Patent ID: 8348489

Claim:
An illuminating system, comprising: a single LED emitter having a square or rectangular emitting aperture that is d1 by d2, a four sided etendue preserving angle transforming reflector whose input aperture is disposed just above the output emitting aperture of said single LED emitter receiving LED emission, a light guiding pipe whose input aperture receives light from the output aperture of said etendue preserving angle transforming reflector element, said light guiding pipe comprising one or more of a light guide bar having rectangular cross-section and a first refractive index, a tapered light guide bar having rectangular cross-section with a knife edge at one end and a first refractive index, a first optical film having a second refractive index, and a first prismatic lens sheet having a first refractive index plus a specularly reflecting coating deposited upon the facets of said first prismatic lens sheet, said light guiding pipe providing evenly distributed output light along one rectangular edge, collimated in one meridian, a light guiding plate one edge of which is disposed adjacent to said rectangular edge of said light guiding pipe, receiving said evenly distributed output light from said light guiding pipe, said light guiding plate comprising one or more of a light guide plate having rectangular cross-section and a first refractive index, a tapered light guide plate having rectangular cross-section with a knife edge at one end and a first refractive index, a second optical film having a second refractive index, a second prismatic lens sheet having a first refractive index plus a specularly reflecting coating deposited upon the facets of said second prismatic lens sheet, and a plane specularly-reflecting mirror, said light guiding plate providing an evenly distributed output beam across one rectangular output face, said output beam being substantially square or rectangular in cross-section and well-collimated in both output meridians.