JP2011243372A - Light-emitting device, illumination device, and vehicle headlight - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source with a long life by restraining temperature rise of a temperature-increasing region including an irradiation zone at a light-emitting section irradiated with exciting light and its neighboring zone.SOLUTION: The headlight 1 includes a laser diode 3 for emitting a laser beam, an optical fiber 5 having an incident end 5b for receiving the laser beam emitted from the laser diode 3 and an emitting end 5a for emitting the laser beam incident from the incident end 5b, a light-emitting section 7 for light-emitting by receiving the laser beam emitted from the emitting end 5a, and a cooler 20 and a nozzle 21 for cooling the temperature-increasing region including the irradiation zone at the light-emitting section irradiated with the exciting light and its neighboring zone in the light-emitting section 7.

Description

  The present invention relates to a light emitting device that functions as a high-intensity light source, an illumination device including the light emitting device, and a vehicle headlamp.

  In recent years, semiconductor light emitting devices such as light emitting diodes (LEDs) and semiconductor lasers (LDs) are used as excitation light sources, and excitation light generated from these excitation light sources is emitted to light emitting units including phosphors. Research on light-emitting devices that use fluorescence generated by the above as illumination light has become active.

  Examples of techniques relating to such a light emitting device include lamps disclosed in Patent Documents 1 and 2. In these lamps, a semiconductor laser is used as an excitation light source in order to realize a high-intensity light source. Since the laser light oscillated from the semiconductor laser is coherent light, the directivity is strong, and the laser light can be condensed and used as excitation light without waste. A light-emitting device using such a semiconductor laser as an excitation light source (referred to as an LD light-emitting device) can be suitably applied to a vehicle headlamp.

  On the other hand, as an example of a technique for realizing a vehicle headlamp using an incoherent white LED (Light Emitting Diode), there is a vehicle headlamp disclosed in Non-Patent Document 1.

  This Non-Patent Document 1 describes that the light distribution pattern (light distribution) of light generated from the light emitting part of the vehicle headlamp is narrow in the vertical direction and wide in the horizontal direction.

JP 2005-150041 A (released on June 9, 2005) JP 2003-295319 A (published on October 15, 2003)

Masaru Sasaki, “Application of White LED to Automotive Lighting”, Journal of Applied Physics, 2005, Vol. 74, No. 11, p. 1463-1466

  However, the inventor has found that when a minute light-emitting part including a phosphor is excited with high-power excitation light (that is, when the light-emitting part is excited with a high power density), the light-emitting part is severely deteriorated.

  One cause of deterioration of the light emitting part is an increase in temperature in an irradiation region and an adjacent region (referred to as a temperature rising region) in the light emitting unit irradiated with excitation light. In this case, when high-power excitation light (laser light) is irradiated from the semiconductor laser to the light emitting portion, only the temperature rising region of the light emitting portion is locally extremely hot, so that the temperature rising region rapidly deteriorates. The problem of end up occurs. In the simulation, when the heat dissipation process is not performed on this region, the temperature in the temperature rising region exceeds 500 degrees Celsius immediately after the excitation light irradiation.

  Therefore, in a configuration in which a minute light-emitting part including a phosphor is excited with high-power excitation light, in order to prevent the light-emitting part from deteriorating and to realize a bright and long-life light source, It is desired to suppress the temperature rise in the temperature rising region including

  The present invention has been made to solve the above-described problems, and its object is to realize a long-life light source by suppressing a temperature rise in a temperature rising region in a light emitting unit irradiated with excitation light. It is providing the light-emitting device which can carry out, the illuminating device provided with the said light-emitting device, and a vehicle headlamp.

  In order to solve the above problems, a light emitting device according to the present invention includes an excitation light source that emits excitation light, an incident end that receives the excitation light emitted from the excitation light source, and excitation light that is incident from the incident end. A light guide portion having an emission end portion that emits light, a light emission portion that emits light by receiving excitation light emitted from the emission end portion, and an irradiation region in the light emission portion irradiated with the excitation light and the vicinity thereof And a cooling unit that cools the temperature rising region including the region.

  According to the above configuration, the excitation light emitted from the excitation light source enters the incident end of the light guide and is emitted from the emission end of the light guide. When the excitation light is applied to the light emitting part, the light emitting part emits light. When excitation light from the emission end is irradiated onto the light emitting unit, the region including the irradiated region and the region in the vicinity thereof is heated (that is, this region becomes the heated region). The temperature raising area is cooled.

  Therefore, since the light emitting device includes a cooling unit, a long-life light source can be obtained by suppressing a temperature rise in a temperature rising region including an irradiation region and a region in the vicinity of the light emitting unit irradiated with excitation light. Can be realized. That is, the light emitting device can realize a high-luminance light source having high reliability.

  Further, in the light emitting device according to the present invention, the cooling unit is configured to generate a wind for blowing air to the temperature rising region, and an inflow unit to which the wind generated by the air blowing unit is fed, It is preferable that the air supply unit includes an air guide unit having a sending unit to which the wind sent from the sending unit is sent out, and the sending unit is located in the vicinity of the temperature raising region.

  According to the said structure, the wind which the ventilation part generated enters into the sending-in part of a baffle part, and is sent out from the sending part of a baffle part located in the vicinity of a temperature rising area. Thereby, since the light-emitting device can make the wind generated by the blower part reach the temperature rising region, the temperature rising region can be cooled by the wind.

  Furthermore, in the light emitting device according to the present invention, it is preferable that the light emitting unit is supported by the sending unit.

  According to the above configuration, in the light emitting device, since the light emitting unit is supported by the sending unit, the air guide unit not only carries the wind generated by the air blowing unit to the temperature rising region but is also effective as a support member for the light emitting unit. Can be used.

  Furthermore, in the light emitting device according to the present invention, it is preferable that an emission end portion of the light guide portion is inserted into the air guide portion.

  According to the above configuration, since the emission end portion of the light guide portion is inserted into the air guide portion, space saving can be achieved compared to a configuration in which the light guide portion and the air guide portion are provided separately. .

  Moreover, according to the said structure, it is the structure which provided integrally the sending part which sends out the wind which the ventilation part generated, and the output end part which radiate | emits the excitation light which the excitation light source radiate | emitted. Therefore, for example, the length of the wind guide section, the distance between the sending section and the light emitting section (surface irradiated with excitation light), the direction of the wind guide section in consideration of the incident angle of the wind with respect to the light emitting section (temperature rising region), etc. The design in consideration of the above can be easily performed as compared with the case where the light guide portion and the air guide portion are provided separately.

  Furthermore, in the light emitting device according to the present invention, it is preferable that the air guide portion has flexibility.

  According to the above configuration, since the wind guide portion has flexibility, the positional relationship between the feeding portion and the sending portion can be easily changed, and the positional relationship between the blower portion and the light emitting portion is easily changed. be able to. Therefore, the design freedom of the light emitting device can be increased.

  Furthermore, an illumination device according to the present invention includes the light emitting device and a reflecting mirror that reflects a light emitted from the light emitting unit to form a light bundle that travels within a predetermined solid angle. .

  According to the above configuration, the light emitted from the light emitting unit is reflected by the reflecting mirror, and a light beam traveling within a predetermined solid angle is formed. Therefore, an illumination device suitable for a vehicle headlamp or a searchlight can be realized.

  Furthermore, an illumination device according to the present invention includes the light emitting device, and a reflecting mirror that reflects light emitted from the light emitting unit to form a light bundle that travels within a predetermined solid angle. Is a curved surface having an opening in which the direction of travel of the light beam is opened, and the light emitting device includes the reflecting mirror and a transparent member that covers the opening of the reflecting mirror and that transmits the light beam. It is preferable that at least one hole for discharging the wind staying in the space is formed in the reflecting mirror.

