Open AccessRectangular illumination using a secondary optics with cylindrical lens for LED street light
Author(s) -
HsiChao Chen,
Junyu Lin,
Hsuan-Yi Chiu
Publication year - 2013
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.21.003201
Subject(s) - optics , curvature , ray tracing (physics) , lens (geology) , geometrical optics , nonimaging optics , physics , position (finance) , divergence (linguistics) , physical optics , materials science , mathematics , geometry , linguistics , philosophy , finance , economics
The illumination pattern of an LED street light is required to have a rectangular distribution at a divergence-angle ratio of 7:3 for economical illumination. Hence, research supplying a secondary optics with two cylindrical lenses was different from free-form curvature for rectangular illumination. The analytical solution for curvatures with different ratio rectangles solved this detail by light tracing and boundary conditions. Similarities between the experiments and the simulation for a single LED and a 9-LED module were analyzed by Normalized Cross Correlation (NCC), and the error rate was studied by the Root Mean Square (RMS). The tolerance of position must be kept under ± 0.2 mm in the x, y and z directions to ensure that the relative illumination is over 99%.