Using secondary prismatic microarrays to refine the light distribution of automotive lightguide luminaires

Previous work has demonstrated the optimization of spatial distribution, angular pointing, angular widths, and design efficiency of light guide luminaires using prismatic light extraction elements. See, for instance, 1-4. Increasingly, in the automotive industry—and for signal lighting in particular—light guide luminaires that use secondary arrays of micro-optics are becoming more common. Typically, these secondary micro-optics are used either to scatter light selectively (micro partially scattering arrays), or to steer light (for example, micro prism arrays). In this work, we focus on the latter type of secondary optic arrays: micro prism arrays. As in previous studies, for this work, all geometrical elements were created in, and optical simulations were performed in, a CATIA V5 Based environment 5. We build on previous optimization techniques to create signal lamps; used in conjunction with arrays of prismatic elements that are part of secondary lenses. The secondary lenses are used to refine the angular distributions further. These modifications help to meet intensity test point specifications while at the same time preserving quality visual appearance. Typical sizes of the arrays studied are 0.25mm to 1mm pitch, with tens of elements to tens of thousands of elements.