JP6109521B2 - Light emitting device, vehicle headlamp, lighting device, and projector - Google Patents

Description

The present invention relates to a light emitting device, a vehicle headlamp, a lighting device, and a projector that emit illumination light with a desired light projection pattern.

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

  For example, as shown in FIG. 24, a vehicle headlamp 100 disclosed in Patent Document 1 includes a metal plate 111 and a phosphor 112 that is disposed on the surface of the metal plate 111 and emits light when excited by blue laser light. A laser light source (not shown) that emits blue laser light incident on the phosphor 112 and a surface of the metal plate 111 around the phosphor 112 are disposed so as to suppress reflection of the blue laser light incident from the laser light source. And a reflection suppressing member 113. This prevents (or reduces) color unevenness and luminance unevenness of the emitted color caused by the blue laser light emitted from the laser light source being reflected by the surface of the metal plate 111 around the phosphor 112. Yes.

  Further, for example, in the vehicle headlamp 200 disclosed in Patent Document 2, as shown in FIG. 25, a semiconductor light emitting element 201 that generates light, a phosphor 202 that is provided apart from the semiconductor light emitting element 201, and A lens 210 that condenses the light generated by the semiconductor light emitting element 201 on the phosphor 202, and an optical center at the position where the phosphor 202 is provided, and is fluorescent according to the light collected by the lens 210. A reflecting mirror 220 that irradiates the outside of the vehicle headlamp 200 with the light generated by the body 202 is provided. The reflecting mirror 220 has an oblique reflecting surface 221 and a horizontal reflecting surface 222 as shown in FIG. As a result, as shown in FIG. 26 (b), as a low beam light distribution pattern formed on a virtual vertical screen arranged at a position 25m ahead of the vehicle headlamp 200, a horizontal line that defines a light and dark boundary in a substantially horizontal direction. A light distribution pattern 230 having a cut line 231 and an oblique cut line 232 that defines a light / dark boundary in a predetermined oblique direction that forms an angle of about 15 ° with respect to the horizontal direction is formed. The reflecting mirror 220 is commonly called a multi-faceted mirror.

  Further, for example, an optical fiber illuminating device 300 disclosed in Patent Document 3 includes a semiconductor laser 310 that emits pumping light 301 and pumping light emitted from the semiconductor laser 310, as shown in FIGS. A single fiber 320 guided through 301, a phosphor unit 330 that receives excitation light 301 emitted from the single fiber 320 and emits fluorescence having a wavelength different from that of the excitation light 301, and fluorescence emitted from the phosphor unit 330 The fiber bundle 340 guides at least a part of the fiber bundle 340. The optical fiber lighting device 300 further includes at least a part of the light that is not directly incident on the incident region of the fiber bundle 340 among the reflected scattered light generated by the phosphor unit 330 and the fluorescence emitted from the phosphor unit 330. Is reflected toward the incident region of the fiber bundle 340.

JP 2011-181381 A (published September 15, 2011) JP 2005-150041 A (released on June 9, 2005) JP 2009-043668 A (published February 26, 2009)

  However, the conventional light emitting device, the vehicle headlamp, and the lighting device have a problem that a loss of illumination light occurs and the light projecting efficiency decreases.

  Specifically, in the vehicle headlamp 100 disclosed in Patent Document 1, in order to obtain an illumination pattern having a clear edge, the surface of the metal plate 111 around the phosphor 112 is covered with a reflection suppressing member 113. ing. As a result, a part of the blue laser light incident from the laser light source is shielded. Therefore, a loss of illumination light occurs, and the light projecting efficiency is reduced. Further, the contrast at the edge is deteriorated by stray light caused by scattering on the surface of the metal plate 111. Furthermore, there is a problem that the temperature of the metal plate rises due to light absorption by the metal plate 111 and the characteristics of the phosphor 112 are affected by chromaticity change, intensity change, and the like.

  Moreover, in the vehicle headlamp 200 disclosed in Patent Document 2, a multifaceted mirror is used as the reflecting mirror 220. As a result, it is difficult to obtain an illumination pattern having clear edges with a multifaceted mirror, and a larger reflecting mirror 220 is required. Further, there is a problem that stray light is generated in an unnecessary area such as the sky, that is, efficiency is lowered.

  On the other hand, in the optical fiber lighting device 300 disclosed in Patent Document 3, in order to prevent the loss of illumination light, the reflected scattered light generated in the phosphor unit 330 and the fluorescence emitted from the phosphor unit 330 are reduced. Among them, a reflector 350 is provided in order to cause at least a part of the light not directly incident on the incident region of the fiber bundle 340 to enter the incident region of the fiber bundle 340. However, since the optical fiber lighting device 300 disclosed in Patent Document 3 discloses application to an endoscope, there is no description regarding an irradiation pattern. Therefore, it is insufficient for application to a vehicle headlamp.

The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to efficiently form a clear edge in the light emitting portion, and to efficiently form a clear edge of the light projection pattern on the light projecting surface. It is an object of the present invention to provide a light emitting device, a vehicle headlamp, a lighting device, and a projector that can be well formed.

  In order to solve the above-described problems, a light-emitting device of the present invention is a light-emitting device that includes a light-emitting element that emits excitation light and a light-emitting unit that includes a transparent dispersion layer in which a phosphor is dispersed. The excitation light is incident from the first end face of the light-emitting part, and the excitation light incident from the first end face of the light-emitting part is guided by the transparent dispersion layer of the light-emitting part. A luminance distribution at a second end surface that is non-parallel to the first end surface of the light-emitting element is formed, and an edge of the luminance distribution at the second end surface is formed by the concentration control of the phosphor in the light-emitting portion. The fluorescent light emitted from the end face 2 is used as illumination light.

  The light-emitting device of the present invention is characterized in that, in the above-described light-emitting device, the first end surface and the second end surface are orthogonal to each other.

  The light-emitting device of the present invention is the light-emitting device described above, wherein the light-emitting portion has a two-layer laminated structure of a transparent dispersion layer in which the phosphor is dispersed and a transparent non-dispersion layer in which the phosphor is not dispersed. And the transparent dispersion layer is formed such that the thickness gradually increases from the first end face toward the third end face opposed to the first end face. The non-dispersion layer is formed so that the thickness gradually decreases from the first end face toward the third end face, and the excitation light emitted from the light emitting element is emitted from the light emitting section. A luminance distribution having an edge formed in the light emitting portion is formed by being incident from one end face and being guided by the transparent non-dispersion layer and the transparent dispersion layer of the light emitting portion.

  The light-emitting device of the present invention is the light-emitting device described above, wherein a light guide member that guides incident light from the light-emitting element and emits the light to the light-emitting part is provided between the light-emitting element and the light-emitting part. It is characterized by being.

  The light-emitting device of the present invention is the light-emitting device described above, wherein a light guide member that guides incident light from the light-emitting element and emits the light to the light-emitting part is provided between the light-emitting element and the light-emitting part. It is characterized by being.

  The light-emitting device of the present invention is characterized in that, in the above-described light-emitting device, a convex lens is provided between the optical paths of the light-emitting element and the light-emitting portion.

  The light-emitting device of the present invention is characterized in that in the above-described light-emitting device, a condensing mirror is provided between the light paths of the light-emitting element and the light-emitting portion.

  The light-emitting device of the present invention is characterized in that in the above-described light-emitting device, the transparent dispersion layer is formed so that the thickness gradually changes toward a part of the end of the light-emitting portion.

  A vehicle headlamp according to the present invention includes the light emitting device described above.

  An illumination device according to the present invention includes the light-emitting device described above.

  A projector according to the present invention includes the light-emitting device described above.

  As described above, the light-emitting device of the present invention guides the excitation light emitted from the light-emitting element through the transparent dispersion layer of the light-emitting part, thereby forming a luminance distribution in the light-emitting part and the light emission. The edge of the luminance distribution is formed according to the form of the part.

  As described above, the vehicle headlamp according to the present invention includes the light-emitting device described above.

  As described above, the lighting device of the present invention includes the light emitting device described above.

