JP2012221634A - Lighting system and headlamp - Google Patents

Abstract

The color temperature of illumination light is changed.
A headlamp includes a semiconductor laser that emits laser light, a first light emitting unit that emits first fluorescence upon receiving the laser light, and a peak different from the first fluorescence upon receiving the laser light. The irradiation range of the laser light applied to the second light emitting unit 2b is changed after making the irradiation range of the laser light in the second light emitting unit 2b emitting the second fluorescence having the wavelength and the first light emitting unit 2a constant. A support member 11 and a support member drive unit 12 to be provided.
[Selection] Figure 1

Description

  The present invention relates to an illumination device that functions as a high-intensity light source and a headlamp that includes the illumination device.

  In recent years, semiconductor light emitting devices such as light emitting diodes (LEDs) and semiconductor lasers (LDs) are used as excitation light sources, and excitation light generated from these excitation light sources is emitted to light emitting units including phosphors. Studies of lighting devices that use fluorescent light generated as a result of illumination have become active.

  Examples of techniques relating to such a light emitting device include lamps disclosed in Patent Documents 1 and 2. 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.

JP 2005-150041 A (released on June 9, 2005) JP 2003-295319 A (published on October 15, 2003)

  However, Patent Documents 1 and 2 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 1 and 2 did not recognize the necessity of changing the color temperature.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an illumination device capable of changing the color temperature of illumination light.

  In order to solve the above problems, an illumination device according to the present invention receives an excitation light source that emits excitation light, a first light-emitting unit that emits first fluorescence upon receiving the excitation light, and receives the excitation light. The second light emitting unit emitting second fluorescence having a peak wavelength different from that of the first fluorescence and the irradiation range of the excitation light in the first light emitting unit are made constant, and then the second light emitting unit is irradiated. And an irradiation range changing mechanism for changing the irradiation range of the excitation light.

  According to the above configuration, upon receiving excitation light emitted from the excitation light source, the first light emitting unit emits the first fluorescence, and the second light emitting unit has the second peak wavelength different from that of the first fluorescence. Fluoresce.

  The irradiation range changing mechanism changes the irradiation range of the excitation light applied 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.

  In order to solve the above problems, an illumination device according to 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 excitation light. A second light emitting unit that emits second fluorescence having a peak wavelength different from that of the first fluorescent light, and irradiation that changes an irradiation range of the excitation light irradiated to the first light emitting unit and the second light emitting unit. And a range change mechanism.

  According to the above configuration, upon receiving excitation light emitted from the excitation light source, the first light emitting unit emits the first fluorescence, and the second light emitting unit has the second peak wavelength different from that of the first fluorescence. Fluoresce.

  The irradiation range changing mechanism changes the irradiation range of the excitation light applied 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.

  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.

  In the lighting device according to 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.

  Moreover, compared with the case where the 1st light emission part and the 2nd light emission part are arrange | positioned in non-contact, the irradiation range change mechanism can change the said irradiation range efficiently.

  In the illumination device according to 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 illumination device according to the present invention, it is preferable that the first light emitting unit and the second light emitting unit are integrally formed.

  According to the said structure, compared with the case where each light emission part is manufactured separately and it equips with an illuminating device, a manufacturing process and manufacturing cost can be reduced.

  In the illumination device according to the present invention, 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. It is preferable to make it.

  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.

  Moreover, the illumination device according to 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, and the irradiation range. The 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 illumination device according to 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 that the 1st fluorescent substance emitted as 1 fluorescence is included.

  In the lighting device according to the present invention, it is preferable that the first phosphor is yttrium, aluminum, and garnet.

  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 illumination device according to 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 green region. It is preferable that the 1st fluorescent substance emitted as 1 fluorescence is included.

  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 illumination device according to 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, an illuminating device with high conversion efficiency to illumination light can be realized.

  In the illumination device according to 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 lighting device according to 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.

  Moreover, it is preferable that the illumination device according to the present invention 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 in accordance with the user operation received by the input unit, it is possible to realize a change in color temperature according to the user's preference.

  Moreover, it is preferable that the headlamp which concerns on this invention is provided with the illuminating device as described above.

  According to the above configuration, since the headlamp includes the illumination 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.

  As described above, the illumination device according to 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 source that receives the excitation light. A second light emitting unit that emits second fluorescence having a peak wavelength different from the fluorescence, and an excitation light irradiation range in the first light emitting unit is made constant, and the excitation light irradiated to the second light emitting unit And an irradiation range changing mechanism that changes the irradiation range.

  In addition, as described above, the illumination device according to the present invention includes an excitation light source that emits excitation light, a first light emitting unit that emits first fluorescence in response to the excitation light, and the first light source that receives the excitation light. A second light emitting unit that emits second fluorescence having a peak wavelength different from that of the first fluorescence, and 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. .

  Therefore, the lighting device of the present invention has an effect that the color temperature of the illumination light can be changed.

