JP2012089687A - Light-emitting unit, light-emitting device and headlight - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light-emitting unit which can enhance conversion efficiency of light while limiting enlargement of a fluorescent member.SOLUTION: A light-emitting unit 10 comprises a fluorescent member 11 including a bottom face 11a on which exciting light impinges to cause emission of fluorescent light, and a reflective film 12 including a light reflection surface 12a that reflects light. The light reflection surface 12a includes a region 12b arranged on the optical axis C1 of the exciting light P1 impinging on the bottom face 11a, and a region 12c arranged on the optical axis C2 of the exciting light P2 reflected on the region 12b.

Description

  The present invention relates to a light emitting unit, a light emitting device, and a headlamp, and more particularly, to a light emitting unit, a light emitting device, and a headlamp provided with a fluorescent member that converts excitation light into fluorescence.

  Conventionally, a light-emitting device including a fluorescent member that converts excitation light into fluorescence is known (see, for example, Patent Document 1).

  In Patent Document 1, an ultraviolet LD element (excitation light source) that emits ultraviolet light (excitation light) and an excitation light emitted from the ultraviolet LD element that is disposed in front of the ultraviolet LD element are converted into visible light (fluorescence). A light source device including a phosphor (fluorescent member), an ultraviolet reflector that is disposed in front of the phosphor and reflects ultraviolet rays that have passed through the phosphor, and a visible light reflector that reflects visible light emitted from the phosphor (Light Emitting Device) is disclosed.

  In the structure in which the excitation light is irradiated to the fluorescent member as in Patent Document 1, a part of the excitation light is transmitted through the fluorescent member without being converted into fluorescence. For this reason, in the said patent document 1, the ultraviolet reflective mirror which reflects the ultraviolet-ray (excitation light) which permeate | transmitted the fluorescent substance is provided in front of the fluorescent substance. Thereby, the excitation light transmitted through the phosphor can be incident again on the phosphor, and the excitation light can be easily converted into fluorescence. That is, it is possible to suppress to some extent the decrease in light conversion efficiency.

JP 2003-295319 A

  However, even when configured as in Patent Document 1, a portion of the excitation light reflected by the ultraviolet reflector and re-entered the phosphor passes through the phosphor without being converted into fluorescence, and the ultraviolet LD element. Will return to. For this reason, there is a problem that it is difficult to further improve the light conversion efficiency.

  In order to suppress the excitation light from being transmitted through the phosphor without being converted into fluorescence, the phosphor may be enlarged. In this case, the phosphor is enlarged and the phosphor Costs increase.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to emit light capable of improving light conversion efficiency while suppressing an increase in size of a fluorescent member. It is to provide a unit, a light emitting device and a headlamp.

  To achieve the above object, a light emitting unit according to a first aspect of the present invention has a function of converting excitation light into fluorescence, a light incident surface on which excitation light is incident, and light emission that emits fluorescence. A fluorescent member including a surface and a reflecting member including a light reflecting surface for reflecting light, and the light reflecting surface of the reflecting member is disposed on the optical axis of the excitation light incident on the light incident surface and reflects the excitation light. And a second reflection region that is disposed on the optical axis of the excitation light reflected by the first reflection region and reflects the excitation light.

  In this specification, the optical axis refers to the direction (axis) in which the luminous flux is highest.

  In the light emitting unit according to the first aspect, as described above, the light reflecting surface of the reflecting member is disposed on the optical axis of the excitation light incident on the light incident surface, and the first reflection region that reflects the excitation light; A second reflection region is provided that is disposed on the optical axis of the excitation light reflected by the first reflection region and reflects the excitation light. As a result, the excitation light that has entered the fluorescent member is reflected twice or more by the reflecting member and is emitted from the light emitting unit (fluorescent member) to the outside. For this reason, for example, the optical path of the excitation light in the fluorescent member is not compared with the case where the excitation light is not reflected once or reflected only once and the excitation light is emitted from the light emitting unit (fluorescent member) to the outside. The length can be increased. Thereby, it can suppress that excitation light is radiate | emitted outside from a light emission unit (fluorescence member), without being converted into fluorescence. As a result, the light conversion efficiency can be improved.

  Moreover, since the optical path length of the excitation light in the fluorescent member can be increased, the fluorescent member is made large in order to suppress the excitation light from being emitted from the light emitting unit (fluorescent member) without being converted into fluorescence. There is no need to Thereby, it can suppress that a fluorescent member enlarges, and can suppress that the cost of a fluorescent member increases.

  In the light emitting unit according to the first aspect, preferably, the first reflection region of the light reflecting surface is inclined with respect to the optical axis of the excitation light incident on the light incident surface. If comprised in this way, it can suppress easily that the excitation light reflected in the 1st reflective area is not reflected in a 2nd reflective area, but is radiate | emitted outside from a fluorescent member (light emitting unit).

  In the light emitting unit according to the first aspect, preferably, the second reflection region of the light reflection surface is formed to extend in a direction intersecting the first reflection region. If comprised in this way, the advancing direction of the excitation light reflected in the 2nd reflective area | region can be controlled easily.

  In the light emitting unit according to the first aspect, preferably, the light reflecting surface of the reflecting member is disposed on the optical axis of the excitation light reflected by the second reflection region, and further includes a third reflection region that reflects the excitation light. Including. If comprised in this way, excitation light can be reflected 3 times or more by a reflection member. Thereby, since the optical path length of the excitation light in the fluorescent member can be further increased, the light conversion efficiency can be further improved.

  In the light emitting unit according to the first aspect, the fluorescent member forms at least a part of a conical shape or a polygonal pyramid shape including a bottom surface and a side surface, the light incident surface and the light emitting surface form a bottom surface, and light The reflective surface may be formed so as to cover the side surface.

  In the light emitting unit according to the first aspect, the fluorescent member forms at least part of a conical shape or a polygonal pyramid shape including a bottom surface and a side surface, the light incident surface forms a side surface, and the light emitting surface is The bottom surface may be formed, and the light reflecting surface may be formed to cover the side surface.

  In the light emitting unit according to the first aspect, the fluorescent member forms at least a part of a cylindrical shape or a polygonal prism shape including one surface, the other surface, and the side surface, and the light incident surface and the light emitting surface are on one surface. The light reflecting surface may be formed so as to cover the other surface and the side surface.

  In the light emitting unit according to the first aspect, the fluorescent member forms at least a part of a cylindrical shape or a polygonal prism shape including one surface, the other surface, and the side surface, and the light incident surface forms the other surface, The light emitting surface may form one surface, and the light reflecting surface may be formed to cover at least the side surface.

  In the light emitting unit according to the first aspect, the fluorescent member forms at least part of a truncated cone shape or a polygonal truncated cone shape including one surface, the other surface, and the side surface, and the other surface is larger than the one surface. The light incident surface may form the other surface, the light emitting surface may form one surface, and the light reflecting surface may cover the other surface and the side surface.

  In the light emitting unit according to the first aspect, preferably, the reflecting member is provided in close contact with the surface of the fluorescent member. If comprised in this way, it can suppress easily that a reflecting member enlarges. In addition, the light emitting unit can be easily manufactured.

  In the light emitting unit provided so that the reflective member is in close contact with the surface of the fluorescent member, the reflective member preferably includes a metal film formed on the surface of the fluorescent member. If comprised in this way, a reflecting member can be easily provided so that it may closely_contact | adhere to the surface of a fluorescent member. Moreover, since it can suppress that a reflecting member enlarges and weights, it can suppress that a light emitting unit enlarges and weights.

  In the light emitting unit according to the first aspect, the light reflecting surface is formed in a concave shape, and the fluorescent member is disposed in the vicinity of the vertex of the light reflecting surface or in the region including the vertex of the light reflecting surface. A part of the light may reflect the light emitted from the fluorescent member in a predetermined direction.

  In the light emitting unit in which the light reflecting surface is formed in a concave shape, the reflecting member is preferably provided with a through hole for allowing excitation light to pass therethrough. If comprised in this way, excitation light can be entered in the desired position of a fluorescent member and a desired incident angle.

  In the light emitting unit in which the light reflecting surface is formed in a concave shape, preferably, at least a part of the light reflecting surface is formed by one of a parabolic surface and an elliptical surface. If comprised in this way, the light (illumination light) radiate | emitted from a light emission unit can be easily made into a parallel light, or can be condensed by arrange | positioning a fluorescent member in the area | region containing the focus of a light reflection surface. .

  In the light emitting unit in which the light reflecting surface is formed in a concave shape, preferably, the light reflecting surface is formed in a shape having a focal point, and the fluorescent member is a region including the focal point of the light reflecting surface, or light reflecting. Located near the focal point of the surface. If comprised in this way, the light (illumination light) radiate | emitted from the light emission unit can be easily made into a parallel light, for example, or can be condensed.

  In the light emitting unit in which the light reflecting surface is formed in a concave shape, preferably, the light reflecting surface is formed with a recess for housing the fluorescent member. If comprised in this way, since a recessed part can be made into a desired shape easily, a fluorescent member can be easily made into a desired shape.

  In the light emitting unit according to the first aspect, preferably, the excitation light incident on the fluorescent member is P-polarized light, and the incident angle of the excitation light with respect to the fluorescent member is a Brewster angle. If comprised in this way, surface reflection at the time of excitation light entering a fluorescent member can be suppressed, making an incident angle into angles other than about 0 degree.

