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LED professional Review (LpR) - Articles

Smart Lighting + IoT | Outdoor Applications | Resources | LpR Article | May 16, 2017

Enabling Total Control in the Next Generation of Outdoor Lighting

Outdoor lighting is certainly one of the applications with the greatest potential for energy saving. Although many approaches are discussed, they all end up with a smart lighting solution. In order to accommodate this, intelligent software and electronics are required as well as standardized, robust interfaces. Ronald Weber, Global Industry Manager, Building Automation and Benjamin Nelson, Business Development Manager, Intelligent Buildings, both from TE Connectivity, present a Zhaga compliant solution. Read more »

Resources | LpR Article | Quality | Applications | May 16, 2017

Technology Challenges in Professional Tunnel Lighting Applications

The guide for tunnel lighting CIE 088:2004 is the most established international standard for the illumination of road tunnels. However, Switzerland’s ASTRA (Bundesamt für Strassen) and the ASFINAG in Austria both provide guidelines that go well beyond these requirements. Maximilian Herzig, Product and Key Account Manager Lighting at SWAREFLEX GmbH shows solutions to satisfy these requirements and explains why the commonly used value of "lumen per watt" is not a perfect method of evaluating system performance and efficiency. Read more »

Variability in LED Production and the Impact on Performance

LEDs are subject to manufacturing deviations, which have an impact on the end product. Benoit Bataillou and T. Merelle, guest authors from Pi Lighting, review the surprisingly large impact on LED performance and light quality. They used traditional as well as modern indicators like CRI and TM-30 as well as the latest circadian indices to measure. The results are explained by spectral modeling and a variability study. They show the large impact on CRI, even with small deviations inside the same bin. Read more »

Smart LED System in Package through Wafer Level Integration Approach

It is believed that LEDs will dominate all lighting applications in the near future. Integration and packaging are the two critical issues that, if resolved, will enable efficient and reliable solutions for lighting requirements. Z. Kolahdouz, H. van Zeijl, and G. Q. Zhang from the Institute of Microsystems and Nanoelectronics (DIMES) at the Delft University of Technology, and M. Kolahdouz from the Thin Film Laboratory and Nano-Electronics at the Department of Electrical and Computer Engineering of the University of Tehran show that wafer level packaging is a promising method to ensure lower cost, higher scale, and superior yield. A new integration approach of a smart unit of LED lighting is introduced: LED System in Package (SiP). Read more »

Resources | LpR Article | Research | Optics | May 16, 2017

Ultrathin Direct-Lit LED Module with Beam Shaping Thin-Film Optics

Thin, high quality, LED light panels are still a challenge. LED professional’s scientific partner, CSEM, investigated and developed a new approach with its partners, GAIKER-IK4 and BASF-SE. The authors, Oscar Fernández and Rolando Ferrini, from CSEM, Leire Barruetabeña, from GAIKER-IK4, and Sorin Ivanovici from BASF SE, present a solution that uses low-cost and spectrally poor, ultra-cool white LEDs in conjunction with optical color conversion foils, to transform the output to a high-quality light. They also describe a combination with added lime and red LEDs for a color tunable solution. Read more »

Resources | LpR Article | Research | Light Conversion | May 16, 2017

New Glass-Based Phosphors for White Light-Emitting Diodes

Phosphors were always the key component of high quality white LED light. With the increased effîcacy and the higher power capabilities of blue high power LEDs, the phosphors become even more important for reliability, color consistency and overall light quality. Franziska Steudel, Florian Wagner, A. Charlotte Rimbach, Bernd Ahrens, Peter W. Nolte and Stefan Schweizer, scientists at the Fraunhofer Application Center for Inorganic Phosphors, a Branch Lab of Fraunhofer Institute for Microstructure of Materials and Systems IMWS, investigated different glass and ceramics based phosphors for white LEDs. Read more »

Tech-Talks BREGENZ - Philipp Henrici, President and Managing Director at BJB

It’s unusual for a lighting company to be older than electric lighting itself, but BJB in Arnsberg, Germany is celebrating their 150th anniversary this year. LED professional’s Siegfried Luger and Dr. Günther Sejkora spoke with Philipp Henrici, the President and Managing Director at BJB about disruptive technology changes, starting from petroleum lamps to electric lighting as well as conventional lighting versus solid state lighting. They also touched on the subjects of chances and drawbacks of LED component standardization, modular systems and automated production processes. Read more »

