JP2016162579A - Fluorescent light source device and luminaire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluorescent light source device capable of radiating white light while ensuring necessary safety, and luminaire.SOLUTION: A fluorescent light source device includes: an excitation light source configured to radiate laser light as excitation light; a phosphor configured to receive the laser light from the excitation light source and emit fluorescent light to a laser light incident side; a concave reflection mirror configured to reflect the fluorescent light radiated from the phosphor; a window member configured to transmit the light reflected on the concave reflection mirror; and a blue light mixing mechanism configured to mix blue light to laser light. At least one of the concave reflection mirror and the window member has a light blockage characteristic of blocking light in a wavelength region of laser light. A luminaire includes the fluorescent light source device.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a fluorescence light source device that excites a phosphor with laser light to extract fluorescence, and an illumination device including the fluorescence light source device.

  Currently, for example, a technique using a fluorescent light source device as a light source for illumination is known. The fluorescent light source device emits light emitted from the phosphor by exciting the phosphor with light from a solid light source such as a semiconductor laser.

As such a fluorescent light source device, for example, laser light as excitation light is incident from the top side of a reflecting mirror and irradiated on a fluorescent plate having the same excitation light incident surface and fluorescent emission surface to excite the phosphor. As a result, a configuration is known in which the fluorescence emitted from the phosphor is reflected by a reflecting mirror and emitted (see, for example, Patent Document 1).
In addition, a technique is known in which pseudo white light is obtained by mixing light in a blue wavelength range and fluorescence.

JP 2005-150041 A

  Thus, in the above-described fluorescent light source device, laser light as excitation light that is light in the wavelength range of the blue region and fluorescence from the phosphor are mixed to emit white light. However, when such a fluorescent light source device is used as a light source for illumination such as general illumination, the laser light is radiated to the outside, which is dangerous and has a safety problem.

  The present invention has been made based on the above circumstances, and an object thereof is to provide a fluorescent light source device and an illuminating device that can irradiate white light while ensuring necessary safety. .

The fluorescent light source device of the present invention includes an excitation light source that emits laser light as excitation light, a phosphor that emits fluorescence on the laser light incident side upon receiving laser light from the excitation light source, and fluorescence emitted from the phosphor. In a fluorescent light source device comprising a concave reflecting mirror that reflects light and a window member that transmits light reflected by the concave reflecting mirror,
A blue mixing mechanism for mixing blue light into the laser light is provided, and at least one of the concave reflecting mirror and the window member has a light blocking characteristic for blocking light in a wavelength region of the laser light. .

  In the fluorescent light source device of the present invention, it is preferable that the excitation light incident surface of the phosphor has a characteristic of reflecting and diffusing blue light mixed with the laser light.

  Furthermore, in the fluorescent light source device of the present invention, a laser light transmission filter that reflects blue light mixed with the laser light is provided on the excitation light incident side of the phosphor, and the laser light transmission property is provided. It is preferable that a blue light diffusing member for diffusing blue light mixed with the laser light is provided between the filter and the concave reflecting mirror.

  Furthermore, in the fluorescent light source device of the present invention, it is preferable that the window member has an optical film having a light blocking characteristic that blocks light in a wavelength region of the laser beam.

  Furthermore, in the fluorescent light source device of the present invention, it is preferable that the concave reflecting mirror has an optical film having a light blocking characteristic for blocking light in the wavelength region of the laser beam.

  The illuminating device of this invention is equipped with said fluorescence light source device, It is characterized by the above-mentioned.

According to the fluorescent light source device of the present invention, white light can be obtained by mixing blue light by the blue mixing mechanism and fluorescence from the phosphor without emitting laser light for exciting the phosphor to the outside. .
In addition, since laser light is not emitted to the outside, a highly safe fluorescent light source device that can be used for general illumination or the like can be provided.

