RETROREFLECTIVE SHEETING MATERIAL, A METHOD OF ITS PRODUCTION AND ITS USE

摘要

PCT No. PCT/DK94/00366 Sec. 371 Date Sep. 25, 1995 Sec. 102(e) Date Sep. 25, 1995 PCT Filed Oct. 4, 1994 PCT Pub. No. WO95/10827 PCT Pub. Date Apr. 20, 1995A retroreflective sheeting material comprising at least one retroreflective optical system (200, 300, 400) consisting of an entrance transmission optical element (201, 301) for receiving and focusing incident electromagnetic radiation from an irradiation source, and a reflective optical element (205, 405) for reflecting the incident electromagnetic radiation back toward the irradiation source; said reflective optical element being positioned in or near the effective focal point of the transmission optical element and the space between the optical elements optionally being constituted by a spacing material (202); wherein at least one of the optical elements (205, 301, 405) is a diffractive optical element, the reflective optical element (205, 405) for substantially all angles of incidence sends at least a part of the incident electromagnetic radiation back along the direction of the incoming chief ray (204), and the reflective optical element does not exclusively consist of a specular mirror type reflective optical element; methods of making such a retroreflective sheeting material; and use of the retroreflective sheeting material for the manufacture of a sign, a marker, or a decoration all of which exhibit retroreflective reflexes upon illumination.