Trends

Trends

Technologies | Measurement | Jun 18, 2014
How Much Can the Color of Nominal CCT Vary?
How Much Can the Color of Nominal CCT Vary? The threshold at which a color difference becomes perceptible is defined by a MacAdam ellipse. A MacAdam ellipse is drawn over the color space in such a way that the color at its center point deviates by a certain amount from colors at any point along its edge. The scale of a MacAdam ellipse is determined by the standard deviation of color matching (SDCM). A color difference of 1 SDCM “step” is not visible; 2 to 4 steps is barely visible; and 5 or more steps is readily noticeable. Read more »
Technology | Apr 14, 2014
Developing Phosphor-Free White Light from Nanopyramid LEDs
Developing Phosphor-Free White Light from Nanopyramid LEDs Researchers in China have used nitride semiconductor nanopyramid structures to create light-emitting diodes (LEDs) with spectra that are similar to those provided by ‘white light’ LEDs with yellow phosphors [Kui Wu et al, J. Appl. Phys., vol115, p123101, 2014]. The researchers are at the Chinese Academy of Sciences’s institutes of Semiconductors and Mechanics, and Tsinghua University. A similar CAS/Tsinghua team previously reported such devices, using a polystyrene nanosphere mask to make holes for selective-area growth of nanopyramids. Read more »
Technology | Mar 19, 2014
New Technique Makes LEDs Brighter, More Resilient
New Technique Makes LEDs Brighter, More Resilient Researchers from North Carolina State University have developed a new processing technique that makes light emitting diodes (LEDs) brighter and more resilient by coating the semiconductor material gallium nitride (GaN) with a layer of phosphorus-derived acid. Read more »
White Paper | Technology | Mar 14, 2014
Quantum Materials Secures Los Alamos Thick-Shell Quantum Dot Technology to Increase Brightness
Quantum Materials Secures Los Alamos Thick-Shell Quantum Dot Technology to Increase Brightness Quantum Materials Corporation and Los Alamos National Laboratory's today announce Quantum Materials optioning Thick-Shell 'Giant' Quantum Dot patented technology with the potential of 10 to 100-fold improvement in solid-state brightness over conventional nanocrystal quantum dots (QD). High brightness leads to efficient use of materials and increased performance in electronic displays and solid state (LED) lighting. Read more »
Technology | Mar 11, 2014
Two-Dimensional Material Shows Promise for Optoelectronics
Two-Dimensional Material Shows Promise for Optoelectronics A team of MIT researchers has used a novel material that’s just a few atoms thick to create devices that can harness or emit light. This proof-of-concept could lead to ultrathin, lightweight, and flexible photovoltaic cells, light emitting diodes (LEDs), and other optoelectronic devices, they say. Read more »
Technology | Mar 11, 2014
Scientists Build Thinnest-Possible LEDs and Find It To Be Stronger, More Energy Efficient
Scientists Build Thinnest-Possible LEDs and Find It To Be Stronger, More Energy Efficient Most modern electronics, from flat-screen TVs and smartphones to wearable technologies and computer monitors, use tiny light-emitting diodes, or LEDs. These LEDs are based off of semiconductors that emit light with the movement of electrons. As devices get smaller and faster, there is more demand for such semiconductors that are tinier, stronger and more energy efficient. Read more »
Technology | Feb 24, 2014
A Roadmap to Efficient Green-Blue-Ultraviolet LEDs
A Roadmap to Efficient Green-Blue-Ultraviolet LEDs Scientists at the U.S. Naval Research Laboratory (NRL) have suggested a method that could significantly increase the efficiency of green-blue-ultraviolet light-emitting diodes based on GaInN/GaN, AlGaN/GaN, and AlInN/GaN quantum wells. Their approach could enable advances in solid state lighting and the creation of low threshold lasers and high power light emitting diodes (LEDs). Their research is published in the January 25 and November 26, 2013 issues of Applied Physics Letters. Read more »
White Paper | Technology
WHITE PAPER: Intelligent Over Temperature Protection for LED Lighting Applications
WHITE PAPER: Intelligent Over Temperature Protection for LED Lighting Applications LED lighting is becoming increasingly popular. It offers numerous advantages over conventional lighting, but there are still some issues. One is thermal management. Bernd Pflaum and Hakan Yilmazer from Infineon Technologies explain how LED driver ICs with smart over temperature protection help to increase lifetime and optimize system costs of LED lighting systems. Read more »
Technology | Feb 03, 2014
Target Group-Adequate Lighting of Shop and Retail Areas – New Retail Study by Zumtobel
Target Group-Adequate Lighting of Shop and Retail Areas – New Retail Study by Zumtobel n a laboratory study conducted by Zumtobel and Gruppe Nymphenburg it has been possi-ble for the first time to measure people's affective responses to various lighting scenarios in shops on an empirical basis. In the process, the lighting preferences of seven different groups of customers were analysed using a neuropsychological target group model. The findings of this study will help to develop lighting concepts for retail, to present goods per-fectly and to increase the customers' sense of well-being, thus making them stay in the shop longer. Read more »
