is emitted from the wavelength converter 17 with its emission range restricted and is incident on the base 24 of the optical member 23.

[0074] Thus, according to the present embodiment, due to the second portion 19 of the wavelength converter 17 having the constricted portion 35, or due to the side surfaces 35S and 36S of the second portion 19 being smoothed compared to the upper surface 19T, the light emitted from the light-emitting element 15 can be condensed on the upper surface 19T and incident on the optical member 23.

[0075] For example, in the case of a light-emitting device of a comparative example in which a simple flat plate-shaped wavelength converter is used instead of the wavelength converter 17 having the second portion 19, the light extracted from the light-emitting device of the comparative example had a wide light distribution angle, as shown in FIG. 8 described later. Specifically, it was confirmed that the light emitted in the above case exhibits characteristics close to Lambertian light distribution.

[0076] On the other hand, according to this embodiment, since the wavelength converter 17 has the above-described configuration, as shown in FIG. 7 described later, it was confirmed that light narrower than Lambertian distribution can be extracted from the light-emitting device 10. In other words, the light distribution angle of the light emitted from the light-emitting device 10 can be controlled.

[0077] In addition, the thickness of the second portion 19 of the wavelength converter 17 in the vertical direction in the drawing is preferably 20% or more and 70% or less with respect to the total thickness of the wavelength converter 17. This is because when the thickness of the second portion 19 is less than 20% of the total thickness of the wavelength converter 17, sufficient narrow-angle performance of the emitted light cannot be obtained, and when it exceeds 70%, the thickness of the first portion 18 becomes extremely small, so that light cannot be sufficiently propagated from the first portion 18 to the second portion 19.

[0078] In FIG. 4, the width W1 of the upper surface 19T of the second portion 19 is preferably 80% or less, particularly preferably 50% to 60%, with respect to the width W2 of the bottom surface of the lens portion 25. This is because when the width W1 of the upper surface 19T exceeds 80% of the width W2 of the bottom surface of the lens portion 25, sufficient narrow-angle performance of the emitted light cannot be obtained, and when it is less than 50%, the light extraction efficiency decreases because the light emission range is narrowed more than necessary.

[0079] In addition, the concentration of the TiO2 particles contained in the first reflecting member 21 and the second reflecting member 27 is preferably 25 wt% or more in order to achieve sufficient light scattering, and particularly preferably 60 wt% or more in order to achieve high light scattering.

[0080] [Elimination of dark lines during projection of emitted light] Next, the elimination of dark lines during projection of the emitted light from the light-emitting device 10 will be described. In FIG. 4, the angle formed by the center of the upper surface 19T of the second portion 19 and both ends of the bottom surface of the lens portion 25 is defined as the angle θ. The angle θ becomes smaller as the thickness of the base portion 24 in the vertical direction in the drawing increases.

[0081] When projecting the emitted light from the light-emitting device 10, the smaller the angle θ is, that is, the larger the thickness of the base 24 is, the more the light spreads over the entire base 24, and the dark line during the projection of the emitted light is eliminated. However, when the angle θ becomes smaller, the light propagating in the base 24 increases more than necessary, and the light traveling toward the upper surface 19T of the second portion 19 increases.

[0082] When the light traveling from the base 24 side toward the upper surface 19T increases more than necessary, the YAG phosphor in the wavelength converter 17 may be excited by the light, and a large amount of yellowish light may be emitted. That is, when the angle θ becomes smaller, the color temperature of the emitted light may decrease. Also, when the angle θ becomes smaller, the light propagating in the end face direction of the base 24 increases, which may cause leakage light from the end of the base 24.

[0083] Therefore, the angle θ is preferably in the range of 80° to 130°, particularly preferably in the range of 90° to 120°, as a range that reduces the occurrence of dark lines during the projection of the emitted light from the light-emitting device 10 and does not affect the color temperature.

[0084] According to this embodiment, by configuring the wavelength converter 17 and the optical member 23 as described above, it is possible to achieve narrowing of the emitted light from the light-emitting device 10 and reduce the dark line during the projection of the emitted light.

[0085] In this embodiment, the second portion 19 of the wavelength converter 17 has a narrowing portion 35 that narrows upward from the first portion 18. However, the formation position of the narrowing portion 35 is not limited to this. For example, a configuration in which the narrowing portion 35 is formed on the columnar portion 36 may be used.

