LED professional Review (LpR) - Articles

LpR Article | Research | Aug 29, 2016

Quality and Health Aspects of LED Lamps for the European Residential Lighting Market

Quality and Health Aspects of LED Lamps for the European Residential Lighting Market Because of shortfalls in regards to consumer information about high quality, energy efficient, substitute products for incandescent lamps, there has been a significant amount of irritation on the side of the consumer. As part of the Intelligent Energy Europe Program of the European Union, Prof. Dr. Georges Zissis from the Paul Sabatier - University Toulouse and his team investigated 370 LED lamps. All relevant parameters of 95 different lamp types from store shelves in 12 European countries were measured and evaluated regarding quality and health issues. Read more »

LpR Article | Aug 25, 2016

LED Lamps Recycling Technology for a Circular Economy

LED Lamps Recycling Technology for a Circular Economy While having a long propagated lifetime, LED lighting products, especially lamps, have a foreseeable end of life. And since they contain many valuable elements they practically beg to be recycled. However, like other highly integrated electronics products recycling is not a simple task. Andrea Gassmann, Jörg Zimmermann, Roland Gauß, Rudolf Stauber and Oliver Gutfleisch from the Fraunhofer Project Group Materials Recycling and Resource Strategies IWKS and the Technische Universität Darmstadt Institute for Materials Science respectively, present and discuss a method that could open the way to successful recirculation of precious components and materials. Read more »

LpR Article | Technologies | Medical | Aug 22, 2016

High-End White Light Sources Fiber Optics Technology for Medical Applications

High-End White Light Sources Fiber Optics Technology for Medical Applications Often technologies that are too expensive for the mass market at the beginning are already adopted in medical applications. When reaching a certain level of maturity, costs usually become more reasonable and adaptations for the consumer market begins. Holger Laabs, Oliver Mehl and Henning Rehn from Osram GmbH present a light source technology and its prerequisites for fiber optics that could become one of these technologies. Read more »

LpR Article | Aug 19, 2016

Status of Micro- and Nanostructured 3D LED Technologies

Status of Micro- and Nanostructured 3D LED Technologies Conventional LEDs are planar, two-dimensional (2D) devices that emit light from a thin material layer at or near their flat surface. The vast majority of LEDs are made of GaN and InGaN material requiring expensive substrate wafers made of sapphire, silicon carbide or gallium nitride. The 3D WireLED technology uses silicon wafers for wafer diameters of 8 inches or larger. On each wafer, millions of vertical microwires and microrods of GaN are grown, each with a diameter of less than one micron. Mr. Arno Grabher-Meyer and Mr. Siegfried Luger from LED professional, talked with the General Manager of Aledia, Mr. Giorgio Anania about the status of this innovative technology. Read more »

LpR Article | Quality | Aug 17, 2016

TM-30 or the Quest for New Metrics to Measure Light Color Quality

TM-30 or the Quest for New Metrics to Measure Light Color Quality As the lighting industry’s need for an unambiguous measure of lighting color quality becomes more urgent, the TM-30 test method put forward by the Illumination Engineering Society of America (IES) is one approach that could offer a solution. Arno Grabher-Meyer, Editor in Chief at LED professional gives a quick status overview. Read more »

LpR Article | Technologies | Aug 15, 2016

Concepts to Overcome Lifetime Issues of LED Drivers

Concepts to Overcome Lifetime Issues of LED Drivers Lighting technology has changed significantly in recent years after a century of little to modest advancements. LED luminaires offer advancement in lower power consumption and expected life. Maggie Nadjmi, EE Product Manager at SL Power Electronics, explains why this new technology will probably not meet the life and reliability expectations if no attention is paid to the drivers and power supplies used to power LEDs. She discusses the main components affecting lifetime and how to eliminate them or design a product to still achieve the desired lifetime. Read more »

