Homofocal reflectors are an approach to improving headlamp performance by creating sectionalized reflector surfaces that distribute light rays in desired directions. As the sections become infinitely small, these reflectors may approach continuous, variable radius of curvature (VRC) surfaces. Using new reflector design software and the FiELD (Tm) photometric analysis program, a range of variable curvature reflector surfaces have been evaluated. Aperture and filament position effects on photometric performance with a 9004 halogen bulb are described and the ability of this type of reflector to satisfy Federal automotive roadway illumination requirements with non-optically active covers is discussed.
