JP2012104267A - Light source device and lighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source device capable of achieving higher luminance.SOLUTION: The light source device 20 includes a solid light source 5 which emits light with a prescribed wavelength out of a wavelength region from ultraviolet light to visible light, and a phosphor layer 2 including at least one kind of phosphor which, excited by excitation light from the solid light source 5, emits fluorescent light with a longer wavelength than a light-emitting wavelength of the solid light source 5. The solid light source 5 and the phosphor layer 2 are located spatially in separation, and the fluorescent light is at least extracted by reflection from a surface of an excitation-light-incident side of the phosphor layer 2. On a face of the side where excitation light of the phosphor layer 2 is incident, a light-diffusing means 1 is arranged for diffusion of excitation light from the solid light source 5.

Description

  The present invention relates to a light source device and an illumination device.

  A light source device in which a solid light source (photo semiconductor) such as an LED and a phosphor layer are combined is widely known as described in Patent Document 1, for example.

  FIG. 1 shows a light source device described in Patent Document 1. In this light source device, the phosphor layer 92 is generated in the phosphor layer 92 by directly bonding the phosphor layer 92 to an optical semiconductor (solid light source) 95 as shown in FIG. It is intended to dissipate the heat to the optical semiconductor (fixed light source) 95 side.

JP 2006-005367 A

  Incidentally, in the conventional light source device in which the optical semiconductor (solid light source) 95 and the phosphor layer 92 are directly bonded as shown in FIG. 1, the phosphor layer excited by the excitation light from the optical semiconductor (solid light source) 95. The light emitted from the light 92 (fluorescence) is emitted to the side opposite to the optical semiconductor (solid light source) 95 side, and the light semiconductor (solid light source) 95 that is not absorbed by the phosphor layer 92 and passes through the phosphor layer 92. The excitation light from is used. That is, the light source device of FIG. 1 is of a transmissive type that uses light transmitted through the phosphor layer 92.

  Here, when light emitted from the phosphor layer 92 is considered, there is also light reflected from the interface with the phosphor layer 92 together with the transmitted light and returning to the optical semiconductor (solid light source) 95 side, that is, reflected light. This light (reflected light) is re-absorbed by the optical semiconductor (solid light source) 95, so that there is a problem that the light cannot be used as illumination light.

  1 is intended to dissipate the heat of the phosphor layer 92 to the optical semiconductor (solid light source) 95 side, but the excitation light intensity of the optical semiconductor (solid light source) 95 is increased. Since heat is generated not only in the phosphor layer 92 but also in the optical semiconductor (solid light source) 95, the heat generated in the phosphor layer 92 is dissipated from the side of the optical semiconductor (solid light source) 95 that is also generating heat. There was a problem that the efficiency of was not good.

  As described above, the light source device shown in FIG. 1 has a limitation on high luminance because it is of a transmissive type and the efficiency of heat dissipation with respect to the heat generation of the phosphor layer 92 is not good.

  In the prior application (Japanese Patent Application No. 2009-286397) of the present application, the applicant of the present application, as shown in FIG. Are spaced apart from each other, and the light source device 10 is devised in which the excitation light from the solid light source 5 is incident on the phosphor layer 2 and the fluorescence and excitation light from the phosphor layer 2 are extracted in a reflective manner. Here, the reflection method is a method of taking out the fluorescence and the excitation light by using the reflection by the reflection surface provided on the opposite side of the surface of the phosphor layer 2 on the side where the excitation light is incident, By adopting the reflection method, the reflected light of the fluorescence and the reflected light of the excitation light can be used with little optical loss, so that high luminance can be achieved. In FIG. 2, reference numeral 4 denotes a heat dissipation substrate, and reference numeral 3 denotes a joint portion between the phosphor layer 2 and the heat dissipation substrate.

