TW202045961A - Color conversion element - Google Patents

Abstract

A color conversion element (1) is provided with: a substrate (2); a fluorescent part (3) that is disposed on the substrate (2) and that receives a laser beam (L) from the outside and emits light of a color different from that of the laser beam (L); a first planarization layer (6) that is laminated on a first main surface (31) of the fluorescent part (3) on the opposite side to the substrate (2); a second planarization layer (7) that is laminated on a second main surface (32) of the fluorescent part (3) on the substrate (2) side; a reflection layer (4) that is formed by a dielectric multilayer film and laminated on the main surface of the second planarization layer (7) on the substrate side; and a joining part (5) that is interposed between the reflection layer (4) and the substrate (2) so as to join the reflection layer (4) and the substrate (2).

Description

Color conversion element

The present invention relates to a color conversion element with a phosphor layer laminated on a substrate.

For example, in a fluorescent wheel (color conversion element) used in a projection device such as a projector, a technique for bonding a fluorescent portion and a substrate with a thermally conductive adhesive to improve heat dissipation is disclosed (see, for example, Patent Document 1) . In addition, a reflective layer is laminated on the main surface of the substrate on the side of the fluorescent portion, whereby the light from the fluorescent portion is reflected by the reflective layer to improve conversion efficiency. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] JP 2016-99566 A

[Problem to be solved by invention]

In recent years, we hope to improve the conversion efficiency of color conversion in the color conversion element.

Therefore, the object of the present invention is to provide a color conversion element that can improve conversion efficiency. [Solving the problem]

One aspect of the color conversion element of the present invention includes: a substrate; a fluorescent part, which is arranged on the substrate, receives laser light from the outside, and emits light of a different color from the laser light; and a first planarization layer, The fluorescent part is formed by laminating the first main surface on the side opposite to the substrate; the second planarization layer is formed by laminating the second main surface on the substrate side of the fluorescent part; the reflective layer, It is laminated on the main surface of the second planarization layer on the substrate side and is composed of a dielectric multilayer film; and the junction part is sandwiched between the reflective layer and the substrate, and the reflective layer and the substrate are joined. [Invention Effect]

According to the color conversion element of the present invention, the conversion efficiency can be improved.

Hereinafter, the color conversion element according to the embodiment of the present invention will be described using drawings. In addition, the embodiments described below are all preferred specific examples of the present invention. Therefore, the numerical values, shapes, materials, constituent elements, arrangement and connection forms of the constituent elements, etc. shown in the following embodiments are only examples, and they are not intended to limit the present invention. Therefore, among the constituent requirements in the following embodiments, the constituent requirements that are not described in the independent claim representing the highest concept are described as arbitrary constituent elements.

Moreover, each figure is a schematic diagram, not necessarily a rigorous illustration. In each figure, the same symbols are attached to the same components.

Hereinafter, the embodiment will be described.

Fig. 1 is a schematic diagram of the schematic configuration of the color conversion element of the embodiment. Fig. 2 is a cross-sectional view of the cross section including the line II-II in Fig. 1.

The color conversion element 1 is a fluorescent wheel used in a projection device such as a projector. The projection device is provided with a semiconductor laser element as a light source unit, and the semiconductor laser element emits blue-violet to blue (430-490 nm) wavelength laser light L to the color conversion element 1. The color conversion element 1 uses laser light L irradiated from the light source unit as excitation light, and emits white light. Hereinafter, the color conversion element 1 will be specifically described.

As shown in FIGS. 1 and 2, the color conversion element 1 includes a substrate 2, a fluorescent portion 3, a first planarization layer 6, a second planarization layer 7, a reflective layer 4 and a bonding portion 5. In addition, in the following description, the main surface on the light source side of each laminate of the color conversion element 1 is referred to as the "front surface", and the main surface on the opposite side is referred to as the "back surface". In addition, in Figs. 1 and 2, the laser light L is represented by a dotted hatching. In the color conversion element 1, the area irradiated by the laser light L is referred to as an irradiation area R. Although the irradiation area R is fixed, because the color conversion element 1 rotates, the irradiation area R relatively moves on the color conversion element 1 in the circumferential direction.

The substrate 2 is a substrate having, for example, a circular shape in plan view, and a through hole 21 is formed in the center portion thereof. By installing the rotating shaft in the projection device to the through hole 21, the substrate 2 can be driven to rotate.

The substrate 2 is a substrate having a higher thermal conductivity than the phosphor part 3. Thereby, the heat conducted from the fluorescent part 3 can be effectively dissipated from the substrate 2. Specifically, the substrate 2 is formed of metal materials such as Al, Al ₂ O ₃ , AlN, Fe, and Ti. In addition, the substrate 2 only needs to have a higher thermal conductivity than the phosphor portion 3, and it may be formed of materials other than metal materials. Examples of materials other than metal materials include Si (silicon), ceramics, sapphire, and graphite. One surface 22 of the substrate 2 is formed in a flat shape, and the fluorescent portion 3 is arranged on the surface 22 side.

The fluorescent part 3 has a uniform wall thickness as a whole. For example, the fluorescent part 3 is provided with a plurality of fluorescent particles (fluorescent particles 34) that are excited by laser light L to emit fluorescence in a dispersed state, and the fluorescent particles 34 are emitted by irradiation of the laser light L Fluorescent. Therefore, the surface 31 of the fluorescent part 3 becomes a light-emitting surface. The surface 31 is the first main surface of the fluorescent portion 3 on the opposite side to the substrate 2. In addition, the back surface 32 of the fluorescent portion 3 is the second main surface on the side of the substrate 2 in the fluorescent portion 3. In the present embodiment, the normal direction of the back surface 32 of the fluorescent portion 3 and the incident direction of the laser light L to the fluorescent portion 3 are substantially the same. Here, "substantially consistent" means: not only is there a complete agreement, but also an error of several% can be tolerated. In addition, the surface 31 and the back surface 32 of the phosphor part 3 each have a surface roughness Ra greater than 100 nm. Specifically, the surface roughness Ra of each of the front surface 31 and the back surface 32 of the phosphor portion 3 is about 200 nm.

As a whole, the planar shape of the fluorescent portion 3 is formed in a ring shape. The fluorescent part 3 is formed by arranging a plurality of sheet-like monoliths 33 with uniform thickness in a ring shape. The plurality of single pieces 33 have the same shape and the same kind. Specifically, the single piece 33 is formed in a trapezoidal shape in plan view. In addition, the single piece 33 may be any shape as long as it has a sheet shape. As other planar shapes of the single piece 33, rectangular, triangular, other polygonal shapes, etc. are exemplified.

The adjacent single pieces 33 are arranged so that the adjacent sides are substantially the same. The single sheet 33 contains at least one kind of phosphor particles 34. In the case of this embodiment, the single plate 33 emits white light, and includes a red phosphor that emits red by the irradiation of the laser light L, a yellow phosphor that emits yellow, and a green phosphor in an appropriate ratio. 3 kinds of phosphor particles 34 of green phosphor.