LpR Article | Research | Aug 11, 2016

Flicker Beyond Perception Limits - A Summary of Lesser Known Research Results

Flicker Beyond Perception Limits - A Summary of Lesser Known Research Results Since the introduction of fluorescent lamps, the lighting industry knows about flicker issues. However, many aspects are still unclear. Especially effects beyond the flicker fusion threshold are mostly ignored, and sometimes even denied. Dr. Walter Werner, CEO of Werner Consulting, gives a summary of research results indicating that further research is needed and that for high quality lighting very likely a much higher PWM modulation frequency is required. Read more »

LpR Article | Aug 08, 2016

Form Factor Luminaires and Light Effects

Form Factor Luminaires and Light Effects If luminaires designed for traditional light sources are simply retrofitted with LED light sources like it occurs in the so-called “1st wave of LEDification”, they will always fall short of expectations in many points. Herbert Weiß and Thomas Noll from Osram GmbH, Martin Möck from the University of Erlangen-Nuremberg, Martin Creusen from Philips Lighting, and Friedhelm Holtz from Insta Elektro GmbH explain why these shortcomings were addressed and which solutions were developed in the EnLight project. Read more »

LpR Article | Technologies | Aug 05, 2016

Reliability Oriented Design of LED-Based Light Sources

Reliability Oriented Design of LED-Based Light Sources The transition from traditional light sources to SSL systems requires a different design philosophy to achieve the advantages offered by LED light sources. The key approach is based on the parallel design of thermal, electrical, optical and spectral properties of the light source. Matteo Meneghini, Gaudenzio Meneghesso, Enrico Zanoni and Matteo Dal Lago from the Department of Information Engineering at the University of Padova, and Nicola Trivellin from LightCube SRL explain this approach including the importance of the electrical management of LEDs, comparing modulation techniques to constant current, differentiating between versatility and efficiency. Read more »

LpR Article | Aug 01, 2016

DMI Specification Defines Electrical Interface between LED Drivers and Modules

DMI Specification Defines Electrical Interface between LED Drivers and Modules Enabling LED modules and LED drivers to be fully interchangeable at the component level requires a specification for the electrical interface between the driver and module (DMI). Arnulf Rupp of Osram GmbH, a member of both the Zhaga Consortium and MD-SIG, explains the role of both organizations in developing and implementing a consistent, easy to use, cross-vendor DMI specification. Read more »

LpR Article | Jul 29, 2016

Contactless LED Technology

Contactless LED Technology While Contactless power distribution using electromagnetic induction technology is not new, it is rarely used in an LED illumination system. Alain Guimont, an IES member and Product Specialist at HEICO lighting™, one of the few companies that designs products based on this type of an approach, explains how it works and discusses the advantages of this technology. Read more »

LpR Article | Technologies | Jul 28, 2016

InGaN Nanowires Make Light Mixing Efficient and Smart

InGaN Nanowires Make Light Mixing Efficient and Smart The correlated color temperature (CCT) of high color rendering index (CRI) LED lighting systems can, in principle, be tuned over a wide range. As an alternative approach to conventional phosphor based LEDs, a full-color LED array consisting of red, green and blue (RGB) InGaN based nanowire LEDs monolithically integrated on a micro-scale level has been proposed and fabricated. J. Lee from the Nano Electronics Lab at the Samsung Advanced Institute of Technology, Renjie Wang, Hieu P. T. Nguyen, Ashfiqua T. Connie, Ishiang Shih, and Zetian Mi from the Department of Electrical and Computer Engineering at McGill University in Montreal explain how this technology works and how the three multi-color subpixels on the same chip can be separately biased and can exhibit full-color emission which can be tuned controllably in a wide CCT range. Read more »

LpR Article | Jul 25, 2016

More Efficient Plant Growth with Quantum Dots by Nanoco Lighting

More Efficient Plant Growth with Quantum Dots by Nanoco Lighting Using LEDs for plant growth lights is nothing new, nor is the use of QDs in LED lighting. While it is already proven that LED systems have big advantages over conventional plant lighting technologies, it is not common knowledge that Cd-free QDs are ideal candidates for optimizing the light spectrum for plant growth systems. Dale Needham, Business Development Director-Lighting at Nanoco Lighting, explains the opportunities and advantages based on Nanoco’s proprietary and patentprotected CFQD® cadmium-free quantum dot LED grow lighting systems. Read more »

