Articles & Interviews

LFI 2018 | LiFi | Videos | May 14, 2018

LFI 2018 Award: LumEfficient's LiFi System

LFI 2018 | Beam Shaping | Award | Videos | May 14, 2018

LFI 2018 Award: Ledra Brands's Wireless Beam Shaping Downlight

Full-Color InGaN/AlGaN Nanowire Light-Emitting Diodes for SSL and Displays

III-nitride based nanowire light-emitting diodes (LEDs) have received a staggering response as a future candidate for solid-state lighting and full-color displays due to their unique and exceptional features including drastically reduced polarization fields, dislocation densities as well as the associated quantum confined Stark effect (QCSE) on account of their effective strain relaxation. Moab Rajan Philip and his supervisor Dr. Hieu P Nguyen in the Nano-Optoelectronic Materials and Devices Laboratory at the New Jersey Institute of Technology (NJIT) present astonishing ideas to fabricate and control the color emission of III-nitride nanowire LEDs via molecular beam epitaxy (MBE) growth techniques. The advantage of such LEDs and their characteristics is also discussed. Read more »

A Near Infrared Enhanced LED Lighting Approach

With the evolution of LED lighting, one topic has come more and more in the focus of the lighting industry: Human Centric Lighting (HCL). While HCL is not clearly defined, a common understanding is that this is light and lighting that supports health and the well-being of humans. Some new proposals are going beyond the approach of providing just visible light in adequate quality, but also to providing invisible radiation, UV and/or NIR that support health and well-being. Some research and the evolution of humans show clear evidence for positive effects of this kind of illumination. Scott Zimmerman, CEO at Silas, presents a new approach that adds NIR radiation to LED illumination. He explains the background of this idea, how it also improves the quality of visible light and discusses the health benefits. Read more »

Lifetime- and Economic Efficiency Simulation of LED Luminaires in Dymola/Modelica

Article from LpR 66 | page 40: The lifetime of an LED system is usually specified by the LM-80 report using the TM-21 method. Unfortunately, this value is solely valid for one specific application. Sebastian Hämmerle and Thomas Schmitt from the University of Applied Sciences in Vorarlberg developed a new open-source Modelica library for dynamic simulation of LEDs: The DynaLed library. The aim of the work was to evaluate the lifetime and the corresponding economic efficiency of LEDs in dynamic operation by means of the LM-80 report and according to the TM-21 calculation method. Furthermore, it should be possible to use the library for component dimensioning, e.g. the heatsink. The primary task was to develop simulation models which can be parametrized with manufacturer information, e.g. the datasheet, but still provide sufficient accuracy. As an application example an LED louvre luminaire (Article Code: 29001077) from LEDON Lamp GmbH was simulated utilizing the developed library. At the end, results from the lifetime- and the economic efﬁciency simulation were discussed. Read more »

Electrical Over Stress - How to Prevent an LED Failing Earlier than Expected

Article from LpR 66, page 70: While LEDS are, in general, very robust, failures still happen due to electrical over stress. Mauro Ceresa, EMEA Field Application Engineer Manager at Cree, will cover all aspects related to electrical over stress, or when an LED fails due to being subjected to a voltage beyond its specification limits. He will explain why the failure occurs and how to prevent this from happening. The article will explain the fundamental aspects of a good PCB layout design and how this is linked to the longevity of an LED. Read more »

Method and Circuit to Maintain Constant Light Output for LED Luminaires

Article from LpR 66 | page 80: It is difficult to accurately predict the lifetime or the light output degradation of LED luminaires. A Constant Light Output (CLO) operation is implemented in some of the latest drivers. However, there are many factors that require a different algorithm in terms of time rate and forward current values that are usually not taken into account. Prof.Dr.Eng. Stelian Matei, from the Photometry and Electromagnetic Compatibility Laboratory at Electromagnetica SA, proposes and explains a new method is maintaining the luminous flux over the lifetime of the LED luminaire, considering the luminaire global light degradation. Read more »

Blue Light Hazard - How Dangerous Is SSL Lighting?

