JP2013038010A - Light source unit for vehicular headlight and vehicular headlight using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source unit for a vehicular headlight capable of making a luminous flux, which cannot hitherto be made incident to a projection lens, incident to the projection lens and having high light use efficiency, and the vehicular headlight using the light source unit.SOLUTION: The light source unit for a vehicular headlight includes a semiconductor laser light source 22a, a wavelength conversion member 22c arranged in front of the semiconductor laser light source, and a reflector 22d containing an incident port as one end side opening and an emitting port at an opposite side of the incident port as the other end side opening and containing a conic cylinder-shaped reflecting surface extended to be narrowed down in a conic shape as it moves from the emitting port to the incident port. At least a part of the conic cylinder-shaped reflecting surface is arranged in front of the wavelength conversion member so as to be irradiated forward while the luminous flux emitted from the wavelength conversion member is incident to the conic cylinder-shaped reflecting surface from the incident port and the luminous flux is emitted from the emitting port by reflecting with the conic cylinder-shaped reflecting surface or the luminous flux is directly emitted from the emitting port without reflecting at the conic cylinder-shaped reflecting surface.

Description

  The present invention relates to a light source unit for a vehicle headlamp and a vehicle headlamp using the same, and more particularly to a light source unit for a vehicle headlamp using a semiconductor laser light source and a vehicle front using the same. Regarding lighting.

  Conventionally, as shown in FIG. 19, a vehicular headlamp including a projection lens 210 and an LED 220 (having a light emitting surface of about 1 × 2 mm square) arranged in the vicinity of the focal point on the vehicle rear side of the projection lens 210. A lamp 200 has been proposed (see, for example, Patent Document 1).

  The luminous flux emitted from the LED 220 passes through the projection lens 210 and is irradiated forward (that is, the light source image of the LED 220 is projected forward). Thereby, a predetermined light distribution pattern is formed on the virtual vertical screen (for example, disposed about 25 m ahead of the front end of the vehicle).

JP 2007-335301 A

  However, when a light source having a light distribution characteristic of Lambertian (for example, a light source combining a LED 220 or a laser diode and a wavelength conversion member such as a phosphor) is used as a light source of a vehicle headlamp, a projection lens (projector type or In the case of parabolic vehicular headlamps, only the luminous flux within the directivity angle corresponding to the light capturing angle is incident on the projection lens among the light beams emitted from the light source in relation to the light capturing angle of the reflecting surface. There is a problem that light utilization efficiency is low.

  In particular, when forming a hot zone light distribution pattern for irradiating a hot zone with a so-called direct projection type vehicle headlamp described in Patent Document 1, the focal length of the projection lens is made larger than when a diffuse light distribution pattern is formed. Since it is necessary to make it longer, there is a problem that the light capture angle of the projection lens is further reduced and the light utilization efficiency is further reduced.

  The present invention has been made in view of such circumstances, and it is possible to make a light beam that could not be incident on a projection lens or the like conventionally enter the projection lens or the like, and has high light utilization efficiency. It is an object of the present invention to provide a light source unit for a vehicle headlamp and a vehicle headlamp using the same.

  In order to achieve the above object, an invention according to claim 1 is arranged in front of a semiconductor laser light source and the semiconductor laser light source so that laser light from the semiconductor laser light source is incident, A wavelength converting member that receives laser light and generates light having a longer wavelength than the semiconductor laser light source; an incident port that is an opening on one end side; and an exit port that is an opening on the other end side opposite thereto; And a reflector including a conical cylindrical reflecting surface extending so as to narrow in a conical shape as it goes from the incident port to the incident port, and at least a part of the conical cylindrical reflecting surface radiates from the wavelength conversion member. The incident light beam is incident on the cone-shaped cylindrical reflecting surface from the incident port, reflected by the cone-shaped cylindrical reflecting surface, and emitted from the emitting port or reflected by the cone-shaped cylindrical reflecting surface. Ku emitted directly from said exit, so as to irradiate to the front, characterized in that disposed in front of the wavelength conversion member.

  According to the first aspect of the invention, the directivity angle of the light beam emitted from the wavelength conversion member can be narrowed by the action of the conical cylindrical reflection surface disposed in front of the wavelength conversion member. Conventionally, a light beam that could not be incident on the projection lens, the reflection surface, or the like can be incident on the projection lens, the reflection surface, or the like. This makes it possible to configure a vehicle headlamp with high light utilization efficiency.

  The invention according to claim 2 is characterized in that, in the invention according to claim 1, the angle at which the light beam within the directivity angle / light source light beam becomes maximum is selected as the taper angle of the conical cylindrical reflection surface. And

  According to the second aspect of the present invention, a brighter light distribution pattern (for example, spot distribution) is selected by selecting an angle at which the light beam within the directivity angle / the light source light beam is maximized as the taper angle of the conical cylindrical reflection surface. Light pattern) can be formed.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, a ratio in the range of 1: 1.5 to 1: 4.0 is selected as a ratio of the incident aperture to the exit aperture. It is characterized by being.

  According to the third aspect of the present invention, by selecting a ratio in the range of 1: 1.5 to 1: 4.0 as the ratio of the entrance aperture to the exit aperture, the lamp unit (for example, spot light distribution) is selected. The light flux required for the light distribution pattern (for example, spot light distribution pattern) can be ensured while realizing a reduction in the size of the unit.

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein an angle in the range of 15 to 40 ° is selected as the taper angle of the conical cylindrical reflection surface. It is characterized by.

  According to the fourth aspect of the present invention, by selecting an angle within the range of 15 to 40 ° as the taper angle of the conical cylindrical reflection surface, the directivity angle 40 to be effectively used as a vehicle headlamp. It is possible to maximize the luminous flux within 100 ° (full angle).

According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the area of the emission port is 2 mm ² or less.

  According to the fifth aspect of the present invention, it is possible to form a virtual light source having a light emitting area equivalent to that of the LED, a luminance higher than that of the LED, and a narrower directivity angle than that of the LED at the emission port. Thus, according to the invention described in claim 5, since it is possible to make the light emitting area equivalent to that of the LED, by combining the optical system designed for the LED and the optical unit of claim 5 Thus, it is possible to configure a vehicle headlamp with high light utilization efficiency.

  The invention according to claim 6 is the invention according to any one of claims 1 to 5, wherein the reflector is a solid transparent member, and the conical cylindrical reflection surface is applied to a surface of the transparent member. It is characterized by comprising a metal film.

  According to the sixth aspect of the present invention, the same effects as those of the first to fifth aspects can be obtained.

  The invention according to claim 7 includes a projection lens disposed on an optical axis extending in the vehicle front-rear direction, and the light source unit according to any one of claims 1 to 6, wherein the light source unit includes: The exit port is arranged in the vicinity of the focal point on the vehicle rear side of the projection lens.

  According to the invention described in claim 7, it is possible to narrow the directivity angle of the light beam emitted from the wavelength conversion member by the action of the cone-shaped cylindrical reflection surface disposed in front of the wavelength conversion member. Conventionally, a light beam that could not be incident on the projection lens can be incident on the projection lens. Thereby, it is possible to configure a so-called direct projection type vehicle headlamp with high light utilization efficiency.

  The invention according to claim 8 is the invention according to claim 7, wherein, as the taper angle of the cone-shaped cylindrical reflection surface, the light flux within the directivity angle / the light source light flux corresponding to the light capture angle of the projection lens is maximum. An angle is selected.

  According to the invention described in claim 8, by selecting the angle at which the luminous flux within the directivity angle / light source luminous flux corresponding to the light capturing angle of the projection lens is maximized as the taper angle of the cone-shaped cylindrical reflecting surface, A brighter light distribution pattern (for example, a spot light distribution pattern) can be formed.

  The invention according to claim 9 is the invention according to claim 7 or 8, wherein the projection lens is configured to refract a light beam passing therethrough to form a cut-off line in the light distribution pattern for the passing beam. It is characterized by including the lens surface made.

  According to the ninth aspect of the present invention, it is possible to form the cut-off line without loss of the light beam, as compared with the case where a part of the light beam is shielded by the shade to form the cut-off line.

  A tenth aspect of the invention includes a parabolic reflecting surface and the light source unit according to any one of the first to sixth aspects, wherein the emission port of the light source unit includes the reflecting surface. It is characterized by being arranged in the vicinity of the focal point.

  According to the invention of claim 10, it is possible to narrow the directivity angle of the light beam emitted from the wavelength conversion member by the action of the conical cylindrical reflection surface arranged in front of the wavelength conversion member. Conventionally, a light beam that could not be incident on the reflecting surface can be incident on the reflecting surface. This makes it possible to configure a parabolic vehicular headlamp with high light utilization efficiency.

  According to an eleventh aspect of the present invention, in the invention according to the tenth aspect, as the taper angle of the cone-shaped cylindrical reflection surface, the light flux within the directivity angle / the light source light beam corresponding to the light capturing angle of the reflection surface is maximum. An angle is selected.

  According to the invention of claim 11, by selecting the angle at which the luminous flux within the directivity angle / light source luminous flux corresponding to the light capturing angle of the reflective surface is maximized as the taper angle of the cone-shaped cylindrical reflective surface, A brighter light distribution pattern (for example, a spot light distribution pattern) can be formed.

  The invention according to claim 12 includes a spheroid reflection surface and the light source unit according to any one of claims 1 to 6, wherein the emission port of the light source unit is formed of the reflection surface. It is arranged near the first focal point.

  According to the twelfth aspect of the present invention, it is possible to narrow the directivity angle of the light beam emitted from the wavelength conversion member by the action of the conical cylindrical reflection surface disposed in front of the wavelength conversion member. Conventionally, a light beam that could not be incident on the reflecting surface can be incident on the reflecting surface. This makes it possible to configure a projector-type vehicle headlamp with high light utilization efficiency.

  According to a thirteenth aspect of the present invention, in the invention of the twelfth aspect, as the taper angle of the cone-shaped cylindrical reflection surface, the light flux within the directivity angle / the light source light beam corresponding to the light capturing angle of the reflection surface is maximum. An angle is selected.

  According to the invention of claim 13, by selecting the angle at which the luminous flux within the directivity angle / light source luminous flux corresponding to the light capturing angle of the reflective surface becomes the maximum as the taper angle of the conical cylindrical reflective surface, A brighter light distribution pattern (for example, a spot light distribution pattern) can be formed.

  Advantageous Effects of Invention According to the present invention, a light beam that could not be incident on the projection lens and the reflecting surface can be incident on the projection lens and the reflecting surface. A light source unit and a vehicle headlamp using the light source unit can be provided.

It is an example of the vehicle headlamp 10 of 1st Embodiment arrange | positioned on the right side of the vehicle front end. It is a cross-sectional view taken along the spot light distribution unit 20 in a horizontal plane including the optical axis AX _20. It is the cross-sectional view which cut | disconnected the light source unit 22 in the horizontal surface containing the optical axis _AX22e . It is the graph which plotted the result of having simulated how light flux in a directivity angle / light source light flux will change when the exit aperture / incident aperture of reflector 22d is changed. It is the graph which plotted the result of having simulated how the inside of a directivity angle / light source luminous flux will change when taper angle (alpha) is changed. 6 is a graph in which the taper angle α at which the light beam within the directivity angle / the light source light beam becomes maximum when the exit aperture / incident aperture is changed is plotted for each of the directivity angles of 40 °, 60 °, 80 °, and 100 °. It is an example of the light distribution pattern P1 for the passing beam which is a combined light distribution pattern obtained by combining the spot light distribution pattern P1a formed by the spot light distribution unit 20 and the wide light distribution pattern P1b formed by the diffusion light distribution unit 30. . The diffused light distribution unit 30 is a cross-sectional view taken along a horizontal plane including the optical axis AX _30. For a traveling beam, which is a combined light distribution pattern obtained by combining a spot light distribution pattern P2a formed by the spot light distribution unit 20 (modification) and a wide light distribution pattern P2b formed by the diffusion light distribution unit 30 (modification) It is an example of the light distribution pattern P2. It is the cross-sectional view which cut | disconnected the spot light distribution unit 20A (modification) by the horizontal surface containing the optical axis AX _20A . Diffused light distribution unit 30A of Modification is a cross-sectional view taken along a horizontal plane including the optical axis AX _30A. It is the cross-sectional view which cut | disconnected the spot light distribution unit 20B (modification) by the horizontal surface containing the optical axis AX _20B . It is a longitudinal sectional view taken along the spot light distribution unit 40 in a vertical plane including the optical axis AX ₄₀ constituting the vehicle headlamp according to a second embodiment of the present invention. It is the longitudinal cross-sectional view which cut | disconnected the spot light distribution unit 40A (modification) by the vertical plane containing the optical axis AX _40A . It is the longitudinal cross-sectional view which cut | disconnected the spot light distribution unit 40B (modification) by the vertical plane containing the optical axis _AX40B . It is a longitudinal sectional view taken along the spot light distribution unit 50 in a vertical plane including the optical axis AX ₅₀ of the third constituting a vehicle headlamp according to an embodiment of the present invention. It is the longitudinal cross-sectional view which cut | disconnected the spot light distribution unit 50A (modification) by the vertical plane containing the optical axis AX _50A . It is the longitudinal cross-sectional view which cut _| disconnected the spot light distribution unit 50B (modification) by the vertical plane containing the optical axis AX _50B . It is the longitudinal cross-sectional view which cut | disconnected the conventional vehicle headlamp 200 by the vertical surface containing the optical axis AX.

