Automatic obscuration elimination for off-axis mirror systems without plane of symmetry

We proposed a method to automatically eliminate the obscuration in the design of off-axis mirror systems without plane of symmetry. Off-axis settings and local surface expression are designed to simplify the system representation. Obscuration error function is established based on the positional relation between the proposed mirror boxes and ray boxes, and through function optimization, the obscuration is eliminated. The method is demonstrated by two examples, indicating its ability to eliminate obscuration for totally off-axis mirror system and the searching for such systems from co-axial starting points.