As described above, the projector according to the present invention includes the light-emitting device described above.

Therefore, it is possible to provide a light emitting device, a vehicle headlamp, a lighting device, and a projector that can efficiently form a clear edge in a light emitting portion, and thus can efficiently form a clear edge of a light projection pattern on a light projecting surface. The effect of doing.

(A) shows one Embodiment in the headlamp as a vehicle headlamp provided with the light-emitting device in this invention, Comprising: It is a front view which shows the light intensity distribution of a laser emission end part, (b) is a front view showing the light intensity distribution of the irradiation pattern in the light emitting part, (c) is a front view showing the light intensity distribution of the light emitting pattern in the light emitting part, and (d) is a light projecting pattern on the light projecting surface. It is a front view which shows light intensity distribution. It is a schematic block diagram which shows the whole said headlamp which is not provided with the light guide member between the light source part and the light emission part. FIG. 9 is a schematic configuration diagram showing a whole headlamp, showing a modified example of the headlamp in which a light guide member is not provided between the light source section and the light emitting section. FIG. 9 is a schematic configuration diagram showing the whole headlamp, showing another modification of the headlamp that does not include a light guide member between the light source section and the light emitting section. It is a schematic block diagram which shows the further another modification of the said headlamp which is not provided with the light guide member between the light source part and the light emission part, Comprising: The whole headlamp is shown. It is a schematic block diagram which shows the whole said headlamp provided with two sets of light source parts, and provided with the light guide member between the light source part and the light emission part. It is a schematic block diagram which shows the whole said headlamp which is not provided with the light guide member between the light source part and the light emission part. It is sectional drawing which shows the structure of the light source part in the said headlamp provided with the light guide member between the light source part and the light emission part. It is a front view which shows an example of the shape of the laser beam spot in the laser beam irradiation surface of the light emission part in the said headlamp. It is sectional drawing which shows the structure of the modification of the light source part in the said headlamp provided with the light guide member between the light source part and the light emission part. It is sectional drawing which shows the structure of the other modification of the light source part in the said headlamp provided with the light guide member between the light source part and the light emission part. It is sectional drawing which shows the structure of the further another modification of the light source part in the said headlamp provided with the light guide member between the light source part and the light emission part. It is sectional drawing which shows the structure of the modification in the said headlamp which is not provided with the light guide member between the light source part and the light emission part. It is sectional drawing which shows the structure of the modification of the light source part in the said headlamp which is not provided with the light guide member between the light source part and the light emission part. It is sectional drawing which shows the structure of the other modification of the light source part in the said headlamp which is not provided with the light guide member between the light source part and the light emission part. It is a front view which shows the laser beam spot in the light emission part of the said headlamp. It is a front view which shows the light emission pattern in the light emission part of the said headlamp. (A) is a distribution diagram showing a light intensity distribution having an ideal Gaussian distribution, and (b) is a distribution diagram showing a light intensity distribution with a large top width of the light intensity distribution. (A) is a distribution diagram which shows the definition of the edge in light intensity distribution, (b) is a distribution diagram which shows an example in case an edge is not comprised by a definition, when an edge is comprised by a definition. It is sectional drawing which shows the internal structure in the light emission part of the said headlamp. It is sectional drawing which shows the other internal structure in the light emission part of the said headlamp. It is sectional drawing which shows a structure when changing the light intensity distribution of the light emission pattern from a light emission part by changing the density | concentration of the fluorescent substance in the light emission part of the said headlamp. It is sectional drawing which shows another structure when changing the light intensity distribution of the light emission pattern from a light emission part by changing the density | concentration of the fluorescent substance in the light emission part of the said headlamp. It is a perspective view which shows the structure of the conventional vehicle headlamp. It is sectional drawing which shows the structure of the other conventional vehicle headlamp. (A) is a front view which shows the structure of the multi facet mirror provided in the said conventional vehicle headlamp, (b) is a perspective view shown in the light distribution pattern of the irradiation surface of the said vehicle headlamp. (A) is sectional drawing which shows the structure of the further another conventional vehicle headlamp, (b) is sectional drawing which shows the structure of the light emission part of the said vehicle headlamp.

  One embodiment of the present invention is described below with reference to FIGS.

  In the present embodiment, a headlamp as a vehicle headlamp that satisfies the light distribution characteristic standard of a vehicle headlight (low beam) equipped with the light emitting device of the present invention will be described as an example. However, the present invention is not necessarily limited thereto, and the light emitting device of the present invention may be, for example, a traveling headlamp (high beam), or a vehicle or moving object other than an automobile (for example, a human, a ship, an aircraft, a submersible craft). -It may be implement | achieved as a headlamp of a rocket etc., and may be implement | achieved as another illuminating device. Examples of other lighting devices include a searchlight, a projector, a home lighting device, a commercial lighting device, and an outdoor lighting device.

  Here, in the present specification, the light projecting pattern is a light intensity distribution on the light projecting surface and means a light intensity distribution emitted from the light emitting unit. The light projecting surface is a virtual surface for viewing the light projecting pattern.

<Configuration of headlamp>
The structure of the headlamp as the vehicle headlamp according to the present embodiment will be described with reference to FIGS. 2 to 7 are schematic configuration diagrams showing the entirety of various headlamps. FIG. 7 is also a cross-sectional view taken along line AA ′ of FIG.

  As shown in FIG. 2, the headlamp 1 according to the present embodiment includes a light source unit 10, a lens 3, a light emitting unit 4, a reflector 5, a metal base 7, and fins 8.

  The headlamp 1 generates fluorescence in the light emitting unit 4 by irradiating the light emitting unit 4 with excitation light from the light source unit 10, and uses the fluorescence as illumination light.

  Here, the configuration of the headlamp 1 is not necessarily limited thereto. For example, as shown in FIG. 3, the lens 3 as an optical component and the cap 15 of the light source unit 10 may be integrated. Is possible. In the case where the lens 3 and the cap 15 of the light source unit 10 are separated, a space is required between the cap 15 and the lens 3, and thus the lens 3 as a large optical component is required. Further, since the number of parts increases, the cost increases. Furthermore, optical axis alignment becomes complicated. However, in the case of a configuration in which the lens 3 and the cap 15 of the light source unit 10 are integrated, space can be saved by integrating the lens 3 with the light source unit 10 including a laser chip. Further, the optical axis adjustment (alignment) between the laser chip and the lens 3 is facilitated, and the coupling efficiency can be further increased.

  However, the configuration shown in FIG. 3 is not aligned with the light emitting unit 4. Actually, it is necessary to dissipate heat in both the light emitting unit 4 and the light source unit 10. In the case of such a configuration, each part is installed on the heat radiating member via a heat radiating grease or a heat radiating sheet (not shown), but it is difficult to achieve both optical alignment and heat radiating properties. Therefore, it is desirable to perform die bonding after alignment using solder or the like. Moreover, since the density of the excitation light irradiated to the light emitting part 4 is high, there is also a problem that the light emitting part 4 becomes dirty due to the dust collection effect of the ultraviolet light that is the excitation light, and the luminous efficiency gradually deteriorates. Furthermore, since the laser light used in this embodiment has a high output, it needs to be cut so as not to enter the human eye. And it is required to make the space as small as possible.

  Therefore, as shown in FIG. 4, a condensing mirror 18 is used instead of the lens 3, the light source unit 10 having the laser chip 11 inside the cap 15, the light emitting unit 4, and the condensing mirror 18 are integrated, and further light emission It is possible to make the part 4 into a package storage type that is sealed with dry air. In this case, a high-pass filter that cuts the laser light and extracts only the light from the light emitting unit 4 is used for the window portion of the cap 15. The high-pass filter is preferably a reflection type from the viewpoint of preventing the deterioration of the filter. However, the present invention is not limited to this, and an absorption type is also possible.

  In the headlamp 1 shown in FIG. 4, the reflector 5 is used. However, as shown in FIG. 5, a projection lens can be used instead of the reflector 5.

  Further, as shown in FIG. 6, the headlamp 1 in which the light guide member 13 is provided between the light source unit 10 and the lens 3 can be used.