  According to the said structure, the illuminating device is arrange | positioned in the space enclosed by the curved-surface-shaped reflective mirror which has the opening part which the direction which a light beam advances opened, and the transparent member which covers the said reflective mirror. For this reason, when the wind generated in the blowing section is sent from the sending section of the air guide section to the temperature rising area, the wind is warmed in the temperature rising area and stays in the space, resulting in the result As a result, the cooling effect may be diminished.

  Accordingly, the lighting device allows at least one hole for discharging the wind staying in the space to be formed in the reflecting mirror so that the air warmed by the temperature rising region is released from the hole. Therefore, the wind can be prevented from staying in the space. Thereby, the illuminating device can reduce the possibility of impairing the cooling effect in the temperature rising region.

  A vehicle headlamp according to the present invention includes the light-emitting device and a reflecting mirror that reflects a light emitted from the light-emitting unit to form a light bundle that travels within a predetermined solid angle. Yes.

  According to the above configuration, the light emitted from the light emitting unit is reflected by the reflecting mirror, and a light beam traveling within a predetermined solid angle is formed. Therefore, a vehicle headlamp with a small size, high luminance and long life can be realized.

  A light-emitting device according to the present invention includes a pumping light source that emits excitation light, an incident end that receives excitation light emitted from the excitation light source, and an emission end that emits excitation light incident from the incident end. Cooling a temperature rising region including a light portion, a light emitting portion that emits light upon receiving excitation light emitted from the emission end portion, and an irradiation region in the light emitting portion irradiated with the excitation light and a region in the vicinity thereof And a cooling unit.

  Therefore, the light-emitting device according to the present invention has an effect that a long-life light source can be realized by suppressing the temperature rise of the irradiation region in the light-emitting portion irradiated with the excitation light.

It is sectional drawing which shows the structure of the headlamp which concerns on one Embodiment of this invention. It is a figure which shows the positional relationship of the emission end part and light emission part of the headlamp which concern on one Embodiment of this invention. It is a figure which shows the temperature characteristic regarding the light emission intensity | strength of each fluorescent substance used for the light emission part which irradiated the excitation light of fixed intensity | strength. It is sectional drawing which shows another structure of the headlamp which concerns on one Embodiment of this invention. It is sectional drawing which shows another structure of the headlamp which concerns on one Embodiment of this invention. (A) is a figure which shows the circuit diagram of a semiconductor laser typically, (b) is a perspective view which shows the basic structure of a semiconductor laser. It is the schematic which shows the external appearance of the light emission unit with which the laser downlight which concerns on one Embodiment of this invention is equipped, and the conventional LED downlight. It is sectional drawing of the ceiling in which the said laser downlight was installed. It is sectional drawing of the said laser downlight. It is sectional drawing which shows the example of a change of the installation method of the said laser downlight. It is sectional drawing of the ceiling in which the said LED downlight was installed. It is a figure for comparing the specifications of the laser downlight and the LED downlight.

[Embodiment 1]
The following describes one embodiment of the present invention with reference to FIGS. Here, a headlamp (vehicle headlamp) 1 for an automobile will be described as an example of the illumination device of the present invention. However, the lighting device of the present invention may be realized as a headlamp of a vehicle other than an automobile or a moving object (for example, a human, a ship, an aircraft, a submersible craft, a rocket), or may be realized as another lighting device. Also good. Examples of other lighting devices include a searchlight, a projector, and a home lighting device.

  The headlamp 1 may satisfy the light distribution characteristic standard of the traveling headlamp (high beam), or may satisfy the light distribution characteristic standard of the passing headlamp (low beam).

  In the following description, the optical fiber 5 shown in FIG. 1 is described as a plurality of bundles (that is, a configuration including a plurality of emission end portions 5a). However, the configuration is not limited to this, and only one optical fiber 5 ( That is, it may consist of only one exit end 5a.

(Configuration of headlamp 1)
First, the configuration of the headlamp 1 will be described with reference to FIG. FIG. 1 is a cross-sectional view showing the configuration of the headlamp 1. As shown in the figure, a headlamp 1 includes a semiconductor laser array (excitation light source) 2, an aspheric lens 4, an optical fiber (light guide part) 5, a ferrule 6, a light emitting part 7, a reflecting mirror 8, a transparent plate (transparent member). ) 9, a housing 10, an extension 11, and a lens 12.

  The semiconductor laser array 2 functions as an excitation light source that emits excitation light, and includes a plurality of semiconductor lasers (semiconductor laser elements) 3 on a substrate. Laser light is oscillated from each of the semiconductor lasers (excitation light sources) 3. It is not always necessary to use a plurality of semiconductor lasers 3 as the excitation light source, and only one semiconductor laser 3 may be used. However, in order to obtain a high-power laser beam, it is preferable to use a plurality of semiconductor lasers 3.

  The semiconductor laser 3 has one light emitting point in one chip, for example, oscillates a laser beam of 405 nm (blue violet), has an output of 1.0 W, an operating voltage of 5 V, and a current of 0.6 A. It is enclosed in a package with a diameter of 5.6 mm. The laser light oscillated by the semiconductor laser 3 is not limited to 405 nm, and may be any laser light having a peak wavelength in a wavelength range of 380 nm to 470 nm. If a high-quality short-wavelength semiconductor laser that oscillates laser light having a wavelength smaller than 380 nm can be manufactured, the laser light having a wavelength smaller than 380 nm is oscillated as the semiconductor laser 3 of the present embodiment. It is also possible to use a semiconductor laser designed as described above.

  The aspherical lens 4 is a lens for causing laser light (excitation light) oscillated from the semiconductor laser 3 to enter an incident end 5 b that is one end of the optical fiber 5. For example, as the aspheric lens 4, FLKN1 405 manufactured by Alps Electric can be used. The shape and material of the aspherical lens 4 are not particularly limited as long as the lens has the above function, but it is preferably a material having a high transmittance near 405 nm and a good heat resistance.

  The optical fiber 5 is a light guide member that guides the laser light oscillated by the semiconductor laser 3 to the light emitting unit 7 and is a bundle of a plurality of optical fibers. The optical fiber 5 has a plurality of incident end portions 5b that receive the laser light and a plurality of emission end portions 5a that emit the laser light incident from the incident end portion 5b. The plurality of emission end portions 5 a emit laser beams to different regions on the laser beam irradiation surface (light receiving surface) 7 a (see FIG. 2) of the light emitting unit 7. More specifically, the portions with the highest light intensity in the light intensity distributions of the laser beams emitted from the plurality of emission end portions 5 a are irradiated to the different portions of the light emitting unit 7.

  Here, the laser beam emitted from one emitting end portion 5a reaches the laser beam irradiation surface 7a while spreading at a predetermined angle. Further, when laser beams are emitted from the plurality of emission end portions 5a, a plurality of irradiation regions are formed on the laser beam irradiation surface 7a. Therefore, even if the emission end portions 5a of the plurality of optical fibers 5 are arranged side by side in a plane parallel to the laser light irradiation surface 7a, the irradiation region formed by the laser light from these emission end portions 5a , May overlap each other.

  Even in such a case, the place where the light intensity is the highest in the light intensity distribution of the laser light emitted from the emission end portion 5a (the central portion of the irradiation region formed by each laser light on the laser light irradiation surface 7a (the maximum light intensity portion). )) Is emitted to different portions of the laser light irradiation surface 7a of the light emitting section 7, the laser light can be irradiated to the laser light irradiation surface 7a in a two-dimensionally distributed manner.