It is a front view which shows roughly the structure in an example of the fluorescence light source device of this invention. It is the sectional view on the AA line in FIG. It is an expanded sectional view which shows a part of fluorescence light source device shown in FIG. It is explanatory drawing which shows schematically the structure of the optical system in the other example of the fluorescence light source device of this invention. It is explanatory drawing which shows schematically the structure of the optical system in an example of the illuminating device using the fluorescence light source device of this invention.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is a front view showing a schematic configuration in an example of the fluorescent light source device of the present invention. FIG. 2 is a cross-sectional view taken along the line AA in FIG. FIG. 3 is an enlarged sectional view showing a part of the fluorescent light source device shown in FIG.
The fluorescent light source device includes a phosphor 15 that receives laser light as excitation light from the excitation light source 10 and emits fluorescence on the laser light incident side. The phosphor 15 is constituted by a phosphor plate made of, for example, a cerium-activated YAG phosphor (peak emission wavelength: around 550 nm), and is held by a cylindrical phosphor holding member 20. The holding structure of the phosphor 15 will be described later.

The phosphor holding member 20 is made of a heat conductive material such as aluminum or an aluminum alloy, for example, and has a cylindrical base portion (rim) 21 and a central axis C of the phosphor holding member 20 from the inner peripheral surface of the base portion 21. And a plurality of heat conducting portions (spokes) 22 that constitute a heat transfer path for exhaust heat of the phosphor 15.
Each heat conducting portion 22 is constituted by a flat heat conducting plate 23 extending along the central axis (the central axis of the base portion 11) C of the phosphor holding member 20, for example. In this example, the two heat conducting plates 23 are arranged at axially symmetric positions with the central axis C of the phosphor holding member 20 as the symmetric axis. The heat conducting plates 23 are joined to each other at their inner ends in the radial direction, and form, for example, a columnar phosphor holding portion 23 a on the central axis C of the phosphor holding member 20. In addition, the outer end portion in the radial direction of each heat conducting plate 23 is integrally joined to the inner peripheral surface of the base portion 21 and thermally connected thereto. The phosphor holding member 20 is integrated by joining the material forming the base portion 21 and each heat conducting plate 23 forming the heat conducting portion 22, and is integrally formed by casting or the like, for example. It may be a thing.

  The thickness and the axial length dimension of the heat conducting plate 23 can be set so as to obtain a certain amount of exhaust heat (amount of heat transfer) while suppressing the degree of light loss by the heat conducting plate 23 itself. For example, the thickness of the heat conducting plate 23 is preferably 2 mm or more and 5 mm or less, and the length of the heat conducting plate 23 in the axial direction is 7 to 20 mm. Is preferred. Thereby, it can avoid that the light quantity of the fluorescence emitted from the fluorescent substance 15 falls by the temperature quenching accompanying the temperature rise of the fluorescent substance 15.

  A phosphor support substrate 17 made of, for example, a sintered body of copper (Cu) and molybdenum (Mo) is provided on one side surface of the phosphor holding portion 23a. A body 15 is provided. One side surface of the phosphor holding member 20 and the other surface of the phosphor support substrate 17, and the other surface of the phosphor 15 whose one surface is the excitation light incident surface (fluorescence emission surface) 16 and one surface of the phosphor support substrate 17 are For example, they are joined and thermally connected to each other by solder (not shown) such as a Sn—Ag—Cu alloy.

  At one end of the phosphor holding member 20, a reflecting mirror holding member 40 that holds the concave reflecting mirror 30 that reflects the fluorescence emitted from the phosphor 15 is provided. The reflecting mirror holding member 40 includes a cylindrical portion 41 extending along the central axis C of the phosphor holding member 20 and an inward flange portion 42 formed at the other end of the cylindrical portion 41. The reflecting mirror holding member 40 is provided integrally with the phosphor holding member 20 in a state where the outer surface of the inner flange portion 42 is in contact with one end face of the phosphor holding member 20.