(Light source)
The light source unit 10 has a light emitting element that emits excitation light. In the present embodiment, for example, a semiconductor laser is used. However, the present invention is not necessarily limited to this, and an LED can also be used. However, since the semiconductor laser has better coupling efficiency with respect to the light guide member 13 than the LED, it is preferable to use the semiconductor laser as an excitation light source.

  A plurality of the light source units 10 may be provided as shown in FIG. In this case, laser light as excitation light is emitted from each of the plurality of light source units 10. Although only one light source unit 10 may be used, it is preferable to use a plurality of light source units 10 in order to obtain a high-power laser beam. In FIG. 6, each set of the light source unit 10 and the lens 3 irradiates another part of the light emitting unit 4, but may be set to irradiate the same part.

  Further, the light source unit 10 may have one light emitting point on one chip, or may have a plurality of light emitting points on one chip. The wavelength of the laser light of the light source unit 10 is, for example, 395 nm (blue violet) or 450 nm (blue), but is not limited thereto, and is appropriately selected according to the type of phosphor included in the light emitting unit 4 such as 405 nm. That's fine. Details of the light source unit 10 will be described later.

(lens)
The lens 3 irradiates the light emitting unit 4 with the laser light emitted from the optical rod 13 </ b> A of the light source unit 10, and irradiates the light emitting unit 4 by controlling the size of the laser light spot.

  By providing the lens 3, as shown in FIG. 6, the emission end face 13 b as the light guide member emission end face and the laser beam spot 4 b as the irradiation area of the excitation light irradiated on the light emitting unit 4 are in an optically conjugate relationship. This makes it easy to control the size of the laser beam spot 4b of the excitation light irradiated on the light emitting unit 4.

  By changing the design of the curved surface of the lens 3 or changing the distance between the lens 3 and the light emitting unit 4, the size of the laser light spot on the laser light irradiation surface 4 a of the light emitting unit 4 can be changed. it can.

  The lens 3 is a convex lens, for example. The lens 3 is disposed with respect to each of the light source units 10 so that the emission end surface 13b and the laser beam spot 4b of the excitation light irradiated on the light emitting unit 4 have a substantially optical conjugate relationship. The positional relationship between the lens 3 and the light emitting unit 4 is defined.

  The lens 3 can be changed to a concave mirror, for example. In addition, a multi-element lens using a plurality of lenses may be used, and a prism, mirror, cube, or the like may be included to control the optical path. That is, the lens 3 is not particularly limited as long as the size of the laser beam spot can be controlled.

(Light emitting part)
In the present embodiment, the light emitting section 4 is roughly sized such that the area of the light emitting surface is 2000 μm wide × 500 μm long and the thickness is 100 μm.

  The light emitting unit 4 emits fluorescence upon receiving laser light emitted from the light source unit 10, and includes a phosphor that emits light upon receiving laser light, that is, a fluorescent material. Specifically, the light emitting unit 4 is one in which a phosphor is dispersed inside a transparent dispersion layer such as a phosphor-containing glass layer. The light emitting unit 4 can be said to be a wavelength conversion element because it converts laser light into fluorescence.

  The light emitting unit 4 is disposed on the metal base 7 and at a substantially focal position on the reflector 5. Therefore, the fluorescence emitted from the light emitting unit 4 is reflected on the reflection curved surface of the reflector 5 to control the optical path. An antireflection structure for preventing the reflection of the laser beam may be formed on the laser beam irradiation surface 4 a of the light emitting unit 4.

In the present embodiment, BAM (BaMgAl) is used as the phosphor of the light emitting unit 4 so as to emit white spontaneous emission light (fluorescence) upon receiving laser light having a wavelength of 395 nm oscillated by the laser chip 11 serving as a light emitting element. ₁₀ O ₁₇ : Eu), BSON (Ba ₃ Si ₆ O ₁₂ N ₂ : Eu), Eu-α (Ca-α-SiAlON: Eu), etc. are mixed and used. However, the phosphor is not limited to these. For example, when the headlamp 1 is used for an automobile, the illumination light of the headlamp 1 has a chromaticity within a predetermined range defined by law. What is necessary is just to select suitably so that it may become white which has. In addition, for applications such as lighting, the phosphors may be used alone or a plurality of types of phosphors may be mixed as appropriate so that necessary chromaticity is obtained.

For example, other oxynitride phosphors (for example, sialon phosphors such as JEM (LaAl (SiAl) ₆ N ₉ O: Ce) and β-SiAlON), nitride phosphors (for example, CASN (CaAlSiN ₃ : Eu)) Phosphor, SCASN ((Sr, Ca) AlSiN ₃ : Eu) phosphor), Apatite ((Ca, Sr) ₅ (PO ₄ ) ₃ Cl: Eu) system, Silicate ((Ba, Sr, Mg) ₂ SiO ₄ : Eu, Mn) -based phosphor or III-V compound semiconductor nanoparticle phosphor (for example, indium phosphorus: InP).

  For example, when blue, green, and red phosphors are included in the light emitting unit 4 and irradiated with laser light of 405 nm, white light is generated. Alternatively, a yellow phosphor (or green and red phosphor) is included in the light-emitting portion 4 and a so-called blue laser beam having a peak wavelength in a wavelength range of 450 nm (blue) to 450 nm (blue) (or 440 nm to 490 nm). ) Can also be used to obtain white light.

  The transparent dispersion layer of the light emitting unit 4 is, for example, a glass material such as inorganic glass or organic-inorganic hybrid glass. Low melting glass may be used as the glass material. The transparent dispersion layer preferably has a high transparency, and when the laser beam has a high output, a high heat resistance is preferable.

Further, the total reflection critical angle is reduced by using, for example, ZrO 2 having a refractive index substantially the same as that of the phosphor as the main component of the glass that is a transparent dispersant. Accordingly, the excitation light is easily confined in the light emitting unit 4, and light emission from the phosphor is easily emitted from the light emitting unit 4. Therefore, by providing the phosphor concentration distribution, it is possible to form a luminance distribution in the light emitter according to the fluorescence concentration distribution. The refractive index is important, and glass other than ZrO ₂ may be used. However, since ZrO ₂ can be formed by a sol-gel method, it can be formed at a low temperature. Although this effect is reduced, TiO ₂ , AlOx, SiOx or the like may be used instead of ZrO ₂ , but if a substance having a refractive index higher than that of the phosphor is used, the light extraction efficiency is deteriorated.

  Therefore, for example, as shown in FIG. 7, in order to suppress the loss of excitation light scattered by the phosphor and increase the absorption efficiency of the excitation light within the light emitting unit 4, the phosphor concentration is increased in the excitation light traveling direction. Is preferred. This is because when the phosphor on the incident side is dark, it is difficult to control the phosphor concentration so that a desired luminance distribution is obtained, and this is not suitable for mass production.

  In the present embodiment, excitation light is coupled to the light emitting unit 4 and an edge is formed by the shape of the light emitting unit 4 and the phosphor concentration.

  However, leakage light from the side surface is generated. Therefore, particularly in a portion where an edge is to be formed, HR (High Reflection) coating (dielectric multilayer film or high reflection metal film such as Al) is applied, thereby leaking light. And an edge with high contrast can be formed.

  Further, from the viewpoint of improving efficiency, it is desirable to apply an AR (Anti Reflection) coat (λ / 4 film) to the excitation light incident end face of the light emitting section 4 and to apply an HR coat to the other side face.

  In addition, a metal base 7 for heat dissipation from the light emitting unit 4 exists on the bottom side of the light emitting unit 4, but an HR coat is also provided on the bottom side for the purpose of reducing unnecessary absorption by the metal base 7. May be. In this case, in order to prevent a mirror loss in the waveguide of excitation light, a dielectric multilayer structure is desirable.

  In addition, it is desirable that the light emitting unit 4 is thin in order to prevent the contrast of the projected edge from being lowered due to the fluorescence being guided in the planar direction inside the light emitting unit 4. Specifically, it is desirable that the thickness is ½ or less of the half width of the irradiation pattern (light intensity distribution) formed on the laser light irradiation surface 4 a of the light emitting unit 4.

