- 标题
- 摘要
- 关键词
- 实验方案
- 产品
过滤筛选
- 2018
- sodium lighting system
- modeling
- radiation curves
- LED lighting system
- software goniophotometer
- upper half-space
- light-emitting diode (LED)
- bulb's replacement
- lighting parameters at the workplace
- light sources for household
- Electrical Engineering and Automation
- VSB-TU Ostrava
- Poznan University of Technology
- Central Institute for Labour Protection - National Research Institute
-
OLED Lighting: The Differentiation Challenge
摘要： OLED lighting trails inorganic LEDs in almost every market segment, and therefore has to play catch-up. OLED displays are likely to lose this battle in the short and medium term, given that OLED displays are both under-performing and over-priced. The endgame, however, is promising because customers will buy OLED devices if the cost and performance gap substantially narrows. Lighting companies have little choice but to hedge their bets and stay the course with OLEDs or else risk losing out in the decades to come. In the meantime, these companies need to create stepping stones that generate at least limited cash flow and allow them to accumulate production/marketing experience. In fact, substantial innovation and pressure are building up in the value chain, which will ultimately enable a cost reduction in OLED lighting.
关键词： performance gap,OLED lighting,LED lighting,design attributes,cost reduction
更新于2025-09-19 17:13:59
-
Cyan phosphors for full-visible-spectrum lighting: shining new light on high-CRI white pc-LEDs
摘要： Nowadays, solid-state lighting sources based on white light-emitting diodes (LEDs) are extensively replacing the traditional illumination devices (incandescent and fluorescent lamps) due to their unique and appealing properties, such as high efficiency, high brightness, long working lifetime, small size, fast response time and eco-friendliness. Because of this, white LEDs have permeated deeply into many important sectors, including indoor and outdoor lightings, signals, displays and therapeutic applications. In order to make sure that white LEDs can provide artificial lighting source with good color quality and high vision performance, there are several important figures of merit that are used to characterize white LEDs: color rendering index (CRI), correlated color temperature, luminous efficacy of radiation and luminous efficacy.
关键词： full-visible-spectrum lighting,Cyan phosphors,high-CRI white pc-LEDs
更新于2025-09-19 17:13:59
-
Two-Phase Resonant Converter to Drive High-Power LED Lamps
摘要： This paper presents the design and modeling of a two-phase resonant converter that drives a LED lamp with a high-frequency pulsed current free of instabilities and flicker effect, fulfilling the recommendations of the IEEE PAR 1789-2015, so that it enables visible light-based communication at a 10 kB/s bit rate. The dynamic study of the converter takes into consideration the effect of the reflected impedance of the output filter on the AC side. In order to evaluate the dynamic response of the converter, a Spice model is defined. A 120 W prototype intended for street lighting applications has been built to validate the analysis and modeling.
关键词： phase shifters,lighting control,LED lamps,closed-loop systems,small-signal modeling,light sources
更新于2025-09-19 17:13:59
-
Novel efficient deep-red-emitting Ca2LuTaO6:Mn4+ double-perovskite phosphors for plant growth LEDs
摘要： Deep-red-emitting phosphors are important for fabricating light-emitting diodes (LEDs) toward applications in plant growth lighting. Herein, we reported on novel efficient deep-red-emitting Mn4+-activated Ca2LuTaO6 (CLT) double-perovskite phosphors. A series of CLT:xMn4+ (x = 0.1, 0.2, 0.4, 0.6, 0.8, and 1.0 mol%) samples were prepared by the conventional high-temperature solid-state reaction technique, and they were characterized by using X-ray diffraction (XRD), field-emission scanning electron microscope (FE-SEM), elemental mapping, photoluminescence excitation and emission, decay curves, CIE chromaticity coordinates, internal quantum efficiency (IQE), and temperature-dependent emission spectra. The CLT host crystallized in a monoclinic structure with space group of P21/n, and it contained an octahedral site of TaO6 for Mn4+ doping. Impressively, under 351 ultraviolet light excitation these CLT:xMn4+ phosphors exhibited bright deep-red emissions around 682 nm with CIE chromaticity coordinates of (0.7272, 0.2728) and full width at half maximum (FWHM) of 25 nm. Notably, the optimal CLT:0.2%Mn4+ sample possessed an IQE of 37% and good resistance to thermal quenching (I423 K/I303K = 47%). Considering the emission spectrum of CLT:0.2%Mn4+ deep-red-emitting phosphors matched well with the absorption spectrum of phytochrome PFR, the as-prepared CLT:0.2%Mn4+ phosphors showed great potential in plant growth LEDs.
