JP2012129135A - Light source device, illumination device, and method of manufacturing phosphor layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source device capable of attaining further improved high luminance and preventing color separation of illumination light.SOLUTION: The light source device is provided with a solid light source 5 emitting a prescribed wavelength light out of the wavelength region from ultraviolet light to visible light and a phosphor layer 12 containing at least one kind of phosphor emitting fluorescent light of a wavelength longer than the emitted wavelength of the solid light source 5 by being excited by an exciting light from the solid light source 5. The solid power source 5 and the phosphor layer 12 are arranged spatially in separation and the fluorescent light is taken out by a reflection method at least from a face on an incident side where the excited light of the phosphor layer 12 enters. The phosphor layer 12 has a structure wherein a plurality of phosphor pieces 12a are bundled and between adjacent phosphor pieces 12a, there are formed light shielding layers 13.

Description

  The present invention relates to a light source device, an illumination device, and a phosphor layer manufacturing method.

  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 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 6 denotes a light reflective substrate (heat dissipation substrate), and reference numeral 7 denotes a joint portion between the phosphor layer 2 and the light reflective substrate (heat dissipation substrate) 6.

  In such a light source device 10, when a phosphor ceramic that does not substantially contain a resin component is used as the phosphor layer 2, the phosphor ceramic does not contain a resin component, so no discoloration occurs. Since the temperature sensitivity is low, temperature quenching does not occur, and higher brightness can be achieved.

  That is, the phosphor layer 2 is made of phosphor ceramics substantially free of a resin component, and is joined to the light reflective substrate (heat dissipation substrate) 6 by a metal joint 7 to thereby remove the phosphor layer 2 from the phosphor layer 2. It is possible to promote heat dissipation and achieve higher brightness.

  However, in the light source device 10 of FIG. 2, when using a phosphor ceramic that does not substantially contain a resin component as the phosphor layer 2, the phosphor ceramic has a high refractive index with respect to air and further scatters pores and the like inside. Therefore, when light is propagated inside the phosphor ceramic and molded into a plate shape, the emission component emitted from the side surface increases and the emission component emitted in the front direction decreases. This causes a malfunction. At this time, excitation light from the solid light source 5 and fluorescence from the phosphor layer (phosphor ceramic) 2 excited by the excitation light from the solid light source 5 (light having a wavelength longer than the wavelength of the excitation light) For example, white illumination light is obtained by mixing the two colors, but in the phosphor layer (phosphor ceramic) 2, the degree of propagation of the excitation light from the solid light source 5 and the fluorescence from the phosphor layer (phosphor ceramic) 2 is different. The illumination light has a problem of color separation.

  In the present invention, even when using a phosphor ceramic that does not substantially contain a resin component as the phosphor layer, it is possible to prevent a decrease in the light emitting component emitted in the front direction and further increase the brightness. An object of the present invention is to provide a light source device, an illumination device, and a phosphor layer manufacturing method capable of preventing color separation of illumination light.

  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 by a reflection method from a surface on which excitation light is incident on the phosphor layer, wherein the phosphor layer has a structure in which a plurality of phosphor pieces are bundled, and adjacent phosphors A layer having a light shielding property is formed between the body pieces.

  According to a second aspect of the present invention, in the light source device according to the first aspect, the light-shielding layer is formed over the entire side surface of each phosphor piece.

  According to a third aspect of the present invention, in the light source device according to the first or second aspect, the plurality of phosphor pieces are phosphor ceramics.

  According to a fourth aspect of the present invention, there is provided an illuminating device in which the light source device according to any one of the first to third aspects is used.

  Further, in the invention according to claim 5, after forming a light-shielding layer on the surface of the plurality of rod-shaped phosphor pieces, and bundling each phosphor piece having the light-shielding layer formed on the surface, A light-shielding layer formed on the surface of the phosphor piece is melted to form an integrated structure in which a light-shielding layer is formed between adjacent phosphor pieces, and this is a rod-like phosphor piece The phosphor layer is produced by cutting perpendicularly to the length direction of the phosphor layer.

  According to the first to fourth aspects of the present invention, the solid light source that emits light of 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 that extracts at least fluorescence by a reflection method from a surface of a body layer on which excitation light is incident, wherein the phosphor layer has a structure in which a plurality of phosphor pieces are bundled, and adjacent phosphor pieces In the meantime, a light-shielding layer is formed, so that even when using phosphor ceramics that do not substantially contain a resin component as the phosphor layer, it is possible to prevent a decrease in light emitting components emitted in the front direction. To achieve even higher brightness It is possible further to prevent color separation of the illuminating light.

