scholarly journals Study of Exposure Uniformity of UV LED Exposure System for Wafer-Level Camera Lenses

2019 ◽  
Vol 9 (19) ◽  
pp. 4110 ◽  
Author(s):  
Kuo-Tsai Wu ◽  
Sheng-Jye Hwang ◽  
Huei-Huang Lee
Keyword(s):  
Experimental Data ◽  
Uv Light ◽  
Optical Simulation ◽  
Curing Process ◽  
Wafer Level ◽  
Exposure System ◽  
Light Emitting ◽  
Uv Led ◽  
Simulation Results ◽  
Standard Range

Wafer-level camera lenses are a very promising process for camera lens fabrication. However, there exist some problems with this technology, such as uneven exposure due to curing non-uniformities. In this study, an optical simulation was implemented to simulate the UV light-emitting diodes (LEDs) curing process. We design the LED arrangement, and then find the corresponding LED and adjust the LED power to improve exposure uniformity. The simulation results are very close to the experimental data, and the uniformity is also within the standard range.

scholarly journals Double-Sided Freeform Lens for Light Collimation of Light Emitting Diodes

2019 ◽  
Vol 9 (24) ◽  
pp. 5452
Author(s):  
Yong-Sin Syu ◽  
Chun-Ying Wu ◽  
Yung-Chun Lee
Keyword(s):  
Light Emitting Diodes ◽  
Uv Light ◽  
Design Parameters ◽  
Injection Molding Process ◽  
Light Sources ◽  
Molding Process ◽  
Light Emitting ◽  
Uv Led ◽  
Simulation Results ◽  
Freeform Lens

A double-sided freeform lens is proposed for collimating light emitted from light emitting diodes (LEDs). The surface profiles of the lens are mathematically characterized and precisely determined based on a point-source assumption and differential geometry theory. The proposed lens design method is straightforward, flexible, and effective. Moreover, the optical performance of the lens can be intuitively adjusted by tuning just a small number of design parameters. The simulation results showed that the proposed lens achieved an excellent collimating effect for a commercial ultraviolet (UV) LED. A prototype lens is fabricated in UV-grade poly(methyl methacrylate) material using a standard injection molding process. The light collimating effect of the lens/UV-LED assembly was measured experimentally and was shown to be in good agreement with the simulation results. The collimating angle at the half-energy level was equal to 1.88°. The performance of the UV-LED is thus comparable to that of conventional lithography UV light sources based on mercury arc lamps. Consequently, the proposed double freeform lens showed significant potential for photolithography applications within the industry.

Side-Emitting LED Lens Design for Generating Planar Lighting Source

2007 ◽  
Vol 364-366 ◽  
pp. 152-155
Author(s):  
Yi Ting Sun ◽  
Yu Nan Pao ◽  
T.H. Lin
Keyword(s):  
Horizontal Plane ◽  
Light Emitting Diode ◽  
Design Procedure ◽  
Normal Direction ◽  
Optical Simulation ◽  
Lens Design ◽  
Simulation Tool ◽  
Light Emitting ◽  
Led Light ◽  
Simulation Results

Side-emitting LED (Light emitting diode) modulation lens is proposed here for generating planar lighting source that can be applied in many fields like LCD backlight or general lighting. The light emitted form the LED light source will be modulated by the proposed lens by the mechanism of multi-refraction. The optical simulation tool ASAP was used during the design procedure. Optimal lens dimension was designed to module 70 percent of the emitting energy to the angle range from 70 degree to 110 degree, the angle was calculated from the normal direction of the LED horizontal plane to the direction of the emitting light. The lens prototype was also fabricated and the optical performance was measured to verify the simulation results. Finally, the comparison between the optical simulation and the experiment performances is also disclosed.

scholarly journals Transcriptome and metabolome analyses revealed that narrowband 280 and 310 nm UV-B induce distinctive responses in Arabidopsis

2021 ◽  
Author(s):  
Tomohiro Tsurumoto ◽  
Yasuo Fujikawa ◽  
Daisaku Ohta ◽  
Atsushi Okazawa
Keyword(s):  
Anthocyanin Biosynthesis ◽  
Uv Light ◽  
Current Model ◽  
Phenylpropanoid Pathway ◽  
Metabolic Responses ◽  
Uv Resistance ◽  
Light Emitting ◽  
Uv Led ◽  
Uv Leds ◽  
Led Irradiation