The type and characteristics of the phosphor particles 34 are not particularly limited. However, since the laser light L having a relatively high output becomes the excitation light, the one with high thermal resistance is preferable. In addition, the type of the substrate 35 holding the phosphor particles 34 in a dispersed state is not particularly limited, but the substrate 35 is highly transparent to the wavelength of the excitation light and the wavelength of the light emitted from the phosphor particles 34 Appropriate. Specifically, the base material 35 is made of glass, ceramics, or the like. In addition, the phosphor part 3 may be a polycrystalline body or a single crystal body formed of one type of phosphor.

In addition, the first planarization layer 6 is laminated on the entire surface 31 of each single piece 33, and the second planarization layer 7 is laminated on the entire back surface 32 of each single piece 33.

The first planarization layer 6 is made flat by directly covering the surface 31 of the fluorescent portion 3 (single piece 33) to fill up the fine depressions of the surface 31. Therefore, the surface roughness Ra of the surface of the first planarization layer 6 is smaller than the surface roughness Ra of the surface 31 of the fluorescent portion 3.

The second planarization layer 7 is made flat by directly covering the back surface 32 of the fluorescent portion 3 (single piece 33) to fill in the fine recesses of the back surface 32. Therefore, the surface roughness Ra of the back surface in the second planarization layer 7 is smaller than the surface roughness Ra of the back surface 32 of the phosphor portion 3. Specifically, the surface roughness Ra of the back surface of the second planarization layer 7 may be 20 nm or less. In addition, the refractive index of the second planarization layer 7 is smaller than the refractive index of the fluorescent portion 3.

At least one of the first planarization layer 6 and the second planarization layer 7 has a visible light transmittance of 90% or more. In this embodiment, the visible light transmittance of each of the first planarization layer 6 and the second planarization layer 7 is set to 90% or more. Specifically, the first planarization layer 6 is formed of a material having translucency. The light-transmitting material includes, for example, transparent resin or SiO ₂ . If the first planarization layer 6 is formed of SiO _{2, the} heat resistance can be improved. For example, by applying a silicone-containing paste material to each single piece 33 and sintering, the first planarization layer 6 made of SiO ₂ can be formed. For the second planarization layer 7, the same material as the first planarization layer 6 is used. In addition, the first planarization layer 6 and the second planarization layer 7 can also be made of different materials.

In addition, at least one of the first planarization layer 6 and the second planarization layer 7 has a thickness of 1.0 μm or more. In this embodiment, the thicknesses of the first planarization layer 6 and the second planarization layer 7 are the same, but they may be different.

On the entire surface of the first planarization layer 6, a reflection suppression layer 8 such as an AR coating is laminated. The use of this reflection suppression layer 8 can improve the light extraction efficiency. Since the surface of the first planarization layer 6 has a smaller surface roughness Ra than the surface 31 of the fluorescent portion 3, the reflection suppression layer 8 can also be laminated on the surface of the first planarization layer 6 with a uniform layer thickness 31, the reflection suppression performance possessed by the reflection suppression layer 8 can be more reliably exerted.

On the entire back surface of the second planarization layer 7, a reflective layer 4 is laminated with a uniform thickness. The reflective layer 4 transmits the light transmitted through the second planarization layer 7 (from the laser light L and the phosphor particles 34). Radiated light) to be reflected.

The reflective layer 4 is a dielectric multilayer film. The dielectric multilayer film is formed by alternately laminating multiple layers of a transparent dielectric material with a high refractive index (n=2.0-3.0) and a transparent dielectric material with a low refractive index (n=1.0-1.9). The dielectric multilayer film can achieve desired reflection characteristics by adjusting the refractive index of the material or the thickness of the dielectric multilayer film. Specifically, for the dielectric multilayer film used as the reflective layer 4, the refractive index of the material or the thickness of the dielectric multilayer film can be adjusted so that the laser light L and the light emitted from the phosphor particles 34 can be adjusted The reflectivity becomes higher. The reflective layer 4 is laminated on the back surface of the second planarization layer 7 by, for example, sputtering or vapor deposition. Since the back surface of the second planarization layer 7 has a smaller surface roughness Ra than the back surface 32 of the fluorescent portion 3, the reflective layer 4 can also be laminated on the back surface of the second planarization layer 7 with a uniform layer thickness. The reflective performance of the reflective layer 4 can be more reliably displayed.

The bonding part 5 is sandwiched between the reflective layer 4 and the substrate 2 and joins the reflective layer 4 and the substrate 2. Specifically, the bonding portion 5 is formed of a resin-based adhesive such as silicone resin. After coating the bonding portion 5 on the surface 22 of the substrate 2, the reflective layer 4 of each single piece 33 is adhered to the bonding portion 5, whereby each single piece 33 becomes a fluorescent portion in a plan view on the substrate 2 3. In this state, the reflective layer 4 of each single piece 33 also resembles the fluorescent portion 3 and becomes a ring shape in plan view.

The joining part 5 includes a first joining part 51 and a second joining part 52. The first joint 51 and the second joint 52 have uniform wall thickness. The first joining portion 51 and the second joining portion 52 are formed into concentric annular rings arranged at a predetermined interval in the radial direction. The first joining portion 51 has a smaller diameter than the second joining portion 52 and is disposed inside the second joining portion 52. The first joining portion 51 joins the inner peripheral portion of the reflective layer 4 located on the inner side of the irradiation area R and the substrate 2.

On the other hand, the second joint portion 52 has a larger diameter than the first joint portion 51 and is arranged outside the first joint portion 51. The second joining portion 52 joins the outer peripheral portion of the reflective layer 4 located further outside the irradiation area R and the substrate 2.

Between the first joint 51 and the second joint 52, an air layer 53 that is concentric to the first joint 51 and the second joint 52 is formed. The centers of the first joint 51, the second joint 52 and the air layer 53 are the rotation center of the color conversion element 1. Since each of the first joining portion 51 and the second joining portion 52 is an integral body that is continuous in the circumferential direction, the air layer 53 is sealed by the first joining portion 51 and the second joining portion 52.

The air layer 53 exposes the reflective layer 4 and the substrate 2. That is, the reflective layer 4 and the substrate 2 are brought into contact with the air by the air layer 53.

The air layer 53 is arranged at a position overlapping with at least a part of the irradiation region R in a plan view. In this embodiment, the air layer 53 is formed in a position and size that can be incorporated into the entire irradiation area R in a plan view. As described above, the air layer 53 is a circular ring centered on the rotation center of the color conversion element 1. Therefore, when the color conversion element 1 rotates, the air layer 53 always overlaps the irradiation area R in a plan view.

[The operation of the projection device] Next, the operation of the projection device will be described.

When the laser light L is irradiated from the light source of the projection device, the color conversion element 1 receives the laser light L from the fluorescent part 3 via the reflection suppression layer 8 and the first planarization layer 6 while being rotated and driven. At this time, the reflection suppression layer 8 suppresses the reflection of the laser light L, so that most of the laser light L can surely enter the fluorescent portion 3.

