Papers by Author: Po Hung Yao

Abstract: A wide angle light-deflected lens combining collimation and total internal reflection (TIR) optical mechanics for LED package is proposed. Utilizing angle-dividing method the angle of emitting distribution of LED chip was cut into several angular zones and then a light-collimating curve surface with corresponding declined plane performing TIR for the collimated incident ray was designed. Thereby, the light-deflected lens, consisting of multi pairs of collimating curve surfaces and declined planes, can achieve wide-angle deflection of light emitting from LED chip. The design rule and experiment results of the lens with optimization optical design are demonstrated and discussed in this paper.

Abstract: Laser light source is a potential illumination light source for non-emissive display applications, especially for liquid crystal projection displays, due to its requirement of low etendue source and highly polarized light. In order to make a conversion from a circular Gaussian beam profile to a rectangular uniform distribution, a microlens array has been proposed as a homogenizer. The analytical and experimental results show that the microlens array with a pitch of 100um under laser beam illumination works as a diffractive element, and a promising uniformity can be obtained with a stack of two microlens array.