JP6022176B2 - Light emitting device, lighting device, and vehicle headlamp - Google Patents

Description

  The present invention relates to an illumination device including a semiconductor light emitting element and a vehicle headlamp.

  In recent years, semiconductor light-emitting elements such as LEDs (Light Emitting Diodes) and LDs (Laser Diodes) are used as excitation light sources, and illumination light is generated by irradiating light-emitting parts including phosphors with excitation light generated from these excitation light sources. There has been proposed a lighting device.

  In relation to such an illuminating device, Patent Document 1 discloses an illuminating device that irradiates a light emitting unit including a phosphor with a laser beam using an LD and uses fluorescence emitted from the light emitting unit as illumination light. Has been. In this illumination device, the fluorescence emitted from the light emitting unit is reflected by the reflector and emitted toward a predetermined light projection range.

JP 2003-295319 A (published on October 15, 2003)

  Here, in general lighting devices, by making the light projection range variable, it is possible to expand the light projection range according to the situation, or to illuminate only the necessary range with the necessary light amount to save power Can be achieved.

  Particularly in recent years, in the field of vehicle headlamps such as automobile headlights, it has been desired to develop a technique for changing the projection range of illumination light emitted from the headlights in accordance with the traveling state of the vehicle. For example, it is preferable to efficiently illuminate a narrow area in front of the vehicle when traveling at high speed on an expressway or the like, while it is preferable to illuminate a wide area including the vicinity of the front of the vehicle when traveling at low speed in an urban area or the like.

  Therefore, it is desirable from the viewpoint of realizing a safe traffic environment to secure a good field of view of the driver by changing the projection range of the illumination light to an optimal range according to the traveling state of the vehicle.

  However, Patent Document 1 does not describe a technique for changing the projection range, and cannot contribute to the development of a technique for changing the projection range of illumination light.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to change the projection range of the emitted illumination light with a simple configuration by changing the radiation angle distribution of the light emitting unit. An object of the present invention is to provide a lighting device and a vehicle headlamp.

  In order to solve the above-described problem, an illumination device according to the present invention includes a light emitting unit that emits light and a light projecting unit that projects light emitted from the light emitting unit, and the light emitting unit emits light. The radiation angle distribution of the light can be changed at least between the first radiation angle distribution and a second radiation angle distribution wider than the first radiation angle distribution.

In the above configuration, the light emitting unit can change the radiation angle distribution of the emitted light at least between the first radiation angle distribution and the second radiation angle distribution wider than the first radiation angle distribution. It is. Therefore, the light projecting range in which the light emitted from the light emitting unit with the first radiation angle distribution is projected by the light projecting unit, and the light emitted from the light projecting unit with the second radiation angle distribution by the light projecting unit. The light projection range to be projected can be made different.

  Therefore, according to said structure, the illuminating device which can change the light projection range of the illumination light to radiate | emit with a simple structure is realizable by changing the radiation angle distribution of a light emission part.

  In the illumination device according to the present invention, the light emitting unit includes at least a first light emitting portion that emits light with the first radiation angle distribution and a second light that emits light with the second radiation angle distribution. It is preferable that one of the first light-emitting portion and the second light-emitting portion selectively emit light.

  In the above configuration, the light emitting unit includes at least a first light emitting part that emits light with a first radiation angle distribution and a second light emitting part that emits light with a second radiation angle distribution, One of the light emitting portion and the second light emitting portion is selectively caused to emit light. Therefore, the radiation angle distribution of the light emitted from the light emitting unit can be changed between the first radiation angle distribution and the second radiation angle distribution.

  Therefore, according to said structure, the light projection range of the illumination light radiate | emitted from an illuminating device can be changed by selectively making one of a 1st light emission part and a 2nd light emission part light-emit.

  In the illumination device according to the present invention, the light emitting unit includes a phosphor that receives excitation light and emits fluorescence that is the light, and one of the first light emitting part and the second light emitting part includes: It is preferable that the excitation light is selectively irradiated.

  In the above configuration, the light emitting unit includes a phosphor that emits fluorescence upon receiving excitation light, and excitation light is selectively irradiated to one of the first light emitting portion and the second light emitting portion. Therefore, one of the first light emitting portion and the second light emitting portion irradiated with the excitation light can be selectively emitted to emit fluorescence.

  Therefore, according to the above configuration, it is possible to change the radiation angle distribution of the fluorescence emitted from the light emitting unit by selectively irradiating one of the first light emitting part and the second light emitting part with the excitation light. it can.

  Moreover, in the illuminating device according to the present invention, the illuminating device further includes a movable placing portion for placing the light emitting portion, and the placing portion is provided on one of the first light emitting portion and the second light emitting portion. It is preferable to change the relative position or angle of the light emitting unit with respect to the excitation light so that the excitation light is irradiated.

  In the above configuration, the mounting unit is provided to change the relative position or angle of the light emitting unit with respect to the excitation light so that one of the first light emitting part and the second light emitting part is irradiated with the excitation light. A light emitting unit is mounted on the mounting unit. Therefore, it is possible to irradiate one of the first light emitting portion and the second light emitting portion with excitation light by controlling the movable mounting portion.

  Therefore, according to the above configuration, the emission angle of the fluorescence emitted from the light emitting unit by selectively emitting one of the first light emitting part and the second light emitting part by controlling the mounting part. Distribution can be changed.

  Moreover, in the illuminating device which concerns on this invention, it is preferable that the said excitation light is irradiated toward the focus of the said light projection part.

  In the above configuration, since the excitation light is irradiated toward the focal point of the light projecting unit, one of the first light emitting part and the second light emitting part can be emitted at the focal point.

  Therefore, according to the above configuration, the fluorescence emitted from the first light emitting part or the second light emitting part can be efficiently projected far away by controlling the optical path by the light projecting unit. The light projection characteristics of the apparatus can be improved.

  In the lighting device according to the present invention, it is preferable that the second light emitting portion has a shape larger in thickness than the first light emitting portion.

  The emission angle distribution of the emitted fluorescence varies depending on the shape of the light emitting unit including the phosphor. Normally, the emission angle distribution of fluorescence becomes narrower as the thickness of the light emitting portion is smaller, and the emission angle distribution of fluorescence becomes wider as the thickness of the light emitting portion is larger. Therefore, by forming the second light emitting part in a shape having a thickness larger than that of the first light emitting part, the radiation angle distribution (second radiation angle distribution) of the second light emitting part is changed to the first light emitting part. The radiation angle distribution (first radiation angle distribution) can be made wider.

  Therefore, according to said structure, the light emission part which can change the radiation angle distribution of the emitted fluorescence is realizable by changing the thickness of a light emission part partially.

  In the illumination device according to the present invention, the first light emitting portion has a flat plate shape substantially parallel to a placement surface on which the light emitting portion is placed, and the second light emitting portion is as described above. It is preferable that the cross-sectional area parallel to the bottom surface is gradually reduced in a direction perpendicular to the bottom surface in contact with the placement surface.

  In the above configuration, the first light emitting portion has a flat plate shape substantially parallel to the mounting surface, and the second light emitting portion is directed in a direction perpendicular to the bottom surface in contact with the mounting surface. The cross-sectional area parallel to the bottom surface is gradually reduced. Therefore, the radiation angle distribution of the first light emitting part can be limited, and the radiation angle distribution of the second light emitting part can be effectively widened.

  Therefore, according to said structure, the light emission part which radiate | emits fluorescence with different radiation angle distribution is suitably realizable.

  Moreover, in the illuminating device according to the present invention, the light emitting portion has a continuous shape with a gradually changing thickness, and a portion having an arbitrary thickness among the continuous shapes becomes the first light emitting portion. It is preferable that a portion having a larger thickness than the portion having the arbitrary thickness is the second light emitting portion.

  In said structure, a light emission part is a continuous shape from which thickness changes gradually. In this case, of the continuous shape, a portion having an arbitrary thickness acts as the first light emitting portion, and a portion having a larger thickness than the portion having the arbitrary thickness acts as the second light emitting portion. Become. Therefore, for example, the irradiation angle distribution of the fluorescence emitted from the light emitting unit can be gradually widened by irradiating the excitation light along the direction in which the thickness of the light emitting unit increases.

