JP5688990B2 - Vehicle lighting - Google Patents

Description

  The present invention relates to a vehicular lamp.

  Conventionally, as a vehicular lamp such as a headlight for an automobile, a lamp using a semiconductor light emitting element and a phosphor as a light source is known (see, for example, Patent Document 1). In this type of vehicle lamp, by irradiating the phosphor with excitation light (for example, blue light) from the semiconductor light emitting element, the light emitted by excitation of the phosphor (for example, yellow light) and the excitation light are mixed and visible. Light (for example, white light) is emitted, and this visible light is projected forward of the vehicle by an optical system such as a projection lens.

Japanese Patent No. 4124445

  However, in the above conventional vehicle lamp, when excitation light is incident on the phosphor from the light extraction direction of the phosphor, a part of the excitation light is regularly reflected on the surface of the phosphor and mixed into a predetermined color. Since the light is emitted as it is from the projection lens or the like, partial color unevenness occurs in the light distribution pattern that is a projected image.

  This invention is made | formed in view of the said situation, and makes it a subject to provide the vehicle lamp which can suppress the color nonuniformity of a light distribution pattern.

In order to solve the above-mentioned problem, the invention described in claim 1
A semiconductor light emitting device;
A phosphor that receives excitation light emitted from the semiconductor light emitting element and emits visible light;
A reflective surface that is disposed so as to cover the phosphor from behind the phosphor and that reflects the visible light emitted from the phosphor forward;
In a vehicle lamp comprising:
The phosphor is
While being arranged to receive the excitation light from behind,
The excitation light that is specularly reflected on the surface of the phosphor does not affect the light distribution pattern formed by the vehicular lamp in a region obliquely above the front of the phosphor and in front of the reflecting surface. The surface is inclined backward with respect to the front-rear direction so as to go to the area,
A condensing reflection surface is provided in a region where excitation light specularly reflected on the surface of the phosphor is directed and reflects the excitation light while condensing the excitation light on the phosphor .

Invention according to claim 2,
A semiconductor light emitting device;
A phosphor that receives excitation light emitted from the semiconductor light emitting element and emits visible light;
A reflective surface that is disposed so as to cover the phosphor from behind the phosphor and that reflects the visible light emitted from the phosphor forward;
A projection lens disposed in front of the phosphor and the reflecting surface;
In a vehicle lamp comprising:
The phosphor is
While being arranged to receive the excitation light from behind,
The excitation light that is regularly reflected on the surface of the phosphor is a front obliquely upper side of the phosphor, a front side of the reflection surface, and a rear side of the projection lens, and the vehicle lamp The surface is inclined backward with respect to the front-rear direction so as to be directed to a region that does not affect the light distribution pattern formed by.

The invention according to claim 3 is the vehicle lamp according to claim 2,
A condensing reflection surface is provided in a region where excitation light specularly reflected on the surface of the phosphor is directed and reflects the excitation light while condensing the excitation light on the phosphor .
According to a fourth aspect of the present invention, in the vehicular lamp according to the first or third aspect,
The condensing reflection surface is formed integrally with the reflection surface.

Invention of Claim 5 is a vehicle lamp as described in any one of Claims 1-4 ,
The semiconductor light emitting element emits laser light.

  According to the present invention, a part of the excitation light incident on the phosphor that has not been made visible is incident on the surface of the phosphor from the rear and is regularly reflected upward and obliquely upward on the surface. It heads to a region that is obliquely above the front of the body and in front of the reflecting surface and that does not affect the light distribution pattern. Therefore, it is possible to prevent the excitation light regularly reflected on the surface of the phosphor from being projected onto the light distribution pattern, thereby suppressing color unevenness of the light distribution pattern.

It is a sectional side view of the vehicle lamp in 1st embodiment. It is a figure for demonstrating the optical path in the vehicle lamp in 1st embodiment. It is a sectional side view which shows the modification of the vehicle lamp in 1st embodiment. It is a sectional side view of the vehicle lamp in 2nd embodiment. It is a figure for demonstrating the optical path in the vehicle lamp in 2nd embodiment. It is a sectional side view which shows the modification of the vehicle lamp in 2nd embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In the following description, unless otherwise specified, the description of “up”, “down”, “front”, “rear”, “left”, and “right” refers to the direction viewed from the vehicle lamp in each embodiment. These are used in correspondence with the descriptions in the drawings.