(Heat dissipation part)
The metal base 7 is a plate-like support member that supports the light emitting unit 4 and is made of a metal such as aluminum or copper. Therefore, the metal base 7 has high thermal conductivity, and can efficiently dissipate heat generated by the light emitting unit 4.

  In addition, the member which supports the light emission part 4 is not limited to what consists of metals, For example, the member containing substances with high heat conductivity other than metals, such as silicon carbide or aluminum nitride, may be sufficient. The surface of the metal base 7 in contact with the light emitting unit 4 may be a reflective surface. Since the surface is a reflection surface, after the laser light incident from the laser light irradiation surface 4a of the light emitting unit 4 is converted into fluorescence, the generated fluorescence is reflected by the reflection surface and directed toward the reflector 5. it can. The reflecting surface needs to be appropriately designed so as not to damage the edge.

  The fin 8 functions as a cooling unit that cools the metal base 7, that is, a heat dissipation mechanism. The fin 8 has a plurality of heat radiating plates, and increases the heat radiation efficiency by increasing the contact area with the atmosphere. The cooling part that cools the metal base 7 may have any function of cooling by heat dissipation, and may be a heat pipe, a water cooling system, or an air cooling system.

(Reflector)
The Paris reflector 5 is an example of a light projecting member that reflects the fluorescence generated by the light emitting unit 4 and forms a light bundle (illumination light) that travels within a predetermined solid angle. The reflector 5 may be, for example, a member having a metal thin film formed on the surface thereof or a metal member.

  Further, the reflector 5 has at least a part of a partial curved surface obtained by cutting a parabolic curved surface formed by rotating the parabola around the axis of symmetry of the parabola along a plane including the rotational axis. It is included in the reflective surface.

  Furthermore, a window 6 is formed in the reflector 5. This is because the light source unit 10 is disposed outside the reflector 5, so that the laser light from the light source unit 10 is transmitted or passed through the window 6 of the reflector 5. The window 6 may be an opening or may include a transparent member that can transmit laser light. For example, a transparent plate provided with a filter that transmits laser light and reflects white light that is fluorescence of the light emitting section 4 may be provided as the window section 6. In this configuration, the fluorescence of the light emitting unit 4 can be prevented from leaking from the window unit 6.

  One common window unit 6 may be provided for the plurality of light source units 10, or a plurality of window units 6 corresponding to the respective light source units 10 may be provided.

  In addition, the reflector 5 may be a projection mirror such as a parabolic mirror having a closed circular opening, or may include a parabolic shape such as an off-axis parabolic mirror. It is also possible to use a projection optical system such as a projection optical system that combines an elliptical mirror and a projection lens as a reflector.

  Note that the irradiation pattern in the light emitting unit 4 is characterized by the fact that it is possible to project the edge shape without projecting loss using a simple projecting optical system as described above. It does not exclude use.

  The reflector 5 may be an optical system that projects and projects the light projection pattern in the light emitting unit 4, and an elliptical shape, a free-form surface shape, a multi-faceted multi-reflector, or the like can be used as appropriate. In this case, the relationship between the irradiation pattern and the light projection pattern may not necessarily be a simple shape deformation. However, it is effective to form an edge in the irradiation pattern in the sense that the edge is efficiently formed in the projection pattern.

(Light source details)
Next, details of the light source unit 10 will be described with reference to FIGS. FIG. 8 is a cross-sectional view illustrating the configuration of the light source unit in the headlamp including a light guide member between the light source unit and the light emitting unit. FIG. 9 is a front view illustrating an example of the shape of a laser beam spot on the laser beam irradiation surface of the light emitting unit in the headlamp. FIG. 10 is a cross-sectional view showing a configuration of a modified example of the light source unit in the headlamp including a light guide member between the light source unit and the light emitting unit, and FIG. 11 shows another modified example of the light source unit in the headlamp. FIG. 12 is a cross-sectional view illustrating a configuration of still another modification example of the light source unit in the headlamp including the light guide member between the light source unit and the light emitting unit. FIG. 13 is a cross-sectional view illustrating a configuration of a modified example of the headlamp that does not include a light guide member between the light source unit and the light emitting unit, and FIG. 14 illustrates a light guide member between the light source unit and the light emitting unit. FIG. 15 is a cross-sectional view illustrating a configuration of a modified example of the light source unit in the headlamp that is not provided, and FIG. 15 is another modification of the light source unit in the headlamp that is not provided with a light guide member between the light source unit and the light emitting unit. It is sectional drawing which shows the structure of an example. 8 and FIGS. 10 to 12 will be described with respect to those provided with a light guide member, and FIGS. 13 to 15 will be described with respect to those not provided with a light guide member.

  As shown in FIG. 8, the light source unit 10 includes a laser chip 11 as a light emitting element, a submount 12, an optical rod 13A as a light guide member, an AR (Anti Reflection) coat film 14, a cap 15, a stem 16, and a lead terminal. 17 is provided.

(Laser chip)
The laser chip 11 is a chip-shaped semiconductor laser element that emits laser light as excitation light. The laser chip 11 of the present embodiment is a nitride semiconductor laser, and its oscillation wavelength is 395 nm. However, the laser chip 11 is not limited to a nitride-based semiconductor laser, and the oscillation wavelength is not limited to 395 nm. In order to obtain a desired chromaticity, the light-emitting portion 4 of the light-emitting device 1 described later is obtained. What is necessary is just to select suitably according to the relationship with the fluorescent material which comprises.

  Further, the configuration of the laser chip 11, for example, the material of the semiconductor layer is not particularly limited.

  Further, the laser chip 11 may have one light emitting point per chip, or may have a plurality of light emitting points per chip. The oscillation wavelength of the laser beam of the laser chip 11 is preferably in the wavelength range of 365 nm to 470 nm. In addition to the oscillation wavelength of 395 nm of the present embodiment, for example, 405 nm (blue violet) or 450 nm (blue) or the like emits light. What is necessary is just to select suitably according to the kind of fluorescent substance included in the part 4. FIG. The oscillation wavelength of the laser light from the laser chip 11 is more preferably in the wavelength range of 350 nm to 415 nm (ultraviolet light region).

(Submount)
Since the laser chip 11 has a large difference in thermal expansion coefficient between the laser chip and the metal stem 16, in consideration of characteristic deterioration and peeling due to stress, the submount is soldered to a heat dissipating member called a submount 12. Then, fix the submount to the stem. As the material for the submount, a material having a thermal expansion coefficient close to that of the laser chip and high thermal conductivity is selected.

  Although the constituent material of the submount 12 of this Embodiment is AlN, it is not limited to this. For example, aluminum nitride, SiC, CuW, Cu, diamond, or Si can be used.

  If the stem 16 is made of a ceramic such as AlN having a thermal expansion coefficient close to that of the laser chip and high thermal conductivity, the submount may not be required.

(Stem)
The stem 16 is made of a core material containing iron and copper coated with gold. The core material of the stem 16 may be copper or iron only, and the coating may be Ag, Pt, PtRd or the like, and may be uncoated as long as the weather resistance is not a problem.

  From the viewpoint of member cost, workability of the member, and heat generated in the laser chip 11, the stem 16 is preferably made of a metal having high thermal conductivity. However, it is not limited to metals, and may be ceramics such as AlN and SiC.

  The lead terminal 17 is a terminal for supplying power from an external power source.

  A lead terminal 17 is connected to the laser chip 11 through a gold wire (not shown), and power is supplied from an external power source through these wires.

(Optical rod)
The optical rod 13A is made of a transparent material such as glass, acrylic, or polycarbonate, for example, and is a light guide member that converts a light intensity distribution composed of a substantially Gaussian distribution of laser light emitted from the laser chip 11 into a predetermined distribution. It is an optical member. The optical rod 13A includes an incident end face 13a that receives laser light and an exit end face 13b that emits laser light. The incident end face 13a is formed at one end of the optical rod 13A, and the exit end face 13b is formed at the other end of the optical rod 13A.

