| 摘要 |
<p>Device for automatically dialling stored telephone numbers for use in conjunction with a telephone handset. The device comprises a flat support consisting of two thin plates (8, 9). A disc-shaped acoustic transducer (2) operating at voice frequency and made of a resonating sheet, is inserted between said plates (8, 9), one of said plates having a cut out portion (at 10) located at the location of said sheet. The unit has a thin cross section (e) and can be made to the size of a credit card.</p> |
