Transparent optical identification label.

摘要

An optical identification label (3) consisting of an area of hologram (10) or diffraction grating which is transparent to visible light but reflects incident light with a specific reflective directivity. By identifying the reflectivity directivity, it is possible to identify the authenticity of the label (3) and, hence the object to which the identification label is affixed. The fact that the identification label (3) is transparent to human eyes offers a strong discouraging effect on potential forgers. Further, the pattern of the reflected light may be used for encoding data.