WO2015141376A1 - Fluorescent light source device - Google Patents

Fluorescent light source device Download PDF

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Publication number
WO2015141376A1
WO2015141376A1 PCT/JP2015/054734 JP2015054734W WO2015141376A1 WO 2015141376 A1 WO2015141376 A1 WO 2015141376A1 JP 2015054734 W JP2015054734 W JP 2015054734W WO 2015141376 A1 WO2015141376 A1 WO 2015141376A1
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WO
WIPO (PCT)
Prior art keywords
fluorescent
wavelength conversion
source device
light source
conversion member
Prior art date
Application number
PCT/JP2015/054734
Other languages
French (fr)
Japanese (ja)
Inventor
井上　正樹
政治 北村
Original Assignee
ウシオ電機株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by ウシオ電機株式会社 filed Critical ウシオ電機株式会社
Publication of WO2015141376A1 publication Critical patent/WO2015141376A1/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V29/00—Protecting lighting devices from thermal damage; Cooling or heating arrangements specially adapted for lighting devices or systems
    • F21V29/50—Cooling arrangements
    • F21V29/56—Cooling arrangements using liquid coolants
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21K—NON-ELECTRIC LIGHT SOURCES USING LUMINESCENCE; LIGHT SOURCES USING ELECTROCHEMILUMINESCENCE; LIGHT SOURCES USING CHARGES OF COMBUSTIBLE MATERIAL; LIGHT SOURCES USING SEMICONDUCTOR DEVICES AS LIGHT-GENERATING ELEMENTS; LIGHT SOURCES NOT OTHERWISE PROVIDED FOR
    • F21K9/00—Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
    • F21K9/60—Optical arrangements integrated in the light source, e.g. for improving the colour rendering index or the light extraction
    • F21K9/64—Optical arrangements integrated in the light source, e.g. for improving the colour rendering index or the light extraction using wavelength conversion means distinct or spaced from the light-generating element, e.g. a remote phosphor layer
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V29/00—Protecting lighting devices from thermal damage; Cooling or heating arrangements specially adapted for lighting devices or systems
    • F21V29/50—Cooling arrangements
    • F21V29/502—Cooling arrangements characterised by the adaptation for cooling of specific components
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
    • F21Y2115/00—Light-generating elements of semiconductor light sources
    • F21Y2115/10—Light-emitting diodes [LED]
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
    • F21Y2115/00—Light-generating elements of semiconductor light sources
    • F21Y2115/30—Semiconductor lasers
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B19/00—Condensers, e.g. light collectors or similar non-imaging optics
    • G02B19/0033—Condensers, e.g. light collectors or similar non-imaging optics characterised by the use
    • G02B19/0047—Condensers, e.g. light collectors or similar non-imaging optics characterised by the use for use with a light source
    • G02B19/0061—Condensers, e.g. light collectors or similar non-imaging optics characterised by the use for use with a light source the light source comprising a LED
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/04—Prisms
    • G02B5/045—Prism arrays

