LED package design for high optical efficiency and low viewing angle

Light extraction efficiency of an LED package can be improved by optimizing the cup angle and lens curvature. However, this conventional package is not appropriate for many applications that require low viewing angle and distance view if secondary collimator optics is not used. The use of secondary collimator lens can reduce power output more than 10%. In response to this limitation, we design a low viewing angle and high extraction package based on total internal reflection (HEP- TIR) lens. The HEP-TIR package produces the light output with low dispersion angle without the use of secondary optics and has smaller size than secondary optics while its extraction efficiency is as high as the best conventional package. The total light output of HEP-TIR within 10⁰ degree is 287% higher than that of the conventional package.