  That is, the position of the maximum light intensity portion that is the portion with the highest light intensity in the projection image formed by irradiating the light emitting portion 7 with the laser light emitted from one of the plurality of emission end portions 5a. What is necessary is just to differ from the position of the maximum light intensity part of the projection image originating in the other output end part 5a. Therefore, it is not always necessary to completely separate the irradiated areas from each other.

  The emission end 5a may be in contact with the laser light irradiation surface 7a or may be disposed at a slight interval. In particular, when the emission end 5a is spaced from the laser light irradiation surface 7a, the laser light emitted from the emission end 5a and spreading in a conical shape is irradiated to the laser light irradiation surface 7a. It is preferable to be determined as follows. For example, in the case where the laser light irradiation surface 7a has an elliptical shape, the positional relationship between the emission end portion 5a and the light emitting portion 7 is set so that the laser light spreading in a conical shape has a distance not exceeding its short axis. It is preferable to define.

  The optical fiber 5 has a two-layer structure in which an inner core is covered with a clad having a refractive index lower than that of the core. The core is mainly composed of quartz glass (silicon oxide) having almost no absorption loss of laser light, and the clad is composed mainly of quartz glass or a synthetic resin material having a refractive index lower than that of the core. . For example, the optical fiber 5 is made of quartz having a core diameter of 200 μm, a cladding diameter of 240 μm, and a numerical aperture NA of 0.22. However, the structure, thickness, and material of the optical fiber 5 are limited to those described above. Instead, the cross section perpendicular to the long axis direction of the optical fiber 5 may be rectangular.

  Moreover, since the optical fiber 5 has flexibility, the arrangement | positioning with respect to the laser beam irradiation surface 7a of the output end part 5a can be changed easily. Therefore, the emission end portion 5a can be arranged along the shape of the laser beam irradiation surface 7a, and the laser beam can be irradiated mildly over the entire surface of the laser beam irradiation surface 7a.

  Moreover, since the optical fiber 5 has flexibility, the relative positional relationship between the semiconductor laser 3 and the light emitting unit 7 can be easily changed. Further, by adjusting the length of the optical fiber 5, the semiconductor laser 3 can be installed at a position away from the light emitting unit 7.

  Therefore, the degree of freedom in designing the headlamp 1 can be increased, for example, the semiconductor laser 3 can be installed at a position where it can be easily cooled or replaced. That is, the positional relationship between the incident end portion 5b and the emitting end portion 5a can be easily changed, and the positional relationship between the semiconductor laser 3 and the light emitting portion 7 can be easily changed. The degree of freedom can be increased.

  In addition, you may use what combined members other than an optical fiber, or an optical fiber and another member as a light guide member. The light guide member only needs to have at least one incident end that receives laser light oscillated by the semiconductor laser 3 and a plurality of emission ends that emit laser light incident from the incident end. For example, an incident part having at least one incident end part and an emitting part having a plurality of outgoing end parts may be formed as members different from the optical fiber, and the incident part and the outgoing part may be connected to both ends of the optical fiber. Good.

  Next, the positional relationship between the emission end portion 5a and the light emitting portion 7 will be described with reference to FIG. FIG. 2 is a diagram showing a positional relationship between the emission end portion 5 a and the light emitting portion 7. As shown in the figure, the ferrule 6 holds a plurality of emission end portions 5 a of the optical fiber 5 in a predetermined pattern with respect to the laser light irradiation surface 7 a of the light emitting unit 7. The ferrule 6 may be formed with holes for inserting the emission end portion 5a in a predetermined pattern, and can be separated into an upper part and a lower part, and is formed on the upper and lower joint surfaces, respectively. The exit end portion 5a may be sandwiched by a groove.

  The ferrule 6 may be fixed to the reflecting mirror 8 by a rod-like or cylindrical member extending from the reflecting mirror 8. The material of the ferrule 6 is not specifically limited, For example, it is stainless steel. A plurality of ferrules 6 may be arranged for one light emitting unit 7. In FIG. 1, for convenience, three emission end portions 5a are shown, but the number of emission end portions 5a is not limited to three.

  The light emitting section 7 emits light upon receiving the laser light emitted from the emission end 5a, and includes a phosphor that emits light upon receiving the laser light. Specifically, the light emitting unit 7 is a phosphor in which a phosphor is dispersed inside a silicone resin as a phosphor holding substance. The ratio of silicone resin to phosphor is about 10: 1. In addition, the light emitting unit 7 may be formed by pressing a fluorescent material. The phosphor holding substance is not limited to the silicone resin, and may be a glass material including an inorganic glass material or an organic / inorganic hybrid material.

  The phosphor is of an oxynitride type, and blue, green and red phosphors are dispersed in a silicone resin. Since the semiconductor laser 3 oscillates 405 nm (blue-violet) laser light, white light is generated when the light emitting unit 7 is irradiated with the laser light. Therefore, it can be said that the light emitting portion 7 is a wavelength conversion material.

  The semiconductor laser 3 may oscillate a 450 nm (blue) laser beam (or a so-called “blue” laser beam having a peak wavelength in a wavelength range of 440 nm to 490 nm). The phosphor is a yellow phosphor or a mixture of a green phosphor and a red phosphor. A yellow phosphor is a phosphor that emits light having a peak wavelength in a wavelength range of 560 nm to 590 nm. The green phosphor is a phosphor that emits light having a peak wavelength in a wavelength range of 510 nm or more and 560 nm or less. The red phosphor is a phosphor that emits light having a peak wavelength in a wavelength range of 600 nm to 680 nm.

The phosphor is preferably a so-called sialon phosphor. Sialon is a substance in which a part of silicon atoms in silicon nitride is replaced with aluminum atoms and a part of nitrogen atoms is replaced with oxygen atoms. The sialon phosphor can be made by dissolving alumina (Al ₂ O ₃ ), silica (SiO ₂ ), rare earth elements, and the like in silicon nitride (Si ₃ N ₄ ).

  As another suitable example of the phosphor, a semiconductor nanoparticle phosphor using nanometer-sized particles of a III-V compound semiconductor can be exemplified.

  One of the features of semiconductor nanoparticle phosphors is that even if the same compound semiconductor (for example, indium phosphorus: InP) is used, the emission color is changed by the quantum size effect by changing the particle diameter to nanometer size. It is a point that can be. For example, InP emits red light when the particle size is about 3 to 4 nm (here, the particle size was evaluated with a transmission electron microscope (TEM)).

  In addition, since this semiconductor nanoparticle phosphor is semiconductor-based, it has a short fluorescence lifetime and can emit the excitation light power as fluorescence quickly, so that it is highly resistant to high-power excitation light. This is because the emission lifetime of the semiconductor nanoparticle phosphor is about 10 nanoseconds, which is five orders of magnitude smaller than that of a normal phosphor material having a rare earth as the emission center.

  Furthermore, as described above, since the emission lifetime is short, the absorption of the laser beam and the emission of the phosphor can be quickly repeated. As a result, high efficiency can be maintained with respect to strong laser light, and heat generation from the phosphor can be reduced.

  Therefore, it is possible to further suppress the deterioration (discoloration or deformation) of the light emitting unit 7 due to heat. Thereby, when using the light emitting element with a high light output as a light source, it can suppress more that the lifetime of a light-emitting device (it mentions later about a basic structure) becomes short.