A Lighting Designers Relativity of Light Performance

The LED will always be the superstar of light sources. Their precise and clear lighting possibilities have been targeted by lighting planners and architects for the past ten years. The coming years will see the performance of the LED getting progressively closer to the spectrum of daylight and that will, in turn, generate biologically effective LEDs that are even higher in contrast and promise a new kind of feel-good light. Read more »

CIE Fosters Co-Ordination of Global Research and Standardization on Temporal Light Modulation

Dr. Jennifer Veitch, recently convened the CIE Stakeholder Workshop for Temporal Light Modulation Standards for Lighting Systems. Below is the exclusive report she provided on the workshop findings and the attitude of the CIE towards this important issue. Read more »

Roadway Lighting Optics for Environment Adaptive Spatial Light Distribution

Roadway lighting for different environmental conditions is a challenging task. But even more challenging is to find a solution with outstanding task efficiency for both dry and wet tarmac surface conditions. The drawback of these types of solutions is that they are usually made up of two different lighting systems. Since the two systems are not usually used to an equal degree, they age at a different rate. Solving this problem is very complex. Viktor Zsellér, PhD student, and Dr. Krisztián Samu, Senior Lecturer, both from the Budapest University of Technology and Economics, propose an optical system that solves this conundrum. Read more »

Resources | LpR Article | Applications | Horticulture | Mar 13, 2017

SSL Growth Strategies and USDA Corn Breeding Objectives

The SSL horticulture lighting industry has become one of the fastest growing branches of lighting worldwide. Much research has already been done in regards to horticultural SSL technology and continues to be rigorously explored. While most other inputs for plant growth are monitored and controlled based on plant needs, it is still common practice for light control to be rudimentary (on/off). Brandon Newkirk, Marketing Communications Manager at LumiGrow Inc., gives a short overview on the current state of dynamic LED lighting with a focus on USDA corn breeding trials and objectives. Read more »

Resources | LpR Article | Applications | Animal Farming | Mar 13, 2017

Bio-Effective Lighting for Humans, Livestock and Plants

Mood lighting is often misleadingly interpreted as HCL. But HCL is much more because it includes biologically effective light that is beneficial or dangerous, depending on the correct application. While the relevant parts of the radiation spectrum may differ, light is also biologically effective for plants and animals and it is used to achieve well-defined effects. Volker Neu, General Manager LED at Vossloh-Schwabe Lighting Solutions, presents examples, discusses similarities and differences between humans, animals and plants in respect to the relevant spectra, and scrutinizes possible consequences. Read more »

Resources | LpR Article | Technologies | Thermal Management | Mar 13, 2017

Looking for the Best Thermal Solution for CSP Module Designs

Chip Scale Package (CSP) LED technology is not new but while it has been used for a while in TV backlighting applications, it is relatively new to lighting applications. In many respect CSPs are a new world for lighting module manufacturers as they are smaller, usually don’t have any ESD protection, have different light distribution, and, last but not least, have a smaller heat dissipation area. The latter asks for re-thinking the traditional thermal design for modules. Dr. Giles Humpston, Applications Engineer at Cambridge Nanotherm, explains in detail why CSP LEDs present a significant thermal challenge for module designers and outlines some fundamentals in calculating the thermal flow required to keep CSP LEDs cool. Read more »

A Standardized Open Platform Is Key to the Future of Smart Lighting System Design

The LED industry’s pace of evolution is more prevalent now than it has ever been. The shift from traditional standalone LED bulb lighting to fully connected digital LED systems is upon us and is transforming the industry for the better. For years, LED manufacturers have focused on driving cost down rather than focusing on improving quality, but with the advent of connected lighting, smart lighting and human-centric lighting, the focus has shifted back onto quality. Dr. Kyeongik Min, Principal Engineer in the LED business team at Samsung Electronics, explores how the LED industry can accelerate the transition from standalone lighting to fully connected lighting through a deeper understanding of current market trends. Read more »

