Abstract
The principal component analysis was applied to the spectral power distributions of actual fluorescent lamps, and three characteristic functions SF1 (λ), SF2 (λ) and SF3 (λ) were derived. Based on the average spectral power distribution J (λ) and these three characteristic functions, reconstituted spectral power distributions of fluorescent lamps JFt (λ) were derived with arbitrary chromaticity coordinates and with arbitrary general color-rendering index by the following equation.
JFt (λ) =J(λ) +k1SF1 (λ) +k2SH2 (λ) +k3SF3 (λ)
By use of these spectral power distributions, the following subjects were discussed;
(1) The maximum value of the general color-rendering index was Rα =93.4 for reconstituted fluorescent lamps with the same chromaticity coordnates as those of the CIE standard illuminant C.
(2) The value of σ2, variance of deviations in spectral power distributions between the test and the reference illuminant, had its minimum corresponding to the maximum value of the general colorrendering index.
(3) Deviations of chromaticity coordinates of eight test object colors for the general color-rendering index were clarified between the CIE illuminant C and each of reconstituted fluorescent lamps with different values of Rα.
(4) On twelve gray object colors which were metameric with respect to the CIE standard illuminant C and the CIE 1931 standard observer, failures of preserving color match among them were discussed under each of the above reconstituted fluorescent lamps. Average color differences ΔEM, the measure of the failure of preserving color matching among metameric object colors, have the following simple relations with Rα for the actual fluorescent lamps.
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