WO2012128384A1

WO2012128384A1 - Light-emitting device, illumination device, and headlight

Info

Publication number: WO2012128384A1
Application number: PCT/JP2012/057718
Authority: WO
Inventors: 克彦岸本; 洋史貴島
Original assignee: シャープ株式会社
Priority date: 2011-03-24
Filing date: 2012-03-26
Publication date: 2012-09-27

Abstract

A head lamp (10) is provided with an excitation light source unit (6) for radiating laser light, and a light-emitting unit (2) for emitting fluorescent light by irradiation of the laser light radiated by the excitation light source unit (6). The surface area of a spot when the laser light is irradiated toward the light-emitting unit (2) is greater than the surface area of the light-emitting unit (2) when the light-emitting unit (2) is viewed from the side from which the laser light is irradiated.

Description

Light emitting device, lighting device and headlamp

The present invention relates to a light-emitting device including a light-emitting body including a phosphor that generates fluorescence when irradiated with excitation light. The present invention also relates to a light-emitting device that functions as a high-intensity light source, a lighting device, and a headlamp that includes the lighting device. Furthermore, the present invention relates to a light emitting device, a lighting device, and a vehicle headlamp (headlamp) that can change the characteristics of illumination light with a simple structure.

In recent years, a semiconductor light emitting device such as a light emitting diode (LED) or a semiconductor laser (LD) is used as an excitation light source, and the excitation light generated from these excitation light sources is converted into a light emitting body including a phosphor (light emission). Studies of light-emitting devices that use fluorescence generated by irradiating a part) as illumination light have become active.

An example of such a light emitting device is the light emitting device disclosed in Patent Document 1. This light-emitting device includes a base, a semiconductor laser element (hereinafter sometimes simply referred to as “semiconductor laser”), a diffusion member (diffusion portion), and a wavelength conversion member (hereinafter simply referred to as “light emitter” or “light-emitting portion”). In some cases). In addition, said base has a recessed part with a bottom face and an inner wall. The semiconductor laser is arranged so that its optical axis faces the inner wall of the recess in the base. The diffusion member is disposed on the optical axis of the semiconductor laser. The light emitter is disposed not on the optical axis of the semiconductor laser but at a distance from the diffusion member with respect to the opening direction of the recess. Thereby, the light emitting device described above improves the safety of the illumination light emitted to the outside of the device.

An example of such an illumination device is disclosed in Patent Document 2. In this illumination device, in order to realize a high-intensity light source, a GaN-based semiconductor laser that emits laser light of 450 nm or less is used as an excitation light source. In general, since laser light oscillated from a semiconductor laser is coherent light, the directivity is strong, and the laser light can be condensed and used as excitation light without waste.

Patent Document 2 discloses an illumination device that uses a GaN-based light-emitting diode instead of the GaN-based semiconductor laser as an excitation light source. This light emitting diode includes a laminated body composed of a contact layer, a clad layer, and the like, and the laminated body is provided with a recess. And the fluorescent extraction efficiency is improved by filling the concave portion with a fluorescent material.

Furthermore, there are lamps disclosed in

Patent Documents

3 and 4 as examples of techniques relating to such a light emitting device. In these lamps, a semiconductor laser is used as an excitation light source in order to realize a high-intensity light source. Since the laser light oscillated from the semiconductor laser is coherent light, the directivity is strong, and the laser light can be condensed and used as excitation light without waste. A light-emitting device using such a semiconductor laser as an excitation light source (referred to as an LD light-emitting device) can be suitably applied to a vehicle headlamp.

Further, examples of such an illumination device are disclosed in

Patent Documents

5 and 6. The vehicle headlamps described in

Patent Documents

5 and 6 include a plurality of LED chips that emit different colors. In the technique of Patent Document 5, in order to suppress a decrease in visibility in rainy weather, dense fog, snowfall, or the like, the amount of white light is reduced according to the situation, and light such as green or orange is emitted. Moreover, in the technique of patent document 6, the red light and green light which are easy to distinguish a pedestrian from another target object are radiate | emitted so that a pedestrian can be recognized rapidly.

Japanese Patent Publication “Japanese Unexamined Patent Publication No. 2009-170723 (released on July 30, 2009)” Japanese Patent Publication “JP 2000-174346 A (published on June 23, 2000)” Japanese Patent Publication “Japanese Patent Laid-Open No. 2005-150041 (published on June 9, 2005)” Japanese Patent Publication “Japanese Patent Laid-Open No. 2003-295319 (published on October 15, 2003)” Japanese Patent Publication “Japanese Patent Laid-Open No. 2006-351369 (published on Dec. 28, 2006)” Japanese Patent Publication “JP 2009-286198 A” (published on Dec. 10, 2009)

However, in the technique described in Patent Document 1, scattered light generated by irradiating the diffusing member with laser light (excitation light) is indirectly irradiated on the light emitter. Further, the light emitter is not disposed on the optical axis of the semiconductor laser, but is disposed at a distance from the diffusion member with respect to the opening direction of the recess. For this reason, since many scattered light which is not irradiated to a light-emitting body arises, there exists a problem that the irradiation efficiency of the excitation light with respect to a light-emitting body will fall remarkably.

Therefore, in order to suppress a decrease in the irradiation efficiency of the excitation light with respect to the light emitter, it is preferable to irradiate the light emitter with the laser light generated from the semiconductor laser as it is.

Incidentally, it is known that the intensity distribution of laser light generated from a semiconductor laser has a predetermined spread and is almost Gaussian. Therefore, the intensity of the bottom part of the spot of the laser beam decreases rapidly as the distance from the maximum intensity part increases.

For this reason, if the spot size when the laser beam generated from the semiconductor laser is irradiated to the light emitter is less than or equal to the size of the light emitter, there is a possibility of large unevenness in the intensity distribution of the laser light on the irradiated surface of the light emitter. There is. If it does so, the intensity | strength of a laser beam may concentrate on a part of irradiation surface of a light-emitting body, and deterioration of a light-emitting body may be accelerated | stimulated.

On the other hand, as described above, in order to set the spot size when the laser beam generated from the semiconductor laser is irradiated to the light emitter to be equal to or smaller than the size of the light emitter, the optical system constituting the apparatus has high work accuracy. Required. For this reason, there is a problem that the degree of freedom in designing the apparatus is lowered.

Furthermore, in Patent Document 2, the above-described semiconductor laser or light-emitting diode is used as an excitation light source to achieve a high-intensity light source or to improve the fluorescence extraction efficiency. However, the technique for adjusting the color temperature of illumination light is known. No idea is disclosed. This is because Patent Document 2 does not recognize the necessity of the color temperature adjustment.

Similarly,

Patent Documents

3 and 4 disclose lamps using a semiconductor laser as an excitation light source, but do not disclose changing the color temperature of illumination light emitted from these lamps. This is because

Patent Documents

3 and 4 did not recognize the necessity of changing the color temperature.

Further, neither of

Patent Documents

5 and 6 needs to prepare a plurality of LED chips, and does not relate to a technique of emitting a plurality of different colors by a single LED chip (excitation light source). For this reason, the techniques of

Patent Documents

5 and 6 require the use of a plurality of LED chips, which causes various problems such as manufacturing costs and arrangement of LED chips in a vehicle headlamp.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a light-emitting device that can increase the degree of freedom in designing the device while suppressing deterioration of the light-emitting body. It is in. In addition, the present invention has been made in view of the above problems, and an object thereof is to provide a light emitting device that can change (adjust) the color temperature of illumination light. Furthermore, the present invention has been made to solve the above-described problems, and an object thereof is to provide a light-emitting device that can change the characteristics of illumination light with a simple structure.

In order to solve the above-described problems, a light-emitting device of the present invention includes an excitation light source that emits excitation light and a light-emitting body that emits fluorescence when irradiated with excitation light emitted from the excitation light source. The area of the spot when the excitation light is irradiated is larger than the area of the light emitter when the light emitter is viewed from the side irradiated with the excitation light.

Here, it is known that the intensity distribution of the excitation light generated from the excitation light source has a predetermined spread and is almost Gaussian. Therefore, the intensity of the bottom part of the spot of the excitation light decreases rapidly as the distance from the maximum intensity part increases.

Therefore, the area of the spot when the excitation light generated from the excitation light source is irradiated toward the illuminant is the area of the illuminant when the illuminant is viewed from the side irradiated with the excitation light (projection area). If it is as follows, there is a possibility that large unevenness occurs in the intensity distribution of the excitation light on the irradiation surface of the light emitter. If it does so, the intensity | strength of excitation light will concentrate on a part of irradiation surface of a light-emitting body, and deterioration of a light-emitting body may be accelerated | stimulated.

Therefore, in the above configuration of the present invention, the area of the spot when the excitation light is irradiated toward the light emitter is the area of the cross section of the light emitter when the light emitter is viewed from the side irradiated with the excitation light. Is bigger than. For this reason, compared with the case where the area of the spot of the laser beam is equal to or less than the area of the cross section of the light emitter, unevenness generated in the intensity distribution of the excitation light on the irradiation surface of the light emitter irradiated with the excitation light can be reduced. . For this reason, the intensity of the excitation light is not concentrated on a part of the irradiation surface of the illuminator, and the excitation light is radiated mildly over the entire irradiation surface, so that deterioration of the illuminant can be suppressed.

In the above configuration, since the area of the excitation light spot only needs to be larger than the area of the cross section of the light emitter, the area of the laser light spot is less than or equal to the area of the light emitter. In comparison, high working accuracy is not required for the optical system constituting the apparatus. This also increases the degree of freedom in device design.

As described above, according to the above-described configuration of the present invention, it is possible to increase the degree of freedom in designing the device while suppressing deterioration of the light emitter.

In addition, since the technique of the said patent document 1 is not the structure to which the excitation light radiate | emitted from the semiconductor laser (excitation light source) is directly irradiated toward a light-emitting body, when the excitation light is irradiated toward a light-emitting body, There is no room to discuss the area of the spot.

In order to solve the above-described problem, the light emitting device of the present invention emits at least one excitation light source that emits excitation light and at least one that emits fluorescence upon receiving the excitation light emitted from the excitation light source. It is characterized by comprising a light emitting section and a characteristic changing mechanism for changing the characteristics of the emitted light by changing the ratio of the fluorescence contained in the emitted light emitted from the device itself to the outside.

According to the above configuration, the characteristic changing mechanism changes the characteristic of the emitted light by changing the ratio of the fluorescence contained in the emitted light emitted from the device itself to the outside, which is emitted from at least one light emitting unit. Therefore, the characteristics of the emitted light, particularly the color temperature can be changed.

As described above, the light-emitting device of the present invention includes an excitation light source that emits excitation light and a light emitter that emits fluorescence when irradiated with the excitation light emitted from the excitation light source, and the excitation light is emitted toward the light emitter. The area of the spot when irradiated with light is larger than the area of the light emitter when the light emitter is viewed from the side irradiated with the excitation light.

Therefore, it is possible to increase the degree of freedom in designing the device while suppressing the deterioration of the light emitter.

In addition, as described above, the light-emitting device of the present invention includes at least one excitation light source that emits excitation light, and at least one light-emitting unit that emits fluorescence in response to the excitation light emitted from the excitation light source. The apparatus includes a characteristic changing mechanism that changes a characteristic of the emitted light by changing a ratio of the fluorescence contained in the emitted light emitted to the outside.

Therefore, it is possible to change the characteristics of the emitted light, particularly the color temperature.

1 is a half sectional view showing a schematic configuration of a headlamp (transmission type) according to an embodiment of the present invention. (A) is sectional drawing which shows an example of each arrangement method of a board | substrate, a light-emitting body (light emission part), and a spreading | diffusion part regarding the said headlamp, (b) is a cross section which shows another example of the said arrangement method. (C) is a cross-sectional view showing still another example of the arrangement method, (d) is a cross-sectional view showing still another example of the arrangement method, and (e) It is sectional drawing which shows another example of the arrangement | positioning method. (A) is a figure which shows typically the circuit diagram of an example of an excitation light source (LED) regarding the said headlamp, (b) is a front view which shows the external appearance of the said LED, (c) is It is a figure which shows typically the circuit diagram of other examples (LD) of the said excitation light source, (d) is a perspective view which shows the external appearance (basic structure) of said LD. It is a half sectional view which shows schematic structure of the headlamp (reflection type) which is other embodiment of this invention. (A) is a half sectional view showing a schematic configuration of a headlamp (transmission type) of a comparative example, and (b) shows the distance (r) from the center (O) of the spot of the laser beam and the laser beam It is a distribution map which shows the relationship with an intensity | strength. It is the schematic which shows the external appearance of the light emission unit with which the laser downlight which is further another embodiment of this invention is provided, and the conventional LED downlight. It is sectional drawing of the ceiling in which the said laser downlight was installed. It is sectional drawing of the said laser downlight. It is a figure which shows an example of the positional relationship of the output end part (ferrule) of the optical fiber with which the said laser downlight is provided, and a light emission part. It is sectional drawing of the ceiling in which the said LED downlight was installed. It is a figure for comparing the specifications of the laser downlight and the LED downlight. It is sectional drawing which shows the structure of the headlamp which concerns on another another embodiment of this invention. It is a figure which shows the positional relationship of the output end part and light emission part of an optical fiber with which the said headlamp is provided. 3 is a graph showing characteristics of a Caα-SiAlON: Ce phosphor. It is a graph which shows the spectrum at the time of exciting the light emission part with which the said headlamp is equipped with the laser beam of wavelength 405nm. It is a graph which shows a spectrum at the time of irradiating the said light emission part with the blue laser beam of wavelength 460nm. It is a figure which shows the structure of the headlamp which concerns on another another embodiment of this invention. It is a graph which shows the white chromaticity range requested | required of the vehicle headlamp. It is sectional drawing of the ceiling in which the laser downlight which concerns on one Embodiment of this invention was installed. It is sectional drawing of the said laser downlight. It is sectional drawing which shows the example of a change of the installation method of the said laser downlight. It is a half sectional view which shows the outline | summary structure of the headlamp which concerns on another another embodiment of this invention. It is a block diagram which shows schematic structure of the headlamp which concerns on said one Embodiment. It is a figure which shows the positional relationship of the light emission part and light guide member which are shown in FIG. 22, and the magnitude | size of the laser beam irradiation area | region at that time. (A) shows the case where the size of the laser light irradiation region is substantially the same as the size of the light receiving surface of the light emitting unit, and (b) shows the position of the light emitting unit and the light guide member separated from each other as compared with the case of (a). (C) shows a case where the positions of the light emitting part and the light guide member are closer than in the case of (a). It is a figure which shows a mode that the magnitude | size of the laser beam irradiation area | region contained in the light-receiving surface of the light emission part shown in FIG. 22 changes. (A) shows the case where a light emission part moves to the direction perpendicular | vertical to the optical axis direction of a laser beam, (b) shows the case where a light emission part rotates. It is a graph which shows the white chromaticity range requested | required of the vehicle headlamp. It is a figure which shows the modification of the headlamp shown in FIG. (A) And (b) is a figure which shows another modification of the headlamp shown in FIG. It is a figure which shows schematic structure of the headlamp which concerns on another another embodiment of this invention. It is a figure which shows schematic structure of the headlamp which concerns on another another embodiment of this invention. It is sectional drawing of the laser downlight which concerns on one Embodiment of this invention. It is a half sectional view which shows the outline | summary structure of the headlamp which concerns on another another embodiment of this invention. It is a block diagram which shows schematic structure of the headlamp which concerns on said one Embodiment. It is a figure which shows the example of arrangement | positioning of each light emission part in the light emission part of the headlamp shown in FIG. 32, (a) is an example of arrangement | positioning in case the whole light emission part is a rectangular parallelepiped shape, (b) is a 1st light emission part and 2nd. Example of arrangement when light emitting part is non-contact, (c) is an example of arrangement when whole light emitting part is cylindrical, (d) is a whole light emitting part is cylindrical, and light emitting part has a triple structure. An arrangement example in a case is shown. It is a figure which shows the modification of the light emission part shown in FIG. 32, (a) is sectional drawing which shows an example of the light emission part adhere | attached on the translucent board | substrate, (b) is the light emission part shown to (a). It is a perspective view which shows an example. It is a figure which shows the positional relationship of the light emission part and light guide member in the headlamp shown in FIG. 32, and the magnitude | size of the laser beam irradiation area | region at that time, (a) is a laser beam is the whole light-receiving surface of a 1st light emission part. The case where the size of the laser light irradiation area is the smallest when it is irradiated is shown in (b), and the position of the light emitting part and the light guide member is farther than in the case of (a), and the laser light irradiation area is The case where it is large is shown, and (c) shows the case where the positions of the light emitting part and the light guide member are further separated and the laser light irradiation region is larger than in the case of (b). It is a graph which shows the white chromaticity range requested | required of the vehicle headlamp. It is a figure which shows the modification of the headlamp shown in FIG. It is a half sectional view which shows the outline | summary structure of the headlamp which concerns on another another embodiment of this invention. It is a figure which shows the example of arrangement | positioning of each light emission part in the light emission part of the headlamp shown in FIG. 39, (a) is the case where the 1st light emission part and the 2nd light emission part are the same shape, and are arrange | positioned in contact. An arrangement example, (b) is a modification example of (a), an arrangement example in which the shapes of the first light emitting part and the second light emitting part are different, and (c) is a modification example of (a), and the first light emission. The example of arrangement | positioning when a part and a 2nd light emission part are non-contact is shown. It is a figure which shows the change of the magnitude | size of the laser beam irradiation area | region in the light emission part of the headlamp shown in FIG. 39, (a) shows the case where the laser beam is irradiated only to the 1st light emission part, (b) is. A case where both the first light emitting unit and the second light emitting unit are irradiated with laser light is shown. It is sectional drawing of the laser downlight which concerns on one Embodiment of this invention. It is a figure which shows an example of the positional relationship of the output end part and light emission part of an optical fiber with which the said laser downlight is equipped. It is sectional drawing which shows the structure of the headlamp which concerns on further one Embodiment of this invention. It is a figure which shows the structure of the 1st light emission part which concerns on said one Embodiment, a 2nd light emission part, and a position control part. It is a figure for demonstrating operation | movement of the 2nd light emission part in the Example of said one Embodiment, (a) is the state where the distance between a 2nd light emission part and the optical axis of a laser beam is the most separated (B) is a figure which shows a mode that the 2nd light emission part is moving toward the optical axis of a laser beam, (c) is a figure which shows a 2nd light emission part and the optical axis of a laser beam. It is a figure which shows the state from which the distance between was closest. It is a chromaticity diagram for demonstrating the effect acquired by the headlamp shown in FIG. In the structure of the headlamp shown in FIG. 45, it is a figure for demonstrating other operation | movement of the 2nd light emission part which concerns on another Example of the said one Embodiment, (a) is a 2nd light emission part and a laser beam. (B) is a figure which shows a mode that the 2nd light emission part is moving toward the optical axis of a laser beam. c) is a diagram showing a state in which the distance between the second light emitting unit and the optical axis of the laser beam is closest. It is a figure for demonstrating the 1st light emission part with which the LED chip was embedded, (a) is sectional drawing of a 1st light emission part, (b) is a perspective view of a 1st light emission part. It is the figure which combined the 1st light emission part shown in FIG. 49, the 2nd light emission part, and the position control part. It is sectional drawing of the laser downlight which concerns on one Embodiment of this invention. It is sectional drawing which shows the example of a change of the installation method of the said laser downlight.

[Embodiment 1]
An embodiment of the present invention will be described with reference to FIGS. 1 to 5 as follows. Descriptions of configurations other than those described in the following specific items may be omitted as necessary. However, in the case where they are described in other items, the configurations are the same. For convenience of explanation, members having the same functions as those shown in each item are given the same reference numerals, and the explanation thereof is omitted as appropriate.

Hereinafter, as an embodiment of the present invention, a headlamp (light emitting device, lighting device, headlamp) 10 and a headlamp (light emitting device, lighting device, headlamp) 20 will be described as examples.

In addition, although each form of the

headlamps

10 and 20 demonstrated below is demonstrated as a light-emitting device part (light-emitting member) of a headlamp, the form which actualized this invention is not restricted to these forms, front The present invention can also be applied to a light emitting member of a lighting device other than a lighting lamp.

[1. Configuration of headlamp 10]
First, a headlamp 10 according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a half sectional view showing a schematic configuration of the headlamp 10.

As shown in FIG. 1, a headlamp 10 includes a translucent substrate (thermally conductive substrate) 1, a light emitting part (light emitting body) 2, a diffusing part (diffusing member) 3, a parabolic reflector (reflecting mirror) 4, A substrate 5, an excitation light source unit (excitation light source) 6, screws 7L and 7R, and an optical member 8 are provided.

<Translucent substrate 1>
The translucent substrate 1 of the present embodiment is a flat member that is not bent, and has translucency at least with respect to the oscillation wavelength of laser light (440 nm to 480 nm in this case) that is excitation light.

The translucent substrate 1 is an Al ₂ O ₃ (sapphire) substrate having a length of 10 mm × width of 10 mm × thickness of 0.5 mm. Note that the outer diameter of the translucent substrate 1 shown in FIG. 1 is larger than the outer diameter of the diffusing portion 3, but may be approximately the same as the outer diameter of the diffusing portion 3.

The light emitting unit 2 is arranged on the surface SUF2 side facing the surface SUF1 on the side on which the laser light of the translucent substrate 1 is incident, and can be thermally exchanged with the light emitting unit 2 (that is, heat energy can be transferred). Connected). In the present embodiment, the translucent substrate 1 and the light emitting unit 2 are described as being bonded (adhered) using an adhesive, but the bonding method of the translucent substrate 1 and the light emitting unit 2 is described. Is not limited to adhesion, and may be, for example, fusion.

Also, as the adhesive, so-called organic adhesives and glass paste adhesives are suitable, but not limited thereto.

The translucent substrate 1 has the configuration, shape, and connection form with the light emitting unit 2 as described above, so that the light emitting unit 2 is fixed (held) by the surface SUF2 and the translucent substrate 1 is interposed therebetween. Thus, since the heat generated from the light emitting unit 2 can be radiated to the outside, the cooling efficiency of the light emitting unit 2 is improved.

The thermal conductivity of the translucent substrate 1 is preferably 20 W / mK (watts / meter · Kelvin) or more in order to efficiently release the heat of the light emitting part 2. In this case, the translucent substrate 1 has a thermal conductivity about 20 times higher than that of the light emitting unit 2 (about 1 W / mK), and emits light by efficiently absorbing the heat generated in the light emitting unit 2. Part 2 can be cooled.

Further, the laser light that excites the light emitting unit 2 is applied to the light emitting unit 2 and the diffusing unit 3 through the translucent substrate 1. That is, the laser light incident on the surface SUF <b> 1 of the translucent substrate 1 passes through the translucent substrate 1 and reaches the light emitting unit 2. Therefore, the translucent substrate 1 is preferably made of a material having excellent translucency.

Considering the above points, the material of the light-transmitting substrate 1 is preferably magnesia (MgO), gallium nitride (GaN), or spinel (MgAl ₂ O ₄ ) in addition to the sapphire (Al ₂ O ₃ ) described above. By using these materials, a thermal conductivity of 20 W / mK or more can be realized.

However, the material of the translucent substrate 1 is not limited to the above materials, and may be glass (quartz), for example.

However, since magnesia has deliquescence, when selecting magnesia as the constituent material of the translucent substrate 1, it is preferable to fill the periphery of the translucent substrate 1 with dry air. For example, the translucent substrate 1 is stored in a housing (not shown) and filled with dry air and sealed, or inside a parabolic reflector 4 and an optical member 8 described later, or a half parabolic reflector (reflector). 4h, housed inside the heat conducting member 4p and the optical member 8, filled with dry air and sealed. Thereby, it can prevent that the translucent board | substrate 1 is damaged by deliquescence.

Further, the thickness of the translucent substrate 1 shown in FIG. 1 (the distance between the surface SUF1 and the surface SUF2) is more preferably 0.2 mm or more and 5.0 mm or less.

If the thickness of the translucent substrate 1 is 0.2 mm or more, it is possible to sufficiently dissipate heat from the light emitting unit 2 and to prevent deterioration of the light emitting unit 2.

On the other hand, when the thickness of the translucent substrate 1 exceeds 5.0 mm, the rate at which the laser light irradiated toward the light emitting unit 2 is absorbed by the translucent substrate 1 increases, and the use of the laser light is increased. Efficiency is reduced.

In addition, by joining the light-transmitting substrate 1 to the light emitting unit 2 with an appropriate thickness, even when the laser beam is irradiated with an extremely strong laser beam that generates heat exceeding 1 W (watts) in particular, the heat generation occurs. Can be quickly and efficiently dissipated to prevent the light emitting section 2 from being damaged (deteriorated).

Note that, as described above, the translucent substrate 1 may have a flat plate shape without bending, but may have a bent portion or a curved portion. However, when the translucent substrate 1 and the light emitting unit 2 are bonded, the portion to which the light emitting unit 2 is bonded is preferably flat (plate-shaped) from the viewpoint of adhesion stability.

<Light emitting part 2>
(Composition of light emitting part)
Next, the light emitting unit 2 generates fluorescence when irradiated with laser light, and includes a phosphor that generates fluorescence upon receiving the laser light. More specifically, in the light emitting unit 2, the phosphor is dispersed inside the low melting point inorganic glass (n = 1.760) as the sealing material.

In this embodiment, a YAG: Ce phosphor (NYAG4454) manufactured by Intematix was used as the phosphor, but the type of the phosphor is not limited to this. The YAG: Ce phosphor is an yttrium (Y) -aluminum (Al) -garnet phosphor activated with Ce. This Intematix YAG: phosphor has an external quantum efficiency of 90%, an emission peak wavelength (hereinafter simply referred to as “peak wavelength”) of 558 nm (yellow), chromaticity points of x = 0.444, y = 0. .536 and is well excited by excitation light of 430 nm to 490 nm.

The YAG: Ce phosphor generally has a broad emission spectrum in which an emission peak exists in the vicinity of 550 nm (slightly longer than 550 nm).

The light emitting unit 2 is manufactured by dispersing the YAG: Ce phosphor in a low melting point glass. The compounding ratio of the YAG: Ce phosphor and the low melting point glass is about 30: 100, but is not limited to such a ratio. In addition, the light emitting unit 2 may be one obtained by pressing a fluorescent material.

The sealing material is not limited to the inorganic glass of the present embodiment, and may be a so-called organic-inorganic hybrid glass or a resin material such as a silicone resin.

The refractive index difference Δn between the translucent substrate 1 and the light emitting part 2 is preferably 0.35 or less.

When a resin material such as a silicone resin is selected as the sealing material, the light emitting portion 2 has a refractive index of about 1.5 (lower limit), and the light emitting portion 2 was produced using 100% of the YAG: Ce phosphor. In this case, the refractive index of the light emitting unit 2 is about 2.0.

On the other hand, when sapphire, magnesia, gallium nitride, or spinel is used as the translucent substrate 1, the refractive index is in the range of about 1.5-2. Therefore, assuming that the refractive indexes of the light emitting unit 2 and the light transmitting substrate 1 are both about 1.5 to 2.0, when one of the refractive indexes is 1.5, the refractive index difference Δn. Is 0.35 (that is, the other refractive index is 1.85), the reflectance RE at the interface is 1%.

Also, when the refractive index difference of one is 2.0 and the refractive index difference Δn is 0.35 (that is, the other refractive index is 1.65), the reflectance RE is 0.92%.

Therefore, if the refractive index difference Δn between the translucent substrate 1 and the light emitting unit 2 is 0.35 or less, the reflectance RE of the interface between the translucent substrate 1 and the light emitting unit 2 is 1% or less. can do.

Next, the refractive index of the translucent substrate 1 is preferably 1.65 or more. As described above, assuming that the upper limit of the refractive index of the light emitting unit 2 is 2.0, if the refractive index of the translucent substrate 1 is 1.65 or more, the refractive index is 1.5 to 2.0. The refractive index difference Δn ≦ 0.35 can be satisfied with respect to the light emitting unit 2.

In this embodiment, inorganic glass is used as the sealing material of the light emitting unit 2 because the refractive index (1.760) of the light-transmitting substrate 1 made of sapphire (= 1.785). This is because there is almost no reflection at the interface between the two. Note that the reflectance at the interface between sapphire and inorganic glass is 0.005%, which is almost zero.

Therefore, the irradiation efficiency of the laser light with respect to the light emission part 2 further improves. In addition, it summarizes about each physical characteristic of the sapphire used for the translucent board | substrate 1 of this embodiment, and the inorganic glass used for the light emission part 2, and it becomes as the following table | surfaces.

(Type of light emitting part)
Next, in general, white light or pseudo-white light used as illumination light can be realized by mixing three colors satisfying the principle of color matching or mixing two colors satisfying a complementary color relationship. Based on the principle / relationship of this equal color or complementary color, for example, in the headlamp 10 of the present embodiment, a blue laser beam emitted from an excitation light source unit 6 described later and a YAG: Ce phosphor (yellow light emitting phosphor). (A mixed color of two colors satisfying the complementary color relationship) and a pseudo white color is realized.

However, the phosphor included in the light emitting unit 2 is not limited to one type of YAG: Ce phosphor (yellow light emitting phosphor) as in this embodiment, and may be a plurality of types.

For example, if the light emitting unit 2 includes a combination of a green light emitting phosphor and a red light emitting phosphor, which will be described later, white light can be realized by mixing with blue laser light.

The yellow light emitting phosphor is a phosphor that emits fluorescence having a peak wavelength in a wavelength range of 560 nm or more and 590 nm or less. The green light emitting phosphor is a phosphor that emits fluorescence having a peak wavelength in a wavelength range of 510 nm or more and 560 nm or less. The red light-emitting phosphor is a phosphor that generates fluorescence having a peak wavelength in a wavelength range of 600 nm or more and 680 nm or less.

(Yellow-emitting phosphor)
Specific examples of the yellow light emitting phosphor include the YAG: Ce phosphor of this embodiment and the Caα-SiAlON: Eu phosphor doped with Eu ²⁺ . The Caα-SiAlON: Eu phosphor exhibits strong light emission with a peak wavelength of about 580 nm by near ultraviolet to blue excitation light.

(Green light emitting phosphor)
Specific examples of the green light emitting phosphor include various nitride-based or oxynitride-based phosphors. Since these nitride-based or oxynitride-based phosphors have excellent heat resistance and are stable materials with high light emission efficiency, the light emitting portion 2 having excellent heat resistance and stable with high light emission efficiency can be realized.

Examples of the oxynitride phosphor that emits green light include β-SiAlON: Eu phosphor doped with Eu ²⁺ and Caα-SiAlON: Ce phosphor doped with Ce ³⁺ . The β-SiAlON: Eu phosphor exhibits strong emission with a peak wavelength of about 540 nm by excitation light from near ultraviolet to blue (350 nm to 460 nm). The half width of the emission spectrum of this phosphor is about 55 nm. Further, the Caα-SiAlON: Ce phosphor exhibits strong light emission with a peak wavelength of about 510 nm by near ultraviolet to blue excitation light.

The above α-SiAlON and β-SiAlON (sialon) are so-called sialon phosphors (oxynitride phosphors), and there are α-type and β-type depending on the crystal structure, similar to silicon nitride. In particular, alpha-sialon has the general formula _{_{_{_{Si 12- (m + n) Al}}}} (m + n) O n N 16-n (m + n <12,0 <m, n <11; m, n is an integer) from 28 atom represented by There are two voids in the unit structure, and various metals can enter and dissolve therein. A phosphor is obtained by dissolving a rare earth element. When calcium (Ca) and europium (Eu) are dissolved, a phosphor that emits light having a longer wavelength range from yellow to orange than the YAG: Ce phosphor is obtained.

Moreover, the sialon phosphor can be excited by light from near ultraviolet to blue (350 nm or more and 460 nm or less), and is suitable for a phosphor for a white LED.

(Red light emitting phosphor)
Specific examples of the red light-emitting phosphor include various nitride-based phosphors.

For example, examples of the nitride-based phosphor include Eu ²⁺ doped CaAlSiN ₃ : phosphor (CASN: Eu phosphor), Eu ²⁺ doped SrCaAlSiN ₃ phosphor (SCASN: Eu phosphor), and the like. It is done. By combining these nitride-based phosphors with the oxynitride phosphors described above, color rendering can be further improved.

CASN: Eu phosphor emits red fluorescence when its excitation wavelength is 350 nm to 450 nm, its peak wavelength is 650 nm, and its luminous efficiency is 73%. Further, the SCASN: Eu phosphor emits red fluorescence when the excitation wavelength is 350 nm to 450 nm, its peak wavelength is 630 nm, and its luminous efficiency is 70%.

By using these red light emitting phosphors, white light with very good color rendering can be realized. Moreover, if it is a red light emission fluorescent substance, when the target object which irradiates the white light is red, the visibility of the target object can be improved. Since red, yellow, and blue are used as the background colors of traffic signs, it is effective to use a red light-emitting phosphor for the light emitting unit 2 provided in the headlamp 10 for visually recognizing traffic signs with a red background color. It is.

Examples of nitride phosphors that emit red light include Eu-activated nitride phosphors such as (Mg, Ca, Sr, Ba) AlSiN ₃ : Eu, and (Mg, Ca, Sr, Ba) AlSiN ₃ : Examples include Ce-activated nitride phosphors such as Ce.

(About nanoparticle phosphors)
Next, a nanoparticle phosphor will be described as an example of another phosphor. Typical semiconductor materials that constitute the nanoparticle phosphor are II-VI group compounds such as ZnSe, ZnTe, CdSe, and CdTe, 4B group elements such as Si and Ge, and III-V group compounds such as GaAs and InP. is there. A semiconductor nanoparticle refers to a particle having a diameter of about 1 to 10 nm made of a semiconductor material, and the number of atoms contained in one nanoparticle is 10 ² to 10 ⁴ . The quantum size effect absorbs and emits light having a wavelength different from that of a bulk semiconductor. For example, since it is an indirect transition type, Si that does not normally emit light can be emitted by forming nanoparticles.

Quantum size effect is a phenomenon in which the state of electrons in a material changes as particles become smaller, and light of shorter wavelengths is absorbed or emitted. In particular, it is often noticeable for particles having a diameter of 10 nm or less.

That is, one of the characteristics of the nanoparticle phosphor is that even if the same compound semiconductor (for example, indium phosphorus: InP) is used, the particle size is changed to a size on the order of nm, so that the emission color can be obtained by the quantum size effect. It is a point that can be changed. For example, InP emits red light when the particle size is about 3 to 4 nm [where the particle size was evaluated with a transmission electron microscope (TEM)].

In addition, since the nanoparticle phosphor is semiconductor-based, it has a short fluorescence lifetime, and can emit the excitation light power quickly as fluorescence, and thus has a feature of high resistance to high-power excitation light. This is because the emission lifetime of the nanoparticle phosphor is about 10 ns (nanoseconds), which is five orders of magnitude shorter than that of a normal rare earth activated phosphor having a rare earth as the emission center.

Furthermore, as described above, since the emission lifetime is short, absorption of excitation light and emission of the phosphor can be repeated quickly. As a result, high efficiency can be maintained even with strong laser light, and heat generation from the phosphor can be reduced.

Therefore, by making the phosphor contained in the light emitting unit 2 into a nanoparticle phosphor, the light emitting unit 2 can be further suppressed from being deteriorated (discolored or deformed) by heat. Thereby, when using the light emitting element with high light output as a light source, it can suppress more that the lifetime of the headlamp 10 of this embodiment and the headlamp 20 mentioned later becomes short.

In addition, it is thought that deterioration of the light emission part 2 is mainly due to deterioration of the phosphor sealing material (for example, silicone resin) included in the light emission part 2. For example, the above-described sialon phosphor and nitride phosphor generate fluorescence with an efficiency of 60 to 80% when irradiated with laser light, but the rest is emitted as heat. It is considered that the sealing material deteriorates due to this heat.

Therefore, a sealing material with high heat resistance is preferable as the sealing material. As a sealing material with high heat resistance, glass etc. can be illustrated, for example.

As an example of the nanoparticle phosphor, semiconductor nanoparticles made of Si (hereinafter referred to as Si nanoparticles) can be listed. Si nanoparticles have a particle size of about 1.9 nm and emit blue-violet to blue (peak wavelength around 420 nm) fluorescence. Further, it emits green fluorescence (peak wavelength is around 500 nm) when the particle diameter is around 2.5 nm. Furthermore, it emits red (peak wavelength is around 720 nm) fluorescence with a particle size of about 3.3 nm.

(Method for producing Si nanoparticles)
Next, taking a Si nanoparticle as an example, a method for producing a nanoparticle phosphor will be described. In addition, the manufacturing method of nanoparticle fluorescent substance is not limited to the method described here.

Si nanoparticles can be produced, for example, using chemical etching methods such as the following (1) to (4).
(1) A silicon wafer or the like is pulverized to make Si a powder having a particle size of about 50 nm.
(2) The powdered Si is put in a solvent (for example, pure water + methanol), and a mixed solution of hydrofluoric acid (HF) and nitric acid (HNO ₃ ) is further added.
(3) Apply ultrasonic vibration to the solution of (2). Thereby, Si in a powder state is etched. The etching time is controlled according to the particle size.
(4) The solution after the etching in (3) is filtered with a filter (such as a PVDF membrane filter). Thereby, Si nanoparticles of a desired size can be obtained.

Other nanoparticle phosphors can be manufactured in the same manner.

(Shape and size of light emitting part 2)
Next, the size of the light emitting unit 2 is 1.5 mm (vertical length a) × 4 mm (horizontal length b) × 0.5 mm (depth), and in this embodiment, the shape is a rectangular parallelepiped shape. It is. The area of the irradiation surface (cross section) SUF4 of the light emitting unit 2 irradiated with the laser light is 6 mm ² . In addition, the light emission part 2 may not be a rectangular parallelepiped, but may be a cylindrical shape. For example, in a laser downlight (light emitting device, lighting device) 200 described later, the light emitting unit 2 has a cylindrical shape whose bottom surface is a circle having a diameter of 1 cm.

Here, the required thickness of the light emitting unit 2 varies according to the ratio of the phosphor and the sealing material in the light emitting unit 2. If the phosphor content in the light emitting unit 2 is increased, the efficiency of conversion of laser light to white light increases up to a certain content, so that the thickness of the light emitting unit 2 can be reduced. If the light emitting part 2 is made thin, the heat dissipation effect to the translucent substrate 1 is also increased. However, if the light emitting part 2 is made too thin, the laser light may not be converted into fluorescence but may be emitted to the outside. From the viewpoint of absorption, the thickness of the light emitting portion 2 is preferably at least 10 times the particle size of the phosphor. From this point of view, the thickness of the light-emitting portion 2 when using the nanoparticle phosphor should be 0.01 μm or more, but considering the ease of the manufacturing process such as dispersion in the sealing material It is preferably 10 μm or more, that is, 0.01 mm or more.

On the other hand, the thickness of the light emitting part 2 when the above oxynitride phosphor is used as the phosphor contained in the light emitting part 2 is preferably 0.2 mm or more and 2 mm or less. However, when the content of the phosphor is extremely increased (typically 100% of the phosphor), the lower limit of the thickness is not limited to this.

<Diffusion part 3>
Next, around the light emitting unit 2, a diffusion unit (diffusion member) 3 having the same depth is provided without a gap. The diffusing unit 3 preferably diffuses at least the laser beam irradiated to the outside of the irradiation surface SUF4 of the light emitting unit 2.

According to the above configuration, the laser light that has not hit the light emitting unit 2 is diffused and scattered by the diffusing unit 3, so that an eye safe can be realized. Further, the chromaticity variation of the headlamp 10 can be suppressed by the light diffusing action of the diffusing unit 3.

As will be described later, the ratio of the area of the irradiated surface SUF4 of the light emitting unit 2 to the area of the laser beam spot is preferably ¼ or more and ／ or less. Therefore, in this embodiment, the area of the spot of the laser beam is 6 mm ² × 4 = 24 mm ² at the maximum, and when the laser beam is irradiated with a single circular spot, the spot diameter R1 (diameter) is 5.53 mm.

Therefore, in this embodiment, when the spot shape of the laser beam is a single circle, it is preferable that the outer diameter of the diffusion portion 3 is at least 5.53 mm in both length and width. However, the point that the length of the irradiation surface SUF4 is different in length and width is ignored here.

Here, the relationship between the spot diameter of the laser beam and the diameter of the irradiated surface SUF4 will be examined a little more strictly.

First, let us consider a case where both the spot shape of the laser beam and the shape of the irradiation surface SUF4 of the light emitting unit 2 are perfect circles or squares. Here, the relationship between the spot diameter (in the case of a square, the length of one side) and the diameter of the irradiation surface SUF4 (in the case of a square, the length of one side) will be described.

Here, it is assumed that the center of the laser beam spot substantially coincides with the center of the irradiated surface SUF4.

At this time, the ratio of the diameter of the irradiated surface SUF4 to the diameter of the spot is preferably 1/2 or more and √ (2/3) or less.

On the other hand, the shape of the spot of the laser beam and the shape of the irradiation surface SUF4 of the light emitting unit 2 are different from a perfect circle or a square, so that at least two different diameters such as a maximum diameter and a minimum diameter can be defined. Think about a case. Here, the relationship between the maximum diameter / minimum diameter of the spot shape and the maximum diameter / minimum diameter of the irradiation surface SUF4 will be described.