The shape and size of the light emitting unit 7 are, for example, a rectangular parallelepiped of 3 mm × 1 mm × 1 mm. In this case, the area of the laser light irradiation surface 7a that receives the laser light from the semiconductor laser 3 is 3 mm ² . The light distribution pattern (light distribution) of a vehicle headlamp that is legally regulated in Japan is narrow in the vertical direction and wide in the horizontal direction. By making the cross section substantially rectangular), the light distribution pattern can be easily realized. The light emitting unit 7 may not be a rectangular parallelepiped, and may be a cylinder whose laser light irradiation surface 7a is an ellipse (the long axis is 0.1 mm to 3 mm, for example). Further, the laser light irradiation surface 7a is not necessarily a flat surface, and may be a curved surface. However, in order to control the reflection of the laser beam, the laser beam irradiation surface 7a is preferably a plane perpendicular to the optical axis of the laser beam.

  Moreover, as shown in FIG. 1, the light emission part 7 is being fixed to the position inside the transparent plate 9 (the side in which the output end part 5a is located) facing the output end part 5a. The method for fixing the position of the light emitting unit 7 is not limited to this method, and the position of the light emitting unit 7 may be fixed by a rod-like or cylindrical member extending from the reflecting mirror 8.

  The reflecting mirror 8 reflects the light emitted from the light emitting unit 7 to form a light beam that travels within a predetermined solid angle. That is, the reflecting mirror 8 reflects the light from the light emitting unit 7 to form a light beam that travels forward of the headlamp 1. The reflecting mirror 8 is, for example, a curved (cup-shaped) member having a metal thin film formed on the surface thereof.

  The transparent plate 9 is a transparent resin plate that covers the opening of the reflecting mirror 8, and holds the light emitting unit 7. The transparent plate 9 is preferably formed of a material that blocks the laser light from the semiconductor laser 3 and transmits white light (incoherent light) generated by converting the laser light in the light emitting unit 7. In addition to the resin plate, an inorganic glass plate can also be used. Most of the coherent laser light is converted into incoherent white light by the light emitting unit 7. However, there may be a case where a part of the laser beam is not converted for some reason. Even in such a case, the laser beam can be prevented from leaking to the outside by blocking the laser beam with the transparent plate 9. In addition, when such an effect is not expected and the light emitting unit 7 is held by a member other than the transparent plate 9, the transparent plate 9 can be omitted.

  The housing 10 forms the main body of the headlamp 1 and houses the reflecting mirror 8 and the like. The optical fiber 5 passes through the housing 10, and the semiconductor laser array 2 is installed outside the housing 10. The semiconductor laser array 2 generates heat when the laser light is oscillated, but the semiconductor laser array 2 can be efficiently cooled by being installed outside the housing 10. Moreover, since the semiconductor laser 3 may break down, it is preferable to install it at a position where it can be easily replaced. If these points are not taken into consideration, the semiconductor laser array 2 may be accommodated in the housing 10.

  The extension 11 is provided on the front side of the reflecting mirror 8 to improve the appearance by concealing the internal structure of the headlamp 1 and enhance the sense of unity between the reflecting mirror 8 and the vehicle body. The extension 11 is also a member having a metal thin film formed on the surface thereof, like the reflecting mirror 8.

  The lens 12 is provided in the opening of the housing 10. The light generated by the light emitting unit 7 and reflected by the reflecting mirror 8 is emitted to the front of the headlamp 1 through the lens 12.

  Furthermore, the headlamp 1 includes a cooler (cooling unit, air blowing unit) 20, a nozzle (cooling unit, air guide unit) 21, and a nozzle 23, and a hole 22 is formed in a part of the reflecting mirror 8. Yes. The basic structure of the light-emitting device is formed by adding the cooler 20 and the nozzle 21 to the semiconductor laser array 2, the optical fiber 5, the ferrule 6, and the light-emitting unit 7 described above. The basic structure of the cooling unit is formed by the cooler 20 and the nozzle 21.

  The cooler 20 includes an irradiation region (region in the laser light irradiation surface 7a opposite to the laser light emission surface 6a) and a region in the vicinity thereof in the light emitting unit 7 irradiated with the laser light, housed in the housing 10. The temperature region is cooled. The cooler 20 cools the said temperature rising area | region by generating the wind for ventilating to a temperature rising area | region, for example, The air blower which has the structure of a general electric fan is mentioned. In this case, the cooler 20 includes a shaft, an impeller fixed to the shaft, a magnet for rotating the shaft, and a drive circuit for driving the shaft. For example, Japanese Unexamined Patent Application Publication No. 2009-19573. The structure of the electric fan as listed in the Gazette. Note that the shaft, the magnet, and the drive circuit realize a function as a general motor.

  Moreover, as another structure of the cooler 20, when producing the cold wind for cooling a temperature rising area | region, the air blower which has the structure of a general air conditioner is mentioned, for example. The air conditioner generates cold air by generating heat of vaporization when a liquid (for example, Freon gas) as a refrigerant evaporates. In this case, the cooler 20 includes, for example, an evaporator, a blower fan, a pipe, a compressor, a condenser, a cooling fan, and a solenoid valve.

  The evaporator evaporates the chlorofluorocarbon gas sent from the condenser via the pipe, and includes a fin made of, for example, Al, and is cooled by the heat of vaporization generated when the chlorofluorocarbon gas evaporates. The blower fan has the same structure as the above-described fan, for example, and sends the wind generated by rotating the impeller fixed to the shaft to the evaporator. Thereby, the cooler 20 can send the air around the evaporator cooled by the heat of vaporization to the nozzle 21 as cold air.

  The piping is a tube through which the chlorofluorocarbon gas connecting the evaporator and the condenser or compressor passes. As described above, the chlorofluorocarbon gas is passed from the condenser to the evaporator, and the evaporator is evaporated to compress the chlorofluorocarbon gas that has become gas It is passed through the vessel.

  The condenser is a casing in which CFC gas, which is a gas, is compressed by a compressor, and CFC gas that has become hot at this time is sent to it, and includes a fin made of, for example, Al. When the chlorofluorocarbon gas having reached a high temperature is cooled by a cooling fan in the condenser, the chlorofluorocarbon gas becomes liquid by being sent from the condenser to an electromagnetic valve for adjusting the pressure of the chlorofluorocarbon gas. Then, the chlorofluorocarbon gas that has become liquid by the electromagnetic valve is sent to the evaporator through a pipe.

  Since the high-temperature chlorofluorocarbon gas is cooled by the cooling fan, hot air is discharged from the condenser. For this reason, the nozzle (not shown) for discharging | emitting a warm air to the exterior of the headlamp 1 may be provided in the discharge | release area | region where the warm air of a condenser is discharged | emitted. Moreover, the structure by which the cooler 20 is provided in the headlamp 1 so that a condenser (or its discharge | release area | region) may become the exterior of the headlamp 1 may be sufficient.

  The nozzle 21 cools the temperature rising region, and is a tube for sending the wind (cool air) generated by the cooler 20 to the temperature rising region. The nozzle 21 is a cylindrical tube made of, for example, highly transparent quartz so that the light beam formed by the reflecting mirror 8 can be transmitted. The nozzle 21 has, for example, a diameter (inner diameter) of 2 mm (only about 0.5 to 4 mm). In addition, when the material of the nozzle 21 is a metal, it is also possible to radiate the air (air) warmed in the temperature rising region to the cooler 20 side.

  Moreover, the nozzle 21 has the inflow part 21b which receives the wind which the cooler 20 generate | occur | produced, and the sending-out part 21a which sends out the wind sent in from the inflow part 21b. As shown in FIG. 2, the delivery unit 21 a has a position and direction (nozzle where the wind from the cooler 20 reaches the temperature rising region of the laser light irradiation surface 7 a facing the laser light emitting surface 6 a of the ferrule 6. 21 in the direction in which the temperature rising region exists on the extension of the major axis direction of 21).

