Articles & Interviews

LpR Article | Jun 20, 2016
Light Guide Technology for Obtaining a Different Bi-Directional Direct/Indirect Light Emission Pattern
Light Guide Technology for Obtaining a Different Bi-Directional Direct/Indirect Light Emission Pattern Market requirements ask for a solution for use in suspended light fixtures that will allow the light to be distributed upward, for indirect illumination, as well as downward, for direct illumination. However, existing light guide technology typically produces fairly indirect light and relatively uncontrolled distribution. Brett Shriver, Vice President at Global Lighting Technologies, explains a new approach with individual light extraction features used within the light guide in order to control light in multiple directions and provide the required semi-Lambertian distribution in the downward direction with low glare while obtaining a bat-wing type distribution in the upward direction. Read more »
LpR Article | Jun 20, 2016
Advanced Passive Thermal Management Solutions for High Power LEDs by Advanced Cooling Technologies (ACT)
Advanced Passive Thermal Management Solutions for High Power LEDs by Advanced Cooling Technologies (ACT) There are two main solutions to improve passive thermal management in LED devices. One is to increase the surface area of a heat sink. This requires additional size, weight and material and offers only marginal improvement. The second solution is to increase the thermal conductivity between the heat source and the sink. The latter is supported by well-established technologies like heat pipes and vapor chambers. Richard Bonner, Manager for Custom Products, and Peter Ritt, Vice President at Advanced Cooling Technologies (ACT) give insight into the latest developments and explain how they work, how they are designed and applied correctly, and discuss their opportunities, advantages and limitations. Read more »
LpR Article | Jun 20, 2016
Lighting & Building Automation Technologies
Lighting & Building Automation Technologies The transition from traditional lighting technology to LED is old news. People in the lighting business no longer talk about the “LED Revolution”. Today’s revolution, perhaps spurred on by LED technology, is in building automation and lighting controls. Lighting experts know that while LED products have the potential to achieve terawatts of power savings worldwide over the next decade, even larger power savings might be achieved through effective lighting control and building automation systems. Greg Galluccio, Director at Leviton Manufacturing discusses lighting load-shedding strategies, such as daylight harvesting, occupancy sensing, task management and demand response as well as the trends towards the interaction of lighting control with other building functions. Read more »
LpR Article | Technologies | Jun 20, 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 | Jun 20, 2016
Discomfort Glare Perception of Non-Uniform Light Sources in an Office Setting
Discomfort Glare Perception of Non-Uniform Light Sources in an Office Setting LED based luminaires with different luminance patterns and recently, with increasingly non-uniform luminance patterns are becoming mainstream. This trend makes discomfort due to glare an important topic. Based on an office setting and the comparison of results from three different regions, L. M. Geerdinck, J. R. Van Gheluwe and M.C.J.M. Vissenberg from Philips Research have reviewed the currently used formulae to predict discomfort glare to ascertain if they are still valid. Read more »
LpR Article | Jun 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 | Jun 21, 2016
Optimization of SSL LED Devices by Osram Opto Semiconductors
Optimization of SSL LED Devices by Osram Opto Semiconductors There are different levers to improve LED performance. Ralph Bertram, application engineer for SSL products, and Alexander Wilm, key expert in the SSL application engineering department at Osram Opto Semiconductors, have a look into the device itself and explore the principal limitations of the different contributors to device efficacy. They show how to balance driving current and chip size to define the right LED, and explain the impact on performance and system costs of LED packages for the intended lighting task approaches for lighting strategies. Read more »
LpR Article | Technologies | Jun 21, 2016
Safety Issues for LED Drivers with PWM Operation Modes by Product Approvals Ltd.
