JP2014157842A - Lighting device, vehicular headlight - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a headlamp that is excellent in usability and made compact and lightweight.SOLUTION: The lighting device comprises: a semiconductor laser (2) for emitting a laser beam; a light emitting part (7) for receiving the laser beam and emitting light in a wavelength range from visible light to near-infrared light; and resin-made light projecting parts (8, 12) for projecting the light emitted by the light emitting part (7) to the outside of the device. The semiconductor laser (2) is provided so as to be separated from the light projecting parts (8, 12).

Description

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

  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 parts containing fluorescent materials. Accordingly, research on light-emitting devices that generate incoherent 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, there are vehicle headlamps disclosed in Non-Patent Documents 1 and 2.

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

  Non-Patent Document 2 describes an LED headlamp for a vehicle that takes into consideration weight reduction and design by making an optical component to be used made of resin.

  Furthermore, Patent Documents 3 to 5 describe bicycle lights using LEDs or LDs as excitation light sources. In the bicycle light, the excitation light source is disposed inside a bulk lens made of resin having a lens action.

JP 2005-150041 A (released on June 9, 2005) JP 2003-295319 A (published on October 15, 2003) JP 2002-225762 A (released on August 14, 2002) JP 2002-231023 A (released on August 16, 2002) JP 2009-1277 A (published January 8, 2009)

Masaru Sasaki, “Application of White LED to Automotive Lighting”, Journal of Applied Physics, 2005, Vol. 74, No. 11, p. 1463-1466 Stanley Electric Co., Ltd., “Application of High Power LEDs to Automotive Headlamps”, 5th Nitride Semiconductor Application Study Group, May 29, 2009

  However, in general, in a lighting device such as a vehicle headlamp equipped with such a light emitting device, a reflecting mirror that reflects light emitted from the light emitting unit and a condensing mirror are formed of a metal material, inorganic glass, or the like. The lighting devices described in Patent Documents 1 and 2 and Non-Patent Document 1 are no exception. Therefore, since the reflecting mirror and the condensing mirror are made of a metal material or the like, the illuminating device has to be increased in weight and price, and its usability is not sufficiently high for the user.

  Non-Patent Document 2 describes that an optical component of an LED headlamp is formed of a resin material. However, Non-Patent Document 2 only describes that, and how to use a resin material in a configuration in which an excitation light source and a light emitting unit are combined, how to reduce the size and weight of the lighting device itself, and so on. There is no explanation for whether it will be realized.

  The bicycle light described in Patent Document 3 does not include a light emitting unit. In addition, the entire excitation light source (LED or LD) is disposed inside a bulk lens made of resin or the like. Therefore, Patent Document 3 discloses that when an excitation light source and a light emitting unit are combined, the positioning of the light emitting unit or the excitation light source, the light emitting unit, and It does not disclose any technical matters such as bulk lens layout.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an illuminating device that is excellent in usability, realizes a reduction in size and weight, and a vehicle headlight including the illuminating device. There is.

In order to solve the above problems, a lighting device according to one embodiment of the present invention includes:
A semiconductor laser that emits laser light;
A light emitting unit that receives the laser light and emits light in a wavelength range from visible light to near infrared; and
A light projection member made of resin that projects the light emitted by the light emitting unit to the outside of the device,
The semiconductor laser is provided apart from the light projection member.

The lighting device according to one embodiment of the present invention is as described above.
A semiconductor laser that emits laser light;
A light emitting unit that receives the laser light and emits light in a wavelength range from visible light to near infrared; and
A light projection member made of resin that projects the light emitted by the light emitting unit to the outside of the device,
The semiconductor laser is provided apart from the light projection member.

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 an optical fiber with which the headlamp which concerns on one Embodiment of this invention is provided. It is sectional drawing which shows the example of a change of the positioning method of a light emission part. (A) And (b) is a figure which shows an example of the pattern which arrange | positions the several output end part of an optical fiber with respect to the laser beam irradiation surface of a light emission part. (A) is a figure which shows light intensity distribution of the laser beam radiate | emitted from the output end part of an optical fiber, (b) is a figure which shows the positional relationship of several laser beam irradiation area | region. (A) is a circuit diagram of a semiconductor laser, (b) is a perspective view showing the basic structure of a semiconductor laser. It is a figure which shows the heat conductivity of various materials. 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]
An embodiment of the present invention will be described below with reference to FIGS. Here, as an example of the lighting device of the present invention, a headlamp 1 for an automobile will be described as an example. 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).