  In other words, the nozzle 21 has an infeed part 21b into which the wind generated by the cooler 20 is sent in, and a delivery part 21a into which the wind sent from the infeed part 21b is sent out, The delivery part 21a is installed so that it may be located in the vicinity of a temperature rising area. Thereby, since the headlamp 1 can make the wind which the cooler 20 generated reach | attain to a temperature rising area, it can cool the said temperature rising area with the said wind.

  In FIG. 2, the nozzle 21 has a linear shape (bar shape), but is not limited to this, and has the flexibility that allows the shape to be deformed (bendable) as with the optical fiber 5. It may be a tube.

  When the nozzle 21 has flexibility, the relative positional relationship between the cooler 20 and the light emitting unit 7 can be easily changed. Further, by adjusting the length of the nozzle 21, the cooler 20 can be installed at a position away from the light emitting unit 7. In this case, the cooler 20 is not limited to the configuration in which the cooler 20 is housed in the housing 10 as shown in FIG. 2. Like the optical fiber 5, the nozzle 21 penetrates the housing 10 so that the cooler 20 is installed outside the housing 10. It is also possible to do.

  Therefore, when the cooler 20 breaks down, it can be installed at a position where it can be easily repaired or replaced, and the design flexibility of the headlamp 1 can be increased.

  The hole 22 prevents the wind that has reached the temperature rising region (that is, the wind warmed in the temperature rising region (air)) from staying in the space surrounded by the reflecting mirror 8 and the transparent plate 9 (that is, In order to release the wind from the space), at least one of the reflecting mirrors 8 is formed. The size of the hole 22 may be, for example, a diameter of 3 mm (only about 1 to 5 mm).

  In other words, the light emitting unit 7 is surrounded by a reflecting mirror 8 having a curved shape having an opening in which the direction of travel of the light beam is opened, and a transparent plate 9 that covers the opening of the reflecting mirror 8 and transmits the light beam. It can be said that at least one hole 22 is formed in the reflecting mirror 8 for discharging the wind staying in the space. Thereby, since the wind warmed by the temperature rising region can be escaped from the hole 22, the stay of the wind in the space can be prevented. For this reason, the headlamp 1 can reduce the possibility of impairing the cooling effect in the temperature rising region.

  Further, the position where the hole 22 is formed may be any position on the reflecting mirror 8, but for example, after the wind sent from the sending portion 21a reaches the temperature rising region of the laser light irradiation surface 7a, the reflecting mirror 8 is formed. It is preferable to be provided at a position that reaches. For example, the position includes a position and direction in which the nozzle 21 penetrates the reflecting mirror 8 and a position and direction that are symmetric with respect to the long axis of the optical fiber 5.

  The nozzle 23 is a tube inserted into the hole 22 in order to discharge the air entering from the hole 22 to the outside of the space. For example, the diameter is made using Teflon (registered trademark) resin or silicone resin. It is a cylindrical tube of 3 mm (may be about 1 to 5 mm). Further, the inner diameter of the nozzle 23 is 2 mm (may be about 0.5 to 4 mm).

  In addition, it sent to the nozzle 23 at the sending end opposite to the end inserted into the hole 22 of the nozzle 23 (that is, the end from which the wind sent to the nozzle 23 is discharged). An air suction device for sucking wind may be provided.

  Further, the delivery end of the nozzle 23 is on the surface of the lens 12 (which may be a surface facing the transparent plate 9 (a surface on the inner side of the headlamp 1) or a surface opposite to the surface). You may provide in the position which can send out a wind. In the case where the air suction unit is provided at the delivery end of the nozzle 23, another nozzle different from the nozzle 23 is provided in the air suction unit, and the delivery end of the nozzle is connected to the lens. You may be provided in the position which can send a wind to 12 surfaces. In this case, the headlamp 1 can discharge the air warmed in the temperature rising region to the outside of the space, and can prevent the surface of the lens 12 from freezing.

  As described above, the headlamp 1 according to this embodiment includes the semiconductor laser 3 that emits laser light, the incident end 5b that receives the laser light emitted from the semiconductor laser 3, and the laser light that is incident from the incident end 5b. An optical fiber 5 having an exit end 5a that emits light, a light emitting unit 7 that receives and emits laser light emitted from the exit end 5a, and an irradiation region in the light emitting unit 7 that is irradiated with the laser light and a region in the vicinity thereof. The cooler 20 and the nozzle 21 for cooling the temperature rising region including

  Here, the inventor of the present invention has found that when the light emitting portion is excited with high power laser light and at a high power density, the light emitting portion is severely deteriorated. Even if the emitted light from the LED is used as the excitation light, the same problem is considered to occur if the power is high. The deterioration of the light emitting part is mainly caused by the deterioration of the substance (for example, silicone resin) surrounding the phosphor together with the deterioration of the phosphor itself included in the light emitting part. The sialon phosphor described above generates light with an efficiency of 60 to 80% when irradiated with laser light, but the rest is emitted as heat. It is considered that the material surrounding the phosphor is deteriorated by this heat.

  In consideration of the above problems, the headlamp 1 can realize a long-life light source by suppressing the temperature rise in the temperature rising region by having the above configuration. That is, the headlamp 1 can realize a high-intensity light source having high reliability.

(About emission intensity of the light emitting part)
Next, the light emission intensity of the light emitting unit will be described with reference to FIG. FIG. 3 is a diagram illustrating temperature characteristics related to the emission intensity of each phosphor used in the light emitting unit irradiated with excitation light having a constant intensity. In FIG. 3, (a) is a sialon phosphor A having the chemical formula Ca _0.98 Eu _0.02 AlSiN ₃ , (b) is a sialon phosphor B having the chemical formula Ca _0.95 Eu _0.05 AlSiN ₃ , and (c) is A YAG: Ce ³⁺ phosphor (product number P46-Y3, manufactured by Kasei Optonics) in which cerium Ce ³⁺ is introduced as an activator into yttrium aluminate (Y ₃ Al ₅ O ₁₂ : YAG) is shown. In FIG. 3, the vertical axis represents “Normalized Intensity (au)” and the horizontal axis represents “Temperature (° C.)”.

As shown in FIG. 5C, when YAG: Ce ³⁺ phosphor is used, the emission intensity of the light emitting part when reaching 150 degrees is about 60% of the emission intensity at room temperature (30 degrees Celsius). It has become. On the other hand, as shown in FIG. 5A, when sialon phosphors A and B are used, the emission intensity of the light emitting part when reaching 150 degrees is about the emission intensity at room temperature (30 degrees Celsius). 90% and about 83%. That is, it can be said that the phosphor used in the light emitting portion is preferably a sialon phosphor with a small decrease in emission intensity with respect to a temperature rise due to irradiation with excitation light.

However, as shown in the figure, even when a sialon phosphor is used for the light emitting portion, the light emission intensity (light emission efficiency) decreases with increasing temperature. In particular, since the intensity (unit: watts) and power density (unit: watts / mm ² ) of the laser light used as excitation light in this embodiment are high, the temperature rise of the light emitting unit 7 using the sialon phosphor is significant. I can say that. That is, even in the light emitting portion 7, it is considered that the light emission efficiency is lowered with a remarkable temperature rise, and consequently the light emitting portion 7 is deteriorated.

  Therefore, the headlamp 1 according to this embodiment uses the cooler 20 and the nozzle 21 to cool the temperature rising region of the light emitting unit 7 and suppress the temperature rise of the light emitting unit 7, thereby emitting light from the sialon phosphor. A reduction in efficiency (and hence deterioration of the light emitting section 7) is prevented.

(Another configuration of the headlamp 1)
Next, another configuration of the headlamp 1 will be described with reference to FIG. FIG. 4 is a cross-sectional view showing another configuration of the headlamp 1. Since the configuration similar to that of the headlamp 1 shown in FIG. 1 has been described above, the description thereof will be omitted.

