LED professional Review (LpR) - Articles

Resources | LpR Article | Drivers | Automation | Special Applications | Feb 10, 2020

LED Driver for High Power Machine Vision Flash

LED Driver for High Power Machine Vision Flash Automation is nothing new and its demands are rapidly increasing, either in production or inspection. More sensors are used and many are based on direct or reflected light detection. Some work in the visible range and others work in the non-visible spectrum of light. LED lighting has become the standard in most applications as the solid-state light source offers numerous advantages over other lighting technologies. However, the LED lighting system is only as good as the peripheral components and LED drivers are one key element in many applications. Keith Szolusha, LED driver applications manager and Kyle Lawrence, associate applications engineer, identified the challenges for machine vision flash applications and propose a solution example with Analog Devices' LT3932 high speed LED driver. Read more »

Resources | LpR Article | Technologies | UV | Horticulture | Feb 10, 2020

Transparent Material Considerations for UV Optics in Horticultural Lighting Applications

Transparent Material Considerations for UV Optics in Horticultural Lighting Applications Advancements in UV LED technology have begun changing the horticultural lighting landscape. Research is still ongoing to discover the extent of benefits and best practices of using UV light in horticulture. Using optics in tandem with UV LED light systems can help reach performance goals and optimize growing. Although there are several UV- transmitting materials available, not all are equivalent or able to meet the requirements for UV applications. Justine Galbraith, glass engineer, and Sharayah Follett, market development manager at Kopp Glass, Inc. discuss the performance considerations of various UV-transmitting materials and how application challenges are addressed by integrating optical elements. Read more »

Resources | LpR Article | Research | LEDs | Manufacturing | Feb 05, 2020

Hermetic Polymer-Free White LEDs for Harsh Environments

Hermetic Polymer-Free White LEDs for Harsh Environments LpR 73 Article, page 42: AlGaInN-based white LED can easily achieve lifetimes of up to 100,000 h depending on junction temperature and current density. However, state of the art silicone encapsulated LEDs with powder-based phosphors reveal a strong dependence of field lifetimes on environmental conditions such as humidity, corrosive gas and air pollutant exposure. Dr. Michael Kunzer, Group Leader LED Modules at Fraunhofer Institute for Applied Solid State Physics and his colleagues, Ralf Schmidt, Andreas Zibold, Vasileios Georgiou-Sarlikiotis, Michael Arnold and Isabel Kinski propose luminescent ceramics as an interesting alternative to polymer-dispersed phosphors. This provides entirely new opportunities for the manufacturing of white LEDs. The authors explain the properties and advantage of this hermetic, light converting cap material and how to completely avoid polymers. Read more »

Resources | LpR Article | Research | Thermal Management | Testing | Measurement | Feb 05, 2020

A New Approach for Fast and Accurate Measurement of Light Emitting Diodes Junction Temperatures

A New Approach for Fast and Accurate Measurement of Light Emitting Diodes Junction Temperatures LpR 73 Article, page 48: Junction temperature of LEDs is one crucial parameter to being thoroughly observed. In this paper, Ahmet Mete Muslu, Onuralp Isil and Prof. Mehmet Arik from the Energy Efficient Electronics and Lighting Technologies Center (EVATEG), Department of Mechanical Engineering at the College of Engineering Ozyegin Universitywill at first describe the importance of Tj for LED systems including RGB and white LEDs. Then they will present techniques from literature and recently in-house developed novel methods and a new Junction Temperature Measurement Device (EVAtherm). Results in selected general lighting and automotive lighting applications will be demonstrated. Read more »

Resources | LpR Article | Special Applications | Artificial Intelligence | Dec 16, 2019

AI & Lighting

AI & Lighting LpR 73 Article, page 62: Recently, Artificial Intelligence has emerged as an evolutionary force in almost every industry, demonstrating its potential to radically change existing processes. In common literature, AI is interchangeably used with Machine Learning for which various tools have already become commonplace. Henri Juslén, D.Sc (tech.), Chief Future Illuminator, Omar Nasir, M.Sc (tech.), Data Scientist, and Javad Nouri, M.Sc, Data Scientist at Helvar Oy Ab discuss AI on the context of the lighting industry where the scope of applications of AI is similarly quite broad, impacting the various stages involved in the lighting life-cycle such as design, installation, commissioning and configuration. Read more »