[First Embodiment]
Hereinafter, the vehicle headlamp 10 which is 1st Embodiment of this invention is demonstrated, referring drawings.

  FIG. 1 shows an example of a vehicle headlamp 10 disposed on the right side of the front end of the vehicle.

  The vehicle headlamp 10 includes at least one spot light distribution unit 20 (in FIG. 1, two spot light distribution units 20 arranged near the center of the vehicle are illustrated), and at least one diffusion light distribution unit 30 (FIG. 1). Middle, two diffused light distribution units 30 arranged near the vehicle side surface), an outer lens L arranged in front of each unit 20, 30 and the like. In addition, each unit 20 and 30 can increase / decrease the number suitably according to the brightness of the light distribution pattern calculated | required. Each unit 20 and 30 is connected to a known aiming mechanism (not shown) so that the respective optical axes can be adjusted.

[Spot light distribution unit 20]
Figure 2 is a cross-sectional view taken along the spot light distribution unit 20 in a horizontal plane including the optical axis AX _20.

The spot light distribution unit 20 of the present embodiment is a so-called direct projection type lamp unit. As shown in FIG. 2, the projection lens 21 and the projection lens 21 are arranged on an optical axis AX ₂₀ extending in the vehicle front-rear direction. The light source unit 22 etc. which are arrange | positioned back are provided.

The projection lens 21 is a meniscus lens having a convex front surface and a concave rear surface. In the present embodiment, from the viewpoint of forming a spot light distribution pattern with high light collecting properties, the rear lens side focal length of the projection lens 21 is 50 mm, and the light capturing angle θ1 is 60 ° (full angle) in consideration of the size of the light source. ) Projection lens. The projection lens 21 is held on the lens holder 23 and arranged on the optical axis AX ₂₀ . The light capture angle θ1 is an angle (full angle) at which a light beam emitted from a light source disposed near the vehicle rear side focal point F _{21 of the} projection lens 21 enters the projection lens 21 (effective diameter). .

Vehicle front side surface of the projection lens 21 (convex), the light beam emitted from a light source disposed in the vicinity of the vehicle rear-side focal point F ₂₁ and transmitted through the projection lens 21 diffuses larger than in the horizontal direction vertically, The light beam transmitted through the projection lens 21 is refracted in a predetermined direction so as to form a spot light distribution pattern including a cut-off line on a virtual vertical screen (for example, disposed about 25 m ahead of the front end of the vehicle). (See, for example, JP 2010-153402 A). The projection lens 21 is not limited to a meniscus lens, and may be a plano-convex lens having a convex surface on the front side of the vehicle and a flat surface on the rear side of the vehicle.

FIG. 3 is a cross-sectional view of the light source unit 22 cut along a horizontal plane including the optical axis AX _22e .

As shown in FIG. 3, the light source unit 22 includes a semiconductor laser light source 22a, a condenser lens 22b, a phosphor 22c, a reflector 22d, a laser holder 22e for holding them, and the like. The semiconductor laser light source 22a, a condenser lens 22b, the phosphor 22c and the reflector 22d is held by a laser holder 22e, it is arranged on the optical axis _{AX 20.}

The laser holder 22e is a metal tube portion (for example, a cylindrical tube portion) such as aluminum, and includes a plate portion 22f that closes the front end opening thereof. The laser holder 22e is fixed to the lens holder 23 with its axis AX _22e coinciding with the optical axis AX ₂₀ and with the plate portion 22f facing the projection lens 21 (see FIG. 2).

A through hole H _22f is formed in a portion of the plate portion 22f on the axis AX _22e of the laser holder 22e (for example, on the central axis of the cylindrical tube portion). The through hole H _22f is covered with a phosphor 22c.

The semiconductor laser light source 22a is, for example, a laser diode that emits blue laser light (wavelength: 450 [nm]). The semiconductor laser light source 22a is fixed to the rear end side of the laser holder 22e with its axis AX _22a coinciding with the axis AX _22e of the laser holder 22e and its light emitting surface facing the plate portion 22f.

  The condenser lens 22b is fixed to the laser holder 22e and disposed in front of the semiconductor laser light source 22a so that the laser light emitted from the semiconductor laser light source 22a enters.

  The phosphor 22c is a wavelength conversion member (YAG phosphor in this embodiment) that receives laser light from the semiconductor laser light source 22a and generates light having a longer wavelength than the semiconductor laser light source 22a.

The phosphor 22c is arranged so that the laser beam from the semiconductor laser light source 22a collected by the condenser lens 22b is incident (that is, the light source image of the semiconductor laser light source 22a is projected). It is fixed to the formed through hole H _22f ) and disposed in front of the condenser lens 22b.

In this embodiment, as the phosphor 22c, a circular phosphor ceramic having a center on the optical axis AX ₂₀ (thickness: 80 μm, diameter: 0.6 mm, concentration of YAG: 20%, concentration of ceramic material such as alumina: 80%). The thickness of the phosphor ceramic, the diameter, the concentration of YAG, and the concentration of the ceramic material such as alumina are not limited to these, and can be appropriately adjusted. The shape of the phosphor 22c is not limited to a circle, and may be, for example, an ellipse or a rectangle having a longitudinal direction in the vehicle left-right direction (vehicle width direction). The rectangular phosphor 22c can be configured, for example, by covering the phosphor having a predetermined shape with a mask member in which a rectangular opening is formed.

The through hole H _22f formed in the plate portion 22f includes a large-diameter hole on the projection lens 21 side (vehicle front side) and a small-diameter hole on the opposite side (vehicle rear side). A step portion is formed at the boundary between the large diameter hole and the small diameter hole. The large-diameter hole has substantially the same diameter as the phosphor 22c. The phosphor 22c is inserted into the through hole H _22f (inside the large-diameter hole) until it contacts the stepped portion, and is fixed to the plate portion 22f (inside the large-diameter hole) using a known means such as an adhesive. . Phosphor 22c is located behind the vehicle rear side focal point _{F 21} of the projection lens 21.

  The phosphor 22c is white light (pseudo white light) due to a color mixture of the laser light from the semiconductor laser light source 22a that passes through the phosphor 22c and the light from the phosphor 22c that is excited by the laser light incident from the semiconductor laser light source 22a. Radiate. The amount of heat generated from the phosphor 22c and the semiconductor laser light source 22a is radiated by the action of the laser holder 22e, which is a metal cylinder such as aluminum.

  On the semiconductor laser light source 22a side of the surface of the phosphor 22c, an antireflection film (AR coating) for preventing the reflection of the laser light from the semiconductor laser light source 22a and the laser light from the semiconductor laser light source 22a are transmitted. Alternatively, dichroic coating that reflects yellow light from the phosphor 22c may be applied. When the antireflection film is applied, the laser light from the semiconductor laser light source 22a can be efficiently incident on the phosphor 22c, so that the light utilization efficiency can be improved. When dichroic coating is applied, yellow light traveling from the phosphor 22c toward the semiconductor laser light source 22a can be reflected toward the projection lens 21, and thus the light utilization efficiency can be improved.

The directivity characteristic of the light beam emitted from the phosphor 22c is substantially Lambertian. Lambertian is the ratio of luminous intensity in a direction inclined by a predetermined angle θ with respect to the phosphor 22c when the on-axis luminous intensity on the phosphor 22c is 100% (I ₀ ) (θ = 0). , I (θ) = I ₀ × cos θ. This represents the spread of the luminous flux emitted from the phosphor 22c.

Since the directivity characteristic of the light beam emitted from the phosphor 22c is substantially Lambertian as described above, when the light capturing angle θ1 of the projection lens 21 is 60 ° (full angle), the phosphor 22c is used as the vehicle of the projection lens 21. When arranged near the rear focal point F ₂₁ , only about 25% of the luminous flux emitted from the phosphor 22 c passes through the projection lens 21, and about 75% does not pass through the projection lens 21. In this case, the light utilization efficiency is about 25%.

  In the present embodiment, a reflector 22d is disposed in front of the phosphor 22c in order to increase the light flux that passes through the projection lens 21.

As shown in FIG. 3, the reflector 22d, as well as including the entrance 22d2 is one side opening and its opposite side of the other end side opening at a light output port 22D3, the vehicle near the rear side focal point F ₂₁ of the projection lens 21 A through hole extending so as to narrow in a conical shape is included as it goes from the arranged exit port 22d3 toward the entrance port 22d2 disposed in the vicinity of the phosphor 22c.

In the present embodiment, the through hole of the reflector 22d is a conical through hole whose axis of rotation is the axis AX _22e of the light source unit 22 (see FIG. 3). The reflector 22d is formed by, for example, injecting resin (acrylic, polycarbonate, or the like) into a mold, and cooling and solidifying. Then, the inner peripheral surface of the through hole of the reflector 22 d, by performing mirror finishing of aluminum vapor deposition or the like, arranged near the phosphor 22c from the vehicle rear side focal point F ₂₁ exit opening 22d3 disposed in the vicinity of the projection lens 21 A conical cylindrical reflection surface 22d1 is formed extending so as to narrow in a conical shape toward the incident port 22d2. In the present embodiment, the conical cylindrical reflection surface 22d1 is a conical cylindrical reflection surface having a reflectance of, for example, 0.85 and including a straight line in a cross section including the axis AX _22e of the light source unit 22.

The entrance 22d2 and the exit 22d3 have a circular shape centered on the axis AX _22e of the light source unit 22 in accordance with the shape of the phosphor 22c.

The entrance 22d2 has substantially the same size as the phosphor 22c (in this embodiment, diameter: 0) so that the light beam emitted from the phosphor 22c enters the reflector 22d (conical cylindrical reflection surface 22d1) without leakage. .6 mm). A virtual light source image is formed at the exit port 22d3 by the light beam from the phosphor 22c that passes through the exit port 22d3. Exit port 22d3, in order to project the virtual light source image formed to the front is disposed near the vehicle rear-side focal point F ₂₁ of the projection lens 21.

The reflector 22d is fixed to the plate portion 22f using a known means such as a screw or an adhesive in a state where the entrance 22d2 and the through hole H _22f formed in the plate portion 22f are substantially aligned and are in close contact with each other. ing. The phosphor 22c may be disposed on the vehicle rear side with respect to the incident port 22d2, or may be disposed in the incident port 22d2 (in the cone-shaped cylindrical reflecting surface 22d1).

  The ratio of the entrance aperture (diameter) and the exit aperture (diameter) of the reflector 22d is 1: 2 from the following viewpoint.

  The inventor of the present application performed a simulation on how the luminous flux within the directivity angle / the light source luminous flux changes when the exit aperture / incident aperture of the reflector 22d is changed. FIG. 4 is a graph plotting the results of the simulation. The horizontal axis represents the exit aperture / incident aperture of the reflector 22d, and the vertical axis represents the beam within the directivity angle / the light source beam.

In this simulation, the entrance port 22d2, the exit port 22d3, and the phosphor 22c are each circular, the entrance aperture diameter = the phosphor diameter (= 0.6 mm), and the taper angle α = the angle at which the luminous flux within the directivity angle becomes maximum at the exit port 22d3. Under the conditions, the directivity angles were 40 °, 60 °, 80 °, and 100 °. The taper angle α is an angle formed by the cross section (straight line) of the conical cylindrical reflection surface 22d1 including the axis AX _22e of the light source unit 22 and the optical axis AX ₂₀ (see FIG. 3). The light source luminous flux is the total luminous flux emitted from the phosphor 22c.