[1 First embodiment]
FIG. 1 is a side sectional view of a vehicular lamp 3 according to a first embodiment of the present invention.
As shown in this figure, the vehicular lamp 3 is a so-called projector-type lamp, and includes a laser diode (hereinafter referred to as LD) 31, a condensing lens 32, a phosphor 34, a reflector 35, and a shade 16. And a projection lens 17.
Among these, the LD 31 is a semiconductor light emitting device according to the present invention, and emits blue laser light as excitation light of the phosphor 34 forward along an optical axis Ax of the projection lens 17 described later.

  The condensing lens 32 is disposed in front of the LD 31 and condenses the blue light emitted forward from the LD 31 onto the surface (upper surface) of the phosphor 34 disposed further forward. More specifically, the condensing lens 32 condenses the blue light from the LD 31 at the approximate center in the thickness direction through the surface of the phosphor 34.

The phosphor 34 is disposed in front of the condenser lens 32. The phosphor 34 is a fluorescent material that emits yellow light when excited by receiving blue light emitted from the LD 31. Therefore, when the phosphor 34 receives blue light, the blue light scattered by the phosphor 34 is mixed with yellow light, so that white light is emitted from the phosphor 34. The area of the surface of the phosphor 34 is substantially the same as the area of the blue light condensing spot collected by the condensing lens 32. Thereby, the phosphor 34 emits white light like a point light source having substantially the same size as the blue light condensing spot. Further, the phosphor 34 is supported on the upper surface of the inclined metal flat plate 18 similarly to the phosphor 34. The upper surface of the metal flat plate 18 is a mirror surface on which aluminum deposition is performed, and reflects the white light emitted downward from the phosphor 34 upward.
In addition, the phosphor 34 has a surface (upper surface) that is inclined rearward at an angle of 22.5 degrees with respect to the front-rear direction. As described later, among the blue light incident from the rear, the phosphor 34 What is regularly reflected on the surface of 34 is configured to be directed to a predetermined region obliquely upward and forward. Here, the “predetermined region” is a region obliquely above the front of the phosphor 34 and in front of a reflection surface 351 described later, and is a region where light from the phosphor 34 does not affect the light distribution pattern (passing beam). Thus, in the first embodiment, the light is not emitted from the phosphor 34 to the outside of the lamp.

The reflector 35 is formed in a curved plate shape that opens obliquely forward and downward, and is disposed so as to cover the phosphor 34. The lower surface of the reflector 35 is a reflecting surface 351 that reflects the white light emitted from the phosphor 34 forward.
The reflection surface 351 is a free-form surface based on a spheroid with the position of the phosphor 34 as the first focal point, and is formed so that the eccentricity gradually increases from the vertical section toward the horizontal section. . The reflecting surface 351 is disposed so as to cover the phosphor 34 from the rear to the top of the phosphor 34, and the white light emitted from the phosphor 34 is converted to the vicinity of the front end of the shade 16 in the vertical cross section. And the light is gradually reflected forward as it goes to the horizontal section.

  The shade 16 is a light shielding member disposed in front of the phosphor 34. The shade 16 blocks a part of white light reflected by the reflecting surface 351 of the reflector 35 to form a low beam cut-off line. Further, the upper surface of the shade 16 has a height that substantially coincides with a horizontal plane (surface orthogonal to the vertical direction) including the optical axis Ax of the projection lens 17 described later, and aluminum deposition is performed in the same manner as the upper surface of the metal flat plate 18. The white light reflected by the reflecting surface 351 and incident on the upper surface is reflected toward the front projection lens 17.

  The projection lens 17 is an aspheric plano-convex lens having a convex front surface, and is disposed in front of the phosphor 34 and the reflector 35 so that the upper surface of the shade 16 and the phosphor 34 are positioned on the optical axis Ax along the front-rear direction. ing. The projection lens 17 has an object-side focal point located in the vicinity of the front end of the shade 16, and reversely projects the white light reflected by the reflecting surface 351 of the reflector 35 and incident on the projection lens 17 to the front of the vehicle.