1 is a half sectional view showing a schematic configuration of a headlamp according to an embodiment of the present invention. It is a block diagram which shows schematic structure of the headlamp which concerns on one 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 which concerns on one Embodiment of this invention, (a) is an example of arrangement | positioning in case the whole light emission part is a rectangular parallelepiped shape, (b) is 1st light emission. (C) is an arrangement example when the whole light emitting part is cylindrical, (d) is the whole light emitting part is cylindrical, and the light emitting part is An arrangement example in the case of a triple structure is shown. It is a figure which shows the modification of the light emission part which concerns on one Embodiment of this invention, (a) is sectional drawing which shows an example of the light emission part adhere | attached on the translucent board | substrate 1, (b) is (a). It is a perspective view which shows an example of the light emission part shown in FIG. It is a figure which shows the positional relationship of the light emission part and light guide member in the headlamp which concerns on one Embodiment of this invention, and the magnitude | size of the laser beam irradiation area | region at that time, (a) is a laser beam 1st light emission part The case where the size of the laser light irradiation area is the smallest when the entire light receiving surface is irradiated is shown, and (b) shows the position where the light emitting part and the light guide member are separated from each other and the laser is smaller than the case of (a). The case where the light irradiation area is large is shown, and (c) shows the case where the positions of the light emitting part and the light guide member are farther apart and the laser light irradiation area 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 basic structure of a semiconductor laser, (a) shows the circuit diagram of a semiconductor laser typically, (b) is a perspective view which shows the basic structure of a semiconductor laser. It is a figure which shows the modification of the headlamp which concerns on one Embodiment of this invention. It is a half sectional view which shows schematic structure of the headlamp which concerns on 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 which concerns on another embodiment of this invention, (a) is the 1st light emission part and the 2nd light emission part being the same shape, and arrange | positioning in contact (B) is a modified example of (a), an arranged example when the shapes of the first light emitting part and the second light emitting part are different, and (c) is a modified example of (a). Yes, an arrangement example in the case where the first light emitting unit and the second light emitting unit 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 which concerns on another embodiment of this invention, (a) shows the case where the laser beam is irradiated only to the 1st light emission part. , (B) shows the case where both the first light emitting unit and the second light emitting unit are irradiated with laser light. It is the schematic which shows the external appearance of the light emission unit with which the laser downlight which concerns on one Embodiment of this invention is equipped, 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 and light emission part of an optical fiber with which the said laser downlight is equipped. 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.

[Embodiment 1]
The following describes one embodiment of the present invention with reference to FIGS. Here, a headlamp (headlight) 10 for an automobile will be described as an example of the illumination device of the present invention. However, the lighting device of the present invention may be realized as a headlamp of a vehicle other than an automobile or a moving object (for example, a 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 10 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 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, the headlamp 10 includes a translucent substrate 1, a light emitting unit 2, a reflecting mirror 4, a fixing member 5, an excitation light source unit (excitation light source) 6, a screw 7, a lens 8, a light guide member 9, A support member 11 and a support member drive unit 12 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 11 and the support member driving unit 12 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 with respect to laser light (excitation light) having an oscillation wavelength of at least 440 nm to 480 nm. 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. In addition, although the outer diameter of the translucent board | substrate 1 shown in FIG. 1 is larger than the outer diameter of the light emission part 2, it may be comparable as the outer diameter of the light emission part 2. FIG.

  A light emitting unit 2 is disposed on the surface of the translucent substrate 1 that faces the surface on which laser light 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 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.

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.

  Further, the thickness of the translucent substrate 1 shown in FIG. 1 is preferably 30 μm or more and 1.0 mm or less, more preferably 0. More preferably, it is 2 mm or more and 1.0 mm or less. If the thickness of the translucent substrate 1 exceeds 1.0 mm, the rate at which the laser light applied to the light emitting unit 2 is absorbed by 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 the laser light emitted from the semiconductor laser 61, 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 61 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 inorganic glass, and may be a so-called organic-inorganic hybrid glass or a resin material such as a 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 consideration of reducing the reflectance R 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 R 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 10, a combination of a blue laser beam emitted from a semiconductor laser 61 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).

  Here, the yellow light emitting phosphor is a phosphor that generates 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 luminous efficiency, the first light emitting portion 2a with excellent heat resistance and stable with high luminous efficiency can be realized.

Examples of oxynitride phosphors that emit green light include β-SiAlON: Eu phosphors, Ca ³ -SiAlON: Ce phosphors doped with Ce ³⁺ , and the like. The β-SiAlON: Eu phosphor exhibits strong light 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-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 made by dissolving alumina (Al ₂ O ₃ ), silica (SiO ₂ ), rare earth elements, 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, examples of the nitride-based phosphor include CASN: Eu phosphor and SCASN: Eu phosphor. The CASN: Eu phosphor emits red fluorescence when the 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.

  Further, as another suitable 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).

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

(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 beam that travels forward of the headlamp 10. The reflecting mirror 4 is, for example, a curved surface (cup shape) member having a metal thin film formed on the surface thereof.

