Light emitting device, illuminating device, and headlamp
View Patent ↗A light emitting device of the present invention includes: an LD chip for emitting excitation light; a light emitting body for emitting fluorescence upon irradiation with the excitation light from the LD chip; and a mirror including a light reflecting concave surface for reflecting the fluorescence from the light emitting body, the light reflecting concave surface of the mirror having a through-hole at a region other than a bottom region in the vicinity of the bottom of the light reflecting concave surface, and a truncated pyramid light converging section being inserted into the through-hole in order to guide the excitation light from the LD chip to the light emitting body.
1. A light emitting device, comprising:
an excitation light source for emitting excitation light;
a light emitting body for emitting fluorescence upon irradiation with the excitation light from the excitation light source; and
a reflection mirror including a light reflecting concave surface for reflecting the fluorescence from the light emitting body,
the light reflecting concave surface of the reflection mirror having a through-hole at a region other than a high-illuminance region that comprises a position where fluorescence from the light emitting body is incident with highest illuminance,
a light guiding member being inserted into the through-hole in order to guide the excitation light from the excitation light source to the light emitting body, and
an optical axis of the reflection mirror passing through the high-illuminance region.
2. The light emitting device as set forth in claim 1 , wherein the high-illuminance region includes a position where a distance between the light reflecting concave surface and the light emitting body is shortest.
3. The light emitting device as set forth in claim 2 , wherein the high-illuminance region is in a vicinity of a bottom of the light reflecting concave surface of the reflection mirror.
4. The light emitting device as set forth in claim 3 , wherein the light guiding member is inserted into the through-hole toward the light emitting body in a direction extending along a vertical direction when the light emitting device is in a normal use.
5. The light emitting device as set forth in claim 3 , wherein the light guiding member is inserted into the through-hole toward the light emitting body in a direction forming an angle of not less than 15° and not more than 30° with respect to a vertical direction when the light emitting device is in a normal use.
6. The light emitting device as set forth in claim 1 , wherein the light reflecting concave surface of the reflection mirror has an elliptic opening whose long axis and short axis have different lengths, the light reflecting concave surface has parabolic cross sections when cut in planes vertical to the long axis and the short axis, respectively, and the long axis is along a horizontal direction when the light emitting device is in a normal use.
7. The light emitting device as set forth in claim 1 , wherein the light guiding member is made of a material whose reflectance is larger than 1.
8. The light emitting device as set forth in claim 1 , wherein
the light guiding member guides excitation light incident to one end of the light guiding member to another end of the light guiding member so that the excitation light is radiated to the light emitting body, and
said another is smaller in cross sectional area than said one end.
9. An illuminating device, comprising a light emitting device as set forth in claim 1 .
10. A headlamp, comprising a light emitting device as set forth in claim 1 .
11. The light emitting device as set forth in claim 1 , wherein the high-illuminance region is a region at which luminous flux from the light emitting body is incident with higher density than other region.