  In the headlamp 1 shown in FIG. 4, the light emitting portion 7 is fixed to the tip of a cylindrical member that extends through the central portion of the reflecting mirror 8. This cylindrical member is a nozzle 21 having a function of carrying the wind from the cooler 20 to the temperature rising region, and is configured to support the light emitting unit 7 in the delivery unit 21a.

  Further, as shown in the figure, the emission end portion 5a of the optical fiber 5 can be passed through the nozzle 21 (the optical fiber 5 and the nozzle 21 are provided coaxially). In this case, a hole for passing the optical fiber 5 extending from the semiconductor laser 3 through the nozzle 21 is provided.

  In other words, it can be said that the headlamp 1 shown in FIG. 4 has a configuration in which the nozzle 21 includes at least the emission end portion 5 a of the optical fiber 5. Thereby, space can be saved as compared with the configuration in which the optical fiber 5 and the nozzle 21 are provided separately. For example, the length of the nozzle 21, the distance between the delivery portion 21 a and the laser light irradiation surface 7 a, It is possible to simplify the design considering the orientation and the like.

  Note that at least one hole is formed in the vicinity of the laser light irradiation surface 7 a of the nozzle 21 in order to allow the air (air) that has reached the laser light irradiation surface 7 a and heated in the temperature rising region to escape from the inside of the nozzle 21. The part 24 may be formed. The size of the hole 24 is, for example, a circular shape having a diameter of 2 mm (only about 1 to 3 mm) or a rectangular shape having a size of 1 mm × 3 mm, and efficiently releases the air heated in the temperature rising region to the outside. It is only necessary to be able to secure strength sufficient to withstand the support of the light emitting unit 7.

  In addition, the hole portion 22 has an appropriate position for preventing the wind emitted from the hole portion 24 and warmed in the temperature rising region from staying in the space surrounded by the reflecting mirror 8 and the transparent plate 9. In this case, for example, it may be provided at a position where a straight line can be formed between the center of the hole 22 and the center of the hole 24.

  Further, another configuration in which the nozzle 21 supports the light emitting unit 7 in the delivery unit 21a will be described with reference to FIG. FIG. 5 is a cross-sectional view showing still another configuration of the headlamp 1.

  As shown in the figure, a protruding portion 25 as a support member for supporting the light emitting portion 7 by fixing it is formed at the tip of the nozzle 21 (the sending portion 21a). The protruding portion 25 may be any size and shape that allows the light emitting portion 7 to be fixed, and may be, for example, a single fan-like plate-like member or a plurality of rod-like members. Further, the protruding portion 25 may be formed so as to protrude from the nozzle 21 or may be attached to the nozzle 21 as a separate body from the nozzle 21.

  As described above, the headlamp 1 shown in FIGS. 4 and 5 has a configuration in which the light emitting unit 7 is supported by the sending unit 21a. Accordingly, the headlamp 1 can effectively use the nozzle 21 as a support member for the light emitting unit 7 as well as carry the wind generated by the cooler 20 to the temperature rising region. That is, the headlamp 1 can effectively use the nozzle 21 provided for cooling the temperature rising region.

(Another configuration of the cooler 20)
In the above description, the cooler 20 is described as a configuration in which air is blown to the temperature rising region. However, the present invention is not limited to this. For example, the cooler 20 may be an air suction device that sucks air near the temperature rising region through the nozzle 21. In this case, it is not necessary to provide the hole 22 and the nozzle 23. In addition, the cooler 20 as an air suction device has a configuration including, for example, a sirocco fan suitable for air suction.

  Further, in order to release at least the air in the vicinity of the temperature rising region to the outside of the cooler 20, the cooler 20 is provided with another nozzle different from the nozzle 21, and the delivery end of the nozzle is connected to the lens 12. You may provide in the position which can send a wind to the surface. Thereby, the headlamp 1 can discharge the air heated in the temperature rising region to the outside of the space surrounded by the reflecting mirror 8 and the transparent plate 9 and prevent the surface of the lens 12 from freezing. can do.

  Even with this configuration, the headlamp 1 can realize a long-life light source by suppressing a temperature rise in the temperature rising region. That is, the headlamp 1 can realize a high-intensity light source having high reliability.

  The cooler 20 may have a configuration shared with a cooling device for cooling a specific member of the automobile.

  Further, the cooler 20 may be configured to operate only (for example, generate wind) when laser light is emitted from the semiconductor laser 3. Further, the cooler 20 may be configured to operate only when the intensity of the laser light applied to the light emitting unit 7 or the temperature of the temperature rising region becomes a certain value or more. Further, when the headlamp 1 is designed to guide the wind generated by the traveling of the automobile to the light emitting unit 7, the headlamp 1 may control the operation / non-operation of the cooler 20 according to the speed of the automobile. .

(Structure of semiconductor laser 3)
Next, the basic structure of the semiconductor laser 3 will be described. FIG. 6A schematically shows a circuit diagram of the semiconductor laser 3, and FIG. 6B is a perspective view showing the basic structure of the semiconductor laser 3. As shown in the figure, the semiconductor laser 3 has a configuration in which a cathode electrode 19, a substrate 18, a cladding layer 113, an active layer 111, a cladding layer 112, and an anode electrode 17 are laminated in this order.

The substrate 18 is a semiconductor substrate, and it is preferable to use GaN, sapphire, or SiC in order to obtain blue to ultraviolet excitation light for exciting the phosphor as in the present application. In general, as other examples of a substrate for a semiconductor laser, a group IV semiconductor represented by a group IV semiconductor such as Si, Ge and SiC, GaAs, GaP, InP, AlAs, GaN, InN, InSb, GaSb and AlN Group V compound semiconductors, Group II-VI compound semiconductors such as ZnTe, ZeSe, ZnS and ZnO, oxide insulators such as ZnO, Al ₂ O ₃ , SiO ₂ , TiO ₂ , CrO ₂ and CeO ₂ , and SiN Any material of the nitride insulator is used.

  The anode electrode 17 is for injecting current into the active layer 111 through the cladding layer 112.

  The cathode electrode 19 is for injecting current into the active layer 111 from the lower part of the substrate 18 through the clad layer 113. The current is injected by applying a forward bias to the anode electrode 17 and the cathode electrode 19.

  The active layer 111 has a structure sandwiched between the clad layer 113 and the clad layer 112.

  As the material for the active layer 111 and the cladding layer, a mixed crystal semiconductor made of AlInGaN is used to obtain blue to ultraviolet excitation light. Generally, a mixed crystal semiconductor mainly composed of Al, Ga, In, As, P, N, and Sb is used as an active layer / cladding layer of a semiconductor laser, and such a configuration may be used. Moreover, you may be comprised by II-VI group compound semiconductors, such as Zn, Mg, S, Se, Te, and ZnO.

  The active layer 111 is a region where light emission is caused by the injected current, and the emitted light is confined in the active layer 111 due to a difference in refractive index between the cladding layer 112 and the cladding layer 113.

  Further, the active layer 111 is formed with a front side cleaved surface 114 and a back side cleaved surface 115 provided to face each other in order to confine light amplified by stimulated emission, and the front side cleaved surface 114 and the back side cleaved surface 115. Plays the role of a mirror.

  However, unlike a mirror that completely reflects light, a part of the light amplified by stimulated emission is obtained by cleaving the front side cleaved surface 114 and the back side cleaved surface 115 of the active layer 111 (in this embodiment, the front side cleaved surface 114 for convenience. And the excitation light L0. Note that the active layer 111 may form a multilayer quantum well structure.

