title: High-output LED-based light engine for profile lighting fixtures with high color uniformity using freeform reflectors.
abstract: In the stage lighting and entertainment market, light engines (LEs) for lighting fixtures are often based on high-intensity discharge (HID) bulbs. Switching to LED-based light engines gives possibilities for fast switching, additive color mixing, a longer lifetime, and potentially, more energy-efficient systems. The lumen output of a single LED is still not sufficient to replace an HID source in high-output profile fixtures, but combining multiple LEDs can create an LE with a similar output, but with added complexity. This paper presents the results of modeling and testing such a light engine. Custom ray-tracing software was used to design a high-output red, green and blue LED-based light engine with twelve CBT-90 LEDs using a dual-reflector principle. The simulated optical system efficiency was 0.626 with a perfect (R=1) reflector coating for light delivered on a target surface through the entire optical system. A profile lighting fixture prototype was created, and provided an output of 6744 lumen and an efficiency of 0.412. The lower efficiency was mainly due to a non-optimal reflector coating, and the optimized design is expected to reach a significantly higher efficiency.
authors.forename: Jesper
authors.initials: J
authors.lastname: Gadegaard
authors.forename: Thøger Kari
authors.initials: TK
authors.lastname: Jensen
authors.forename: Dennis Thykjær
authors.initials: DT
authors.lastname: Jørgensen
authors.forename: Peter Kjær
authors.initials: PK
authors.lastname: Kristensen
authors.forename: Thomas
authors.initials: T
authors.lastname: Søndergaard
authors.forename: Thomas Garm
authors.initials: TG
authors.lastname: Pedersen
authors.forename: Kjeld
authors.initials: K
authors.lastname: Pedersen