  Therefore, according to the above configuration, it is possible to emit fluorescence with a number of different radiation angle distributions from the light emitting unit according to the thickness of the light emitting unit irradiated with the excitation light. Can be changed to a desired range.

  Moreover, in the illuminating device which concerns on this invention, it is preferable that the said light emission part is ring shape.

  In said structure, a light emission part is a ring shape from which thickness changes gradually. Therefore, for example, by rotating the light emitting unit, it is possible to irradiate excitation light to a portion having a different thickness in the ring-shaped light emitting unit.

  Therefore, according to the above configuration, it is possible to emit fluorescence with a number of different radiation angle distributions according to the irradiation position of the excitation light with respect to the ring-shaped light emitting unit. The range can be changed.

  Moreover, in the illuminating device which concerns on this invention, it is preferable that the said excitation light is a laser beam.

  In said structure, since the laser beam is used as excitation light, the fluorescent substance contained in a light emission part can be excited efficiently.

  Therefore, according to said structure, a high-intensity illuminating device is realizable.

  Further, by using laser light as the excitation light, it becomes easy to squeeze the excitation light into a small spot and irradiate the light emitting portion. Therefore, since a light emitting part (point light source) having a small size and high brightness can be realized, the optical path of the fluorescence emitted from the light emitting part can be accurately controlled by the small light projecting part.

  Therefore, according to said structure, the light projection characteristic of an illuminating device can be improved.

  In the illumination device according to the present invention, the light emitting unit includes at least a first light emitting element that emits light with the first radiation angle distribution and a second light that emits light with the second radiation angle distribution. It is preferable that one of the first light emitting element and the second light emitting element is selectively lit.

  In the above configuration, the light emitting unit includes at least a first light emitting element that emits light with a first radiation angle distribution and a second light emitting element that emits light with a second radiation angle distribution, One of the first light emitting element and the second light emitting element is selectively lit. Therefore, the radiation angle distribution of the light emitted from the light emitting unit can be changed between the first radiation angle distribution and the second radiation angle distribution.

  Therefore, according to the above configuration, the light projection range of the illumination light emitted from the illumination device can be changed by selectively lighting one of the first light-emitting element and the second light-emitting element.

  In the lighting device according to the present invention, a movable mounting portion for mounting the first light emitting element and the second light emitting element, and lighting of the first light emitting element and the second light emitting element. A lighting switching unit that switches between the first light emitting element and the second light emitting element at the focal point of the light projecting unit. It is preferable to turn on the first light emitting element or the second light emitting element arranged at the focal point.

In the above configuration, the movable light-emitting unit on which the first light-emitting element and the second light-emitting element are mounted, and one of the first light-emitting element and the second light-emitting element is projected by the mounting unit. And a lighting switching unit that lights the first light emitting element or the second light emitting element arranged at the focal point when arranged at the focal point of the unit. Therefore, one of the first light emitting element and the second light emitting element can be turned on at the focal point of the light projecting unit.

  Therefore, according to the above configuration, the light emitted from the first light emitting element or the second light emitting element can be efficiently projected far away by controlling the optical path by the light projecting unit. The light projection characteristics of the apparatus can be improved.

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

  According to said structure, since a 1st light emitting element and a 2nd light emitting element are LED, it radiate | emits from an illuminating device by selectively switching lighting of two LED from which the radiation angle distribution of the emitted light differs. The projection range of the illumination light to be emitted can be changed.

  Moreover, in the illuminating device which concerns on this invention, it is preferable that the said description part is provided so that a slide or rotation is possible.

  According to said structure, since the mounting part is provided so that sliding or rotation is possible, the position or angle of a light emission part, etc. in an illuminating device can be changed easily.

  In the illuminating device according to the present invention, it is preferable that the light emitting unit can change the radiation angle distribution of the emitted light to three or more radiation angle distributions different from each other.

  According to the above configuration, since the light emitting unit can change the radiation angle distribution of the emitted light to three or more different radiation angle distributions, illumination is performed according to the radiation angle distribution that can be changed by the light emitting unit. The projection range of the illumination light emitted from the apparatus can be changed.

  The vehicle headlamp according to the present invention includes the above-described illumination device in order to solve the above-described problems.

  Therefore, according to said structure, the vehicle headlamp which can change the light projection range of the illumination light to radiate | emit with a simple structure by changing the radiation angle distribution of a light emission part is realizable. .

  Further, in the vehicle headlamp according to the present invention, the radiation angle distribution of the light emitted from the light emitting unit is changed between the first radiation angle distribution and the first radiation according to the speed of the vehicle on which the illumination device is mounted. It is preferable to change between two radiation angle distributions.

  In the above configuration, the vehicle headlamp changes the radiation angle distribution of the light emitted from the light emitting unit between the first radiation angle distribution and the second radiation angle distribution according to the speed of the vehicle. To do. Therefore, the projection range of the illumination light emitted from the illumination device can be changed according to the speed of the vehicle.

  For example, when the traveling speed of the vehicle becomes equal to or lower than a predetermined speed, the radiation angle distribution of the light emitted from the light emitting unit is changed from the first radiation angle distribution to the second radiation angle distribution, thereby Can be illuminated by a vehicular headlamp. On the other hand, when the traveling speed of the vehicle exceeds a predetermined speed, the radiation angle distribution of the light emitted from the light emitting unit is changed from the second radiation angle distribution to the first radiation angle distribution, so that the front of the vehicle Can be illuminated by a vehicle headlamp.

For this reason, it is possible to switch, for example, to illuminate a wide range including the vicinity of the front of the vehicle when traveling at low speed in an urban area or the like, and to brightly illuminate only the front of the vehicle when traveling at high speed on an expressway or the like.

  Therefore, according to the above configuration, it is possible to change the projection range of the illumination light emitted from the illumination device according to the traveling speed of the vehicle, so that it is possible to ensure a good view of the driver, A safe driving environment can be realized.

  As described above, the illumination device according to the present invention includes a light emitting unit that emits light and a light projecting unit that projects light emitted from the light emitting unit, and the light emitting unit emits emitted light. The angle distribution can be changed at least between the first radiation angle distribution and a second radiation angle distribution wider than the first radiation angle distribution.

  Therefore, according to the present invention, there is provided an illumination device and a vehicle headlamp that can change the projection range of emitted illumination light with a simple configuration by changing the radiation angle distribution of the light emitting unit. There is an effect that can be.

1 is a cross-sectional view illustrating a schematic configuration of a headlight according to Embodiment 1. FIG. It is a perspective view which shows the external appearance structure of the light emission part shown by FIG. It is a perspective view which shows the external appearance structure of the reflector shown by FIG. FIG. 2 is a top view of the headlight shown in FIG. 1. It is a bottom view which shows an example of the crank mechanism which implement | achieves the reciprocating motion of the mounting base shown by FIG. It is a block diagram which shows the principal part structure of the headlight shown by FIG. (A) is the perspective view which showed typically the emission angle distribution of the fluorescence when the 1st light emission part was light-emitted, and the mode of light projection, (b) was made to light-emit the 2nd light emission part. It is the perspective view which showed typically the distribution of fluorescence and the mode of light projection at the time. (A) is a top view showing the headlight when the first light emitting portion is arranged at the focal point of the reflector, and (b) is the head when the second light emitting portion is arranged at the focal point of the reflector. It is a top view which shows a light. It is a graph which shows the projection angle distribution of the illumination light projected from the reflector of the headlight shown by Fig.8 (a) and (b). It is a top view for demonstrating the change of the light projection range of the illumination light projected from the reflector of the headlight shown by Fig.8 (a) and (b). (A) And (b) is a perspective view which shows the external appearance structure of the modification regarding the light emission part shown by FIG. (A)-(c) is a perspective view which shows another modification regarding the light emission part shown by FIG. (A)-(c) is a perspective view which shows another modification regarding the light emission part shown by FIG. (A)-(c) is a perspective view which shows the other modification regarding the light emission part shown by FIG. (A) is a top view which shows the further another modification regarding the light emission part shown by FIG. 2, (b) is a perspective view which shows the cross-sectional shape of the ring-shaped light emission part shown by (a). . It is a top view which shows a headlight provided with the ring-shaped light emission part shown by Fig.15 (a) and (b). It is sectional drawing which shows an example of the mechanism which implement | achieves the rotational motion of the mounting base shown by FIG. 6 is a cross-sectional view illustrating a schematic configuration of a headlight according to a second embodiment. FIG. (A) is sectional drawing which shows 1st LED shown by FIG. 18, (b) is sectional drawing which shows 2nd LED shown by FIG. It is a block diagram which shows the principal part structure of the headlight shown by FIG. (A) is a top view showing the headlight when the first LED is arranged at the focal point of the reflector, and (b) is the headlight when the second LED is arranged at the focal point of the reflector. FIG. (A) And (b) is sectional drawing which shows an example of the structure for controlling the radiation angle distribution of LED.

