Patent ID: 8177374

Claim:
A retroreflective sheet structure comprising a transparent layer having a front light-receiving surface and a rear retroreflecting surface whereby light incident on the front surface will pass through the layer, impinge on the rear retroreflective surface and reflect back out through the front surface in a predetermined direction; wherein a large majority of the retroreflective elements have three faces that are planar without any out-thrusts or depressions, wherein at least some of the remaining elements have at least one disturbed face including a planar-disturbance which disrupts the planar profile of the face; wherein the disturbed faces are arranged in a pattern to collectively form a chosen identifying indicia on the retroreflecting surface; wherein most of the disturbed face reflective regions remain intact; wherein identifying indicia becomes visually detectable at an inspection distance of about 20 cm or less; and wherein the identifying indicia will not interfere with or detract from the retroreflective qualities of the structure.