Prismatic retroreflective sheeting with reduced retroreflectivity of infra-red light

摘要

The present application relates to retroreflective sheeting that is capable of use in a license plate and that can be accurately read and/or detected by an ALPR system. The retroreflective sheeting is a prismatic retroreflective sheeting that provides reduced retroreflectivity of infra-red light. The retroreflective sheeting can also be a prismatic retroreflective sheeting that exhibits reduced retroreflectivity of incident infra-red light and substantially unaffected retroreflectivity of incident visible light.

主权项

1. A retroreflective sheet defining a first side and a second side opposite to the first side, the retroreflective sheet comprising:
cube corner elements including a substantially planar viewing surface and a structured surface, wherein the substantially planar viewing surface is nearer the first side than the structured surface is; a reflector layer adjacent to the structured surface of the cube corner elements, wherein the reflector layer is configured to reflect at least visible light incident transmitted through the cube corner elements to the reflector layer; and an infra-red non-transmissive material in the retroreflective sheet between the reflector layer and the first side of the retroreflective sheet, wherein the infra-red non-transmissive material leaves retroreflectivity of visible light incident on the substantially planar viewing surface of the cube corner elements and transmitted through the cube corner elements to the reflector layer substantially unaffected.