Embodiment 1
The following describes one embodiment of the present invention with reference to FIGS. In the present embodiment, a headlight (vehicle headlamp) 1 that satisfies the light distribution characteristic standard of a traveling headlamp (high beam) for an automobile is taken as an example of a vehicle headlamp including the lighting device according to the present invention. Will be described.

  The vehicle headlamp according to the present invention may be a low-beam headlamp, and is used for a vehicle other than an automobile or a moving object (for example, a ship, an aircraft, a submersible, a rocket). It may be realized as a lamp.

  The lighting device according to the present invention can be applied to, for example, a searchlight, a projector, a home lighting device, a commercial lighting device, an outdoor lighting device, and the like in addition to the vehicle headlamp.

<Configuration of headlight 1>
First, a schematic configuration of the headlight 1 according to the present embodiment will be described with reference to FIGS. The headlight 1 according to the present embodiment switches the light projection range of the illumination light emitted from the headlight 1 by selectively causing portions of the light emitting unit 4 having different shapes to emit light.

  FIG. 1 is a cross-sectional view showing a schematic configuration of a headlight 1 according to the present embodiment. As shown in FIG. 1, the headlight 1 includes a laser element 2, a lens 3, a light emitting unit 4, a reflector (light projecting unit) 5, a mounting table (mounting unit) 7, a metal base 8, and a radiation fin 9. I have.

(Laser element 2)
The laser element 2 is an excitation light source that oscillates laser light (excitation light). The laser element 2 may have one light emitting point on one chip, or may have a plurality of light emitting points on one chip. The wavelength of the laser beam of the laser element 2 is, for example, 405 nm (blue violet) or 450 nm (blue), but is not limited thereto, and is appropriately selected according to the type of phosphor included in the light emitting unit 4.

  The laser element 2 is disposed in a state where the laser element 2 is positioned so that the laser beam is irradiated toward the focal point P (see FIG. 3 and the like) of the reflector 5.

  In the present embodiment, two laser elements 2 are provided, but the number of laser elements 2 is not limited to this, and may be one, or three or more. However, in order to obtain a high-power laser beam, it is easier to use a plurality of laser elements 2. In this case, laser light is oscillated from each of the plurality of laser elements 2.

  Further, instead of the laser element 2, a light emitting diode (LED) or the like can be used as the excitation light source.

(Lens 3)
The lens 3 is for adjusting (for example, enlarging) the irradiation range of the laser beam so that the laser beam oscillated from the laser element 2 is appropriately irradiated to the light emitting unit 4. Specifically, the lens 3 adjusts the irradiation range of the laser light so that the first light emitting part 4a or the second light emitting part 4b included in the light emitting unit 4 is appropriately irradiated with the laser light. The lens 3 is disposed in each of the laser elements 2.

(Light emitting part 4)
The light emitting unit 4 emits fluorescence (light) with different radiation angle distributions. The light emitting unit 4 includes a phosphor that emits fluorescence upon receiving the laser light oscillated from the laser element 2. The light emitting unit 4 is, for example, a phosphor in which a phosphor is dispersed inside a sealing material, or a phosphor that is solidified. The light emitting unit 4 is a wavelength conversion element for converting laser light into fluorescence.

  FIG. 2 is a perspective view showing an external configuration of the light emitting unit 4 shown in FIG. As shown in FIG. 2, the light emitting unit 4 includes a first light emitting portion 4 a and a second light emitting portion 4 b.

  The first light emitting portion 4 a is a flat light emitting member that is substantially parallel to the mounting surface of the mounting table 7. The first light emitting portion 4a has two long sides facing each other substantially parallel to a virtual axis (hereinafter referred to as a light projecting axis) that passes through the focal point P of the reflector 5 and extends in the main direction of light projection. It is mounted on the mounting table 7 in such a direction. The first light emitting portion 4a is formed in, for example, a rectangular flat plate shape having a long side of 2 mm, a short side of 1 mm, and a thickness of 0.1 mm.

  The second light emitting portion 4b is a three-dimensional light emitting member having a thickness larger than that of the first light emitting portion 4a. The second light emitting portion 4b is formed so that the cross section perpendicular to the light projecting axis has a shape that is higher (thickness is greater) at the center than at both ends. In the present embodiment, the second light emitting portion 4b is formed in a semi-cylindrical shape, and is mounted on the first light emitting portion 4a in a direction in which the rotation axis of the circumferential surface is substantially parallel to the light projecting axis. Is placed. The second light-emitting portion 4b has, for example, a semi-cylindrical shape with a radius of 0.5 mm and a length of 1 mm, and is unevenly distributed on one short side of the first light-emitting portion 4a so as to form the first light-emitting portion 4a. Placed. In the present embodiment, the second light emitting portion 4b is placed on the first light emitting portion 4a in a state of being unevenly distributed on the opening 5a side of the reflector 5. In addition, the arrangement | positioning relationship between the 1st light emission part 4a and the 2nd light emission part 4b is not specifically limited. For example, the 2nd light emission part 4b may be mounted in the 1st light emission part 4a in the state unevenly distributed by the closing part (bottom part) side of the reflector 5. FIG.

  Here, the first light-emitting portion 4a and the second light-emitting portion 4b have different emission angle distributions of emitted fluorescence due to the difference in shape. Since the fluorescence emitted from the surface of the light emitting unit 4 including the phosphor is emitted from an arbitrary position on the surface according to Lambert's cosine law, the surface is curved compared to the first light emitting portion 4a having a flat surface. The second light emitting portion 4b has a wider radiation angle distribution as a whole. Therefore, the radiation angle distribution (second radiation angle distribution) of the cylindrical second light emitting portion 4b is wider than the radiation angle distribution (first radiation angle distribution) of the flat plate-shaped first light emitting portion 4a. It has become.

  Thus, since the light emission part 4 contains the 1st light emission part 4a and the 2nd light emission part 4b from which radiation angle distribution differs, a laser is used for one of the 1st light emission part 4a and the 2nd light emission part 4b. By irradiating with light, fluorescence can be emitted from the light emitting unit 4 with different radiation angle distributions. Accordingly, it is possible to switch the projection range of the illumination light (fluorescence) emitted from the headlight 1 in accordance with the change in the radiation angle distribution of the light emitting unit 4. The principle of switching the light projection range in the headlight 1 will be described later.

Examples of the phosphor included in the light emitting unit 4 include an oxynitride phosphor (for example, a sialon phosphor), a nitride phosphor (for example, a CASN (CaAlSiN ₃ ) phosphor), or a III-V group compound semiconductor nanoparticle. A phosphor (for example, indium phosphorus: InP) can be used. However, the fluorescent substance contained in the light emission part 4 is not limited to the above-mentioned thing, Other fluorescent substance may be sufficient.

