Patent ID: 7909485

Claim:
A light distribution board used as an illuminating cover for a lamp set, said light distribution board comprising: a transparent board including a top surface defining a plurality of gratings regions extending across a central line, said gratings regions each having a plurality of arcuately extending saw toothed light gratings, with said saw toothed light gratings of adjacent gratings regions being non-concentrically disposed, wherein: each of said saw toothed light gratings includes a convex lens surface and a bevel plane lens surface, said saw toothed light gratings being arranged at two lateral sides of said central line of said transparent board to extend symmetrically therefrom, one of said bevel plane and convex lens surfaces being arranged to face away from said central line, the other of said bevel plane and convex lens surfaces being arranged to face toward said central line; adjacent ones of said saw toothed light gratings are disposed with said convex lens surface of one said saw toothed light grating extending to terminate at said bevel plane lens surface of the other; and, said top surface forms a light receiving surface of said lamp set.