JP5204885B2 - Lighting device and vehicle headlamp - Google Patents

Description

  The present invention relates to an illuminating device that combines an excitation light source such as a semiconductor laser and a light emitting unit such as a phosphor, and a vehicle headlamp including the illuminating device.

  Patent Documents 1 and 2 are known as illumination light sources that emit non-excitation light from a light emitting unit by irradiating the light emitting unit with excitation light from an excitation light source and use the non-excitation light as illumination light.

  In Patent Document 1, a laser diode (excitation light source) that emits short-wavelength laser light (excitation light), a collimator that uses the laser light from the laser diode as a parallel beam bundle, and a laser with a parallel beam bundle from the collimator A condenser for condensing light, a phosphor that absorbs laser light collected by the condenser and emits incoherent light as natural light, and the phosphor is substantially a focal point of a parabolic reflection surface or an elliptic reflection surface There is disclosed a light source device including a visible light reflecting mirror provided to be located at a position and a laser light reflecting mirror that reflects laser light that has passed through the phosphor and concentrates the laser light on the phosphor. In this light source device, the incoherent light emitted from the phosphor is reflected in a fixed direction by the visible light reflecting mirror to become illumination light.

  In Patent Document 2, a GaN-based semiconductor laser that emits a laser beam (excitation light) having a wavelength of 450 nm is used as an excitation light source, and fluorescence in the visible region (non-excitation light) is excited by the laser light from the excitation light source. A light emitting device in which a phosphor (light emitting unit) is combined with the excitation light source is disclosed.

JP 2003-295319 A (published on October 15, 2003) JP 2000-174346 A (published June 23, 2000)

  However, in Patent Documents 1 and 2, the excitation light from the excitation light source is emitted when the light emitting part is displaced from a predetermined location at some time or the optical axis of the excitation light source is shifted and the excitation light from the excitation light source does not hit the light emission part. Is emitted to the outside of the apparatus and the excitation light is irradiated to the human eye, the human eye may be harmed.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to emit non-excitation light from a light emitting unit by irradiating the light emitting unit with excitation light from an excitation light source, and An illumination device that is used as illumination light, and the excitation light from the excitation light source is outside the device even if the light emission unit is displaced or the optical axis of the excitation light source is shifted and the excitation light from the excitation light source does not hit the light emission unit. An object of the present invention is to provide an illuminating device that can be prevented from being emitted and a vehicle headlamp including the illuminating device.

  In order to solve the above problems, an illumination device according to the present invention includes an excitation light source that emits excitation light in one direction, a light emitting unit that emits non-excitation light upon receiving the excitation light, and the non-excitation light. And a reflection part that reflects in an illumination direction that is different from the emission direction of the excitation light.

  According to said structure, the excitation light from an excitation light source is converted into non-excitation light by a light emission part, and the non-excitation light is discharge | released as illumination light. Therefore, illumination light with high luminance can be obtained using the excitation light source.

  The light emission direction of the excitation light is set to a direction different from the illumination direction of the illumination light. Therefore, even if the position of the light emitting unit or the emission direction of the excitation light is shifted and the excitation light is separated from the light emitting unit, the excitation light is emitted in the illumination direction (that is, the excitation light is emitted as illumination light). Can be prevented.

  It is desirable to further include an excitation light termination unit that terminates the excitation light at a position facing the excitation light source via the light emitting unit.

  According to the above configuration, since the excitation light termination is disposed at a position facing the excitation light source via the light emitting unit, the position of the light emission unit is shifted, or the optical axis of the excitation light source is shifted and the excitation light is emitted from the light emission unit. If it is off, the excitation light from the excitation light source enters the excitation light termination and terminates.

  Therefore, even if the position of the light emitting unit is shifted or the optical axis of the excitation light source is shifted and the excitation light is separated from the light emitting unit, the excitation light can be prevented from being emitted to the outside of the illumination device.

  The excitation light termination is preferably an integrating sphere that scatters and attenuates the excitation light inside.

  According to said structure, the excitation light which injected into the excitation light termination | terminus part is scattered and attenuate | damped inside this, and is finally extinguished (namely, termination | terminus). Therefore, the pumping light termination unit can be configured with a simple configuration.

  The excitation light termination portion is formed so as to taper from the bottom surface side toward the opening portion side at the bottomed cylinder portion having an opening for entering the excitation light and the bottom surface of the bottomed cylinder portion, It is desirable that the tip end portion is sharp and the base end surface has a tapered portion having the same size as the bottom surface.

  According to the above configuration, the excitation light that has entered the excitation light terminal portion from the opening is repeatedly reflected between the inner surface of the bottomed cylindrical portion and the outer peripheral surface of the tapered portion, and is reflected on the inner side of the bottomed cylindrical portion. move on. In this excitation light terminal portion, the tip end portion of the taper portion is pointed, and the base end surface of the taper portion is the same size as the bottom surface of the bottomed tube portion (that is, the bottom surface of the bottomed tube portion is the taper portion). Completely occupied).