[0086] In this embodiment, the side surfaces 35S and 36S of the second part 19 and the upper surface of the first part 18 are smoother than the upper surface 19T of the second part 19. However, a process may be performed to increase the roughness of the upper surface 19T. For example, by performing mechanical processing or chemical processing on the upper surface 19T, a structure may be formed that facilitates light emission from the upper surface 19T.

[0087] Also, in this embodiment, the corner C at the lower end of the second part 19 has a rounded shape. However, the corner C does not necessarily have to be rounded.

[0088] In this embodiment, the wavelength converter 17 only needs to be able to collect light on the upper surface 19T of the second part 19 with the above-described configuration, and the first reflecting member 21 does not have to be filled between each of the second parts 19. For example, a gas such as air may be filled between each of the second parts 19 instead of the first reflecting member 21. Also, for example, a light-transmitting filling member that does not contain TiO2 may be arranged instead of the first reflecting member 21.

[0089] In this embodiment, each of the plurality of lens parts 25 of the optical member 23 is configured to be separated from each other by the upper surface 24T of the base part 24, but it is not limited to this. That is, the lens parts 25 may be arranged to be in contact with each other on the base part 24.

[0090] In this modification, the second part 19 of the wavelength converter 17 and the lens parts 25 of the optical member 23 are arranged in a 3×3 array, but the arrangement mode is not limited to this. For example, the second part 19 and the lens parts 25 may be arranged in a staggered manner between adjacent columns. Also, for example, the second part 19 and the lens parts 25 may be arranged in a mode of only one column.

[0091] Note that each dimension of the light-emitting device 10 is not limited to the above dimensions as long as any of the above-described effects such as the narrow-angle effect and dark line elimination can be obtained.

[0092] [Verification Experiments] The following describes in detail various verification experiments conducted on the light-emitting device 10 of the present invention, including comparisons with a light-emitting device as a comparative example and verification results when parameters of constituent members are changed.

[0093] [Regarding the Directivity Characteristics of Emitted Light] The directivity characteristics of the light emitted from the light-emitting device 10 of the present invention will be described below while comparing the light-emitting device 10 of Example 1 with a light-emitting device as a comparative example.

[0094] FIG. 5 is a cross-sectional view of a light-emitting device 50 (Comparative Example 1) as a comparative example of the light-emitting device 10. The light-emitting device 50 differs from the light-emitting device 10 in that it does not have the optical member 23, and has the same configuration as the light-emitting device 10 in other respects.

[0095] FIG. 6 is a cross-sectional view of a light-emitting device 60 (Comparative Example 2) as a comparative example of the light-emitting device 10. The light-emitting device 60 differs from the light-emitting device 10 in that it uses a simple flat wavelength converter 38 instead of the wavelength converter 17, and has the same configuration as the light-emitting device 10 in other respects.

[0096] FIG. 7 is a diagram showing the directivity characteristics (hereinafter simply referred to as directivity characteristics) in the x direction (the left-right direction in FIG. 3) and the y direction (the depth direction in FIG. 3) of the light emitted from the light-emitting device 10 of the present invention. From FIG. 7, the light emitted from the light-emitting device 10 showed a half-value angle (the angle at which the light flux becomes 50% relative to the case where the light flux on the central axis of 0° is 100%) of 82°, and the light flux ratio within ±30° was about 36%.

[0097] FIG. 8 is a diagram showing the directivity characteristics of the light emitted from the light-emitting device 50 of Comparative Example 1. From FIG. 8, the light emitted from the light-emitting device 50 showed characteristics close to Lambertian distribution with a half-value angle of about 120°. Also, the light flux ratio within ±30° of the light emitted from the light-emitting device 50 was about 26%.

[0098] FIG. 9 is a diagram showing the directivity characteristics of the light emitted from the light-emitting device 60 of Comparative Example 2. From FIG. 8, the light emitted from the light-emitting device 60 showed characteristics similar to Lambertian light distribution with a half-value angle of about 120°, similar to the light-emitting device 50. Also, the light flux ratio within ±30° of the light emitted from the light-emitting device 60 was about 26%, similar to the light-emitting device 50.

