| 摘要 |
The present invention relates to improvements in security devices that can be used in varying shapes and sizes for various authenticating or security applications, and in particular to an optically variable security device utilising colourshift materials. The security device (10) comprises a first and a second layer (11a, lib) of a colourshifting material at least partially overlying each other and each having different colourshifting properties. At least partially applied over surface of one of the colourshifting layers is a light control layer (12) having a surface structure which modifies the angle of reflected light, such that light reflected by the security device is seen at a different viewing angle. |
