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Resources | LpR Article | Research News | CIE | Quality | Jan 01, 2018

Color Reproduction and Measurement of 3D Objects

Color Reproduction and Measurement of 3D Objects CIE Division 8 Image Technology is responsible for the study of the optical, visual and metrological aspects of the communication, processing, and reproduction of images, using all types of analogue and digital imaging devices, storage media, and imaging media. The Division is continually working on recommendations to improve color image reproduction techniques, including, for example, colorappearance models, color-difference evaluation and gamut-mapping algorithms. Current technology is able to transform color images from one digital medium to another, under various viewing conditions, while maintaining the appearance of each color in the image. This process has been applied in the graphic arts industry with great success. According to Kaida Xiao, Chair of CIE's Division 8 TC 8-17, the CIE standard observer and psychophysical data for color-appearance and color-difference modelling were developed using flat, 2D color samples. He explains that to meet the increasing requirements for color image reproduction for 3D objects, new research and recommendations are highly desired. Read more »

Resources | LpR Article | Automotive | Driver IC | Controls | Dec 28, 2017

Interior Automotive Lighting Control Redefined

Interior Automotive Lighting Control Redefined In modern car’s interior lighting, tough requirements and rising complexity are a huge challenge. A new industry consortium was formed to meet this technological challenge and to provide a comprehensive ecosystem for the new digital LED lighting paradigm. The founding members of the Open ISELED Alliance are Inova Semiconductors (ISELED "Digital LED" concept and LED controller), Dominant Opto Technologies (LED manufacturing and packaging), NXP (system microcontroller), TE Connectivity (system integration and connection technology) and Pforzheim University (theoretical framework). The alliance recently added LucieLabs (software, firmware), a French IoT Software startup to its line-up. The goal of all these organizations is to work in close cooperation to present a complete system solution - a true ecosystem. Roland Neumann, CTO of Inova Semiconductors introduces the challenges and the worked out innovative solution that uses a single system controller to individually address up to 4,096 LEDs. Read more »

Resources | LpR Article | Event-Reports | Technologies | Trends | Dec 13, 2017

LpS Gets a Younger Sibling to Foster a Holistic System Approach

LpS Gets a Younger Sibling to Foster a Holistic System Approach For the most part our readers are aware of the fact that the LpS has a strong focus on the component level, but after the 6th event, the Luger Research team realized that it was time to find a way to push the more holistic system approach. After much consideration and careful planning, the Trends in Lighting (TiL) Forum and Show was initiated and took place in conjunction with the LpS 2017. Arno Grabher-Meyer, Editor-in-Chief at LED professional took a close look at both exhibitions and the lectures to find out what the audience thought of the extension and broader outlook. Read more »

Resources | LpR Article | Quality | Measurement | Calibration | Dec 11, 2017

Avoiding Brightness and Color Mismatch with Proper RGB Gamut Calibration

Avoiding Brightness and Color Mismatch with Proper RGB Gamut Calibration For well over a decade, proponents of Solid-State Lighting (SSL) have been offering bullish forecasts concerning the adoption of LEDs for general and specialized lighting applications. Recent years have seen those rosy predictions come true, with LED lighting now almost completely dominating the market for new construction, retrofit, and many replacement lighting applications. For many of these applications accurate color calibration is required. Rood Bouten, CTO at Admesy, explains the reasons and how to perform a proper RGB gamut calibration. Read more »

Resources | LpR Article | Commentary | Test Equipment | Dec 11, 2017

The Value of High-End Labs for High Quality Lighting

The Value of High-End Labs for High Quality Lighting With the relocation to the Augsburg site in 2015, the Osram laboratory equipment includes a number of integrating spheres of different sizes up to 3 meters in diameter, several goniophotometers A/B/C types, a rotary mirror light distribution meter and a hemispherical goniometer with a measurement radius of 2.65 meters, optical bench measuring systems with up to 35 meter measuring distance, corresponding high-quality photometric receivers and spectral radiometers as well as the necessary components for the electrical operation of lamps - according to customer or standardized specifications. Read more »

Technologies | Resources | Smart Lighting + IoT | Electronics | LpR Article | Nov 30, 2017