The concave reflecting mirror 30 is disposed such that the opening end surface thereof is in contact with the flat inner surface of the inner flange portion 42 with the reflecting surface 31 facing the excitation light incident surface 16 of the phosphor 15. As the concave reflecting mirror 30, for example, an ellipsoidal mirror or a parabolic mirror can be used. The optical axis O _M of the concave reflecting mirror 30 is positioned on the center axis C of the phosphor support member 20, the focal point of the concave reflector 30 (if it is ellipsoidal mirror, the first focal point), the phosphor 15 on the excitation light incident surface 16. Here, the inner surface of the inner flange portion 42 is set as a reflecting mirror positioned defining surface N _S. An excitation light entrance surface 16 of the phosphor 15, the axial distance between the reflector position defining surface N _S is the size of the range of, for example, 20～75Mm.
A light introducing opening 32 is formed at the center of the concave reflecting mirror 30, and a condensing lens 35 is provided in the light introducing opening 32. The condenser lens 35 is arranged in a state where the optical axis coincides with the central axis C of the phosphor holding member 20 and the focal point is positioned on the excitation light incident surface 16 of the phosphor 15.

The concave reflecting mirror 30 preferably has an optical film having a light blocking property for blocking light in the wavelength region of the laser light from the excitation light source 10 on the inner surface or the outer surface of the substrate.
In the concave reflecting mirror 30, for example, a film that absorbs light in the wavelength region of the laser light is formed on the reflecting surface 31 of the base material. Furthermore, it is configured by depositing a multilayer film as an optical film designed to transmit light in the wavelength region of the laser light and reflect fluorescence. Examples of the base material include metals such as Al and Ni, glass, plastics, and the like.
In the above example, a film is formed on the inner surface of the concave reflecting mirror 30 to block or absorb the light in the wavelength region of the laser light. In the case of a plastic substrate, an absorption layer that absorbs light in the wavelength region of the laser beam can be provided on the back surface of the substrate.

A heat radiating member 45 is provided on the back side of the concave reflecting mirror 30. The heat radiating member 45 includes a cylindrical portion 46 extending along the central axis C of the phosphor holding member 20 and a plurality of plate-like heat radiating fins 47 provided radially on the outer peripheral surface of the cylindrical portion 46. The inner surface of each heat radiating fin 47 is arranged along the outer peripheral edge of the columnar space with the central axis C of the phosphor holding member 20 as the center. The heat dissipating member 45 is held and fixed at the front end by the reflecting mirror holding member 40 in a state where the front end surface of each heat dissipating fin 47 is in contact with the back surface of the concave reflecting mirror 30.
The collimator lens 12 is provided at the other end side opening of the cylindrical portion 46 in the heat radiating member 45 in a state where the optical axis thereof coincides with the central axis C of the phosphor holding member 20.

  In addition, an excitation light source 10 that emits laser light as excitation light is provided at one end side opening of the cylindrical portion 46 in the heat radiating member 45. The excitation light source 10 is configured by a laser light source including a semiconductor laser element (LD element) 11 that emits laser light having an oscillation wavelength of 440 to 455 nm, for example. The semiconductor laser element 11 is held and fixed to the cylindrical portion 46 of the heat radiating member 45 with the optical axis coinciding with the central axis C of the phosphor holding member 20.

  On the other end side opening end face of the phosphor holding member 20, a window member holding portion 24 made of a recess in which a disk-like window member 28 is accommodated and disposed is formed. The window member 28 has the outer peripheral surface over the entire circumference by an adhesive (not shown) injected into a gap formed between the outer peripheral surface of the window member 28 and the inner peripheral surface of the window member holding portion 24. Is joined to. As the adhesive, for example, a ceramic adhesive having heat resistance can be used. Furthermore, the surface of the adhesive layer formed by curing the adhesive may be sealed with, for example, a silicone resin.

The window member 28 preferably has an optical film having a light blocking characteristic that blocks light in the wavelength region of the laser light from the excitation light source.
The window member 28 is configured, for example, by depositing a multilayer film as an optical film designed to reflect light in the wavelength region of laser light on the surface of the substrate. Examples of the base material include white plate glass having a high transmittance in the fluorescent region, and light-resistant plastic.

Thus, the above-described fluorescent light source device includes the blue mixing mechanism 50 that mixes blue light for forming white light into laser light (hereinafter also referred to as “LD light”) from the excitation light source 10. ing.
The blue mixing mechanism 50 includes a blue LED light source 51 and a dichroic mirror 55 for combining light from the blue LED light source 51 with LD light from the excitation light source.

