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 an upper surface of the substrate; a wavelength conversion member having a bottom part arranged on the light emitting element to cover the upper surface of the light emitting element and a plurality of protrusions extending from the bottom part, the wavelength conversion member 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 immediately above the protrusions in the upper surface of the substrate. The side surfaces of the protrusions are more smooth than the upper surface of the protrusions.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] There is a light emitting device that controls the emitted color by passing light emitted from a light emitting element through a phosphor. For example, Patent Document 1 discloses a light emitting device that includes 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 reflecting 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] Special Publication No. 2011-515846 Summary of the Invention [Problem to be solved by the invention]

[0004] For example, when a light emitting device such as that described in Patent Document 1 is used as a light source for a vehicle lamp, it is preferable that the light emitted from the light emitting device is narrowed in angle according to the downstream optical system. Also, it is preferable that no dark lines are generated when the light emitted from the light emitting device is projected.

[0005] The present invention has been made in consideration of the above-mentioned points, and has an object to provide a light emitting device capable of narrowing the angle of emitted light while reducing the occurrence of dark lines due to the emitted light. [Means for solving the problem]

[0006] The light emitting device according to the present invention comprises a substrate, a light emitting element arranged on an upper surface of the substrate, a wavelength conversion member arranged on the light emitting element and having a bottom covering an upper surface of the light emitting element and a plurality of protrusions extending upward from the bottom, converting the wavelength of light emitted from the light emitting element, and an optical member having a base extending continuously over the wavelength conversion member and a plurality of lens portions in a region directly above the plurality of protrusions on the upper surface of the base, wherein the side surfaces of the plurality of protrusions are smoother than the upper surfaces of the plurality of protrusions. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view of a light emitting device according to a first embodiment. [Diagram 2] FIG. 2 is a top view of the light emitting device according to the first embodiment. [Diagram 3] 1 is a cross-sectional view of a light emitting device according to a first embodiment. [Figure 4] 2 is an enlarged cross-sectional view of the light emitting device according to the first embodiment. [Diagram 5] 1 is a cross-sectional view of a light emitting device according to Comparative Example 1. FIG. [Figure 6] 11 is a cross-sectional view of a light emitting device according to Comparative Example 2. FIG. [Figure 7] 4 is a diagram showing the directional characteristics of emitted light in the light emitting device according to the first embodiment. FIG. [Figure 8] 11 is a diagram showing the directional characteristics of emitted light in a light emitting device according to Comparative Example 1. FIG. [Figure 9] 13 is a diagram showing the directional characteristics of emitted light in a light emitting device according to Comparative Example 2. FIG. [Figure 10] 13 is a diagram showing the luminance distribution of the light exit surface in the light emitting device according to Comparative Example 1. FIG. [Figure 11] 13 is a diagram showing the luminance distribution of the light exit surface in the light emitting device according to Comparative Example 2. FIG. [Figure 12] 4 is a diagram showing the directional characteristics of emitted light in the light emitting device according to the first embodiment. FIG. [Figure 13] 4 is a diagram showing the directional characteristics of emitted light in the light emitting device according to the first embodiment. FIG. [Figure 14]4 is a diagram showing the luminance distribution of the light exit surface in the light emitting device according to Example 1. FIG. [Figure 15] 4 is a diagram showing the luminance distribution of the light exit surface in the light emitting device according to Example 1. FIG. [Figure 16] 4 is a diagram showing a half-value angle of the directivity of emitted light in the light emitting device according to Example 1. FIG. [Figure 17] 4 is a diagram showing the proportion of luminous flux within ±30° of the directivity of emitted light in the light emitting device according to Example 1. FIG. [Figure 18] 5 is a diagram showing the chromaticity of emitted light from the light emitting device according to Example 1. FIG. [Figure 19] 4 is a diagram showing the output of emitted light in the light emitting device according to Example 1. FIG. [Figure 20] 11 is a cross-sectional view of a light emitting device according to Modification 1. FIG. [Figure 21] FIG. 11 is a cross-sectional view of a light emitting device according to Modification 2. [Figure 22] FIG. 11 is a cross-sectional view of a light emitting device according to Modification 3. [Figure 23] FIG. 11 is a top view of a light emitting device according to Modification 4. [Figure 24] FIG. 13 is a perspective view of a light emitting device according to Modification 5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the drawings, the same components are designated by the same reference numerals, and the description of the same components will be omitted. EXAMPLES

[0009] The light-emitting device 10 of Example 1 of the present invention comprises a light-emitting element 15 mounted on a support 11, a wavelength converter 17 bonded 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 a light emitting device 10 according to Example 1 will be described with reference to Figures 1 to 3. Figure 1 is a perspective view of the light emitting device 10. In Figure 1, in order to avoid complication of the illustration, a peripheral wall portion 13 and a second reflecting member 27 are shown by dashed lines as virtual lines.

[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 has a rectangular upper surface and is a member on which the light emitting element 15 is mounted. In this embodiment, the substrate 12 is composed of an insulating substrate such as aluminum nitride (AlN), aluminum oxide (Al2O3), or silicon nitride (Si3N4), 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 disposed on the substrate 12, has a light emission region on its 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 in the wavelength range of about 450 nm.