Definitions

  • the present invention relates to a fluorescent light source device including a wavelength conversion member that emits fluorescence by excitation light.
  • a fluorescent light source device a device including a wavelength conversion member that uses laser light as excitation light and emits fluorescence using the excitation light as a light emission source is known (see, for example, Patent Document 1).
  • the phosphor is heated to a high temperature by heating the excitation light incident surface due to the heat generated by the excitation light irradiation, resulting in temperature quenching.
  • the conversion efficiency of excitation light into fluorescence is reduced.
  • Such a problem becomes conspicuous when the incident power of excitation light (excitation energy of excitation light) is increased.
  • Patent Document 2 discloses a technique for cooling the wavelength conversion member by blowing cooling air onto the excitation light incident surface of the wavelength conversion member.
  • the wavelength conversion member cannot be sufficiently cooled, particularly when the incident power of the excitation light is large.
  • the micro crack gradually grows due to the penetration of the liquid refrigerant, and becomes a large crack. And when a liquid refrigerant further permeates into the inside of a wavelength conversion member from the crack, a new interface will be formed and a non-light-emitting layer will occur.
  • penetration of the liquid refrigerant into the cracks causes oxidation of the phosphor activator at the interface, further reducing the emission intensity.
  • the liquid refrigerant is water
  • the phosphor activator is particularly easily oxidized, and as a result, the valence and crystal structure of the activator tend to change in the phosphor. For this reason, in the wavelength conversion member, the excitation light capture efficiency decreases with time, and the amount of fluorescence generated decreases accordingly. As a result, there is a problem that the luminous efficiency decreases with time.
  • the present invention has been made based on the above circumstances, and its purpose is to increase the temperature of the wavelength conversion member even when the wavelength conversion member is irradiated with excitation light having high excitation energy. It is an object of the present invention to provide a fluorescent light source device capable of suppressing light emission and obtaining high luminous efficiency over a long period of time.
  • the fluorescent light source device of the present invention is a fluorescent light source device provided with a wavelength conversion member provided on a substrate and emitting fluorescence by excitation light.
  • a liquid refrigerant circulation mechanism is provided that circulates a liquid refrigerant having optical transparency along at least the excitation light incident surface of the wavelength conversion member;
  • the wavelength conversion member is provided with a coating layer made of a light transmissive material that covers the excitation light incident surface.
  • the coating layer has an uneven structure on the surface.
  • the liquid refrigerant circulation mechanism is provided, and the excitation light incident surface that is particularly heated by the heat generated by the excitation light irradiation is preferentially cooled by the liquid refrigerant.
  • the wavelength conversion member can be efficiently cooled.
  • the coating layer is provided on the excitation light incident surface, even if the liquid refrigerant circulates along the excitation light incident surface, the wavelength conversion member deteriorates with time due to contact with the liquid refrigerant, It can prevent or suppress that the luminous efficiency falls resulting from it.
  • the fluorescent light source device of the present invention even when the wavelength conversion member is irradiated with excitation light having high excitation energy, the temperature increase of the wavelength conversion member is suppressed, and high light emission over a long period of time. Efficiency is obtained.
  • the coating layer has a concavo-convex structure formed on the surface thereof, so that excitation light can be sufficiently taken into the wavelength conversion member through the coating layer.
  • the fluorescence generated inside the wavelength conversion member can be emitted to the outside with high efficiency via the coating layer.
  • heating of the wavelength conversion member due to the fluorescence generated inside the wavelength conversion member being confined in the inside is suppressed.
  • the temperature increase of the wavelength conversion member is further suppressed, and higher luminous efficiency is obtained.
  • FIG. 3 is a sectional view taken along line AA in FIG. 2. It is an expanded sectional view for description which expands and shows the structure of the fluorescence light emitting member in the fluorescence light source device of FIG. It is an expanded sectional view for description which shows the structure of the fluorescence light emission member in the other example of the fluorescence light source device of this invention.
  • FIG. 1 is an explanatory diagram showing an outline of the configuration of an example of the fluorescent light source device of the present invention
  • FIG. 2 is an explanatory diagram showing the configuration of the fluorescent light emitting member and the liquid refrigerant circulation mechanism in the fluorescent light source device of the present invention of FIG.
  • FIG. 3 is a cross-sectional view taken along line AA of FIG.
  • FIG. 4 is an explanatory enlarged sectional view showing the configuration of the fluorescent light emitting member in the fluorescent light source device of FIG. 1 in an enlarged manner. As shown in FIG.
  • the fluorescent light source device 10 includes, for example, a semiconductor laser 11 that emits light in a blue region, and laser light emitted from the semiconductor laser 11 that is disposed to face the semiconductor laser 11. And a fluorescent light emitting member 20 having a wavelength conversion member that is excited by certain excitation light L and emits fluorescent light L1. 2 and 3, the fluorescent light emitting member 20 is supported by a support member 41, and a hemispherical excitation light condensing lens 18 is connected to the semiconductor laser 11 and the fluorescent light emission on the support member 41.
  • a liquid refrigerant flow passage is provided so as to be positioned between the member 20 and the liquid refrigerant.
  • a collimator lens 15 that emits the excitation light L incident from the semiconductor laser 11 as a parallel light beam is disposed at a position between the semiconductor laser 11 and the fluorescent light emitting member 20 close to the semiconductor laser 11.
  • a dichroic mirror 16 that transmits the excitation light L from the semiconductor laser 11 and reflects the fluorescence L1 from the wavelength conversion member in the fluorescent light emitting member 20 is provided between the collimator lens 15 and the fluorescent light emitting member 20. For example, it is arranged in a posture inclined at an angle of 45 ° with respect to the 15 optical axes.
  • the fluorescent light emitting member 20 has a rectangular wavelength conversion member recess 32 formed on the surface (upper surface in FIG. 4) of the substantially rectangular flat plate-like substrate 31, from the rectangular fluorescent member 22.
  • the wavelength conversion member which becomes is provided.
  • the wavelength conversion member recess 32 has a vertical and horizontal dimension that is larger than the vertical and horizontal dimensions of the fluorescent member 22, and the depth of the recess is slightly larger than the thickness of the fluorescent member 22 (the vertical dimension in FIG. 4).
  • the fluorescent light emitting member 20 is disposed so that the surface of the fluorescent member 22 (the upper surface in FIG. 4) faces the semiconductor laser 11 through the excitation light condensing lens 18, the dichroic mirror 16, and the collimator lens 15.
  • the surface of the fluorescent member 22 is the excitation light incident surface of the wavelength conversion member and the fluorescent emission surface of the wavelength conversion member.
  • a light reflecting film (not shown) is provided on each of the back surface (lower surface in FIG. 4) and side surfaces of the fluorescent member 22.
  • As the light reflection film for example, an increased reflection aluminum film or a multilayer film composed of a silver layer, an increased reflection silver film or the like and a nickel layer is used.
  • a bonding member (not shown) is interposed between the light reflecting film provided on the back surface of the fluorescent member 22 and the bottom wall of the wavelength conversion member recess 32, and the fluorescent member 22 is attached to the substrate 31 by the bonding member. Joined on top.
  • the joining member solder, a silver sintered material, or the like is used from the viewpoint of exhaust heat.
  • the rectangular annular space formed between the light reflecting film provided on the side surface of the fluorescent member 22 and the side wall of the wavelength conversion member recess 32 is filled with a protective member 23.
  • the protective member 23 is for preventing the side surface of the wavelength conversion member, that is, the side surface of the fluorescent member 22 from coming into contact with the cooling medium, and has a liquid refrigerant intrusion preventing function. Further, by making the protective member 23 have a high diffuse reflection function, the fluorescence generated inside the wavelength conversion member can be more easily taken out from the fluorescence emission surface.
  • the protective member 23 for example, ceramics such as titania (TiO 2 ) and alumina (Al 2 O 3 ) are used from the viewpoint of impermeability to the liquid refrigerant, adhesion to the fluorescent member 22, and high diffuse reflectance. .
  • the fluorescent member 22 contains a phosphor.
  • the fluorescent member 22 is made of a single crystal or polycrystalline phosphor, or a mixture of a single crystal or polycrystalline phosphor and a ceramic binder. It consists of a knot. That is, the fluorescent member 22 is composed of a single crystal or polycrystalline phosphor.
  • the sintered body of the mixture of the phosphor and the ceramic binder used as the fluorescent member 22 nano-sized alumina particles are used as the ceramic binder. This sintered body is obtained by mixing several mass% to several tens mass% ceramic binder with respect to 100 mass% of the phosphor, pressing the mixture, and then firing.
  • the single crystal phosphor constituting the fluorescent member 22 can be obtained, for example, by the Czochralski method. Specifically, the seed crystal is brought into contact with the melted raw material in the crucible, and in this state, the seed crystal is pulled up in the vertical direction while rotating the seed crystal to grow the single crystal on the seed crystal. The body is obtained.
  • the polycrystalline fluorescent substance which comprises the fluorescent member 22 can be obtained as follows, for example. First, raw materials such as a base material, an activator, and a baking aid are pulverized by a ball mill or the like to obtain raw material fine particles of submicron or less. Next, the raw material fine particles are molded and sintered by, for example, a slip casting method. Thereafter, a polycrystalline phosphor having a porosity of 0.5% or less, for example, is obtained by subjecting the obtained sintered body to hot isostatic pressing.
  • the phosphor constituting the fluorescent member 22 include YAG: Ce, YAG: Pr, YAG: Sm, and LuAG: Ce.
  • the doping amount of the rare earth element (activator) is about 0.5 mol%.
  • the thickness of the fluorescent member 22 is, for example, 0.05 to 2.0 mm from the viewpoint of the conversion efficiency of the excitation light L into the fluorescent light L1 and the exhaust heat.
  • the wavelength conversion member is provided with a coating layer 25 on the excitation light incident surface, that is, the surface of the fluorescent member 22 so as to cover the entire excitation light incidence surface.
  • the coating layer 25 has a flat surface (upper surface in FIG. 4).
  • the coating layer 25 has a function of suppressing or preventing the excitation light incident surface from coming into contact with the liquid refrigerant. Due to the provision of the coating layer 25, the wavelength conversion member deteriorates when it comes into contact with the liquid refrigerant, and as a result, the excitation light capturing efficiency decreases with time, and the amount of fluorescence generated is thus reduced. It is possible to prevent or suppress the decrease.
  • the covering layer 25 is made of a light transmissive material and has light transmissive properties with respect to the excitation light L and the fluorescence L1.
  • the covering layer 25 is preferably impermeable to the liquid refrigerant from the viewpoint of preventing the excitation light incident surface from coming into contact with the liquid refrigerant.
  • the light transmissive material constituting the coating layer 25 is an inorganic material since the energy for exciting the phosphor constituting the fluorescent member 22 in the wavelength conversion member has an excitation density of about 5 W / mm 2 or more. preferable. Further, the light-transmitting material constituting the coating layer 25 is higher in refractive index than the wavelength conversion member, that is, the refractive index of the fluorescent member 22, from the viewpoint of emitting the fluorescence L1 from the surface of the coating layer 25 to the outside with high efficiency. It is preferable that it has a rate.
  • the coating layer 25 has high thermal conductivity, and from the viewpoint of the impermeability of the coating layer 25 to the liquid refrigerant, it has resistance to the liquid refrigerant. It is preferable. Furthermore, from the viewpoint of adhesion between the coating layer 25 and the excitation light incident surface, it is preferable to have a thermal expansion coefficient equivalent to that of the wavelength conversion member, that is, the fluorescent member 22.
  • the light transmissive material constituting the coating layer 25 include silica (SiO 2 ), alumina (Al 2 O 3 ), hafnium oxide (HfO 2 ), magnesium oxide (MgO), and tin oxide (SnO 2 ).
  • Tungsten oxide WO 3
  • yttrium oxide Y 2 O 3
  • indium tin oxide ITO
  • zirconia ZrO 2
  • tantalum oxide Ta 2 O 5
  • titania TiO 2
  • niobium oxide Nb 2 O 5
  • zinc oxide ZnO
  • other metal oxides composite oxides of these metal oxides, and mixtures of zirconia (ZrO 2 ) and titania (TiO 2 ).
  • thermal expansion coefficient approximate to the thermal expansion coefficient (6 ⁇ 10 ⁇ 6 to 8 ⁇ 10 ⁇ 6 / K) of the phosphors (LuAG, YAG), zirconia (thermal expansion)
  • a coefficient of 10.5 ⁇ 10 ⁇ 6 / K), indium tin oxide (thermal expansion coefficient 6.8 ⁇ 10 ⁇ 6 / K) and titania (thermal expansion coefficient 7.9 ⁇ 10 ⁇ 6 / K) are preferable.
  • zirconia is more preferable because of its small absorption coefficient (specifically, 13 cm ⁇ 1 (absorption coefficient for light having a wavelength of 550 nm)).
  • zirconia since it has a higher refractive index than the refractive index (1.85) of the phosphor (LuAG, YAG), titania (refractive index 2.0-2.35), zirconia (refractive index 1. 8 to 2.15) are preferred. In addition, zirconia is preferable because it has resistance to the liquid refrigerant.
  • the coating layer 25 include a sol-gel film, a ceramic film, and a vapor deposition film.
  • the coating layer 25 made of a sol-gel film is formed by, for example, applying a sol-like material containing an alkoxide such as silicon, titanium, or zirconium to the excitation light incident surface by, for example, a spin coating method, and then 200 to 500 ° C. It can manufacture by obtaining films
  • the coating layer 25 made of a ceramic film is formed by, for example, spin-coating a slurry containing nanoparticles of zirconia, titania, yttrium oxide, zinc oxide, alumina, magnesium oxide, or composite oxide on the excitation incident surface. After coating and drying the organic solvent in the slurry, it can be produced by obtaining a film by heating at 150 to 500 ° C. in a nitrogen atmosphere. Further, the coating layer 25 made of a vapor deposition film is formed by using, for example, a sputtering apparatus, using silica, zirconia, titania, zinc oxide, alumina, magnesium oxide, or the like as a target material, and circulating the inert gas and oxygen gas.
  • the thickness is 600 nm by forming the molding time for 4 hours under the formation conditions of high frequency power of 250 W, an argon gas flow rate of 20 sccm and an oxygen gas flow rate of 0.5 sccm as an inert gas.
  • the covering layer 25 made of a sputtered film having a degree (specifically, 550 nm) can be obtained.
  • the thickness of the coating layer 25 is, for example, 200 to 2000 nm, and preferably 400 to 600 nm.
  • the fluorescent light source device 10 is provided with a liquid refrigerant distribution mechanism that distributes the liquid refrigerant at least along the excitation light incident surface.
  • the liquid refrigerant circulation mechanism includes a liquid refrigerant flow passage provided in the support member 41 and liquid refrigerant circulation means for flowing the liquid refrigerant through the liquid refrigerant flow passage.
  • the liquid refrigerant circulation means includes a liquid refrigerant circulation path (not shown) connected to the liquid refrigerant flow path.
  • the liquid refrigerant circulation path is provided with an electric pump for circulating the liquid refrigerant, a radiator, and a fan motor for cooling the radiator with air.
  • the support member 41 is made of a metal such as aluminum and has a substantially rectangular flat plate-like appearance, and a thickness direction of the support member 41 (see FIG. 2 and the vertical direction in FIG. 3, a through hole 42 extending in a direction perpendicular to the vertical direction is formed.
  • the through hole 42 has a substantially rectangular cross-sectional shape in a direction perpendicular to the penetrating direction, and has an upper part 42A having a large width (a dimension in the left-right direction in FIG. 2) and a width smaller than the upper part 42A. It consists of the lower side part 42B.
  • steps 43 and 43 are formed by the upper side portion 42 ⁇ / b> A and the lower side portion 42 ⁇ / b> B.
  • the fluorescent light emitting member 20 is supported by the steps 43, 43, and the excitation light incident surface is parallel to the surface of the support member 41 (upper surface in FIGS. 2 and 3). It is arrange
  • the fluorescent light emitting member 20 is a region other than the region where the entire surface of the fluorescent light emitting member 20 faces the upper portion 42 ⁇ / b> A and is in contact with the steps 43, 43 on the back surface of the fluorescent light emitting member 20. Is positioned so as to face the lower side portion 42B.
  • an opening 45 that communicates with the through hole 42 and has the same shape and size as the bottom surface of the excitation light condensing lens 18 is provided at the center of the surface of the support member 41, that is, a position directly above the fluorescent light emitting member 20.
  • the excitation light condensing lens 18 is disposed in the opening 45.
  • the liquid refrigerant flow path is constituted by the through hole 42, and the liquid refrigerant flows along the surface of the fluorescent light emitting member 20 including the excitation light incident surface and the back surface of the fluorescent light emitting member 20. is there.
  • the liquid refrigerant flow passage is located on the surface of the fluorescent light emitting member 20 in the upper portion 42A, and is located on the surface flow portion where the liquid refrigerant flows along the surface and below the back surface of the fluorescent light emitting member 20 in the lower portion 42B. And a rear surface circulation portion through which the liquid refrigerant flows along the rear surface.
  • the through hole 42 extends along the surface of the support member 41 in one direction perpendicular to the thickness direction of the support member 41 (the direction perpendicular to the paper surface in FIG. 2 and the left direction in FIG. 3). It extends in a straight line.
  • the flow direction of the liquid refrigerant is indicated by an arrow.
  • the width of the upper portion 42 ⁇ / b> A has the same width as that of the fluorescent light emitting member 20, and both side walls of the upper portion 42 ⁇ / b> A are in contact with the side surfaces of the fluorescent light emitting member 20.
  • the liquid refrigerant one having optical transparency to the excitation light L and the fluorescence L1 is used. Moreover, it is preferable that a liquid refrigerant is a thing with a low viscosity from a heat transport viewpoint. Specifically, the viscosity at a temperature of 30 ° C. is preferably 0.5 mPa ⁇ s or less, or the viscosity at a temperature of 100 ° C. is preferably 1.5 mPa ⁇ s or less. When the viscosity of the liquid refrigerant at 30 ° C. is 0.5 mPa ⁇ s or less, or the viscosity of the liquid refrigerant at 100 ° C.
  • the temperature of the wavelength conversion member can be changed by temperature quenching.
  • the conversion efficiency of the excitation light L to the fluorescence L1 can be set to a temperature at which the conversion efficiency is extremely lowered, specifically 200 ° C. or less.
  • liquid refrigerant examples include water and inert liquids such as alkyldiphenyl-based inert liquid and fluorine-based inert liquid.
  • the supply conditions of the cooling medium to the liquid refrigerant flow path include, for example, the type of liquid refrigerant, the area of the excitation light incident surface, the thickness of the coating layer 25, and the thicknesses of the front and back flow parts in the liquid refrigerant flow path (FIGS. 2 and 2). 3 is determined appropriately according to the excitation energy of the excitation light L, and the flow rate is, for example, 3 m / s.
  • the substrate 31 has exhaust heat properties. From the viewpoint of exhaust heat, the substrate 31 has a large surface area in which the wavelength conversion member, that is, the surface on which the fluorescent member 22 is disposed is larger than the back surface of the wavelength conversion member.
  • the thickness of the substrate 31 is, for example, 0.5 to 1.0 mm.
  • copper an alloy of molybdenum and copper (Mo—Cu), an alloy of tungsten and copper (W—Cu), or the like can be used.
  • the excitation light L which is the laser light in the blue region emitted from the semiconductor laser 11, is collimated by the collimator lens 15. Thereafter, the excitation light L passes through the dichroic mirror 16, is collected by the excitation light condensing lens 18, and passes through the coating layer 25, so that the excitation light incident surface of the wavelength conversion member in the fluorescent light emitting member 20, that is, fluorescence. Irradiation is substantially perpendicular to the surface of the member 22. And in the fluorescent member 22, the fluorescent substance which comprises the said fluorescent member 22 is excited, and fluorescence L1 is radiated
  • the fluorescence L1 is emitted from the fluorescence emission surface of the wavelength conversion member, that is, the surface of the fluorescence member 22, is reflected in the vertical direction by the dichroic mirror 16, and is then emitted to the outside of the fluorescence light source device 10.
  • the wavelength conversion member particularly the excitation light incident surface is heated by the heat generated by the irradiation of the excitation light L, but along the front and back surfaces of the fluorescent light emitting member 20 by the liquid refrigerant circulation mechanism.
  • the wavelength conversion member is cooled by circulating the liquid refrigerant.
  • the liquid refrigerant since the liquid refrigerant is circulated along the excitation light incident surface to be heated, and the excitation light incident surface can be cooled by the liquid refrigerant through the coating layer 25 having a small thickness, It can be cooled efficiently.
  • the cooling process of the wavelength conversion member by the liquid refrigerant circulation mechanism will be described.
  • Heat generated by the irradiation of the excitation light L in the wavelength conversion member is conducted to the substrate 31 and to the liquid refrigerant flowing through the liquid refrigerant flow path from the excitation light incident surface through the coating layer 25. Further, the heat conducted to the substrate 31 is conducted to the liquid refrigerant from the area in contact with the liquid refrigerant on the front surface, back surface, and side surface of the substrate 31. As described above, the heat of the wavelength conversion member is conducted to the liquid refrigerant through the coating layer 25 or the substrate 31, whereby the wavelength conversion member is cooled by the liquid refrigerant.
  • the liquid refrigerant that has been heated to a high temperature as a result of conduction of heat from the wavelength conversion member is sent to the radiator via the liquid refrigerant circulation path, and in this radiator, the heat of the liquid refrigerant acts as an action of cooling air from the fan motor. To efficiently dissipate heat. Then, the cooled and cooled liquid refrigerant is supplied again to the liquid refrigerant flow path through the liquid refrigerant circulation path. Further, in the fluorescent light source device 10, since the coating layer 25 is provided on the excitation light incident surface, the wavelength conversion member comes into contact with the liquid refrigerant even when the liquid refrigerant flows along the excitation light incident surface.
  • the fluorescent light source device 10 even when the wavelength conversion member is irradiated with excitation light having high excitation energy, the temperature increase of the wavelength conversion member is suppressed, and high luminous efficiency is obtained over a long period of time. can get.
  • FIG. 5 is an enlarged sectional view for explanation showing an enlarged configuration of a fluorescent light emitting member in another example of the fluorescent light source device of the present invention.
  • the coating layer 50 constituting the fluorescent light emitting member 20 has a concavo-convex structure 51 formed on the entire surface (the upper surface in FIG. 5). (Specifically, conical) convex portions 52 are periodically arranged.
  • the configuration of the substrate 31, the fluorescent member 22, the covering layer 50, and the protective member 23 is such that the fluorescent member 22 has a circular plate shape and the covering layer 50 has a substantially circular plate shape, 1 is the same as the substrate 31, the fluorescent member 22, the covering layer 25, and the protective member 23 of the fluorescent light source device 10 of FIG.
  • the covering layer 50 has a periodic structure 51 formed on the entire surface thereof, and the fluorescent member 22 has a circular plate shape, and the covering layer 50 is substantially the same. Except for the circular plate shape, it has the same configuration as the fluorescent light source device 10 of FIG.
  • the period d is preferably a size in a range (Bragg condition) in which diffraction of fluorescence emitted from the phosphor constituting the fluorescent member 22 occurs.
  • the period d of the concavo-convex structure 51 is a value obtained by dividing the peak wavelength of the fluorescence emitted from the phosphor by the refractive index of the material (specifically, the light transmissive material) constituting the concavo-convex structure 51. (Hereinafter referred to as “optical length”) or a value of several times the optical length.
  • the period of the concavo-convex structure means a center-to-center distance (nm) between the convex portions adjacent to each other in the concavo-convex structure.
  • the aspect ratio which is ratio (h / d) of the height h of the convex part 25 with respect to the period d in the uneven structure 51 is 0.2 or more.
  • the covering layer 50 is made of a light-transmitting material, like the covering layer 25 in the fluorescent light source device 10 of FIG. 1, and the light-transmitting material having a higher refractive index than the fluorescent member 22 is used. Accordingly, it is possible to form the concavo-convex structure 51 having a small period d. Therefore, since the convex portion 52 constituting the concave-convex structure 51 can be designed with a small height even if the aspect ratio is large, the concave-convex structure 51 can be easily formed. For example, when the nanoprint method is used, a mold can be easily produced or imprinted.
  • the concavo-convex structure 51 can be formed by a nanoimprint method and a dry etching process when the coating layer 50 is made of a ceramic film or a vapor deposition film.
  • a resist is applied to the surface of the circular plate-shaped coating layer by, for example, spin coating, and then the resist coating film is patterned by, for example, nanoimprinting.
  • a periodic structure is formed by performing a dry etching process on the exposed region on the surface of the coating layer.
  • a specific example of the dry etching method is an ICP (Inductive Coupling Plasma) etching method.
  • the uneven structure 51 can be formed on the surface of the coating layer 50 by using a sol-gel method and a nanoimprint method. Specifically, a sol-like material containing an alkoxide such as silicon, titanium, or zirconium is applied to the excitation light incident surface of the wavelength conversion member, that is, the surface of the fluorescent member 22 by, for example, spin coating, and the mold is pressed. A heat treatment is performed in the state of being attached, and after releasing the mold, a heat treatment is performed. By this heat treatment, the reaction (hydrolysis and condensation polymerization) proceeds, and the coating layer 50 having the uneven structure 51 formed on the surface is formed.
  • a sol-like material containing an alkoxide such as silicon, titanium, or zirconium
  • the excitation light which is the laser light in the blue region emitted from the semiconductor laser, is collimated by the collimator lens. Thereafter, the excitation light passes through the dichroic mirror, is condensed by the excitation light condensing lens, and is incident on the excitation light incident surface of the wavelength conversion member in the fluorescent light emitting member 20 through the coating layer 50, that is, the surface of the fluorescent member 22. Irradiated substantially perpendicularly to. And in the fluorescent member 22, the fluorescent substance which comprises the said fluorescent member 22 is excited, and fluorescence is emitted. The fluorescence is emitted from the fluorescence emission surface of the wavelength conversion member, that is, the surface of the fluorescence member 22, reflected in the vertical direction by the dichroic mirror, and then emitted to the outside of the fluorescence light source device.
  • the fluorescent light source device of FIG. 5 similarly to the fluorescent light source device 10 of FIG. 1, even when the wavelength conversion member is irradiated with excitation light having high excitation energy, the temperature of the wavelength conversion member increases. Is suppressed, and high luminous efficiency is obtained over a long period of time.
  • the uneven structure 51 is formed on the surface of the coating layer 50, excitation light can be sufficiently taken into the wavelength conversion member through the coating layer 50, Further, the fluorescence generated inside the wavelength conversion member can be emitted to the outside through the coating layer 50 with high efficiency. In addition, heating of the wavelength conversion member due to the fluorescence generated inside the wavelength conversion member being confined in the inside is suppressed. As a result, the temperature increase of the wavelength conversion member is further suppressed, and higher luminous efficiency is obtained.
  • FIG. 6 is an enlarged sectional view for explanation showing an enlarged configuration of a fluorescent light emitting member in still another example of the fluorescent light source device of the present invention.
  • the coating layer 55 constituting the fluorescent light emitting member 20 has a concavo-convex structure 51 formed on a part (specifically, the central part) of the surface (upper surface in FIG. 6).
  • the concavo-convex structure 51 is formed by periodically arranging substantially conical (specifically conical) convex portions 52.
  • the substrate 31, the fluorescent member 25, the covering layer 55, and the protective member 23 are configured as shown in the figure except that the uneven structure 51 is formed only on a part of the surface of the covering layer 55.
  • the fluorescent light source device of FIG. 6 is the same as the fluorescent light source device of FIG. 5 except that the coating layer 55 of the fluorescent light emitting member 20 is formed with a concavo-convex structure 51 on a part of the surface thereof. It has a configuration.
  • the area of the surface of the covering layer 55 where the uneven structure 51 is formed (hereinafter also referred to as “uneven structure forming region”) is 22 to 88% of the area of the entire surface of the covering layer 55. It is preferable that
  • the excitation light that is the laser light in the blue region emitted from the semiconductor laser is converted into parallel rays by the collimator lens. Thereafter, the excitation light passes through the dichroic mirror, is condensed by the excitation light condensing lens, and passes through the coating layer 55, the excitation light incident surface of the wavelength conversion member in the fluorescent light emitting member 20, that is, the surface of the fluorescent member 22. Irradiated substantially perpendicularly to. And in the fluorescent member 22, the fluorescent substance which comprises the said fluorescent member 22 is excited. Thereby, fluorescence is emitted in the fluorescent member 22.
  • the concavo-convex structure forming region that is, the region where the concavo-convex structure 51 is formed on the surface of the coating layer 55, reflected in the vertical direction by the dichroic mirror, and then outside the fluorescent light source device. Emitted.
  • the fluorescent light source device of FIG. 6 similarly to the fluorescent light source device 10 of FIG. 1 and the fluorescent light source device of FIG. 5, even when the wavelength conversion member is irradiated with excitation light having high excitation energy, While the temperature rise of the wavelength conversion member is suppressed, high luminous efficiency can be obtained over a long period of time.
  • the excitation light can be sufficiently taken into the wavelength conversion member through the coating layer 55, and the The fluorescence generated inside the wavelength conversion member can be emitted to the outside with high efficiency via the coating layer 55.
  • heating of the wavelength conversion member due to the fluorescence generated inside the wavelength conversion member being confined in the inside is suppressed.
  • the temperature increase of the wavelength conversion member is further suppressed, and higher luminous efficiency is obtained.
  • the concavo-convex structure 51 is formed on a part (center portion) of the surface of the coating layer 55, and the concavo-convex structure forming region where the concavo-convex structure 51 is formed, Most of the fluorescence generated in is emitted. Therefore, the wavelength conversion member provided with the coating layer 55 has a high heat exhaust property, and heat generated by irradiation of excitation light in the wavelength conversion member is radiated with high efficiency, and the temperature increase of the wavelength conversion member is suppressed. The In addition, since the fluorescence generated inside the wavelength conversion member can be extracted with high efficiency from the concavo-convex structure forming region having a small area, a high fluorescent light flux can be obtained. As a result, the temperature rise of the wavelength conversion member is further suppressed, and the fluorescence generated inside the wavelength conversion member can be used with high efficiency.
  • the liquid refrigerant distribution mechanism may be any mechanism that can distribute liquid refrigerant at least along the excitation light incident surface of the wavelength conversion member, and various configurations can be employed.
  • the liquid refrigerant circulation mechanism is liquid on the back surface side (the lower surface side in FIGS. 2 and 3) of the wavelength conversion member as shown in FIGS. 2 and 3.
  • coolant is preferable, the thing of a structure as shown in FIG. 7 may be sufficient.
  • the through hole 47 has a rectangular cross-sectional shape in the direction perpendicular to the through direction, and the fluorescent light emitting member 20 has the through hole.
  • 1 is the same as the fluorescent light source device of FIG. 1 except that it is supported by the bottom wall of 47 and the opening 49 communicating with the through hole 47 has an opening having a smaller diameter than the bottom surface of the excitation light collecting lens 18. It has the structure of.
  • the overall structure of the fluorescent light source device is not limited to that shown in FIG. 1, and various configurations can be employed.
  • the light of one laser light source for example, a semiconductor laser
  • a condensing lens is arranged in front of the fluorescent plate to collect The form which irradiates light to a fluorescence plate may be sufficient.
  • the excitation light is not limited to the light from the laser light source, but may be one that condenses the LED light as long as it can excite the fluorescent plate, and further from a lamp in which mercury, xenon, or the like is enclosed. It may be light.
  • the wavelength of the excitation light is a main radiation wavelength region emitted from the lamp or the like.
  • the present invention is not limited to this.
  • Example 1 Basically, three fluorescent light emitting members (20) having the configuration shown in FIG. 6 and the following specifications were produced.
  • the coating layer (55) was made of a vapor deposition film, and the concavo-convex structure (51) of the coating layer (55) was formed by a nanoimprint method and a dry etching process.
  • a resist was applied to the surface of the circular plate-shaped coating layer by a spin coating method, and then the resist coating film was patterned by a nanoimprint method.
  • the coating layer (55) shall have an intended shape dimension by die-sharing.
  • each of the produced fluorescent light emitting members (20) was supported by a support member (41) as shown in FIG. 7, and three fluorescent light source devices were produced based on the configuration of FIG.
  • the width of the flow passage formed by the through hole (47) (the dimension in the left-right direction in FIG. 7) is 17 mm, and is positioned on the surface of the fluorescent light emitting member (20) in the flow passage.
  • the thickness of the portion (the vertical dimension in FIG. 7) is 2.5 mm.
  • air, fluorine-based inert liquid, and water are used as refrigerants, and these refrigerants are supplied to the through-hole (47) under the conditions of a temperature of 30 ° C.
  • the light emitting member (20) was irradiated with excitation light having an excitation energy of 100W. And while measuring the fluorescence light beam radiate
  • fluorescent light source device (1) Three fluorescent light source devices (hereinafter also referred to as “fluorescent light source device (1)”) having the same configuration as the fluorescent light source device of Experimental Example 1 were produced.
  • three types of liquid refrigerants having different viscosities specifically, water, a fluorine-based inert liquid, and an alkyldiphenyl-based inert liquid are used as liquid refrigerants, and these refrigerants are heated to a temperature of 30.
  • the fluorescent light emitting member (20) was irradiated with excitation light while being supplied to the flow path formed of the through hole (47) under the conditions of 0 ° C. and a flow rate of 3 m / s.
  • the temperature (surface temperature) of the fluorescent member (22) was measured with the radiation thermometer.
  • Table 2 “viscosity” indicates viscosity at a temperature of 100 ° C.
  • the temperature of the wavelength conversion member is set to be equal to or lower than the temperature at which the conversion efficiency of excitation light into fluorescence is extremely reduced by temperature quenching. Specifically, it was confirmed that the temperature could be 200 ° C. or lower.
  • fluorescent light source device (1) A fluorescent light source device (hereinafter also referred to as “fluorescent light source device (1)”) having the same configuration as the fluorescent light source device of Experimental Example 1 was produced. Further, a fluorescent light source device (hereinafter referred to as “comparison”) having the same configuration as that of the fluorescent light source device (1) except that a coating layer is not provided on the excitation light incident surface of the wavelength conversion member, ie, the surface of the fluorescent member (22) Fluorescent light source device (also referred to as “1”). In each of the produced fluorescent light source device (1) and comparative fluorescent light source device (1), water is used as a refrigerant, and this refrigerant is distributed through the through holes (47) under the conditions of a temperature of 30 ° C.
  • the fluorescent light emitting member (20) was irradiated with excitation light for 430 hours. Then, immediately after the excitation light irradiation, that is, immediately after the surface of the fluorescent light emitting member (20) was immersed in water, the fluorescent light flux (initial light flux) emitted from the surface of the fluorescent member (22) was measured. Further, after 430 hours have passed since the excitation light irradiation was started, that is, after the surface of the fluorescent light emitting member (20) was immersed in water for 430 hours, the light was emitted from the surface of the fluorescent member (22).
  • Fluorescent light flux (hereinafter also referred to as “430 hours elapsed light flux”) was measured.
  • a luminous flux maintenance factor which is a ratio of a 340 hour lapsed light beam to an initial light beam, was calculated from the obtained initial light beam and 340 time lapsed light beam.
  • the luminous flux maintenance factor of the fluorescent light source device (1) was 91%, while the luminous flux maintenance factor of the comparative fluorescent light source device (1) was 87%.