  In the light emitting unit according to the first aspect, the incident angle of the excitation light with respect to the fluorescent member is preferably 0 ° or more and 80 ° or less. If comprised in this way, it can suppress that the incident angle of excitation light becomes large too much, Therefore The surface reflection at the time of excitation light entering into a fluorescence member can be reduced.

  In the light emitting unit according to the first aspect, preferably, the excitation light includes laser light. If the laser light is emitted to the outside without being converted into fluorescence, it may cause harm to human eyes. Therefore, the configuration as described above is particularly effective when the excitation light includes laser light.

  A light-emitting device according to a second aspect of the present invention includes the light-emitting unit having the above-described configuration and an excitation light source that emits excitation light applied to a fluorescent member of the light-emitting unit. If comprised in this way, the light-emitting device which can improve the light conversion efficiency can be obtained, suppressing the enlargement of a fluorescent member.

  A headlamp according to a third aspect of the present invention includes the light emitting device having the above configuration. If comprised in this way, the headlamp which can improve the conversion efficiency of light can be obtained, suppressing that a fluorescent member enlarges.

  As described above, according to the present invention, it is possible to easily obtain a light-emitting unit, a light-emitting device, and a headlamp that can improve light conversion efficiency while suppressing an increase in the size of a fluorescent member. .

1 is a cross-sectional view schematically illustrating an overall configuration of a light emitting device according to a first embodiment of the present invention. It is sectional drawing which showed the structure of the light emission unit shown in FIG. It is the front view which showed the structure of the light emission unit shown in FIG. It is sectional drawing which showed the structure of the light emission unit shown in FIG. It is a figure for demonstrating the manufacturing method of the light emission unit shown in FIG. It is sectional drawing which showed roughly the whole structure of the light-emitting device by 2nd Embodiment of this invention. It is sectional drawing which showed the structure of the light emission unit shown in FIG. It is the top view which showed the structure of the light emission unit shown in FIG. It is the front view which showed the structure of the light emission unit shown in FIG. It is sectional drawing which showed the structure of the light emission unit shown in FIG. It is a figure for demonstrating the manufacturing method of the light emission unit shown in FIG. It is sectional drawing which showed roughly the whole structure of the light-emitting device by 3rd Embodiment of this invention. It is sectional drawing which showed the structure of the light emission unit shown in FIG. It is the front view which showed the structure of the light emission unit shown in FIG. It is sectional drawing which showed the structure of the light emission unit shown in FIG. It is a figure for demonstrating the manufacturing method of the light emission unit shown in FIG. It is sectional drawing which showed roughly the whole structure of the light-emitting device by 4th Embodiment of this invention. It is sectional drawing which showed the structure of the light emission unit shown in FIG. It is the front view which showed the structure of the light emission unit shown in FIG. It is the rear view which showed the structure of the light emission unit shown in FIG. It is sectional drawing which showed the structure of the light emission unit shown in FIG. It is a figure for demonstrating the manufacturing method of the light emission unit shown in FIG. It is sectional drawing which showed schematically the structure of the headlamp by 5th Embodiment of this invention. FIG. 24 is an enlarged cross-sectional view illustrating a structure of the light emitting unit illustrated in FIG. 23. FIG. 24 is an enlarged cross-sectional view illustrating a structure of the light emitting unit illustrated in FIG. 23. It is sectional drawing which showed roughly the structure of the headlamp by 6th Embodiment of this invention. FIG. 27 is an enlarged cross-sectional view illustrating a structure of the light emitting unit illustrated in FIG. 26. FIG. 27 is an enlarged cross-sectional view illustrating a structure of the light emitting unit illustrated in FIG. 26. It is sectional drawing which showed roughly the structure of the headlamp by 7th Embodiment of this invention. FIG. 30 is an enlarged cross-sectional view illustrating the structure of the light emitting unit illustrated in FIG. 29. FIG. 30 is an enlarged cross-sectional view illustrating the structure of the light emitting unit illustrated in FIG. 29. It is sectional drawing which showed roughly the structure of the headlamp by 8th Embodiment of this invention. It is an expanded sectional view which showed the structure of the light emission unit shown in FIG. It is an expanded sectional view which showed the structure of the light emission unit shown in FIG. It is sectional drawing which showed the structure of the light emission unit by the 1st modification of this invention. It is sectional drawing which showed the structure of the light-emitting device by the 2nd modification of this invention. It is a figure for demonstrating the manufacturing method of the light emission unit shown in FIG.

  Embodiments of the present invention will be described below with reference to the drawings. In order to facilitate understanding, even a cross-sectional view may not be hatched.

(First embodiment)
First, the structure of the light emitting device 1 according to the first embodiment of the invention will be described with reference to FIGS.

  The light emitting device 1 according to the first embodiment of the present invention includes a semiconductor laser element 2 and a light emitting unit 10 as shown in FIG. The semiconductor laser element 2 is an example of the “excitation light source” in the present invention.

  The semiconductor laser element 2 emits laser light that functions as excitation light. The semiconductor laser element 2 is configured to emit blue-violet laser light (excitation light) having a center wavelength of about 405 nm, for example.

  The light emitting unit 10 includes a fluorescent member 11 to which excitation light emitted from the semiconductor laser element 2 is irradiated, and a reflection film 12 having a light reflection surface 12a that reflects light (excitation light and fluorescence). The reflective film 12 is an example of the “reflective member” in the present invention.

  Here, in the first embodiment, as shown in FIGS. 2 and 3, the fluorescent member 11 is formed in a conical shape having a diameter D1, a height H1, and an apex angle θx1. For example, in the first embodiment, the diameter D1 of the fluorescent member 11 may be about 5 mm, the height H1 may be about 2.5 mm, and the apex angle θx1 may be about 90 °.

  The fluorescent member 11 includes a bottom surface 11a and a side surface 11b. In the first embodiment, the bottom surface 11a functions as a light incident surface on which excitation light emitted from the semiconductor laser element 2 is incident, and also functions as a light emitting surface that emits fluorescence. The bottom surface 11a is an example of the “light incident surface” and “light emitting surface” in the present invention.

  In addition, the fluorescent member 11 is made of, for example, a mixed powder of three kinds of phosphor particles that convert blue-violet light (excitation light) into red light, green light, and blue light, and emits the same, and a sealing material (for example, glass Material). The red light, green light, and blue light emitted from the fluorescent member 11 are mixed to obtain white light.

The phosphor particle sealing material may be any material that transmits excitation light (blue-violet light) and white light (red light, green light, and blue light). For example, AlN, sapphire, TiO ₂ , SiO _2. Silicon resin, epoxy resin or zirconia can be used.

  In the first embodiment, the fluorescent member 11 and the reflective film 12 are formed so that the excitation light transmitted through the fluorescent member 11 is reflected twice by the reflective film 12.

Specifically, in the first embodiment, as shown in FIG. 4, the angle of the excitation light P1 emitted from the semiconductor laser element 2 and incident on the fluorescent member 11 with respect to the bottom surface 11a of the optical axis C1 (the refraction of the excitation light P1). Angle) θ1 is
θ1 + θx1 ≦ 90 ° (1)
The fluorescent member 11 is formed so as to satisfy the above.

  The refractive index of the fluorescent member 11 is n1, the refractive index of air is n0, and the angle of the excitation light P0 emitted from the semiconductor laser element 2 with respect to the bottom surface 11a of the optical axis C0 (incident angle of the excitation light P0) is θ0. Then, the refraction angle θ1 of the excitation light P1 satisfies n1 × sin θ1 = n0 × sin θ0. For example, in the first embodiment, the refractive index n1 of the fluorescent member 11 may be about 1.44, and the incident angle θ0 of the excitation light P0 may be about 0 °. If the incident angle θ0 of the excitation light P0 is set to about 0 °, the excitation light P0 can be prevented from being reflected from the surface of the fluorescent member 11. Further, if the excitation light P0 is P-polarized and the incident angle θ0 of the excitation light P0 with respect to the fluorescent member 11 is matched to the Brewster angle, the excitation light P0 enters the fluorescent member 11 while the incident angle θ0 is set to an angle other than about 0 °. It is possible to suppress surface reflection upon incidence.

  The incident position of the excitation light P0 emitted from the semiconductor laser element 2 with respect to the fluorescent member 11 is separated from the end of the fluorescent member 11 by a distance L1. For example, in the first embodiment, the distance L1 may be about 1 mm.

  The light reflection surface 12 a of the reflection film 12 is formed so as to cover the side surface 11 b of the fluorescent member 11. The reflective film 12 is provided so as to be in close contact with the side surface 11 b of the fluorescent member 11.

  The reflection film 12 is formed of a metal film having a function of reflecting light. Specifically, the reflective film 12 is formed of, for example, a Ti film having a thickness of about 30 nm and an Au film having a thickness of about 300 nm. The reflective film 12 is not limited to the above structure as long as it has a function of reflecting light. For example, the reflective film 12 may be formed by a Mo film having a thickness of about 30 nm, a Pt layer having a thickness of about 20 nm, and an Au film having a thickness of about 200 nm.