LpR Article | Jul 25, 2016

Zhaga Evolves: Focus on Component Standardization Drives New Book Development

Zhaga Evolves: Focus on Component Standardization Drives New Book Development With new specifications covering COB LED arrays, LED drivers, and other LED modules and light engines, Zhaga is making rapid progress in standardizing these types of components in response to the needs of the market. Musa Unmehopa, Secretary General of the Zhaga Consortium, and Tim Whitaker, Director of Marketing Communications of the Zhaga Consortium, describe how Zhaga is evolving and changing its focus in a number of areas. Read more »

LpR Article | Research | Jul 21, 2016

A Graphene-Based, Spectrally Tunable, Flexible Field-Effect Light-Emitting Device by the Tsinghua University and the Tsinghua National Laboratory for Information Science and Technology

A Graphene-Based, Spectrally Tunable, Flexible Field-Effect Light-Emitting Device by the Tsinghua University and the Tsinghua National Laboratory for Information Science and Technology The continuous tuning of the emission spectrum of a single light-emitting diode (LED) by an external electrical bias is of great technological significance as a crucial property in high-quality displays and may be used in high quality lighting applications, yet this capability has not been demonstrated in existing LEDs. Graphene, a tunable optical platform, is a promising medium to achieve this goal. Xiaomu Wang, He Tian, Mohammad Ali Mohammad, Cheng Li, Can Wu, Yi Yang, and Tian-Ling Ren from the Institute of Microelectronics at the Tsinghua University in Beijing and the Tsinghua National Laboratory for Information Science and Technology (TNList) demonstrate a bright spectrally tunable electroluminescence from blue (~450 nm) to red (~750 nm) at the graphene oxide/reduced-graphene oxide interface. Read more »

LpR Article | Jul 20, 2016

Concept of a Time-Proven LED Luminaire Design and Manufacturing Process by Lumitec Lighting

Concept of a Time-Proven LED Luminaire Design and Manufacturing Process by Lumitec Lighting While doing successful business has always been a tough job, it has become even tougher with the introduction of solid-state technology into the lighting industry. Besides high quality criteria, time to market has become a crucial success factor. Innovative processes and tools and, last but not least, a talented and inspired team are necessary. Angela Betancourt presents an approved process used by Lumitec Lighting. Read more »

LpR Article | Technologies | Jul 18, 2016

Mastering Thermal Issues in LED PCB Design & Laminate Selection by Ventec Europe

Mastering Thermal Issues in LED PCB Design & Laminate Selection by Ventec Europe LED applications are not the only applications that are driving the need for thermal issues to be considered and mastered in PCB design, but they are certainly amongst the most challenging. Designing LED PCBs requires many considerations and key are those that arise from multiple heat sources in close proximity. Martin Cotton, Director OEM Technology of Ventec Europe describes the process and criteria used when designing PCBs (Printed Circuit Boards) for use in LED applications using thermally conductive IMS (Insulated Metal Substrates). He goes into technical detail with charts and diagrams that explain everything the designer would need to consider when selecting a laminate and commencing a design. Read more »

LpR Article | Jul 14, 2016

Light-Emitting Surface (LES) Concept Enables Comparison of Photometric Properties by Osram GmbH

Light-Emitting Surface (LES) Concept Enables Comparison of Photometric Properties by Osram GmbH The concept of the light-emitting surface (LES) has been developed by the Zhaga Consortium to enable comparisons of the photometric properties of different LED light engines. Stefan Lorenz, a Systems Architect with Osram GmbH, describes the theory behind the LES and how it applies to the different Zhaga Books. Read more »

LpR Article | Research | Jul 11, 2016

Al2O3 Coated Europium- Activated Aluminum Silicon Nitride for COB LED Technology by the Graz University of Technology and Tridonic Jennersdorf