  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.

  In consideration of increasing the utilization efficiency of the fluorescent light emitted from the light emitting unit 2 as the illumination light, the light emitting unit 2 is preferably 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 5)
The fixing member 5 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 portion 2 (with the translucent substrate 1 and It is fixed to the reflecting mirror 4 with screws 7 so that the center of the contact surface) substantially coincides. In the light emitting unit 2 shown in FIG. 1, the light emitting member 9 is fixed so that the center of the light emitting end portion of the light guide member 9 and the center of the light receiving surface of the first light emitting unit 2 a substantially coincide. The excitation light source unit 6 is joined to the fixing member 5 so as to surround the insertion port. Although the material of the fixing member 5 is not particularly limited, metals such as iron and copper can be exemplified.

  The fixing member 5 is formed with a storage portion 51 that can store the support member 11. Due to the presence of the storage portion 51, the support member 11 can be moved in the optical axis direction of the laser beam in accordance with the drive of the support member drive portion 12. By this movement, the laser light irradiation range (the size of the laser light irradiation region 30 (see FIG. 5)) 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 30 will be described later with reference to FIG.

(Excitation light source unit 6)
The excitation light source unit 6 is a housing that houses, for example, three semiconductor lasers (excitation light sources) 61. About the fixing method and wiring method of the semiconductor laser 61, since the conventional fixing method and wiring method should just be utilized, description is abbreviate | omitted here.

  The semiconductor laser 61 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 part 2 can be irradiated with laser light having high output and high coherency, so that the light emitting part 2 can be made small and a high-luminance headlamp 10 can be realized. Although three semiconductor lasers 61 are shown in FIG. 1, it is not always necessary to provide a plurality of semiconductor lasers 61, and only one semiconductor laser 61 may be provided. However, it is easier to use a plurality of semiconductor lasers 61 in order to obtain high output pump light.

  The semiconductor laser 61 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 the 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 61 may have a plurality of light emitting points on one chip. The oscillation wavelength of the semiconductor laser 61 is not limited to 450 nm, and may be any wavelength in the blue region from 440 nm to 480 nm.

  Thus, the semiconductor laser 61 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. Further, 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 8)
Next, the lens 8 is provided in the opening of the reflecting mirror 4 and seals the headlamp 10. 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 10 through the lens 8.

  The lens 8 may be a convex lens or a concave lens. Further, the lens 8 does not necessarily have a lens function, and has at least translucency for transmitting 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.

(Light guide member 9)
The light guide member 9 guides the laser light oscillated by the semiconductor laser 61 to the light emitting unit 2, and includes an incident end (semiconductor laser 61 side) on which the laser light emitted from the semiconductor laser 61 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.

  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.

  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 radiate 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 61, the light emission part 2 can be designed small. In other words, the headlamp 10 with high output and high brightness can be realized.

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

  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 11)
The support member 11 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 12. It is a thing. When the support member 11 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 30 (see FIG. 5). It can be changed.

  Moreover, the support member 11 is provided so that it may contact with the gear of the support member drive part 12, and the groove | channel is provided in the surface which contacts, so that it may mesh with a gear. As a result, the support member 11 can move in accordance with the drive of the support member drive unit 12. Note that the surface of the support member 11 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 11 is not particularly limited. However, considering that the support member 11 is inserted into the reflecting mirror 4 due to its movement, the material of the support member 11 is a light-transmitting material like the light-transmitting substrate 1. Is preferred. Further, the shape of the support member 11 may be a flat plate shape or a rod shape. Further, the support member 11 may be formed integrally with the translucent substrate 1.

  In the present embodiment, the support member 11 is described as moving in the optical axis direction of the laser beam. However, if the size of the laser beam irradiation region 30 can be freely changed, the optical axis is not necessarily required. There is no need to move in the direction.

(Supporting member driving unit 12)
The support member drive unit 12 is for moving the support member 11 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 11. The gear is provided such that the surface thereof is in contact with the support member 11 and the rotation axis thereof is in a direction perpendicular to the moving direction of the support member 11. There may be one gear for the support member 11 or a plurality of combinations. Moreover, the stepping motor should just be provided so that the rotation can be propagated to a gear.

  When the support member drive unit 12 receives a move instruction from the move control unit 141 (see FIG. 2), the stepping motor is driven and the gear rotates. Since the gear and the support member 11 are provided in contact with each other, the rotational force of the gear is transmitted to the support member 11 and moves the support member 11 in the optical axis direction of the laser light.

  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 in the state at the time of manufacture, the headlamp 10 will radiate | emit the 1st fluorescence emitted from the 1st light emission part 2a as illumination light. Then, when the support member driving unit 12 moves the light emitting unit 2 through the support member 11, the second light emitting unit 2b is also irradiated with laser light, and the second fluorescence is included in a part of the illumination light. it can.

