Enhanced brightness light emitting device spot emitter
View Patent ↗The amount of usefully captured light in an optical system may be increased by concentrating light in a region where it can be collected by the optical system. A light emitting device may include a substrate and a plurality of semiconductor layers. In some embodiments, a reflective material overlies a portion of the substrate and has an opening through which light exits the device. In some embodiments, reflective material overlies a portion of a surface of the semiconductor layers and has an opening through which light exits the device. In some embodiments, a light emitting device includes a transparent member with a first surface and an exit surface. At least one light emitting diode is disposed on the first surface. The transparent member is shaped such that light emitted from the light emitting diode is directed toward the exit surface.
1. A light emitting device comprising:
a transparent member having a first surface, a second surface, a third surface, a fourth surface, and an exit surface;
at least a first light emitting diode disposed on the first surface; and
a second light emitting diode disposed on the third surface; wherein
the second surface is reflective;
the fourth surface is reflective;
the transparent member is shaped such that light emitted from the at least one light emitting diode is directed toward the exit surface;
the first and third surfaces form a wedge with an apex opposite the exit surface; and
the second and fourth surfaces are substantially parallel.
2. The light emitting device of claim 1 further comprising a reflective coating disposed on a portion of the first surface not covered by the first light emitting diode.
3. The light emitting device of claim 1 wherein the first light emitting diode and the second light emitting diode each emits light at a different wavelength.
4. The light emitting device of claim 1 wherein the second light emitting diode emits red light, the device further comprising a dichroic material disposed between the second light emitting diode and the third surface.
5. The light emitting device of claim 4 further comprising a third light emitting diode disposed on one of the first surface and the third surface, wherein one of the first and the third light emitting diodes emits green light and the other of the first and the third light emitting diodes emits blue light.
6. The light emitting device of claim 1 wherein the first light emitting diode and the second light emitting diode each emits light of substantially the same color.
7. The light emitting device of claim 1 wherein the first light emitting diode comprises:
a transparent substrate;
a plurality of semiconductor layers that are transparent to light emitted by the first light emitting diode; and
a contact reflective of light emitted by the light emitting diode, wherein the plurality of semiconductor layers are disposed between the transparent substrate and the contact.
8. The light emitting device of claim 7 further comprising a submount attached to the contact, wherein the first light emitting diode is mounted on the first surface such that the transparent substrate is closest to the first surface.
9. The light emitting device of claim 1 wherein the first surface and the exit surface are not parallel.
10. The light emitting device of claim 1 wherein the transparent member is selected from the group consisting of sapphire, glass, acrylic, and silicone.