FIGS. 2A and 2B are diagrams for explaining an optical path in the vehicular lamp 3.
As shown in FIG. 2A, in the vehicular lamp 3, when blue light is emitted from the LD 31, the blue light is collected by the condenser lens 32 and then incident on the surface of the phosphor 34 from the rear. To do. Then, although most of the blue light incident on the phosphor 34 is white light and is emitted radially upward, a part of the blue light is not white light and is regularly reflected on the inclined surface of the phosphor 34. It heads toward a region that is obliquely above the front of the phosphor 34 and in front of the reflecting surface 351 and that does not affect the light distribution pattern (passing beam).
As shown in FIG. 2B, the white light emitted upward from the phosphor 34 is reflected forward by the reflecting surface 351 of the reflector 35 and irradiated from the projection lens 17 forward of the vehicle. At this time, a part of white light incident on the lower part of the projection lens 17 is shielded by the shade 16, thereby forming a passing beam in which the irradiation light above the cutoff line is blocked.

  As described above, according to the vehicular lamp 3, some of the blue light that has not been converted into white light out of the blue light incident on the phosphor 34 from behind is obliquely forward and upward on the surface of the inclined phosphor 34. It is regularly reflected and heads toward a region that is obliquely above the phosphor 34 and in front of the reflecting surface 351 and that does not affect the light distribution pattern (passing beam). Therefore, it is possible to prevent the blue light regularly reflected on the surface of the phosphor 34 from being projected onto the light distribution pattern, and thus to suppress the color unevenness of the light distribution pattern.

  Moreover, since it can prevent that the blue light which is a laser beam is radiate | emitted out of a lamp, it is preferable also at the point which ensures the maximum permissible exposure amount (MPE).

  As shown in FIG. 3, a condensing / reflecting surface 352 that reflects the blue light while condensing the blue light on the phosphor 34 may be provided in a region where the blue light regularly reflected on the surface of the phosphor 34 is directed. . By providing such a condensing / reflecting surface 352, the blue light regularly reflected by the phosphor 34 can be condensed to the phosphor 34 to be white light, and the luminous flux utilization factor can be increased. Moreover, it is preferable that the condensing reflection surface 352 is formed integrally with the reflection surface 351 from the viewpoint of suppressing the number of parts.

[2 Second Embodiment]
Next, a second embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected to the component similar to said 1st embodiment, and the description is abbreviate | omitted.

FIG. 4 is a side sectional view of the vehicular lamp 4 according to the second embodiment of the present invention.
As shown in this figure, the vehicular lamp 4 is a so-called parabolic lamp, and in addition to the LD 31 and the condenser lens 32 configured in the same manner as in the first embodiment, a phosphor 44, a reflector 45, It has.

  Among these, the phosphor 44 is disposed in front of the condenser lens 32. The phosphor 44 has a surface (upper surface) inclined backward at an angle of 27.5 degrees with respect to the front-rear direction, and is regularly reflected on the surface of the phosphor 44 out of blue light incident from the rear. It is configured so that the formed object is directed to a predetermined area obliquely upward at the front. Here, the “predetermined region” is a region obliquely above the front side of the phosphor 44 and in front of a reflection surface 451 described later, and is a region where the light from the phosphor 44 does not affect the light distribution pattern (passing beam). Thus, in the second embodiment, the light is not emitted from the phosphor 44 to the outside of the lamp. In addition, the configuration of the phosphor 44 other than the above is the same as the configuration of the phosphor 34 in the first embodiment.

The reflector 45 is formed in a curved plate shape that opens obliquely forward and downward, and is disposed so as to cover the upper side of the phosphor 44. The lower surface of the reflector 45 is a reflecting surface 451 that reflects the white light emitted from the phosphor 44 forward.
The reflection surface 451 is a free-form surface based on a rotating paraboloid focusing on the position of the phosphor 44, and is disposed so as to cover the phosphor 44 from the rear side of the phosphor 44. Yes.