  Further, the type of phosphor and the wavelength of the laser beam may be selected so that the illumination light of the headlight 1 has a desired range of chromaticity. For example, when blue, green, and red phosphors are included in the light emitting unit 4 and irradiated with laser light of 405 nm, white light can be generated. Alternatively, a yellow phosphor (or green and red phosphor) is included in the light-emitting portion 4, and a so-called blue laser having a peak wavelength in a wavelength range of 450 nm (blue) to 450 nm (blue) or 440 nm to 490 nm. White light can be generated.

The sealing material of the light emitting unit 4 is, for example, a resin material such as a glass material (inorganic glass or organic-inorganic hybrid glass) or a silicone resin. Low melting glass may be used as the glass material. The sealing material is preferably highly transparent, and when the laser beam has a high output, a material having high heat resistance is preferable.
(Reflector 5)
The reflector 5 is a half parabolic mirror that reflects the fluorescence emitted from the light emitting unit 4 with a reflecting surface and forms a light bundle (illumination light) that travels within a predetermined solid angle. The reflector 5 may be, for example, a resin member having a metal thin film formed on the surface thereof, or may be a metal member.

  FIG. 3 is a perspective view showing an external configuration of the reflector 5 shown in FIG. As shown in FIG. 3, the reflector 5 has a semicircular opening 5a. The reflector 5 is formed with a radius of 15 mm and a depth of 15 mm of the opening 5a, for example.

  The reflector 5 is at least a part of a partial curved surface obtained by cutting a parabolic surface formed by rotating the parabola with the axis of symmetry of the parabola as a rotation axis by a plane including the rotation axis. As a reflecting surface. Thereby, the fluorescence emitted from the light emitting unit 4 can be efficiently projected within a predetermined solid angle, and as a result, the use efficiency of the fluorescence can be increased.

  At the position of the focal point P of the reflector 5, a mounting table 7 is provided so as to be slidable along the projection axis.

  Further, the reflector 5 is formed with a window 6 through which the laser light is transmitted or passed, and the laser element 2 is disposed outside the reflector 5. The window 6 may be an opening or may include a transparent member that can transmit laser light.

  For example, a filter that transmits laser light and reflects white light (fluorescence of the light emitting unit 4) may be provided as the window unit 6. Thereby, it is possible to prevent the fluorescence emitted from the light emitting part 4 from leaking from the window part 6.

  Thus, by providing the reflector 6 with the window portion 6, the laser light can be irradiated to the light emitting portion 4 from the outside of the reflector 5 through the window portion 6. Therefore, the freedom degree of arrangement | positioning of the laser element 2 can be raised. For example, it becomes easy to set the irradiation angle of the laser beam to the light emitting unit 4 to a preferable angle.

One common window portion 6 may be provided for the plurality of laser elements 2, or a plurality of window portions 6 corresponding to the respective laser elements 2 may be provided.

  In the present embodiment, the reflector 5 has a half parabolic shape which is a partial curved surface obtained by cutting the parabola along a plane including the rotation axis. However, the shape of the reflector 5 is not limited to this. For example, the shape of the reflector 5 may be a parabola or may be a partial curved surface of a part of a spheroid. That is, the reflector 5 only needs to include at least a part of a curved surface formed by rotating a figure (an ellipse, a circle, a parabola) about the rotation axis on the reflection surface. Further, the reflector 5 may be a free-form surface or a multi-faceted mirror.

(Mounting table 7)
The mounting table 7 is for mounting the light emitting unit 4 and is made of, for example, metal (for example, aluminum, copper, or iron). Therefore, the mounting table 7 has high thermal conductivity, and can efficiently receive the heat generated in the light emitting unit 4.

  Note that the mounting table 7 on which the light emitting unit 4 is mounted is not limited to one made of metal, and may be a member containing a material (glass, sapphire, etc.) having high thermal conductivity other than metal. However, it is preferable that the surface of the mounting table 7 in contact with the light emitting unit 4 functions as a reflecting surface. Since the surface of the mounting table 7 in contact with the light emitting unit 4 is a reflecting surface, the laser light incident on the light emitting unit 4 is converted into fluorescence, and then reflected by the reflecting surface and can be directed to the reflector 5. . Alternatively, the laser light incident on the light emitting unit 4 can be reflected by the reflecting surface and again directed to the inside of the light emitting unit 4 to be converted into fluorescence.

  FIG. 4 is a top view of the headlight 1 shown in FIG. As shown in FIG. 4, the mounting table 7 is provided in a recess 8 a formed in the metal base 8. The mounting table 7 is attached to the metal base 8 at the focal point P of the reflector 5 so as to be slidable along the direction of the light projecting axis (the direction of the arrow in the figure). Therefore, by controlling the mounting table 7, one of the first light emitting portion 4 a and the second light emitting portion 4 b can be arranged at the focal point P of the reflector 5.

  As described above, the laser element 2 is disposed in a state of being positioned so that the laser beam is irradiated toward the focal point P of the reflector 5. Therefore, by controlling the mounting table 7 and placing one of the first light emitting portion 4a and the second light emitting portion 4b at the focal point P of the reflector 5, the first light emitting portion 4a and the first light emitting portion 4a at the focal point P are arranged. One of the two light emitting portions 4b can selectively emit light. Accordingly, the fluorescent light emitted from the first light emitting portion 4a or the second light emitting portion 4b and having a different radiation angle distribution can be efficiently projected far away by controlling the optical path by the reflector 5. The light projection characteristics of the light 1 can be improved.

  FIG. 5 is a bottom view showing an example of the crank mechanism 70 that realizes the reciprocating motion of the mounting table 7 shown in FIG. 4. As shown in FIG. 5, the crank mechanism 70 includes a crank disk 71 and a connecting rod 72.

  The crank disk 71 is connected to a motor (not shown), and rotates in the direction of the arrow in the drawing in response to the rotation of the motor. The rotational movement of the crank disk 71 is controlled by the mounting table drive unit 11 (see FIG. 6). Then, the rotational movement of the crank disk 71 is transmitted to the mounting table 7 via the connecting rod 72. At this time, the rotational motion of the crank disk 71 is transmitted to the mounting table 7 as a reciprocating motion. Therefore, the mounting table 7 can slide along the direction of the light projecting axis in accordance with the rotational movement of the crank disk 71.

  The mounting table 7 is preferably made of the same material as the metal base 8 to which the mounting table 7 is attached. Thereby, the contact corrosion between the dissimilar metals which generate | occur | produces when a different kind of metal material contacts electrically can be prevented.

  Moreover, the direction in which the mounting table 7 slides is not particularly limited, and for example, the mounting table 7 may be attached to the metal base 8 so as to be slidable in a direction perpendicular to the light projecting axis or in an oblique direction. However, even in this case, the second light emitting portion 4b is placed on the mounting table so that the rotation axis of the circumferential surface thereof is arranged at the focal point of the reflector 5 in a direction substantially parallel to the light projecting axis. 7 (first light emitting portion 4a). Thereby, as will be described later, the radiation angle distribution of the second light-emitting portion 4b in the horizontal direction perpendicular to the light projection axis can be effectively widened.

(Metal base 8)
The metal base 8 is a plate-like support member that supports the mounting table 7 and is made of metal (for example, aluminum, copper, or iron). Therefore, the metal base 8 has high thermal conductivity, and can receive heat generated by the light emitting unit 4 via the mounting table 7 and efficiently radiate heat.

  In addition, the metal base 8 may be a member including a material having high thermal conductivity other than metal (such as high thermal conductive ceramics).

(Heat radiation fin 9)
The heat radiating fins 9 function as a heat radiating mechanism that radiates heat from the metal base 8. The radiating fins 9 are made of a material having high thermal conductivity, like the mounting table 7 and the metal base 8. The heat radiating fins 9 have a plurality of heat radiating plates, and the heat radiation efficiency is enhanced by increasing the contact area with the atmosphere.

  FIG. 6 is a block diagram showing a main configuration of the headlight 1 shown in FIG. As shown in FIG. 6, the headlight 1 further includes a laser element driving unit 10, a mounting table driving unit 11, and a control unit 12.

