Overall Illuminance Uniformity of IRED Lighting in Nighttime CCTV

Abstract

This study looks at optimizinge light redistribution to improve the overall illuminance uniformity of commercial IRED modules. To obtain uniform illumination over a prescribed rectangular area, a freeform surface lens was evaluated using TracePro. The LED light overall illuminance uniformity regulated in KSC 7658 was verified using Relux software. Experimental test results showed 0.81 overall illuminance uniformity for rectangular light distribution of LED lights having a radiation angle of 80°. After fabricating prototype IRED lights based on these simulation results, illuminance performance was observed when used as actual IRED lighting with a nighttime CCTV system. Image observation photographs of the prototype 80° rectangular IRED lights confirmed that object images can be seen clearly owing to high overall illuminance uniformity, and that dark regions of the CCTV screen were not shown.