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Abstract

The purpose of the present invention is to provide a fluorescent light source device wherein it is possible to achieve high light-emission efficiency over a long period of time, and an increase in the temperature of a wavelength conversion member is inhibited even when the wavelength conversion member is irradiated with excitation light having a high excitation energy. This fluorescent light source device is provided with a wavelength conversion member which is disposed on a substrate and emits fluorescent light by means of excitation light, the fluorescent light source device being characterized in that a liquid refrigerant circulation mechanism for circulating a light-permeable liquid refrigerant at least along the excitation light incident surface of the wavelength conversion member is provided, and a cover layer formed from a light-permeable material and for covering the excitation light incident surface is provided to the wavelength conversion member.

Description

蛍光光源装置Fluorescent light source device
　本発明は、励起光により蛍光を出射する波長変換部材を備えた蛍光光源装置に関する。 The present invention relates to a fluorescent light source device including a wavelength conversion member that emits fluorescence by excitation light.
　従来、蛍光光源装置としては、レーザ光を励起光とし、その励起光により蛍光を出射する波長変換部材を発光源として備えたものが知られている（例えば、特許文献１参照。）。
　このような蛍光光源装置の波長変換部材においては、励起光の照射によって発生する熱により、特に励起光入射面が加熱されるなどして蛍光体が高温となり、それに起因して温度消光が生じて、励起光の蛍光への変換効率が低下する、という問題がある。
　このような問題は、励起光の入射パワー（励起光の励起エネルギー）を大きくした場合に顕著となる。 2. Description of the Related Art Conventionally, as a fluorescent light source device, a device including a wavelength conversion member that uses laser light as excitation light and emits fluorescence using the excitation light as a light emission source is known (see, for example, Patent Document 1).
In such a wavelength conversion member of the fluorescent light source device, the phosphor is heated to a high temperature by heating the excitation light incident surface due to the heat generated by the excitation light irradiation, resulting in temperature quenching. There is a problem that the conversion efficiency of excitation light into fluorescence is reduced.
Such a problem becomes conspicuous when the incident power of excitation light (excitation energy of excitation light) is increased.
　而して、蛍光光源装置においては、波長変換部材を冷却することが行われている（例えば、特許文献２参照。）。
　具体的に、特許文献２には、波長変換部材の励起光入射面に冷却風を吹き付けることによって当該波長変換部材を冷却する技術が開示されている。
　しかしながら、冷却風を励起光入射面に吹き付けることによっては、特に励起光の入射パワーが大きい場合には、波長変換部材を十分に冷却することができない。 Thus, in the fluorescent light source device, the wavelength conversion member is cooled (for example, see Patent Document 2).
Specifically, Patent Document 2 discloses a technique for cooling the wavelength conversion member by blowing cooling air onto the excitation light incident surface of the wavelength conversion member.
However, when the cooling air is blown onto the excitation light incident surface, the wavelength conversion member cannot be sufficiently cooled, particularly when the incident power of the excitation light is large.
　一方、ＬＥＤチップや半導体レーザを発光源とする光源装置においては、液体冷媒を用いて当該発光源を冷却する技術が開示されている（例えば、特許文献３参照。）。
　そこで、発明者らは、蛍光光源装置において、波長変換部材を、水などの液体媒体を用いて冷却することを検討したが、問題があることが明らかとなった。
　具体的に説明すると、特に加熱される励起光入射面を十分に冷却するために、波長変換部材の一部または全部を液体冷媒に浸漬した場合には、当該波長変換部材における液体冷媒に浸漬した部分の表面近傍の蛍光体の付活材が酸化され、発光強度が低下する。更に波長変換部材に微小クラックがある場合には、液体冷媒の浸入によって当該微小クラックが次第に成長し、大きなクラックになってしまう。そして、そのクラックから液体冷媒が、波長変換部材の内部に更に浸入することにより、新たな界面が形成され、非発光層が発生する。しかも、クラックへの液体冷媒の浸入によって、前記界面の蛍光体の付活材に酸化が生じ、更に発光強度が低下する。
　また、液体冷媒が水である場合には、特に蛍光体の付活材が酸化されやすく、それに起因して蛍光体において付活材の価数や結晶構造に変化が生じやすい。
　そのため、波長変換部材においては、経時的に励起光の取り込み効率が低下し、それに起因して蛍光の発生量が低下する。その結果、経時的に発光効率が低下する、という問題がある。 On the other hand, in a light source device using an LED chip or a semiconductor laser as a light source, a technique for cooling the light source using a liquid refrigerant is disclosed (for example, see Patent Document 3).
Therefore, the inventors examined cooling the wavelength conversion member using a liquid medium such as water in the fluorescent light source device, but it became clear that there was a problem.
More specifically, when a part or all of the wavelength conversion member is immersed in the liquid refrigerant to sufficiently cool the excitation light incident surface to be heated, the surface is immersed in the liquid refrigerant in the wavelength conversion member. The phosphor activator in the vicinity of the surface of the portion is oxidized, and the emission intensity decreases. Further, when the wavelength conversion member has a micro crack, the micro crack gradually grows due to the penetration of the liquid refrigerant, and becomes a large crack. And when a liquid refrigerant further permeates into the inside of a wavelength conversion member from the crack, a new interface will be formed and a non-light-emitting layer will occur. In addition, penetration of the liquid refrigerant into the cracks causes oxidation of the phosphor activator at the interface, further reducing the emission intensity.
In addition, when the liquid refrigerant is water, the phosphor activator is particularly easily oxidized, and as a result, the valence and crystal structure of the activator tend to change in the phosphor.
For this reason, in the wavelength conversion member, the excitation light capture efficiency decreases with time, and the amount of fluorescence generated decreases accordingly. As a result, there is a problem that the luminous efficiency decreases with time.
特開２０１１－１９８５６０号公報JP 2011-198560 A 特開２０１２－１９９２５８号公報JP 2012-199258 A 特許第３７５３１３７号公報Japanese Patent No. 3753137
　本発明は、以上のような事情に基づいてなされたものであって、その目的は、波長変換部材に高い励起エネルギーを有する励起光が照射された場合であっても、波長変換部材の温度上昇が抑制されると共に、長期間にわたって高い発光効率が得られる蛍光光源装置を提供することにある。 The present invention has been made based on the above circumstances, and its purpose is to increase the temperature of the wavelength conversion member even when the wavelength conversion member is irradiated with excitation light having high excitation energy. It is an object of the present invention to provide a fluorescent light source device capable of suppressing light emission and obtaining high luminous efficiency over a long period of time.
　本発明の蛍光光源装置は、基板上に設けられた、励起光により蛍光を出射する波長変換部材を備えた蛍光光源装置において、
　少なくとも前記波長変換部材の励起光入射面に沿って光透過性を有する液体冷媒を流通する液体冷媒流通機構が設けられており、
　前記波長変換部材には、前記励起光入射面を被覆する、光透過性材料よりなる被覆層が設けられていることを特徴とする。 The fluorescent light source device of the present invention is a fluorescent light source device provided with a wavelength conversion member provided on a substrate and emitting fluorescence by excitation light.
A liquid refrigerant circulation mechanism is provided that circulates a liquid refrigerant having optical transparency along at least the excitation light incident surface of the wavelength conversion member;
The wavelength conversion member is provided with a coating layer made of a light transmissive material that covers the excitation light incident surface.
　本発明の蛍光光源装置においては、前記被覆層は、表面に凹凸構造が形成されていることが好ましい。 In the fluorescent light source device of the present invention, it is preferable that the coating layer has an uneven structure on the surface.
　本発明の蛍光光源装置においては、液体冷媒流通機構が設けられており、励起光の照射によって発生する熱によって特に加熱される励起光入射面が液体冷媒によって優先的に冷却されることから、当該波長変換部材を効率的に冷却することができる。しかも、励起光入射面には被覆層が設けられていることから、液体冷媒を励起光入射面に沿って流通しても、波長変換部材が液体冷媒と接触することによって経時的に劣化し、それに起因して発光効率が低下することを防止または抑制することができる。
　従って、本発明の蛍光光源装置によれば、波長変換部材に高い励起エネルギーを有する励起光が照射された場合であっても、波長変換部材の温度上昇が抑制されると共に、長期間にわたって高い発光効率が得られる。 In the fluorescent light source device of the present invention, the liquid refrigerant circulation mechanism is provided, and the excitation light incident surface that is particularly heated by the heat generated by the excitation light irradiation is preferentially cooled by the liquid refrigerant. The wavelength conversion member can be efficiently cooled. Moreover, since the coating layer is provided on the excitation light incident surface, even if the liquid refrigerant circulates along the excitation light incident surface, the wavelength conversion member deteriorates with time due to contact with the liquid refrigerant, It can prevent or suppress that the luminous efficiency falls resulting from it.
Therefore, according to the fluorescent light source device of the present invention, even when the wavelength conversion member is irradiated with excitation light having high excitation energy, the temperature increase of the wavelength conversion member is suppressed, and high light emission over a long period of time. Efficiency is obtained.
　本発明の蛍光光源装置においては、被覆層を、表面に凹凸構造が形成されたものとすることにより、当該被覆層を介して励起光を波長変換部材の内部に十分に取り込むことができ、また当該被覆層を介して波長変換部材の内部において生成された蛍光を高い効率で外部に出射することができる。しかも、波長変換部材の内部において生成された蛍光が当該内部に閉じ込められることに起因して波長変換部材が加熱されることが抑制される。その結果、波長変換部材の温度上昇がより一層抑制されると共に、より高い発光効率が得られる。 In the fluorescent light source device of the present invention, the coating layer has a concavo-convex structure formed on the surface thereof, so that excitation light can be sufficiently taken into the wavelength conversion member through the coating layer. The fluorescence generated inside the wavelength conversion member can be emitted to the outside with high efficiency via the coating layer. In addition, heating of the wavelength conversion member due to the fluorescence generated inside the wavelength conversion member being confined in the inside is suppressed. As a result, the temperature increase of the wavelength conversion member is further suppressed, and higher luminous efficiency is obtained.
本発明の蛍光光源装置の一例における構成の概略を示す説明図である。It is explanatory drawing which shows the outline of a structure in an example of the fluorescence light source device of this invention. 図１の本発明の蛍光光源装置における蛍光発光部材および液体冷媒流通機構の構成を示す説明図である。It is explanatory drawing which shows the structure of the fluorescence light emission member and liquid refrigerant distribution mechanism in the fluorescence light source device of this invention of FIG. 図２のＡ－Ａ線の断面図である。FIG. 3 is a sectional view taken along line AA in FIG. 2. 図１の蛍光光源装置における蛍光発光部材の構成を拡大して示す説明用拡大断面図である。It is an expanded sectional view for description which expands and shows the structure of the fluorescence light emitting member in the fluorescence light source device of FIG. 本発明の蛍光光源装置の他の例における蛍光発光部材の構成を示す説明用拡大断面図である。It is an expanded sectional view for description which shows the structure of the fluorescence light emission member in the other example of the fluorescence light source device of this invention. 本発明の蛍光光源装置の更に他の例における蛍光発光部材の構成を示す説明用拡大断面図である。It is an expanded sectional view for description which shows the structure of the fluorescence light emission member in the further another example of the fluorescence light source device of this invention. 本発明の蛍光光源装置における液体冷媒流通機構の構成の他の例を示す説明図である。It is explanatory drawing which shows the other example of a structure of the liquid refrigerant | coolant distribution mechanism in the fluorescence light source device of this invention.
　以下、本発明の蛍光光源装置の実施の形態について説明する。
　図１は、本発明の蛍光光源装置の一例における構成の概略を示す説明図であり、図２は、図１の本発明の蛍光光源装置における蛍光発光部材および液体冷媒流通機構の構成を示す説明図であり、図３は、図２のＡ－Ａ線の断面図である。また、図４は、図１の蛍光光源装置における蛍光発光部材の構成を拡大して示す説明用拡大断面図である。
　この蛍光光源装置１０は、図１に示すように、例えば青色領域の光を出射する半導体レーザ１１と、この半導体レーザ１１に対向して配置された、当該半導体レーザ１１から出射されるレーザ光である励起光Ｌによって励起されて蛍光Ｌ１を出射する波長変換部材を有する蛍光発光部材２０とを備えている。この蛍光発光部材２０は、図２および図３に示すように、支持部材４１によって支持されており、その支持部材４１には、半球状の励起光集光レンズ１８が、半導体レーザ１１と蛍光発光部材２０との間に位置するように配設されており、また液体冷媒を流通させるための液体冷媒流通路が設けられている。
　半導体レーザ１１と蛍光発光部材２０との間における当該半導体レーザ１１に接近した位置には、半導体レーザ１１から入射された励起光Ｌを平行光線として出射するコリメータレンズ１５が配置されている。また、コリメータレンズ１５と蛍光発光部材２０との間には、半導体レーザ１１からの励起光Ｌを透過すると共に蛍光発光部材２０における波長変換部材からの蛍光Ｌ１を反射するダイクロイックミラー１６が、コリメータレンズ１５の光軸に対して例えば４５°の角度で傾斜した姿勢で配置されている。 Hereinafter, embodiments of the fluorescent light source device of the present invention will be described.
FIG. 1 is an explanatory diagram showing an outline of the configuration of an example of the fluorescent light source device of the present invention, and FIG. 2 is an explanatory diagram showing the configuration of the fluorescent light emitting member and the liquid refrigerant circulation mechanism in the fluorescent light source device of the present invention of FIG. FIG. 3 is a cross-sectional view taken along line AA of FIG. FIG. 4 is an explanatory enlarged sectional view showing the configuration of the fluorescent light emitting member in the fluorescent light source device of FIG. 1 in an enlarged manner.
As shown in FIG. 1, the fluorescent light source device 10 includes, for example, a semiconductor laser 11 that emits light in a blue region, and laser light emitted from the semiconductor laser 11 that is disposed to face the semiconductor laser 11. And a fluorescent light emitting member 20 having a wavelength conversion member that is excited by certain excitation light L and emits fluorescent light L1. 2 and 3, the fluorescent light emitting member 20 is supported by a support member 41, and a hemispherical excitation light condensing lens 18 is connected to the semiconductor laser 11 and the fluorescent light emission on the support member 41. A liquid refrigerant flow passage is provided so as to be positioned between the member 20 and the liquid refrigerant.
A collimator lens 15 that emits the excitation light L incident from the semiconductor laser 11 as a parallel light beam is disposed at a position between the semiconductor laser 11 and the fluorescent light emitting member 20 close to the semiconductor laser 11. A dichroic mirror 16 that transmits the excitation light L from the semiconductor laser 11 and reflects the fluorescence L1 from the wavelength conversion member in the fluorescent light emitting member 20 is provided between the collimator lens 15 and the fluorescent light emitting member 20. For example, it is arranged in a posture inclined at an angle of 45 ° with respect to the 15 optical axes.
　蛍光発光部材２０は、図４に示すように、略矩形平板状の基板３１の表面（図４における上面）に形成された矩形状の波長変換部材用凹部３２に、矩形状の蛍光部材２２よりなる波長変換部材が設けられたものである。波長変換部材用凹部３２は、その縦横寸法が、蛍光部材２２の縦横寸法よりも大きく、凹み深さが蛍光部材２２の厚み（図４における上下方向の寸法）よりわずかに大きいものである。
　この蛍光発光部材２０は、蛍光部材２２の表面（図４における上面）が、励起光集光レンズ１８、ダイクロイックミラー１６およびコリメータレンズ１５を介して半導体レーザ１１に対向するように配置されている。そして、蛍光部材２２の表面は、波長変換部材の励起光入射面とされていると共に、当該波長変換部材の蛍光出射面とされている。