Resources | LpR Article | Special Topics | LiFi | Dec 16, 2019

LiFi as a Paradigm-Shifting 5G Technology

LiFi as a Paradigm-Shifting 5G Technology LpR 73 Articles, page 54: There are many misconceptions about LiFi, a wireless communication technology that uses the infrared and visible light spectrum for high speed data communication. Prof. Harald Haas, Professor of Mobile Communications at the Institute for Digital Communications from the University of Edinburgh, will explain what Light-Fidelity (LiFi) is and argue why it is a 5th Generation (5G) technology. Peak transmission speeds of 8 Gbps from a single light source have been demonstrated, and complete cellular networks based on LiFi have been created. Besides discussing numerous misconceptions, the potential impact this technology can have across a number of existing and emerging industries will be explained as well as new applications that LiFi can unlock in the future. Read more »

Resources | LpR Article | Research | Thermal Management | Sep 23, 2019

Thermal and Optical Challenges for SSL in Automotive Applications

Thermal and Optical Challenges for SSL in Automotive Applications LpR 72 Article, page 50: Solid State Lighting changed the lighting environment in automotive lighting almost more than in the field of general lighting. While efficiency of the devices increased and every few weeks new improvements are reported, thermal management remains crucial and a critical part of the system. Umut Zeynep Uras, Ahmet Mete Muslu and Mehmet Arik, from the Energy Efficient Electronics and Lighting Technologies Center (EVATEG), Department of Mechanical Engineering, College of Engineering at Ozyegin University, and Fatih Goren from the FARBA Corporation, explain the dependencies between photometric, electrical and thermal parameters of an automotive lighting application. Read more »

Resources | LpR Article | Technologies | DC-Grids | Sep 18, 2019

LED Lighting Systems in Smart Buildings with DC Microgrids

LED Lighting Systems in Smart Buildings with DC Microgrids LpR 72 Article, page 60: While electric motors for ventilation and air-conditioning systems were already DC-based in the past, powerful IT systems, LED lighting systems, photovoltaic systems with batteries and charging systems for electro mobility are now increasingly being used in modern building environments. They all need direct current (DC). Therefore, an obvious step is to equip modern buildings with DC grids. Carsten Moellers from Abalight discusses a number of unresolved questions and presents possible solutions in this article. Read more »

Resources | LpR Article | Research | Micro-Optics | Aug 13, 2019

Semi-Empirical Characterization of Freeform Microlens Arrays

Semi-Empirical Characterization of Freeform Microlens Arrays LpR 72 Article - page 42: Microlens arrays (MLA) have been used for imaging and non-imaging applications for a long time as cost-effective solutions. Non-symmetrical beam shapes require more advanced non-symmetrical freeform microlens arrays (FMLA). The required FMLA molding tools convey a high cost and an iteration process is required for the final design. Oscar Fernández, Tamara Aderneuer, Rolando Ferrini from the Centre Suisse d'Electronique et de Microtechnique, CSEM, and Julien Duchene from ANSYS proposed a method to overcome these limitations based on 3D surface sampling, computer generation of a ray-traceable model and ray-tracing performance simulation and demonstrate feasibility for several commercially available freeform asymmetric thin-film diffusers. Read more »

Applications | Smart Lighting + IoT | Resources | LpR Article | Aug 13, 2019

Technologies for Shared Office Space

Technologies for Shared Office Space LpR 72 Article, page 66: Shared office spaces are gaining popularity as a flexible, resource-efficient and creativity-inspiring way to work. The dynamic nature of such office spaces requires building automation and lighting control solutions that can quickly be deployed and easily be adapted to new office layouts. Matthias Kassner, Vice President Product Marketing at EnOcean GmbH, takes a look at different connectivity architectures (wired, wireless, hybrid) and protocols (Bluetooth, ZigBee, EnOcean, PoE) to assess their usability and show how minimizing the need for maintenance is a key for increasing profitability of service-based offerings. Read more »

Resources | Human Centric Lighting | Light Generation | Health + Environment | LpR Article | Aug 01, 2019

