| 摘要 |
PURPOSE:To decrease the number of components and to suppress a magnetic leak by arranging the upper yoke on the reverse surface of a key opposite closely to a lower yoke on a shelf plate composed of individual yokes with coils which are arranged zigzag on both sides of a common yoke. CONSTITUTION:When a voltage is applied to the coil 34 of the key driving device 30 corresponding to a specific key 31, the upper yoke 35 on the reverse surface of the key is attracted to the lower yoke 33 to strike on it with strength corresponding to the voltage. The yokes 35 and 33 are held not in contact at all times, so the generation of a mechanical noise is prevented to relieve a feeling of physical disorder at the time of key depression. The device 30 consists of four members, i.e. the coil 34, and the upper, lower, and common yokes to decrease inspection items and also realize high productivity. Further, the individual yokes 37 are arranged zigzag to suppress the lead of a magnetic field generated by coils 34 between adjacent devices 30, a magnetic circuit is shortened, and the thrust to the stroke of the keys is smoothed and made large. |
