Quantitative Analysis of Full Spectrum LEDs for High Quality Lighting

With the latest progress in new generation of phosphor and packaging design, higher quality, full spectrum, white LEDs become possible. By engineering the spectrum power distribution (SPD), we have developed full spectrum light sources and proposed methods for evaluating thelight sources' color quality, spectral continuity, and eye-safety. The spectral continuity, which is termed as C_s, quantifies the color quality of a light source in comparison to the reference illuminants. The calculation is based on a spectral area coincidence between the measured light source and the reference light source. In order to provide a guidance of minimizing harmful blue light of a spectral power distribution of a LED, we also defined the hazard blue light ratio which is termed as B_r and formulated by combining the methods used by IEC/EN 62471 standard and TUV Rheinland. Several approaches of creating full spectrum LEDs have been studied and evaluated from aspects including color rendering index (CRI), IES TM-30-15, spectral continuity C_s, blue light hazard ratio B_r. These assessments provide a helpful method to guide the optimization of future light sources.