Abstract: In an MRI-room LED lighting system having a plurality of LED lighting fixtures and a power supply located outside of the MRI room, the improvement comprising: driver circuitry and PWM dimmer circuitry in each of the lighting fixtures and a dimmer control located outside of the MRI room for controlling the light output of the lighting fixtures, the dimmer control having a variable DC output to control the PWM dimmer circuitry in each lighting fixture, whereby conductor lines from the power supply and dimmer control do not require electrical shielding avoid interference between a MRI scanner and the lighting system.

Abstract: In a sealed recessed lighting fixture having a housing forming a ceiling-alignment plane and a light-emitting opening, at least one elongate lamp mounted to and within the housing and defining a fixture direction, at least one reflector surface parallel to the fixture direction, and a lens, the improvement wherein the at least one reflector surface is/are part(s) of a unibody-reflector assembly which includes: (a) two reflector sections terminating in longitudinal inner edges forming a gap therebetween; (b) a distal edge perimetrically along the light-emitting opening of the housing; (c) a seal between the distal edge and the housing at the opening; (d) two opposed substantially parallel endwalls each having a lens-engaging proximal edge; (e) the lens being an elongate shaped member terminating at opposite lens ends, the lens enveloping the at least one lamp and being of substantially constant cross-section along its length, whereby the unibody-reflector assembly is removable from the housing as a single unit

Abstract: A lens system for LED based light fixtures having a substantially coplanar array of LED's with a requirement for a wide angle of illumination. And in particular, light fixtures comprising LED lights used in low bay applications.

Abstract: A thermal management and heat transfer system for light fixtures. And in particular, light fixtures comprising LED lights requiring lower temperatures than those required by incandescent of neon based light fixtures. The heat transfer includes taking advantage of the thermal updrafts caused by free convection of waste heat to cool the fixture.

Abstract: A cost effective illumination control system calculating motion and daylight or surrounding light inputs, particularly in large structures where the light distribution is not uniform across time. The system divides the structure into zones each having input capability with regard to occupation and background light levels. Each zone being able to make independent decisions with regard to control of lighting levels in the zone, yet the zones being able to cooperate in a coordinated fashion to provide uniform lighting to the structure as a whole.

Abstract: In a sealed recessed lighting fixture having a housing forming a ceiling-alignment plane and a light-emitting opening, at least one elongate lamp mounted to and within the housing and defining a fixture direction, at least one reflector surface parallel to the fixture direction, and a lens, the improvement wherein the at least one reflector surface is/are part(s) of a unibody-reflector assembly which includes: (a) two reflector sections terminating in longitudinal inner edges forming a gap therebetween; (b) a distal edge perimetrically along the light-emitting opening of the housing; (c) a seal between the distal edge and the housing at the opening; (d) two opposed substantially parallel endwalls each having a lens-engaging proximal edge; (e) the lens being an elongate shaped member terminating at opposite lens ends, the lens enveloping the at least one lamp and being of substantially constant cross-section along its length, whereby the unibody-reflector assembly is removable from the housing as a single unit

Abstract: In an MRI-room LED lighting system having a plurality of LED lighting fixtures and a power supply located outside of the MRI room, the improvement comprising: driver circuitry and PWM dimmer circuitry in each of the lighting fixtures and a dimmer control located outside of the MRI room for controlling the light output of the lighting fixtures, the dimmer control having a variable DC output to control the PWM dimmer circuitry in each lighting fixture, whereby conductor lines from the power supply and dimmer control do not require electrical shielding avoid interference between a MRI scanner and the lighting system.