SUMMARYIn plants, the UV-B photoreceptor UV RESISTANCE LOCUS8 (UVR8) perceives UV-B and induces UV-B responses including synthesis of UV-B absorbing phenolic compounds such as anthocyanins. UVR8 absorbs a range of UV-B (260–335 nm). However, the responsiveness of plants to each UV-B wavelength has not been intensively studied so far. Here, we performed transcriptome and metabolome analyses of Arabidopsis using UV light emitting diodes (LEDs) with peak wavelengths of 280 and 310 nm to investigate the differences in the wavelength-specific UV-B responses. Irradiation with both UV-LEDs induced gene expression of the transcription factor ELONGATED HYPOCOTYL 5 (HY5), which has a central role in the UVR8 signaling pathway. However, the overall transcriptomic and metabolic responses to 280 and 310 nm UV-LED irradiation were different. Most of the known UV-B-responsive genes, such as salicylic acid, jasmonic acid, and defense-related genes, responded only to 280 nm UV-LED irradiation. Lipids, polyamines and organic acids were the metabolites most affected by 280 nm UV-LED irradiation, whereas the effect of 310 nm UV-LED irradiation on the metabolome was considerably less. Enzymatic genes involved in the phenylpropanoid pathway upstream in anthocyanin biosynthesis were up-regulated only by 280 nm UV-LED irradiation. On the other hand, no enzymatic genes downstream in anthocyanin biosynthesis were induced by the UV-LEDs, but rather, they were down-regulated by 310 nm UV-LED irradiation. These results revealed that the responsivenesses of Arabidopsis to 280 and 310 nm UV-B were significantly different, suggesting that UV-B signaling is mediated by more complex pathways than the current model.

Origins and suppressions of parasitic emissions in ultraviolet light-emitting diode structures

2010 ◽  
Vol 25 (6) ◽  
pp. 1037-1040 ◽  
Author(s):  
Weihuang Yang ◽  
Shuping Li ◽  
Hangyang Chen ◽  
Dayi Liu ◽  
Junyong Kang
Keyword(s):  
Quantum Wells ◽  
Uv Light ◽  
Light Emitting Diode ◽  
Multiple Quantum ◽  
Light Emitting ◽  
Force Microscopy ◽  
Uv Led ◽  
Hole Blocking Layer ◽  
To Come ◽  
P Type

The AlGaN-based ultraviolet (UV) light-emitting diode (LED) structures with AlN as buffer were grown on sapphire substrate by metalorganic vapor-phase epitaxy (MOVPE). A series of cathodoluminescence (CL) spectra were measured from the cross section of the UV-LED structure using point-by-point sampling to investigate the origins of the broad parasitic emissions between 300 and 400 nm, and they were found to come from the n-type AlGaN and AlN layers rather than p-type AlGaN. The parasitic emissions were effectively suppressed by adding an n-type AlN as the hole-blocking layer. Electroluminescence (EL) and atomic force microscopy (AFM) measurements have revealed that the interface abruptness and crystalline quality of the UV-LED structure are essential for the achievement of the EL emissions from the multiple quantum wells (MQWs).

scholarly journals Photocatalytic Degradation of 2-Chlorophenol Using Ag-Doped TiO2Nanofibers and a Near-UV Light-Emitting Diode System

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Ju-Young Park ◽  
In-Hwa Lee
Keyword(s):  
Phase Transformation ◽  
Photocatalytic Degradation ◽  
Uv Light ◽  
Light Emitting Diode ◽  
Sol Gel ◽  
Order Equation ◽  
Light Emitting ◽  
First Order ◽  
Uv Led ◽  
Diode System

This report investigated the photocatalytic degradation of 2-chlorophenol using TiO2nanofibers and Ag-doped TiO2nanofibers, synthesized using the sol-gel and electrospinning techniques, and an ultraviolet light-emitting diode (UV-LED) system as a UV light source. The crystallite size of the Ag-doped TiO2nanofibers was smaller than that of the TiO2nanofibers, because silver retrained phase transformation not only controls the phase transformation but also inhibits the growth of anatase crystallites. The activation energies for the grain growth of the TiO2nanofibers and the Ag-doped TiO2nanofibers were estimated to be 20.84 and 27.01 kJ/mol, respectively. The photocatalytic degradation rate followed a pseudo-first-order equation. The rate constants (k) of the TiO2nanofibers and the Ag-doped TiO2nanofibers were 0.056 and 0.144 min−1, respectively.

scholarly journals UV light-emitting diode (UV-LED) at 265 nm as a potential light source for disinfecting human platelet concentrates