(Configuration of headlamp 1)
FIG. 1 is a cross-sectional view showing the configuration of the headlamp 1. As shown in the figure, the headlamp 1 includes a semiconductor laser array (excitation light source) 2, an aspherical lens 4, an optical fiber (light guide part) 5, a ferrule 6, a light emitting part 7, a reflecting mirror 8, a transparent plate 9, and a housing. 10, an extension 11 and a lens (transparent member) 12. The semiconductor laser array 2, the optical fiber 5, the ferrule 6 and the light emitting unit 7 form a basic structure of the light emitting device.

  The semiconductor laser array 2 functions as an excitation light source that emits excitation light, and includes a plurality of semiconductor lasers 3 on a substrate. Laser light is oscillated from each of the semiconductor lasers 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 400 nm to 420 nm.

  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. If it is a lens which has the above-mentioned function, the shape and material of the aspherical lens 4 will not be specifically limited.

  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. In other words, the plurality of emission end portions 5 a emit laser beams to different portions of the light emitting unit 7. The emission end portion 5a may be in contact with the laser light irradiation surface 7a or may be disposed at a slight interval.

  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.

  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.

  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 material of the ferrule 6 is not specifically limited, For example, it is a synthetic resin. In FIG. 2, 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 silicone resin, and may be inorganic glass or organic-inorganic hybrid glass.

  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 also be used. One of the characteristics of semiconductor nanoparticle phosphors is that even if the same compound semiconductor (for example, indium phosphorus: InP) is used, the emission color can be changed by the quantum size effect by changing the particle diameter. is there. (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 phosphor is semiconductor-based, it has a short fluorescence lifetime, and can quickly radiate excitation light power as fluorescence, 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-based emission center. Since the emission lifetime is short, absorption of excitation light and emission of fluorescence can be repeated quickly. As a result, high efficiency can be maintained against strong excitation light, and heat generation from the phosphor is reduced. Therefore, it is possible to further suppress the light conversion member from being deteriorated (discolored or deformed) by 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 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 does not have to be a rectangular parallelepiped, and may have a cylindrical shape whose laser light irradiation surface 7a is an ellipse. 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 high heat conductive member extending from the reflecting mirror 8. In addition, if the light emission part 7 is arrange | positioned in the optical focus position of the reflective mirror (light projection member) 8 and the lens (light projection member) 12, the light radiate | emitted from the light emission part 7 can be more efficiently projected outside. it can.

  The reflecting mirror 8 reflects the light emitted from the light emitting unit 7 to form a light bundle 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.

  In the present embodiment, the reflecting mirror 8 is formed of a resin material. The reason why the reflecting mirror 8 can be formed of a resin material is as follows. That is, the wavelength range of the laser light emitted from the semiconductor laser 3 is the visible light range, and the wavelength range of the light emitted from the light emitting unit 7 upon receiving the laser light is from the visible light range to the near infrared range. The reflected light also changes from visible light to the near infrared region. Therefore, the light reflected by the reflecting mirror 8 does not include far-infrared rays (heat rays) that is a wavelength region that raises the temperature of the object to be irradiated, or ultraviolet rays that are wavelength regions that cause the resin to fade or change quality. For such a reason, the reflecting mirror 8 can be formed of a resin material. The lens 12 described later can also be formed of a resin material for the same reason.

  Thus, since the resin material forming the reflecting mirror 8 does not need to have high resistance to high temperatures and ultraviolet rays, various types of resin materials can be used. Therefore, the resin material used as the reflecting mirror 8 may be a thermoplastic resin, a thermosetting resin, or may not have translucency.

Here, thermoplastic resins are roughly classified into general-purpose resins, general-purpose engineering resins, and super-engineering resins depending on the difference in heat resistance. The general-purpose resin has characteristics such as a heat distortion temperature of less than 100 ° C., a tensile strength of less than 500 kgf / cm ² , and an impact resistance of less than 5 kgf.cm/cm. The general-purpose engineering resin has characteristics such as a heat distortion temperature of 100 ° C. or more, a tensile strength of 500 kgf / cm ² or more, and an impact resistance of 5 kgf.cm/cm or more. The super engineering resin has a characteristic that it can be used for a long period of time at a heat deformation temperature of 150 ° C. or higher, which is higher than that of the general-purpose engineering resin.

  In the headlamp 1, since it is not necessary to consider heat resistance, the resin material forming the reflecting mirror 8 may be any of general-purpose resin, general-purpose engineering resin, and super-engineering resin. Among them, general-purpose resins are comparatively inexpensive and easy to process, so polyethylene (PE), polypropylene (PP), vinyl chloride (PVC), polystyrene (PS), etc., which are called four major general-purpose resins, can be particularly preferably employed. .

