JP6297268B2 - Lighting device - Google Patents

Description

  The present invention relates to a lighting device and a projector.

  In recent years, semiconductor light emitting devices such as LEDs (Light Emitting Diodes) and LDs (Laser Diodes) are used as excitation light sources, and the light emitted from these excitation light sources is irradiated onto a light emitting unit containing a fluorescent material to provide incoherent illumination. Research on light-emitting devices that generate light has been conducted.

  Among these, in lamps and lighting devices where a high-intensity light source is desired, a configuration in which a semiconductor laser is used as an excitation light source has been proposed. Since the laser light oscillated from the semiconductor laser is coherent light, the directivity is high, and the laser light can be condensed without waste as excitation light and used as excitation light.

Patent Document 1 includes a semiconductor light emitting element and a projection lens that receives blue light emitted from the semiconductor light emitting element and projects white light to the front of the vehicle. There is disclosed a vehicular lamp in which a diffusing portion for diffusing blue light incident on is formed. Patent Document 2 discloses an illumination device that obtains illumination light by exciting a phosphor with laser light having a visible color band and mixing laser light and fluorescence emitted from the phosphor. An illuminating device characterized in that a light mixing layer is provided on the surface is disclosed.
Patent Document 3 discloses a semiconductor laser element that emits laser light, a light emitting part that emits fluorescence obtained by wavelength-converting a part of the laser light emitted from the semiconductor laser element, and a light emitting part. A headlamp system including a diffusion plate that mixes laser light and fluorescence contained in illumination light is disclosed. That is, the techniques described in Patent Documents 1 to 3 are common in that the uniformity of the color of the illumination light is improved by scattering the laser light or the projected light.

JP 2012-119173 A (released on June 21, 2012) JP 2012-054084 A (published March 15, 2012) JP2013-026161A (released on Feb. 04, 2013)

  However, the prior art as described above improves the uniformity of the color of the projected light by diffusing and mixing the laser light or the projected light, so that the spread of the projected light increases. There is a problem that the apparent light source size becomes large.

  That is, in the techniques described in Patent Documents 1 to 3, instead of improving the uniformity of the color of the light to be projected, the laser light is used as the excitation light for exciting the phosphor, so that a small light source or a narrow light projection can be used. The advantage of realizing a high-intensity light source is impaired.

  The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide an illumination device and a projector that use a high-intensity light source, in which color unevenness is reduced.

In order to solve the above-described problem, an illumination device according to one embodiment of the present invention includes a laser light source that emits laser light, and a light-emitting unit that includes a phosphor that emits fluorescence by receiving the laser light emitted from the laser light source. And an optical system that radiates light emitted from the light emitting unit to the outside, and there are a plurality of the light projectors, and the number of light projected from the light projectors overlaps each other. The number is the same as the number of the projectors, the number of types of the phosphors is 2 or more, and the number of the plurality of projectors is 4 or more.
In order to solve the above problems, an illumination device according to one embodiment of the present invention includes a light source including a laser light source that emits laser light and a phosphor that emits fluorescence by receiving the laser light emitted from the laser light source. parts and comprises a projector having an optical system, each emitting light the emitting portion is emitted to the outside, the projector, the number of kinds of the phosphors included in the light emitting portion and the same number or more, a plurality The regions that are present and irradiated with the light projected from the plurality of projectors match each other, and the number of phosphor types is two or more.
In order to solve the above problems, an illumination device according to one embodiment of the present invention includes a light source including a laser light source that emits laser light and a phosphor that emits fluorescence by receiving the laser light emitted from the laser light source. parts and comprises a projector having an optical system, each emitting light the emitting portion is emitted to the outside, the projector is often one or more than the number of kinds of the phosphors included in the light emitting portion, And, there are a plurality of light emitted from the plurality of projectors so that one or more light beams overlap each other more than the number of phosphor types, and the number of phosphor types is 3 or more.

  In addition, a projector according to an aspect of the present invention includes a laser light source that emits laser light, a light emitting unit that emits light by the laser light emitted from the laser light source, and light emitted from the light emitting unit from a plurality of light emission surfaces. An optical system that radiates to the outside, and projects the light radiated from the plurality of light emitting surfaces to the outside by overlapping each other.

  Further, a projector according to an aspect of the present invention includes a laser light source that emits laser light, a light emitting unit that emits light by the laser light emitted from the laser light source, and a reflecting mirror that reflects light emitted from the light emitting unit; The reflecting surface of the reflecting mirror has a plurality of reflecting structures, and the lights reflected by the plurality of reflecting structures are superimposed on each other and projected to the outside.

  In addition, a projector according to an aspect of the present invention includes a laser light source that emits laser light, a light emitting unit that emits light by the laser light emitted from the laser light source, and a light projection that emits light emitted from the light emitting unit to the outside. The projection lens has a plurality of refractive structures on an incident surface on which the light emitted from the light emitting portion is incident, and the light refracted by the plurality of refractive structures is superposed on each other. To the outside.

  According to said structure, there exists an effect that the illuminating device and projector as a high-intensity light source which utilized the laser beam as excitation light and improved the uniformity of the color of the light to project can be provided. .

It is a figure which shows schematic structure of the headlamp which concerns on embodiment of this invention. It is sectional drawing which shows an example of the structure of the light projector used for the headlamp which concerns on embodiment of this invention. (A) is a figure which shows the circuit diagram of a semiconductor laser typically, (b) is a perspective view which shows the basic structure of a semiconductor laser. It is a figure which shows schematic structure of the headlamp which concerns on the 2nd Embodiment of this invention. It is sectional drawing which shows an example of the structure of the projector used for the headlamp which concerns on the 2nd Embodiment of this invention. It is sectional drawing which shows an example of the structure of the projector which concerns on the 3rd Embodiment of this invention. It is a front view which shows the basic structure of the reflector of the projector shown in FIG. 6, and arrangement | positioning of a holding member. It is sectional drawing which shows the example of a shape of the reflector shown in FIG. It is sectional drawing which shows an example of the structure of the projector which concerns on the 4th Embodiment of this invention. It is sectional drawing which shows the example of the micro reflection structure provided in the reflector of the projector shown in FIG. It is sectional drawing which shows an example of the structure of the projector which concerns on the 5th Embodiment of this invention. It is sectional drawing which shows the example of the micro refraction structure provided in the light projection lens of the light projector shown in FIG.

Embodiment 1
The embodiment of the present invention will be described below with reference to FIGS. In FIG. 1, as an example of the illumination device of the present invention, an automotive headlamp (vehicle headlamp) 10 a (illumination device) configured by combining a plurality of projectors 1 a 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 ship, an aircraft, a submersible craft, a rocket), or may be realized as another lighting device. . Examples of other lighting devices include a searchlight, a projector, a flashlight, and a home lighting device. Moreover, the light projecting device of the present invention may be used as a headlamp of a vehicle / moving object other than an automobile, or may be used as another lighting device, similarly to the lighting device.

  Further, the headlamp 10a 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).

(Schematic configuration of the headlamp 10a)
First, a schematic configuration of the headlamp 10a will be described with reference to FIG. FIG. 1 (a) shows a schematic configuration example when a headlamp 10a composed of a plurality of projectors 1a is viewed from above a vehicle traveling on the ground with the headlamp 10a. FIG. 1B is a perspective view showing the arrangement of the projector 1a constituting the headlamp 10a shown in FIG. 1A when viewed from an oblique front of the headlamp 10a.