In the fluorescent part 3, a part of the laser light L directly hits the phosphor particles 34. In addition, the laser light L that does not directly touch a part of the phosphor particles 34 is reflected on the reflective layer 4 through the second planarization layer 7 and hits the phosphor particles 34. The laser light L reaching the phosphor particles 34 is converted into white light by the phosphor particles 34 and emitted. A part of the white light emitted from the phosphor particles 34 is directly emitted to the outside from the phosphor portion 3 through the first planarization layer 6 and the reflection suppression layer 8. In addition, the other part of the light emitted from the phosphor particles 34 is reflected by the reflective layer 4 and is emitted from the phosphor portion 3 to the outside through the first planarization layer 6 and the reflection suppression layer 8.

Here, in the reflective layer 4 formed of the dielectric multilayer film, although there is a small amount of light, there is still light transmitted through the reflective layer 4. In response to this situation, an air layer 53 is provided at the junction 5. In detail, as described above, in the irradiation area R, the air layer 53 is disposed directly under the reflective layer 4. The critical angle θc in this case. The critical angle θc in this case is expressed by the following formula (1) according to Snell's Law.

θc=arcsin(n2/n1)・・・(1)

Here, if the refractive index n1 of the fluorescent portion 3, which is the incident source, is set to 1.8, and the refractive index n2 of the air layer 53 which is the travel target is set to 1.0, the critical angle θc is 33.8 degrees. In addition, the thickness of the second planarization layer 7 and the reflective layer 4 is very thin compared to the thickness of the fluorescent portion 3 or the thickness of the air layer 53, and has only a slight influence, so it can be ignored in the calculation of the critical angle θc.

On the other hand, suppose that the air layer 53 is not provided in the joint 5. That is, in the irradiated area R, the junction part 5 is arranged directly under the reflective layer 4, and the reflective layer 4 is not exposed. In this case, if the incident source, that is, the refractive index n1 of the fluorescent portion 3 is set to 1.8, and the travel target, that is, the refractive index n2 of the junction 5 is set to 1.4 (the refractive index when the junction 5 is made of silicone) , The critical angle θc is 51.1 degrees.

In this way, in this embodiment, the critical angle θc can be reduced compared to the case where the air layer 53 is not provided in the joint 5. In other words, the range of the incident angle (90 degrees-θc) of total reflection can be expanded. As described above, for the reflective layer 4, not only the laser light L will directly enter, but also the white light emitted from each phosphor particle 34 will also enter. Although the incident angles of the white light to the reflective layer 4 are various, as long as the range of the incident angle of total reflection becomes larger, more white light can be totally reflected. Therefore, the reflectance of the reflective layer 4, which is the dielectric multilayer film, can be improved. In particular, as described above, if the reflective layer 4 is laminated on the back surface of the second planarization layer 7, its reflective performance can be reliably exerted.

[Effects etc.] As described above, the color conversion element 1 of this embodiment includes: the substrate 2; the phosphor part 3 is arranged on the substrate 2, receives the laser light L from the outside, and emits light of a different color from the laser light L; A planarization layer 6 is formed by laminating the first main surface (surface 31) on the opposite side of the substrate 2 in the phosphor portion 3; the second planarization layer 7 is formed by laminating the phosphor portion 3 and the substrate The second main surface (back surface 32) on the 2 side is laminated; the reflective layer 4 is laminated on the main surface (back surface) on the substrate side of the second planarization layer 7, and is composed of a dielectric multilayer film ; And the junction 5, sandwiched between the reflective layer 4 and the substrate 2, and the reflective layer 4 and the substrate 2 are joined.

Thereby, the first planarization layer 6 is laminated on the surface 31 of the phosphor portion 3. Since the surface roughness Ra of the surface of the first planarization layer 6 is smaller than the surface roughness Ra of the surface 31 of the phosphor portion 3, the light diffusion of the laser light L can be suppressed, and most of the laser light L can be reliably entered into the phosphor Within the light section 3. That is, light leakage can be suppressed.

On the other hand, a second planarization layer 7 is interposed between the back surface 32 of the fluorescent portion 3 and the surface of the reflective layer 4. The back surface of the second planarization layer 7 has a smaller surface roughness Ra than the back surface 32 of the phosphor 3, so the reflective layer 4 can also be laminated on the back surface of the second planarization layer 7 with a uniform layer thickness on. In this way, the reflective performance of the reflective layer 4 can be more reliably exerted.

In this way, by suppressing light leakage and increasing the reflectivity of the reflective layer 4, the conversion efficiency of the color conversion element 1 can be improved.

Here, the surface 31 and the back surface 32 of the phosphor portion 3 may be polished separately to improve the flatness. However, polishing the phosphor part 3 will cause a significant increase in cost and is therefore not suitable. If the first planarization layer 6 and the second planarization layer 7 are laminated on the phosphor portion 3 as shown in the above-mentioned embodiment, even the polishing process does not need to be performed, and the manufacturing cost can be suppressed.

In addition, the junction part 5 has an air layer 53 exposing the reflective layer 4 at a position overlapping at least a part of the irradiation area R irradiated by the laser light L in the fluorescent part 3 in a plan view.

Thereby, since the air layer 53 overlaps with at least a part of the irradiation region R in a plan view, the range of the incident angle of total reflection (90 degrees-θc) can be expanded compared with the case where the air layer 53 is not provided. Therefore, the reflectance of the dielectric multilayer film, that is, the reflective layer 4 can be improved, and the conversion efficiency can be improved.

In particular, in the present embodiment, the air layer 53 is formed so as to be able to fit into the entire irradiation area R in a plan view. Therefore, the reflectance can be improved for the entire irradiation area R. That is, the conversion efficiency can be further improved.

In addition, a reflection suppression layer 8 is laminated on the main surface (surface) of the first planarization layer 6 opposite to the phosphor portion 3.

Thereby, since the reflection suppression layer 8 is laminated on the surface of the first planarization layer 6, the reflection of the laser light L can be suppressed. In this way, most of the laser light L can surely enter the fluorescent part 3.

In addition, since the surface roughness Ra of the first planarization layer 6 is smaller than that of the surface 31 of the fluorescent portion 3, the reflection suppression layer 8 can also be laminated on the first planarization layer 6 with a uniform layer thickness. On the surface 31, the reflection suppression performance of the reflection suppression layer 8 can be more reliably exerted.

In addition, at least one of the first planarization layer 6 and the second planarization layer 7 has a visible light transmittance of 90% or more.

Thereby, the visible light transmittance of at least one of the first planarization layer 6 and the second planarization layer 7 is 90% or more. Therefore, the first planarization layer 6 and the second planarization layer 7 can be suppressed from absorbing the light (laser light L) captured by the color conversion element 1 and the light (white light) emitted by the color conversion element 1. Therefore, the conversion efficiency of the color conversion element 1 can be further improved.

In addition, the refractive index of the second planarization layer 7 is smaller than the refractive index of the fluorescent portion 3.

