Resources | LpR Article | Research | Optics | Engineering | Apr 13, 2018

Optimization of Freeform Optics Using T-Splines in LED Illumination Design

Optimization of Freeform Optics Using T-Splines in LED Illumination Design Freeform optics is the game changer in the illumination industry in terms of its ability to redirect the light into the target area. Non-Uniform Rational B-splines, commonly known as NURBS are widely used to represent freeform curves and surfaces. There are certain optical systems where local modification of the surface is necessary during the design or optimization phase. In such cases, NURBS cannot offer such transformations. But a new mathematical representation called T-splines make this feasible. Though its potentiality is well described, this has not been implemented in any optimization routine so far. Annie Shalom Isaac, Jiayi Long and Cornelius Neumann from the Karlsruhe Institute of Technology demonstrate the advantage of the local refinement ability of T-splines by implementing it in the optimization routine and the results are evaluated. Results show that T-splines provide more uniform and homogenous light distribution as compared to NURBS at a faster convergence rate. This makes optical design or optimization using T-splines an intuitive approach for future freeform design tasks. Read more »

Resources | LpR Article | Quality | Optics | Mar 13, 2018

Glare Reduction Made Easy

Glare Reduction Made Easy A pleasant lighting atmosphere due to low glare at the workstation is not only pleasant and performance-enhancing, but also legally required according to EU standard EN 12464-1. But what does “glaring” mean here? Dr. Claudius Noack, Technical Director at NORKA Leuchten, explains if luminaires with the same luminous flux are glaring to the same degree and if the same luminaires are glaring to the same degree at different workstations. He answers the questions of what a manufacturer does and if manufacturers are lying to themselves and therefore to their customers when providing information on the glare rating. Read more »

Technologies | Optics | Manufacturing | Displays | Feb 23, 2018

VTT and Neonelektro Have Made LED Advertising Boards Light, Flexible and Energy-Efficient

VTT and Neonelektro Have Made LED Advertising Boards Light, Flexible and Energy-Efficient Through a European project, VTT Technical Research Centre of Finland and Neonelektro have developed new types of LED displays that combine the flexibility, low cost and high technical performance enabled by roll-to-roll mass manufacturing technology. Read more »

Resources | LpR Article | Research | Measurement | Lighting Simulation | Optics | Sep 25, 2017

Measurement of Angular and Spatial Resolved Spectral Rayfiles

Measurement of Angular and Spatial Resolved Spectral Rayfiles The enhanced complexity of modern lighting systems has increased the importance of realistic light source models during the optical design process of LED-based luminaires. I. Rotscholl, Research Associate, K. Trampert, C. Neumann, I. Leopoldo Sayanca from the Karlsruhe Institute of Technology, U. Krüger and F. Schmidt from the TechnoTeam Bildverarbeitung GmbH, propose a method to enhance the often used LED light source model “rayfile” towards a “spectral rayfile”. A spectral rayfile would be a model that associates each ray with its own spectrum and therefore describes varying spectra as a function of angular direction and spatial starting position. The PMBS (physical motivated basis spectra) method is based on the assumption that each LED spectrum consists of a weighted sum of individual basis spectra, for instance those of individual semiconductors and phosphors. There is no need for any special measurement equipment but a classic nearfield goniophotometer and some off-the-shelf optical filters. This method requires at least one spectral measurement and just a minimum of goniophotometric measurements with different optical filters. Finally, the authors demonstrate the potential of this method by applying the concept on a typical LED and compare the results to the often used Blue/Yellow approach in terms of accuracy and applicability. Read more »

Resources | LpR Article | Tech-Talks Bregenz | Quality | Human Centric Lighting | Optics | Sep 25, 2017

Tech-Talks BREGENZ - Dr. Wilfried Pohl, Research Director, Bartenbach GmbH

Tech-Talks BREGENZ - Dr. Wilfried Pohl, Research Director, Bartenbach GmbH Bartenbach is one of the pioneers in light planning and lighting research. Since Christian Bartenbach Senior founded the engineering office in 1976, the company has been dedicated to light and visual perception. Several lighting inventions made over the years, can be attributed to Bartenbach. Dr. Wilfried Pohl, as a member of the Managing Board and Director of Research at Bartenbach GmbH, has played a substantial role in many developments. LED professional talked with him about Bartenbach’s history, education in the lighting business, the lighting parameters he deems very important, the quality of light, "Human Centric Lighting" and "Biodynamic Lighting“, and how LEDs have changed the light planning and lighting research company, in general. Read more »