Circadian-Friendly Light Emitters: From CCT-Tuning to Blue-Free Technology

Circadian-Friendly Light Emitters: From CCT-Tuning to Blue-Free Technology Common levels of blue radiation are sufficient to disrupt the circadian cycle, calling for blue-depleted emitters in the evening. Most current solutions employ low-CCT and suffer from poor light quality. Aurelien David, chief scientist at Soraa explains the melanopic lumen and its possible sources of inaccuracy related to the uncertainty in assessing the circadian action spectrum. In addition, he also discusses the concept of a blue-free emitter with minimal melanopic lumen at very low CCT and how such a spectrum providing a good light quality can be optimized. Read more »

Resources | LpR Article | Research | SciPiL | Medical | Jul 29, 2019

Flex LED Based Smart Light System for Healing of Chronic Wounds

Flex LED Based Smart Light System for Healing of Chronic Wounds LpR 71 Article - page 48: Chronic wounds are notoriously challenging to treat, because they do not follow the typical healing process or time-frame. The resulting burden is significant, affecting over 40 million patients. Blue light is known for its anti-microbial and anti-inflammatory effects in the initial stages of the healing process. David Kallweit, researcher at CSEM, reports about the joint development of a chronic wound treatment device with their MEDILIGHT partners, URGO RID, University of Heidelberg, SignalGenerix, Microsemi, Technical University of Berlin, and Amires. He furthermore shows how it works and discusses future prospects. Read more »

Technologies | Smart Lighting + IoT | Resources | LpR Article | Jul 29, 2019

Voice Controlled Lighting that Protects Privacy and Data

Voice Controlled Lighting that Protects Privacy and Data LpR 71 Article - page 54: Intelligent lighting systems undoubtedly offer high comfort and energy efficiency. But especially conventional voice control systems like Amazon Alexa, Apple Siri or OK Google, with connected lamps and lighting fixtures are also becoming targets for uninvited guests. The benefits and technology of a new approach offering local voice control and artificial intelligence will be explained by Genia Shipova, Director Global Communications at Snips. Read more »

Human Centric Lighting | Health | Resources | Health + Environment | LpR Article | May 27, 2019

Healthy Light - LED Technology for Health and Care Applications

Healthy Light - LED Technology for Health and Care Applications The right light, at any time during the day or night, is absolutely essential for health and well-being especially in health and care applications. Peter Haumer, Head of Technical Sales at Lumitech/Kiteo reveals why, besides full spectrum and high color rendering, mimicking real daylight conditions with extended daylight curves, a direct and an indirect component (CCT 1.800–16.000 K), are essential. The article discusses the benefits that can be derived from special colors for medical staff, patients and residents. Read more »

Resources | LpR Article | Research | Health | Medical | Human Centric Lighting | May 20, 2019

Implications for Human-Centric Lighting Design in Tropical Nursing Homes: A Pilot Study

Implications for Human-Centric Lighting Design in Tropical Nursing Homes: A Pilot Study Light synchronizes our physiological and psychological rhythms to the 24-hour rhythm of the ambient changes. For the elderly, adequate environments to compensate for increasing frailty and sensory loss are crucial. Dr. Szu-Cheng Chien, Assistant Professor at the Singapore Institute of Technology reports from a pilot study that aimed to explore HCL design strategies in nursing homes in Singapore. Pre-/post implementation user surveys and quantitative evaluations were conducted. Read more »

Human Centric Lighting | Wellbeing | Resources | Health + Environment | LpR Article | May 07, 2019

Melanopic Green - The Other Side of Blue

Melanopic Green - The Other Side of Blue LpR 71 Article - page 74: For years now, there has been a controversial discussion about the amount of blue light in LEDs. Medical studies have shown that, depending on the amount, blue light at night disrupts the circadian rhythm. As a result, warm white (<3000 K) light sources are often touted as a solution for street lighting as well. Ian Ashdown, P. Eng. (Ret.), FIES Senior Scientist at SunTracker Technologies discusses whether or not it is sufficient to only look at the CDT or if other wavelengths and aspects should be considered. Numerous medical studies have shown that exposure to blue light at night suppresses the production of melatonin by the pineal gland in our brains and so disrupts our circadian rhythms. As a result, we may have difficulty sleeping. It is therefore only common sense that we should specify warm white (3000 K) light sources wherever possible, especially for street lighting. - True or false? Read more »