  Note that a reflective film (not shown) for laser oscillation is formed on the back side cleaved surface 115 opposite to the front side cleaved surface 114, and the difference in reflectance between the front side cleaved surface 114 and the back side cleaved surface 115 is different. By providing, for example, most of the excitation light L0 can be emitted from the light emitting point 103 from the front-side cleavage surface 114 which is a low reflectance end face.

  The clad layer 113 and the clad layer 112 are made of n-type and p-type GaAs, GaP, InP, AlAs, GaN, InN, InSb, GaSb, and AlN group III-V compound semiconductors, and ZnTe, ZeSe. , ZnS, ZnO, and other II-VI group compound semiconductors, and by applying a forward bias to the anode electrode 17 and the cathode electrode 19, current can be injected into the active layer 111. It has become.

  As for film formation with each semiconductor layer such as the clad layer 113, the clad layer 112, and the active layer 111, MOCVD (metal organic chemical vapor deposition) method, MBE (molecular beam epitaxy) method, CVD (chemical vapor deposition) method. The film can be formed using a general film forming method such as a laser ablation method or a sputtering method. The film formation of each metal layer can be configured using a general film forming method such as a vacuum deposition method, a plating method, a laser ablation method, or a sputtering method.

(Light emission principle of the light emitting unit 7)
Next, the light emission principle of the phosphor by the laser light oscillated from the semiconductor laser 3 will be described.

  First, the laser light oscillated from the semiconductor laser 3 is irradiated onto the phosphor included in the light emitting unit 7, whereby electrons existing in the phosphor are excited from a low energy state to a high energy state (excited state).

  Since this excited state is unstable, the energy state of the electrons in the phosphor is changed to the original low energy state after a certain time (the energy state of the ground level or the level between the excited level and the ground level). Transition to a stable level energy state).

  In this way, the phosphors emit light when electrons excited to the high energy state transition to the low energy state.

  White light can be composed of a mixture of three colors that satisfy the principle of equal color, or a mixture of two colors that satisfy the relationship of complementary colors. Based on this principle, the color of the laser light emitted from the semiconductor laser and the phosphor White light can be generated by combining the color of emitted light as described above.

When ten semiconductor lasers 3 are provided and a laser beam of 405 nm is received from each of the semiconductor lasers 3, a luminous flux of 1500 lumen is emitted from the light emitting unit 7. The brightness in this case is 80 candela / mm ² .

[Embodiment 2]
The following will describe another embodiment of the present invention with reference to FIGS. In addition, about the member similar to Embodiment 1, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  Here, the laser downlight 200 as an example of the illuminating device of this invention is demonstrated. The laser downlight 200 is an illumination device installed on the ceiling of a structure such as a house or a vehicle, and uses fluorescence generated by irradiating the light emitting unit 7 with laser light emitted from the semiconductor laser 3 as illumination light. It is.

  Note that an illuminating device having the same configuration as that of the laser downlight 200 may be installed on the side wall or floor of the structure, and the installation location of the illuminating device is not particularly limited.

  FIG. 7 is a schematic view showing the appearance of the light emitting unit 210 and the conventional LED downlight 300. FIG. 8 is a cross-sectional view of the ceiling where the laser downlight 200 is installed. FIG. 9 is a cross-sectional view of the laser downlight 200. As shown in FIGS. 7 to 9, the laser downlight 200 is embedded in the top plate 400 and emits illumination light, and an LD light source unit that supplies laser light to the light emitting unit 210 via the optical fiber 5. 220, and a cooler 20 that supplies wind for cooling the light emitting unit 7 to the light emitting unit 210 via the nozzle 21. The LD light source unit 220 and the cooler 20 are not installed on the ceiling, but are installed at a position where the user can easily touch them (for example, a side wall of a house). The positions of the LD light source unit 220 and the cooler 20 can be freely determined in this way because the LD light source unit 220 and the light emitting unit 210 are connected by the optical fiber 5 and the nozzle 21, respectively. The optical fiber 5 is disposed in a gap between the top plate 400 and the heat insulating material 401.

(Configuration of light emitting unit 210)
As shown in FIG. 9, the light emitting unit 210 includes a housing 211, an optical fiber 5, a light emitting unit 7, and a light transmitting plate 213.

  A recess 212 is formed in the housing 211, and the light emitting unit 7 is disposed on the bottom surface of the recess 212. A metal thin film is formed on the surface of the recess 212, and the recess 212 functions as a reflecting mirror.

  In addition, a passage 214 for passing the optical fiber 5 and the nozzle 21 is formed in the housing 211, and the optical fiber 5 and the nozzle 21 extend to the light emitting unit 7 through the passage 214. The positional relationship between the emission end portion 5a of the optical fiber 5 and the delivery portion 21a of the nozzle 21 and the light emitting portion 7 is the same as described above.

  The translucent plate 213 is a transparent or translucent plate disposed so as to close the opening of the recess 212. The translucent plate 213 has a function similar to that of the transparent plate 9, and the fluorescence of the light emitting unit 7 is emitted as illumination light through the translucent plate 213. The translucent plate 213 may be removable from the housing 211 or may be omitted.

  In FIG. 7, the light emitting unit 210 has a circular outer edge, but the shape of the light emitting unit 210 (more precisely, the shape of the housing 211) is not particularly limited.

  In the downlight, unlike a headlamp, an ideal point light source is not required, and a level of one light emitting point is sufficient. Therefore, there are fewer restrictions on the shape, size and arrangement of the light emitting section 7 than in the case of the headlamp.

(Configuration of LD light source unit 220)
The LD light source unit 220 includes a semiconductor laser 3, an aspheric lens 4, and an optical fiber 5.

  The incident end 5b, which is one end of the optical fiber 5, is connected to the LD light source unit 220, and the laser light oscillated from the semiconductor laser 3 is incident on the incident end 5b of the optical fiber 5 via the aspherical lens 4. Is incident on.

  Only one pair of the semiconductor laser 3 and the aspherical lens 4 is shown inside the LD light source unit 220 shown in FIG. 9, but when there are a plurality of light emitting units 210, the optical fibers 5 extending from the light emitting units 210 respectively. The bundle may be guided to one LD light source unit 220. In this case, a pair of a plurality of semiconductor lasers 3 and an aspheric lens 4 (or a pair of a plurality of semiconductor lasers 3 and one rod-shaped lens (not shown)) is accommodated in one LD light source unit 220. Thus, the LD light source unit 220 functions as a centralized power supply box.

(Example of changing the installation method of the laser downlight 200)
FIG. 10 is a cross-sectional view showing a modified example of the installation method of the laser downlight 200. As shown in the figure, as a modified example of the installation method of the laser downlight 200, the top plate 400 has only a small hole 402 through which the optical fiber 5 and the nozzle 21 are passed, and the laser downlight main body is utilized by taking advantage of the thin and lightweight features. It can also be said that (light emitting unit 210) is attached to the top plate 400. In this case, there are advantages that restrictions on installation of the laser downlight 200 are reduced, and that construction costs can be significantly reduced.

(Comparison between laser downlight 200 and conventional LED downlight 300)
As shown in FIG. 7, the conventional LED downlight 300 includes a plurality of light transmitting plates 301, and illumination light is emitted from each light transmitting plate 301. That is, the LED downlight 300 has a plurality of light emitting points. The LED downlight 300 has a plurality of light emitting points because the light flux of light emitted from each light emitting point is relatively small. Therefore, if a plurality of light emitting points are not provided, light having a sufficient light flux as illumination light is provided. This is because it cannot be obtained.

  On the other hand, since the laser downlight 200 is an illumination device with a high luminous flux, the number of emission points may be one. Therefore, it is possible to obtain an effect that the shadow caused by the illumination light is clearly displayed. Moreover, the color rendering property of illumination light can be improved by making the phosphor of the light emitting portion 7 a high color rendering phosphor (for example, a combination of several kinds of oxynitride phosphors).