  Referring to FIG. 4, when the directivity angle is 60 °, the light flux within the directivity angle / light source light flux becomes maximum (about 75%) when the exit aperture / incident aperture of the reflector 22d is about 4 or more. In FIG. 4, the light beam within the directivity angle / light source light beam (about 25%) when the directivity angle is 60 ° and the exit aperture / incident aperture = 1 is within the directivity angle beam / light source beam when the reflector 22d is omitted. Represents.

  In consideration of miniaturization of the spot light distribution unit 20, it is desirable to reduce the exit aperture by reducing the exit aperture / incident aperture as much as possible. However, if the exit aperture / incident aperture is reduced, the light beam within the directivity angle / light source beam also decreases accordingly (see FIG. 4).

  As the light source of the vehicle headlamp, it is desirable that the light source size is small and the luminous flux is large. From this point of view, in the range of full angle of directional angle of 40 to 100 ° that can be effectively used as the vehicle headlamp, FIG. It is desirable to use a magnification of 1.5 to 4.0 near the inflection point.

  In the present embodiment, in consideration of the above, from the viewpoint of realizing a reduction in the size of the spot light distribution unit 20 and securing a light flux required for the spot light distribution pattern, the ratio of the incident aperture diameter to the exit aperture diameter is 1 : 2 is selected.

  The taper angle α of the reflector 22d is 15 ° from the following viewpoint.

  The inventor of the present application performed a simulation on how the in-directional angle / light source light flux changes when the taper angle α is changed. FIG. 5 is a graph plotting the results of the simulation. The horizontal axis represents the taper angle α, and the vertical axis represents the directivity angle / light source light flux.

  This simulation is based on the condition that the exit aperture / incident aperture = 2, the entrance aperture 22d2, the exit aperture 22d3, and the phosphor 22c are circular, and the entrance aperture = the phosphor diameter (= 0.6 mm). It was performed every 60 °, 80 °, and 100 °.

  Referring to FIG. 5, when the taper angle α is a specific angle, the light beam within the directivity angle / the light source light beam is maximized. For example, when the directivity angle is 60 °, the taper angle α is 15 °. It can be seen that the beam within the directional angle / the light source beam is maximized.

  As described above, when the taper angle α is a specific angle, the light beam within the directivity angle / the light source light beam is maximized. For example, when a light beam with a directivity angle (full angle) of 80 ° is desired, the taper angle α is small. In the region, since the light beam within the directivity angle (full angle) 80 ° of the direct light from the light source (phosphor 22c) is also reflected, a reflection loss occurs, and the size of the exit port 22d3 is fixed, so the taper angle If α is large, the length of the reflector 22d is shortened, and the luminous flux that does not hit the cone-shaped cylindrical reflection surface 22d1 increases, which is considered to be a cause of the decrease in efficiency.

  Note that, even when the exit aperture / incident aperture is other than 2, the in-directivity beam / light source beam is maximized when the taper angle α is a specific angle, according to the simulation conducted by the inventors of the present application. (See FIG. 6). FIG. 6 is a graph in which the taper angle α at which the light flux within the directivity angle / light source light flux becomes maximum when the exit aperture / incident aperture is changed is plotted for each orientation angle of 40 °, 60 °, 80 °, and 100 °. It is. The horizontal axis represents the exit aperture / incident aperture of the reflector 22d, and the vertical axis represents the taper angle α at which the beam within the directivity angle / the light source beam is maximized.

  Referring to FIG. 6, when the ratio of the entrance aperture to the exit aperture is between 1: 1.5 and 1: 4.0, the taper angle α is set within 15 to 40 °, so that the vehicle headlamp is set. It can be seen that the luminous flux within a directivity angle of 40 to 100 ° (full angle) that can be effectively used as a lamp can be maximized.

  In the present embodiment, from the viewpoint of forming a brighter spot light distribution pattern, the angle of 15 ° at which the luminous flux within the directivity angle / light source luminous flux corresponding to the light capturing angle θ1 of the projection lens 21 is maximized as the taper angle α of the reflector 22d. Is selected.

The dimension of the reflector 22d in the direction of the optical axis AX ₂₀ is automatically determined by selecting the ratio of the entrance aperture to the exit aperture of the reflector 22d and the taper angle α as described above.

  According to the spot light distribution unit 20 configured as described above, the laser light emitted from the semiconductor laser light source 22a is condensed by the action of the condensing lens 22b and irradiated onto the phosphor 22c (that is, the semiconductor laser light source 22a). A light source image is projected onto the phosphor 22c). In the present embodiment, the light source image of the semiconductor laser light source 22a projected onto the phosphor 22c is substantially the same circle as the phosphor 22c. A circular light source image can be formed, for example, by adjusting the focal position of the condenser lens 22b.

  The phosphor 22c irradiated with the laser light is excited by the laser light (scattered light) from the semiconductor laser light source 22a scattered on the surface (and / or inside) and the laser light incident from the semiconductor laser light source 22a to emit light. White light (pseudo white light) is emitted by color mixing with light from the phosphor 22c.

  The light beam emitted from the phosphor 22c enters the cone-shaped cylindrical reflection surface 22d1 from the entrance port 22d2, is reflected by the reflection surface 22d1, and exits from the exit port 22d3 (or is reflected by the reflection surface 22d1). Without being emitted directly from the exit port 22d3), the light passes through the projection lens 21 and is irradiated forward. That is, a virtual light source image is formed on the exit port 22d3 by the light beam passing through the exit port 22d3, and this virtual light source image is projected forward.

  Accordingly, the spot light distribution pattern P1a for irradiating the hot zone Hz in the passing beam light distribution pattern P1 which is a combined light distribution pattern on a virtual vertical screen (for example, disposed about 25 m ahead of the front end of the vehicle). Is formed (see FIG. 7). The spot light distribution pattern P1a includes a cut-off line CL1a formed by the action of the projection lens 21 (vehicle front side surface) at the upper edge. The cut-off line CL1a can be formed without loss of the light beam, as compared with the case where a part of the light beam is shaded by the shade to form the cut-off line.

  The spot light distribution unit 20 uses a known aiming mechanism (not shown) to irradiate the hot zone Hz in the passing beam light distribution pattern P1 in which the spot light distribution pattern P1a is a combined light distribution pattern. It has been adjusted.

  As described above, according to the spot light distribution unit 20 of the present embodiment, the luminous flux emitted from the phosphor 22c by the action of the reflector 22d (conical cylindrical reflection surface 22d1) disposed in front of the phosphor 22c. Therefore, it is possible to allow a light beam that could not be incident on the projection lens 21 to be incident on the projection lens 21. This makes it possible to configure a vehicle headlamp with high light utilization efficiency.

  According to the spot light distribution unit 20 of the present embodiment, the reflector 22c in which the ratio of the entrance aperture to the exit aperture and the taper angle α are set as described above is disposed in front of the phosphor 22c, thereby the phosphor 22c. About 65% of the luminous flux emitted from the light passes through the projection lens 21 (see FIG. 4). That is, according to the spot light distribution unit 20 of the present embodiment, it is possible to use approximately 2.5 times the luminous flux for forming the spot light distribution pattern P1a as compared with the case where the reflector 22d is not disposed. It is possible to configure a spot light distribution unit 20 having an extremely high height.

  Moreover, according to the spot light distribution unit 20 of this embodiment, the directivity angle of the light beam radiated | emitted from the fluorescent substance 22c by the effect | action of the reflector 22d (conical cylindrical reflection surface 22d1) arrange | positioned ahead of the fluorescent substance 22c. Therefore, the spot light distribution pattern P1a having sufficient brightness can be formed even if the size of the projection lens 21 or the like is reduced.

The area of the exit port 22d3 is desirably 2 mm ² or less. In this way, it is possible to form a virtual light source having a light emitting area equivalent to that of an LED and having a narrower directivity angle than that of the LED at the exit port 22d3. Thus, since it becomes possible to make it the light emission area equivalent to LED, the headlight for vehicles with high light utilization efficiency by combining the optical system designed for LED and the light source unit 22 of this embodiment. It becomes possible to construct a lamp.

  Further, according to the spot light distribution unit 20 of the present embodiment, since the semiconductor laser light source 22a and the phosphor 22c are arranged apart from each other, the heat of the semiconductor laser light source 22a is not directly transmitted to the reflector 22d. . For this reason, even if the reflector 22d is formed of resin or the like, it is possible to suppress the reflector 22d from being damaged by the influence of the heat of the semiconductor laser light source 22a.

[Diffusion light distribution unit 30]
FIG. 8 is a cross-sectional view of the diffusing light distribution unit 30 cut along a horizontal plane including the optical axis AX ₃₀ .

The diffusion light distribution unit 30 is a so-called direct projection type lamp unit, and as shown in FIG. 8, the projection lens 31 is disposed on the optical axis AX ₃₀ extending in the vehicle front-rear direction, and is disposed behind the projection lens 31. The light source unit 22 is provided. The light source unit 22 is the same as that described in the first embodiment.

  Comparing the diffused light distribution unit 30 and the spot light distribution unit 20 having the above configuration, the former rear-side focal length and the light capture angle θ2 of the projection lens 31 are 10 mm and 100 ° (full angle), respectively. The latter differs in that the rear focal length of the projection lens 21 and the light capture angle θ1 are 50 mm and 60 ° (full angle), respectively.

  Further, the ratio of the entrance aperture to the exit aperture of the former reflector 22d and the taper angle α are 1: 2 and 25 °, whereas the ratio of the entrance aperture to the exit aperture of the latter reflector 22d and the taper angle α are 1. : 2 and 15 °, both differ.

  Except for the above differences, the diffusion light distribution unit 30 is the same as the spot light distribution unit 20.

  Hereinafter, the diffusion light distribution unit 30 will be described focusing on differences from the spot light distribution unit 20. In addition, about the structure same as the spot light distribution unit 20, the same code | symbol is attached | subjected and description is abbreviate | omitted.

The projection lens 31 is a meniscus lens having a convex surface on the vehicle front side and a concave surface on the vehicle rear side. In the present embodiment, from the viewpoint of forming a wide light distribution pattern that diffuses greatly in the left-right direction (for example, the range of 50 ° left and right), the rear lens on the vehicle has a focal length of 10 mm in consideration of the size of the light source. A projection lens having a light capture angle θ2 of 100 ° (full angle) is used. The projection lens 31 is held on the lens holder 33 and disposed on the optical axis AX ₃₀ . Note that the light acceptance angle θ2 is the angle of the light beam emitted from the arranged near the vehicle rear-side focal point F ₃₁ of the projection lens 31 light source is incident on the projection lens 31 (effective diameter) (em) .

Vehicle front side surface of the projection lens 31 (convex), the light beam emitted from a light source disposed in the vicinity of the vehicle rear-side focal point F ₃₁ and transmitted through the projection lens 31 diffuses larger than in the horizontal direction vertically, The light beam transmitted through the projection lens 31 is refracted in a predetermined direction so as to form a wide light distribution pattern including a cut-off line on a virtual vertical screen (for example, disposed about 25 m ahead of the front end of the vehicle). (See, for example, JP 2010-153402 A). The projection lens 31 is not limited to a meniscus lens, and may be a plano-convex lens having a convex surface on the front side of the vehicle and a flat surface on the rear side of the vehicle.

Since the directivity characteristic of the light beam emitted from the phosphor 22c is substantially Lambertian as described above, when the light capturing angle θ2 of the projection lens 31 is 100 ° (full angle), the phosphor 22c is used as the vehicle of the projection lens 31. When placed near the rear side focal point F _31, only about 60% of the light beam emitted from the phosphor 22c is transmitted through the projection lens 31, about 40% is not transmitted through the projection lens 31. In this case, the light utilization efficiency is about 60%.

  In the present embodiment, a reflector 22d is disposed in front of the phosphor 22c in order to increase the luminous flux transmitted through the projection lens 31.

Reflector 22d, as well including entrance 22d2 is one side opening and its opposite side of the other end side opening at a light output ports 22D3, from the exit 22D3 arranged near the vehicle rear-side focal point F ₃₁ of the projection lens 31 It includes a through hole extending so as to narrow in a cone shape toward the entrance 22d2 disposed in the vicinity of the phosphor 22c.

