| 摘要 |
<p>The invention concerns an extra-flat device for detecting the presence or absence of one or several objects, for example a credit card or identity card, which detects the presence or absence of an object through a compact sensor (1) supplying an electric signal, which itself activates an integrated circuit (6) generating a light or sound signal through an light indicator or a sound generator (3). Said detector can be powered by a battery, a cell or a solar generator (4) inserted in the printed circuit (2) to make the apparatus autonomous, or still any other electric generator connected to a standard electric network. Said system is characterised by its compactness which enables it to be housed or removed very easily in standard sites in cards, provided in normal wallets or card carriers supplied by banks or sold in shops. Said detector is permanently removable. It is also characterised in that it does not require any support, envelope, or receptacle to function properly, and it is not exclusively used for bank cards and further still by its simple method of production, its actually practical use, its dependability and its very low cost.</p> |