  In the first embodiment, the light reflecting surface 12a of the reflective film 12 is disposed on the optical axis C1 of the excitation light P1 incident on the bottom surface 11a of the fluorescent member 11, and includes a region 12b that reflects the excitation light P1, and a region The region 12c is disposed on the optical axis C2 of the excitation light P2 reflected by the light 12b and reflects the excitation light P2. The region 12b is an example of the “first reflection region” in the present invention, and the region 12c is an example of the “second reflection region” in the present invention.

  The regions 12b and 12c of the light reflecting surface 12a are inclined with respect to the bottom surface 11a of the fluorescent member 11. The region 12b is inclined (not vertical) with respect to the optical axis C1 of the excitation light P1 incident on the bottom surface 11a. The region 12c is formed to extend in a direction intersecting (orthogonal) with respect to the region 12b.

  Next, the optical path of the excitation light (the optical path of the light traveling on the optical axis of the excitation light) will be described with reference to FIG.

  In the first embodiment, as shown in FIG. 4, the excitation light P0 emitted from the semiconductor laser element 2 enters the bottom surface 11a of the fluorescent member 11 at an incident angle θ0. The excitation light P1 incident on the fluorescent member 11 travels at a refraction angle θ1.

  The excitation light P1 incident on the fluorescent member 11 and transmitted through the fluorescent member 11 is reflected by the region 12b of the reflective film 12. Then, the excitation light P2 reflected by the region 12b travels toward the region 12c of the reflective film 12.

  At this time, in the first embodiment, since the fluorescent member 11 is formed so as to satisfy the above formula (1), the excitation light P2 reflected by the region 12b is parallel to the bottom surface 11a or on the bottom surface 11a. On the other hand, it travels inclined in the direction away from it. For this reason, the excitation light P2 reflected by the region 12b always reaches the region 12c (region of the light reflecting surface 12a opposite to the region 12b). That is, the excitation light P2 is not reflected from the region 12c and does not exit from the bottom surface 11a.

  The excitation light P2 that has passed through the fluorescent member 11 is reflected by the region 12c of the reflective film 12. Then, the excitation light P3 reflected by the region 12c travels toward the bottom surface 11a of the fluorescent member 11 and exits from the bottom surface 11a.

  Note that most of the excitation light traveling in the fluorescent member 11 is converted into fluorescence by the phosphor particles in the fluorescent member 11 in the course of travel, so there is almost no excitation light emitted from the fluorescent member 11.

  As described above, in the first embodiment, the excitation light can be reflected by the regions 12b and 12c of the reflective film 12 by forming the fluorescent member 11 so as to satisfy the above formula (1). That is, the excitation light can be reflected twice by the reflective film 12. However, it is not essential to form the fluorescent member 11 so as to satisfy the above formula (1). That is, when the fluorescent member 11 is formed so as not to satisfy the above formula (1), the excitation light P2 reflected by the region 12b travels in a direction approaching the bottom surface 11a, but the excitation light P1 is reflected. If the position (region 12b) to be set is set apart from the bottom surface 11a, the excitation light P2 can sufficiently reach the region 12c. For this reason, even if the fluorescent member 11 is formed so as not to satisfy the formula (1), it is possible to reflect the excitation light twice by the reflection film 12.

  Next, with reference to FIG. 2 and FIG. 5, the manufacturing method of the light emission unit 10 is demonstrated.

  First, a conical fluorescent member 11 is prepared. The conical fluorescent member 11 can be easily formed by, for example, injecting a sealing material (for example, a glass material) containing phosphor particles into a mold (not shown) and hardening.

  Then, a resist 20 (see FIG. 5) is formed on the bottom surface 11a of the fluorescent member 11. Thereafter, as shown in FIG. 5, the fluorescent member 11 and the resist 20 are placed on the substrate 30.

  Then, using, for example, an EB (Electron Beam) vapor deposition apparatus or the like, a Ti film and an Au film (or a Mo film, a Pt film, an Au film, and the like) are sequentially stacked on the side surface 11b of the fluorescent member 11, and the reflective film 12 (See FIG. 2).

  In this way, the light emitting unit 10 is manufactured.

  In the first embodiment, as described above, the region 12b that is disposed on the light reflection surface 12a of the reflective film 12 on the optical axis C1 of the excitation light P1 incident on the bottom surface 11a and reflects the excitation light P1, and the region 12b The region 12c is disposed on the optical axis C2 of the excitation light P2 reflected in step S2 and reflects the excitation light P2. As a result, the excitation light incident on the fluorescent member 11 is reflected twice by the reflective film 12 and emitted from the light emitting unit 10 (fluorescent member 11) to the outside. For this reason, for example, it is reflected in the reflective film 12 only once (or never reflected), and the excitation light is emitted from the light emitting unit 10 (fluorescent member 11) to the outside. The optical path length of the excitation light can be increased. Thereby, it is possible to suppress the excitation light from being emitted from the light emitting unit 10 (fluorescent member 11) without being converted into fluorescence. As a result, the light conversion efficiency can be improved.

  In addition, since the optical path length of the excitation light in the fluorescent member 11 can be increased, the fluorescent light is suppressed in order to prevent the excitation light from being emitted from the light emitting unit 10 (fluorescent member 11) without being converted into fluorescence. There is no need to increase the size of the member 11. Thereby, it can suppress that the fluorescent member 11 enlarges, and can suppress that the cost of the fluorescent member 11 increases.

  In the first embodiment, as described above, the region 12b of the light reflecting surface 12a is inclined with respect to the optical axis C1 of the excitation light P1 incident on the bottom surface 11a. Thereby, it can suppress easily that the excitation light P1 reflected in the area | region 12b does not reflect in the area | region 12c, but radiate | emits outside from the fluorescent member 11 (light emitting unit 10).

  In the first embodiment, as described above, the region 12c of the light reflecting surface 12a is formed to extend in a direction intersecting (orthogonal) with respect to the region 12b. Thereby, the traveling direction of the excitation light P3 reflected by the region 12c can be easily controlled.

  In the first embodiment, as described above, the reflective film 12 made of a metal film is provided on the surface (side surface 11 b) of the fluorescent member 11. Thereby, since it can suppress that the reflecting film 12 enlarges and weights, it can suppress that the light emission unit 10 enlarges and weights. Moreover, the light emitting unit 10 can be manufactured easily.

  In the first embodiment, as described above, laser light is used as excitation light. If the laser light is emitted to the outside without being converted into fluorescence, it may cause harm to human eyes. Therefore, when the laser light is used as the excitation light, the above configuration is particularly effective.

(Second Embodiment)
In the second embodiment, with reference to FIGS. 6 to 11, unlike the first embodiment, the case where the excitation light is reflected by the reflective film 112 three times or more and is emitted from the fluorescent member 111 will be described.

  First, the structure of the light-emitting device 101 according to the second embodiment of the present invention will be described with reference to FIGS.

  A light emitting device 101 according to the second embodiment of the present invention includes a semiconductor laser element 2 and a light emitting unit 110 as shown in FIG.

  In the second embodiment, the semiconductor laser element 2 is disposed on the rear side of the light emitting unit 110, and the excitation light is applied to the light emitting unit 110 (a fluorescent member 111 described later) from the rear side. As described above, by disposing the semiconductor laser element 2 on the rear side of the light emitting unit 110, the semiconductor laser element 2 is not likely to block the light from the light emitting unit 110, and the degree of freedom of the installation position of the semiconductor laser element 2 is high. As a result, the degree of freedom in designing the light emitting device 101 and its peripheral portion is increased.

  The light emitting unit 110 includes a fluorescent member 111 and a reflective film 112. The reflective film 112 is an example of the “reflective member” in the present invention.

  Here, in 2nd Embodiment, as shown in FIGS. 7-9, the fluorescent member 111 is formed in the shape which cut off a part of cone shape. For example, in the second embodiment, the fluorescent member 111 is formed in a shape obtained by cutting off a part of the fluorescent member 11 of the first embodiment.

  The fluorescent member 111 includes a bottom surface 111a, a side surface 111b, and a cut surface 111c inclined with respect to the bottom surface 111a. The bottom surface 111a is an example of the “light emitting surface” in the present invention, and the side surface 111b is an example of the “light incident surface” in the present invention.

  In the second embodiment, the bottom surface 111a forms a part of a conical bottom surface and functions as a light emitting surface that emits fluorescence.

  In the second embodiment, the side surface 111b forms a part of a conical side surface and functions as a light incident surface on which laser light (excitation light) emitted from the semiconductor laser element 2 is incident.

  As shown in FIG. 7, the cut surface 111 c is formed in parallel with a region 112 e (described later) of the reflective film 112 as viewed in cross section.

  The reflective film 112 is formed so as to cover the side surface 111b and the cut surface 111c of the fluorescent member 111. In the second embodiment, the reflective film 112 is formed with a through hole 112 a for allowing excitation light (laser light) emitted from the semiconductor laser element 2 to enter the fluorescent member 111. For example, the diameter of the through hole 112a may be about 1 mm.

  Here, in the second embodiment, the fluorescent member 111 and the reflective film 112 are formed so that the excitation light transmitted through the fluorescent member 111 is reflected by the reflective film 112 three times or more.