Al2O3 Coated Europium- Activated Aluminum Silicon Nitride for COB LED Technology by the Graz University of Technology and Tridonic Jennersdorf Eu2+ activated nitride phosphors have drawn much interest for solid state lighting because of their interesting photoluminescence. While they show excellent optical properties, they are hygroscopic and have the potential of being degraded by atmospheric moisture and high temperatures. A coating layer on the surface is an effective method to improve stability against moisture and oxidation. For use in chip on board technology, Nika Mahne, master student at the Institute of Inorganic Chemistry, A. Reichmann, B. Bitschnau, R. Fischer, from the Graz University of Technology, and F. Schrank from Tridonic Jennersdorf propose an approach where a CaAlSiN3:Eu2+ [1, 2, 3] phosphor was coated with Al2O3, obtained via a Brønsted precipitation reaction based on a solution-coating process from a mixture of aluminum halide with a base after annealing at a temperature of 400°C. Read more »

LpR Article | Technologies | Jul 07, 2016

New Class of Siloxane Polymers for Advanced LED Packaging

New Class of Siloxane Polymers for Advanced LED Packaging Packaging presents a major challenge to further improve LED device efficiency and reliability. A novel class of high stability siloxanes forms a technology platform to address such opportunities in die attach, encapsulation, and light outcoupling applications. Dr. Juha Rantala, CEO & Founder, Dr. Joerg Rockenberger, Director Application & Business Development, Dr. Jyri Paulasaari, Vice President Technology, Dr. Jarkko Heikkinen, Director Inks & Pastes. Markus Laukkanen, Application Manager, and Dr. Janne Kylmä, Vice President Engineering & Production at Inkron Oy explain the material properties and give examples of how these new materials in combination with novel nanomaterials enable products fully compatible with current process tools and flows while having superior properties. Read more »

LpR Article | Technologies | Jul 06, 2016

LED Light Spectrum Enhancement with Transparent Pigmented Glazes

LED Light Spectrum Enhancement with Transparent Pigmented Glazes While LED bulbs have the distinct economic advantages of using less energy, producing less heat and lasting years longer than traditional incandescent bulbs, when objects are viewed under LED light, they frequently appear to be of different colors than when viewed in sunlight or with incandescent lights. Jan-Marie A Spanard from Light Spectrum Glazes proposes and explains an approach to optimize the spectral distribution of LED light to overcome this weakness. Read more »

LpR Article | Jul 05, 2016

Focus Tunable Lenses for LED Lighting by Optotune AG

Focus Tunable Lenses for LED Lighting by Optotune AG Focus tunable lenses open up new possibilities in the design of LED based luminaires. With these shape changing lenses, the beam angle of a spotlight can be flexibly adjusted while keeping the efficiency on a constant, high level. Compact solutions combining a floodlight and a spotlight in one product can therefore be realized. This innovative technology reduces complexity and offers more flexibility in lighting design, especially for changing environments like museums, and shops. Joerg Wertli from Optotune AG demonstrates a very interesting technology for these applications. Read more »

LpR Article | Jul 05, 2016

Development Process for a Metal-Halide Replacement LED Module by Neonlite International Ltd.

Development Process for a Metal-Halide Replacement LED Module by Neonlite International Ltd. Seen for the first time at this year’s Light + Building, the TECOH® MHx, has provided specifiers and designers with a viable LED metal halide alternative. Talking about the issues surrounding such a development, Fred Bass, Managing Director of Neonlite International Ltd., the brand owner of MEGAMAN, shows how the module series has been developed and highlights its potential for metal halide replacement moving forward. Read more »

LpR Article | Jul 05, 2016

Aspects of Light Quality in Solid State Lighting by OSRAM Opto Semiconductors

Aspects of Light Quality in Solid State Lighting by OSRAM Opto Semiconductors For ages the quality of light has been one of the biggest topics for luminaire manufacturers. But since the introduction of LEDs in general lighting the definition of light quality has got a new dimension. Pros and cons of LED lighting quality are often very controversial. Alexander Wilm, Application Engineering Manager of OSRAM Opto Semiconductors, presents facts about LED lighting quality that provide a sound basis for discussions. Read more »

