| 摘要 |
<p>Retroreflector e.g. for road marking comprises light-transmitting sheet, pref. of organic polymeric material, in an angular position as a normal at one point of the sheet is at 5-85 degrees to an incident light beam. The sheet has parallel front and rear surfaces, of which the front surface is smooth and refractive, and the rear surface is provided with reflective units. At least some of the reflective units comprises three mutually perpendicular surfaces defining a trihedral angle of a rectangular parallel piped and located relative to the front surface with the diagonal of the parallel piped at 15 degrees to incident light refracted by the frong surface. Arrangement provides greater retroreflective capacity for wider angles of incidence.</p> |