[0099] From the above experimental results, it was found that the light emitted from the light-emitting device 10 of the present invention does not have a light distribution close to the Lambertian light distribution confirmed in the light-emitting device 50 of Comparative Example 1 and the light-emitting device 60 of Comparative Example 2, but has higher directivity. Also, according to the light-emitting device 10 of the present invention, compared with the light-emitting device 50 of Comparative Example 1 and the light-emitting device 60 of Comparative Example 2, in the emitted light, the angular range where the light flux becomes 50% relative to the central axis 0° can be narrowed. In other words, narrowing of the emitted light can be achieved.

[0100] [Regarding the luminance distribution of the light-emitting surface] Next, the luminance distribution of the surface of the optical member 23, which is the light-emitting surface of the light emitted from the light-emitting device 10 of the present invention, will be described below while comparing it with the light-emitting device 50 of Comparative Example 1 and the light-emitting device 60 of Comparative Example 2 described above.

[0101] Here, when the luminance at the center of each of the light-emitting device 10, the light-emitting device 50, and the light-emitting device 60 in a top view, or the center of the light-emitting surface, is taken as the origin, that is, the maximum luminance (100%), the luminance when moving in the horizontal direction (the left-right direction in FIG. 3) from the origin was measured. Specifically, the origin was the center of the upper surface of the lens portion 25 at the center of the light-emitting surface.

[0102] FIGS. 14 and 15 are diagrams showing the luminance distribution of the light emitted from the light-emitting device 10 of the present invention. In FIGS. 14 and 15, the region where the luminance drops (the broken line in the figure) corresponds to the region of the upper surface 24T of the base portion 24 of the optical member 23, that is, the region between each of the lens portions 25 (hereinafter referred to as the inter-lens region). The luminance in the inter-lens region of the light emitted from the light-emitting device 10 was able to obtain 20% or more with respect to the maximum luminance.

[0103] FIG. 10 is a diagram showing the luminance distribution of the light emitted from the light-emitting device 50 of Comparative Example 1. From FIG. 10, the luminance in the region between adjacent upper surfaces 19T of the light emitted from the light-emitting device 50 was about 5% of the maximum luminance.

[0104] FIG. 11 is a diagram showing the luminance distribution of the light emitted from the light-emitting device 60 of Comparative Example 2. From FIG. 11, the luminance in the region between the lenses of the light emitted from the light-emitting device 60 was about 18% of the maximum luminance.

[0105] From the above experimental results, it was found that the light-emitting surface of the light-emitting device 10 of the present invention has a higher luminance distribution in the region between the lenses than the luminance distributions in the light-emitting devices 50 of Comparative Example 1 and 60 of Comparative Example 2. That is, the light-emitting device 10 can reduce the generation of dark lines during projection of the emitted light.

[0106] In addition, the non-light-emitting portion around the optical member 23, that is, the leakage light (hereinafter referred to as glare) emitted from the second reflecting member 27 was also evaluated.

[0107] As a result, as shown in FIGS. 10 and 11, in the light-emitting device 50 of Comparative Example 1 and the light-emitting device 60 of Comparative Example 2, the luminance at a predetermined glare evaluation position was confirmed to be 1% or more with respect to the maximum luminance. On the other hand, as shown in FIGS. 14 and 15, according to the light-emitting device 10 of the present invention, the luminance at a predetermined glare evaluation position could be made 0.5% or less with respect to the maximum luminance.

[0108] That is, it was confirmed that the light-emitting device 10 of the present invention can suppress stray light to the second reflecting member as compared with the light-emitting device 50 of Comparative Example 1 and the light-emitting device 60 of Comparative Example 2.

[0109] [Regarding the directivity characteristics of the emitted light when changing the thickness of the base of the optical member] The directivity characteristics of the light emitted from the light-emitting device 10 of the present invention when the thickness of the base 24 of the optical member 23 is changed will be described below.

[0110] In this verification, an optical member 23 having a base 24 with a thickness of 80 μm and an optical member 23 having a base 24 with a thickness of 160 μm were used. When the thickness of the base 24 of the optical member 23 used in this verification is expressed by the above-mentioned angle θ (see Fig. 4), when the thickness of the base 24 is 80 μm, the angle θ is 128.3°, and when the thickness of the base 24 is 160 μm, the angle θ is 91.8°.

[0111] Fig. 12 is a diagram showing the directivity characteristics of the light emitted from the light-emitting device 10 when the thickness of the base 24 is 80 μm. From Fig. 12, the light emitted from the light-emitting device 10 showed a half-value angle of about 70°.