  Specifically, in the second embodiment, as shown in FIG. 10, the light reflection surface 112 b of the reflection film 112 is disposed on the optical axis C <b> 101 of the excitation light P <b> 101 incident on the side surface 111 b of the fluorescent member 111. A region 112c that reflects the light P101, a region 112d that reflects the excitation light P102, is disposed on the optical axis C102 of the excitation light P102 reflected by the region 112c, and an optical axis C103 of the excitation light P103 that is reflected by the region 112d And an area 112e that reflects the excitation light P103.

  In other words, the region 112c (the cut surface 111c of the fluorescent member 111) is formed so that the excitation light P102 reflected by the region 112c reaches the region 112d. The region 112d is formed so that the excitation light P103 reflected by the region 112d reaches the region 112e. The region 112c is an example of the “first reflection region” in the present invention, and the region 112d is an example of the “second reflection region” in the present invention. The region 112e is an example of the “third reflection region” in the present invention.

  Further, the through holes 112a of the semiconductor laser element 2 and the reflective film 112 are arranged so that the excitation light P101 incident on the fluorescent member 111 reaches the region 112c of the reflective film 112 (the cut surface 111c of the fluorescent member 111). . For example, the semiconductor laser element 2 is arranged such that the incident angle θ100 of the excitation light P100 emitted from the semiconductor laser element 2 with respect to the side surface 111b of the fluorescent member 111 is about 20 °. Further, the through hole 112a has a distance L100 from the top of the conical shape to the center of the through hole 112a (a distance in the A direction from the region 112d to the center of the through hole 112a) L100 in the A direction of the cut surface 111c (region 112c). You may form so that it may become smaller than length L101.

  The remaining structure of the second embodiment is the same as that of the first embodiment.

  Next, the optical path of the excitation light (the optical path of the light traveling on the optical axis of the excitation light) will be described with reference to FIG.

  In the second embodiment, as shown in FIG. 10, the excitation light P100 emitted from the semiconductor laser element 2 enters the side surface 111b of the fluorescent member 111 at an incident angle θ100 (for example, about 20 °). Then, the excitation light P101 incident on the fluorescent member 111 travels at a refraction angle θ101 (for example, about 14 °).

  The excitation light P101 incident on the fluorescent member 111 and transmitted through the fluorescent member 111 is reflected by the region 112c of the reflective film 112. Then, the excitation light P102 reflected by the region 112c travels toward the region 112d of the reflective film 112.

  The excitation light P102 that has passed through the fluorescent member 111 is reflected by the region 112d of the reflective film 112. Then, the excitation light P103 reflected by the region 112d travels toward the region 112e of the reflective film 112.

  The excitation light P103 transmitted through the fluorescent member 111 is reflected by the region 112e of the reflective film 112. Then, the excitation light P104 reflected by the region 112e travels toward the bottom surface 111a of the fluorescent member 111 and exits from the bottom surface 111a. Note that the excitation light P104 reflected by the region 112e of the reflective film 112 travels again toward the region 112c of the reflective film 112 by changing the installation angle of the semiconductor laser element 2 (incident angle θ100 of the excitation light P100). It is also possible to emit light from the bottom surface 111a after repeating reflection between the region 112c and the region 112e. That is, the excitation light can be reflected by the reflective film 112 four or more times.

  Thus, in 2nd Embodiment, the excitation light which permeate | transmits the fluorescence member 111 is reflected by the reflective film 112 3 times or more, and is radiate | emitted outside from the light emission unit 110 (fluorescence member 111).

  Next, a method for manufacturing the light emitting unit 110 will be described with reference to FIGS.

  First, the fluorescent member 111 is prepared. At this time, the fluorescent member 111 having the shape shown in FIG. 11 may be formed by a mold (not shown), or by cutting a part of the fluorescent member 11 of the first embodiment, the fluorescent member 111 is formed. It may be formed.

  Then, a resist 120 (see FIG. 11) is formed on the bottom surface 111a of the fluorescent member 111. Thereafter, as shown in FIG. 11, the fluorescent member 111 and the resist 120 are placed on the substrate 30.

  Then, a resist 121 is formed on the region of the side surface 111b of the fluorescent member 111 where the through hole 112a (see FIG. 7) is to be formed.

  Thereafter, the reflective film 112 (see FIG. 7) is formed on the side surface 111b and the cut surface 111c of the fluorescent member 111 using, for example, an EB vapor deposition apparatus.

  In this way, the light emitting unit 110 is manufactured.

  In addition, the other manufacturing method of 2nd Embodiment is the same as that of the said 1st Embodiment.

  In the second embodiment, the regions 112c, 112d, and 112e are provided on the light reflecting surface 112b of the reflecting film 112 as described above. Thereby, the excitation light can be reflected by the reflective film 112 three times or more. Thereby, since the optical path length of the excitation light in the fluorescent member 111 can be further increased, the light conversion efficiency can be further improved.

  Other effects of the second embodiment are the same as those of the first embodiment.

(Third embodiment)
In the third embodiment, a case where the fluorescent member 211 is formed in a columnar shape will be described with reference to FIGS. 12 to 16, unlike the first and second embodiments.

  First, the structure of the light emitting device 201 according to the third embodiment of the invention will be described with reference to FIGS.

  A light emitting device 201 according to the third embodiment of the present invention includes a semiconductor laser element 2 and a light emitting unit 210 as shown in FIG. The light emitting unit 210 includes a fluorescent member 211 and a reflective film 212. The reflective film 212 is an example of the “reflective member” in the present invention.

  Here, in 3rd Embodiment, as shown in FIG.13 and FIG.14, the fluorescent member 211 is formed in the column shape which has the diameter of D201, and the height of H201. For example, in the third embodiment, the fluorescent member 211 may have a diameter D201 of about 5 mm and a height H201 of about 3.5 mm.

  The fluorescent member 211 includes one surface 211a, a side surface 211b, and the other surface 211c. In the third embodiment, the one surface 211a functions as a light incident surface on which laser light (excitation light) emitted from the semiconductor laser element 2 is incident, and also functions as a light emitting surface that emits fluorescence. The one surface 211a is an example of the “light incident surface” and “light emitting surface” in the present invention.

  In the third embodiment, the fluorescent member 211 and the reflective film 212 are formed so that the excitation light transmitted through the fluorescent member 211 is reflected by the reflective film 212 three or more times.

Specifically, in the third embodiment, as shown in FIG. 15, the incident position of the excitation light P200 emitted from the semiconductor laser element 2 with respect to the fluorescent member 211 is set to a distance L201 from the end (side surface 211b) of the fluorescent member 211. If it is a distant position, the angle (the refraction angle of the excitation light P201) θ201 of the excitation light P201 incident on the fluorescent member 211 with respect to the one surface 211a of the optical axis C201 is
H201 ≧ (L201 + D201) / 2 tan θ201 (2)
The fluorescent member 211 is formed so as to satisfy the above.

  For example, in the third embodiment, the distance L201 may be about 1 mm, the incident angle θ200 of the excitation light P200 may be about 57 °, and the refraction angle θ201 of the excitation light P201 may be about 40 °. If the incident angle θ200 of the excitation light P200 becomes too large, surface reflection when the excitation light P200 enters the fluorescent member 211 increases, and therefore the incident angle θ200 is about 0 ° or more and about 80 ° or less. Is preferred.

  The light reflection surface 212a of the reflection film 212 is formed so as to cover the side surface 211b and the other surface 211c of the fluorescent member 211.

  In the third embodiment, the light reflection surface 212a of the reflection film 212 is disposed on the optical axis C201 of the excitation light P201 incident on the one surface 211a of the fluorescent member 211, and a region 212b that reflects the excitation light P201; An excitation light P202 reflected on the region 212b is disposed on the optical axis C202, the excitation light P202 is reflected on the region 212c, and an excitation light P203 reflected on the region 212c is disposed on the optical axis C203. And a reflective region 212d. The region 212b is an example of the “first reflection region” in the present invention, and the region 212c is an example of the “second reflection region” in the present invention. The region 212d is an example of the “third reflection region” in the present invention.

  The regions 212b and 212d are arranged on the side surface 211b of the fluorescent member 211, and the region 212c is arranged on the other surface 211c of the fluorescent member 211.

  The remaining structure of the third embodiment is the same as that of the first and second embodiments.

  Next, the optical path of the excitation light (the optical path of the light traveling on the optical axis of the excitation light) will be described with reference to FIG.

  In the third embodiment, the excitation light P200 emitted from the semiconductor laser element 2 enters the one surface 211a of the fluorescent member 211 at an incident angle θ200. Then, the excitation light P201 incident on the fluorescent member 211 travels at a refraction angle θ201.

  The excitation light P201 incident on the fluorescent member 211 and transmitted through the fluorescent member 211 is reflected by the region 212b of the reflective film 212. Then, the excitation light P202 reflected by the region 212b travels toward the region 212c of the reflective film 212.

  The excitation light P202 that has passed through the fluorescent member 211 is reflected by the region 212c of the reflective film 212. Then, the excitation light P203 reflected by the region 212c travels toward the region 212d of the reflective film 212.

  At this time, in the third embodiment, since the fluorescent member 211 is formed so as to satisfy the above formula (2), the excitation light P203 reflected by the region 212c reaches the region 212d. That is, the excitation light P203 is not reflected from the region 212d and does not exit from the one surface 211a.

  Then, the excitation light P203 transmitted through the fluorescent member 211 is reflected by the region 212d of the reflective film 212. The excitation light P204 reflected by the region 212d travels toward the one surface 211a of the fluorescent member 211 and exits from the one surface 211a.