  That is, the support member drive unit 12 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 61 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 61 is generally increased according to the distance from the emission point. For this reason, the laser irradiation range (ratio of the second light emitting unit 2b included in the laser light irradiation region 30) in the second light emitting unit 2b can be changed by the change.

<Further structure of the headlamp 10>
Next, the further structure of the headlamp 10 is demonstrated using FIG. FIG. 2 is a block diagram illustrating an example of a schematic configuration of the headlamp 10. The headlamp 10 includes an input unit 13 (input means), a control unit 14 and a storage unit 15 in addition to the components shown in FIG. Since the support member drive unit 12 and the semiconductor laser 61 have been described above, description thereof will be omitted. In the present embodiment, these members are described as components of the headlamp 10. 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 10 is attached. May be realized.

(Input unit 13)
The input unit 13 receives user operations such as a drive instruction of the support member drive unit 12 and an output change instruction of the semiconductor laser 61, and is realized by a touch pad or the like.

  For example, when the input unit 13 receives a driving instruction as a user operation, the movable control unit 141 operates the support member driving unit 12 according to the received user operation. In this case, the user can give the drive instruction via the input unit 13 while confirming the intensity of the illumination light with his / her own eyes, so that the support member 11 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 14)
The control unit 14 mainly includes a movable control unit 141 and an output control unit 142. The control part 14 controls the member which comprises the headlamp 10, for example by running a control program. The control unit 14 reads the program stored in the storage unit 15 to 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 12. Various processes such as control and output control of the semiconductor laser 61 are performed.

  The movable control unit 141 performs drive control of the support member drive unit 12 in accordance with the drive instruction received from the input unit 13. For example, every time a drive instruction is received, the movable control unit 141 performs predetermined drive on the stepping motor of the support member drive unit 12. Apply voltage.

  The output control unit 142 performs output control of the semiconductor laser 61 and applies, for example, a drive voltage set during manufacturing to the semiconductor laser 61.

(Storage unit 15)
The storage unit 15 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. It is. The control unit 14 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 primary storage unit may be described as having the function of the primary storage unit. The storage unit 15 stores, for example, a driving voltage value for the support member driving unit 12 or the semiconductor laser 61.

<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. 3 shows an arrangement example of the first light emitting unit 2 a and the second light emitting unit 2 b in the headlamp 10. (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.

  FIG. 3 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 12 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. For this reason, in the arrangement of FIG. 3, for example, the laser light irradiation region 30 (the ratio of the second light emitting unit 2b included in the region) is changed more efficiently than in the arrangement shown in FIG. 10A, for example. be able to.

  FIG. 3A shows an arrangement example of the light emitting unit 2 shown in FIG. 1, 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 30 (see FIG. 5) when the distance from the light guide member 9 is the shortest. I just need it. Further, 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 30 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 emission part 2 is a rectangle is illustrated, not only this but a square may be sufficient. However, considering that the irradiation area formed by the laser light emitted from the semiconductor laser 61 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. 3A, for example, two low-melting-point glasses having the above shape are manufactured, and a YAG: Ce phosphor is dispersed inside one, and a CASN: Eu phosphor is dispersed inside the other, and 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, the case where the 1st light emission part 2a and the 2nd light emission part 2b are arrange | positioned non-contact like FIG.3 (b) is shown. In the present embodiment, the laser light emitted from the plurality of semiconductor lasers 61 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 12 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. 3A, 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 the 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 10 is configured to use the laser light emitted from the non-contact area A as the 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. In FIG. 3B, in the headlamp 10, the laser light irradiation region 30 includes the first light emitting unit 2 a and the non-contact region A when the light emitting unit 2 is located closest to the light guide member 9. Designed to be

  FIG. 3C is a modification of FIG. 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. 3A. For example, if the above light distribution characteristic standards are considered An elliptical shape is preferable.

  The light emitting unit 2 is not limited to a double structure, and may have a triple structure as shown in FIG. 3D, for example. In FIG.3 (d), the light emission part 2 has a hollow part by the magnitude | size of the 1st light emission part 2a and the 2nd light emission part 2b, and is a cylinder-shaped 3rd light emission of diameter 4.0mm and height 0.5mm. 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 10 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 12 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 10 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, when the illumination light having a low color temperature is emitted (second fluorescence is emitted), the laser light irradiation region 30 (light emitting unit) is compared with the case where only the first fluorescence is used as illumination light. 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 8. 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 consideration, the phosphor with the longest peak wavelength is used as the first phosphor among the phosphors used in the light emitting section 2 and used in the state as manufactured. 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 manufacturing cost can be reduced as compared with the case where each light emitting unit is manufactured separately and provided in the headlamp 10.

  When each light emitting part is integrally formed, the light emitting part 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. 4 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 portion 2a and the second light-emitting portion 2b) formed by straight lines connecting the vertices of the light-receiving surface 201a and the vertices of the emission surface 201b 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. 4 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 included. It can also be realized when manufactured separately.

<Movement control of light emitting unit 2>
(Regarding changes in the laser light irradiation region 30)
Next, how the size of the laser light irradiation region 30 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 30 has an elliptical shape and the light emitting unit 2 has a rectangular parallelepiped shape.