[0014] The wavelength converter 17 is disposed on the light emitting element 15 and is a wavelength conversion member containing a phosphor that converts the wavelength of 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 firing an yttrium aluminum garnet (YAG) phosphor and Al2O3 at high temperature. 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 first portion 18 and a plurality of second portions 19 extending in a columnar shape upward from the first portion 18. In other words, the wavelength converter 17 has a plurality of protrusions extending upward on the upper surface. The wavelength converter 17 is composed of the first portion 18 and the second portion 19 formed continuously and integrally.

[0016] The first reflecting member 21 is a reflecting member filled between each of the second portions 19 on the first portion 18 of the wavelength converter 17. The first reflecting member 21 is made of a light-transmitting 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 on the first reflecting member 21 from the wavelength converter 17 is totally reflected and scatteredly reflected at the interface between the wavelength converter 17 and the first reflecting member 21 and in the vicinity of the interface. As a result, by providing the first reflecting member 21, the light emitted from the wavelength converter 17 is fixed on the upper surface of each of the second portions 19.

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

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

[0019] Each of the lens portions 25 is disposed corresponding to each of the second portions 19 of the wavelength converter 17. In this embodiment, the center of each of the lens portions 25 and the center of each of the second portions 19 corresponding to each of the lens portions 25 are disposed to overlap in the vertical direction in the figure.

[0020] The lens unit 25 may be, for example, a plano-convex spherical lens, a plano-convex aspherical lens, a cylindrical lens, etc. In this embodiment, the lens unit 25 is made of a hemispherical convex lens, and refracts the light incident from the wavelength converter 17 toward each optical axis of the lens unit 25 and emits it.

[0021] The second reflecting member 27 is a reflecting member that extends continuously on the substrate 12 so as to cover the outer surfaces of the above-mentioned light emitting element 15, the first reflecting member 21, the wavelength converter 17, and the optical member 23. The second reflecting member 27 can be made of a light-transmitting member containing light-scattering particles, similar to the first reflecting member 21. In this 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] 2 is a top view of the light emitting device 10. The wavelength converter 17 is disposed approximately in 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, each of which is provided on the first portion 18 and also has a rectangular upper surface shape.

[0023] In this embodiment, the second portions 19 are arranged in multiple rows on the first portion 18. Specifically, the second portions 19 are arranged in 3×3 rows as shown in Fig. 2. In this embodiment, the second portions 19 are arranged such that adjacent second portions 19 are equally spaced from each other in the up-down and left-right directions in the figure.

[0024] The optical member 23 has a base 24 having a rectangular top surface shape and a plurality of lens portions 25 disposed on the base 24. In this embodiment, the first portion 18 of the wavelength converter 17 and the base 24 of the optical member 23 have approximately the same shape and size.

[0025] In this embodiment, the lens portions 25 are arranged in multiple rows on the base portion 24, similar to the above-described second portion 19. Specifically, the lens portions 25 are arranged in 3×3 rows as shown in Fig. 2. In this embodiment, the lens portions 25 are arranged such that adjacent lens portions 25 are equally spaced from each other in the vertical and horizontal directions in the figure.

[0026] Each of the multiple lens portions 25 is positioned at the same position as each of the second portions 19 of the wavelength converter 17 when viewed from above, 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 an upper surface outer shape of a rectangular frame, and extends continuously along the outer edge of the first portion 18 and the outer edge of the base 24 within the opening 13O so as to surround the first portion 18 and the base 24. In other words, the second reflecting member 27 is surrounded by the peripheral wall 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 13 and the light emitting element 15, and between the peripheral wall 13 and the wavelength converter 17.

[0028] Fig. 3 is a cross-sectional view taken along line 3-3 in the top view of the light-emitting device 10 in Fig. 2. As described above, the support 11 is composed of the flat substrate 12 and the peripheral wall portion 13 that is continuously disposed along the outer edge of the upper surface of the substrate 12. The substrate 12 has a mounting surface on the upper surface of 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 stacking a frame-shaped ceramic green sheet that will become the peripheral wall portion 13 on a flat ceramic green sheet that will become the substrate 12, and firing the stacked sheets.

[0030] The light emitting element 15 is mounted in the center of the upper surface of the substrate 12, and is configured to include a support substrate 31 and a semiconductor layer 32 disposed on the support substrate 31.

[0031] The supporting substrate 31 is a flat substrate having a rectangular top surface that is disposed on the top surface of the substrate 12. The supporting substrate 31 is made of a semiconductor material such as silicon (Si) or silicon carbide (SiC).

[0032] The semiconductor layer 32 is a flat semiconductor layer having a rectangular upper surface formed on the upper surface of the support substrate 31. The semiconductor layer 32 is made of a nitride-based semiconductor such as gallium nitride (GaN), 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 of the semiconductor layer 32 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. The light emitting element 15 may also be configured to include the 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] The light-emitting element 15 has 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, and the element electrodes are electrically connected to wiring (not shown) made of a conductive metal formed on the substrate 12.

[0036] Moreover, the wiring on the substrate 12 is connected to a terminal of an external power supply (not shown), for example, via a conductive through via that vertically penetrates the substrate 12. In other words, the light emitting device 10 is configured so 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 so as to cover the upper and side surfaces of the semiconductor layer 32 and also to cover the upper surface of the support substrate 31 exposed outside the semiconductor layer 32. In this embodiment, the adhesive layer 34 is made of a transparent silicone resin that is translucent 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 portion bonded onto the light emitting element 15 via an adhesive layer 34, and a plurality of second portions 19 which extend upward from the first portion 18. In this embodiment, the first portion 18 and the second portion 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 emission surface of the upper surface of the light emitting element 15 and serves as a light incidence surface into which light emitted from the light emitting element 15 is incident. In this embodiment, the bottom surface 18B and the upper surface of the support substrate 31 have approximately the same shape and size.