  On the other hand, a thermosetting resin is a polymer having a linear three-dimensional structure, and has a property of softening when heated and solidifying by a chemical reaction. And the thermosetting resin once solidified by heating does not dissolve even if heated again. Examples of thermosetting resins include phenolic resin (PF), epoxy resin (EP), polyurethane (PU), and silicone resin.

  In addition, it is preferable to select the resin material of the reflecting mirror 8 according to a use. For example, when the headlamp 1 is used as an in-vehicle headlight, it is necessary to select a resin material in consideration of a temperature rise in the engine room.

  Further, the light reflecting surface of the reflecting mirror 8 is mirror-finished by aluminum vapor deposition or the like, and the light emitted from the light emitting unit 7 is reflected toward the lens 12. For example, an example in which the reflecting mirror 8 is injection-molded with ABS resin and aluminum plating is vapor-deposited on the light reflecting surface can be given.

  Next, the semiconductor laser 3 and the reflecting mirror 8 will be described. As shown in FIG. 1, in the present embodiment, the semiconductor laser 3, which is the part that generates the most heat when the headlamp 1 is operated, is placed away from the reflecting mirror 8. That is, as shown in the figure, the semiconductor laser 3 is provided outside a space (reflection space) surrounded by the reflecting mirror 8 and the lens 12, and heat generated by the semiconductor laser 3 reaches the reflecting mirror 8. The mutual positional relationship is adjusted so that there is not. This is because the optical fiber 5 that guides the laser light emitted from the semiconductor laser 3 to the light emitting unit 7 is appropriately designed, that is, the length of the light guide unit is adjusted as appropriate, so that the semiconductor laser 3 is reflected by the reflecting mirror 8. It becomes possible to install in the position away from (that is, the position where it is easy to cool). In this way, the positional relationship between the semiconductor laser 3 and the reflecting mirror 8 can be adjusted as appropriate to a position where the heat generated from the semiconductor laser 3 does not reach the reflecting mirror 8 made of resin.

  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. . 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 may also be formed of a resin material 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 and seals the headlamp 1. The light generated in 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.

  The lens 12 is formed of a resin material as in the case of the reflecting mirror 8, and is formed of a resin material having translucency, that is, an amorphous resin. An amorphous resin refers to a polymer resin in which the molecular main chain is randomly attached with side chains, or a polymer resin that is branched or cross-linked and is in an amorphous state. The amorphous state includes a hard glass state and a soft rubber state, and many of them usually have excellent transparency.

  Examples of amorphous resins include thermoplastic resins such as polystyrene (PS), acrylonitrile / styrene resin (AS), acrylonitrile / butadiene / styrene resin (ABS), methacrylic resin (PMMA), and vinyl chloride (PVC). . In particular, acrylic resin (methacrylic resin PMMA), epoxy resin, silicone resin (resin type with high hardness), polyethylene terephthalate, polycarbonate, organic-inorganic hybrid glass, and the like can be suitably used.

  FIG. 3 is a cross-sectional view showing a modified example of the positioning method of the light emitting unit 7. As shown in the figure, the light emitting portion 7 may be fixed to the tip of a cylindrical portion 15 made of a high heat conductive member extending through the central portion of the reflecting mirror 8. In this case, the emission end portion 5a of the optical fiber 5 can be passed through the cylindrical portion 15, but it is not always necessary to do so. For example, the cylindrical portion 15 may be arranged perpendicular to the direction described in FIG. 3, that is, in a direction perpendicular to the drawing, and the optical fiber 5 may be provided so as to penetrate the central portion of the reflecting mirror 8. Good.

  In addition, it is preferable that the cylindrical part 15 is formed with a material with high heat conductivity. Thereby, if a part of the cylindrical portion 15 protrudes outside the reflection space (the space surrounded by the reflecting mirror 8 and the lens 12), the heat generated in the light emitting portion 7 is efficiently outside the reflection space. Heat is dissipated. Examples of the material for forming the high thermal conductive member include materials having high thermal conductivity shown in FIG. 7, such as zirconia, titanium oxide, Ag, Cu, AlN (aluminum nitride), and Al. Moreover, the material which is not described in FIG. 7 may be sufficient, for example, graphite etc. can be employ | adopted suitably as a material which forms a high heat conductive member.