  As shown to (a) of FIG. 1, the headlamp 10a is provided with the some light projector 1a which projects the light L toward the direction A (front of a vehicle etc.) as shown with a broken line. Each projector 1a projects the light L so as to irradiate the irradiation destination R ahead of the headlamp 10a by a predetermined distance. Each projector 1a is configured such that the light L projected from each projector 1a overlaps each other at the irradiation destination R. As a result, since the light projected from the plurality of projectors 1a is mixed by overlapping each other at the irradiation destination R, the color unevenness of the light illuminating the irradiation destination R is reduced, and irradiation light with high color uniformity is obtained. Can be obtained.

  In addition, although the case where the number of the projectors 1a which comprise the headlamp 10a is arrange | positioned horizontally is shown here, the number of the projectors 1a which comprise the headlamp 10a is not limited to this, Arbitrary numbers The projector 1a may be combined. For example, as the number of the projectors 1a that superimpose the light projections increases, the uniformity of the color of the irradiated light is improved. Therefore, there is no upper limit to the number of the light projectors 1a that superimpose the light projections on each other.

  On the other hand, it is sufficient that there are at least two projectors 1a for superimposing the projections on each other. However, by superimposing the light L emitted from the same number of the projectors 1a as the number of phosphors used in the projector 1a, the color unevenness of the light illuminating the irradiation destination R is reduced, and the color uniformity of the light is more improved. It was confirmed that it improved effectively. Furthermore, it has been found that the light color uniformity is more preferable by superimposing the light L from the light projector 1a, which is one or more than the number of types of phosphors used in the light projector 1a.

  Therefore, in order to reduce the color unevenness of the light, the number of the projectors 1a that project light so as to overlap each other in the irradiation destination R is equal to or more than the number of types of phosphors used in the projector 1a, and more than one. It is desirable to be. In order to reduce the color unevenness of the light, it is more preferable that the number of phosphors used in the projector 1a is at least one more.

  In addition, the light intensity of the light L emitted from each projector 1a can be adjusted so that the light obtained by superimposing the light L emitted from each projector 1a has a desired light intensity for irradiating the irradiation destination R. For example, in the case of the headlamp 10a of FIG. 1, the light quantity of the light L emitted from each of the five projectors 1a may be 1/5 of the light quantity required to irradiate the irradiation destination R.

(Structure of the projector 1a)
Next, the basic structure of the projector 1a constituting the headlamp 10a will be described with reference to FIG. FIG. 2 is a cross-sectional view showing an example of the structure of the projector 1a used in the headlamp 10a. As shown in FIG. 2, the projector 1 a includes a semiconductor laser element 3 (laser light source), a condenser lens 4, a light emitting unit 7, a reflector 8 (optical system), and a base 13. FIG. 2 shows only a part of the electric system E for oscillating the laser beam.

  The projector 1a of the present embodiment is configured to mainly use light emitted from the laser light receiving surface of the light emitting unit 7.

(Semiconductor laser element 3)
The semiconductor laser element 3 oscillates laser light used as excitation light. The semiconductor laser element 3 has one light emitting point per chip, for example, oscillates 405 nm (blue-violet) laser light, has an output of 2 W, and is enclosed in a package having a diameter of 5.6 mm. The wavelength of the laser beam oscillated by the semiconductor laser element 3 is not limited to 405 nm, and may be a laser beam having a peak wavelength in a wavelength range of 380 nm or more and 470 nm or less. The configuration of the semiconductor laser element 3 will be described in detail later.

If it is possible to produce a high-quality semiconductor laser device 3 for short wavelength that oscillates laser light having a wavelength shorter than 380 nm, laser light having a wavelength shorter than 380 nm may be used as the semiconductor laser device 3 of this embodiment. It is also possible to apply a semiconductor laser designed to oscillate.
(Configuration of Semiconductor Laser Element 3)
Next, the basic structure of the semiconductor laser element 3 will be described. FIG. 3A is a schematic view showing a circuit for driving the semiconductor laser element 3, and FIG. 3B is a perspective view showing a basic structure of the semiconductor laser element 3. As shown in FIGS. 3A and 3B, the semiconductor laser device 3 includes a cathode electrode 23, a substrate 22, a cladding layer 113, an active layer 111, a cladding layer 112, and an anode electrode 21 stacked in this order. It is a configuration.

The substrate 22 is a semiconductor substrate, and it is preferable to use GaN, sapphire, or SiC when obtaining blue to ultraviolet excitation light for exciting the phosphor. 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 in the direction from the anode electrode 21 to the cathode electrode 23.

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

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

  In addition, 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 split into a front side cleavage surface 114 and a back side cleavage surface 115 of the active layer 111 (in this embodiment, the front side cleavage surface 114 for convenience. To be 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 a difference is provided in the reflectance between the front-side cleaved surface 114 and the back-side cleaved surface 115. Thus, 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 cladding layer 113 and the cladding 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 and ZeSe. , ZnS and ZnO, and any other semiconductors of II-VI group compound semiconductors, and by applying a forward bias from the anode electrode 21 to 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.

(Condensing lens 4)
The condensing lens 4 shown in FIG. 2 is an aspherical lens for condensing the laser light oscillated from the semiconductor laser element 3 on the light emitting unit 7. The shape and material of the condensing lens 4 are not particularly limited as long as the lens has the above-described function. However, the condenser lens 4 is formed of a material having high light transmittance in a wavelength region near 405 nm and high heat resistance. Is preferred.

(Light Emitting Unit 7)
The light emitting unit 7 emits light upon receiving the laser light collected by the condenser lens 4 and includes a phosphor that emits light when excited by the laser light. As shown in FIG. 2, the light emitting unit 7 is fixed in contact with a part of the base 13 on the surface opposite to the surface irradiated with the laser light.

  The surface of the base 13 that is in contact with the light emitting unit 7 shown in FIG. It is tilted to cross the outside. Thereby, there is an effect that the light emitted from the light emitting unit 7 can be reflected by the reflector 8 and used as the light L without waste. Furthermore, since the light from the light emitting point on the light emitting unit 7 of the projector 1a is not directly emitted to the outside, it is possible to suppress a person who sees the projector 1a from the direction A from being dazzled.

  When the shape of the reflector 8 described later is a rotary paraboloid, the light emitter 7 is arranged near the focal point of the rotary paraboloid, and the central portion of the light emitter 7 is excited by laser light.

  The light-emitting portion 7 is formed into a thin piece by sintering phosphor powder. The shape and size of the light emitting unit 7 are, for example, a rectangular parallelepiped having a size of 1 mm × 1 mm and a thickness of 0.2 mm. For example, any one or more of phosphors that emit red, green, and blue light are sintered so that the light-emitting body 7 emits white light. Since the semiconductor laser element 3 oscillates 405 nm (blue-violet) laser light, a plurality of colors are mixed and white light is generated when the light emitting unit 7 is irradiated with the laser light.

The light emitting unit 7 can be formed, for example, by mixing and sintering the following three types of phosphors (1), (2), and (3).
(1) CaAlSiN ₃ : Eu: phosphor emitting red fluorescence (2) β-SiAlON: Eu: phosphor emitting green fluorescence (3) (BaSr) MgAl ₁₀ O ₁₇ : Eu: fluorescence emitting blue fluorescence However, the phosphor used for the light emitting unit 7 is not limited to these, and various phosphors can be used for the light emitting unit 7. Further, the types of phosphors to be mixed are not limited to three types, and may be appropriately changed according to the wavelength of the laser light oscillated by the semiconductor laser element 3. For example, when the semiconductor laser element 3 oscillates a laser beam having a peak wavelength in a wavelength range of 450 nm, 440 nm or more and 490 nm or less, the phosphor is a yellow phosphor or a green phosphor and a red phosphor. What is necessary is just to mix a fluorescent substance.

  Here, the yellow phosphor is a phosphor that emits light having a peak wavelength in a wavelength range of 560 nm or more and 590 nm or less. 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 or more and 680 nm or less. The blue phosphor is a phosphor that emits light having a peak wavelength in the wavelength range of a visible light region of 450 nm or less.