  However, in the reflection-type light source device 10 in which the solid light source 5 and the phosphor layer 2 are arranged spatially apart as shown in FIG. 2, the reflected light of the excitation light reflected by the phosphor layer 2 depends on the angle of the emission intensity. Since there are two components having different properties, there is a problem that not all the reflection components can be used effectively. Referring to FIG. 3, in the reflection-type light source device 10, a solid light source 5 that emits excitation light with strong directivity such as a semiconductor laser is used, and the excitation light from the solid light source 5 is converted into a phosphor. When the layer 2 is irradiated, a diffuse reflection component having no angle dependency and a regular reflection component having strong directivity in the direction of the reflection angle are generated. Among them, the diffuse reflection component of the excitation light having no angle dependency is emitted in the light extraction direction (direction perpendicular to the surface of the phosphor layer 2) together with the fluorescence emitted by the phosphor layer having no angle dependency ( Hereinafter, in the present application, for convenience of explanation, light that is emitted around and used in the light extraction direction is referred to as illumination light), and can be used as illumination light, but is a regular reflection component that has a strong angle dependency. Is emitted in a direction significantly different from the light extraction direction (Note that the specular reflection component having a strong angle dependency is emitted in a direction significantly different from the light extraction direction, particularly in the reflection method, from the solid light source 5. It was not available as illumination light (by causing the excitation light to enter the phosphor layer 2 obliquely). For this reason, there is a limit to further increasing the brightness.

  An object of the present invention is to provide a light source device and an illuminating device that can achieve higher luminance.

  In order to achieve the above object, the invention described in claim 1 is excited by a solid light source that emits light of a predetermined wavelength in a wavelength region from ultraviolet light to visible light, and excitation light from the solid light source. A phosphor layer containing at least one type of phosphor that emits fluorescence having a longer wavelength than the emission wavelength of the solid-state light source, and the solid-state light source and the phosphor layer are arranged spatially apart from each other, A light source device that extracts at least fluorescence from a surface of the phosphor layer on which the excitation light is incident by a reflection method, wherein the excitation light from the solid-state light source is disposed on the surface of the phosphor layer on which the excitation light is incident. A light diffusing means for diffusing light is provided.

  According to a second aspect of the present invention, in the light source device according to the first aspect, the phosphor layer is phosphor ceramic.

  The invention described in claim 3 is an illumination device characterized in that the light source device described in claim 1 or claim 2 is used.

  According to the first to third aspects of the present invention, the solid light source that emits light having a predetermined wavelength in the wavelength region from ultraviolet light to visible light, and the solid that is excited by the excitation light from the solid light source. A phosphor layer containing at least one phosphor that emits fluorescence having a wavelength longer than the emission wavelength of the light source, and the solid-state light source and the phosphor layer are arranged spatially separated from each other, and the fluorescence A light source device for extracting at least fluorescence from a surface of the body layer on which the excitation light is incident by a reflection method, wherein the excitation light from the solid-state light source is irradiated on the surface of the phosphor layer on which the excitation light is incident. Since the light diffusing means for diffusing is provided, it is possible to reduce the regular reflection component of the two reflection components of the excitation light, increase the diffuse reflection component, and further increase the luminance. .

It is a figure which shows the conventional light source device. It is a figure which shows the light source device as described in the prior application of this application. It is a figure for demonstrating a reflection-type light source device. It is a figure which shows the example of 1 structure of the light source device of this invention. It is a figure which shows the example of the uneven structure which has a light-diffusion function as a light-diffusion means. It is a figure which shows one structural example of the illuminating device of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 4 is a diagram illustrating a configuration example of the light source device according to the embodiment of the present invention. In FIG. 4, the same reference numerals are given to the same portions as those in FIG. 2. Referring to FIG. 4, the light source device 20 is excited by a solid light source 5 that emits light having a predetermined wavelength in a wavelength region from ultraviolet light to visible light, and excitation light from the solid light source 5. The phosphor layer 2 includes at least one type of phosphor that emits fluorescence having a wavelength longer than the emission wavelength of the light source 5, and the solid light source 5 and the phosphor layer 2 are arranged spatially separated from each other.

  Here, the phosphor layer 2 is substantially free of a resin component.

