| 摘要 |
The present invention uses“Chip-on-Board”(COB) metal core printed circuit board (PCB) technology in conjunction with high efficiency compact imaging and non-imaging optics to provide an emergency light that is more compact, offers higher performance with respect to luminance levels (higher brightness), longer life, and lower cost relative to systems incorporating pre-packaged LED devices. The thermal impedance between the LED junction and the heat sink is significantly reduced for COB technology by placing the LED die directly on a metal core (or other high thermal conductivity material substrate), thereby increasing temperature dependant life and thermally dependant output power. Additionally, because there is no encapsulant or domed optic over the LED die initially, it is possible to get a much more compact and efficient substantially Etendue (area, solid angle, index squared product) preserving collection optic directly over the die. Cost is significantly reduced for COB configurations due to elimination of the expense of additional components attached to the LED die for the case of pre-packaged LED devices.
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