  FIG. 11 is a cross-sectional view of the ceiling where the LED downlight 300 is installed. As shown in the figure, in the LED downlight 300, a casing 302 that houses an LED chip, a power source, and a cooling unit is embedded in the top plate 400. The housing 302 is relatively large, and a recess along the shape of the housing 302 is formed in a portion of the heat insulating material 401 where the housing 302 is disposed. A power line 303 extends from the housing 302, and the power line 303 is connected to an outlet (not shown).

  Such a configuration causes the following problems. First, since there is a light source (LED chip) and a power source that are heat sources between the top plate 400 and the heat insulating material 401, the use of the LED downlight 300 raises the ceiling temperature, and the cooling efficiency of the room. Problem arises.

  Further, the LED downlight 300 requires a power source for each light source, which causes a problem that the total cost increases.

  Moreover, since the housing | casing 302 is comparatively large, the problem that it is often difficult to arrange | position the LED downlight 300 in the clearance gap between the top plate 400 and the heat insulating material 401 arises.

  On the other hand, in the laser downlight 200, since the light emitting unit 210 does not include a large heat source, the cooling efficiency of the room is not reduced. As a result, an increase in room cooling costs can be avoided.

  Further, since it is not necessary to provide a power source for each light emitting unit 210, the laser downlight 200 can be made small and thin. As a result, the space restriction for installing the laser downlight 200 is reduced, and installation in an existing house is facilitated.

  Further, since the laser downlight 200 is small and thin, as described above, the light emitting unit 210 can be installed on the surface of the top plate 400, and the installation restrictions are made smaller than those of the LED downlight 300. As well as drastically reducing construction costs.

  FIG. 12 is a diagram for comparing the specifications of the laser downlight 200 and the LED downlight 300. As shown in the figure, in the laser downlight 200, in one example, the volume is reduced by 94% and the mass is reduced by 86% compared to the LED downlight 300.

  Further, since the LD light source unit 220 can be installed in a place where the user can easily reach, the semiconductor laser 3 can be easily replaced even if the semiconductor laser 3 breaks down. Similarly, since the cooler 20 can also be installed in a place that can be easily reached by the user, even if the cooling mechanism inside the cooler 20 breaks down, it can be easily repaired. Further, by guiding the optical fibers 5 extending from the plurality of light emitting units 210 to one LD light source unit 220, the plurality of semiconductor lasers 3 can be collectively managed. Therefore, even when a plurality of semiconductor lasers 3 are replaced, the replacement can be easily performed.

  In the case of a type using a high color rendering phosphor in the LED downlight 300, a light beam of about 500 lm can be emitted with a power consumption of 10 W, but in order to realize the light of the same brightness with the laser downlight 200, 3 .3W light output is required. If the LD efficiency is 35%, this light output corresponds to power consumption of 10 W, and the power consumption of the LED downlight 300 is also 10 W. Therefore, there is no significant difference in power consumption between the two. Therefore, in the laser downlight 200, the above-described various advantages can be obtained with the same power consumption as that of the LED downlight 300.

  As described above, the laser downlight 200 includes the LD light source unit 220 including at least one semiconductor laser 3 that emits laser light, the at least one light emitting unit 210 including the light emitting unit 7 and the recess 212 as a reflecting mirror, The optical fiber 5 that guides the laser light to each of the light emitting units 210 and the cooler 20 for cooling each of the light emitting units 7 of the light emitting unit 210 are included. In addition, the laser downlight 200 may be configured such that the cooler 20 generates wind and includes a nozzle 21 for blowing the wind generated by the cooler 20 to each light emitting unit 7. .

  Therefore, in the laser downlight 200, it is possible to suppress an increase in the temperature of the irradiation region in the light emitting unit 7 irradiated with the laser light. As a result, a long-life laser downlight 200 can be realized.

(Another expression of the present invention)
The present invention may be expressed as follows.

  A light-emitting device (high-intensity light source) according to the present invention includes an excitation light source composed of a semiconductor laser capable of high-power oscillation, and a light-emitting unit that emits light by excitation light from the excitation light source. In this configuration, a gas (gas) is sprayed onto the region irradiated with the excitation light.

  Furthermore, in the light emitting device according to the present invention, the excitation light source may be not only a semiconductor laser but also a high output light emitting diode.

  Furthermore, the light emitting device according to the present invention is not only a semiconductor laser having one laser beam emitting end for one excitation light source, but also a semiconductor laser having a plurality of laser beam emitting ends for one excitation light source. It may be.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims. That is, embodiments obtained by combining technical means appropriately modified within the scope of the claims are also included in the technical scope of the present invention.

  For example, a high-power LED may be used as the excitation light source. In this case, a light emitting device that emits white light can be realized by combining an LED that emits light having a wavelength of 450 nm (blue) and a yellow phosphor or green and red phosphors.

  As the excitation light source, a solid-state laser other than a semiconductor laser, for example, a light emitting diode capable of high-power oscillation may be used. However, it is preferable to use a semiconductor laser because the excitation light source can be reduced in size.

  The present invention can be applied to a light emitting device with high brightness and long life, particularly a headlamp for a vehicle or the like.

1 Headlamp (light emitting device, lighting device, vehicle headlamp)
2 Semiconductor laser array (excitation light source)
3 Semiconductor laser (excitation light source)
5 Optical fiber (light guide)
5a Output end portion 5b Incident end portion 7 Light emitting portion 8 Reflecting mirror 9 Transparent plate (transparent member)
20 Cooler (cooling section, blower section)
21 Nozzle (cooling part, wind guide part)
21a sending part 21b sending part 22 hole part 200 laser downlight (illumination device)

Claims (8)

An excitation light source that emits excitation light;
A light guide having an incident end for receiving the excitation light emitted from the excitation light source and an emission end for emitting the excitation light incident from the incident end;
A light emitting unit that emits light by receiving excitation light emitted from the emission end;
A light emitting device comprising: a cooling unit that cools a temperature rising region including an irradiation region and a region in the vicinity thereof in the light emitting unit irradiated with the excitation light. The cooling part is
An air blowing section for generating wind for blowing air to the temperature raising region;
A wind guide section having an input section to which the wind generated by the air blowing section is input and an output section to which the wind input from the input section is transmitted;
The light emitting device according to claim 1, wherein the delivery unit is located in the vicinity of the temperature rising region.   The light-emitting device according to claim 2, wherein the light-emitting unit is supported by the delivery unit.   The light emitting device according to claim 2, wherein an emission end portion of the light guide portion is inserted into the air guide portion.   The light-emitting device according to any one of claims 2 to 4, wherein the air guide portion has flexibility. A light emitting device according to any one of claims 1 to 5,
An illuminating device comprising: a reflecting mirror that reflects light emitted from the light emitting unit to form a light bundle that travels within a predetermined solid angle. The light emitting device according to any one of claims 2 to 4,
A reflecting mirror that forms a light bundle that travels within a predetermined solid angle by reflecting the light emitted from the light emitting unit, and
The reflecting mirror has a curved surface shape having an opening in which the traveling direction of the light beam is opened,
The light emitting device is disposed in a space surrounded by the reflecting mirror and a transparent member that covers the opening of the reflecting mirror and through which the light beam passes.
The lighting device according to claim 1, wherein the reflecting mirror is formed with at least one hole for discharging the wind staying in the space. A light emitting device according to any one of claims 1 to 5,
A vehicular headlamp comprising: a reflecting mirror that reflects light emitted from the light emitting unit to form a light bundle that travels within a predetermined solid angle.

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