SoC Technologies in Lighting - Today’s Landscape and Tomorrow's Practices

SoC Technologies in Lighting - Today’s Landscape and Tomorrow's Practices A system-on-chip (SoC) quite suddenly became an important component in the lighting industry, fueling IoT innovation and opening new opportunities, while at the same time bringing disruption and new challenges. With rapid advancements in wireless communication, the impact of connected technologies on the lighting business will only keep increasing. This means deeper integration with SoCs and more attention from silicon vendors as they start competing for market share in this promising segment. But what is the current state of SoC design from the lighting perspective? Are chipmakers keeping up with the growing expectations for wireless lighting control solutions that are mature and truly reliable? When developing its complete Bluetooth software stack for professional lighting, Silvair worked with a number of different SoCs. Therefore, Piotr Winiarczyk, Wireless Solution Architect, and Szymon Rzadkosz might have found the answers to these questions. Read more »

Resources | LpR Article | Technologies | Electronics | Drivers | Nov 09, 2017

LED Driver Miniaturization - Opening New Opportunities for Solid State Lighting

LED Driver Miniaturization - Opening New Opportunities for Solid State Lighting While LEDs have significantly improved over the past decade, driver technologies have not kept pace and are, in some respects, the limiting factors for new applications. Size is a particular issue. Dramatically increasing the switching frequency helps to reduce size but often causes other issues or is costly. Mickey Madsen, CEO of Nordic Power Converters, explains how his company has overcome the hurdles and made it feasible by designing very high frequency LED drivers. Read more »

Resources | LpR Article | Research | Electronics | Drivers | Nov 02, 2017

LED-Retrofit Based on AlGaN/GaN-on-Si Field- Effect Transistor Drivers

LED-Retrofit Based on AlGaN/GaN-on-Si Field- Effect Transistor Drivers Efficient driver technologies for LED systems are still a relevant topic. Several new approaches are proposed and new technologies are under development. Andreas Zibold, PhD student at the Fraunhofer Institute for Applied Solid State Physics IAF, and his co-authors, M. Kunzer, R. Reiner, B. Weiß, P. Waltereit, R. Quay, J. Wagner, and O. Ambacher demonstrate the suitability of AlGaN/GaNon- Si field effect transistors (FETs) for their use in LED drivers. The transistors are tested in an isolated buck converter and an efficiency of 86% is measured for the full converter circuit. The driver circuit is combined with an LED module based on a laser-structured Aluminum Nitride (AlN) ceramic board onto which 21 high power white-emitting LED chips are mounted. This combination resulted in an LEDRetrofit lamp with a total light output of 2676 lm at an efficacy level of 119 lm/W. The results compare favorably to state-of-the-art commercial solutions. Read more »

Resources | LpR Article | Interview | Trends | Horticulture | Sep 25, 2017

Trends in Horticulture Lighting

Trends in Horticulture Lighting Cree has been a leader in general lighting applications for over 20 years and has customers ranging from restaurant chains to global government agencies. Paul Scheidt began his career in Cree in 2005, working on the development of their lighting applications. During this time, he has seen an increase in the horticulture lighting application. LED professional spoke to Paul Scheidt about horticulture lighting and what he thinks is behind this recent trend. He also shares his views of what he thinks the future holds for both Cree and horticulture lighting applications. Read more »

Resources | LpR Article | Quality | Perception | Sep 25, 2017

Lighting to Achieve Optimal Appearance

Lighting to Achieve Optimal Appearance Visual appearance of an object or space depends on the characteristics of the lighting applied. The objective definition of light quality often doesn’t tell the whole story. Light intensity, its spectral composition and distribution in space, as well as individual preference, must be considered. Nevertheless, aiming for the absolute optimum is only recommended when private rooms are concerned. As visual appearance is key in driving consumer demand, it is important to tune the light to maximize effectiveness and visual pleasure for most consumers. Markus Reisinger, owner and CEO of the Lighting Research Studio, discusses this complex situation with examples. Read more »

Resources | LpR Article | Measurement | Special Applications | UV | Sep 25, 2017

Issue 63 | Challenges in UV Measurement

Issue 63 | Challenges in UV Measurement Over the past decade UV LEDs have emerged as a highly attractive alternative to conventional UV emission sources. They are cost effective and energy efficient devices in a small housing. These advantages allow new fields of applications and access to a larger group of users - even in the consumer market, e.g. water purification. Dr. Tobias Roesener, Product Manager at Instrument Systems, explains what makes accurate measurement of UV LEDs so complicated and what the crucial requirements on the measurement equipment are. In addition, he discusses calibration and stray light issues. Read more »