  Further, in the light source device 20, similarly to the light source device 10 shown in FIG. 2, the reflection provided on the opposite side of the surface of the phosphor layer 2 from the surface on which the excitation light from the solid light source 5 is incident. A method of taking out light such as fluorescence by using reflection by a surface (hereinafter referred to as a reflection method) is employed.

  In this way, the light source device 20 basically has the solid light source 5 and the phosphor layer 2 installed spatially apart from the phosphor layer 2 in the same manner as the light source device 10 shown in FIG. The light emission (fluorescence) is used in a reflection system.

  In the conventional light source device shown in FIG. 1, among the excitation light from the solid light source 95 and the fluorescence from the phosphor layer 92, the fluorescence emitted to the opposite side of the solid light source 95 and the phosphor layer 92 are absorbed. The excitation light from the fixed light source 95 that is transmitted without being transmitted is used. That is, the transmission method is used.

  Here, in the transmission method, when the emitted light from the phosphor layer 92 is considered, the excitation light is reflected at the interface with the phosphor layer 92 together with the transmitted light and is returned to the solid light source 95 side, that is, reflected. There is also light, and this reflected light is reabsorbed by the solid light source 95 and becomes light that cannot be used as illumination light. Further, since the fluorescence from the phosphor layer 92 is emitted from both sides of the phosphor layer 92, the light emitted to the solid light source 95 side cannot be used. Thus, in the transmission method, the light use efficiency is reduced.

  On the other hand, in the light source device 20 of FIG. 4, a reflection method in which light (excitation light, fluorescence) emitted to the side opposite to the solid light source 5 is reflected to the solid light source 5 side by a reflection surface (for example, a reflection surface of the substrate). 2 is used, similarly to the light source device 10 shown in FIG. 2, light emission (fluorescence) from the phosphor layer 2 excited by excitation light from the solid light source 5 (ie, emitted to the solid light source 5 side). Fluorescent light and excitation light from the solid light source 5 that is not absorbed by the phosphor layer 2 (that is, reflected light of the light from the solid light source 5 that is not absorbed by the phosphor layer 2) are used for illumination light with little light loss. Therefore, high brightness can be achieved.

  As described above, in the light source device 20 of FIG. 4, basically, as in the light source device 10 shown in FIG. 2, the solid light source 5 and the phosphor layer 2 are arranged spatially separated to form a phosphor layer. Since the light emission (fluorescence) from 2 is used in a reflective manner, higher brightness can be achieved compared to the conventional case.

  Further, in the light source device 20 of FIG. 4, since the phosphor layer 2 that does not substantially contain a resin component is used, there is no discoloration due to heat and less light absorption. The brightness can be increased.

  Here, the phosphor layer 2 substantially not containing a resin component means that the resin component normally used for forming the phosphor layer is 5 wt% or less of the phosphor layer. In order to realize such a phosphor layer, a phosphor powder dispersed in glass, a glass phosphor in which a luminescent center ion is added to a glass matrix, a phosphor single crystal, or a phosphor polycrystal (hereinafter referred to as a phosphor) And so on). The phosphor ceramic is a lump of phosphor that is formed by firing a material into an arbitrary shape before firing in the phosphor manufacturing process. Phosphor ceramics may use an organic substance as a binder in the molding process during the manufacturing process. However, an organic resin component is included in the fired phosphor ceramic because a degreasing process is provided after molding to burn off the organic components. Remains only 5 wt% or less. Therefore, the phosphor layer mentioned here does not substantially contain a resin component and is composed only of an inorganic substance, so that no discoloration due to heat occurs. In addition, glass or ceramics made of only an inorganic substance generally has a higher thermal conductivity than a resin, and is therefore advantageous in heat dissipation from the phosphor layer 2 to the substrate 4. In particular, phosphor ceramics generally have higher thermal conductivity than glass and are less expensive to manufacture than single crystals. Therefore, it is preferable to use them for the phosphor layer 2.

