Technology | Sep 08, 2015

Background Information on the Luxeon C LED Family from Lumileds

In an exclusive interview, Rahul Bammi, Vice President of Marketing & Product Management at Lumileds, and David Cosenza, Product Manager for the Luxeon Color LED Family, disclosed some background information on why this new product family was designed and why the very specific, new, and unique properties were implemented.

The new product line shows many unique features and properties that are clearly application driven. This is probably a result of Lumileds formerly being a subsidiary of Philips - one of the world’s largest lighting companies. The new product line is optimized for the ease of the module or luminaire designer and improvement of the final product’s light quality. Everything that was technically possible has been done to provide a broad range of 18 LEDs in different colors with harmonized technical parameters by the end of 2015. The harmonization begins with very obvious parameters, like geometric dimensions, but that is by far not all. The thermal resistance, the focal length of the semi-domed LEDs and the typical angle included are optimized or equalized as advantageously as possible. While it might seem obvious that this should be done, it is a big technical challenge because four completely different LED technologies need to be optimized to satisfy this ambitious objective.

For the optics engineer the identical focal length for all LEDs in combination with an almost identical light distribution, characterized by the total included angle, are very important advantages. For an application with a certain specification, just one lens or reflector needs to be designed. This optics can be used for any color out of the broad Luxeon C portfolio delivering identical light distribution. In addition, in multi-color applications, the identical lens or a lens array with identical properties for any segment of the array can be used. This design simplification also helps to reduce costs significantly, and it may also help to improve system performance. With an identical focal length, products with much reduced color fringing, virtually without the so-called halos, can be designed. This is a requirement that is especially important in high quality applications like stage lighting or studio and TV lighting, but also absolutely desirable for architectural lighting and many other applications.

Another point is the measures taken to improve system performance. For Lumileds, this means finding the perfect balance between efficiency, luminous flux and source size. As we all know, domed LEDs help to improve flux gain, but the drawback of this technology is the magnification of the source by the dome. In contrast, the unmagnified small dimensions of the light source of undomed LEDs allow a more compact optical design at the cost of flux gain. With their so-called semi-dome design, Lumileds combines the best of both worlds. The flux gain, compared to undomed LEDs like the Luxeon Z, is improved significantly without significant magnification effects, which means that the source size for the secondary optics design appears to be about 23% smaller than in traditional domed LEDs like the Luxeon Rebel. This improves candelas per lumen performance and provides high luminance. It also allows a much compacter design, using less material for products with similar performance. The flat semi-dome (low-dome) design also minimizes or even eliminates cross-talk between the different LEDs of an array. This is especially important when blue/royal blue LEDs are combined with phosphor converted LEDs like white or PC amber. Cross-talk is especially undesirable because it could excite the phosphor of a completely turned off white or other PC converted LED in a tightly packed system and cause a distinct color shift.  

Compact design and high performance are also supported by the small 2x2 mm physical dimensions and the low thermal resistance of the package. The Luxeon C thermal resistance is approximately half the thermal resistance of currently competing products on the market. This is achieved by using a ceramics substrate. The low thermal resistance gives the developers different advantages. They can drive the LEDs harder for higher luminous flux and run the LEDs cooler to extend lifetime. And they can design a luminaire to maintain color stability and constant luminous flux during operation. Both physical dimensions and low thermal resistance allow designs with high packing density.

Very important for a quick and reliable development is the newly introduced Hot-Testing and Hot Binning for all colors. As 100% of the shipped LEDs are tested at 85°C, a very realistic temperature for luminaire designs, a first estimation of how a design could look can easily be done. Cost intense iterations for coming to the final design can be reduced significantly.

More details can be discussed with Lumileds' experts at LpS 2015 from September 22nd to the 24th, 2015 in Bregenz, where Lumileds will be exhibiting the new product line.

For technical specifications, you may also download the Luxeon C Datasheet

FEATURED

Cree® XLamp® CMT LEDs Deliver up to 45 Percent Higher Lumen Density than Competition

Cree® XLamp® CMT LEDs Deliver up to 45 Percent Higher Lumen Density than Competition The new CMT LEDs extend Cree’s metal-based chip-on-board (COB) LED technology to the most prevalent COB form factors. Cree’s XLamp High Current LED Arrays provide up to 45% more lumen density and up to 17% higher efficacy, and feature an innovative metal substrate technology that delivers higher ... Read more »

FEATURED

BJB Launches Innovative Single-row LED Optic Series for Linear and Area Lighting with Slim Design and Integrated Fixing Elements

BJB Launches Innovative Single-row LED Optic Series for Linear and Area Lighting with Slim Design and Integrated Fixing Elements Optics are a critical part of the lighting system, especially when it comes to efficiency and precision beam control. Even the most efficient light sources would be rendered useless without high-quality optics. They enable the designer to extract light from the source and precisely direct it ... Read more »

FEATURED

Accredited Quality for Colorimetric Quantities

Accredited Quality for Colorimetric Quantities Since 2009 Instrument Systems has received accreditation to DIN EN ISO / IEC 17025 for photometric tests and now offers its certified measurement solutions with the flexible scope of application of Category III. Read more »

FEATURED

Smart Control with GRE’s Dimming Modules

Smart Control with GRE’s Dimming Modules Smart and sustainable technologies have been on the forefront at the international lighting events. With the advance of smart devices and return on investment requirements, the smart building is widely becoming the new standard building model. Read more »

FEATURED

Light is the Efficiency Booster

Light is the Efficiency Booster In order to cut costs while providing high-quality light, many luminaire manufacturers today rely on robust LED components and intelligent control technology from OSRAM. Our future-proof lighting systems reduce the power consumption as well as the maintenance effort. Read more »

FEATURED

A.A.G. Stucchi Presents New IP66/68 Connectors

A.A.G. Stucchi Presents New IP66/68 Connectors A.A.G. Stucchi, an Italian company and leader in the lighting components industry, is ready to present 2 new series of IP66/68 connections: 3800 series of mini connectors and 610 series of distributors. The two product series have their very compact design in common. 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 »

page_peel