  FIG. 5 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 30 at that time. (A) of the figure shows a case where the size of the laser light irradiation region 30 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 same figure shows the case where the position of the light emission part 2 and the light guide member 9 is separated from the case of (a), and the laser light irradiation area | region 30 is large, (c) is (b). The case where the position of the light emission part 2 and the light guide member 9 leaves | separates and the laser beam irradiation area | region 30 is larger than the case of is shown.

First, as shown in FIG. 5 (a), when the distance between the light emitting portion 2 and the light guide member 9 is d _A, the laser beam is irradiated on the entire light receiving surface of the first light emitting portion 2a, a second light emitting 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 only necessary 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 30, only the first light emitting unit 2a is used. Is irradiated with laser light.

Next, in FIG. 5 (b), indicates when the distance between the light emitting portion 2 and the light guide member 9 becomes _d B (> _{d A).} In this case, by the movement control portion 141 drives the supporting member driving unit 12, the supporting member driving unit 12, via a support member 11, a distance between the light emitting portion 2 and the light guide member 9 is d _B The light emitting unit 2 is moved.

  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 30 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.

In other words, due to the above movement, in FIG. 5B, the support member drive unit 12 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 30 is changed. The ratio of the 2nd light emission part 2b contained is larger than the case of Fig.5 (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.5 (a) by increasing the ratio of the 2nd fluorescence contained in illumination light.

FIG. 5C 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 2b included in the laser light irradiation region 30. Is larger than in the case of FIG. Therefore, the color temperature of the illumination light can be further reduced.

On the other hand, for example, the second light included in the illumination light is moved from the position of the light emitting unit 2 in FIG. 5C to the position of the light emitting unit 2 in FIG. 5A (changed from the distance d _C to the distance d _A ). Therefore, the color temperature of the illumination light can be increased.

  As described above, the support member drive unit 12 changes the size of the laser light irradiation region 30 in the light emitting unit 2 via the support member 11. In other words, the support member driving unit 12 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 illuminating. 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 driving unit 12 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 30 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 30 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. 5A 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 12 gradually changes the state in which the laser light irradiation region 30 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 61 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. 6 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 61 is 440 nm (chromaticity point 41: blue region) and the peak wavelength of the phosphor is 570 nm (chromaticity point 42: yellow region), 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 61 is 440 nm (chromaticity point 41: blue region) and the peak wavelength of the phosphor is 649 nm (chromaticity point 43: red region), yellow light is emitted as shown by a straight line 44. 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. 6, the laser light is also applied to the light receiving surface of the second light emitting unit 2 b from the state where the entire light receiving surface of the first light emitting unit 2 a 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.

<Structure of semiconductor laser 61>
Next, the basic structure of the semiconductor laser 61 will be described. FIG. 7A schematically shows a circuit diagram of the semiconductor laser 61, and FIG. 7B is a perspective view showing the basic structure of the semiconductor laser 61. As shown in the figure, the semiconductor laser 61 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 other examples of a substrate for a semiconductor laser, a group IV semiconductor represented by a group IV semiconductor such as Si, Ge and SiC, GaAs, GaP, InP, AlAs, GaN, InN, InSb, GaSb and AlN Group V compound semiconductors, Group II-VI compound semiconductors such as ZnTe, ZeSe, ZnS and ZnO, oxide insulators such as ZnO, Al ₂ O ₃ , SiO ₂ , TiO ₂ , CrO ₂ and CeO ₂ , and SiN Any material of the nitride insulator is used.

  The anode electrode 17 is for injecting current into the active layer 111 through the cladding 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 clad layer 113 and the clad layer 112.

  As the 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. Moreover, you may be comprised by II-VI group compound semiconductors, such as Zn, Mg, S, Se, Te, and ZnO.

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

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

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

  Note that a reflective film (not shown) for laser oscillation is formed on the back side cleaved surface 115 opposite to the front side cleaved surface 114, and 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 front-side cleavage surface 114 which is a low reflectance end face.

  The clad layer 113 and the clad layer 112 are made of n-type and p-type GaAs, GaP, InP, AlAs, GaN, InN, InSb, GaSb, and AlN group III-V compound semiconductors, and ZnTe, ZeSe. , ZnS, ZnO, and other II-VI group compound semiconductors, and by applying a forward bias to the anode electrode 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 semiconductor laser 61 will be described.

  First, the laser light oscillated from the semiconductor laser 61 is irradiated onto the phosphor included in the light emitting unit 2, whereby electrons existing in the phosphor are excited from a low energy state to a high energy state (excited state).

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

  In this way, the phosphors emit light when electrons excited to the high energy state transition to the low energy state.

  White light can be composed of a mixture of three colors that satisfy the principle of equal colors, or a mixture of two colors that satisfy the relationship of complementary colors, 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.

