High-efficiecy optical element for led display backlight systems

New design of refractive optical element for display backlight systems is presented. The presented design can be used instead of linear light sources (like electroluminescent lamp with cold cathode). It is intended for uniform illumination of two line segments on the diffuse reflector. The problem of computation of optical surface is reduced to integration of a set of two explicit first-order differential equations. Simulation data for backlight unit containing matrix of designed optical elements demonstrates uniform illumination of rectangular area at the distance of 12-16 mm for LED sources. Light efficiency of the presented optical system is more than 94 %.