  Therefore, the excitation light that has entered the excitation light termination from the opening cannot be reflected to the opening within the excitation light termination, but is attenuated and finally disappears (ie, terminates) at each reflection. Therefore, the pumping light termination unit can be configured with a simple configuration.

  It is desirable that the excitation light termination portion has a light absorbing member that absorbs the excitation light from the excitation light source.

  According to said structure, since the said excitation light termination | terminus part has the light absorption member which absorbs the said excitation light from the said excitation light source, it can comprise an excitation light termination | terminus part by simple structure.

  It is desirable to further include an auxiliary illumination light source that emits auxiliary illumination light.

  According to the above configuration, when the light emitting unit is displaced from a predetermined place or the optical axis of the excitation light source is shifted and the excitation light from the excitation light source does not hit the light emitting unit, the illumination light does not come out from the device at all. Can be prevented.

  For this reason, a device for recognizing a person or / and an object that may occur in the case of a lighting device that does not have the above-described configuration is used for recognizing a person or / and an object, and / or the presence of the lighting device is known to surrounding people. When there is no light source that emits light to fix, it is possible to solve the problem that the object cannot be recognized and / or the presence of the lighting device cannot be informed to the surroundings.

  In other words, even when the non-excitation light is extinguished because the position of the light emitting unit is shifted or the excitation light is displaced from the light emitting unit due to the deviation of the optical axis of the excitation light source, the minimum illumination light can be secured by the auxiliary illumination light source.

  It is desirable that the auxiliary illumination light has a wavelength different from the wavelength of the excitation light.

  The illumination light is composed of combined light of non-excitation light emitted from the light emitting unit excited by excitation light and auxiliary illumination light.

  According to the above configuration, since the auxiliary illumination light has a wavelength different from the wavelength of the excitation light, the color temperature of the illumination light can be adjusted by adjusting the wavelength of the auxiliary illumination light.

  Also, since the color temperature varies with different wavelengths, the color temperature of the illumination light when the illumination light is composed of non-excitation light and auxiliary illumination light, and the case where the illumination light is composed only of the auxiliary illumination light It is different from the color temperature of the illumination light. Therefore, the presence or absence of a failure of the lighting device can be determined from the color temperature of the illumination light.

  It is desirable that the light emitting unit has a characteristic that the absorption rate for the excitation light is higher than the absorption rate for the auxiliary illumination light.

  In the light emitting unit, the higher the absorption rate for the excitation light, the higher the conversion efficiency for converting the excitation light into non-excitation light. Further, in the light emitting unit, the lower the absorptance with respect to the auxiliary illumination light, the higher the transmittance of the auxiliary illumination light that passes through the light emitting unit.

  Therefore, according to the above configuration, since the light absorption rate for the excitation light is higher than the light absorption rate for the auxiliary illumination light, the conversion efficiency for converting the excitation light into non-excitation light is relatively high. In addition, the transmittance with which the auxiliary illumination light passes through the light emitting portion is also relatively high. Therefore, it becomes easy to utilize auxiliary illumination light as illumination light together with non-excitation light without impairing the conversion efficiency of excitation light into non-excitation light.

  It is desirable to further include an excitation light cut filter disposed on the side of the illumination direction in the light emitting unit.

  According to said structure, the excitation light contained in illumination light is removed by the excitation light cut filter. Therefore, it can prevent that excitation light is mixed with illumination light and is inject | emitted outside.

  The auxiliary illumination light source preferably includes a light emitting element and a phosphor that emits white light by receiving light from the light emitting element.

  According to said structure, the auxiliary illumination light source can irradiate white auxiliary illumination light.

  Moreover, the vehicle headlamp provided with the said illuminating device is also contained in the technical scope of this invention. In this vehicle headlamp, the presence of the vehicle can be confirmed from the surroundings even if the excitation light source is not irradiated onto the light emitting unit.

  The illumination device of the present invention includes an excitation light source that emits excitation light in one direction, a light emitting unit that emits non-excitation light upon receiving the excitation light, and a direction different from the emission direction of the excitation light. And a reflecting portion that reflects in the illumination direction.

  Therefore, even if the position of the light emitting unit or the emission direction of the excitation light is shifted and the excitation light is separated from the light emitting unit, the excitation light is emitted in the illumination direction (that is, the excitation light is emitted as illumination light). The effect that can be prevented.

It is sectional drawing explaining the structure of the illuminating device which concerns on one embodiment of this invention. It is sectional drawing explaining the excitation light termination | terminus part of FIG. It is sectional drawing explaining the modification of an excitation light termination | terminus part. It is a perspective view explaining the other modification of an excitation light termination | terminus part. (A) is a schematic diagram showing a circuit diagram of a semiconductor laser, and (b) is a perspective view showing a basic structure of the semiconductor laser. It is sectional drawing explaining the structure of the illuminating device which concerns on other embodiment of this invention. It is explanatory drawing explaining the positional relationship of a light emission part, a metal plate, and the opening part for excitation light discharge | emission, (a) is the conceptual diagram seen from the direction of the arrow X of FIG. 6, (b) is a light emission part, It is a conceptual diagram explaining the method of arrangement | positioning on the opening part for excitation light discharge | release of a metal plate.