<Modification 1 of the headlamp 10>
FIG. 8 is a view showing a modified example of the headlamp 10. The headlamp 10 bends the laser light emitted from the semiconductor laser 61 between the light-transmitting substrate 1 and the light guide member 9 and forms at least one of the first light emitting unit 2a and the second light emitting unit 2b. A convex lens 16 (optical member) that emits light is provided, and a support member 11 is provided on a part of the outer periphery of the convex lens 16. That is, in the headlamp 10, the support member driving unit 12 moves the convex lens 16 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 16, the optical path width of the laser light after passing through the convex lens 16 is different from the optical path width of the laser light before entering the convex lens 16, as shown in FIG. It can be emitted so as to change according to the distance. In other words, the laser light is transmitted through the convex lens 16, and the optical path width is newly changed with the convex lens 16 as a base point. For this reason, by moving the convex lens 16, the distance between the convex lens 16 and the first light emitting unit 2a and / or the second light emitting unit 2b can be changed. Since the irradiation range of the laser light in the second light emitting unit 2b changes according to the distance between the convex lens 16 and the light emitting unit 2, the support member driving unit 12 changes the distance, resulting in the color temperature of the illumination light. Can be changed.

  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 16, 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 16. That is, the convex lens 16 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 16 is preferably coated with an optical film (reflection film) that prevents reflection of laser light. Moreover, if it is a lens which has the above-mentioned function, although the shape and material of the convex lens 16 are not specifically limited, It is preferable that the transmittance | permeability of 440-480 nm is high.

<Effect of the headlamp 10>
The headlamp 10 includes a support member 11 and a support member driving unit 12 that change the irradiation range of the laser light irradiated to the second light emitting unit 2b after making 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 2]
The following will describe another embodiment of the present invention with reference to FIGS. FIG. 9 is a diagram illustrating a schematic configuration of the headlamp 20 (lighting device, headlamp). In addition, about the member similar to Embodiment 1, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The headlamp 20 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 light by the translucent substrate driving unit 12a. In FIG. 9, the movement in the vertical direction is realized without the support member 11. However, the movement is not limited to this, and the movement may be realized via the support member 11.

(Translucent substrate 1a)
The function and material of the light-transmitting substrate 1a are the same as those of the light-transmitting substrate 1 of the first 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 (the light guide member 9 side) so as to mesh with the gear of the translucent substrate driving unit 12a. 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 unit 12a)
The translucent substrate driving unit 12a 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 12a.

  The gear is provided so 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.

  Moreover, the translucent board | substrate drive part 12a moves the translucent board | substrate 1a by the movement instruction | indication from the movable control part 141 (refer FIG. 2) similarly to Embodiment 1. FIG.

  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 30 can be changed, the translucent board | substrate drive part 12a will transmit 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. 10 shows an arrangement example of the first light emitting unit 2 a and the second light emitting unit 2 b in the headlamp 20. (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. 10 (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 only an example, and it may be a size in consideration of laser light irradiation, conversion efficiency to fluorescence, heat dissipation efficiency, and the like, as in the first embodiment.

  When the first light emitting unit 2a and the second light emitting unit 2b are provided in contact with each other, as with the first 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. 10B is a modification of FIG. 10A, and shows a case where the first light emitting unit 2a and the second light emitting unit 2b are different in size. In FIG. 10, 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. Similar to FIG. 10A, the size is not limited to this.

  In the headlamp 20, the light emitting unit 2 and the like are positioned so that the laser light irradiation area 30 (see FIG. 11A) is included in the light receiving surface of the first light emitting unit 2a. For this reason, in the case of FIG. 10B, 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 20 is used in the state at the time of manufacture, the 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, the color temperature can be changed more finely as in FIG.

(Regarding changes in the laser light irradiation region 30)
Next, how the size of the laser light irradiation region 30 changes will be described with reference to FIG. FIG. 11 is a diagram showing a change in the size of the laser light irradiation region 30 in the light emitting unit 2. FIG. 11A shows 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. 11A, as in the first embodiment, the first fluorescence emitted from the first light emitting unit 2a has a color temperature higher than the second fluorescence 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. 11B, the translucent substrate driving unit 12a moves the translucent substrate 1a from the state of FIG. 11A in the direction perpendicular to the optical axis direction of the laser beam, thereby irradiating the laser beam. The center of the region is moved from the first light emitting unit 2a toward the second light emitting unit 2b while keeping the size of 30 constant. By this movement, the ratio of the laser light irradiation region 30 included in the first light emitting unit 2a is reduced and the ratio of the laser light irradiation region 30 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.

  Moreover, if the ratio of the 2nd fluorescence becomes larger than the case of FIG.11 (b), the color temperature of irradiated light can be lowered | hung further. On the other hand, when the translucent substrate 1a is moved from the state of FIG. 11B to the state of FIG. 11A, the color temperature of the irradiated light can be increased.