Resources | LpR Article | Horticulture | Applications | Apr 17, 2019

Enriching Horticultural Lighting for Faster Growth and Better Crops

Enriching Horticultural Lighting for Faster Growth and Better Crops Horticulture lighting is no new lighting application, but it gained momentum with the introduction and evolution of LED lighting, and it is meanwhile one of the fastest growing markets in lighting. Dr. Richard Blakey, Application Engineer at Würth Elektronik eiSos, explains how LED-based horticultural lighting can deliver even bigger advantages for commercial growers by introducing additional wavelengths that increase photosynthetic response - like Würth Elektronik's new members of the WL-SMDC SMD Mono-Color Ceramic LED Waterclear family that is used as a reference in the article. Read more »

Resources | LpR Article | Special Topics | DC-Grids | Applications | Apr 15, 2019

48 VDC Integrated Drivers Offer New Options

48 VDC Integrated Drivers Offer New Options LpR 70 Article, page 102: In the telecommunication and IT businesses, especially, 48 VDC grids have become quite popular. This growing global trend to facilitate direct current (DC) power supply in building "microgrids" presents new opportunities for solid state lighting designers. TE's Lighting Industry Manager, Ron Weber, and Global Product Manager, Scott Hamilton, describe how LED lighting fixture designers can now design luminaires around a 48 VDC constant voltage input, available to take advantage of the benefits of a low voltage DC distribution grid in a building. Read more »

Resources | LpR Article | Technologies | Driver Modules | NFC | Apr 12, 2019

Standardized Programming of Lighting Components Using NFC Technology

Standardized Programming of Lighting Components Using NFC Technology LpR 70 Article, page 88: NFC programming of LED drivers is rapidly gaining popularity as a fast, feature-rich, flexible and easy method to set the operating characteristics of LED drivers inside luminaires. Arnulf Rupp, Chair of MD-SIG, describes how the MD-SIG specification for NFC programming of lighting components makes it easy for luminaire manufacturers to use NFC programming in a production line where multiple brand drivers are used one after the other. Read more »

Resources | LpR Article | Technologies | Controls | Wireless | Bluetooth | Apr 10, 2019

Bluetooth Mesh Protocol as Applied to Lighting

Bluetooth Mesh Protocol as Applied to Lighting Little more than one year ago, Bluetooth SIG released the Bluetooth Mesh standardization. Meanwhile, it has become widely adopted and is also one of the favorite systems for lighting controls. Russ Sharer, Vice President of Global Marketing and Business Development for Fulham, starts with an explanation of the Bluetooth Mesh protocol as applied to lighting control and defining its key elements. In a second portion of the article, he answers questions that lighting control evaluators could be asking their vendor. Read more »

Resources | LpR Article | Research | Environment | Apr 08, 2019

When Nights Are No Longer Dark: Effects of Artificial Light at Night on Agroecosystems

When Nights Are No Longer Dark: Effects of Artificial Light at Night on Agroecosystems In recent decades, artificial lighting has become an integral part of the modern world. While the use of artificial light at night (ALAN) greatly benefits people, it often has unintended, negative consequences for wildlife and ecosystems. In particular, the increasing use of LED lighting raises ecological concerns due to its high content of blue light, to which many organisms are sensitive. Dr. Maja Grubisic, Researcher at the Leibniz-Institute and Guest Lecturer at Free University Berlin discusses how ALAN can directly and indirectly influence agroecosystems, with potential consequences for food production and biodiversity. Given the current lack of integrative studies on this important topic, the better understanding of effects of ALAN in agroecosystems is urgently needed. Read more »

Resources | LpR Article | Research | Environment | Apr 03, 2019

Hazard or Hope? LEDs and Wildlife

Hazard or Hope? LEDs and Wildlife LpR 70 Article, page 52: The introduction and widespread uptake of LEDs as outdoor lighting has caused no small amount of concern amongst conservation biologists. The prevailing impression that LEDs are always blue-white is well founded as adoption of LEDs for streetlights were invariably high color temperatures and with the deterioration of phosphors the blue wavelengths penetrated even more. But LEDs do have characteristics that differentiate them from other light sources and may allow for the reduction of environmental effects of lighting on species and habitats: direction, duration, intensity, and spectrum. Travis Longcore, Assistant Professor at the University of Southern California's School of Architecture, sheds light on all these aspects. Read more »

