SYSTEM AND METHOD FOR MIXING LIGHT FOR A LED-PUMPED PHOSPHOR ARRAY LIGHT SOURCE
A LED-pumped phosphor array light source and a method of manufacturing the phosphor array light source are disclosed. The phosphor array light source includes a light emitting diode (LED) array, an imaging optics, a phosphor module array, and a light mixing pipe. The imaging optics focuses the light rays from the LED array on the phosphor module array. The phosphor modules are pumped by the incoming light rays and emit colored light into the light mixing pipe. In some embodiments, the imaging optics include a short-pass filter to minimize light loss through back scattering.
1 . A LED-pumped remote phosphor light source comprising:
a plurality of light emitting diodes (LEDs);
an imaging optics over the plurality of LEDs;
a phosphor array attached over the imaging optics on an opposite side from the plurality of LEDs, the phosphor array including more than one color type; and
a light mixing pipe bonded to the phosphor array to provide total internal reflection of light rays from the phosphor array for light ray angles larger than a critical angle with respect to a normal vector of a surface of the light mixing pipe.
2 . The LED-pumped remote phosphor light source of claim 1 , wherein the imaging optics having a reflective exterior except where the imaging optics is exposed to the LEDs and where the imaging optics is exposed to the phosphor array.
3 . The LED-pumped remote phosphor light source of claim 2 , wherein the reflective exterior is achieved with a reflective coating.
4 . The LED-pumped remote phosphor light source of claim 2 , wherein the reflective exterior is achieved with micro-grooves pattern on the exterior.
5 . The LED-pumped remote phosphor light source of claim 1 , wherein the imaging optics is optically bonded via silicone gel to the plurality of the LEDs.
6 . The LED-pumped remote phosphor light source of claim 1 , wherein the imaging optics is a convex lens.
7 . The LED-pumped remote phosphor light source of claim 1 , wherein the imaging optics includes air gaps.
8 . The LED-pumped remote phosphor light source of claim 1 , wherein the phosphor array includes hemispherical phosphor layers with a concave side facing the imaging optics.
9 . The LED-pumped remote phosphor light source of claim 1 , wherein the imaging optics has an imaging well between each surface bonded to each phosphor module of the phosphor array.
10 . The LED-pumped remote phosphor light source of claim 9 , wherein the light mixing pipe has a protrusion extending into each of the imaging well.
11 . The LED-pumped remote phosphor light source of claim 1 , wherein the light mixing pipe has a collimation well between each surface bonded to each phosphor module of the phosphor array
12 . The LED-pumped remote phosphor light source of claim 1 , wherein the imaging optics has a collimation well between each surface bonded to each LED of the plurality of LEDs.
13 . The LED-pumped remote phosphor light source of claim 1 , wherein the collimation well has a reflective coating.
14 . The LED-pumped remote phosphor light source of claim 1 , further comprising a cold plate surrounding the phosphor array, the cold plate contoured around the imaging optics.
15 . A LED-pumped remote phosphor light source comprising:
a plurality of light emitting diodes (LEDs);
an imaging optics over the plurality of LEDs, the imaging optics including a short pass filter therein;
a phosphor array attached over the imaging optics on a side facing away from the plurality of LEDs, the phosphor array including more than one color type; and
a light mixing pipe optically bonded to the phosphor array to provide total internal reflection of light rays from the phosphor array for light ray angles larger than a critical angle with respect to a normal vector of a surface of the light mixing pipe.
16 . The LED-pumped remote phosphor light source of claim 15 , wherein the imaging optics includes a first imaging lens attached over the plurality of LEDs with a first spacing and a second imaging lens attached over the first imaging lens with a second spacing.
17 . The LED-pumped remote phosphor light source of claim 16 , wherein the short pass filter is between the first imaging lens and the second imaging lens to reflect colored backscattering from the phosphor array back to phosphor modules of the phosphor array.
18 . The LED-pumped remote phosphor light source of claim 15 , wherein the short pass filter is hemispherical with the concave side of the short pass filter facing the phosphor array.
19 . The LED-pumped remote phosphor light source of claim 18 , wherein the short pass filter is embedded within the imaging optics
20 . The LED-pumped remote phosphor light source of claim 15 , same colored phosphor modules have a radial symmetry within the phosphor array.
21 . A method of manufacturing a LED-pumped remote phosphor light source comprising:
providing a plurality of light emitting diodes (LEDs);
optically bonding an imaging optics over the plurality of LEDs;
optically bonding a light mixing pipe to a phosphor array of different colors; and
attaching the imaging optics to the phosphor array on a side of the imaging optics facing away from the plurality of LEDs.
22 . The method of claim 21 , further comprising installing a short pass filter within the imaging optics.
23 . The method of claim 21 , wherein installing a short pass filter within the imaging optics includes:
coating a hemispherical lens with a short-pass filter coating;
inserting the hemispherical lens within a base imaging lens with a concave opening; and
optically bonding the hemispherical lens within the base imaging lens.