  According to the invention of claim 5, after forming a light-shielding layer on the surface of a plurality of rod-shaped phosphor pieces and bundling each phosphor piece having a light-shielding layer formed on the surface The light-shielding layer formed on the surface of each phosphor piece is melted to form an integrated structure in which a light-shielding layer is formed between adjacent phosphor pieces. Since the phosphor layer is produced by cutting perpendicularly to the length direction of the body piece, the phosphor layer having a uniform film thickness and a large area (with a structure in which a plurality of phosphor pieces are bundled) is obtained by a simple process. In addition, a phosphor layer in which a light-shielding layer is formed between adjacent phosphor pieces can be provided.

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 which shows the example of 1 structure of the light source device of this invention. It is a figure which shows the case where the cross-sectional shape of each fluorescent substance piece is a regular hexagon (each fluorescent substance piece is a hexagonal column shape). It is a figure for demonstrating the preparation methods of a fluorescent substance layer. It is a figure which shows the case where a different kind (several kinds) fluorescent substance is used for every different area | region (site | part) in a fluorescent substance layer as each fluorescent substance piece of a fluorescent substance layer, respectively. It is a figure which shows the other structural example of the light source device of this invention.

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

  FIGS. 3A and 3B are diagrams showing a configuration example of the light source device of the present invention. 3A is a diagram illustrating the entire light source device, FIG. 3B is a perspective view of a portion where the phosphor layer is provided, and FIG. 3A is a diagram where the phosphor layer is provided. About the part which has been shown, it is shown as sectional drawing in the AA of FIG.3 (b). 3 (a) and 3 (b), the same reference numerals are given to the same portions as those in FIGS. 2 (a) and 2 (b). Referring to FIG. 3A, 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 12 containing at least one type of phosphor that emits fluorescence having a wavelength longer than the emission wavelength of the solid-state light source 5 and the surface of the phosphor layer 12 opposite to the surface on which excitation light is incident. A light-reflective substrate (heat dissipation substrate) 6 provided on the side surface is provided, and the solid light source 5 and the phosphor layer 12 are arranged spatially separated.

  Here, as shown in FIGS. 3A and 3B, the phosphor layer 12 is attached to the light-reflecting substrate 6 by the joint portion 7.

  As described above, the light source device 20 basically has the solid light source 5 and the phosphor layer 12 arranged spatially separated in the same manner as the prior application (Japanese Patent Application No. 2009-286397) of the present application. Of the surface of the layer 12, the light-reflective substrate 6 provided on the surface opposite to the surface on which excitation light from the solid light source 5 is incident (in the present invention, this surface is referred to as the phosphor layer incident surface). The method of taking out the reflection component of the excitation light from the solid light source 5 and the reflection component of the fluorescence from the phosphor layer 12 (for example, as illumination light) using the reflection by the light source (hereinafter referred to as a reflection method or a reflection type) is adopted ing. Thereby, it is possible to achieve a sufficiently high luminance as compared with the conventional case.

  Furthermore, in the present invention, even when a phosphor ceramic that does not substantially contain a resin component is used as the phosphor layer, a reduction in the light emitting component emitted in the front direction is prevented to further increase the brightness. Further, it is intended to prevent color separation of the illumination light. For this reason, in the light source device 20 of FIGS. 3A and 3B, the phosphor layer 12 bundles a plurality of phosphor pieces 12a. A light shielding layer 13 is formed between adjacent phosphor pieces 12a.

  Here, each phosphor piece 12a has a rod-like shape (a rod shape with a minute cross-sectional area (in the example of FIG. 3B, a columnar shape (a cross-sectional shape is circular)). In the example of FIG. 3B, each phosphor piece 12a has a circular cross-sectional shape, but the cross-sectional shape is not limited to a circular shape and may be any shape. However, since each phosphor piece 12a can be arranged uniformly, the cross-sectional shape of each phosphor piece 12a is preferably a circle, a regular hexagon, a square, or the like. FIG. 4 shows a case where the cross-sectional shape of each phosphor piece 12a is a regular hexagon (each phosphor piece 12a is a hexagonal column).