First, among the diameters of the irradiation surface SUF4 of the light emitting unit 2, the diameter in the direction in which the diameter is maximum is referred to as “the maximum diameter of the irradiation surface SUF4”, and the diameter in the direction in which the diameter is minimum is referred to as “the irradiation surface SUF4. This is called “minimum diameter”. Further, among the laser beam spot diameters, the diameter in the direction in which the diameter is maximum is referred to as the “spot maximum diameter”, and the diameter in the direction in which the diameter is minimum is referred to as the “spot minimum diameter”.

Here, the center of the spot of the laser beam substantially coincides with the center of the irradiation surface SUF4, and the longitudinal direction (direction in which the maximum diameter is taken) of the spot of the laser light and the longitudinal direction (direction in which the maximum diameter is taken) of the irradiation surface SUF4. ) And are consistent with each other.

At this time, the ratio of the maximum diameter of the irradiated surface SUF4 to the maximum diameter of the spot is preferably 1/2 or more and √ (2/3) or less. The ratio of the minimum diameter of the irradiated surface SUF4 to the minimum spot diameter is also preferably ½ or more and √ (2/3) or less.

In the present embodiment, the shape of the irradiation surface SUF4 is a rectangle, the maximum diameter is 4 mm, and the minimum diameter is 1.5 mm. On the other hand, the spot of the laser beam is a single circle (its diameter is R1). In this case, the laser beam spot may be considered that the maximum diameter and the minimum diameter coincide with each other. Then, since the ratio of the maximum diameter (4 mm) of the irradiation surface SUF4 to the spot diameter R1 is preferably ½ or more and √ (2/3) or less, the spot diameter R1 is 4.90 mm or more, It is preferable that it is 8.0 mm or less.

Further, since the ratio of the minimum diameter (1.5 mm) of the irradiated surface SUF4 to the spot diameter R1 is preferably ½ or more and √ (2/3) or less, the spot diameter R1 is 1.84 mm. As mentioned above, it is preferable that it is 3.0 mm or less. However, it is assumed that the center of the laser beam spot substantially coincides with the center of the irradiation surface SUF4. From the above, it is preferable that the outer diameter of the diffusion portion 3 is 3.0 mm or more in length and 8.0 mm or more in width.

Next, the center of the spot of the laser beam is substantially coincident with the center of the irradiation surface SUF4, and the longitudinal direction (direction in which the maximum diameter is taken) of the spot of the laser beam and the short direction (in which the minimum diameter is taken) of the irradiation surface SUF4. Let us consider a case where the (direction) matches each other.

At this time, it is preferable that the ratio of the minimum diameter of the irradiation surface SUF4 to the maximum diameter of the spot is 1/2 or more and √ (2/3) or less. Further, the ratio of the maximum diameter of the irradiated surface SUF4 to the minimum spot diameter is preferably ½ or more and √ (2/3) or less.

For example, when the spot shape of the laser beam is made rectangular using a lens or a diaphragm, it is preferable that the center of the rectangle of the laser beam spot substantially coincides with the center of the rectangle on the irradiation surface SUF4 of the present embodiment. . In this case, the diameter of the laser beam spot in the longitudinal direction is not less than √ (3/2) times and not more than 2 times the maximum diameter (4 mm in this case) of the irradiation surface SUF4, that is, 4.90 mm or more, 8 It is preferable that it is 0.0 mm or less. On the other hand, the diameter of the laser beam spot in the short direction is √ (3/2) times or more and 2 times or less of the minimum diameter (here, 1.5 mm) of the irradiated surface SUF4, that is, 1.84 mm or more, 3 It is preferable that it is 0.0 mm or less. From the above, it can be estimated that the outer diameter of the diffusion part 3 is preferably 3.0 mm or more in length and 8.0 mm or more in width.

Next, as an example in which the laser beam spot is not a single spot, the laser beam spot shape has a plurality of circles in the lateral direction (irradiation) with respect to the rectangular parallelepiped light emitting section 2 (irradiation surface SUF4 is rectangular). Consider a case where the shapes are arranged in a rectangular longitudinal direction on the surface SUF4. In this case, at least the diameter of each circle of the laser beam spot is √ (3/2) times or more and 2 times or less of the minimum diameter (1.5 mm here) of the irradiation surface SUF4, that is, 1.84 mm or more, It is preferable that it is 3.0 mm or less. However, it is assumed that the center of each circle of the spot of the laser beam is located on or near the symmetry axis in the longitudinal direction of the rectangle on the irradiation surface SUF4. Moreover, it is estimated that it is preferable that the outer diameter of the spreading | diffusion part 3 is 3.0 mm or more.

The diffusion part 3 is obtained by mixing about 10 to 30% by weight of fine powder (about 10 nm to 5 μm) of aerosil and Al ₂ O ₃ in the low melting point glass. The light emitting unit 2 and the diffusing unit 3 are bonded to the translucent substrate 1. In addition, the joining method of the light emission part 2 (diffusion part 3) and the translucent board | substrate 1 is not restricted to adhesion | attachment, For example, fusion etc. may be sufficient.

Note that “diffuse at least the laser beam irradiated to the outside of the irradiation surface SUF4” means that the laser beam irradiated to the outside of the irradiation surface SUF is diffused and toward all or part of the irradiation surface SUF4. It means that the case of diffusing irradiated laser light is also included.

Next, based on FIGS. 2A to 2E, the translucent substrate 1, the light emitting unit 2 and the diffusing unit satisfying the above-mentioned condition of “at least diffusing the laser beam irradiated to the outside of the irradiation surface SUF4” 3 will be described.

2 (a) to 2 (e) are cross-sectional views showing variations of the arrangement method of the translucent substrate 1, the light emitting part 2, and the diffusing part 3 with respect to the headlamp.

In the example shown in FIG. 2A, the light emitting portion 2 is bonded to the vicinity of the center on the translucent substrate 1. Moreover, the diffusion part (diffusion member) 3a surrounds the periphery of the light emitting part 2 from the side. Note that the diffusion portion 3 a does not exist near the upper center of the light emitting portion 2. That is, an opening is formed in the vicinity of the center of the diffusion portion 3a above the light emitting portion 2. In this case, the diffusing portion 3a does not exist on the optical path of the laser light emitted from the light guide member 9 over the entire irradiation surface SUF4 of the light emitting portion 2. Therefore, in this case, only the laser light irradiated to the outside of the irradiation surface SUF4 is scattered by the diffusing unit 3a, and all the laser beams irradiated toward all or part of the irradiation surface SUF4 are irradiated to the light emitting unit 2. The

In the example shown in FIG. 2 (b), a diffusion part (diffusion member) 3 b is bonded on the light-transmitting substrate 1. In addition, the vicinity of the center of the diffusion portion 3b is an opening. Moreover, the light emission part 2 is arrange | positioned so that the opening of the spreading | diffusion part 3b may be covered. In this case, at the outer edge of the irradiation surface SUF4 of the light emitting unit 2, the diffusion unit 3b exists on the optical path of the laser light emitted from the light guide member 9. Therefore, in this case, the laser light irradiated to the outside of the irradiation surface SUF4 is not only scattered by the diffusion portion 3b, but also the laser light irradiated toward a part (outer edge) of the irradiation surface SUF4 is diffused by the diffusion portion 3b. It is scattered by hitting.

In the example shown in FIG. 2C, the translucent substrate 1, the diffusion part (diffusion member) 3c, and the light emitting part 2 are laminated in this order. In addition, the light emission part 2 is joined to the center vicinity of the upper surface of the spreading | diffusion part 3c. In this case, the diffusing portion 3c exists on the optical path of the laser light emitted from the light guide member 9 over the entire irradiation surface SUF4 of the light emitting portion 2. Therefore, in this case, not only the laser beam irradiated outside the irradiation surface SUF4 is scattered by the diffusion unit 3, but also the laser beam irradiated toward the entire irradiation surface SUF4 hits the diffusion unit 3c and is scattered. .

However, in this case, since the light emitting unit 2 and the diffusing unit 3c are joined (the light emitting unit 2 and the diffusing unit 3c are not separated from each other), compared to the technique described in Patent Document 1, It is considered that the irradiation efficiency of the excitation light to the light emitting unit 2 is high.

2B and 2C, since the light-transmitting substrate 1 and the light-emitting portion 2 are not joined, the heat radiation effect of the heat generated in the light-emitting portion 2 by the light-transmitting substrate 1 is as follows. It becomes difficult to obtain. However, the form in which the translucent substrate 1 and the light emitting part 2 are not joined like these forms is also included in the category of the present invention.

In the example shown in FIG. 2D, the translucent substrate 1, the light emitting part 2, and the diffusion part (diffusion member) 3d are laminated in this order. In addition, the light emission part 2 is joined to the center vicinity of the lower surface of the spreading | diffusion part 3d. In this case, the diffusing portion 3d does not exist on the optical path of the laser light emitted from the light guide member 9 over the entire irradiation surface SUF4 of the light emitting portion 2. Therefore, in this case, the laser light irradiated to the outside of the irradiation surface SUF4 is scattered by the diffusion unit 3d, and the laser light irradiated toward all or part of the irradiation surface SUF4 is irradiated to the light emitting unit 2. . In addition, it is thought that the excitation light which permeate | transmitted the light emission part 2 is scattered by the spreading | diffusion part 3d.

In the example shown in FIG. 2 (e), the light emitting unit 2 is bonded on the translucent substrate 1. Moreover, the side and the upper part of the light emitting part 2 are covered with a diffusion part (diffusion member) 3e. In this case, the diffusing portion 3e does not exist on the optical path of the laser light emitted from the light guide member 9 over the entire irradiation surface SUF4 of the light emitting portion 2. Therefore, in this case, the laser light irradiated to the outside of the irradiation surface SUF4 is scattered by the diffusion unit 3e, and the laser light irradiated toward all or part of the irradiation surface SUF4 is irradiated to the light emitting unit 2. . In addition, it is thought that the excitation light which permeate | transmitted the light emission part 2 is scattered by the spreading | diffusion part 3e.

<Parabolic reflector 4>
Next, the parabolic reflector 4 has a light reflecting concave surface SUF3 that reflects the fluorescent light from the light emitting unit 2 or the scattered light scattered by the diffusing unit 3, and is scattered by the fluorescent light or the diffusing unit 3 generated from the light emitting unit 2. The scattered light is reflected by the light reflecting concave surface SUF3 to form a light bundle that travels within a predetermined solid angle.

Since the shape of the light reflecting concave surface SUF3 of the present embodiment employs a so-called rotating paraboloid, as shown in FIG. 1, the cross-sectional shape cut by a plane including the optical axis (rotating axis) is a parabola ( Parabola).

Further, a rectangular fitting hole is formed at the bottom of the paraboloid of the light reflecting concave surface SUF3, and the translucent substrate 1 is fitted into the fitting hole.

The material of the parabolic reflector 4 is not particularly limited, but considering the reflectance, it is preferable to produce a reflector using copper or SUS (stainless steel) and then apply silver plating and chromate coating. In addition, the parabolic reflector 4 may be manufactured using aluminum and an antioxidant film may be provided on the surface, or a metal thin film may be formed on the surface of the resinous parabolic reflector 4 body.

<Substrate 5>
Next, the substrate 5 is a plate-like member formed with an insertion port through which the emission end 9 b side of the light guide member 9 in the excitation light source unit 6 is inserted, and the parabolic reflector 4 is attached to the substrate 5. It is fixed by

screws

7L and 7R. The center of the emission end portion 9b of the light guide member 9 and the center of the irradiation surface SUF4 of the light emitting unit 2 are substantially coincident. Therefore, the laser light emitted from the light guide member 9 enters the surface SUF1 of the translucent substrate 1, passes through the translucent substrate 1, and is bonded to the surface SUF2 facing the surface SUF1. 2 or the diffusion part 3 is reached.

Thereby, the laser light is transmitted through the inside of the light emitting unit 2, and the transmitted light is scattered by the phosphor particles contained in the light emitting unit 2, so that the transmitted light is diffused in the parabolic reflector 4. Further, part of the laser light transmitted through the translucent substrate 1 is scattered by the diffusion unit 3 and becomes scattered light. Although the material in particular of the board | substrate 5 is not ask | required, metals, such as iron and copper, can be illustrated.

<Excitation light source unit 6>
Next, as shown in FIG. 1, the excitation light source unit 6 includes a total of three LD chips (excitation light sources) 11 and a light guide member 9 housed in a rectangular parallelepiped housing (housing).

In addition, about the fixing method and wiring method of LD chip 11, what is necessary is just to use the conventional fixing method and wiring method, Therefore Description is abbreviate | omitted here.

(LD chip 11)
Each LD chip 11 of this embodiment is mounted on a metal package (stem) having 1.6 W (current value: 1.2 A, voltage value: 4.7 V), oscillation wavelength: 450 nm, and φ9 mm. The oscillation wavelength of the LD chip 11 is not limited to 450 nm, and may be any wavelength in the blue region from 440 nm to 480 nm. The output of the excitation light source unit 6 as a whole is about 4.8 W.

As a result, the total luminous flux of a total of three LD chips 11 becomes a luminous flux of the entire light source by simple calculation, so that the luminous flux of the entire light source is about four times larger than when only a single LD chip 11 is used. can do. However, the performance of the LD chip 11 is assumed to be equal.

In this embodiment, the number of LD chips 11 is three. However, the number of LD chips 11 is not limited to this, and may be one, two, or four or more.

The excitation light source may be a 1-chip 1-strip type semiconductor laser chip having a single light-emitting point, such as the LD chip 11 of the present embodiment, or a single-chip, multi-stripe having a plurality of light-emitting points. It may be a type of semiconductor laser chip.

Further, the excitation light source may generate coherent excitation light (laser light) like the LD chip 11 of the present embodiment, or incoherent like the LED chip (excitation light source) 130 described later. It may generate excitation light (EL light; Electro-luminescence light).

Further, when a plurality of excitation light sources are used, the light source may be composed of only LD or LED, or LD and LED may be mixed.

Note that the laser light generated from the LD chip 11 is blue light (oscillation wavelength: 450 nm) that protrudes from the irradiation surface SUF4 of the light emitting unit 2 (or does not hit the irradiation surface SUF4) and enters the diffusion unit 3. This is to use the scattered light scattered as illumination light.

(Light guide member 9)
Next, the light guide member 9 has a surrounding structure surrounded by a light-reflecting side surface that reflects each laser beam incident from an incident end (the one closer to the excitation light source) 9a, and an emission end (light emission). 9b is smaller than the cross-sectional area of the incident end 9a, and each laser beam incident from the incident end 9a is guided to the emission end 9b by the surrounding structure of the light reflecting side surface. Shine.

Further, a fitting insertion opening is provided on the side surface of the excitation light source unit 6 close to the light emitting unit 2, and the emission end 9 b side of the light guide member 9 is directed from the inside to the outside of the excitation light source unit 6. It is inserted and the connection part with the said side surface around an insertion opening is fixed with an adhesive agent etc.

In addition, the light guide member 9 of the present embodiment has a cylindrical shape with a quadrangular pyramid shape as a whole, and the cross section (opening) of the emission end 9b is a rectangle of 1 mm × 3 mm, and the incident end 9a The cross section (opening) is a 10 mm × 30 mm rectangle. That is, the cross-sectional area of the exit end 9b is smaller than the cross-sectional area of the entrance end 9a. The shape of the light guide member is not limited to the quadrangular frustum shape, and various shapes such as a polygonal frustum shape other than the quadrangular frustum shape, a frustum shape, and an elliptic frustum shape can be employed. The distance from the incident end 9a to the exit end 9b is 25 mm.

According to the light guide member 9 described above, each laser beam incident from the incident end 9a is guided to the emission end 9b having a smaller cross-sectional area than the incident end 9a by the surrounding structure. Each laser beam can be condensed on the emission end 9b.

The light guide member 9 is made of BK (borosilicate crown) 7, quartz glass, acrylic resin, or other transparent material.

According to the above configuration, by reducing both the area of the emission end portion 9b and the size of the light emitting portion 2, light with high luminance and high luminous flux corresponding to the number of LD chips 11 included in the excitation light source unit 6 is generated. Therefore, the light emitting unit 2 to be downsized can be downsized. Here, the surrounding structure is configured to surround all the optical paths of the respective laser beams generated from the respective LD chips 11.

In addition, each laser beam is reflected only once on the surrounding structure and guided to the emission end portion 9b. When each laser beam is reflected on the surrounding structure multiple times and guided to the

emission end portion

9b, 1 laser beam is reflected on the surrounding structure. The light is guided by any one of the optical paths in the case where the light is guided to the emission end portion 9b without being reflected.

In the present embodiment, the light guide member 9 has been described as a configuration (cylindrical configuration) having a surrounding structure in which the entrance end portion 9a and the exit end portion 9b each have an opening. However, the light guide member 9 may be made of a material having a refractive index higher than 1 and may have a structure without a surrounding structure (a structure that is not cylindrical). Thus, even if a light reflecting side surface that reflects laser light is not particularly formed on the boundary surface between the light guide member 9 and air (refractive index = 1), light incident at a certain angle or more is an interface having a different refractive index. Causes total reflection. For this reason, the laser light can be guided in the light guide member 9 only by selecting the material of the light guide member 9, so that the light guide member 9 can be easily manufactured. As such a material, BK (borosilicate crown) 7 can be exemplified, and its refractive index is 1.52.

<Characteristic Configuration of One Embodiment According to the Present Invention>
Next, a characteristic configuration of an embodiment according to the present invention will be described based on a comparative headlamp 30 shown in FIG. 5A and FIG. 5B.

FIG. 5A is a half sectional view showing a schematic configuration of a headlamp 30 (transmission type) of a comparative example. FIG. 5B is a distribution diagram showing the relationship between the distance (r) from the center (O) of the laser beam spot and the intensity of the laser beam.

The headlamp 30 shown in FIG. 5A is different from the headlamp 10 in that the light guide member 9 of the headlamp 10 is replaced with a light guide member 9 '.

As shown by the light intensity distribution C in FIG. 5B, it is known that the intensity distribution of the laser light generated from the semiconductor laser has a predetermined spread and is almost Gaussian. That is, the intensity of the bottom part of the laser beam spot decreases rapidly as the distance r from the maximum intensity part (near the center O) increases. Such a situation is also substantially applicable to the excitation light source unit 6 that guides each laser beam emitted from the plurality of LD chips 11 by the light guide member 9 (or the light guide member 9 ').

Therefore, like the headlamp 30 in FIG. 5A, the light emitting unit 2 is arranged on the optical path of the laser light emitted from the excitation light source unit 6, and the laser light generated from the excitation light source unit 6 is emitted from the light emitting unit 2. The area (or spot diameter R1 ′) of the laser light spot when irradiated toward the irradiation surface SUF4 is the area of the light emitting section 2 when the light emitting section 2 is viewed from the side irradiated with the laser light ( If the area of the irradiation surface SUF4 is equal to or less than the vertical length a or the horizontal length b), a large unevenness may occur in the intensity distribution of the laser light on the irradiation surface SUF4 of the light emitting unit 2. If it does so, the intensity | strength of a laser beam will concentrate on a part of irradiation surface SUF4 of the light emission part 2, and degradation of the light emission part 2 may be accelerated | stimulated.

On the other hand, as described above, the light emitting unit 2 is arranged on the optical path of the excitation light source unit 6, and the spot area (or spot diameter R1 ′) of the laser light is set to the light emitting unit 2 from the side irradiated with the laser light. In order to make the area of the light emitting unit 2 (the area of the irradiation surface SUF4, or the vertical length a or the horizontal length b) equal to or smaller than the optical system (particularly the light guide) included in the headlamp 30. High work accuracy is required for the shape and size of the emission end 9b ′ of the optical member 9 ′, the distance between the emission end 9b ′ and the irradiation surface SUF4 of the light emitting unit 2, and the like. For this reason, there also exists a problem that the freedom degree of design of the headlamp 30 will become low.

In view of this situation, the inventor of the present invention has advanced the development of the headlamp 10 of the present embodiment shown in FIG. 1 (or the headlamp 20 shown in FIG. 4 described later). That is, the headlamp 10 (or the headlamp 20) includes the excitation light source unit 6 that emits laser light, and the light emitting unit 2 that emits fluorescence when irradiated with the laser light emitted from the excitation light source unit 6. The area (or the diameter R1) of the spot when the laser beam is irradiated toward the surface is the area of the light emitting unit 2 (the area of the irradiation surface SUF4) when the light emitting unit 2 is viewed from the side irradiated with the laser beam. Or the headlamp 10 (or the headlamp 20) which is larger than the vertical length a or the horizontal length b).

Moreover, it may be said that the characteristic configuration according to the embodiment of the present invention is that, in another viewpoint, the region exceeding the size of the light emitting unit 2 (irradiation surface SUF4) is irradiated with laser light.

The inventor of the present invention thought that the degree of freedom in designing the headlamp 10 (or the headlamp 20) can be increased while the deterioration of the light emitting unit 2 is suppressed by the configuration as described above.

That is, in the headlamp 10 (or the headlamp 20), the spot area (or the spot diameter R1) when the laser beam is irradiated toward the light emitting unit 2 is the light emitting unit 2 from the side irradiated with the laser beam. Is larger than the area of the light emitting unit 2 (the area of the irradiation surface SUF4, or the vertical length a or the horizontal length b). For this reason, compared with the case where the area (or spot diameter R1) of the laser light spot is set to be equal to or less than the area of the light emitting portion 2 (the area of the irradiation surface SUF4, or the vertical length a or the horizontal length b). Thus, unevenness in the intensity distribution of the laser beam with respect to the irradiation surface SUF4 of the light emitting unit 2 irradiated with the laser beam can be reduced. For this reason, the intensity of the laser beam does not concentrate on a part of the irradiation surface SUF4 of the light emitting unit 2, and the laser beam is irradiated gently over the entire irradiation surface SUF4, so that the deterioration of the light emitting unit 2 is suppressed. Can do.

Further, in the above configuration, the area (or spot diameter R1) of the spot of the laser beam is set to the area of the light emitting unit 2 when the light emitting unit 2 is viewed from the side irradiated with the laser beam (the area of the irradiation surface SUF4, Alternatively, since it is only necessary to make it larger than the vertical length a or the horizontal length b), the spot area (or spot diameter R1) of the laser beam is set to the area of the light emitting section 2 (the area of the irradiation surface SUF4, Or, compared with the case where the vertical length a or the horizontal length b) or less, the optical system constituting the headlamps 10 and 20 (particularly the shape and size of the emission end 9b of the light guide member 9, High working accuracy is not required for the distance between the emission end portion 9b and the irradiation surface SUF4 of the light emitting unit 2). This also increases the degree of freedom in designing the headlamp 10 (or the headlamp 20).

As described above, according to the headlamp 10 (or the headlamp 20), it is possible to increase the degree of freedom in designing the headlamp 10 (or the headlamp 20) while suppressing the deterioration of the light emitting unit 2.

In addition, it is preferable that the ratio of the area of the irradiation surface SUF4 of the light emitting unit 2 to the area of the laser beam spot is ¼ or more and ／ or less. This is because if the above ratio is smaller than ¼, the irradiation efficiency of the laser light on the light emitting portion 2 becomes too low.

On the other hand, when the ratio of the excitation light is larger than 2/3, large unevenness occurs in the intensity distribution of the laser light on the irradiation surface SUF4 irradiated with the laser light of the light emitting unit 2.

For example, in the headlamp 10 (or headlamp 20) of the present embodiment, since the area of the irradiation surface SUF4 (or irradiation surface SUF4 ′) is 6 mm ^2, it is a plane including the irradiation surface SUF4 (or irradiation surface SUF4 ′). The area of the laser beam spot is preferably 4 × 6 mm ² = 24 mm ² (spot diameter R1 (diameter) ≈5.53 mm) or less.

Further, from another viewpoint, in the light intensity distribution C as shown in FIG. 5B, 50% or less of the integrated intensity is leaked light (light that does not hit the irradiation surface SUF4 of the light emitting part 2 but hits the diffusing part 3). It is preferable to become.

<Optical member 8>
Next, the optical member 8 is provided in the opening of the light reflecting concave surface SUF3 of the parabolic reflector 4, and seals the headlamp 10. The fluorescence generated from the light emitting unit 2, the scattered light scattered by the diffusing unit 3, or the fluorescent or scattered light reflected by the parabolic reflector 4 is emitted to the front of the headlamp 10 through the optical member 8. .

In the present embodiment, the optical member 8 has a convex lens shape and a lens function, but may have a concave lens shape as well as a convex lens shape. The optical member 8 does not necessarily have a structure having a lens function. The fluorescence generated from the light emitting unit 2, the scattered light scattered by the diffusion unit 3, or the fluorescent light or scattered light reflected by the light reflecting concave surface SUF3. As long as it has at least translucency to transmit light.

The coherent laser light transmitted through the light emitting unit 2 excites the phosphor contained in the light emitting unit 2 to be converted into fluorescence, or is scattered by the phosphor, and the emission point size is sufficiently expanded. However, there may be a case where the emission point size is not enlarged for some reason. Even in such a case, by blocking the laser beam by the optical member 8, it is possible to prevent the laser beam having a small emission point size and dangerous to the human eye from leaking to the outside.

[2. Overview of the excitation light source configuration)
Next, a specific example of the excitation light source will be described based on FIGS. 3 (a) to 3 (d).

FIG. 3A is a circuit diagram of an LED lamp (excitation light source) 13 which is an example of an excitation light source, and FIG. 3B is a front view showing the appearance of the LED lamp 13, and FIG. FIG. 3 is a circuit diagram of an LD chip 11 which is another example of an excitation light source, and FIG. 3B is a perspective view showing an appearance of the LD chip 11.

As shown in FIG. 3B, the LED lamp 13 has a configuration in which an LED chip (excitation light source) 130 connected to the anode 14 and the cathode 15 is sealed with an epoxy resin cap 16.

As shown in FIG. 3A, the LED chip 130 has a pn junction between a p-type semiconductor 131 and an n-type semiconductor 132, the anode 14 is connected to the p-type electrode 133, and the cathode 15 is connected to the n-type electrode 134. Is done. The LD chip 11 is connected to the power source E via the resistor R.

Further, by connecting the anode 14 and the cathode 15 to the power source E, a circuit is configured, and when power is supplied from the power source E to the LED chip 130, incoherent excitation light is generated near the pn junction.

The material of the LED chip 130 is GaP, AlGaAs, GaAsP, etc., whose emission color is red, such as GaAsP, whose emission color is orange, GaAsP, GaP, whose emission color is yellow, GaP, whose emission color is green, and emission color. Compound semiconductors such as SiC and GaN that are blue can be exemplified.

The LED chip 130 operates at a low voltage of about 2V to 4V, is small and lightweight, has a fast response speed, has a long life, and is low in cost.

Next, the configuration of the LD chip 11 will be described. As shown in FIGS. 3C and 3D, the LD chip 11 has a configuration in which a cathode electrode 19, a substrate 18, a clad layer 113, an active layer 111, a clad layer 112, and an anode electrode 17 are laminated in this order. .

The substrate 18 is a semiconductor substrate, and it is preferable to use GaN, sapphire, or SiC in order to obtain blue to ultraviolet excitation light for exciting the phosphor as in the present application. In general, as a substrate for a semiconductor laser, in addition, a group IV semiconductor such as Si, Ge, and SiC, GaAs, GaP, InP, AlAs, GaN, InN, InSb, GaSb, and AlN are represented by III. -V group compound semiconductor, ZnTe, ZeSe, II-VI group compound such as ZnS and ZnO _{_{_{semiconductor, ZnO, Al 2 O 3,}}} SiO 2, TiO 2, CrO 2 and CeO ₂ or the like oxide insulator, and, SiN Any material of a nitride insulator such as is used.

The anode electrode 17 is for injecting current into the active layer 111 through the clad layer 112.

The cathode electrode 19 is for injecting current into the active layer 111 from the lower part of the substrate 18 through the clad layer 113. The current is injected by applying a forward bias to the anode electrode 17 and the cathode electrode 19.

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

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

The active layer 111 is a region where light emission occurs due to the injected current, and the emitted light is confined in the active layer 111 due to a difference in refractive index between the cladding layer 112 and the cladding layer 113.

Further, the active layer 111 is formed with a front side cleaved surface 114 and a back side cleaved surface 115 provided to face each other in order to confine light amplified by stimulated emission, and the front side cleaved surface 114 and the back side cleaved surface 115. Plays the role of a mirror.

However, unlike a mirror that completely reflects light, a part of the light amplified by stimulated emission is obtained by cleaving the front side cleaved surface 114 and the back side cleaved surface 115 of the active layer 111 (in this embodiment, the front side cleaved surface 114 for convenience. ) And becomes excitation light L0 (laser light). Note that the active layer 111 may form a multilayer quantum well structure.

Note that a reflective film (not shown) for laser oscillation is formed on the back side cleaved surface 115 opposite to the front side cleaved surface 114, and the difference in reflectance between the front side cleaved surface 114 and the back side cleaved surface 115 is different. By providing, for example, most of the excitation light L0 can be emitted from the light emitting point 103 from the cleaved surface 114 which is a low reflectance end face.

The cladding layer 113 and the cladding layer 112 are made of n-type and p-type GaAs, GaP, InP, AlAs, GaN, InN, InSb, GaSb, and AlN, III-V group compound semiconductors, and ZnTe, ZeSe. , ZnS, ZnO, or any other II-VI compound semiconductor, and by applying a forward bias to the anode electrode 17 and the cathode electrode 19, current can be injected into the active layer 111. It has become.

As for film formation with each semiconductor layer such as the clad layer 113, the clad layer 112, and the active layer 111, MOCVD (metal organic chemical vapor deposition) method, MBE (molecular beam epitaxy) method, CVD (chemical vapor deposition) method. The film can be formed using a general film forming method such as a laser ablation method or a sputtering method. The film formation of each metal layer can be configured using a general film forming method such as a vacuum deposition method, a plating method, a laser ablation method, or a sputtering method.

(Light emission principle of the light emitting part 2)
Next, the light emission principle of the phosphor by the laser light oscillated from the LD chip 11 will be described.

First, the laser light oscillated from the LD chip 11 is irradiated onto the phosphor included in the light emitting unit 2, whereby the electrons existing in the phosphor are excited from the low energy state to the high energy state (excited state).

Since this excited state is unstable, the energy state of the electrons in the phosphor is changed to the original low energy state after a certain time (the energy state of the ground level or the level between the excited level and the ground level). Transition to a stable level energy state).

Thus, the phosphors emit light when the electrons excited to the high energy state transition to the low energy state.

White light can be composed of a mixture of three colors that satisfy the principle of equal colors, or a mixture of two colors that satisfy the relationship of complementary colors, and based on this principle and relationship, the color and fluorescence of laser light oscillated from a semiconductor laser. White light can be generated by combining the color of light emitted by the body as described above.

[3. Configuration of headlamp 20]
Next, a headlamp 20 according to another embodiment of the present invention will be described with reference to FIG. FIG. 4 is a half sectional view showing a schematic configuration of the headlamp 20.

As shown in FIG. 4, the headlamp 20 includes a reflective member 1 ′ in place of the above-described translucent substrate 1. In addition to the above-described light emitting unit 2, the above-described diffusion unit 3, and the above-described excitation light source unit 6, A half parabolic reflector (reflecting mirror) 4h, a heat conducting member (reflecting member) 4p, and the optical member 8 described above are provided.

Since the configuration other than the configuration described in the present embodiment is substantially the same as described above, here, the reflecting member 1 ′, the half parabolic reflector 4h, the heat conducting member 4p, and the excitation light source unit 6 are described. Only explained.

<Reflection member 1 '>
The reflecting member 1 ′ is a member that reflects the laser light that passes through the light emitting unit 2, and the constituent material is preferably a metal. In addition, the reflecting member 1 ′ is bonded to the side facing the surface SUF 4 ′ irradiated with the laser light of the light emitting unit 2. Thereby, the light emission part 2 is hold | maintained by reflection member 1 '.

According to said structure, since the laser beam which permeate | transmitted the light emission part 2 and reflected by reflection member 1 'excites the light emission part 2 again, compared with the form which permeate | transmits a laser beam as it is, the irradiation direction of a laser beam Even if the thickness of the light emitting portion 2 is halved, sufficient luminous efficiency can be obtained.

<Half parabolic reflector 4h>
The half parabolic reflector 4h is the same as the parabolic reflector 4 described above except that the parabolic reflector 4 is cut in half by a plane including the optical axis (rotation axis). is there.

<Heat conduction member 4p>
As shown in FIG. 4, the surface SUF1 side of the reflecting member 1 ′ is joined to the heat conducting member 4p.

The constituent material of the heat conducting member 4p may be any material as long as it has thermal conductivity that diffuses heat generated in the reflecting member 1 ', but metal or ceramic is preferable.

Since metal has high thermal conductivity, the heat dissipation effect of the heat conductive member 4p can be expected.

<Excitation light source unit 6>
In the headlamp 20 of the present embodiment, the laser beam emitted from the emission end portion 9b of the light guide member 9 in the excitation light source unit 6 is a window portion (or opening) provided on the outer surface of the half parabolic reflector 4h. ) Is directed toward the irradiation surface SUF4 ′ side of the light emitting section 2 (from the upper left side to the lower right side).

[4. Configuration of laser downlight 200]
The following will describe still another embodiment of the present invention with reference to FIGS.

Here, the laser downlight 200 as an example of the illumination device of the present invention will be described. The laser downlight 200 is an illumination device installed on the ceiling of a structure such as a house or a vehicle, and uses fluorescence generated by irradiating the light emitting unit 2 with laser light emitted from the LD chip 11 as illumination light. It is.

Note that an illumination device having the same configuration as the laser downlight 200 may be installed on the side wall or floor of the structure, and the installation location of the illumination device is not particularly limited.

FIG. 6 is a schematic view showing the external appearance of the light emitting unit 210 and the conventional LED downlight 300. FIG. 7 is a cross-sectional view of the ceiling where the laser downlight 200 is installed. FIG. 8 is a cross-sectional view of the laser downlight 200.

As shown in FIGS. 7 and 8, the laser downlight 200 (light emitting unit 210) has only a small hole 402 through which the optical fiber bundle (light guide member) 215 is passed through the top plate 400, and the light emitting unit 210 is thin and lightweight. Utilizing the features, it is affixed to the top 400 using a strong adhesive tape or the like. In this case, there are advantages that restrictions on installation of the laser downlight 200 are reduced, and that construction costs can be significantly reduced. In addition, if the light emission part 2 is a structure which can move, the light emission unit 210 may be embed | buried under the top plate 400. FIG.

The laser downlight 200 includes a light emitting unit 210 that emits illumination light and an excitation light source unit (excitation light source) 6 a that supplies laser light to the light emitting unit 210 via an optical fiber bundle 215. The excitation light source unit 6a is not installed on the ceiling, but is installed at a position where the user can easily touch it (for example, a side wall of a house). The position of the excitation light source unit 6 a can be freely determined in this way because the excitation light source unit 6 a and the light emitting unit 210 are connected by the optical fiber bundle 215. The optical fiber bundle 215 is disposed in a gap between the top plate 400 and the heat insulating material 401.

(Configuration of light emitting unit 210)
As shown in FIG. 8, the light emitting unit 210 includes a light transmitting substrate 1, a light emitting unit 2, a diffusing unit 3, a support member 61, a support member driving unit 62, a housing 211, a light transmitting plate 213, an optical fiber bundle 215, and a ferrule. 217.

(Light emitting part 2)
In the present embodiment, the light emitting unit 2 has a cylindrical shape with a bottom surface having a diameter of 1 cm. In addition, since it is as having mentioned above about the thickness of the light emission part 2, and a constituent material, description is abbreviate | omitted here.

(Support member 61)
The support member 61 supports the translucent substrate 1 including the columnar light emitting unit 2 having a circular bottom surface with a diameter of 1 cm. The translucent substrate 1 is coupled with the driving of the support member driving unit 62. It is movable in the direction of the optical axis of the laser beam. As the support member 61 moves, the position of the light emitting unit 2 can be changed. As a result, when the optical path width of each laser beam emitted from the three emission end portions 215a of the optical fiber bundle 215 increases (or decreases) in proportion to the distance from the emission end portion 215a, the spot of each laser beam. The size of can be changed.

Further, the support member 61 is provided so as to come into contact with the gear of the support member driving unit 62, and a groove is provided on the contact surface so as to mesh with the gear. As a result, the support member 61 can move in accordance with the drive of the support member drive unit 62. Note that the surface of the support member 61 may have any shape as long as it operates in conjunction with the gear, and may not be particularly processed. For the reason described above, the driving range of the support member 61 is such that the ratio of the minimum diameter (here, 1 cm) of the irradiation surface SUF4 to the spot diameter R1 of each laser beam emitted from the three emission end portions 215a is 1/2. As described above, it is preferable to set a range that takes a value of √ (2/3) or less. That is, the driving range of the support member 61 is such that the spot diameter R1 (diameter) of each laser beam on the plane including the irradiation surface SUF4 of the light emitting unit 2 takes a value of 1.24 cm or more and 2.00 cm or less. It is preferable to set the range.

The material of the support member 61 is not particularly limited. However, considering that the support member 61 is inserted into a case 211 (recessed portion 212) to be described later due to the movement of the support member 61, the light transmissive property is the same as that of the light transmissive substrate 1. It is preferable that the material has Further, the shape of the support member 61 may be a flat plate shape or a rod shape. Further, the support member 61 may be formed integrally with the translucent substrate 1.

In the present embodiment, the support member 61 is described as moving in the optical axis direction of the laser beam. However, if the spot size of the laser beam can be freely changed, the support member 61 is not necessarily in the optical axis direction. There is no need to move it.

(Supporting member driving unit 62)
Next, the support member drive unit 62 is for moving the support member 61 in the direction of the optical axis of the laser beam, and includes, for example, a stepping motor and a gear, and is provided for each support member 61. The gear is provided such that the surface thereof is in contact with the support member 61 and the rotation axis thereof is in a direction perpendicular to the moving direction of the support member 61. One gear may be provided for the support member 61 or a plurality of combinations may be included. Moreover, the stepping motor should just be provided so that the rotation can be propagated to a gear.

In the support member drive unit 62, when a drive instruction is received from a predetermined drive control unit (not shown), the stepping motor is driven and the gear rotates. Since the gear and the support member 61 are provided in contact with each other, the rotational force of the gear is transmitted to the support member 61 and moves the support member 61 in the optical axis direction of the laser beam.

When the light emitting unit 2 is moved in a direction perpendicular to the optical axis direction of the laser beam, for example, the gear of the support member driving unit 62 is brought into contact with the surface of the translucent substrate 1 perpendicular to the optical axis of the laser beam. You may let them. In this case, a groove is provided on the surface so as to mesh with the gear, and it is not necessary to provide the support member 61.

As described above, the support member driving unit 62 changes the irradiation light amount of the laser light to the light emitting unit 2 by changing the distance between the light emitting unit 2 and the emission end 215a of the optical fiber bundle 215 via the support member 61. In addition, it is possible to change the light quantity of the laser light that is not directly applied to the light emitting unit 2 and that directly becomes illumination light. That is, since the balance between the amount of fluorescent light and the amount of laser light contained in the illumination light can be changed, the color temperature of the illumination light can be changed.

In other words, the support member drive unit 62 changes the ratio of laser light that is not converted into fluorescence by the light emitting unit 2 in the laser light emitted from the LD chip 11 (hereinafter referred to as conversion ratio). By changing the conversion ratio and changing the amount of laser light that is not converted to fluorescence, the ratio of fluorescence to illumination light changes, so that the color temperature of the illumination light can be changed.

Next, a recess 212 is formed in the housing 211. A metal thin film is formed on the surface of the recess 212, and the recess 212 functions as a reflecting mirror. Further, near the bottom surface of the recess 212, the position of the light emitting unit 2 is changed by the driving mechanism described above to change the size of each laser beam spot emitted from the three emission end portions 215a of the optical fiber bundle 215. The translucent board | substrate 1 provided with the light emission part 2 and the spreading | diffusion part 3 is arrange | positioned in the position which can be made to do. As described above, the position of the light emitting unit 2 is changed by the support member driving unit 62 moving the translucent substrate 1 provided with the light emitting unit 2 in the optical axis direction of the laser light via the support member 61. Realize. In order to realize this movement, the housing 211 is formed with a storage portion 218 in which the support member 61 can be stored.

In an eighth embodiment (see FIG. 31) described later, for example, as shown in FIGS. 24A to 24C, the position of the light emitting unit 2 is changed and the size of the laser light irradiation region 79 is changed. The translucent board | substrate 1 provided with the light emission part 2 and the spreading | diffusion part 3 is arrange | positioned in the position which can be made to do. In Embodiment 11 (see FIG. 42), which will be described later, for example, as shown in FIGS. 36A to 36C, the position of the light emitting unit 2 is changed to change the size of the laser light irradiation region 79. The translucent board | substrate 1 provided with the light emission part 2 is arrange | positioned in the position which can be made to do.

Further, a small hole 219 through which the optical fiber bundle 215 is passed is formed in the housing 211, and the optical fiber bundle 215 extends to the vicinity of the light emitting unit 2 through the hole 219. As a result, the laser light emitted from the LD chip 11 is applied to the light emitting unit 2 via the optical fiber bundle 215. Further, the exit end 215 a of the optical fiber bundle 215 is held by a ferrule 217. The optical fiber bundle 215 and the ferrule 217 will be described later.

The translucent plate 213 is a transparent or translucent plate disposed so as to close the opening of the recess 212, and the fluorescence of the light emitting unit 2 is emitted as illumination light through the translucent plate 213.

The translucent plate 213 is preferably formed of a material that blocks the laser light from the LD chip 11 and transmits incoherent light generated by converting the laser light in the light emitting section 2.