Modern Solid State Lighting (SSL) technology has long since found its way into our normal working and living environments. In the early phases, consumers were most concerned with lifetime, pricing and light quality of the new LED-based light sources. Now they have become almost ubiquitous, a focus has been placed on safety. At the recent Light+Building exhibition topics such as photobiological safety and blue light hazard (BLH) were highly ranked among both visitors and exhibitors. Read more »

A Manufacturing Revolution for the LED Lighting Industry

LpR 67 Article, page 76: Western business investments in local manufacturing facilities have been declining since the 1980s due to partnering with contract manufacturers in Asia. But with increasing and hidden costs in Asia, companies are now seeking to bring manufacturing back home. A recent innovation, microfactories, could be the solution. Paavo Käkelä, Chairman and VP at EID Tech in Finland, presents the microfactory called Ant PlantTM. He explains this new, flexible manufacturing concept, shows how it works and how it is set up, and analyzes the benefits of local, automated production of LED lighting products as an alternative to contract manufacturing in Asia. Read more »

Resources | Tech-Talks Bregenz | Security | IoT | Jul 20, 2018

Tech-Talks BREGENZ - Ken Munro, Partner & Founder, Pen Test Partners

Today, hardly a day goes by that we don’t hear about security breaches, hacker attacks or comprimized data; often as a result of insufficient security measures. IoT does not really improve this situation and it is therefore necessary for the industry to take this threat seriously. This is especially true for the lighting industry, whose aim is to become the IoT enabler. Ken Munro, founder and partner at Pen Test Partners, is an ethical hacker whose passion is to hack any technical product he can get his hands on. Unfortunately, he succeeds way to often. LED professional talked with him about ethical hacking, where he sees the risks in various products, where the risks are hidden and what can be done to minimize them. Read more »

Abrasion in Transparent Lens Materials for Exterior Aircraft Lighting

Research, Engineering, and Quality Assurance at Kopp Glass, reports how Taber abrasion and high-velocity particulate testing was performed on three different jet aircraft lens materials, including: heat strengthened borosilicate glass (Kopp 9000), hard-coated polycarbonate, and aviation grade acrylic (Makrolon AR and Plexiglas II UVA). Read more »

Automatic Panel Level Transient Thermal Tester

LpR 67 Article, page 44:The thermal resistance junction in case is an important parameter for the reliability of LEDs because degradation of the LED is temperature driven. Simulation and testing has advanced over the past few years but transient thermal analysis (TTA), which is required to understand the thermal transfer path, is especially work and time consuming - and not automated. Gordon Elger, Professor for Electronic Manufacturing Technologies, Technische Hochschule Ingolstadt, and his co-authors, Maximilian Schmidt, Alexander Hans, and Dominik Müller, present and discuss an automatic panel level TTA tester. They explain the challenges and the solution and demonstrate the applicability of using LED test board-panels. Read more »

Roll-to-Roll UV Nanoimprint Lithography for Large-Area Nano- and Micro-Structuring of Flexible Substrates

LpR 67 Article, page 50: Cost and time-efficient methods for the fabrication of optical elements are highly desirable in the field of lighting. Imprinting optical structures in combination with large area fabrication turns out to become an effective approach in this regard. In particular roll-to-roll UV nanoimprint lithography (R2R-UV-NIL) has a large potential to set new benchmarks for the fabrication of miniaturized, low-cost and low-weight optics that can be applied in many fields of applications. In the following, the Joanneum Research Forschungsgesellschaft m.b.H team, Claude Leiner, Stephan Ruttloff, Dieter Nees, Anja Haase, Ladislav Kuna, Wolfgang Nemitz, Franz-Peter Wenzl, Christian Sommer, Barbara Stadlober and Ursula Palfinger, led by Paul Hartmann, demonstrates the maturity of the related process chain, combining optical design, direct laser lithography, step&repeat imprinting for shim fabrication and R2R reproduction. Read more »

LED Lighting Requires New Approaches in Optics

LpR 67 Article, page 88: Even though LED technology has been established LEDs still need new approaches in electronics, thermal management or optics to make complete use of their advantages. Marek Škereň, Chief Technology Officer of IQ Structures, explains how new optical devices, with the trade name Nanoptiqs, based on principles of diffraction are applied to achieve improved performance of white light illumination systems. This unique solution is based on full control over the modulation of material and geometric properties of the optical elements at a nano-level. A combination of complex transmission diffractive elements, with specially designed systems of micro-reflectors (produced using an innovative mass-production technique) is also presented as a promising flexible building unit for the construction of new generation luminaires. Read more »