In the present embodiment, the through hole of the reflector 22d is a conical through hole whose axis of rotation is the axis AX _22e of the light source unit 22 (see FIG. 8).

The entrance 22d2 has substantially the same size as the phosphor 22c (in this embodiment, diameter: 0) so that the light beam emitted from the phosphor 22c enters the reflector 22d (conical cylindrical reflection surface 22d1) without leakage. .6 mm). A virtual light source image is formed at the exit port 22d3 by the light beam from the phosphor 22c that passes through the exit port 22d3. Exit port 22d3, in order to project the virtual light source image formed to the front, is disposed in the vicinity vehicle rear side focal point F ₃₁ of the projection lens 31.

  The ratio of the entrance aperture (diameter) and the exit aperture (diameter) of the reflector 22d is 1: 2 from the following viewpoint.

  Referring to FIG. 4, when the directivity angle is 100 °, the light flux within the directivity angle / light source light flux becomes maximum (about 88%) when the exit aperture / incident aperture of the reflector 22d is about 2 or more. In FIG. 4, the light beam within the directivity angle / light source light beam (about 60%) when the directivity angle is 100 ° and the exit aperture / incident aperture is 1 is within the directivity angle beam / light source beam when the reflector 22d is omitted. Represents.

  In the present embodiment, 1: 2 is selected as the ratio of the entrance aperture to the exit aperture from the viewpoint of securing the luminous flux required for the wide light distribution pattern.

  The taper angle α of the reflector 22d is 25 ° from the following viewpoint.

  Referring to FIG. 5, it can be seen that when the directivity angle is 100 °, the light flux within the directivity angle / light source light flux becomes maximum when the taper angle α is 25 °.

  In the present embodiment, from the viewpoint of forming a brighter wide light distribution pattern, an angle 25 ° at which the luminous flux within the directivity angle / light source luminous flux corresponding to the light capturing angle θ2 of the projection lens 31 is maximized as the taper angle α of the reflector 22d. Is selected.

The dimension of the reflector 22d in the direction of the optical axis AX ₃₀ is automatically determined by selecting the ratio of the entrance aperture to the exit aperture of the reflector 22d and the taper angle α as described above.

  According to the diffusing light distribution unit 30 having the above configuration, the laser light emitted from the semiconductor laser light source 22a is condensed by the action of the condensing lens 22b and irradiated to the phosphor 22c (that is, the semiconductor laser light source 22a). A light source image is projected onto the phosphor 22c). In the present embodiment, the light source image of the semiconductor laser light source 22a projected onto the phosphor 22c is substantially the same circle as the phosphor 22c. A circular light source image can be formed, for example, by adjusting the focal position of the condenser lens 22b.

  The phosphor 22c irradiated with the laser light is excited by the laser light (scattered light) from the semiconductor laser light source 22a scattered on the surface (and / or inside) and the laser light incident from the semiconductor laser light source 22a to emit light. White light (pseudo white light) is emitted by color mixing with light from the phosphor 22c.

  The light beam emitted from the phosphor 22c enters the cone-shaped cylindrical reflection surface 22d1 from the entrance port 22d2, is reflected by the reflection surface 22d1, and exits from the exit port 22d3 (or is reflected by the reflection surface 22d1). Without being emitted directly from the exit port 22d3), and passes through the projection lens 31 to be irradiated forward. That is, a virtual light source image is formed on the exit port 22d3 by the light beam passing through the exit port 22d3, and this virtual light source image is projected forward.

  As a result, a wide light distribution pattern P1b that irradiates the diffusion region A in the passing beam light distribution pattern P1 that is a combined light distribution pattern on a virtual vertical screen (for example, disposed about 25 m ahead of the front end of the vehicle). Is formed (see FIG. 7). The wide light distribution pattern P1b includes a cut-off line CL1b formed by the action of the projection lens 31 (vehicle front side surface) at the upper edge. The cut-off line CL1b can be formed without loss of the light beam, as compared with the case where a part of the light beam is shaded by the shade to form the cut-off line.

  The diffusion light distribution unit 30 uses a known aiming mechanism (not shown) to irradiate the diffusion region A in the passing beam light distribution pattern P1 in which the wide light distribution pattern P1b is a combined light distribution pattern. It has been adjusted.

  As described above, according to the diffusion light distribution unit 30 of the present embodiment, the luminous flux emitted from the phosphor 22c by the action of the reflector 22d (conical cylindrical reflection surface 22d1) disposed in front of the phosphor 22c. Therefore, it is possible to make the light beam that could not be incident on the projection lens 31 conventionally enter the projection lens 31. Thereby, it becomes possible to improve light utilization efficiency.

  According to the diffusing light distribution unit 30 of the present embodiment, the reflector 22d in which the ratio of the entrance aperture to the exit aperture and the taper angle α are set as described above is disposed in front of the phosphor 22c. About 88% of the luminous flux emitted from the light passes through the projection lens 31 (see FIG. 4). That is, according to the diffusing light distribution unit 30 of the present embodiment, it is possible to use about 1.5 times the luminous flux for forming the wide light distribution pattern P1b as compared with the case where the reflector 22d is not disposed. It is possible to construct a very high diffusion light distribution unit 30.

  Further, according to the diffusion light distribution unit 30 of the present embodiment, the directivity angle of the light beam emitted from the phosphor 22c by the action of the reflector 22d (conical cylindrical reflection surface 22d1) disposed in front of the phosphor 22c. Therefore, it is possible to reduce the size of the projection lens 31 and the like.

The area of the exit port 22d3 is desirably 2 mm ² or less. In this way, it is possible to form a virtual light source having a light emitting area equivalent to that of an LED and having a narrower directivity angle than that of the LED at the exit port 22d3. Thus, since it becomes possible to make it the light emission area equivalent to LED, the headlight for vehicles with high light utilization efficiency by combining the optical system designed for LED and the light source unit 22 of this embodiment. It becomes possible to construct a lamp.

  Further, according to the diffusion light distribution unit 30 of the present embodiment, since the semiconductor laser light source 22a and the phosphor 22c are arranged apart from each other, the heat of the semiconductor laser light source 22a is not directly transmitted to the reflector 22d. . For this reason, even if the reflector 22d is formed of resin or the like, it is possible to suppress the reflector 22d from being damaged by the influence of the heat of the semiconductor laser light source 22a.

[Synthetic light distribution pattern P1]
Next, a passing beam light distribution pattern P1 which is a combined light distribution pattern formed on a virtual vertical screen (for example, disposed about 25 m ahead of the vehicle front end) by the vehicle headlamp 10 having the above-described configuration. explain.

  FIG. 7 shows a light distribution pattern P1 for a passing beam, which is a combined light distribution pattern obtained by combining the spot light distribution pattern P1a formed by the spot light distribution unit 20 and the wide light distribution pattern P1b formed by the diffusion light distribution unit 30. It is an example.

The cut-off line extends in the horizontal direction with a difference in the left and right steps from the VV line, which is a vertical line passing through HV, which is the vanishing point in the front direction of the lamp, and the right side of the VV line is on the opposite lane together they are formed so as to extend in the horizontal direction as a side cut-off line CL _R, left of the line V-V extends horizontally stepped up than the opposite lane side cut-off line CL _R as a self-lane side cutoff line CL _L It is formed in this way. Then, the ends of the line V-V closer in the own lane side cut-off line CL _L is formed as an oblique cut-off line CL _S. The oblique cutoff line CL _S extends from the intersection between the oncoming vehicle lane side cut-off line CL _R and the line V-V in upper left of the inclination angle (e.g. about 45 °).

In low-beam light distribution pattern P1, an elbow point E which is the point of intersection between the oncoming vehicle lane side cut-off line CL _R and the line V-V is positioned approximately 0.5 to 0.6 ° below the H-H A hot zone Hz that is a high luminous intensity region is formed so as to surround the elbow point E slightly to the left. A diffusion region A diffused from the hot zone Hz is formed on the outside thereof. The hot zone Hz is irradiated with a light beam from the spot light distribution unit 20, and the diffusion region A is irradiated with a light beam from the diffusion light distribution unit 30. As a result, it is possible to form the light distribution pattern P1 for the passing beam that is optimal for a vehicle headlamp that has a brighter hot zone Hz and is more distantly visible.

  As described above, according to the vehicle headlamp 10 of the present embodiment configured by combining the spot light distribution unit 20 and the diffusion light distribution unit 30, the following effects can be obtained.

  That is, according to the vehicle headlamp 10 of the present embodiment, the hot zone Hz is irradiated with a light beam from the exit port 22d3, which is a virtual light source having a light emitting area equivalent to that of the LED and having a narrower directivity angle than the LED. Therefore, compared with the case where the hot zone Hz is illuminated with a luminous flux from an LED having a light emitting area equivalent to this, the combined light distribution pattern optimal for a vehicle headlamp having a brighter hot zone Hz and excellent visibility in the distance It is possible to form the light distribution pattern P1 for the passing beam.

  Moreover, according to the vehicle headlamp 10 of the present embodiment, the hot zone Hz is irradiated with the light flux from the emission port 22d3 which is a virtual light source having a light emitting area equivalent to that of the LED and having a narrower directivity angle than the LED. Therefore, it is possible to irradiate the hot zone Hz sufficiently brightly with a smaller number of spot light distribution units 20 than in the case of irradiating the hot zone Hz with a light beam from an LED having a light emitting area equivalent to this. Thus, according to the vehicle headlamp 10 of the present embodiment, the hot zone Hz can be irradiated sufficiently brightly even if the number of the spot light distribution units 20 is reduced. Space saving of the lighting 10 can be realized.

  Similarly, according to the vehicle headlamp 10 of the present embodiment, the diffusion region A is irradiated with a light beam from the emission port 22d3 that is a virtual light source having a light emitting area equivalent to that of the LED and having a narrower directivity angle than the LED. Therefore, it is possible to irradiate the diffusion region A sufficiently brightly with a smaller number of diffusion light distribution units 30 than when irradiating the diffusion region A with a light beam from an LED having a light emitting area equivalent to this. . As described above, according to the vehicle headlamp 10 of the present embodiment, it is possible to irradiate the diffusion region A sufficiently brightly even if the number of the diffusion light distribution units 30 is reduced. Space saving of the lighting 10 can be realized.

  Next, a modified example will be described.

  In the above embodiment, the combined light distribution pattern obtained by combining the spot light distribution pattern P1a formed by the spot light distribution unit 20 and the wide light distribution pattern P1b formed by the diffusion light distribution unit 30 is a light distribution pattern for passing beam. Although the example which is P1 was demonstrated, this invention is not limited to this.

  For example, a combined light distribution pattern obtained by synthesizing the light distribution pattern P2a formed by the spot light distribution unit 20 and the light distribution pattern P2b formed by the diffusion light distribution unit 30 is shown in FIG. The light pattern P2 may be sufficient. For example, the traveling beam light distribution pattern P <b> 2 can be formed by adjusting the vehicle front side surfaces of the projection lenses 21 and 31 of the units 20 and 30.

  In the above embodiment, the shape of the entrance 22d2 and the exit 22d3 is described as being circular. However, the shape of the entrance 22d2 and the exit 22d3 may be any shape that matches the shape of the phosphor 22c. It is not limited to a circle.

  For example, when a rectangular or elliptical phosphor 22c having an aspect ratio (for example, 1: 2 to 1: 5) is used instead of the circular phosphor 22c, the shapes of the entrance 22d2 and the exit 22d3 are also the same. It is possible to use a rectangular or elliptical shape with a ratio (eg 1: 2 to 1: 5).

  In this way, it is possible to realize a light source that is long in the left-right direction of the vehicle (vehicle width direction), and therefore it is possible to form an optimal light distribution pattern as a vehicle headlamp.

  4 to 6 show simulation results when the entrance 22d2, the exit 22d3, and the phosphor 22c are each circular, but the entrance 22d2, the exit 22d3, and the phosphor 22c are each other than a circle (for example, (Rectangular or elliptical shape), it has been found that the same result as in the case of a circle is obtained.

Moreover, although the said embodiment _demonstrated that the cross section containing the axis _| shaft AX22e of the light source unit 22 of the cone-shaped cylindrical reflective surface 22d1 was a straight line, the axis _| shaft of the light source unit 22 of the cone-shaped cylindrical reflective surface 22d1. The cross section including AX _22e is not limited to a straight line as long as the light beam from the phosphor 22c reflected by the conical cylindrical reflection surface 22d1 enters the projection lens 21.