[0040] The second portion 19 is a protrusion extending upward from the upper surface 18T of the first portion 18. The second portion 19 has a quadrangular pyramid-shaped narrowed portion 35 that narrows upward from the lower end of the second portion 19. In other words, the second portion 19 has a side surface 35S that slopes inwardly toward the top.

[0041] In this manner, it is preferable that the second portion 19 has the narrowed portion 35. This is because the second portion 19 has the narrowed portion 35, i.e., has an inclined side surface, and thus the incident light from the light emitting element 15 can be guided to the upper surface 19T of the second portion 19 more efficiently than when the second portion 19 does not have an inclined side surface. The side surface 35S of the second portion 19 may be a flat surface or a curved surface, but if it is a curved surface, it is preferable that the side surface 35S of the second portion 19 is an inwardly convex inclined curved surface.

[0042] The second portion 19 has a rectangular columnar portion 36 that extends upward and perpendicular to the upper surface of the narrowed portion 35. In other words, the second portion 19 has a side surface 36S that is perpendicular to the upper surface of the narrowed portion 35. The bottom surface of the columnar portion 36 is approximately the same in shape and size as the upper surface of the narrowed portion 35.

[0043] The first portion 18 of the wavelength converter 17 receives the 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 is emitted from the upper surface of the second portion 19. At this time, the light that has traveled to the side surface 35S of the second portion 19 is reflected inward and upward by the side surface 35S. Specifically, for example, the light that has traveled to 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 serves as a light exit surface from which light incident from the bottom surface 18B of the first portion 18 is exited. The light exiting from the upper surface 19T of the second portion 19 is incident on the optical member 23 disposed on the second portion 19. That is, the light exiting from the light emitting element 15 is incident on the optical member 23 via the upper surfaces 19T of the multiple second portions 19 of the wavelength converter 17.

[0045] As described above, in this embodiment, wavelength converter 17 contains a YAG phosphor, and yellow fluorescence is generated by exciting the YAG phosphor with the blue light emitted from light emitting element 15. A portion of the blue light emitted from light emitting element 15 and incident on wavelength converter 17 excites the YAG phosphor, and a portion of the blue light travels upward without exciting the YAG phosphor.

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

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

[0048] Specifically, upper surface 19T of second portion 19 has the surface roughness of the sintered ceramic body after firing, 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 surface without irregularities) is 1.2 to 1.3. In contrast, side surfaces 35S and 36S of second portion 19 and upper surface 18T of first portion 18 have a ratio of the surface area to the cross-sectional area of ​​1.0 to 1.1, which is smaller than that of upper surface 19T of second portion 19.

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

[0050] In this embodiment, side surfaces 35S and 36S of second portion 19 and top surface 18T of first portion 18 are smooth, which can increase the total reflection component of light at the interfaces between each of side surfaces 35S, 36S and top surface 18T and first reflecting member 21. This is because interfaces are formed between each of side surfaces 35S, 36S and top surface 18T and the light-transmitting member that constitutes first reflecting member 21.

[0051] In particular, when the second portion 19 has a narrowed portion 35, the inclined side surface 35S can direct a greater amount of the total reflected component of light at the interface with the first reflecting member 21 toward the upper surface 19T, compared to when the side surface is not inclined.

[0052] For example, a part of the light that is incident on the wavelength converter 17 and proceeds to the side surface 35S of the second portion 19 is totally reflected at the interface between the side surface 35S and the light-transmitting member that constitutes the first reflecting member 21, and proceeds toward the upper surface 19T of the second portion 19. Therefore, the total reflection component of the light at the interface increases, and the light proceeding toward the upper surface 19T can be increased.

[0053] As described above, the top surface 19T of the second portion 19 has a surface roughness larger than those of the side surfaces 35S and 36S and the top surface 18T of the first portion 18. Since the top surface 19T has a large surface roughness, total reflection is unlikely to occur on the surface. Therefore, the light that has traveled to the top surface 19T is unlikely to be reflected by the top surface 19T toward the light emitting element 15, and is incident on the optical member 23 bonded onto the top 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, if the corner C is configured as a right angle, when the light emitting device 10 is subjected to an external force or the like, stress is generated within the wavelength converter 17, which may cause the stress to concentrate at the corner C, resulting in cracks or breakage. According to this embodiment, the corner C has a rounded shape, which makes it difficult for stress to concentrate at the corner C, thereby making it possible to prevent cracks or breakage.

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

[0057] The top surface of the first reflecting member 21 coincides with the top surface 19T of the second portion 19. In addition, 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] The first reflecting member 21 reflects, for example, light that has traveled to the side surfaces 35S and 36S of the second portion 19, out of the light emitted from the light emitting element 15 and incident on the wavelength converter 17, inwardly and upwardly at the interfaces between the side surfaces 35S and 36S and the first reflecting member 21. In other words, the first reflecting member 21 reflects light traveling from the wavelength converter 17 toward itself toward the wavelength converter 17 without allowing the light to enter.

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

[0060] The base 24 has a bottom surface 24B that extends continuously over 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-transmitting optical member adhesive layer (not shown). In other words, the base 24 is a continuous portion that extends continuously over 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, and condenses the light to the lens portions 25 while spreading the light between the adjacent lens portions 25, i.e., to the upper surface 24T of the base 24.