Thereby, since the refractive index of the second planarization layer 7 is smaller than the refractive index of the fluorescent portion 3, the reflectance of the reflective layer 4 can be improved. Therefore, the conversion efficiency of the color conversion element 1 can be further improved.

In addition, at least one of the first planarization layer 6 and the second planarization layer 7 has a thickness of 1.0 μm or more.

In the front surface 31 and the back surface 32 of the fluorescent part 3, the thickness direction space|interval of each convex part vertex and a recessed part vertex is about 1.0 micrometer or less. If the thickness of at least one of the first planarization layer 6 and the second planarization layer 7 is 1.0 μm or more, the respective recesses of the front surface 31 and the back surface 32 of the phosphor portion 3 can be filled, and planarization can be surely achieved.

In addition, at least one of the first planarization layer 6 and the second planarization layer 7 is formed of SiO ₂ .

Thereby, since at least one of the first planarization layer 6 and the second planarization layer 7 is formed of SiO ₂ , the heat resistance of the first planarization layer 6 and the second planarization layer 7 can be improved. Therefore, a long-term stable color conversion element 1 can be realized, and as a result, the conversion efficiency can also be stabilized for a long time.

In addition, the main surface (back surface) on the reflective layer 4 side of the second planarization layer 7 has a surface roughness Ra of 20 nm or less.

Thereby, since the surface roughness Ra of the back surface of the second planarization layer 7 is 20 nm or less, it is possible to suppress a decrease in reflectance. FIG. 3 is a graph showing the relationship between the surface roughness Ra and the reflectance of the base material laminated with the reflective layer 4 according to the embodiment. As shown in FIG. 3, in the wavelength range of 450 nm to 800 nm, the smaller the surface roughness Ra of the substrate, the smaller the drop in reflectivity. Therefore, the surface roughness Ra of the back surface of the second planarization layer 7 on which the reflective layer 4 is laminated is set to 20 nm or less. In addition, if the surface roughness Ra of the back surface of the second planarization layer 7 is 10 nm or less, the decrease in reflectance can be suppressed, if it is 5 nm or less, the decrease in reflectance can be suppressed more, and if it is 2 nm or less, the reflection can be suppressed even more. The rate of decline.

In addition, the fluorescent part 3 is formed by arranging a plurality of sheet-like single sheets 33 containing at least one kind of fluorescent substance (fluorescent substance particles 34) in a planar shape.

Thereby, since the fluorescent portion 3 is formed of a plurality of single sheets 33 arranged in a planar shape, the stress applied during heating can be dispersed. Thereby, the deformation of the fluorescent part 3 when the laser light L is received can be suppressed. Therefore, the positional relationship between the fluorescent portion 3 and the air layer 53 can be stabilized, and stable reflection characteristics can be maintained.

Here, when the phosphor portion is integrally formed as a whole, it is difficult to resist stress concentration if its planar shape is a ring shape, and the above-mentioned problems are likely to occur. However, as in the present embodiment, if it is the phosphor part 3 formed by arranging a plurality of single pieces 33 in a ring shape, the stress can be dispersed, so a high stress relaxation effect can be obtained.

In addition, in the above-mentioned embodiment, the case where the fluorescent portion 3 is formed of a plurality of single pieces 33 is taken as an example. However, the fluorescent part may also be an integral object formed by integral molding.

[Modification 1] Next, modification 1 will be described. FIG. 4 is a cross-sectional view of the schematic configuration of the color conversion element 1A of Modification 1, specifically, a diagram corresponding to FIG. 2. In addition, in the following description, the same reference numerals are given to the same parts as the color conversion element 1 of the embodiment, and the description thereof is omitted, and only the different parts are described.

In the above embodiment, the case where the reflection suppression layer 8 is laminated on the surface of the first planarization layer 6 is taken as an example. In this modification example 1, the reflection suppression layer is not provided on the surface of the first planarization layer 6a, but the surface is exposed. On the surface of the first flattening layer 6a, a concavo-convex structure 63a composed of a plurality of fine concave portions 61a and convex portions 62a is formed on the entire surface. The uneven structure 63a is formed by applying, for example, wet blast processing to the first planarization layer 6a having no uneven structure 63a on the surface. The first planarization layer 6a is formed of transparent resin or SiO ₂ as described above. Since the material (glass or ceramic) used as the substrate 35 of the fluorescent part 3 is weaker than these materials, if wet sandblasting is applied to the fluorescent part 3, the fluorescent part 3 may be broken. If wet sandblasting is applied to the first planarization layer 6a, the fluorescent portion 3 itself can be protected.

In this way, the main surface (surface) of the first planarization layer 6a opposite to the fluorescent portion 3 has a fine uneven structure 63a.

Thereby, since the fine uneven structure 63a is formed on the surface of the first planarization layer 6a, the reflectance of the surface can be reduced, and the light extraction efficiency and the light collection efficiency can be improved.

[Modification 2] Next, modification 2 will be described. FIG. 5 is a cross-sectional view of the schematic configuration of the color conversion element 1B of Modification 2, and specifically, is a diagram corresponding to FIG. 2. In addition, in the following description, the same reference numerals are given to the same parts as the color conversion element 1 of the embodiment, and the description thereof is omitted, and only the different parts are described.

In the above embodiment, the case where the reflection suppression layer 8 is laminated on the surface of the first planarization layer 6 is taken as an example. In this modification example 2, the reflection suppression layer is not provided on the surface of the first planarization layer 6b, and the surface is exposed. The first planarization layer 6b includes: a base 65b having translucency; and a plurality of hollow particles 64b dispersed in the base 65b. That is, the plurality of hollow particles 64b are embedded in the first planarization layer 6b in a dispersed state.

The base 65b is formed of the aforementioned transparent material. In the hollow particles 64b, the outer shell is formed of a light-transmitting material, and the inside thereof is a cavity containing air. The material for forming the outer shell of the hollow particles 64b is, for example, SiO ₂ . That is, the hollow particles 64b can also be called hollow silica. Hollow silica is better at a point where it is easier to manufacture than other hollow particles.

Since the hollow particles 64b are all buried in the base 65b, the diameter of the hollow particles 64b is smaller than the thickness of the base 65b. Furthermore, the diameter of the hollow particles 64b is preferably smaller than the wavelength of the laser light L. As described above, the wavelength of the laser light L is a value within the range of 430 nm to 490 nm, and the diameter of the hollow particles 64b is a value below the wavelength of the laser light L. Thereby, the interference of the laser light L and the hollow particles 64b can be suppressed. For example, when the wavelength of the laser light L is 450 nm, the diameter of the hollow particles 64b may be less than 450 nm. Furthermore, if the diameter of the hollow particles 64b is set to 1/10 or less of the wavelength of the laser light L, since the content can be increased, the refractive index can be further reduced, and the effect of reducing Fresnel loss can be improved. Specifically, the diameter of the hollow particles 64b is 40 nm or less.