For example, the cross section of the cone-shaped cylindrical reflection surface 22d1 including the axis AX _22e of the light source unit 22 is on the outer side as viewed from the phosphor 22c so that the light beams within and outside the directivity angle are incident on the projection lens 21. It may be a convex curve. In this way, in addition to the light beam within the directivity angle, the light beam outside the directivity angle is incident on the projection lens 21. Accordingly, the light utilization efficiency is further improved, and a higher bright spot light distribution. Patterns and wide light distribution patterns can be formed.

  Next, Modification 1 in which the direct projection type spot light distribution unit 20A is configured using a single optical fiber will be described.

FIG. 10 is a cross-sectional view of the spot light distribution unit 20A cut along a horizontal plane including the optical axis AX _20A .

  Compared with the spot light distribution unit 20A of the present modification and the spot light distribution unit 20 of the first embodiment, the former phosphor 22c and reflector 22d are fixed to the lens holder 23 via the support member 24 instead of the light source unit 22. On the other hand, they are different in that the latter phosphor 22c and reflector 22d are fixed to the light source unit 22.

  Further, the former is different in that the former light source unit 22 is not fixed to the lens holder 23, whereas the latter light source unit 22 is fixed to the lens holder 23.

  The former is different from the former in that the optical fiber 25 is provided, whereas the latter is not provided with the optical fiber 25.

  Except for the above differences, the spot light distribution unit 20A of the present modification is the same as the spot light distribution unit 20 of the first embodiment.

  Hereinafter, the spot light distribution unit 20A of the present modification will be described focusing on differences from the spot light distribution unit 20 of the first embodiment. In addition, about the structure same as the spot light distribution unit 20 of 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The optical fiber 25 (corresponding to the light guide of the present invention) is a thin fibrous material formed of quartz glass or plastic, and includes a core at the center and a clad covering the periphery. The core has a higher refractive index than the clad. The light introduced from the one end face 25a of the optical fiber 25 is guided (or transmitted) to the other end face 25b in a state of being confined inside the core using total reflection at the boundary between the core and the clad. The light is emitted from the other end surface 25b.

As shown in FIG. 10, at one end of the optical fiber 25, the laser light from the semiconductor laser light source 22a collected by the condenser lens 22b is incident on the one end face 25a (core) (that is, the semiconductor laser). The light source 22a is fixed to the plate portion 22f (through hole H _22f formed in the support member 26) so that the light source image of the light source 22a is projected.

  The core of the optical fiber 25 has a circular cross section (for example, diameter: 0.6 mm) in accordance with the shape of the phosphor 22c.

  The other end of the optical fiber 25 is fixed to the lens holder 23 via the support member 24 in a state in which the other end face 25b (core) and the phosphor 22c are substantially aligned and in close contact with each other.

  The spot light distribution unit 20A of the present modification functions as follows.

  That is, the laser light emitted from the semiconductor laser light source 22a is introduced into the inside from one end face 25a (core) of the optical fiber 25, is emitted from the other end face 25b (core), and irradiates the phosphor 22c.

  The phosphor 22c irradiated with the laser light is excited by the laser light (scattered light) from the semiconductor laser light source 22a scattered on the surface (and / or inside) and the laser light incident from the semiconductor laser light source 22a to emit light. White light (pseudo white light) is emitted by color mixing with light from the phosphor 22c.

  The light beam emitted from the phosphor 22c enters the cone-shaped cylindrical reflection surface 22d1 from the entrance port 22d2, is reflected by the reflection surface 22d1, and exits from the exit port 22d3 (or is reflected by the reflection surface 22d1). Without being emitted directly from the exit port 22d3), the light passes through the projection lens 21 and is irradiated forward. That is, a virtual light source image is formed on the exit port 22d3 by the light beam passing through the exit port 22d3, and this virtual light source image is projected forward.

  Accordingly, the spot light distribution pattern P1a for irradiating the hot zone Hz in the passing beam light distribution pattern P1 which is a combined light distribution pattern on a virtual vertical screen (for example, disposed about 25 m ahead of the front end of the vehicle). Is formed (see FIG. 7). The spot light distribution pattern P1a includes a cut-off line CL1a formed by the action of the projection lens 21 (vehicle front side surface) at the upper edge. The spot light distribution unit 20A has an optical axis by a known aiming mechanism (not shown) so as to irradiate the hot zone Hz in the passing beam light distribution pattern P1 in which the spot light distribution pattern P1a is a combined light distribution pattern. It has been adjusted.

  According to the spot light distribution unit 20A of the present modification, in addition to the effects described in the first embodiment, the following effects are further achieved.

  First, by using the semiconductor laser light source 22a and the optical fiber 25, it becomes possible to efficiently transmit the laser light to the phosphor 22c without a large loss. This is because the directivity angle of the semiconductor laser light source 22a is narrow and the light source size is small.

  Second, by using the optical fiber 25, the semiconductor laser light source 22a and the like (that is, the light source unit 22 excluding the phosphor 22c and the reflector 22d) can be disposed outside the spot light distribution unit 20A. Thereby, the spot light distribution unit 20A can be made smaller and lighter than when the semiconductor laser light source 22a, the cooling structure, and the like are installed inside the spot light distribution unit 20A.

  Third, since the spot light distribution unit 20A can be reduced in weight as described above, when a known aiming mechanism is connected to the spot light distribution unit 20A, the weight load applied to the aiming mechanism can be reduced. . Thereby, it is possible to reduce various problems caused by the weight load applied to the aiming mechanism.

  In addition, the cross section of the core of the optical fiber 25 should just be a shape suitable for the shape of the fluorescent substance 22c, and is not limited to a circle. For example, when a rectangular or elliptical phosphor 22c having an aspect ratio (for example, 1: 2 to 1: 5) is used instead of the circular phosphor 22c, the cross section of the core of the optical fiber 25 also has an aspect ratio (for example, A rectangular or elliptical shape of 1: 2 to 1: 5) can be used.

  In this way, it is possible to realize a light source that is long in the left-right direction of the vehicle (vehicle width direction), and therefore it is possible to form an optimal light distribution pattern as a vehicle headlamp.

  When the rectangular or elliptical core is compared with the circular core, the transmission efficiency is almost the same even with the rectangular or elliptical core, and a substantially uniform luminance distribution matching the core shape is formed on the other end face 25b. It becomes possible to do.

  Although the example in which the spot light distribution unit 20A is configured using the optical fiber 25 has been described above, the diffusion light distribution unit 30A can be configured using the optical fiber 25 in the same manner (see FIG. 11).

  Next, Modification 2 in which a direct projection type spot light distribution unit 20B is configured using a plurality of optical fibers will be described.

FIG. 12 is a cross-sectional view of the spot light distribution unit 20B cut along a horizontal plane including the optical axis AX _20B .

  Compared with the spot light distribution unit 20B of the present modification and the spot light distribution unit 20A of the modification 1, the former includes one light source unit 22 and one optical fiber 25, whereas the latter includes a plurality of light sources. They are different in that they include a unit 22 and a plurality of individual optical fibers 27.

  Except for the above differences, the spot light distribution unit 20B of the present modification is the same as the spot light distribution unit 20A of the modification 1.

  Hereinafter, the spot light distribution unit 20B of the present modification will be described focusing on differences from the spot light distribution unit 20A of Modification 1. In addition, about the structure same as the spot light distribution unit 20A of the modification 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The individual optical fiber 27 (corresponding to the light guide of the present invention) is a thin fibrous material formed of quartz glass or plastic, and includes a central core and a clad covering the periphery thereof. The core has a higher refractive index than the clad. The light introduced from one end surface 27a of the individual optical fiber 27 is guided to the other end surface 27b in a state of being confined inside the core using total reflection at the boundary between the core and the clad, and the other end surface 27b. Emanates from. The same applies to the common optical fiber 28 (corresponding to the common light guide of the present invention).

As shown in FIG. 12, at one end of the individual optical fiber 27, the laser light from the semiconductor laser light source 22a collected by the condenser lens 22b is incident on one end surface 27a (core) (that is, the semiconductor). The light source image of the laser light source 22a is projected), and is fixed to the plate portion 22f of the corresponding light source unit 22 (through hole H _22f formed in) through the support member 26.

  The other end surface 27 b (core) of each individual optical fiber 27 is connected to one end surface 28 a (core) of the common optical fiber 28 so that laser light emitted from the other optical fiber 27 enters the one end surface 28 a of the common optical fiber 28.

  The core of the individual optical fiber 27 has a circular cross section (for example, diameter: 0.2 mm). The core of the common optical fiber 28 has an area larger than the total core area of each individual optical fiber 27 in order to efficiently capture the laser light from each individual optical fiber 27 (for example, long side 0.8 mm × short side 0.4 mm). Oval core). Instead of the common optical fiber 28, a light guide member such as a glass rod may be used.

  The other end of the common optical fiber 28 is fixed to the lens holder 23 via the support member 24 in a state in which the other end face 28b (core) and the phosphor 22c are substantially aligned and in close contact with each other.

  The spot light distribution unit 20B of the present modification functions as follows.

  That is, the laser light emitted from each semiconductor laser light source 22a is introduced into the inside from one end face 27a (core) of the corresponding individual optical fiber 27, and further introduced into the inside from one end face 28a of the common optical fiber 28, The light is emitted from the other end surface 28b (core) and irradiated with the phosphor 22c.

  The phosphor 22c irradiated with the laser light is excited by the laser light (scattered light) from the semiconductor laser light source 22a scattered on the surface (and / or inside) and the laser light incident from the semiconductor laser light source 22a to emit light. White light (pseudo white light) is emitted by color mixing with light from the phosphor 22c.

  The light beam emitted from the phosphor 22c enters the cone-shaped cylindrical reflection surface 22d1 from the entrance port 22d2, is reflected by the reflection surface 22d1, and exits from the exit port 22d3 (or is reflected by the reflection surface 22d1). Without being emitted directly from the exit port 22d3), the light passes through the projection lens 21 and is irradiated forward. That is, a virtual light source image is formed on the exit port 22d3 by the light beam passing through the exit port 22d3, and this virtual light source image is projected forward.

  Accordingly, the spot light distribution pattern P1a for irradiating the hot zone Hz in the passing beam light distribution pattern P1 which is a combined light distribution pattern on a virtual vertical screen (for example, disposed about 25 m ahead of the front end of the vehicle). Is formed (see FIG. 7). The spot light distribution pattern P1a includes a cut-off line CL1a formed by the action of the projection lens 21 (vehicle front side surface) at the upper edge. The spot light distribution unit 20B has an optical axis by a known aiming mechanism (not shown) so as to irradiate the hot zone Hz in the passing beam light distribution pattern P1 in which the spot light distribution pattern P1a is a combined light distribution pattern. It has been adjusted.

  According to the spot light distribution unit 20B of this modified example, in addition to the effects described in the modified example 1, the following effects are further exhibited.

  When a plurality of individual optical fibers 27 are bundled and the laser light emitted from the other end surface 27b is directly incident on the phosphor 22c, the clad layer of each individual optical fiber 27 becomes a shadow and uneven brightness occurs. There is a problem that 22c cannot be uniformly irradiated.

  On the other hand, according to the spot light distribution unit 20B of the present modification, the laser light from each individual optical fiber 27 is incident on the common optical fiber 28 and becomes uniform. Compared with the case of directly irradiating the phosphor 22c with the laser light from 27, it becomes possible to irradiate the phosphor 22c uniformly without uneven brightness.

  The example in which the spot light distribution unit 20B is configured using the individual optical fiber 27 and the common optical fiber 28 has been described above. Similarly, a diffusion light distribution unit (not shown) is configured using the individual optical fiber 27 and the common optical fiber 28. It is possible to configure.

[Second Embodiment]
Next, a vehicle headlamp according to a second embodiment of the present invention will be described with reference to the drawings.

FIG. 13 is a longitudinal sectional view of the spot light distribution unit 40 constituting the vehicle headlamp according to the second embodiment of the present invention cut along a vertical plane including the optical axis AX ₄₀ .

