Figure 6
SPFD, PFD, and mixing ratio of PFD for each LED type. Independent five SPFDs (A, colored) emitted by each LED type alone were estimated from the measured single SPFD curve (A, solid black line) at x = y = 0 at z = 17.3 cm, when standard forward current IFss were fed to every LED. Gaussian function was used to separate the five peaks from the measured SPFD curve (A). Distributions of PFDs (C–G) at the irradiated area (x = ±30 cm and y = ±15 cm at z = 17.3 cm) provided from each LED type alone were determined using Gaussian function with the estimation error of less than 3.71% for the 91 points of the irradiated area. The mixing ratios of each LED type’s PFD against the total PFD (B) were calculated for the irradiated area (H–L).