In this way, the first planarization layer 6b contains a plurality of dispersed hollow particles 64b. Thereby, the refractive index of the first flattening layer 6b can be reduced, and the light emitted from the fluorescent portion 3 can be suppressed from being scattered by the first flattening layer 6b.

[Modification 3] Next, modification 3 will be described. FIG. 6 is a cross-sectional view of a schematic configuration of a color conversion element 1C of Modification 3, and specifically, is a diagram corresponding to FIG. 2. In addition, in the following description, the same reference numerals are given to the same parts as the color conversion element 1 of the embodiment, and the description thereof is omitted, and only the different parts are described.

In the above-mentioned embodiment, the case where the joint 5 has the air layer 53 is taken as an example. In this modification 3, the case where the joint 5c does not have an air layer is taken as an example. In other words, the bonding portion 5c covers the entire back surface of the reflective layer 4. Thereby, the junction part 5c is arrange|positioned at the position where the whole pair of irradiation area R in the fluorescent part 3 overlaps in a plan view. Here, the bonding portion 5c is formed of silicon resin containing at least one of oxide and nitride. The oxide is, for example, TiO ₂ , ZnO, Al ₂ O ₃ and the like.

In this way, the bonding portion 5c is formed of silicon resin containing at least one of oxide and nitride, and is arranged at a position overlapping the entire irradiation area R irradiated by the laser light L in the fluorescent portion 3 in a plan view .

Thereby, since the bonding portion 5c directly contacts the irradiated area R in the fluorescent portion 3, the heat from the hottest area (irradiated area R) of the fluorescent portion 3 can be conducted to the substrate 2 through the bonding portion 5c. Therefore, heat dissipation can be improved. In particular, since the bonding portion 5c is formed of silicon resin containing at least one of oxide and nitride, the thermal conductivity of the bonding portion 5c alone can be improved, and a higher heat dissipation effect can be exerted.

In addition, the bonding portion 5c is set to overlap at least a part of the irradiated region R in the fluorescent portion 3 in a plan view, and a certain heat dissipation effect can also be obtained.

[Modification 4] Next, modification 4 will be described. FIG. 7 is a cross-sectional view of the schematic configuration of the color conversion element 1D of Modification 4, and specifically, is a diagram corresponding to FIG. 4. In addition, in the following description, the same reference numerals are given to the same parts as the color conversion element 1A of Modification 1, and the description thereof is omitted, and only the different parts are described.

In the first modification described above, the case where the joint 5 has the air layer 53 is taken as an example. In this modification 4, a case where the joint 5d does not have an air layer is taken as an example. That is, the bonding portion 5d covers the entire back surface of the reflective layer 4. Thereby, the bonding portion 5d is arranged at a position where the entire irradiated area R in the fluorescent portion 3 overlaps in a plan view. Here, the bonding portion 5d is formed of silicon resin containing at least one of oxide and nitride.

In this modification 4, since the bonding portion 5d directly contacts the irradiated area R in the fluorescent portion 3, the heat from the hottest part (irradiated area R) of the fluorescent portion 3 can be conducted to the substrate through the bonding portion 5d 2. Therefore, heat dissipation can be improved. In addition, if the bonding portion 5d overlaps at least a part of the irradiated region R in the fluorescent portion 3 in a plan view, a certain heat dissipation effect can also be obtained.

[Modification 5] Next, modification 5 will be explained. FIG. 8 is a cross-sectional view of the schematic configuration of the color conversion element 1E of Modification 5, and specifically, is a diagram corresponding to FIG. 5. In addition, in the following description, the same reference numerals are given to the same parts as the color conversion element 1B of Modification 2, and the description thereof is omitted, and only the different parts are described.

In the second modification described above, the case where the joint 5 has the air layer 53 is taken as an example. In this modified example 5, a case where the joint 5e does not have an air layer is taken as an example. That is, the bonding portion 5e covers the entire back surface of the reflective layer 4. Thereby, the bonding portion 5e is arranged at a position where the entire irradiated area R in the fluorescent portion 3 overlaps in a plan view. Here, the bonding portion 5e is formed of silicon resin containing at least one of oxide and nitride.

In this modification 5, since the junction 5e directly contacts the irradiated area R in the fluorescent portion 3, the heat from the hottest part (irradiated area R) of the fluorescent portion 3 can be conducted through the junction 5e to Substrate 2. Therefore, heat dissipation can be improved. In addition, the bonding portion 5e is configured to overlap at least a part of the irradiation area R in the fluorescent portion 3 in a plan view, and a certain heat dissipation effect can also be obtained.

[Modification 6] Next, modification 6 will be described. FIG. 9 is a cross-sectional view of the schematic configuration of the color conversion element 1F of Modification Example 6, and specifically, is a diagram corresponding to FIG. 5. In addition, in the following description, the same reference numerals are given to the parts equivalent to the modification 2 and the description thereof is omitted, and only the different parts will be described.

In the aforementioned modification 2, the case where the first planarization layer 6b has a single-layer structure is taken as an example. In this modification 6, a case where the first planarization layer 6f has a multiple-layer structure is taken as an example.

As shown in FIG. 9, the first planarization layer 6f includes: a first layer 610f laminated on the surface 31 of the fluorescent portion 3; and a second layer 620f laminated on the first layer 610f and the fluorescent portion 3 It is the opposite side (surface).

The first layer 610f is flat by directly covering the surface 31 of the fluorescent portion 3 to fill the fine depressions of the surface 31. Therefore, the surface roughness Ra of the surface of the first layer 610f is smaller than the surface roughness Ra of the surface 31 of the fluorescent portion 3. The second layer 620f directly covers the surface of the first layer 610f, and the surface roughness Ra of the surface is equal to or higher than that of the first layer 610.

The first layer 610f does not contain hollow particles 64b; in the second layer 620f, a plurality of hollow particles 64b are dispersed.

The base 65b of the first layer 610f and the second layer 620f may be formed of SiO ₂ series materials, respectively. The material of the first layer 610f and the material of the base 65b of the second layer 620f may be completely the same material, and if it is an SiO ₂ system, the additives may be different. In addition, in terms of reducing Fresnel loss, the refractive index of the material of the base 65b of the second layer 620f is preferably lower than the refractive index of the material of the first layer 610f.

As described above, according to the color conversion element 1F of Modification 6, the first planarization layer 6f includes: a first layer 610f laminated on the surface 31 of the phosphor portion 3; and a second layer 620f laminated on the first layer The surface of 610f is the opposite side to the fluorescent part 3, and the first layer 610f does not contain granules; in the second layer 620f, plural granules (hollow granules 64b) are dispersed.

Thereby, a first layer 610f that does not contain granules is laminated on the surface 31 of the fluorescent portion 3, and the first layer 610f can be flattened. That is, since the surface roughness Ra of the surface of the first layer 610f is smaller than the surface roughness Ra of the surface 31 of the phosphor portion 3, the light diffusion of the laser light L passing through the second layer 620f can be suppressed, and most of the laser light The incident light L enters the fluorescent part 3 more reliably. Therefore, since a lot of light can be captured in the fluorescent part 3, the light emitted from the fluorescent part 3 can also be increased.

