CAPACITANCE-SENSITIVE SWITCH AND SWITCH ARRAY

摘要

A capacitance-sensitive switch unit (10) including a capacitive element (18) operable to produce an effective capacitance dependent upon the physical proximity of objects relative thereto, a first selector signal input (14) connected to the capacitive element (18) to enable a first input signal to charge the effective capacitance, a threshold signal producing circuit (35) connected to the capacitive element (18) for producing a threshold signal which is rendered active when the effective capacitance charges to a pre-defined potential, a switching circuit (33) for selectively connecting the capacitive element (18) to the treshold signal producing circuit (35) in response to a switching signal and a discharge control circuit (11) connected to the capacitive element (18), for selectively discharging the effective capacitance independently of the input signal, in response to a discharge signal. Also disclosed is a switch array (100) employing structure similar to the above.