[0112] Fig. 13 is a diagram showing the directivity characteristics of the light emitted from the light-emitting device 10 when the thickness of the base 24 is 160 μm. From Fig. 13, the light emitted from the light-emitting device 10 showed a half-value angle of about 50°.

[0113] From the above experimental results, according to the light-emitting device 10 of the present invention, when the thickness of the base 24 is 160 μm, the angular range in which the light flux becomes 50% relative to the central axis 0° in the emitted light can be made narrower than when the thickness of the base 24 is 80 μm. That is, the light-emitting device 10 can achieve a greater narrowing of the emitted light when the thickness of the base 24 is 160 μm.

[0114] [Regarding the luminance distribution of the light-emitting surface when changing the thickness of the base of the optical member] Next, the luminance distribution of the surface of the optical member 23, which is the light-emitting surface of the light emitted from the light-emitting device 10 of the present invention, when the thickness of the base 24 of the optical member 23 is changed will be described.

[0115] Also in this experiment, when the luminance at the center of each of the light-emitting device 10 and the light-emitting device 50 in a top view or the center of the light-emitting surface was taken as the origin, that is, the highest luminance, the luminance when moving in the horizontal direction from the origin was measured.

[0116] FIG. 14 is a diagram showing the luminance distribution of the light emitted from the light-emitting device 10 when the thickness of the base 24 is 80 μm. From FIG. 14, the luminance in the region between the lenses of the light emitted from the light-emitting device 10 was about 20% of the maximum luminance.

[0117] FIG. 15 is a diagram showing the luminance distribution of the light emitted from the light-emitting device 10 when the thickness of the base 24 is 160 μm. From FIG. 15, the luminance in the region between the lenses of the light emitted from the light-emitting device 10 was about 27% of the maximum luminance.

[0118] From the above experimental results, it was found that the light-emitting surface of the light-emitting device 10 of the present invention has a higher luminance distribution in the region between the lenses when the thickness of the base 24 is 160 μm than when the thickness of the base 24 is 80 μm. That is, the light-emitting device 10 can further reduce the generation of dark lines during the projection of the emitted light when the thickness of the base 24 is 160 μm. In other words, it was found that the smaller the above-described angle θ, the higher the luminance of the light in the region between the lenses.

[0119] [Regarding the half-value angle in the directivity characteristics of the emitted light when changing the angle θ] When the thickness of the base 24 of the optical member 23 is represented by the above-described angle θ (see FIG. 4), the half-value angle in the directivity characteristics of the light emitted from the light-emitting device 10 when changing the angle θ will be described.

[0120] FIG. 16 is a graph showing the correlation between the angle θ and the half-value angle in the directivity characteristics of the light emitted from the light-emitting device 10. From the graph, the half-value angle showed about 120° when the angle θ was about 180°, and showed about 60° when the angle θ was about 80°.

[0121] From the above results, it was found that in the light-emitting device 10, the half-value angle shows a smaller value as the angle θ becomes smaller, and the narrow-angle performance becomes higher. Also, it was found that the directivity characteristics of the emitted light show characteristics closer to Lambertian distribution as the angle θ becomes larger.

[0122] [Beam Ratio in the Directivity Characteristics of the Emitted Light when the Angle θ is Changed] Subsequently, when the thickness of the base 24 of the optical member 23 is represented by the above-described angle θ, the beam ratio within ±30° in the directivity characteristics of the emitted light from the light-emitting device 10 when the angle θ is changed will be described.

[0123] FIG. 17 is a graph showing the correlation between the angle θ and the beam ratio within ±30° in the directivity characteristics of the emitted light from the light-emitting device 10. From this graph, the beam ratio within ±30° showed approximately 26% when the angle θ was about 180°, and showed 33 - 37% when the angle θ was in the range of about 80° to 150°.

[0124] From the above results, it was found that in the light-emitting device 10, the beam ratio within ±30° in the range where the angle θ is from about 80° to 150° is higher than the beam ratio within ±30° when the angle θ is about 180°.

[0125] [Chromaticity of the Emitted Light when the Angle θ is Changed] Subsequently, when the thickness of the base 24 of the optical member 23 is represented by the above-described angle θ, the chromaticity of the emitted light when the angle θ is changed will be described.

[0126] FIG. 18 is a graph showing the correlation between the angle θ and the chromaticity of the emitted light. In this graph, the closer the chromaticity value Cx and the chromaticity value Cy are to 0.33 (dashed line in the figure) together, the more it indicates that the emitted light is white.