  The light-emitting body 7 may be one in which a phosphor is dispersed inside a transparent member as a phosphor-holding substance (sealing agent). In this case, as the phosphor holding substance, a material such as inorganic glass is used, but is not limited thereto. As long as the material has heat resistance that can withstand high heat generated by excitation of the phosphor by laser light and heat conductivity that conducts the generated heat to, for example, the base 13, the phosphor holding substance is , Resin, organic-inorganic hybrid glass. In addition, the light emitting unit 7 may be formed by pressing a fluorescent material.

(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 element 3 will be described.

  First, the laser light oscillated from the semiconductor laser element 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. Based on this principle and relationship, the color of light emitted by a plurality of phosphors By combining as described above, white light can be generated.

(Reflector 8)
The reflector 8 reflects the fluorescence emitted from the light emitting unit 7 in the direction A, thereby forming a light bundle that travels within a predetermined solid angle. That is, the reflector 8 reflects the light radiated from the light emitting unit, thereby forming the light L including the light beam traveling forward of the projector 1a.

  The reflector 8 is a member in which a metal thin film such as aluminum is formed on the inner surface of a curved surface shape (cup shape) such as a rotating paraboloid made of resin. In addition, the reflector 8 can be provided with a through hole 6 at an appropriate location so that the laser beam from the semiconductor laser element 3 is irradiated to the light emitting unit 7. The through hole 6 is not necessarily a hole, and may be a portion where a part of the reflector 8 is configured to have light transmittance.

  The shape of the inner surface of the reflector 8 can be formed with a paraboloid of revolution as a prototype, and is configured as a free-form surface so as to form a light bundle that reflects light from the light emitting portion 7 and proceeds in a desired direction. Good. The shape and size of the reflector 8 are, for example, a semicircular shape with a front opening provided on the side in the direction A in which the light L is projected and having a radius of 10 mm, and a depth from the front opening is 8.3 mm. .

(Base 13)
The base 13 is a member that is disposed below the reflector and has a function of fixing the light emitting unit 7. 2 illustrates an example in which the light emitting unit 7 and the semiconductor laser element 3 are installed on the base 13, but the installation position of the semiconductor laser element 3 is not limited to the base 13. For example, it is possible to guide laser light oscillated from the semiconductor laser element 3 provided outside the projector 1a to the light emitting unit 7 provided in the projector 1a using an optical fiber or the like.

  The base 13 is preferably a member made of a metal such as aluminum having high thermal conductivity for receiving heat generated in the semiconductor laser element 3 and the light emitting unit 7. Accordingly, the heat generated in the semiconductor laser element 3 and the light emitting unit 7 is transmitted to the light emitting unit 1a by being thermally connected to the semiconductor laser element 3 and the light emitting unit 7 (that is, so as to be able to exchange heat energy). It can dissipate heat to the outside.

(Effect of the headlamp 10a)
The light projector 1 a irradiates the light emitting unit 7 with high-density laser light oscillated from the semiconductor laser element 3 to excite the phosphor contained in the light emitting unit 7. Thereby, the size of the light emitting point that emits light upon receiving the excitation light on the light emitting unit 7 is small, and high luminance light can be obtained from the light emitting unit 7. Thus, the projector 1a can be designed to be small by obtaining light emission with high luminance from a small light emission point.

  Since the light emitting section 7 is irradiated with a laser beam having a high light density, the phosphor particles contained in the light emitting section 7 generate a large amount of heat, and thus it is necessary to efficiently dissipate the heat generated in the phosphor particles. Therefore, in order to improve the thermal conductivity of the light emitting part 7, it is desirable that the light emitting part 7 is one in which the phosphor particles are closely packed and the distance between the phosphor particles is short. Further, the light emitting portion 7 is formed in a thin plate shape, the light emitting point on the surface of the light emitting portion 7 that receives the laser light, and the surface that faces the surface that receives the laser light of the light emitting portion 7 and is in contact with the base 13. It is desirable to make it possible to effectively dissipate heat from the light-emitting portion 7 by shortening the distance between the two.

  However, if the size of the light emitting point on the surface of the light emitting unit 7 that receives the laser light is reduced, and the size of the phosphor particles contained in the light emitting unit 7 with respect to the size of the light emitting point is relatively large, the light emitting unit The distribution of the phosphor particles at the light emitting point 7 can cause the unevenness of the color of the light emitted from the light emitting unit 7. Furthermore, if the light emitting part 7 is formed thinly, the light emission from each phosphor particle is emitted without being sufficiently mixed at the light emitting point of the light emitting part 7, resulting in light color unevenness on the surface of the light emitting part 7. Can be a cause.

  Therefore, the headlamp 10a according to the present embodiment includes a plurality of projectors, projects light from the projectors 1a toward the irradiation destination R, and superimposes them on the irradiation destination R. Thereby, the color nonuniformity of the light which each projector 1a emits is reduced in the light which irradiates the irradiation destination R which is a light projection destination.

  As described above, the headlamp 10a according to the present embodiment includes the semiconductor laser element 3 that emits laser light, the light emitting unit 7 that includes the phosphor that emits fluorescence by receiving the laser light emitted from the semiconductor laser element 3, and And a reflector 8 (optical system) that radiates light emitted from the light-emitting unit 7 to the outside. The projector 1 a includes at least the same number as the number of types of phosphors included in the light-emitting unit 7. It has a configuration that exists and emits light so that the light projected from the plurality of projectors 1a overlap each other.

  By providing a plurality of projectors 1a equal to or more than the number of types of phosphors included in the light emitting unit 7 that emits fluorescence upon receiving laser light, the light projected to the outside from the plurality of projectors 1a is mutually overlap. Thereby, the color unevenness of the light from the headlamp 10a can be reduced.

  Furthermore, the color L of the light at the light projecting destination can be more effectively reduced by overlapping the light L from the light projectors 1a, which is one or more more than the number of types of phosphors, with each other. For example, when three types of phosphors are used for the light emitting unit 7, by using at least three projectors 1a, more preferably four or more projectors 1a, and superimposing the light L projected from the projector 1a, The uniformity of the light L emitted from the headlamp 10a to the outside can be improved.

  Therefore, according to the present embodiment, it is possible to realize the headlamp 10a as a high-intensity light source with improved color uniformity of the projected light L.

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

(Schematic configuration of the headlamp 10b)
Here, another embodiment of an automotive headlamp (vehicle headlamp) 10b (illumination device) configured by combining a plurality of projectors 1b will be described as an example of the illumination device of the present invention.

  However, the lighting device of the present invention may be realized as a headlamp of a vehicle other than an automobile or a moving object (for example, a ship, an aircraft, a submersible craft, a rocket), or may be realized as another lighting device. . Examples of other lighting devices include a searchlight, a projector, a flashlight, and a home lighting device. The light projecting device of the present invention may be used as a headlamp for a vehicle / moving object other than an automobile, as well as the light projecting device 1a, or may be used as another illumination device.

  FIG. 4 (a) shows a schematic configuration example when a headlamp 10b composed of a plurality of projectors 1b is viewed from above a vehicle traveling on the ground with the headlamp 10b. FIG. 4B is a perspective view showing a state when the arrangement of the projector 1b constituting the headlamp 10b shown in FIG. 4A is viewed obliquely from the front of the headlamp 10b. Unlike the projector 1a of the first embodiment, the projector 1b of the present embodiment includes a projector lens 15 on the side from which the light L is emitted. The projector lens 15 will be described later together with the structure of the projector 1b.

