| 摘要 |
The keyboard (1) has a cover (11), keys (2) and means (3) to bring each key into a working position in which the key can action means (13) to deliver a key identification signal. The keyboard is fitted with means (3,5,6,12) which are not visible when the cover is mounted , these means trigger an intrusion signal when the keyboard cover is moved from its mounted position. The means (3,5,6,12) have an intrusion detection key (12) which has a first position when the cover (11) is in its mounted position and a second position when the cover is removed. The means (3) automatically displaces the key (12) from the first to second position when the cover is moved from its mounted position. The key (2) identification means includes a printed circuit (4) conductors (5,13) and the means (3,5,6,12) and conductors (16) mechanically coupled to the cover (11) and electrically connected to a conductor (5) of the printed circuit. Movement of the cover from its mounted position triggers the intrusion signal by modifying the electrical arrangement of one at least of the conductors (5,13).
|