[Modification 7] Next, modification 7 will be described. FIG. 10 is a cross-sectional view of the schematic configuration of the color conversion element 1G of Modification Example 7, and specifically, is a diagram corresponding to FIG. 9. In addition, in the following description, the same reference numerals are given to the parts equivalent to those in Modification 6, and the description thereof will be omitted, and only the different parts will be described.

In the above-mentioned modification 6, a case where the first planarization layer 6f has a two-layer structure is taken as an example. In this modification 7, a case where the first planarization layer 6g has a four-layer structure is taken as an example.

As shown in FIG. 10, the first planarization layer 6g includes: a first layer 610f; a second layer 620g, laminated on the surface of the first layer 610f on the opposite side to the fluorescent portion 3 (surface; third layer 630g , Laminated on the surface (surface) of the second layer 620g opposite to the fluorescent portion 3; and the fourth layer 640g, laminated on the surface of the third layer 630g opposite to the fluorescent portion 3 ( surface).

Here, in the first layer 610f, the hollow particles 64b are not contained, and in the second layer 620g, the third layer 630g, and the fourth layer 640g, plural hollow particles 64b are dispersed. Specifically, the concentration (density) of the hollow particles 64b has the relationship of the second layer 620g<the third layer 630g<the fourth layer 640g. In this way, the concentration of the plurality of hollow particles 64b in each layer (the first layer 610f to the fourth layer 640g) is determined to be that the first planarization layer 6g increases gradually as the distance from the fluorescent portion 3 is as a whole. Thereby, in the first planarization layer 6g, the refractive index gradually decreases as the distance from the fluorescent portion 3 is increased. That is, the refractive index of the first planarization layer 6g is closer to the refractive index of air as it moves away from the fluorescent portion 3. For example, the refractive index of the first layer 610f is 1.5, the refractive index of the second layer 620g is 1.4, the refractive index of the third layer 630g is 1.3, and the refractive index of the fourth layer 640g is 1.2. And the closer to the refractive index of air.

In addition, the material used as the base of each layer may be formed of a SiO ₂ system material. The material used as the matrix of each layer may be completely the same material, and if it is an SiO ₂ system, the additives may be different. In this case, a material whose refractive index formed by the matrix of each layer gradually decreases as the distance from the fluorescent part 3 is increased.

As a method for producing the first planarization layer 6g, such as by a powder-based SiO ₂ material, in accordance with the amount of the added concentration of the respective layers of the hollow body particles 64b, and a plurality of layers corresponding to the production and preparation of materials. Thereafter, the surface 31 of the phosphor portion 3 is arranged as a preparation material for the first layer 610f and sintered, thereby forming the first layer 610f. Next, on the surface of the first layer 610f, a preparation material for the second layer 620g is arranged and sintered, thereby forming the second layer 620g. Next, on the surface of the second layer 620g, the preparation material for the third layer 630g is arranged and sintered, thereby forming the third layer 630g. Next, on the surface of the third layer 630g, the preparation material for the fourth layer 640g is arranged and sintered, thereby forming the fourth layer 640g. Thereby, the first planarization layer 6g is formed.

As described above, according to the color conversion element 1G of Modification 7, the concentration of the plurality of particles (hollow particles 64b) in the first flattened layer 6g gradually increases as they move away from the fluorescent portion 3.

Thereby, in the first planarization layer 6g, the refractive index gradually decreases as the distance from the fluorescent portion 3 is increased. Therefore, the Fresnel loss can be greatly reduced.

In addition, the first planarization layer 6g is formed by a plurality of layers (a first layer 610f, a second layer 620g, a third layer 630g, and a fourth layer 640g), and the plurality of granules (hollow granules 64b) in each layer The concentration of is determined to be that the first planarization layer 6g gradually increases as the distance from the phosphor part 3 is increased as a whole.

Thereby, since the first planarization layer 6g is formed of a plurality of layers with different concentrations of the hollow particles 64b, it is easy to control the concentration of the hollow particles 64b in each layer during manufacturing. Therefore, it is also easy to control the refractive index of each layer.

In addition, the first planarization layer may have a three-layer structure or a five-layer structure or more.

[Modification 8] Next, modification 8 will be described. FIG. 11 is a cross-sectional view of the schematic configuration of the color conversion element 1H of Modification 8, and specifically, is a diagram corresponding to FIG. 5. In addition, in the following description, the same reference numerals are given to the parts equivalent to the modification 2 and the description thereof is omitted, and only the different parts will be described.

In the above modification 7, the case where the first planarization layer 6g is formed of a plurality of layers, and the concentration of the plurality of hollow particles 64b in each layer is different is taken as an example. In this modification 8, the first planarization layer 6h is a single layer, and the concentration of hollow particles 64b in this layer is different. Specifically, in the first flattened layer 6h, the concentration of the plurality of hollow particles 64b gradually increases as the distance from the fluorescent portion 3 is increased. Thereby, in the first planarization layer 6h, the refractive index gradually decreases as the distance from the fluorescent portion 3 is increased. Therefore, the Fresnel loss can be greatly reduced.

[Modification 9] In the above-mentioned embodiment, a case where the color conversion element 1 is applied to a projection device is taken as an example for description, but the color conversion element can also be used in a lighting device. In this case, since the color conversion element does not rotate, it may not be wheel-shaped. Hereinafter, an example of the color conversion element used in the lighting device will be described.

FIG. 12 is a schematic configuration diagram of a lighting device 100 according to Modification 9. As shown in FIG. 12, the lighting device 100 includes a light source unit 101, a light guide member 102, and a color conversion element 1I. In addition, in FIG. 12, the illustration of the first planarization layer, the second planarization layer, and the reflection suppression layer included in the color conversion element 1I is omitted.

The light source unit 101 is a device that generates laser light L1 and supplies the laser light L1 to the color conversion element 1F via the light guide member 102. For example, the light source unit 101 is a semiconductor laser element that emits laser light L1 having a wavelength of blue-violet to blue (430 to 490 nm). The light guide member 102 is a light guide member that guides the laser light L1 emitted by the light source unit 101 to the color conversion element 1I, and is, for example, an optical fiber.

The substrate 2i of the color conversion element 1I has a rectangular shape in a plan view, and a reflective layer 4i and a fluorescent portion 3i are laminated on one surface 22i of the color conversion element 1I via the bonding portion 5i. The phosphor portion 3i is formed in a rectangular shape in a plan view, and a reflective layer 4i made of a dielectric multilayer film is laminated on the entire main surface of the substrate 2i. The joining portion 5i is formed in a continuous frame shape with respect to the outer peripheral edge of the fluorescent portion 3i. Thereby, the air layer 53i which exposes the reflective layer 4i is formed inside the junction part 5i. The air layer 53i is arranged at a position overlapping the irradiation area R1 of the laser light L1 in a plan view.

