Secondary optical lens designed in the method of source-target mapping

Abstract

A secondary optical lens was designed and investigated in three-dimensional (3D) space, which was far more accurate than a two-dimensional space in far-field lighting. The shape of the lens surface was from numerical solutions to a group of equations based on source-target mapping; calculating time was only 1.6 s. Neglecting absorption and scattering loss, the main results show that, for circular lighting, light efficiency can reach as high as 95%, and uniformity, which is the ratio of the minimum illuminance to average illuminance, is 92.2%. For rectangular lighting, light efficiency can reach 83.6% and uniformity can reach 66.7%. Performance of lenses under different parameters was studied to provide direct references for production and application.

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.…”

Freeform lens design for light-emitting diode uniform illumination by using a method of source–target luminous intensity mapping

“…Owing to freeform optics capable of achieving high efficiency and compact fixtures for LED lighting, many related methods have been proposed in the past years, for example, the tailored freeform surface method [1], the source-target energy mapping method [2][3][4][5], the feedback modification method [6], and the simultaneous multiple surface (SMS) method [7]. However, most methods involve iterative calculation or complex Monge-Ampère equations, and this results in complicated LED lens designs.…”

Freeform lenses for illumination of specific shapes in (u,v) coordinate system

“…In freeform lens design, due to the complexity of solving Monge-Ampère equation directly [4], ray mapping method [5][6][7][8][9] and supporting surface method [10] have been widely researched in recent years. In ray mapping method, light source and target plane are divided into a series of grids according to energy conservation law and method of separation of variables, numerical solutions of curves are obtained and freeform lens can be constructed.…”