| 摘要 |
A primary portion of a security tag for attachment to an article comprising a locking mechanism for locking to a secondary portion of the security tag, and a metal portion 1003 which contracts when energised to release the locking mechanism as a result of the contraction. The metal may be a shape-memory-alloy wire and the energising may be resistance heating, preferably by receiving an electrical current from an input charging device such as a capacitor 1011 which is charged via a battery. The locking mechanism may also include a spring and the release of the locking mechanism is affected by compression of the spring in response to the contraction. The release procedure may be activated via an external signal, e.g. from a mobile phone. Also claimed is a security tag portion with a detection device that activates if the primary portion is removed from the article. |