Resources | LpR Article | Technologies | Light Conversion | Quantum Dots | Sep 25, 2017

Quantum Dot Based White LEDs for General Illumination

Quantum Dot Based White LEDs for General Illumination Colloidal quantum dot based white LEDs can be integrated into commercial products meeting the stringent reliability requirements for general illumination and providing LED efficiency gains of 5% to 15% over commercial phosphor based LEDs at CCT’s ranging from 5000 K to 2700 K. Unlike earlier demonstrations, the QD material is applied in an on-chip configuration resulting in drop-in fit, form, and function compatibility to existing LED based luminaires and lamps. Ken T. Shimizu, Director, Novel Technologies and Devices, Research and Development, M. Böhmer, D. Estrada, S. Gangwal, S. Grabowski, H. Bechtel, E. Kang, K. J. Vampola, D. Chamberlin, O. B. Shchekin, and J. Bhardwaj from Lumileds showcase the advantages of on-chip QD LEDs: A commercial lamp at 3000K color temperature and 90 CRI is substituted with QD based LEDs resulting in a system level efficiency gain up to 17%, attributed to the reduced blue LED droop from the lower drive current and the lower heat sink temperature when compared to the standard phosphor based LED lamp output. Read more »

Resources | LpR Article | Research | Medical | Sep 25, 2017

Challenges when Designing LED-Based Illumination Systems in Medical Applications and Diagnostics

Challenges when Designing LED-Based Illumination Systems in Medical Applications and Diagnostics LEDs have become indispensable in medical technology and dentistry. But the requirements placed on these lighting products are very high: Minimized size, high, application specific color rendering index, efficient temperature management, usability and excellent disinfection opportunities are all extremely important. Prof. Paola Belloni from the Steinbeis Transfer Center Illumination Optics and Lighting Engineering and Furtwangen University, and Alexander Gärtner from the Faculty of Mechanical and Medical Engineering of the Furtwangen University discuss the requirements for different applications such as endoscopy, surgeries, dental devices, and photodynamic therapy. Further topics are the development of a self-disinfecting operation interface with edge-lit UV-A LEDs, and a new optimization approach, taking into account the reflection and absorption properties of human tissues. 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 »

FEATURED

Emergency Lighting Just Got Smarter

Emergency Lighting Just Got Smarter NEW NOW: OSRAM’s standalone solution for emergency lighting testing, reporting and maintenance. Meet the QBM DALI EL-T CONV, a converter transforming existing DALI emergency luminaires into wireless ones, all controlled by the same lighting system. Its benefits? Allowing you to design all the ... Read more »

FEATURED

Continuous versus Discrete Calibration Sources: Consideration for Use

Continuous versus Discrete Calibration Sources: Consideration for Use Rapid advancements in the field of solid-state lighting have presented opportunities for the use of LED-based systems for calibrations typically performed with lamp-based sources. Their highly efficient and long-lived performance, rapid power up, and compact size have made LED-based sources an ... Read more »

FEATURED

LUXTECH Offers First Compelling Flex Modules Designed to Replace Traditional Rigid Modules: LUXroll (UL Listed)

LUXTECH Offers First Compelling Flex Modules Designed to Replace Traditional Rigid Modules:  LUXroll (UL Listed) The Indirect Costs of Using Rigid Boards Make Switching to Flexible LED Modules a Compelling Choice. Read more »

EDITORIAL

New LUXEON Rubix Cyan LED Enables 96-98 CRI Across CCT Range in Color Driven Solutions for Entertainment, Stage, and Studio

New LUXEON Rubix Cyan LED Enables 96-98 CRI Across CCT Range in Color Driven Solutions for Entertainment, Stage, and Studio Lumileds added cyan, its eighth color, to the LUXEON Rubix high-power LED family enabling multi-color driven systems to produce very high CRI white light that is so important in entertainment lighting. Adding the cyan LED fills a significant wavelength gap between blue and green in a system and ... Read more »

EDITORIAL

New date: Light + Building Autumn Edition 2022

New date: Light + Building Autumn Edition 2022 Frankfurt am Main, January 10, 2022. As the pandemic situation continues to develop very dynamically, Messe Frankfurt is postponing the world's leading trade fair for light and building technology to autumn 2022. Last December, intensive discussions with customers and cooperation partners had ... Read more »

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