| Title |
A Study on S/P Ratio and Color Rendering Properties by Simulating Combination of 7 Phosphors Spectra with A Blue LED Varying Peak Wavelength and Full Width at Half Maximum |
| Authors |
Jong-Oh Kimi ; Uh-Chan Ryu |
| DOI |
http://doi.org/10.5207/JIEIE.2021.35.5.001 |
| Keywords |
close Blue LED Wavelength; Outdoor LED Lighting; Phosphor Combination; Phosphor-Converted LED; S/P Ratio |
| Abstract |
Recently, interest in convenience facilities for road safety and urban aesthetic conditions increased needs to improve visibility and color recognition of night road lightings. To meet the needs, scotopic/photopic (S/P) ratio and color rendering properties, such as color rendering index (CRI), color fidelity (Rf), color gamut (Rg), and color quality scale (Qa) should be considered for outdoor lighting products. It is well known that S/P ratio and CRI are in trade-off relation and, therefore, it is important to optimize them to certain levels through color combinations. In this paper, optimization of phosphor converted LED with a blue LED and 7 phosphors was performed by simulation of changing peak wavelength and full width at half maximum (FWHM) of a blue LED with combinations of 7 phosphors. The results showed that color rendering properties of Ra≥82, R9～14≥76, R9～12≥82, Qa≥95, Rf≥89, Rg≥100, and S/P ratio values were increased by 0.29∼0.61 and 0.22∼0.5 compared to those of the typical warm white LED and cool white LED suggested in the IES (Illuminating Engineering Society) TM (Technical Memorandum) 12-12. |