[Embodiment 1]
Hereinafter, embodiments of the present invention will be described in detail.

(1. Configuration)
An embodiment of the lighting device according to the present invention will be described below with reference to FIGS. 1 and 2.

  The illuminating device 1 of the present invention can be used for a headlamp that satisfies a light distribution characteristic standard of a traveling headlamp (high beam) for an automobile, for example. However, the lighting device of the present invention includes a headlamp that satisfies the light distribution characteristic standard of a low-beam headlight for automobiles, and vehicles / moving objects other than automobiles (for example, humans, ships, aircrafts, submersibles) -It may be realized as a headlamp of a rocket or the like. Further, as other lighting devices, for example, a searchlight, a projector, a home lighting device, a store lighting device, an office lighting device, and an outdoor lighting device may be realized.

  As shown in FIG. 1, the illumination device 1 includes an excitation light source 3 that emits excitation light C1, a light emitting unit 5 that receives the excitation light C1 and emits non-excitation light C3, and an auxiliary light that emits auxiliary illumination light C2. An illumination light source 7, a reflector (reflecting unit) 9 that irradiates illumination light C 4 composed of non-excitation light C 3 and auxiliary illumination light C 2 in a predetermined illumination direction H, and excitation light termination that terminates excitation light C 1 from the excitation light source 3. The unit 11 and the excitation light cut filter 13 for preventing the excitation light C1 from leaking outside the illumination device 1 are provided.

(Reflector 9)
The reflector 9 (reflecting portion) is formed in a parabolic shape that is rotationally symmetric about the center line L1. The inner surface 9a of the reflector 9 is a parabolic reflecting surface (parabolic reflecting surface) (hereinafter also referred to as a parabolic reflecting surface 9a). One end side of the reflector 9 in the direction of the center line L1 is open and serves as an illumination light opening 9b for emitting the illumination light C4 to the outside. That is, in the reflector 9, the light C2 and C3 from the light emitting unit 5 are reflected in the illumination direction H by the parabolic reflecting surface 9a and emitted from the opening 9b to the outside. The illumination direction H is parallel to the center line L1. The member of the reflector 9 may be, for example, a member having a metal thin film formed on the surface thereof, or a member made of metal, and a member having a high reflectance in the wavelength range of the illumination light C4. Is preferred.

(Light emitting part 5)
The light emitting unit 5 is disposed inside the reflector 9 (for example, a focal position). The light emitting unit 5 includes, for example, a phosphor (not shown) that is excited by receiving excitation light C1 from the excitation light source 3 and emits fluorescence (non-excitation light) C3, and a phosphor holding material (not shown) that seals the phosphor. (Not shown). The phosphor holding substance is preferably an inorganic material.

  More specifically, the light emitting unit 5 is one in which a phosphor is dispersed inside a low melting point glass as a phosphor holding material. The ratio between the low melting point glass and the phosphor is about 10: 1. In addition, the light emitting unit 5 may be one obtained by hardening a phosphor by an appropriate process, for example, one obtained by pressing and hardening a phosphor and applying heat treatment. The phosphor holding substance is not limited to the low melting point glass, and may be organic / inorganic hybrid glass (HBG), inorganic glass, or silicone resin.

  The phosphor is, for example, an oxynitride type or a nitride type, and blue, green, and red phosphors are divided into low-melting glass. As will be described later, the excitation light source 3 is configured, for example, as a semiconductor laser, and oscillates 405 nm (blue-violet) laser light. Therefore, when the light emitting unit 5 is irradiated with the laser light, white light is generated. Therefore, it can be said that the light emitting portion 5 is a wavelength conversion material.

  The semiconductor laser may oscillate 450 nm (blue) laser light (or so-called blue laser light having a peak wavelength in the wavelength range of 440 nm to 490 nm) as described above. In addition, 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.

Among the phosphors, for example, a green phosphor may be a so-called sialon. 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. It 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).

  Further, since this semiconductor nanoparticle phosphor is based on a semiconductor, it has a short fluorescence lifetime and can emit laser light power quickly as fluorescence, and thus has a feature that it is highly resistant to high power laser 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 conversion efficiency can be maintained for strong laser light, and heat generation from the phosphor can be reduced.

  Therefore, it is possible to further suppress deterioration (discoloration or deformation) of the light emitting unit 5 due to heat. Thereby, the lifetime of the light emission part 5 can be extended.

(Excitation light source 3)
The excitation light source 3 is configured as, for example, a semiconductor laser (hereinafter also referred to as a semiconductor laser 3), and emits (oscillates) laser light that is excitation light C1 (hereinafter also referred to as laser light C1) in one direction. As described above, the wavelength of the excitation light C1 is, for example, ultraviolet light or blue-violet light.

  As described above, the semiconductor laser 3 functions as an excitation light source that emits the laser light C1. Laser light (excitation light) C 1 is oscillated from the semiconductor laser 3. Of course, a plurality of semiconductor lasers 3 may be provided. In this case, laser light C1 is oscillated from each of the plurality of semiconductor lasers 3.

