Fujitsu Corporation

Norio Endoh

Kazutoshi Hayashi

Shigeo Tanji

Hideo Yamada

An input detecting apparatus, method in a switching matrix in which a plurality of switches are provided in the form of a matrix, which discriminates a sneak pass signal current caused by overlapping keying of up to 10 switches and is provided with a switching matrix including a driver circuit, a detecting circuit, a first group of a plurality of lines (1.sub.0 -1.sub.6), each connected to the driver circuit (2), a second group of a plurality of lines (3.sub.0 -3.sub.6), each connected to the detecting circuit, and a plurality of switching devices including a resistor (6) and a switching element (5) serially arranged, one end of each switching device being connected to one of the first group of lines and the other end to one of the second group of lines, the driver circuit having a decoder (11) which in turn connects one end of each oen of the plurality of lines of the first group (1.sub.0 -1.sub.6 ) to an electrical source having 0 voltage, one by one, the detecting circuit having a selector ( 7) selectively connecting in turn one end of the plurality of lines of the second group (3.sub.0 -3.sub.6) to a voltage detecting circuit thereof, the rest of the end of the plurality lines of the second group being connected to a decoder in which the ends of the plurality lines of the second group are in turn opened in synchronization with the operation of the selector, and a means is provided for applying a predetermined voltage higher than the detecting voltage to detect the switching operation.

Detecting apparatus for detecting input operation in a switching matrix

A sheet switch comprises a pair of flexible insulative films, one of which is provided with a plurality of electrodes, resistances connected to the electrodes, respectively, and line patterns for externally connecting the electrodes via the resistances. The other insulative film is also provided with a plurality of second electrodes at positions corresponding to the first electrodes, respectively, and a space is defined between each of the facing electrodes. The line pattern is a laminated structure consisting of an underlayer formed of a low resistance paste and an upper layer formed of a high resistance paste coated over the underlayer. The underlayer formed of a low resistance paste is partially disconnected to define a gap, so that the resistance is formed integrally with the upper layer formed of a high resistance paste at a position corresponding to the gap.

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Suzaka, Japan

Norio Endoh