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Previous Page | Contents | Zoom in | Zoom out | Front Cover | Search Issue | Next PageABE FMaGSluminaires | COLOR CONTROLluminaires for general lighting applications.As well as higher light output andlonger lifetime, the luminaires can havesmaller embedded heat sinks, a loweroverall cost thermal management solution,and a larger ambient operating temperaturecapability.The selection of COB as the underlyingtechnology for ChromaWhite moduleproducts provides high packing den-ysity and the capability to use high drivecurrents. It also provides high accuracychip placement and easy assembly andincorporation into existing luminaireheat sinks. COB is a flexible technologythat can integrate additional embeddedelectronics, and is a low cost alternativeto high power LED packages.However, COB modules are typicallyperceived to suffer from complexity ofproduction scaling when small to mediumvolumes are exceeded. In the case of lightingapplications, the scaling problems arealleviated by incorporation of multiple highpowerLED chips (typically 6 to 24 power chips)on a single COB module capable of generating400–2500 lm of white light. This approach is0.90.80.70.60.50.40.30.20.10.0500490480520470460380540T c (°K)5600.0 0.1 0.2 0.3 0.4x5804000 30002500600010,0002000 1500able to generate adequate luminous flux anddirectly replace a lamp such as a 25W T5 fluorescentlamp, a 2 × 26 W CFL lamp or even acluster of LED modules on an IMS board. This6006200.5 0.6 0.7 0.8FIG. 5. The white triangledefi nes the color space regionfor the ChromaWhite module.dramatically reduces the numberof light sources to be manufacturedand hence lends itselfto the model of one light sourceper luminaire.Proprietary optics700 In order to fully benefit fromthe high efficiency of LED lighting,it is necessary to identifyan appropriate light extractionand far-field light-shapingmethod from the LED moduleto the luminaire. Typical CFLor metal halide luminaires sufferfrom poor light output ratio(LOR) values (typically 55% to75%) due to the isotropic emissionnature of the light source requiring multiplereflections to re-direct the light into thedesired far-field profile. By adopting boardlevelprimary optics the ChromaWhite module________38 SEPTEMBER/OCTOBER 2008 LEDsmagazine.comPrevious Page | Contents | Zoom in | Zoom out | Front Cover | Search Issue | Next PageABE FMaGS