  The phosphor layer 2 includes at least one kind of phosphor that is excited by excitation light from the solid light source 5 and emits fluorescence having a longer wavelength than the emission wavelength of the solid light source 5. Specifically, when the solid-state light source 5 emits ultraviolet light, the phosphor layer 2 includes at least one kind of phosphor among phosphors such as blue, green, and red. When the solid light source 5 emits ultraviolet light, the phosphor layer 2 contains, for example, blue, green, and red phosphors (the blue, green, and red phosphors are, for example, uniformly When the phosphor layer 2 is irradiated with ultraviolet light from the solid light source 5, white illumination light can be obtained as reflected light. Moreover, when the solid light source 5 emits blue light as visible light, the phosphor layer 2 includes at least one kind of phosphor among phosphors such as green, red, and yellow. When the solid-state light source 5 emits blue light as visible light, when the phosphor layer 2 contains, for example, green and red phosphors (the green and red phosphors are dispersed uniformly, for example) In the case where the phosphor layer 2 is irradiated with blue light from the solid light source 5, illumination light such as white can be obtained as reflected light. Further, when the solid light source 5 emits blue light as visible light, for example, when the phosphor layer 2 contains only a yellow phosphor, the blue light from the solid light source 5 is emitted from the phosphor layer 2. When illuminating, illumination light such as white can be obtained as reflected light.

  Further, in the light source device 20 of FIG. 4, the heat dissipation substrate 4 includes light (emission (fluorescence) from the phosphor layer 2 excited by excitation light from the solid light source 5) and solids not absorbed by the phosphor layer 2. The role of the reflecting surface with respect to the excitation light from the light source 5, the role of radiating the heat dissipated from the phosphor layer 2, and the role of the support substrate of the phosphor layer 2 are also assumed. For this reason, high light reflection characteristics, heat transfer characteristics, and workability are required. The heat dissipation substrate 4 can be a metal substrate, oxide ceramics such as alumina, or non-oxide ceramics such as aluminum nitride, but a metal substrate having particularly high light reflection characteristics, heat transfer characteristics, and workability is used. It is desirable to be done.

  In addition, an organic adhesive, an inorganic adhesive, low-melting glass, metal (metal brazing), or the like can be used for the joint 3 between the phosphor layer 2 and the heat dissipation substrate 4. The junction 3 also has a reflection surface for light (light emission (fluorescence) from the phosphor layer 2 excited by the excitation light from the solid light source 5 and excitation light from the solid light source 5 not absorbed by the phosphor layer 2). Therefore, it is desirable to use a metal (metal brazing) having both high light reflection characteristics and heat transfer characteristics.

  By the way, as described above, in the reflection type light source device, when the phosphor layer 2 is irradiated with the excitation light from the solid light source 5, the diffuse reflection component having no angle dependency and the strong directivity in the direction of the reflection angle are obtained. The specular reflection component with strong directivity (strong angle dependency) is emitted in a direction that is significantly different from the light extraction direction (illumination light extraction direction) (in addition, strong angle dependency) The specular reflection component having a light output in a direction that is significantly different from the light extraction direction is due to the excitation light from the solid light source 5 entering the phosphor layer 2 obliquely, particularly in the reflection method) It could not be used, and there was a limit to further increasing the brightness.

  In the light source device 20 of FIG. 4, in order to further increase the brightness, light diffusion for diffusing the excitation light from the solid light source 5 is performed on the surface of the phosphor layer 2 on which the excitation light is incident. Means 1 are provided. That is, the light source device 20 of FIG. 4 has a light diffusing function for converting a regular reflection component having strong directivity in the direction of the reflection angle of excitation light on the surface of the phosphor layer 2 into a diffuse reflection component having no angle dependency. The concavo-convex structure is formed as the light diffusion means 1.