FIGS. 5A and 5B are diagrams for explaining an optical path in the vehicular lamp 4.
As shown in FIG. 5A, in the vehicular lamp 4, when blue light is emitted from the LD 31, the blue light is collected by the condenser lens 32 and then incident on the surface of the phosphor 44 from behind. To do. Then, although most of the blue light incident on the phosphor 44 is white light and is emitted radially upward, a part of the blue light is not white light but is regularly reflected on the inclined surface of the phosphor 44, It heads to a region that is obliquely above the front of the phosphor 44 and in front of the reflecting surface 451 and that does not affect the light distribution pattern (passing beam).
As shown in FIG. 5B, the white light emitted upward from the phosphor 44 is reflected forward by the reflecting surface 451 of the reflector 45 and irradiated forward of the vehicle, forming a passing beam as a light distribution pattern. .

The above vehicle lamp 4 can also provide the same effects as the vehicle lamp 3 in the first embodiment.
As shown in FIG. 6, a condensing reflection surface 452 that reflects the blue light while condensing the blue light onto the phosphor 44 may be provided in a region where the blue light specularly reflected on the surface of the phosphor 44 is directed. . By providing such a condensing / reflecting surface 452, the blue light regularly reflected by the phosphor 44 can be condensed to the phosphor 44 to be white light, and the luminous flux utilization factor can be increased. Further, the condensing reflection surface 452 is preferably formed integrally with the reflection surface 451 from the viewpoint of suppressing the number of parts.

  It should be noted that the present invention should not be construed as being limited to the first and second embodiments described above, and of course can be modified or improved as appropriate.

  For example, although the LD 31 has been described as the semiconductor light emitting device according to the present invention, the semiconductor light emitting device is not limited to a laser diode, and may be a light emitting diode or the like.

  Further, the LD 31 emits blue light and the phosphors 34 and 44 emit yellow light by the blue light. However, the present invention is not limited to this, and other configurations (excitation light and phosphor and Combination). Furthermore, the light emitted from the phosphors 34 and 44 is not limited to white light, and may be visible light of other colors.

3,4 Vehicle lamp 31 LD (semiconductor light emitting device)
32 Condensing lens 34, 44 Phosphor 35, 45 Reflector 351, 451 Reflecting surface 352, 452 Condensing reflecting surface 16 Shade 17 Projection lens Ax Optical axis

Claims (5)

A semiconductor light emitting device;
A phosphor that receives excitation light emitted from the semiconductor light emitting element and emits visible light;
A reflective surface that is disposed so as to cover the phosphor from behind the phosphor and that reflects the visible light emitted from the phosphor forward;
In a vehicle lamp comprising:
The phosphor is
While being arranged to receive the excitation light from behind,
The excitation light that is specularly reflected on the surface of the phosphor does not affect the light distribution pattern formed by the vehicular lamp in a region obliquely above the front of the phosphor and in front of the reflecting surface. The surface is inclined backward with respect to the front-rear direction so as to go to the area,
A vehicular lamp comprising a condensing reflection surface that is disposed in a region where excitation light specularly reflected by the surface of the phosphor is directed and reflects the excitation light while condensing the excitation light on the phosphor . A semiconductor light emitting device;
A phosphor that receives excitation light emitted from the semiconductor light emitting element and emits visible light;
A reflective surface that is disposed so as to cover the phosphor from behind the phosphor and that reflects the visible light emitted from the phosphor forward;
A projection lens disposed in front of the phosphor and the reflecting surface;
In a vehicle lamp comprising:
The phosphor is
While being arranged to receive the excitation light from behind,
The excitation light that is regularly reflected on the surface of the phosphor is a front obliquely upper side of the phosphor, a front side of the reflection surface, and a rear side of the projection lens, and the vehicle lamp A vehicular lamp characterized in that the surface is inclined backward with respect to the front-rear direction so as to be directed to a region that does not affect the light distribution pattern formed by . 3. A condensing reflection surface that is disposed in a region where excitation light regularly reflected on the surface of the phosphor is directed and reflects the excitation light while condensing the excitation light on the phosphor. Vehicle lamps. The vehicular lamp according to claim 1 , wherein the condensing reflection surface is formed integrally with the reflection surface . The vehicular lamp according to any one of claims 1 to 4, wherein the semiconductor light emitting element emits laser light.

Images