  The incident end face 13a is disposed in the vicinity of the light emitting point of the laser chip 11, and the laser light emitted from the light emitting point enters the optical rod 13A from the incident end face 13a. In this case, for example, as a light intensity distribution on the emission end face 13b of the optical rod 13A, a top hat-shaped distribution may be considered in order to form an edge. The light incident on the optical rod 13A is not limited to light from one laser chip, but may be light from a plurality of laser chips. An optical member such as a lens or a mirror may be inserted between the optical rod 13A and the laser chip.

  However, when applied to a passing headlamp (low beam) as in the headlamp 1 of the present embodiment, it is necessary to form a clear contrast above the projection pattern on the projection surface. In addition, there are many illuminations that require contrast between light and dark, such as illumination that illuminates risk factors such as obstacles or stage illumination represented by spotlights so as not to give glare to oncoming vehicles. Therefore, the light intensity distribution on the exit end face 13b of the optical rod 13A does not necessarily have a top hat-shaped distribution, and it is only necessary to have an edge at least partially.

  Next, as shown in FIG. 8, the emission end portion of the optical rod 13 </ b> A where the emission end surface 13 b is formed extends through the cap 15 to the outside of the light source unit 10, and the emission end surface 13 b and the light emitting unit 4. The positional relationship between the emission end face 13b, the lens 3 and the light emitting portion 4 is defined so that the laser beam spot 4b of the excitation light irradiated on the lens has a substantially optical conjugate relationship. Since the aperture ratio NA of the lens is set to be larger than the aperture ratio NA of the optical rod 13A, the light emitting unit 4 efficiently irradiates the laser light irradiation surface 4a.

  An AR coating film 14 that is an antireflection film is disposed on the incident end face 13a. Therefore, it is possible to prevent the laser light from being reflected on the incident end face 13a, and it is possible to reduce a loss when the laser light is incident on the inside of the optical rod 13A. The AR coating film 14 may be provided on the emission end face 13b. The AR coating film 14 is an example of an antireflection structure, and other antireflection structures including a moth-eye structure may be provided on the incident end face 13a.

  In addition, it is not always necessary to extend the exit end portion on which the exit end surface 13b of the optical rod 13A is formed to the outside of the cap 15 in the light source unit 10, and the exit end surface 13b is accommodated inside the cap 15 so that the exit end surface 13b A cap glass may be provided on the cap 15 as a window portion that transmits the emitted laser light. Whether or not the exit end portion on which the exit end face 13b is formed is extended to the outside of the cap 15 in the light source unit 10 depends on the optical rod 13A necessary for converting laser light into light having a predetermined light intensity distribution. Depends on length.

  In the example shown in FIG. 8, the length of the optical rod 13A is 20 mm, for example, and the rod diameter is 0.4 mm. However, the size of the optical rod 13A is not limited to this.

  Here, the shape of the emission end face 13b in the optical rod 13A of the present embodiment can be formed in, for example, a polygon. However, it is not necessarily limited to this, and a general circular or elliptical shape may be used. Accordingly, for example, when the shape of the emission end face 13b is a quadrangle such as a rectangle or a square, that is, when the three-dimensional shape of the optical rod 13A is a quadrangular prism, the irradiation region on the laser light irradiation surface 4a of the light emitting unit 4 is As shown in FIG. 9, the shape of the laser light spot 4b reflects a rectangle such as a rectangle or a square of the emission end face 13b. As a result, the shape of the laser light spot 4b can be changed to a desired shape by changing the shape of the emission end face 13b.

By the way, in said FIG. 8, the shape of the incident end surface 13a of the optical rod 13A is the same shape as the shape of the output end surface 13b. However, the present invention is not necessarily limited thereto. For example, as shown in FIG. 10, the shape on the incident end face 13a side may be different from the shape on the exit end face 13b side. For example, the shape on the incident end face 13a side is a compound parabolic concentrator (Compound Parabolic Concentrator).
: CPC) shape (shape in which the incident end face is larger than the light emitting area of the laser element and then expands in a substantially parabolic shape in the waveguide direction). Thereby, it is possible to couple the laser beam from the laser chip 11 efficiently.

  8 and 10 described above, the optical rod 13A and the laser chip 11 are connected to each other. Thereby, since the laser chip 11 and the optical rod 13A are directly connected, there is no need to provide a lens or the like for optically connecting the laser chip 11 and the optical rod 13A. Is simple.

  However, the present invention is not limited to this, and as shown in FIG. 11, the laser chip 11 and the optical rod 13B can be provided apart from each other. In this case, a coupling lens 18 is required in the light source unit 10 in order to couple the light emitted from the laser chip 11 to the optical rod 13B. Thereby, the light source unit 10 having the laser chip 11 can be provided separately from the optical rod 13B. As a result, the freedom degree of the attachment position of the light source part 10 can be improved.

  In the present embodiment, the optical rods 13A and 13B are made of a transparent material such as acrylic or glass. However, the present invention is not limited to this, and as shown in FIG. 12, an optical rod 13C made of a multimode fiber. It is also possible.

  In other words, the optical fiber has a triple structure consisting of a core called a core, a portion called a clad outside the core, and a coating covering them, and by making the refractive index of the core higher than the cladding. The structure is such that light is propagated only to the central core as much as possible by total reflection and refraction. The mode of the optical fiber is divided depending on the path of light propagating through the optical fiber. That is, a fiber having one optical path (= one group velocity and one mode) is a single mode fiber, and the other is a multimode fiber. Multimode fiber has a larger core diameter and resistance to bending than single mode fiber, and it is relatively easy to connect between optical fibers and between optical fiber and equipment. However, it has the feature of being inexpensive.

  As a result, by using the optical rod 13C using a multimode fiber, for example, it is less expensive than using an optical fiber that is not an optical fiber, and the light guide distance can be increased. For this reason, there is an advantage in the case where the distance from the light source unit 10 to the light emitting unit 4 is long and cannot be connected in a straight line.

  Therefore, when the light-emitting device is used for the headlamp 1, the light source unit 10 can be arranged in an empty space inside the hood of the vehicle, so that the degree of design freedom is widened. In addition, the multimode fiber has an advantage that the degree of freedom in designing the light distribution at the fiber output end is high.

  When the optical rod 13C using a multimode fiber is used, the core diameter can be set to 0.4 mm, for example.

(cap)
The cap 15 is a member for enclosing or sealing a member such as the laser chip 11 as shown in FIG. Particularly, the cap 15 fixes the relative position between the laser chip 11 and the optical rod 13A. The inside of the cap 15 may be hollow, and may be filled with a material such as resin or low-melting glass. Moreover, you may form the whole cap 15 with low melting glass.

<Configuration for forming clear edges of projection pattern>
In the headlamp 1 according to the present embodiment, when there is no light guide member between the light source unit 10 and the light emitting unit 4, the light is emitted from a laser chip 11 as a light emitting element as shown in FIG. The excited light is condensed on the end face of the light emitting unit 4 by the lens 3. In this case, as shown in FIG. 14, the light source unit 10, the light collecting mirror 18, and the light emitting unit 4 may be integrated using a light collecting mirror 18 instead of the lens 3.

  Further, as shown in FIG. 15, the light emitting unit 4 and the laser chip 11 may be directly connected to each other without condensing the excitation light.

  When the lens 3 and the condensing mirror 18 are used, it is preferable to arrange the laser chip 11 and the light emitting unit 4 so that the normal vectors for the surfaces of the laser chip 11 and the light emitting unit 4 are in the same plane. Coupling efficiency is good. However, as shown in FIG. 15, in the case of butt connection, the coupling efficiency is better if the normal vectors with respect to the surfaces of the laser chip 11 and the light emitting unit 4 are orthogonal to each other.