Most of the coherent laser light is converted into incoherent light by the light emitting unit 2. However, there may be a case where a part of the laser light is not converted into incoherent light for some reason. Even in such a case, it is possible to prevent the laser light from leaking to the outside by blocking the laser light by the translucent plate 213. The translucent plate 213 may be removable from the housing 211 or may be omitted.

In FIG. 6, the light emitting unit 210 has a circular outer edge, but the shape of the light emitting unit 210 (more precisely, the shape of the housing 211) is not particularly limited.

In the downlight, unlike the headlamp, an ideal point light source is not required, and a level of one light emitting point is sufficient. Therefore, there are fewer restrictions on the shape, size, and arrangement of the light emitting unit 2 than in the case of a headlamp.

(Configuration of excitation light source unit 6a)
The excitation light source unit 6 a includes three LD chips 11, an optical fiber bundle 215, and three aspheric lenses 216.

An incident end 215 b, which is one end of the optical fiber bundle 215, is connected to the excitation light source unit 6 a, and the laser light oscillated from the LD chip 11 is incident on the incident end of the optical fiber bundle 215 via the aspherical lens 216. It is incident on the portion 215b.

The aspheric lens 216 is a lens for causing the laser light (excitation light) oscillated from the LD chip 11 to enter the incident end 215 b that is one end of the optical fiber bundle 215. For example, as the aspheric lens 216, FLKN1 405 manufactured by Alps Electric can be used. The shape and material of the aspherical lens 216 are not particularly limited as long as the lens has the above-described function. However, it is preferable that the aspherical lens 216 is a material having a high transmittance of about 405 nm, which is the wavelength of excitation light, and good heat resistance.

In FIG. 8, three LD chips 11 and three aspheric lenses 216 are provided inside the excitation light source unit 6 a, and a bundle of optical fibers extending from each aspheric lens 216 is guided to one light emitting unit 210. . That is, in FIG. 8, one set of light sources including three LD chips 11 and three aspherical lenses 216 functions as a light source for one light emitting unit 210. When there are a plurality of light emitting units 210, a bundle of optical fibers respectively extending from the light emitting units 210 may be guided to one excitation light source unit 6a. In this case, one excitation light source unit 6a stores a plurality of the above-mentioned one set of light sources, and the excitation light source unit 6a functions as a centralized power supply box.

(Optical fiber bundle 215 and ferrule 217)
The optical fiber bundle 215 is a light guide member that guides the laser light oscillated by the LD chip 11 to the light emitting unit 2 and is a bundle of a plurality of optical fibers. The optical fiber bundle 215 includes an optical fiber having an incident end 215b that receives laser light emitted from the LD chip 11 and an output end 215a that emits laser light incident from these incident ends.

FIG. 9 is a diagram illustrating a positional relationship between the light emitting portion 215a and the light emitting portion 2 when the distance between the light emitting portions 2 and the plurality of light emitting end portions 215a of the optical fiber bundle 215 is the shortest. At this time, as shown in the figure, the plurality of emission end portions 215a emit laser beams to different regions on the laser beam irradiation surface (light receiving surface) 201 of the light emitting unit 2. With this configuration, since the laser beam is not locally applied to the light emitting unit 2, it is possible to prevent a part of the light emitting unit 2 from being significantly deteriorated. In FIG. 9, the translucent substrate 1 and the diffusion part 3 are not shown.

The optical fiber constituting the optical fiber bundle 215 has a two-layer structure in which the core of the core is covered with a clad having a refractive index lower than that of the core. The core is mainly composed of quartz glass (silicon oxide) having almost no absorption loss of laser light, and the clad is composed mainly of quartz glass or a synthetic resin material having a refractive index lower than that of the core. . For example, the optical fiber constituting the optical fiber bundle 215 is made of quartz having a core diameter of 200 μm, a cladding diameter of 240 μm, and a numerical aperture NA of 0.22, but the structure, thickness, and material of the optical fiber are the same as those described above. The cross section perpendicular to the major axis direction of the optical fiber may be rectangular.

Further, as shown in FIG. 8, the ferrule 217 has a plurality of emission end portions 215a of the optical fiber bundle 215 with respect to the translucent substrate 1 (the laser light irradiation surface 201 of the light emitting portion 2 and the light receiving surface of the diffusion portion 3). Hold in a predetermined pattern. The ferrule 217 may have holes for inserting the emission end portion 215a formed in a predetermined pattern, and can be separated into an upper portion and a lower portion, and is formed on the upper and lower joint surfaces, respectively. The exit end portion 215a may be sandwiched between grooves.

The ferrule 217 only needs to be fixed to the light emitting unit 210 by a rod-like or cylindrical member extending from the casing 211. The material of the ferrule 217 is not particularly limited, and is stainless steel, for example.

(Comparison between laser downlight 200 and conventional LED downlight 300)
As shown in FIG. 6, the conventional LED downlight 300 includes a plurality of light transmitting plates 301, and illumination light is emitted from each light transmitting plate 301. That is, the LED downlight 300 has a plurality of light emitting points. The LED downlight 300 has a plurality of light emitting points because the light flux of light emitted from each light emitting point is relatively small. Therefore, if a plurality of light emitting points are not provided, light having a sufficient light flux as illumination light is provided. This is because it cannot be obtained.

On the other hand, since the laser downlight 200 is an illumination device with a high luminous flux, it may have one light emitting point. Therefore, it is possible to obtain an effect that the shadow caused by the illumination light is clearly displayed. Moreover, the color rendering property of illumination light can be improved by making the phosphor of the light emitting section 2 a high color rendering phosphor (for example, a combination of several kinds of oxynitride phosphors or nitride phosphors).

This makes it possible to achieve a high color rendering approaching that of an incandescent bulb downlight. For example, not only the average color rendering index Ra is 90 or more, but also the special color rendering index R9 is 95 or more. It is feasible.

FIG. 10 is a cross-sectional view of the ceiling where the LED downlight 300 is installed. As shown in the figure, in the LED downlight 300, a casing 302 that houses an LED chip, a power source, and a cooling unit is embedded in the top plate 400. The housing 302 is relatively large, and a recess along the shape of the housing 302 is formed in a portion of the heat insulating material 401 where the housing 302 is disposed. A power line 303 extends from the housing 302, and the power line 303 is connected to an outlet (not shown).

Such a configuration causes the following problems. First, since there is a light source (LED chip) and a power source that are heat sources between the top plate 400 and the heat insulating material 401, the use of the LED downlight 300 raises the ceiling temperature, and the cooling efficiency of the room. Problem arises.

In addition, the LED downlight 300 requires a power source and a cooling unit for each light source, resulting in a problem that the total cost increases.

Also, since the housing 302 is relatively large, there is a problem that it is often difficult to arrange the LED downlight 300 in the gap between the top 400 and the heat insulating material 401.

In contrast, in the laser downlight 200, since the light emitting unit 210 does not include a large heat source, the cooling efficiency of the room is not reduced. As a result, an increase in room cooling costs can be avoided.

Further, since it is not necessary to provide a power source and a cooling unit for each light emitting unit 210, the laser downlight 200 can be made small and thin. As a result, the space restriction for installing the laser downlight 200 is reduced, and installation in an existing house is facilitated.

Further, since the laser downlight 200 is small and thin, as described above, the light emitting unit 210 can be installed on the surface of the top plate 400, and the space on the back side of the top plate is hardly required. It is possible to make the restrictions on installation smaller than 300 and to greatly reduce the construction cost.

FIG. 11 is a diagram for comparing the specifications of the laser downlight 200 and the LED downlight 300. As shown in the figure, in the laser downlight 200, in one example, the volume is reduced by 94% and the mass is reduced by 86% compared to the LED downlight 300.

Moreover, since the excitation light source unit 6a can be installed at a place (height) that can be easily reached by the user, even if the LD chip 11 breaks down, the LD chip 11 can be easily replaced. Further, by guiding the optical fiber bundle 215 extending from the plurality of light emitting units 210 to one excitation light source unit 6a, the plurality of LD chips 11 can be managed collectively. Therefore, even when a plurality of LD chips 11 are replaced, the replacement can be easily performed.

When the LED downlight 300 is a type using a high color rendering phosphor, a light flux of about 500 lm (lumen) can be emitted with a power consumption of 10 W, but in order to realize the light of the same brightness with the laser downlight 200. Requires an optical output of 3.3 W. If the LD efficiency is 35%, this light output corresponds to power consumption of 10 W, and the power consumption of the LED downlight 300 is also 10 W. Therefore, there is no significant difference in power consumption between the two. Therefore, in the laser downlight 200, the above-described various advantages can be obtained with the same power consumption as that of the LED downlight 300.

As described above, the laser downlight 200 includes the excitation light source unit 6a including at least one LD chip 11 that emits laser light, and at least one light emitting unit 210 including the light emitting unit 2 and the recess 212 as a reflecting mirror. Prepare. Then, the support member driving unit 62 changes the position of the light emitting unit 2 through the support member 61, and thereby the ratio of the laser light that is not converted into fluorescence by the light emitting unit 2 out of the laser light emitted from the LD chip 11 is set. Change. Thereby, since the ratio of the fluorescence with respect to illumination light changes, the laser downlight 200 which can change the color temperature of illumination light is realizable.

Further, for example, it is possible to irradiate laser light emitted from each of the plurality of emission end portions 215a of the optical fiber bundle 215 to different regions of the irradiation surface SUF4 of the light emitting unit 2. In other words, the laser light from each of the plurality of emission end portions 215a of the optical fiber bundle 215 is distributed and applied to the light emitting unit 2.

Therefore, it is possible to reduce the possibility that the light emitting section 2 is significantly deteriorated by irradiating the laser light to one place of the light emitting section 2, and to reduce the laser life with a longer life without lowering the luminous flux of the emitted light. The light 200 can be realized. In addition, since it is not necessary to reduce the intensity of the laser light applied to the light emitting unit 2, not only the luminous flux of the laser downlight 200 but also the luminance can be increased. Therefore, a small and high-intensity laser downlight 200 can be realized.

[Another Expression of Invention According to Embodiment 1]
The present invention can also be expressed as follows.

That is, the laser illumination light source (light emitting device, illumination device, headlamp) of the present invention relates to a laser illumination light source comprising a phosphor light emitting unit (light emitting unit, light emitting unit) and a semiconductor laser as an excitation light source. As the light irradiation area, an area exceeding the size of the phosphor light emitting portion may be irradiated with excitation light (area of the excitation light irradiation area> area of the irradiation surface of the phosphor light emitting portion).

The laser illumination light source of the present invention uses a blue semiconductor laser as an excitation light source, and as a phosphor, a yellow light emitting phosphor that emits yellow light, or a green light emitting phosphor that emits green light and a red light emitting that emits red light. You may combine with fluorescent substance.

The laser illumination light source of the present invention may be a transmission type or a reflection type. In the case of the reflection type, a reflection member may be provided under the diffusion member.

Here, the case where a yellow light emitting phosphor is used will be described as an example. By adopting the above configuration, it is not necessary to transmit excitation light in a region where the yellow light emitting phosphor exists (of course, it may be transmitted). Therefore, the concentration / thickness design considering only the excitation efficiency of the phosphor can be performed, and the efficiency as the light emitting device can be improved.

Further, the excitation light can be irradiated over the entire irradiation surface of the yellow light emitting phosphor (in other words, the excitation light does not concentrate locally on the phosphor light emitting portion). Therefore, since the burden (excitation) does not become strong only for a part of the phosphor, the efficiency of the phosphor light emitting portion can be maximized.

Furthermore, the excitation light emitted from the excitation light source necessarily has an intensity distribution (typically said to have a Gaussian distribution shape). If it is the said structure of the laser illumination light source of this invention, it can be made not to hit the part to which intensity | strength of surrounding intensity falls rapidly among such intensity distributions of excitation light. That is, since the phosphor light emitting portion can be excited more uniformly, the luminous efficiency of the entire light emitting device is improved. In other words, in the conventional light emitting device, the excitation light intensity in the peripheral portion of the excitation light spot to be irradiated is inevitably low.

Also, with the above-described configuration of the laser illumination light source of the present invention, the excitation light (laser light) that did not hit the phosphor light emitting part is diffused and scattered by the diffusing member, so that eye-safe can be realized.

Also, with the above-described configuration of the laser illumination light source of the present invention, there is a margin in the design of the excitation light irradiation optical system, so the cost of the light emitting device can be reduced. For example, in order to irradiate the entire area of the phosphor light emitting portion with excitation light and to prevent the excitation light from hitting the area where the phosphor light emitting portion does not exist as much as possible, the optical system must be designed precisely and the work accuracy It is necessary to assemble it properly using good parts. However, since the laser illumination light source of the present invention is based on the premise that the excitation light protrudes from the region where the phosphor light emitting portion exists, the degree of freedom of design in each part of the apparatus is increased.

[Outline of Embodiments 2 to 14]
Next, Embodiments 2 to 14 will be described. Before specific description thereof, headlamps 40 to 110 (light emitting device, illumination device, headlight) and laser downlight according to Embodiments 2 to 14 will be described. An outline of 200 (light emitting device, lighting device) will be described.

The headlamps 40 to 110 and the laser downlight 200 include at least one excitation light source that emits excitation light, at least one light emitting unit that emits fluorescence in response to the excitation light emitted from the excitation light source, and the device itself And a characteristic changing mechanism that changes the characteristics of the emitted light by changing the ratio of the fluorescence contained in the emitted light emitted to the outside.

In the following second to fourth embodiments, the excitation light source mainly functions as the main light source 27, the light emitting unit functions as the light emitting unit 2, and the characteristic changing mechanism functions as the sub light source (second light source) 28. The case will be described.

In the fifth to eighth embodiments, the excitation light source mainly functions as the semiconductor laser 63, the semiconductor laser (first excitation light source) 63a, and the semiconductor laser (second excitation light source) 63b, and the light emitting unit is the light emitting unit 2. , Functioning as a light emitting unit (first light emitting unit) 2a and a light emitting unit (second light emitting unit) 2b, and the characteristic changing mechanism (light quantity changing mechanism) as a supporting member 61, a supporting member driving unit 62, and an output control unit 642. The case of functioning will be described.

In the ninth to eleventh embodiments, mainly, the excitation light source functions as the semiconductor laser 63, and the light emitting unit functions as the light emitting unit 2 (first light emitting unit 2a, second light emitting unit 2b). A case where the mechanism (irradiation range changing mechanism) functions as the support member 61, the support member drive unit 62, and the translucent substrate drive unit 62a will be described.

In the twelfth to fourteenth embodiments, the excitation light source mainly functions as the semiconductor laser 63, the light-emitting portion functions as the first light-emitting

portions

93 and 99, and the second light-emitting portion 94, and the characteristic changing mechanism is positioned. A case of functioning as the control unit 95 will be described.

[Embodiment 2]
The following will describe another embodiment of the present invention with reference to FIGS. 12 to 16 and FIG. Here, as an example of the illumination device of the present invention, an automotive headlamp (headlamp) 1 will be described as an example. However, the lighting device of the present invention may be realized as a headlamp of a vehicle other than an automobile or a moving object (for example, a human, a ship, an aircraft, a submersible craft, a rocket), or may be realized as another lighting device. Also good. Examples of other lighting devices include a searchlight, a projector, and a home lighting device.

The headlamp 40 may satisfy the light distribution characteristic standard of the traveling headlamp (high beam), or may satisfy the light distribution characteristic standard of the passing headlamp (low beam).

<About color temperature>
It is theoretically possible to increase the color temperature of the illumination light by irradiating the blue phosphor with excitation light having an oscillation wavelength from the ultraviolet region to the blue-violet region (around 350 to 405 nm). However, it is difficult to increase the color temperature of the illumination light by this method because the blue phosphors that have high luminous efficiency and are suitable for illumination devices including a laser light source are rare.

Further, for example, together with an excitation light source having an oscillation wavelength near 405 nm, a phosphor excited by the excitation light (blue-green emission phosphor + red emission phosphor) is used, and the excitation light is all fluorescent in the phosphor. White light is emitted as the illumination light. However, in this case, the blue component contained in the fluorescence emitted from the phosphor is reduced compared to the case where the blue phosphor is used. Therefore, the chromaticity range of the white light, that is, the amount of the blue component is small, that is, The range that can be “white” becomes narrow.

Therefore, in a conventional lighting device that emits white light as illumination light using a blue-green phosphor and a red light-emitting phosphor excited by excitation light having an oscillation wavelength near 405 nm, the color temperature of the illumination light is set. It was difficult to increase.

An example of a chromaticity range called “so-called white” is a range surrounded by six points 35 shown in FIG. FIG. 18 is a graph (chromaticity diagram) showing a white chromaticity range required for a vehicle headlamp. In the figure, a range surrounded by a point 35 is a white chromaticity range required for a vehicle headlamp stipulated by law, and a curve 33 indicates a color temperature (K: Kelvin).

In addition, an example of the blue-green light emitting phosphor includes a Caα-SiAlON: Ce phosphor, and an example of a red light-emitting phosphor includes a CASN: Eu phosphor. In FIG. 18, the chromaticity range that the illumination light can take when using the Caα-SiAlON: Ce phosphor (chromaticity point 31) and the CASN: Eu phosphor (chromaticity point 32) is shown by a straight line 34. ing.

Therefore, since it is difficult to realize illumination light having a high color temperature in the conventional illumination device, it is difficult to adjust the color temperature in the first place. For this reason, it has also been difficult to develop applications that meet various needs and user preferences using such lighting devices.

On the other hand, the headlamp 40 according to this embodiment emits the fluorescence emitted from the light emitting unit 7 and the blue laser light emitted from the sub light source 28 as illumination light after being diffused in the light emitting unit 7, for example. With this configuration, it is possible to adjust the color temperature, which is difficult to realize in the conventional lighting device. Hereinafter, the configuration and the like will be specifically described.

<Configuration of headlamp 40>
FIG. 12 is a cross-sectional view showing the configuration of the headlamp 40. As shown in the figure, the headlamp 40 includes a main light source (first light source, laser light source) 27, a sub light source (second light source) 28, an aspheric lens 29, an optical fiber 55, a ferrule 65, a light emitting unit 7, and a reflecting mirror. 81, a cutoff filter 91, a housing 75, an extension 76, and a lens 77. The main light source 27, the sub light source 28, the optical fiber 55, the ferrule 65, and the light emitting unit 7 form a basic structure of the light emitting device.

(Main light source 27)
The main light source 27 is a light emitting element that functions as an excitation light source that emits excitation light, and is a semiconductor laser or an LED. In the following description, it is assumed that the main light source 27 is a semiconductor laser. In the case of a semiconductor laser, the light emitting unit 7 can be irradiated with laser light having high output and high coherency, so that the light emitting unit 7 can be made small and a headlamp 40 with high brightness can be realized. Although two main light sources 27 are illustrated in FIG. 12, it is not always necessary to provide a plurality of main light sources 27, and only one main light source 27 may be provided. However, it is easier to use a plurality of main light sources 27 in order to obtain high output excitation light.

The main light source 27 has, for example, one light emitting point per chip, oscillates 405 nm (blue-violet) laser light, has an output of 1.0 W, an operating voltage of 5 V, and a current of 0.6 A. It is enclosed in a package with a diameter of 5.6 mm.

However, the package is not limited to one having a diameter of 5.6 mm, and may be, for example, a diameter of 3.8 mm, a diameter of 9 mm, or other, and it is preferable to select a package having a smaller thermal resistance. Further, the main light source 27 may have a plurality of light emitting points on one chip.

The laser light oscillated by the main light source 27 is not limited to 405 nm, but is laser light having a peak wavelength in the wavelength range of 350 nm to 420 nm, that is, laser light having an oscillation wavelength in the wavelength range from the ultraviolet region to the blue-violet region. I just need it.

The main light source 27 can also emit laser light having a peak wavelength in a wavelength range of 470 nm or less. However, in the present embodiment, light (second light) having a blue region oscillation wavelength emitted from the sub light source 28 is used as illumination light. For this reason, in order for the light to be efficiently used as illumination light, it is preferable that the light is not easily absorbed by the light emitting unit 7. In consideration of this, the peak wavelength of the laser light oscillated by the main light source 27 is 420 nm or less. Preferably there is. Further, in consideration of the absorption rate of excitation light in the light emitting unit 7 when the light emitting unit 7 includes a Caα-SiAlON: Ce ³⁺ phosphor (Caα-SiAlON: Ce phosphor), the peak wavelength is 420 nm or less. Is preferred. This absorption rate will be described later with reference to FIG.

When light emitted from the sub-light source 28 does not need to be diffused in the light emitting unit 7 or when the light is diffused in a member other than the light emitting unit 7 (for example, the diffusing unit 71 of the third embodiment). The peak wavelength of the laser light oscillated by the main light source 27 may be 350 nm or more and 470 nm or less.

(Sub-light source 28)
The sub light source 28 is a semiconductor laser that emits light having a wavelength region different from that of the laser light emitted from the main light source 27. More specifically, the sub light source 28 irradiates the light emitting unit 7 with light (referred to as blue laser light) having an oscillation wavelength in a blue region (wavelength 440 to 460 nm).

The blue laser light irradiated to the light emitting unit 7 is diffused in the light emitting unit 7 and is emitted to the outside of the headlamp 40 as illumination light after coherency is lowered. Therefore, the blue laser light can be used as part of the illumination light after suppressing the influence of the blue laser light on the human body. That is, since the blue laser light is emitted as illumination light together with the fluorescence emitted from the light emitting unit 7, the illumination light that has been difficult to be achieved by the conventional illumination device designed to emit only the fluorescence as illumination light. The color temperature can be adjusted. Further, when the sub-light source 28 emits laser light having high coherency, it is not necessary to enlarge the light emitting portion 7 for irradiation with blue laser light, so that the color temperature can be maintained while maintaining high luminance light emission characteristics. Adjustments can be made.

The sub light source 28 may be configured to emit light having a peak wavelength in the blue region, and may be, for example, an LED. In the following description, it is assumed that the sub light source 28 is a semiconductor laser.

(Aspherical lens 29)
The aspheric lens 29 is a lens for causing the laser light oscillated from the main light source 27 or the sub light source 28 to enter the incident end portions 51 b to 53 b that are one end portions of the optical fiber 55. For example, as the aspherical lens 29, FLKN1 405 manufactured by Alps Electric can be used. The shape and material of the aspherical lens 29 are not particularly limited as long as the lens has the above-described function. However, it is preferable that the aspherical lens 29 is a material having a high transmittance of about 405 nm, which is the wavelength of excitation light, and good heat resistance.

(Optical fiber 55)
The optical fiber 55 is a light guide member that guides the laser light oscillated by the main light source 27 and the sub light source 28 to the light emitting unit 7, and is a bundle of a plurality of optical fibers. The optical fiber 55 includes

incident end portions

51b and 52b that receive laser light emitted from the main light source 27, and

emission end portions

51a and 52a that emit laser light incident from these incident end portions (see FIG. 13). Includes optical fiber. The optical fiber 55 is an optical fiber having an incident end portion 53b that receives the laser light emitted from the sub-light source 28 and an emission end portion 53a (see FIG. 13) that emits the laser light incident from these incident end portions. Contains.

FIG. 13 is a diagram showing a positional relationship between the emission end portions 51a to 53a and the light emitting portion 7. As shown in FIG. As shown in FIG. 13, the plurality of emission end portions 51a to 53a emit laser beams to different regions on the laser beam irradiation surface (light receiving surface) 7a of the light emitting unit 7. With this configuration, since the laser beam is not locally applied to the light emitting unit 7, it is possible to prevent a part of the light emitting unit 7 from being significantly deteriorated.

The optical fiber 55 has a two-layer structure in which the core of the core is covered with a clad having a refractive index lower than that of the core. The core is mainly composed of quartz glass (silicon oxide) having almost no absorption loss of laser light, and the clad is composed mainly of quartz glass or a synthetic resin material having a refractive index lower than that of the core. . For example, the optical fiber 55 is made of quartz having a core diameter of 200 μm, a cladding diameter of 240 μm, and a numerical aperture NA of 0.22, but the structure, thickness, and material of the optical fiber 55 are limited to those described above. Instead, the cross section perpendicular to the major axis direction of the optical fiber 55 may be rectangular.

In addition, as shown in Embodiment 3, a member other than the optical fiber may be used as the light guide member, and the type of the light guide member is not limited. Further, the laser light from the main light source 27 and the sub light source 28 may be condensed on the light emitting unit 7 using an optical lens or the like without using the light guide member.

Further, it is not always necessary to irradiate the same surface of the light emitting unit 7 with the laser light from the main light source 27 and the laser light from the sub light source 28. For example, the laser light from the main light source 27 may be applied to the laser light irradiation surface 7a, and the laser light from the sub light source 28 may be applied to the side surface with respect to the laser light irradiation surface 7a.

(Ferrule 65)
As shown in FIG. 13, the ferrule 65 holds the plurality of emission end portions 51 a to 53 a of the optical fiber 55 in a predetermined pattern with respect to the laser light irradiation surface 7 a of the light emitting unit 7. The ferrule 65 may have holes for inserting the emission end portions 51a to 53a formed in a predetermined pattern, and can be separated into an upper portion and a lower portion, and the upper and lower joint surfaces are respectively provided. The exit end portions 51a to 53a may be sandwiched between the formed grooves.

The ferrule 65 may be fixed to the reflecting mirror 81 with a rod-like or cylindrical member extending from the reflecting mirror 81. The material of the ferrule 65 is not specifically limited, For example, it is stainless steel. A plurality of ferrules 65 may be arranged for one light emitting unit 7.

(Light Emitting Unit 7)
The light emitting unit 7 emits fluorescence by receiving the laser light emitted from the main light source 27, and includes a phosphor that emits light by receiving the laser light. The light emitting unit 7 is, for example, a phosphor dispersed in a sealing material. The ratio (weight ratio) between the sealing material and the phosphor is about 100: 5. As the sealing material, for example, an inorganic glass of about 1 W / mK can be used.

In addition, the sealing material is not limited to inorganic glass, and may be a resin material such as so-called organic-inorganic hybrid glass or silicone resin. However, when inorganic glass is used as the sealing material, the effect of increasing the heat resistance and lowering the thermal resistance of the light emitting portion 7 is obtained, and therefore inorganic glass is preferable. In addition, the light emitting unit 7 may be formed by pressing a fluorescent material.

The phosphor is an oxynitride or nitride phosphor, and blue, green and red phosphors are dispersed in a silicone resin. Since the main light source 27 oscillates 405 nm (blue-violet) laser light, white light is generated when the light emitting unit 7 is irradiated with the laser light. Therefore, it can be said that the light emitting portion 7 is a wavelength conversion material.

The shape and size of the light emitting unit 7 is, for example, a rectangular parallelepiped of 3 mm × 1 mm × 1 mm. The light distribution pattern (light distribution) of a vehicle headlamp that is legally regulated in Japan is narrow in the vertical direction and wide in the horizontal direction. By making the cross section substantially rectangular), the light distribution pattern can be easily realized.

The light emitting unit 7 may not be a rectangular parallelepiped, and may be a cylindrical shape in which the laser light irradiation surface 7a is an ellipse.

Further, the laser light irradiation surface 7a of the light emitting unit 7 is not necessarily a flat surface, and may be a curved surface. However, in order to control the reflected laser light, the laser light irradiation surface 7a preferably has a flat surface. When the laser light irradiation surface 7a is a curved surface, at least the incident angle to the curved surface changes greatly, so that the direction in which the reflected light travels greatly changes depending on the location where the laser light is irradiated. For this reason, it may be difficult to control the reflection direction of the laser light. On the other hand, if the laser light irradiation surface 7a is flat, the direction in which the reflected light travels hardly changes even if the irradiation position of the laser light is slightly deviated. Therefore, it is easy to control the direction in which the laser light is reflected. In some cases, it is easy to take measures such as placing a laser beam absorber in a place where the reflected light strikes.

Note that the laser light irradiation surface 7a is not necessarily perpendicular to the optical axis of the laser light. When the laser light irradiation surface 7a is perpendicular to the optical axis of the laser light, the reflected laser light returns in the direction of the laser light source, and in some cases, the laser light source may be damaged.

In addition, the light emitting unit 7 is fixed to the inner surface of the blocking filter 91 in FIG. 12, but the method for fixing the position of the light emitting unit 7 is not limited to this method, and a bar-like shape extending from the reflecting mirror 81 or You may fix the position of the light emission part 7 with a cylindrical member.

Further, the light emitting unit 7 has a function of diffusing laser light. This function can be realized by utilizing the difference in refractive index between the sealing material included in the light emitting unit 7 and the phosphor. For this purpose, the light emitting unit 7 is designed to have a volume (particularly thickness) that can sufficiently diffuse the laser light oscillated by the sub light source 28.

Further, in order to further enhance the diffusion function of the light emitting unit 7 or to reduce the size of the light emitting unit 7, the light emitting unit 7 may include diffusion particles. Particles such as zirconium oxide and diamond can be used as the diffusing particles. Although particles other than these may be used, particles that can withstand the heat generation of the light emitting portion 7 are preferable.

Since the light emitting unit 7 has the above-described diffusing function, even if the sub-light source 28 is a laser light source, the headlamp 40 is a blue laser that emits from the sub-light source 28 with high coherence and has a very small emission point size. Light can be converted into light having a large emission point size that has little influence on the human body and can be emitted as illumination light. That is, the headlamp 40 can use the blue laser light emitted from the sub light source 28 as illumination light while ensuring safety. Further, since it is not necessary to provide the diffusing portion 71 (see FIG. 17) as in the third embodiment, the headlamp 40 can be manufactured at a lower cost.

Details of the phosphor included in the light emitting unit 7 will be described later.

(Reflector 81)
The reflecting mirror 81 reflects the light emitted from the light emitting unit 7 to form a light bundle that travels within a predetermined solid angle. That is, the reflecting mirror 81 reflects the light from the light emitting unit 7 to form a light beam that travels forward of the headlamp 40. The reflecting mirror 81 is, for example, a curved (cup-shaped) member having a metal thin film formed on the surface thereof.

Further, the reflecting mirror 81 is not limited to a hemispherical mirror, and may be an ellipsoidal mirror, a parabolic mirror, or a mirror having a partial curved surface thereof. That is, the reflecting mirror 81 only needs to include at least a part of a curved surface formed by rotating a figure (ellipse, circle, parabola) about the rotation axis on the reflecting surface. The shape of the opening in the reflecting mirror 81 is not limited to a circle. The shape of the opening can be determined as appropriate according to the design of the headlamp 40 and its surroundings.

(Blocking filter 91)
The blocking filter 91 transmits white light generated by converting the laser light in the light emitting unit 7 and blocks laser light from the main light source 27 and the sub light source 28. As the cutoff filter 91, for example, TY418 manufactured by Isuzu Seiko Glass Co., Ltd. can be used.

Most of the coherent laser light is absorbed by the phosphor and converted into incoherent light by the light emitting unit 7. However, there may be a case where a part of the laser light is not converted into incoherent light for some reason. Even in such a case, the laser beam can be prevented from leaking to the outside by blocking the laser beam by the blocking filter 91. As a result, even if the emission point size of the laser light (excitation light) is very small and the output power is high, or the laser light belongs to a wavelength range other than the visible light region, the laser light leaks to the outside. The influence on the human body can be suppressed.

Even when the main light source 27 is an LED, there is a possibility of affecting the human body such as skin and eyes when emitting excitation light in the ultraviolet region (350 nm or more, 380 nm or less or 400 nm or less). Therefore, it is preferable to select a blocking filter 91 that can block light of 400 nm or less.

Further, when the main light source 27 emits light having a wavelength longer than 400 nm, the light need not necessarily be blocked by the blocking filter 91. However, in the case of laser light, in order to enlarge the light emission point size and make the light safe for the human eye, most of the laser light is converted into fluorescence in the light emitting unit 7 or a plurality of light is emitted. Must be scattered or diffused once.

(Ensuring safety when using laser light)
When light having high energy is emitted from a light source having a small light emitting spot size and the light enters the human eye, the light source image is narrowed down to the small light emitting spot size on the retina. The energy density can be very high. For example, laser light emitted from a laser light source (semiconductor laser) may have a spot size smaller than 10 μm square. When laser light emitted from such a light source is directly incident on the eye or is incident on the eye in such a way that a small light emitting point can be seen directly even through an optical member such as a lens or a reflecting mirror, the imaged portion on the retina is It can be damaged.

The emission point size in a typical high-power semiconductor laser is, for example, 1 μm × 10 μm. That is, the emission area of the semiconductor laser is 10 μm ² = 1.0 × 10 ⁻⁵ mm ² . For this reason, even if the light emitted from the semiconductor laser is, for example, light having the same energy as that of a light source having a light emitting point size of 1 mm ² , the energy density of the image formation location on the retina in the case of the semiconductor laser is light emission. point size is increased even ¹⁰⁵ times higher than the case of the 1 mm ² light sources.

In order to avoid this, it is necessary to enlarge the light emitting spot size to a certain size (finite size) (specifically, for example, 1 mm × 1 mm or more). By enlarging the emission point size, the image size on the retina can be enlarged, so even if light of the same energy is incident on the eye, the energy density on the retina is reduced. It becomes possible.

In order to increase the light emission point size, it is necessary to make the light emission point of the light source itself invisible. For this reason, in the present embodiment, as described above, the light emitting unit 2 is provided with a diffusion function, and the light emission point sizes of the main light source 27 and the sub light source 28 are enlarged, so that safety to the human body, particularly for human eyes. Ensures safety (Eye safe).

In addition, it is necessary to consider the enlargement of the light emitting spot size not only in the laser light source but also in the LED light source. However, since the laser light is more monochromatic than the light emitted from the LED light source, that is, has a uniform wavelength, there is no blurring of the image on the retina (so-called chromatic aberration) due to the difference in wavelength, and it is more dangerous than the light. It is. For this reason, in an illuminating device that uses light emitted from a laser light source as illumination light, it is preferable to more firmly consider the expansion of the emission point size.

(Housing 75)
The housing 75 forms the main body of the headlamp 40 and houses the reflecting mirror 81 and the like. The optical fiber 55 passes through the housing 75, and the main light source 27 and the sub light source 28 are installed outside the housing 75. The semiconductor laser generates heat when the laser beam oscillates, but the main light source 27 and the sub light source 28 can be efficiently cooled by being installed outside the housing 75.

Also, it is preferable to install the main light source 27 and the sub light source 28 at positions where they can be easily replaced in consideration of a failure. If these points are not taken into consideration, the main light source 27 and the sub light source 28 may be housed in the housing 75.

(Extension 76)
The extension 76 is provided on the front side of the reflecting mirror 81 to improve the appearance by concealing the internal structure of the headlamp 40 and enhance the sense of unity between the reflecting mirror 81 and the vehicle body. The extension 76 is also a member having a metal thin film formed on the surface thereof, like the reflecting mirror 81.

(Lens 77)
The lens 77 is provided in the opening of the housing 75 and seals the headlamp 40. The light generated by the light emitting unit 7 and reflected by the reflecting mirror 81 is emitted to the front of the headlamp 40 through the lens 77.

<Details of the light emitting unit 7>
(Phosphor composition)
As described above, the main light source 27 emits laser light having an oscillation wavelength from the ultraviolet region to the blue-violet region, and the light emitting unit 7 receives this laser light and emits white light. A mixture of a phosphor or green-emitting phosphor and a red-emitting phosphor is preferable. In other words, the main light source 27 may emit laser light having an oscillation wavelength in the above region, and in this case, the material (phosphor material) of the light emitting unit for generating white light can be easily selected and manufactured. it can. The yellow light emitting phosphor is a phosphor that emits light having a peak wavelength in a wavelength range of 560 nm to 590 nm. The green light emitting phosphor is a phosphor that emits light having a peak wavelength in a wavelength range of 510 nm or more and 560 nm or less. The red light emitting phosphor is a phosphor that emits light having a peak wavelength in a wavelength range of 600 nm or more and 680 nm or less.

The phosphor is preferably a so-called sialon phosphor. Sialon is a substance in which a part of silicon atoms in silicon nitride is replaced with aluminum atoms and a part of nitrogen atoms is replaced with oxygen atoms. The sialon phosphor can be produced by dissolving alumina (Al ₂ O ₃ ), silica (SiO ₂ ), a rare earth element, and the like in silicon nitride (Si ₃ N ₄ ).

As another preferred example of the phosphor, a semiconductor nanoparticle phosphor using nanometer-size particles of a III-V compound semiconductor can also be used. One of the characteristics of semiconductor nanoparticle phosphors is that even if the same compound semiconductor (for example, indium phosphorus: InP) is used, the emission color can be changed by the quantum size effect by changing the particle diameter. is there. For example, InP emits red light when the particle size is about 3 to 4 nm. Here, the particle size was evaluated with a transmission electron microscope (TEM).

Also, since this phosphor is based on a semiconductor, it has a short fluorescence lifetime and is characterized by strong resistance to high-power excitation light because it can quickly radiate the excitation light power as fluorescence. This is because the emission lifetime of the semiconductor nanoparticle phosphor is about 10 nanoseconds, which is five orders of magnitude smaller than that of a normal phosphor material having a rare earth-based emission center. Since the emission lifetime is short, absorption of excitation light and emission of fluorescence can be repeated quickly.

As a result, high efficiency can be maintained against strong excitation light, and heat generation from the phosphor is reduced. Therefore, it is possible to further suppress the light conversion member from being deteriorated (discolored or deformed) by heat. Thereby, when using the light emitting element with a high light output as a light source, it can suppress more that the lifetime of a light-emitting device becomes short.

In the present embodiment, the main light source 27 emits laser light having an oscillation wavelength near 405 nm. For this reason, in order for the headlamp 40 to emit white light, the phosphors of the light emitting unit 7 include Caα-SiAlON: Ce phosphor (first phosphor) and CaAlSiN ₃ : Eu ²⁺ phosphor (CASN). : Eu phosphor and second phosphor) are used.

The Caα-SiAlON: Ce phosphor emits fluorescence from blue to green when the excitation wavelength is 405 nm, and the wavelength of the emission peak is 510 nm. Further, the luminous efficiency of the phosphor is 65% (see FIG. 14), and the luminous efficiency is high. Furthermore, since this phosphor has high heat resistance, there is little possibility that the light emitting section 7 will deteriorate even if the light emitting section 7 is irradiated with a high output laser beam at a high light density.

The CASN: Eu phosphor emits red fluorescence when the excitation wavelength is 405 nm, and the wavelength of the emission peak is 650 nm. Further, the luminous efficiency of this phosphor is 73%, and the luminous efficiency is high. Furthermore, since this phosphor also has high heat resistance, there is little possibility that the light emitting section 7 will deteriorate even if the light emitting section 7 is irradiated with high output excitation light at a high light density.

As a red-emitting phosphor, CASN: instead of Eu phosphor, SrCaAlSiN _3: ^{Eu 2+} phosphor (SCASN: Eu phosphor, a second phosphor) may be used. The SCASN: Eu phosphor emits red fluorescence when the excitation wavelength is 350 nm to 450 nm, its peak wavelength is 630 nm, and its luminous efficiency is 70%.

As described above, by using the Caα-SiAlON: Ce phosphor as the green phosphor and the CASN: Eu phosphor or the SCASN: Eu phosphor as the red phosphor in the light emitting unit 7, a high luminance and high luminous flux white color is obtained. An illumination device (headlight) that emits light can be realized. Further, by using this red light emitting phosphor, that is, a phosphor that emits fluorescence having a peak wavelength in a wavelength range of 630 nm or more and 650 nm or less, a light emitting portion having high color rendering properties can be realized.

(Characteristics of Caα-SiAlON: Ce phosphor)
One of the reasons why the Caα-SiAlON: Ce phosphor is used in the present embodiment is that, as described above, the luminous efficiency is high when the excitation light emitted from the main light source 27 is irradiated. On the other hand, the Caα-SiAlON: Ce phosphor has a low luminous efficiency when irradiated with the blue laser light emitted from the sub-light source 28. Here, the characteristics of the Caα-SiAlON: Ce phosphor will be described with reference to FIG. In the graph shown in FIG. 14, the internal quantum efficiency, the absorption rate, and the external quantum efficiency of the Caα-SiAlON: Ce phosphor are shown. The external quantum efficiency is so-called luminous efficiency, and is obtained by internal quantum efficiency × absorption rate.

As shown in the figure, the Caα-SiAlON: Ce phosphor exhibits a high absorptance (the ratio of the excitation light absorbed by the phosphor to the entire excitation light) particularly for light in the wavelength range of 350 nm to 420 nm. Yes. In other words, it can be said that the Caα-SiAlON: Ce phosphor has an absorption peak wavelength of light in a wavelength range of 350 nm or more and 420 nm or less.

Specifically, in the case of the Caα-SiAlON: Ce phosphor, it can be seen that the wavelength range of the laser light emitted from the main light source 27 when the absorption rate is 70% or more is approximately 420 nm or less. In general, even if the phosphor is different from the Caα-SiAlON: Ce phosphor, if the phosphor has a light absorption peak wavelength of 420 nm or less, the oscillation wavelength of the laser light emitted from the main light source 27 is In the case of approximately 420 nm or less, the absorption rate of the laser light in the phosphor shows 70% or more. As shown in the figure, in the case of a Caα-SiAlON: Ce phosphor, the external quantum efficiency (luminous efficiency) when the absorption rate is 70% is about 50%, and high luminous efficiency is realized.