关键词： Deep-red emissions,Phosphors,Luminescence,Double-perovskite,Mn4+,Plant growth lighting
更新于2025-09-19 17:13:59
-
From physics to fixtures to food: current and potential LED efficacy
摘要： Light-emitting diodes (LEDs) have enabled a historic increase in the conversion of electric energy to photons, but this is approaching a physical limit. The theoretical maximum efficiency occurs when all input energy is converted to energy in photosynthetic photons. Blue LEDs can be 93% efficient, phosphor-converted “whites” 76% efficient, and red LEDs 81% efficient. These improvements open new opportunities for horticultural lighting. Here we review (1) fundamental physics and efficiency of LEDs, (2) the current efficacy of LEDs, (3) the effect of spectral quality on crop yield, and (4) the potential efficacy of horticultural fixtures. Advances in the conversion of photons to yield can be achieved by optimization of spectral effects on plant morphology, which vary among species. Conversely, spectral effects on photosynthesis are remarkably similar across species, but the photons conventional (400–700 nm) may need to be modified. The upper limit of LED fixture efficacy is determined by the LED package efficacy multiplied by four factors inherent to all fixtures: thermal droop, driver (power supply) current droop, inefficiencies, and optical losses. With current LED technology, the calculations indicate efficacy limits of 3.4 μmol J?1 for white + red fixtures, and 4.1 μmol J?1 for blue + red fixtures. Adding optical protection from water and high humidity reduces these values by ~10%. We describe tradeoffs between peak efficacy and cost.
关键词： spectral quality,fixture efficacy,horticultural lighting,LEDs,photosynthetic photons
更新于2025-09-19 17:13:59
-
Improvement in Efficiency of LED Lighting System Based on Reduction of Voltage across MOSFET
摘要： In this paper, a LED dimming circuit powered by the KY converter, which is named after the ?rst capitals of two authors’ names: Kuo-Ing Hwu and Yeu-Torng Yau, is presented, which is controlled based on the ?eld-programmable gate array (FPGA). By a given dimming command and the proposed maximum gate voltage detector, the voltage across the MOSFET in the linear current regulator can be reduced so as to upgrade the e?ciency of the overall system. Aside from this, each LED string takes level dimming, and is powered by the KY converter, which has an output inductor and hence upgrades the life of the output capacitor. Furthermore, via some experimental results, the e?ciency based on the proposed control method is higher than that based on the traditional control one.
关键词： KY converter,LED lighting,E?ciency
更新于2025-09-19 17:13:59
-
Lighting in the third dimension: laser scanning as an architectural survey and representation method
摘要： This paper proposes tridimensional (3D) laser scanning to architects and lighting designers as a lighting enquiry and visualization method for existing built environments. The method constitutes a complement to existing lighting methods by responding to limitations of photometric measurements, computer simulation and HDR imagery in surveying and visualizing light in actual buildings. The research explores advantages and limitations of 3D laser scanning in a case study addressing a vast, geometrically complex and fragmented naturally and artificially lit space. Lighting patterns and geometry of the case study are captured with a 3D laser scanner through a series of four scans. A single 3D model of the entire space is produced from the aligned and fused scans. Lighting distribution patterns are showcased in relation to the materiality, lighting fixtures and day geometry and position of windows, walls, lighting sources. The point cloud model of the case study is also generated into a video format representing the entire building as well as different viewpoints. The study shows that the proposed method provides powerful visualization results due to the unlimited number of images that can be generated from a point cloud and facilitates understanding of existing lighting conditions in spaces.