  On the other hand, in the headlamp 1 according to the present embodiment, when a light guide member is present between the light source unit 10 and the light emitting unit 4, the laser chip 11 as a light emitting element is used as shown in FIG. The excitation light emitted in this manner is incident on an optical rod 13A serving as a light guide member. This excitation light is guided by the optical rod 13A, and the emitted light from the optical rod 13A is incident on the light emitting unit 4. Then, in the light emitting unit 4, fluorescence is emitted by the phosphor, and as shown in FIGS. 1C and 1D, the fluorescence is projected as a projection pattern P3 on the projection surface.

  Here, in order to form a clear edge of the light projecting pattern P3 on the light projecting surface, conventionally, in order to obtain a desired irradiation pattern, an irradiation area in the light emitting part of the light emitted from the light guide member is more than the light emitting part. After that, the light emitting part was shielded in a similar shape of a desired irradiation pattern, or the irradiation surface was irradiated through a multi-faceted mirror. As a result, there is a problem that a loss of illumination light occurs.

  In order to solve this problem, the light emitting device and the headlamp 1 according to the present embodiment have the following configuration. These configurations will be described with reference to FIGS. 1A, 1B, 1C, and 1D and FIGS. FIG. 1A is a front view showing the light intensity distribution at the laser emission end, FIG. 1B is a front view showing the light intensity distribution of the irradiation pattern P1 in the light emitting part, and FIG. It is a front view which shows the light intensity distribution of the light emission pattern P2 in a light emission part, FIG.1 (d) is a front view which shows the light intensity distribution of the light projection pattern P3 in a light projection surface. FIG. 16 is a front view showing the configuration of the laser beam spot 4 b in the light emitting section 4 of the headlamp 1. FIG. 17 is a front view showing a light emission pattern in the light emitting portion of the headlamp. FIG. 18A is a distribution diagram showing a light intensity distribution composed of an ideal Gaussian distribution, and FIG. 18B is a distribution diagram showing a light intensity distribution with a large top width of the light intensity distribution. FIG. 19A is a distribution diagram showing the definition of the edge in the light intensity distribution, and FIG. 19B is a distribution diagram showing an example of the case where the edge is configured by the definition and the case where the edge is not configured by the definition. FIG. 20 is a cross-sectional view showing an internal configuration of the light emitting unit 4 in the headlamp 1 as a vehicle headlamp including the light emitting device. FIG. 21 is a cross-sectional view showing another internal configuration of the light-emitting portion of the headlamp. FIG. 22 is a cross-sectional view showing a configuration when the light intensity distribution of the light emission pattern from the light emitting part is changed by changing the concentration of the phosphor in the light emitting part of the headlamp. FIG. 23 is a cross-sectional view showing another configuration when the light intensity distribution of the light emission pattern from the light emitting part is changed by changing the concentration of the phosphor in the light emitting part of the headlamp.

  20 to 23 are cross-sectional views taken along the line A-A 'of FIG. Moreover, in the following description, the optical rod 13A as a light guide member will be described. However, the same can be applied to the optical rods 13 </ b> B and 13 </ b> C as light guide members, and it can also be applied to a headlamp 1 that does not include a light guide member.

  In the light emitting device according to the present embodiment, as shown in FIGS. 1A, 1B, 1C, and 16, a laser beam spot that is an irradiation region of the light emitted from the optical rod 13A in the light emitting section 4 is used. 4 b is smaller than the laser light irradiation surface 4 a of the light emitting unit 4. For this reason, since the total amount of light emitted from the optical rod 13A is incident on a partial region of the light emitting portion in its shape, the light emitting portion 4 can use the total amount of light emitted from the optical rod 13A. Efficient.

  By the way, since the light emission part 4 has the transparent dispersion layer which disperse | distributed fluorescent substance, the transparent dispersion layer has a light guide effect. For this reason, it is possible to guide the light incident on the irradiation region of the light emitting unit 4 from the optical rod 13A to the end 4c of the light emitting unit 4 by the light guide action and to emit the light from the end 4c.

  Here, in the present embodiment, as shown in FIG. 16, the shape of the end portion 4 c of the light emitting unit 4 is formed in the shape of the end portion of the light projecting pattern. As a result, as shown in FIG. 1B, the light incident as the irradiation pattern P <b> 1 from the optical rod 13 </ b> A to the irradiation region of the light emitting unit 4 is one of the light projection patterns P <b> 3 by the light guide action in the light emitting unit 4. As shown in FIG. 1C and FIG. 17, a light emission pattern P2 is formed in a state where the light intensity is high at a part of the end portion 4c of the light emitting portion 4 formed in the same shape as the end portion of the portion. Emitted. Therefore, the edge shape of the end 4c of the light emitting unit 4 is reflected in the edge shape of the light projection pattern P3 on the light projection surface. Thereby, a clear edge can be formed in the edge part of the light projection pattern P3 in a light projection surface.

  Therefore, it is possible to provide a light emitting device that can efficiently form a clear edge of the light projection pattern on the light projection surface.

  Here, the clear edge of the light projection pattern on the light projection surface ideally means a discontinuous light intensity distribution. Therefore, that there is no clear edge of the light projection pattern on the light projection surface means that the light intensity distribution changes continuously as shown in FIG. Thus, no edge is formed in an ideal Gaussian distribution. However, even if it has the same light intensity gradient as the light intensity distribution shown in FIG. 18A, when the top width of the light intensity distribution is large as shown in FIG. 18B, FIG. The light intensity gradient shown in FIG.

As described above, the edge refers to a light intensity distribution that is a light intensity attenuation profile that is tighter than the light intensity attenuation profile in the Gaussian distribution, and this edge is affected by the width of the light intensity distribution. Therefore, in the present embodiment, as shown in FIG. 19 (a), in detail, the edge is a position at 80% of the peak light intensity and a position at 1 / (e ² ) of the peak light intensity. This is a case where the interval is equal to or less than ½ of the half width. That is, the edge is correctly defined in relation to the half-value width in order to consider the width of the light intensity distribution. In consideration of this half-value width, for example, in the light intensity distribution shown in FIG. 19B, the left light intensity gradient is an edge, but the right light intensity gradient is not an edge. Note that this edge does not necessarily have a light intensity of 0 at the bottom.

  In the light emitting device according to the present embodiment, as shown in FIG. 20, the light emitted from the optical rod 13 </ b> A is irradiated obliquely toward a part of the end 4 c of the light emitting unit 4 within the surface of the light emitting unit 4. The Note that an antireflection film 4 d is provided on the surface of the light emitting unit 4.

  Thereby, since the fluorescent substance containing glass layer FG of the light emission part 4 consists of a transparent member, this transparent member itself functions as a light guide member. For this reason, the light emitted from the optical rod 13A is irradiated obliquely toward the end 4c of a part of the light emitting unit 4 within the surface of the light emitting unit 4, so that the light emitted from the optical rod 13A is emitted from the light emitting unit. 4 enters the phosphor-containing glass layer FG and is guided toward a part of the end portion 4 c of the light emitting unit 4.

  As a result, it is possible to increase the light intensity of the projection pattern P3 projected from the partial end 4c of the light emitting unit 4 onto the projection surface, thereby forming a clearer edge of the projection pattern P3 on the projection surface. can do.

  In the light-emitting device of this embodiment, as shown in FIG. 21, a glass light guide as a light-emitting portion light-guiding member having a refractive index higher than that of the phosphor-containing glass layer FG is provided below the phosphor-containing glass layer FG. The portion LG is formed. At the end 4e side, the phosphor-containing glass layer FG is thin, and at the end 4c on the side where the luminance is desired to be increased, the phosphor-containing glass layer FG is thick. Moreover, in this structure, it irradiates the side surface in the edge part 4e on the opposite side to the edge part 4c of the light emission part 4 toward the edge part 4c of the light emission part 4 in part. The end 4e is provided with an AR coat film 4f, and the end 4c is provided with an AR coat film 4g.

  As a result, the excitation light that has entered the glass light guide LG is initially totally reflected, but the total reflection condition is gradually broken and leaks into the phosphor-containing glass layer FG.

  As a result, it is possible to increase the light intensity of the projection pattern P3 projected from the partial end 4c of the light emitting unit 4 onto the projection surface, and to provide a clearer edge of the projection pattern P3 on the projection surface. Can be formed.