(Effect of the headlamp 20)
The headlamp 20 includes a translucent substrate driving unit 12a 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 12a 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 part 2b (that is, the relative position between the semiconductor laser 61 and these light emitting parts) is changed. In this case, since the position of the laser light irradiation region 30 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 3]
The following will describe another embodiment of the present invention with reference to FIGS. In addition, about the member similar to Embodiment 1 and 2, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  Here, the laser downlight 200 as an example of the illuminating device of this invention is demonstrated. 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 semiconductor laser 61 as illumination light. It is.

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

  FIG. 12 is a schematic diagram showing the appearance of the light emitting unit 210 and the conventional LED downlight 300. FIG. 13 is a cross-sectional view of the ceiling where the laser downlight 200 is installed. FIG. 14 is a cross-sectional view of the laser downlight 200.

  As shown in FIGS. 13 and 14, the laser downlight 200 (light emitting unit 210) is powerful by taking advantage of the thin and lightweight features of the light emitting unit 210 by opening only a small hole 402 through the optical fiber 215 in the top plate 400. It is affixed on the top plate 400 using an 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 6 a that supplies laser light to the light emitting unit 210 via an optical fiber 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 215. The optical fiber 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. 14, the light emitting unit 210 includes a light transmissive substrate 1, a light emitting unit 2 including a first light emitting unit 2 a and a second light emitting unit 2 b, a support member 11, a support member driving unit 12, a case 211, a transparent unit. An optical plate 213, an optical fiber 215, and a ferrule 217 are provided.

  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, in the vicinity of the bottom surface of the recess 212, for example, as shown in FIGS. 5A to 5C, the size of the laser light irradiation region 30 can be changed by changing the position of the light emitting unit 2. The translucent substrate 1 including the light emitting unit 2 is disposed at the position. As described in the first embodiment, the change in the position of the light emitting unit 2 is caused by the support member driving unit 12 passing the support member 11 through the translucent substrate 1 provided with the light emitting unit 2 to the optical axis of the laser beam. Realized by moving in the direction. In order to realize this movement, the housing 211 is formed with a storage portion 218 in which the support member 11 can be stored.

  Further, a small hole 219 through which the optical fiber 215 is passed is formed in the housing 211, and the optical fiber 215 extends to the vicinity of the light emitting unit 2 through the hole 219. As a result, the laser light emitted from the semiconductor laser 61 is applied to the light emitting unit 2 via the optical fiber 215. Further, the emission end 215 a of the optical fiber 215 is held by a ferrule 217. The optical fiber 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. The translucent plate 213 has the same function as the lens 8, and the fluorescence of the light emitting unit 2 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 FIG. 12, the light emitting unit 210 has a circular outer edge, but the shape of the light emitting unit 210 (more strictly, the shape of the housing 211) is not particularly limited.

  In the downlight, unlike a 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 6a includes a semiconductor laser 61, an optical fiber 215, and an aspheric lens 216.

  An incident end 215b, which is one end of the optical fiber 215, is connected to the excitation light source unit 6a, and laser light oscillated from the semiconductor laser 61 is incident on the incident end 215b of the optical fiber 215 via the aspherical lens 216. Is incident on.

  The aspheric lens 216 is a lens for causing the laser light (excitation light) oscillated from the semiconductor laser 61 to enter the incident end 215 b that is one end of the optical fiber 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 high transmittance near 450 nm and good heat resistance.

  In FIG. 14, three semiconductor lasers 61 and three aspherical lenses 216 are provided inside the excitation light source unit 6 a, and a bundle of optical fibers extending from each aspherical lens 216 is guided to one light emitting unit 210. . That is, in FIG. 14, one set of light sources including three semiconductor lasers 61 and three aspheric 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 215 and ferrule 217)
The optical fiber 215 is a light guide member that guides the laser light oscillated by the semiconductor laser 61 to the light emitting unit 2, and is a bundle of a plurality of optical fibers. The optical fiber 215 includes an optical fiber having an incident end 215b that receives laser light emitted from the semiconductor laser 61 and an emission end 215a that emits laser light incident from these incident ends.

  FIG. 15 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.

  The optical fiber 215 has a two-layer structure in which an intermediate 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 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 215 are limited to those described above. Instead, the cross section perpendicular to the major axis direction of the optical fiber 215 may be rectangular.

  Further, as shown in FIG. 14, the ferrule 217 holds the plurality of emission end portions 215 a of the optical fiber 215 in a predetermined pattern with respect to the light emitting unit 2. 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 with a rod-like or cylindrical member extending from the housing 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. 12, 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, the number of emission points may be one. Therefore, it is possible to obtain an effect that the shadow caused by the illumination light is clearly displayed. Further, as described in the first embodiment, the color rendering property of illumination light is obtained by using several types of oxynitride phosphors for the entire light emitting unit 2, such as using a high color rendering phosphor for the phosphor of the second light emitting unit 2b. Can be increased.

  FIG. 16 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.

  Further, the LED downlight 300 requires a power source and a cooling unit for each light source, which causes a problem that the total cost increases.

