| 摘要 |
An improved security device that can be used in for various authenticating or security applications, and in particular to an optically variable security device utilising multilayer polymer films comprises a first multilayer film 12 which comprises alternating layers of at least two different polymers and a second multilayer 13 film which comprises alternating layers of at least two different polymers and which exhibits different reflective characteristics to the first film. At least one of the layers comprises a light absorbing dye or pigment which lies between the first and second films. |