Lead Halide Perovskite Nanocrystals - A New Promise for Light Emitting Devices

Perovskites structured materials have attracted scientific and technological interest in the last four years. Recent studies have shown that these materials could deliver high photoluminescence efficiency at any desired wavelength in the visible spectrum. Mirko Prato and Francesco Di Stasio, Technologist and Marie Curie Fellow of the Institute of Photonic Sciences at the Istituto Italiano di Tecnologia focus on the application in single color LEDs (red, green and blue) and white emitting color-converting layers. They discuss what limits their application in everyday technology like toxicity and limited functional stability. Read more »

Tech-Talks BREGENZ - Norman Bardsley, President of Bardsley Consulting

Professor of Physics, Dr. J. Norman Bardsley, has become an internationally recognized expert in SSL through his activities as an advisor for DoE and ISA. Dr. Bardsley has a profoundly deep knowledge and understanding of OLED technology, which includes the manufacturing thereof, cost structures and research activities. LED professional talked with him about the different aspects of OLED lighting technology and asked for his thoughts on future perspectives. Read more »

From Component to System, Andreas Weisl, CEO at Seoul Semiconductor Europe GmbH

The history of Light-Emitting Diodes (LED) is quite short compared with some other electronic device industries. However, it has changed and revolutionized the entire world of light within a very short period of time. The history of Light-Emitting Diodes (LED) is quite short compared with some other electronic device industries. However, it has changed and revolutionized the entire world of light within a very short period of time. Read more »

LpR Article | Research | Jan 26, 2017

Lifetime Calculation of White HP-LEDs from 16,000 Hours Aging Data

Accurate models are a relevant tool for correctly calculating the so-called useful lifetime predictions of LED lighting products. Until recently, only the efficiency decay and related reduced lumen output was taken into account. Max Wagner, Research Assistant, TU Darmstadt, and his co-authors, Alexander Herzog, Hristo Ganev, and Prof. Tran Quoc Khanh asked themselves if there are other lifetime limiting factors that can be modelled and predicted. Their findings showed that color shift might be more critical and in the following, propose a method to simulate and predict this behavior. Read more »

Technical Aspects Regarding the Equipment of Show Caves with Modern LED Systems

Caves have an almost magical attraction over people, drawing them again and again into their depths. The first electrification started in the 19th century, culminating in today’s digitalization and “LEDification”. Vladimir Vashkevich, Technical Manager at Cave Lighting CL GmbH & Co KG, describes the tough requirements on luminaires and the whole installation. He explains the advantages for the operators and the ecosystem and finally discusses solutions, practical examples and future prospects. Read more »

Enhancing the LED Experience - UI & UX as Success Factors for IoT Based Lighting Controls

As LED lighting systems become part of the Internet of Things, getting the interface right is essential if all of the potential benefits are to be realized. Karl Jónsson and Christian Moormann of Tridonic explain why UI and UX are crucial for the acceptance of the “Internet of Things”, give design hints and describe what this type of user interface that accommodates scalability, simplicity and ease of handling could look like. The authors also discuss examples based on a system Tridonic pre-launched in 2016. Read more »

Swiss Photonics Workshop on Intelligent Efficient Solid State Lighting

Swiss Photonics held their Swiss Solid State Lighting Workshop in the Pantheon at Muttenz near Basel on December 12th of last year. The ambience of the automobile museum was perfect! The program covered a broad range of topics including Human Centric Lighting, Internet of Things and the results of the LASSIE project (Large Area Solid State Lighting Intelligent Efficient: A 7th Framework Program for Research and Technological Development). In the following article, Arno Grabher-Meyer, Editor-in-Chief at LED professional, summarizes the highlights. Read more »

LuxLive and SILE Sharpen Focus on End-Users

On November 23rd and 24th, as in previous years, LuxLive was held in the Excel Center close to London’s City Airport. This year, for the second time since the merger of Revo Media and Pennwell, LuxLive and Strategies in Light Europe were co-located. Arno Grabher-Meyer, Editor-in-Chief at LED professional, summarizes his impressions of the event, picking out the more technical oriented lectures held in the different "arenas". Read more »

Resources | LpR Article | Tech-Talks Bregenz | Light Conversion | Jan 26, 2017

Tech-Talks BREGENZ - Dr. Rubén D. Costa, Group Leader, University of Erlangen-Nuremberg