(Arrangement style of emission end 5a)
FIGS. 4A and 4B are diagrams illustrating an example of a pattern in which a plurality of emission end portions 5 a of the optical fiber 5 are arranged with respect to the laser light irradiation surface 7 a of the light emitting unit 7. In the figure, the position where the emission end portion 5a is in contact with (or is opposed to) the laser beam irradiation surface 7a is indicated by a circle. As shown in FIG. 6A, the laser light irradiation surface 7a of the light emitting unit 7 has a long axis, and at least a part of the plurality of emission end portions 5a is arranged along the long axis. Also good. Specifically, five exit end portions 5a may be densely arranged in two stages. With this configuration, the light emitting unit 7 that is long in the horizontal direction can be excited efficiently.

  Further, as shown in FIG. 5B, the emission end 5a may be arranged in three stages only at the center of the laser light irradiation surface 7a. That is, the density of the plurality of emission end portions 5a arranged with respect to the laser light irradiation surface 7a of the light emitting unit 7 is biased in the laser light irradiation surface 7a. With this configuration, the central portion of the light-emitting portion 7 (the portion where the density of the emission end portion 5a is high) shines stronger than the other portions, so that the illuminance at the central portion of the region irradiated by the headlamp 1 can be increased.

  Further, a plurality of emission end portions 5a may be arranged in a matrix with respect to the entire surface of the laser light irradiation surface 7a of the light emitting unit 7. According to this configuration, the light emitting unit 7 can be excited efficiently and without unevenness.

(Positional relationship of laser light irradiation area)
A region where the laser beam emitted from one emitting end 5a is irradiated on the laser beam irradiation surface 7a of the light emitting unit 7 is referred to as a laser beam irradiation region. Since the optical fiber 5 has a plurality of emission end portions 5a, a plurality of laser light irradiation regions are also formed. FIG. 5A is a diagram showing a light intensity distribution of laser light emitted from the emission end portion 5a of the optical fiber 5, and FIG. 5B is a diagram showing a positional relationship between a plurality of laser light irradiation regions. . In FIG. 5A, the light intensity distribution of the laser light emitted from the emission end 5a of the optical fiber 51 constituting the optical fiber 5 is indicated by a curve 21, and the light of the laser light emitted from the emission end 5a of the optical fiber 52 is shown. The intensity distribution is shown by a curve 22. The horizontal axis of the graph in FIG. 5A indicates the position of the optical fiber 5, and the vertical axis indicates the light intensity of the laser light irradiated on the laser light irradiation surface 7a.

  As shown in FIG. 5A, the laser light emitted from one emitting end 5a reaches the laser light irradiation surface 7a while spreading at a predetermined angle. Therefore, even if the emission end portions 5a of the optical fibers 51 and 52 are arranged side by side in a plane parallel to the laser light irradiation surface 7a, as shown in FIG. The laser beam irradiation regions 23 and 24 formed by the laser beam 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 5a (near the central axes 21a and 22a shown in FIG. 5A) is the laser of the light emitting section 7. If the light is emitted to different portions of the light irradiation surface 7a, the laser light irradiation surface 7a can be irradiated in a two-dimensionally distributed manner.

  That is, the maximum light intensity portion (laser light) which is the portion having 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. The position of the central portion of the irradiation region may be different from the position of the maximum light intensity portion of the projection image derived from the other emission end 5a. Therefore, it is not always necessary to completely separate the laser light irradiation regions from each other.

(Structure of semiconductor laser 3)
Next, the basic structure of the semiconductor laser 3 will be described. FIG. 6A is 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 generally a compound semiconductor such as GaAs or GaN is used, but a group IV semiconductor such as Si, Ge and SiC, GaAs, GaP, InP, AlAs, GaN, InN III-V compound semiconductors typified by InSb, GaSb and AlN, II-VI compound semiconductors such as ZnTe, ZeSe, ZnS and ZnO, ZnO, Al ₂ O ₃ , SiO ₂ , TiO ₂ , CrO ₂ and CeO _It may be composed of any semiconductor such as an oxide insulator such as ₂ and a nitride insulator such as SiN. In particular, the substrate 18 is preferably a nitride semiconductor.

  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.

  The material of the active layer 111 includes undoped GaAs, GaP, InP, AlAs, GaN, InN, InSb, GaSb, and AlN group III-V compound semiconductors, ZnTe, ZeSe, ZnS, and ZnO. It may be composed of any of the II-VI compound semiconductors.

  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.

  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.

  The active layer 111 has 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. The front side cleaved surface 114 and the back side cleaved surface 115 are formed. Plays the role of a mirror.

  However, unlike a mirror that completely reflects light, when a part of the light amplified by stimulated emission is amplified to some extent, either the front side cleavage surface 114 or the back side cleavage surface 115 of the active layer 111 is selected. (In this embodiment, it is emitted from the front side cleavage surface 114 for the sake of convenience) and becomes 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 colors, or a mixture of two colors that satisfy the relationship of complementary colors, and based on this principle and relationship, the color and fluorescence of laser light oscillated from a semiconductor laser. White light can be generated by combining the color of light emitted by the body 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 .

