| 摘要 |
An electrostatic impulse key suitable for use in electronic keyboards or as a separate item is described. An individual key comprises a single or plural metallic target area which may be formed on one surface of a printed circuit board. A dome spring is mounted above the metallic target and a foam cylinder is mounted between the dome spring and an actuator element. The actuator element is operated by a key mechanically connected thereto. In addition, a coil spring located about the foam cylinder between the printed circuit board and the actuator is provided for loading the actuator and key to a predetermined level prior to actuation (depression) of the key. When the key is depressed, the actuator presses the foam cylinder against the upper surface of the dome spring to cause the dome spring to change position. This position change changes the separation distance between the dome spring and the metallic target in a rapid or "snap action" manner. Because the separation distance is changed, the capacitance between the dome spring and the metallic target increases to cause a rapid decrease in a voltage connected between the dome spring and the target. This voltage decrease is in the form of a signal pulse and is suitable for use in electronic keyboard subsystems.
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