White Paper | Technology | Jan 24, 2014
Cree Sets New Efficiency Benchmark with First 200 lpw LED Luminaire Prototype
Cree, Inc. raises the performance bar again with the demonstration of the first 200 lumen-per-watt (LPW) LED concept luminaire, which is more than twice the efficiency of the best linear fluorescent luminaires. The latest Department of Energy (DoE) projections* had estimated that this level of luminaire efficiency would not occur until after 2020, but Cree’s latest innovation has made this possible six years sooner than projected. The prototype leverages Cree’s vertical integration with innovations in LED chips, optics, materials technology and novel system design to deliver unprecedented performance. Read more »
Technology | Jan 14, 2014
Details of the 200lm/W TLED Lighting Technology Breakthrough Unraveled
Details of the 200lm/W TLED Lighting Technology Breakthrough Unraveled Philips is the world’s first to present a lamp prototype that produces a record 200 lumen per watt (lm/W) of high quality warm white light. This LED technology breakthrough brings energy-efficient LED light suitable for general lighting applications to a whole new level. The 200lm/W LED is expected to hit the market in 2015 and will ultimately be used in a wide range of applications. Read more »
Technologies | Electronics | LiFi | Jan 14, 2014
Enhanced Data Transmission for Li-Fi Communications using LED Lighting
Enhanced Data Transmission for Li-Fi Communications using LED Lighting Despite continuous improvements in wireless communication technology, e.g. 3G, LTE, 4G etc., a looming crisis is anticipated due to a lack of sufficient radio frequency bandwidth to support the growth in demand for data transmission, in the so called “Spectrum Crunch”. Visible Light Communication (Li-Fi) offers an economical solution. LED lighting is now widely deployed and can, in parallel with its primary function, also be used for wireless communication. Li-Fi demonstrates significant improvements in security, safety and capacity over radio frequency communication, and ease of deployment as compared with fibre-optic cable. The LED link is untethered, enables links with many mobile devices, and is independent of any one host. Improvements to the data rate achievable using LEDs as the transmitter allows services based on Li-Fi concept to outperform other communication modes. Read more »
Technology | Jan 14, 2014
Epistar Lab has Released the Infrared (850nm) Product with High Photoelectric Efficiency
Epistar Lab has Released the Infrared (850nm) Product with High Photoelectric Efficiency EPISTAR LAB is consistently devoting in LED research and design. Lots of forward-looking technologies have been well developed and now applied to LED chip production like novel transparent conductive thin film, compound mirror structure, and new EPI structure design for reducing the absorption of light. The abovementioned innovation technologies will raise the light extraction efficiency and LED performance. Read more »
White Paper | Technology | Dec 11, 2013
The Right Choice of Current-Limiting Resistors for Constant Voltage LED Drivers
The Right Choice of Current-Limiting Resistors for Constant Voltage LED Drivers While LEDs are mostly driven by current sources, there are also several applications where constant voltage drivers are used. In that case current limiting resistors are mandatory. But that raises the question which resistor is the right one to guarantee reliable and accurate control while not compromising efficiency. Phil Ebbert, VP of Engineering at Riedon Inc. explains what to take care of and how to determine the correct parameters. Read more »
Technology | Nov 15, 2013
ILT Introduces New ILT950 / ILT950UV Portable Spectroradiometer Systems
ILT Introduces New ILT950 / ILT950UV Portable Spectroradiometer Systems New ILT950UV / improved ILT950 is now equipped with a higher pixel CCD array for improved performance including nearly 50% more sensitivity and higher S/N ratio increased from 200:1 to 300:1 with larger quantum well depth. This most cost-effective, fully integrated, CCD-based spectroradiometer family is available with ISO17025 accredited calibration. Read more »
White Paper | Technology | Oct 23, 2013
Latest LRC Program Aims to Fine Tune Light for Greenhouse Crops & Medicinal Plants
Light and plants expert Tessa Pocock, Ph.D., recently joined the Lighting Research Center (LRC) at Rensselaer Polytechnic Institute as a senior research scientist, leading the development of a new plant physiology lighting program. Her research focuses on plant photosynthesis, and plant development and regulation by light for traditional greenhouse crops and the emerging field of medicinal plants. Read more »
White Paper | Technology | Oct 08, 2013
Two-Switch Flyback Solution for LED Street Lighting
