RESULTS AND DISCUSSIONS
From the ray and illumination simulation as a function
of flux, we investigated illumination, efficiency any rays
distribution from different types of material and lens
structures. The efficiency is the total incidence flux on
target area per emitted flux of LED. The ray's distribution
is defined as the ratio between average and maximum
values of illumination on the target area.
designed lens surfaces, three different types of materials,
Poly Methyl Methacrylate (PMMA), Poly Styrene (PS) and
Poly Carbonate (PC) have been investigated for each lens
material. The results from different materials have been
compared. From our study, it was found that PMMA had
the highest efficiency compared with PS and PC as shown
in Figure