Ghost key preventing circuit

A ghost key preventing circuit, comprising:

• plural driving lines, wherein the plural driving lines are discretely arranged;
• plural sensing lines, wherein the plural sensing lines are discretely arranged, and the plural driving lines and the plural sensing lines are arranged in a matrix and collaboratively formed as a matrix circuit;
• plural key switches, wherein plural switch circuits are defined by the plural key switches, the plural driving lines and the plural sensing lines collaboratively, wherein each of the plural key switches is electrically connected with a corresponding driving line of the plural driving lines and a corresponding sensing line of the plural sensing lines, and each of the plural key switches, the corresponding driving line and the corresponding sensing line are collaboratively formed as a corresponding switch circuit of the plural switch circuits;
• plural bias resistors, wherein a first terminal of each bias resistor of the plural bias resistors is electrically connected with the corresponding sensing line, and a second terminal of each bias resistor of the plural bias resistors is connected to a ground terminal;
• and
• a controller electrically connected with the plural driving lines and the plural sensing lines,
• wherein each of the plural switch circuits and the corresponding bias resistor are electrically connected with each other through the corresponding sending line to form an electric connection path, wherein when the key switch of a specified switch circuit is turned on, a divided voltage is generated and outputted from the specified switch circuit, wherein the controller judges whether the key switch of the specified switch circuit is normally turned on according to the divided voltage;
• wherein if the divided voltage lies in a first voltage range, the controller judges that the key switch of the corresponding switch circuit is normally turned on, if the divided voltage lies in a second voltage range, the controller judges that the key switch of the corresponding switch circuit is turned off;
• wherein each of the plural switch circuits further comprises a resistor, and a resistance of the resistor is equal to or nearly equal to a resistance of the corresponding bias resistor;
• wherein the resistor and the first terminal of the corresponding bias resistor are directly and electrically connected together through the corresponding sensing line.