Freeform lens design for LED collimating illumination

Abstract

We present a simple freeform lens design method for an application to LED collimating illumination. The method is derived from a basic geometric-optics analysis and construction approach. By using this method, a highly collimating lens with LED chip size of 1.0 mm × 1.0 mm and optical simulation efficiency of 86.5% under a view angle of ± 5 deg is constructed. To verify the practical performance of the lens, a prototype of the collimator lens is also made, and an optical efficiency of 90.3% with a beam angle of 4.75 deg is measured.

Design and optimization for total internal reflection collimators based on slope-error tolerance analysis

“…The fixed slope error can be formed either by shrinkage during the molding process or by B-spline fitting. 16 On the other hand, stochastic slope error is always caused during the process of manufacturing and is difficult to eliminate from mass production. 21 Considering the complexity of the program, the TIR surface is designed with a 0.1-mm x-coordinate increment of adjacent points.…”

“…11 Optimizations of initial parameters for better efficiency and CLI with different extended light sources were reported by Chen, 12 and the effects of an extended LED light source on the efficiency and CLI of TIR lenses were studied by Chen 12 and Kari et al 3 In fact, there is an extreme of the CLI, as every infinitesimal surface on the exit pupil has no more than a single ray emitting toward the center as a result of luminance conservation and Etendue conservation. In theory, it is not complicated to achieve the maximum CLI by the methods recommended by Parkyn, Shen, and Chen, [13][14][15][16] as each ray from the center of the LED was designed to emit in the collimation direction so that the luminous intensity always reaches the maximum theoretical value for a light source of any size. As a result, it is not theoretically difficult to optimize the CLI in the design stage.…”

LED Lens for Rectangular Beam with Small Divergence Angles

“…[7,8] has a refraction limit; the divergence angle can't be smaller than 120°. As we know, a common TIR lens can obtain circular illumination with small divergence angle for an LED source [11][12][13][14][15][16]. And Chen in Ref.…”

Influence of the characteristics of a light source and target on the Monge–Ampére equation method in freeform optics design

“…The fill operation can avoid complications associated with singularities in the cylindrical coordinate system. Due to the excellent characteristics that can be used to achieve a large angle of deflection, high energy efficiency, and a compact design, the total internal reflection (TIR) lens is very popular in general lighting [1,8,9]. Currently, the TIR lens is mostly used to produce rotational illumination, and it may still be a challenge to design a TIR lens for nonrotational illumination.…”