[0127] From FIG. 18, the chromaticity value Cx and the chromaticity value Cy showed approximately 0.3 respectively when the angle θ was about 180°. Also, the chromaticity value Cx showed approximately 0.31 - 0.335 when the angle θ was in the range of about 80° to 120°. Also, the chromaticity value Cy showed approximately 0.31 - 0.325 when the angle θ was in the range of about 80° to 120°.

[0128] From the above results, it was found that in the light-emitting device 10, the chromaticity in the range where the angle θ is from about 80° to 120° is higher than the chromaticity when the angle θ is about 180°. That is, in the light-emitting device 10, it was found that the emitted light in the range where the angle θ is from about 80° to 120° is closer to white than the emitted light when the angle θ is about 180°.

[0129] [Output of emitted light when changing the surface roughness of the wavelength converter] The output of the emitted light from the light-emitting device 10 when changing the surface roughness on the side surfaces 35S and 36S of the second portion 19 and the upper surface 18T of the first portion 18 of the wavelength converter 17 will be described.

[0130] FIG. 19 is a graph showing the output of the emitted light from the light-emitting device 10 (output of the maximum luminance of white light / output of blue light from the light-emitting element) when changing the ratio of the surface area to the cross-sectional area on the side surfaces 35S and 36S of the second portion 19 and the upper surface 18T of the first portion 18 of the wavelength converter 17.

[0131] From the graph, the output of the emitted light was improved by about 2.6% when the ratio of the surface area to the cross-sectional area was about 1.10 compared to when the ratio was about 1.18. Also, the output of the emitted light was improved by about 4.0% when the ratio of the surface area to the cross-sectional area was about 1.07 compared to when the ratio was about 1.18.

[0132] From the above results, it was found that in the light-emitting device 10, the output of the emitted light increases as the ratio of the surface area to the cross-sectional area described above decreases. That is, the output of the emitted light from the light-emitting device 10 can be improved by reducing the surface roughness on the side surfaces 35S and 36S of the second portion 19 and the upper surface 18T of the first portion 18.

[0133] [Method for manufacturing a light-emitting device] Hereinafter, the method for manufacturing the light-emitting device 10 in this embodiment will be described.

[0134] First, dicing is performed on a ceramic plate (corresponding to the wavelength converter 17) formed by high-temperature firing of a YAG phosphor and Al₂O₃, and a plurality of second portions 19 are formed on the above-described first portion 18 (Step 1). At this time, by using a dicing blade having a narrow shape and a columnar shape, the second portion 19 having a narrow portion 35 and a columnar portion 36 can be formed.

[0135] Next, a smoothing process is performed on the side surfaces 35S and 36S of the second portion 19 and the upper surface of the first portion 18 (Step 2). Specifically, for example, the surfaces are processed into smooth mirror surfaces by spraying an abrasive using a mirror finishing device on the side surfaces 35S and 36S of the second portion 19 and the upper surface of the first portion 18.

[0136] Next, a resin material (corresponding to the first reflecting member 21) in which TiO₂ is dispersed in a silicone resin is filled into the region between the plurality of second portions 19 using a dispenser or the like and cured (Step 3). At this time, the resin material is flattened so that the upper surface of the resin material coincides with the upper surface of the second portion 19. After curing the resin material, by dicing with a dicing blade, the wavelength converter 17 filled with the first reflecting member 21 can be obtained.

[0137] Next, a light-emitting element 15 mounted on a substrate 12 of a support 11 via a gold-tin (AuSn) paste is prepared. Then, the wavelength converter 17 filled with the first reflecting member 21 produced in Step 3 is joined to the upper surface of the light-emitting element 15 using an adhesive such as a silicone resin (Step 4).

[0138] Next, an optical member 23 is joined to the wavelength converter 17 filled with the first reflecting member 21 using an adhesive such as a silicone resin (Step 5). Specifically, the optical member 23 is joined so that each of the lens portions 25 of the optical member 23 is positioned directly above each of the second portions 19 of the wavelength converter 17.

[0139] Finally, a resin material in which TiO2 is dispersed in a silicone resin (corresponding to the second reflecting member 27) is filled upward from the lower end of the light-emitting element 15 (step 6). Specifically, the resin material is filled until the height of the resin material coincides with the upper surface of the base portion 24 of the optical member 23, and then cured.

