Patent ID: 7171075

Claim:
A luminaire comprising: a light-directing element having a light emission window, said light-directing element having a shape for directing light, which light originates from an electric light source to be accommodated, into an optical fiber system, wherein said shape is calculated in accordance with a ray-tracing algorithm which takes into account that said light source to be accommodated is voluminous, wherein said shape is composed of n solids of revolution of parabolic sectors, wherein adjoining parabolic sectors form an integral surface and wherein said parabolic sectors are parts of parabola defined by the following set of equations: a ( i )=( z ( i )− z ( i+ 1))/( x ( i ) 2 −x ( i+ 1) 2 ) b ( i )= a ( i ) c ( i )=( x ( i ) 2 * z ( i+ 1)−(( x ( i+ 1) 2 * z ( i ))/( x ( i ) 2 −x ( i+ 1) 2 ) wherein: a(i), b(i) and c(i) are polynomial coefficients of the parabolic sectors such that coordinates of each point of the reflective surface fulfill the condition: a ( i )* x 2 +b ( i )* y 2 −z+c ( i )=0; x, y, z are coordinates of the i th surface of revolution of the parabola in a linear x, y, z tri-coordinate system; the coordinates x(i), z(i), x(i+1), z(i+1) are limits of the i th parabolic sector in a plane xz; i is an integer from 1 to n.