Safety Issues for LED Drivers with PWM Operation Modes by Product Approvals Ltd. In many cases LED drivers manage their output power with PWM controlled switched mode power supply-topologies. The output voltages are filtered and normally DC voltages with low ripple apply at the output connectors of LED drivers. During dimming these circuits can behave very differently and therefore safety issues may arise. Siegfried Luger, CEO at Luger Research e.U. and John Showell, Product Safety Consultant at Product Approvals Ltd. have a closer look at those operation modes and the requirements on voltage limits. Read more »
LpR Article | Jun 21, 2016
Using Integrating Spheres Correctly to Measure LEDs
Using Integrating Spheres Correctly to Measure LEDs LEDs have opened up new dimensions of design freedom, allowing architects and designers to give free rein to their creativity. Light-emitting diodes permit manifold design solutions as a light source in illumination products. However, a suitable measuring method for comparing key technical data is required in order to get the best out of the diversity of illumination products available. Mikolaj Przybyla from GL OPTIC, a Just Normlicht GmbH division, explains crucial product requirements and what to take care about when calibrating a measurement system. Read more »
LpR Article | Jun 27, 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 | Jun 28, 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 | Jun 28, 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 | Technologies | Jun 28, 2016
LED and Lens Degradation Through Volatile Organic Compounds
LED and Lens Degradation Through Volatile Organic Compounds In general, LEDs are very resistant light sources. Nevertheless, glues, conformal coatings, o-rings, gaskets, and potting compounds, all materials that are frequently used in the construction of LED based luminaires or lamps and often contain volatile organic compounds (VOCs) may have a negative impact on performance, reliability and lifetime. Edward Steinke, application engineer at Cree, explains the set of problems and how to prevent these issues based on Cree’s products, using their test kit components, as well as components for lamp and luminaire applications. Read more »
LpR Article | Jun 28, 2016
Natural Design for Heat Sinks
Natural Design for Heat Sinks The luminous flux of LEDs decreases with the rise of the operating temperature. Therefore the dissipation of the heat is, aside from the efficiency of the LED chip itself, an essential part in the development of efficient LED systems. Christian Herbold and Cornelius Neumann from the Light Technology Institute at the Karlsruhe Institute of Technology analyzed natural inspired shapes and show an approach to heat sinks that combine high thermal performance with a high aesthetic value. Read more »
LpR Article | Technologies | Jun 28, 2016
OLED Technology in Lighting Applications
OLED Technology in Lighting Applications Prototypes and niche applications with OLEDs for lighting have been demonstrated over the past few years. Now there are indications that OLED technology is ready for mass production or at least will be ready very soon. Franco Musiari, Technology Specialist at ASSODEL analyzed the current status and future perspectives of OLED technology. Read more »
LpR Article | Technologies | Jun 28, 2016
MOCVD Platform for Cost-Effective Production of GaN-based HB LEDs
MOCVD Platform for Cost-Effective Production of GaN-based HB LEDs GaN-based blue and ultraviolet light emitting diodes (LEDs) are steadily becoming more widely used in solid-state lighting (SSL) applications [1-3]. Enabling dramatic energy savings when compared to contemporary incandescent bulbs and fluorescent lamps, these high-brightness LEDs (HB-LEDs) have a market potential in the billions of dollars. Yole Development estimates that by 2017, the market for LEDs will be approximately $75 billion [4, 5]. Shiping Guo, the Senior Technology Director of Advanced Micro-Fabrication Equipment Inc. presents a new approach to support this goal with a cost effective MOCVD solution for HB-GaN LED manufacturing. Read more »
LpR Article | Technologies | Jun 28, 2016
High-Index Nanocrystals - Key to Next Generation Advancements in Lighting
High-Index Nanocrystals - Key to Next Generation Advancements in Lighting Solid-State Lighting is destined to be a next generation lighting option. LEDs have already entered main stream applications and OLED technology has advanced greatly in the past few years in terms of efficacy and performance. Both technologies need to continue to improve performance to achieve high market acceptance. Dr. Gregory Cooper, Chief Technology Officer and Founder of Pixelligent Technologies LLC, illustrates how LED and OLED technology can advance to the next level by incorporating nanomaterials into existing packaging. Read more »
LpR Article | Jun 29, 2016
Handheld Photometry Supports LED Lighting Design
Handheld Photometry Supports LED Lighting Design With SSL new dimensions were introduced to light measurement, especially concerning handheld light measurement tools. Norbert Harkam, General Manager at SalesLink GmbH, a Representative of UPRtek, explains what criteria have to be considered and what the requirements of a handheld photometer are. Read more »
LpR Article | Technologies | Jun 29, 2016
Optical Lithography Method for Advanced Light Extraction in LEDs
Optical Lithography Method for Advanced Light Extraction in LEDs Objective material selection for various target applications is key for successful product development. Efficient light extraction features are crucial for highly efficient LEDs. Thomas Uhrmann and Harun Solak, et.al* from EV Group and Eulitha AG will demonstrate a novel lithography method, PHABLE™, that enables the printing of sub-μm patterns in a non-contact, proximity process. Read more »
LpR Article | Jul 01, 2016
Thermal Management for LEDs Beyond Thermal Conductivity Values by Electrolube
Thermal Management for LEDs Beyond Thermal Conductivity Values by Electrolube Specifically designed and formulated chemical products are widely used in the electronics industry for a vast array of applications. Jade Bridges, European Technical Support Specialist at Electrolube explains why such products have become an essential factor in ensuring the performance and quality of electronic devices, whether it is during PCB manufacture or for the protection of components or complete devices. Read more »
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