There is a number of known illumination devices. Some of the devices are simple incandescent lamps, fluorescent lamps, LED (Light Emitting Diode) based lamps and others. In light emitting diodes (LEDs) based devices, light is produced by one or more LEDs organized to deliver a desired level of illumination on a defined surface area. LEDs are more efficient than incandescent or fluorescent lamps, e.g., LEDs produce up to 100 lumens per watt of consumed electrical energy vs 10-50 lumens per watt produced by incandescent or fluorescent lamps.
One of the problems related to LEDs based is reduction in efficiency as operating currents rise, making the devices too hot to power in large-scale applications.
U.S. Pat. Nos. 5,535,238, 6,791,259, 7,086,765, 7,281,823, 8,742,654, 8,625,097, 8,593,956, 8,948,564 and US Patent Application Publications 2015/0219315, 2016/0061392, disclose different configurations of LEDs based illumination devices.
However, the life constantly requires brighter and more efficient light sources or devices using less energy than the existing light devices. Use of laser diodes as excitation source to excite different inorganic phosphors in illumination devices is believed to be alternative means for high-power white light instead of the traditional LEDs. The more directional nature of the laser diode beams, as compared to LEDs, may be utilized to avoid some optical inefficiencies. The laser diode based lighting devices are higher in efficiency, although in some cases they require excitation by blue laser diodes and a combination of different phosphors.
Patent Cooperation Treaty WO2005/107240, WO2007/073496 and WO 2007/107420 and U.S. Pat. Nos. 8,625,097, 8,948,564 and US Patent Application Publication No. 20140334126, disclose different configurations of laser diodes based illumination devices.