[0140] Through the above steps, the light-emitting device 10 including the above-described light-emitting element 15, wavelength converter 17, first reflecting member 21, optical member 23, and second reflecting member 27 can be manufactured.

[0141] [Modification Example 1 of Example 1] Hereinafter, a modification example of Example 1 will be described with reference to FIGS. 20 to 24.

[0142] FIG. 20 is a cross-sectional view of a light-emitting device 110 according to Modification Example 1. The light-emitting device 110 has a configuration similar to that of the light-emitting device 10 except that the shape of the wavelength converter is different from that of the light-emitting device 10.

[0143] Similar to the above-described light-emitting device 10, the light-emitting device 110 includes a light-emitting element 15 disposed substantially at the center of an opening 13O formed by the peripheral wall portion 13 of the support 11, a wavelength converter 41 joined to the light-emitting element 15, and an optical member 23 disposed on the wavelength converter 41.

[0144] In this modification example, the wavelength converter 41 has a first portion 18 and a plurality of second portions 42 extending upward from the first portion 18. The second portion 42 is a frustum-shaped portion having a shape that narrows upward. That is, the second portion 42 has a side surface 42S that inclines inward.

[0145] The second portion 42 corresponds to the narrowed portion 35 of the second portion 19 in the light-emitting device 10 of Example 1. That is, the wavelength converter 41 can condense the light incident from the light-emitting element 15 and traveling inside the wavelength converter 41 onto the upper surface 42T of the second portion 42 by reflecting the light on the side surface 42S of the second portion 42.

[0146] In this modified example, the second portion 42 has only a side surface 42S that inclines inward. That is, since all the side surfaces of the second portion 19 in the first embodiment incline inward, as compared with the light-emitting device 10, it becomes a configuration that is more likely to reflect light, and light can be collected on the upper surface 42T of the second portion 42.

[0147] Thus, even when the shape of the second portion 42 of the wavelength converter 41 is changed, narrowing of the emitted light from the light-emitting device 110 and generation of dark lines during projection of the emitted light can be reduced.

[0148] [Output of emitted light when changing the inclination angle of the second portion] Here, with reference to FIG. 20, the light output of the emitted light with respect to the inclination angle of the second portion 42 of the wavelength converter 41 will be described. In FIG. 20, the inclination angle of the second portion 42 with respect to the upper surface 18T of the first portion 18 is shown as an angle α.

[0149] It was confirmed that the output of the emitted light from the light-emitting device 10 increases as the above-described angle α decreases. Specifically, compared with a light-emitting device in which the angle α is 90°, that is, the second portion 42 is formed perpendicular to the upper surface 18T, when the angle α is 75°, the light output is improved by about 0.9%, when the angle α is 60°, the light output is improved by about 1.4%, and when the angle α is 45°, the light output is improved by about 1.9%.

[0150] Note that the configuration for forming the second portion having the angle α is also applicable in the first embodiment. That is, in the first embodiment, by reducing the inclination angle of the second portion 19 of the light-emitting device 10 with respect to the upper surface 18T of the first portion 18, an effect of improving the output of the emitted light can be obtained.

[0151] [Modified Example 2 of the First Embodiment] FIG. 21 is a cross-sectional view of a light-emitting device 120 according to the modified example 2. The light-emitting device 120 has a configuration similar to that of the light-emitting device 10 except that the shape of the wavelength converter is different from that of the light-emitting device 10.

[0152] The light-emitting device 120, similar to the above-described light-emitting device 10, has a configuration including a light-emitting element 15 disposed substantially at the center of an opening 13O formed by a peripheral wall portion 13 of a support 11, a wavelength converter 44 bonded to the light-emitting element 15, and an optical member 23 disposed on the wavelength converter 44.

[0153] In this modification, the wavelength converter 44 has a first portion 18 and a plurality of second portions 45 extending upward from the first portion 18. The second portion 45 has a narrowing portion 46 having a shape that narrows upward and a columnar portion 47 having a square column shape that is perpendicular to and extends upward with respect to the upper surface of the narrowing portion 46.

[0154] In this modification, the narrowing portion 46 of the second portion 45 has a curved surface from the lower end to the upper end. That is, the second portion 45 has a side surface 46S with a curved cross-section. In this modification, adjacent second portions 45 are configured such that their side surfaces 46S face each other, forming a U-shaped cross-section.

