| 摘要 |
<p>A system and method for determining which of a plurality of visually indistinguishable objects (14) have been marked with a covert indicator (10) in which a portion of a surface (12) of each of a first type of objects (14) are provided with a covert holographic indicator (10) which is exposed to be viewed but which is detectable only when illuminated with a coherent reference light of predetermined wavelength. The surfaces (12) of objects (14) are scanned with a coherent reference light with the predetermined wavelength, and evaluated to determine whether the scanned surfaces include the covert holographic indicator (10). The presence of the covert holographic indicator (10) indicates that the object (14) on which the covert holographic indicator (10) is detected is one of the first type of objects. The first type of object may be a winning game ticket, or a genuine, as opposed to counterfeit, article.</p> |