  As described above, in the third embodiment, by forming the fluorescent member 211 to satisfy the above formula (2), the excitation light can be reflected by the regions 212b, 212c, and 212d of the reflective film 212. That is, the excitation light can be reflected by the reflective film 212 three times.

  For example, the excitation light can be reflected four or more times by the reflection film 212 by increasing the incident angle θ200 of the excitation light P200 or increasing the height H201 of the fluorescent member 211.

  Next, a method for manufacturing the light emitting unit 210 will be described with reference to FIGS.

  First, a cylindrical fluorescent member 211 is prepared. Then, a resist 220 (see FIG. 16) is formed on one surface 211a of the fluorescent member 211. Thereafter, as shown in FIG. 16, the fluorescent member 211 and the resist 220 are placed on the substrate 30.

  Then, the reflective film 212 (see FIG. 13) is formed on the side surface 211b and the other surface 211c of the fluorescent member 211 using, for example, an EB vapor deposition apparatus.

  In this way, the light emitting unit 210 is manufactured.

  In addition, the other manufacturing method of 3rd Embodiment is the same as that of the said 1st and 2nd embodiment.

  The remaining effects of the third embodiment are similar to those of the aforementioned first and second embodiments.

(Fourth embodiment)
In the fourth embodiment, a case where the fluorescent member 311 is formed in a truncated cone shape will be described with reference to FIGS. 17 to 22, unlike the first to third embodiments.

  First, the structure of the light emitting device 301 according to the fourth embodiment of the invention will be described with reference to FIGS.

  The light emitting device 301 according to the fourth embodiment of the present invention includes a semiconductor laser element 2 and a light emitting unit 310 as shown in FIG. The light emitting unit 310 includes a fluorescent member 311 and a reflective film 312. The reflective film 312 is an example of the “reflective member” in the present invention.

  Here, in the fourth embodiment, as shown in FIGS. 18 to 20, the fluorescent member 311 includes one surface 311a, a side surface 311b, and the other surface 311c having an area (diameter) larger than the one surface 311a. It is formed in a truncated cone shape. The one surface 311a is an example of the “light emitting surface” in the present invention, and the other surface 311c is an example of the “light incident surface” in the present invention.

  The one surface 311a functions as a light emitting surface that emits fluorescence.

  As shown in FIG. 18, the side surface 311b is inclined at an angle θx301 with respect to the other surface 311c. For example, in the fourth embodiment, the angle θx301 may be about 75 °.

  The other surface 311c has a diameter of D301 and functions as a light incident surface on which laser light (excitation light) emitted from the semiconductor laser element 2 is incident. For example, in the fourth embodiment, the diameter D301 may be about 5 mm.

  The reflective film 312 is formed so as to cover the side surface 311b and the other surface 311c of the fluorescent member 311. In the third embodiment, the reflective film 312 is formed with a through hole 312 a for allowing excitation light (laser light) emitted from the semiconductor laser element 2 to enter the fluorescent member 311. For example, the diameter of the through hole 312a may be about 1 mm.

  In the fourth embodiment, the fluorescent member 311 and the reflective film 312 are formed so that the excitation light transmitted through the fluorescent member 311 is reflected by the reflective film 312 three or more times (for example, five times).

  Specifically, in the fourth embodiment, as shown in FIG. 21, the light reflecting surface 312b of the reflecting film 312 is disposed on the optical axis C301 of the excitation light P301 incident on the other surface 311c of the fluorescent member 311. The region 312c that reflects the excitation light P301, the region 312d that reflects the excitation light P302, is disposed on the optical axis C302 of the excitation light P302 reflected by the region 312c, and the optical axis of the excitation light P303 that is reflected by the region 312d The region 312e that is disposed on the C303 and reflects the excitation light P303, and the region 312f that is disposed on the optical axis C304 of the excitation light P304 reflected by the region 312e and reflects the excitation light P304, and is reflected by the region 312f. The region 312g is disposed on the optical axis C305 of the excitation light P305 and reflects the excitation light P305.

  In other words, the region 312c is formed such that the excitation light P302 reflected by the region 312c reaches the region 312d. The region 312d is formed such that the excitation light P303 reflected by the region 312d reaches the region 312e. The region 312e is formed so that the excitation light P304 reflected by the region 312e reaches the region 312f. The region 312f is formed so that the excitation light P305 reflected by the region 312f reaches the region 312g. The region 312c is an example of the “first reflection region” in the present invention, and the region 312d is an example of the “second reflection region” in the present invention. The region 312e is an example of the “third reflection region” in the present invention.

  Further, the through holes 312a of the semiconductor laser element 2 and the reflective film 312 are arranged so that the excitation light P301 incident on the fluorescent member 311 reaches the region 312c of the reflective film 312 (the side surface 311b of the fluorescent member 311). For example, the semiconductor laser element 2 is arranged so that the incident angle θ300 of the excitation light P300 emitted from the semiconductor laser element 2 with respect to the other surface 311c of the fluorescent member 311 is about 46 °, and the excitation light incident on the fluorescent member 311 is obtained. The refraction angle θ301 of P301 may be about 30 °.

  In addition, the through hole 312a is formed at a position away from the end of the fluorescent member 311 by a distance L301. For example, in the fourth embodiment, the distance L301 may be about 0.8 mm.

  The remaining structure of the fourth embodiment is similar to that of the aforementioned first to third embodiments.

  Next, the optical path of the excitation light (the optical path of the light traveling on the optical axis of the excitation light) will be described with reference to FIG.

  In the fourth embodiment, as shown in FIG. 21, the excitation light P300 emitted from the semiconductor laser element 2 enters the other surface 311c of the fluorescent member 311 at an incident angle θ300. The excitation light P301 incident on the fluorescent member 311 travels at a refraction angle θ301.

  The excitation light P301 incident on the fluorescent member 311 passes through the fluorescent member 311 and is reflected by the region 312c of the reflective film 312. Then, the excitation light P302 reflected by the region 312c travels toward the region 312d of the reflective film 312.

  The excitation light P302 that has passed through the fluorescent member 311 is reflected by the region 312d of the reflective film 312. Then, the excitation light P303 reflected by the region 312d travels toward the region 312e of the reflective film 312.

  The excitation light P303 transmitted through the fluorescent member 311 is reflected by the region 312e of the reflective film 312. Then, the excitation light P304 reflected by the region 312e travels toward the region 312f of the reflective film 312.

  The excitation light P304 that has passed through the fluorescent member 311 is reflected by the region 312f of the reflective film 312. Then, the excitation light P305 reflected by the region 312f travels toward the region 312g of the reflective film 312.

  The excitation light P305 that has passed through the fluorescent member 311 is reflected by the region 312g of the reflective film 312. Then, the excitation light P306 reflected by the region 312g travels toward the one surface 311a of the fluorescent member 311 and exits from the one surface 311a.

  As described above, in the fourth embodiment, the excitation light transmitted through the fluorescent member 311 is reflected five times by the reflective film 312 and is emitted to the outside from the light emitting unit 310 (fluorescent member 311).

  For example, by changing the incident angle θ300 of the excitation light P300, the diameter D301 and the angle θx301 of the fluorescent member 311, the excitation light can be reflected by the reflective film 312 six times or more.

  Next, a method for manufacturing the light emitting unit 310 will be described with reference to FIGS.

  First, a frustoconical fluorescent member 311 is prepared. Then, a resist 320 (see FIG. 22) is formed on one surface 311a of the fluorescent member 311. Thereafter, as shown in FIG. 22, the fluorescent member 311 and the resist 320 are placed on the substrate 30.

  Then, a resist 321 is formed on a region of the other surface 311c of the fluorescent member 311 where the through hole 312a (see FIG. 18) is to be formed.

  Thereafter, the reflective film 312 (see FIG. 18) is formed on the side surface 311b and the other surface 311c of the fluorescent member 311 using, for example, an EB vapor deposition apparatus.

  In this way, the light emitting unit 310 is manufactured.

  In addition, the other manufacturing method of 4th Embodiment is the same as that of the said 1st-3rd embodiment.

  In the fourth embodiment, as described above, since the excitation light can be reflected, for example, five times, the optical path length of the excitation light in the fluorescent member 311 can be further increased. Thereby, the light conversion efficiency can be further improved.

  Other effects of the fourth embodiment are the same as those of the first to third embodiments.

(Fifth embodiment)
In the fifth embodiment, a case where the light emitting device is used as a headlamp will be described with reference to FIGS. 23 to 25.

  First, with reference to FIG. 23 and FIG. 24, the structure of the headlamp 401 by 5th Embodiment of this invention is demonstrated. The headlamp 401 is an example of the “light emitting device” in the present invention.

  A headlamp 401 according to a fifth embodiment of the present invention is mounted on a vehicle (for example, an automobile) (not shown) or the like and illuminates the front of the vehicle. As shown in FIG. 23, the headlamp 401 includes a semiconductor laser element 2 and a light emitting unit 410. The light emitting unit 410 includes a fluorescent member 411, a reflective film 412, and a reflective plate 413. The reflective film 412 and the reflective plate 413 are examples of the “reflective member” in the present invention.