Resources | LpR Article | Research | Optics | Aug 10, 2017

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

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 | Optics | Applications | Jul 17, 2017

Roadway Lighting Optics for Environment Adaptive Spatial Light Distribution

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 »

Technologies | Optics | Waveguides | Apr 18, 2017

Method to Control Light Propagation in Waveguides

Method to Control Light Propagation in Waveguides A team of Columbia Engineering researchers, led by Applied Physics Assistant Professor Nanfang Yu, has invented a method to control light propagating in confined pathways, or waveguides, with high efficiency by using nano-antennas. To demonstrate this technique, they built photonic integrated devices that not only had record-small footprints but were also able to maintain optimal performance over an unprecedented broad wavelength range. Read more »

Resources | LpR Article | Technologies | Optics | Jan 12, 2017

Structured Glass Light Guides for Efficient Lighting

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 »

Resources | Intellectual Properties | Optics | Sep 30, 2016

Fraen Color-Mixing Zoom System Patent for LED Lighting Issued by USPTO

Fraen Color-Mixing Zoom System Patent for LED Lighting Issued by USPTO Fraen is pleased to announce that the U.S. Patent and Trademark Office recently issued a patent on the cornerstone product of Fraen’s entertainment lighting optics portfolio. Patent number 9,411,083 was granted on August 9, 2016, and covers Fraen’s system for colormixing zoom LED lighting optics. Read more »

Technologies | Optics | Material Science | May 12, 2015

ORNL Superhydrophobic Glass Coating Offers Clear Benefits - Maybe Also for Lighting Optics

Schematic representation of the coated product and applications. The properties could also be useful in different lighting applications lke outdoor lighting, street lighting or for automotive headlights A moth’s eye and lotus leaf were the inspirations for an antireflective water-repelling, or superhydrophobic, glass coating that holds significant potential for solar panels, lenses, detectors, windows, weapons systems and many other products. The discovery by researchers at the Department of Energy’s Oak Ridge National Laboratory, detailed in a paper published in the Journal of Materials Chemistry C, is based on a mechanically robust nanostructured layer of porous glass film. The coating can be customized to be superhydrophobic, fog-resistant and antireflective. Read more »

Technologies | Optics | Material Science | Jul 04, 2014

Novel Nanoparticle Production Method Could Lead to Better LED Lights, Lenses and Solar Cells

Sandia National Laboratories researchers Dale Huber, left, and Todd Monson have come up with an inexpensive way to synthesize titanium-dioxide nanoparticles, which could be used in everything from solar cells to light-emitting diodes. (Photo by Randy Montoya) Sandia National Laboratories has come up with an inexpensive way to synthesize titanium-dioxide nanoparticles and is seeking partners who can demonstrate the process at industrial scale for everything from solar cells to LEDs. Titanium-dioxide (TiO2) nanoparticles show great promise as fillers to tune the refractive index of anti-reflective coatings on signs and optical encapsulants for LEDs, solar cells and other optical devices. Read more »

FEATURED

LUXTECH Introduces FLEX Color, Architectural Grade RGB Tape

LUXTECH Introduces FLEX Color, Architectural Grade RGB Tape LUXTECH, a leading American manufacturer of architectural grade LED modules, introduces FLEX Color to their line of flexible LED strips. The RGB strip light is populated by high quality LEDs with tight binning to maintain color consistency. Read more »

FEATURED

Job Opportunity

Job Opportunity Synergy 21 has been a successful, well-known brand in the lighting industry for around 9 years. We satisfy our customers with top-notch planning, development, production, and distribution of high-quality lighting fixtures. We also offer an attractive working environment to over 200 employees at 6 ... Read more »

FEATURED

XP-G2 High Efficacy LEDs Use Less Power, Drop-in Compatible

XP-G2 High Efficacy LEDs Use Less Power, Drop-in Compatible Cree, Inc. announces the new High Efficacy (HE) version of the XLamp® XP-G2 LED that delivers improved performance compared to standard XP-G2 LEDs, with higher output and greater efficiency to enable smaller, lighter, lower-cost designs. The original XLamp XP-G2 LED pioneered a broad set of LED ... Read more »

EDITORIAL

High Conductive Foils Enabling Large Area Lighting

High Conductive Foils Enabling Large Area Lighting Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP as one of the leading partners for research and development for surface technologies and organic electronics and Sefar AG, a leading manufacturer of precision fabrics from monofilaments, developed a roll-to-roll ... Read more »

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