关键词： LiDAR,Post occupancy,Site evaluation,Lighting,Architecture,Visualization
更新于2025-09-19 17:13:59
-
[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Paths for maximal light incoupling and excellent electrical performances in silicon heterojunction solar cells
摘要： This paper presents the implementation of an automated roll-to-roll ?uidic self-assembly system based on the surface tension driven self-assembly with applications in the ?eld of macroelectronics. The reported system incorporates automated agitation, web motion, component dispensing, and recycling. The process enables the assembly and electrical connection of semiconductor dies/chips in a continuous and parallel method achieves an assembly rate of 15 000 chips per hour and an assembly yield exceeding 99%, testing assembly of standard square-shaped dies, 300–1000 μm size. Scaling the system to any desired throughput is possible due to the parallel manner of self-assembly. The identi?cation and the modeling of the relationship between process parameters and forces have been studied and experimentally veri?ed by testing the effect of the web angle, agitation on assembly, and detachment rates. As an application, we demonstrate the realization of a solid-state lighting module. This particular application requires the assembly of a conductive multilayer sandwich structure, which is achieved by combining the introduced assembly process with a novel lamination step.
关键词： solid state lighting,Roll-to-roll,fluidic self-assembly,flexible electronics
更新于2025-09-19 17:13:59
-
[IEEE IECON 2018 - 44th Annual Conference of the IEEE Industrial Electronics Society - D.C., DC, USA (2018.10.21-2018.10.23)] IECON 2018 - 44th Annual Conference of the IEEE Industrial Electronics Society - Steady-state equivalent circuit of LED bulbs accounting for the current harmonics
摘要： Nowadays, the light-emitting diode (LED) bulb is one of the preferred choice in lighting system design. Electrical models of the LED lamps have to consider their nonlinear behavior involving current distortion on the mains. With this purpose, an equivalent electrical circuit emulating the current drawn by a LED Bulbs is carried out. In this work, different lamps have been tested under variable supply voltage. The comparison between the simulations performed by means of PSpice and the experimental measurements has highlighted that linear interpolation for the amplitude of each harmonic current, as function of the voltage on the main, provides a good estimation of the total current waveform.
关键词： LED Bulbs,power conversion,LED lamps,Current harmonics,equivalent circuits,lighting,total harmonic distortion,power quality
更新于2025-09-19 17:13:59
-
Towards white light emission from a hybrid thin film of a self-assembled ternary samarium( <scp>iii</scp> ) complex
摘要： A new samarium complex [Sm(hfaa)3(Py-Im)] (ML) was synthesized by utilizing hexafluoroacetylacetone (hfaa) and 2-(2-pyridyl)benzimidazole (Py-Im) as coordinating ligands. A single crystal X-ray analysis shows that in the solid-state the complex dimerizes through intermolecular hydrogen-bonding with N–H···O (2.127 ?) and N–H···F (2.576 ?) interactions. The complex in the solid-state displayed highly monochromatic brilliant red emission with Commission International de I’Eclairage (CIE) color coordinates of 0.6532; 0.3336, with a remarkably long luminescence lifetime (≈ 204.47 ± 4.043 μs) and a high intrinsic quantum yield (≈ 6.60 %). Furthermore, the complex in different organic media displayed color tunability from orange (CIE; 0.6071; 0.3568) to violet (CIE; 0.3634; 0.2144) with from 105.50 ± 0.143 – 14.27 ± 0.033 μs. Hybrid and flexible thin films obtained by doping different concentrations (1%, 2%, 4% and 6%) of the complex into the poly(urethane) (PU) polymer matrix also exhibited color tunability from violet (CIE; 0.3380; 0.2162) to light orange (CIE; 0.5666; 0.3408). White light emission from a 1% doped thin film of the complex was realized by changing the excitation wavelength. The new material could be a potential candidate for the fabrication of full-color display devices and for solid-state lighting (SSL) applications.
关键词： luminescence,white light emission,color tunability,samarium complex,solid-state lighting
更新于2025-09-19 17:13:59