In other words, when a phosphor having an absorption peak wavelength of excitation light below 420 nm (particularly Caα-SiAlON: Ce phosphor) is irradiated with light having a wavelength longer than 420 nm, the absorptance is Less than 70%. In particular, when the light emitting unit 7 is irradiated with light having a peak wavelength in the wavelength range of 440 nm or more (blue laser light emitted from the sub-light source 28), the blue laser light absorption rate is 50% as illustrated. Lower than. For this reason, the luminous efficiency at this time is further lower than when the absorptance is 70%.

Specifically, when the wavelength of the irradiated light is 440 nm, the absorptance is about 45%, and the external quantum efficiency (luminous efficiency) is about 35%. The inventors have confirmed that when a Caα-SiAlON: Ce phosphor is irradiated with blue laser light having a wavelength of 445 nm, the phosphor hardly emits fluorescence. Note that the light emission efficiency when irradiated with light having a wavelength of 445 nm is about 30% (see FIG. 14).

That is, the phosphor having a light absorption peak wavelength in the wavelength range of 350 nm or more and 420 nm or less on the light emitting unit 7 and an absorption rate of 70% or more when irradiated with the laser light emitted from the main light source 27. Is used, the blue laser light emitted from the sub-light source 28 is hardly absorbed by the light emitting unit 7. Therefore, since the attenuation of the blue laser light in the light emitting unit 7 can be suppressed, the headlamp 40 can efficiently adjust the color temperature of the illumination light as described below.

(Spectrum of light emitted from the light emitting unit 7)
Next, the spectrum of the light emitted from the light emitting unit 7 will be described. The spectrum when only the main light source 27 is used will be described with reference to FIG. 15, and the spectrum when the main light source 27 and the sub light source 28 are used will be described with reference to FIG.

15 and 16, the main light source 27 emits laser light having an oscillation wavelength near 405 nm to excite the Caα-SiAlON: Ce phosphor and the CASN: Eu phosphor of the light emitting unit 7. The weight ratio of these phosphors is 3: 1, and the light output of the main light source 27 is 5W.

In FIG. 16, the sub light source 28 irradiates the light emitting unit 7 with blue laser light having an oscillation wavelength near 460 nm, and the light output of the sub light source 28 is 0.5 W.

In FIG. 15, the light emitting section 7 emits fluorescence (white light) having a wavelength of about 500 to 700 nm in addition to laser light having an oscillation wavelength near 405 nm. The headlamp 40 can emit the illumination light while blocking the laser light with the blocking filter 91 so as not to cause any damage to the human body such as skin and eyes.

On the other hand, in FIG. 16, the light emitting unit 7 also emits blue laser light having an oscillation wavelength near 460 nm. As described above, since the Caα-SiAlON: Ce phosphor is used for the light emitting unit 7, the blue laser light absorption rate in the light emitting unit 7 is low. That is, as shown in FIG. 16, when the blue laser light is emitted from the sub light source 28, the amount of light in the blue region (near 460 nm) emitted from the light emitting unit 7 is increased compared to the case of FIG. ing.

For this reason, although the blue component of the fluorescence obtained from the laser light having an oscillation wavelength of 350 nm or more and 420 nm or less emitted from the main light source 27 is small, the bluish component can be supplemented with the light in the blue region. it can. That is, by diffusing the blue laser light emitted from the sub light source 28 and using it as illumination light, the bluish component can be compensated for and the color temperature of the illumination light can be increased.

In addition, by using the blue laser light after diffusion as the illumination light, it is possible to adjust the color temperature of the illumination light, which has been difficult with the conventional illumination device designed to use only fluorescence as the illumination light. it can. Further, since the blue laser light is difficult to be converted into fluorescence by the light emitting unit 7, the diffused blue laser light can be efficiently used as illumination light. That is, it can be efficiently used for adjusting the color temperature.

The basic structure of the semiconductor laser as the main light source 27 and the sub light source 28 is the same as the basic structure of the LD chip 11 described with reference to FIGS. 3C and 3D described in the first embodiment. Therefore, the explanation is omitted. In addition, the light emission principle of the light emitting unit 7 is the same as the light emission principle of the light emitting unit 2 described in the first embodiment, and thus the description thereof is omitted.

<Effect of the headlamp 40>
The headlamp 40 emits the fluorescent light emitted from the light emitting unit 7 and the blue laser light emitted from the sub light source 28 as illumination light after being diffused in the light emitting unit 7, for example. As a result, the headlamp 40 excites the light emitting unit 7 with the laser light emitted from the main light source 27 to obtain the fluorescence, thereby maintaining the high-luminance emission characteristics, and the blue laser light after diffusion with the fluorescence. Adjustment of the color temperature of the illumination light can also be realized by using the illumination light.

When the sub light source 28 is not a semiconductor laser, the light emitted from the sub light source 28 can be used as illumination light without being diffused in the light emitting unit 7.

[Embodiment 3]
Another embodiment of the present invention will be described below with reference to FIG. In addition, about the member similar to Embodiment 2, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

Unlike the above-described headlamp 40, the headlamp 50 of the present embodiment includes a diffusing unit 71 that diffuses the blue laser light emitted from the sub-light source 28. The headlamp 50 includes a light guide 511 as a light guide member that guides the excitation light from the main light source 27 to the light emitting unit 7, and guides the blue laser light from the sub light source 28 to the diffusion unit 71. It has.

(Diffusion part 71)
The diffusion unit 71 is, for example, one in which diffusion particles that diffuse laser light are dispersed in a base material.

Since it is assumed that the diffusing unit 71 is irradiated with high-power laser light, the diffusing unit 71 is preferably heat resistant. Considering this point, it is preferable to use inorganic glass as the base material.

On the other hand, for example, fumed silica, Al ₂ O ₃ , zirconium oxide, or diamond can be used as the diffusing particles. These fine powders (diameter of about 10 nm to 5 μm) are mixed with inorganic glass at a weight ratio of about 10 to 30%.

The refractive index of inorganic glass is about 1.5 to 1.8, for example, while the refractive index of zirconium oxide and diamond is about 2.4. Therefore, the difference in refractive index between the inorganic glass and the diffusing particles becomes large, so that the diffusion effect can be enhanced.

Further, since the melting point of zirconium oxide is 2715 ° C. and the melting point of diamond is 3550 ° C., it does not melt or change at the melting temperature of ordinary inorganic glass, and is dispersed in the inorganic glass as diffusion particles. Suitable as a material.

The material of the diffusion part 71 described above is merely an example, and the material of the diffusion part 71 is not particularly limited as long as it can diffuse blue laser light. Further, the shape and size (thickness) of the diffusing portion 71 may be set to a shape and size that can sufficiently diffuse the blue laser light in consideration of the diffusion efficiency.

The shape and size of the diffusion part 71 may be the same as that of the light emitting part 7, but it is preferably formed so as to cover the light emitting part 7. In addition, the light emitting unit 7 and the diffusing unit 71 are preferably disposed in the vicinity of the focal position of the reflecting mirror 81.

As described above, since the blue laser light emitted from the sub-light source 28 is diffused in the diffusing unit 71, the emission point size of the blue laser light can be expanded. Light can be used as illumination light.

(Light guides 511 and 512)
The light guides 511 and 512 are frustoconical light guide members, and are optically coupled to the main light source 27 and the sub light source 28 via the aspherical lens 29 (or directly).

The light guides 511 and 512 have a light incident surface for receiving the laser light emitted from the main light source 27 or the sub light source 28 and a light emitting surface for emitting the laser light received on the light incident surface.

Since the area of the light emitting surface is smaller than the area of the light incident surface, each laser beam incident from the light incident surface is converged by traveling forward while being reflected on the side surfaces of the

light guide portions

511 and 512. It is emitted from.

The light guides 511 and 512 are made of BK7, quartz glass, acrylic resin, or other transparent material. Further, the light incident surface and the light emitting surface may be planar or curved.

The light guides 511 and 512 may have a truncated pyramid shape, and the shape is not limited.

[Embodiment 4]
The following will describe another embodiment of the present invention with reference to FIGS. In addition, about the member similar to Embodiment 2 * 3, the same code | symbol is attached | subjected and the description is abbreviate | omitted. Further, in the following description, a schematic diagram showing the appearance of the light emitting unit 210 and the conventional LED downlight 300, a cross-sectional view showing a ceiling where the LED downlight 300 is installed, and specifications of the laser downlight 200 and the LED downlight 300 are shown. For comparison, refer to FIGS. 6, 10, and 11 of the first embodiment, respectively.

Here, the laser downlight 200 as an example of the illumination device of the present invention will be described. The laser downlight 200 is an illumination device installed on the ceiling of a structure such as a house or a vehicle. The laser downlight 200 uses the fluorescence by irradiating the light emitting unit 7 with the laser light emitted from the main light source 27 and the blue laser light emitted from the sub light source 28 and diffused by the light emitting unit 7 as illumination light. Is.

FIG. 19 is a cross-sectional view of the ceiling where the laser downlight 200 is installed. FIG. 20 is a cross-sectional view of the laser downlight 200. As shown in FIGS. 6, 19, and 20, the laser downlight 200 is embedded in the top plate 400 and supplies laser light to the light emitting unit 210 via the light emitting unit 210 that emits illumination light and the optical fiber 55. An LD light source unit 220. The LD light source unit 220 is not installed on the ceiling, but is installed at a position where the user can easily touch it (for example, a side wall of a house). The position of the LD light source unit 220 can be freely determined in this way because the LD light source unit 220 and the light emitting unit 210 are connected by the optical fiber 55. The optical fiber 55 is disposed in a gap between the top plate 400 and the heat insulating material 401.

(Configuration of light emitting unit 210)
As shown in FIG. 20, the light emitting unit 210 includes a housing 211, an optical fiber 55, a light emitting unit 7, and a light transmitting plate 213.

A recess 212 is formed in the housing 211, and the light emitting unit 7 is disposed on the bottom surface of the recess 212. A metal thin film is formed on the surface of the recess 212, and the recess 212 functions as a reflecting mirror.

Further, a passage 214 for passing the optical fiber 55 is formed in the housing 211, and the optical fiber 55 extends to the light emitting unit 7 through the passage 214. The positional relationship between the emission end portions 51a to 53a of the optical fiber 55 and the light emitting portion 7 is the same as described above.

The translucent plate 213 is a transparent or translucent plate disposed so as to close the opening of the recess 212. The translucent plate 213 has a function similar to that of the blocking filter 91, and the fluorescence of the light emitting unit 7 is emitted as illumination light through the translucent plate 213. The translucent plate 213 may be removable from the housing 211 or may be omitted.

In the downlight, unlike the headlamp, an ideal point light source is not required, and a level of one light emitting point is sufficient. Therefore, there are fewer restrictions on the shape, size and arrangement of the light emitting section 7 than in the case of the headlamp.

(Configuration of LD light source unit 220)
The LD light source unit 220 includes a main light source 27, a sub light source 28, an aspheric lens 29, and an optical fiber 55.

The incident end portion 5 b, which is one end portion of the optical fiber 55, is connected to the LD light source unit 220, and the laser beams oscillated from the main light source 27 and the sub light source 28 are respectively connected to the optical fiber 55 via the aspherical lens 29. Is incident on the incident end 5b.

In FIG. 20, a pair of main light source 27 and aspherical lens 29 and a pair of sub-light source 28 and aspherical lens 29 are provided inside LD light source unit 220, and a bundle of optical fibers extending from each aspherical lens 29. It is guided to one light emitting unit 210. That is, in FIG. 20, one set of light sources including a pair of main light sources 27 and aspherical lenses 29 and a pair of sub light sources 28 and aspherical lenses 29 functions as a light source for one light emitting unit 210. The main light source 27 and the sub light source 28 do not need to be provided one by one, and the number of the light sources includes the output amount per light source, the color temperature of illumination light realized by the laser downlight 200, or the adjustment width thereof. It may be determined in consideration.

Further, when there are a plurality of light emitting units 210, a bundle of optical fibers extending from the light emitting units 210 may be guided to one LD light source unit 220. In this case, one LD light source unit 220 contains a plurality of the above-mentioned one set of light sources, and the LD light source unit 220 functions as a centralized power supply box.

(Example of changing the installation method of the laser downlight 200)
FIG. 21 is a cross-sectional view showing a modified example of the installation method of the laser downlight 200. As shown in the figure, as a modified example of the installation method of the laser downlight 200, only a small hole 402 through the optical fiber 55 is opened in the top plate 400, and the laser downlight main body (light emitting unit) is utilized by taking advantage of the thin and light weight. 210) can be attached to the top plate 400 using a strong adhesive tape or the like. In this case, there are advantages that restrictions on installation of the laser downlight 200 are reduced, and that construction costs can be significantly reduced.

(Comparison between laser downlight 200 and conventional LED downlight 300)
Since the comparison between the laser downlight 200 and the conventional LED downlight 300 has been described with reference to FIGS. 13 and 14 in the first embodiment, the description thereof is omitted here.

In the present embodiment, as in the first embodiment, the LD light source unit 220 can be installed at a place (height) that can be easily reached by the user, so that even if the main light source 27 and the sub light source 28 break down. You can easily replace these light sources. Further, by guiding the optical fibers 55 extending from the plurality of light emitting units 210 to one LD light source unit 220, the plurality of main light sources 27 and the plurality of sub light sources 28 can be collectively managed. Therefore, even when the plurality of main light sources 27 and the plurality of sub light sources 28 are replaced, the replacement can be easily performed.

As described above, the laser downlight 200 is irradiated with the LD light source unit 220 including at least one main light source 27 that emits laser light and one sub-light source 28 that emits blue laser light, and the laser light and the blue laser light. And at least one light-emitting unit 210 including the light-emitting unit 7 to be operated. Then, the fluorescent light emitted from the light emitting unit 7 upon receiving the laser light emitted from the main light source 27 and the blue laser light emitted from the sub light source 28 (blue laser light diffused by the light emitting unit 7) are used as illumination light. To be emitted.

Therefore, since the laser downlight 200 can use blue laser light different from the fluorescence emitted by the light emitting unit 7 as illumination light, the laser light as excitation light is prevented from leaking to the outside, and only fluorescence is used as illumination light. It is possible to adjust the color temperature, which is difficult in the conventional lighting device designed to be used.

[Another Expression of Inventions According to Embodiments 2 to 4]
The inventions according to Embodiments 2 to 4 can also be expressed as follows.

That is, an illuminating device (solid-state illumination light source) according to an embodiment of the present invention includes a phosphor light emitting unit and a semiconductor laser or LED having an oscillation wavelength in the blue-violet region near 405 nm, or in the ultraviolet to blue-violet region from 350 nm to 400 nm. The present invention relates to a solid-state illumination light source comprising an excitation light source. The first aspect of the illumination device is that Caα-SiAlON: Ce ³⁺ is used as a phosphor constituting at least a part of the phosphor light emitting portion. A second aspect of the illumination device is to have a blue semiconductor laser (having a laser oscillation peak at 440 nm to 460 nm) for the purpose of increasing the color temperature of the illumination light. The illumination device is made eye-safe by irradiating the phosphor light emitting portion with the laser light emitted from the blue semiconductor laser, and scattering the phosphor light emitting portion to enlarge the emission point size of the laser light. The blue light component of the illumination light emitted from the light emitting unit is compensated.

[Additional notes pertaining to Embodiments 2 to 4]
For example, when the user changes the output of the sub light source 28, the color temperature can be adjusted to the user's preference. That is, in this case, the user can customize the color temperature.

Further, the phosphor used in the light emitting unit 7 is not limited to the composition described in the second embodiment. For example, the phosphor used in the light emitting unit 7 may be composed of only a yellow light emitting phosphor. In this case, the output of the main light source 27 can be 3 to 4 W, and the output of the sub light source 28 can be 0.3 to 0.4 W. When only the red light emitting phosphor is used, the output of the main light source 27 can be set to 3.5 to 5 W.

That is, the outputs of the main light source 27 and the sub light source 28 can be appropriately changed by changing the composition of the phosphor in the light emitting unit 7. Further, it is sufficient that the color temperature can be adjusted or improved by using the light emitted from the sub light source 28 as the illumination light, and the illumination light is not limited to white light.

[Embodiment 5]
The following will describe another embodiment of the present invention with reference to FIGS. Here, as an example of the illumination device of the present invention, a headlamp (headlamp) 60 for an automobile will be described as an example. However, the lighting device of the present invention may be realized as a headlamp of a vehicle other than an automobile or a moving object (for example, a human, a ship, an aircraft, a submersible craft, a rocket), or may be realized as another lighting device. Also good. Examples of other lighting devices include a searchlight, a projector, and a home lighting device.

The headlamp 60 may satisfy the light distribution characteristic standard of the traveling headlamp (high beam), or may satisfy the light distribution characteristic standard of the passing headlamp (low beam).

<Configuration of headlamp 60>
First, based on FIG. 22, the headlamp 60 which is one Embodiment of this invention is demonstrated. FIG. 22 is a half sectional view showing a schematic configuration of the headlamp 60. As shown in FIG. 22, the headlamp 60 includes a translucent substrate 1, a light emitting unit 2, a diffusing unit 3, a reflecting mirror 4, a fixing member 56, an excitation light source unit (excitation light source) 6, screws 78, a lens 82, a light guide. The optical member 9, the support member 61, and the support member drive part 62 are provided. The excitation light source unit 6, the light guide member 9, and the light emitting unit 2 form a basic structure of the light emitting device. Further, the support member 61 and the support member driving unit 62 form a basic structure of the light amount changing mechanism.

(Translucent substrate 1)
The translucent substrate 1 is a flat member and has translucency at least with respect to the oscillation wavelength of laser light (440 nm to 480 nm in this case) as excitation light. The translucent substrate 1 may have a curved portion instead of a flat plate shape. However, when the translucent substrate 1 and the light emitting unit 2 are bonded, at least the portion to which the light emitting unit 2 is bonded is bonded. From the viewpoint of stability, the surface is preferably flat (plate-like).

The translucent substrate 1 is an Al ₂ O ₃ (sapphire) substrate having a length of 10 mm × width of 10 mm × thickness of 0.5 mm. Note that the outer diameter of the translucent substrate 1 shown in FIG. 22 is larger than the outer diameter of the diffusing portion 3, but may be approximately the same as the outer diameter of the diffusing portion 3.

The light emitting unit 2 is disposed on the surface of the translucent substrate 1 that faces the surface on which the laser beam is incident, and is thermally connected to the light emitting unit 2 (that is, capable of transferring thermal energy). ing. In the present embodiment, the light-transmitting substrate 1 and the light-emitting portion 2 are described as being bonded (adhered) using an adhesive, but the light-transmitting substrate 1 and the light-emitting portion 2 are bonded. The method is not limited to adhesion, and may be, for example, fusion. As the adhesive, so-called organic adhesives and glass paste adhesives are suitable, but not limited thereto.

The translucent substrate 1 has the configuration, shape, and connection form with the light emitting unit 2 as described above, so that the heat generated in the light emitting unit 2 while fixing (holding) the light emitting unit 2 to the substrate surface. Since heat is radiated to the outside, the cooling efficiency of the light emitting unit 2 can be improved.

Moreover, the material of the translucent substrate 1 is preferably magnesia (MgO), gallium nitride (GaN), or spinel (MgAl ₂ O ₄ ) in addition to the sapphire (Al ₂ O ₃ ) described above. This is because these materials have excellent thermal conductivity (for example, 20 W / mK or more) and translucency. If this point is not taken into consideration, the material is not limited to these materials, and may be glass (quartz), for example.

The thickness of the translucent substrate 1 shown in FIG. 22 is preferably 30 μm or more and 5.0 mm or less, more preferably 0. More preferably, it is 2 mm or more and 5.0 mm or less. In addition, when the thickness of the translucent substrate 1 exceeds 5.0 mm, the ratio of the laser light irradiated to the light emitting unit 2 absorbed in the translucent substrate 1 is increased, but the heat dissipation effect is not so much. It does not improve, and the cost of the member also increases.

(Light emitting part 2)
The light emitting unit 2 emits fluorescence upon receiving laser light emitted from the semiconductor laser 63.

In this embodiment, a YAG: Ce phosphor (NYAG4454) manufactured by Intematix is used as a light emitter that realizes the light emission of the fluorescence, but the type of the phosphor is not limited to this. The YAG: Ce phosphor is an yttrium (Y) -aluminum (Al) -garnet phosphor activated with Ce. This Intematix YAG: Ce phosphor has an external quantum efficiency of 90%, an emission peak wavelength (hereinafter simply referred to as “peak wavelength”) of 558 nm (yellow), chromaticity points of x = 0.444, y = 0.536, which is well excited by excitation light from 430 nm to 490 nm. The YAG: Ce phosphor generally has a broad emission spectrum in which an emission peak exists in the vicinity of 550 nm (slightly longer than 550 nm).

The light emitting part 2 is manufactured by dispersing YAG: Ce phosphor inside a low melting point inorganic glass (refractive index n = 1.760) as a sealing material. The compounding ratio of the YAG: Ce phosphor and the low melting point inorganic glass (low melting point glass) is, for example, about 30: 100. However, the present invention is not limited to this, and when the laser light is diffused by the light emitting section 2 and the color component (for example, blue component) of the laser light is used, the above blending ratio is preferably about 10: 100. In addition, the light emitting unit 2 may be one obtained by pressing a fluorescent material.

The sealing material is not limited to the above inorganic glass, and may be a so-called organic-inorganic hybrid glass or a resin material such as a silicone resin. However, considering heat resistance, the sealing material is preferably made of glass.

In consideration of reducing the reflectance RE of the interface between the translucent substrate 1 and the light emitting unit 2 as much as possible and increasing the utilization efficiency of the laser light in the light emitting unit 2, the translucent substrate 1 and The refractive index difference Δn with respect to the light emitting unit 2 is preferably 0.35 or less. In this case, the reflectance RE can be 1% or less. Further, when the refractive index difference Δn is set to 0.35 or less, it is preferable to set the refractive index of the translucent substrate 1 to 1.65 or more and the refractive index of the light emitting unit 2 to 2.0 or less.

In general, white light or pseudo white light used as illumination light can be realized by mixing three colors satisfying the principle of color matching, or mixing two colors satisfying a complementary color relationship. Based on the principle of the same color or complementary color, for example, in the headlamp 60, a combination of blue laser light emitted from a semiconductor laser 63 described later and a YAG: Ce phosphor (yellow light emitting phosphor) (complementary color relationship). A pseudo white color is realized by mixing two colors satisfying In other words, the semiconductor laser 63 emits light having an oscillation wavelength in the blue region as laser light, and the light emitting unit 2 generates a yellow light emitting phosphor (first phosphor) that emits fluorescence having a peak wavelength in the yellow region. It is the composition which includes. In this case, the color temperature of the illumination light can be changed in a wide range.

However, the phosphor included in the light emitting unit 2 is not limited to one type of YAG: Ce phosphor, and may be a plurality of types. For example, if the light emitting unit 2 includes a combination of a green light emitting phosphor and a red light emitting phosphor, which will be described later, white light can be realized by mixing with blue laser light.

Here, the yellow light emitting phosphor is a phosphor that emits fluorescence having a peak wavelength in a wavelength range of 560 nm or more and 590 nm or less. The green light emitting phosphor is a phosphor that emits fluorescence having a peak wavelength in a wavelength range of 510 nm or more and 560 nm or less. The red light-emitting phosphor is a phosphor that generates fluorescence having a peak wavelength in a wavelength range of 600 nm or more and 680 nm or less.

Specific examples of the yellow light emitting phosphor include a YAG: Ce phosphor and a Caα-SiAlON: Eu phosphor doped with Eu ²⁺ . The Caα-SiAlON: Eu phosphor exhibits strong light emission with a peak wavelength of about 580 nm by near ultraviolet to blue excitation light.

Specific examples of the green light emitting phosphor include various nitride-based or oxynitride-based phosphors. In particular, since the oxynitride phosphor is excellent in heat resistance and stable with high light emission efficiency, the light emitting portion 2 with excellent heat resistance and stable with high light emission efficiency can be realized.

The above-mentioned α-SiAlON and β-SiAlON (sialon) are commonly called so-called sialon phosphors (oxynitride phosphors). Sialon is a substance in which a part of silicon atoms in silicon nitride is replaced with aluminum atoms and a part of nitrogen atoms is replaced with oxygen atoms. The sialon phosphor can be produced by dissolving alumina (Al ₂ O ₃ ), silica (SiO ₂ ), a rare earth element, and the like in silicon nitride (Si ₃ N ₄ ). When calcium (Ca) and europium (Eu) are dissolved in this sialon phosphor, a phosphor that emits light having a longer wavelength range from yellow to orange than the YAG: Ce phosphor can be obtained.

Specific examples of the red light-emitting phosphor include various nitride-based phosphors. For example, as a nitride-based phosphor, Eu ²⁺ doped CaAlSiN ₃ : Eu phosphor (CASN: Eu phosphor), Eu ²⁺ doped SrCaAlSiN ₃ : Eu phosphor (SCASN: Eu phosphor) Etc. These nitride-based phosphors can enhance color rendering properties by combining with the above-described oxynitride phosphors.

For example, CASN: Eu phosphor emits red fluorescence when its excitation wavelength is 350 nm to 450 nm, its peak wavelength is 650 nm, and its luminous efficiency is 73%. Further, the SCASN: Eu phosphor emits red fluorescence when the excitation wavelength is 350 nm to 450 nm, its peak wavelength is 630 nm, and its luminous efficiency is 70%.

In other words, the light emitting unit 2 includes, for example, a yellow light emitting phosphor and a red light emitting phosphor (second phosphor) that emits fluorescence having a peak wavelength in a wavelength range of 630 nm or more and 650 nm or less in order to improve color rendering. It is preferable to include.

Further, the light emitting unit 2 is a rectangular 1.5 mm × 4 mm × 0.5 mm, the area of the light receiving surface of the light-emitting portion 2 that laser light is irradiated (cross-section) is 6 mm ^2. In addition, the light emission part 2 may not be a rectangular parallelepiped, but may be a cylindrical shape.

(Diffusion part 3)
The diffusing unit 3 diffuses and scatters laser light emitted outside without passing through the light emitting unit 2. For example, the diffusion unit 3 is provided around the light emitting unit 2 without a gap and has the same thickness as the light emitting unit 2. For this reason, a laser beam with a very small emission point emitted from the excitation light source unit (excitation light source) 6 can be emitted to the outside by expanding the emission point, thereby suppressing the influence on the human body (for example, making it eye-safe). Can do.

The size of the diffusing unit 3 may be any size as long as all of the laser light not irradiated on the light emitting unit 2 is irradiated. Moreover, the diffusion part 3 does not need to be provided with the same thickness around the light emitting part as long as the laser light that has not been irradiated onto the light emitting part 2 can be sufficiently diffused to increase the size of the light emitting point. For example, the diffusing unit 3 may have a larger cross section than the light emitting unit 2 and may be laminated on the surface of the light emitting unit 2 facing the laser light incident side. The diffusion part 3 is obtained by mixing low-melting glass with fine powder of aerosil or Al ₂ O ₃ (about 10 nm to 5 μm) in a weight ratio of about 10 to 30%. Similar to the light emitting unit 2, the diffusion unit 3 is bonded (or fused) to the translucent substrate 1.

For example, when the light emitting unit 2 has a function of diffusing laser light, or when the lens 82 has a filter function of blocking laser light, the diffusing unit 3 is not necessarily provided. . For example, when the light emitting unit 2 has a diffusing function, it can be realized by utilizing the difference between the refractive index of the sealing material included in the light emitting unit 2 and the phosphor. Therefore, the light emitting unit 2 is designed so as to have a deposition (particularly thickness) that can sufficiently diffuse the laser beam. Further, the diffusion function of the light emitting unit 2 may be realized by including diffusing particles (such as zirconium oxide or diamond) in the light emitting unit 2.

(Reflector 4)
The reflecting mirror 4 reflects the light emitted from the light emitting unit 2 to form a light beam that travels within a predetermined solid angle. That is, the reflecting mirror 4 reflects the light from the light emitting unit 2 to form a light bundle that travels forward of the headlamp 60. The reflecting mirror 4 is, for example, a curved surface (cup shape) member having a metal thin film formed on the surface thereof.

Further, the reflecting mirror 4 is not limited to a hemispherical mirror, and may be an ellipsoidal mirror, a parabolic mirror, or a mirror having a partial curved surface thereof. That is, the reflecting mirror 4 only needs to include at least a part of a curved surface formed by rotating a figure (ellipse, circle, parabola) about the rotation axis on the reflecting surface. Further, the shape of the opening in the reflecting mirror 4 is not limited to a circle. The shape of the opening can be determined as appropriate according to the design of the headlamp 60 and its surroundings.

(Fixing member 56)
The fixing member 56 is a plate-like member having an insertion port through which the light guide member 9 is inserted, and the center of the light emitting end portion of the light guide member 9 and the center of the light receiving surface of the light emitting portion 2 substantially coincide with each other. As described above, the reflecting mirror 4 is fixed by a screw 78. The excitation light source unit 6 is joined to the fixing member 56 so as to surround the insertion port. Although the material of the fixing member 56 is not particularly limited, metals such as iron and copper can be exemplified.

Further, the fixing member 56 is formed with a storage portion 51 in which the support member 61 can be stored. Due to the presence of the storage portion 51, the support member 61 can be moved in the optical axis direction of the laser beam in accordance with the drive of the support member drive portion 62. By this movement, the laser light irradiation area (laser light irradiation region 79 (see FIG. 24)) in the light emitting section 2 (transparent member 1) can be changed. Details of the relationship between the movement of the light emitting unit 2 and the laser light irradiation region 79 will be described later with reference to FIGS. 24 and 25.

(Excitation light source unit 6)
The excitation light source unit 6 is a housing that houses, for example, three semiconductor lasers (excitation light sources) 63. Regarding the fixing method and wiring method of the semiconductor laser 63, the conventional fixing method and wiring method may be used, and the description thereof is omitted here.

The semiconductor laser 63 is a light emitting element that functions as an excitation light source that emits excitation light. In this embodiment, a case where a semiconductor laser is used as an excitation light source will be described. However, for example, an LED may be used. In the case of a semiconductor laser, the light emitting unit 2 can be irradiated with laser light having high output and high coherency, so that the light emitting unit 2 can be made small and a high-intensity headlamp 60 can be realized. Although three semiconductor lasers 63 are illustrated in FIG. 22, it is not always necessary to provide a plurality of semiconductor lasers 63, and only one semiconductor laser 63 may be provided. However, it is easier to use a plurality of semiconductor lasers 63 in order to obtain high output pump light.

The semiconductor laser 63 has, for example, one light emitting point per chip, oscillates 450 nm (blue) laser light, has an output of 1.6 W, an operating voltage of 4.7 V, and a current of 1.2 A. , Enclosed in a metal package (stem) having a diameter of 9 mm. Therefore, the output as the whole excitation light source unit 6 is about 4.8W.

However, the metal package is not limited to one having a diameter of 9 mm, and may be, for example, a diameter of 3.8 mm, a diameter of 5.6 mm, or other, and it is preferable to select a package having a smaller thermal resistance. The semiconductor laser 63 may have a plurality of light emitting points on one chip. The oscillation wavelength of the semiconductor laser 63 is not limited to 450 nm, and may be any wavelength in the blue region from 440 nm to 480 nm.

(Lens 82)
Next, the lens 82 is provided in the opening of the reflecting mirror 4 and seals the headlamp 60. The fluorescence emitted from the light emitting unit 2, the scattered light scattered by the diffusion unit 3, or the fluorescence or scattered light reflected by the reflecting mirror 4 is emitted through the lens 82 to the front of the headlamp 60.

The lens 82 may be a convex lens or a concave lens. In addition, the lens 82 does not necessarily have a lens function, and transmits the fluorescence emitted from the light emitting unit 2, the scattered light scattered by the diffusion unit 3, or the fluorescence reflected by the reflecting mirror 4 or the scattered light. What is necessary is just to have at least light property.

(Light guide member 9)
The light guide member 9 guides the laser beam oscillated by the semiconductor laser 63 to the light emitting unit 2, and includes an incident end (semiconductor laser 63 side) on which the laser beam emitted from the semiconductor laser 63 is incident, and an incident end. A light emitting end (on the light emitting unit 2 side) that emits laser light incident from the light source.

In addition, the light guide member 9 has a surrounding structure surrounded by a light reflection side surface that reflects the laser light incident on the incident end portion, and the light emitting member 9 has a light emitting end portion (on the light emitting portion 2 side) cut off. The area is smaller than the cross-sectional area of the incident end.

Specifically, the light guide member 9 has a rectangular pyramid-shaped cylindrical shape as a whole, and a cross section (opening) of the exit end is a rectangle of 1 mm × 3 mm, and a cross section of the incident end (opening). ) Is a rectangle of 15 mm × 15 mm. The shape of the light guide member 9 is not limited to the quadrangular frustum shape, and various shapes such as a polygonal frustum shape other than the quadrangular frustum shape, a frustum shape, and an elliptic frustum shape can be employed. The length from the incident end to the exit end is 25 mm.

With this surrounding structure, the light guide member 9 can emit the laser light incident on the incident end portion to the light emitting portion 2 after condensing the laser light on the emission end portion having a smaller cross-sectional area than the incident end portion. For this reason, even if it aims at high output using the some semiconductor laser 63, the light emission part 2 can be designed small. That is, it is possible to realize a headlamp 60 with high output and high brightness.

The laser light may be condensed on the light emitting unit 2 using an optical fiber or an optical lens instead of the light guide member 9.

(Support member 61)
The support member 61 supports the translucent substrate 1 including the light emitting unit 2, and can move the translucent substrate 1 in the optical axis direction of the laser light in conjunction with the drive of the support member driving unit 62. It is. As the support member 61 moves, the position of the light emitting unit 2 can be changed. As a result, when the optical path width of the laser light emitted from the light guide member 9 increases (or decreases) in proportion to the distance from the light guide member 9, the size of the laser light irradiation region 79 (see FIG. 24) is increased. It can be changed.

Further, the support member 61 is provided so as to come into contact with the gear of the support member driving unit 62, and a groove is provided on the contact surface so as to mesh with the gear. As a result, the support member 61 can move in accordance with the drive of the support member drive unit 62. Note that the surface of the support member 61 may have any shape as long as it operates in conjunction with the gear, and may not be particularly processed.

The material of the support member 61 is not particularly limited. However, considering that the support member 61 is inserted into the reflecting mirror 4 due to its movement, the material of the support member 61 is a material having translucency, similar to the translucent substrate 1. Is preferred. Further, the shape of the support member 61 may be a flat plate shape or a rod shape. Further, the support member 61 may be formed integrally with the translucent substrate 1.

In the present embodiment, the support member 61 is described as moving in the optical axis direction of the laser beam. However, if the size of the laser beam irradiation region 79 can be freely changed, the optical axis is not necessarily required. There is no need to move in the direction.

For example, the storage portion 51 of the support member 61 and the fixing member 56 may be provided so as to be movable in a direction having a predetermined angle from the optical axis of the laser beam. In addition, the support member 61 may be provided in a direction perpendicular to the optical axis direction of the laser light, and a storage portion in which the support member 61 can be stored may be provided in the reflecting mirror 4 so that the support member 61 can move in that direction. In this case, the light emitting unit 2 can be moved in a direction perpendicular to the optical axis direction of the laser light, and the irradiation region irradiated on the light emitting unit 2 in the laser light irradiation region 79 can be changed (FIG. 25). (See (a)).

(Supporting member driving unit 62)
The support member driving unit 62 is for moving the support member 61 in the direction of the optical axis of the laser beam, and includes, for example, a stepping motor and a gear, and is provided for each support member 61. The gear is provided such that the surface thereof is in contact with the support member 61 and the rotation axis thereof is in a direction perpendicular to the moving direction of the support member 61. One gear may be provided for the support member 61 or a plurality of combinations may be included. Moreover, the stepping motor should just be provided so that the rotation can be propagated to a gear.

In the support member driving unit 62, when a movement instruction is received from the movement control unit 641 (see FIG. 23), the stepping motor is driven and the gear rotates. Since the gear and the support member 61 are provided in contact with each other, the rotational force of the gear is transmitted to the support member 61 and moves the support member 61 in the optical axis direction of the laser beam.

In this way, the support member drive unit 62 changes the amount of laser light applied to the light emitting unit 2 by changing the distance between the light emitting unit 2 and the light guide member 9 via the support member 61, and also the light emitting unit. It is possible to change the light amount of the laser light that is not irradiated onto 2 but directly becomes illumination light. That is, since the balance between the amount of fluorescent light and the amount of laser light contained in the illumination light can be changed, the color temperature of the illumination light can be changed.

In other words, the support member driving unit 62 changes the ratio of laser light that is not converted into fluorescence by the light emitting unit 2 in the laser light emitted from the semiconductor laser 63 (hereinafter referred to as a conversion ratio). By changing the conversion ratio and changing the amount of laser light that is not converted to fluorescence, the ratio of fluorescence to illumination light changes, so that the color temperature of the illumination light can be changed. The relationship between the ratio of fluorescence and the change in color temperature of illumination light will be described later with reference to FIGS.

<Further structure of the headlamp 60>
Next, a further configuration of the headlamp 60 will be described with reference to FIG. FIG. 23 is a block diagram illustrating an example of a schematic configuration of the headlamp 60. The headlamp 60 includes an input unit 613 (input means), a control unit 614, and a storage unit 615 in addition to the components shown in FIG. Since the support member driving unit 62 and the semiconductor laser 63 have been described above, description thereof will be omitted. In the present embodiment, these members are described as components of the headlamp 60. However, the present invention is not limited to this. For example, an input unit, a control unit, and a storage unit included in a vehicle or the like to which the headlamp 60 is attached. May be realized.

(Input unit 613)
The input unit 613 receives user operations such as a drive instruction of the support member drive unit 62 and an output change instruction of the semiconductor laser 63, and is realized by a touch pad or the like.

For example, when the input unit 613 receives a driving instruction as a user operation, the movable control unit 641 operates the support member driving unit 62 according to the received user operation. In this case, the user can give the above-described driving instruction via the input unit 613 while confirming the intensity of the illumination light with his / her eyes, so that the support member 61 can be driven each time the user performs an operation. . Therefore, the color temperature of the illumination light can be changed according to the user preference.

(Control unit 614)
The control unit 614 mainly includes a movable control unit 641 and an output control unit 642. The control unit 614 controls members constituting the headlamp 60, for example, by executing a control program. The control unit 614 reads the program stored in the storage unit 615 into a primary storage unit (not shown) configured by, for example, a RAM (Random Access Memory) and executes the program, thereby driving the support member driving unit 62. Various processes such as control and output control of the semiconductor laser 63 are performed.

The movable control unit 641 performs drive control of the support member drive unit 62 in accordance with the drive instruction received from the input unit 613. For example, every time a drive instruction is received, the movable control unit 641 performs predetermined drive on the stepping motor of the support member drive unit 62. Apply voltage.

The output control unit 642 controls the output of the semiconductor laser 63, and applies, for example, a drive voltage set during manufacture to the semiconductor laser 63. Alternatively, the output control unit 642 applies a predetermined drive voltage to the semiconductor laser 63 every time an output change instruction received from the input unit 613 is received.

(Storage unit 615)
The storage unit 615 records (1) a control program for each unit, (2) an OS program, (3) an application program, and (4) various data to be read when the program is executed by the control unit 614. It is. The control unit 614 is configured by a nonvolatile storage device such as a ROM (Read Only Memory) flash memory. The primary storage unit described above is configured by a volatile storage device such as a RAM. However, in the present embodiment, the storage unit 615 may be described as having the function of the primary storage unit. The storage unit 615 stores, for example, a driving voltage value for the support member driving unit 62 or the semiconductor laser 63.

<About safety>
When light having high energy is emitted from a light source having a small light emitting spot size and the light enters the human eye, the light source image is narrowed down to the small light emitting spot size on the retina. The energy density can be very high. For example, laser light emitted from a laser light source (semiconductor laser) may have a spot size smaller than 10 μm square. When laser light emitted from such a light source is directly incident on the eye or is incident on the eye in such a way that a small light emitting point can be seen directly even through an optical member such as a lens or a reflecting mirror, the imaged portion on the retina is It can be damaged.

In order to avoid this, it is necessary to enlarge the emission point size to some extent (finite size) (specifically, for example, 1 mm × 1 mm or more). By enlarging the emission point size, the image size on the retina can be enlarged, so even if light of the same energy is incident on the eye, the energy density on the retina is reduced. It becomes possible.

In order to increase the light emission point size, it is necessary to make the light emission point of the light source itself invisible. For this reason, in the present embodiment, as described above, the light emitting unit 2 is provided with a diffusion function, and the light emitting point size of the semiconductor laser 63 is increased, thereby ensuring safety for the human body, particularly for human eyes. (I make it safe).

It should be noted that the enlargement of the light emission point size can be considered not only for the laser light source but also for the LED light source. However, since the laser light is more monochromatic than the light emitted from the LED light source, that is, has a uniform wavelength, there is no blurring of the image on the retina (so-called chromatic aberration) due to the difference in wavelength, and it is more dangerous than the light. It is. For this reason, in an illuminating device that uses light emitted from a laser light source as illumination light, it is preferable to firmly consider the expansion of the emission point size.

<Movement control of light emitting unit 2>
(Regarding changes in the laser light irradiation region 79)
Next, FIG. 24 and FIG. 25 are used to describe how the size of the laser light irradiation region 79 changes or how the size (shape) of the laser light irradiation region 79 included in the light receiving surface of the light emitting unit 2 changes. I will explain. Here, in order to make the state easy to understand, the shape of the light emitting section 2 is a cylindrical shape in FIG. 24, a rectangular parallelepiped (light receiving surface is square) in FIG. 25A, and a rectangular parallelepiped (light receiving surface in FIG. 25B). Is assumed to be a rectangle). 24 and 25, the diffusion unit 3 is not shown.