  Furthermore, in the light emitting device of the present embodiment, as shown in FIG. 22, the phosphor-containing glass layer FG of the light emitting unit 4 has a concentration of the phosphor L gradually toward a part of the end 4 c of the light emitting unit 4. It can be said that it is high.

  That is, since the phosphor-containing glass layer FG of the light emitting unit 4 is made of a transparent member, the transparent member itself functions as a light guide member. As a result, in the phosphor-containing glass layer FG of the light emitting unit 4, the concentration of the phosphor L is gradually increased toward a part of the end 4 c of the light emitting unit 4, so that a part of the end 4 c in the light emitting unit 4 is obtained. Thus, the light intensity of the light projection pattern P3 projected on the light projection surface can be increased.

  Therefore, a clearer edge of the light projection pattern P3 on the light projection surface can be formed.

  In FIG. 22, the surface of the light emitting unit 4 is irradiated with excitation light. However, the present invention is not limited to this. For example, as shown in FIG. Similar effects can be obtained.

  As described above, the light-emitting device of the present embodiment includes the laser chip 11 that emits excitation light and the light-emitting unit 4 that includes the phosphor-containing glass layer FG in which the phosphor L is dispersed, and emits light from the laser chip 11. The excited excitation light is guided by the phosphor-containing glass layer FG of the light emitting unit 4 to form a luminance distribution in the light emitting unit 4, and the end shape, thickness, phosphor concentration, etc. in the light emitting unit 4 The edge of the luminance distribution is formed according to the form.

  Therefore, it is possible to provide a light emitting device that can efficiently form clear edges of the light projection pattern P3 on the light projection surface.

  Further, in the light emitting device of the present embodiment, the phosphor-containing glass layer FG of the light emitting unit 4 is formed so as to be thin toward a part of the end 4c of the light emitting unit 4. Therefore, a clearer edge of the light projection pattern P3 on the light projection surface can be formed.

  Further, in the light emitting device of the present embodiment, the phosphor-containing glass layer FG of the light emitting unit 4 is assumed to have a higher phosphor concentration toward a part of the end 4c of the light emitting unit 4. it can. Therefore, a clearer edge of the light projection pattern P3 on the light projection surface can be formed.

  Further, in the light emitting device of the present embodiment, the light from the laser chip 11 may be irradiated obliquely toward a part of the end portion 4 c of the light emitting unit 4 within the surface of the light emitting unit 4. it can. As a result, it is possible to increase the light intensity of the projection pattern P3 projected from the partial end 4c of the light emitting unit 4 onto the projection surface, thereby forming a clearer edge of the projection pattern P3 on the projection surface. can do.

  Further, in the light emitting device according to the present embodiment, the light from the laser chip 11 is directed toward a part of the end part 4 c of the light emitting part 4 and the end opposite to the part of the end part 4 c of the light emitting part 4. It can be assumed that the side surface of the portion is irradiated obliquely. As a result, it is possible to increase the light intensity of the projection pattern P3 projected from the partial end 4c of the light emitting unit 4 onto the projection surface, thereby forming a clearer edge of the projection pattern P3 on the projection surface. can do.

  In the light emitting device of the present embodiment, the optical rod 13 </ b> B provided to be separated from the laser chip 11 can be used. Thereby, the light source unit 10 accommodating the laser chip 11 can be provided separately from the optical rod 13B, and therefore the degree of freedom of the mounting position of the light source unit 10 accommodating the laser chip 11 can be improved.

  In the light emitting device according to the present embodiment, the optical rod 13 </ b> A as a light guide member that guides incident light from the laser chip 11 and emits it to the light emitting unit 4 between the laser chip 11 and the light emitting unit 4. It can be assumed that 13B and 13C are provided.

  In the light emitting device of the present embodiment, an optical rod 13C made of a multimode fiber can be used. Thereby, it is cheaper than using a custom-made product that is not an optical fiber, and the light guide distance can be increased. For this reason, there is an advantage when the distance from the laser chip 11 to the light emitting unit 4 is long and cannot be connected in a straight line. In addition, the multimode fiber has an advantage that the degree of freedom in designing the light distribution at the fiber output end is high.

  Therefore, when the light-emitting device is used for the headlamp 1, the light source unit 10 can be arranged in an empty space inside the hood of the vehicle, so that the degree of design freedom is widened.

  Moreover, the headlamp 1 of this Embodiment is provided with the light-emitting device of this Embodiment. As a result, the light distribution shape of the light projection pattern P3 of the headlamp 1 can be adapted to the light distribution shape of a vehicle headlamp such as a legally defined passing lamp.

  Therefore, it is possible to provide the headlamp 1 including the light emitting device that can efficiently form clear edges of the light projection pattern P3 on the light projection surface.

  Furthermore, the lighting device of this embodiment includes the light-emitting device of this embodiment. Therefore, it is possible to provide an illumination device including a light emitting device that can efficiently form clear edges of the light projection pattern P3 on the light projection surface.

  Note that the present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the claims, and can be obtained by appropriately combining technical means disclosed in the present embodiment. Embodiments are also included in the technical scope of the present invention.

As described above, in order to solve the above problems, the light-emitting device of the present invention is a light-emitting device including a light-emitting element that emits excitation light and a light-emitting unit that has a transparent dispersion layer in which a phosphor is dispersed. Excitation light emitted from the light emitting element is guided by the transparent dispersion layer of the light emitting unit to form a luminance distribution in the light emitting unit, and an edge of the luminance distribution is formed by the form of the light emitting unit. It is characterized by being.

  According to said invention, the excitation light radiate | emitted by the light emitting element injects into a light emission part. And in a light emission part, fluorescence is emitted by a fluorescent substance by being guided by a transparent dispersion layer, luminance distribution is formed, and it projects on a light projection surface as a light projection pattern.

  Here, in order to form a clear edge of the light projection pattern on the light projecting surface, conventionally, in order to obtain a desired light projection pattern, an irradiation area of the light emitting part in the light emitted from the light guide member is more than the light emitting part. After that, the light emitting part was shielded in a similar shape to a desired light projecting pattern, or was projected onto the light projecting surface via a multi-facet mirror. As a result, there is a problem that a loss of illumination light occurs.

  In the present invention, since the light emitting portion has a transparent dispersion layer in which phosphors are dispersed, the transparent dispersion layer has a light guide function. For this reason, light incident on the light emitting portion from the light emitting element can be guided to the end portion of the light emitting portion by the light guide action and emitted from the end portion.

  Here, in the present invention, the edge of the luminance distribution is formed according to the form of the light emitting portion. As a result, the light incident on the light emitting part is emitted in a state where the edge of the luminance distribution is formed according to the form of the light emitting part and the light intensity is increased. Therefore, the edge of the luminance distribution in the light emitting unit is reflected on the edge of the light projection pattern. Thereby, a clear edge can be formed at the end of the light projection pattern on the light projection surface.

  Therefore, it is possible to provide a light-emitting device that can efficiently form a clear edge in the light-emitting portion, and thus can efficiently form a clear edge of the light-projection pattern on the light-projecting surface.

  In the light emitting device of the present invention, it is assumed that a light guide member having a thickness gradually reduced toward a part of the end of the light emitting unit is provided below the transparent dispersion layer of the light emitting unit. it can.

  That is, a light guide member having a thickness gradually reduced toward a part of the end of the light-emitting part is provided below the transparent dispersion layer of the light-emitting part, thereby projecting from a part of the end of the light-emitting part. The light intensity of the light projection pattern projected onto the light surface can be increased.

  Therefore, it is possible to efficiently form a clear edge in the light emitting portion, and thus to form a clearer edge of the light projection pattern on the light projection surface.

  In the light emitting device of the present invention, the transparent dispersion layer of the light emitting unit can be said that the concentration of the phosphor gradually increases toward a part of the end of the light emitting unit.

