LightFair International (LFI) is the premier lighting exhibition in the US drawing tens of thousands of people each year. LFI is equal lighting education and product showcase with the first half of the conference filled with panel discussions, keynote events and seminars with topics ranging from aesthetic lighting design to detailed lighting controls. As part of an ongoing full day seminar series, five subject matter experts teach on the, “Fundamentals of Luminaire Design”. The experts cover the five main disciplines: LED device construction and performance, electronic power and control, thermal management, optical control and systems engineering to codify the other four elements.
The optical control portion the presenter, Bob Householder, Director of LED Solutions Engineering at Universal Lighting Technologies, presented the fundamentals of light interaction with objects with a focus on LED light control for modern lighting fixtures. For the 2014 session at LFI, the speaker used a common replacement lamp as the foundation to teach on the use of illumination engineering software to “design” a reflective optic for a PAR38 light. A PAR38 lamp is used in screw based, recessed light fixtures for indoor and outdoor applications. The PAR38 lamp is defined by strict ANSI guidelines for shape and until recently has been one of the sought after challenges for LED adoption. Previous LED designs for this lamp used a multiple of lower power LEDs and individual cone shaped lenses to collect and shape the light. With improved materials and methods, fewer higher power LEDs were then adapted to the task again using the same cone shaped lens concept. The rise of the Chip on Board (COB) LED offers the use of a reflector to collect and shape the light from this new solid state source.
The presentation showcased reflector designs from a number of designers including Mr. Oleg Rybakovsky of Optics for Hire (OFH). Mr. Rybakovsky’s design was formed in the optical engineering software Zemax using OFH proprietary Bezier spline curves for natural, continuous control of optical shapes best suited for illumination design. The resulting light field was the correct size and shape providing uniform lighting for the task. OFH designers have yet agin helped this year to teach the more than one thousand participants in the, “Fundamentals of Luminaire Design” class since inception furthering greater understanding of the nature of light in the growing field of LED illumination.