  Moreover, since the housing | casing 302 is comparatively large, the problem that it is often difficult to arrange | position the LED downlight 300 in the clearance gap between the top plate 400 and the heat insulating material 401 arises.

  On the other hand, 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 reduced in size and thickness. 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. 17 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.

  In addition, since the excitation light source unit 6a can be installed at a place (height) that can be easily reached by the user, the semiconductor laser 61 can be easily replaced even if the semiconductor laser 61 breaks down. In addition, the plurality of semiconductor lasers 61 can be collectively managed by guiding the optical fibers 215 extending from the plurality of light emitting units 210 to one excitation light source unit 6a. Therefore, even when a plurality of semiconductor lasers 61 are replaced, the replacement can be easily performed.

  In the case of a type using a high color rendering phosphor in the LED downlight 300, a light beam of about 500 lm 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, 3 .3W light output is required. 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 semiconductor laser 61 that emits laser light, the first light emitting unit 2a, the second light emitting unit 2b, and the recess 212 as a reflecting mirror. And at least one light emitting unit 210. Then, the support member driving unit 12 changes the position of the light emitting unit 2 through the support member 11, thereby making the irradiation range of the laser light in the first light emitting unit 2a constant and irradiating the second light emitting unit 2b. The irradiation range of the laser beam to be changed is changed. Accordingly, as in the first 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 (the light emitting unit 2 of Embodiment 1) shown in FIGS. 3A to 3D is used as the laser downlight 200 is described as an example. Not limited to this, it is also possible to use the light emitting section 2 (the light emitting section 2 of the second embodiment) shown in FIGS.

  In this case, for example, as described in Embodiment 2, the laser downlight 200 does not include the support member 11 but includes the translucent substrate drive unit 12a that can directly move the translucent substrate 1a. . The translucent substrate driving unit 12a moves the translucent substrate 1a in a direction parallel to the emission surface of the emission end 5a and in the direction in which the first light emitting unit 2a and the second light emitting unit 2b are arranged. In other words, the translucent substrate drive unit 12a 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 30. . 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.

[Another expression of the present invention]
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.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims. That is, embodiments obtained by combining technical means appropriately modified within the scope of the claims are also included in the technical scope of the present invention.

  The 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.

  In addition, information for identifying 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 have selected in the storage unit 15. Information indicating the color temperature may be stored in association with each other. In this case, for example, the input unit 13 acquires information for identifying the owner or the user, the movable control unit 141 reads out information indicating the color temperature corresponding to the information from the storage unit 15, and moves the support member driving unit 12. Driven to move the support member 11. 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.

  The present invention can change the color temperature of illumination light, and is particularly suitable for a headlamp for a vehicle or the like.

2 light emitting parts (first light emitting part, second light emitting part)
2a 1st light emission part 2b 2nd light emission part 6 Excitation light source unit (excitation light source)
10 Headlamp (lighting device, headlamp)
11 Support member (irradiation range changing mechanism)
12 Support member drive (irradiation range changing mechanism)
12a Translucent substrate driving unit (irradiation range changing mechanism)
13 Input section (input means)
16 Convex lens (optical member)
30 Laser beam irradiation area (irradiation range)
61 Semiconductor laser (excitation light source)

Claims (15)

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 illumination device comprising: an irradiation range changing mechanism that changes an irradiation range of the excitation light applied to the second light emitting unit while making the irradiation range of the excitation light in the first light emitting unit constant. . 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 illumination device comprising: an irradiation range changing mechanism that changes an irradiation range of excitation light applied to the first light emitting unit and the second light emitting unit.   The lighting device according to claim 1, wherein the first light emitting unit and the second light emitting unit are disposed in contact with each other.   The lighting device according to claim 3, wherein the second light emitting unit is disposed around the first light emitting unit.   The lighting device according to claim 3 or 4, wherein the first light emitting unit and the second light emitting unit are integrally formed.   The said irradiation range change mechanism changes the said irradiation range by changing the relative position of the said excitation light source and the said 1st light emission part and the said 2nd light emission part, The said irradiation range is characterized by the above-mentioned. The lighting device according to any one of 5. 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 illumination device according to any one of claims 1 to 5, 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,
8. The illumination device according to claim 1, 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. 9. .   The lighting device according to claim 8, wherein the first phosphor is yttrium aluminum garnet. The excitation light source emits light having an oscillation wavelength in a blue region as the excitation light,
The lighting device according to claim 1, wherein the first light emitting unit includes a first phosphor that emits fluorescence having a peak wavelength in a green region as the first fluorescence. .   The lighting device according to claim 10, wherein the first phosphor is a β-SiAlON: Eu phosphor.   12. The illumination device according to claim 1, 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. .   The lighting device according to claim 12, wherein the second phosphor is a CASN: Eu phosphor or a SCASN: Eu phosphor. An input means for accepting a user operation;
The illumination device according to claim 1, wherein the irradiation range changing mechanism operates according to a user operation received by the input unit. A headlamp comprising the illumination device according to claim 1.

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