  As shown in FIG. 24, the fluorescent member 411 is formed in a dome shape (hemispherical shape) including a bottom surface 411a and a convex surface 411b. The bottom surface 411a is an example of the “light incident surface” and the “light exit surface” in the present invention.

  The light reflecting surface 412a of the reflective film 412 is formed so as to cover the convex surface 411b of the fluorescent member 411.

  In the fifth embodiment, the fluorescent member 411 and the reflective film 412 are formed so that the excitation light transmitted through the fluorescent member 411 is reflected twice by the reflective film 412.

  In addition, an adhesive layer (not shown) made of solder or the like is provided between the reflective film 412 and the reflective plate 413, and the reflective film 412 and the fluorescent member 411 are fixed to the reflective plate 413 by the adhesive layer. ing.

  The reflection plate 413 is formed of a metal plate having a high thermal conductivity such as aluminum. Further, as shown in FIG. 23, the reflection plate 413 is formed with a through hole 413a for allowing the excitation light emitted from the semiconductor laser element 2 to pass therethrough. The through hole 413 a is formed in a portion of the reflector 413 that is in front of the fluorescent member 411.

  Here, in the fifth embodiment, the light reflecting surface 413b of the reflecting plate 413 is formed in a concave shape and has a function of reflecting light. The light reflecting surface 413b is formed by a parabolic surface, for example.

  And in 5th Embodiment, as shown in FIG. 24, the fluorescent member 411 is arrange | positioned in the vertex V401 vicinity of the light reflection surface 413b of the reflecting plate 413. As shown in FIG. The fluorescent member 411 may be disposed in a region including the vertex V401 of the light reflecting surface 413b.

  In the fifth embodiment, the fluorescent member 411 is disposed in a region including the focal point F401 of the light reflecting surface 413b. The fluorescent member 411 may be disposed in the vicinity of the focal point F401 of the light reflecting surface 413b. Thereby, the light emitted from the fluorescent member 411 is made into substantially parallel light by the light reflecting surface 413b and emitted forward from the light emitting unit 410 (headlamp 401).

  The remaining structure of the fifth embodiment is similar to that of the aforementioned first embodiment.

  Next, the optical path of the excitation light (the optical path of the light traveling on the optical axis of the excitation light) will be described with reference to FIGS.

  In the fifth embodiment, as shown in FIG. 25, the excitation light P400 emitted from the semiconductor laser element 2 (see FIG. 23) is reflected by the light reflecting surface 413b of the reflecting plate 413 and then the bottom surface 411a of the fluorescent member 411. Is incident on.

  Then, the excitation light P401 that has entered the fluorescent member 411 is reflected from the regions 412b and 412c of the reflective film 412, and then exits from the bottom surface 411a. The region 412b is an example of the “first reflection region” in the present invention, and the region 412c is an example of the “second reflection region” in the present invention.

  As described above, in the fifth embodiment, the excitation light transmitted through the fluorescent member 411 is reflected twice by the reflective film 412, and is emitted to the outside from the light emitting unit 410 (fluorescent member 411).

  In addition, the manufacturing method of the fluorescent member 411 and the reflective film 412 of 5th Embodiment is the same as that of the said 1st Embodiment.

  In the fifth embodiment, as described above, the fluorescent member 411 is disposed in the vicinity of the vertex V401 of the light reflecting surface 413b (or the region including the vertex V401 of the light reflecting surface 413b). Thereby, since the fluorescent member 411 can be disposed close to the reflecting plate 413, the heat generated by the fluorescent member 411 can be easily radiated to the reflecting plate 413. Thereby, since it can suppress that the fluorescent member 411 becomes high temperature too much, it can suppress that the light conversion efficiency of the fluorescent member 411 falls.

  Moreover, in 5th Embodiment, as mentioned above, the through-hole 413a for allowing excitation light to pass through is provided in the reflecting plate 413. FIG. Accordingly, the excitation light can be incident on the fluorescent member 411 at a desired position and at a desired incident angle.

  In the fifth embodiment, as described above, the fluorescent member 411 is disposed in the region including the focal point F401 (or the vicinity of the focal point F401) of the light reflecting surface 413b. Thereby, the light (illumination light) emitted from the light emitting unit 410 can be easily made into substantially parallel light.

  Note that when the fluorescent member 411 is enlarged, the light emitted from the light emitting unit 410 (light reflected by the light reflecting surface 413b) hardly becomes parallel light, but the present invention can reduce the fluorescent member 411 in size. The light emitted from the light emitting unit 410 can be brought close to parallel light. Thereby, the illumination area | region of illumination light can be controlled easily.

  Other effects of the fifth embodiment are the same as those of the first embodiment.

(Sixth embodiment)
In the sixth embodiment, a case where excitation light is irradiated from the rear side of the fluorescent member 511, unlike the fifth embodiment, will be described with reference to FIGS.

  First, with reference to FIG. 26 and FIG. 27, the structure of the headlamp 501 according to the sixth embodiment of the present invention will be described. The headlamp 501 is an example of the “light emitting device” in the present invention.

  A headlamp 501 according to a sixth embodiment of the present invention includes a semiconductor laser element 2 and a light emitting unit 510 as shown in FIG. The light emitting unit 510 includes a fluorescent member 511, a reflective film 512, a reflective plate 513, and a reflective piece 514. The reflective film 512, the reflective plate 513, and the reflective piece 514 are examples of the “reflective member” in the present invention.

  As shown in FIG. 27, the fluorescent member 511 is formed in a shape obtained by cutting a part of a dome shape (hemispherical shape).

  The fluorescent member 511 includes a bottom surface 511a, a convex surface 511b, and a cut surface 511c inclined with respect to the bottom surface 511a. The bottom surface 511a is an example of the “light emitting surface” in the present invention, and the convex surface 511b is an example of the “light incident surface” in the present invention.

  The bottom surface 511a functions as a light reflecting surface that emits light.

  The convex surface 511b functions as a light incident surface on which excitation light emitted from the semiconductor laser element 2 enters.

  The light reflecting surface 512a of the reflective film 512 is formed so as to cover the convex surface 511b of the fluorescent member 511.

  The reflective film 512 is formed with a through hole 512b for allowing the excitation light emitted from the semiconductor laser element 2 (see FIG. 26) to enter the fluorescent member 511.

  The reflection plate 513 is formed with a through hole 513a for allowing the excitation light emitted from the semiconductor laser element 2 (see FIG. 26) to pass therethrough. The through hole 513 a is formed so as to be connected to the through hole 512 b of the reflective film 512, and is formed in a portion of the reflective plate 513 on the rear side of the fluorescent member 511.

  The reflection piece 514 is provided on the cut surface 511c of the fluorescent member 511. The reflection piece 514 is formed with a light reflection surface 514a having a function of reflecting light.

  The light reflecting surface 514a is formed to be inclined with respect to the optical axis of the excitation light incident on the fluorescent member 511. That is, the light reflection surface 514 a is formed so that the excitation light reflected by the light reflection surface 514 a reaches the reflection film 512.

  In the sixth embodiment, the fluorescent member 511, the reflective film 512, and the reflective piece 514 are so reflected that the excitation light transmitted through the fluorescent member 511 is reflected by the reflective film 512 and the reflective piece 514 three or more times (for example, four times). Is formed.

  The remaining structure of the sixth embodiment is similar to that of the aforementioned second and fifth embodiments.

  Next, the optical path of the excitation light (the optical path of light traveling on the optical axis of the excitation light) will be described with reference to FIGS.

  In the sixth embodiment, as shown in FIG. 28, the excitation light P500 emitted from the semiconductor laser element 2 is incident on the convex surface 511b of the fluorescent member 511.

  Then, the excitation light P501 incident on the fluorescent member 511 is reflected by the region 514b of the light reflecting surface 514a of the reflecting piece 514 and the regions 512c, 512d and 512e of the reflecting film 512, and then exits from the bottom surface 511a. Note that the fluorescent member 511, the reflective film 512, and the reflective piece 514 may be formed so that the excitation light reflected by the region 512d of the reflective film 512 is emitted from the bottom surface 511a without reaching the region 512e. The region 514b is an example of the “first reflection region” in the present invention, and the region 512c is an example of the “second reflection region” in the present invention. The region 512d is an example of the “third reflection region” in the present invention.

  As described above, in the sixth embodiment, the excitation light transmitted through the fluorescent member 511 is reflected four times (three times or more) by the reflective film 512 and the reflective piece 514, and is emitted from the light emitting unit 510 (fluorescent member 511) to the outside. Exit.

  In addition, the manufacturing method of the fluorescent member 511 and the reflective film 512 of 6th Embodiment is the same as that of the said 2nd and 5th Embodiment.

  The effects of the sixth embodiment are the same as those of the second and fifth embodiments.

(Seventh embodiment)
In the seventh embodiment, a case where the fluorescent member 611 is embedded in the recess 613c of the reflector 613 will be described with reference to FIGS. 29 to 31, unlike the fifth and sixth embodiments.

  First, with reference to FIG. 29 and FIG. 30, the structure of the headlamp 601 according to the seventh embodiment of the present invention will be described. The headlamp 601 is an example of the “light emitting device” in the present invention.

  A headlamp 601 according to the seventh embodiment of the present invention includes a semiconductor laser element 2 and a light emitting unit 610 as shown in FIG. The light emitting unit 610 includes a fluorescent member 611, a reflective film 612 having a light reflecting surface 612a (see FIG. 30), and a reflective plate 613. The reflective film 612 and the reflective plate 613 are examples of the “reflective member” in the present invention.

