COOLED LIGHT EMITTING APPARATUS

摘要

A cooled light emitting apparatus 1 comprises a light source including a close packed array 2 of light emitting diode device (high intensity LEDs) and a cooling system for cooling the light source. The cooling system comprises a thermoelectric cooling device in the form of a Peltier device 4 connected via a heat spreader 3 to the light source and a heat exchange system 5, 6 for removing heat from the Peltier device 4 . The heat exchange system 5,6 uses liquid coolant (or refrigerant) to cool the Peltier device 4 . By extracting heat from the LED array 2 at a rate greater than 5 W cm^-2 it is possible to maintain the LED array at a temperature of less than -10 degrees Celsius, and thus emit light having an optical power density of greater than 1 Wcm^-2.