  As shown to (a) of FIG. 4, the headlamp 10b is equipped with the light projector 1b which projects the light L as shown with a broken line with respect to the direction A (front of a vehicle etc.). In addition, although the case where the number of the projectors 1b which comprise the headlamp 10b is arrange | positioned horizontally is shown here, the number of the projectors 1b which comprise the headlamp 10b is not limited to this, Arbitrary numbers The projector 1b may be combined.

  In the headlamp 10b illustrated in FIG. 4A, the four projectors 1b irradiate two light projectors 1b that irradiate light L that overlaps each other at the irradiation destination R1, and the light L that overlaps each other at the irradiation destination R2. One projector 1b. In other words, the light that irradiates the irradiation destination R1 and the irradiation destination R2 is mixed by overlapping the light emitted from the two projectors 1b with each other, thereby reducing color unevenness of the light that illuminates the irradiation destination R1 and the irradiation destination R2. As a result, the irradiation light has high color uniformity.

  For example, the greater the number of projectors 1b that emit light L in the same irradiation range, the more uniform the color of the irradiated light. Therefore, there is no upper limit to the number of projectors 1b that superimpose the light L on each other.

  On the other hand, the number of the projectors 1b that superimpose the light L on each other may be at least two. However, by superimposing the light L emitted from the same number of types of light projectors 1b as the number of phosphors used in the light projector 1b, the color unevenness of the light illuminating the irradiation destination R1 and the irradiation destination R2 is reduced, and the color of the light It was confirmed that the uniformity was improved more effectively. Furthermore, it has been found that the light color uniformity is more preferable by superimposing the light L from the projector 1b that is one or more than the number of types of phosphors used in the projector 1b.

  In addition, the luminous intensity of the light L emitted from each projector 1b so that the light obtained by superimposing the light L emitted from each projector 1b has a desired luminous intensity for irradiating the projection destination defined as the headlamp 10b. Can be adjusted. For example, in the case of the headlamp 10b of FIG. 4, the light quantity of the light L emitted from each of the two projectors 1b that irradiate the irradiation destination R1 among the four projectors 1b provided is the light quantity required to irradiate the irradiation destination R1. It may be set to 1/2 of this.

(Structure of the light projecting portion 1b)
Next, the basic structure of the projector 1b which comprises the illuminating device 10b of this embodiment is demonstrated, referring FIG. FIG. 5 is a cross-sectional view showing an example of the structure of the projector 1b. As shown in FIG. 5, the projector 1 b includes a semiconductor laser element 3, a condenser lens 4, a light emitting unit 7, a holding member 9, a case 11, and a projector lens 15. FIG. 5 shows only a part of the power supply circuit E for oscillating the laser beam.

  The projector 1b of the present embodiment is configured to mainly use light emitted from the surface of the light emitting unit 7 that faces the surface that receives the laser light.

(Semiconductor laser element 3)
The semiconductor laser element 3 oscillates laser light used as excitation light. The semiconductor laser element 3 has one light emitting point per chip, for example, oscillates 405 nm (blue-violet) laser light, has an output of 2.5 W, and is enclosed in a package having a diameter of 5.6 mm. The wavelength of the laser beam oscillated by the semiconductor laser element 3 is not limited to 405 nm. In this embodiment, the semiconductor laser element 3 is used as an excitation light source, but an LED (light emitting diode) can be used instead of the semiconductor laser element 3.

(Light Emitting Unit 7)
The light emitting part 7 is formed in a flake shape by sintering phosphor particles. The shape and size of the light emitting unit 7 are, for example, a disk shape having a diameter of 1 mm and a thickness of 0.5 mm. For example, any one or more of phosphors that emit yellow and blue light are sintered so that the light-emitting body 7 emits white light. Since the semiconductor laser element 3 oscillates 405 nm (blue-violet) laser light, a plurality of colors are mixed and white light is generated when the light emitting unit 7 is irradiated with the laser light.

The light emitting part 7 can be formed, for example, by mixing and sintering the following two types of phosphors (1) and (2).
(1) α-SiAlON: phosphor that emits yellow fluorescence (2) (BaSr) MgAl ₁₀ O ₁₇ : Eu: phosphor that emits blue fluorescence However, the phosphor used in the light emitting unit 7 is limited to these. Instead, various phosphors can be used for the light emitting unit 7. Further, the types of phosphors to be mixed are not limited to two types, and may be appropriately changed according to the wavelength of the laser light oscillated by the semiconductor laser element 3.

(Holding member 9)
The holding member 9 is formed of a transparent material provided with a hole for holding the light emitting unit 7 at the center of the circular plate, and is a member that holds the light emitting unit 7 inside the projector 1b. For example, as shown in FIG. 5, the holding member 9 is in contact with the side surface adjacent to the surface of the light emitting unit 7 that receives the laser light. However, the manner in which the holding member 9 holds the light emitting unit 7 is not particularly limited. That is, any holding is possible as long as the laser beam is held so as to be incident on the light emitting unit 7 and the light emitted from the surface of the light emitting unit 7 facing the laser beam is projected to the outside of the projector 1b. It may be a style.

  The holding member 9 is preferably formed of a material having high thermal conductivity in order to dissipate heat generated in the light emitting unit 7.

(Case 11)
The case 11 is a member that constitutes the projector 1b by storing each member of the projector 1b in the projector. The case 11 is formed using, for example, metal.

(Projecting lens 15)
The light projecting lens 15 is a lens for projecting the light L including the fluorescence emitted from the light emitting unit 7 in the direction A. The light projecting lens 15 is, for example, a resin-made convex lens, and may be configured as a free-form surface in order to realize light projection to a desired irradiation destination R1 or irradiation destination R2. An example of the size and shape of the projection lens 15 is a circular shape having a diameter of 20 mm.

(Effect of the headlamp 10b)
As described above, the headlamp 10b according to the present embodiment includes the semiconductor laser element 3 that emits laser light, the light emitting unit 7 that includes the phosphor that emits fluorescence by receiving the laser light emitted from the semiconductor laser element 3, and A projector 1b having a projection lens 15 (optical system) that radiates light emitted from the light emitting unit 7 to the outside, and the projector 1b is equal to or more than the number of types of phosphors included in the light emitting unit 7. There are a plurality of configurations in which light emitted from the plurality of projectors 1b is radiated to the outside so as to overlap each other.

  By providing a plurality of projectors 1b that are equal to or more than the number of types of phosphors included in the light emitting unit 7 that emits fluorescence upon receiving laser light, the light projected to the outside from the plurality of projectors 1b is mutually connected. overlap. Thereby, the color unevenness of the light from the headlamp 10b can be reduced.

  Furthermore, the light L from the projector 1b, which is one or more more than the number of types of phosphors, is overlapped with each other, so that the color unevenness of the light at the projection destination can be reduced more effectively. For example, when two types of phosphors are used for the light emitting unit 7, by using at least two projectors 1b, more preferably three or more projectors 1b, and superimposing the light L projected from the projectors 1b, It is possible to improve the uniformity of the light L emitted from the headlamp 10b to the outside.

  Therefore, according to the present embodiment, it is possible to realize the headlamp 10b as a high-intensity light source with improved color uniformity of the projected light L.

[Embodiment 3]
The following will describe another embodiment of the present invention with reference to FIGS. In addition, about the member similar to the member demonstrated in Embodiment 1, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  Hereinafter, a projector 1c that is installed and used in the front right or left front of a vehicle will be described as an example of a traveling headlamp (so-called high beam) for an automobile. The light projecting device 1c may be used as a headlamp for a vehicle / moving object other than an automobile, or may be used as another illumination device.