　また、蛍光部材２２の裏面（図４における下面）および側面の各々には、光反射膜（図示省略）が設けられている。光反射膜としては、例えば増反射アルミニウム膜、または、銀層、増反射銀膜等とニッケル層とよりなる多層膜などが用いられる。蛍光部材２２の裏面に設けられた光反射膜と波長変換部材用凹部３２の底壁との間には、接合部材（図示省略）が介在されており、当該接合部材によって蛍光部材２２が基板３１上に接合されている。接合部材としては、排熱性の観点から、半田、銀焼結材などが用いられる。また、蛍光部材２２の側面に設けられた光反射膜と波長変換部材用凹部３２の側壁との間に形成された矩形環状の空間には、保護部材２３が充填されている。この保護部材２３は、波長変換部材の側面、すなわち蛍光部材２２の側面が冷却媒体と接触することを防止するためのものであり、液体冷媒浸入防止機能を有している。また、保護部材２３を高い拡散反射機能を有するものとすることにより、波長変換部材の内部において生成された蛍光が蛍光出射面からより取り出しやすくなる。保護部材２３としては、液体冷媒に対する不透過性、蛍光部材２２との密着性および高拡散反射性の観点から、例えばチタニア（ＴｉＯ2 ）、アルミナ（Ａｌ2 Ｏ3 ）等のセラミックなどが用いられる。 As shown in FIG. 4, the fluorescent light emitting member 20 has a rectangular wavelength conversion member recess 32 formed on the surface (upper surface in FIG. 4) of the substantially rectangular flat plate-like substrate 31, from the rectangular fluorescent member 22. The wavelength conversion member which becomes is provided. The wavelength conversion member recess 32 has a vertical and horizontal dimension that is larger than the vertical and horizontal dimensions of the fluorescent member 22, and the depth of the recess is slightly larger than the thickness of the fluorescent member 22 (the vertical dimension in FIG. 4).
The fluorescent light emitting member 20 is disposed so that the surface of the fluorescent member 22 (the upper surface in FIG. 4) faces the semiconductor laser 11 through the excitation light condensing lens 18, the dichroic mirror 16, and the collimator lens 15. The surface of the fluorescent member 22 is the excitation light incident surface of the wavelength conversion member and the fluorescent emission surface of the wavelength conversion member.
A light reflecting film (not shown) is provided on each of the back surface (lower surface in FIG. 4) and side surfaces of the fluorescent member 22. As the light reflection film, for example, an increased reflection aluminum film or a multilayer film composed of a silver layer, an increased reflection silver film or the like and a nickel layer is used. A bonding member (not shown) is interposed between the light reflecting film provided on the back surface of the fluorescent member 22 and the bottom wall of the wavelength conversion member recess 32, and the fluorescent member 22 is attached to the substrate 31 by the bonding member. Joined on top. As the joining member, solder, a silver sintered material, or the like is used from the viewpoint of exhaust heat. The rectangular annular space formed between the light reflecting film provided on the side surface of the fluorescent member 22 and the side wall of the wavelength conversion member recess 32 is filled with a protective member 23. The protective member 23 is for preventing the side surface of the wavelength conversion member, that is, the side surface of the fluorescent member 22 from coming into contact with the cooling medium, and has a liquid refrigerant intrusion preventing function. Further, by making the protective member 23 have a high diffuse reflection function, the fluorescence generated inside the wavelength conversion member can be more easily taken out from the fluorescence emission surface. As the protective member 23, for example, ceramics such as titania (TiO 2 ) and alumina (Al 2 O 3 ) are used from the viewpoint of impermeability to the liquid refrigerant, adhesion to the fluorescent member 22, and high diffuse reflectance. .
　蛍光部材２２は、蛍光体が含有されてなるものであり、具体的には、単結晶または多結晶の蛍光体よりなるもの、または単結晶または多結晶の蛍光体とセラミックバインダーとの混合物の焼結体よりなるものである。すなわち、蛍光部材２２は、単結晶または多結晶の蛍光体によって構成されたものである。
　ここに、蛍光部材２２として用いられる蛍光体とセラミックバインダーとの混合物の焼結体においては、セラミックバインダーとしてナノサイズのアルミナ粒子が用いられる。そして、この焼結体は、蛍光体１００質量％に対して数質量％～数十質量％のセラミックバインダーを混合し、その混合物をプレスした後、焼成することによって得られるものである。 The fluorescent member 22 contains a phosphor. Specifically, the fluorescent member 22 is made of a single crystal or polycrystalline phosphor, or a mixture of a single crystal or polycrystalline phosphor and a ceramic binder. It consists of a knot. That is, the fluorescent member 22 is composed of a single crystal or polycrystalline phosphor.
Here, in the sintered body of the mixture of the phosphor and the ceramic binder used as the fluorescent member 22, nano-sized alumina particles are used as the ceramic binder. This sintered body is obtained by mixing several mass% to several tens mass% ceramic binder with respect to 100 mass% of the phosphor, pressing the mixture, and then firing.
　蛍光部材２２を構成する単結晶の蛍光体は、例えば、チョクラルスキー法によって得ることができる。具体的には、坩堝内において種子結晶を溶融された原料に接触させ、この状態で、種子結晶を回転させながら鉛直方向に引き上げて当該種子結晶に単結晶を成長させることにより、単結晶の蛍光体が得られる。
　また、蛍光部材２２を構成する多結晶の蛍光体は、例えば以下のようにして得ることができる。先ず、母材、付活材および焼成助剤などの原材料をボールミルなどによって粉砕処理することによって、サブミクロン以下の原材料微粒子を得る。次いで、この原材料微粒子を例えばスリップキャスト法によって成形して焼結する。その後、得られた焼結体に対して熱間等方圧加圧加工を施すことによって、気孔率が例えば０．５％以下の多結晶の蛍光体が得られる。 The single crystal phosphor constituting the fluorescent member 22 can be obtained, for example, by the Czochralski method. Specifically, the seed crystal is brought into contact with the melted raw material in the crucible, and in this state, the seed crystal is pulled up in the vertical direction while rotating the seed crystal to grow the single crystal on the seed crystal. The body is obtained.
Moreover, the polycrystalline fluorescent substance which comprises the fluorescent member 22 can be obtained as follows, for example. First, raw materials such as a base material, an activator, and a baking aid are pulverized by a ball mill or the like to obtain raw material fine particles of submicron or less. Next, the raw material fine particles are molded and sintered by, for example, a slip casting method. Thereafter, a polycrystalline phosphor having a porosity of 0.5% or less, for example, is obtained by subjecting the obtained sintered body to hot isostatic pressing.
　蛍光部材２２を構成する蛍光体の具体例としては、ＹＡＧ：Ｃｅ、ＹＡＧ：Ｐｒ、ＹＡＧ：Ｓｍ、ＬｕＡＧ：Ｃｅなどが挙げられる。このような蛍光体において、希土類元素（付活材）のドープ量は、０．５ｍｏｌ％程度である。 Specific examples of the phosphor constituting the fluorescent member 22 include YAG: Ce, YAG: Pr, YAG: Sm, and LuAG: Ce. In such a phosphor, the doping amount of the rare earth element (activator) is about 0.5 mol%.
　また、蛍光部材２２の厚みは、励起光Ｌの蛍光Ｌ１への変換効率および排熱性の観点から、例えば０．０５～２．０ｍｍである。 Further, the thickness of the fluorescent member 22 is, for example, 0.05 to 2.0 mm from the viewpoint of the conversion efficiency of the excitation light L into the fluorescent light L1 and the exhaust heat.
　そして、波長変換部材には、図４に示されているように、励起光入射面、すなわち蛍光部材２２の表面に、当該励起光入射面の全面を覆うように、被覆層２５が設けられている。この被覆層２５は、表面（図４における上面）が平坦なものである。
　被覆層２５は、励起光入射面が液体冷媒と接触することを抑制または防止する機能を有するものである。
　被覆層２５が設けられていることにより、波長変換部材が液体冷媒と接触することによって劣化し、それに起因して、経時的に励起光の取り込み効率が低下し、因って蛍光の発生量が低下することを防止または抑制することができる。 As shown in FIG. 4, the wavelength conversion member is provided with a coating layer 25 on the excitation light incident surface, that is, the surface of the fluorescent member 22 so as to cover the entire excitation light incidence surface. Yes. The coating layer 25 has a flat surface (upper surface in FIG. 4).
The coating layer 25 has a function of suppressing or preventing the excitation light incident surface from coming into contact with the liquid refrigerant.
Due to the provision of the coating layer 25, the wavelength conversion member deteriorates when it comes into contact with the liquid refrigerant, and as a result, the excitation light capturing efficiency decreases with time, and the amount of fluorescence generated is thus reduced. It is possible to prevent or suppress the decrease.
　被覆層２５は、光透過性材料よりなるものであり、励起光Ｌおよび蛍光Ｌ１に対する光透過性を有している。
　この被覆層２５は、励起光入射面が液体冷媒と接触することを防止する観点からは、液体冷媒に対する不透過性を有するものであることが好ましい。 The covering layer 25 is made of a light transmissive material and has light transmissive properties with respect to the excitation light L and the fluorescence L1.
The covering layer 25 is preferably impermeable to the liquid refrigerant from the viewpoint of preventing the excitation light incident surface from coming into contact with the liquid refrigerant.
　被覆層２５を構成する光透過性材料は、波長変換部材において、蛍光部材２２を構成する蛍光体を励起するエネルギーが約５Ｗ／ｍｍ2 以上の励起密度を有することから、無機材料であることが好ましい。
　また、被覆層２５を構成する光透過性材料は、当該被覆層２５の表面から蛍光Ｌ１を高い効率で外部に出射させる観点からは、波長変換部材、すなわち蛍光部材２２の屈折率よりも高屈折率を有するものであることが好ましい。また、被覆層２５の放熱性の観点からは、高い熱伝導性を有するものであることが好ましく、被覆層２５の液体冷媒に対する不透過性の観点からは、液体冷媒に対する耐性を有するものであることが好ましい。更に、被覆層２５の励起光入射面との密着性の観点からは、波長変換部材、すなわち蛍光部材２２と同等の熱膨張係数を有するものであることが好ましい。 The light transmissive material constituting the coating layer 25 is an inorganic material since the energy for exciting the phosphor constituting the fluorescent member 22 in the wavelength conversion member has an excitation density of about 5 W / mm 2 or more. preferable.
Further, the light-transmitting material constituting the coating layer 25 is higher in refractive index than the wavelength conversion member, that is, the refractive index of the fluorescent member 22, from the viewpoint of emitting the fluorescence L1 from the surface of the coating layer 25 to the outside with high efficiency. It is preferable that it has a rate. In addition, from the viewpoint of heat dissipation of the coating layer 25, it is preferable that the coating layer 25 has high thermal conductivity, and from the viewpoint of the impermeability of the coating layer 25 to the liquid refrigerant, it has resistance to the liquid refrigerant. It is preferable. Furthermore, from the viewpoint of adhesion between the coating layer 25 and the excitation light incident surface, it is preferable to have a thermal expansion coefficient equivalent to that of the wavelength conversion member, that is, the fluorescent member 22.
　被覆層２５を構成する光透過性材料としては、具体的には、シリカ（ＳｉＯ2 ）、アルミナ（Ａｌ2 Ｏ3 ）、酸化ハフニウム（ＨｆＯ2 ）、酸化マグネシウム（ＭｇＯ）、酸化スズ（ＳｎＯ2 ）、酸化タングステン（ＷＯ3 ）、酸化イットリウム（Ｙ2 Ｏ3 ）、酸化インジウムスズ（ＩＴＯ）、ジルコニア（ＺｒＯ2 ）、酸化タンタル（Ｔａ2 Ｏ5 ）、チタニア（ＴｉＯ2 ）、酸化ニオブ（Ｎｂ2 Ｏ5 ）、酸化亜鉛（ＺｎＯ）などの金属酸化物、これらの金属酸化物による複合酸化物、およびジルコニア（ＺｒＯ2 ）とチタニア（ＴｉＯ2 ）との混合物などが挙げられる。
　これらのうちでは、蛍光体（ＬｕＡＧ、ＹＡＧ）の熱膨張係数（６×１０-6～８×１０-6／Ｋ）に近似した熱膨張係数を有するものであることからは、ジルコニア（熱膨張係数１０．５×１０-6／Ｋ）、酸化インジウムスズ（熱膨張係数６．８×１０-6／Ｋ）およびチタニア（熱膨張係数７．９×１０-6／Ｋ）が好ましい。特に、ジルコニアは、吸収係数が小さい（具体的には、１３ｃｍ-1（波長５５０ｎｍの光に関する吸収係数））ことから更に好ましい。また、蛍光体（ＬｕＡＧ、ＹＡＧ）の屈折率（１．８５）よりも高屈折率を有するものであることからは、チタニア（屈折率２．０～２．３５）、ジルコニア（屈折率１．８～２．１５）が好ましい。また、液体冷媒に対する耐性を有するものであることからは、ジルコニアが好ましい。 Specific examples of the light transmissive material constituting the coating layer 25 include silica (SiO 2 ), alumina (Al 2 O 3 ), hafnium oxide (HfO 2 ), magnesium oxide (MgO), and tin oxide (SnO 2 ). ), Tungsten oxide (WO 3 ), yttrium oxide (Y 2 O 3 ), indium tin oxide (ITO), zirconia (ZrO 2 ), tantalum oxide (Ta 2 O 5 ), titania (TiO 2 ), niobium oxide (Nb) 2 O 5 ), zinc oxide (ZnO) and other metal oxides, composite oxides of these metal oxides, and mixtures of zirconia (ZrO 2 ) and titania (TiO 2 ).
Among these, since it has a thermal expansion coefficient approximate to the thermal expansion coefficient (6 × 10 −6 to 8 × 10 −6 / K) of the phosphors (LuAG, YAG), zirconia (thermal expansion) A coefficient of 10.5 × 10 −6 / K), indium tin oxide (thermal expansion coefficient 6.8 × 10 −6 / K) and titania (thermal expansion coefficient 7.9 × 10 −6 / K) are preferable. In particular, zirconia is more preferable because of its small absorption coefficient (specifically, 13 cm −1 (absorption coefficient for light having a wavelength of 550 nm)). Further, since it has a higher refractive index than the refractive index (1.85) of the phosphor (LuAG, YAG), titania (refractive index 2.0-2.35), zirconia (refractive index 1. 8 to 2.15) are preferred. In addition, zirconia is preferable because it has resistance to the liquid refrigerant.
　被覆層２５の具体例としては、ゾルゲル膜、セラミック膜および蒸着膜などが挙げられる。
　ここに、ゾルゲル膜よりなる被覆層２５は、例えば、珪素、チタン、ジルコニウムなどのアルコキシドを含むゾル状の材料を、励起光入射面に、例えばスピンコート法によって塗布し、その後、２００～５００℃に加熱することによってシリカ、チタニア、ジルコニア等の膜を得ることにより、製造することができる。
　また、セラミック膜よりなる被覆層２５は、例えば、ジルコニア、チタニア、酸化イットリウム、酸化亜鉛、アルミナ、酸化マグネシウム、または複合酸化物のナノ微粒子を含んだスラリーを励光入射面に、例えばスピンコートによって塗布し、スラリーの有機溶剤を乾燥させた後、窒素雰囲気中で１５０～５００℃で加熱することによって膜を得ることにより、製造することができる。
　また、蒸着膜よりなる被覆層２５は、例えば、スパッタ装置を用い、シリカ、ジルコニア、チタニア、酸化亜鉛、アルミナ、酸化マグネシウムなどをターゲット物質とし、不活性ガスおよび酸素ガスを流通させながら、当該ターゲットに高周波電力をかけることによって励起光入射面にスパッタ膜を形成することにより、製造することができる。この製造方法によれば、高周波電力が２５０Ｗ、不活性ガスとしてのアルゴンガスの流量が２０ｓｃｃｍ、酸素ガスの流量が０．５ｓｃｃｍの形成条件で、成形時間を４時間とすることにより、厚みが６００ｎｍ程度（具体的には５５０ｎｍ）のスパッタ膜よりなる被覆層２５を得ることができる。 Specific examples of the coating layer 25 include a sol-gel film, a ceramic film, and a vapor deposition film.
Here, the coating layer 25 made of a sol-gel film is formed by, for example, applying a sol-like material containing an alkoxide such as silicon, titanium, or zirconium to the excitation light incident surface by, for example, a spin coating method, and then 200 to 500 ° C. It can manufacture by obtaining films | membranes, such as a silica, a titania, a zirconia, by heating to.
The coating layer 25 made of a ceramic film is formed by, for example, spin-coating a slurry containing nanoparticles of zirconia, titania, yttrium oxide, zinc oxide, alumina, magnesium oxide, or composite oxide on the excitation incident surface. After coating and drying the organic solvent in the slurry, it can be produced by obtaining a film by heating at 150 to 500 ° C. in a nitrogen atmosphere.
Further, the coating layer 25 made of a vapor deposition film is formed by using, for example, a sputtering apparatus, using silica, zirconia, titania, zinc oxide, alumina, magnesium oxide, or the like as a target material, and circulating the inert gas and oxygen gas. It is possible to manufacture by forming a sputtered film on the excitation light incident surface by applying high frequency power to. According to this manufacturing method, the thickness is 600 nm by forming the molding time for 4 hours under the formation conditions of high frequency power of 250 W, an argon gas flow rate of 20 sccm and an oxygen gas flow rate of 0.5 sccm as an inert gas. The covering layer 25 made of a sputtered film having a degree (specifically, 550 nm) can be obtained.
　また、被覆層２５の厚みは、例えば２００～２０００ｎｍとされ、好ましくは４００～６００ｎｍである。 The thickness of the coating layer 25 is, for example, 200 to 2000 nm, and preferably 400 to 600 nm.
　そして、蛍光光源装置１０には、少なくとも励起光入射面に沿って液体冷媒を流通する液体冷媒流通機構が設けられている。
　この液体冷媒流通機構は、支持部材４１に設けられた液体冷媒流通路と、この液体冷媒流通路に液体冷媒を流通させるための液体冷媒流通手段とよりなるものである。
　この図の例において、液体冷媒流通手段は、液体冷媒流通路に接続された液体冷媒循環路（図示省略）を備えたものである。そして、液体冷媒循環路には、液体冷媒を循環させるための電動ポンプと、ラジエーターと、当該ラジエーターを空気によって冷却するためのファンモーターとが設けられている。 The fluorescent light source device 10 is provided with a liquid refrigerant distribution mechanism that distributes the liquid refrigerant at least along the excitation light incident surface.
The liquid refrigerant circulation mechanism includes a liquid refrigerant flow passage provided in the support member 41 and liquid refrigerant circulation means for flowing the liquid refrigerant through the liquid refrigerant flow passage.
In the example of this figure, the liquid refrigerant circulation means includes a liquid refrigerant circulation path (not shown) connected to the liquid refrigerant flow path. The liquid refrigerant circulation path is provided with an electric pump for circulating the liquid refrigerant, a radiator, and a fan motor for cooling the radiator with air.