[0155] According to this modification, since the side surface 46S has a curved surface, it is easier to reflect the light incident on the wavelength converter 44 upward compared to the case where the upper surface 18T has a flat shape. That is, the wavelength converter 44 can condense the light incident from the light-emitting element 15 and traveling inside the wavelength converter 44 onto the upper surface 45T of the second portion 45 more than in Example 1 by reflecting it on the side surface 46S of the second portion 45.

[0156] Further, in the light-emitting device 120, since the side surface 46S of the second portion 45 has a curved surface shape, an effect similar to the effect of the shape of the corner portion C shown in Example 1 can be obtained. That is, according to this modification, when the light-emitting device 120 receives an external force or the like, it is possible to prevent stress from concentrating on the portion where the second portion 45 rises from the upper surface 18T of the first portion 18, resulting in cracks or fractures.

[0157] Thus, even when the shape of the second portion 45 of the wavelength converter 44 is changed, it is possible to reduce the narrowing of the emitted light from the light-emitting device 120 and the generation of dark lines when the emitted light is projected.

[0158] [Modification Example 3 of Example 1] FIG. 22 is a cross-sectional view of a light-emitting device 130 according to Modification Example 3. The light-emitting device 130 has a configuration similar to that of the light-emitting device 10 except that the shape of the wavelength converter is different from that of the light-emitting device 10.

[0159] Similar to the above-described light-emitting device 10, the light-emitting device 130 includes a light-emitting element 15 disposed substantially at the center of an opening 13O formed by the peripheral wall portion 13 of the support 11, a wavelength converter 48 joined to the light-emitting element 15, and an optical member 23 disposed on the wavelength converter 48.

[0160] In this modification, the wavelength converter 48 has a first portion 18 and a plurality of second portions 49 extending upward from the first portion 18. The second portion 49 is a columnar portion extending perpendicularly to the first portion 18. That is, the second portion 42 has a side surface 49S perpendicular to the first portion 18.

[0161] In this modification, the corner C at the lower end of the second portion 49 has a rounded shape as in Example 1. In other words, the portion where the second portion 49 rises from the upper surface 18T of the first portion 18 has a curved surface shape. With this configuration, for example, as in Example 1, it is possible to prevent stress from concentrating on the corner C and causing cracks or fractures when the light-emitting device 10 receives an external force or the like.

[0162] Also in this modification, the wavelength converter 48 can condense the light incident from the light-emitting element 15 and traveling inside the wavelength converter 48 onto the upper surface 49T of the second portion 49 by reflecting the light on the side surface 49S of the second portion 49.

[0163] Thus, even when the shape of the second portion 49 of the wavelength converter 48 is changed, it is possible to reduce the narrowing of the emitted light from the light-emitting device 130 and the generation of dark lines when the emitted light is projected.

[0164] [Modification Example 4 of Example 1] FIG. 23 is a top view of a light-emitting device 140 according to Modification Example 4. The light-emitting device 140 has a configuration different from that of the light-emitting device 10 in the shape of the members constituting the light-emitting device 140, and is otherwise the same as the light-emitting device 10.

[0165] Specifically, as shown in FIG. 23, the wavelength converter 17 of the light-emitting device 140 has a first portion 18 having a rectangular upper surface shape and a plurality of second portions 19 having a rectangular upper surface shape arranged on the first portion. Further, the optical member 23 of the light-emitting device 140 has a base portion 24 having a rectangular upper surface shape on the wavelength converter 17 and a lens portion 25 having an oval upper surface shape arranged on the base portion.

[0166] Thus, even when the shape of the members constituting the light-emitting device 140 is changed, it is possible to reduce the narrowing of the emitted light from the light-emitting device 140 and the generation of dark lines when the emitted light is projected. That is, according to this modification example, it is possible to reduce the generation of dark lines due to the emitted light while achieving narrowing of the emitted light regardless of the shape of the light-emitting device.

[0167] [Modification Example 5 of Example 1] FIG. 24 is a perspective view of a light-emitting device 150 according to Modification Example 5. The light-emitting device 150 has a configuration different from that of the light-emitting device 10 in the shape of the optical member, and is otherwise the same as the light-emitting device 10. In FIG. 24, as in Example 1, in order to avoid complication of the drawing, the peripheral wall portion 13 and the second reflecting member 27 are shown as phantom lines by a one-dot chain line.

