| Title |
Simulation of S/P Ratio Changes by Combination of 455nm LED and Phosphor Spectra |
| Authors |
Jong-Oh Kim ; Hyeong-Seob Jo ; Uh-Chan Ryu |
| DOI |
http://dx.doi.org/10.5207/JIEIE.2019.33.11.001 |
| Keywords |
LED Lighting; S/P Ratio; CRI; CCT; Mesopic Vision |
| Abstract |
Color rendering index (CRI), light efficiency, and S/P ratio are important parameters for evaluating LED lightings. In the case of mesopic vision, analysis of S/P ratio has been proposed as a guideline of testing and installing road lightings. In this paper, relations of S/P ratio and CRI values will be investigated by combining 455-nm blue LED and various phosphor spectra through a simulation method. LED spectra will be proposed after optimizing S/P ratio and CRI values (R1～R14) according to correlated color temperatures (CCTs). The spectral combination of 455-nm blue LED and phosphors resulted in improving S/P ratios by 0.17～0.6 compared to 1.21 of WW-LED and by 0.21～0.56 compare to 2.04 of CW-LED in IES TM-12-12, showing CRIs more than 80 at the same time. |