　支持部材４１は、図２および図３に示すように、例えばアルミニウムなどの金属よりなり、略矩形平板状の外観形状を有するものであり、その内部には、当該支持部材４１の厚み方向（図２および図３における上下方向）に垂直な方向に伸びる貫通孔４２が形成されている。この貫通孔４２は、貫通方向に垂直な方向の断面形状が略矩形状であり、大きな幅（図２における左右方向の寸法）を有する上側部４２Ａと、この上側部４２Ａよりも小さい幅を有する下側部４２Ｂとよりなるものである。また、貫通孔４２の両側壁には、上側部４２Ａと下側部４２Ｂとによって段差４３，４３が形成されている。そして、貫通孔４２内には、蛍光発光部材２０が、段差４３，４３によって支持され、励起光入射面が支持部材４１の表面（図２および図３における上面）と平行となるよう、貫通方向の中心部に配設されている。この貫通孔４２内において、蛍光発光部材２０は、当該蛍光発光部材２０の表面の全面が上側部４２Ａを臨み、当該蛍光発光部材２０の裏面における段差４３，４３と接触している領域以外の領域が下側部４２Ｂを臨むように位置している。
　また、支持部材４１の表面の中央部、すなわち蛍光発光部材２０の直上位置には、貫通孔４２に連通し、励起光集光レンズ１８の底面部と同等の形状および寸法を有する開口部４５が形成されており、この開口部４５には、励起光集光レンズ１８が配設されている。
　このように、液体冷媒流通路は貫通孔４２によって構成されており、励起光入射面を含む蛍光発光部材２０の表面と、この蛍光発光部材２０の裏面とに沿って液体冷媒を流通させるものである。この液体冷媒流通路は、上側部４２Ａにおける蛍光発光部材２０の表面上に位置し、当該表面に沿って液体冷媒が流通する表面流通部分と、下側部４２Ｂにおける蛍光発光部材２０の裏面下に位置し、当該裏面に沿って液体冷媒が流通する裏面流通部分とを有している。
　この図の例において、貫通孔４２は、支持部材４１の厚み方向に垂直な一方向（図２における紙面に垂直な方向であって図３における左方向）に、当該支持部材４１の表面に沿って直線状に伸びている。ここに、図３においては、矢印によって液体冷媒の流動方向を示している。また、貫通孔４２において、上側部４２Ａの幅は、蛍光発光部材２０と同等の幅を有しており、上側部４２Ａにおける両側壁と蛍光発光部材２０の側面とは接触している。 As shown in FIGS. 2 and 3, the support member 41 is made of a metal such as aluminum and has a substantially rectangular flat plate-like appearance, and a thickness direction of the support member 41 (see FIG. 2 and the vertical direction in FIG. 3, a through hole 42 extending in a direction perpendicular to the vertical direction is formed. The through hole 42 has a substantially rectangular cross-sectional shape in a direction perpendicular to the penetrating direction, and has an upper part 42A having a large width (a dimension in the left-right direction in FIG. 2) and a width smaller than the upper part 42A. It consists of the lower side part 42B. Further, on both side walls of the through hole 42, steps 43 and 43 are formed by the upper side portion 42 </ b> A and the lower side portion 42 </ b> B. In the through hole 42, the fluorescent light emitting member 20 is supported by the steps 43, 43, and the excitation light incident surface is parallel to the surface of the support member 41 (upper surface in FIGS. 2 and 3). It is arrange | positioned in the center part. Within this through hole 42, the fluorescent light emitting member 20 is a region other than the region where the entire surface of the fluorescent light emitting member 20 faces the upper portion 42 </ b> A and is in contact with the steps 43, 43 on the back surface of the fluorescent light emitting member 20. Is positioned so as to face the lower side portion 42B.
In addition, an opening 45 that communicates with the through hole 42 and has the same shape and size as the bottom surface of the excitation light condensing lens 18 is provided at the center of the surface of the support member 41, that is, a position directly above the fluorescent light emitting member 20. The excitation light condensing lens 18 is disposed in the opening 45.
As described above, the liquid refrigerant flow path is constituted by the through hole 42, and the liquid refrigerant flows along the surface of the fluorescent light emitting member 20 including the excitation light incident surface and the back surface of the fluorescent light emitting member 20. is there. The liquid refrigerant flow passage is located on the surface of the fluorescent light emitting member 20 in the upper portion 42A, and is located on the surface flow portion where the liquid refrigerant flows along the surface and below the back surface of the fluorescent light emitting member 20 in the lower portion 42B. And a rear surface circulation portion through which the liquid refrigerant flows along the rear surface.
In the example of this figure, the through hole 42 extends along the surface of the support member 41 in one direction perpendicular to the thickness direction of the support member 41 (the direction perpendicular to the paper surface in FIG. 2 and the left direction in FIG. 3). It extends in a straight line. Here, in FIG. 3, the flow direction of the liquid refrigerant is indicated by an arrow. In addition, in the through hole 42, the width of the upper portion 42 </ b> A has the same width as that of the fluorescent light emitting member 20, and both side walls of the upper portion 42 </ b> A are in contact with the side surfaces of the fluorescent light emitting member 20.
　液体冷媒としては、励起光Ｌおよび蛍光Ｌ１に対する光透過性を有するものが用いられる。
　また、液体冷媒は、熱輸送性の観点からは、粘度の低いものであることが好ましい。具体的には、温度３０℃における粘度が０．５ｍＰａ・ｓ以下であることが好ましく、あるいは温度１００℃における粘度が１．５ｍＰａ・ｓ以下であることが好ましい。
　液体冷媒の温度３０℃における粘度が０．５ｍＰａ・ｓ以下であること、あるいは液体冷媒の温度１００℃における粘度が１．５ｍＰａ・ｓ以下であることにより、波長変換部材の温度を、温度消光によって励起光Ｌの蛍光Ｌ１への変換効率が極端に低下することとなる温度以下、具体的には２００℃以下とすることができる。 As the liquid refrigerant, one having optical transparency to the excitation light L and the fluorescence L1 is used.
Moreover, it is preferable that a liquid refrigerant is a thing with a low viscosity from a heat transport viewpoint. Specifically, the viscosity at a temperature of 30 ° C. is preferably 0.5 mPa · s or less, or the viscosity at a temperature of 100 ° C. is preferably 1.5 mPa · s or less.
When the viscosity of the liquid refrigerant at 30 ° C. is 0.5 mPa · s or less, or the viscosity of the liquid refrigerant at 100 ° C. is 1.5 mPa · s or less, the temperature of the wavelength conversion member can be changed by temperature quenching. The conversion efficiency of the excitation light L to the fluorescence L1 can be set to a temperature at which the conversion efficiency is extremely lowered, specifically 200 ° C. or less.
　液体冷媒の具体例としては、水、並びにアルキルジフェニール系不活性液体およびフッ素系不活性液体等の不活性液体などが挙げられる。 Specific examples of the liquid refrigerant include water and inert liquids such as alkyldiphenyl-based inert liquid and fluorine-based inert liquid.
　液体冷媒流通路に対する冷却媒体の供給条件は、例えば液体冷媒の種類、励起光入射面の面積、被覆層２５の厚み、液体冷媒流通路における表面流通部分および裏面流通部分の厚み（図２および図３における上下方向の寸法）、励起光Ｌの励起エネルギーなどに応じて適宜に定められるが、例えば流速が３ｍ／ｓである。 The supply conditions of the cooling medium to the liquid refrigerant flow path include, for example, the type of liquid refrigerant, the area of the excitation light incident surface, the thickness of the coating layer 25, and the thicknesses of the front and back flow parts in the liquid refrigerant flow path (FIGS. 2 and 2). 3 is determined appropriately according to the excitation energy of the excitation light L, and the flow rate is, for example, 3 m / s.
　基板３１は、排熱性を有するものである。そして、この基板３１は、排熱性の観点から、波長変換部材、すなわち蛍光部材２２が配設される表面が、当該波長変換部材の裏面よりも縦横寸法が大きくて、大きな面積を有する大きさとされる。また、基板３１の厚みは、例えば０．５～１．０ｍｍである。
　基板３１を構成する材料としては、銅、モリブデンと銅の合金（Ｍｏ－Ｃｕ）およびタングステンと銅の合金（Ｗ－Ｃｕ）などを用いることができる。 The substrate 31 has exhaust heat properties. From the viewpoint of exhaust heat, the substrate 31 has a large surface area in which the wavelength conversion member, that is, the surface on which the fluorescent member 22 is disposed is larger than the back surface of the wavelength conversion member. The The thickness of the substrate 31 is, for example, 0.5 to 1.0 mm.
As a material constituting the substrate 31, copper, an alloy of molybdenum and copper (Mo—Cu), an alloy of tungsten and copper (W—Cu), or the like can be used.
　上記の蛍光光源装置１０においては、半導体レーザ１１から出射された青色領域のレーザ光である励起光Ｌは、コリメータレンズ１５によって平行光線とされる。その後、この励起光Ｌは、ダイクロイックミラー１６を透過し、励起光集光レンズ１８によって集光されて、被覆層２５を介して、蛍光発光部材２０における波長変換部材の励起光入射面、すなわち蛍光部材２２の表面に対して略垂直に照射される。そして、蛍光部材２２においては、当該蛍光部材２２を構成する蛍光体が励起され、蛍光Ｌ１が放射される。この蛍光Ｌ１は、波長変換部材の蛍光出射面、すなわち蛍光部材２２の表面から出射され、ダイクロイックミラー１６によって垂直方向に反射された後、蛍光光源装置１０の外部に出射される。 In the above-described fluorescent light source device 10, the excitation light L, which is the laser light in the blue region emitted from the semiconductor laser 11, is collimated by the collimator lens 15. Thereafter, the excitation light L passes through the dichroic mirror 16, is collected by the excitation light condensing lens 18, and passes through the coating layer 25, so that the excitation light incident surface of the wavelength conversion member in the fluorescent light emitting member 20, that is, fluorescence. Irradiation is substantially perpendicular to the surface of the member 22. And in the fluorescent member 22, the fluorescent substance which comprises the said fluorescent member 22 is excited, and fluorescence L1 is radiated | emitted. The fluorescence L1 is emitted from the fluorescence emission surface of the wavelength conversion member, that is, the surface of the fluorescence member 22, is reflected in the vertical direction by the dichroic mirror 16, and is then emitted to the outside of the fluorescence light source device 10.
　この蛍光光源装置１０においては、励起光Ｌの照射によって発生する熱によって、波長変換部材、特に励起光入射面が加熱されるが、液体冷媒流通機構によって蛍光発光部材２０の表面および裏面に沿って液体冷媒が流通されることにより、波長変換部材が冷却される。しかも、特に加熱される励起光入射面に沿って液体冷媒が流通されており、当該励起光入射面を厚みの小さい被覆層２５を介して液体冷媒によって冷却することができるため、波長変換部材を効率的に冷却することができる。
　ここに、液体冷媒流通機構による波長変換部材の冷却過程について説明する。
　波長変換部材において励起光Ｌの照射によって発生した熱は、基板３１に伝導されると共に、液体冷媒流通路を流通する液体冷媒に、励起光入射面から被覆層２５を介して伝導される。また、基板３１に伝導された熱は、基板３１の表面、裏面および側面における液体冷媒と接触した領域から液体冷媒に伝導される。このように、波長変換部材の熱が、被覆層２５または基板３１を介して液体冷媒に伝導されることにより、当該波長変換部材は液体冷媒によって冷却される。一方、波長変換部材からの熱が伝導されて高温となった液体冷媒は、液体冷媒循環路を介してラジエーターに送られ、このラジエーターにおいて、液体冷媒の熱がファンモーターからの冷却用空気の作用によって効率的に放熱される。そして、冷却されて温度の下がった液体冷媒は、液体冷媒循環路を介して再び液体冷媒流通路に供給される。
　また、蛍光光源装置１０においては、励起光入射面に被覆層２５が設けられていることから、励起光入射面に沿って液体冷媒を流通しても、波長変換部材が液体冷媒と接触することによって経時的に劣化し、それに起因して発光効率が低下することを防止または抑制することができる。
　従って、蛍光光源装置１０によれば、波長変換部材に高い励起エネルギーを有する励起光が照射された場合であっても、波長変換部材の温度上昇が抑制されると共に、長期間にわたって高い発光効率が得られる。 In this fluorescent light source device 10, the wavelength conversion member, particularly the excitation light incident surface is heated by the heat generated by the irradiation of the excitation light L, but along the front and back surfaces of the fluorescent light emitting member 20 by the liquid refrigerant circulation mechanism. The wavelength conversion member is cooled by circulating the liquid refrigerant. In addition, since the liquid refrigerant is circulated along the excitation light incident surface to be heated, and the excitation light incident surface can be cooled by the liquid refrigerant through the coating layer 25 having a small thickness, It can be cooled efficiently.
Here, the cooling process of the wavelength conversion member by the liquid refrigerant circulation mechanism will be described.
Heat generated by the irradiation of the excitation light L in the wavelength conversion member is conducted to the substrate 31 and to the liquid refrigerant flowing through the liquid refrigerant flow path from the excitation light incident surface through the coating layer 25. Further, the heat conducted to the substrate 31 is conducted to the liquid refrigerant from the area in contact with the liquid refrigerant on the front surface, back surface, and side surface of the substrate 31. As described above, the heat of the wavelength conversion member is conducted to the liquid refrigerant through the coating layer 25 or the substrate 31, whereby the wavelength conversion member is cooled by the liquid refrigerant. On the other hand, the liquid refrigerant that has been heated to a high temperature as a result of conduction of heat from the wavelength conversion member is sent to the radiator via the liquid refrigerant circulation path, and in this radiator, the heat of the liquid refrigerant acts as an action of cooling air from the fan motor. To efficiently dissipate heat. Then, the cooled and cooled liquid refrigerant is supplied again to the liquid refrigerant flow path through the liquid refrigerant circulation path.
Further, in the fluorescent light source device 10, since the coating layer 25 is provided on the excitation light incident surface, the wavelength conversion member comes into contact with the liquid refrigerant even when the liquid refrigerant flows along the excitation light incident surface. Therefore, it is possible to prevent or suppress the deterioration of the light emission efficiency due to the deterioration over time.
Therefore, according to the fluorescent light source device 10, even when the wavelength conversion member is irradiated with excitation light having high excitation energy, the temperature increase of the wavelength conversion member is suppressed, and high luminous efficiency is obtained over a long period of time. can get.
　図５は、本発明の蛍光光源装置の他の例における蛍光発光部材の構成を拡大して示す説明用拡大断面図である。
　この図５の蛍光光源装置において、蛍光発光部材２０を構成する被覆層５０は、その表面（図５における上面）の全面に、凹凸構造５１が形成されており、この凹凸構造５１は、略錐状（具体的には、円錐状）の凸部５２が周期的に配列されてなるものである。また、蛍光発光部材２０において、基板３１、蛍光部材２２、被覆層５０および保護部材２３の構成は、蛍光部材２２の形状が円形板状であって被覆層５０が略円形板状であること、および当該被覆層５０の表面の全面に凹凸構造５１が形成されていること以外は、図１の蛍光光源装置１０の基板３１、蛍光部材２２、被覆層２５および保護部材２３と同様である。
　また、図５の蛍光光源装置は、被覆層５０が、その表面の全面に周期構造５１が形成されたものであること、および蛍光部材２２の形状が円形板状であって被覆層５０が略円形板状であること以外は、図１の蛍光光源装置１０と同様の構成を有するものである。 FIG. 5 is an enlarged sectional view for explanation showing an enlarged configuration of a fluorescent light emitting member in another example of the fluorescent light source device of the present invention.
In the fluorescent light source device of FIG. 5, the coating layer 50 constituting the fluorescent light emitting member 20 has a concavo-convex structure 51 formed on the entire surface (the upper surface in FIG. 5). (Specifically, conical) convex portions 52 are periodically arranged. Further, in the fluorescent light emitting member 20, the configuration of the substrate 31, the fluorescent member 22, the covering layer 50, and the protective member 23 is such that the fluorescent member 22 has a circular plate shape and the covering layer 50 has a substantially circular plate shape, 1 is the same as the substrate 31, the fluorescent member 22, the covering layer 25, and the protective member 23 of the fluorescent light source device 10 of FIG. 1 except that the uneven structure 51 is formed on the entire surface of the covering layer 50.
Further, in the fluorescent light source device of FIG. 5, the covering layer 50 has a periodic structure 51 formed on the entire surface thereof, and the fluorescent member 22 has a circular plate shape, and the covering layer 50 is substantially the same. Except for the circular plate shape, it has the same configuration as the fluorescent light source device 10 of FIG.
　被覆層５０の表面に形成された凹凸構造５１において、周期ｄは、蛍光部材２２を構成する蛍光体から放射される蛍光の回折が発生する範囲（ブラッグの条件）の大きさであることが好ましい。
　具体的には、凹凸構造５１の周期ｄは、蛍光体から放射される蛍光のピーク波長を、凹凸構造５１を構成する材料（具体的には、光透過性材料）の屈折率で割った値（以下、「光学長さ」という。）または光学長さの数倍程度の値である。ここに、本発明において、凹凸構造の周期とは、凹凸構造において互いに隣接する凸部間の中心間距離（ｎｍ）を意味する。