  The light-shielding layer 13 formed between the adjacent phosphor pieces 12a may be any material as long as it has a high light-shielding property and can be subjected to a welding process. Metal materials with thermal properties are preferred. Further, the light-shielding layer 13 is formed at least between the adjacent phosphor pieces 12a, but as shown in FIGS. 3A and 3B, it is formed over the entire side surface of each phosphor piece 12a. May be.

  Thus, in this light source device 20, the phosphor layer 12 has a structure in which a plurality of rod-like phosphor pieces 12a are bundled, and a light-shielding layer 13 is provided between adjacent phosphor pieces 12a. By being formed, the excitation light incident on one of the phosphor pieces 12a and the fluorescence from the phosphor excited by the excitation light are adjoined by the light-shielding layer 13 to the adjacent phosphor pieces 12a. Propagation to is blocked. As a result, even when a phosphor ceramic that does not substantially contain a resin component is used for each phosphor piece 12a, an increase in the emission component emitted from the side surface of the phosphor layer 12 is suppressed, and the front surface of the phosphor layer 12 is suppressed. Further reduction of the light emission component emitted in the direction can be prevented, and the luminance can be further increased. In accordance with this, excitation from the solid light source 5 in each phosphor piece (phosphor ceramic) 12a. The difference in the degree of propagation between the light and the fluorescence from the phosphor piece (phosphor ceramic) 12a is reduced, and it is possible to prevent color separation of the illumination light.

  More specific description will be given below.

  As each phosphor piece 12a of the phosphor layer 2, it is preferable to use one that does not substantially contain a resin component. That is, when each phosphor piece 12a of the phosphor layer 2 is substantially free of a resin component, there is no discoloration due to heat and less light absorption. Can be achieved.

  Here, the phosphor piece 12a substantially containing no resin component means that the resin component normally used for forming the phosphor piece is 5 wt% or less of the phosphor piece. In order to realize such a phosphor piece, 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, since the phosphor piece mentioned here does not contain a resin component substantially and is comprised only from the inorganic substance, the discoloration by a heat | fever does not generate | occur | produce. In addition, since glass or ceramics made of only an inorganic substance generally has a higher thermal conductivity than a resin, it is advantageous for heat dissipation from the phosphor layer 12 to the substrate 6. 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 each phosphor piece 12a.

  Each phosphor piece 12 a 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, each phosphor piece 12a includes at least one phosphor among phosphors such as blue, green, and red. . In the case where the solid light source 5 emits ultraviolet light, each phosphor piece 12a includes, for example, blue, green, and red phosphors (the blue, green, and red phosphors are each uniform, for example). When the phosphor pieces 12a are irradiated with ultraviolet light from the solid light source 5, white illumination light can be obtained as reflected light. When the solid light source 5 emits blue light as visible light, each phosphor piece 12a contains 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, each phosphor piece 12a includes, for example, green and red phosphors (each of the green and red phosphors is, for example, uniformly) When 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 each phosphor piece 12a includes only a yellow phosphor, the blue light from the solid light source 5 is converted to each phosphor. When the piece 12a is irradiated, illumination light such as white can be obtained as reflected light.

  In the light source device 20, the light-reflective substrate 6 includes light (luminescence (fluorescence) from the phosphor layer 12 (each phosphor piece 12 a) excited by excitation light from the solid light source 5), and the phosphor layer. 12 (excitation light from the solid light source 5 that has not been absorbed by each phosphor piece 12a) and the role of the reflecting surface and the role of radiating the heat dissipated from the phosphor layer 12 (each phosphor piece 12a) to the outside And also serves as a support substrate for the phosphor layer 12. For this reason, high light reflection characteristics, heat transfer characteristics, and workability are required. As the light-reflective substrate 6, a metal substrate, oxide ceramics such as alumina, non-oxide ceramics such as aluminum nitride, and the like can be used, but a metal substrate having particularly high light-reflecting characteristics, heat transfer characteristics, and workability. Is preferably used.

  In addition, an organic adhesive, an inorganic adhesive, low-melting glass, metal (metal brazing), or the like can be used for the joint 7 between the phosphor layer 12 and the light reflective substrate 6. The junction 7 also absorbs light (fluorescence) from the phosphor layer 12 (each phosphor piece 12a) excited by the excitation light from the solid light source 5 and the phosphor layer 12 (each phosphor piece 12a). Since it plays a role of a reflection surface for the excitation light from the solid light source 5 that has not been performed and a role of dissipating heat from the phosphor layer 12 (each phosphor piece 12a), it has high light reflection characteristics and heat transfer. It is desirable to use a metal having characteristics (metal brazing or a conductive adhesive containing a metal component).