(Effect of reflecting mirror made of resin)
In the conventional lighting device, the ultraviolet rays irradiated from the lamp and the heat generated by the lamp induce deformation and modification of the resin. Therefore, a metal material is used for the reflecting mirror and lens that are components of the lighting device. It was. For this reason, the lighting device has been increased in weight and price, which has been a factor in reducing the usability of the device.

  In consideration of the problem, the present inventors have found that the excitation light source (semiconductor laser 3) is used as the light source of the headlamp 1 and that the resin material is used for the reflecting mirror 8 and the lens 12. The wavelength range of the laser light emitted from the semiconductor laser 3 is the visible light range, and the wavelength range of the light emitted from the light emitting unit 7 upon receiving the laser light is from the visible light range to the near infrared range. The wavelength range of the light to be transmitted and the light transmitted through the lens 12 also changes from visible light to the near infrared range. Therefore, far-infrared rays (heat rays), which is a wavelength region that raises the temperature of the irradiated object, or light that does not contain ultraviolet rays, which is a wavelength region that fades or denatures the resin, is reflected by the reflecting mirror 8 and the lens 12. Will be transmitted. Therefore, even if the reflecting mirror 8 and the lens 12 are formed of a resin material, problems such as component deterioration of the resin material over time can be reliably avoided.

  And the following merit can be enjoyed by using a resin material. That is, by using the resin material, the light weight and low cost characteristics of the resin material can be directly connected to the weight reduction and price reduction of the headlamp 1. In addition, the design of the headlamp 1 can be enhanced by taking advantage of the high workability that is a characteristic of the resin material. Combined with such many advantages, the usability of the headlamp 1 can be enhanced for the user.

  Further, in the headlamp 1, the semiconductor laser 3 is provided outside the reflection space surrounded by the reflecting mirror 8 and the lens 12. Thereby, the following effects can be produced.

  Specifically, by providing the semiconductor laser 3 outside the reflection space surrounded by the reflecting mirror 8 and the lens 12, the volume required for the reflection space compared to the case where the semiconductor laser 3 is provided inside the reflection space. Can be reduced. That is, by providing the semiconductor laser 3 outside the reflection space, the size of the reflecting mirror 8 and the lens 12 is reduced, and accordingly, the weight of the reflecting mirror 8 and the lens 12 can be further reduced. As a result, the headlamp 1 can be further reduced in size and weight. In addition, since the amount of the resin material used is reduced, the advantage of further cost reduction of the headlamp 1 can be enjoyed.

  There are also voices concerned about the influence of heat generated from the semiconductor laser 3 on the resin-made reflecting mirror 8. With respect to this, by appropriately designing the optical fiber 5 that guides the laser light emitted from the semiconductor laser 3 to the light emitting unit 7, that is, by appropriately adjusting the length of the moving light unit and the like, What is necessary is just to install in the position away from 8 (namely, position which is easy to cool). Thereby, the situation where the heat generated from the semiconductor laser 3 affects the reflecting mirror 8 made of resin can be avoided. Further, if the length of the optical fiber 5 and the like can be adjusted as appropriate, the semiconductor laser 3 can be installed at a position where it can be easily replaced, so that the design flexibility of the headlamp 1 can be further increased.

  The headlamp 1 has the following effects. Specifically, in the headlamp 1, the light emitting part 7 can be fixed to the tip of the cylindrical part 15 made of a highly heat conductive member. Thereby, the heat generated in the light emitting unit 7 can be efficiently radiated to the outside of the reflection space via the cylindrical portion 15, and the problem that the light emitting unit 7 causes a malfunction due to the heat generated by itself can be obviated. It can be prevented.

  Furthermore, since a resin material can be used as the material of the reflecting mirror 8 and the lens 12, the reflecting mirror 8 and the lens 12 can be molded by injection molding. Therefore, since a finely formed mold can be used, it is possible to realize a headlamp 1 that is further reduced in size and weight.

  The headlamp 1 can also be suitably applied to a vehicle headlight. A headlight for a vehicle needs to satisfy the light distribution characteristic standard of a traveling headlamp (high beam), the light distribution characteristic standard of a low-pass headlight, and the like. In this respect, the headlamp 1 is characterized in that the semiconductor laser 3 is characterized by high brightness and high luminous flux. As described above, the headlamp 1 is excellent in usability, and is small and light. Therefore, it can be suitably applied to a vehicle headlight. And it is also possible to manufacture the lens 12 which is not a simple curved surface suitably according to the required light distribution characteristic.