　凹凸構造５１の周期ｄが蛍光部材２２の内部で生じる蛍光Ｌ１の回折が発生する範囲の大きさとされることにより、被覆層５０の表面から蛍光Ｌ１を高い効率で外部に出射することができる。 In the concavo-convex structure 51 formed on the surface of the coating layer 50, the period d is preferably a size in a range (Bragg condition) in which diffraction of fluorescence emitted from the phosphor constituting the fluorescent member 22 occurs. .
Specifically, the period d of the concavo-convex structure 51 is a value obtained by dividing the peak wavelength of the fluorescence emitted from the phosphor by the refractive index of the material (specifically, the light transmissive material) constituting the concavo-convex structure 51. (Hereinafter referred to as “optical length”) or a value of several times the optical length. Here, in the present invention, the period of the concavo-convex structure means a center-to-center distance (nm) between the convex portions adjacent to each other in the concavo-convex structure.
By setting the period d of the concavo-convex structure 51 to a size in which the diffraction of the fluorescence L1 generated inside the fluorescent member 22 occurs, the fluorescence L1 can be emitted from the surface of the coating layer 50 to the outside with high efficiency.
　また、凹凸構造５１における周期ｄに対する凸部２５の高さｈの比（ｈ／ｄ）であるアスペクト比は、０．２以上であることが好ましい。
　凹凸構造５１におけるアスペクト比が０．２以上とされることにより、被覆層５０の表面に励起光が照射されたときに、当該励起光の後方散乱が抑制され、その結果、励起光を波長変換部材、すなわち蛍光部材２２の内部に十分に取り込むことができる。また、蛍光部材２２を構成する蛍光体から放射される蛍光を高い効率によって被覆層５０の表面から外部に取り出すことができる。 Moreover, it is preferable that the aspect ratio which is ratio (h / d) of the height h of the convex part 25 with respect to the period d in the uneven structure 51 is 0.2 or more.
By setting the aspect ratio in the concavo-convex structure 51 to 0.2 or more, when the surface of the coating layer 50 is irradiated with excitation light, backscattering of the excitation light is suppressed, and as a result, wavelength conversion of the excitation light is performed. It can be sufficiently taken into the member, that is, the fluorescent member 22. In addition, the fluorescence emitted from the phosphor constituting the fluorescent member 22 can be extracted from the surface of the coating layer 50 to the outside with high efficiency.
　被覆層５０は、図１の蛍光光源装置１０における被覆層２５と同様に、光透過性材料よりなるものであるが、当該光透過性材料として蛍光部材２２より高屈折率のものを用いることによれば、周期ｄが小さい凹凸構造５１を形成することが可能となる。従って、凹凸構造５１を構成する凸部５２としてアスペクト比が大きくても高さが小さいものを設計することができるので、凹凸構造５１の形成が容易となる。例えば、ナノプリント法を利用する場合には、モールドの作製やインプリント作業を容易に行うことができる。 The covering layer 50 is made of a light-transmitting material, like the covering layer 25 in the fluorescent light source device 10 of FIG. 1, and the light-transmitting material having a higher refractive index than the fluorescent member 22 is used. Accordingly, it is possible to form the concavo-convex structure 51 having a small period d. Therefore, since the convex portion 52 constituting the concave-convex structure 51 can be designed with a small height even if the aspect ratio is large, the concave-convex structure 51 can be easily formed. For example, when the nanoprint method is used, a mold can be easily produced or imprinted.
　被覆層５０において、凹凸構造５１は、当該被覆層５０がセラミック膜または蒸着膜からなる場合には、ナノインプリント法とドライエッチング処理とによって形成することができる。具体的には、円形板状の被覆層の表面に、例えばスピンコート法によってレジストを塗布し、次いで、レジストの塗布膜を例えばナノインプリント法によりパターニングする。その後、被覆層の表面における露出した領域に、ドライエッチング処理を施すことにより、周期構造が形成される。ここに、ドライエッチング処理の手法の具体例としては、ＩＣＰ（Inductive  Coupling  Plasma，誘電結合方式）エッチング法が挙げられる。
　また、被覆層５０がゾルゲル膜からなる場合には、ゾルゲル法とナノインプリント法とを用いることによって、当該被覆層５０の表面に凹凸構造５１を形成することができる。具体的には、珪素、チタン、ジルコニウム等のアルコキシドを含むゾル状の材料を、例えばスピンコート法によって波長変換部材の励起光入射面、すなわち蛍光部材２２の表面に塗布して、モールド型を押付しつけた状態で加熱処理を行い、離型した後、熱処理を行う。この熱処理によって、反応（加水分解および縮重合）が進み、表面に凹凸構造５１が形成された被覆層５０が形成される。 In the coating layer 50, the concavo-convex structure 51 can be formed by a nanoimprint method and a dry etching process when the coating layer 50 is made of a ceramic film or a vapor deposition film. Specifically, a resist is applied to the surface of the circular plate-shaped coating layer by, for example, spin coating, and then the resist coating film is patterned by, for example, nanoimprinting. Then, a periodic structure is formed by performing a dry etching process on the exposed region on the surface of the coating layer. Here, a specific example of the dry etching method is an ICP (Inductive Coupling Plasma) etching method.
Moreover, when the coating layer 50 consists of a sol-gel film, the uneven structure 51 can be formed on the surface of the coating layer 50 by using a sol-gel method and a nanoimprint method. Specifically, a sol-like material containing an alkoxide such as silicon, titanium, or zirconium is applied to the excitation light incident surface of the wavelength conversion member, that is, the surface of the fluorescent member 22 by, for example, spin coating, and the mold is pressed. A heat treatment is performed in the state of being attached, and after releasing the mold, a heat treatment is performed. By this heat treatment, the reaction (hydrolysis and condensation polymerization) proceeds, and the coating layer 50 having the uneven structure 51 formed on the surface is formed.
　上記の図５の蛍光光源装置においては、半導体レーザから出射された青色領域のレーザ光である励起光は、コリメータレンズによって平行光線とされる。その後、この励起光は、ダイクロイックミラーを透過し、励起光集光レンズによって集光されて、被覆層５０を介して蛍光発光部材２０における波長変換部材の励起光入射面、すなわち蛍光部材２２の表面に対して略垂直に照射される。そして、蛍光部材２２においては、当該蛍光部材２２を構成する蛍光体が励起され、蛍光が放射される。この蛍光は、波長変換部材の蛍光出射面、すなわち蛍光部材２２の表面から出射され、ダイクロイックミラーによって垂直方向に反射された後、蛍光光源装置の外部に出射される。 In the fluorescent light source device of FIG. 5 described above, the excitation light, which is the laser light in the blue region emitted from the semiconductor laser, is collimated by the collimator lens. Thereafter, the excitation light passes through the dichroic mirror, is condensed by the excitation light condensing lens, and is incident on the excitation light incident surface of the wavelength conversion member in the fluorescent light emitting member 20 through the coating layer 50, that is, the surface of the fluorescent member 22. Irradiated substantially perpendicularly to. And in the fluorescent member 22, the fluorescent substance which comprises the said fluorescent member 22 is excited, and fluorescence is emitted. The fluorescence is emitted from the fluorescence emission surface of the wavelength conversion member, that is, the surface of the fluorescence member 22, reflected in the vertical direction by the dichroic mirror, and then emitted to the outside of the fluorescence light source device.
　この図５の蛍光光源装置によれば、図１の蛍光光源装置１０と同様に、波長変換部材に高い励起エネルギーを有する励起光が照射された場合であっても、当該波長変換部材の温度上昇が抑制されると共に、長期間にわたって高い発光効率が得られる。 According to the fluorescent light source device of FIG. 5, similarly to the fluorescent light source device 10 of FIG. 1, even when the wavelength conversion member is irradiated with excitation light having high excitation energy, the temperature of the wavelength conversion member increases. Is suppressed, and high luminous efficiency is obtained over a long period of time.
　また、図５の蛍光光源装置においては、被覆層５０の表面に凹凸構造５１が形成されているため、当該被覆層５０を介して励起光を波長変換部材の内部に十分に取り込むことができ、また当該被覆層５０を介して波長変換部材の内部において生成された蛍光を高い効率で外部に出射することができる。しかも、波長変換部材の内部において生成された蛍光が当該内部に閉じ込められることに起因して波長変換部材が加熱されることが抑制される。その結果、波長変換部材の温度上昇がより一層抑制されると共に、より高い発光効率が得られる。 In the fluorescent light source device of FIG. 5, since the uneven structure 51 is formed on the surface of the coating layer 50, excitation light can be sufficiently taken into the wavelength conversion member through the coating layer 50, Further, the fluorescence generated inside the wavelength conversion member can be emitted to the outside through the coating layer 50 with high efficiency. In addition, heating of the wavelength conversion member due to the fluorescence generated inside the wavelength conversion member being confined in the inside is suppressed. As a result, the temperature increase of the wavelength conversion member is further suppressed, and higher luminous efficiency is obtained.
　図６は、本発明の蛍光光源装置の更に他の例における蛍光発光部材の構成を拡大して示す説明用拡大断面図である。
　この図６の蛍光光源装置において、蛍光発光部材２０を構成する被覆層５５は、その表面（図６における上面）の一部（具体的には、中央部）に、凹凸構造５１が形成されており、この凹凸構造５１は、略錐状（具体的には、円錐状）の凸部５２が周期的に配列されてなるものである。また、蛍光発光部材２０において、基板３１、蛍光部材２５、被覆層５５および保護部材２３の構成は、当該被覆層５５の表面の一部にのみ凹凸構造５１が形成されていること以外は、図５の蛍光光源装置の基板３１、蛍光部材２２、被覆層５０および保護部材２３と同様である。
　また、この図６の蛍光光源装置は、蛍光発光部材２０における被覆層５５が、その表面の一部に凹凸構造５１が形成されたものであること以外は、図５の蛍光光源装置と同様の構成を有するものである。 FIG. 6 is an enlarged sectional view for explanation showing an enlarged configuration of a fluorescent light emitting member in still another example of the fluorescent light source device of the present invention.
In the fluorescent light source device of FIG. 6, the coating layer 55 constituting the fluorescent light emitting member 20 has a concavo-convex structure 51 formed on a part (specifically, the central part) of the surface (upper surface in FIG. 6). The concavo-convex structure 51 is formed by periodically arranging substantially conical (specifically conical) convex portions 52. In the fluorescent light emitting member 20, the substrate 31, the fluorescent member 25, the covering layer 55, and the protective member 23 are configured as shown in the figure except that the uneven structure 51 is formed only on a part of the surface of the covering layer 55. 5 is the same as the substrate 31, the fluorescent member 22, the coating layer 50, and the protective member 23 of the fluorescent light source device 5.
Further, the fluorescent light source device of FIG. 6 is the same as the fluorescent light source device of FIG. 5 except that the coating layer 55 of the fluorescent light emitting member 20 is formed with a concavo-convex structure 51 on a part of the surface thereof. It has a configuration.
　被覆層５５の表面において、凹凸構造５１が形成された領域（以下、「凹凸構造形成領域」ともいう。）の面積は、被覆層５５の表面全面の面積に対して２２～８８％の大きさであることが好ましい。 The area of the surface of the covering layer 55 where the uneven structure 51 is formed (hereinafter also referred to as “uneven structure forming region”) is 22 to 88% of the area of the entire surface of the covering layer 55. It is preferable that
　上記の図６の蛍光光源装置においては、半導体レーザから出射された青色領域のレーザ光である励起光は、コリメータレンズによって平行光線とされる。その後、この励起光は、ダイクロイックミラーを透過し、励起光集光レンズによって集光されて、被覆層５５を介して蛍光発光部材２０における波長変換部材の励起光入射面、すなわち蛍光部材２２の表面に対して略垂直に照射される。そして、蛍光部材２２においては、当該蛍光部材２２を構成する蛍光体が励起される。これにより、蛍光部材２２において蛍光が放射される。この蛍光は、その大部分が、凹凸構造形成領域、すなわち被覆層５５の表面における凹凸構造５１が形成された領域から出射され、ダイクロイックミラーによって垂直方向に反射された後、蛍光光源装置の外部に出射される。 In the fluorescent light source device of FIG. 6 described above, the excitation light that is the laser light in the blue region emitted from the semiconductor laser is converted into parallel rays by the collimator lens. Thereafter, the excitation light passes through the dichroic mirror, is condensed by the excitation light condensing lens, and passes through the coating layer 55, the excitation light incident surface of the wavelength conversion member in the fluorescent light emitting member 20, that is, the surface of the fluorescent member 22. Irradiated substantially perpendicularly to. And in the fluorescent member 22, the fluorescent substance which comprises the said fluorescent member 22 is excited. Thereby, fluorescence is emitted in the fluorescent member 22. Most of the fluorescence is emitted from the concavo-convex structure forming region, that is, the region where the concavo-convex structure 51 is formed on the surface of the coating layer 55, reflected in the vertical direction by the dichroic mirror, and then outside the fluorescent light source device. Emitted.
　この図６の蛍光光源装置によれば、図１の蛍光光源装置１０および図５の蛍光光源装置と同様に、波長変換部材に高い励起エネルギーを有する励起光が照射された場合であっても、当該波長変換部材の温度上昇が抑制されると共に、長期間にわたって高い発光効率が得られる。 According to the fluorescent light source device of FIG. 6, similarly to the fluorescent light source device 10 of FIG. 1 and the fluorescent light source device of FIG. 5, even when the wavelength conversion member is irradiated with excitation light having high excitation energy, While the temperature rise of the wavelength conversion member is suppressed, high luminous efficiency can be obtained over a long period of time.
　また、この蛍光光源装置においては、被覆層５５の表面に凹凸構造５１が形成されているため、当該被覆層５５を介して励起光を波長変換部材の内部に十分に取り込むことができ、また当該被覆層５５を介して波長変換部材の内部において生成された蛍光を高い効率で外部に出射することができる。しかも、波長変換部材の内部において生成された蛍光が当該内部に閉じ込められることに起因して波長変換部材が加熱されることが抑制される。その結果、波長変換部材の温度上昇がより一層抑制されると共に、より高い発光効率が得られる。 In this fluorescent light source device, since the uneven structure 51 is formed on the surface of the coating layer 55, the excitation light can be sufficiently taken into the wavelength conversion member through the coating layer 55, and the The fluorescence generated inside the wavelength conversion member can be emitted to the outside with high efficiency via the coating layer 55. In addition, heating of the wavelength conversion member due to the fluorescence generated inside the wavelength conversion member being confined in the inside is suppressed. As a result, the temperature increase of the wavelength conversion member is further suppressed, and higher luminous efficiency is obtained.
　更に、この蛍光光源装置においては、凹凸構造５１が被覆層５５の表面の一部（中央部）に形成されており、この凹凸構造５１が形成された凹凸構造形成領域から、波長変換部材の内部において生成された蛍光の大部分が出射される。そのため、被覆層５５が設けられた波長変換部材は高い排熱性を有するものとなり、当該波長変換部材において励起光の照射によって発生する熱が高い効率で放熱され、波長変換部材の温度上昇が抑制される。しかも、波長変換部材の内部において生じた蛍光を、小さな面積の凹凸構造形成領域から高い効率で取り出すことができるため、高い蛍光光束を得ることができる。その結果、波長変換部材の温度上昇が更により一層抑制されると共に、波長変換部材の内部において生成された蛍光を高い効率で利用することができる。 Furthermore, in this fluorescent light source device, the concavo-convex structure 51 is formed on a part (center portion) of the surface of the coating layer 55, and the concavo-convex structure forming region where the concavo-convex structure 51 is formed, Most of the fluorescence generated in is emitted. Therefore, the wavelength conversion member provided with the coating layer 55 has a high heat exhaust property, and heat generated by irradiation of excitation light in the wavelength conversion member is radiated with high efficiency, and the temperature increase of the wavelength conversion member is suppressed. The In addition, since the fluorescence generated inside the wavelength conversion member can be extracted with high efficiency from the concavo-convex structure forming region having a small area, a high fluorescent light flux can be obtained. As a result, the temperature rise of the wavelength conversion member is further suppressed, and the fluorescence generated inside the wavelength conversion member can be used with high efficiency.
　以上、本発明の実施の形態について説明したが、本発明は上記の実施の形態に限定されるものではなく、種々の変更を加えることが可能である。