The blue LED light source 51 is an LED substrate 52 and an LED that is provided on one surface of the LED substrate 52 and emits light having a peak wavelength within a wavelength range of 460 to 485 nm (hereinafter also referred to as “LED light”). A light emitting element 53, a heat dissipation substrate 54 provided on the other surface of the LED substrate 52, and a collimator lens 58 that collimates the LED light emitted from the LED light emitting element 53 are provided.
In the blue LED light source 51, the light axis of the LED light emitting element 53 is substantially the optical axis of the excitation light source 10 in a light source holding portion (not shown) formed in a part of the heat radiation fins 47 constituting the heat radiation member 45. In a posture extending perpendicularly, the heat radiating substrate 54 is disposed in thermal connection with the heat radiating fins 47.

The dichroic mirror 55 reflects, for example, light in the wavelength range of 460 to 495 nm and transmits light in other wavelength ranges, that is, transmits LD light from the excitation light source, and transmits LED light from the blue LED light source 51. Has a wavelength selection characteristic of reflecting the light.
In this dichroic mirror 55, the LD light incident surface and the LD light emitting surface (LED light incident surface) are the light of the excitation light source 10 in the cylindrical space formed by the inner surface of each radiating fin 47 constituting the heat radiating member 45. It is arranged in an inclined state with respect to the axis.

Further, a laser light transmissive filter 60 that reflects blue light (LED light) mixed with LD light from the excitation light source 10 is provided on the excitation light incident side of the phosphor 15, and the laser light transmissive filter is provided. A blue light diffusing member 65 that diffuses and reflects blue light (LED light) is disposed between 60 and the concave reflecting mirror 30.
Specifically, a plate-like base material 68 having optical transparency with respect to the fluorescence emitted from the LD light, LED light, and fluorescent material is provided on the excitation light incident surface 16 side of the fluorescent material 15 through the spacer member 69. The blue light diffusing member 65 is provided on one surface of the base material 68 and the laser light transmitting filter 60 is provided on the other surface of the base material 68. Is provided. The laser light transmissive filter 60 and the blue light diffusing member 65 are located on the optical path between the phosphor 15 and the excitation light source 10.

For example, quartz glass, borosilicate glass, or translucent ceramics such as alumina can be used as the material constituting the substrate 68.
As a material constituting the spacer member 69, for example, a metal material such as stainless steel having a thickness of 50 μm can be used.

The laser light transmissive filter 60 reflects light in a wavelength range of, for example, 455 to 500 nm and transmits light in other wavelength ranges, that is, reflects LED light from the blue LED light source 51 and LD from the excitation light source 10. It has a wavelength selection characteristic that transmits light. The laser light transmissive filter 60 is made of a dielectric multilayer film such as ZrO ₂ + SiO ₂ or Ta ₂ O ₅ + SiO ₂ .

  The blue light diffusing member 65 is transmissive for the LD light from the excitation light source 10, and is formed of, for example, a member having a fine uneven surface of μm level on the member surface or a curved surface.

In the fluorescent light source device having the above configuration, the LD light B _LD from the excitation light source 10 is collimated by the collimator lens 12 and is incident on the dichroic mirror 55. In FIG. 2, the ray tracing line of the LD light B _LD is indicated by a solid line.
As described above, since the dichroic mirror 55 has a wavelength selection characteristic that transmits laser light, the LD light B _LD from the excitation light source 10 passes through the dichroic mirror 55 and enters the condenser lens 35. The LD light B _LD incident on the condenser lens 35 is condensed by the condenser lens 35 and irradiated on the excitation light incident surface 16 of the phosphor 15. At this time, as shown in FIG. 3, LD light (ray tracking line indicated by a solid line) B _LD is transmitted through the blue light diffusing member 65, the base material 68, and the laser light transmitting filter 60.
By irradiating the phosphor 15 with the LD light B _LD as the excitation light, the fluorescent material in the phosphor 15 is excited, and fluorescence (ray tracing line indicated by a two-dot chain line) Y _F is emitted from the excitation light incident surface 16. . The fluorescence Y _F from the phosphor 15 is reflected by the concave reflecting mirror 30.