[0168] The light-emitting device 150 includes a light-emitting element 15 arranged substantially at the center of an opening 13O formed by the peripheral wall portion 13 of the support 11, a wavelength converter 17 joined to the light-emitting element 15, and an optical member 51 arranged on the wavelength converter 17.

[0169] In this modification, the optical member 51 has a base portion 52 and a plurality of lens portions 53 that project upward on the base portion 52 and extend along each of the three columns. In other words, each of the plurality of lens portions 53 has a club-shaped form.

[0170] Thus, even when the configuration of the lens portion 53 of the optical member 51 is changed, it is possible to reduce the dark lines at the time of projection of the emitted light while achieving narrowing of the emitted light from the light-emitting device 150, as in the first embodiment.

[0171] Further, according to this modification, since the optical member 51 has a plurality of lens portions 53 having a club-shaped form, alignment becomes easier when the optical member 51 is bonded onto the wavelength converter 17 as compared with the optical member 23 in the first embodiment.

[0172] The shape or dimensions of each part in the light-emitting device according to the present invention are not limited to those in the above-described embodiments and modifications, and can be appropriately changed according to the application and the like.

Explanation of Reference Numerals

[0173] 10, 50, 60, 110, 120, 130, 140, 150 Light-emitting device 11 Support 12 Substrate 13 Peripheral wall portion 15 Light-emitting element 17, 38, 41, 44, 48 Wavelength converter 18 First portion 19, 42, 45, 49 Second portion 21 First reflecting member 23, 51 Optical member 24, 52 Base portion 25, 53 Lens portion 27 Second reflecting member 31 Support substrate 32 Semiconductor layer 34 Adhesive layer 35, 46 Narrow portion 36 and 47 columnar portions

Claims

1. a substrate, a light-emitting element disposed on the upper surface of the substrate, a wavelength conversion member bonded to the upper surface of the light-emitting element and having a bottom portion covering the upper surface of the light-emitting element and a plurality of protruding portions extending upward from the bottom portion, the wavelength conversion member converting the wavelength of light emitted from the light-emitting element, an optical member having a base portion continuously extending over the wavelength conversion member and a plurality of lens portions in a region directly above the plurality of protruding portions on the upper surface of the base portion, the plurality of protruding portions include a narrowed portion having a shape narrowed upward, each of the plurality of protruding portions is provided at a position overlapping the light-emitting element in a top view of the light-emitting element, a light-emitting device, characterized in that a first reflecting member that reflects light emitted from the light-emitting element is filled in a region between the plurality of protruding portions.

2. A substrate, a light-emitting element disposed on the upper surface of the substrate, a wavelength conversion member bonded to the upper surface of the light-emitting element and having a bottom portion covering the upper surface of the light-emitting element and a plurality of protruding portions extending upward from the bottom portion, the wavelength conversion member converting the wavelength of light emitted from the light-emitting element, an optical member having a base portion continuously extending over the wavelength conversion member and a plurality of lens portions in a region directly above the plurality of protruding portions on the upper surface of the base portion, the plurality of protruding portions include a narrowed portion having a shape narrowed upward, each of the plurality of protruding portions is provided at a position overlapping the light-emitting element in a top view of the light-emitting element, a light-emitting device, characterized in that side surfaces of the plurality of protruding portions are smoother than upper surfaces of the plurality of protruding portions.

3. The light-emitting device according to claim 1 or 2, characterized in that a curved surface is formed from a bottom surface to a side surface of the plurality of protruding portions.

4. The light-emitting device according to any one of claims 1 to 3, wherein the narrow portion has a frustum shape.

5. having a second reflecting member that covers, on the substrate, from the side surface of the light-emitting element of 1 to the side surface of the wavelength conversion member and to the side surface of the optical member; The light-emitting device according to claim 1, wherein an upper surface of the second reflecting member is higher than a bottom surface of the optical member.

6. The light-emitting device according to claim 5, wherein the first reflecting member and the second reflecting member are made of a translucent member containing light-scattering particles.

7. The light-emitting device according to any one of claims 1 to 6, wherein each of the plurality of lens portions is provided in a region directly above each of the plurality of protruding portions on the upper surface of the base portion.

8. The light-emitting device according to any one of claims 1 to 7, wherein the wavelength conversion member is made of a ceramic sintered body containing a phosphor.

9. The light-emitting device according to any one of claims 1 to 8, wherein a thickness of the bottom portion of the wavelength conversion member is 20 to 70% of an overall thickness of the wavelength conversion member.

Images