(Structure of the projector 1c)
Here, the projector 1c according to the present embodiment will be described with reference to FIG. FIG. 6 is a cross-sectional view showing an example of the structure of the projector 1c according to the present embodiment. As shown in FIG. 6, the projector 1c includes a semiconductor laser element array 2 (laser light source), a condensing lens 4, an optical fiber 5, a light emitting unit 7, a reflector 8 (optical system), a holding member 9a, a case 11, and a transparent cover. 12 and a convex lens 14.

  The projector 1c of the present embodiment is configured to mainly use light emitted from the surface of the light emitting unit 7 that receives laser light.

(Semiconductor laser element array 2 / semiconductor laser element 3)
The semiconductor laser element array 2 functions as an excitation light source that emits excitation light, and includes a plurality of (for example, eight) semiconductor lasers 3 on a substrate. Laser light as excitation light is oscillated from each of the semiconductor lasers 3.

  It is not always necessary to use a plurality of semiconductor lasers 3 as an 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. Easy.

  The semiconductor laser 3 has one light emitting point per chip and oscillates, for example, a 400 nm (blue-violet) laser beam.

  Semiconductor laser element array 2, condenser lens 4, heat sink (not shown) for radiating heat generated in the semiconductor laser element, and electric system for oscillating laser light with a desired output from each semiconductor laser element 3 E and wiring (not shown) may be packaged as a laser module part.

(Optical fiber 5)
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 includes a plurality of incident end portions 5b that receive the laser light from each semiconductor laser element 3, and bundles the incident end portions 5b so that all the laser beams are incident, guided, and emitted. And an optical fiber 5. The optical fiber 5 emits laser light to the laser light irradiation surface of the light emitting unit 7.

  Note that the optical fiber 5 is not necessarily a single optical fiber, and may have a configuration having a plurality of emission end portions. For example, by providing a plurality of emission end portions, the light emitting portion 7 is not locally irradiated with laser light, and a significant deterioration of a part of the light emitting portion 7 can be prevented.

(Material and structure of optical fiber 5)
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, but the structure, thickness, and material of the optical fiber 5 are as described above. It is not limited to. For example, the cross section perpendicular to the major axis direction of the optical fiber 5 may be rectangular.

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

  Therefore, the degree of freedom in designing the headlamp 1 can be increased, such that the semiconductor laser 3 can be installed at a position where it can be easily cooled or easily replaced. That is, the positional relationship between the incident end portion 5b and the emitting end portion of the optical fiber 5 can be easily changed, and the positional relationship between the semiconductor laser 3 and the light emitting portion 7 can be easily changed. 1 degree of freedom of design can be increased. Furthermore, it becomes possible to increase the degree of freedom in designing the automobile on which the headlamp 1 according to the present embodiment is mounted.

  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. For example, one or a plurality of rod-shaped light guide members having a laser light incident end and an output end or a truncated cone (or truncated pyramid) light guide may be used.

(Light Emitting Unit 7)
The light emitting section 7 is formed by forming a thin layer containing phosphor powder partially on the surface of the holding member 9a. The light emitting unit 7 is disposed in the vicinity of the focal point of a rotating paraboloid used as a base of the shape of the reflector 8 described later, and for example, the central portion of the light emitting unit 7 is excited by laser light.

  The shape and size of the light emitting unit 7 are, for example, a disk shape having a diameter of 1 mm and a thickness of 0.1 mm. For example, any one or more of phosphors that emit red, green, and blue light are sintered so that the light-emitting body 7 emits white light. Since the semiconductor laser element 3 oscillates a 400 nm (blue-violet) laser beam, when the light emitting unit 7 is irradiated with the laser beam, a plurality of colors are mixed to generate white light.

The light emitting unit 7 can be formed, for example, by mixing and sintering the following three types of phosphors (1), (2), and (3).
(1) CaAlSiN ₃ : Eu: phosphor emitting red fluorescence (2) β-SiAlON: Eu: phosphor emitting green fluorescence (3) (BaSr) MgAl ₁₀ O ₁₇ : Eu: fluorescence emitting blue fluorescence However, the phosphor used for the light emitting unit 7 is not limited to these, and various phosphors can be used for the light emitting unit 7. Further, the types of phosphors to be mixed are not limited to three types, and may be appropriately changed according to the wavelength of the laser light oscillated by the semiconductor laser element 3.

(Transparent cover 12)
Similar to the case 11, the transparent cover 12 is a member that constitutes the projector 1c by storing and sealing each member of the projector 1c in the projector. The case 11 is formed using a transparent material with high light transmittance.

(Convex lens 14)
It is an optical system member for irradiating the light emitting part 7 in the reflector with the laser light emitted from the emitting end part of the optical fiber 5.

(Reflector 8)
The reflector 8 forms a light bundle that travels within a predetermined solid angle by reflecting the fluorescence emitted from the light emitting unit 7 in the direction A to the light reflecting surface 8a. That is, the reflector 8 reflects the light emitted from the light emitting unit, thereby forming light L including a light bundle traveling forward of the projector 1c.

  The reflector 8 is a member in which a metal thin film such as aluminum is formed on the surface that becomes the light reflecting surface 8a inside the curved surface shape (cup shape) of a rotating paraboloid made of resin, for example. In addition, the reflector 8 can be provided with a through hole 6 at an appropriate location so that the laser beam from the semiconductor laser element 3 is irradiated to the light emitting unit 7. The through hole 6 is not necessarily a hole, and may be a portion where a part of the reflector 8 is configured to have light transmittance.

  The shape of the light reflecting surface 8a of the reflector 8 can be formed based on a rotating paraboloid, and becomes a light bundle that reflects light from the light emitting portion 7 on the light reflecting surface 8a and travels in a desired direction. Thus, it may be configured with a free-form surface. However, the light reflecting surface 8a of the reflector 8 is provided with segments S (light emitting surfaces), which are a plurality of partial regions, and each segment S has a surface having a shape different from that of the paraboloid of revolution. Yes. An example of the structure of the segment S provided on the light reflecting surface 8a of the reflector 8 and its effect will be described in detail later.

  FIG. 7 is a front view showing the basic structure of the reflector 8 of the projector shown in FIG. 6 and the arrangement of the holding members 9a. As illustrated in FIG. 7, the reflector 8 is substantially circular when the projector 1 c is viewed from the direction A. As shown in FIGS. 6 and 7, the holding member 9a is a thin columnar member so that the surface receiving the laser light of the light emitting portion 7 receives the laser light emitted from the emission end of the optical fiber 5. Yes, and extends almost to the center of the reflector 8. The light emitted from the surface of the light emitting unit 7 that receives the laser light is reflected on the substantially front surface of the light reflecting surface 8a of the reflector 8 provided to face the surface, and the light L is projected in the direction A. The

(Structure of the light reflecting surface 8a of the reflector 8)
Here, the structure of the light reflecting surface 8a of the reflector 8 will be described with reference to FIG. FIG. 8 is a cross-sectional view showing an example of the structure of the segment S provided in the reflector 8.

  As described above, the segment S provided on the light reflecting surface 8a has a curved surface different from the paraboloid used as the reference shape of the shape of the light reflecting surface 8a. That is, the light reflecting surface 8a of the reflector 8 is a free-form surface using the rotating paraboloid shown in FIG. However, the light reflecting surface 8a of the reflector 8 is divided into a plurality of segments S, and the light reflecting surface 8a in each segment S is configured to be a curved surface or a plane different from the rotating paraboloid as a base. The

  For example, in the light reflecting surface 8a shown in FIG. 8B, each segment S is constituted by a plane, and in the light reflecting surface 8a shown in FIG. 8C, each segment S is a paraboloid of revolution. Are composed of different curved surfaces. In addition, the shape of all the segments S does not have to be configured by a curved surface different from that of the paraboloid of revolution. For example, some segments S may have the same curved surface as the paraboloid of revolution.