[0062] The lens portions 25 are disposed directly above the upper surfaces 19T of the second portions 19, and transmit outward light that is emitted from the upper surfaces 19T of the second portions 19 and travels through the base portions 24 to the lens portions 25. In other words, the surfaces of the lens portions 25 are the light extraction surfaces of the light-emitting device 10. In this embodiment, the above-mentioned 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 converter 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 to be substantially the same as the height of the base 24 of the optical member 23, i.e., the height of the bottom surface of the lens portion 25.

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

[0066] The second reflecting member 27 reflects, for example, light that travels to the side surface 18S of the first portion 18 among the light emitted from the light-emitting element 15 and incident on the wavelength converter 17, inwardly and upwardly at the interface between the side surface 18S and the second reflecting member 27.

[0067] In addition, the second reflecting member 27 reflects inward and upward at the interface between the first reflecting member 21 and the second reflecting member 27, for example, light that enters the first reflecting member 21 via the wavelength converter 17 and then travels to the inner surface of the second reflecting member 27 without entering the wavelength converter 17.

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

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

[0070] In this embodiment, the second portion 19 of the wavelength converter 17 has the quadrangular pyramid-shaped narrowed portion 35 as described above. In other words, the second portion 19 of the wavelength converter 17 has a side surface 35S that slopes inward. According to this embodiment, when light EL is incident on the second portion 19, the light EL is reflected upward by the side surface 35S, and the light is collected on the upper surface 19T.

[0071] That is, according to this 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 the emission range narrowed, and is incident on the base 24 of the optical member 23. In other words, only the light emitted from a partial region of the upper surface of the wavelength converter 17 is incident on the base 24 of the optical member 23.

[0072] In the present embodiment, the side surfaces 35S and 36S of the second portion 19 of the wavelength converter 17 and the top surface 18T of the first portion 18 are smoother than the top surface 19T, as described above. As a result, of the light incident on the side surfaces 35S and 36S of the second portion 19 and the top surface 18T of the first portion 18, the component emitted to the outside of the wavelength converter 17 is reduced, and the component reflected to the first portion 18 or the second portion 19 is increased.

[0073] In particular, the light reflected by the side surface 35S of the second portion 19 proceeds toward the upper surface 19T. That is, when the light EL is incident on the second portion 19, the light EL is reflected upward by the side surface 35S, and 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 narrowed, and is incident on the base 24 of the optical member 23.

[0074] Thus, according to this embodiment, since the second portion 19 of the wavelength converter 17 has a narrowed portion 35, or since the side surfaces 35S and 36S of the second portion 19 are smoothed compared to the upper surface 19T, the light emitted from the light-emitting element 15 can be concentrated on the upper surface 19T and made incident on the optical element 23.

[0075] For example, in the case of a light emitting device of the comparative example in which a simple flat wavelength converter was 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 exhibited characteristics close to a Lambertian light distribution.

[0076] In contrast, according to this embodiment, it has been confirmed that, since the wavelength converter 17 has the above-mentioned configuration, it is possible to extract light having a narrower light angle than the Lambertian light distribution from the light emitting device 10, as shown in Fig. 7 described later. In other words, it is possible to control the light distribution angle of the light emitted from the light emitting device 10.

[0077] The thickness of the second portion 19 of the wavelength converter 17 in the vertical direction in the figure is preferably 20% or more and 70% or less of the total thickness of the wavelength converter 17. This is because, if 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, if it exceeds 70%, the thickness of the first portion 18 becomes extremely small, making it impossible to sufficiently propagate light from the first portion 18 to the second portion 19.

[0078] 4, the width W1 of the top surface 19T of the second portion 19 is preferably 80% or less, and particularly preferably 50% to 60%, of the width W2 of the bottom surface of the lens portion 25. This is because if the width W1 of the top 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 if it is less than 50%, the light emission range is narrowed more than necessary, resulting in a decrease in light extraction efficiency.

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

[0080] [Eliminating dark lines when projecting emitted light] Next, an explanation will be given of the elimination of dark lines when projecting light emitted from the light emitting device 10. In Fig. 4, angle θ is the angle formed by the center of upper surface 19T of second portion 19 and both ends of the bottom surface of lens portion 25. Angle θ becomes smaller as the thickness of base 24 in the vertical direction in the figure becomes larger.

[0081] When projecting the light emitted from the light emitting device 10, the smaller the angle θ, i.e., the thicker the base 24, the more the light spreads over the entire base 24, and the more the dark lines disappear when the light is projected. However, when the angle θ becomes smaller, the amount of light propagating within the base 24 increases more than necessary, and the amount of light traveling toward the upper surface 19T of the second portion 19 increases.

[0082] If the amount of light traveling from the base 24 side toward the top surface 19T increases more than necessary, the light may excite the YAG phosphor in the wavelength converter 17, causing a large amount of yellowish light to be emitted. That is, if the angle θ becomes small, the color temperature of the emitted light may decrease. Also, if the angle θ becomes small, the amount of light propagating toward the end face of the base 24 increases, which may cause light to leak from the end of the base 24.

[0083] Therefore, the angle θ is preferably in the range of 80° to 130°, and particularly preferably in the range of 90° to 120°, in order to reduce the occurrence of dark lines when the light emitted from the light emitting device 10 is projected, while not affecting 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 narrow the angle of the light emitted from the light emitting device 10 while reducing dark lines when the emitted light is projected.