  Furthermore, the headlamp 1 can also be suitably applied to a vehicle headlight for the following reasons. Specifically, the headlamp 1 is excellent in usability, and realizes a reduction in size and weight. Therefore, when the headlamp 1 is applied to a vehicle headlight, the degree of freedom in designing the vehicle can be greatly increased because of its high usability and miniaturization. Moreover, since the weight is reduced by using a resin material, the fuel efficiency of the vehicle is also improved. Such a headlamp 1 can be more suitably applied to a vehicle headlight against the background of the recent increase in environmental awareness.

(Effect of using semiconductor laser 3)
Conventionally, LEDs, halogen lamps, HID lamps (high-intensity discharge lamps), and the like are used as light sources for lighting devices.

However, various problems and problems have been pointed out with these light sources. For example, current LEDs or halogen lamps have low luminance and luminous flux per lamp, and require a plurality of lamps depending on the application such as a headlight for an automobile. Therefore, in such a case, the lighting device inevitably increases in size, for example, because it is necessary to increase the area of the condensing lens used in the lighting device or the mounting area of the light source. In addition, although the HID lamp exhibits high luminance of 60 to 80 cd / cm ² , a glass tube and two discharge electrodes are essential for light emission, and is not suitable for downsizing of the lighting device. Moreover, the HID lamp has a problem that it is difficult to achieve a configuration that exhibits high brightness when combined with an optical system. Specifically, two electrodes are extended to the vicinity of the light emitting point, and a glass tube is required to contain the atmospheric gas. Therefore, when combined with an optical system (reflecting mirror, lens), shadows appear. Therefore, there is a problem that the high brightness, which is a feature of the HID lamp, cannot be fully utilized.

  In this regard, the above-mentioned problems can be effectively solved by using a high-intensity light source combining a semiconductor laser (LD) and a phosphor for an illumination device. That is, by combining the LD and the phosphor, (a) because of the LD, it is possible to realize high luminance and high luminous flux while being ultra-compact, and (b) because the LD emits light, the excitation light can be transmitted to the light emitting unit 7 without waste. (C) Because of the high brightness, the optical system area of the headlamp can be reduced, thereby making it possible to reduce the size of the illuminating device. (D) The light emitting unit 7 is provided with the semiconductor laser 3. By converting the excitation light emitted by the light from coherent to incoherent light, it is possible to realize a lighting device that is gentle to the human eye (eye-safe).

[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. 8 is a schematic view showing the appearance of the light emitting unit 210 and the conventional LED downlight 300. FIG. 9 is a cross-sectional view of the ceiling where the laser downlight 200 is installed. FIG. 10 is a cross-sectional view of the laser downlight 200. As shown in FIGS. 8 to 10, 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. The LD light source unit 220 is not installed on the ceiling, but is installed at a position where the user can easily touch it (for example, a side wall of a house). The position of the LD light source unit 220 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. 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. 10, 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 is formed in the casing 211, and the optical fiber 5 extends 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 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. 8, the light emitting unit 210 has a circular outer edge, but the shape of the light emitting unit 210 (more strictly, 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. 10, 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 32) is accommodated in one LD light source unit 220. The LD light source unit 220 functions as a central power supply box.

(Example of changing the installation method of the laser downlight 200)
FIG. 11 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, only a small hole 402 through which the optical fiber 5 passes is formed in the top plate 400, and the laser downlight main body (light emitting unit) is utilized by taking advantage of the thin and light weight. 210) may be attached to the top board 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. 8, 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. 12 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 and a cooling unit 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 and a cooling unit for each light emitting unit 210, the laser downlight 200 can be reduced in size and thickness. As a result, the space restriction for installing the laser downlight 200 is reduced, and installation in an existing house is facilitated.

  As a modification of the laser downlight 200, as shown in FIG. 13, only a small hole through which an optical fiber can be passed is formed in the ceiling, and the laser downlight main body can be affixed to the ceiling taking advantage of the thin and lightweight features. . In this case, there are merits that restrictions on installation are reduced and construction costs can be significantly reduced.

  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. 13 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. 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 light source unit 220 including at least one semiconductor laser 2 that emits laser light, the light emitting unit 7 and the at least one light emitting unit 210 including the concave portion 212 as a reflecting mirror, and light emission. And an optical fiber 5 for guiding the laser beam to each of the units 210.

  A plurality of emission end portions 5b of the optical fiber 5 are arranged with respect to one light emitting unit 7 included in the light emitting unit 210, and light intensity distributions respectively possessed by laser beams emitted from the plurality of arranged emission end portions 5b. The portion with the highest light intensity is irradiated to the different portions of the light emitting units 7 to be arranged.