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0251650
Author(s):  
Tomoya Hayashi ◽  
Kumiko Oguma ◽  
Yoshihiro Fujimura ◽  
Rika A. Furuta ◽  
Mitsunobu Tanaka ◽  
...  
Keyword(s):  
Platelet Transfusion ◽  
Uv Light ◽  
Light Emitting Diode ◽  
Platelet Concentrates ◽  
Platelet Surface ◽  
Light Emitting ◽  
Peak Emission Wavelength ◽  
Uv Led ◽  
Bacterial Transmission ◽  
Induced Aggregation

The risk of sepsis through bacterial transmission is one of the most serious problems in platelet transfusion. In processing platelet concentrates (PCs), several methods have been put into practice to minimize the risk of bacterial transmission, such as stringent monitoring by cultivation assays and inactivation treatment by photoirradiation with or without chemical agents. As another potential option, we applied a light-emitting diode (LED) with a peak emission wavelength of 265 nm, which has been shown to be effective for water, to disinfect PCs. In a bench-scale UV-LED exposure setup, a 10-min irradiation, corresponding to an average fluence of 9.2 mJ/cm2, resulted in >2.0 log, 1.0 log, and 0.6 log inactivation (mean, n = 6) of Escherichia coli, Staphylococcus aureus, and Bacillus cereus, respectively, in non-diluted plasma PCs. After a 30-min exposure, platelet counts decreased slightly (18 ± 7%: mean ± SD, n = 7); however, platelet surface expressions of CD42b, CD61, CD62P, and PAC-1 binding did not change significantly (P>0.005), and agonist-induced aggregation and adhesion/aggregation under flow conditions were well maintained. Our findings indicated that the 265 nm UV-LED has high potential as a novel disinfection method to ensure the microbial safety of platelet transfusion.

Ultraviolet Light Stable and Transparent Sol–Gel Methyl Siloxane Hybrid Material for UV Light-Emitting Diode (UV LED) Encapsulant

2015 ◽  
Vol 7 (2) ◽  
pp. 1035-1039 ◽  
Author(s):  
Jun-young Bae ◽  
YongHo Kim ◽  
HweaYoon Kim ◽  
YuBae Kim ◽  
Jungho Jin ◽  
...  
Keyword(s):  
Ultraviolet Light ◽  
Hybrid Material ◽  
Uv Light ◽  
Light Emitting Diode ◽  
Sol Gel ◽  
Light Emitting ◽  
Uv Led ◽  
Siloxane Hybrid Material

scholarly journals Photocatalytic Oxidative Degradation of Carbamazepine by TiO2 Irradiated by UV Light Emitting Diode

Catalysts ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 540 ◽  
Author(s):  
Zhilin Ran ◽  
Yuanhang Fang ◽  
Jian Sun ◽  
Cong Ma ◽  
Shaofeng Li
Keyword(s):  
Photocatalytic Degradation ◽  
Uv Light ◽  
Reaction System ◽  
Reference Method ◽  
Degradation Efficiency ◽  
Mixed Phase ◽  
Light Emitting ◽  
Led Light ◽  
Irradiation Intensity ◽  
Uv Led

Here, ultraviolet light-emitting diodes (UV-LED) combined with TiO2 was used to investigate the feasibility of carbamazepine (CBZ) degradation. The effects of various factors, like crystal form of the catalyst (anatase, rutile, and mixed phase), mass concentration of TiO2, wavelength and irradiation intensity of the UV-LED light source, pH of the reaction system, and coexisting anions and cations, on the photocatalytic degradation of CBZ were studied. The mixed-phase (2.8 g/L) showed the best degradation efficiency at 365 nm among three kinds of TiO2, wherein CBZ (21.1 µM) was completely oxidized within 1 h. The results of batch experiments showed that: (i) CBZ degradation efficiency under UV-LED light at 365 nm was higher than 275 nm, due to stronger penetrability of 365 nm light in solution. (ii) The degradation efficiency increased with increase in irradiation intensity and pH, whereas it decreased with increase in initial CBZ concentration. (iii) The optimal amount of mixed-phase TiO2 catalyst was 2.8 g/L and excessive catalyst decreased the rate. (iv) The co-existence of CO32−, HCO3−, and Fe3+ ions in water significantly accelerated the degradation rate of photocatalytic CBZ, whereas Cu2+ ions strongly inhibited the degradation process of CBZ. ·OH was found to be the main active species in the UV-LED photocatalytic degradation of CBZ. UV-LED is more environmentally friendly, energy efficient, and safer, whereas commercial TiO2 is economical and readily available. Therefore, this study provides a practically viable reference method for the degradation of pharmaceuticals and personal care products (PPCPs).

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