| 摘要 |
The present invention relates to improvements in security devices that can be used in for various authend security applications, and in particular to an optically variable security device utilising multiple colour shift layers. The security device comprises a first colourshifting layer and a second colourshifting layer which exhibits different reflective characteristics to the first colourshifting layer. A partial first light absorbing layer is between first surfaces of the first and second colourshifting lay¬ers and a second light absorbing layer applied to a second surface of the second coloursliifting layer. The colour of the partial first absorbing layer is selected to substantially match the colour of light reflected at a normal angle of incidence by the combination of the second colourshifting layer and the second absorbing layer. |