  The laser light C1 emitted from the semiconductor laser 3 is excitation light for exciting a phosphor that is a constituent element of the light emitting unit 5, and is coherent light having coherency. In general, coherent light is light that is spatially and temporally aligned in phase, and has a single wavelength.

  The semiconductor laser 3 has 10 light emitting points (10 stripes) in one chip, and oscillates a laser beam of, for example, 405 nm (blue violet), an output of 11.2 W, an operating voltage of 5 V, and a current of 6.4 A. It is mounted on a stem having a diameter of 15 mm. If the laser beam C1 is output from the semiconductor laser 3 at 11.2 W described above, the power consumption is 32 W (5 V × 6.4 A). Of course, the laser beam C1 oscillated by the semiconductor laser 3 is not limited to 405 nm, but may be any laser beam having a peak wavelength in the wavelength range of 400 nm to 420 nm.

  Further, the laser beam C1 emitted from the semiconductor laser 3 may be a laser beam having a peak wavelength in a wavelength range of 420 nm or more, for example, a blue (450 nm) laser beam or a blue wavelength range (440 to 490 nm or less). Good.

  FIG. 5A schematically shows a circuit diagram of the semiconductor laser 3, and FIG. 5B is a perspective view showing a basic structure of the semiconductor laser 3. As shown in the figure, the semiconductor laser 3 has a configuration in which a cathode electrode 23, a substrate 22, a clad layer 113, an active layer 111, a clad layer 112, and an anode electrode 21 are laminated in this order.

The substrate 22 is a semiconductor substrate, and it is preferable to use GaN, sapphire, or SiC in order to obtain blue to ultraviolet laser 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 21 is for injecting a current into the active layer 111 through the cladding layer 112.

  The cathode electrode 23 is for injecting current into the active layer 111 from the lower part of the substrate 22 through the clad layer 113. The current is injected by applying a forward bias to the anode electrode 21 and the cathode electrode 23.

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

  As a material for the active layer 111 and the cladding layer, a mixed crystal semiconductor made of AlInGaN is used to obtain blue to ultraviolet laser 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 occurs due to 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 laser beam 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 laser light L0 can be irradiated from the light emitting point 116 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 21 and the cathode electrode 23, 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.

  The excitation light source 3 is disposed at a predetermined position outside the reflector 9 (more specifically, a position outside the excitation light incident opening 9c provided in the reflector 9), and emits light through the opening 9c. Laser light C <b> 1 is emitted toward the unit 5.

  Here, as shown in FIG. 1, the opening 9 c is formed at a location including a point where a predetermined virtual line L <b> 2 passing through the focal position P <b> 1 of the reflector 9 and orthogonal to the center line L <b> 1 passes through the reflector 9. In addition, the formation position of the opening 9c is not limited in this way. As long as the emission direction of the laser light C <b> 1 emitted from the excitation light source 3 is different from the illumination direction H, the excitation light incident opening 9 c may be formed at any location of the reflector 9. That is, the excitation light source 3 may be disposed at any location outside the reflector 9 as long as the emission direction of the laser light C1 emitted from the excitation light source 3 is different from the illumination direction H.

  The excitation light termination unit 11 terminates the excitation light C <b> 1 emitted from the excitation light source 3 and passed without being absorbed by the light emitting unit 5.

  The term “termination” means that the excitation light C1 is terminated at the end of an effective optical path with a diffuse reflector or absorber having an appropriate reflectance and appropriate thermal characteristics. Here, the appropriate reflectance is a reflectance such that even if the excitation light C1 is reflected, the output of the reflected excitation light C1 is an output that does not harm humans. Appropriate thermal characteristics indicate that the local heat generated when the excitation light C1 is absorbed has a thermal conductivity that can be diffused to such an extent that the excitation light termination unit 11 is not destroyed.

(Excitation light termination unit 11)
The excitation light termination unit 11 is disposed at a position of the reflector 9 that faces the excitation light source 3 through the light emitting unit 5. An excitation light discharge opening 9d is formed at the position where the reflector 9 is disposed.

  Here, the pumping light termination unit 11 is configured as a beam damper 11A as shown in FIG. 2, for example. The beam damper 11A is formed on the bottomed cylinder part 11b having an opening 11a for receiving the excitation light C1, the tapered part 11c formed on the bottom surface 11e of the bottomed cylinder part 11b, and the outer surface of the bottomed cylinder part 11b. The heat dissipating fin 11d is provided.

  The bottomed cylinder portion 11b is arranged so that the cylinder axis direction L3 thereof is parallel to the opposing direction (the same direction as L2) of the excitation light termination portion 11 (that is, the beam damper 11A) and the excitation light source 3. Moreover, the opening part 11a of the bottomed cylinder part 11b is arrange | positioned so as to oppose the opening part 9d for excitation light discharge | emission.