Light quality and costs of LED systems remain an important topic even though big improvements have been made. New approaches are always welcome and stir up hope. It was exactly a year ago that LED professional published the article by Dr. Rubén D. Costa, Liebig Group Leader at the University of Erlangen-Nuremberg, about his amazing new „Bio-Hybrid“ white LED approach. At LpS 2016 his presentation on the latest research results and improvements also won him the LpS 2016 Scientific Award. Consequently, we just had to invite him to a Tech-Talk Bregenz! In the interview below he gives us some interesting background information about why he started the project, how it works and what he expects in the future. He also gives us his views on LEDs and lighting in general. Read more »

Commentary | Smart Lighting + IoT | Resources | LpR Article | Jan 26, 2017

Lighting Up Smart Cities, Dr. Wu Chou, Huawei

Although streetlights have been associated with cities for more than a thousand years, they are rarely considered for functions other than luminary purposes. One of the distinct features of streetlights is their geographic location. In particular, streetlights follow the roads and streets that are the arteries of the city, and at night they outline the city so it can be seen from many miles away. Read more »

Trends | Smart Lighting + IoT | Resources | LpR Article | Nov 28, 2016

Smart Lighting Market and Technology Trends

Intelligent lighting technology that enables its users to control lighting through connected devices such as smart phones or remote controls is a big topic in the industry. A new report sheds light on different aspects of this business including drivers, restraints and opportunities. Jasmine Hinduja, Research Analyst at The Insight Partners, summarizes the major findings and how the trend to intelligent systems affects the companies regarding technology skills and strategies. Read more »

Trends | Smart Lighting + IoT | Resources | LpR Article | Nov 28, 2016

Flicker: Standards and Test Methods

Much has been written and said about Temporal Light Artifacts (TLAs). What is essential about TLAs is that they consist of flicker and/or stroboscopic effects induced by a light stimulus whose luminance or spectral distribution fluctuates with time and causes undesired changes in visual perception for an observer in a certain environment. Walter Parmiami, Senior Engineer at UL International Italia S.r.l., discusses the current status of regulations and measurement standards and proposes a certification to help manufacturers to generate user confidence, and consumers and specifiers to find the right product for an application Read more »

Resources | LpR Article | Technologies | Optics | Nov 28, 2016

Structured Glass Light Guides for Efficient Lighting

Glass injection molding technology (GIMT) for precision glass optics is a relatively new manufacturing technology. This expertise allows for producing efficient glass optics for LED lighting applications with special properties like undercut geometry or mounting flanges. A lot of progress has been made since it was introduced. Christian Passlick, Optical Engineer at Auer Lighting, shows how this improved technology supports making state-of-the-art light mixing structures for RGB/RGBW LED systems. Read more »

Comparing New Dielectric Materials for Chip-on-Board LED Packages

Thermal management is still one of the most challenging issues in solid state lighting. With the increased application of COB LED technology, the portion of the dielectric material on the overall thermal resistance has become an important topic. Different solutions and new materials have been proposed over the last few years. Hui Zhang, Max Wagner, and Prof. Tran Quoc Khanh from the Laboratory of Lighting Technology at the Technische Universität Darmstadt compared different materials and present the results of their extensive research. Read more »

Event Post Show Report | LpR Article | Nov 28, 2016

LpS Event: A Perfect Platform for New Ideas and Innovations

Like in any “Light + Building year”, there is always the question of which, if any, other shows one should attend in Europe. The visitors to the LpS 2016 knew right from the start that they had made the right decision with Bregenz. As always, the show attracted attendees, exhibitors and visitors from all over the world. Arno Grabher-Meyer, Editor-in-Chief at LED professional summarizes the highlights and shows how the newly introduced program points were received. Read more »

LpR Article | Research | Nov 28, 2016

The Perspective of Bio-Hybrid White Light-Emitting Diodes Based on Rubber-Like Down- Converting Coatings

At first, white LED technology seems to be mature. But in truth, the technology is still far from being perfect and research on all LED materials and components is ongoing. At the LpS 2016 the research of Rubén D. Costa, Lukas Niklaus, Katharina Weber and Prof. Uwe Sonnewald from the University of Erlangen-Nuremberg (FAU) was honored with the LED professional Scientific Award. These authors investigated the use of organic light conversion materials for white LEDs. Their research shows that these bio-hybrid white LEDs could lower costs and improve light quality. The article describes the current status of the research and future perspectives. Read more »