In this way, in the lighting device 100 of Modification 9, the reflective layer 4i is exposed at a position where the air layer 53i overlaps with at least a part of the irradiated region R1 in the fluorescent portion 3i in a plan view. Therefore, compared with the case where the air layer 53i is not provided, the range of the incident angle of total reflection (90 degrees-θc) can be expanded. Therefore, the reflectance of the dielectric multilayer film, that is, the reflective layer 4i can be increased, and the conversion efficiency can be improved.

In addition, in the color conversion element used in the lighting device, the fluorescent part may also be formed by a plurality of single pieces.

[Modification 10] Next, modification 10 will be described. FIG. 13 is a cross-sectional view of a schematic configuration of a color conversion element 1J of Modification Example 10. Specifically, it is a diagram corresponding to FIG. 2. In addition, in the following description, the same reference numerals are given to the same parts as the color conversion element 1 of the embodiment, and the description thereof is omitted, and only the different parts are described.

In the above embodiment, the case where the reflection suppression layer 8 such as an AR coating is laminated on the surface of the first planarization layer 6 is taken as an example. In the color conversion element 1J of this modification 10, the surface of the first planarization layer 6 is laminated with a reflection suppression layer 8j different from the AR coating.

The reflection suppression layer 8j includes: a base layer 81j having translucency; and a plurality of bubbles 82j dispersed in the base layer 81j.

The base layer 81j is formed of the aforementioned transparent material. The air bubble 82j is a bubble made of air, and is buried in the base layer 81j. Therefore, the diameter of the bubble 82j is smaller than the thickness of the base layer 81j. Furthermore, the diameter of the bubble 82j is preferably smaller than the wavelength of the laser light L. As described above, since the wavelength of the laser light L falls within the range of 430 nm to 490 nm, the diameter of the bubble 82j is a value equal to or less than the wavelength of the laser light L. Thereby, interference of the laser light L and the air bubble 82j can be suppressed. For example, when the wavelength of the laser light L is 450 nm, the diameter of the bubble 82j may be less than 450 nm. Furthermore, if the diameter of the bubble 82j is set to 1/10 or less of the wavelength of the laser light L, the content can be increased, so the refractive index can be lowered, and the effect of reducing Fresnel loss can be improved. Specifically, the diameter of the bubbles 82j is 40 nm or less.

In this way, since the reflection suppression layer 8j has a plurality of bubbles 82j dispersed in the translucent base layer 81j, the effect of reducing Fresnel loss can be improved, and the reflection of the laser light L can be suppressed.

Here, dry processing is necessary when forming the AR coating as the reflection suppression layer 8. When performing dry processing, vacuum in the work area is necessary, which leads to an increase in the size of the manufacturing equipment. On the other hand, in the reflection suppression layer 8j of this modification, although the base layer 81j in which plural bubbles 82j are dispersed is formed, it can also be formed in a wet process without vacuumization. That is, it is possible to suppress the increase in the size of the manufacturing device, and as a result, it is possible to reduce the manufacturing cost.

[Modification 11] Next, modification 11 will be described. FIG. 14 is a cross-sectional view of the schematic configuration of the color conversion element 1K of Modification Example 11. Specifically, it is a diagram corresponding to FIG. 13. In addition, in the following description, the same reference numerals are given to the same parts as the color conversion element 1J of Modification 10, and the description thereof is omitted, and only the different parts are described.

In the aforementioned modification 10, the case where only the air bubbles 82j are dispersed in the base layer 81j is taken as an example. In the color conversion element 1K of this modification 11, the space formed by the aggregated plurality of fine particles 83k is set as the air bubble 82k.

Specifically, the reflection suppression layer 8k included in the color conversion element 1K has a base layer 81k formed of the aforementioned translucent material, and a plurality of microparticle groups 84k dispersed in the base layer 81k.

The plural microparticle groups 84k are each in a state where the plural microparticles 83k are aggregated. The fine particles 83k are formed of a material having translucency such as SiO ₂ . The microparticle 83k is a solid particle. In the center of the microparticle group 84k, there is a space closed by the aggregation of a plurality of microparticles 83k. This space is a bubble 82k. It is preferable that the air bubble 82k be the same size as the air bubble 82j of Modification 10. In addition, in the fine particles 83k, the hollow particles 64b of Modification Example 2 may have the same size.

In this way, the reflection suppression layer 8k including a plurality of microparticle groups 84k on the base layer 81k is formed by, for example, a well-known sol-gel method, which is an example of wet processing. Therefore, the reflection suppression layer 8k may also be referred to as a sol-gel layer.

In this way, in the reflection suppression layer 8k, since the space formed by the plurality of fine particles 83k aggregated in the base layer 81k is set as the air bubble 82k, the plurality of air bubbles 82k improve the Fresnel loss reduction effect and can suppress thunder The reflection of light L.

[Modification 12] Next, modification 12 will be described. 15 is a cross-sectional view of the schematic configuration of the color conversion element 1M of Modification 12. Specifically, it is a diagram corresponding to FIG. 5. In addition, in the following description, the same reference numerals are given to the same parts as the color conversion element 1B of Modification 2, and the description thereof is omitted, and only the different parts are described.

In Modification 2, a case where the first planarization layer 6b includes a matrix 65b and a plurality of hollow particles 64b dispersed in the matrix 65b is taken as an example. In the color conversion element 1M of this modification 12, a case where a plurality of bubbles 82m are dispersed as particles in the matrix 65m of the first planarization layer 6m is taken as an example.

The first planarization layer 6m includes: a base 65m, which is translucent; and 82m of plural bubbles, dispersed in the base 65m. The base 65m is made of the aforementioned translucent material. The bubble 82m is a bubble made of air, and is buried in the base 65m. In addition, the air bubbles 82m may be a space formed by agglomerated plural particles. The air bubble 82m is preferably the same size as the air bubble 82j of Modification 10.

In this way, since the first planarization layer 6m has a plurality of bubbles 82m dispersed in the translucent base 65m, the effect of reducing Fresnel loss can be improved, and the reflection of the laser light L can be suppressed. That is, the first planarization layer 6m can be used as a reflection suppression layer.

[Other embodiments] As mentioned above, the lighting device of the present invention has been described based on the above-mentioned embodiment and each modification, but the present invention is not limited to the above-mentioned embodiment and each modification.

For example, in the above-mentioned embodiment, the case where the entire fluorescent portion 3 is formed of a single sheet 33 that emits white light is taken as an example. However, when the fluorescent part emits multi-color light, the parts emitting each color in the fluorescent part may also be formed by the same type of single chip. For example, suppose the case of a fluorescent portion formed by arranging three layers of a red fluorescent portion, a green fluorescent portion, and a blue fluorescent portion in a planar shape. The red fluorescent part is formed by a plurality of single pieces of the same kind containing red fluorescent substance. The blue fluorescent part is formed by a plurality of single pieces of the same kind containing blue fluorescent substance. The green fluorescent part is formed by a plurality of single pieces of the same kind containing green fluorescent substance.