Research Reports | Smart Lighting + IoT | Resources | LpR Article | Oct 12, 2018

Integrating Lighting in the Internet of Things

LpR 67 Article, page 80: Following the rapid penetration of LEDs, lighting now becomes integrated into the Internet of Things. Over the past three years a consortium of leading European companies worked on the OpenAIS project, partly funded by the EU within the Horizon 2020 program. Now showing the results, the consortium is working on a full size demonstrator. Ben Pronk, System Architect at Philips Lighting Research, and Frank van Tuijl, Project Manager at Philips Lighting show how OpenAIS creates an open ecosystem to enable a wider community to deliver the smartness of light and they explain how it is possible to adapt the system to cater to the diversity of people and demands. Read more »

Smart Lighting + IoT | Tech-Talks Bregenz | Resources | Outdoor Applications | Oct 12, 2018

Tech-Talks BREGENZ - Rico Kramer, Inventor, Founder & CEO, esave ag

In recent years there has been a strong focus on safe communication and controls in the lighting industry. The success story of esave ag, however, started much earlier, when Rico Kramer, the founder and CEO of esave, travelled to Taiwan due to his dissatisfaction with the quality of early LED replacement bulbs. What the former Apple employee learned there led to the development of the esave concept and its technology. In the interview he talks about his intentions, the beginning of esave, wireless technologies in general, system security, commissioning, system incompatibilities, markets and their peculiarities. Read more »

A Study on Aerosol Jet Printing in LED Module Manufacturing

LpR 68 Article, page 38: LED module manufacturing technologies have certainly improved over the last few years but the requirements have also increased. More components are packed on today’s modules causing additional thermal stress, and, at the same time, the demand for lower cost challenges module manufacturers. So the (re-) search for new materials and new manufacturing processes and manufacturing technologies is still on. Paul Hartmann, Director of the Institute of Surface Technologies and Photonics at the Joanneum Research Forschungsgesellschaft m.b.H., and his team, Andreas Rudorfer, Martin Tscherner, Christian Palfinger, Frank Reil, Franz P. Wenzl with Ioannis E. Seferis, Eugeniusz Zych from the Faculty of Chemistry of the University of Wroclaw investigated the opportunities of aerosol jet printing and proved the applicability for alternative ways of phosphor deposition and integration and to replace wire bonding of dies. Read more »

Resources | Commentary | Oct 19, 2018

UV-Light for Plant Development

Commentary from LpR 68: Since the development of the incandescent lamp, greenhouse farmers have been using electric light sources as a supplement to natural sunlight. Initially, light intensity was the major concern. Later, growers learned to manipulate plant development by altering the power distribution of the light spectrum for added value such as taste and appearance. Read more »

Laser Technology for Lighting Applications: A Review and Analysis of a Promising Technology

LpR 68 Article, page 44: LEDs are currently the dominating light source: efficient and cost effective. But LEDs also have some drawbacks. Another interesting technology developed slowly in the shadow of LEDs and has become an interesting solution for some specific applications: GaN based blue solid state laser devices. Although this technology offers some very interesting advantages, it also has challenges. Nicola Trivellin, Matteo Buffolo, Carlo De Santi, Gaudenzio Meneghesso, Enrico Zanoni and Matteo Meneghini from the University of Padova and its spin-off LightCube have been working toward the development of experimental systems and demonstrators and disclose their findings of the comparison between LED and LD systems. Read more »

Research Reports | Smart Lighting + IoT | Resources | LpR Article | Oct 19, 2018

Challenges of the Integration of Lighting Systems and Components in IoT

LpR 68 Article, page 50: Following the rapid penetration of LEDs, lighting is now becoming integrated into the Internet of Things. Over the past three years a consortium of leading European companies worked on the OpenAIS project, which was partly funded by the EU within the Horizon 2020 program, and now showing the results working at a full size demonstrator. In this follow up article to the introduction article of LpR 67, Ben Pronk, System Architect at Signify, and Stefan Verbrugh, Project Manager at Signify and Work Package leader in OpenAIS give deeper insight into the project. They explain the lighting specific challenges, describe the generic challenges for IP controlled lighting and present the approach to these challenges. They conclude by summarizing the findings from the pilot. Read more »