[0085] In this embodiment, the second portion 19 of the wavelength converter 17 has the narrowed portion 35 narrowing upward from the first portion 18, but the position where the narrowed portion 35 is formed is not limited thereto. For example, the narrowed portion 35 may be formed on the columnar portion 36.

[0086] In this embodiment, the side surfaces 35S and 36S of the second portion 19 and the upper surface of the first portion 18 are smoother than the upper surface 19T of the second portion 19, but the upper surface 19T may be subjected to a treatment that increases the roughness. For example, the upper surface 19T may be subjected to a mechanical treatment or a chemical treatment to form a structure that makes it easier for light to be emitted from the upper surface 19T.

[0087] In the present embodiment, the corner C at the lower end of the second portion 19 has a rounded shape, but the corner C does not necessarily have to be rounded.

[0088] In this embodiment, the wavelength converter 17 may have the above-mentioned configuration so long as it is capable of collecting light on the upper surface 19T of the second portion 19, and the first reflecting member 21 may not be filled between the second portions 19. For example, the second portions 19 may be configured to be filled with a gas such as air instead of the first reflecting member 21. Also, for example, a translucent filling member that does not contain TiO2 may be disposed instead of the first reflecting member 21.

[0089] In this embodiment, the lens portions 25 of the optical member 23 are separated from one another by the upper surface 24T of the base 24, but the present invention is not limited to this. That is, the lens portions 25 may be arranged on the base 24 so as to be in contact with one another.

[0090] In this modification, the second portions 19 of the wavelength converter 17 and the lens portions 25 of the optical member 23 are arranged in a 3×3 array, but the arrangement is not limited to this. For example, the second portions 19 and the lens portions 25 may be arranged in a staggered pattern with adjacent rows. Also, for example, the second portions 19 and the lens portions 25 may be arranged in only one row.

[0091] The dimensions of the light emitting device 10 are not limited to those mentioned above as long as any one of the above-mentioned effects such as narrow angle effect and elimination of dark lines can be obtained.

[0092] [Verification experiment] Various verification experiments carried out on the light emitting device 10 of the present invention will be described in detail below, including comparisons with light emitting devices as comparative examples and verification results when parameters of the constituent members are changed.

[0093] [Directional characteristics of emitted light] The directional 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 the first embodiment with a light emitting device as a comparative example.

[0094] 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 an optical member 23, but has a similar configuration to the light emitting device 10 in other respects.

[0095] 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 a simple flat plate-shaped wavelength converter 38 is used instead of the wavelength converter 17, but has a similar configuration to the light emitting device 10 in other respects.

[0096] Fig. 7 is a diagram showing the directional characteristics (hereinafter simply referred to as directional characteristics) in the x direction (left and right direction in Fig. 3) and y direction (depth direction in Fig. 3) of light emitted from the light emitting device 10 of the present invention. As shown in Fig. 7, the light emitted from the light emitting device 10 had a half-value angle (the angle at which the luminous flux is relatively 50% when the luminous flux at the central axis of 0° is taken as 100%) of 82°, and the proportion of luminous flux within ±30° was about 36%.

[0097] Fig. 8 is a diagram showing the directional characteristics of the light emitted from the light emitting device 50 of Comparative Example 1. As can be seen from Fig. 8, the light emitted from the light emitting device 50 exhibited characteristics close to a Lambertian light distribution with a half-value angle of about 120°. Moreover, the proportion of luminous flux within ±30° of the light emitted from the light emitting device 50 was about 26%.

[0098] Fig. 9 is a diagram showing the directional characteristics of light emitted from the light emitting device 60 of Comparative Example 2. As shown in Fig. 8, the light emitted from the light emitting device 60 exhibited characteristics close to a Lambertian light distribution with a half-value angle of about 120°, similar to the light emitting device 50. In addition, the luminous 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 emitted light from the light emitting device 10 of the present invention has a higher directivity, rather than 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. Furthermore, according to the light emitting device 10 of the present invention, the angle range in which the luminous flux is 50% relative to the central axis 0° can be narrowed in the emitted light, compared to the light emitting device 50 of Comparative Example 1 and the light emitting device 60 of Comparative Example 2. In other words, a narrow angle of the emitted light can be achieved.

[0100] [Luminance distribution on the light exit surface] Next, the luminance distribution on the surface of the optical member 23, which serves as the light exit surface for 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, the luminance at the center of each of light-emitting devices 10, 50, and 60 when viewed from above, or at the center of the light exit surface, is taken as the origin, i.e., the maximum luminance (100%), and the luminance was measured when moving in the horizontal direction (left and right direction in FIG. 3) from the origin. Specifically, the origin was taken as the center of the upper surface of lens portion 25 at the center of the light exit surface.

[0102] Figures 14 and 15 are diagrams showing the luminance distribution of light emitted from the light emitting device 10 of the present invention. In Figures 14 and 15, the area where the luminance is lower (indicated by the dashed lines in the figures) is the area corresponding to the upper surface 24T of the base 24 of the optical member 23, i.e., the area between each of the lens portions 25 (hereinafter referred to as the inter-lens area). The luminance of the light emitted from the light emitting device 10 in the inter-lens area was 20% or more of the maximum luminance.

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

[0104] Fig. 11 is a diagram showing the luminance distribution of light emitted from the light emitting device 60 of Comparative Example 2. As can be seen from Fig. 11, the luminance of the light emitted from the light emitting device 60 in the inter-lens region was approximately 18% of the maximum luminance.

