Patent ID: 7957082

Claim:
A light redirecting article for redirecting light toward a target angle, the light redirecting article comprising: (a) an input surface comprising a plurality of light redirecting structures each light redirecting structure having: (i) a near surface having two slopes, sloping away from normal in one direction as defined by a first inclination base angle β 1 , a second inclination angle β 2 , and a first half apex angle α 2 , for accepting incident illumination over a range of incident angles; (ii) a far surface sloping away from normal, in the opposite direction relative to the near surface, as defined by a second base angle γ 1 and a second half apex angle α 1 ; and (b) an output surface opposing to the input surface wherein the near and far surfaces are opposed to each other at an angle (α 1 +α 2 ) that is in the range from 60 to 70 degrees, and the base angle β 1 is in the range from 82 to 87 degrees.