(Laser element drive unit 10)
The laser element driving unit 10 controls driving of the laser element 2. Specifically, the laser element driving unit 10 switches ON / OFF of the laser element 2 based on a control signal output from the control unit 12.

  For example, when a control signal for turning on the laser element 2 is output from the control unit 12, the laser element driving unit 10 starts supplying power to the laser element 2 and oscillates laser light from the laser element 2. On the other hand, when a control signal for turning off the laser element 2 is output from the control unit 12, the laser element driving unit 10 ends the power supply to the laser element 2 and stops the oscillation of the laser light.

(Mounting table driving unit 11)
The mounting table drive unit 11 controls the driving of the mounting table 7. Specifically, the mounting table drive unit 11 controls the rotational movement of the crank disk 71 based on the control signal output from the control unit 12.

For example, the mounting table driving unit 11 rotates the crank disk 71 by 180 degrees based on the control signal output from the control unit 12 to slide the mounting table 7 along the light projecting axis. One of the first light emitting part 4 a and the second light emitting part 4 b of the light emitting unit 4 placed on the mounting table 7 is arranged at the focal point P of the reflector 5.

(Control unit 12)
The control part 12 controls each part with which the headlight 1 is provided comprehensively. For example, the control unit 12 switches the laser element 2 ON / OFF by controlling the laser element driving unit 10 in accordance with an input operation of the driver.

  Further, the control unit 12 controls the mounting table driving unit 11 in accordance with the input operation of the driver or the traveling state of the vehicle, so that the first light emitting portion 4a of the light emitting unit 4 mounted on the mounting table 7 and The mounting table 7 is slid so that one of the second light emitting portions 4 b is disposed at the focal point P of the reflector 5. Thereby, the control part 12 switches the light projection range of the headlight 1 by selectively making one of the 1st light emission part 4a and the 2nd light emission part 4b light-emit in the focus P of the reflector 5. FIG.

<Principle of switching the light projection range in the headlight 1>
Next, the principle of switching the light projection range in the headlight 1 according to the present embodiment will be described with reference to FIGS.

  FIG. 7A is a perspective view schematically showing the emission angle distribution of fluorescence and the state of light projection when the first light emitting portion 4a is caused to emit light, and FIG. It is the perspective view which showed typically the radiation angle distribution of the fluorescence when the light emission part 4b was light-emitted, and the mode of light projection.

  As shown in FIG. 7A, when the plate-shaped first light emitting portion 4a of the light emitting section 4 is irradiated with laser light to emit light, the fluorescence emitted from the first light emitting portion 4a is emitted. The radiation angle distribution is relatively narrow. On the other hand, as shown in FIG. 7B, when the semi-cylindrical second light emitting portion 4b is irradiated with laser light to emit light, the emission angle distribution of the fluorescence emitted from the second light emitting portion 4b is obtained. In particular, the radiation angle distribution in the horizontal direction perpendicular to the light projection axis becomes relatively wide.

  As described above, the fluorescence emitted from the surface of the light emitting unit 4 including the phosphor is emitted from an arbitrary position on the surface according to Lambert's cosine law. This is because the radiation angle distribution as a whole is wider in the second light emitting portion 4b having a curved surface than in 4a.

  8A is a top view showing the headlight 1 when the first light emitting portion 4a is disposed at the focal point P of the reflector 5, and FIG. 8B is a diagram showing the second light emitting portion 4b being the reflector. 6 is a top view showing the headlight 1 when it is disposed at a focal point 5 of FIG. FIG. 9 is a graph showing the projection angle distribution of the illumination light projected from the reflector 5 of the headlight 1 shown in FIGS. 8 (a) and 8 (b).

  In addition, the broken line in FIG. 9 has shown the light projection angle distribution when the 1st light emission part 4a arrange | positioned at the focus P of the reflector 5 is light-emitted, as shown to Fig.8 (a). Moreover, the solid line in FIG. 9 has shown the projection angle distribution when the 2nd light emission part 4b arrange | positioned at the focus P of the reflector 5 is light-emitted, as FIG.8 (b) shows.

  As shown in FIG. 9, when the first light emitting portion 4a disposed at the focal point P of the reflector 5 is caused to emit light, the projection angle of the illumination light projected from the reflector 5 is about ± 5 degrees, Light is projected from the reflector 5 at a relatively narrow angle.

On the other hand, when the second light emitting portion 4b arranged at the focal point P of the reflector 5 is caused to emit light, the projection angle of the illumination light projected from the reflector 5 is about ± 8 degrees, and the focal point P of the reflector 5 The light is emitted from the reflector 5 at a relatively wide angle as compared with the case where the arranged first light emitting portion 4a emits light.

  This principle is explained by Etendue's conservation law. Etendue is an invariant that relates the cross-sectional area of the light beam passing through the optical system and the spatial spread of the light beam, and is always preserved from the light source to the light projecting system to the light projecting range. The value can be simply expressed by the following equation (1).

E (etendue) = (light emitting area of light source) x (radiant solid angle of light source)
In the headlight 1, the emission area of the light source (the spread of laser light) and the optical area of the reflector 5 are unchanged, while the radiation angle distribution (radiation solid angle of the light source) of the light emitting unit 4 is variable. Therefore, according to said Formula (1), according to radiation angle distribution of the light emission part 4, the light projection angle radiate | emitted from the reflector 5 can be made variable.

  Therefore, since the etendue of the light emitting unit 4 when the second light emitting portion 4b emits light is larger than the etendue when the first light emitting portion 4a emits light, the etendue from the reflector 5 at a wider angle. Illumination light can be projected.

  As another method of changing the etendue of the light source, for example, a method of changing the light emitting area of the light emitting unit 4 (changing the spread of the laser light) can be considered. However, according to the headlight 1, it is possible to change the etendue by selectively irradiating the laser light to the portions having different surface shapes of the light emitting unit 4 while maintaining the laser light irradiation area constant. It is. Therefore, it can be said that it is excellent in that the etendue can be accurately changed with a simpler configuration.

  FIG. 10 is a top view for explaining changes in the light projection ranges A1 and A2 of the illumination light projected from the reflector 5 of the headlight 1 shown in FIGS. 8A and 8B. Note that A1 in FIG. 10 is a light projection range when the first light emitting portion 4a emits light in a state where the first light emitting portion 4a shown in FIG. 8A is arranged at the focal point P of the reflector 5. Is shown. Further, A2 in FIG. 10 is a light projection range when the second light emitting portion 4b emits light in a state where the second light emitting portion 4b shown in FIG. 8B is arranged at the focal point P of the reflector 5. Is shown.

  As shown in FIG. 10, when the first light emitting portion 4a disposed at the focal point P of the reflector 5 is caused to emit light, the illumination light projected from the reflector 5 has a relatively narrow horizontal width. Light is projected toward the light range A1. Therefore, only the front of the vehicle c can be illuminated brighter to a greater distance.

  On the other hand, when the second light emitting portion 4b arranged at the focal point P of the reflector 5 is caused to emit light, the illumination light projected from the reflector 5 passes through the first light emitting portion 4a arranged at the focal point P of the reflector 5. The light is projected toward a light projection range A2 having a relatively wide horizontal width as compared with the case of emitting light. Therefore, a wider range including the front periphery of the vehicle c can be illuminated.

  Thus, according to the headlight 1 according to the present embodiment, the illumination light emitted from the headlight 1 is selectively emitted by selectively emitting one of the first light emitting portion 4a and the second light emitting portion 4b. The projection range can be switched between the projection range A1 and the projection range A2.

In addition, when the illumination light is projected toward the projection range A2 having a wider horizontal width than the projection range A1, the projection distance (reach distance) of the illumination light is shortened. Therefore, in order to make the projection distance of the illumination light approximately the same, when the illumination light is projected toward a wider range in the horizontal direction, control such as increasing the output of the laser element 2 is performed. Thus, the luminous flux of the laser light applied to the second light emitting portion 4b may be increased.

