Vehicle headlamp and illuminating device
View Patent ↗A headlamp 1 includes a laser diode 3 that emits a laser beam, a light emitting part 7 that emits light upon receiving the laser beam emitted from the laser diode 3 , and a reflection mirror 8 that reflects the light emitted from the light emitting part 7 . According to the headlamp 1 , the light emitting part 7 has a luminance greater than 25 cd/mm 2 , and an area size of an aperture plane 8 a perpendicular to a direction in which an incoherent light travels outward from the headlamp 1 is less than 2000 mm 2 .
1. A vehicle headlamp, comprising:
an excitation light source that emits excitation light;
a light emitting part that emits light upon receiving the excitation light emitted from the excitation light source; and
an optical system that distributes the light emitted from the light emitting part,
the light emitting part having a luminance greater than 75 cd/mm 2 , and
an area size of the optical system, when viewed from a direction in which the light travels outward from the vehicle headlamp, being less than 1500 mm 2 , and at least 100 times as large as an area size of a surface of the light-emitting part, which surface receives the excitation light.
2. The vehicle headlamp according to claim 1 , wherein the area size of the optically system is greater than or equal to 100 mm 2 .
3. The vehicle headlamp according to claim 1 , wherein the excitation light emitted from the excitation light source has a peak wavelength falling within a range of not less than 400 nm but not more than 420 nm.
4. The vehicle headlamp according to claim 1 , wherein the excitation light emitted from the excitation light source has a peak wavelength falling within a range of not less than 440 nm but not more than 490 nm.
5. The vehicle headlamp according to claim 1 , which vehicle headlamp serves as a driving headlamp for an automobile.
6. A vehicle headlamp according to claim 1 , wherein the excitation light source is provided outside the optical system, and the light-emitting part is provided inside the optical system.
7. An illuminating device, comprising:
an excitation light source that emits excitation light;
a light emitting part that emits light upon receiving the excitation light emitted from the excitation light source; and
an optical system that distributes the light emitted from the light emitting part,
the light emitting part having a luminance greater than 75 cd/mm 2 , and
an area size of the optical system, when viewed from a direction in which the light travels outward from the illumination device being less than 1500 mm 2 , and at least 100 times as large as an area size of a surface of the light-emitting part, which surface receives the excitation light.