• Journal of Korean Ophthalmic Optics Society
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• v.16 no.3
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• pp.283-291
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• 2011

Purpose: To find an empirical fitting curve to represent the relationship between the luminous transmittance and tinted time in tinted lenses using exponential decay curves. Methods: Total ninety tinted lenses were prepared with CR-39 lenses and six different colored dyes. Single, double and triple exponential decay curves were used as trial curves in order to find the empirical fitting curve. Result: The results showed that the best empirical fitting curve was triple exponential decay curves. Conclusions: We propose triple exponential decay curves as proper empirical fitting curves to represent the tinted-time dependence of the luminous transmittance in tinted lenses.

• Journal of Korean Ophthalmic Optics Society
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• v.8 no.1
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• pp.53-57
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• 2003

R, G, Y, B color lenses Manufactured increasing tinted time by 5 min term. CIE $L^*a^*b^*$ coordination's analysis used spectrophotometer and CIE $L^*a^*b^*$ color system. CIE $L^*a^*b^*$ coordination transfer form about tinted time being $$b^*(Y-B)={\beta}a^*+{\alpha}$$ change to do linear almost. In red case, move in $G{\rightarrow}R$, $B{\rightarrow}Y$ form tinted time increases, and Parameter ${\alpha}$, ${\beta}$ value got each -3.49 and 0.90. In green case, CIE $L^*a^*b^*$ coordination transfer form is $R{\rightarrow}G$, $B{\rightarrow}Y$ form. Got the pure green color color in 10 min's tinted time. Parameter ${\alpha}$, ${\beta}$ value got each -0.72 and -0.55. Get into pure yellow and blue color case tinted time increases. Parameter ${\alpha}$, ${\beta}$ value are 14.11 and 1.58 in yellow, and Parameter ${\alpha}$, ${\beta}$ value are -11.62 and 1.30 in blue color.

• Journal of Korean Ophthalmic Optics Society
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• v.16 no.4
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• pp.403-408
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• 2011

Purpose: To study the concentration distribution and diffusion depth in tinted lenses using the law of diffusion. Methods: The measured values taken from experiments were fitted with the theoretical fitting curve induced on the basis of Fick's second law of diffusion. Results: The fitting curves were in very good agreement with the measured values. As the results, we found the quantitative relationship between mass of dye solution diffused into the tinted lens per unit area and dyeing time, and evaluated concentration distribution of dye in tinted lens, diffusion depth, etc. Conclusions: The dyeing mechanism of tinted lenses can be well described by diffusion theory.

• Journal of Korean Ophthalmic Optics Society
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• v.5 no.2
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• pp.151-155
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• 2000

We calculated a refractive index of the lens surface by measuring a spectral reflectance for a tinted time on manufacturing of the color lens. The longer a tinted time, the larger a reflectance and reflective index. The refractive index increased for a time up to the colorant's saturation state on the lens surface. The refractive index's change curve of blue color lens for a time depended on the Boltzmann growth curve. then we obtained the parameter's values of $n_{min}=1.482$, $n_{max}=1.497$, $t_c=11.53$ and $d_0=2.287$.

• Journal of Korean Ophthalmic Optics Society
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• v.4 no.2
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• pp.65-71
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• 1999

The optical absorption spectrum was measured of the tinted powder, tinted solution and tinted lens in the visible regions. The tinted powder was very different with color of tinted lens that the optical absorptions was so higher, composed of the thick-gray color. The optical absorptions of tinted solution were just a little appeared by the energy split of a transition metal ion, so constructed with each color space. The optical absorptions of the tinted lens were appeared with the energy split peaks to a transition metal ion, so its were affected by the color constructions. The optical absorption peaks of each lens were depend on the tinted time. Blue color lens had a lot of absorption in the short wavelength regions than 500nm, and had a little appeared in the high wavelength regions than 500nm. In case of a yellow color, the optical absorptions were appeared quite contrary to the blue color, so these colors had the opponent-colors each other. In case of green color, the optical absorptions had a high in the both edges, had a low in the middle regions. In the pink color, by the optical absorptions form of quite contrary to the green color it, these colors had the opponent-colors each other. In the brown color, the optical absorptions had a maximum values in the short wavelength regions, and it gradually decreased goes by the long wavelength regions.