The spot light distribution unit 40 of the present embodiment is a so-called parabolic lamp unit, and is a virtual parabolic reflection surface 41 and a virtual surface disposed near the focal point F ₄₁ of the reflection surface 41 as shown in FIG. A light source unit 22 including an emission port 22d3 as a light source is provided. The light source unit 22 is the same as that described in the first embodiment.

The reflection surface 41 is a parabolic reflection surface having an optical axis AX ₄₀ (rotation axis) extending in the vehicle front-rear direction, reflects a light beam incident from the emission port 22d3 of the light source unit 22, and includes a cut-off line CL1a. The spot light distribution pattern P1a is formed.

The light source unit 22 is arranged in such a posture that the light beam emitted from the emission port 22d3 is substantially downward. Exit port 22d3 is located near the focal point _{F 41} of the reflective surface 41.

  In the present embodiment, it is desirable to select the ratio of the entrance aperture and the exit aperture of the reflector 22d in the same manner as in the first embodiment (for example, 1: 2). In addition, as in the first embodiment, the taper angle α of the reflector 22d is maximized in the beam within the directivity angle / the light source beam corresponding to the light capturing angle of the reflecting surface 41 from the viewpoint of forming a brighter spot light distribution pattern. It is desirable to select an angle.

  According to the spot light distribution unit 40 having the above configuration, the light beam emitted from the emission port 22d3 and incident on the reflection surface 41 is reflected by the reflection surface 41 and irradiated forward. As a result, as shown in FIG. 7, the hot zone Hz in the light distribution pattern P1 for the passing beam, which is a combined light distribution pattern, is displayed on a virtual vertical screen (for example, disposed about 25 m ahead of the front end of the vehicle). The spot light distribution pattern P1a to be irradiated is formed. The spot light distribution pattern P1a includes a cut-off line CL1a at the upper end edge. The spot light distribution unit 40 uses a known aiming mechanism (not shown) to irradiate the hot zone Hz in the light distribution pattern P1 for the passing beam whose spot light distribution pattern P1a is a combined light distribution pattern. It has been adjusted.

  Conventionally, in a parabolic lamp unit, the size of the reflecting surface (the reflecting surface corresponding to the reflecting surface 41) is determined in the specification without considering the directivity characteristics of the light source. In some cases, a light beam emitted from a light source having cyan directivity (particularly a light beam irradiated to the front side of the vehicle) cannot be incident on the reflecting surface.

  On the other hand, according to the spot light distribution unit 40 of the present embodiment, the luminous flux emitted from the phosphor 22c by the action of the reflector 22d (conical cylindrical reflection surface 22d1) disposed in front of the phosphor 22c. It becomes possible to narrow the directivity angle.

  Therefore, by selecting the ratio of the entrance aperture and the exit aperture of the reflector 22d as described above, and selecting the taper angle α that maximizes the beam within the directivity angle / the light source beam corresponding to the light capture angle of the reflection surface 41, Conventionally, a light beam that could not be incident on the reflecting surface 41 (particularly, a light beam irradiated on the front side of the vehicle) can be incident on the reflecting surface 41. Thereby, it becomes possible to improve light utilization efficiency.

  The example of configuring the parabolic spot light distribution unit 40 has been described above, but a parabolic diffusion light distribution unit (not shown) can be configured in the same manner.

  The vehicle headlamp configured by combining the spot light distribution unit 40 and the diffusion light distribution unit according to the present embodiment can achieve the same effects as the vehicle headlamp 10 according to the first embodiment. Become.

As shown in FIG. 13, the light source unit 22 may be arranged such that its optical axis AX _22e extends in the vertical direction, or its optical axis AX _22e (below) is on the vehicle rear side. You may arrange | position so that it may extend in the inclined direction. When the light source unit 22 is arranged so that its optical axis AX _22e (below) extends in a direction inclined backward, the directivity distribution of the light beam emitted from the light source unit 22 is also inclined toward the vehicle rear side. Can be further improved.

  Next, Modification 3 in which the parabolic spot light distribution unit 40A is configured using one optical fiber will be described.

FIG. 14 is a cross-sectional view of the spot light distribution unit 40A cut along a horizontal plane including its optical axis AX _40A .

  Compared with the spot light distribution unit 40A of this modification and the spot light distribution unit 40 of the second embodiment, the former phosphor 22c and reflector 22d are fixed to the reflection surface 41 side via the support member 24 instead of the light source unit 22. In contrast, the latter is different in that the latter phosphor 22 c and reflector 22 d are fixed to the light source unit 22.

  The former is different from the former in that the optical fiber 25 is provided, whereas the latter is not provided with the optical fiber 25.

  Except for the above differences, the spot light distribution unit 40A of the present modification is the same as the spot light distribution unit 40 of the second embodiment.

  Hereinafter, the spot light distribution unit 40A of the present modification will be described focusing on differences from the spot light distribution unit 40 of the second embodiment. In addition, about the structure same as the spot light distribution unit 40 of 2nd Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

As shown in FIG. 14, at one end of the optical fiber 25, the laser light from the semiconductor laser light source 22a collected by the condenser lens 22b is incident on the one end face 25a (core) (that is, the semiconductor laser). The light source 22a is fixed to the plate portion 22f (through hole H _22f formed in the support member 26) so that the light source image of the light source 22a is projected.

  The core of the optical fiber 25 has a circular cross section (for example, diameter: 0.6 mm) in accordance with the shape of the phosphor 22c.

  The other end portion of the optical fiber 25 is fixed to the reflecting surface 41 via the support member 24 in a state where the other end surface 25b (core) and the phosphor 22c are substantially aligned and in close contact with each other.

  The spot light distribution unit 40A of the present modification functions as follows.

  That is, the laser light emitted from the semiconductor laser light source 22a is introduced into the inside from one end face 25a (core) of the optical fiber 25, is emitted from the other end face 25b (core), and irradiates the phosphor 22c.

  The phosphor 22c irradiated with the laser light is excited by the laser light (scattered light) from the semiconductor laser light source 22a scattered on the surface (and / or inside) and the laser light incident from the semiconductor laser light source 22a to emit light. White light (pseudo white light) is emitted by color mixing with light from the phosphor 22c.

  The light beam emitted from the phosphor 22c enters the cone-shaped cylindrical reflection surface 22d1 from the entrance port 22d2, is reflected by the reflection surface 22d1, and exits from the exit port 22d3 (or is reflected by the reflection surface 22d1). Without being emitted directly from the exit port 22d3), reflected by the reflecting surface 41 and irradiated forward. That is, a virtual light source image is formed on the exit port 22d3 by the light beam passing through the exit port 22d3, and this virtual light source image is projected forward.

  Accordingly, the spot light distribution pattern P1a for irradiating the hot zone Hz in the passing beam light distribution pattern P1 which is a combined light distribution pattern on a virtual vertical screen (for example, disposed about 25 m ahead of the front end of the vehicle). Is formed (see FIG. 7). The spot light distribution pattern P1a includes a cut-off line CL1a at the upper end edge. Note that the spot light distribution unit 40A has an optical axis by a known aiming mechanism (not shown) so as to irradiate the hot zone Hz in the light distribution pattern P1 for the passing beam whose spot light distribution pattern P1a is a combined light distribution pattern. It has been adjusted.

  According to the spot light distribution unit 40A of this modified example, in addition to the effects described in the second embodiment, the following effects are further achieved.

  First, by using the semiconductor laser light source and the optical fiber 25, it becomes possible to efficiently transmit the laser light to the phosphor 22c without a large loss. This is because the directivity angle of the semiconductor laser light source 22a is narrow and the light source size is small.

  Second, by using the optical fiber 25, the semiconductor laser light source 22a and the like (that is, the light source unit 22 excluding the phosphor 22c and the reflector 22d) can be disposed outside the spot light distribution unit 40A. Thereby, the spot light distribution unit 40A can be made smaller and lighter than when the semiconductor laser light source 22a, the cooling structure, and the like are installed inside the spot light distribution unit 20A.

  Third, since the spot light distribution unit 40A can be reduced in weight as described above, the semiconductor laser light source 22a and the like (that is, the light source unit 22 excluding the phosphor 22c and the reflector 22d) are disposed outside the spot light distribution unit 40A. By doing so, since the spot light distribution unit 40A can be reduced in weight, when a known aiming mechanism is connected to the spot light distribution unit 40A, it is possible to reduce the weight load applied to the aiming mechanism. Thereby, it is possible to reduce various problems caused by the weight load applied to the aiming mechanism.

  In addition, the cross section of the core of the optical fiber 25 should just be a shape suitable for the shape of the fluorescent substance 22c, and is not limited to a circle. For example, when a rectangular or elliptical phosphor 22c having an aspect ratio (for example, 1: 2 to 1: 5) is used instead of the circular phosphor 22c, the cross section of the core of the optical fiber 25 also has an aspect ratio (for example, A rectangular or elliptical shape of 1: 2 to 1: 5) can be used.

  In this way, it is possible to realize a light source that is long in the left-right direction of the vehicle (vehicle width direction), and therefore it is possible to form an optimal light distribution pattern as a vehicle headlamp.

  When the rectangular or elliptical core is compared with the circular core, the transmission efficiency is almost the same even with the rectangular or elliptical core, and a substantially uniform luminance distribution matching the core shape is formed on the other end face 25b. It becomes possible to do.

  The example in which the parabolic spot light distribution unit 40A is configured using the optical fiber 25 has been described above. Similarly, a parabolic diffusion light distribution unit (not shown) may be configured using the optical fiber 25. Is possible.

  Next, Modification 4 in which a parabolic spot light distribution unit 40B is configured using a plurality of optical fibers will be described.

FIG. 15 is a cross-sectional view of the spot light distribution unit 40B cut along a horizontal plane including the optical axis AX _40B .

  Compared with the spot light distribution unit 40B of this modification and the spot light distribution unit 40A of modification 3, the former includes one light source unit 22 and one optical fiber 25, whereas the latter includes a plurality of light sources. They are different in that they include a unit 22 and a plurality of individual optical fibers 27.

  Except for the above differences, the spot light distribution unit 20B of this modification is the same as the spot light distribution unit 40A of modification 3.

  Hereinafter, the spot light distribution unit 40B of the present modification will be described focusing on differences from the spot light distribution unit 40A of Modification 3. In addition, about the structure same as the spot light distribution unit 40A of the modification 3, the same code | symbol is attached | subjected and description is abbreviate | omitted.

As shown in FIG. 15, at one end of the individual optical fiber 27, the laser light from the semiconductor laser light source 22a collected by the condenser lens 22b is incident on the one end surface 27a (core) (that is, the semiconductor). The light source image of the laser light source 22a is projected), and is fixed to the plate portion 22f of the corresponding light source unit 22 (through hole H _22f formed in) through the support member 26.

  The other end surface 27 b (core) of each individual optical fiber 27 is connected to one end surface 28 a (core) of the common optical fiber 28 so that laser light emitted from the other optical fiber 27 enters the one end surface 28 a of the common optical fiber 28.

  The core of the individual optical fiber 27 has a circular cross section (for example, diameter: 0.2 mm). The core of the common optical fiber 28 has an area larger than the total core area of each individual optical fiber 27 in order to efficiently capture the laser light from each individual optical fiber 27 (for example, long side 0.8 mm × short side 0.4 mm). Oval core). Instead of the common optical fiber 28, a light guide member such as a glass rod may be used.

  The other end portion of the common optical fiber 28 is fixed to the reflecting surface 41 side via the support member 24 in a state where the other end surface 28b (core) and the phosphor 22c are substantially aligned and in close contact with each other.

  The spot light distribution unit 40B of this modification functions as follows.

  That is, the laser light emitted from each semiconductor laser light source 22a is introduced into the inside from one end face 27a (core) of the corresponding individual optical fiber 27, and further introduced into the inside from one end face 28a of the common optical fiber 28, The light is emitted from the other end surface 28b (core) and irradiated with the phosphor 22c.

  The phosphor 22c irradiated with the laser light is excited by the laser light (scattered light) from the semiconductor laser light source 22a scattered on the surface (and / or inside) and the laser light incident from the semiconductor laser light source 22a to emit light. White light (pseudo white light) is emitted by color mixing with light from the phosphor 22c.

  The light beam emitted from the phosphor 22c enters the cone-shaped cylindrical reflection surface 22d1 from the entrance port 22d2, is reflected by the reflection surface 22d1, and exits from the exit port 22d3 (or is reflected by the reflection surface 22d1). Without being emitted directly from the exit port 22d3), reflected by the reflecting surface 41 and irradiated forward. That is, a virtual light source image is formed on the exit port 22d3 by the light beam passing through the exit port 22d3, and this virtual light source image is projected forward.

