title: Free-form lens for rectangular illumination with the target plane rotating at a certain angle.
abstract: We have proposed a method for rectangular illumination in a (u, v) coordinate system with high collection efficiency and favorable uniformity. In our proposed approach, with the target plane rotating at a certain angle around the z axis, one of the diagonals on the rectangular target plane moves to the coordinate axis; then, we partition the light source and target plane into grids. The intersection points of the grids are in one-to-one correspondence from the source to the target plane. This improved method will avoid the one-to-many correspondence topological relationship in the traditional (u, v) mapping method; uniformity of the illuminance pattern will be promoted. Based on this method, lenses are designed for rectangular target plane illumination; uniformity over 0.83 and efficiency of about 0.92 are obtained with a 1  mm×1  mm LED Lambertian source.
authors.forename: Dianhong
authors.initials: D
authors.lastname: Liu
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Zhang
authors.forename: Chen
authors.initials: C
authors.lastname: Chen