| 摘要 |
<p>Disclosed is a device for the authentication of an optically variable entity exhibiting a color shift with changing viewing-angle, the device comprising a plate of light-refractive material, said plate having two surfaces and an array of light-refracting protrusions or recesses on at least one of said surfaces, and being disposed in said device such as to provide, aside each other, a direct view and a view through said plate onto at least parts of said optically variable entity, said view through said plate being an angularly deflected view, resulting from light refraction at said protrusions or recesses. Further disclosed is a method for authenticating an optically variable entity, as well as the use of a plate having two parallel surfaces and an array of positive or negative light- refracting protrusions or recesses on at least one of said surfaces for authenticating an optically variable entity.</p> |