  The light-shielding layer 13 formed between the adjacent phosphor pieces 12a plays a role of preventing the propagation of light between the adjacent phosphor pieces 12a, and thus has high light-shielding characteristics. Is desirable. In particular, a metal material having high heat transfer characteristics is desirable, but not limited thereto.

  Next, the light source device 20 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, the solid-state light source 5 may be, 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. In this case, the phosphor of each phosphor piece 12a 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, Sr) AlSiN ₃ : Eu ²⁺ , Ca ₂ Si ₅ N ₈ : Eu ²⁺ , (Ca, Sr) ₂ Si ₅ N ₈ : Eu ²⁺ , KSiF ₆ : Mn ⁴⁺ , KTiF ₆ : Mn ^{4+ and the} like are used as the yellow phosphor. (Sr, Ba) ₂ SiO ₄ : Eu ²⁺ , Ca _x (Si, Al) ₁₂ (O, N) ₁₆ : Eu ^2+, etc. are used, and (Ba, Sr) ₂ SiO ₄ is used for the green phosphor. : Eu ²⁺ , Ba ₃ Si ₆ O ₁₂ N ₂ : Eu ²⁺ , (Si, Al) ₆ (O, N) ₈ : Eu ²⁺ , BaMgAl ₁₀ O ₁₇ : Eu ²⁺ , Mn ^2+, etc. As the blue phosphor, BaMgAl ₁₀ O ₁₇ : Eu ²⁺ or the like can be used (Eu ²⁺ and Mn ⁴⁺ are elements that act as luminescence centers of the phosphor and are called activators).

The solid-state light source 5 may be, for example, a light emitting diode or 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 each phosphor piece 12a is excited by blue light having a wavelength of about 440 nm to about 470 nm. For example, the red phosphor includes CaAlSiN ₃ : Eu ²⁺ , (Ca, Sr) AlSiN ₃ : Eu ²⁺ , Ca ₂ Si ₅ N ₈ : Eu ²⁺ , (Ca, Sr) ₂ Si ₅ N ₈ : Eu ²⁺ , KSiF ₆ : Mn ⁴⁺ , KTiF ₆ : Mn ^{4+ and the} like are used as the yellow phosphor. Y ₃ Al ₅ O ₁₂ : Ce ³⁺ , (Sr, Ba) ₂ SiO ₄ : Eu ²⁺ , Ca _x (Si, Al) ₁₂ (O, N) ₁₆ : Eu ^2+, etc. are used as a green phosphor. ^{_{is, Lu 3 Al 5 O 12:}} Ce 3+, (Lu, Y) 3 Al 5 O 12: Ce 3+, Y 3 (Ga, Al) 5 O 12: Ce 3+, Ca 3 Sc 2 Si 3 O ^{_{2: 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, Al) 6 (O, N) 8: Eu ²⁺ or the like can be used (where Eu ²⁺ , Mn ^4+, and Ce ³⁺ are elements that act as luminescence centers of the phosphor and are called activators).

As each phosphor piece 12a, 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. be able to. 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. As the glass phosphor in which the luminescent center ion is added to the glass matrix, an acid such as Ca—Si—Al—O—N or Y—Si—Al—O—N containing Ce ³⁺ or Eu ²⁺ as an activator is used. Nitride glass phosphors may be mentioned. 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 it uses as each fluorescent substance piece 12a, it can take out and use from each fluorescent substance piece 12a, without losing excitation light and fluorescence by diffusion, and also dissipates the heat generated in each fluorescent substance piece 12a efficiently. Can do. 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 starting materials, yttrium oxide, cerium oxide, alumina, and the like, oxides of constituent elements of Y ₃ Al ₅ O ₁₂ : Ce ³⁺ phosphor, carbonates, nitrates, sulfates and the like that become oxides after firing are 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. At this time, by forming a molded body using a mold or injection hole having a diameter of 10 to 50 μm, a light-transmitting Y ₃ Al ₅ O ₁₂ : Ce ³⁺ rod-shaped phosphor ceramic having a diameter of 10 to 100 μm can be obtained.

  FIGS. 5A to 5G are views for explaining a method for producing the phosphor layer 12 using the rod-shaped phosphor ceramic formed as described above.