(Effect of the projector 1c)
For example, when the shape of the light reflecting surface 8a of the reflector 8 is a rotating paraboloid, light emitted from the light emitting unit 7 disposed near the focal point of the rotating paraboloid is reflected by the light reflecting surface 8a. As shown in FIG. 2, the light L is emitted toward the direction A.

  On the other hand, the light reflecting surface 8a of the reflector 8 of the present embodiment is divided into a plurality of segments S, and each segment S has a surface different from the paraboloid of revolution. Therefore, the light L reflected from the light reflecting surface 8a and irradiated in the direction A (see FIG. 6) has a wider irradiation range than the light L shown in FIG. That is, at least a part of the light L reflected by a certain segment S and the light L reflected by another segment overlaps and is projected in the direction A.

  Note that the number, curved surface shape, and arrangement of the segments S included in the light reflecting surface 8a can be designed so as to improve the uniformity of the color of the projected light. For example, what is necessary is just to design it as arbitrary shapes by adjusting the direction and spread of the light reflected in each segment S. The degree to which the light reflected by each segment overlaps with the light reflected by the other segments can be adjusted by setting the number of each segment S, the shape of the curved surface, and the arrangement.

  In this way, by providing a plurality of segments S on the light reflecting surface 8a of the reflector 8, the light L reflected by the segments S is irradiated onto the projection destination so as to overlap each other. Thereby, the color unevenness of the light L emitted from the projector 1c is reduced in the light L that illuminates the projection destination.

  As described above, the projector 1c according to this embodiment includes the semiconductor laser element 3 that emits laser light, the light emitting unit 7 that emits light using the laser light emitted from the semiconductor laser element 3, and the light emitted by the light emitting unit. And a reflector 8 that radiates to the outside from the plurality of segments S, and has a configuration in which light radiated from the plurality of segments S is superimposed on each other and projected to the outside.

  With this configuration, the projector 1c according to the present embodiment superimposes light emitted from each of the plurality of segments S and projects the light to the outside, so that color unevenness can be reduced. In addition, the projector 1c includes the reflector 8 divided into a plurality of segments S, so that color unevenness can be reduced only by the own projector without using the plurality of projectors 1c.

(Modification)
As shown in the above-described second embodiment, the spread of the light L is also increased with respect to the projector 1c having a configuration that mainly uses the light emitted from the surface of the light emitting unit 7 that faces the surface that receives the laser light. Thus, the segment S of the present embodiment that overlaps each other can be applied.

  For example, at least one of the surface of the light projecting lens 15 included in the light projector 1c illustrated in FIG. 5 on the side on which the light L including the light from the light emitting unit 7 is incident and the surface on the side on which the light L is emitted. One side may be divided into a plurality of segments S. As a result, the light L emitted in the direction A through the different segments S of the light projecting lens 15 overlaps with each other, so that color unevenness can be reduced only by the self-projector 1c without using a plurality of light projectors. Can do.

[Embodiment 4]
Another embodiment of the present invention will be described below with reference to FIGS. 9 and 10. For convenience of explanation, members having the same functions as those described in the above embodiment are denoted by the same reference numerals and description thereof is omitted.

  Hereinafter, a projector 1d that is installed and used on the right front or left front of a vehicle will be described as an example of a traveling headlamp (so-called high beam) for an automobile. The light projecting device 1d may be used as a headlamp for a vehicle / moving object other than an automobile, or may be used as another illumination device.

(Configuration of the projector 1d)
Here, a projector 1d as an example of a projector according to the present embodiment will be described with reference to FIG. FIG. 9 is a cross-sectional view showing an example of the structure of the projector 1d according to the present embodiment. As shown in FIG. 9, the projector 1d includes a semiconductor laser element array 2 (laser light source), a condensing lens 4, an optical fiber 5, a light emitting unit 7, a reflector 8 (reflecting mirror), a holding member 9a, a case 11, and a transparent cover. 12 and a convex lens 14.

  The basic configuration is the same as the projector 1d of the third embodiment, and the projector 1d of the present embodiment is a configuration that mainly uses light emitted from the surface of the light emitting unit 7 that receives the laser light.

(Reflector 8)
The reflector 8 forms a light bundle that travels within a predetermined solid angle by reflecting the fluorescence emitted from the light emitting unit 7 in the direction A to the light reflecting surface 8a. That is, the reflector 8 reflects the light emitted from the light emitting unit, thereby forming the light L including the light bundle traveling forward of the projector 1d.

  The reflector 8 is a member in which a metal thin film such as aluminum is formed on the surface that becomes the light reflecting surface 8a inside the curved surface shape (cup shape) of a rotating paraboloid made of resin, for example.

  As shown in FIG. 9, unlike the projector 1d according to the third embodiment, the reflector 8 included in the projector 1d according to the present embodiment is not divided into a plurality of segments. Instead, the light reflecting surface 8a of the reflector 8 provided in the projector 1d according to the present embodiment is provided with a plurality of small concavo-convex structures (micro reflective structures) having reflectivity. The minute reflecting structure of the light reflecting surface 8a will be described in detail below.

(Slight reflection structure of the light reflecting surface 8a of the reflector 8)
Here, the minute reflection structure provided on the light reflection surface 8a of the reflector 8 will be described with reference to FIG. FIG. 10 is a cross-sectional view showing an example of a minute reflection structure provided on the light reflection surface 8 a of the reflector 8.

  The shape of the light reflecting surface 8a of the reflector 8 is formed based on a paraboloid of revolution as shown in FIG. A minute reflection structure is formed on the light reflection surface 8 a of the reflector 8.

  The reflectors 8 shown in FIGS. 10B, 10C, and 10D are all different in shape from the light reflecting surface 8a based on the paraboloid of revolution shown in FIG. It has a minute reflection structure.

  In the following, description will be made by taking as an example the minute reflection structure shown in FIG. FIG. 10B is a cross-sectional view of the reflector 8 in which a plurality of conical convex portions T1 (reflection structures) are provided on the light reflecting surface 8a. In addition, the figure enclosed with the circle | round | yen shown to (b)-(d) of FIG. 10 shows a mode that the cross section of the reflector 8 was expanded in order to demonstrate the shape of a microreflection structure.

  The light reflecting surface 8a shown in (b) of FIG. 10 is provided with a convex portion T1 on the rotating paraboloid shown in (a) of FIG. That is, a part of the surface on the light reflecting portion 8a belongs to the convex portion T1. On the other hand, the surface B1 (reflection structure) that does not belong to the convex portion T1 is a surface along the paraboloid of revolution shown in FIG. Therefore, the surface B1 is a surface corresponding to a paraboloid of revolution, and constitutes a relatively recessed surface with respect to the convex portion T1 provided on the surface on the light reflecting portion 8a.

  When the light from the light emitting unit 7 enters the light reflecting surface 8a, light reflected by the convex portion T1 and light reflected by the surface B1 are generated.

  The light reflected on the surface B1 is radiated in the direction A, and an orientation pattern necessary as a traveling headlamp is realized. On the other hand, the light reflected by the convex portion T1 is reflected in a different direction from the light reflected by the surface B1. As a result, a part of the reflected light from the surface B1 and a part of the reflected light from the convex portion T1 which is a minute reflection structure are overlapped.

  Thereby, the color unevenness in the light L projected in the direction A shown in FIG. 9 is reduced.

  FIG. 10C shows a case where the convex portion T2 has a truncated cone shape, and FIG. 10D shows a case where the convex portion T3 has a hemispherical shape. Thus, in the example shown in FIG. 10B, the shape of the micro-reflection structure is not limited to this. Note that the surface B2 shown in (c) of FIG. 10 and the surface B3 shown in (d) of FIG. 10 are also surfaces corresponding to the paraboloid of revolution shown in (a) of FIG. is there.