<Switching control of light projection range in headlight 1>
Next, an example of the projection range switching control in the headlight 1 will be described. Here, the control which switches the projection range of illumination light according to the traveling speed of the vehicle c is demonstrated.

  For example, when the traveling speed of the vehicle c exceeds a predetermined speed, the control unit 12 controls the mounting table driving unit 11 so that the first light emitting portion 4 a is disposed at the focal point P of the reflector 5. The mounting table 7 is slid. Accordingly, the illumination light projection range is switched from the projection range A2 to the projection range A1 by causing the first emission portion 4a to emit light at the focal point P of the reflector 5 instead of the second emission portion 4b. Can do.

  On the other hand, when the traveling speed of the vehicle c becomes equal to or lower than the predetermined speed, the control unit 12 controls the mounting table driving unit 11 so that the second light emitting portion 4 b is disposed at the focal point P of the reflector 5. Then, the mounting table 7 is slid. Accordingly, the second light emitting portion 4b emits light at the focal point P of the reflector 5 instead of the first light emitting portion 4a, so that the illumination light projection range of the headlight 1 is changed from the light projection range A1 to the light projection range. It is possible to switch to A2.

  Accordingly, for example, when traveling at high speed on a highway or the like, the first light-emitting portion 4a is caused to emit light so that a narrow range (light projection range A1) in front of the vehicle c is brightly illuminated. The light emitting portion 4b is caused to emit light so that a wider range including the front periphery of the vehicle c (light projection range A2) can be illuminated.

  Thus, according to the headlight 1, the illumination light projection range can be switched between the projection range A1 and the projection range A2 according to the traveling speed of the vehicle c. Therefore, it is possible to secure a good visibility of the driver, and a safe driving environment can be realized.

<Overview of Embodiment 1>
As described above, the headlight 1 according to the present embodiment includes the light emitting unit 4 that emits fluorescence and the reflector 5 that projects the fluorescence emitted from the light emitting unit 4. It includes a first light emitting portion 4a that emits fluorescence with a single radiation angle distribution, and a second light emitting portion 4b that emits fluorescence with a second radiation angle distribution wider than the first radiation angle distribution.

  Therefore, the emission angle distribution of the fluorescence emitted from the light emitting unit 4 can be changed by selectively emitting light by irradiating one of the first light emitting portion 4a and the second light emitting portion 4b. .

  Therefore, according to this embodiment, by changing the radiation angle distribution of the light emitting unit 4, the projection range of the emitted illumination light can be easily switched between the projection range A1 and the projection range A2. A possible headlight 1 can be realized.

<Modification>
Next, modified examples of the headlight 1 according to the present embodiment will be described with reference to FIGS.

(Modification 1)
FIGS. 11A and 11B are perspective views showing a modification example of the light emitting unit 4 shown in FIG. The 2nd light emission part 4b is not restricted to a semi-cylindrical shape, Other solid shapes may be sufficient.

  For example, as shown in FIG. 11A, the second light emitting portion 4b may have a triangular prism shape that is provided horizontally along the light projecting axis. In addition, as shown in FIG. 11B, the second light emitting portion 4b may have a trapezoidal columnar shape that is provided horizontally along the light projecting axis.

  In this case, the second light emitting portion 4b has a pair of inclined surfaces facing each other so that a cross-sectional area parallel to the bottom surface gradually decreases in a direction perpendicular to the bottom surface in contact with the first light emitting portion 4a. Is placed on the first light emitting portion 4a. Therefore, according to the second light emitting portion 4b, since the fluorescence is emitted from one set of inclined surfaces, the radiation angle distribution in the horizontal direction perpendicular to the light projecting axis is more effective than the first light emitting portion 4a. Can be expanded.

(Modification 2)
FIGS. 12A to 12C are perspective views showing another modification example of the light emitting unit 4 shown in FIG. As shown in FIGS. 12A to 12C, the first light-emitting portion 4a and the second light-emitting portion 4b of the light-emitting portion 4 are not connected to each other and are mounted on the mounting table 7 in a state of being separated from each other. It may be.

  For example, as shown in FIG. 12A, the flat plate-shaped first light emitting portion 4a and the semi-cylindrical second light emitting portion 4b are mounted on the mounting table 7 in a state of being separated from each other. It may be. Also, as shown in FIG. 12B, the flat plate-shaped first light emitting portion 4a and the triangular prism-shaped second light emitting portion 4b are mounted on the mounting table 7 in a state of being separated from each other. It may be. Further, as shown in FIG. 12C, the flat plate-shaped first light emitting portion 4a and the semi-cylindrical second light emitting portion 4b are mounted on the mounting table 7 in a state of being separated from each other. May be.

  In this case, the first light emitting portion 4a is formed in a square flat plate shape having, for example, a vertical side of 1 mm, a horizontal side of 1 mm, and a thickness of 0.1 mm.

(Modification 3)
FIGS. 13A to 13C are perspective views showing still another modified example related to the light emitting unit 4 shown in FIG. As shown in FIGS. 13A to 13C, the light emitting unit 4 has a shape including a third light emitting part 4c in addition to the first light emitting part 4a and the second light emitting part 4b. Also good.

  For example, as shown in FIG. 13A, the light emitting section 4 is thicker than the flat plate-shaped first light emitting portion 4a, the semi-cylindrical second light emitting portion 4b, and the second light emitting portion 4b. The shape may include a semi-cylindrical third light emitting portion 4c having a large. As shown in FIG. 13B, the light emitting section 4 is thicker than the first light emitting portion 4a having a flat plate shape, the second light emitting portion 4b having a triangular prism shape, and the second light emitting portion 4b. The shape may include a large triangular prism-shaped third light emitting portion 4c. Further, as shown in FIG. 13C, the light emitting section 4 is thicker than the flat plate-shaped first light emitting portion 4a, the trapezoidal columnar second light emitting portion 4b, and the second light emitting portion 4b. The shape may include a trapezoidal columnar third light emitting portion 4c having a large.

  If the light emitting section 4 having such a shape is used, three different radiation angle distributions can be obtained by selectively emitting one of the first light emitting portion 4a, the second light emitting portion 4b, and the third light emitting portion 4c. Thus, fluorescence can be emitted from the light emitting unit 4. Therefore, the projection range of the illumination projected from the headlight 1 can be switched in three stages.

In addition, the light emission part 4 may be a shape which can change the radiation angle distribution of the emitted light into four or more radiation angle distributions different from each other.
(Modification 4)
14 (a) to 14 (c) are perspective views showing other modified examples related to the light emitting unit 4 shown in FIG. As shown in FIGS. 14A to 14C, the light emitting unit 4 may have a continuous shape whose thickness gradually changes.

  For example, as shown in FIG. 14 (a), the light emitting unit 4 has two end faces facing each other, one end face having a flat shape and the other end face having a semicircular shape. It may be a continuous shape in which the thickness gradually increases from the end toward the other end face. As shown in FIG. 14 (b), the light emitting unit 4 has a flat shape on one end surface and a triangular shape on the other end surface, and the other end surface has a triangular shape. It may be a continuous shape whose thickness gradually increases toward the other end face. Furthermore, as shown in FIG. 14 (c), the light emitting unit 4 has a flat shape on one end surface and a trapezoidal shape on the other end surface, and the trapezoidal shape on the other end surface. It may be a continuous shape whose thickness gradually increases toward the other end face.

  If the light emitting part 4 having such a shape is used, the continuous light emitting part 4 is thicker than the part having the arbitrary thickness (the first light emitting part 4a) and the part having the arbitrary thickness. By selectively causing the portion (second light emitting portion 4b) to emit light, the light projection range of the illumination light projected from the reflector 5 can be continuously changed.

  Further, since the light emitting unit 4 has a shape in which the thickness gradually changes continuously, the emission angle distribution of emitted fluorescence is changed according to the thickness of the light emitting unit 4 that emits light. Therefore, the projection range of the headlight 1 can be changed to a desired range by controlling the irradiation position of the laser beam on the light emitting unit 4.