  The taper portion 11c is formed so as to taper from the bottom surface 11e side of the bottomed tube portion 11b toward the opening portion 11a along the tube axis direction L3. The front end portion 11f is pointed, and the base end surface 11g is formed in the same size as the bottom surface 11e. That is, the distance between the inner side surface 11h of the bottomed cylindrical portion 11b and the outer peripheral surface 11i of the tapered portion 11c becomes narrower from the opening 11a side to the bottom surface 11e side, and becomes zero on the bottom surface 11e. Thereby, the excitation light C1 incident on the inside of the beam damper 11A from the opening portion 11a is repeatedly reflected between the inner side surface 11h of the bottomed cylindrical portion 11b and the outer peripheral surface 11i of the tapered portion 11c, so that the opening portion 11a side. Without being reflected, the light propagates to the bottom of the bottomed cylindrical portion 11b, attenuates and disappears.

  In addition, the black coating (black non-reflective coating) which makes the excitation light C1 non-reflective may be given to the inner surface 11h of the bottomed cylinder part 11b, and the outer peripheral surface 11i of the taper part 11c. Thereby, the effect of attenuating the excitation light C1 can be enhanced.

  It should be noted that the aperture 11a has a diameter that the excitation light C1 emitted from the excitation light source 3 and transmitted through the light emitting portion 5 is incident on the inside of the beam damper 11A even when the emission direction of the excitation light C1 of the excitation light source 3 is deviated. Therefore, it is desirable to set the size appropriately.

(Auxiliary illumination light source 7)
The auxiliary illumination light source 7 is composed of, for example, a light emitting diode. The auxiliary illumination light source 7 emits light (for example, blue light or blue-violet light) having a wavelength different from the wavelength (for example, ultraviolet light or blue-violet light) of the excitation light C1 emitted from the excitation light source 3 as auxiliary illumination light C2.

  Here, the auxiliary illumination light source 7 emits natural light (non-excitation light), but may emit excitation light.

  The auxiliary illumination light source 7 may include a light emitting element that emits natural light and a phosphor that emits white light upon receiving light from the light emitting element. Thereby, white light can be emitted from the auxiliary illumination light source 7. Thereby, when the light emission part 5 slip | deviates and the illumination light C4 becomes only the auxiliary illumination light C2 from the auxiliary illumination light source 7, white illumination light C4 can be discharge | released.

  The auxiliary illumination light source 7 is disposed at a predetermined position outside the reflector 9 (more specifically, a position facing the auxiliary illumination light incident opening 9e formed in the reflector 9), and through the opening 9e. The auxiliary illumination light C <b> 2 is emitted toward the light emitting unit 5.

  Here, the opening 9e is formed at the apex of the reflector 9 (that is, a location including a point where a virtual line L4 passing through the focal position P1 of the reflector 9 and parallel to the center line L1 passes through the reflector 9). In addition, the formation position of the opening 9e is not limited in this way. The opening 9e may be formed at any position as long as the auxiliary illumination light C2 emitted from the auxiliary illumination light source 7 through the opening 9e can irradiate the light emitting unit 5.

(About the absorptance with respect to the excitation light C1 and the auxiliary illumination light C2 of the light emission part 5)
The light emitting unit 5 has a characteristic that the absorption rate with respect to the excitation light C1 is higher than the absorption rate with respect to the auxiliary illumination light C2. For example, when the auxiliary illumination light C2 from the auxiliary illumination light source 7 is blue light or blue-violet light and the excitation light C1 from the excitation light source 3 is ultraviolet light or blue-violet light, the phosphor is excited by ultraviolet light or blue-violet light. It is preferable that the external quantum efficiency is high (at least 60% or more) and the absorption rate of blue or blue-violet light is 40% or less.

  In this case, in the light emission part 5, the conversion efficiency which converts excitation light C1 into non-excitation light becomes high, so that the absorption factor with respect to excitation light C1 is high. Moreover, in the light emission part 5, the transmittance | permeability which the auxiliary illumination light C2 permeate | transmits the light emission part 5 becomes so high that the absorption factor with respect to the auxiliary illumination light C2 is low, and the auxiliary illumination light C2 is utilized as illumination light C4 with non-excitation light. It becomes easy.

  That is, the light emitting unit 5 has a relatively high conversion efficiency for converting the excitation light C1 into the non-excitation light, while the transmissivity through which the auxiliary illumination light C2 passes through the light emitting unit 5 is also relatively high. Therefore, the auxiliary illumination light C2 can be easily used as illumination light together with the non-excitation light without impairing the conversion efficiency of the excitation light C1 into the non-excitation light.

(Excitation light cut filter 13)
The excitation light cut filter 13 is disposed so as to cover the illumination light opening 9 b of the reflector 9. That is, the excitation light cut filter 13 is arranged on the illumination direction H side when viewed from the light emitting unit 5.

  The excitation light cut filter 13 has a transmittance of 10% for the excitation light C1 emitted from the excitation light source 3 in order to prevent the excitation light C1 emitted from the excitation light source 3 from being emitted outside the illumination device 1. It is desirable that the transmittance of the auxiliary illumination light C2 emitted from the auxiliary illumination light source 7 is 70% or more. The excitation light cut filter 13 may not be provided.

(2. Operation)
Next, based on FIG. 1, operation | movement of this illuminating device 1 is demonstrated.

