LEDS

LEDS

LEDs have already proven themselves in the automotive world in interior lighting and in signal functions (tail, brake, turn, daytime running lights). In the last couple of years LEDs have also emerged in headlamp applications. Increasingly more advanced options are becoming available with the introduction of LEDs which were not possible with conventional light-sources. The first implementations focused on styling differentiation, i.e. creating a unique and attractive appearance of the headlamp. Beyond just styling, LEDs allow advanced features such as dynamic beam adaptation in adaptive front lighting systems (AFS). AFS systems dynamically change the illumination pattern on the road, depending on the driving conditions, which makes driving safer and more comfortable. Driven by the new hybrid and electrical vehicle category (HEV), energy efficient LED headlights will ultimately penetrate the mainstream volume automotive market in the coming decade.

While the solid-state lighting revolution (to replace obsolete energy inefficient lighting) accelerates, the path to victory is not fully defined. How does the solid-state lighting industry develop a roadmap for success during the battle?  Understandably, great attention is afforded to the LED component. Will efficacy continue to improve? At what point do incremental improvements matter? How quickly can the cost be reduced?  Are there alternatives to improve ROI? Can lifetime projections continue to improve or is there really value in 100,000+ hour life? What aspects of LED performance really matter?  While LED companies proliferate talking points about their products and lifetimes like rival political parties, the real success of the lighting revolution will always be defined by one word: adoption! This presentation will explore potential game changers to drive adoption of solid state lighting beyond the important, but myopic, focus on the LED component’s performance and cost.

This presentation will review the latest trends in LED general lighting from an LED manufacturer’s perspective. The balance between the performance, quality and cost of light through the selection of LED packaging technology is essential to the success of LED general lighting. Technical platforms of chip, phosphor, and packaging will be evaluated for typical lighting applications. The feasibility of multiple design paths drives the diversification of LED packages. Downstream integration issues such as thermal management, optical control and driver efficiency will be addressed along with the LED component manufacturing. Also, the author will present a total cost of ownership model for LED lighting in both retrofit and new applications.


LED data sheet information usually does not allow an easy thermal design of LED applications as it is not always clear if emitted optical power was considered during the measurement of thermal resistance/impedance values. Luminous flux depreciation due to elevated junction temperature is also provided by means of relative light output versus temperature graphs only – again making life difficult if the lighting designer wants to check the performance of a luminaire at real-life operating temperatures. This presentation aims at introducing characterization techniques which provide real thermal metrics of LED devices together with their hot lumens and the temperature sensitivity of their luminous flux. It will also describe measurement, modeling and simulation options through the example of a streetlight luminaire design project, starting from the selection of LEDs and LED thermal management solutions through the final design of the luminaire.