A novel full-
color mixing optic using known RGB LEDs is proposed. Thanks to its small size, it is particularly suitable for pixels in variable message signs and display boards, but also for any other applications. Based on a known design according to WO 2012 / 068603, which presents
complete mixing of the LED light colors and has since been considered state of the art, limiting the number of chips used in the light sources and their arrangement reveals a previously unknown freedom in the design of the
light guide and the upstream converging lens, and thus in the achievable light distribution. This not only allows for improved
color mixing and more precise
adaptation of the light distribution to specifications, but can also open up new applications.The chips used (R, G, B) must be arranged in a linear, dense configuration of the same size and emission characteristics, which has become standard practice anyway. In this case,
color mixing is only necessary in this linear direction. For this purpose, the
optical fiber (3) has two reflection planes (4a, 4b) on either side of the linear direction and symmetrically to each other. These planes generate an endless series of mirror images of the
light source (1) for mixing. Freely shaped connecting surfaces (5a, 5b) are present in the transverse direction. The converging lens (7) has a focal point (Fh) on its
exit surface (6) only in the linear direction. In the transverse direction, it has a different focal point, focal spot, or
focal length profile. The lens tip (8) thus forms a freeform surface.