  As described above, when the light emitting unit 4 including a phosphor formed in a continuous shape with a gradually changing thickness is used, a portion having a different thickness of the light emitting unit 4 is excited to emit light from the reflector 5. The projection range of the illuminated illumination light can be continuously changed.

  Therefore, this modification is excellent in that characteristics such as the light projection range of the headlight 1 can be continuously changed.

(Modification 5)
FIG. 15A is a top view showing still another modification example of the light emitting unit 4 shown in FIG. 2, and FIG. 15B shows a cross-sectional shape of the ring-shaped light emitting unit 4 shown in FIG. It is a perspective view. As shown in FIGS. 15A and 15B, the light emitting section 4 may have a ring shape whose thickness gradually changes.

  If such a ring-shaped light emitting part 4 is used, a part (first light emitting part 4a) having a certain thickness in the light emitting part 4 and a part having a large thickness (the first light emitting part 4a) The light emission range of illumination light projected from the reflector 5 can be switched by selectively causing the second light emitting portion 4b) to emit light.

  FIG. 16 is a top view showing a headlight 1a including the ring-shaped light emitting section 4 shown in FIGS. 15 (a) and 15 (b). As shown in FIG. 16, the ring-shaped light emitting unit 4 is mounted on the disk-shaped mounting table 7 so as to include the focal point P of the reflector 5. This disk-shaped mounting table 7 is connected to a motor (see FIG. 17), and rotates (displaces) in the direction of the arrow in the figure in response to the rotational operation of the motor.

  FIG. 17 is a cross-sectional view showing an example of a mechanism for realizing the rotational movement of the disk-shaped mounting table 7 shown in FIG. As shown in FIG. 17, in the headlight 1 a, a disk-shaped mounting table 7 is attached in a recess 8 a formed in the upper part of the metal base 8. A ring-shaped light emitting section 4 is placed concentrically on the disk-shaped mounting table 7.

  A motor 30 is disposed below the metal base 8, and this motor 30 is connected to a disk-shaped mounting table 7 through a shaft. Therefore, by controlling the driving of the motor 30, the disk-shaped mounting table 7 can be rotated in the direction of the arrow in FIG.

  Therefore, according to the headlight 1a, the rotational movement of the disk-shaped mounting table 7 is controlled so that a portion having a different thickness is located in the ring-shaped light emitting section 4 at the focal point P of the reflector 5. By selectively causing different portions to emit light, the projection range of the illumination light emitted from the headlight 1a can be changed to a desired range.

[Embodiment 2]
Another embodiment of the present invention will be described below with reference to FIGS. In addition, about the member similar to Embodiment 1, the same code | symbol is attached | subjected and the description is abbreviate | omitted.
<Configuration of headlight 101>
First, a schematic configuration of the headlight 101 according to the present embodiment will be described with reference to FIGS. The headlight 101 according to the present embodiment includes a first LED (first light emitting element) 104a and a second LED (second light emitting element) 104b. And mainly different.

  FIG. 18 is a cross-sectional view illustrating a schematic configuration of the headlight 101 according to the first embodiment. As shown in FIG. 18, the headlight 1 includes a light emitting unit 104, a reflector 5, a mounting table 7, a metal base 8, and heat radiating fins 9.

(Light Emitting Unit 104)
The light emitting unit 104 emits illumination light including fluorescence with different radiation angle distributions. The light emitting unit 104 includes a first LED 104a that emits illumination light including fluorescence with a predetermined radiation angle distribution (first radiation angle distribution), and a wider radiation angle distribution (second radiation angle distribution) than the first LED 104a. ) And the second LED 104b that emits illumination light including fluorescence, and each is mounted on the mounting table 7.

  FIG. 19A is a cross-sectional view showing the first LED 104a shown in FIG. 18, and FIG. 19B is a cross-sectional view showing the second LED 104b shown in FIG.

  As shown in FIG. 19A, the first LED 104a includes an LED chip 105, a sealing material 106, a phosphor 108, a case body 109, a case electrode 111a, a case electrode 111b, and a heat sink 113.

  In the first LED 104 a, the phosphors 108 are scattered around the LED chip 105. The LED chip 105 and the phosphor 108 are sealed in the case body 109 by a sealing material 106. The material of the phosphor 108 and the sealing material 106 may be the same as the material of the phosphor and the sealing material constituting the light emitting unit 4 described in the first embodiment, and is not particularly limited.

The LED chip 105 is mounted on a heat sink 113 made of a material having high thermal conductivity such as metal (aluminum, copper, or iron). Further, the LED chip 105 has an anode electrode (
The case electrode 111a, which is an anode, and the case electrode 111b, which is a cathode electrode (cathode), are electrically connected via wiring, and power is supplied from these electrodes.

  In the first LED 104a, the excitation light emitted from the LED chip 105 is irradiated onto the phosphor 108, whereby fluorescence is emitted from the phosphor 108, and illumination light including the fluorescence is emitted from the upper surface of the first LED 104a. The

  Here, the first LED 104a has a flat surface (upper surface) shape of the sealing material 106, and illumination light including fluorescence is emitted from the flat upper surface. For this reason, in the first LED 104a, the emission of illumination light including fluorescence in the horizontal direction is restricted, so that the radiation angle distribution becomes relatively narrow.

  On the other hand, the second LED 104b is such that the surface shape of the sealing material 107 is formed on the circumferential surface so that the radiation angle distribution of illumination light including fluorescence emitted from the first LED 104a is wider. Different from the first LED 104a. The second LED 104b emits illumination light including fluorescence from the circumferential surface, and therefore has a radiation angle distribution that spreads in the horizontal direction as compared to the first light emitting portion 4a.

  The second LED 104b is mounted on the mounting table 7 so that the rotation axis of the circumferential surface is substantially parallel to the light projecting axis.

  As described above, the light emitting unit 104 includes the first LED 104a and the second LED 104b having different radiation angle distributions. Therefore, by selectively causing one of the first light emitting LED 104a and the second LED 104b to emit light, illumination light including fluorescence can be emitted from the light emitting unit 104 with different radiation angle distributions.

  FIG. 20 is a block diagram showing a main configuration of the headlight 101 shown in FIG. As shown in FIG. 20, the headlight 101 further includes an LED driving unit 110, a mounting table driving unit 11, and a control unit 112.

(LED drive unit 110)
The LED driving unit 110 individually controls driving of the first LED 104a and the second LED 104b. Specifically, the LED drive unit 110 selectively switches on / off of the first LED 104a and the second LED 104b based on a control signal output from the control unit 112.

(Control unit 112)
The control unit 112 comprehensively controls each unit included in the headlight 101. For example, the control unit 112 controls the mounting table driving unit 11 in accordance with an input operation of the driver or the traveling state of the vehicle, so that one of the first LED 104 a and the second LED 104 b mounted on the mounting table 7. However, the mounting table 7 is slid so as to be arranged at the focal point P of the reflector 5. In addition, the control unit 112 controls the LED driving unit 110 to turn on one of the first LED 104a and the second LED 104b arranged at the focal point P of the reflector 5.

  Thereby, the control part 112 switches the light projection range of the headlight 101 by selectively making one of the first LED 104a and the second LED 104b emit light at the focal point P of the reflector 5.

<Projection range switching control in the headlight 101>
Next, an example of the projection range switching control in the headlight 101 will be described with reference to FIG. Here, the control which switches the projection range of illumination light according to the traveling speed of the vehicle c (refer FIG. 10) is demonstrated.

  FIG. 21A is a top view showing the headlight 101 when the first LED 104a is disposed at the focal point P of the reflector 5, and FIG. 21B is a focal point P of the reflector 5 at the second LED 104b. It is a top view which shows the headlight 101 when arrange | positioning.