Resources | LpR Article | Research | Health | Medical | Human Centric Lighting | Apr 01, 2019

Lighting and Emergency Dept. Clinician Wellness and Performance Improvement

Lighting and Emergency Dept. Clinician Wellness and Performance Improvement LpR 70 Article, page 38: Short wavelength ("blue") light is known for its strong impact on humans covering "visual" function, wellness and performance of humans. Lighting has been recognized to have an effect on clinician wellness and performance as well as the occurence of medical errors. In a pilot study, Octavio L. Perez, Ph.D, WELL Accredited Professional and Adjunct Researcher at the Department of Population Health Science and Policy, and his team of scientists and physicians, Christopher Strother, Richard Vincent, Barbara Rabin and Harold S. Kaplan, from the Mount Sinai Hospital, New York, systematically investigated if and how a radically new lighting concept could improve wellness and performance in an emergency department. Read more »

Research Reports | Resources | Smart Lighting + IoT | OpenAIS | LpR Article | Mar 29, 2019

User Evaluation of the OpenAIS Pilot Installation

User Evaluation of the OpenAIS Pilot Installation The OpenAIS project (2015-2018) has developed an open IoT lighting solution to enable a wider community to deliver the smartness of light, allowing easy adaptability to cater for the diversity of people and demands. The project is a cooperation between seven leading companies in the European industry and two academic partners: Signify, Zumtobel, Tridonic, Johnson Controls, Dynniq Belgium, NXP, ARM, Eindhoven University of Technology. Thomas van de Werff, Harm van Essen and Berry Eggen from the Eindhoven University of Technology describe the evaluation results of the pilot installation in a real office building in Eindhoven (The Netherlands), a former Philips factory. Read more »

Resources | LpR Article | Technologies | Thermal Management | Feb 18, 2019

Materials, Manufacturing and Technologies for Designing Passive Cooling Devices

Materials, Manufacturing and Technologies for Designing Passive Cooling Devices Until recently, incandescent bulbs and fluorescent lights were the dominant light sources. Today it’s the energy efficient, durable and, in the meantime, cost effective, LED. But to achieve these attributes appropriate cooling is still necessary and due to progress over the last few years the need for active cooling solutions is limited to a few high power applications as long as the material and technology is carefully chosen. John Broadbent, Managing Director at Columbia-Staver Ltd., describes the different technologies and materials and gives practical advice on how to find the right solution for an application. Read more »

Resources | LpR Article | Engineering | Optics | Feb 11, 2019

Additive Optics Design and Fabrication for Smart Lighting Systems and Tailored Project Solutions

Additive Optics Design and Fabrication for Smart Lighting Systems and Tailored Project Solutions Since its initial invention back in 2009, printed optics has come a long way in the lighting industry. Additive optics fabrication is a future proof methodology of rapid prototyping custom LED optics by means of digital manufacturing technologies. Marco de Visser, Luximprint’s Director of Marketing & Sales, breaks down the technology and explains how its features add value to the design and manufacture of smart lighting applications. From one of Luximprint’s preferred optical design partners Physionary, Ramon van der Hilst, Founder and Business Development Manager, and Suresh Christopher, inventor of the state-of-the-art “target-to-source” optics design software, explain the benefits of an optimized design process. Read more »

Technologies | LpR Article | Smart Lighting + IoT | Resources | Bluetooth | Jan 31, 2019

Qualified Bluetooth Mesh – Making Lighting Controls Future-Proof

Qualified Bluetooth Mesh – Making Lighting Controls Future-Proof LpR 69 Article, page 88: At Lightfair USA, Siegfried Luger met with Patrick Durand, Worldwide Technical Director at Future Lighting Solutions. One of Mr. Durand’s striking statements was: “Basically, what we need is to future-proof lighting control.” This was the first time that this important aspect was so clearly addressed by a representative of the industry. This led us to asking Mr. Durand to provide LED professional with a technical article to clarify the current situation, explain the technical background that led him to making that statement and to give an idea of which requirements a controls solution must fulfill to be truly future-proof. Read more »

Resources | LpR Article | Applications | Artificial Intelligence | Controls | Jan 31, 2019