  Excitation light C1 emitted from the excitation light source 3 is applied to the light emitting unit 5 in the reflector 9 through the opening 9c. Most of the excitation light C1 from the excitation light source 3 is absorbed by the light emitting unit 5 and excites the phosphor. The fluorescence (non-excitation light) C3 is emitted in all directions from the light emitting unit 5 excited by the excitation light C1, and the fluorescence C3 is converged in the illumination direction H by the parabolic reflection surface 9a of the reflector 9 to be excited. It passes through the light cut filter 13 and is emitted from the opening 9 b of the reflector 9 to the outside of the illumination device 1.

  At that time, a part of the excitation light C 1 from the excitation light source 3 is not absorbed by the light emitting unit 5 but is scattered or diffused by the light emitting unit 5 and converged in the illumination direction H by the parabolic reflection surface 9 a of the reflector 9. And is absorbed by the excitation light cut filter 13. Thereby, the excitation light C1 scattered or diffused by the light emitting unit 5 is prevented from being emitted to the outside of the illumination device 1.

  In addition, a part of the excitation light C1 from the excitation light source 3 (excitation light C1 that has not been absorbed by the light emitting unit 5) passes through the light emitting unit 5 and passes through the opening 9d of the reflector 9 to be the excitation light termination unit 11. And is absorbed by the excitation light termination unit 11 and terminates. Thereby, the excitation light C1 emitted from the excitation light source 3 and transmitted through the light emitting unit 5 is prevented from being reflected by the parabolic reflection surface 9a of the reflector 9 and emitted to the outside of the illumination device 1. It should be noted that some of the excitation light C1 that has not been absorbed by the light emitting unit 5 is scattered or diffused by the light emitting unit 5, and as a result, is not directed toward the excitation light terminal unit 11, but is reflected along the illumination direction H. There is also light traveling toward the opening 9b.

  On the other hand, the auxiliary illumination light C2 emitted from the auxiliary illumination light source 7 is irradiated to the light emitting unit 5 in the reflector 9 through the opening 9e, and is transmitted through the light emitting unit 5, scattered in the light emitting unit 5, or the light emitting unit 5. The illumination light C4 is formed together with the fluorescent light C3 emitted from the light emitting part 5 through any of the reflections on the surface or a combination of them, and emitted from the opening 9b of the reflector 9 to the outside.

  The auxiliary illumination light C2 transmitted through the light emitting unit 5 is not reflected by the parabolic reflection surface 9a of the reflector 9, but propagates in the illumination direction H and is emitted to the outside together with the fluorescence C3 from the opening 9b of the reflector 9. The Further, the auxiliary illumination light C2 scattered or reflected by the light emitting unit 5 is reflected in the illumination direction H by the parabolic reflection surface 9a of the reflector 9, and is emitted to the outside together with the fluorescence C3 from the opening 9b of the reflector 9.

  As described above, in the illumination device 1, the illumination light C <b> 4 is configured by the combined light of the fluorescence C <b> 3 emitted from the light emitting unit 5 and the auxiliary illumination light C <b> 2 transmitted, scattered, or reflected by the light emitting unit 5. That is, the illumination light C4 is constituted by a color mixture of the fluorescence C3 and the auxiliary illumination light C2.

(Main effect)
With this configuration, the illuminating device 1 is a illuminating device that is safe for human eyes because the highly coherent laser beam C1 is not emitted outside the illuminating device 1. Even if the light emitting unit 5 is displaced, the excitation light cut filter 13 and the excitation light termination unit 11 are provided, so that the excitation light C1 is not emitted to the outside of the illumination device 1.

  The auxiliary illumination light C2 from the auxiliary illumination light source 7 is emitted to the outside regardless of whether or not the light emitting unit 5 is at a desired position. Even when the light emitting unit 5 is deviated from a predetermined position, it is emitted to the outside of the illumination device 1, and therefore it is possible to prevent the illumination light C <b> 4 from being emitted from the illumination device 1. Thereby, even when the light emitting unit 5 is displaced from a predetermined position and the fluorescent light C3 is not emitted from the light emitting unit 5, the presence of the lighting device 1 can be notified to the surroundings.

  In addition, since the color temperature of the illumination light C4 differs depending on whether or not the illumination light C4 includes the fluorescence C3, the user of the illumination device 1 (driving state of the excitation light source 3, at least from the excitation light source 3) Notifying a person other than the person who can control the on / off of the emission of the excitation light C1 by his / her own will to notify the abnormality of the illumination device 1 (positional deviation of the light emitting part 5, an abnormality such as opening of a hole in the light emitting part 5). it can.

  Moreover, the chromaticity of the illumination light C4 can be changed by arbitrarily adjusting the output (that is, the wavelength) of the auxiliary illumination light C2 from the auxiliary illumination light source 7.

  In the illumination device 1, for example, the color temperature of the fluorescence C3 emitted from the light emitting unit 5 is increased while exciting the light emitting unit 5 with excitation light C1 having a wavelength of around 405 nm or less (or light in the blue region). As a purpose, the light emitting unit 5 is irradiated with the blue laser light C2, and the light emitting unit 5 scatters and diffuses the blue laser light C2, thereby making the fluorescence C3 emitted from the light emitting unit 5 incoherent.