  Here, the concavo-convex structure having a light diffusing function as the light diffusing unit 1 has a concavo-convex structure whose height and width are both 0.05 μm or more and 50 μm or less as in the example shown in FIG. In the example of (a), the surface of the phosphor layer 2 can be processed into a concavo-convex structure, and in this case, the concavo-convex structure is made of the same material as the phosphor layer 2), or FIG. As shown in the example shown in b), particles having a particle size of 0.05 μm or more and 50 μm or less arranged (in this case, the concavo-convex structure is a particulate material deposited on the phosphor layer 2) It is desirable that the concavo-convex structure be made of a material different from that of the phosphor layer 2). In particular, when the unevenness and the particle diameter are 0.5 μm or more and 20 μm or less, it is desirable because many forward scattering occurs. This is because when the excitation light or fluorescence is visible light, if the unevenness or particle size is 0.5 μm or more, the forward scattering component of Mie scattering increases, and if it is 20 μm or more, the light is reflected or refracted. This is because the forward scattering component is reduced.

  As described above, in the light source device 20 of FIG. 4, the surface of the phosphor layer 2 has an uneven structure having a light diffusion function that converts a regular reflection component that cannot be used as illumination light into a diffuse reflection component that can be used as illumination light. Since it is formed as means 1, it is possible to further improve the utilization efficiency of the excitation light to the illumination light and further increase the brightness.

  Next, the light source device 20 of FIG. 4 will be described in more detail.

  In the light source device 20, a light emitting diode or a semiconductor laser having a light emission wavelength from the ultraviolet light to the visible light region can be used as the solid light source 5.

More specifically, in the light source device 20, for the solid light source 5, for example, a light emitting diode or semiconductor laser that emits near ultraviolet light having an emission wavelength of about 380 nm to about 400 nm using an InGaN-based material is used. Can do. In this case, the phosphor of the phosphor layer 2 is excited by ultraviolet light having a wavelength of about 380 nm to about 400 nm. For example, the red phosphor has CaAlSiN ₃ : Eu ²⁺ , Ca ₂ Si ₅ N _8. : Eu ²⁺ , La ₂ O ₂ S: Eu ³⁺ , KSiF ₆ : Mn ⁴⁺ , KTiF ₆ : Mn ⁴⁺ can be used, and (Ba, Sr) ₂ SiO ₄ : Eu ²⁺ , BaMgAl can be used for the green phosphor. ₁₀ O ₁₇ : Eu ²⁺ , Mn ²⁺ , (Si, Al) ₆ (O, N) ₈ : Eu ^{2+ and the} like can be used, and (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) Use ₆ C ₁₂ : Eu ²⁺ , LaAl (Si, Al) ₆ (O, N) ₁₀ : Ce ³⁺ , BaMgAl ₁₀ O ₁₇ : Eu ²⁺ , Mn ^2+, etc. Can do.

In the light source device 20, the solid-state light source 5 can be, for example, a light emitting diode or a semiconductor laser that emits blue light having a light emission wavelength of about 460 nm using a GaN-based material. In this case, the phosphor of the phosphor layer 2 is excited by blue light having a wavelength of about 440 nm to about 470 nm. For example, the red phosphor has CaAlSiN ₃ : Eu ²⁺ , Ca ₂ Si ₅ N _8. : Eu ²⁺ , KSiF ₆ : Mn ⁴⁺ , KTiF ₆ : Mn ^4+, etc. can be used, and Y ₃ Al ₅ O ₁₂ : Ce ³⁺ (YAG), (Sr, Ba) ₂ SiO ₄ : Eu ²⁺ , Ca _x (Si, Al) ₁₂ (O, N) ₁₆ : Eu ^{2+, and the} like can be used, and Y ₃ (Ga, Al) ₅ O ₁₂ : Ce ³⁺ , Ca ₃ Sc can be used as a green phosphor. ^{_{2 Si 3 O 12: Ce 3+}} , CaSc 2 O 4: Eu 2+, (Ba, Sr) 2 SiO 4: Eu 2+, Ba 3 Si 6 O 12 N 2: Eu 2+, (Si, _{l) 6 (O, N)} 8: Eu 2+ or the like can be used.