  Accordingly, the spot light distribution pattern P1a for irradiating the hot zone Hz in the passing beam light distribution pattern P1 which is a combined light distribution pattern on a virtual vertical screen (for example, disposed about 25 m ahead of the front end of the vehicle). Is formed (see FIG. 7). The spot light distribution pattern P1a includes a cut-off line CL1a at the upper end edge. The spot light distribution unit 40B has an optical axis by a known aiming mechanism (not shown) so as to irradiate the hot zone Hz in the passing beam light distribution pattern P1 in which the spot light distribution pattern P1a is a combined light distribution pattern. It has been adjusted.

  According to the spot light distribution unit 40B of the present modification, in addition to the effects described in Modification 3, the following effects are further achieved.

  When a plurality of individual optical fibers 27 are bundled and the laser light emitted from the other end surface 27b is directly incident on the phosphor 22c, the clad layer of each individual optical fiber 27 becomes a shadow and uneven brightness occurs. There is a problem that 22c cannot be uniformly irradiated.

  On the other hand, according to the spot light distribution unit 40B of the present modification, the laser light from each individual optical fiber 27 is incident on the common optical fiber 28 and becomes uniform. Compared with the case of directly irradiating the phosphor 22c with the laser light from 27, it becomes possible to irradiate the phosphor 22c uniformly without uneven brightness.

  The example in which the parabolic spot light distribution unit 40B is configured using the individual optical fiber 27 and the common optical fiber 28 has been described above. Similarly, the parabolic diffusion light distribution unit using the individual optical fiber 27 and the common optical fiber 28 is described. (Not shown) can be configured.

[Third Embodiment]
Next, a vehicle headlamp according to a third embodiment of the present invention will be described with reference to the drawings.

Figure 16 is a longitudinal sectional view taken along the spot light distribution unit 50 in a vertical plane including the optical axis AX ₅₀ of the third constituting a vehicle headlamp according to an embodiment of the present invention.

The spot light distribution unit 50 of the present embodiment is a projector-type lamp unit. As shown in FIG. 16, the projection lens 51 disposed on the optical axis AX ₅₀ extending in the vehicle front-rear direction, the rear side of the projection lens 51 A light source unit 22 including an emission port 22d3 as a virtual light source arranged behind the focal point F ₅₁ and in the vicinity of the optical axis AX ₅₀ , a reflection surface 52 arranged above the emission port 22d3, and reflected by the reflection surface 52 A shade 53 or the like disposed between the projection lens 51 and the exit port 22d3 is provided so as to shield a part of the light beam from the exit port 22d3. The light source unit 22 is the same as that described in the first embodiment.

The projection lens 51 is a planoconvex aspheric lens having a convex front surface and a flat rear surface. For example, the projection lens 51 is held by a lens holder 54 and disposed on the optical axis AX ₅₀ .

The light source unit 22 is fixed to the shade 53 in such a posture that the light beam emitted from the emission port 22d3 is substantially upward. Exit port 22d3 is located _{AX 50} near the rear side of the vehicle and the optical axis of the rear side focal point _{F 51} of the projection lens 51.

Reflecting surface 52, a first focal point _{F1 52} is set in the vicinity of the exit port 22D3, the vehicle rear-side focal point _{F 51} reflecting surface of the spheroid system set in the vicinity (spheroid of the second focal point _{F2 52} projection lens 51 Or a free-form surface similar to this).

  The reflecting surface 52 extends from the side of the exit port 22d3 (the side on the vehicle rear side in FIG. 16) toward the projection lens 51 so that the light beam emitted substantially upward from the exit port 22d3 enters. The upper part of the emission port 22d3 is covered.

  In the present embodiment, it is desirable to select the ratio of the entrance aperture and the exit aperture of the reflector 22d in the same manner as in the first embodiment (for example, 1: 2). In addition, as in the first embodiment, the taper angle α of the reflector 22d is maximized in the beam within the directivity angle / the light source beam corresponding to the light capturing angle of the reflecting surface 52 from the viewpoint of forming a brighter spot light distribution pattern. It is desirable to select an angle.

Shade 53 includes a mirror surface 53a extending exit port 22d3 side from the vehicle rear-side focal point _{F 51} of the projection lens 51. The front end edge of the shade 53 is concavely curved along the focal plane of the projection lens 51 on the vehicle rear side. Light incident on the mirror surface 53a and reflected upward is refracted by the projection lens 51 and travels in the road surface direction. In other words, the light incident on the mirror surface 53a is folded back at the cutoff line and superimposed on the light distribution pattern below the cutoff line. Thereby, as shown in FIG. 7, a spot light distribution pattern P1a including the cut-off line CL1a is formed.

According to the spot light distribution unit 50 having the above structure, the light beam incident on the reflecting surface 52 is emitted from the exit 22d3 it is reflected by the reflective surface 52, and converged at the rear side focal point F ₅₁ near the projection lens 51 Thereafter, the light passes through the projection lens 51 and is irradiated forward. As a result, as shown in FIG. 7, the hot zone Hz in the light distribution pattern P1 for the passing beam, which is a combined light distribution pattern, is displayed on a virtual vertical screen (for example, disposed about 25 m ahead of the front end of the vehicle). The spot light distribution pattern P1a to be irradiated is formed. The spot light distribution pattern P1a includes a cut-off line CL1a formed by the action of the shade 53 at the upper end edge. The spot light distribution unit 50 uses a known aiming mechanism (not shown) to irradiate the hot zone Hz in the passing beam light distribution pattern P1 in which the spot light distribution pattern P1a is a combined light distribution pattern. It has been adjusted.

  Conventionally, in a projector-type lamp unit, the size and thickness of a projection lens (projection lens corresponding to the projection lens 51) are determined in the specification without considering the directivity characteristics of the light source. Depending on the lens thickness, a light beam emitted from a light source having a Lambertian directional characteristic (particularly a light beam irradiated to the front side of the vehicle) may not be able to enter (or enter) the projection lens. Even if it was possible, there was a case where it was not possible to irradiate the range required for the light distribution pattern for the passing beam).

  On the other hand, according to the spot light distribution unit 50 of the present embodiment, the luminous flux emitted from the phosphor 22c by the action of the reflector 22d (conical cylindrical reflection surface 22d1) disposed in front of the phosphor 22c. It becomes possible to narrow the directivity angle.

  Therefore, by selecting the ratio between the entrance aperture and the exit aperture of the reflector 22d as described above, and selecting the taper angle α that maximizes the beam within the directivity angle / the light source beam corresponding to the light capture angle of the reflection surface 52, Conventionally, a light beam that could not be incident on the projection lens 51 (particularly, a light beam irradiated on the front side of the vehicle) can be incident on the projection lens 51. Thereby, it becomes possible to improve light utilization efficiency.

  The example of configuring the projector-type spot light distribution unit 50 has been described above, but a projector-type diffusion light distribution unit (not shown) can be configured in the same manner.

  The vehicle headlamp configured by combining the spot light distribution unit 50 and the diffusion light distribution unit of the present embodiment can also achieve the same effects as the vehicle headlamp 10 of the first embodiment. Become.

As shown in FIG. 16, the light source unit 22 may be arranged such that its optical axis AX _22e extends in the vertical direction, or its optical axis AX _22e (above) is on the vehicle rear side. You may arrange | position so that it may extend in the inclined direction. When the light source unit 22 is arranged so that its optical axis AX _22e (above) extends in a direction inclined backward, the directivity distribution of the light beam emitted from the light source unit 22 is also inclined toward the vehicle rear side. Can be further improved.

  Next, Modification 5 in which the projector-type spot light distribution unit 50A is configured using one optical fiber will be described.

FIG. 17 is a cross-sectional view of the spot light distribution unit 50A cut along a horizontal plane including the optical axis AX _50A .

  Compared with the spot light distribution unit 50A of the present modification and the spot light distribution unit 50 of the third embodiment, the former phosphor 22c and reflector 22d are fixed to the shade 53 instead of the light source unit 22, They are different in that the latter phosphor 22c and reflector 22d are fixed to the light source unit 22.

  Further, the former is different in that the former light source unit 22 is not fixed to the shade 53 while the latter light source unit 22 is fixed to the shade 53.

  The former is different from the former in that the optical fiber 25 is provided, whereas the latter is not provided with the optical fiber 25.

  Except for the above differences, the spot light distribution unit 50A of the present modification is the same as the spot light distribution unit 50 of the third embodiment.

  Hereinafter, the spot light distribution unit 50A of the present modification will be described focusing on differences from the spot light distribution unit 50 of the third embodiment. In addition, about the structure same as the spot light distribution unit 50 of 3rd Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

As shown in FIG. 17, at one end of the optical fiber 25, laser light from the semiconductor laser light source 22a condensed by the condenser lens 22b is incident on one end surface 25a (core) (that is, semiconductor laser). The light source 22a is fixed to the plate portion 22f (through hole H _22f formed in the support member 26) so that the light source image of the light source 22a is projected.

  The core of the optical fiber 25 has a circular cross section (for example, diameter: 0.6 mm) in accordance with the shape of the phosphor 22c.

  The other end of the optical fiber 25 is fixed to the shade 53 via the support member 24 in a state where the other end face 25b (core) and the phosphor 22c are substantially aligned and in close contact with each other.

  The spot light distribution unit 50A of the present modification functions as follows.

  That is, the laser light emitted from the semiconductor laser light source 22a is introduced into the inside from one end face 25a (core) of the optical fiber 25, is emitted from the other end face 25b (core), and irradiates the phosphor 22c.

  The phosphor 22c irradiated with the laser light is excited by the laser light (scattered light) from the semiconductor laser light source 22a scattered on the surface (and / or inside) and the laser light incident from the semiconductor laser light source 22a to emit light. White light (pseudo white light) is emitted by color mixing with light from the phosphor 22c.

The light beam emitted from the phosphor 22c enters the cone-shaped cylindrical reflecting surface 22d1 from the entrance port 22d2, is reflected by the reflecting surface 22d1, and exits from the exit port 22d3 (or is reflected by the reflecting surface 22d1). emitted directly from the exit port 22d3 without), it is reflected by the reflecting surface 52, after converging at the rear side focal point F ₅₁ near the projection lens 51 and is irradiated forward through the projection lens 51. That is, a virtual light source image is formed on the exit port 22d3 by the light beam passing through the exit port 22d3, and this virtual light source image is projected forward.

  Accordingly, the spot light distribution pattern P1a for irradiating the hot zone Hz in the passing beam light distribution pattern P1 which is a combined light distribution pattern on a virtual vertical screen (for example, disposed about 25 m ahead of the front end of the vehicle). Is formed (see FIG. 7). The spot light distribution pattern P1a includes a cut-off line CL1a formed by the action of the shade 53 at the upper end edge. The spot light distribution unit 50A uses a known aiming mechanism (not shown) to irradiate the hot zone Hz in the passing beam light distribution pattern P1 in which the spot light distribution pattern P1a is a combined light distribution pattern. It has been adjusted.

  According to the spot light distribution unit 50A of the present modification, in addition to the effects described in the third embodiment, the following effects are further achieved.

  First, by using the semiconductor laser light source and the optical fiber 25, it becomes possible to efficiently transmit the laser light to the phosphor 22c without a large loss. This is because the directivity angle of the semiconductor laser light source 22a is narrow and the light source size is small.

  Second, by using the optical fiber 25, the semiconductor laser light source 22a and the like (that is, the light source unit 22 excluding the phosphor 22c and the reflector 22d) can be disposed outside the spot light distribution unit 50A. Thus, the spot light distribution unit 50A can be made smaller and lighter than when the semiconductor laser light source 22a, the cooling structure, and the like are installed inside the spot light distribution unit 50A.

  Third, since the spot light distribution unit 50A can be reduced in weight as described above, the semiconductor laser light source 22a and the like (that is, the light source unit 22 excluding the phosphor 22c and the reflector 22d) are disposed outside the spot light distribution unit 50A. By doing so, since the spot light distribution unit 50A can be reduced in weight, when a known aiming mechanism is connected to the spot light distribution unit 50A, the weight load applied to the aiming mechanism can be reduced. Thereby, it is possible to reduce various problems caused by the weight load applied to the aiming mechanism.