Interactive Lighting Control is Opening New Doors for LED Applications

Interactive Lighting Control is Opening New Doors for LED Applications LpR 69 Article, page 98: Advancements in lighting control technology are allowing for sophisticated interactivity in LED mapping. These new technologies are bridging the gap between lighting control and AI, with the ability to analyze and map data input (such as audio) in real-time. Installations driven by interactive LED control technologies have their place in a variety of application spaces. Manjinder Benning, Founder and CTO of Limbic Media, explains how this new technology works, what its applications are, and what the future of interactive lighting control looks like – not only for end-users, but also for lighting designers and technicians. Read more »

Resources | LpR Article | Engineering | Lighting Simulation | Standardization | Jan 15, 2019

Rethinking the Photometric Data File Format

Rethinking the Photometric Data File Format With increasing computing power, engineering disciplines cannot be imagined without simulations anymore. In lighting, photometric data and electronic processing of this data has become one of the most important tools for luminaire design and lighting design. This data is today provided in IES LM-63 format, a format that meanwhile has come to its limits. P. Eng. (Ret) Ian Ashdown, Senior Scientist at SunTracker Technologies Ltd., explains why the time for a change to a new standard has come and discusses the newly proposed standard and its properties in detail: ANSI/IES TM-33 respectively UNI 1603054. Read more »

Resources | LpR Article | Research | SciPiL | Optics | Jan 15, 2019

Optical Designs to Improve LED Lighting Efficiency of Medical Endoscopes

Optical Designs to Improve LED Lighting Efficiency of Medical Endoscopes Lighting efficiency for endoscopic instruments has been deemed very poor, at only about 20%. While laboratory tests demonstrate that fiber optics bending is not problematic, optical simulations clearly show that lighting efficiency is strongly limited by the Étendue. Because of strong geometrical constraints in the light coupling area of an endoscope system, only a radical new optical design can provide significant improvement. Alexander Gaertner and Paola Belloni from the Faculty of Mechanical and Medical Engineering and the Steinbeis Transferzentrum Lichttechnik und Beleuchtungsoptik at the University Furtwangen discuss these issues and propose possible approaches. Read more »

FEATURED

WHITE PAPER - Why an EMI Filter in Your Lighting Application is a Must

WHITE PAPER - Why an EMI Filter in Your Lighting Application is a Must From high voltage ballasts for fluorescent bulbs to LED accent lighting, advancements in lighting technologies for industrial and domestic markets have led to a surge in EMI concerns. Luckily, mitigating EMI early on, avoiding costly product redesigns and delays, can be as simple as ... Read more »

FEATURED

Precise Measurement of UV Light Sources for Disinfection

Precise Measurement of UV Light Sources for Disinfection UV radiation encompasses a very wide wavelength spectrum between 10 and 400 nm and is subdivided in ISO Standard 21348 into three ranges. The UVC range between 100 and 280nm is currently extremely relevant for air and water disinfection for combating COVID-19. Since the outbreak of the pandemic ... Read more »

EDITORIAL

Signify: New EU Ecodesign and Energy Labeling Regulations Are Met

Signify: New EU Ecodesign and Energy Labeling Regulations Are Met Signify (Euronext: LIGHT), confirms that its leading lighting portfolio will meet the new EU Ecodesign and Energy labeling regulations, which will affect all lighting products in the EU Member States from September 2021 onwards. The new regulations are representative of the enormous transition that ... Read more »

EDITORIAL

New DLC Report: Interoperability for Networked Lighting Controls

New DLC Report: Interoperability for Networked Lighting Controls Interoperability for Networked Lighting Controls explores the current interest in networked lighting controls (NLC) and the benefits various stakeholders can attain from championing interoperable systems. The report details three specific and actionable use cases and explains why interoperability ... Read more »

EDITORIAL

Tech-Talks BREGENZ - Prof. Ruairí O'Brien, Founder of Ruairí O'Brien Lighting Design

Tech-Talks BREGENZ - Prof. Ruairí O'Brien, Founder of Ruairí O'Brien Lighting Design Ruairí O'Brien, associate professor and head of the Architecture and Visual design department at the German University in Cairo and CEO of Ruairí O'Brien. Architektur. Licht Raumkunst, surprised and delighted the audience with his lecture at LpS 2016 when he talked about allowing darkness. He ... Read more »