FIG. 24 is a diagram showing the positional relationship between the light emitting unit 2 and the light guide member 9 and the size of the laser light irradiation region 79 at that time. (A) of the figure shows a case where the size of the laser beam irradiation region 79 substantially matches the size of the light receiving surface of the light emitting unit 2. Further, (b) in the figure shows a case where the light emitting unit 2 and the light guide member 9 are separated from each other as compared with the case (a), and (c) shows a case where the light emitting unit 2 and the light emitting unit 2 are guided more than the case (a). The case where the position with the optical member 9 becomes close is shown.

First, as shown in FIG. 24A, when the distance between the light emitting unit 2 and the light guide member 9 is d, the size of the light receiving surface of the light emitting unit 2 and the size of the laser light irradiation region 79 are substantially equal. I'm doing it. In this case, the color temperature of the illumination light assumed at the time of manufacture is realized.

In the present embodiment, considering that the use efficiency of the fluorescent light emitted from the light emitting unit 2 as illumination light is increased, the light emitting unit 2 is positioned at the focal position of the reflecting mirror 4 when the distance is d. Is provided. However, if the utilization efficiency is not taken into consideration, the light emitting unit 2 is not necessarily provided at the focal position of the reflecting mirror 4.

Next, FIG. 24B shows a case where the distance between the light emitting unit 2 and the light guide member 9 is d1 (> d). In this case, when the movable control unit 641 drives the support member driving unit 62, the support member driving unit 62 moves through the support member 61 until the distance between the light emitting unit 2 and the light guide member 9 becomes d1. I am letting. At this time, the size of the laser light irradiation region 79 is larger than the size of the light receiving surface of the light emitting unit 2.

On the other hand, FIG. 24C shows a case where the distance between the light emitting unit 2 and the light guide member 9 is d2 (<d). In this case, as in FIG. 24B, the movable control unit 641 drives the support member driving unit 62 to move the light emitting unit 2 and the light guide member 9 until the distance is d2. At this time, the size of the laser light irradiation region 79 is smaller than the size of the light receiving surface of the light emitting unit 2.

In general, when a condensing member such as a convex lens does not exist between the translucent substrate 1 and the light guide member 9, or when the exit end of the light guide member 9 is not in a shape capable of condensing laser light. The optical path width of the laser light emitted from the light guide member 9 increases in proportion to the distance from the light guide member 9. That is, the laser light irradiation region 79 becomes larger as the light emitting unit 2 is separated from the light guide member 9. The shape of the laser beam in this case is a tapered cone shape (more precisely, an elliptical cone shape). The shape of the laser beam may be a perfect circular cone shape. For the purpose of realizing the cone shape, a condensing member may be provided between the translucent substrate 1 and the light guide member 9. Good.

When the support member driving unit 62 changes the distance d1 within a range larger than d, the size of the laser light irradiation region 79 formed outside the light emitting unit 2 shown in FIG. Can be changed. That is, since the laser light leaking from the light emitting unit 2 can be used as a part of the illumination light, it is possible to realize a change in the color temperature of the illumination light, which is difficult when the illumination light is composed only of fluorescence.

In other words, in this case, the support member driving unit 62 changes the ratio of the laser light that is not irradiated to the light emitting unit 2 in the laser light emitted from the semiconductor laser 63. By changing this ratio, the conversion ratio can be changed, so that the color temperature of the illumination light can be changed. When the laser light that is not irradiated to the light emitting unit 2 increases, the color temperature of the illumination light (laser light + fluorescence) shifts to the laser light (blue region) side. Further, in this case, the amount of laser light applied to the light emitting unit 2 is reduced, so that the amount of fluorescence is also reduced, and the color temperature of the illumination light is further shifted to the laser light side.

On the other hand, the support member driving unit 62 changes the laser beam irradiation region 79 formed on the light receiving surface of the light emitting unit 2 shown in FIG. The size of can be changed. When the laser light irradiation region 79 is small on the light receiving surface of the light emitting unit 2 (when the density of the laser light is high), the phosphor contained in the light emitting unit 2 is insufficient compared to the amount of laser light, or As the temperature of the portion increases, the conversion efficiency to fluorescence decreases. As a result, the amount of transmitted laser light increases, and the color temperature of illumination light can be increased.

Note that the amount of the phosphor contained in the light emitting unit 2 is overwhelmingly larger than the amount of laser light, and the laser light can be transmitted through the light emitting unit 2 to some extent. When a situation occurs in which the amount exceeds a certain amount, when the laser light irradiation region 79 becomes smaller, the amount of laser light transmitted through the light emitting unit 2 becomes smaller than the amount converted to fluorescence. Therefore, in this case, when the size of the laser light irradiation region 79 is reduced, the color temperature of the illumination light is lowered.

In any case, even when the size of the laser light irradiation region 79 on the light receiving surface of the light emitting unit 2 is changed, the change in the color temperature of the illumination light, which is difficult when the illumination light is composed only of fluorescence, is changed. realizable.

In other words, the support member driving unit 62 changes the size (irradiation area) of the laser light irradiation region 79 in the light emitting unit 2 of the laser light emitted from the semiconductor laser 63. Thereby, since said conversion ratio can be changed, the color temperature of illumination light can be changed. When the amount of fluorescence decreases due to a change in the size of the laser light irradiation region 79, the amount of laser light relatively increases, so that the color temperature of the illumination light shifts to the laser light side.

As described above, when the optical path width of the laser light changes according to the distance from the light guide member 9 (semiconductor laser 63), the above conversion ratio depends on the distance between the semiconductor laser 63 and the light emitting unit 2. Change. For this reason, since the support member drive unit 62 can change the conversion ratio by moving the light emitting unit 2 via the support member 61 or the translucent substrate 1, the color temperature of the illumination light is changed. Can be made.

That is, the illumination light emitted from the headlamp 60 of the present embodiment is the light emitting unit in the case of FIG. 24B (when the size of the laser light irradiation region 79 is larger than the light receiving surface of the light emitting unit 2). 2 and the laser light emitted from the semiconductor laser 63 (excitation light that is not converted into fluorescence). 24A and 24C (when the size of the laser light irradiation region 79 is the same as or smaller than the light receiving surface of the light emitting unit 2), the laser light is transmitted through the light emitting unit 2 to some extent. In the case of a possible configuration, it can be said that the illumination light includes fluorescence and laser light.

In the above description, the support member driving unit 62 is configured to move the light emitting unit 2. However, the present invention is not limited thereto, and for example, a configuration in which the conversion ratio is changed by moving the light guide member 9 may be used. .

In the above description, the optical path width of the laser light emitted from the light guide member 9 is increased in proportion to the distance from the light guide member 9, but the optical path width is decreased in proportion to the distance. Even in this case, the conversion ratio can be changed by moving the light emitting unit 2 or the light guide member 9.

(Modification)
24, the case where the light emitting unit 2 has moved in the optical axis direction of the laser beam has been described. However, as shown in FIG. 25, even if the light emitting unit 2 does not move in the optical axis direction, the light receiving surface of the light emitting unit 2 The size of the laser light irradiation region 79 formed on the substrate can be changed. That is, the conversion efficiency can be changed also by the movement (rotation) of the light emitting unit 2 shown in FIG. FIG. 25 is a diagram illustrating how the size (shape) of the laser light irradiation region 79 included in the light receiving surface of the light emitting unit 2 changes.

FIG. 25A shows a case where the light emitting unit 2 moves in a direction perpendicular to the optical axis direction of the laser light. In this case, a part of the laser light leaks to the outside of the light emitting unit 2 due to the movement of the light emitting unit 2 from a state in which the light emitting unit 2 has been irradiated with all the laser light. By using the leaked laser light as illumination light, the color temperature of the illumination light can be increased. Further, by changing the amount of movement, the amount of laser light leaking out of the light emitting section 2 can be changed, so that the color temperature of the illumination light can be changed.

FIG. 25B shows a case where the light emitting unit 2 rotates. Also in this case, as the light emitting unit 2 rotates, the amount of laser light leaking out of the light emitting unit 2 can be changed, so that the color temperature of the illumination light can be changed. In this case, for example, a thin rod-like support member 61 is joined to the central axis of the light emitting unit 2, and a gear of the support member driving unit 62 is provided so as to rotate the support member 61.

(About changes in color temperature)
Next, the relationship between the laser light emitted from the semiconductor laser 63 and the phosphor included in the light emitting unit 2 and the color temperature of the illumination light at that time will be described with reference to FIG. FIG. 26 is a graph (chromaticity diagram) showing a white chromaticity range required for a vehicle headlamp. As shown in the figure, the white chromaticity range required for vehicle headlamps is regulated by law. The chromaticity range is inside a polygon having six points 35 as vertices. A curve 33 indicates the color temperature (K: Kelvin).

As shown in the figure, when the oscillation wavelength of the semiconductor laser 63 is 440 nm (chromaticity point 41: blue region) and the phosphor has a peak wavelength of 570 nm (chromaticity point 42: yellow region), the support member driving unit 62 is By changing the conversion ratio, the color temperature of the illumination light can be changed in the chromaticity range on the straight line 39. In this case, the color temperature can be changed over a wide range from about 4500K to 8500K.

The oscillation wavelength of the semiconductor laser 63 is 475 nm (chromaticity point 44: blue region), and the peak wavelength of the phosphor is 580 nm (chromaticity point 45 (x = about 0.5, y = about 0.49): yellow region. In the case of), the support member driving unit 62 can change the conversion ratio, thereby changing the illumination light in the chromaticity range on the straight line 43. In this case, the color temperature can be changed over a very wide range of about 3000K to 20000K.

The basic structure of the semiconductor laser 63 is the same as the basic structure of the LD chip 11 described with reference to FIGS. 3C and 3D in the first embodiment, and therefore the description thereof is omitted. Further, the light emission principle of the light emitting unit 2 is the same as the light emission principle of the light emitting unit 2 described in the first embodiment, and thus the description thereof is omitted.

<Variation 1 of the headlamp 60>
FIG. 27 is a view showing a modification of the headlamp 60. The headlamp 60 includes a convex lens 161 (optical member) that bends the laser light emitted from the semiconductor laser 63 and emits the light to the light emitting unit 2 between the translucent substrate 1 and the light guide member 9. The support member 61 is provided on a part of the outer periphery of the convex lens 161. That is, in the headlamp 60, the support member driving unit 62 moves the convex lens 161 instead of the light emitting unit 2, thereby realizing a change in the color temperature of the illumination light.

Specifically, by providing the convex lens 161, the optical path width of the laser light after passing through the convex lens 161 is different from the optical path width of the laser light before entering the convex lens 161, as shown in FIG. It can be emitted so as to change according to the distance. That is, the laser light is transmitted through the convex lens 161, and the optical path width is newly changed with the convex lens 161 as a base point. For this reason, since said conversion ratio changes according to the distance of the convex lens 161 and the light emission part 2, when the support member drive part 62 changes the distance, the color temperature of illumination light can be changed as a result. it can.

In the case of a lens having a sufficiently long focal length with respect to the optical path of the laser light emitted from the light guide member 9, the optical path width of the laser light can be changed as shown in FIG. For this reason, as the convex lens 161, a biconvex lens, a plano-convex lens or the like having a sufficiently long focal length can be used. In addition, when the laser light emitted from the light guide member 9 is parallel and thin laser light, a concave lens such as a biconcave lens or a plano-concave lens can be used instead of the convex lens 161. That is, the convex lens 161 may be any lens that can change the emission angle of the incident laser light, and may be an aspherical lens as long as it has the function.

The convex lens 161 is preferably coated with an optical film (reflection film) that prevents reflection of laser light. In addition, the shape and material of the convex lens 161 are not particularly limited as long as the lens has the above function, but it is preferable that the transmittance of 440 to 480 nm is high.

<Modification 2 of the headlamp 60>
FIG. 28 is a view showing another modification of the headlamp 60. The case where the optical axis of the laser light coincides with the straight line l passing through the center of the light emitting unit 2 and the optical path width of the laser light is increased in proportion to the distance from the light guide member 9 is described above. did. In this modification, when the optical path width of the laser light applied to the light emitting unit 2 is constant (parallel light), the support member driving unit 62 (not shown) is connected to the excitation light source unit 6 (semiconductor laser 63) and the light guide. For example, the optical member 9 is rotated about the light emitting unit 2 to change the incident angle of the laser light with respect to the light emitting unit 2. The headlamp 60 in FIG. 28 includes a lens 25.

(Lens 25)
The lens 25 is a lens that emits laser light emitted from the light guide member 9 as parallel light. If it is a lens which has the function, the shape and material of the lens 25 will not be specifically limited, However, It is preferable that it is a material with the high transmittance | permeability of 450 nm vicinity, and favorable heat resistance.

(Regarding changes in the laser light irradiation region 79)
FIG. 28A shows the laser beam when the incident angle of the laser beam emitted from the light guide member 9 with respect to the light receiving surface of the light emitting section 2 is 90 degrees (the optical axis of the laser beam coincides with the straight line l). The size of the irradiation area 79 is shown. On the other hand, FIG. 28B shows the case where the incident angle of the laser light emitted from the light guide member 9 with respect to the light receiving surface of the light emitting portion 2 is 60 degrees (the optical axis of the laser light does not coincide with the straight line l). The size of the laser beam irradiation region 79 is shown. When the excitation light source unit 6 and the light guide member 9 are moved from the position shown in FIG. 28A to the position shown in FIG. 28B, the luminous flux of the laser light emitted from the light guide member 9 is not changed. The laser beam irradiation region 79 is enlarged due to the change in the incident angle.

In other words, the support member driving unit 62 changes the incident angle of the laser light incident on the light emitting unit 2 to change the laser light not irradiated on the light emitting unit 2 with respect to the total amount of laser light emitted from the light guide member 9. The ratio of can be changed. That is, even when the optical path width of the laser light emitted from the light guide member 9 is constant (parallel light), the color temperature of the illumination light can be changed by changing the incident angle. .

In FIG. 28, the case where the laser light irradiation region 79 is larger than the light receiving surface of the light emitting unit 2 has been described. However, even when the laser light irradiation region 79 is entirely included in the light receiving surface, the incident angle is changed. Thus, the color temperature of the illumination light can be changed. 28, the case of parallel light has been described. However, as described above, the lens 25 is not provided, and the optical path width of the laser light increases (or decreases) in proportion to the distance from the light guide member 9. Even if it exists, the effect similar to the case of FIG. 28 is acquired.

<Effect of headlamp 60>
As described above, the headlamp 60 includes the support member driving unit 62 that changes the ratio of the laser light that is not converted into fluorescence by the light emitting unit 2 in the laser light emitted from the semiconductor laser 63. Thereby, since the ratio of the fluorescence with respect to illumination light changes, the color temperature of illumination light can be changed.

In particular, in the present embodiment, an example of the configuration of the headlamp 60 that uses laser light as illumination light is shown. In this case, under the condition that the total amount of light (total luminous flux) of the laser light is constant, if the amount of laser light that is not converted to fluorescence changes, the amount of fluorescence changes, so the laser light that has not been converted to fluorescence itself The effect on the illumination light changes.

Specifically, in the present embodiment, as described with reference to FIGS. 24 to 26, under the above conditions, the support member driving unit 62 has the size of the laser light irradiation region 79 and the light receiving surface of the light emitting unit 2. By changing the ratio of the laser beam irradiation region 79 to the laser beam, the amount of laser beam that is not converted into fluorescence is changed. Then, for example, in the case of FIG. 24B and FIG. 24C, the ratio increases due to phosphor shortage relative to the amount of laser light or temperature rise of the light emitting unit 2 due to laser light irradiation. On the other hand, in the case of FIG. 24C, when the laser beam can be transmitted through the light emitting unit 2 to some extent, the light amount of the laser beam is reduced and the above ratio is reduced. As described above, when the size (ratio) of the laser light irradiation region 79 is changed, the influence of the laser light itself that has not been converted into fluorescence on the illumination light is changed.

As a result, the headlamp 60 changes the ratio of the fluorescence to the illumination light (the amount of fluorescence finally used as the illumination light), so that the color temperature of the illumination light can be changed.

[Embodiment 6]
The following will describe another embodiment of the present invention with reference to FIG. FIG. 29 is a diagram showing a schematic configuration of the headlamp 70 (illumination device, headlamp). In addition, about the member similar to Embodiment 5, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

Unlike the above-described headlamp 60, the headlamp 70 according to the present embodiment includes a semiconductor laser 63 and a light emitting diode 64 (second light source). The headlamp 70 includes a light guide 513 that guides the excitation light emitted from the semiconductor laser 63 to the light emitting unit 2, and a light guide 514 that guides the blue light from the light emitting diode 64 to the reflection member 26. Yes.

(Light emitting diode 64)
The light emitting diode 64 emits light (second light) different from the laser light emitted from the semiconductor laser 63. The different light refers to incoherent light emitted from the light emitting diode 64, for example. The light emitted from the light emitting diode 64 has the same wavelength as the oscillation wavelength of the semiconductor laser 63. That is, the light emitted from the light emitting diode 64 is blue light.

(Light guide part 513/514)
The light guides 513 and 514 are truncated cone-shaped light guide members, which are optically coupled to the semiconductor laser 63 and the light emitting diode 64 and have the same functions as the light guide member 9. The light guides 513 and 514 may have a truncated pyramid shape, and the shape is not limited.

(Reflecting mirror 4, support member 61, support member drive unit 62)
Further, a support member 61 is joined to the light guide 513 in order to move the light guide 513 in the optical axis direction of the laser light. For this reason, the light guide part 513 can be moved by the support member drive part 62 moving the support member 61. However, in the present embodiment, it is not necessary to use the laser light leaking from the light emitting unit 2, so that in principle, the entire laser light irradiation region 79 is designed to be within the light receiving surface of the light emitting unit 2.

In addition, the reflecting mirror 4 is provided with a storage portion 46 so that the support member 61 can be moved. The storage unit 46 has the same function as the storage unit 51.

(Light Emitting Unit 2 / Reflecting Member 26)
The reflecting member 26 reflects the light emitted from the light emitting diode 64 to the reflecting mirror 4. The shape and material of the reflection member 26 may be any as long as it has the reflection function. Further, the light emitting unit 2 and the reflecting member 26 are provided at the focal position of the reflecting mirror 4 in order to increase the use efficiency of the fluorescence emitted from the light emitting unit 2 and the light emitted from the light emitting diode 64 as illumination light. preferable.

In addition, instead of the reflecting member 26, the diffusing unit 3 may be provided to diffuse the light emitted from the light emitting diode 64. Moreover, the structure which makes the said light directly as illumination light, without providing the reflection member 26 may be sufficient.

(Effect of headlamp 70)
The headlamp 70 includes a light emitting diode 64 that is a light source different from the semiconductor laser 63, so that the light emitted from the light emitting diode 64 can be used as part of the illumination light. In this case, the support member driving unit 62 changes the conversion ratio and changes the amount of fluorescence, thereby changing the ratio of the fluorescence to the illumination light (the amount of fluorescence finally used as the illumination light). be able to. Thereby, the color temperature of illumination light can be changed. That is, in the headlamp 70, the color temperature change of the illumination light can be realized without using the laser light emitted from the semiconductor laser 63.

[Embodiment 7]
The following will describe an embodiment of the present invention with reference to FIG. FIG. 30 is a diagram illustrating a schematic configuration of a headlamp 80 (illumination device, headlamp). In addition, about the member similar to

Embodiment

5 and 6, the same code | symbol is attached | subjected and the description is abbreviate | omitted. The headlamp 80 according to the present embodiment is different from the above-described headlamp 70 in that the

semiconductor lasers

63a and 63b (first excitation light source and second excitation light source) and the

light emission units

24a and 24b (first light emission unit and second light emission). Part).

(

Semiconductor lasers

63a and 63b)
The

semiconductor lasers

63a and 63b have the same function as the semiconductor laser 63, but their oscillation wavelengths are different. For example, the oscillation wavelength of the semiconductor laser 63a is the same as that of the semiconductor laser 63 (wavelength of 450 nm or more and 480 nm or less) in order to mainly excite the yellow light emitting phosphor efficiently. On the other hand, the oscillation wavelength of the semiconductor laser 63b is an oscillation wavelength in the vicinity of 405 nm in order to mainly excite the green light emitting phosphor efficiently. In other words, the semiconductor laser 63b emits a second laser beam (second excitation beam) having an oscillation wavelength different from that of the laser beam (first excitation beam) emitted from the semiconductor laser 63a.

(Light emitting part 24a / 24b)
Like the light emitting unit 2, the light emitting unit 24a includes a yellow light emitting phosphor, and receives the laser light emitted from the semiconductor laser 63a to emit fluorescence (first fluorescence). On the other hand, the light emitting unit 24b includes a green light emitting phosphor, and receives the second laser light emitted from the semiconductor laser 63b to emit fluorescence (second fluorescence). Similarly to the light emitting unit 2, the

light emitting units

24a and 24b may include a red light emitting phosphor in order to improve color rendering.

(Reflecting mirror 4, support member 61, support member drive unit 62)
In the present embodiment, in order to move the light guides 513 and 514 in the optical axis direction of the laser light, the support members 61 are joined to the light guides 513 and 514, respectively. Also in the present embodiment, as in the sixth embodiment, it is not necessary to use the laser light leaking from the

light emitting portions

24a and 24b. Therefore, in principle, all of the laser light irradiation regions 79 are light receiving surfaces of the

light emitting portions

24a and 24b. Designed to fit within.

Further, in order to enable the movement of each of the support members 61, the reflecting mirror 4 is provided with storage portions 46 at two locations.

(Effect of headlamp 80)
The headlamp 80 includes a plurality of excitation light sources and light emitting units, and when using fluorescence emitted from each light emitting unit (including at least fluorescent light of different colors) as illumination light, the amount of the fluorescence changes. The ratio of each fluorescence to the illumination light changes.

Specifically, the support member driving unit 62 moves the two support members 61 separately, so that the laser beams emitted from the

light guide units

513 and 514 are formed on the light receiving surfaces of the

light emitting units

24a and 24b. Each size of the light irradiation region 79 can be changed separately. In other words, the support member driving unit 62 has a ratio of the laser light that is not converted into fluorescence by the light emitting unit 24a in the laser light emitted from the semiconductor laser 63a, and the light emission of the laser light emitted from the semiconductor laser 63b. At least one of the proportions of the second laser light that is not converted into fluorescence by the unit 24b is changed.

As a result, the amount of fluorescence emitted from each of the

semiconductor lasers

63a and 63b changes, and the ratio of each fluorescence to the illumination light changes. Therefore, the amount of fluorescence finally used as illumination light changes, and the illumination light The color temperature can be changed. That is, also in the headlamp 80, the color temperature change of the illumination light can be realized without using the laser light emitted from the

semiconductor lasers

63a and 63b.

<Modification of

Embodiments

6 and 7>
In the

headlamps

70 and 80, the support member driving unit 62 moves only the light guide unit 513 or the

light guide units

513 and 514 via the support member 61, thereby realizing a change in the color temperature of the illumination light. It was. However, the color temperature change of the illumination light may be realized by changing the outputs of the

semiconductor lasers

63, 63a and 63b and the light emitting diode 64.

In this case, for example, the input unit 613 acquires an output change instruction, and the output control unit 642 controls the output of the

semiconductor lasers

63, 63a and 63b or the light emitting diode 64 according to the instruction. In other words, the output control unit 642 functions as a light amount changing mechanism that changes at least one of the output of the laser light emitted from the semiconductor laser 63 and the output of the second light emitted from the light emitting diode 64. Alternatively, the output control unit 642 functions as a light amount changing mechanism that changes at least one of the output of the laser light emitted from the semiconductor laser 63a and the output of the second laser light emitted from the semiconductor laser 63b.

[Embodiment 8]
In the present embodiment, a laser downlight 200 as an example of an illumination device of the present invention will be described based on FIG.

A laser downlight 200 according to the present embodiment includes an excitation light source unit 6a including at least one semiconductor laser 63 that emits laser light, and at least one light emitting unit 210 including a light emitting unit 2 and a recess 212 as a reflecting mirror. Is provided. Then, the support member driving unit 62 changes the position of the light emitting unit 2 through the support member 61, and thereby the ratio of the laser light that is not converted into fluorescence by the light emitting unit 2 out of the laser light emitted from the semiconductor laser 63 is set. Change. Thereby, since the ratio of the fluorescence with respect to illumination light changes like Embodiment 2, the laser downlight 200 which can change the color temperature of illumination light is realizable.

As shown in FIG. 31, except that the LD chip 11 shown in FIG. 8 of the first embodiment is replaced with the semiconductor laser 63, and the translucent plate 213 has the same function as the lens 82. Since the configuration is the same as that of the laser downlight 200 described in the first embodiment, the description thereof is omitted.

[Another Expression of Inventions According to Embodiments 5 to 8]
The inventions according to Embodiments 5 to 8 can be expressed as follows.

That is, an illumination device (laser illumination light source) according to an embodiment of the present invention relates to a laser illumination light source including a phosphor light emitting unit and a semiconductor laser that is an excitation light source. Excitation light is irradiated from a region smaller than the size of the phosphor light emitting part to an area exceeding it (that is, excitation light irradiation area ≦ phosphor light emitting part area ≦ excitation light irradiation area), and the excitation light irradiation area is changed. The color temperature is changed by changing the ratio of fluorescence.

The laser illumination light source uses a blue semiconductor laser as an excitation light source, and as a phosphor, a yellow phosphor that emits yellow light, or a green phosphor that emits green light and a red phosphor that emits red light. Is preferred.

[Additional Notes on Embodiments 5 to 8]
The visibility of an object when the object is irradiated with illumination light varies depending on the color temperature of the illumination light. Since the lighting device of the present invention can change the color temperature by providing the light quantity changing mechanism, for example, a measuring instrument (tester) capable of measuring the visibility is manufactured and installed in the lighting device store. By doing this, it is possible to allow an individual to select a color temperature that suits the taste of the individual. That is, each user can purchase an illumination device that emits illumination light having a color temperature that suits the user's preference. When the illuminating device of the present invention is realized as a vehicle headlamp, the above-mentioned measuring instrument is installed in an automobile dealer so that the above selection can be made when an individual purchases an automobile.

In addition, the storage unit 615 selects information that identifies the owner of the lighting device of the present invention (or an object (such as a vehicle) including the lighting device) or a user who frequently uses the lighting device, and the owner or the user selects it. Information indicating the color temperature may be stored in association with each other. In this case, for example, the input unit 613 acquires information specifying the owner or the user, the movable control unit 641 reads out information indicating the color temperature corresponding to the information from the storage unit 615, and the support member driving unit 62 is moved. Driven to move the support member 61. Thereby, on condition that the color temperature suitable for the owner or the user is stored, the lighting device of the present invention can automatically switch to the color temperature suitable for the preference.

[Embodiment 9]
The following will describe one embodiment of the present invention with reference to FIGS. Here, a headlamp (headlight) 90 for an automobile will be described as an example as an example of the illumination device of the present invention. However, the lighting device of the present invention may be realized as a headlamp of a vehicle other than an automobile or a moving object (for example, a human, a ship, an aircraft, a submersible craft, a rocket), or may be realized as another lighting device. Also good. Examples of other lighting devices include a searchlight, a projector, and a home lighting device.

The headlamp 90 may satisfy the light distribution characteristic standard of the traveling headlamp (high beam), or may satisfy the light distribution characteristic standard of the passing headlamp (low beam).

<Configuration of headlamp 90>
First, based on FIG. 32, the headlamp 90 which is one Embodiment of this invention is demonstrated. FIG. 32 is a half sectional view showing a schematic configuration of the headlamp 90. As shown in FIG. 32, the headlamp 90 includes a translucent substrate 1, a light emitting unit 2, a reflecting mirror 4, a fixing member 56, an excitation light source unit (excitation light source) 6, screws 78, a lens 82, a light guide member 9, A support member 61 and a support member driving unit 62 are provided. The excitation light source unit 6, the light guide member 9, and the light emitting unit 2 form a basic structure of the light emitting device. The support member 61 and the support member drive unit 62 form a basic structure of the irradiation range changing mechanism.

In the present embodiment, the light emitting unit 2 includes a plurality of light emitting units (for example, the first light emitting unit 2a and the second light emitting unit 2b), but it is not particularly necessary to explain each individual light emitting unit. May be collectively referred to as “light emitting unit 2”.

(Translucent substrate 1)
The translucent substrate 1 is a flat member and has translucency at least with respect to the oscillation wavelength of laser light (440 nm to 480 nm in this case) as excitation light. The translucent substrate 1 may have a curved portion instead of a flat plate. However, when the translucent substrate 1 and the light emitting unit 2 are bonded, at least the portion to which the light emitting unit 2 is bonded is From the viewpoint of adhesion stability, a flat surface (plate shape) is preferable.

The translucent substrate 1 is an Al ₂ O ₃ (sapphire) substrate having a length of 10 mm × width of 10 mm × thickness of 0.5 mm. Note that the outer diameter of the light-transmitting substrate 1 illustrated in FIG.

The translucent substrate 1 has the configuration, shape, and connection form with the light emitting unit 2 as described above, so that heat generated from the light emitting unit 2 while fixing (holding) the light emitting unit 2 to the substrate surface. Since heat is radiated to the outside, the cooling efficiency of the light emitting unit 2 can be improved.

Further, the thickness of the translucent substrate 1 shown in FIG. 32 is preferably 30 μm or more and 5.0 mm or less, more preferably 0. More preferably, it is 2 mm or more and 5.0 mm or less. If the thickness of the translucent substrate 1 exceeds 5.0 mm, the rate at which the laser light applied to the light emitting unit 2 is absorbed in the translucent substrate 1 increases, but the heat dissipation effect is greatly improved. In addition, the cost of the member also increases.

(Light emitting part 2)
The light emitting unit 2 emits fluorescence upon receiving laser light emitted from the semiconductor laser 63, and includes a first light emitting unit 2a and a second light emitting unit 2b. In the present embodiment, the second light emitting unit 2b is provided so as to be in contact with the outer periphery of the first light emitting unit 2a. In other words, the first light emitting unit 2a and the second light emitting unit 2b have a double structure. Further, the first light emitting unit 2a is disposed on the translucent substrate 1 so that the optical axis of the laser light emitted from the light guide member 9 passes through the center thereof. In addition, the example of arrangement | positioning of the 1st light emission part 2a and the 2nd light emission part 2b is mentioned later.

The first light emitting unit 2 a includes a first phosphor that emits first fluorescence upon receiving laser light emitted from the semiconductor laser 63 via the light guide member 9. In the present embodiment, a YAG: Ce phosphor (NYAG4454) manufactured by Intematix is used as a yellow phosphor that emits fluorescence having a peak wavelength in the yellow region by receiving laser light in the blue region as the first phosphor. However, the type of phosphor is not limited to this. The YAG: Ce phosphor is an yttrium (Y) -aluminum (Al) -Garnet phosphor activated with Ce. The phosphor manufactured by Intematix has an emission efficiency of 90%, an emission peak wavelength (hereinafter simply referred to as “peak wavelength”) of 558 nm (yellow), chromaticity points of x = 0.444 and y = 0.536. Yes, it is excited well by excitation light of 430 nm to 490 nm. The YAG: Ce phosphor generally has a broad emission spectrum in which an emission peak exists in the vicinity of 550 nm (slightly longer than 550 nm).

The second light emitting unit 2b includes a second phosphor that receives laser light and emits second fluorescence having a peak wavelength different from that of the first fluorescence. In the present embodiment, as the second phosphor, a CaAlSiN ₃ : Eu phosphor (CASN: doped with Eu ²⁺ as a red light-emitting phosphor that emits fluorescence having a peak wavelength in the red region upon receiving laser light in the blue region. Eu phosphor). The kind of the phosphor used for the second phosphor is not limited to this, and for example, SrCaAlSiN ₃ : Eu phosphor doped with Eu ²⁺ (SCASN: Eu phosphor) may be used as the second phosphor.

The first light emitting unit 2a disperses the YAG: Ce phosphor and the second light emitting unit 2b disperses the CASN: Eu phosphor inside the low melting point inorganic glass (refractive index n = 1.760) as a sealing material. Manufactured. The compounding ratio of the YAG: Ce phosphor and the low melting point inorganic glass (low melting point glass) in the first light emitting unit 2a is, for example, about 30: 100. In addition to this, considering the fact that the first light emitting unit 2a diffuses the laser light and uses the color component (for example, blue component) of the laser light, the above blending ratio is preferably about 10: 100. Moreover, although the compounding ratio of CASN: Eu fluorescent substance and low melting glass in the 2nd light emission part 2b is about 20: 100, for example, it does not need to be restricted to this. In addition, the light emitting unit 2 may be one obtained by pressing a fluorescent material.

The sealing material is not limited to the above-mentioned inorganic glass, and may be a so-called organic-inorganic hybrid glass or a resin material such as silicon resin. However, considering heat resistance, the sealing material is preferably made of glass.

In addition, the first phosphor of the first light emitting unit 2a is doped with Eu ²⁺ as a green phosphor emitting a fluorescent light having a peak wavelength in the green region by receiving laser light in the blue region instead of the yellow light emitting phosphor. Alternatively, β-SiAlON: Eu phosphor may be used.

In the above description, each of the first light emitting unit 2a and the second light emitting unit 2b includes one type of phosphor. However, the present invention is not limited thereto, and two or more types of phosphors may be included. For example, the first light emitting unit 2a may include a YAG: Ce phosphor and a β-SiAlON: Eu phosphor, and the second light emitting unit 2b may include a CASN: Eu phosphor and a β-SiAlON: Eu phosphor. Further, at least a part of the phosphors included in the first light emitting unit 2a and the second light emitting unit 2b may be different. For example, the first light emitting unit 2a includes a YAG: Ce phosphor and a CASN: Eu phosphor. The second light emitting unit 2b may include a CASN: Eu phosphor. In particular, when the first light emitting unit 2a includes two types of phosphors that satisfy the complementary color relationship, the first light emitting unit 2a irradiates the first light emitting unit 2a with laser light without diffusing the laser light. Can produce white light.

In general, white light or pseudo white light used as illumination light can be realized by mixing three colors satisfying the principle of color matching, or mixing two colors satisfying a complementary color relationship. Based on the principle of the same color or complementary color, for example, in the headlamp 90, a combination of blue laser light emitted from a semiconductor laser 63 described later and a YAG: Ce phosphor (yellow light emitting phosphor), or the blue A pseudo white color is realized by a combination of a laser beam and a β-SiAlON: Eu phosphor (green light-emitting phosphor) (mixture of two colors satisfying a complementary color relationship).

Specific examples of the green light emitting phosphor include various nitride-based or oxynitride-based phosphors. In particular, since the oxynitride phosphor is excellent in heat resistance and stable with high luminous efficiency, the first light emitting portion 2a with excellent heat resistance and stable with high luminous efficiency can be realized.

Examples of the oxynitride phosphor that emits green light include a β-SiAlON: Eu phosphor and a Ca α-SiAlON: Ce phosphor doped with Ce ³⁺ . The β-SiAlON: Eu phosphor exhibits strong emission with a peak wavelength of about 540 nm by excitation light from near ultraviolet to blue (350 nm to 460 nm). The half width of the emission spectrum of this phosphor is about 55 nm. Further, the Caα-SiAlON: Ce phosphor exhibits strong light emission with a peak wavelength of about 510 nm by near ultraviolet to blue excitation light.

Specific examples of the red light-emitting phosphor include various nitride-based phosphors. For example, examples of the nitride-based phosphor include CASN: Eu phosphor and SCASN: Eu phosphor. The CASN: Eu phosphor emits red fluorescence when its excitation wavelength is 350 nm to 450 nm, its peak wavelength is 649 nm, and its luminous efficiency is 73%. Further, the SCASN: Eu phosphor emits red fluorescence when the excitation wavelength is 350 nm to 450 nm, its peak wavelength is 630 nm, and its luminous efficiency is 70%. These nitride-based phosphors can enhance color rendering properties when combined with the above-described oxynitride phosphors such as the yellow light-emitting phosphor and the green light-emitting phosphor. Examples of nitride phosphors that emit red light include Eu-activated nitride phosphors such as (Mg, Ca, Sr, Ba) AlSiN ₃ : Eu, and (Mg, Ca, Sr, Ba) AlSiN ₃ : Examples include Ce-activated nitride phosphors such as Ce.

In other words, the light emitting unit 2 includes a first light emitting unit 2a including a yellow light emitting phosphor or a green light emitting phosphor and a red light emitting phosphor that emits fluorescence having a peak wavelength in a wavelength range of 630 nm to 650 nm. Two light emitting portions 2b are provided. Thereby, when blue laser light is irradiated to both the 1st light emission part 2a and the 2nd light emission part 2b, the color rendering property as the light emission part 2 whole can be improved.

As another preferred example of the first phosphor and the second phosphor, a semiconductor nanoparticle phosphor using nanometer-sized particles of a III-V compound semiconductor can also be used. One of the characteristics of semiconductor nanoparticle phosphors is that even if the same compound semiconductor (for example, indium phosphorus: InP) is used, the emission color can be changed by the quantum size effect by changing the particle diameter. is there. For example, InP emits red light when the particle size is about 3 to 4 nm. Here, the particle size was evaluated with a transmission electron microscope (TEM).

(Reflector 4)
The reflecting mirror 4 reflects the light emitted from the light emitting unit 2 to form a light beam that travels within a predetermined solid angle. That is, the reflecting mirror 4 reflects the light from the light emitting unit 2 to form a light bundle that travels forward of the headlamp 90. The reflecting mirror 4 is, for example, a curved surface (cup shape) member having a metal thin film formed on the surface thereof.

Further, the reflecting mirror 4 is not limited to a hemispherical mirror, and may be an ellipsoidal mirror, a parabolic mirror, or a mirror having a partial curved surface thereof. That is, the reflecting mirror 4 only needs to include at least a part of a curved surface formed by rotating a figure (ellipse, circle, parabola) about the rotation axis on the reflecting surface. Further, the shape of the opening in the reflecting mirror 4 is not limited to a circle. The shape of the opening can be determined as appropriate according to the design of the headlamp 90 and its periphery.

In consideration of increasing the utilization efficiency of the fluorescent light emitted from the light emitting unit 2 as illumination light, it is preferable that the light emitting unit 2 is provided at the focal position of the reflecting mirror 4. In the present embodiment, the laser light irradiation is set so that the first fluorescence emitted from the first light emitting unit 2a is used as illumination light at the time of manufacture. For this reason, it is preferable that the 1st light emission part 2a is arrange | positioned in the focus position of the reflective mirror 4. FIG.

(Fixing member 56)
The fixing member 56 is a plate-like member formed with an insertion port through which the light guide member 9 is inserted, and the center of the light emitting end portion of the light guide member 9 and the light receiving surface of the light emitting unit 2 (with the translucent substrate 1 and It is fixed to the reflecting mirror 4 with a screw 78 so that the center of the contact surface) substantially coincides with the center. In the light emitting unit 2 shown in FIG. 32, the center of the light emitting end of the light guide member 9 is fixed so that the center of the light receiving surface of the first light emitting unit 2a substantially coincides. The excitation light source unit 6 is joined to the fixing member 56 so as to surround the insertion port. Although the material of the fixing member 56 is not particularly limited, metals such as iron and copper can be exemplified.

Further, the fixing member 56 is formed with a storage portion 51 in which the support member 61 can be stored. Due to the presence of the storage portion 51, the support member 61 can be moved in the optical axis direction of the laser beam in accordance with the drive of the support member drive portion 62. By this movement, the laser light irradiation range (the size of the laser light irradiation region 79 (see FIG. 36)) in the light emitting unit 2 can be changed. Details of the relationship between the movement of the light emitting unit 2 and the laser light irradiation region 79 will be described later with reference to FIG.

The semiconductor laser 63 is a light emitting element that functions as an excitation light source that emits excitation light. In this embodiment, a case where a semiconductor laser is used as an excitation light source will be described. However, for example, an LED may be used. In the case of a semiconductor laser, the light emitting unit 2 can be irradiated with a laser beam having high output and high coherency, so that the light emitting unit 2 can be made small and a high-luminance headlamp 90 can be realized. Although three semiconductor lasers 63 are illustrated in FIG. 32, it is not always necessary to provide a plurality of semiconductor lasers 63, and only one semiconductor laser 63 may be provided. However, it is easier to use a plurality of semiconductor lasers 63 in order to obtain high output pump light.

Thus, the semiconductor laser 63 emits laser light having an oscillation wavelength in the blue region. The first light emitting unit 2a includes at least a YAG: Ce phosphor that emits fluorescence having a peak wavelength in the yellow region as a first phosphor, or a β-SiAlON: Eu phosphor that emits fluorescence having a peak wavelength in the green region. including. With these configurations, the color temperature of the illumination light emitted from the first light emitting unit 2a can be increased. In addition, since the β-SiAlON: Eu phosphor has high luminous efficiency, when the phosphor is used as the first phosphor, the luminous efficiency of the first light emitting unit 2a can be increased.

(Lens 82)
Next, the lens 82 is provided in the opening of the reflecting mirror 4 and seals the headlamp 90. The fluorescence or scattered light emitted from the light emitting unit 2 or the fluorescence or scattered light reflected by the reflecting mirror 4 is emitted to the front of the headlamp 90 through the lens 82.

The lens 82 may be a convex lens or a concave lens. The lens 82 does not necessarily have a lens function, and has at least translucency that transmits the fluorescence or scattered light emitted from the light emitting unit 2 or the fluorescence or scattered light reflected by the reflecting mirror 4. Just do it.