  Referring to FIGS. 5A to 5G, first, the rod-like phosphor ceramic 12a as shown in FIG. 5A is formed by the above-described method (in this example, the rod-like phosphor ceramic 12a is It is cylindrical (the cross-sectional shape is circular). Next, as shown in FIG. 5B, a metal film is uniformly formed as a layer 13 on the surface of the rod-shaped phosphor ceramic 12a (in this example, it is formed on the surface of the rod-shaped phosphor ceramic 12a. Although the layer 13 is a metal film, the layer 13 formed on the surface of the rod-shaped phosphor ceramic 12a may be any material as long as it has a high light-shielding property and can be welded. For forming the metal film 13 on the surface of the rod-shaped phosphor ceramic 12a, a vacuum deposition method, a sputtering method, a refractory metal method, or the like can be used. Here, 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. Next, as shown in FIG. 5 (c), by sticking the rod-shaped phosphor ceramics 12a having the metal film 13 formed on the surface thereof in the same direction in close contact and heating, as shown in FIG. 5 (d), The metal films 13 are welded together. Next, as shown in FIG. 5 (e), this is cut perpendicularly to the longitudinal direction of the rod-shaped phosphor ceramic 12 a to form a thin film phosphor layer 12. At this time, by polishing the surface, the thickness of the thin-film phosphor layer 12 can be made uniform and the surface shape can be made smooth. The thin-film phosphor layer 12 thus formed is bonded to the light reflective substrate 6 as shown in FIG. 5 (f), so that the structure as shown in FIG. 3 (b) is obtained. can do. Further, as shown in FIG. 5G, a phosphor layer having a uniform film thickness and a larger area can be easily formed by combining a plurality of thin-film phosphor layers 12.

  That is, according to the present invention, after the light-shielding layer 13 is formed on the surface of the plurality of rod-shaped phosphor pieces 12a and the phosphor pieces 12a having the light-shielding layer 13 formed on the surface are bundled. The light-shielding layer 13 formed on the surface of each phosphor piece 12a is melted (welded), and the light-shielding layer 13 is formed between the adjacent phosphor pieces 12a. Since the phosphor layer 12 is produced by cutting this perpendicularly to the length direction of the rod-like phosphor piece 12a, the phosphor layer having a uniform film thickness and a large area can be obtained by a simple process. (Phosphor layer having a structure in which a plurality of phosphor pieces 12a are bundled and a light-shielding layer 13 is formed between adjacent phosphor pieces 12a) 12 can be provided.

  The light-reflective substrate 6 can be a metal substrate, oxide ceramics, non-oxidized ceramics, etc., but 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, and Pd and alloys containing them can be used. The surface of the light reflective substrate 6 may be coated for the purpose of increasing reflection and preventing corrosion. Further, the substrate 6 may be provided with a structure such as a fin in order to improve heat dissipation.

  Further, a resin, an organic adhesive, an inorganic adhesive, a low melting point glass, brazing, or the like can be used for the joint 7 between the phosphor layer 12 and the light reflective substrate 6. Above all, brazing that can achieve both high reflectivity and heat transfer characteristics is desirable. The phosphor layer 12 and the light reflective substrate 6 can be joined by first forming a metal film on the phosphor layer 12 side and brazing the metal film and the light reflective substrate (metal substrate) 6. . The metal film can be formed on the phosphor layer 12 by using 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 the phosphor layer 12 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. As the 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 light-reflective substrate (metal substrate) 6 is removed with a flux, a brazing material is disposed on the joint surface, heated to 200 to 800 ° C., and cooled to join. I can do it. In addition, in order to prevent destruction of the bonding surface due to the difference in thermal expansion coefficient between the phosphor layer 12 and the light reflective substrate (metal substrate) 6 after bonding, an intermediate between the phosphor layer 12 and the light reflective substrate (metal substrate) 6 is used. Bonding may be performed by interposing a substance having a thermal expansion coefficient.

  In the above-described example, the same kind (one kind) of phosphor is used for each phosphor piece 12 a of the phosphor layer 12. However, as each phosphor piece of the phosphor layer 12, a predetermined in the phosphor layer 12 is used. Different types (plural types) of phosphors may be used for each of the regions. FIG. 6 shows a case where different types (plural types) of phosphors are used for each different region (part) in the phosphor layer 12 as each phosphor piece of the phosphor layer 12. That is, in the example of FIG. 6, the phosphor layer 12 has three types of phosphors (for example, yellow, green, and so on) for each different region (in the example of FIG. 6, for each different region according to the distance from the center). A case is shown in which each of the phosphor pieces (three kinds of phosphor pieces) 12a, 12b, and 12c made of red light-emitting phosphor is formed. As described above, when different types (plural types) of phosphors are used for each different region (part) in the phosphor layer 12 as each phosphor piece of the phosphor layer 12, The emission color can be adjusted by adjusting the irradiation position of the excitation light.

