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Proceedings Paper

Utilization of the Crawford transformation in evaluation of the spectral efficiency of solid state light sources
Author(s): H. Zwick; P. Edsall; J. Ness; L. Hare; B. Stuck
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Paper Abstract

The purpose of this study is to develop procedures for evaluating the transient effects of solid state light sources used as illumination sources at night. Traditional light sources used at night are designed to preserve dark adaptation by employing long wavelength visible sources that minimally affect rod photoreceptor sensitivity, while new LED light sources provide a mix of visible spectral sources with visible spectral components that may effect rod function and possibly impede night vision. The Crawford transformation was used generate spectral dark adaptation functions for LED flashlight background effects on dark adaptation induced by background exposure conditions from four solid state light sources. Increment background spectral sensitivity functions were generated for each of four LED flashlight sources (S1, S2, & S3) as well as from a merger of each LED source with a broadband Goldman-Weekers (GW) dark adaptometer source (S5) to simulate transition for day to night light environments. Increment background spectral sensitivity for both methods of generating increment spectral sensitivity were consistent in showing similar spectral background effects on spectral sensitivity but differed in the dynamic range of recovery. Those spectra that had components in the middle wavelength region (S2 and S3) showed a more restricted rod function as compared with S1 and S2.

Paper Details

Date Published: 12 September 2006
PDF: 10 pages
Proc. SPIE 6337, Sixth International Conference on Solid State Lighting, 63370N (12 September 2006); doi: 10.1117/12.679154
Show Author Affiliations
H. Zwick, U.S. Army Medical Research Detachment (United States)
P. Edsall, Northrop Grumman (United States)
J. Ness, U.S. Military Academy, West Point (United States)
L. Hare, U.S. Military Academy, West Point (United States)
B. Stuck, U.S. Army Medical Research Detachment (United States)

Published in SPIE Proceedings Vol. 6337:
Sixth International Conference on Solid State Lighting
Ian T. Ferguson; Nadarajah Narendran; Tsunemasa Taguchi; Ian E. Ashdown, Editor(s)

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