Two-Switch Flyback Solution for LED Street Lighting LEDs provide high efficiency and long life compared to conventional lighting sources. Therefore, they are becoming first priority of lamp types to reduce energy consumption for internal or external lighting. This is also the case in street lightings where better efficiency and longer life are essential for less cost. A switching power supply designed to power up LED lamp should also have high efficiency and robustness to assure maintenance free lifetime as long as LED lamp. Resonant converters are one of the most popular power supply topologies here since their performance delivers increased power efficiency. LLC resonant converter has drawn attention thanks to its features such as high power conversion efficiency and low voltage stress on secondary rectifier. However, complicated design and high manufacturing cost of LLC resonant converters have been obstacles to fast time-to-market and cost reduction. Another problem of LLC resonant converter is large circulating current that is required to maintain zero voltage switching (ZVS). It causes relatively high power consumption at light load. LLC resonant converter also has potential failure issue when MOSFET with poor body diode performance is used. Two-switch flyback converter is proposed as an alternative solution to overcome the limitations of the LLC resonant converter. With additional switch on the high side, leakage inductance energy is clamped and recycled back to input to improve efficiency. The dissipative snubber circuit is no longer needed. A 120W rated switching power supply is designed utilizing two-switch flyback topology. The details of design specification and test results are presented. Read more »
White Paper | Technology | Oct 08, 2013
Why Pin Fin LED Coolers Perform Better Under Tilted Position?
Why Pin Fin LED Coolers Perform Better Under Tilted Position? For the experiment we compare the ModuLED 9980 with the LPF11180-ZHE. The ModuLED 9980 is a passive LED cooler from extruded aluminium with a diameter. of 99mm and a height of 80 millimeter, thermal resistance under vertical position 1.02°C/W. The LPF11180-ZHE is a passive LED cooler with pin fin structure with a diameter of 111mm and a height of 80mm, thermal resistance under vertical position 1.07°C/W. Read more »
White Paper | Technology | Aug 28, 2013
PI's New Reference Design, DER-350 for PAR38 LED Spotlight, Promises Excellent Dimming Performance with TRIAC Dimmers
PI's New Reference Design, DER-350 for PAR38 LED Spotlight, Promises Excellent Dimming Performance with TRIAC Dimmers Power Integrations, the leader in high-efficiency, high-reliability LED driver ICs, today announced a reference design for a dimmable PAR38 spotlight, developed in collaboration with Cree, Inc., a leading LED lighting company. The new reference design, described in DER-350, uses Power Integrations’ new LYT4317E, a member of the company’s LYTSwitchTM-4 family of single-stage drivers, along with Cree’s MT-G2 EasyWhite® LEDs. Read more »
Technology | Aug 27, 2013
“1 bin” Wavelength LED Wafer Is Demonstrated by Azzurro
“1 bin” Wavelength LED Wafer Is Demonstrated by Azzurro Azzurro LED Technologies announced the breaking news during a talk at ICNS-10 today. While showing production values of less than 3 nm wavelength uniformity, the 1.0 nm result came straight from development. The record 1.0 nm result demonstrates the capability to achieve “1 bin” GaN-on-Si LED wafers with Azzurro’s technology. Read more »
White Paper | Technology | Jul 31, 2013
Rensselaer Researchers Identify Cause of LED “Efficiency Droop”
Rensselaer Researchers Identify Cause of LED “Efficiency Droop” Rensselaer Polytechnic Institute researchers have identified the mechanism behind a plague of LED light bulbs: a flaw called “efficiency droop” that causes LEDs to lose up to 20 percent of their efficiency as they are subjected to greater electrical currents. Efficiency droop, first reported in 1999, has been a key obstacle in the development of LED lighting for situations, like household lighting, that call for economical sources of versatile and bright light. Read more »
Technologies | Thermal Management | Jul 30, 2013
NRL Researchers Discover Novel Material for Cooling of Electronic Devices
NRL Researchers Discover Novel Material for Cooling of Electronic Devices A team of theoretical physicists at the U.S. Naval Research Laboratory (NRL) and Boston College has identified cubic boron arsenide as a material with an extraordinarily high thermal conductivity and the potential to transfer heat more effectively from electronic devices than diamond, the best-known thermal conductor to date. Read more »
Technology | Jul 18, 2013
LDS Process Allows for New LED Lighting Product Layouts
LDS Process Allows for New LED Lighting Product Layouts Due to technical progress with LEDs, ever more luminous semiconductors are coming onto the market. However, in order to replace the conventional light bulb, there are still some obstacles to be faced. One of them is now being overcome: MID technology and laser direct structuring are being presented with interesting new concepts at the “International LED professional Symposium.” Read more »
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