  As shown in FIG. 30, the fluorescent member 611 is formed in a conical shape including a bottom surface 611a and a side surface 611b. The bottom surface 611a is an example of the “light incident surface” and “light emitting surface” in the present invention.

  In the seventh embodiment, the fluorescent member 611 and the reflective film 612 are formed so that the excitation light transmitted through the fluorescent member 611 is reflected by the reflective film 612 two or more times (for example, four times). For example, in the seventh embodiment, the vertical angle of the fluorescent member 611 may be about 60 °.

  As shown in FIG. 29, the reflection plate 613 is formed with a through hole 613a for allowing the excitation light emitted from the semiconductor laser element 2 to pass therethrough.

  Here, in the seventh embodiment, as shown in FIG. 30, a conical recess 613 c in which the fluorescent member 611 is embedded (contained) is formed on the light reflecting surface 613 b of the reflecting plate 613. The recess 613c is formed in a region of the reflecting plate 613 that includes the apex of the light reflecting surface 613b. Further, the recess 613c is formed in a region in the vicinity of the focal point of the light reflecting surface 613b in the reflecting plate 613.

  In addition, the peripheral part of the recessed part 613c of the reflecting plate 613 may be formed thicker than the part other than the periphery of the recessed part 613c of the reflecting plate 613 (the front part of the reflecting plate 613).

  Other structures of the seventh embodiment are the same as those of the first and fifth embodiments.

  Next, with reference to FIGS. 29 and 31, the optical path of the excitation light (the optical path of the light traveling on the optical axis of the excitation light) will be described.

  In the seventh embodiment, as shown in FIG. 31, the excitation light P600 emitted from the semiconductor laser element 2 (see FIG. 29) enters the bottom surface 611a of the fluorescent member 611. The excitation light P601 incident on the fluorescent member 611 is reflected from the regions 612b, 612c, 612d, and 612e of the light reflecting surface 612a of the reflective film 612, and then exits from the bottom surface 611a. The region 612b is an example of the “first reflection region” in the present invention, and the region 612c is an example of the “second reflection region” in the present invention. The region 612d is an example of the “third reflection region” in the present invention.

  As described above, in the seventh embodiment, the excitation light transmitted through the fluorescent member 611 is reflected four times by the reflective film 612 and is emitted to the outside from the light emitting unit 610 (fluorescent member 611).

  In addition, the manufacturing method of the fluorescent member 611 and the reflective film 612 of 7th Embodiment is the same as that of the said 1st Embodiment.

  In the seventh embodiment, as described above, the concave portion 613c that accommodates the fluorescent member 611 is formed in the light reflecting surface 613b of the reflecting plate 613. Thereby, since the recessed part 613c can be easily made into a desired shape (triangular pyramid shape), the fluorescent member 611 can be easily made into a desired shape (triangular pyramid shape).

  The other effects of the seventh embodiment are the same as those of the first and fifth embodiments.

(Eighth embodiment)
In the eighth embodiment, a case where the fluorescent member 711 is formed in a truncated cone shape will be described with reference to FIGS. 32 to 34, unlike the fifth to seventh embodiments.

  First, with reference to FIG. 32 and FIG. 33, the structure of the headlamp 701 according to the eighth embodiment of the present invention will be described. The headlamp 701 is an example of the “light emitting device” in the present invention.

  A headlamp 701 according to the eighth embodiment of the present invention includes a semiconductor laser element 2 and a light emitting unit 710 as shown in FIG. The light emitting unit 710 includes a fluorescent member 711, a reflective film 712 having a light reflecting surface 712b (see FIG. 33), and a reflective plate 713. The reflective film 712 and the reflective plate 713 are examples of the “reflective member” in the present invention.

  As shown in FIG. 33, the fluorescent member 711 is formed in a truncated cone shape including one surface 711a, a side surface 711b, and the other surface 711c. The one surface 711a is an example of the “light emitting surface” in the present invention, and the other surface 711c is an example of the “light incident surface” in the present invention.

  The reflective film 712 is formed with a through hole 712 a for allowing excitation light emitted from the semiconductor laser element 2 (see FIG. 32) to enter the fluorescent member 711.

  In the eighth embodiment, the fluorescent member 711 and the reflective film 712 are formed so that the excitation light transmitted through the fluorescent member 711 is reflected by the reflective film 712 three or more times (for example, five times).

  A concave portion 713b in which the fluorescent member 711 is embedded is formed in the light reflecting surface 713a of the reflecting plate 713.

  The reflector 713 is formed with a through hole 713c for allowing the excitation light emitted from the semiconductor laser element 2 (see FIG. 32) to pass therethrough. The through hole 713c is connected to the recess 713b.

  Other structures of the eighth embodiment are the same as those of the fourth, sixth and seventh embodiments.

  Next, with reference to FIGS. 32 and 34, the optical path of the excitation light (the optical path of the light traveling on the optical axis of the excitation light) will be described.

  In the eighth embodiment, as shown in FIG. 34, the excitation light P700 emitted from the semiconductor laser element 2 (see FIG. 32) is incident on the other surface 711c of the fluorescent member 711. The excitation light P701 incident on the fluorescent member 711 is reflected from the regions 712c, 712d, 712e, 712f, and 712g of the light reflecting surface 712b of the reflective film 712, and then exits from the one surface 711a. The region 712c is an example of the “first reflection region” in the present invention, and the region 712d is an example of the “second reflection region” in the present invention. The region 712e is an example of the “third reflection region” in the present invention.

  As described above, in the eighth embodiment, the excitation light transmitted through the fluorescent member 711 is reflected five times by the reflective film 712 and is emitted from the light emitting unit 710 (fluorescent member 711) to the outside.

  In addition, the manufacturing method of the fluorescent member 711 and the reflective film 712 of 8th Embodiment is the same as that of the said 4th Embodiment.

  The effects of the eighth embodiment are the same as those of the fourth, sixth and seventh embodiments.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  For example, in the fifth to eighth embodiments, the example in which the light-emitting device of the present invention is applied to a headlight of a vehicle (for example, an automobile) is shown. However, the present invention is not limited to this, and the light-emitting device of the present invention. May be applied to headlights of airplanes, ships, robots, motorcycles or bicycles, and other moving objects. In addition, the light-emitting device of the present invention may be applied to a downlight, a spotlight, or other lighting devices.

  In the above embodiment, an example in which the excitation light source (semiconductor laser element) and the fluorescent member are configured to emit white light has been described. However, the present invention is not limited thereto, and light other than white light is emitted. As such, an excitation light source and a fluorescent member may be configured.

  In the above embodiment, an example in which excitation light is converted into visible light (red light, green light, and blue light) has been described. However, the present invention is not limited to this, and excitation light is converted into light other than visible light. May be. For example, when excitation light is converted into infrared light, it can be applied to a night illumination device (light emitting device) of a security CCD camera, an infrared light emitting device of an infrared heater, or the like.

  In the above-described embodiment, an example in which a semiconductor laser element is used as an excitation light source that emits laser light has been described. A laser generator may be used.

  Moreover, although the said embodiment demonstrated the example which used the semiconductor laser element which radiate | emits a laser beam as an excitation light source, this invention is not restricted to this, LED (Light Emitting Diode) etc. are used as an excitation light source. Also good. In this case, you may provide the lens which makes the light radiate | emitted from LED parallel light (or condenses) in the light emission side of LED.

  Moreover, the numerical value shown by the said embodiment is an example, and each numerical value is not limited.

  Further, a light guide member for guiding laser light (excitation light) emitted from the semiconductor laser element to the fluorescent member may be provided.

  Moreover, in the said embodiment, although the example which formed the light reflection surface of the reflecting plate by the paraboloid was shown, this invention is not restricted to this, Even if a light reflection surface is formed by a part of ellipsoidal surface. Good. Further, the reflection plate may be formed of a CPC (Compound Parabolic Concentrator) type reflection plate.

  In the above embodiment, an example in which only one excitation light source is provided has been described. However, the present invention is not limited to this, and a plurality of excitation light sources may be provided.

  Moreover, although the said 1st-4th embodiment demonstrated the example which forms a reflecting film by vapor deposition, this invention is not restricted to this, Generally known thin film formation of sputtering etc. other than vapor deposition A reflective film can be formed by the method.

  Further, for example, in the first embodiment, the example in which the reflection film is formed on the entire side surface of the fluorescent member has been described. However, the present invention is not limited to this, and only the portion that needs to reflect the excitation light is reflected. A film may be formed.

  In the above-described embodiment, an example in which the fluorescent member is formed in, for example, a conical shape, a cylindrical shape, or a truncated cone shape has been described. However, the present invention is not limited thereto, and the fluorescent member is formed in a polygonal pyramid shape, a polygonal prism shape. Alternatively, it may be formed in a polygonal frustum shape, or may have other various shapes.

  Moreover, although the said 1st-4th embodiment demonstrated the example which provided the reflecting film on the surface of the fluorescent member, this invention is not restricted to this, A reflecting plate is provided on the surface of the fluorescent member. Also good.

