US Patent 7528337 Pressure sensitive conductive sheet and panel switch using same

A first resistor layer is formed on the lower surface of a base in film form, and at the same time, a second resistor layer in which particles of different particle diameters are dispersed is formed and layered on the lower surface of the first resistor layer, and thus, a pressure sensitive conductive sheet is formed. In this configuration, the second resistor layer in uneven form makes contact with the fixed contacts in accordance with a pressing force so that electrical connection is made via the second resistor layer and the first resistor layer, and therefore, a thin panel switch with little fluctuation in the resistance value resulting from repeated operation where a stable resistance value can be gained can be realized.