The models for spectra of a phosphor-coated white (p-W) LED and a white light LED cluster are developed based on
the principle of additive color mixture. The simulation results show that p-W LEDs consisting of a blue chip (450nm),
green phosphor (507 nm), yellow phosphor (580 nm) and red phosphor (655 nm) could realize color rendering indices
(CRIs) above 97.7 and special CRIs of R1 to R14 above 91.1, but luminous efficacies of radiation (LERs) below 250.3
lm/W, that white/red clusters consisting of red LEDs and p-W LEDs with a blue chip (450nm), green (507 nm) and
yellow (580 nm) phosphors could realize given color temperature white light with CRIs above 97.9 and special CRIs of
R1 to R14 above 89.6, as well as LERs above 296.3 lm/W, and that a neutral-white /red//blue cluster consisting of blue
LEDs (465 nm), red LEDs (628 nm) and neutral-white LEDs with a blue chip (452 nm), green (530 nm) and yellow
(586 nm) phosphors could realize CCT tunable white lights with CRIs above 97.9 and special CRIs of R1 to R14 above
89.6, as well as LER above 296.3 lm/W.
The Polyethylene terephthalate (PET) fiber is so sleek that its surface has high reflectance. Therefore it is difficulty to dye the PET fiber dark color by using the disperse dyes. In order to solve this problem, the laser processing technology is applied to change the surface dyeing property of the PET fiber. How to quantify the treated layer thickness of laser irradiated PET fabric and how to foretell its spectrum reflectivity distribution are two problems that needs the solution urgently. In this paper, both the simplified structure model and optical transmission model of PET fabric irradiated by laser are developed, the reflectance formula for laser irradiated PET fabric is derived. The characteristic parameters, both the equivalent optical thickness and the gain of dye strength, are introduced, which represented surface performance of laser irradiated PET fabric. When the equivalent optical thickness of the treated layer and the unit k/s ratio of the dyestuff are measured, the spectrum reflectivity distribution of the laser irradiated PET fabric for given concentrations of the various colorants can be calculated, thereby its tristimulus values can be obtained.
According to the optical transmission model of laser irradiated Polyethylene terephthalate (PET) fabric, the method of measuring the surface characteristic parameters, both the equivalent optical thickness and the gain of dye strength, is presented in detail. The PET fabrics untreated and irradiated by UV laser (308 nm, mJ/cm2, 10 pulses) are used in our experiment. They are dyed respectively by three disperse dyes (Ciba Terasil Red G 150%, Ciba Terasil Blue BG-02 200% and Ciba Terasil Navy GRL-C 200%) with various concentrations. The spectral reflectance distributions of the untreated and irradiated PET fabrics dyed are carried out with the color measuring and matching system (Datacolor, SF600plus). The experimental data indicated that the dye strength of disperse dye in the UV laser irradiated PET fabric was greater than that in the untreated, that the gain of dye strength is relative to dyestuff, and that the calculated reflectance of UV laser irradiated PET fabric is accordant well to the measured. The results show that the optical transmission model of laser irradiated PET fabric is reasonable and available.
In this paper, a new whiteness formula in the CIELUV uniform color space is developed. The results show that it is superior to the CIE whiteness formula and the others in visual correlativity, uniformity and applicability.