Free-form lens design for LED indoor illumination

Kuang Lung Huang, Jin-Jia Chen, Te Yuan Wang, Li Lin Huang

Research output: Chapter in Book/Report/Conference proceedingConference contribution

6 Citations (Scopus)


This paper presents a free-form lens design for indoor illumination. The lens consists of a TIR (total internal reflection) surface on the sidewall, a refractive surface on the front side, and a concave surface on the rear side. The TIR surface is decorated with a free-form profile that light rays emitted from the LED with a larger spread angle to the axis will experience a total internal refection and output from the front refractive surface. While the central part of the front refractive surface has a convex surface that makes light rays closing to the optical axis more evenly distributed. The purpose of the rear concave surface is to let light rays emitted from the LED enter the lens straightforwardly. With this lens light rays from a Lambertian-type LED light source can be redistributed so that a uniform illumination can be achieved. The optical simulation results show that the measured optical efficiency is 75% while the uniformity is 80% on a target plane of 6-m diameter and at 2.5-m away.

Original languageEnglish
Title of host publicationLED and Display Technologies
Publication statusPublished - 2010 Dec 1
EventLED and Display Technologies - Beijing, China
Duration: 2010 Oct 182010 Oct 19


OtherLED and Display Technologies

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

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