  Further, for example, in the fifth embodiment, the example in which the light emitting unit is configured by the fluorescent member, the reflective film, and the reflective plate has been described. However, the present invention is not limited thereto, and the light emitting unit is configured by the fluorescent member and the reflective plate. May be. That is, the excitation light may be reflected by the light reflection surface of the reflection plate without providing a reflection film on the surface of the fluorescent member. In this case, the fluorescent member may be formed by pouring and sealing a sealing material (for example, a glass material) containing phosphor particles into the reflecting plate (or the inside of the recess).

  Moreover, in the said 2nd Embodiment, in order to reflect excitation light 3 times or more, although the example which formed the fluorescent member in the shape which cut off a part of cone shape was demonstrated, this invention is not limited to this, For example, you may comprise like the light emission unit 810 by the 1st modification of this invention shown in FIG. That is, as shown in FIG. 35, the reflective film 812 is formed not only on the side surface 11b of the fluorescent member 11 but also on a part of the bottom surface 11a. Even if comprised in this way, it is possible to reflect excitation light 3 times or more (for example, 5 times).

  Moreover, in the said 3rd Embodiment, when the fluorescent member was formed in the column shape, it showed about the example which irradiated the light emission unit from the front side, but this invention is not limited to this, For example, it showed in FIG. As in the light emitting device 901 according to the second modified example of the present invention, the semiconductor laser element 2 may be arranged on the rear side of the light emitting unit 910, and the light emitting unit 910 may be irradiated with the excitation light from the rear side.

  Specifically, as shown in FIG. 36, the fluorescent member 911 is formed in a cylindrical shape having a diameter of D901 (for example, about 20 mm) and a height of H901 (for example, about 40 mm). Further, the light reflecting surface 912a of the reflecting film 912 is formed so as to cover the side surface 911b and the other surface (light incident surface) 911c of the fluorescent member 911, and the excitation light P900 is incident on the reflecting member 911 on the fluorescent member 911. A through hole 912b (for example, a diameter of about 1 mm) is formed.

  The incident position of the excitation light P900 emitted from the semiconductor laser element 2 with respect to the fluorescent member 911 is set to a position away from the end (side surface 911b) of the fluorescent member 911 by a distance L900 (for example, about 8 mm), and the excitation light P900. If the incident angle θ900 is about 70 ° and the refraction angle θ901 of the excitation light P901 incident on the fluorescent member 911 is about 41 °, the excitation light transmitted through the fluorescent member 911 is reflected by the reflective film 912 two or more times. The light is emitted from one surface (light emitting surface) 911a of the fluorescent member 911. For example, the excitation light can be reflected three or more times by the reflective film 912 by reducing the diameter D901 of the fluorescent member 911 or increasing the height H901.

  The light emitting unit 910 can be manufactured in the same manner as in the above embodiment. That is, a cylindrical fluorescent member 911 is prepared, and a resist 920 (see FIG. 37) is formed on one surface 911a of the fluorescent member 911. Then, the fluorescent member 911 and the resist 920 are installed on the substrate 30. Thereafter, a resist 921 is formed on a region where the through hole 912b (see FIG. 36) is to be formed in the other surface 911c of the fluorescent member 911. The light emitting unit 910 can be manufactured by forming the reflective film 912 on the side surface 911b and the other surface 911c of the fluorescent member 911.

  Moreover, although the said embodiment demonstrated the example which provided the reflecting member (reflective film) so that it might closely_contact | adhere to a fluorescent member, this invention is not restricted to this, A clearance gap (( Space) may be provided.

1, 101, 201, 301, 901 Light emitting device 2 Semiconductor laser element (excitation light source)
10, 110, 210, 310, 410, 510, 610, 710, 810, 910 Light emitting unit 11, 111, 211, 311, 411, 511, 611, 711, 911 Fluorescent member 11a, 411a, 611a Bottom surface (light incident surface , Light exit surface)
11b, 211b, 311b, 611b, 711b, 911b Side surface 12, 112, 212, 312, 412, 512, 612, 712, 812, 912 Reflective film (reflective member)
12a, 112b, 212a, 312b, 412a, 413b, 512a, 514a, 612a, 613b, 712b, 713a, 912a Light reflecting surface 12b, 112c, 212b, 312c, 412b, 514b, 612b, 712c region (first reflecting region)
12c, 112d, 212c, 312d, 412c, 512c, 612c, 712d region (second reflection region)
111a, 511a, 711a Bottom surface (light exit surface)
111b Side surface (light incident surface)
112e, 212d, 312e, 512d, 612d, 712e area (third reflection area)
211a One side (light incident surface, light exit surface)
211c Other side 311a, 911a One side (light emitting surface)
311c, 711c, 911c The other surface (light incident surface)
401, 501, 601, 701 Headlamp (light emitting device)
413, 513, 613, 713 Reflector (reflective member)
413a, 513a, 613a, 713c Through hole 511b Convex surface (light incident surface)
514 Reflective piece (reflective member)
613c, 713b Recess C0-C2, C101-C103, C201-C203, C301-C305 Optical axis F401 Focus P0-P3, P100-P104, P200-P203, P300-P306, P400, P401, P500, P501, P600, P601 , P700, P701, P900, P901 Excitation light V401 vertex

Claims (21)

A fluorescent member having a function of converting excitation light into fluorescence, a light incident surface on which the excitation light is incident, and a fluorescent member including a light emission surface that emits the fluorescence;
A reflection member including a light reflection surface for reflecting light,
The light reflecting surface of the reflecting member is
A first reflection region disposed on the optical axis of the excitation light incident on the light incident surface and reflecting the excitation light;
A light emitting unit, comprising: a second reflection region disposed on an optical axis of the excitation light reflected by the first reflection region and reflecting the excitation light.   2. The light emitting unit according to claim 1, wherein the first reflection region of the light reflecting surface is inclined with respect to an optical axis of the excitation light incident on the light incident surface.   3. The light emitting unit according to claim 1, wherein the second reflection region of the light reflection surface is formed to extend in a direction intersecting the first reflection region.   The light reflecting surface of the reflecting member is further disposed on the optical axis of the excitation light reflected by the second reflection region, and further includes a third reflection region that reflects the excitation light. The light emitting unit according to any one of? The fluorescent member forms at least a part of a conical shape or a polygonal pyramid shape including a bottom surface and a side surface,
The light incident surface and the light emitting surface form the bottom surface,
The light-emitting unit according to claim 1, wherein the light reflecting surface is formed so as to cover the side surface. The fluorescent member forms at least a part of a conical shape or a polygonal pyramid shape including a bottom surface and a side surface,
The light incident surface forms the side surface;
The light exit surface forms the bottom surface;
The light-emitting unit according to claim 1, wherein the light reflecting surface is formed so as to cover the side surface. The fluorescent member forms at least a part of a cylindrical shape or a polygonal prism shape including one side, the other side and a side surface,
The light incident surface and the light emitting surface form the one surface,
The light-emitting unit according to claim 1, wherein the light reflecting surface is formed so as to cover the other surface and the side surface. The fluorescent member forms at least a part of a cylindrical shape or a polygonal prism shape including one side, the other side and a side surface,
The light incident surface forms the other surface;
The light exit surface forms the one surface;
The light-emitting unit according to claim 1, wherein the light reflecting surface is formed so as to cover at least the side surface. The fluorescent member forms at least a part of a truncated cone shape or a polygonal frustum shape including one surface, the other surface and side surfaces,
The other surface has a larger area than the one surface;
The light incident surface forms the other surface;
The light exit surface forms the one surface;
The light-emitting unit according to claim 1, wherein the light reflecting surface is formed so as to cover the other surface and the side surface.   The light emitting unit according to claim 1, wherein the reflecting member is provided so as to be in close contact with the surface of the fluorescent member.   The light emitting unit according to claim 10, wherein the reflecting member includes a metal film formed on a surface of the fluorescent member. The light reflecting surface is formed in a concave shape,
The fluorescent member is disposed in the vicinity of the vertex of the light reflecting surface, or in a region including the vertex of the light reflecting surface,
The light emitting unit according to claim 1, wherein a part of the light reflecting surface reflects light emitted from the fluorescent member in a predetermined direction.   The light emitting unit according to claim 12, wherein the reflecting member is provided with a through hole for allowing the excitation light to pass therethrough.   The light emitting unit according to claim 12 or 13, wherein at least a part of the light reflecting surface is formed by one of a parabolic surface and an elliptical surface. The light reflecting surface is formed in a shape having a focal point,
The light emitting unit according to any one of claims 12 to 14, wherein the fluorescent member is disposed in a region including a focal point of the light reflecting surface or in the vicinity of the focal point of the light reflecting surface. .   The light emitting unit according to any one of claims 12 to 15, wherein a concave portion for accommodating the fluorescent member is formed on the light reflecting surface. Excitation light incident on the fluorescent member is P-polarized light,
The light emitting unit according to claim 1, wherein an incident angle of the excitation light with respect to the fluorescent member is a Brewster angle.   The light emitting unit according to claim 1, wherein an incident angle of the excitation light with respect to the fluorescent member is 0 ° or more and 80 ° or less.   The light emitting unit according to claim 1, wherein the excitation light includes laser light. The light emitting unit according to any one of claims 1 to 19,
A light-emitting device comprising: an excitation light source that emits excitation light that is emitted to the fluorescent member of the light-emitting unit.   A headlamp comprising the light-emitting device according to claim 20.

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