  Therefore, in the laser downlight 200, it is possible to reduce the possibility that the light emitting unit 7 is significantly deteriorated by irradiating the laser light to one place of the light emitting unit 7 in a concentrated manner. As a result, a long-life laser downlight 200 can be realized.

(Other effects)
Since the optical fiber 5 has flexibility, the arrangement of the emission end portion 5a with respect to the laser light irradiation surface 7a can be easily changed. 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, by setting the arrangement pattern of the plurality of emission end portions 5a with respect to the laser light irradiation surface 7a of the light emitting unit 7, the illuminance of the region illuminated by the light from the light emitting unit 7 can be changed in the region. .

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

  The light-emitting device (high-intensity light source) according to the present invention has 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.

  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. In addition, when an LED with high luminance and high luminous flux is developed in the future, it can naturally be suitably applied to the lighting device according to the present invention.

  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.

(Another expression of the present invention)
One embodiment of the present invention can also be expressed as follows.

  That is, an illumination device according to one embodiment of the present invention includes an excitation light source that emits excitation light, an incident end that receives excitation light emitted from the excitation light source, and the incident end. A light guide unit having an exit end that emits incident excitation light; and a light emitting unit that receives the excitation light emitted from the exit end and emits light in a wavelength range from visible light to near infrared. A light-emitting device, a resin-made reflecting mirror that forms a light bundle that travels within a predetermined solid angle by reflecting light emitted from the light-emitting section, and an opening formed in the direction in which the light bundle travels A transparent member made of resin through which the light beam passes, and the excitation light source is provided outside a reflection space surrounded by the reflecting mirror and the transparent member.

  According to said structure, the excitation light which the excitation light source radiate | emitted enters the incident end part of a light guide part, and is radiate | emitted from the output end part of a light guide part. When the excitation light is applied to the light emitting part, the light emitting part emits light. The light emitted from the light emitting unit is reflected by the reflecting mirror, and the light beam reflected by the reflecting mirror is transmitted through the transparent member.

  Here, since the wavelength range of the light emitted from the light emitting unit is the visible to near-infrared wavelength range, the wavelength of the light reflected by the reflecting mirror and the light transmitted through the transparent member is also changed from the visible light to the near-infrared range. Become. Therefore, far-infrared rays (heat rays), which is the wavelength range that raises the temperature of the object to be irradiated, or light that does not contain ultraviolet rays, which is the wavelength range that fades or denatures the resin, is reflected by the reflecting mirror and It will be transparent. Therefore, even if the reflecting mirror and the transparent member are formed of a resin material, problems such as component deterioration of the resin material over time can be reliably avoided.

  And the following merit can be enjoyed by using a resin material. That is, by using a resin material, the light weight and low cost characteristics of the resin material can be directly connected to the weight reduction and price reduction of the lighting device. In addition, it is possible to enhance the design of the lighting device by taking advantage of the high workability that is a characteristic of the resin material. Combined with such many advantages, the usability of the lighting device can be enhanced for the user.

  Furthermore, in the lighting device according to one embodiment of the present invention, the excitation light source is provided outside the reflection space surrounded by the reflecting mirror and the transparent member. Thereby, the following effects are obtained.

  Specifically, by providing the excitation light source outside the reflection space surrounded by the reflecting mirror and the transparent member, the volume required for the reflection space is reduced compared to the case where the excitation light source is provided inside the reflection space. be able to. That is, by providing the excitation light source outside the reflecting space, the reflecting mirror and the transparent member can be miniaturized, and accordingly, the reflector and the transparent member can be further reduced in weight. As a result, it is possible to further reduce the size and weight of the lighting device. In addition, since the amount of resin material used is reduced, it is possible to enjoy the merit of further reducing the price of the lighting device.

  There are voices concerned about the effect of heat generated from the excitation light source on the resin reflector. For this, by appropriately designing the light guide that guides the excitation light emitted by the excitation light source to the light emitting part, that is, by appropriately adjusting the length of the light guide, etc., the excitation light source is separated from the reflector. What is necessary is just to install in the position (that is, the position which is easy to cool). Thereby, it can avoid that the heat which generate | occur | produced from the excitation light source affects the resin-made reflecting mirrors. In addition, if the length of the light guide unit and the like can be adjusted as appropriate, the excitation light source can be installed at a position where it can be easily exchanged, so that the degree of freedom in designing the illumination device can be further increased.

  In this way, it is possible to provide a user with a lighting device that is excellent in usability and has been reduced in size and weight.