LpR Article | Jul 05, 2016

LED Market and Development Trends from the Point of View of a Full-Range Trader in Lighting by Everlight

LED Market and Development Trends from the Point of View of a Full-Range Trader in Lighting by Everlight In an interview with LED professional, Ms. Beate Jungwirth, Director of Marketing & Communications and PR at Everlight and Dr. Christopher Keusch, Senior Sales Manager at Everlight, talk about the market and development trends in the area of LEDs. The experts also discuss Everlight’s focus at the LED professional Symposium +Expo 2012 which takes place in Bregenz, Austria from September 25th to 27th. Read more »

LpR Article | Jul 05, 2016

An LED Solution for Historic Monumental Electric Chandeliers by Ramselaar Light Solutions

An LED Solution for Historic Monumental Electric Chandeliers by Ramselaar Light Solutions The Netherlands Institute for War Documentation (NIOD) is housed in a magnificent monumental late 19th century building at the Amsterdam Herengracht (the Netherlands). Recently, the unique brass chandeliers were provided with LED lamps, which were specially developed for this project by Ramselaar Light Solutions. Ron Ramselaar and M. Brouwers, advisor on behalf of the Government Buildings Agency (RGD), tell us about this extraordinary project. Read more »

LpR Article | Jul 05, 2016

Human-Centric Lighting: Sensor Technology for Full- Spectrum Lighting Solutions by ams

Human-Centric Lighting: Sensor Technology for Full- Spectrum Lighting Solutions by ams While not necessarily common knowledge, research is rapidly validating the common-sense understanding that human beings are “tuned” to the natural lighting cycles of the sun, and can be equally “de-tuned”, to the detriment of both health and productivity, by artificial light sources that operate contrary to these natural flows. Sajol Ghoshal, Director of Sensor Driven Lighting at the Opto Sensor and Lighting BU at ams, discusses the available approaches for full-spectrum solutions, and potential humancentric benefits, of fully integrated intelligent ambient/color light sensor and driver technology. Read more »

LpR Article | Jul 05, 2016

Additive Manufacture of Optics Goes Digital by LUXeXceL B.V.

Additive Manufacture of Optics Goes Digital by LUXeXceL B.V. With a new technology for additive manufacturing, optics fabrication has gone digital, making more product innovation and variety affordable by eliminating the expense of molds and tooling, enabling just-in-time manufacturing and bringing a new freedom for optics and lighting designers. Marco de Visser, Business Development Manager at LUXeXceL B.V. gives an update on this technology and its new opportunities. Read more »

LpR Article | Jul 05, 2016

LED Market and Development Trends from the Point of View of a Full-Range Trader in Lighting by Everlight

LED Market and Development Trends from the Point of View of a Full-Range Trader in Lighting by Everlight In an interview with LED professional, Ms. Beate Jungwirth, Director of Marketing & Communications and PR at Everlight and Dr. Christopher Keusch, Senior Sales Manager at Everlight, talk about the market and development trends in the area of LEDs. The experts also discuss Everlight’s focus at the LED professional Symposium +Expo 2012 which takes place in Bregenz, Austria from September 25th to 27th. Read more »

LpR Article | Jul 05, 2016

DC-Grids - Challenges and Chances for LED Lighting by the Fraunhofer Institute and LED professional

DC-Grids - Challenges and Chances for LED Lighting by the Fraunhofer Institute and LED professional At the beginning of November many important aspects of DC Grids were discussed at the Fraunhofer Institute for Integrated Systems and Device Technology in Erlangen at the European Center for Power Electronics (ECPE) conference. Besides fundamental issues, very specific ones like how the introduction of DC Grids affects lighting technologies and especially LED lighting were part of the program. Below, Arno Grabher-Meyer from LED professional gives a summary of the speeches and expert discussions and gives us an idea of what the key ideas could mean to the LED lighting community. Read more »

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