As the phosphor layer 2, a phosphor in which these phosphor powders are dispersed in glass, a glass phosphor in which a luminescent center ion is added to a glass matrix, a phosphor ceramic not including a binding member such as a resin, or the like is used. Can do. As a specific example of the phosphor powder dispersed in glass, the phosphor powder having the composition listed above is contained in a glass containing components such as P ₂ O ₃ , SiO ₂ , B ₂ O ₃ , and Al ₂ O _3. Are dispersed. Examples of glass phosphors in which a luminescent center ion is added to a glass matrix include Ca—Si—Al—O—N and Y—Si—Al—O—N systems in which Ce ³⁺ or Eu ²⁺ is added as an activator. Examples thereof include oxynitride glass phosphors. Examples of the phosphor ceramic include a sintered body having a phosphor composition having the composition listed above and substantially not including a resin component. Among these, it is desirable to use a phosphor ceramic having translucency. This is a phosphor ceramic that has translucency because there are almost no pores or impurities at grain boundaries that cause light scattering in the sintered body. Since pores and impurities can also prevent thermal diffusion, translucent ceramics exhibit high thermal conductivity. For this reason, when used as a phosphor layer, excitation light and fluorescence can be taken out from the phosphor layer without being lost by diffusion, and heat generated in the phosphor layer can be efficiently dissipated. Even a sintered body that does not show translucency is desirable to have as few pores and impurities as possible. As an index for evaluating the remaining amount of pores, the value of specific gravity of the phosphor ceramic can be used, and it is desirable that the value is 95% or more with respect to the theoretical value by which the value is calculated.

Here, a method of manufacturing a phosphor ceramic having translucency will be described by taking as an example a Y ₃ Al ₅ O ₁₂ : Ce ³⁺ phosphor which is a blue-excited yellow light-emitting phosphor. The phosphor ceramic is manufactured through a starting material mixing step, a forming step, a firing step, and a processing step. As the starting material, an oxide of a constituent element of Y ₃ Al ₅ O ₁₂ : Ce ³⁺ phosphor such as yttrium oxide, cerium oxide, or alumina, or a carbonate, nitrate, sulfate, or the like that becomes an oxide after firing is used. The particle size of the starting material is preferably a submicron size. These raw materials are weighed so as to have a stoichiometric ratio. At this time, for the purpose of improving the transmittance of the ceramic after firing, it is also possible to add a compound such as calcium or silicon. The weighed raw materials are sufficiently dispersed and mixed by a wet ball mill using water or an organic solvent. Next, the mixture is formed into a predetermined shape. As the molding method, a uniaxial pressing method, a cold isostatic pressing method, a slip casting method, an injection molding method, or the like can be used. The obtained molded body is fired at 1600 to 1800 ° C. Thus, translucent ^{_{Y 3 Al 5 O 12: Ce}} 3+ phosphor ceramic can be obtained.

  The phosphor ceramic produced as described above is polished to a thickness of several tens to several hundreds of μm using an automatic polishing apparatus and the like, and is further rounded by dicing or scribing using a diamond cutter or laser. Cut out to a board of any shape such as a square, fan or ring.

  Here, phosphor ceramics have a high refractive index with respect to air, and there are few things that cause scattering such as pores inside, and light is guided inside the ceramics. The light emission component emitted from the side surface increases, and the light emission component emitted in the front direction decreases. In order to solve this problem, the light emission component emitted in the front direction can be increased by providing an uneven light extraction structure by etching on the ceramic surface, mounting a lens, or providing a reflective layer on the side surface. Is also possible.

  Moreover, although a metal substrate, oxide ceramics, non-oxide ceramics, etc. can be used for the heat radiating substrate 4, it is desirable to use a metal substrate having particularly high light reflection characteristics, heat transfer characteristics, and workability. As the metal, simple substances such as Al, Cu, Ti, Si, Ag, Au, Ni, Mo, W, Fe, Pd, and alloys containing them can be used. Further, the surface of the heat dissipation substrate 4 may be coated for the purpose of preventing reflection and corrosion. The heat dissipation board 4 may be provided with a structure such as a fin in order to improve heat dissipation.