　例えば、液体冷媒流通機構は、少なくとも波長変換部材の励起光入射面に沿って液体冷媒を流通させることのできるものであればよく、種々の構成を採用することができる。具体的には、液体冷媒流通機構は、冷却性能の観点からは、図２および図３に示されているように、波長変換部材の裏面側（図２および図３における下面側）にも液体冷媒を流通させることのできるものが好ましいが、図７に示すような構成のものであってもよい。この図７の蛍光光源装置は、液体冷媒流通機構を構成する支持部材４１において、貫通孔４７が貫通方向に垂直な方向の断面形状が矩形状のものであること、蛍光発光部材２０が貫通孔４７の底壁によって支持されていること、および貫通孔４７と連通する開口部４９が励起光集光レンズ１８の底面部よりも小径の開口を有すること以外は、図１の蛍光光源装置と同様の構成を有するものである。 Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made.
For example, the liquid refrigerant distribution mechanism may be any mechanism that can distribute liquid refrigerant at least along the excitation light incident surface of the wavelength conversion member, and various configurations can be employed. Specifically, from the viewpoint of cooling performance, the liquid refrigerant circulation mechanism is liquid on the back surface side (the lower surface side in FIGS. 2 and 3) of the wavelength conversion member as shown in FIGS. 2 and 3. Although the thing which can distribute | circulate a refrigerant | coolant is preferable, the thing of a structure as shown in FIG. 7 may be sufficient. In the fluorescent light source device of FIG. 7, in the support member 41 constituting the liquid refrigerant circulation mechanism, the through hole 47 has a rectangular cross-sectional shape in the direction perpendicular to the through direction, and the fluorescent light emitting member 20 has the through hole. 1 is the same as the fluorescent light source device of FIG. 1 except that it is supported by the bottom wall of 47 and the opening 49 communicating with the through hole 47 has an opening having a smaller diameter than the bottom surface of the excitation light collecting lens 18. It has the structure of.
　また、蛍光光源装置全体の構造は、図１に示すものに限定されず、種々の構成を採用することができる。例えば、図１に係る蛍光光源装置では、１つのレーザ光源（例えば、半導体レーザ）の光を用いているが、レーザ光源が複数あり、蛍光プレートの前に集光レンズを配置して、集光光を蛍光プレートに照射する形態であってもよい。また、励起光はレーザ光源の光に限るものではなく、蛍光プレートを励起できるものであれば、ＬＥＤの光を集光したものでもよく、更には、水銀、キセノン等が封入されたランプからの光であってもよい。尚、ランプやＬＥＤのように放射波長に幅を持つ光源を利用した場合、励起光の波長はランプ等から放射される主たる放射波長の領域である。ただし、本発明においては、これに限定されるものではない。 The overall structure of the fluorescent light source device is not limited to that shown in FIG. 1, and various configurations can be employed. For example, in the fluorescent light source device according to FIG. 1, the light of one laser light source (for example, a semiconductor laser) is used. However, there are a plurality of laser light sources, and a condensing lens is arranged in front of the fluorescent plate to collect The form which irradiates light to a fluorescence plate may be sufficient. In addition, the excitation light is not limited to the light from the laser light source, but may be one that condenses the LED light as long as it can excite the fluorescent plate, and further from a lamp in which mercury, xenon, or the like is enclosed. It may be light. When a light source having a width in the radiation wavelength such as a lamp or LED is used, the wavelength of the excitation light is a main radiation wavelength region emitted from the lamp or the like. However, the present invention is not limited to this.
　以下、本発明の実験例について説明する。 Hereinafter, experimental examples of the present invention will be described.
（実験例１）
　基本的に図６に示す構成を有し、下記の仕様を有する蛍光発光部材（２０）を３個作製した。
　この蛍光発光部材（２０）において、被覆層（５５）は蒸着膜よりなり、当該被覆層（５５）の凹凸構造（５１）は、ナノインプリント法とドライエッチング処理とによって形成した。
　具体的に、凹凸構造（５１）は、先ず、円形板状の被覆層の表面に、スピンコート法によってレジストを塗布し、次いで、レジストの塗布膜をナノインプリント法によりパターニングした。その後、被覆層の表面における露出した領域に、ＩＣＰ（Inductive  Coupling  Plasma，誘電結合方式）エッチング法によってドライエッチング処理を施すことによって形成した。
　なお、被覆層（５５）は、ダイシェアをすることによって所期の形状寸法を有するものとした。 (Experimental example 1)
Basically, three fluorescent light emitting members (20) having the configuration shown in FIG. 6 and the following specifications were produced.
In this fluorescent light emitting member (20), the coating layer (55) was made of a vapor deposition film, and the concavo-convex structure (51) of the coating layer (55) was formed by a nanoimprint method and a dry etching process.
Specifically, in the concavo-convex structure (51), first, a resist was applied to the surface of the circular plate-shaped coating layer by a spin coating method, and then the resist coating film was patterned by a nanoimprint method. Then, it formed by performing the dry etching process by the ICP (Inductive Coupling Plasma, dielectric coupling system) etching method to the exposed area | region in the surface of a coating layer.
In addition, the coating layer (55) shall have an intended shape dimension by die-sharing.
［基板（３１）］
材質：Ｍｏ－Ｃｕ基板
外形寸法：１７ｍｍ（縦）×１７ｍｍ（横）×０．５ｍｍ（最大厚み）
波長変換部材用凹部（３２）の寸法：４ｍｍ（縦）×３ｍｍ（横）×０．１３ｍｍ（凹み深さ）
［蛍光部材（２２）］
材質：ＹＡＧ（屈折率＝１．８５，励起波長＝４４８ｎｍ，蛍光波長＝５６０ｎｍ）
形状：略矩形状
寸法：３ｍｍ（縦）×４ｍｍ（横）×０．１３ｍｍ（厚み）
［被覆層（５５）］
材質：ジルコニア
厚み（最大厚み）：５００ｎｍ
凹凸構造形成領域の寸法：１．７ｍｍ（縦）×３ｍｍ（横）
凹凸構造（５１）の形状：円錐状の凸部（５２）の高さ＝２８０ｎｍ，周期（ｄ）＝４６０ｎｍ，アスペクト比（ｈ／ｄ）＝０．６
［光反射膜］
　材質：増反射アルミニウム膜
［保護部材（２３）］
　材質：チタニアよりなるセラミック [Substrate (31)]
Material: Mo-Cu substrate External dimensions: 17 mm (length) x 17 mm (width) x 0.5 mm (maximum thickness)
Dimension of concave portion for wavelength conversion member (32): 4 mm (vertical) × 3 mm (horizontal) × 0.13 mm (concave depth)
[Fluorescent member (22)]
Material: YAG (refractive index = 1.85, excitation wavelength = 448 nm, fluorescence wavelength = 560 nm)
Shape: Roughly rectangular Dimensions: 3 mm (length) x 4 mm (width) x 0.13 mm (thickness)
[Coating layer (55)]
Material: Zirconia Thickness (maximum thickness): 500nm
Dimension of uneven structure forming region: 1.7 mm (vertical) x 3 mm (horizontal)
Shape of concavo-convex structure (51): height of conical convex part (52) = 280 nm, period (d) = 460 nm, aspect ratio (h / d) = 0.6
[Light reflecting film]
Material: Increased reflective aluminum film [Protective member (23)]
Material: Ceramic made of titania
　作製した蛍光発光部材（２０）の各々を、図７に示したように支持部材（４１）によって支持し、図１の構成に基づいて３個の蛍光光源装置を作製した。これらの蛍光光源装置において、貫通孔（４７）によって形成される流通路の幅（図７における左右方向の寸法）は１７ｍｍであって、当該流通路における蛍光発光部材（２０）の表面上に位置する部分の厚み（図７における上下方向の寸法）は２．５ｍｍである。
　作製した蛍光光源装置の各々において、空気、フッ素系不活性液体および水を冷媒として用いて、これらの冷媒を温度３０℃、流速３ｍ／ｓの条件で貫通孔（４７）に供給しつつ、蛍光発光部材（２０）に対して、励起エネルギー１００Ｗの励起光を照射した。そして、蛍光部材（２２）の表面から出射された蛍光の光束を測定すると共に、蛍光部材（２２）の温度（表面温度）を放射温度計によって測定した。また、蛍光発光部材（２０）に照射された励起光の励起エネルギーのうちの、蛍光部材（２２）内において熱に変換されたエネルギー量（以下、「入熱量」ともいう。）を算出した。結果を表１に示す。この表１において、「光束比」とは、冷媒として空気を用いた場合の蛍光の光束を基準として１としたときの相対値を示す。 Each of the produced fluorescent light emitting members (20) was supported by a support member (41) as shown in FIG. 7, and three fluorescent light source devices were produced based on the configuration of FIG. In these fluorescent light source devices, the width of the flow passage formed by the through hole (47) (the dimension in the left-right direction in FIG. 7) is 17 mm, and is positioned on the surface of the fluorescent light emitting member (20) in the flow passage. The thickness of the portion (the vertical dimension in FIG. 7) is 2.5 mm.
In each of the produced fluorescent light source devices, air, fluorine-based inert liquid, and water are used as refrigerants, and these refrigerants are supplied to the through-hole (47) under the conditions of a temperature of 30 ° C. and a flow rate of 3 m / s. The light emitting member (20) was irradiated with excitation light having an excitation energy of 100W. And while measuring the fluorescence light beam radiate | emitted from the surface of the fluorescent member (22), the temperature (surface temperature) of the fluorescent member (22) was measured with the radiation thermometer. Further, the amount of energy converted into heat in the fluorescent member (22) (hereinafter also referred to as “heat input amount”) of the excitation energy of the excitation light irradiated to the fluorescent light emitting member (20) was calculated. The results are shown in Table 1. In Table 1, “luminous flux ratio” indicates a relative value when the fluorescent luminous flux is 1 when air is used as a refrigerant.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　表１の結果から、冷媒として液体冷媒を用いることにより、冷媒として空気を用いた場合に比して、高い冷却能が得られ、波長変換部材（蛍光部材）の温度上昇をより抑制でき、そのため、励起光の蛍光への変換効率が大きくなって高い蛍光光束が得られることが確認された。 From the results of Table 1, by using a liquid refrigerant as the refrigerant, a higher cooling ability can be obtained compared to the case where air is used as the refrigerant, and the temperature increase of the wavelength conversion member (fluorescent member) can be further suppressed. As a result, it was confirmed that the conversion efficiency of excitation light into fluorescence was increased and a high fluorescent light flux was obtained.
（実験例２）
　実験例１の蛍光光源装置と同様の構成を有する蛍光光源装置（以下、「蛍光光源装置（１）」ともいう。）を３個作製した。
　作製した蛍光光源装置の各々において、粘度の異なる３種類の液体冷媒、具体的には水、フッ素系不活性液体およびアルキルジフェニール系不活性液体を液体冷媒として用いて、これらの冷媒を温度３０℃、流速３ｍ／ｓの条件で貫通孔（４７）よりなる流通路に供給しつつ、蛍光発光部材（２０）に対して励起光を照射した。そして、蛍光部材（２２）の温度（表面温度）を放射温度計によって測定した。結果を表２に示す。
　表２において、「粘度」とは、温度１００℃における粘度を示す。 (Experimental example 2)
Three fluorescent light source devices (hereinafter also referred to as “fluorescent light source device (1)”) having the same configuration as the fluorescent light source device of Experimental Example 1 were produced.
In each of the produced fluorescent light source devices, three types of liquid refrigerants having different viscosities, specifically, water, a fluorine-based inert liquid, and an alkyldiphenyl-based inert liquid are used as liquid refrigerants, and these refrigerants are heated to a temperature of 30. The fluorescent light emitting member (20) was irradiated with excitation light while being supplied to the flow path formed of the through hole (47) under the conditions of 0 ° C. and a flow rate of 3 m / s. And the temperature (surface temperature) of the fluorescent member (22) was measured with the radiation thermometer. The results are shown in Table 2.
In Table 2, “viscosity” indicates viscosity at a temperature of 100 ° C.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　表２の結果から、液体冷媒として粘度の低いものを用いることにより、高い冷却能が得られることが確認された。また、温度１００℃における粘度が１．５ｍＰａ・ｓ以下である場合には、波長変換部材の温度を、温度消光によって励起光の蛍光への変換効率が極端に低下することとなる温度以下、具体的には２００℃以下とすることができることが確認された。 From the results of Table 2, it was confirmed that a high cooling ability can be obtained by using a liquid refrigerant having a low viscosity. Further, when the viscosity at a temperature of 100 ° C. is 1.5 mPa · s or less, the temperature of the wavelength conversion member is set to be equal to or lower than the temperature at which the conversion efficiency of excitation light into fluorescence is extremely reduced by temperature quenching. Specifically, it was confirmed that the temperature could be 200 ° C. or lower.
（実験例３）
　実験例１の蛍光光源装置と同様の構成を有する蛍光光源装置（以下、「蛍光光源装置（１）」ともいう。）を作製した。また、波長変換部材の励起光入射面、すなわち蛍光部材（２２）の表面に被覆層が設けられていないこと以外は蛍光光源装置（１）と同様の構成を有する蛍光光源装置（以下、「比較用蛍光光源装置（１）」ともいう。）を作製した。
　作製した蛍光光源装置（１）および比較用蛍光光源装置（１）の各々において、水を冷媒として用いて、この冷媒を温度３０℃、流速３ｍ／ｓの条件で貫通孔（４７）よりなる流通路に供給しつつ、蛍光発光部材（２０）に対して４３０時間にわたって励起光を照射した。そして、励起光の照射直後、すなわち蛍光発光部材（２０）の表面が水に浸漬した状態とされた直後に蛍光部材（２２）の表面から出射された蛍光の光束（初期光束）を測定した。また、励起光の照射を開始してから４３０時間経過後、すなわち蛍光発光部材（２０）の表面が４３０時間にわたって水に浸漬した状態とされた後にも蛍光部材（２２）の表面から出射された蛍光の光束（以下、「４３０時間経過光束」ともいう。）を測定した。蛍光光源装置（１）および比較用蛍光光源装置（１）の各々について、得られた初期光束および３４０時間経過光束から、初期光束に対する３４０時間経過光束の割合である光束維持率を算出したところ、蛍光光源装置（１）の光束維持率は９１％であり、一方、比較用蛍光光源装置（１）の光束維持率は８７％であった。 (Experimental example 3)
A fluorescent light source device (hereinafter also referred to as “fluorescent light source device (1)”) having the same configuration as the fluorescent light source device of Experimental Example 1 was produced. Further, a fluorescent light source device (hereinafter referred to as “comparison”) having the same configuration as that of the fluorescent light source device (1) except that a coating layer is not provided on the excitation light incident surface of the wavelength conversion member, ie, the surface of the fluorescent member (22) Fluorescent light source device (also referred to as “1”).
In each of the produced fluorescent light source device (1) and comparative fluorescent light source device (1), water is used as a refrigerant, and this refrigerant is distributed through the through holes (47) under the conditions of a temperature of 30 ° C. and a flow rate of 3 m / s. While being supplied to the road, the fluorescent light emitting member (20) was irradiated with excitation light for 430 hours. Then, immediately after the excitation light irradiation, that is, immediately after the surface of the fluorescent light emitting member (20) was immersed in water, the fluorescent light flux (initial light flux) emitted from the surface of the fluorescent member (22) was measured. Further, after 430 hours have passed since the excitation light irradiation was started, that is, after the surface of the fluorescent light emitting member (20) was immersed in water for 430 hours, the light was emitted from the surface of the fluorescent member (22). Fluorescent light flux (hereinafter also referred to as “430 hours elapsed light flux”) was measured. For each of the fluorescent light source device (1) and the comparative fluorescent light source device (1), a luminous flux maintenance factor, which is a ratio of a 340 hour lapsed light beam to an initial light beam, was calculated from the obtained initial light beam and 340 time lapsed light beam. The luminous flux maintenance factor of the fluorescent light source device (1) was 91%, while the luminous flux maintenance factor of the comparative fluorescent light source device (1) was 87%.
　以上の結果から、波長変換部材（蛍光部材）の励起光入射面に、当該励起光入射面を被覆する被覆層を設けることにより、液体冷媒を用いて波長変換部材を冷却した場合であっても、長期間にわたって高い発光効率が得られることが確認された。 From the above results, even when the wavelength conversion member is cooled using a liquid refrigerant by providing a coating layer that covers the excitation light incident surface on the excitation light incident surface of the wavelength conversion member (fluorescent member). It was confirmed that high luminous efficiency can be obtained over a long period of time.
１０　　蛍光光源装置
１１　　半導体レーザ
１５　　コリメータレンズ
１６　　ダイクロイックミラー
１８　　励起光集光レンズ
２０　　蛍光発光部材
２２　　蛍光部材
２３　　保護部材
２５　　被覆層
３１　　基板
３２　　波長変換部材用凹部
４１　　支持部材
４２　　貫通孔
４２Ａ　　上側部
４２Ｂ　　下側部
４３　　段差
４５　　開口部
４７　　貫通孔
４９　　開口部
５０　　被覆層
５１　　凹凸構造
５２　　凸部
５５　　被覆層
                                                                                 DESCRIPTION OF SYMBOLS 10 Fluorescence light source device 11 Semiconductor laser 15 Collimator lens 16 Dichroic mirror 18 Excitation light condensing lens 20 Fluorescence light emission member 22 Fluorescence member 23 Protection member 25 Cover layer 31 Substrate 32 Wavelength conversion member recessed part 41 Support member 42 Through-hole 42A Upper part 42B Lower side portion 43 Step 45 Opening portion 47 Through hole 49 Opening portion 50 Covering layer 51 Uneven structure 52 Convex portion 55 Covering layer