In addition, in the modified example 2 and the like, the hollow particles 64b and the like are taken as an example. However, the particles dispersed in the matrix of the first planarization layer may also be solid particles. In the case of solid particles, the refractive index of the particles may be smaller than the refractive index of the matrix of the first planarization layer. Thereby, the refractive index of the first planarization layer can be reduced, and the Fresnel reflection of the irradiated laser light L on the surface of the first planarization layer can be suppressed.

In addition, the above-mentioned embodiment is a form obtained by applying various modifications that a person having ordinary knowledge in the technical field thinks of, or arbitrarily combining the constituent elements and functions in the embodiment and each modification without departing from the scope of the present invention. The implementation form is also included in the present invention.

1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K, 1M: color conversion components 2,2i: substrate 3,3i: Fluorescent part 4,4i: reflective layer 5, 5c, 5d, 5e, 5i: joint 6, 6a, 6b, 6f, 6g, 6h, 6m: the first planarization layer 7: The second planarization layer 8, 8j, 8k: reflection suppression layer 21: Through hole 22, 22i: surface 31: Surface (first main surface) 32: Back (second main surface) 33: single chip 34: Phosphor particles 35: Substrate 51: The first joint 52: second joint 53,53i: air layer 61a: recess 62a: convex 63a: Concave-convex structure 64b: Hollow corpuscles (granules) 65b, 65m: matrix 81j, 81k: grassroots 82j, 82k, 82m: bubbles 83k: fine particles 84k: Microparticle group 100: lighting device 101: Light Source Department 102: Light guide member 610f: first layer 620f, 620g: second layer 630g: third layer 640g: fourth layer L, L1: Laser light R, R1: Irradiation area

[Fig. 1] Fig. 1 is a schematic diagram of the schematic configuration of the color conversion element of the embodiment. [Fig. 2] Fig. 2 is a cross-sectional view of the cross section including the II-II line of Fig. 1 as viewed. [Fig. 3] Fig. 3 is a graph showing the relationship between the surface roughness Ra and the reflectance of the substrate with the reflective layer laminated in the embodiment. Fig. 4 is a cross-sectional view of the schematic configuration of the color conversion element of Modification 1. [Fig. 5] Fig. 5 is a cross-sectional view of a schematic configuration of a color conversion element of Modification 2. Fig. 6 is a cross-sectional view of the schematic configuration of a color conversion element of Modification 3. [Fig. 7] Fig. 7 is a cross-sectional view showing a schematic configuration of a color conversion element of Modification 4. Fig. 8 is a cross-sectional view showing a schematic configuration of a color conversion element of Modification 5. Fig. 9 is a cross-sectional view of a schematic configuration of a color conversion element of Modification 6. Fig. 10 is a cross-sectional view of a schematic configuration of a color conversion element of Modification 7. Fig. 11 is a cross-sectional view of the schematic configuration of a color conversion element of Modification 8. Fig. 12 is a cross-sectional view of the schematic configuration of a color conversion element of Modification 9. Fig. 13 is a cross-sectional view of a schematic configuration of a color conversion element of Modification 10. Fig. 14 is a cross-sectional view of a schematic configuration of a color conversion element of Modification 11. 15] FIG. 15 is a cross-sectional view of a schematic configuration of a color conversion element of Modification 12.

1: Color conversion components

2: substrate

3: Fluorescent part

4: reflective layer

5: Joint

6: The first planarization layer

7: The second planarization layer

8: Reflection suppression layer

22: Surface

31: Surface (first main surface)

32: Back (second main surface)

33: single chip

34: Phosphor particles

35: Substrate

51: The first joint

52: second joint

53: Air layer

L: Laser light

R: Irradiation area

Claims (21)

A color conversion element, comprising: a substrate; a fluorescent part, which is arranged on the substrate, receives laser light from the outside, and emits light of a different color from the laser light; and a first planarization layer for the fluorescent part It is formed by laminating the first main surface on the side opposite to the substrate; the second planarization layer is formed by laminating the second main surface on the side of the substrate in the phosphor part; the reflective layer, laminated On the main surface of the second planarization layer on the side of the substrate, and is composed of a dielectric multilayer film; and a bonding portion, sandwiched between the reflective layer and the substrate, and the reflective layer and the substrate are attached Splice. The color conversion element of claim 1, wherein the bonding portion has an air layer that exposes the reflective layer at a position overlapping at least a part of the irradiation area irradiated by the laser light in the fluorescent portion in a plan view . The color conversion element of claim 1, wherein the bonding portion is formed of silicon resin containing at least one of oxide and nitride, and is arranged in the fluorescent portion to be irradiated by the laser light At least a part of the area overlaps in a top view. The color conversion element according to claim 1, wherein a reflection suppression layer is laminated on the main surface of the first planarization layer opposite to the phosphor portion. According to claim 4, the color conversion element, wherein the reflection suppression layer includes: a base layer having light transmittance; and a plurality of bubbles dispersed in the base layer. Such as the color conversion element of claim 5, wherein the bubble is a space formed by agglomerated plural particles. The color conversion element of claim 5, wherein the diameter of the bubble is smaller than the wavelength of the laser light. The color conversion element of claim 1, wherein the main surface of the first planarization layer on the opposite side to the phosphor portion has a fine uneven structure. The color conversion element of claim 1, wherein the first planarization layer comprises: a matrix having light transmittance; and a plurality of particles dispersed in the matrix, and the refractive index of the particles is less than the refractive index of the matrix . Such as the color conversion element of claim 9, wherein the particle system is bubbled. Such as the color conversion element of claim 10, wherein the bubble is a space formed by agglomerated plural particles. Such as the color conversion element of claim 9, wherein the particle system is hollow particles. The color conversion element of claim 9, wherein the first planarization layer includes: a first layer laminated on the first main surface of the phosphor portion; and a second layer laminated on the first layer The surface on the opposite side to the fluorescent part; in the first layer, the granules are not contained, and in the second layer, plural of the granules are dispersed. The color conversion element of claim 9, wherein the diameter of the granule is smaller than the wavelength of the laser light. The color conversion element of claim 9, wherein the concentration of the plurality of granules increases as the distance from the fluorescent part in the first planarization layer is. The color conversion element of claim 15, wherein the first planarization layer is formed by a plurality of layers, and the concentration of the plurality of granules in each layer is determined as: viewing the first planarization layer as a whole, The farther away from the fluorescent part, the larger it is. The color conversion element of claim 1, wherein at least one of the first planarization layer and the second planarization layer has a visible light transmittance of more than 90%. The color conversion element according to claim 1, wherein the refractive index of the second planarization layer is less than the refractive index of the fluorescent part. The color conversion element of claim 1, wherein at least one of the first planarization layer and the second planarization layer has a thickness of 1.0 μm or more. The color conversion device of claim 1, wherein at least one of the first planarization layer and the second planarization layer is formed of SiO ₂ . The color conversion element of claim 1, wherein the surface roughness Ra of the main surface on the reflective layer side of the second planarization layer is 20 nm or less.

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