Patent ID: 7275840

Claim:
A luminaire comprising: an elongate reflector extending along an axis and comprising a plurality of elongate surface features extending along one another and along said axis, each with a reflecting surface, said surface feature having a curvature in cross-section; an elongate concave counter-reflector extending along said axis such that the reflecting surfaces of the surface features and a light emission window of the counter-reflector, said window being in a plane T, mutually face one another; contact means positioned between the reflector and the counter-reflector for accommodating at least one electric lamp, wherein the curvature of a surface feature n is such that during operation of the electric lamp light coming from the light emission window and incident on each respective surface feature n is reflected as a beam having a beam angle Φ n with respect to the plane T, bounded by a minimum angle of reflection β with respect to the plane T and a maximum angle of reflection α n , wherein α n is an angle of reflection with respect to the plane T at which the light is reflected such that it shears along the counter-reflector, and wherein the light reflected as a beam at an angle Φ n bounded by said minimum angle of reflection β and said maximum angle of reflection α n by each respective surface feature n, whereby there are transition regions of contrasting brightness between the respective surface features n.