Patent ID: 8858057
Filing Date: 2014-10-14
Classification: F21S,G02B

Abstract:
1. An asymmetric prism structure comprising a plurality of asymmetric prisms arranged in parallel wherein each asymmetric prism has a first slant face, a second slant face, and a bottom face, connected end-to-end together; the first slant face directs light beams propagating perpendicular to the prism direction to a lateral side; the second slant face directs light beams propagating perpendicular to the prism direction to the other lateral side; for a cross-sectional triangle obtained from a plane perpendicular to the prism direction dissecting the asymmetric prism structure, the two slant faces of the asymmetric prism structure correspond to the two slant edges of the cross-sectional triangle, and the bottom face of the asymmetric prism structure corresponds to the bottom edge of the cross-sectional triangle; the cross-sectional triangle is shaped so that the projections of the two slant edges towards the bottom edge all fall within the bottom edge; and the lengths of projection p 1 and p 2 of the two slant edges, respectively, satisfy that p 1 >3×p 2 or p 2 >3×p 1 .