Patent ID: 7163326

Claim:
A luminaire with directional sidelight extraction, comprising: a) a light pipe with a light-carrying core; the light-pipe having a first end in which light from a first light source is received, a second end, and a longitudinal axis; b) light-extraction means on the surface of the core of the light pipe, along a first longitudinal side of the luminaire; the light-extraction means being confined to a radial swath of the luminaire, along the longitudinal axis of the luminaire, of substantially less than 180°; c) angles passing through a first plane intersecting a radial center of the light-extraction means being termed alpha angles or alpha component angles; and angles passing through a second plane orthogonal to the first plane being termed beta angles or beta component angles; d) light-saving means on the second end for directing saved light from the second end towards the first end, at redirection angles other than an excluded range of redirection angles, so long as the photon content of light at alpha redirection angles is at least 10 percent of the photon content of light at beta redirection angles, where the excluded range of redirection angles is defined by: |β r |<=20° and |α r |<|β r |/10, where β r is the beta redirection angle and α r is the alpha redirection angle.