  Thereby, the color temperature of the fluorescence C3 emitted from the light emitting unit 5 can be improved without increasing the light emitting unit 5 of the lighting device 1. Thereby, it is possible to increase the color temperature while maintaining a high luminance light emission characteristic. In addition, while a highly efficient blue phosphor has not been easily developed, it is possible to realize a solid illumination device with high efficiency, high color temperature, and good color rendering.

(Modification 1)
In the above embodiment, the pumping light termination unit 11 is configured as the beam damper 11A. In this modification, the pumping light termination unit 11 is configured as an integrating sphere 11B that scatters and attenuates the pumping light C1 therein. Is done.

  As shown in FIG. 3, the integrating sphere 11B is formed in a hollow sphere shape, and has a small light entrance 11j through which the excitation light C1 is incident. The integrating sphere 11B is disposed outside the reflector 9 so that the light incident port 11j faces the opening 9d of the reflector 9. Thereby, the excitation light C1 that has passed through the light emitting portion 5 and entered the opening 9d can be made incident into the integrating sphere 11B from the light incident port 11j.

  In the integrating sphere 11B, the excitation light C1 incident on the inside of the integrating sphere 11B from the light incident port 11j is scattered and attenuated inside the integrating sphere 11B and disappears.

  Note that a powder material such as black that absorbs the excitation light C1 may be applied to the inner surface of the integrating sphere 11B. Thereby, the excitation light C1 in the integrating sphere 11B can be attenuated more effectively.

(Modification 2)
In the above embodiment, the pumping light termination unit 11 is configured as the beam damper 11A. In this modification, the pumping light termination unit 11 is formed by a light absorbing member 11C that absorbs the pumping light C1. For example, as shown in FIG. 4, the light absorbing member 11C is formed as a laser curtain (that is, a sheet member made of a light absorbing material such as soft vinyl chloride). The light absorbing member 11 </ b> C is disposed outside the reflector 9 so as to face the opening 9 d of the reflector 9. Thereby, the excitation light C1 that has passed through the light emitting portion 5 and entered the opening 9d can be absorbed and extinguished by the light absorbing member 11C.

  Here, the light absorbing member 11C has been described as having a sheet shape, but is not limited to a sheet shape.

[Embodiment 2]
Next, a second embodiment of the present invention will be described. FIG. 6 is a schematic configuration diagram of an illumination apparatus according to Embodiment 2 of the present invention. In addition, about the member similar to Embodiment 1, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The difference between the illumination device 30 according to the second embodiment of the present invention and the illumination device 1 according to the first embodiment is that, instead of the reflector 9, a parabolic mirror (reflecting portion) 41 and a metal plate (reflecting portion) 42 are used. It is a point provided with. Further, in place of the excitation light termination unit 11, an excitation light termination unit 44 is provided.

(Parabolic mirror 41)
The parabolic mirror 41 reflects the fluorescence (non-excitation light) C3 generated by the light emitting unit 5, and forms a light bundle (illumination light) that travels within a predetermined solid angle. The parabolic mirror 41 may be, for example, a member having a metal thin film formed on the surface thereof or a metal member.

  A part of the parabolic mirror 41 is disposed above the upper surface of the light emitting unit 5. That is, the parabolic mirror 41 is disposed at a position covering the upper surface of the light emitting unit 5. If it demonstrates from another viewpoint, a part of side surface of the light emission part 5 has faced the direction of the opening part 51 for illumination light which is one opening part of the parabolic mirror 41. FIG.

  By making the positional relationship between the light emitting unit 5 and the parabolic mirror 41 as described above, the efficiency of condensing the non-excitation light C3 of the light emitting unit 5 within a predetermined solid angle can be increased. The utilization efficiency of the light C3 can be increased.

  The excitation light source 3 is arranged outside the parabolic mirror 41, and the parabolic mirror 41 is formed with an excitation light incident opening 52 through which the laser light C1 passes. The excitation light incident opening 52 is a hole penetrating the outside (excitation light source 3 side) and the inside (light emitting unit 5 side) of the parabolic mirror 41.

  On the other hand, the auxiliary illumination light C2 emitted from the auxiliary illumination light source 7 is applied to the light emitting unit 5 in the parabolic mirror 41 through the auxiliary illumination light incident opening 54 which is the other opening of the parabolic mirror 41, and emits light. The illumination light C4 is transmitted together with the non-excitation light C3 emitted from the light emitting unit 5 through any one of transmission through the unit 5, scattering in the light emitting unit 5 and reflection on the surface of the light emitting unit 5 or a combination thereof. It is configured to be emitted to the outside from the opening 51 of the parabolic mirror 41.

  Instead of the parabolic mirror 41, an elliptical mirror or a hemispherical mirror may be used.

