MEMBRANE KEYBOARD AND METHOD OF PROVIDING SELECTABLE TACTILE PROPERTIES THEREFOR

摘要

MEMBRANE KEYBOARD AND METHOD OF PROVIDING SELECTABLE TACTILE PROPERTIES THEREFOR A "membrane"-type keyboard includes a resilient foam layer having an array of holes therein with the layer being sandwiched between first and second flexible membranes having electrical conductors thereon which are arranged to complete a circuit associated with a hole when the first and second membranes are moved toward each other. Embodiments including dome-shaped areas in the first flexible membranes provide for "tactile feedback" and additional foam layers enhance the operating characteristics of the embodiments. The method generally entails determining the operating parameters of a desired keyboard and simply changing the relative density and/or thicknesses of various layers and flexible membranes in the keyboard to obtain radically variable paremeters, as for example, the location of the "makepoint" of the switch at various positions between the start and end of "key travel".