[0105] The above experimental results show that the light exit surface of the light emitting device 10 of the present invention has a higher luminance distribution in the inter-lens region than the luminance distributions of the light emitting device 50 of Comparative Example 1 and the light emitting device 60 of Comparative Example 2. In other words, the light emitting device 10 can reduce the occurrence of dark lines when the emitted light is projected.

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

[0107] As a result, as shown in Figures 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 the predetermined glare evaluation position was confirmed to be 1% or more relative to the maximum luminance. In contrast, as shown in Figures 14 and 15, in the light emitting device 10 of the present invention, the luminance at the predetermined glare evaluation position could be reduced to 0.5% or less relative to the maximum luminance.

[0108] That is, it was confirmed that 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, was able to suppress stray light to the second reflecting member.

[0109] [Directivity of emitted light when changing the thickness of the optical component base] The following describes the directional characteristics of the light emitted from the light emitting device 10 of the present invention when the thickness of the base portion 24 of the optical member 23 is changed.

[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. If 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 directional characteristics of light emitted from the light emitting device 10 when the thickness of the base 24 is 80 µm. As shown in Fig. 12, the light emitted from the light emitting device 10 exhibits a half-value angle of about 70°.

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

[0113] From the above experimental results, according to the light emitting device 10 of the present invention, the angle range in which the luminous flux is relatively 50% with respect to the central axis 0° in the emitted light can be narrowed when the thickness of the base 24 is 160 μm, compared to when the thickness of the base 24 is 80 μm. In other words, the light emitting device 10 can achieve a narrower angle of the emitted light when the thickness of the base 24 is 160 μm.

[0114] [Brightness distribution on the light exit surface when changing the thickness of the optical component base] Next, the luminance distribution on the surface of the optical member 23, which serves as the light exit surface for light emitted from the light emitting device 10 of the present invention, when the thickness of the base portion 24 of the optical member 23 is changed will be described.

[0115] In this experiment, the luminance at the center of each of the light-emitting devices 10 and 50 when viewed from above, or at the center of the light emission surface, was taken as the origin, i.e., the maximum luminance, and the luminance was measured as the device moved horizontally from the origin.

[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. As shown in Fig. 14, the luminance of the light emitted from the light emitting device 10 in the inter-lens region 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. Fig. 15 shows that the luminance of the light emitted from the light emitting device 10 in the inter-lens region was about 27% of the maximum luminance.

[0118] From the above experimental results, it was found that the light exit surface of the light emitting device 10 of the present invention has a higher luminance distribution in the inter-lens region when the thickness of the base 24 is 160 μm, compared to when the thickness of the base 24 is 80 μm. That is, the light emitting device 10 can further reduce the occurrence of dark lines when the emitted light is projected when the thickness of the base 24 is 160 μm. In other words, it was found that the smaller the angle θ, the higher the luminance of the light in the inter-lens region.

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

[0120] 16 is a graph showing the correlation between the angle θ and the half-value angle in the directional characteristics of the light emitted from the light emitting device 10. From this graph, for example, the half-value angle is approximately 120° when the angle θ is approximately 180°, and is approximately 60° when the angle θ is approximately 80°.

[0121] From the above results, it was found that in the light emitting device 10, the smaller the angle θ, the smaller the half-value angle is, and the higher the narrow-angle performance is. In addition, it was found that the larger the angle θ is, the closer the directional characteristics of the emitted light is to a Lambertian light distribution.

[0122] [Luminous flux ratio in the directional characteristics of the emitted light when the angle θ is changed] Next, when the thickness of the base portion 24 of the optical member 23 is expressed by the above-mentioned angle θ, the luminous flux ratio within ±30° in the directivity characteristic of the light emitted from the light emitting device 10 when the angle θ is changed will be described.

[0123] 17 is a graph showing the correlation between the angle θ and the proportion of luminous flux within ±30° in the directional characteristics of the light emitted from the light emitting device 10. From this graph, the proportion of luminous flux within ±30° was approximately 26% when the angle θ was approximately 180°, and was 33 to 37% when the angle θ was in the range of approximately 80° to 150°.

[0124] The above results show that in the light emitting device 10, the proportion of luminous flux within ±30° when the angle θ is in the range of approximately 80° to 150° is higher than the proportion of luminous flux within ±30° when the angle θ is approximately 180°.

[0125] [Color of the emitted light when the angle θ is changed] Next, the chromaticity of the emitted light when the angle θ is changed in the case where the thickness of the base portion 24 of the optical member 23 is represented by the above-mentioned angle θ will be described.

[0126] 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 (the dashed line in the graph), the whiter the emitted light is.

[0127] 18, the chromaticity value Cx and the chromaticity value Cy each exhibited a value of about 0.3 when the angle θ was about 180°. The chromaticity value Cx exhibited a value of about 0.31 to 0.335 when the angle θ was in the range of about 80° to 120°. The chromaticity value Cy exhibited a value of about 0.31 to 0.325 when the angle θ was in the range of about 80° to 120°.

[0128] The above results show that in the light emitting device 10, the chromaticity when the angle θ is in the range of about 80° to 120° is higher than the chromaticity when the angle θ is about 180°. In other words, in the light emitting device 10, the emitted light when the angle θ is in the range of about 80° to 120° is closer to white than the emitted light when the angle θ is about 180°.

