Abstract: The present invention is a simplified membrane keyboard employing a single flexible sheet. This membrane keyboard is employed in an electronic apparatus having an external case with a nonconducting keyboard surface. This nonconducting keyboard surface has a plurality of depressions corresponding to key switch positions. The keyboard surface is covered by a keyboard sheet. This keyboard sheet has a flexible membrane with opposed first and second surfaces, the first surface disposed adjacent to and substantially covering the keyboard surface of the external case. An interconnection pattern is placed upon the first surface of the flexible membrane. This interconnection pattern has a plurality of conductors and most particularly has a pair of conductors in proximity at each key switch position. Pressure applied to the second surface of the flexible membrane causes the flexible membrane to flex until the two conductors contact a conductive layer disposed in the bottom of the corresponding depression.

Abstract: Disclosed is an area actuated switch which can be used, by way of example, in a keyboard for a calculator, learning aid or the like. An area actuated switch array is formed using two insulating sheets made of polyester or polycarbonate; the insulating sheets overlie one another such that one side of each sheet faces one another. Groups of spaced conductors formed on each of the facing sides also overlie one another, and selected conductors traverse the periphery of the keyboard. A plurality of raised, insulating spacer areas or points are positioned on the facing sides and are in registration and contact with each other. An insulating substrate is formed over the conductors traversing the periphery and this insulating substrate has substantially the same thickness as the spacer points such that the spacer points and the insulating substrate prevent the spaced conductors from making electrical contact.

Abstract: Disclosed is an area actuated switch which can be used, by way of example, in a keyboard for a calculator, learning aid or the like. An area actuated switch array is formed using two insulating sheets which overlie one another such that one side of each sheet faces one another. Sets of spaced conductors formed on each of the facing sides also overlie one another, and selected ones of said conductors traverse the periphery of the keyboard. A plurality of raised, insulating spacer points are positioned on the facing sides and are in registration and contact with each other. An insulating substrate is formed over the conductors traversing the periphery and this insulating substrate has substantially the same thickness as the spacer points such that the spacer points and the insulating substrate prevent the spaced conductors from making electrical contact. An adhesive coating is applied to the spacer points and the insulating substrate to bond these two parts together.