| 摘要 |
<p>Grounded, circular movable electrode (11) and divided electrodes (15a - 15d), formed on a surface of a circular printed board (14), are opposed to each other via a double-face tape (13), functioning also as a spacer, with a slight gap interposed therebetween. As a pad (10) is struck with a stick, the gap between the movable electrode and the divided electrodes changes so that capacitance between the movable electrode and the divided electrodes changes, in response to which signals are output from the divided electrodes. The divided electrodes (15a - 15d) are sandwiched between the grounded movable electrode (11) and a grounded shielded electrode (16) and thus are not influenced from external disturbances. As the pad is struck with the stick, the gap and hence capacitance between the movable electrode and any of the divided electrodes in the struck position changes, in response to which signals are output from the divided electrodes. Position of a particular one of the divided electrodes (15a - 15d), which has output a signal of a maximum level among the output signals from the divided electrodes, is output as information indicative of a struck position on the movable electrode.</p> |