On the other hand, the LED light (blue light) B _LED from the blue LED light source 51 is collimated by the collimator lens 58 and is incident on the dichroic mirror 55. In FIG. 2, the ray tracing line of the LED light (blue light) B _LED is indicated by a broken line.
As described above, the dichroic mirror 55 has a wavelength selection characteristic that reflects the LED light (blue light) B _LED. Therefore, the LED light B _LED from the blue LED light source 51 is reflected on the phosphor holding member 20 by the dichroic mirror 55. The light is reflected in the direction along the central axis C and is incident on the condenser lens 35. The LED light B _LED incident on the condenser lens 35 is condensed by the condenser lens 35 and diffusely reflected by the blue light diffusing member 65 as shown in FIG. A part of the LED light B _LED incident on the blue light diffusing member 65 is transmitted through the blue light diffusing member 65 and the substrate 68, but the transmissive LED light TB _LED is reflected by the laser light transmissive filter 60. Is done.

Then, LED light B _LED reflected by LED light B _LED and laser light transmitting filter 60 that is diffuse reflected by the blue light diffusing member 65 is reflected by the concave reflector 30 and the fluorescent Y _F from the phosphor 15 It is mixed and irradiated as white light through the window member 28. In addition, a part of the LD light B _LD from the excitation light source 10 that does not contribute to excitation of the phosphor 15 is reflected by the phosphor 15. However, since one or both of the concave reflector 30 and the window member 28 and has a light blocking property for blocking LD light B _LD, LD light B _LD is absorbed by the concave reflecting mirror 30 or concave Since the LD light B _LD reflected by the reflecting mirror 30 is reflected by the window member 28, it is avoided that the LD light B _LD reflected by the phosphor 15 is directly emitted to the outside.

On the other hand, the heat generated in the phosphor 15 by irradiating the LD light B _LD as the excitation light is transferred to the base portion 21 through each heat conducting plate 23 in the phosphor holding member 20 to hold the phosphor. The outer peripheral surface of the member 20 functions as a heat radiating surface to radiate heat and is radiated to the outside by the heat radiating member 45.

Thus, according to the above-described fluorescent light source device, the LED light B _LED which is the blue light by the blue LED light source 51 and the fluorescent light Y from the fluorescent material 15 without emitting the laser light for exciting the fluorescent material 15 to the outside. _Since white light can be obtained by mixing with _F , the fluorescent light source device can irradiate white light while ensuring necessary safety. Therefore, for example, it is possible to provide a highly safe fluorescent light source device that can be used as a light source of a general illumination device.

As mentioned above, although embodiment of this invention was described, this invention is not limited to said embodiment, A various change can be added.
FIG. 4 is an explanatory diagram schematically showing the configuration of an optical system in another example of the fluorescent light source device of the present invention.
In this fluorescent light source device, a blue LED light source 51 constituting the blue color mixing mechanism 50 is arranged in a state where its optical axis coincides with the central axis C of the phosphor holding member 20, and the excitation light source 10 has its optical axis as a phosphor. The holding member 20 is arranged in a posture extending perpendicularly to the central axis C of the holding member 20.
As the dichroic mirror 55, for example, a wavelength selection characteristic that transmits light in the wavelength range of 460 to 490 nm and reflects light in other wavelength ranges, that is, the LED light B _LED from the blue LED light source 51 is transmitted. LD light B having a wavelength selection characteristic for reflecting _LD is used.

  Further, the blue color mixing mechanism constituting the fluorescent light source device of the present invention may be configured to include a plurality of blue LED light sources.

As described above, the fluorescent light source device of the present invention can be used as a light source for a general illumination device, for example, a light-up illumination device that emits spot light. FIG. 5 is an explanatory diagram schematically showing a configuration of an optical system in an example of an illumination device using the fluorescent light source device of the present invention.
In this illuminating device, the white light (pseudo white light by a blue light and fluorescence) irradiated from said fluorescence light source device injects into the optical fiber 70, for example, the spot light radiate | emitted from the optical fiber 70 is irradiated. It is said that.