(Metal plate 42)
The metal plate 42 is a plate-like support member that supports the light emitting unit 5 and is made of metal (for example, copper or iron). Therefore, the metal plate 42 has high thermal conductivity and can cool the light emitting unit 5. In addition, the member which supports the light emission part 5 is not limited to what consists of metals, The member containing substances (glass, sapphire, etc.) with high heat conductivity other than a metal may be sufficient.

  A metal thin film 43 is deposited on the surface of the metal plate 42 on the side of the parabolic mirror 41 (excluding the attachment surface of the light emitting unit 5), and the non-excitation light C3 emitted from the light emitting unit 5 is reflected. . The excitation light C1 incident from the upper surface of the light emitting unit 5 can be reflected after being converted into the non-excitation light C3 and directed toward the parabolic mirror 41 side. In this way, the utilization efficiency of the non-excitation light C3 can be improved.

  Since the metal plate 42 is covered with the parabolic mirror 41, it can be said that the metal plate 42 has a surface facing the reflecting surface of the parabolic mirror 41. The surface of the metal plate 42 on the parabolic mirror 41 side is substantially parallel to the rotation axis of the parabolic mirror 41 and substantially includes the rotation axis.

  Although not shown, the metal plate 42 may include fins. The fins function as a cooling unit that cools the metal plate 42. The fin has a plurality of heat dissipation plates, and increases the heat dissipation efficiency by increasing the contact area with the atmosphere. The cooling unit that cools the metal plate 42 may have a cooling (heat radiation) function, and may be a heat pipe, a water cooling method, or an air cooling method instead of the fins.

(Excitation light termination 44)
The excitation light termination portion 44 is disposed on the metal plate 42 at a position facing the excitation light source 3 through the light emitting portion 5. An excitation light discharge opening 53 is formed at the arrangement position of the metal plate 42. Note that the structure of the pumping light termination unit 44 is the same as that of the pumping light termination unit 11 of the first embodiment, and description thereof will not be repeated here.

  FIG. 7 is an explanatory diagram for explaining the positional relationship among the light-emitting portion 5, the metal plate 42, and the excitation light discharge opening 53. FIG. 7A is a conceptual diagram viewed from the direction of the arrow X in FIG. () Is a conceptual diagram illustrating how the light emitting unit 5 is disposed on the excitation light discharging opening 53 of the metal plate 42. As shown in FIG. 7, the light emitting unit 5 is disposed on the excitation light discharge opening 53.

  Part of the excitation light C1 from the excitation light source 3 (excitation light C1 that has not been absorbed by the light emitting unit 5) passes through the light emitting unit 5 and enters the excitation light termination unit 44 through the opening 53 of the metal plate 42. Incident light is absorbed by the pumping light termination 44 and terminates. Accordingly, the excitation light C1 emitted from the excitation light source 3 and transmitted through the light emitting unit 5 is prevented from being reflected by the parabolic mirror 41 and the metal plate 42 and emitted to the outside of the illumination device 30.

  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.

  The present invention can be used for a vehicle headlamp or the like.

DESCRIPTION OF SYMBOLS 1, 30 Illuminating device 3 Excitation light source 5 Light emission part 7 Auxiliary illumination light source 9 Reflector (reflection part)
9a Inner surface 9b, 51 Illumination light opening 9c, 52 Excitation light incident opening 9d, 53 Excitation light discharge opening 9e, 54 Auxiliary illumination light incident opening 11, 44 Excitation light termination 11B Integrating sphere 11C Light Absorbing member 11a Opening portion 11b Bottomed cylindrical portion 11c Tapered portion 11d Heat radiation fin 11e Bottom surface 11f Tip portion 11g Base end surface 11h Inner side surface 11i Outer peripheral surface 11j Light incident port 13 Excitation light cut filter 41 Parabolic mirror (reflection portion)
42 Metal plate (reflective part)
43 Metal thin film C1 Excitation light C2 Auxiliary illumination light C3 Non-excitation light C4 Illumination light H Illumination direction L1 Center line

Claims (7)

An excitation light source that emits excitation light in one direction;
A light-emitting unit that receives the excitation light and emits non-excitation light;
A reflector that reflects the non-excitation light in an illumination direction that is different from the emission direction of the excitation light;
An excitation light termination unit that terminates the excitation light at a position facing the excitation light source via the light emitting unit;
With
Said excitation optical termination unit, the lighting device comprising an integrating sphere der Rukoto be attenuated therein in scatter the excitation light. The illumination device according to claim 1, further comprising an auxiliary illumination light source that emits auxiliary illumination light. The illumination apparatus according to claim 2 , wherein the auxiliary illumination light has a wavelength different from a wavelength of the excitation light. The light emitting portion, than the absorption rate for the auxiliary illumination light, the illumination device according to claim 2 or 3, characterized in that it has a high characteristic towards the absorptance with respect to the excitation light. The illumination device according to any one of claims 1 to 4 , further comprising an excitation light cut filter disposed on the side of the illumination direction in the light emitting unit. The auxiliary illumination light source is
A light emitting element;
A phosphor that emits white light in response to light from the light emitting element;
The lighting device according to claim 2 , wherein: A vehicular headlamp comprising the lighting device according to any one of claims 1 to 6 .

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