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

[0130] Figure 19 is a graph showing the output of light emitted from the light emitting device 10 (output of maximum brightness of white light / output of blue light from the light emitting element) when the ratio of surface area to cross-sectional area is changed on the sides 35S and 36S of the second part 19 of the wavelength converter 17 and on the top surface 18T of the first part 18.

[0131] From this graph, it can be seen that when the ratio of surface area to cross-sectional area is about 1.10, the output of the emitted light is increased by about 2.6% compared to when the ratio is about 1.18, and when the ratio of surface area to cross-sectional area is about 1.07, the output of the emitted light is increased by about 4.0% compared to when the ratio is about 1.18.

[0132] From the above results, it was found that the smaller the ratio of the surface area to the cross-sectional area is, the greater the output of emitted light is in light-emitting device 10. In other words, the output of emitted light from light-emitting device 10 can be improved by reducing the surface roughness of side surfaces 35S and 36S of second portion 19 and top surface 18T of first portion 18.

[0133] [Method of manufacturing a light-emitting device] A method for producing the light emitting device 10 in this embodiment will be described below.

[0134] First, a ceramic plate (corresponding to the wavelength converter 17) formed by firing a YAG phosphor and Al2O3 at high temperature is diced to form a plurality of second portions 19 on the above-mentioned first portions 18 (step 1). At this time, by using a dicing blade having a narrowed shape and a columnar shape, the second portions 19 having narrowed portions 35 and columnar portions 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, an abrasive is sprayed onto the side surfaces 35S and 36S of the second portion 19 and the upper surface of the first portion 18 using a mirror finisher, thereby processing the surfaces into a smooth mirror surface.

[0136] Next, a resin material (corresponding to the first reflecting member 21) in which TiO2 is dispersed in silicone resin is filled into the regions between the second portions 19 using a dispenser or the like, and then 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 portions 19. After the resin material is cured, it is diced into individual pieces using a dicing blade, thereby obtaining the wavelength converter 17 in which the first reflecting member 21 is filled.

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

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

[0139] Finally, a resin material (corresponding to the second reflecting member 27) in which TiO2 is dispersed in silicone resin 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 is equal to the upper surface of the base 24 of the optical member 23, and then cured.

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

[0141] [Modification 1 of Example 1] A modification of the first embodiment will be described below with reference to FIGS.

[0142] 20 is a cross-sectional view of a light emitting device 110 according to Modification 1. The light emitting device 110 has a different shape of the wavelength converter from the light emitting device 10, but has the same configuration as the light emitting device 10 in other respects.

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

[0144] In this modification, 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 portions 42 are truncated quadrangular pyramid portions tapering upward. That is, the second portions 42 have side surfaces 42S that slope 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 collect the light, which is incident from the light emitting element 15 and travels through the wavelength converter 41, onto an upper surface 42T of the second portion 42 by reflecting the light on a side surface 42S of the second portion 42.

[0146] In this modification, the second portion 42 has only side surfaces 42S that are inclined inward. That is, the second portion 19 in the first embodiment has all of its side surfaces inclined inward, and therefore has a configuration that is easier to reflect light than the light-emitting device 10, and can collect light on the upper surface 42T of the second portion 42.

[0147] In this way, even when the shape of the second portion 42 of the wavelength converter 41 is changed, it is possible to reduce the narrowing of the angle of the emitted light from the light emitting device 110 and the occurrence of dark lines when the emitted light is projected.

[0148] [Output light output when changing the tilt angle of the second section] Here, the optical output of emitted light relative to the tilt angle of the second portion 42 of the wavelength converter 41 will be described with reference to Fig. 20. In Fig. 20, the tilt angle of the second portion 42 with respect to the upper surface 18T of the first portion 18 is indicated as angle α.

[0149] It was confirmed that the output of the emitted light from the light emitting device 10 increases as the angle α decreases. Specifically, compared to a light emitting device in which the angle α is 90°, i.e., the second portion 42 is formed perpendicular to the top 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] The configuration of forming the second portion having the angle α can also be applied to Example 1. That is, in Example 1, 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, it is possible to obtain an effect of improving the output of the emitted light.

[0151] [Modification 2 of Example 1] 21 is a cross-sectional view of a light emitting device 120 according to Modification 2. The light emitting device 120 has a different shape of the wavelength converter from the light emitting device 10, but has the same configuration as the light emitting device 10 in other respects.

[0152] Similar to the light emitting device 10 described above, the light emitting device 120 includes a light emitting element 15 arranged approximately in the center of an opening 13O formed by the peripheral wall portion 13 of the support body 11, a wavelength converter 44 joined to the light emitting element 15, and an optical member 23 arranged 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 narrowed portion 46 having an upwardly tapered shape and a rectangular columnar portion 47 extending upward perpendicular to the upper surface of the narrowed portion 46.

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

[0155] According to this modification, the side surface 46S has a curved surface, which makes it easier to reflect light incident on the wavelength converter 44 upward compared to a case in which the top surface 18T has a flat shape. That is, the wavelength converter 44 reflects the light incident from the light emitting element 15 and traveling inside the wavelength converter 44 by the side surface 46S of the second portion 45, so that the light can be more concentrated on the top surface 45T of the second portion 45 compared to the first embodiment.