  Moreover, it is preferable that the said light emission part is hold | maintained by the high heat conductive member with high heat conductivity inside the said reflective space, and a part of said high heat conductive member protrudes outside the said reflective space.

  By providing the above configuration, the heat generated in the light emitting unit is efficiently radiated to the outside of the reflection space via the high thermal conductive member. Therefore, it is possible to prevent a problem in which heat generated from the light emitting unit accumulates in the reflection space and a problem occurs in the light emitting unit.

  The reflecting mirror is formed of at least one resin selected from polyethylene, polypropylene, vinyl chloride, pothistyrene, acrylonitrile / butadiene / styrene resin, phenol resin, epoxy resin, polyurethane resin, silicone resin, and the transparent member. Is preferably formed of at least one resin selected from polystyrene, acrylonitrile / styrene, acrylonitrile / butadiene / styrene resin, methacrylic resin, polyethylene terephthalate, epoxy resin, silicone resin, polycarbonate, and organic-inorganic hybrid glass. .

  As described above, the resin material forming the reflecting mirror does not need to have high resistance to high temperatures and ultraviolet rays. Therefore, any of general-purpose resin, general-purpose engineering resin, and super-engineering resin can be adopted as the resin material for forming the reflecting mirror. Among them, since general-purpose resins are relatively inexpensive and easy to process, polyethylene (PE), polypropylene (PP), vinyl chloride (PVC), and polystyrene (PS), which are called four major general-purpose resins, can be suitably used. it can.

  Also, as the material of the transparent member, since it is formed of a resin material having translucency, that is, an amorphous resin, polystyrene, acrylonitrile / styrene, acrylonitrile / butadiene / styrene resin, methacrylic resin, polyethylene terephthalate, epoxy resin Silicone resin, polycarbonate, organic-inorganic hybrid glass, and the like can be suitably used.

  Also, any one of the above lighting devices can be applied to a vehicle headlight.

  As described above, the lighting device of one embodiment of the present invention is excellent in usability and achieves a reduction in size and weight. Therefore, when the lighting device according to one embodiment of the present invention is applied to a headlight for a vehicle, the degree of freedom in design of the vehicle can be significantly increased because of its high usability and miniaturization. Moreover, since the weight is reduced by using a resin material, the fuel efficiency of the vehicle is also improved. Such a lighting device can be more suitably applied to a vehicle headlight against the background of the recent increase in environmental awareness.

  As described above, an illumination device according to one embodiment of the present invention emits excitation light that emits excitation light, an incident end that receives excitation light emitted from the excitation light source, and emits excitation light that is incident from the incident end. A light-emitting device comprising: a light-guiding unit having a light-exiting end; and a light-emitting unit that receives excitation light emitted from the light-emitting end and emits light in a wavelength range of near-infrared from visible light; and Reflecting the light emitted from the light emitting unit, a resin-made reflecting mirror that forms a light bundle that travels within a predetermined solid angle, and a member that covers the opening formed in the direction in which the light bundle travels, A transparent member made of resin through which the light beam passes, and the excitation light source is provided outside a reflection space surrounded by the reflecting mirror and the transparent member.

  Therefore, it is possible to provide a user with a lighting device that is excellent in usability and has been reduced in size and weight.

  The present invention relates to an illuminating device including a light emitting device that functions as a high-intensity light source, and can be suitably used particularly for a headlamp for a vehicle or the like.

1 Headlamp (lighting device)
2 Semiconductor laser array (excitation light source)
3 Semiconductor laser (excitation light source)
5 Optical fiber (light guide)
5a Emission end portion 5b Incident end portion 6 Ferrule 7 Light emitting portion 7a Laser light irradiation surface 8 Reflecting mirror 11 Extension 12 Lens (transparent member)
30 Semiconductor laser (excitation light source)
200 Laser downlight (lighting device)

Claims (5)

A semiconductor laser that emits laser light;
A light emitting unit that receives the laser light and emits light in a wavelength range from visible light to near infrared; and
A light projection member made of resin that projects the light emitted by the light emitting unit to the outside of the device,
The illumination device, wherein the semiconductor laser is provided apart from the light projection member.   The illumination device according to claim 1, wherein the semiconductor laser is provided at a position where heat generated by the semiconductor laser does not reach the light projection member.   The illumination device according to claim 1, further comprising an optical fiber that guides laser light emitted from the semiconductor laser to the light emitting unit.   The illuminating device according to any one of claims 1 to 3, wherein a wavelength of the laser beam is 400 nm or more.   The vehicle headlight provided with the illuminating device of any one of Claim 1 to 4.

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