The light guide member 9 has a surrounding structure surrounded by a light reflecting side surface that reflects the laser light incident on the incident end portion, and the cross-sectional area of the output end portion of the light guide member 9 is the incident end portion. It is smaller than the cross-sectional area.

With this surrounding structure, the light guide member 9 can emit the laser light incident on the incident end portion to the light emitting portion 2 after condensing the laser light on the emission end portion having a smaller cross-sectional area than the incident end portion. For this reason, even if it aims at high output using the some semiconductor laser 63, the light emission part 2 can be designed small. That is, a high output and high brightness headlamp 90 can be realized.

(Support member 61)
The support member 61 supports the translucent substrate 1 to which the light emitting unit 2 is bonded, and the translucent substrate 1 can be moved in the optical axis direction of the laser light in conjunction with the drive of the support member driving unit 62. Is something. As the support member 61 moves, the position of the light emitting unit 2 can be changed. As a result, when the optical path width of the laser light emitted from the light guide member 9 increases (or decreases) in proportion to the distance from the light guide member 9, the size of the laser light irradiation region 79 (see FIG. 36) is increased. It can be changed.

(Supporting member driving unit 62)
The support member driving unit 62 is for moving the support member 61 in the direction of the optical axis of the laser beam, and includes, for example, a stepping motor and a gear, and is provided for each support member 61. The gear is provided such that the surface thereof is in contact with the support member 61 and the rotation axis thereof is in a direction perpendicular to the moving direction of the support member 61. One gear may be provided for the support member 61 or a plurality of combinations may be used. Moreover, the stepping motor should just be provided so that the rotation can be propagated to a gear.

In the support member driving unit 62, when a movement instruction is received from the movement control unit 641 (see FIG. 33), the stepping motor is driven and the gear rotates. Since the gear and the support member 61 are provided in contact with each other, the rotational force of the gear is transmitted to the support member 61 and moves the support member 61 in the optical axis direction of the laser beam.

In the present embodiment, at the time of manufacture, the entire light receiving surface of the first light emitting unit 2a is designed to be irradiated with laser light. For this reason, if it uses it with the state at the time of manufacture, the headlamp 90 will radiate | emit the 1st fluorescence emitted from the 1st light emission part 2a as illumination light. Then, when the support member driving unit 62 moves the light emitting unit 2 through the support member 61, the second light emitting unit 2b is also irradiated with laser light, and the second fluorescent light is included in a part of the illumination light. it can.

That is, the support member driving unit 62 changes the relative positions of the light guide member 9 and the first light emitting unit 2a and the second light emitting unit 2b (that is, the relative positions of the semiconductor laser 63 and these light emitting units). Thus, the irradiation range of the laser light applied to the second light emitting unit 2b is changed while the irradiation range of the laser light in the first light emitting unit 2a is made constant. By changing the relative position, the optical path width of the laser light emitted from the semiconductor laser 63 is generally increased according to the distance from the emission point. For this reason, the laser irradiation range (the ratio of the second light emitting unit 2b included in the laser light irradiation region 79) in the second light emitting unit 2b can be changed by the change.

<Further structure of the headlamp 90>
FIG. 33 shows a further configuration of the headlamp 90, but each member shown in FIG. 33 has the same function as each member of the headlamp 60 shown in FIG.

<Example of arrangement of each light emitting unit in the light emitting unit 2>
Next, an arrangement example of the first light emitting unit 2a and the second light emitting unit 2b will be described with reference to FIG. FIG. 34 shows an arrangement example of the first light emitting unit 2 a and the second light emitting unit 2 b in the headlamp 90. (A) is an arrangement example in the case where the entire light emitting unit 2 has a rectangular parallelepiped shape, (b) is an arrangement example in which the first light emitting unit 2a and the second light emitting unit 2b are non-contact, and (c) is the light emitting unit 2. An arrangement example when the whole is a cylindrical shape, (d) shows an arrangement example when the entire light emitting unit 2 has a cylindrical shape and the light emitting unit 2 has a triple structure.

34 shows a configuration of the light emitting unit 2 in which the second light emitting unit 2b is arranged around the first light emitting unit 2a. In the present embodiment, the support member driving unit 62 changes the distance between the light guide member 9 and the light emitting unit 2, thereby irradiating the second light emitting unit 2 b with the first light emitting unit 2 a to irradiate the laser light with the color temperature. Change. Therefore, in the arrangement shown in FIG. 34, the laser light irradiation region 79 (the ratio of the second light emitting unit 2b included in the region) is changed more efficiently than in the arrangement shown in FIG. 40A, for example. be able to.

FIG. 34 (a) shows an arrangement example in the light emitting unit 2 shown in FIG. 32, and the second light emitting unit 2b is provided so as to be in contact with the outer periphery of the first light emitting unit 2a. In this case, the first light emitting unit 2a is a rectangular parallelepiped having a length of 1.5 mm, a width of 4 mm, and a thickness of 0.5 mm, and the second light emitting unit 2b has a hollow portion corresponding to the size of the first light emitting unit 2a. It is a rectangular parallelepiped of 4.5 mm × 7 mm wide × 0.5 mm thick. In addition, the magnitude | size of the 1st light emission part 2a and the 2nd light emission part 2b is not restricted to this. For example, the size of the light receiving surface of the first light emitting unit 2a is such that the light emitting unit 2 includes the entire laser light irradiation region 79 (see FIG. 36) when the distance from the light guide member 9 is the shortest. I just need it. In addition, the size of the light receiving surface of the entire light emitting unit 2 may be a size that includes the entire laser light irradiation region 79 when the light emitting unit 2 is farthest from the light guide member 9. Furthermore, the thicknesses of the first light-emitting part 2a and the second light-emitting part 2b are not limited to the above, and for example, it is preferable to have a thickness that increases the conversion efficiency to fluorescence or the heat dissipation efficiency.

Moreover, although the case where the light receiving surface of the light emitting unit 2 is a rectangle is illustrated, the present invention is not limited thereto, and may be a square. However, considering that the irradiation region formed by the laser light emitted from the semiconductor laser 63 is elliptical and satisfies the light distribution characteristic standard of the vehicle headlamp, the light receiving surface of the light emitting unit 2 is When it is a rectangle, it is preferable that it is a rectangle which has a long axis in a horizontal direction.

In FIG. 34A, for example, two low-melting-point glasses having the above-described shape are manufactured, and a YAG: Ce phosphor is dispersed inside one, and a CASN: Eu phosphor is dispersed inside the other, whereby the first light emitting unit 2a And the 2nd light emission part 2b is manufactured. Then, after positioning the 1st light emission part 2a with respect to the translucent board | substrate 1, the 1st light emission part 2a is adhere | attached on the translucent board | substrate 1. FIG. Similarly, the second light emitting unit 2b is bonded to the translucent substrate 1.

Here, as shown in FIG. 34 (b), a case where the first light emitting unit 2a and the second light emitting unit 2b are arranged in a non-contact manner is shown. In the present embodiment, the laser light emitted from the plurality of semiconductor lasers 63 is designed to be collected by the light guide member 9 and irradiated to the light emitting unit 2. For this reason, when the support member drive unit 62 changes the distance between the light guide member 9 and the light emitting unit 2 and irradiates the second light emitting unit 2b together with the first light emitting unit 2a, the non-contact is performed. Since the region (non-contact region A) is irradiated with the laser beam, the utilization efficiency of the laser beam is reduced accordingly.

In FIG. 34 (a), since the first light emitting unit 2a and the second light emitting unit 2b are arranged in contact with each other, it is possible to prevent a situation in which laser light is irradiated and not converted into fluorescence in the non-contact region A. The laser light can be used for conversion of fluorescence without waste. If this point is not taken into account, or if the headlamp 90 is configured to use the laser light emitted from the non-contact area A as illumination light together with the first fluorescence, FIG. As shown, the 1st light emission part 2a and the 2nd light emission part 2b may be arrange | positioned non-contactingly. 34B, in the headlamp 90, when the light emitting unit 2 is located closest to the light guide member 9, the laser light irradiation region 79 includes all of the first light emitting unit 2a and the non-contact region A. Designed to be

FIG. 34 (c) is a modification of FIG. 34 (a). The first light emitting unit 2a is a cylinder having a diameter of 2.0 mm and a height of 0.5 mm, and the second light emitting unit 2b has a hollow portion corresponding to the size of the first light emitting unit 2a. A cylinder with a thickness of 0.5 mm. The size and shape of the first light emitting unit 2a and the second light emitting unit 2b are preferably determined in consideration of the circumstances shown in FIG. 34 (a). An elliptical shape is preferable.

Further, the light emitting unit 2 is not limited to a double structure, and may have a triple structure as shown in FIG. 34 (d), for example. In FIG. 34 (d), the light emitting section 2 has a hollow portion corresponding to the size of the first light emitting section 2a and the second light emitting section 2b, and has a cylindrical shape with a diameter of 4.0 mm and a height of 0.5 mm. Part 2c is provided. For example, the first light emitting unit 2a includes a YAG: Ce phosphor, the second light emitting unit 2b includes a SCASN: Eu phosphor, and the third light emitting unit 2c includes a CASN: Eu phosphor. In this case, the color temperature can be changed more finely than in the case where the light emitting unit 2 includes two light emitting units. In addition, the light emission part 2 may consist of four or more light emission parts.

Here, in the present embodiment, the headlamp 90 is designed so that the first light emitting portion 2a (main body portion) is irradiated with laser light at the time of manufacture, and then the support member driving portion 62 causes the light emitting portion 2 to be irradiated. It is designed to be irradiated with laser light including the second light emitting part 2b (peripheral part) by being moved. In addition, a phosphor having a shorter peak wavelength than the other light emitting units (for example, the second light emitting unit 2b, the third light emitting unit 2c,...) Is used for the first light emitting unit 2a. In the case of this arrangement, the headlamp 90 emits illumination light having the highest color temperature when used in a state as manufactured, and then moves the light emitting unit 2 away from the light guide member 9. Illumination light having a low color temperature is emitted.

Here, in the case where illumination light having a low color temperature is emitted (second fluorescence is emitted), compared with a case where only the first fluorescence is used as illumination light, the laser light irradiation region 79 (light emitting unit) 2). The illumination area of the illumination light emitted from the light emitting unit 2 is enlarged in front of the vehicle by an optical system such as the reflecting mirror 4 and the lens 82. Generally, visibility and safety are higher when the illuminance of the illumination light is lowered and the front of the vehicle is widely irradiated. For example, when a high beam with high illuminance is turned on during dense fog, the visibility decreases. In the present embodiment, the illumination light having a lower color temperature can irradiate the front of the vehicle more widely. Therefore, it is possible to provide a headlamp suitable for irradiation in bad weather (rainy weather, fog, etc.).

If the above visibility and safety are not taken into account, the phosphor having the longest peak wavelength is used as the first phosphor among the phosphors used in the light emitting unit 2 and used as it is at the time of manufacture. The light emitting unit 2 may be configured to emit illumination light having the lowest color temperature.

In the above description, each light emitting unit is manufactured separately and provided on the translucent substrate 1. However, the present invention is not limited to this, and the light emitting units may be integrally formed. When integrally formed, the manufacturing process and the manufacturing cost can be reduced as compared with the case where each light emitting unit is manufactured separately and provided in the headlamp 90.

When the light emitting units are integrally formed, the light emitting unit 2 is manufactured as follows, for example. First, a sealing material having two different melting points (for example, a low melting point glass) is prepared, and a high melting point sealing material in which phosphors are dispersed is used (a cavity corresponding to the size of the first light emitting portion 2a). The second light emitting portion 2b having a portion is formed. Thereafter, the first light emitting unit 2a made of a low melting point sealing material in which another phosphor is dispersed is formed using the second light emitting unit 2b as an outer frame. Thereby, the integrally formed light emitting part 2 is obtained. Then, after positioning the light emission part 2 with respect to the translucent board | substrate 1, the light emission part 2 is adhere | attached on the translucent board | substrate 1. FIG.

FIG. 35 is a view showing an example of the integrally formed light emitting portion 2, (a) is a cross-sectional view showing an example of the light emitting portion 2 bonded to the translucent substrate 1, and (b) is (a) It is a perspective view which shows an example of the light emission part 2 shown to). As shown in the figure, the first light emitting unit 2a has a so-called mortar shape in which the size of the light receiving surface 201a irradiated with the laser light is larger than that of the emitting surface 202a that emits fluorescence. That is, four surfaces (contact surfaces (wall surfaces) of the first light emitting unit 2a and the second light emitting unit 2b) formed by straight lines connecting the respective vertexes of the light receiving surface 201a and the respective vertexes of the emission surface 202a are in relation to the light receiving surface 201a. The slope is formed. Therefore, when the light receiving surface 201a side of the first light emitting unit 2a is bonded to the translucent substrate 1, for example, the first light emitting unit 2a is a rectangular parallelepiped (the size of the light receiving surface 201a is substantially the same as the size of the emitting surface 202a). Compared with the case where it is, it can prevent that the 1st light emission part 2a remove | deviates from the translucent board | substrate 1, and falls.

The shape of the light emitting unit 2 shown in FIG. 35 is not limited to the case where the first light emitting unit 2a and the second light emitting unit 2b are integrally formed, and the first light emitting unit 2a and the second light emitting unit 2b described above are formed. It can also be realized when manufactured separately.

<Movement control of light emitting unit 2>
(Regarding changes in the laser light irradiation region 79)
Next, how the size of the laser light irradiation region 79 changes will be described with reference to FIG. Here, in order to make the situation easy to understand, it is assumed that the laser light irradiation region 79 has an elliptical shape and the light emitting unit 2 has a rectangular parallelepiped shape.

FIG. 36 is a diagram showing the positional relationship between the light emitting unit 2 and the light guide member 9 and the size of the laser light irradiation region 79 at that time. (A) of the figure shows a case where the size of the laser light irradiation region 79 is the smallest when the laser light is irradiated on the entire light receiving surface of the first light emitting unit 2a. Moreover, (b) of the figure shows the case where the positions of the light emitting unit 2 and the light guide member 9 are farther apart and the laser light irradiation region 79 is larger than in the case of (a), and (c) is (b). The case where the positions of the light emitting unit 2 and the light guide member 9 are separated and the laser light irradiation region 79 is larger than the case of FIG.

First, as shown in FIG. 36A, when the distance between the light emitting unit 2 and the light guide member 9 is d _A , the laser light is irradiated to the entire light receiving surface of the first light emitting unit 2a, and the second light emission. The portion 2b is hardly irradiated. For this reason, emission of illumination light having a high color temperature according to the setting of laser beam irradiation at the time of manufacture is realized. Note that it is sufficient that the entire light receiving surface of the first light emitting unit 2a is irradiated with laser light. For example, if the first light emitting unit 2a has an elliptical shape that is the same shape as the laser light irradiation region 79, only the first light emitting unit 2a is used. Is irradiated with laser light.

Next, FIG. 36B shows a case where the distance between the light emitting unit 2 and the light guide member 9 becomes d _B (> d _A ). This case, the movable control unit 641 drives the supporting member driving unit 62, the supporting member driving unit 62, via the support member 61 until the distance between the light emitting portion 2 and the light guide member 9 is d _B The light emitting unit 2 is moved.

That is, by the above movement, in FIG. 36B, the support member driving unit 62 changes the distance between the light emitting unit 2 and the light guide member 9 from d _A to d _B , so that the laser beam irradiation region 79 is changed. The ratio of the 2nd light emission part 2b contained is larger than the case of Fig.36 (a). Since the second fluorescence can be emitted in addition to the first fluorescence, the proportion of the second fluorescence relative to the illumination light can be increased.

In the present embodiment, since the second phosphor has a longer peak wavelength than the first phosphor, the second fluorescence emitted from the second light emitting unit 2b has a lower color temperature than the first fluorescence. For this reason, the color temperature of illumination light can be made lower than the case of Fig.36 (a) by increasing the ratio of the 2nd fluorescence contained in illumination light.

FIG. 36 (c) shows a case where the distance between the light emitting unit 2 and the light guide member 9 is d _C (> d _B ), and the ratio of the second light emitting unit 2 b included in the laser light irradiation region 79. Is larger than the case of FIG. Therefore, the color temperature of the illumination light can be further reduced.

On the other hand, for example, by moving from the position of the light emitting unit 2 in FIG. 36C to the position of the light emitting unit 2 in FIG. 36A (changing from the distance d _C to the distance d _A ), the second included in the illumination light. Therefore, the color temperature of the illumination light can be increased.

As described above, the support member driving unit 62 changes the size of the laser light irradiation region 79 in the light emitting unit 2 through the support member 61. In other words, the support member driving unit 62 changes the irradiation range of the laser light irradiated to the second light emitting unit 2b while keeping the irradiation range of the laser light in the first light emitting unit 2a constant, thereby changing the illumination range. The ratio of the first fluorescence and the second fluorescence to the light can be changed. For this reason, since the spectrum of the illumination light emitted from the light emitting unit 2 can be changed, not only the color temperature of the illumination light but also the chromaticity of the illumination light and the spectrum included in the illumination light can be changed.

In the above description, the support member drive unit 62 is configured to move the light emitting unit 2. However, the configuration is not limited thereto, and for example, the size of the laser light irradiation region 79 is changed by moving the light guide member 9. There may be.

In the above description, the optical path width of the laser light emitted from the light guide member 9 is increased in proportion to the distance from the light guide member 9, but the optical path width is decreased in proportion to the distance. Even in this case, the size of the laser light irradiation region 79 can be changed by moving the light emitting unit 2 or the light guide member 9. However, in this case, the irradiation state of the laser light in FIG. 36A is realized when the light emitting unit 2 is farthest from the light guide member 9 (d = d _C ), and the laser light irradiation in FIG. The irradiation state is realized when the light emitting unit 2 is closest to the light guide member 9 (d = d _A ).

In the present embodiment, when the distance between the light emitting unit 2 and the light guide member 9 changes from d _A to d _C , the change (movement of the light emitting unit 2) is described as being performed continuously. For example, the light emitting unit 2 may be positioned only when the distances are d _A and d _C. That is, the movement of the light emitting unit 2 may be performed stepwise instead of continuously. In this case, the support member driving unit 62 gradually changes the state in which the laser light irradiation region 79 includes only the first light emitting unit 2a or the region includes the first light emitting unit 2a and the second light emitting unit 2b. Switch to. In addition, also when the light emission part 2 contains three or more light emission parts, a color temperature change is realizable by performing the same switching.

(About changes in color temperature)
Next, the relationship between the laser light emitted from the semiconductor laser 63 and the phosphor included in the light emitting unit 2 and the color temperature of the illumination light at that time will be described with reference to FIG. FIG. 37 is a graph (chromaticity diagram) showing a white chromaticity range required for a vehicle headlamp. As shown in the figure, the white chromaticity range required for vehicle headlamps is regulated by law. The chromaticity range is inside a polygon having six points 35 as vertices. A curve 33 indicates the color temperature (K: Kelvin).

As shown in the figure, when the oscillation wavelength of the semiconductor laser 63 is 440 nm (chromaticity point 41: blue region) and the peak wavelength of the phosphor is 570 nm (chromaticity point 42: yellow region), as shown by a straight line 39, about A color temperature of illumination light from 4500K to 8500K can be realized. On the other hand, when the oscillation wavelength of the semiconductor laser 63 is 440 nm (chromaticity point 41: blue region) and the peak wavelength of the phosphor is 649 nm (chromaticity point 431: red region), as shown by a straight line 441, yellow light is emitted. It can be seen that the color temperature of the illumination light is much lower than when a phosphor is used.

Therefore, as can be seen from the chromaticity diagram shown in FIG. 37, the laser light is also applied to the light receiving surface of the second light emitting unit 2b from the state where the entire light receiving surface of the first light emitting unit 2a is applied. By setting the state, the color temperature of the illumination light can be moved in the red direction, that is, the color temperature can be decreased.

<Modification 1 of Headlamp 90>
FIG. 38 is a view showing a modification of the headlamp 90. This headlamp 90 bends the laser light emitted from the semiconductor laser 63 between the translucent substrate 1 and the light guide member 9, and forms at least one of the first light emitting part 2a and the second light emitting part 2b. A convex lens 161 (optical member) that emits light is provided, and a support member 61 is provided on a part of the outer periphery of the convex lens 161. That is, in the headlamp 90, the support member driving unit 62 moves the convex lens 161 instead of the light emitting unit 2, thereby realizing a change in the color temperature of the illumination light.

Specifically, by providing the convex lens 161, the optical path width of the laser light after passing through the convex lens 161 is different from the optical path width of the laser light before entering the convex lens 161, as shown in FIG. It can be emitted so as to change according to the distance. That is, the laser light is transmitted through the convex lens 161, and the optical path width is newly changed with the convex lens 161 as a base point. For this reason, the distance between the convex lens 161 and the first light emitting unit 2a and / or the second light emitting unit 2b can be changed by moving the convex lens 161. Since the irradiation range of the laser light in the second light emitting unit 2b changes according to the distance between the convex lens 161 and the light emitting unit 2, the support member driving unit 62 changes the distance, resulting in the color temperature of the illumination light. Can be changed.

<Effect of headlamp 90>
The headlamp 90 includes a support member 61 and a support member driving unit 62 that change the irradiation range of the laser light irradiated to the second light emitting unit 2b while keeping the irradiation range of the laser light in the first light emitting unit 2a constant. I have. For this reason, since the ratio of the 1st fluorescence contained in illumination light and the 2nd fluorescence can be changed, the color temperature of illumination light can be changed by the change of the ratio.

In particular, the illumination device according to the present invention irradiates illumination light having a color temperature suitable for the situation in consideration of various surrounding situations (weather, time zone, road illumination conditions, etc.) when driving a car at night. As a result, it is possible to further improve the safety of night driving. Moreover, it can be said that it is an illuminating device which can respond also to such needs.

[Embodiment 10]
The following will describe another embodiment of the present invention with reference to FIGS. FIG. 39 is a diagram showing a schematic configuration of the headlamp 100 (lighting device, headlamp). In addition, about the member similar to Embodiment 9, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

The headlamp 100 according to the present embodiment has a configuration in which the translucent substrate 1a can be moved in a direction perpendicular to the optical axis direction of the laser beam by the translucent substrate driving unit 62a. In FIG. 39, the movement in the vertical direction is realized without the support member 61, but the configuration is not limited thereto, and the movement may be realized via the support member 61.

(Translucent substrate 1a)
The function and material of the translucent substrate 1a are the same as those of the translucent substrate 1 of the ninth embodiment, but the size is, for example, 10 mm long × 15 mm wide × 0.5 mm thick. The length (length in the moving direction) is larger than the size of the opening of the reflecting mirror 4 on the light guide member 9 side. Further, the translucent substrate 1a is provided with a groove on the surface of the translucent substrate 1a on the laser light incident side (light guide member 9 side) so as to mesh with the gear of the translucent substrate driving unit 62a. Yes.

However, considering that the translucent substrate 1a has a function of transmitting laser light, it is preferable that the groove is not provided on the surface facing the surface to which the light emitting unit 2 is bonded. Moreover, as long as it operate | moves interlock | cooperating with a gear, the surface of the translucent board | substrate 1a may be what kind of shape, and it does not need to be processed especially.

(Translucent substrate driving part 62a)
The translucent substrate driving unit 62a includes, for example, a stepping motor and a gear, and moves the light emitting unit 2 in the direction by moving the translucent substrate 1a in a direction perpendicular to the optical axis direction of the laser beam. Is. That is, in the present embodiment, the basic structure of the irradiation range changing mechanism is formed by the translucent substrate driving unit 62a.

The gear is provided such that the surface thereof is in contact with the translucent substrate 1a and the rotation axis thereof is perpendicular to the moving direction of the translucent substrate 1a. There may be one gear or a plurality of combinations. Moreover, the stepping motor should just be provided so that the rotation can be propagated to a gear.

Also, the translucent substrate drive unit 62a moves the translucent substrate 1a in accordance with a movement instruction from the movable control unit 641 (see FIG. 33), as in the ninth embodiment.

In addition, if the ratio of the 1st light emission part 2a and the 2nd light emission part 2b contained in the laser beam irradiation area | region 79 can be changed, the translucent board | substrate drive part 62a will be the translucent board | substrate 1a (namely, light emission part). The configuration is not limited to the configuration in which 2) is moved, and may be a configuration in which the light guide member 9, the excitation light source unit 6 and the like are moved.

(Example of arrangement of light emitting units in the light emitting unit 2)
Next, an arrangement example of the first light emitting unit 2a and the second light emitting unit 2b will be described with reference to FIG. FIG. 40 shows an arrangement example of the first light emitting unit 2 a and the second light emitting unit 2 b in the headlamp 100. (A) is the example of arrangement | positioning in case the 1st light emission part 2a and the 2nd light emission part 2b are the same shape, and are arrange | positioned in contact, (b) is a modification of (a), 1st light emission part 2a and 2nd light emission part 2b when the shape differs, (c) is a modification of (a), the arrangement example when the 1st light emission part 2a and the 2nd light emission part 2b are non-contact Show.

In FIG. 40 (a), the size of the first light emitting unit 2a and the second light emitting unit 2b is 4.5 mm long × 3.5 mm wide × 0.5 mm thick. Is provided. This size is merely an example, and it may be any size in consideration of laser light irradiation, conversion efficiency to fluorescence, heat dissipation efficiency, and the like, as in the ninth embodiment.

When the first light emitting unit 2a and the second light emitting unit 2b are provided in contact with each other, as in the case of the ninth embodiment, for example, when both the light emitting units as shown in FIG. It is possible to prevent a situation in which the non-contact area A is irradiated with laser light and is not converted into fluorescence. Therefore, the laser beam can be used for conversion of fluorescence without waste.

FIG. 40 (b) is a modification of FIG. 40 (a) and shows a case where the first light emitting unit 2a and the second light emitting unit 2b are different in size. In FIG. 40, for example, the size of the first light emitting unit 2a is 4.5 mm long × 3 mm wide × 0.5 mm thick, and the size of the second light emitting unit 2b is 4.5 mm long × 4 mm wide × 0.5 mm thick. It has become. As in FIG. 40A, the size is not limited to this.

In the headlamp 100, the light emitting unit 2 and the like are positioned so that the laser light irradiation region 79 (see FIG. 41 (a)) has a size included in the light receiving surface of the first light emitting unit 2a. For this reason, in the case of FIG. 40B, even when the first light emitting unit 2a is irradiated with laser light (laser light irradiation set at the time of manufacture) as shown in FIG. The second fluorescence can be emitted from the second light emitting unit 2b. For this reason, even if the headlamp 100 is used as it is at the time of manufacture, illumination light having a relatively high color temperature and color rendering can be emitted.

Although not shown, for example, by arranging three or more light emitting units side by side, it is possible to change the color temperature more finely as in FIG. 34 (d).

(Regarding changes in the laser light irradiation region 79)
Next, how the size of the laser light irradiation region 79 changes will be described with reference to FIG. FIG. 41 is a diagram illustrating a change in the size of the laser light irradiation region 79 in the light emitting unit 2. FIG. 41A illustrates a case where only the first light emitting unit 2 a is irradiated with laser light, and FIG. The case where the laser beam is irradiated to both the 1st light emission part 2a and the 2nd light emission part 2b is shown.

In the case of FIG. 41A, as in the ninth embodiment, the first fluorescent light emitted from the first light emitting unit 2a has a color temperature higher than the second fluorescent light emitted from the second light emitting unit 2b. high. For this reason, when only the first light emitting unit 2a is irradiated with laser light, emission of illumination light having a high color temperature according to the setting of laser light irradiation at the time of manufacture is realized.

In FIG. 41 (b), the translucent substrate driving unit 62a moves the translucent substrate 1a from the state of FIG. 41 (a) in the direction perpendicular to the optical axis direction of the laser beam, so that the laser light irradiation region is obtained. The center of the region is moved from the first light emitting unit 2a toward the second light emitting unit 2b with the size of 79 being constant. As a result of this movement, the ratio of the laser light irradiation region 79 included in the first light emitting unit 2a is reduced and the ratio of the laser light irradiation region 79 included in the second light emitting unit 2b is larger than in the case of FIG. Become. As a result, the ratio of the first fluorescence and the second fluorescence to the illumination light emitted from the light emitting unit 2 increases. As described above, since the color temperature of the second fluorescence is lower than that of the first fluorescence, the color temperature can be lowered by increasing the ratio of the second fluorescence.

Further, if the ratio of the second fluorescence is further increased as compared with the case of FIG. 41B, the color temperature of the irradiation light can be further reduced. On the other hand, when the translucent substrate 1a is moved from the state of FIG. 41B to the state of FIG. 41A, the color temperature of the irradiated light can be increased.

(Effect of headlamp 100)
The headlamp 100 includes a translucent substrate driving unit 62a that changes the irradiation range of the laser light applied to the first light emitting unit 2a and the second light emitting unit 2b. For this reason, since the ratio of the 1st fluorescence contained in illumination light and the 2nd fluorescence can be changed, the color temperature of illumination light can be changed by the change of the ratio.

Further, as an example of changing the ratio, the translucent substrate driving unit 62a moves the light emitting unit 2 through the translucent substrate 1a, whereby the light guide member 9, the first light emitting unit 2a, and the second light emitting unit 2 are moved. The relative position with respect to the light emitting portion 2b (that is, the relative position between the semiconductor laser 63 and these light emitting portions) is changed. In this case, since the position of the laser light irradiation region 79 in the first light emitting unit 2a and the second light emitting unit 2b can be changed, the size of the region in each of the first light emitting unit 2a and the second light emitting unit 2b can be changed. it can. As a result, the above ratio can be changed.

[Embodiment 11]
In the present embodiment, a laser downlight 200 as an example of the illumination device of the present invention will be described based on FIGS. 42 and 43.

In the laser downlight 200 according to the present embodiment, the light emitting unit 2 includes a first light emitting unit 2a and a second light emitting unit 2b. FIG. 43 is a diagram showing the positional relationship between the emission end 215a and the light emitting unit 2 when the distance between the emission end 215a and the light emitting unit 2 is the shortest, and the light receiving surface 201a of the first light emitting unit 2a The light-receiving surface 201b of the 2nd light emission part 2b is shown. When the distance between the emission end portion 215a and the light emitting portion 2 is the shortest, each emission end portion 215a is irradiated so that the laser light emitted from the plurality of emission end portions 215a includes at least the entire light receiving surface 201a. , The distance, the size of the light receiving surface 201a, and the like are set.

In addition, as shown in FIG. 42, the LD chip 11 shown in FIG. 8 of the first embodiment is replaced with the semiconductor laser 63, and the light transmitting plate 213 has the same function as the lens 82. Since the configuration is the same as that of the laser downlight 200 described in the first embodiment, the description thereof is omitted.

As described above, the laser downlight 200 according to the present embodiment includes the excitation light source unit 6a including at least one semiconductor laser 63 that emits laser light, the first light emitting unit 2a, the second light emitting unit 2b, and the reflecting mirror. And at least one light emitting unit 210 provided with a concave portion 212. Then, the support member driving unit 62 changes the position of the light emitting unit 2 through the support member 61 to make the irradiation range of the laser light in the first light emitting unit 2a constant, and then irradiate the second light emitting unit 2b. The irradiation range of the laser beam to be changed is changed. As a result, as in the ninth embodiment, the ratio of the second fluorescence emitted from the second light emitting unit 2b to the illumination light changes, so that the laser downlight 200 that can change the color temperature of the illumination light. Can be realized.

In the above description, the case where the light emitting unit 2 shown in FIGS. 34A to 34D (the light emitting unit 2 of the ninth embodiment) is used as the laser downlight 200 has been described as an example. Not limited to this, the light emitting section 2 (the light emitting section 2 of Embodiment 10) shown in FIGS. 40A to 40C can also be used.

In this case, for example, as described in Embodiment 10, the laser downlight 200 does not include the support member 61 but includes the translucent substrate drive unit 62a that can directly move the translucent substrate 1a. . The translucent substrate driving unit 62a moves the translucent substrate 1a in the direction in which the first light emitting unit 2a and the second light emitting unit 2b are arranged in parallel with the emission surface of the emission end 215a. In other words, the translucent substrate driving unit 62a changes the irradiation range of the laser light applied to the first light emitting unit 2a and the second light emitting unit 2b without changing the size of the laser light irradiation region 79. . Thereby, since the ratio of the 1st fluorescence contained in illumination light and the 2nd fluorescence can be changed, the color temperature of illumination light can be changed by the change of the ratio.

Further, as described in the ninth embodiment, by using several kinds of oxynitride phosphors or nitride phosphors as the entire light emitting unit 2, such as using a high color rendering phosphor for the phosphor of the second light emitting unit 2b, The color rendering properties of the illumination light can be improved.

[Another Expression of Inventions in Embodiments 9 to 11]
The present invention can also be expressed as follows.

That is, in the illumination device (laser beam illumination light source) according to the present invention, the phosphor light emitting part has at least a double structure (can be triple or more) of the main body part and the peripheral part, and is included in the main body part and the peripheral part At least a part of the phosphors to be emitted is different and has a mechanism for switching the irradiation area of the excitation light emitted from the excitation light source to only the main body part, and the main body part and the peripheral part. Thereby, the color temperature and chromaticity of the illumination light emitted from the phosphor light emitting unit, and the spectrum included in the illumination light can be changed.

[Additional Notes on Embodiments 9 to 11]
The visibility of an object when the object is irradiated with illumination light varies depending on the color temperature of the illumination light. Since the illumination device of the present invention can change the color temperature by providing the irradiation range changing mechanism, for example, a measuring instrument (tester) capable of measuring the visibility can be manufactured and sold to the store of the illumination device. By installing, it is possible to allow an individual to select a color temperature that suits the taste of the individual. That is, each user can purchase an illumination device that emits illumination light having a color temperature that suits the user's preference. When the illuminating device of the present invention is realized as a vehicle headlamp, the above-mentioned measuring instrument is installed in an automobile dealer so that the above selection can be made when an individual purchases an automobile.

[Embodiment 12]
One embodiment of the present invention will be described below with reference to FIGS. 44 to 48. FIG. Here, as an example of the illuminating device of the present invention, an automotive headlamp (light emitting device, illuminating device, vehicle headlamp, headlamp) 110 will be described as an example. However, the lighting device of the present invention may be realized as a headlamp of a vehicle other than an automobile or a moving object (for example, a human, a ship, an aircraft, a submersible craft, a rocket), or may be realized as another lighting device. Also good. Examples of other lighting devices include a searchlight, a projector, and a home lighting device.

Further, the headlamp 110 may satisfy the light distribution characteristic standard of the traveling headlamp (high beam), or may satisfy the light distribution characteristic standard of the passing headlamp (low beam).

(Configuration of the headlamp 110)
First, the configuration of the headlamp 110 will be described with reference to FIG. FIG. 44 is a cross-sectional view showing the configuration of the headlamp 110. As shown in the figure, the headlamp 110 includes a semiconductor laser array 72, an aspheric lens 29, an optical fiber 55, a ferrule 65, a reflecting mirror 81, a transparent plate 92, a housing 75, an extension 76, The lens 77, the 1st light emission part 93, the 2nd light emission part 94, and the position control part 95 are provided.

(Semiconductor laser array 72 / semiconductor laser 63)
The semiconductor laser array 72 functions as an excitation light source that emits excitation light, and includes a plurality of semiconductor lasers (excitation light sources) 63 on a substrate. Laser light as excitation light is oscillated from each of the semiconductor lasers 63, and the peak wavelength of the laser oscillation is, for example, 405 nm to 490 nm. Note that it is not always necessary to use a plurality of semiconductor lasers 63 as an excitation light source, and only one semiconductor laser 63 may be used. However, in order to obtain a high-power laser beam, it is preferable to use a plurality of semiconductor lasers 63. Easy.

The semiconductor laser 63 has one light emitting point per chip, and oscillates, for example, 450 nm laser light. Each semiconductor laser 63 has an output of 1.6 W (operating voltage 4.7 V, current 1.2 A) and is enclosed in a package having a diameter of 9 mm. The laser beam oscillated by the semiconductor laser 63 is not limited to 450 nm, and any laser beam having a peak wavelength in another wavelength range may be used. Further, the package is not limited to the one having a diameter of 9 mm, and may be, for example, a diameter of 3.8 mm or other, and it is preferable to select a package having a smaller thermal resistance.

In this embodiment, the semiconductor laser is used as the excitation light source, but a light emitting diode can be used instead of the semiconductor laser.

(Aspherical lens 29)
The aspherical lens 29 is a lens for causing the laser light (excitation light) oscillated from the semiconductor laser 63 to enter the incident end 5 b that is one end of the optical fiber 55. For example, as the aspherical lens 29, FLKN1 405 manufactured by Alps Electric can be used. The shape and material of the aspherical lens 29 are not particularly limited as long as the lens has the above-described function. However, it is preferable that the aspherical lens 29 is a material having a high transmittance of about 405 nm, which is the wavelength of excitation light, and good heat resistance.

(Optical fiber 55)
(Disposition of optical fiber 55)
The optical fiber 55 is a light guide member that guides the laser light oscillated by the semiconductor laser 63 to the first light emitting unit 93, and is a bundle of a plurality of optical fibers. The optical fiber 55 has a plurality of incident end portions 5b for receiving the laser light and a plurality of emission end portions 5a for emitting the laser light incident from the incident end portion 5b. The plurality of emission end portions 5 a emit laser beams to different regions on the laser beam irradiation surface of the first light emitting unit 93.

For example, the emission end portions 5a of the plurality of optical fibers 55 are arranged side by side in a plane parallel to the laser light irradiation surface. With such an arrangement, the light intensity distribution in the light intensity distribution of the laser beam emitted from the emission end 5a is the highest (the central portion of the irradiation region (maximum light intensity portion) formed by each laser beam on the laser beam irradiation surface) ) Are emitted to different portions of the laser light irradiation surface of the first light emitting unit 93, so that the laser light is dispersed and irradiated two-dimensionally on the laser light irradiation surface of the first light emitting unit 93. can do.

Therefore, it is possible to prevent a part of the first light emitting unit 93 from being significantly deteriorated by locally irradiating the first light emitting unit 93 with the laser light.

The optical fiber 55 does not necessarily have to be a bundle of a plurality of optical fibers (that is, a configuration including a plurality of emission end portions 5a), and may be a single optical fiber.

(Material and structure of optical fiber 55)
The optical fiber 55 has a two-layer structure in which the core of the core is covered with a clad having a refractive index lower than that of the core. The core is mainly composed of quartz glass (silicon oxide) having almost no absorption loss of laser light, and the clad is composed mainly of quartz glass or a synthetic resin material having a refractive index lower than that of the core. . For example, the optical fiber 55 is made of quartz having a core diameter of 200 μm, a cladding diameter of 240 μm, and a numerical aperture NA of 0.22, but the structure, thickness, and material of the optical fiber 55 are limited to those described above. Instead, the cross section perpendicular to the major axis direction of the optical fiber 55 may be rectangular.

In addition, since the optical fiber 55 has flexibility, the relative positional relationship between the semiconductor laser 63 and the first light emitting unit 93 can be easily changed. Further, by adjusting the length of the optical fiber 55, the semiconductor laser 63 can be installed at a position away from the first light emitting unit 93.

Therefore, the degree of freedom in designing the headlamp 110 can be increased, for example, the semiconductor laser 63 can be installed at a position where it can be easily cooled or easily replaced.

Note that a member other than the optical fiber or a combination of the optical fiber and another member may be used as the light guide member. For example, one or a plurality of light guide members having a truncated cone shape (or a truncated pyramid shape) having a laser beam incident end and an emission end may be used.

(Ferrule 65)
The ferrule 65 holds the plurality of emission end portions 5 a of the optical fiber 55 in a predetermined pattern with respect to the laser light irradiation surface of the first light emitting unit 93. The ferrule 65 may be formed with a predetermined pattern of holes for inserting the emission end portion 5a, and can be separated into an upper portion and a lower portion, and is formed on the upper and lower joint surfaces, respectively. The exit end portion 5a may be sandwiched by a groove.

The ferrule 65 may be fixed to the reflecting mirror 81 by a rod-like or cylindrical member extending from the reflecting mirror 81. The material of the ferrule 65 is not specifically limited, For example, it is stainless steel. Further, a plurality of ferrules 65 may be arranged for the first light emitting unit 93.

In addition, when the output end part 5a of the optical fiber 55 is one, the ferrule 65 can be omitted.

(First light emitting part 93 and second light emitting part 94)
(Composition of the 1st light emission part 93)
The first light emitting unit 93 emits light upon receiving the laser light emitted from the emission end 5a, and includes a phosphor that emits light upon receiving the laser light. This phosphor is dispersed inside a glass material as a sealing material.

The first light emitting unit 93 includes one or more of phosphors that emit blue, green, red and the like. Since the semiconductor laser 63 oscillates laser light of 450 nm, when the first light emitting unit 93 is irradiated with the laser light, light in which one or a plurality of colors are mixed is generated.

Note that the phosphor that emits yellow light is a phosphor that emits light having a peak wavelength in a wavelength range of 560 nm to 590 nm. The phosphor that emits green light is a phosphor that emits light having a peak wavelength in a wavelength range of 510 nm or more and 560 nm or less. The phosphor that emits red light is a phosphor that emits light having a peak wavelength in a wavelength range of 600 nm to 680 nm.

(Composition of the 2nd light emission part 94)
The second light emitting unit 94 receives laser light and emits light of a color different from the fluorescence emitted from the first light emitting unit 93. Alternatively, the second light emitting unit 94 receives fluorescence emitted from the first light emitting unit 93 and emits fluorescence having a color different from that of the first light emitting unit 93. The second light emitting unit 94 includes a phosphor that emits light upon receiving laser light. This phosphor is dispersed inside a glass material as a sealing material.

