New structure of side-collimating lens for LED with high collimating performance based on geometrical optics

In order to improve collimating performance, we proposed a new structure of side-collimating lens. The lens surfaces are evaluated based on purely geometric optics. We used a point source for theoretical model, but used a LED chip with a size of 1 mm × 1 mm in all simulations. The ray diverged from the LED chip is collimated perpendicular to the optic axis of LED after refracting or total internal reflecting by the lens. Since the ray is collimated laterally by the lens, we have considered collimating performance in conjunction with a reflector. Effects of initial conditions on the size and collimating performance of the lens were analyzed. Simulation results show that the light flux percentage is achieved 95.23% under a half view angle of ±2° for a LED chip. Most illuminating area (dominating 80% light flux) radii are no more than 3 m when the target surface is 100 m apart from LED. These simulation results manifest that the lens has good collimating performance and its new structure is a valuable.