Further, as in the above-described example, even when the same type (one type) of phosphor is used for each phosphor piece 12a of the phosphor layer 12, each region (part) in the phosphor layer 12 has a different fluorescence. By changing the concentration of the activator of the body piece 12a, the emission intensity can be changed, and the emission position of the excitation light from the solid light source 5 can be adjusted to adjust the emission color. For example, when Y ₃ Al ₅ O ₁₂ : Ce ^3+, which is a blue excited yellow phosphor, is used for each phosphor piece 12a of the phosphor layer 12, for each different region (part) in the phosphor layer 12, By changing the amount of Ce ³⁺ that is the activator of the yellow phosphor, the emission color can be adjusted by changing the emission intensity and adjusting the irradiation position of the excitation light from the solid light source 5.

  Thus, when the phosphor layer 12 has a structure in which regions of different phosphor types and activator concentrations are formed, the emission color is adjusted by adjusting the irradiation position of the excitation light from the solid light source 5. It becomes possible to adjust.

  In the above example, the phosphor layer 12 is formed as shown in FIGS. 7A and 7B, for example (FIG. 7A is a plan view and FIG. 7B is a plan view in FIG. 7A). FIG. 7 is a cross-sectional view taken along line AA, and in the example of FIGS. 7A and 7B, the phosphor layer 12 uses the structure of FIG. It can also be configured as a reflection type fluorescent rotating body 1 (rotated by a motor 4 or the like). That is, the reflection type fluorescent rotator 1 can be realized by connecting the phosphor layer 12 and the light reflective substrate 6 joined by the joint 7 to the motor 4 or the like.

  In the reflection type fluorescent rotating body 1, the light reflective substrate 6 and the joint 7 function as a reflection surface for excitation light and fluorescence. The shape of the light reflective substrate 6 may be a disk shape or a quadrangle. In addition, in order to ensure the stability of rotation, it is possible to cut out a part of the disk or to have a shape with a weight on the contrary.

  In this way, by configuring the phosphor layer 12 as the reflection-type fluorescence rotator 1 that rotates around the rotation axis X (rotates by the motor 4 or the like), that is, the phosphor layer 12 is formed with respect to the solid light source 5. By rotating, it is possible to disperse the places where the excitation light from the solid light source 5 hits, and to suppress the heat generation in the light irradiating part (using the fluorescent rotating body 1 can suppress the heat generation of the fluorescent substance in the first place). This makes it possible to further increase the brightness.

  Further, in each of the above examples, an optical element such as a lens or a mirror can be provided between the solid light source 5 and the phosphor layer 12.

  Further, by combining the above-described light source device of the present invention with a predetermined lens system, a mirror, a reflector, or the like, it is possible to achieve a sufficiently high brightness and prevent color separation of illumination light. A lighting device can be provided.

  The present invention can be used for automotive lighting such as headlamps, projectors, and general lighting.

DESCRIPTION OF SYMBOLS 1 Reflective fluorescent rotating body 4 Motor 5 Solid light source 6 Light reflective board | substrate 12 Phosphor layer 12a, 12b, 12c Fluorescent substance piece 13 Layer which has light-shielding property 20 Light source device

Claims (5)

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 In the light source device for extracting at least fluorescence, the phosphor layer has a structure in which a plurality of phosphor pieces are bundled, and a light-shielding layer is formed between adjacent phosphor pieces. A light source device characterized by that. The light source device according to claim 1, wherein the light-shielding layer is formed over the entire side surface of each phosphor piece. 3. The light source device according to claim 1 or 2, wherein the plurality of phosphor pieces are phosphor ceramics. An illumination device, wherein the light source device according to any one of claims 1 to 3 is used. A light-shielding layer is formed on the surface of a plurality of rod-shaped phosphor pieces, and each phosphor piece having a light-shielding layer formed on the surface is bundled and then formed on the surface of each phosphor piece. The light-shielding layer is melted to form an integrated structure in which a light-shielding layer is formed between adjacent phosphor pieces, and this is cut perpendicular to the length direction of the rod-like phosphor pieces. A phosphor layer manufacturing method, characterized in that a phosphor layer is manufactured.

Images