  The control unit 112 switches the projection range of the illumination light between the projection range A1 and the projection range A2 according to the traveling speed of the vehicle c. For example, when the traveling speed of the vehicle c exceeds a predetermined speed, the control unit 112 controls the mounting table driving unit 11 so that the first focal point P of the reflector 5 is shown in FIG. The mounting table 7 is slid so that the LED 104a is arranged. In addition, the control unit 112 controls the LED driving unit 110 to turn off the second LED 104 b and turn on the first LED 104 a disposed at the focal point P of the reflector 5. Accordingly, the first LED 104a is turned on at the focal point P of the reflector 5 in place of the second light emitting LED 104b, thereby switching the illumination light projection range of the headlight 101 from the projection range A2 to the projection range A1. be able to.

  On the other hand, when the traveling speed of the vehicle c becomes equal to or lower than the predetermined speed, the control unit 112 controls the mounting table driving unit 11 so that the focal point P of the reflector 5 is adjusted to the first level as shown in FIG. The mounting table 7 is slid so that the second LED 104b is arranged. Further, the control unit 112 controls the LED driving unit 110 to turn off the first LED 104 a and turn on the second LED 104 b arranged at the focal point P of the reflector 5. Thereby, it is possible to switch the illumination light projection range from the projection range A1 to the projection range A2 by lighting the second LED 104b at the focal point P of the reflector 5 instead of the first LED 104a.

  Therefore, for example, when traveling at high speed on a highway or the like, the first LED 104a is turned on to illuminate a narrow range (light projection range A1) ahead of the vehicle c, and when traveling at low speed in an urban area or the like, the second LED 104b. Can be switched, such as lighting up a wide range (light projection range A2) including the front periphery of the vehicle c.

  Thus, according to the headlight 101, the projection range of illumination light can be switched between the projection range A1 and the projection range A2 according to the traveling speed of the vehicle c. Therefore, it is possible to secure a good visibility of the driver, and a safe driving environment can be realized.

<Overview of Embodiment 2>
As described above, the headlight 101 according to the present embodiment includes the light emitting unit 104 that emits illumination light including fluorescence, and the reflector 5 that projects the illumination light including fluorescence emitted from the light emitting unit 104. The light emitting unit 104 emits at least a first LED 104a that emits illumination light including fluorescence with a first radiation angle distribution, and illumination light that includes fluorescence with a second radiation angle distribution wider than the first radiation angle distribution. And a second LED 104b that emits light.

  Therefore, by selectively lighting the first LED 104a and the second LED 104b, the radiation angle distribution of the illumination light including the fluorescence emitted from the light emitting unit 104 can be changed.

Therefore, according to the present embodiment, by changing the radiation angle distribution of the light emitting unit 104, the projection range of the emitted illumination light can be easily switched between the projection range A1 and the projection range A2. The possible headlight 101 can be realized.

<Modification>
Next, a modification of the headlight 101 according to the present embodiment will be described with reference to FIG.

  22A and 22B are cross-sectional views showing an example of a configuration for controlling the radiation angle distribution of the LED. As shown in FIGS. 22A and 22B, a transparent or translucent mold is formed on the upper surface of the sealing material 106 formed flat on the first LED 104a shown in FIG. 19A. The radiation angle distribution can be controlled by utilizing the lens effect of this mold.

  For example, when a mold 206 having a nearly flat surface shape is formed as in the LED 204a shown in FIG. 22A, the radiation angle distribution of illumination light including emitted fluorescence approaches a Lambertian distribution. On the other hand, when the semi-cylindrical mold 207 is formed like the LED 204b shown in FIG. 22B, the radiation angle distribution of the illumination light including the emitted fluorescence is made to be more than the Lambert distribution by the lens effect of the mold 207. Can be narrowed.

  Thus, the radiation angle distribution of the illumination light including the fluorescence emitted from the LED can be changed by forming the transparent or translucent mold in different shapes.

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

[Supplement]
The present invention can also be expressed as follows. That is, the illuminating device according to the present invention is an illuminating device including a fluorescent member, an excitation light source that excites the fluorescent member, and a light projecting member that projects the fluorescent light. It is characterized by selective excitation.

  Moreover, in the illuminating device which concerns on this invention, an excitation light source irradiates the area | region containing the focus of a light projection member, It is characterized by the above-mentioned.

  Further, the illumination device according to the present invention is characterized in that the fluorescent member slides.

  Further, the illumination device according to the present invention is characterized in that the ring-shaped fluorescent member rotates.

  Further, the illumination device according to the present invention is characterized in that the spread of light projection is controlled by selecting and exciting a flat portion on the surface of the fluorescent member and a portion having an inclined portion.

  In the illumination device according to the present invention, the excitation light source is particularly a laser.

  The present invention can be used as various lighting devices such as a vehicle headlamp, a lighting device for a moving object other than a vehicle, a search light, and a projector.

1 Headlight (lighting device / vehicle headlamp)
1a Headlight (lighting device / vehicle headlamp)
2 Laser element 4 Light emitting portion 4a First light emitting portion 4b Second light emitting portion 4c Third light emitting portion 5 Reflector (light projecting portion)
7 Mounting table (mounting unit)
101 Headlight (lighting device / vehicle headlamp)
104 light emitting unit 104a first LED (first light emitting element)
104b Second LED (second light emitting element)
110 LED drive unit (lighting switching unit)
204a LED (first light emitting element)
204b LED (first light emitting element)
P Focus A1 Projection range A2 Projection range

Claims (15)

A light emitting unit for emitting light;
The light emitting unit, the radiation angle distribution of the emitted light, at least a first radiation angle distribution, Ri changeable der between the second radiation angle distribution wider than the first radiation angle distribution,
The light-emitting unit includes a phosphor that receives excitation light and emits fluorescence that is the light,
Wherein by the excitation light to a different portion of the thickness of the light-emitting portion is selectively irradiated, the light-emitting device according to claim to switch between a second emission angle distribution and the first radiation angle distribution. The light emitting unit includes at least a first light emitting part that emits light with the first radiation angle distribution, and a second light emitting part that emits light with the second radiation angle distribution,
2. The light emitting device according to claim 1, wherein one of the first light emitting portion and the second light emitting portion selectively emits light. The light emitting portion is provided for one front Symbol first light-emitting portion and the second light emitting portion, the light emitting device according to claim 2, wherein said excitation light is selectively irradiated. It further comprises a movable placing part for placing the light emitting part,
The placement unit changes a relative position or angle of the light emitting unit with respect to the excitation light so that one of the first light emitting part and the second light emitting part is irradiated with the excitation light. The light-emitting device according to claim 3.   The light emitting device according to claim 3 or 4, wherein the excitation light is irradiated toward a focal point of a light projecting unit that projects light emitted from the light emitting unit.   6. The light emitting device according to claim 3, wherein the second light emitting portion has a shape that is thicker than the first light emitting portion. The first light emitting portion has a flat plate shape substantially parallel to a placement surface on which the light emitting portion is placed,
The second light emitting portion has a shape in which a cross-sectional area parallel to the bottom surface gradually decreases in a direction perpendicular to the bottom surface contacting the mounting surface. The light-emitting device of description. The light emitting part has a continuous shape with a gradually changing thickness,
Of the continuous shape, a portion having an arbitrary thickness serves as the first light emitting portion, and a portion having a larger thickness than the portion having the arbitrary thickness serves as the second light emitting portion. The light emitting device according to claim 6.   The light emitting device according to claim 8, wherein the light emitting unit has a ring shape. The excitation light-emitting device according to any one of claims 1, wherein 9 to be a laser beam. The light emitting device according to claim 4, wherein the placement unit is slidably or rotatably provided. The light emitting device according to any one of claims 1 to 11 , wherein the light emitting unit is capable of changing a radiation angle distribution of emitted light to at least three radiation angle distributions different from each other. The light emitting device according to any one of claims 1 to 12 ,
An illumination device comprising: a light projecting unit that projects light emitted from the light emitting unit. A vehicle headlamp comprising the illumination device according to claim 13 . Changing the radiation angle distribution of the light emitted from the light emitting unit between the first radiation angle distribution and the second radiation angle distribution according to the speed of the vehicle on which the illumination device is mounted. The vehicle headlamp according to claim 14 , wherein the vehicle headlamp is characterized in that:

Images