The second light emitting unit 94 includes one or more of phosphors that emit blue, green, red, etc., and the light emitted from the second light emitting unit 94 is a mixture of one or more colors. It will be a thing.

The relative position relationship between the second light emitting unit 94 and the emission end portion 5a is changed by the operation of the position control unit 95 described later, or the relative positional relationship with the first light emitting unit 93 is changed. As a result, the amount of light emitted from the second light emitting unit 94 changes.

(Encapsulant)
As the sealing material, for example, an inorganic glass of about 1 W / mK can be used. The ratio between the glass material and the phosphor is about 10: 1.

In addition, the sealing material is not limited to inorganic glass, and may be a resin material such as so-called organic-inorganic hybrid glass or silicone resin. However, when inorganic glass is used as the sealing material, the effect of increasing the heat resistance and reducing the thermal resistance of the first light emitting portion 93 and the second light emitting portion 94 is obtained, and therefore inorganic glass is preferable.

(Phosphor)
The phosphors of the first light emitting unit 93 and the second light emitting unit 94 are preferably oxynitride phosphors, nitride phosphors or III-V compound semiconductor nanoparticle phosphors. These materials have high resistance to extremely strong laser light (output and light density) emitted from the semiconductor laser 63, and are optimal for laser illumination light sources.

As a typical oxynitride phosphor, there is a so-called sialon phosphor. A sialon phosphor is a substance in which part of silicon atoms in silicon nitride is replaced with aluminum atoms and part of nitrogen atoms is replaced with oxygen atoms. It can be made by dissolving alumina (Al ₂ O ₃ ), silica (SiO ₂ ), rare earth elements and the like in silicon nitride (Si ₃ N ₄ ). Examples of sialon phosphors that emit blue light upon receiving excitation light include Ce ³⁺ activated CAα-SiAlON phosphors, Ce ³⁺ activated β-SiAlON phosphors, and the like.

Other typical oxynitride phosphors include, for example, oxynitride phosphors containing a JEM phase (JEM phase phosphors). The JEM phase phosphor is a substance that has been confirmed to be produced in a process for preparing a sialon phosphor stabilized by a rare earth element. The JEM phase is a ceramic discovered as a grain boundary phase of a silicon nitride-based material, and generally has a composition formula M ¹ Al (Si _6-z Al _z ) N _10-z O _z (where M ¹ Is represented by La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu), and z is a parameter. It is a crystal phase (oxynitride crystal) having a unique atomic arrangement consisting of composition. The JEM phase has excellent heat resistance due to strong covalent bonding of crystals.

An example of a JEM phase phosphor that emits blue light upon receiving excitation light is a Ce ³⁺ activated (doped) JEM phase phosphor (JEM phase: Ce phosphor). The Ce component contained in the JEM phase phosphor absorbs excitation light in the vicinity of 350 nm to 420 nm, makes it easy to obtain light emission from blue to blue-green, and broadens the half-value width of light emission. It is possible to sufficiently cover a wavelength range with high relative visibility in visual observation. The JEM phase: Ce phosphor has a peak wavelength of 480 nm when the excitation wavelength is 360 nm, and the luminous efficiency at that time is 60%. Further, when the excitation wavelength is 405 nm, the peak wavelength is 490 nm, and the light emission efficiency at that time is 50%.

Further, examples of the oxynitride phosphor that emits green light include a β-SiAlON phosphor doped with Eu ²⁺ . The β-SiAlON phosphor doped with Eu ²⁺ exhibits strong emission with an emission peak wavelength of about 540 nm by ultraviolet to blue excitation light. The full width at half maximum of the emission spectrum of this phosphor is about 55 nm.

Examples of nitride phosphors that emit red light include, for example, Eu ²⁺ doped CaAlSiN ₃ : phosphor (CASN: Eu phosphor), Eu ²⁺ doped SrCaAlSiN ₃ phosphor (SCASN: Eu phosphor).

On the other hand, one of the characteristics of semiconductor nanoparticle phosphors is that even if the same compound semiconductor (for example, indium phosphorus: InP) is used, the particle size is changed within a certain range of the nanometer order, thereby providing a quantum size effect. The point is that the emission color can be changed. For example, InP emits red light when the particle size is about 3 to 4 nm (here, the particle size was evaluated with a transmission electron microscope (TEM)).

In addition, since this semiconductor nanoparticle phosphor is based on a semiconductor, it has a short fluorescence lifetime and is characterized by being highly resistant to high-power excitation light because it can quickly emit the excitation light power as fluorescence. This is because the emission lifetime of the semiconductor nanoparticle phosphor is about 10 nanoseconds, which is five orders of magnitude smaller than that of a normal phosphor material having a rare earth as the emission center.

Furthermore, as described above, since the emission lifetime is short, the absorption of the laser beam and the emission of the phosphor can be repeated quickly. As a result, high efficiency can be maintained with respect to strong laser light, and heat generation from the phosphor can be reduced.

(Shapes and sizes of the first light emitting part 93 and the second light emitting part 94)
The shape and size of the first light emitting portion 93 are, for example, a cylindrical shape having a diameter of 3.2 mm and a thickness of 1 mm, and the laser light emitted from the emission end portion 5a is converted into a laser light irradiation surface that is the bottom surface of the cylinder. Receive light.

Moreover, the 1st light emission part 93 may not be a column shape but a rectangular parallelepiped. For example, it is a rectangular parallelepiped of 3 mm × 1 mm × 1 mm. In this case, the area of the laser light irradiation surface that receives the laser light from the semiconductor laser 63 is 3 mm ² . The light distribution pattern (light distribution) of a vehicle headlamp that is legally regulated in Japan is narrow in the vertical direction and wide in the horizontal direction. By making it horizontally long (substantially rectangular in cross section), the light distribution pattern can be easily realized.

The shape and size of the second light emitting unit 94 may be realized in various forms, and details will be described later.

The thickness of the first light emitting unit 93 and the second light emitting unit 94 varies according to the ratio of the sealing material and the phosphor in the first light emitting unit 93 and the second light emitting unit 94. If the phosphor content in the first light-emitting part 93 and the second light-emitting part 94 increases, the efficiency of conversion of laser light into white light increases, so the thickness of the first light-emitting part 93 and the second light-emitting part 94 is reduced. it can. If the first light-emitting portion 93 and the second light-emitting portion 94 are made thin, the thermal resistance is reduced. However, if the thickness is too thin, the laser light may not be converted into fluorescence and may be emitted to the outside. From the viewpoint of absorption of excitation light by the phosphor, the thickness of the light emitting part is preferably at least 10 times the particle size of the phosphor.

Therefore, the thickness of the first light emitting unit 93 and the second light emitting unit 94 using the oxynitride phosphor or the nitride phosphor is preferably 0.2 mm or more and 2 mm or less. However, when the content of the phosphor is extremely increased (typically 100% of the phosphor), the lower limit of the thickness is not limited to this.

From this point of view, the thickness of the light-emitting portion when using the nanoparticle phosphor should be 0.01 μm or more, but considering the ease of the manufacturing process such as dispersion in the sealing material, it is 10 μm or more. That is, 0.01 mm or more is preferable. On the other hand, if the thickness is too thick, the deviation from the focal point of the reflecting mirror 81 becomes large and the light distribution pattern is blurred.

Further, the laser light irradiation surfaces of the first light emitting unit 93 and the second light emitting unit 94 (or the second light emitting unit 94 receives the fluorescence emitted from the first light emitting unit 93 and is different from the fluorescence of the first light emitting unit 93. In the case of emitting color fluorescence, the light receiving surface of the fluorescence emitted from the first light emitting unit 93 is not necessarily a flat surface and may be a curved surface. However, in order to control the reflected laser light, the laser light irradiation surface preferably has a flat surface. When the laser light irradiation surface is a curved surface, at least the incident angle to the curved surface changes greatly, so that the direction in which the reflected light travels greatly changes depending on the location where the laser light is irradiated. For this reason, it may be difficult to control the reflection direction of the laser light. On the other hand, if the laser light irradiation surface is flat, the direction in which the reflected light travels hardly changes even if the irradiation position of the laser light is slightly shifted, so that the direction in which the laser light is reflected can be easily controlled. In some cases, it is easy to take measures such as placing a laser beam absorber in a place where the reflected light strikes.

It should be noted that the laser light irradiation surface is not necessarily perpendicular to the optical axis of the laser light. When the laser light irradiation surface is perpendicular to the optical axis of the laser light, the reflected laser light returns in the direction of the laser light source, and in some cases, the laser light source may be damaged.

(Position controller 95)
The position control unit 95 changes the amount of light emitted from the second light emitting unit 94 by changing the relative positional relationship between the second light emitting unit 94 and the emission end (emission point) 5a. At this time,
(A) The position control unit 95 changes the distance between the second light emitting unit 94 and the optical axis of the laser beam. (B) The position control unit 95 moves the second light emitting unit 94 in the direction of the optical axis of the laser light.
Perform the operation.

Explaining (a), when the position control unit 95 is connected to the second light emitting unit 94, the position control unit 95 changes the position of the second light emitting unit 94 so as to change the distance from the optical axis of the laser beam. Let Or the position control part 95 changes the position of the output end part 5a so that the distance between the optical axes of a laser beam may be changed, when connecting to the output end part 5a. Thereby, the position control part 95 can change the relative positional relationship of the 2nd light emission part 94 and the radiation | emission end part 5a, and can change the irradiation area of the laser beam irradiated to the 2nd light emission part 94. FIG. . As a result, the amount of light emitted from the second light emitting unit 94 changes.

In addition, the following cases can be considered. That is, the position control unit 95 changes the relative positional relationship between the first light emitting unit 93 and the second light emitting unit 94 and changes the amount of light emitted from the second light emitting unit 94. At this time,
(C) The position controller 95 changes the distance between the second light emitter 94 and the optical axis of the laser beam. (D) The position control unit 95 moves the second light emitting unit 94 in the direction of the optical axis of the laser light.
Perform the operation.

Explaining (c), when the position control unit 95 is connected to the second light emitting unit 94, the position control unit 95 changes the position of the second light emitting unit 94 so as to change the distance from the optical axis of the laser beam. Let Or the position control part 95 changes the position of the output end part 5a so that the distance between the optical axis of a laser beam may be changed, when connecting with the output end part 5a. Accordingly, the position control unit 95 can change the relative positional relationship between the first light emitting unit 93 and the second light emitting unit 94, and can change the irradiation area of the laser light applied to the second light emitting unit 94. it can. As a result, the amount of light emitted from the second light emitting unit 94 changes.

The position control unit 95 has, for example, a structure in which a motor and a gear are combined. The position control unit 95 is connected to at least one of the first light emitting unit 93, the second light emitting unit 94, and the emission end portion 5a, and (a) to (d ). Further, the position control unit 95 is not necessarily connected to the first light emitting unit 93 or the like, and performs the operations (a) to (d) using a non-contact type member such as a magnet. Also good. That is, the position control unit 95 changes the relative positional relationship between the second light emitting unit 94 and the emission end 5a, or changes the relative positional relationship between the first light emitting unit 93 and the second light emitting unit 94. Any configuration may be used as long as it is changed.

(Reflector 81)
The reflecting mirror 81 reflects the light emitted from the first light emitting unit 93 and / or the second light emitting unit 94 to form a light bundle that travels within a predetermined solid angle. That is, the reflecting mirror 81 reflects the light from the first light emitting unit 93 and / or the second light emitting unit 94 to form a light bundle that travels forward of the headlamp 110. The reflecting mirror 81 is, for example, a curved (cup-shaped) member having a metal thin film formed on the surface thereof.

(Transparent plate 92)
The transparent plate 92 is a transparent resin plate that covers the opening of the reflecting mirror 81. The transparent plate 92 is formed of a material that blocks the laser light from the semiconductor laser 63 and transmits white light generated by converting the laser light in the first light emitting unit 93 and / or the second light emitting unit 94. It is preferable to do. Most of the coherent laser light is converted into incoherent light by the first light emitting unit 93 and / or the second light emitting unit 94. However, there may be a case where a part of the laser light is not converted into incoherent light for some reason. Even in such a case, the laser beam can be prevented from leaking to the outside by blocking the laser beam by the transparent plate 92.

Further, the transparent plate 92 may be used for fixing the second light emitting unit 94.

At this time, if the transparent plate 92 has a high thermal conductivity (for example, inorganic glass), the transparent plate 92 also functions as a heat conductive member, and the heat radiation effect of the second light emitting unit 94 can be obtained.

(Housing 75)
The housing 75 forms the main body of the headlamp 110 and houses the reflecting mirror 81 and the like. The optical fiber 55 passes through the housing 75, and the semiconductor laser array 72 is installed outside the housing 75. The semiconductor laser array 72 generates heat when the laser light is oscillated, but the semiconductor laser array 72 can be efficiently cooled by being installed outside the housing 75. Therefore, characteristic deterioration, thermal damage, and the like of the first light emitting unit 93 and / or the second light emitting unit 94 due to heat generated from the semiconductor laser array 72 are prevented.

Also, it is preferable to install the semiconductor laser 63 at a position where it can be easily replaced in consideration of a failure. If these points are not taken into consideration, the semiconductor laser array 72 may be accommodated in the housing 75.

(Extension 76)
The extension 76 is provided on the front side of the reflecting mirror 81 to hide the internal structure of the headlamp 110 to improve the appearance of the headlamp 110 and enhance the sense of unity between the reflecting mirror 81 and the vehicle body. Yes. The extension 76 is also a member having a metal thin film formed on the surface thereof, like the reflecting mirror 81.

(Lens 77)
The lens 77 is provided in the opening of the housing 75 and seals the headlamp 110. The light generated by the first light emitting unit 93 and / or the second light emitting unit 94 and reflected by the reflecting mirror 81 is emitted to the front of the headlamp 110 through the lens 77.

The basic structure of the semiconductor laser 63 is the same as the basic structure of the LD chip 11 described with reference to FIGS. 3C and 3D in the first embodiment, and therefore the description thereof is omitted. In addition, the light emission principle of the first light emitting unit 93 and the second light emitting unit 94 is the same as the light emission principle of the light emitting unit 2 described in the first embodiment, and thus the description thereof is omitted. In the present embodiment, the headlamp 110 is not limited to white, and may be realized by a configuration that emits other colors such as red and yellow.

[Example 1]
Hereinafter, examples according to the present embodiment will be described. Note that the description of the already described contents is omitted.

(Form of headlamp 110)
One embodiment of the headlamp 110 according to the present embodiment will be described with reference to FIG. FIG. 45 is a diagram illustrating an embodiment of the configuration of the first light emitting unit 93, the second light emitting unit 94, and the position control unit 95.

(First light emitting unit 93)
In the present embodiment, a Ce-doped YAG phosphor (NYAG4454) manufactured by Intematix is used as the first light emitting unit 93. The first light emitting unit 93 has an external quantum efficiency of 90%, an emission peak wavelength of 558 nm, chromaticity points of x = 0.444, y = 0.536, and is excited well by excitation light of 430 nm to 490 nm. The

The first light emitting unit 93 is manufactured by dispersing a YAG phosphor in a low-melting glass. The compounding ratio of the phosphor and glass is 30: 100. The size of the first light emitting portion 93 is 4 mm long × 4 mm wide × 0.5 mm deep, and is bonded to an Al ₂ O ₃ (sapphire) plate (10 mm × 10 mm) having a thickness of 0.5 mm. The laser light is irradiated through the Al ₂ O ₃ (sapphire) plate in the order of the first light emitting unit 93 and the second light emitting unit 94.

In FIG. 45, the first light emitting unit 93 is placed on the heat conducting member 181, but it is not always necessary to be placed on the heat conducting member 181.

(Second light emitting unit 94)
As the second light emitting unit 94, a CASN: Eu ²⁺ phosphor, which is a nitride phosphor, was used. The external quantum efficiency of the second light emitting unit 94 is 73% when excited at 450 nm, and the emission peak wavelength is 649 nm.

The second light emitting unit 94 is manufactured by dispersing a CASN phosphor in a low melting point glass. The mixing ratio of the phosphor and glass is 20: 100. The second light-emitting portion 94 has a diaphragm blade mechanism such that when it is most squeezed, there is an opening of φ1 mm in the center, and the blade thickness is 0.5 mm.

(Heat conduction member 181)
The heat conducting member 181 is a translucent member that is disposed on the laser light irradiation surface side that is the surface irradiated with the laser light in the first light emitting unit 93 and receives the heat of the first light emitting unit 93. It is thermally connected to the light emitting unit 93 (that is, so as to be able to exchange heat energy). The 1st light emission part 93 and the heat conductive member 181 may be connected by the adhesive agent, for example.

The heat conducting member 181 is a plate-like member, and one end thereof is in thermal contact with the laser light irradiation surface of the first light emitting unit 93. Further, the other end may be realized by a configuration in which it is thermally connected to a cooling unit (not shown).

Since the heat conducting member 181 has such a shape and connection form, the heat generated from the first light emitting unit 93 is transferred to the outside of the headlamp 110 while holding the minute first light emitting unit 93 at a specific position. Dissipate heat.

It is preferable that the heat conductivity of the heat conducting member 181 is 20 W / mK or more in order to efficiently release the heat of the first light emitting unit 93. Further, the laser light emitted from the semiconductor laser 63 passes through the heat conducting member 181 and reaches the first light emitting unit 93. Therefore, it is preferable that the heat conductive member 181 is made of a material having excellent translucency.

Considering these points, the material of the heat conducting member 181 is preferably sapphire (Al ₂ O ₃ ), magnesia (MgO), gallium nitride (GaN), or spinel (MgAl ₂ O ₄ ). By using these materials, a thermal conductivity of 20 W / mK or more can be realized.

The thickness (width in the left-right direction of the drawing) of the heat conducting member 181 is preferably 0.3 mm or more and 5.0 mm or less. If the thickness is less than 0.3 mm, the first light emitting unit 93 cannot sufficiently dissipate heat, and the first light emitting unit 93 may be deteriorated. On the other hand, if the thickness exceeds 5.0 mm, the absorption of the irradiated laser light in the heat conducting member 181 increases, and the utilization efficiency of the excitation light is significantly reduced.

By bringing the heat conducting member 181 into contact with the first light emitting unit 93 with an appropriate thickness, the heat generation is quick even when an extremely strong laser beam that generates heat exceeding 1 W in particular is irradiated. In addition, the heat can be efficiently radiated and the first light emitting portion 93 can be prevented from being damaged (deteriorated).

It should be noted that the heat conducting member 181 may be a plate-like member that is not bent, or may have a bent part or a curved part. However, the portion to which the first light emitting unit 93 is bonded is preferably a flat surface (plate shape) from the viewpoint of adhesion stability.

Here, in order to enhance the heat absorption effect and the heat dissipation effect of the heat conducting member 181, the following changes are effective.
Increase the heat dissipation area (contact area with the first light emitting unit 93).
-Increase the thickness of the heat conducting member 181.
-Increase the thermal conductivity of the heat conducting member 181. For example, a material having high thermal conductivity is used. Alternatively, a member having a high thermal conductivity (such as a thin film or a plate member) is disposed on the surface of the heat conducting member 181.

Note that when a metal thin film or the like is formed on the surface of the heat conducting member 181, there is a possibility that the luminous flux is lowered. In addition, when the surface of the heat conducting member 181 is covered or another member is provided, the manufacturing cost increases.

(Modification example of heat conduction member 181)
The heat conducting member 181 may have a light-transmitting part (light-transmitting part) and a part having no light-transmitting property (light-shielding part). In the case of this configuration, the light transmitting part is arranged so as to cover the laser light irradiation surface of the first light emitting part 93, and the light shielding part is arranged outside thereof.

The light shielding part may be a heat radiating part of metal (for example, copper or aluminum), or aluminum, silver, or other film that has an effect of reflecting illumination light is formed on the surface of the translucent member. May be.

(Relationship between second light emitting unit 94 and position control unit 95)
As illustrated, in the headlamp 110, the second light emitting unit 94 and the position control unit 95 are connected, and the position control unit 95 changes the position of the second light emitting unit 94 through its own operation. Accordingly, the position control unit 95 can change the amount of light emitted from the second light emitting unit 94.

More specifically, the operation of the second light emitting unit 94 via the position control unit 95 will be described. FIG. 46 is a diagram for explaining the operation of the second light emitting unit 94 in the present embodiment. Among these, FIG. 46A is a diagram showing a state where the distance between the second light emitting unit 94 and the optical axis of the laser beam is the longest. FIG. 46B is a diagram illustrating a state in which the second light emitting unit 94 is moving toward the optical axis of the laser light. FIG. 46C is a diagram showing a state in which the distance between the second light emitting unit 94 and the optical axis of the laser light is closest. Although not shown, it is assumed that the optical axis of the laser beam exists at or near the center of the circle shown in FIG. In addition, the circle shown in FIG. 46A represents the light emission center of the first light emitting unit 93.

As shown in the figure, there are a plurality of second light-emitting portions 94, and the plurality of second light-emitting portions 94 are annularly arranged around the optical axis. Then, the second light emitting unit 94 receives the operation of the position control unit 95 and changes the distance from the optical axis of the laser light like the operation of a so-called diaphragm blade mechanism.

That is, the position control unit 95 is connected to each of the plurality of second light emitting units 94, and the plurality of second light emission components in the direction toward the optical axis of the laser light or in the direction away from the optical axis of the laser light. The units 94 are operated simultaneously.

As described above, in the headlamp 110, the irradiation area on the second light emitting unit 94 irradiated with the laser light or the fluorescence emitted from the first light emitting unit 93 is changed by the operation of the position control unit 95. As a result, the amount of light emitted from the second light emitting unit 94 changes, and the characteristics of the illumination light emitted outside the headlamp 110, which is indicated by the light spectrum, chromaticity, color temperature, etc., are easily changed. Can be made.

The position control unit 95 may be realized by a configuration in which each of the plurality of second light emitting units 94 is separately (arbitrarily) operated toward or away from the optical axis of the laser beam.

Further, by determining the moving direction and moving amount of each of the plurality of second light emitting units, and grasping the characteristics of the illumination light in that state in advance, the desired position can be obtained through the operation of the position control unit 95. It is also possible to easily realize the characteristics of the illumination light.

(Effects obtained by the headlamp 110)
The effect obtained by the headlamp 110 will be described with reference to FIG. FIG. 47 is a chromaticity diagram for explaining the effect obtained by the headlamp 110.

P in the figure indicates the chromaticity point of the laser light source. Q indicates the chromaticity point of the fluorescence emitted by the first light emitting unit 93. R indicates the chromaticity point of the fluorescence emitted by the second light emitting unit 94.

According to the above configuration, the second light emitting unit 94 changes the position in response to the operation of the position control unit 95. Thereby, the irradiation area on the second light emitting unit 94 irradiated with the laser light or the fluorescence emitted by the first light emitting unit 93 changes, and the color temperature, chromaticity, and spectrum of the illumination light emitted from the headlamp 110 are changed. The ratio of changes.

That is, by exciting the second light emitting unit 94 in addition to the first light emitting unit 93, the direction from the point Q to the point R in the figure, in which the chromaticity of the illumination light becomes red (the color temperature is lowered). The change in the characteristics of the illumination light in the direction of movement) can be realized.

Thus, the headlamp 110 can easily change the characteristics of illumination light such as spectrum, chromaticity, and color temperature with a simple structure.

The first light emitting unit 93 is preferably larger than the second light emitting unit 94. Thereby, when using the 2nd light emission part 94 etc., the characteristic change of illumination light rich in variation can be brought about, and the headlamp 110 can be applied in various situations.

Further, the configuration shown in FIG. 45 is for explaining one embodiment, and the above-described effect obtained by the headlamp 110 is not limited to the configuration of FIG. That is, in FIG. 45, the first light emitting unit 93 is disposed between the ferrule 65 and the second light emitting unit 94, but for example, the second light emitting unit 94 is disposed between the ferrule 65 and the first light emitting unit 93. The same effect as the configuration of FIG. 45 can be obtained by the configuration.

And the headlamp 110 can emit light of various colors, not limited to red indicated by the point R.

[Example 2]
Hereinafter, other examples according to the present embodiment will be described. Note that the description of the already described contents is omitted.

48 is a view for explaining another operation of the second light emitting unit 94 according to the present embodiment in the structure of the headlamp 110 shown in FIG. Among these, FIG. 48A is a diagram showing a state where the distance between the second light emitting unit 94 and the optical axis of the laser beam is the longest. FIG. 48B is a diagram illustrating a state in which the second light emitting unit 94 is moving toward the optical axis of the laser light. FIG. 48C is a diagram illustrating a state in which the distance between the second light emitting unit 94 and the optical axis of the laser light is closest. Although not shown, it is assumed that the optical axis of the laser light exists at the center position of the circle shown in FIG. Also, the circle shown in FIG. 48A represents the light emission center of the first light emitting unit 93.

48, in FIG. 48, the position of the second light emitting unit 94 changes through the operation of the position control unit 95. Specifically, the position of the second light emitting unit 94 changes as the two second light emitting units 94 formed in a plate shape protrude toward the optical axis. As a result, the irradiation area on the second light emitting unit 94 to which the laser light or the fluorescence emitted from the first light emitting unit 93 is irradiated changes. And the characteristic of illumination light can be changed by the amount of fluorescence generation of the 2nd light emission part 94 changing.

The two second light emitting units 94 formed in a plate shape may be realized by an operation in which one protrudes toward the optical axis and the other moves away from the optical axis.

As can be understood from the above description, the shape and quantity of the second light emitting unit 94 and the method of changing the position of the second light emitting unit 94 by the position control unit 95 can take various forms. As an example, consider the case where the position control unit 95 is configured as a rotating shaft, and the second light emitting unit 94 is attached to the tip of the rotating shaft. At this time, the operation of the position control unit 95 causes the second light emitting unit 94 to rotate, whereby the second light emitting unit 94 can be moved toward (or away from) the optical axis of the laser light. As a result, the irradiation area on the second light emitting unit 94 irradiated with the laser light or the fluorescence emitted from the first light emitting unit 93 changes, and the color temperature, chromaticity, and spectrum of the illumination light emitted from the headlamp 110 are changed. The ratio of can be changed.

That is, as long as the irradiation area on the second light emitting unit 94 irradiated with the laser light or the fluorescence emitted from the first light emitting unit 93 can be changed, the position of the second light emitting unit 94 can be changed in any configuration. A change operation may be realized.

Also, the first light emitting unit 93 and the second light emitting unit 94 can be positioned in the opposite positions. That is, as long as the irradiation area on the first light emitting unit 93 irradiated with the laser light or the fluorescence emitted from the second light emitting unit 94 can be changed, the position of the first light emitting unit 93 can be changed in any configuration. A change operation may be realized.

[Embodiment 13]
Another embodiment of the present invention will be described below with reference to FIGS. 49 and 50. Note that the lighting device according to the present embodiment can be used for various purposes, and may be realized as, for example, a flashlight, an LED bulb, a pen-type light, a traffic light, a home lighting device, a construction light, or the like. Hereinafter, although this Embodiment is demonstrated, about the member similar to Embodiment 12, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

An embodiment in which the excitation light source used in the headlamp 110 is an LED will be described with reference to FIGS. 49 and 50. FIG. 49 is a diagram for explaining the first light emitting unit 99 in which the LED chip 96 is embedded, FIG. 49A is a cross-sectional view of the first light emitting unit 93, and FIG. 3 is a perspective view of a first light emitting unit 99. FIG.

As shown in FIGS. 49A and 49B, the first light emitting unit 99 includes a silicon resin in which a phosphor is dispersed and an LED chip 96 embedded in the silicon resin. Embedded. Electrodes 97 are attached to the side surface and the bottom surface of the package 98, and the electrodes 97 supply power to the LED chip 96 via wiring (not shown).

As the first light emitting unit 99, a SMD (Surface Mount Device) type is preferably used. If the phosphor is a yellow phosphor, the SMD type can emit white light in combination with the LED chip 96 that emits blue light. Moreover, the variation of the color of the emitted light can be changed by changing the combination of the phosphor and the LED chip.

FIG. 50 is a diagram in which the first light emitting unit 99, the second light emitting unit 94, and the position control unit 95 shown in FIG. 49 are combined. As shown in the figure, a second light emitting unit 94 and a position control unit 95 are disposed above the first light emitting unit 99. In this case as well, the color temperature and color of the illumination light emitted from the headlamp 110 by the operations of the second light emitting unit 94 and the position control unit 95 described in the [Example 1] and [Example 2] columns. The degree of spectrum can be changed. At this time, the phosphor contained in the second phosphor portion is preferably CASN: Eu or SCASN: Eu, but is not limited thereto.

[Embodiment 14]
In the present embodiment, a laser downlight 200 as an example of the illumination device of the present invention will be described with reference to FIGS. 51 and 52.

The laser downlight 200 according to the present embodiment includes a first light emitting unit 93 and a second light emitting unit 94, and the laser light emitted from the semiconductor laser 63 is emitted from the first light emitting unit 93 and / or the second light emitting unit 94 (hereinafter referred to as “light emitting unit 94”). The fluorescent light generated by irradiating the light emitting unit 7 including the position control unit 95 may also be used as illumination light. Further, the laser downlight 200 according to the present embodiment includes a heat conducting member 231. Other configurations are the same as those of the laser downlight 200 described in the first embodiment, and thus the description thereof is omitted.

As shown in FIG. 51, the light emitting unit 210 includes a housing 211, an optical fiber 55, a light emitting unit 7, a heat conducting member 231, and a light transmitting plate 213. Similarly to the above-described embodiment, the heat of the light emitting unit 7 is transmitted to the heat conducting member 231 and the heat radiation of the light emitting unit 7 is promoted.

Further, a passage 214 for passing the optical fiber 55 is formed in the housing 211, and the optical fiber 55 extends to the heat conducting member 231 through the passage 214. The laser beam emitted from the emission end portion 5 a of the optical fiber 55 passes through the heat conducting member 231 and reaches the light emitting unit 7.

In the case of the configuration shown in FIG. 52, the heat conducting member 231 is disposed at the bottom of the housing 211 with the laser light incident side surface in full contact therewith. Therefore, the housing 211 can be made of a material having high thermal conductivity so that it can function as a cooling unit for the heat conducting member 231.

51, only one pair of the semiconductor laser 63 and the aspherical lens 29 is shown inside the LD light source unit 220. However, when there are a plurality of light emitting units 210, optical fibers extending from the light emitting units 210, respectively. The bundle of 55 may be guided to one LD light source unit 220. In this case, a pair of a plurality of semiconductor lasers 63 and the aspheric lens 29 is accommodated in one LD light source unit 220, and the LD light source unit 220 functions as a centralized power supply box.

As described above, the laser downlight 200 includes the LD light source unit 220 including at least one semiconductor laser 63 that emits laser light, the at least one light emitting unit 210 including the light emitting unit 7 and the recess 212 as a reflecting mirror, And an optical fiber 55 for guiding the laser light to each of the light emitting units 210.

[Additional Notes on Embodiments 12 to 14]
For example, a high-power LED may be used as the excitation light source. In this case, a light emitting device that emits white light can be realized by combining an LED that emits light having a wavelength of 450 nm (blue) and a yellow phosphor or green and red phosphors.

Further, a solid-state laser other than the semiconductor laser may be used as the excitation light source. However, it is preferable to use a semiconductor laser because the excitation light source can be reduced in size.

[Another expression of the present invention]
The light emitting device according to each of the above embodiments can be expressed as follows.

In other words, in addition to the above-described configuration, the light-emitting device according to an embodiment of the present invention further includes a diffusion unit that diffuses at least the excitation light irradiated outside the irradiation surface irradiated with the excitation light of the light emitter. You may have.

According to the above configuration, the chromaticity variation of the light emitting device can be suppressed by the light diffusing action of the diffusing unit.

“To diffuse at least the excitation light irradiated to the outside of the irradiation surface” means to diffuse the excitation light irradiated to the outside of the irradiation surface and to irradiate all or part of the irradiation surface. It means that the case where the excitation light is diffused is also included.

In addition to the above configuration, the light-emitting device according to an embodiment of the present invention has a ratio of a cross-sectional area of the light emitter to an area of the spot of the excitation light of ¼ or more and ／ or less. Preferably there is.

If the ratio of the cross-sectional area of the illuminant to the spot area of the excitation light is smaller than 1/4, the irradiation efficiency of the excitation light to the illuminant becomes too low.

On the other hand, if the ratio of the cross-sectional area of the illuminant to the area of the excitation light spot is larger than 2/3, the intensity distribution of the laser light on the irradiation surface irradiated with the excitation light of the illuminant will be greatly uneven. End up.

In addition to the above-described configuration, the light-emitting device according to an embodiment of the present invention is configured such that the excitation light source emits blue region excitation light, and the light emitter emits yellow region fluorescence. May be included.

According to the above configuration, the illumination light emitted from the light emitting device becomes (pseudo) white light with high luminous efficiency.

In addition to the above-described configuration, the light-emitting device according to an embodiment of the present invention includes a green-emitting phosphor in which the excitation light source emits blue region excitation light, and the phosphor emits green region fluorescence. And a red light-emitting phosphor that emits fluorescence in the red region.

According to the above configuration, the illumination light generated from the light emitter becomes white light with good color rendering. In addition, the color rendering is better than the combination of the excitation light in the blue region and the yellow light emitting phosphor, and the decrease in the light emission efficiency of the light emitter is also suppressed.

In addition to the above configuration, a light emitting device according to an embodiment of the present invention includes a thermally conductive substrate that diffuses heat generated in the light emitter, and is irradiated with the excitation light of the light emitter. The side of the surface may be held by the thermally conductive substrate.

In the above configuration, the heat conductive substrate diffuses the heat generated in the light emitter. For this reason, deterioration of a light-emitting body can be suppressed.

In addition to the above-described configuration, the light-emitting device according to an embodiment of the present invention includes a reflective member that reflects the excitation light, and the side of the light emitter facing the irradiation surface irradiated with the excitation light is It may be held by the reflecting member.

According to the above configuration, the excitation light that is transmitted through the illuminant and reflected by the reflecting member excites the illuminant again. Even if the thickness is halved, sufficient luminous efficiency can be obtained.

In addition to the above-described configuration, the light-emitting device according to an embodiment of the present invention includes a plurality of the excitation light sources, and guides the excitation light emitted from each of the excitation light sources to the light emitter. A light guide member may be provided.

Thereby, since the excitation light emitted from each of the plurality of excitation light sources can be guided to the light emitter, a light emitting device with high luminous flux and high brightness can be realized. Moreover, an excitation light source and a light-emitting body can be isolate | separated by arbitrary distances by changing the length (distance of an incident end part and an output end part) of a light guide member as needed. Therefore, the design freedom of the light emitting device can be increased.

In addition to the above-described configuration, the light-emitting device according to an embodiment of the present invention has a cross-sectional area closer to the light emitter of the light guide member than a cross-sectional area closer to the excitation light source. May be.

According to the above configuration, it is possible to reduce the size of the light emitter by reducing the cross-sectional area of the light guide member closer to the light emitter.

In addition to the above configuration, in the light emitting device according to an embodiment of the present invention, the light guide member receives excitation light emitted from the plurality of excitation light sources at at least one incident end, and receives the incident light. The excitation light incident from the end may be emitted from each of the plurality of emission ends, and the light emitter may emit fluorescence upon receiving the excitation light emitted from each of the emission ends.

According to the above configuration, for example, it is possible to irradiate the different regions of the light emitter with the excitation light emitted from the respective emission end portions of the light guide member. In other words, the excitation light from the emission end portions of the plurality of light guide portions is distributed and irradiated to the light emitter.

Therefore, it is possible to reduce the possibility of significant deterioration of the light emitter by intensively irradiating excitation light to one place of the light emitter, realizing a longer-life light-emitting device without reducing the luminous flux of the emitted light can do. In addition, since it is not necessary to reduce the intensity of the excitation light applied to the light emitter, not only the luminous flux of the light emitting device but also the luminance can be increased. Therefore, a light emitting device with a small size and high luminance can be realized.

Further, an illumination device according to an embodiment of the present invention may include the light emitting device described above.

Further, a headlamp according to an embodiment of the present invention may include the light emitting device described above.

In addition, a headlamp according to an embodiment of the present invention includes the above light emitting device, a reflecting mirror that forms a light bundle that travels within a predetermined solid angle by reflecting fluorescence emitted from the light emitter, and May be provided. Thereby, the headlamp which radiates | emits the light beam which advances within the predetermined solid angle to the exterior of an apparatus is realizable.

A light-emitting device according to an embodiment of the present invention includes a first light source that emits excitation light, a light-emitting unit that emits fluorescence in response to excitation light emitted from the first light source, and a wavelength region different from the excitation light. It is preferable that the second light source that emits the second light having the above-described characteristics is provided, and the fluorescence emitted from the light emitting unit and the second light emitted from the second light source are emitted as illumination light. The second light source functions as the characteristic changing mechanism.

According to the above configuration, the second light source functioning as a characteristic changing mechanism emits second light having a wavelength region different from that of the excitation light emitted from the first light source. The second light is emitted as illumination light together with the fluorescence emitted from the light emitting unit upon receiving the excitation light emitted from the first light source.

Therefore, the light emitting device according to the embodiment of the present invention can use the second light different from the fluorescence emitted by the light emitting unit as the illumination light, so that, for example, laser light as excitation light is prevented from leaking to the outside. It is possible to adjust the color temperature, which has been difficult in the conventional lighting device designed to use only fluorescence as illumination light.

In the light emitting device according to an embodiment of the present invention, the first light source emits light having an oscillation wavelength from an ultraviolet region to a blue-violet region as the excitation light, and the second light source emits light in a blue region. It is preferable to emit light having a wavelength as the second light.

When the first light source emits light having an oscillation wavelength from the ultraviolet region to the blue-violet region as excitation light, there is little or no fluorescence bluish component obtained from the excitation light. According to the above configuration, since the second light source emits the light having the oscillation wavelength in the blue region (blue light) as the second light, the blue light component of the fluorescence can be compensated by the second light. For this reason, the light emitting device can increase the color temperature of the illumination light.

In the light emitting device according to the embodiment of the present invention, the light emitting unit preferably includes a first phosphor having a light absorption peak wavelength in a wavelength range of 350 nm or more and 420 nm or less.

Moreover, in the light emitting device according to an embodiment of the present invention, the absorption rate of the first phosphor when receiving excitation light in a wavelength range of 350 nm or more and 420 nm or less is preferably 70% or more.

In the light emitting device according to the embodiment of the present invention, the first phosphor is preferably a Caα-SiAlON: Ce phosphor.

Since the first phosphor has an absorption peak wavelength of light in a wavelength range of 350 nm or more and 420 nm or less, the absorption rate of the first phosphor is higher than the absorption rate in other wavelength ranges. In particular, the absorption rate of the first phosphor (especially Caα-SiAlON: Ce phosphor) when receiving excitation light having an oscillation wavelength in the wavelength range of 350 nm or more and 420 nm or less is 70% or more.

Conversely, the absorption rate of the first phosphor with respect to light having a peak wavelength in the other wavelength range is low. That is, when the light emitting unit is irradiated with second light that is not in the wavelength range of 420 nm or less, for example, has a blue region oscillation wavelength (peak wavelength in a wavelength range of 440 nm or more), the light emitting unit of the second light Absorption rate is low.

For this reason, the second light is not easily absorbed by the light emitting unit, so that the attenuation of the second light in the light emitting unit can be suppressed. Therefore, the light emitting device according to the embodiment of the present invention can efficiently use the second light for color temperature adjustment.

In the light emitting device according to the embodiment of the present invention, the light emitting unit preferably includes a second phosphor that emits fluorescence having a peak wavelength in a wavelength range of 630 nm or more and 650 nm or less.

In the light emitting device according to the embodiment of the present invention, the second phosphor is a CaAlSiN ₃ : Eu phosphor (CASN: Eu phosphor) or a SrCaAlSiN ₃ : Eu phosphor (SCASN: Eu phosphor). It is preferable.

According to the above configuration, the second phosphor, that is, the red light-emitting phosphor that emits red light (particularly, the CaAlSiN ₃ : Eu phosphor or the SrCaAlSiN ₃ : Eu phosphor) is mixed with the first phosphor, thereby rendering the color. A highly light-emitting part can be realized.

In the light emitting device according to an embodiment of the present invention, the second light source further includes a diffusion unit that emits laser light as the second light and diffuses the laser light emitted from the second light source. Is preferred.

According to the above configuration, the laser light as the second light is diffused by irradiating the diffusion portion. Thereby, even if the second light source is a laser light source, the light emitting point size of the laser light can be increased by the diffusing unit, so that the second light can be used as illumination light while suppressing the influence on the human body.

In the light emitting device according to an embodiment of the present invention, the light emitting unit functions as the diffusing unit, and the laser light emitted from the second light source is preferably diffused by the light emitting unit. .

According to the above configuration, in order to diffuse the laser light as the second light, a light emitting unit that converts excitation light into fluorescence can be used. For this reason, since it is not necessary to separately provide a member for diffusion, the light emitting device can be manufactured at a lower cost.

Also, since the laser light is highly coherent, it is not necessary to enlarge the light emitting part in order to irradiate the light emitting part with the second light (that is, the light emitting part can be made small). For this reason, a high-luminance light-emitting device can be realized even in the light-emitting device according to an embodiment of the present invention that includes the second light source.

In the light emitting device according to the embodiment of the present invention, the first light source is preferably a laser light source.