• Journal of Technologic Dentistry
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• v.33 no.3
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• pp.219-224
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• 2011

Purpose: The current study focused on investigating color change of dental zirconia block with respect to the block coloring time. Methods: Three types of dental zirconia blocks(Zirtooth, Pearl-HT, D-Max) were tinted with coloring agent under four different time condition (0 minutes, 1 minutes, 10 minutes, 30 minutes). The quantitative evaluation of the tinted dental zirconia blocks was conducted with spectrophotometer. Results: The Zirtooth and D-Max blocks showed lower H value. The Pearl-HT blocks showed poor reflectivity(L value). Conclusion: The study of color change of zirconia block, which consists the substructure of all ceramic Crown, is applicable for deciding appropriate coloring condition when fabricating one layer ceramic Crown or double layer ceramic Crown.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.3D
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• pp.363-371
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• 2009

The purpose of this study is to verify the safety issue of the tinted vehicle based on the field study as well as the issue of the capacity reduction from the tinted vehicle. Through this study, an innovative experimental method to verify the issues was developed using RTK GPS receivers, and a data collection was conducted using the developed experimental method. Using the collected data, the effects of the ahead vehicle with the windows tinted on the traffic condition such as headways and acceleration noise were analyzed to test that the ahead vehicle with windows tinted too darkly affects the increasing vehicle maneuver as following the degree of tinting. This study was conducted as a frontier study and more studies, for example, full scale analyses considering various road and vehicle conditions need to be conducted in the future.

• Korean Journal of Materials Research
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• v.28 no.12
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• pp.685-690
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• 2018

In this study, a multifunctional ophthalmic lens material with an electromagnetic shielding effect, high oxygen permeability, and high water content is tested, and its applicability is evaluated. Metal oxide nanoparticles are applied to the ophthalmic lens material for vision correction to shield harmful electromagnetic waves; the pyridine group is used to improve the antibacterial effect; and silicone substituted with urethane and acrylate is employed to increase the oxygen permeability and water content. In addition, multifunctional tinted ophthalmic lens materials are studied using lens materials with an excellent antibacterial effect (2,6-difluoropyridine, 2-fluoro-4-pyridinecarboxylic acid) and functional (UV protection, high wettability) lens materials (2,4-dihydroxy benzophenone, 2-hydroxy-4-(methacryloyloxy)benzophenone). To solve problems such as air bubbles generated during the polymerization process for the manufacturing and turbidity of the lens surface, polymerization conditions in which the defect rate is minimized are determined. The results show that the polymerization temperature and time are most appropriate when they are $110^{\circ}C$ and 40 minutes, respectively. The optimum injection amount of the polymerization solution is 350 ms. The turbid phenomenon that appears in lens processing is improved by 10 to 95 % according to the test time and conditions.

• Journal of Korean Ophthalmic Optics Society
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• v.6 no.2
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• pp.37-46
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• 2001

In this study, We compared the properties of tinted and colored lenses with the standards m the ordinary optical properties, coloration, UV, IR and luminous transmittance, color acceptance for traffic signal, and chromaticity. The UV, lR and luminous transmittance was analysed in the range of 175 nm to 3000 nm by using a UV-Vis-IR spectrophotometer and was used in the synthesis of spectrum of various color lens. A experimental function was made from the slope obtained from the transmittance change as a function of coloration time. We could expect the ordinary optical properties and color acceptance for traffic signal of various color lenses with the requirements of US standard(ANSI Z-80.3).

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.5
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• pp.48-56
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• 2009

Regulation of Visible Light Transmission Percentage (VLT%) has been argued because it was known that the degree of darkness of tinted vehicle can affect to driving maneuver. Previously, it was proven that low level of VLT affects capacity reduction. But, due to lack of field data they could not analyze the effect of Car-Following model parameters. This study focuses on the effect of a tinted vehicle on following traffic flow. RTK GPS receiving data through field experiment analyzed based on headway distance, acceleration noise, sensitivity, and reaction time. As a result of analysis through GM 1st Model and 3rd Model, influence of following vehicle vary inversely with VLT and risk according as tinting of lead vehicle is third vehicle bigger than second vehicle. Also the results patterns of GM 3rd model include distance-headway are same with GM 1st Model. In the further need to research for influence analysis of traffic flow stability by the level of VLT.