  Further, the minute reflection structure is not limited to being a convex portion like the convex portions T1 to T3 in FIG. 10, and may be a concave portion, or may be a mixture of convex portions and concave portions. Good. Further, it is not necessary that the shape and size of each micro-reflection structure are substantially uniform, and various micro-reflection structures may be formed as appropriate.

  Furthermore, the density of the minute reflecting structures on the light reflecting surface 8a does not need to be uniform, and can be adjusted as appropriate. For example, when there is a light emitting part 7 with large color unevenness and a light emitting part 7 with small color unevenness, a minute reflective structure is formed in the region of the light reflecting surface 8a that mainly reflects light emitted from the light emitting part 7 with large color unevenness. The density may be higher than that of other regions. For example, if the density of the convex portions T1 shown in FIG. 10A is increased, the amount of light reflected by the convex portions T1 increases accordingly. As a result, the amount of light from the convex portion T1 that overlaps with part of the reflected light from the surface B1 increases, so that the uniformity of the color of the light can be further improved.

  On the contrary, in the region of the light reflecting surface 8a that mainly reflects the light emitted from the light emitting unit 7 with small color unevenness, the density of the minute reflecting structure may be set lower than that in the other regions.

(Effect of the projector 1d)
As described above, the projector 1d according to this embodiment includes the semiconductor laser element 3 that emits laser light, the light emitting unit 7 that emits light by the laser light emitted from the semiconductor laser element 3, and the light emitted by the light emitting unit 7. And a light reflecting surface 8a of the reflector 8 has a plurality of minute reflecting structures, and the light reflected by the plurality of minute reflecting structures is superposed on each other and projected to the outside. It is.

  According to the above configuration, the projector 1d superimposes the light reflected by each of the plurality of minute reflection structures and projects the light to the outside, so that color unevenness can be reduced. In addition, by adjusting the shape, size, and density of the plurality of micro-reflective structures, the degree of color unevenness of the light at the projection destination can be controlled.

[Embodiment 5]
The following will describe another embodiment of the present invention with reference to FIGS. For convenience of explanation, members having the same functions as those described in the embodiment are given the same reference numerals, and descriptions thereof are omitted.

  Hereinafter, a projector 1e that is installed and used in the front right or left front of a vehicle will be described as an example of a traveling headlamp (so-called high beam) for an automobile. The light projecting device 1e may be used as a headlamp for a vehicle / moving object other than an automobile, or may be used as another illumination device.

(Configuration of the projector 1e)
Here, a projector 1e as an example of a projector according to this embodiment will be described with reference to FIG. FIG. 11 is a cross-sectional view showing an example of the structure of the projector 1e according to the present embodiment. As shown in FIG. 11, the projector 1e includes a semiconductor laser element 3, a condensing lens 4, an optical fiber 5, a light emitting unit 7, a reflector 8, a holding member 9a, a case 11, a transparent cover 12, a convex lens 14, and a light projecting lens. 15 is provided. FIG. 5 shows only a part of the power supply circuit E for oscillating the laser beam.

  The projector 1e according to the present embodiment is configured to mainly use light emitted from the surface of the light emitting unit 7 that receives laser light.

(Arrangement of the light emitting unit 7, the reflector 8, and the light projecting lens 15)
The arrangement of the light emitting unit 7, the reflector 8, and the light projecting lens 15 constituting the light projector 1e according to the present embodiment will be described below with reference to FIG.

  The reflector 8 has a spheroidal light reflecting surface 8a, and the light reflecting surface 8a reflects light emitted from the light emitting unit 7. Of the two focal points of the spheroid, the light emitting unit 7 is disposed at a focal point closer to the laser light emission side. Thereby, the light reflected by the light reflecting surface 8a is imaged at the other focal point F of the spheroid.

(Projecting lens 15)
The light projection lens 15 is a lens for projecting the light reflected by the light reflecting surface 8a of the reflector 8 in the direction A, and the same position as the focal point F is also referred to as a reference point (or a main point). ). As a material of the light projecting lens 15, for example, resin or glass having good light transmittance is used. The light projecting lens 15 has a shape based on a plano-convex lens. If the projection lens 15 is viewed from the direction A, it is substantially circular.

  Here, the light projecting lens 15 is shown as a lens having a shape based on a plano-convex lens. However, the light projecting lens 15 is not limited to the shape of the plano-convex lens as long as it is configured by a free curved surface so as to obtain a desired light projecting pattern. . Further, the shape when the projection lens 15 is viewed from the direction A is not limited to a circle.

  The light projecting lens 15 is provided with a plurality of small irregularities (micro-refractive structures) having a property of refracting light. The minute refraction structure of the projection lens 15 will be described in detail below.

(Small refractive structure of the projection lens 15)
Here, the micro-refractive structure provided in the light projecting lens 15 will be described with reference to FIG. FIG. 12 is a cross-sectional view illustrating an example in which a minute refractive structure is provided on the light incident surface 15 a (incident surface) of the light projecting lens 15.

  The shape of the light projecting lens 15 is formed based on the shape of a plano-convex lens as shown in FIG. A minute refraction structure is formed on the light incident surface 15 a of the light projecting lens 15.

  The projection lenses 15 shown in FIGS. 12B, 12C, and 12D are all shaped on the light incident surface 15a based on the shape of the plano-convex lens shown in FIG. Have different micro-refractive structures.

  In the following, description will be made by taking the minute refraction structure shown in FIG. FIG. 12B is a cross-sectional view of the light projecting lens 15 in which a plurality of conical convex portions T1 (refractive structures) are provided on the light incident surface 15a. In addition, the figure enclosed by the circle | round | yen shown to (b)-(d) of FIG. 12 shows a mode that the cross section of the light projection lens 15 was expanded in order to demonstrate the shape of a micro refraction structure.

  The light incident surface 15a shown in FIG. 12B is provided with a convex portion T1 as shown in FIG. That is, a part of the surface on the light incident surface 15a belongs to the convex portion T1. On the other hand, a surface B1 (refractive structure) that is a surface that does not belong to the convex portion T1 is a surface along the light incident surface 15a shown in FIG. Therefore, the surface B1 is a surface corresponding to the light incident surface 15a, and constitutes a relatively recessed surface with respect to the convex portion T1 provided on the surface on the light incident surface 15a.

  When light from the light emitting unit 7 enters the light incident surface 15a, light refracted by the convex portion T1 and light refracted by the surface B1 are generated.

  The light refracted on the surface B1 is radiated in the direction A, and an alignment pattern necessary for a traveling headlamp is realized. On the other hand, the light refracted at the convex portion T1 is refracted in a direction different from the light refracted at the surface B1. As a result, a part of the refracted light from the surface B1 and a part of the refracted light from the convex portion T1 that is a micro-refractive structure are superimposed.

  Thereby, the color nonuniformity in the light L (refer FIG. 11) projected toward the direction A is reduced.

  FIG. 12C shows a case where the convex portion T2 has a truncated cone shape, and FIG. 12D shows a case where the convex portion T3 has a hemispherical shape. Thus, in the example shown in FIG. 12B, the shape of the minute refractive structure is not limited to this. Note that the surface B2 shown in FIG. 12C and the surface B3 shown in FIG. 12D are portions corresponding to the same surface as the light incident surface 15a shown in FIG. It is.

  Further, the micro-refractive structure is not limited to the convex portion as the convex portions T1 to T3 in FIG. 12, and may be a concave portion, or may be a mixture of the convex portion and the concave portion. Good. Also, the shape and size of each micro-refractive structure need not be substantially uniform, and various micro-refractive structures may be formed as appropriate.