  In addition, the cross section of the core of the optical fiber 25 should just be a shape suitable for the shape of the fluorescent substance 22c, and is not limited to a circle. For example, when a rectangular or elliptical phosphor 22c having an aspect ratio (for example, 1: 2 to 1: 5) is used instead of the circular phosphor 22c, the cross section of the core of the optical fiber 25 also has an aspect ratio (for example, A rectangular or elliptical shape of 1: 2 to 1: 5) can be used.

  In this way, it is possible to realize a light source that is long in the left-right direction of the vehicle (vehicle width direction), and therefore it is possible to form an optimal light distribution pattern as a vehicle headlamp.

  When the rectangular or elliptical core is compared with the circular core, the transmission efficiency is almost the same even with the rectangular or elliptical core, and a substantially uniform luminance distribution matching the core shape is formed on the other end face 25b. It becomes possible to do.

  The example in which the projector-type spot light distribution unit 50A is configured using the optical fiber 25 has been described above. Similarly, a projector-type diffusion light distribution unit (not shown) may be configured using the optical fiber 25. Is possible.

  Next, Modification 6 in which a projector-type spot light distribution unit 50B is configured using a plurality of optical fibers will be described.

FIG. 18 is a cross-sectional view of the spot light distribution unit 50B cut along a horizontal plane including the optical axis AX _50B .

  Compared with the spot light distribution unit 50B of the present modification and the spot light distribution unit 50A of the modification 5, the former includes one light source unit 22 and one optical fiber 25, whereas the latter includes a plurality of light sources. They are different in that they include a unit 22 and a plurality of individual optical fibers 27.

  Except for the differences described above, the spot light distribution unit 50B of the present modification is the same as the spot light distribution unit 50A of the modification 5.

  Hereinafter, the spot light distribution unit 50B of the present modification will be described focusing on differences from the spot light distribution unit 50A of Modification 5. In addition, about the structure same as the spot light distribution unit 50A of the modification 5, the same code | symbol is attached | subjected and description is abbreviate | omitted.

As shown in FIG. 18, at one end of the individual optical fiber 27, the laser light from the semiconductor laser light source 22a collected by the condenser lens 22b is incident on the one end surface 27a (core) (ie, the semiconductor). The light source image of the laser light source 22a is projected), and is fixed to the plate portion 22f of the corresponding light source unit 22 (through hole H _22f formed in) through the support member 26.

  The other end surface 27 b (core) of each individual optical fiber 27 is connected to one end surface 28 a (core) of the common optical fiber 28 so that laser light emitted from the other optical fiber 27 enters the one end surface 28 a of the common optical fiber 28.

  The core of the individual optical fiber 27 has a circular cross section (for example, diameter: 0.2 mm). The core of the common optical fiber 28 has an area larger than the total core area of each individual optical fiber 27 in order to efficiently capture the laser light from each individual optical fiber 27 (for example, long side 0.8 mm × short side 0.4 mm). Oval core). Instead of the common optical fiber 28, a light guide member such as a glass rod may be used.

  The other end of the common optical fiber 28 is fixed to the shade 53 via the support member 24 in a state where the other end face 28b (core) and the phosphor 22c are substantially aligned and in close contact with each other.

  The spot light distribution unit 50B of the present modification functions as follows.

  That is, the laser light emitted from each semiconductor laser light source 22a is introduced into the inside from one end face 27a (core) of the corresponding individual optical fiber 27, and further introduced into the inside from one end face 28a of the common optical fiber 28, The light is emitted from the other end surface 28b (core) and irradiated with the phosphor 22c.

  The phosphor 22c irradiated with the laser light is excited by the laser light (scattered light) from the semiconductor laser light source 22a scattered on the surface (and / or inside) and the laser light incident from the semiconductor laser light source 22a to emit light. White light (pseudo white light) is emitted by color mixing with light from the phosphor 22c.

  The light beam emitted from the phosphor 22c enters the cone-shaped cylindrical reflection surface 22d1 from the entrance port 22d2, is reflected by the reflection surface 22d1, and exits from the exit port 22d3 (or is reflected by the reflection surface 22d1). Without being emitted directly from the exit port 22d3), reflected by the reflecting surface 52 and irradiated forward. That is, a virtual light source image is formed on the exit port 22d3 by the light beam passing through the exit port 22d3, and this virtual light source image is projected forward.

  Accordingly, the spot light distribution pattern P1a for irradiating the hot zone Hz in the passing beam light distribution pattern P1 which is a combined light distribution pattern on a virtual vertical screen (for example, disposed about 25 m ahead of the front end of the vehicle). Is formed (see FIG. 7). The spot light distribution pattern P1a includes a cut-off line CL1a formed by the action of the shade 53 at the upper end edge. The spot light distribution unit 50B has an optical axis by a known aiming mechanism (not shown) so as to irradiate the hot zone Hz in the passing beam light distribution pattern P1 in which the spot light distribution pattern P1a is a combined light distribution pattern. It has been adjusted.

  According to the spot light distribution unit 50B of this modification, in addition to the effects described in Modification 5, the following effects are further exhibited.

  When a plurality of individual optical fibers 27 are bundled and laser light emitted from the other end surface 27b is directly incident on the phosphor, the clad layer of each individual optical fiber 27 becomes a shadow and uneven brightness occurs, and the phosphor 22c. There is a problem that it cannot be irradiated uniformly.

  On the other hand, according to the spot light distribution unit 50B of the present modification, the laser light from each individual optical fiber 27 is incident on the common optical fiber 28 and is made uniform. Compared with the case of directly irradiating the phosphor 22c with the laser light from 27, it becomes possible to irradiate the phosphor 22c uniformly without uneven brightness.

  The example in which the projector-type spot light distribution unit 50B is configured using the individual optical fiber 27 and the common optical fiber 28 has been described above. Similarly, the projector-type diffusion light distribution unit using the individual optical fiber 27 and the common optical fiber 28 is described. (Not shown) can be configured.

  As described above, the example in which the vehicle headlamp is configured by combining the same kind of spot light distribution unit and the diffusion light distribution unit (for example, the spot light distribution unit 20 and the diffusion light distribution unit 30) has been described. It is not limited to. For example, different types of spot light distribution units and diffuse light distribution units (for example, the diffuse light distribution unit 30 of the first embodiment and the spot light distribution units 40 and 50 of the second or third embodiment) are combined and used in front of the vehicle. An illumination lamp may be configured.

  In each of the above-described embodiments and modifications, the inner peripheral surface of the through hole of the reflector 22d that constitutes the light source unit 22 is subjected to mirror treatment such as aluminum vapor deposition so that it goes from the exit port 22d3 to the entrance port 22d2. As described above, the conical cylindrical reflection surface 22d1 extending so as to narrow in a conical shape has been described, but the present invention is not limited to this.

  For example, the reflector 22d is formed of a solid transparent resin or a glassy transparent member, and the surface of the reflector 22d is subjected to a mirror treatment such as aluminum vapor deposition so that the cone-shaped cylindrical reflection surface 22d1 made of a metal film is formed. It may be formed. Also by the conical cylindrical reflection surface 22d1 made of a metal film applied to the surface of the reflector 22d, it is possible to achieve the same effects as in the above embodiments and modifications.

  In each of the above-described embodiments and modifications, the example in which the light source unit 22 is configured by combining a laser diode that emits blue laser light and a yellow light-emitting phosphor (YAG phosphor) has been described. It is not limited. For example, the light source unit 22 may be configured by combining an ultraviolet light emitting semiconductor laser (for example, a semiconductor laser light source that emits laser light having a wavelength of 405 nm) and blue, green, and red light emitting phosphors.

  The above embodiment is merely an example in all respects. The present invention is not construed as being limited to these descriptions. The present invention can be implemented in various other forms without departing from the spirit or main features thereof.

  DESCRIPTION OF SYMBOLS 10 ... Vehicle headlamp, 20, 20A, 20B ... Direct projection type spot light distribution unit, 21 ... Projection lens, 22 ... Light source unit, 22 ... Light source unit, 22a ... Semiconductor laser light source, 22b ... Condensing lens, 22c ... phosphor, 22d ... reflector, 22d1 ... conical cylindrical reflecting surface, 22d1 ... conical cylindrical reflecting surface, 22d2 ... entrance, 22d3 ... exit, 22e ... laser holder, 22f ... plate part, 22e ... laser holder , 22f ... plate part, 24 ... support member, 25 ... optical fiber, 25a ... one end face, 25b ... other end face, 26 ... support member, 27 ... individual optical fiber, 27a ... one end face, 27b ... other end face, 28 ... common optical fiber, 28a ... one end surface, 28b ... the other end surface, 30, 30A, 30B ... direct projection type diffusion arrangement Unit: 31 ... projection lens, 33 ... lens holder, 40, 40A, 40B ... parabolic spot light distribution unit, 41 ... reflection surface, 50, 50A, 50B ... projector type spot light distribution unit, 51 ... projection lens, 52 ... Reflective surface, 53 ... shade, 53a ... mirror surface, 54 ... lens holder

Claims (13)

A semiconductor laser light source;
A wavelength conversion member that is disposed in front of the semiconductor laser light source so that laser light from the semiconductor laser light source is incident thereon and that receives laser light from the semiconductor laser light source and generates light having a longer wavelength than the semiconductor laser light source; ,
A cone-shaped cylindrical reflecting surface that includes an incident port that is an opening at one end and an exit port that is an opening at the other end on the opposite side, and extends so as to narrow in a cone shape from the exit port toward the incident port. Including a reflector, and
With
At least a part of the cone-shaped cylindrical reflection surface has a light beam emitted from the wavelength conversion member incident on the cone-shaped cylindrical reflection surface, reflected by the cone-shaped cylindrical reflection surface, and from the exit port. The vehicle is characterized in that it is disposed in front of the wavelength conversion member so that it is emitted or directly emitted from the emission port without being reflected by the cone-shaped cylindrical reflecting surface and is emitted forward. Light source unit for headlamps.   2. The light source unit for a vehicle headlamp according to claim 1, wherein an angle at which the light flux within the directivity angle / the light source light flux becomes maximum is selected as the taper angle of the conical cylindrical reflection surface.   3. The vehicle headlamp according to claim 1, wherein a ratio in a range of 1: 1.5 to 1: 4.0 is selected as a ratio of the incident aperture to the exit aperture. Light source unit.   The light source for a vehicle headlamp according to any one of claims 1 to 3, wherein an angle within a range of 15 to 40 ° is selected as a taper angle of the conical cylindrical reflection surface. unit. The light source unit for a vehicle headlamp according to any one of claims 1 to 4, wherein an area of the emission port is 2 mm ² or less. The reflector is a solid transparent member,
The light source unit for a vehicle headlamp according to any one of claims 1 to 5, wherein the conical cylindrical reflecting surface is made of a metal film applied to a surface of the transparent member. A projection lens disposed on an optical axis extending in the vehicle longitudinal direction;
The light source unit according to any one of claims 1 to 6,
With
The vehicle headlamp according to claim 1, wherein the emission port of the light source unit is disposed near a focal point on the vehicle rear side of the projection lens.   The angle at which the light flux within the directivity angle / the light source light beam corresponding to the light capturing angle of the projection lens is maximized is selected as the taper angle of the conical cylindrical reflection surface. Vehicle headlamp.   The vehicle according to claim 7, wherein the projection lens includes a lens surface configured to refract a light beam passing through the projection lens to form a cut-off line in a light distribution pattern for a passing beam. For headlamps. A parabolic reflective surface;
The light source unit according to any one of claims 1 to 6,
With
The vehicle headlamp according to claim 1, wherein the emission port of the light source unit is disposed near a focal point of the reflection surface.   The angle at which the light flux within the directivity angle / light source corresponding to the light capturing angle of the reflection surface is maximized is selected as the taper angle of the cylindrical reflection surface of the cone. Vehicle headlamp. A spheroid reflecting surface;
The light source unit according to any one of claims 1 to 6,
With
The vehicular headlamp characterized in that the light emission port of the light source unit is disposed in the vicinity of a first focal point of the reflection surface.   The angle at which the luminous flux within the directivity angle / light source luminous flux corresponding to the light capturing angle of the reflective surface is maximized is selected as the taper angle of the conical cylindrical reflective surface. Vehicle headlamp.

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