[0156] Furthermore, since the side surface 46S of the second portion 45 of the light emitting device 120 has a curved shape, it is possible to obtain the same effect as that obtained by the shape of the corner C shown in the first embodiment. That is, according to this modification, when the light emitting device 120 is subjected to 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, causing cracks or breakage.

[0157] In this way, 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 angle of the emitted light from the light emitting device 120 and the occurrence of dark lines when the emitted light is projected.

[0158] [Modification 3 of Example 1] 22 is a cross-sectional view of a light emitting device 130 according to Modification 3. The light emitting device 130 has a different shape of the wavelength converter from the light emitting device 10, but has the same configuration as the light emitting device 10 in other respects.

[0159] Similar to the light emitting device 10 described above, the light emitting device 130 includes a light emitting element 15 arranged approximately in the center of an opening 13O formed by the peripheral wall portion 13 of the support body 11, a wavelength converter 48 joined to the light emitting element 15, and an optical member 23 arranged 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 portions 49 are columnar portions extending perpendicular to the first portion 18. That is, the second portions 42 have side surfaces 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, similar to 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 shape. With this configuration, for example, similar to Example 1, it is possible to prevent stress from concentrating on the corner C and causing cracks or breakage when the light emitting device 10 is subjected to an external force or the like.

[0162] Even in this modified example, the wavelength converter 48 can focus the light incident from the light-emitting element 15 and traveling through 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] In this way, 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 angle of the emitted light from the light emitting device 130 and the occurrence of dark lines when the emitted light is projected.

[0164] [Variation 4 of Example 1] 23 is a top view of a light emitting device 140 according to Modification 4. The light emitting device 140 has a similar configuration to the light emitting device 10 except that the shapes of the members constituting the light emitting device 140 are different from those of the light emitting device 10.

[0165] Specifically, the wavelength converter 17 of the light emitting device 140 has a first portion 18 whose upper surface shape is rectangular and a plurality of second portions 19 whose upper surface shape is rectangular and disposed on the first portion, as shown in Fig. 23. The optical member 23 of the light emitting device 140 has a base portion 24 whose upper surface shape is rectangular on the wavelength converter 17 and a lens portion 25 whose upper surface shape is oval and disposed on the base.

[0166] In this way, even when the shape of the components constituting the light-emitting device 140 is changed, it is possible to reduce the narrowing of the angle of the emitted light from the light-emitting device 140 and the occurrence of dark lines due to the projection of the emitted light. That is, according to this modification, it is possible to achieve the narrowing of the angle of the emitted light without being influenced by the shape of the light-emitting device, while reducing the occurrence of dark lines due to the emitted light.

[0167] [Modification 5 of Example 1] Fig. 24 is a perspective view of a light emitting device 150 according to Modification 5. The light emitting device 150 has a similar configuration to the light emitting device 10 except for the shape of the optical member. In Fig. 24, similar to Example 1, the peripheral wall portion 13 and the second reflecting member 27 are shown by dashed lines as virtual lines to avoid complication in the illustration.

[0168] The light emitting device 150 includes a light emitting element 15 arranged approximately in the center of an opening 13O formed by the peripheral wall portion 13 of the support body 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 modified example, the optical member 51 has a base 52 and a plurality of lens portions 53 that protrude upward from the base 52 and extend along each of the three rows. In other words, each of the lens portions 53 has a kamaboko shape.

[0170] In this way, even when the configuration of the lens portion 53 of the optical element 51 is changed, as in Example 1, it is possible to achieve a narrowing of the angle of the light emitted from the light emitting device 150 while reducing dark lines when the emitted light is projected.

[0171] Furthermore, according to this modified example, the optical member 51 has a plurality of lens portions 53 each having a kamaboko shape, which makes it easier to align the optical member 51 when bonding it onto the wavelength converter 17 compared to the optical member 23 in Example 1.

[0172] The shape and dimensions of each part of the light emitting device according to the present invention are not limited to those in the above-described embodiment and modified examples, but can be appropriately changed depending on the application, etc. [Explanation of symbols]

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

Claims

1. A substrate; A light emitting element disposed on an upper surface of the substrate; a wavelength conversion member that is bonded to an upper surface of the first light-emitting element, has a bottom portion that covers the upper surface of the first light-emitting element and a plurality of protrusions that extend upward from the bottom portion, and converts a wavelength of light emitted from the first 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 protrusions on an upper surface of the base, The side surfaces of the plurality of protrusions are smoother than the top surfaces of the plurality of protrusions, each of the plurality of protrusions is provided at a position overlapping with the one light emitting element in a top view of the one light emitting element; A light emitting device, characterized in that a first reflecting member that reflects light emitted from the one light emitting element is filled in an area between the plurality of protrusions.

2. a second reflecting member that covers a side surface of the first light emitting element on the substrate, through a side surface of the wavelength conversion member, and a 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.

3. 3. The light emitting device according to claim 2, wherein the first reflecting member and the second reflecting member are made of a light-transmitting member containing light scattering particles.

4. 4. The light emitting device according to claim 1, wherein each of the plurality of lens portions is provided in an area directly above each of the plurality of protrusions on the upper surface of the base.

5. 4. The light emitting device according to claim 1, wherein the protrusion has a narrowed portion with an inclined side surface.

6. 6. The light emitting device according to claim 1, wherein the wavelength conversion member is made of a ceramic sintered body containing a phosphor.

7. 7. The light emitting device according to claim 1, wherein the thickness of the bottom part of the wavelength conversion member is 20 to 70% of the total thickness of the wavelength conversion member.

Images