Method for ensuring the unambiguous detection of the simultaneous pressing of a number of keys in a cyclically interrogated keypad, such as a phone keypad, whereby decoupling diodes are incorporated in sensing and driving lines

摘要

Method for unambiguous determination of the simultaneous pressing of a number of keys (6, 5, 13) of a matrix type keypad. According to the method decoupling diodes (D1-D4) are connected in the sensing lines (S0-S7), in the driving lines (T0-T7) and or in the current path of the keys. The invention also relates to a corresponding keypad.