  Furthermore, the density of the minute refractive structure does not need to be uniform, and can be adjusted as appropriate. For example, in the case where the light emitting unit 7 having large color unevenness and the light emitting unit 7 having small color unevenness exist, in the region of the light incident surface 15a that mainly refracts the light emitted from the light emitting unit 7 having large color unevenness, a minute refractive structure is formed. The density may be higher than that of other regions. For example, if the density of the convex portions T1 shown in FIG. 12A is increased, the amount of light refracted by the convex portions T1 increases accordingly. As a result, the amount of light from the convex portion T1 that overlaps with part of the refracted light from the surface B1 increases, so that the uniformity of the color of the light can be further improved.

  On the contrary, in the region of the light incident surface 15a that mainly refracts the light emitted from the light emitting portion 7 with small color unevenness, the density of the micro-refractive structure may be set lower than the other regions.

  In addition, although the structure which provided the micro refraction structure in the light-incidence surface 15a of the light projection lens 15 was shown here, it is not limited to this. For example, a micro-refractive structure may be provided on at least one of the light incident surface 15a and the light emitting surface of the light projecting lens 15 (the surface on the side from which light emitted from the projector 1e is emitted).

(Effect of the projector 1e)
As described above, the projector 1e according to this embodiment includes the semiconductor laser element 3 that emits laser light, the light emitting unit 7 that emits light by the laser light emitted from the semiconductor laser element 3, and the light emitted by the light emitting unit 7. A light projecting lens 15 that radiates to the outside, and the light projecting lens 15 has a plurality of minute refractive structures on the light incident surface 15a on which the light emitted from the light emitting unit 7 is incident. In this configuration, the light refracted is superimposed and projected to the outside.

  According to the above configuration, the light projector 1e superimposes the light refracted by each of the plurality of micro-refractive structures and projects the light to the outside, so that color unevenness can be reduced. In addition, by adjusting the shape, size, and density of the plurality of micro-refractive structures, the degree of color unevenness of the light at the projection destination can be controlled.

[Example of change]
The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and technical means or components disclosed in different embodiments are appropriately combined. The obtained embodiment is also included in the technical scope of the present invention.

[Summary]
The illumination device (headlamps 10a and 10b) according to the first aspect of the present invention includes a laser light source (semiconductor laser element 3) that emits laser light and a phosphor that emits fluorescence by receiving the laser light emitted from the laser light source. And a light projector (light projectors 1a and 1b) having an optical system (reflector 8 and light projection lens 15) that radiates light emitted from the light emission unit 7 to the outside. The number of types of phosphors included in the unit 7 is equal to or greater than the number of types of phosphors, and there is a configuration that emits light to the outside so that the light projected from the plurality of projectors overlap each other.

  According to said structure, the illuminating device which concerns on this invention is provided with the same number or more of the kind of fluorescent substance contained in the light emission part which receives a laser beam and emits fluorescence, and is equipped with several projector, The said several projector The light projected from the outside to the outside is emitted overlapping each other. Thereby, the illuminating device which concerns on this invention can reduce the color nonuniformity of light.

  In the lighting device according to aspect 2 of the present invention, in the aspect 1, the number of the projectors may be one or more than the number of types of the phosphors included in the light emitting unit 7.

  According to said structure, the illuminating device which concerns on this invention can reduce a color nonuniformity more effectively.

  The projector (projector 1c) according to the third aspect of the present invention includes a laser light source that emits laser light, a light emitting unit that emits light by the laser light emitted from the laser light source, and a light that emits light emitted from the light emitting unit. An optical system (reflector 8) that emits from the surface (segment S) to the outside may be provided, and the light emitted from the plurality of light emitting surfaces may be superimposed on each other and projected to the outside.

  According to said structure, since the light projector which concerns on this invention superimposes the light radiated | emitted from each of several light emission surfaces and projects outside, it can reduce a color nonuniformity. In addition, the projector according to the present invention includes the above-described optical system, so that color unevenness can be reduced only by the self-projector without using a plurality of projectors.

  The projector (projector 1d) according to the fourth aspect of the present invention includes a laser light source that emits laser light, a light emitting unit that emits light by the laser light emitted from the laser light source, and a reflecting mirror that reflects light emitted from the light emitting unit. (Reflector 8), and the reflecting surface (light reflecting surface 8a) of the reflecting mirror has a plurality of reflecting structures (projections T1 to T3 and surfaces B1 to B3), and the plurality of reflecting structures. The light reflected in step 1 may be superimposed on each other and projected to the outside.

  According to said structure, since the light projector which concerns on this invention superimposes the light reflected by each of several reflective structure and mutually projects outside, it can reduce color nonuniformity. In addition, by adjusting the shape, size, and density of the plurality of reflecting structures, the degree of color unevenness of the light at the projection destination can be controlled.

  The projector (projector 1e) according to the fifth aspect of the present invention emits laser light that emits laser light, a light emitting unit that emits light by the laser light emitted from the laser light source, and light emitted from the light emitting unit to the outside. A light projecting lens, and the light projecting lens has a plurality of refractive structures (convex portions T1 to T3 and surfaces B1 to B3) on an incident surface (light incident surface 15a) on which light emitted from the light emitting unit is incident. It may have a configuration in which the light refracted by the plurality of refractive structures is superimposed on each other and projected to the outside.

  According to the above configuration, the projector according to the present invention superimposes the light refracted by each of the plurality of refractive structures and projects the light to the outside, so that color unevenness can be reduced. Further, by adjusting the shape, size, and density of the plurality of refractive structures, the degree of color unevenness of the light at the projection destination can be controlled.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention. Furthermore, a new technical feature can be formed by combining the technical means disclosed in each embodiment.

  The present invention can be applied to a high-luminance and small light-emitting device, particularly a headlamp for a vehicle or the like.

1a to 1e Projector 2 Semiconductor laser element array 3 Semiconductor laser element (laser light source)
4 condensing lens 5 optical fiber 7 light emitting part 8 reflector (optical system)
8a Light reflecting surface 9 Holding member 10a, 10b Head lamp (lighting device)
11 Case 12 Transparent cover 13 Base 14 Convex lens 15 Projection lens (optical system)
15a Light incident surface (incident surface)
R, R1, R2 Irradiation destination S segment (light emitting surface)
T1-T3 Convex part (reflection structure, refraction structure)
B1-B3 plane (reflective structure, refractive structure)

Claims (3)

Having a laser light source for emitting laser light, a light emitting unit in which the laser light source comprises a phosphor emitting fluorescence by receiving the laser beam emitted, an optical system that emits light the emitting portion is emitted to the outside, respectively Equipped with a floodlight,
There are a plurality of the projectors,
The number of light projected from the plurality of projectors is the same as the number of the plurality of projectors,
The number of types of the phosphors is 2 or more,
The number of the said several projector is 4 or more, The illuminating device characterized by the above-mentioned. Having a laser light source for emitting laser light, a light emitting unit in which the laser light source comprises a phosphor emitting fluorescence by receiving the laser beam emitted, an optical system that emits light the emitting portion is emitted to the outside, respectively Equipped with a floodlight,
More than the number of types of the phosphors included in the light emitting unit, and a plurality of the projectors,
The areas irradiated with the light projected from the plurality of projectors match each other,
The number of types of the phosphors is 2 or more. Having a laser light source for emitting laser light, a light emitting unit in which the laser light source comprises a phosphor emitting fluorescence by receiving the laser beam emitted, an optical system that emits light the emitting portion is emitted to the outside, respectively Equipped with a floodlight,
The projector is one or more than the number of types of the phosphors included in the light emitting unit, and there are a plurality of the phosphors,
The light emitted from the plurality of projectors emits light to the outside so that one or more of the types of phosphors overlap each other,
The number of types of the phosphors is 3 or more.

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