| 摘要 |
An authentication device for authenticating a luminescent security mark, the device comprising an illumination source 30 configured to irradiate the security mark with a pulse of excitation radiation so as to cause the security mark to emit luminescent radiation that decays with time; a radiation detector 31 configured to detect the luminescent radiation emitted by the security mark; and an optical waveguide 22 positioned relative to the illumination source 30 and the radiation detector 31 and configured so as to guide by internal reflection both excitation radiation emitted from the illumination source towards the security mark, and luminescent radiation emitted by the security mark towards the radiation detector. The waveguide is preferably a solid optical material, such as an acrylic glass, and may be cuboidal and elongate. The LEDs that comprise the illumination source and the photo-detector that comprise the radiation detector may abut the optical waveguide. The side surfaces of the optical material may be covered with cladding material. The use of an optical waveguide means that the illumination source need not be focused, giving a larger area for radiating the security mark, which may be of a taggant ink. |