According to the above configuration, since the first light source emits a high-output and highly coherent laser beam, even if the light emitting unit is made small, the irradiation efficiency of the excitation light to the light emitting unit is high and the light emitting unit is strongly excited. Therefore, the same luminous intensity as the conventional one can be obtained. That is, when the first light source is a laser light source, the light emitting unit can be made small, so that a high-luminance light emitting device can be realized.

Moreover, it is preferable that the light emitting device according to the embodiment of the present invention includes a cutoff filter that blocks the excitation light.

According to the above configuration, by providing the cutoff filter, it is possible to reliably prevent the excitation light that has not been converted into fluorescence (or not scattered) from being emitted to the outside. Therefore, even if the emission point size of the excitation light is very small and the output power is high, or the excitation light belongs to a wavelength range other than the visible light region, the excitation light leaks to the outside and is given to the human body. The influence can be suppressed.

Moreover, the headlamp according to an embodiment of the present invention preferably includes the light emitting device described above.

According to the above configuration, since the headlamp includes the light-emitting device, the second light different from the excitation light can be used as the illumination light as in the light-emitting device, so that the color temperature of the illumination light is adjusted. it can.

A light-emitting device according to an embodiment of the present invention includes an excitation light source that emits excitation light, a light-emitting unit that emits fluorescence in response to excitation light emitted from the excitation light source, and excitation light emitted from the excitation light source. It is preferable to include a light amount changing mechanism that changes a ratio of excitation light that is not converted into fluorescence by the light emitting unit. The light quantity change mechanism functions as the characteristic change mechanism.

According to the above configuration, the light quantity changing mechanism that functions as the characteristic changing mechanism changes the ratio of the excitation light that is not converted into fluorescence by the light emitting unit in the excitation light emitted from the excitation light source (hereinafter referred to as the conversion ratio). .

Therefore, by changing the conversion ratio and changing the amount of excitation light that is not converted to fluorescence, the ratio of fluorescence to illumination light changes, so that the color temperature of illumination light can be changed.

Moreover, in the light emitting device according to an embodiment of the present invention, it is preferable that the light amount changing mechanism changes a ratio of excitation light that is not irradiated on the light emitting unit in excitation light emitted from the excitation light source.

According to the above configuration, the light quantity changing mechanism can change the conversion ratio by changing the ratio of the excitation light that is not irradiated to the light emitting portion in the excitation light emitted from the excitation light source.

Moreover, in the light emitting device according to an embodiment of the present invention, it is preferable that the light amount changing mechanism changes an irradiation area of the excitation light emitted from the excitation light source in the light emitting unit.

According to the above configuration, the light quantity changing mechanism can change the conversion ratio by changing the irradiation area in the light emitting portion of the excitation light emitted from the excitation light source.

In the light emitting device according to an embodiment of the present invention, it is preferable that the light amount changing mechanism moves the light emitting unit.

According to the above configuration, when the optical path width of the excitation light emitted from the excitation light source changes according to the distance from the excitation light source, the conversion ratio changes according to the distance between the excitation light source and the light emitting unit. The conversion ratio can be changed by moving the light emitting unit and changing the distance by the light quantity changing mechanism.

The light-emitting device according to an embodiment of the present invention includes an optical member that bends the excitation light emitted from the excitation light source and emits the light to the light-emitting unit, and the light amount changing mechanism moves the optical member. It is preferable to make it.

According to the above configuration, the optical member bends the excitation light emitted from the excitation light source and emits the excitation light to the light emitting part. The optical path width is different from the optical path width of the excitation light before entering the optical member, and can be emitted so as to change according to the distance from the optical member. That is, the excitation light emitted from the excitation light source is transmitted through the optical member, so that the optical path width is newly changed with the optical member as a base point.

For this reason, the light amount changing mechanism moves the optical member, and changes the distance between the optical member and the light emitting unit, thereby providing the same effect as changing the distance between the excitation light source and the light emitting unit when there is no optical member. Can be obtained. That is, in this case, since the conversion ratio changes according to the distance between the optical member and the light emitting unit, the conversion ratio can be changed by the optical change mechanism changing the distance.

In the light emitting device according to the embodiment of the present invention, it is preferable that the light amount changing mechanism changes an incident angle of excitation light incident on the light emitting unit.

According to the above configuration, the light amount changing mechanism changes the incident angle of the excitation light incident on the light emitting unit, thereby changing the ratio of the excitation light that is not irradiated to the light emitting unit out of the excitation light emitted from the excitation light source, or The irradiation area in the light emission part of the excitation light emitted from the excitation light source can be changed. Therefore, the conversion ratio can be changed by the light amount changing mechanism changing the incident angle.

In the light emitting device according to an embodiment of the present invention, the excitation light source emits light having an oscillation wavelength in a blue region as the excitation light, and the light emitting unit emits fluorescence having a peak wavelength in a yellow region. It is preferable that the first phosphor is included.

In the light emitting device according to the embodiment of the present invention, the first phosphor is preferably yttrium, aluminum, and garnet.

According to the above configuration, the first phosphor (especially yttrium aluminum garnet (YAG)) that emits fluorescence having a peak wavelength in the yellow region is used as the excitation light. In this case, the color temperature of the illumination light can be changed in a wide range by changing the conversion ratio by the light quantity changing means.

The light emitting device according to an embodiment of the present invention preferably further includes a second light source that emits second light different from the excitation light.

According to the above configuration, the second light different from the excitation light emitted from the second light source can be used as part of the illumination light. In this case, the light amount changing mechanism changes the conversion ratio and changes the amount of fluorescence, so that the ratio of the fluorescence to the illumination light (the ratio of the second light) changes, so the color temperature of the illumination light is changed. Can be made.

In the light emitting device according to an embodiment of the present invention, the excitation light source emits a first excitation light source that emits the first excitation light and a second excitation light that has an oscillation wavelength different from that of the first excitation light. A second excitation light source that emits first fluorescence upon receiving the first excitation light emitted from the first excitation light source, and the second excitation light source. A second light-emitting unit that emits second fluorescence upon receiving the second excitation light, wherein the light amount changing mechanism includes the first light emission of the first excitation light emitted from the first excitation light source. At least one of a ratio of the first excitation light that is not converted to fluorescence by the second portion and a ratio of the second excitation light that is not converted to fluorescence by the second light emitting portion of the second excitation light emitted from the second excitation light source. It is preferable to change.

According to the above configuration, the light amount changing mechanism changes the ratio (conversion ratio) of the first excitation light and / or the second excitation light that is not converted into fluorescence by the first light emitting unit and / or the second light emitting unit, and The amount of fluorescence emitted from the light emitting unit and / or the second light emitting unit is changed. Thereby, since the ratio of each fluorescence with respect to illumination light changes, the color temperature of illumination light can be changed.

In addition, the light emitting device according to an embodiment of the present invention preferably includes an input unit that receives a user operation, and the light amount changing mechanism operates according to the user operation received by the input unit.

According to the above configuration, since the light quantity changing mechanism operates according to the user operation received by the input means, the color temperature of the illumination light can be changed according to the user's preference.

Furthermore, the light emitting device according to an embodiment of the present invention includes an excitation light source that emits excitation light, a second light source that emits second light different from the excitation light, and excitation light emitted from the excitation light source. And a light emission unit that emits fluorescence, and a light amount changing mechanism that changes at least one of the output of the excitation light emitted from the excitation light source and the output of the second light emitted from the second light source. It is preferable. The light quantity change mechanism functions as the characteristic change mechanism.

According to the above configuration, the light emitting unit receives the excitation light emitted from the excitation light source and emits fluorescence, so that the fluorescence can be used as illumination light. On the other hand, when the second light source emits second light different from the excitation light, the second light can also be used as part of the illumination light. And since the light quantity changing mechanism that functions as the characteristic changing mechanism changes at least one of the output of the excitation light and the output of the second light, the light quantity of the fluorescence and / or the second light used for the illumination light is changed. Can be changed. Therefore, the color temperature of the illumination light can be changed.

Furthermore, a light emitting device according to an embodiment of the present invention includes a first excitation light source that emits first excitation light and a second excitation light source that emits second excitation light having an oscillation wavelength different from that of the first excitation light. A first light emitting unit that emits first fluorescence upon receiving the first excitation light emitted from the first excitation light source, and a second fluorescence upon receiving the second excitation light emitted from the second excitation light source. A second light emitting unit, and a light amount changing mechanism that changes at least one of an output of the first excitation light emitted from the first excitation light source and an output of the second excitation light emitted from the second excitation light source. It is preferable to provide. The first excitation light source and the second excitation light source function as the excitation light source, the first light emission unit and the second light emission unit function as the light emission unit, and the light amount change mechanism functions as the characteristic change mechanism. To do.

According to the said structure, the 1st light emission part and 2nd light emission part which function as a light emission part are respectively the 1st excitation light and 2nd excitation light radiate | emitted from the 1st excitation light source and 2nd excitation light source which function as an excitation light source. In response, first fluorescence and second fluorescence are emitted. Thereby, the light emitting device can use the first fluorescence and the second fluorescence as illumination light. And since the light quantity change mechanism which functions as a characteristic change mechanism changes at least one of the output of the 1st excitation light and the 2nd excitation light, the light quantity of each fluorescence utilized for illumination light can be changed. Therefore, the color temperature of the illumination light can be changed.

According to the above configuration, since the headlamp includes the light emitting device, the ratio of the excitation light converted into fluorescence or the output of the excitation light can be changed as in the light emitting device. Therefore, the color temperature of the illumination light can be changed.

A light emitting device according to an embodiment of the present invention includes an excitation light source that emits excitation light, a first light emitting unit that emits first fluorescence upon receiving the excitation light, and the first fluorescence upon receiving the excitation light. The second light emitting unit emitting second fluorescence having a peak wavelength different from that of the first light emitting unit, and the irradiation range of the excitation light in the first light emitting unit are made constant, and the irradiation of the excitation light irradiated to the second light emitting unit It is preferable to include an irradiation range changing mechanism that changes the range. The first light emitting unit and the second light emitting unit function as the light emitting unit, and the irradiation range changing mechanism functions as the characteristic changing mechanism.

According to the above configuration, upon receiving the excitation light emitted from the excitation light source, the first light emitting unit that functions as the light emitting unit emits the first fluorescence, and the second light emitting unit that functions as the light emitting unit has the first fluorescence. Emits a second fluorescence having a peak wavelength different from

The irradiation range changing mechanism that functions as a characteristic changing mechanism changes the irradiation range of the excitation light irradiated to the first light emitting unit and the second light emitting unit. For example, the irradiation range changing mechanism changes the irradiation range of the excitation light irradiated to the second light emitting unit after making the irradiation range of the excitation light in the first light emitting unit constant. For example, the irradiation range changing mechanism increases the irradiation range from the state where the excitation light is irradiated to the entire first light emitting unit and is not irradiated to the second light emitting unit. 2 light emitting parts are included. Accordingly, since the second fluorescence can be emitted in addition to the first fluorescence, the ratio of the second fluorescence to the illumination light can be increased.

Thus, the irradiation range changing mechanism can change the ratio of the first fluorescence and the second fluorescence included in the illumination light. Therefore, the color temperature of the illumination light can be changed by changing the ratio.

The light emitting device according to an embodiment of the present invention includes an excitation light source that emits excitation light, a first light emitting unit that emits first fluorescence upon receiving the excitation light, and the first light that receives the excitation light. A second light emitting unit that emits second fluorescence having a peak wavelength different from the fluorescence of the first light emitting unit, an irradiation range changing mechanism that changes an irradiation range of excitation light irradiated to the first light emitting unit and the second light emitting unit, It is preferable to provide. The first light emitting unit and the second light emitting unit function as the light emitting unit, and the irradiation range changing mechanism functions as the characteristic changing mechanism.

The irradiation range changing mechanism that functions as a characteristic changing mechanism changes the irradiation range of the excitation light irradiated to the first light emitting unit and the second light emitting unit. For example, the irradiation range changing mechanism reduces the irradiation range in the first light emitting unit by moving the center of the irradiation range from the first light emitting unit to the second light emitting unit while keeping the area of the irradiation range constant. And the irradiation area | region in a 2nd light emission part is enlarged. Since the first light emitting unit and the second light emitting unit emit fluorescence having different peak wavelengths, the ratio of the first fluorescence and the second fluorescence to the illumination light can be changed by changing the irradiation range.

In the light emitting device according to the embodiment of the present invention, it is preferable that the first light emitting unit and the second light emitting unit are arranged in contact with each other.

When the first light emitting unit and the second light emitting unit are arranged in a non-contact manner, unless the laser beam is irradiated to each of the first light emitting unit and the second light emitting unit, the non-contact region (non contact type) There is a possibility that excitation light is irradiated to the region. Since the excitation light irradiated to the non-contact region is not converted into fluorescence, it can be a factor of reducing the utilization efficiency of the excitation light.

According to the above configuration, since the first light emitting unit and the second light emitting unit are arranged in contact with each other, it is possible to prevent a situation in which the non-contact region is irradiated with excitation light and is not converted into fluorescence. That is, according to this configuration, the excitation light can be used for conversion of fluorescence without waste.

Also, the irradiation range changing mechanism can efficiently change the irradiation range as compared with the case where the first light emitting unit and the second light emitting unit are arranged in a non-contact manner.

In the light emitting device according to the embodiment of the present invention, it is preferable that the second light emitting unit is disposed around the first light emitting unit.

According to the above configuration, in particular, the irradiation range changing mechanism is configured to change the irradiation range of the excitation light irradiated to the second light emitting unit after making the irradiation range of the excitation light in the first light emitting unit constant. Moreover, the irradiation range in the second light emitting unit can be changed efficiently.

In the light emitting device according to the embodiment of the present invention, it is preferable that the first light emitting unit and the second light emitting unit are integrally formed.

According to the above configuration, the manufacturing process and the manufacturing cost can be reduced as compared with the case where each light emitting unit is manufactured separately and provided in the light emitting device.

In the light emitting device according to the embodiment of the present invention, the irradiation range changing mechanism may change the relative positions of the excitation light source, the first light emitting unit, and the second light emitting unit. It is preferable to change the irradiation range.

According to the above configuration, when the distance between the excitation light source and the first light emitting unit and / or the second light emitting unit is changed by changing the relative position, the light is emitted from the excitation light source. Since the optical path width of the excitation light generally increases according to the distance from the emission point, the irradiation range in the second light emitting unit can be changed by the change.

Moreover, since the position of the said irradiation range in a 1st light emission part and a 2nd light emission part can be changed by changing said relative position, the irradiation range in each of a 1st light emission part and a 2nd light emission part is changed. be able to.

The light emitting device according to an embodiment of the present invention further includes an optical member that bends the excitation light emitted from the excitation light source and emits the light to at least one of the first light emission unit and the second light emission unit. The irradiation range changing mechanism preferably changes the irradiation range by moving the optical member.

The optical member bends the excitation light emitted from the excitation light source and emits the excitation light to the first light emitting part and / or the second light emitting part. For example, the optical light is collected in the first light emitting part and / or the second light emitting part. The optical path width of the excitation light after passing through the optical member, such as light, can be emitted so as to be different from the optical path width of the excitation light before entering the optical member and according to the distance from the optical member. That is, the excitation light emitted from the excitation light source is transmitted through the optical member, so that the optical path width is newly changed with the optical member as a base point.

For this reason, in the case where the irradiation range changing mechanism is configured to change the irradiation range of the excitation light irradiated to the second light emitting unit, in particular, while keeping the irradiation range of the excitation light in the first light emitting unit constant, By moving the optical member, the distance between the optical member and the first light emitting unit and / or the second light emitting unit can be changed. This change provides the same effect as changing the distance between the excitation light source and the first light emitting unit and / or the second light emitting unit when no optical member is present.

That is, in this case, since the irradiation range is changed according to the distance between the optical member and the first light emitting unit and / or the second light emitting unit, the optical change mechanism moves the optical member and changes the distance. By doing so, the irradiation range can be changed.

In the light emitting device according to an embodiment of the present invention, the excitation light source emits light having an oscillation wavelength in a blue region as the excitation light, and the first light emitting unit emits fluorescence having a peak wavelength in a yellow region. It is preferable to include a first phosphor that emits as the first fluorescence.

When light having an oscillation wavelength in the blue region is used as excitation light and a first phosphor that emits fluorescence having a peak wavelength in the yellow region (particularly YAG (yttrium, aluminum, garnet)) is used, The color temperature of the illumination light emitted from the light emitting unit can be increased. Therefore, emission of illumination light having a high color temperature can be realized.

In the light emitting device according to an embodiment of the present invention, the excitation light source emits light having an oscillation wavelength in a blue region as the excitation light, and the first light emitting unit is a fluorescent light having a peak wavelength in a green region. It is preferable to include a first phosphor that emits as the first fluorescence.

According to the above configuration, when light having an oscillation wavelength in the blue region is used as excitation light and the first phosphor that emits fluorescence having a peak wavelength in the green region is used, the light is emitted from the first light emitting unit. The color temperature of the illumination light can be increased. Therefore, emission of illumination light having a high color temperature can be realized.

In the light emitting device according to an embodiment of the present invention, the first phosphor is preferably a β-SiAlON: Eu phosphor.

According to the above configuration, since the β-SiAlON: Eu phosphor having high luminous efficiency is used as the first phosphor, the luminous efficiency of the first light emitting unit can be increased. Therefore, a light emitting device with high conversion efficiency to illumination light can be realized.

In the light emitting device according to the embodiment of the present invention, it is preferable that the second light emitting unit includes a second phosphor that emits fluorescence having a peak wavelength in a red region as the second fluorescence.

In the light emitting device according to an embodiment of the present invention, the second phosphor is preferably a CASN: Eu phosphor or a SCASN: Eu phosphor.

When the second phosphor, that is, a red light-emitting phosphor that emits red light (especially, CASN: Eu phosphor or SCASN: Eu phosphor) is used, the second fluorescence is lower than the first phosphor. Color temperature fluorescence can be emitted. For this reason, by changing the irradiation range by the irradiation range changing mechanism, for example, the color temperature of the illumination light can be lowered as compared with the case where the illumination light is composed only of the first fluorescence.

Further, the light emitting device according to an embodiment of the present invention preferably includes an input unit that receives a user operation, and the irradiation range changing mechanism operates according to the user operation received by the input unit.

Since the irradiation range changing mechanism operates according to the user operation received by the input means, it is possible to realize a change in color temperature according to the user's preference.

According to the above configuration, since the headlamp includes the light-emitting device, the illumination range changing mechanism changes the ratio of the first fluorescence and the second fluorescence included in the illumination light, similarly to the illumination device. Can be made. Therefore, the color temperature of the illumination light can be changed by changing the ratio.

A light emitting device according to an embodiment of the present invention includes an excitation light source that generates excitation light emitted from an emission point, a first light emitting unit that emits first fluorescence upon receiving the excitation light, and the excitation light. By changing the relative positional relationship between the second light emitting unit capable of emitting second fluorescent light having a color different from that of the first fluorescent light, and the second light emitting unit and the emission point, It is preferable to include a position control unit that changes the amount of fluorescence generated in No. 2. The position controller functions as the characteristic changing mechanism.

According to the above configuration, a light emitting device according to an embodiment of the present invention includes a first light emitting unit and a second light emitting unit that receive excitation light emitted from an excitation light source and emit fluorescence of different colors. Among these, in the second light emitting unit, the relative positional relationship with the emission point is changed by the position control unit, and the generation amount of the second fluorescence is changed accordingly. As a result, the first fluorescent light and the second fluorescent light whose generation amount changes are mixed, and the illumination light whose spectrum, chromaticity, color temperature, that is, the characteristic of the illumination light changes, is emitted to the outside of the light emitting device. Can do.

As described above, the light emitting device according to the embodiment of the present invention changes the characteristics of the illumination light with a simple structure in which the relative positional relationship between the second light emitting unit and the emission point is changed by the position control unit. Accordingly, various problems such as the above-described conventional problems, that is, the manufacturing cost and the arrangement of the LED chips in the vehicle headlamp can be solved.

A light emitting device according to an embodiment of the present invention includes an excitation light source that generates excitation light, a first light emitting unit that emits first fluorescence in response to excitation light from the excitation light source, and the first fluorescence. And changing the relative positional relationship between the second light emitting unit capable of emitting second fluorescence having a color different from the fluorescence of the first light emitting unit, and the second light emitting unit and the first light emitting unit. Thus, it is preferable to include a position control unit that changes the generation amount of the second fluorescence. The position controller functions as the characteristic changing mechanism.

According to the above configuration, the light emitting device according to an embodiment of the present invention includes the first light emitting unit that emits the first fluorescence in response to the excitation light emitted from the excitation light source, and the first light emitting unit that receives the first fluorescence. A second light emitting unit capable of emitting second fluorescent light having a color different from that of the single light emitting unit. Then, when the relative positional relationship between the second light emitting unit and the first light emitting unit is changed by the position control unit, the generation amount of the second fluorescence is also changed. As a result, the first fluorescent light and the second fluorescent light whose generation amount changes are mixed, and the illumination light whose spectrum, chromaticity, color temperature, that is, the characteristic of the illumination light changes, is emitted to the outside of the light emitting device. Can do.

As described above, the light emitting device according to the embodiment of the present invention has a simple structure in which the relative positional relationship between the second light emitting unit and the first light emitting unit is changed by the position control unit. Thus, the above-described conventional problems can be solved.

In the light emitting device according to an embodiment of the present invention, the position control unit may be configured to change a distance between the second light emitting unit and the optical axis of the excitation light.

According to the above configuration, when the distance between the second light emitting unit and the optical axis of the excitation light is reduced, the irradiation area on the second light emitting unit irradiated with the excitation light or the first fluorescence is large. Become. Conversely, when the distance between the second light emitting unit and the optical axis of the excitation light increases, the irradiation area on the second light emitting unit irradiated with the excitation light or the first fluorescence decreases.

Thus, the amount of second fluorescence generated can be changed by the position control unit changing the distance between the second light emitting unit and the optical axis of the excitation light. As a result, the characteristics of the illumination light can be easily changed.

Further, in the light emitting device according to an embodiment of the present invention, there are a plurality of the second light emitting units, and when the plurality of the second light emitting units are annularly arranged around the optical axis, The position control unit may be configured to change the distance between the plurality of second light emitting units and the optical axis.

There may be a plurality of the second light emitting units, and the plurality of second light emitting units may be arranged in a ring around the optical axis.

At this time, the position control unit changes the distance between the plurality of second light emitting units and the optical axis, so that the irradiation area on the second light emitting unit irradiated with the excitation light or the first fluorescence is changed. By changing it, the generation amount of the second fluorescence can be changed. As a result, the characteristics of the illumination light can be easily changed.

Moreover, in the light emitting device according to an embodiment of the present invention, the position control unit changes the position of the plate-shaped second light emitting unit, thereby changing the second light emitting unit and the optical axis of the excitation light. It may be configured to change the distance between them.

For example, if the emission point from which the excitation light is emitted is fixed, the position control unit changes the position of the plate-like second light emission unit to change the position of the second light emission unit and the excitation light. What is necessary is just to change the distance between optical axes, and the design of a light emitting device with a higher degree of freedom can be realized.

Moreover, in the light emitting device according to an embodiment of the present invention, the position control unit may be configured to move the second light emitting unit in the optical axis direction of the excitation light.

According to the above configuration, the second light emitting unit moves in the optical axis direction of the excitation light. At this time, if the second light emitting unit is brought close to the emission point of the excitation light, the irradiation area on the second light emitting unit irradiated with the excitation light or the first fluorescence is increased. Conversely, when the second light emitting unit is far from the excitation light emission point, the irradiation area on the second light emitting unit irradiated with the excitation light or the first fluorescence is reduced.

As described above, the amount of second fluorescence generated can be changed by moving the second light emitting unit in the optical axis direction of the excitation light. As a result, the characteristics of the illumination light can be easily changed.

Further, in the light emitting device according to an embodiment of the present invention, the second light emitting unit may have a translucency.

With the above-described configuration, the second light emitting unit can ensure light transparency, and the luminous intensity of the illumination light irradiated to the outside of the light emitting device can be increased.

In the light emitting device according to the embodiment of the present invention, the second light emitting unit may include a nanoparticle phosphor.

According to the said structure, a 2nd light emission part can improve light transmittance by including nanoparticle fluorescent substance, As a result, the luminous intensity of the illumination light irradiated to the exterior of a light-emitting device can be raised. .

The particle size of the nanoparticle phosphor is not particularly limited, but may be 1 nm to 5 nm.

In the light emitting device according to the embodiment of the present invention, the excitation light source may be a semiconductor laser, and the semiconductor laser and the first light emitting unit may be separated from each other.

Semiconductor lasers are known to generate a large amount of heat. Therefore, since the semiconductor laser and the first light emitting unit are separated from each other, it is possible to avoid a situation in which the first light emitting unit is deteriorated or damaged by heat and the life of the light emitting unit is shortened.

In the light emitting device according to an embodiment of the present invention, the excitation light source may be a light emitting diode, and the light emitting diode and the first light emitting unit may be integrally formed.

The light emitting diode has a lower calorific value than the semiconductor laser, and even if the light emitting diode and the first light emitting unit are integrally formed, the first light emitting unit is deteriorated or damaged by heat, and the life of the light emitting unit is increased. Is rarely shortened. Therefore, the light emitting diode and the first light emitting unit may be integrally formed, whereby the layout in the light emitting device can be kept compact.

Moreover, it is preferable that the illumination device according to an embodiment of the present invention includes any one of the light-emitting devices described above.

Moreover, it is preferable that a headlamp (for example, a vehicle headlamp) according to an embodiment of the present invention includes any one of the light-emitting devices described above.

The light emitting device according to an embodiment of the present invention can be suitably applied to a lighting device, a headlamp, and the like. Thereby, for example, when the light-emitting device according to an embodiment of the present invention is applied to a headlamp, a headlamp capable of emitting illumination light having high efficiency and high color rendering can be realized. .

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the technical means disclosed in different embodiments can be appropriately combined. Such embodiments are also included in the technical scope of the present invention.

The present invention can be applied to a light emitting device, a lighting device, and the like. For example, the present invention can be applied to headlamps for automobiles, headlamps for vehicles other than automobiles and moving objects (for example, humans, ships, aircraft, submersibles, rockets, etc.) and other lighting devices. Further, as other lighting devices, for example, it can be applied to a searchlight, a projector, a home lighting device, and the like.

Also, the present invention can adjust or change the color temperature of the illumination light, and is particularly suitable for a headlamp for vehicles and the like. Furthermore, the present invention can be suitably applied to a light emitting device that is required to change the characteristics of illumination light with a simple structure, in particular, an illumination device and a vehicle headlamp.

1 Translucent substrate (thermally conductive substrate)
1 'reflecting member 2 light emitting part (light emitting body, first light emitting part, second light emitting part)
2a 1st light emission part 2b 2nd

light emission part

3, 3a-3e Diffusion part (diffusion member)
4 Parabolic reflector (reflector)
4 Reflector 4h Half parabolic reflector (reflector)
4p Thermal conduction member 5 Substrate 6 Excitation light source unit (excitation light source)
6a Excitation light source unit (excitation light source)
7 Light emitting part (diffusion part)
7L, 7R Screw 7a Laser light irradiation surface 8 Optical member 9 Light guide member 9 'Light guide member 9a Incident end (one closer to the excitation light source)
9a 'entrance end 9b exit end (the one closer to the light emitter)
9b 'emitting

end

10, 20 to 110 headlamp (light emitting device, lighting device, headlamp)
11 LD chip (excitation light source)
24a Light emitting part (first light emitting part)
24b Light emitting part (second light emitting part)
27 Main light source (first light source, laser light source)
28 Sub-light source (second light source, characteristic change mechanism)
29 Aspherical lens 30 Headlamp 55 Optical fiber 61 Support member (light quantity changing mechanism, irradiation range changing mechanism, characteristic changing mechanism)
62 Support member drive unit (light quantity change mechanism, irradiation range change mechanism, characteristic change mechanism)
62a Translucent substrate driving unit (irradiation range changing mechanism, characteristic changing mechanism)
63 Semiconductor laser (excitation light source)
63a Semiconductor laser (first excitation light source)
63b Semiconductor laser (second excitation light source)
64 Light emitting diode (second light source)
65 Ferrule 71 Diffuser 72 Semiconductor laser array (excitation light source)
75 Housing 76 Extension 77 Lens 79 Laser light irradiation area (irradiation range)
91 Blocking filter 92

Transparent plate

93, 99 First light emitting unit 94 Second light emitting unit 95 Position control unit (characteristic changing mechanism)
96 LED chip 97 Electrode 98 Package 161 Convex lens (optical member)
200 Laser downlight (light emitting device, lighting device)
613 Input unit (input means)
642 Output control unit (light quantity change mechanism, characteristic change mechanism)
215 Optical fiber bundle (light guide member)
C Light intensity distribution R1, R1 ′ Spot diameter a, b Length SUF1 surface SUF2 surface SUF3 Light reflecting concave surface SUF4 Irradiation surface

Claims

An excitation light source that emits excitation light;
A light emitter that emits fluorescence by irradiation of excitation light emitted from the excitation light source,
The area of the spot when the excitation light is irradiated toward the light emitter is larger than the area of the light emitter when the light emitter is viewed from the side irradiated with the excitation light. Light emitting device.
The light-emitting device according to claim 1, further comprising a diffusing unit that diffuses at least the excitation light irradiated to the outside of the irradiation surface irradiated with the excitation light of the light emitter.
3. The light emitting device according to claim 1, wherein a ratio of a cross-sectional area of the light emitter to an area of the spot of the excitation light is ¼ or more and 、２ or less.
The excitation light source emits blue region excitation light,
The light emitting device according to any one of claims 1 to 3, wherein the light emitter includes a yellow light emitting phosphor that emits fluorescence in a yellow region.
The excitation light source emits blue region excitation light,
4. The light emitting device according to claim 1, wherein the phosphor includes a green light-emitting phosphor that emits fluorescence in a green region and a red light-emitting phosphor that emits fluorescence in a red region. 5. apparatus.
Comprising a thermally conductive substrate for diffusing heat generated in the luminous body,
The light emitting device according to any one of claims 1 to 5, wherein an irradiation surface side of the light emitting body on which the excitation light is irradiated is held by the thermally conductive substrate.
A reflection member that reflects the excitation light;
The light emitting device according to any one of claims 1 to 5, wherein a side of the light emitter facing the irradiation surface irradiated with the excitation light is held by the reflecting member.
There are multiple excitation light sources,
The light-emitting device according to claim 1, further comprising a light guide member that guides excitation light emitted from each of the excitation light sources to the light emitter.
The light-emitting device according to claim 8, wherein a cross-sectional area of the light guide member closer to the light emitter is smaller than a cross-sectional area of the light guide member closer to the excitation light source.
The light guide member receives excitation light emitted from the plurality of excitation light sources at at least one incident end, and emits excitation light incident from the incident end from each of the plurality of emission ends.
The light emitting device according to claim 8, wherein the light emitter emits fluorescence in response to excitation light emitted from each of the emission end portions.
At least one excitation light source that emits excitation light;
At least one light emitting unit that emits fluorescence in response to excitation light emitted from the excitation light source;
A light-emitting device comprising: a characteristic changing mechanism that changes a characteristic of the emitted light by changing a ratio of the fluorescence included in the emitted light emitted from the apparatus to the outside.
A first light source that emits excitation light;
A light emitting unit that emits fluorescence in response to excitation light emitted from the first light source;
A second light source that emits second light having a wavelength region different from that of the excitation light,
The fluorescent light emitted from the light emitting unit and the second light emitted from the second light source are emitted as illumination light,
The light emitting device according to claim 11, wherein the second light source functions as the characteristic changing mechanism.
The first light source emits light having an oscillation wavelength from an ultraviolet region to a blue-violet region as the excitation light,
The light emitting device according to claim 12, wherein the second light source emits light having an oscillation wavelength in a blue region as the second light.
The light emitting device according to claim 13, wherein the light emitting unit includes a first phosphor having an absorption peak wavelength of light in a wavelength range of 350 nm or more and 420 nm or less.
The light-emitting device according to claim 14, wherein the first phosphor has an absorptance of 70% or more when receiving excitation light in a wavelength range of 350 nm or more and 420 nm or less.
16. The light emitting device according to claim 14, wherein the first phosphor is a Caα-SiAlON: Ce phosphor.
The light emitting device according to any one of claims 14 to 16, wherein the light emitting unit includes a second phosphor that emits fluorescence having a peak wavelength in a wavelength range of 630 nm or more and 650 nm or less.
The second light source emits laser light as the second light,
18. The light emitting device according to claim 12, further comprising a diffusion unit that diffuses laser light emitted from the second light source.
The light emitting unit functions as the diffusion unit,
The light emitting device according to claim 18, wherein the laser light emitted from the second light source is diffused by the light emitting unit.
The light-emitting device according to any one of claims 12 to 19, wherein the first light source is a laser light source.
21. The light emitting device according to claim 20, further comprising a cutoff filter that blocks the excitation light.
An excitation light source that emits excitation light;
A light emitting unit that emits fluorescence in response to excitation light emitted from the excitation light source;
A light amount change mechanism that changes a ratio of excitation light that is not converted into fluorescence by the light emitting unit in excitation light emitted from the excitation light source,
The light-emitting device according to claim 11, wherein the light quantity change mechanism functions as the characteristic change mechanism.
23. The light emitting device according to claim 22, wherein the light quantity changing mechanism changes a ratio of excitation light that is not irradiated to the light emitting unit in excitation light emitted from the excitation light source.
23. The light emitting device according to claim 22, wherein the light amount changing mechanism changes an irradiation area of the excitation light emitted from the excitation light source in the light emitting unit.
25. The light-emitting device according to claim 22, wherein the light quantity change mechanism moves the light-emitting unit.
An optical member that bends the excitation light emitted from the excitation light source and emits the light to the light emitting unit;
25. The light-emitting device according to claim 22, wherein the light quantity changing mechanism moves the optical member.
25. The light emitting device according to claim 22, wherein the light amount changing mechanism changes an incident angle of excitation light incident on the light emitting unit.
The excitation light source emits light having an oscillation wavelength in a blue region as the excitation light,
28. The light emitting device according to any one of claims 22 to 27, wherein the light emitting unit includes a first phosphor that emits fluorescence having a peak wavelength in a yellow region.
29. The light emitting device according to claim 28, wherein the light emitting unit includes a second phosphor that emits fluorescence having a peak wavelength in a wavelength range of 630 nm or more and 650 nm or less.
30. The light emitting device according to any one of claims 22 to 29, further comprising a second light source that emits a second light different from the excitation light.
The excitation light source includes a first excitation light source that emits first excitation light, and a second excitation light source that emits second excitation light having an oscillation wavelength different from the first excitation light,
The light emitting unit receives a first excitation light emitted from the first excitation light source and emits a first fluorescence, and receives a second excitation light emitted from the second excitation light source and receives a second excitation light. A second light emitting unit that emits fluorescence,
The light quantity changing mechanism includes a ratio of the first excitation light that is not converted into fluorescence by the first light emitting unit in the first excitation light emitted from the first excitation light source, and the first excitation light emitted from the second excitation light source. 28. The light-emitting device according to claim 22, wherein at least one of the ratios of the second excitation light that is not converted into fluorescence by the second light-emitting unit in the two excitation lights is changed.
An input means for accepting a user operation;
32. The light emitting device according to claim 22, wherein the light quantity changing mechanism operates according to a user operation received by the input unit.
An excitation light source that emits excitation light;
A second light source that emits second light different from the excitation light;
A light emitting unit that emits fluorescence in response to excitation light emitted from the excitation light source;
A light amount changing mechanism for changing at least one of the output of the excitation light emitted from the excitation light source and the output of the second light emitted from the second light source,
The light emitting device according to claim 11, wherein the light emitting device functions as the characteristic changing mechanism.
A first excitation light source that emits first excitation light;
A second excitation light source that emits second excitation light having an oscillation wavelength different from that of the first excitation light;
A first light emitting unit that emits first fluorescence in response to the first excitation light emitted from the first excitation light source;
A second light emitting unit that emits second fluorescence in response to the second excitation light emitted from the second excitation light source;
A light amount changing mechanism that changes at least one of the output of the first excitation light emitted from the first excitation light source and the output of the second excitation light emitted from the second excitation light source,
The first excitation light source and the second excitation light source function as the excitation light source,
The first light emitting unit and the second light emitting unit function as the light emitting unit,
The light-emitting device according to claim 11, wherein the light quantity change mechanism functions as the characteristic change mechanism.
An excitation light source that emits excitation light;
A first light emitting unit that emits first fluorescence in response to the excitation light;
A second light emitting unit that receives the excitation light and emits second fluorescence having a peak wavelength different from that of the first fluorescence;
An irradiation range changing mechanism for changing the irradiation range of the excitation light irradiated to the second light emitting unit after making the irradiation range of the excitation light in the first light emitting unit constant,
The first light emitting unit and the second light emitting unit function as the light emitting unit,
The light emitting device according to claim 11, wherein the irradiation range changing mechanism functions as the characteristic changing mechanism.
An excitation light source that emits excitation light;
A first light emitting unit that emits first fluorescence in response to the excitation light;
A second light emitting unit that receives the excitation light and emits second fluorescence having a peak wavelength different from that of the first fluorescence;
An irradiation range changing mechanism for changing an irradiation range of excitation light applied to the first light emitting unit and the second light emitting unit,
The first light emitting unit and the second light emitting unit function as the light emitting unit,
The light emitting device according to claim 11, wherein the irradiation range changing mechanism functions as the characteristic changing mechanism.
37. The light emitting device according to claim 35 or 36, wherein the first light emitting unit and the second light emitting unit are disposed in contact with each other.
38. The light emitting device according to claim 37, wherein the second light emitting unit is disposed around the first light emitting unit.
39. The light emitting device according to claim 37 or 38, wherein the first light emitting unit and the second light emitting unit are integrally formed.
The irradiation range changing mechanism changes the irradiation range by changing a relative position between the excitation light source and the first light emitting unit and the second light emitting unit. 40. The light emitting device according to any one of 39.
An optical member that bends the excitation light emitted from the excitation light source and emits the light to at least one of the first light emitting unit and the second light emitting unit;
The light emitting device according to any one of claims 35 to 39, wherein the irradiation range changing mechanism changes the irradiation range by moving the optical member.
The excitation light source emits light having an oscillation wavelength in a blue region as the excitation light,
The light emitting device according to any one of claims 35 to 41, wherein the first light emitting unit includes a first phosphor that emits fluorescence having a peak wavelength in a yellow region as the first fluorescence. .
43. The light emitting device according to claim 42, wherein the first phosphor is a β-SiAlON: Eu phosphor.
44. The light emitting device according to claim 35, wherein the second light emitting unit includes a second phosphor that emits fluorescence having a peak wavelength in a red region as the second fluorescence. .
An input means for accepting a user operation;
The light emitting device according to any one of claims 35 to 44, wherein the irradiation range changing mechanism operates according to a user operation received by the input means.
43. The light emitting device according to claim 28, wherein the first phosphor is yttrium aluminum garnet.
45. The light emitting device according to claim 17, 29 or 44, wherein the second phosphor is a CASN: Eu phosphor or a SCASN: Eu phosphor.
An excitation light source that generates excitation light emitted from the emission point;
A first light emitting unit that emits first fluorescence in response to the excitation light;
A second light-emitting unit capable of receiving the excitation light and emitting second fluorescence having a color different from that of the first fluorescence;
A position control unit that changes the amount of the second fluorescence generated by changing a relative positional relationship between the second light emitting unit and the emission point;
The first light emitting unit and the second light emitting unit function as the light emitting unit,
The light emitting device according to claim 11, wherein the position control unit functions as the characteristic changing mechanism.
An excitation light source that generates excitation light;
A first light emitting unit that emits first fluorescence in response to excitation light from the excitation light source;
A second light emitting unit capable of receiving the first fluorescence and emitting a second fluorescence of a color different from the fluorescence of the first light emitting unit;
A position control unit that changes the amount of the second fluorescence generated by changing a relative positional relationship between the second light emitting unit and the first light emitting unit;
The first light emitting unit and the second light emitting unit function as the light emitting unit,
The light emitting device according to claim 11, wherein the position control unit functions as the characteristic changing mechanism.
The light emitting device according to claim 48 or 49, wherein the position control unit changes a distance between the second light emitting unit and the optical axis of the excitation light.
There are a plurality of the second light emitting units,
When the plurality of second light emitting units are annularly arranged around the optical axis,
51. The light emitting device according to claim 50, wherein the position control unit changes a distance between a plurality of the second light emitting units and the optical axis.
51. The position control unit changes a distance between the second light emitting unit and the optical axis of the excitation light by changing a position of the plate-like second light emitting unit. The light emitting device according to 1.
51. The light emitting device according to claim 48, wherein the position control unit moves the second light emitting unit in an optical axis direction of the excitation light.
54. The light emitting device according to any one of claims 48 to 53, wherein the second light emitting unit has translucency.
The light emitting device according to any one of claims 48 to 54, wherein the second light emitting unit includes a nanoparticle phosphor.
The excitation light source is a semiconductor laser,
56. The light emitting device according to any one of claims 48 to 55, wherein the semiconductor laser and the first light emitting unit are separated from each other.
The excitation light source is a light emitting diode,
56. The light emitting device according to any one of claims 48 to 55, wherein the light emitting diode and the first light emitting unit are integrally formed.
An illuminating device comprising the light emitting device according to any one of claims 1 to 57.
A headlamp comprising the light-emitting device according to any one of claims 1 to 57.