The excitation light source 10 in this fluorescent light source device includes a plurality of laser light sources 10a that emit laser beams having the same oscillation wavelength, and a plurality of reflection mirrors 13 that correspond to the respective laser light sources 10a. Each laser light source 10 a includes a semiconductor laser element (LD element) 11 that emits laser light (LD light B _LD ) having an oscillation wavelength of 440 to 455 nm, for example, and a collimator lens 12. Each reflection mirror 13 reflects the LD light B _LD from each laser light source 10a by narrowing the irradiation width in a direction orthogonal to the optical axis of the laser light source 10a, and the LD light incident surface is the laser light source 10a. In a state inclined with respect to the optical axis of the laser light source 10a, the laser light sources 10a are disposed at positions displaced in the optical axis direction (stepwise).
In addition, a second reflecting mirror 14 that reflects the LD light B _LD from the excitation light source 10 in the direction along the central axis C of the phosphor holding member 20 is disposed.

  The concave reflecting mirror 30 in this fluorescent light source device is composed of, for example, an ellipsoidal mirror, and the excitation light incident surface 16 of the phosphor 15 is disposed at the first focal point of the elliptical mirror and the light is incident on the second focal point. An incident end face 71 of the fiber 70 is disposed.

According to such an illuminating device, the white light emitted from the fluorescent light source device is obtained by mixing the LED light B _LED from the blue LED light source 51 and the fluorescent light Y _F emitted from the phosphor 15. High safety can be obtained, and for example, it can be used as a lighting device for general lighting.

DESCRIPTION OF SYMBOLS 10 Excitation light source 10a Laser light source 11 Semiconductor laser element 12 Collimator lens 13 Reflection mirror 14 Second reflection mirror 15 Phosphor 16 Excitation light incident surface (fluorescence emission surface)
17 Phosphor support substrate 20 Phosphor holding member 21 Base part (rim)
22 Heat conduction part (spoke)
DESCRIPTION OF SYMBOLS 23 Heat-conducting plate 23a Phosphor holding | maintenance part 24 Window member holding | maintenance part 28 Window member 30 Concave reflecting mirror 31 Reflecting surface 32 Light introduction opening part 35 Condensing lens 40 Reflecting mirror holding member 41 Cylindrical part 42 Inner flange part 45 Heat dissipation member 46 cylindrical portion 47 heat radiation fin 50 blue mixing mechanism 51 blue LED light source 52 LED substrate 53 LED light emitting element 54 heat radiation substrate 55 dichroic mirror 58 collimator lens 60 laser light transmitting filter 65 blue light diffusing member 68 base material 69 spacer member 70 light fiber 71 the optical axis of the central axis N _S reflector position defining surface O _M concave reflector entrance end face C phosphor holding member

Claims (6)

An excitation light source that emits laser light as excitation light, a phosphor that receives the laser light from the excitation light source and emits fluorescence on the laser light incident side, a concave reflector that reflects the fluorescence emitted from the phosphor, In a fluorescent light source device comprising a window member that transmits light reflected by the concave reflecting mirror,
A blue mixing mechanism for mixing blue light into the laser light is provided, and at least one of the concave reflecting mirror and the window member has a light blocking characteristic for blocking light in a wavelength region of the laser light. Fluorescent light source device.   2. The fluorescent light source device according to claim 1, wherein the excitation light incident surface of the phosphor has a characteristic of reflecting and diffusing blue light mixed with the laser light.   A laser light transmitting filter that reflects blue light mixed with the laser light is provided on the excitation light incident side of the phosphor, and the laser is interposed between the laser light transmitting filter and the concave reflecting mirror. The fluorescent light source device according to claim 1, wherein a blue light diffusing member that diffuses blue light mixed with light is provided.   The fluorescent light source device according to any one of claims 1 to 3, wherein the window member includes an optical film having a light blocking characteristic that blocks light in a wavelength region of the laser beam.   5. The fluorescent light source device according to claim 1, wherein the concave reflecting mirror includes an optical film having a light blocking characteristic that blocks light in a wavelength region of the laser beam.   An illumination device comprising the fluorescent light source device according to any one of claims 1 to 5.

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