  That is, in the transparent dispersion layer of the light emitting unit, the phosphor concentration is gradually increased toward a part of the end of the light emitting unit, so that light is projected from a part of the light emitting unit to the light projecting surface. The light intensity of the projection pattern can be increased.

  Therefore, it is possible to efficiently form a clear edge in the light emitting portion, and thus to form a clearer edge of the light projection pattern on the light projection surface.

  In the light emitting device of the present invention, the light from the light emitting element can be irradiated obliquely toward the end of a part of the light emitting unit within the surface of the light emitting unit.

  Thereby, the light from the light emitting element is incident on the transparent dispersion layer of the light emitting unit and is guided toward a part of the end of the light emitting unit.

  As a result, it is possible to increase the light intensity of the light projecting pattern projected onto the light projecting surface from a part of the light emitting unit, efficiently forming a clear edge on the light emitting unit, and eventually the light projecting surface. A clearer edge of the light projection pattern can be formed.

  In the light emitting device according to the aspect of the invention, the light from the light emitting element is irradiated to the side surface of the end portion opposite to the end portion of the light emitting portion toward the end portion of the light emitting portion. It can be.

  As a result, light from the light emitting element is incident on the transparent dispersion layer of the light emitting unit from the side surface at the end opposite to the part of the light emitting unit, toward the end of the light emitting unit. Is guided.

  As a result, it is possible to increase the light intensity of the light projecting pattern projected onto the light projecting surface from a part of the light emitting unit, efficiently forming a clear edge on the light emitting unit, and eventually the light projecting surface. A clearer edge of the light projection pattern can be formed.

  In the light emitting device of the present invention, a light guide member that guides incident light from the light emitting element and emits it to the light emitting part may be provided between the light emitting element and the light emitting part. .

  Thereby, since the light guide distance can be increased, there is an advantage in the case where the distance from the light emitting element to the light emitting portion is long and cannot be connected in a straight line.

  Therefore, when the light-emitting device is used for a vehicle headlamp, the light-emitting element can be arranged in an empty space inside the hood of the vehicle, so that the degree of design freedom increases.

  In order to solve the above-described problems, a vehicle headlamp according to the present invention includes the light-emitting device described above.

  According to said invention, the light distribution shape of the illumination light of a vehicle headlamp can be matched with the light distribution shape of vehicle headlamps, such as a legally defined passing lamp.

  Therefore, it is possible to provide a vehicular headlamp including a light emitting device that can efficiently form a clear edge in a light emitting portion, and thus can efficiently form a clear edge of a light projection pattern on a light projecting surface. .

  In order to solve the above-described problems, an illumination device of the present invention includes the light-emitting device described above.

  According to the invention, it is possible to provide a lighting device including a light emitting device that can efficiently form a clear edge in a light emitting portion, and thus can efficiently form a clear edge of a light projection pattern on a light projecting surface. Can do.

  The light-emitting device of the present invention is a light-emitting device including a light-emitting element that emits excitation light and a light-emitting unit that has a transparent dispersion layer in which a phosphor is dispersed.
  Excitation light emitted from the light emitting element is guided by the transparent dispersion layer of the light emitting unit to form a luminance distribution in the light emitting unit, and an edge of the luminance distribution is formed by the form of the light emitting unit. It is characterized by being.

  The light-emitting device of the present invention is characterized in that in the above-described light-emitting device, the excitation light is incident from an end face of the light-emitting portion.

  The light emitting device of the present invention is characterized in that, in the above light emitting device, the excitation light is incident from an end face of the transparent dispersion layer.

  The light-emitting device of the present invention is the light-emitting device described above, wherein a light guide member that guides incident light from the light-emitting element and emits the light to the light-emitting part is provided between the light-emitting element and the light-emitting part. It is characterized by being.

  The light-emitting device of the present invention is characterized in that, in the above-described light-emitting device, a convex lens is provided between the optical paths of the light-emitting element and the light-emitting portion.

  The light-emitting device of the present invention is characterized in that in the above-described light-emitting device, a condensing mirror is provided between the light paths of the light-emitting element and the light-emitting portion.

  The light-emitting device of the present invention is characterized in that in the above-described light-emitting device, the transparent dispersion layer is formed so that the thickness gradually changes toward a part of the end of the light-emitting portion.

  A vehicle headlamp according to the present invention includes the light emitting device described above.

  An illumination device according to the present invention includes the light-emitting device described above.

  A projector according to the present invention includes the light-emitting device described above.

  The present invention includes a light emitting element that emits excitation light and a light emitting part having a transparent dispersion layer in which a phosphor is dispersed, and the excitation light emitted from the light emitting element is incident on the light emitting part, and fluorescence is emitted from the light emitting part. The present invention relates to a light emitting device, a vehicle headlamp, and a lighting device that project light as a projection pattern P3 on a light projecting surface, and can be applied to a vehicle headlamp such as a headlamp. The lighting device may be a low-beam headlight, or may be applied as a headlamp for a vehicle other than an automobile or a moving object (for example, a human, a ship, an aircraft, a submersible, a rocket). Is possible. Furthermore, for example, the present invention can be applied to lighting devices such as a searchlight, a projector, a home lighting device, a commercial lighting device, and an outdoor lighting device.

1 Headlamp (lighting device, vehicle headlamp)
3 Lens 4 Light emitting part 4a Laser light irradiation surface 4b Laser light spot (irradiation area)
4c end (part of the end)
4d Anti-reflective coating 4e End (the end opposite to the end)
4f AR coating film 5 Reflector 10 Light source 11 Laser chip (light emitting element)
13A Optical rod (light guide member)
13B Optical rod (light guide member)
13C optical rod (light guide member)
13a Incident end face 13b Outlet end face 14 AR coating film 15 Cap 16 Stem 17 Lead terminal 18 Coupling lens FG Phosphor-containing glass layer (transparent dispersion layer)
L phosphor LG glass light guide part (light emitting part light guide member)
P1 Irradiation pattern P2 Light emission pattern P3 Light projection pattern

Claims (10)

In a light-emitting device including a light-emitting element that emits excitation light and a light-emitting unit having a transparent dispersion layer in which a phosphor is dispersed,
Excitation light emitted from the light emitting element is incident from the first end face of the light emitting unit,
The excitation light incident from the first end face of the light emitting part is guided by the transparent dispersion layer of the light emitting part, thereby causing the second end face non-parallel to the first end face in the light emitting part . In addition to forming a luminance distribution, the edge of the luminance distribution on the second end surface is formed by the concentration control of the phosphor in the light emitting unit ,
A light-emitting device using fluorescence emitted from the second end face as illumination light . The light emitting device according to claim 1, wherein the first end surface and the second end surface are orthogonal to each other . The light emitting part has a two-layer laminated structure of a transparent dispersion layer in which the phosphor is dispersed and a transparent non-dispersion layer in which the phosphor is not dispersed,
  The transparent dispersion layer is formed such that the thickness gradually increases from the first end face toward the third end face facing the first end face.
And the said transparent non-dispersion layer is formed so that thickness may decrease gradually as it goes to the said 3rd end surface from the said 1st end surface,
  The excitation light emitted from the light emitting element is incident from the first end face of the light emitting unit and guided by the transparent non-dispersed layer and the transparent dispersed layer of the light emitting unit, thereby forming an edge in the light emitting unit. The light emitting device according to claim 1, wherein a luminance distribution is formed.   A light guide member that guides incident light from the light emitting element and emits the light to the light emitting part is provided between the light emitting element and the light emitting part. 3. The light emitting device according to 3.   The light emitting device according to claim 1, wherein a convex lens is provided between optical paths of the light emitting element and the light emitting unit.   The light-emitting device according to claim 1, wherein a condensing mirror is provided between optical paths between the light-emitting element and the light-emitting portion. The said transparent dispersion layer is formed so that thickness may change gradually toward the one part edge part of the said light emission part, The any one of Claim 1 , 2, 5-6 characterized by the above-mentioned. The light emitting device described.   A vehicle headlamp comprising the light-emitting device according to claim 1.   An illumination device comprising the light-emitting device according to claim 1.   A projector comprising the light emitting device according to claim 1.

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