| 摘要 |
<p>A keyboard includes a resilient foam layer (28) having an array of holes (30) therein with the layer (28) being sandwiched between a flexible sheet having dome-shaped areas (34) aligned with said holes and a dielectric member (38), the flexible sheet and dielectric member having electrodes (36, 40) thereon which are arranged to complete a circuit associated with a hole (30) when the flexible sheet and member are moved toward each other. A snap action of the dome-shaped areas (34) in the switch movement provides for improved tactile response and switch travel and reduced switch actuating force. Additional foam layers enhance the operating characteristics of the embodiments. A method of production of the keyboard entails determining the operating parameters of a desired keyboard and selecting the relative density and thicknesses of various resilient layers and flexible sheets in the keyboard to determine the switch actuating force, the extent of travel of the switch, and the location of the "makepoint" of the switch at a position between the start and end of switch travel. </p> |
