Patent ID: 9575225
Date: 2017-02-21
CPC Classifications: G02B

Claim:
1. A step prismatic retro-reflector with improved wide-angle performance, which has retro-reflector elements arranged thereon, the retro-reflector element comprising: a main reflective corner having a shared reflective surface of a geometric single plane, and a virtual step surface which is in contact with the shared reflective surface at a right angle; and a plurality of sub-reflective corners each having a pair of independent reflective surfaces which are in contact with each other at a right angle, and arranged along the step surface, wherein the retro-reflector elements are arranged such that a corner ratio l/w of each of the sub-reflective corners is 1.5 or more where l defines the length and w defines the width of the sub-reflective corners, a corner orientation Dc of each of the main reflective corners is deflected at 10 degrees or more with respect to a normal line N to an incident plane, a reflection orientation Dr is deflected at a deflection angle of 10 degrees or less, and deflection directions of the corner orientations Dc of the respective main reflective corners are alternately staggered in opposite directions to each other.