Abstract: A fan-line optical principle for use in the design of faceted specular reflectors for sharp-cutoff luminaires is disclosed, and a luminaire embodying this optical principle is described. The luminaire described comprises a high intensity arc discharge lamp, providing a primary light source with finite length and thickness, and a reflector including a plurality of specular reflecting facets with fan-line geometry. Each of these fan-line facets displays (in a given main beam direction) a primary light source image that is parallel and adjacent to the cutoff edge of that facet. The name of this invention relates to the fact that a perspective view toward the front of a sharp-cutoff luminaire embodying the invention shows that fan-line facets, and the images they produce, create a fan-like pattern. An important characteristic of the invention is that the images of the primary light source displayed by fan-line facets, at a given main beam angle, can show substantially all of the primary light source.

Abstract: The present invention is directed to an indirect luminaire, and to a lighting system using at least two such luminaires. The invention comprises a luminaire in which a linear light source and longitudinally linear reflectors are mounted in parallel inside a housing. The reflectors are located underneath and on each side of the light source and have angled facets which are adopted to reflect light to the sides at an upward angle. In the lighting system of this invention, the reflectors beam light onto the ceiling in the midpoint zone between parallel rows of luminaires to provide highly uniform and efficient lighting.