In addition, an organic adhesive, an inorganic adhesive, low-melting glass, metal brazing, or the like can be used for the joint 3 between the phosphor layer 2 and the heat dissipation substrate 4. Among these, it is desirable to use metal brazing that can achieve both high reflectance and heat transfer characteristics. The ceramic (phosphor layer 2) and the metal substrate (heat dissipation substrate 4) can be joined by first forming a metal film on the ceramic side and brazing the metal film to the metal substrate. The metal film can be formed on the ceramic by a vacuum deposition method, a sputtering method, a refractory metal method, or the like. The refractory metal method is a method in which an organic binder containing metal fine particles is applied to the surface of a ceramic and heated to 1000 to 1700 ° C. in a reducing atmosphere containing water vapor and hydrogen. For the metal film formed at this time, a simple substance or an alloy containing Si, Nb, Ti, Zr, Mo, Ni, Mn, W, Fe, Pt, Al, Au, Pd, Ta, Cu, or the like is used. Further, as the metal brazing material, a brazing material containing Ag, Cu, Zn, Ni, Sn, Ti, Mn, In, Bi, or the like can be used. If necessary, the oxide film on the joint surface between the metal film and the metal is removed with a flux, a metal brazing material is disposed on the joint surface, heated to 200 to 800 ° C., and cooled to be joined. Further, in order to prevent destruction of the joint surface due to the difference in expansion coefficient between the ceramic and the metal after joining, the joining may be performed with a substance having an intermediate expansion coefficient between the ceramic and the metal interposed.
The concavo-convex structure on the surface of the phosphor layer 2 is a high-frequency plasma of a reactive gas containing a halide blast of fluorine or chlorine, a sand blast method using ceramic powder or diamond powder, a wet etching method using hydrofluoric acid, nitric acid, sulfuric acid or a mixed acid thereof It can be formed using a dry etching method such as reactive ion etching. In addition, an uneven structure can be formed by depositing organic or inorganic particulate matter. Examples of organic particles include resin particles such as acrylic, styrene, polystyrene, melanin resin, and polyester resin. Examples of the inorganic particles include metal oxide particles such as TiO ₂ , ZrO ₂ , Al ₂ O ₃ , and SiO ₂ . However, considering the heat generation of the phosphor layer 2, it is desirable to use thermally stable inorganic particles. As a method for depositing the particulate matter, there is a method in which a liquid in which the particulate matter is dispersed in a resin is applied by brushing, applied to the surface of the phosphor layer 2 by printing, spraying, etc., and dried to adhere. Can be mentioned.

  Further, by combining the above-described light source device of the present invention with an optical component such as a predetermined lens system, an illumination device capable of increasing the brightness can be provided.

  FIG. 6 shows an illuminating device 30 provided with a predetermined lens system 6 in the light extraction direction of the light source device 20 shown in FIG. In the illuminating device 30 of FIG. 6, since the light source device 20 shown in FIG. 4 is used, it is possible to further increase the luminance.

  In the above description, FIG. 5A or FIG. 5B is illustrated as the concavo-convex structure having a light diffusion function. However, the present invention is not limited to this, and various shapes, etc. Can be given.

The present invention can be used for vehicle lighting such as headlamps and general lighting.

DESCRIPTION OF SYMBOLS 1 Light diffusion means 2 Phosphor layer 3 Junction part 4 Heat radiation board 5 Solid light source 6 Lens system 20 Light source device 30 Illumination device

Claims (3)

A solid-state light source that emits light of a predetermined wavelength in a wavelength region from ultraviolet light to visible light, and at least emits fluorescence having a wavelength longer than the emission wavelength of the solid-state light source when excited by excitation light from the solid-state light source A phosphor layer containing one kind of phosphor, the solid light source and the phosphor layer are spatially separated, and a reflection method from a surface of the phosphor layer on which excitation light is incident A light source device for extracting at least fluorescence, wherein a light diffusing means for diffusing the excitation light from the solid state light source is provided on a surface of the phosphor layer on which the excitation light is incident. A light source device. 2. The light source device according to claim 1, wherein the phosphor layer is phosphor ceramic. An illumination device using the light source device according to claim 1.

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