Fast freeform reflector generation using
source-target maps

Abstract

We propose a freeform reflector design method based on the mapping of equi-flux grids between a point source and a target. This method imposes no restriction on the target distribution, the reflector collection angle or the source intensity pattern. Source-target maps are generated from a small number of target points using the Oliker algorithm. Such maps satisfy the surface integrability condition and can thus be used to quickly generate reflectors that produce continuous illuminance distributions.

Design of freeform optics

“…The generated reflectors can produce continuous illuminance distributions [29,30]. In addition, it can also be combined with other design methods, such as combining with the Monte Carlo ray tracing.…”

Illumination design for extended sources based on phase space mapping

“…[3][4][5] Common examples are Gauss-to-top-hat beam shapers or freeform illumination reflectors for various applications. 6,7 However, real-world physical light sources exhibit a finite area-angle product, corresponding to a finite etendue. Lightemitting diodes in particular exhibit a large etendue due to their extended emission area and Lambertian intensity pattern, which needs to be considered during illumination design.…”

Design Method for a Total Internal Reflection LED Lens with Double Freeform Surfaces for Narrow and Uniform Illumination

“…The LED lens can be designed using a differential equation method [8][9][10][11], a parameter optimization method [12][13][14][15], or a simultaneous multiple surface (SMS) method [16][17][18], and it often includes one or more freeform surfaces, for the sake of low price and high efficiency. The differential equation method is an LED lens design method in which differential equations relating to the propagation of rays through an LED lens are solved assuming that one surface of the lens is already known; then the other surface is freeform.…”

“…In this method, first the location of a ray of light emitted from the LED to impinge on a target plane is determined, depending on an illumination model selected to form a desired illuminance distribution on the target plane. Then the surface slope of a corresponding incident point on the freeform surface is determined so that the ray incident upon the surface will pass through a designated point on the target plane [8][9][10][11]. Though the freeform surface is easily determined, as long as the related simultaneous differential equations can be derived completely, the luminous ISSN: 1226-4776(Print) / ISSN: 2093-6885(Online) DOI: http://dx.doi.org/10.3807/JOSK.2016.…”