Claims (2)

  1. 　基板上に設けられた、励起光により蛍光を出射する波長変換部材を備えた蛍光光源装置において、
    　少なくとも前記波長変換部材の励起光入射面に沿って光透過性を有する液体冷媒を流通する液体冷媒流通機構が設けられており、
    　前記波長変換部材には、前記励起光入射面を被覆する、光透過性材料よりなる被覆層が設けられていることを特徴とする蛍光光源装置。     In a fluorescent light source device provided with a wavelength conversion member provided on a substrate and emitting fluorescence by excitation light,
    A liquid refrigerant circulation mechanism is provided that circulates a liquid refrigerant having optical transparency along at least the excitation light incident surface of the wavelength conversion member;
    The fluorescent light source device, wherein the wavelength conversion member is provided with a coating layer made of a light transmissive material that covers the excitation light incident surface.
  2. 　前記被覆層は、表面に凹凸構造が形成されていることを特徴とする請求項１に記載の蛍光光源装置。



                                                                                         The fluorescent light source device according to claim 1, wherein the coating layer has a concavo-convex structure formed on a surface thereof.



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JP2011198560A (en) * 2010-03-18 2011-10-06 Stanley Electric Co Ltd Vehicular lighting fixture
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JP2013030720A (en) * 2011-07-29 2013-02-07 Sharp Corp Light emitting element, light emitting device, and manufacturing method of light emitting element

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JP2011198560A (en) * 2010-03-18 2011-10-06 Stanley Electric Co Ltd Vehicular lighting fixture
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JP2013030720A (en) * 2011-07-29 2013-02-07 Sharp Corp Light emitting element, light emitting device, and manufacturing method of light emitting element

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JP2017068118A (en) * 2015-09-30 2017-04-06 日東電工株式会社 Infrared reflection film
CN106958753A (en) * 2017-03-21 2017-07-18 超视界激光科技（苏州）有限公司 A kind of Wavelength converter and light source

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