Composite function keyboard circuit

A composite function keyboard circuit, comprising:

• a matrix circuit comprising a driving line group with a plurality of driving lines, a sensing line group with a plurality of sensing lines and a switch unit group with a plurality of switch units, wherein the plurality of driving lines and the plurality of sensing lines are arranged in a matrix, and each of the switch units of the switch unit group is electrically connected with the corresponding sensing line and the corresponding sensing line;
• a bias resistor circuit electrically connected with the sensing line group and serially connected with the switch unit group, wherein the bias resistor circuit comprises a plurality of bias resistors, a first terminal of each bias resistor of the bias resistor circuit is electrically connected with the sensing line group and the switch unit group, and a second terminal of each bias resistor of the bias resistor circuit is connected with a ground terminal;
• and
• a controller electrically connected with the driving line group, the sensing line group and the first terminal of each of the bias resistors of the bias resistor circuit,
• wherein each of the switch units in the switch unit group includes an ink-type force sensing switch and an anti-ghosting unit, a pressure-related resistance of the ink-type force sensing switch is variable according to a pressing mode of a keypress action, and an electrical connection path is defined by the ink-type force sensing switch and the corresponding bias resistor of the bias resistor circuit,
• wherein when the ink-type force sensing switch is electrically conducted, a divided conduction voltage is generated by the electrical connection path,
• wherein according to a level of the divided conduction voltage, the controller generates a corresponding key control instruction, and the controller judges whether the switch unit in the switch unit group is effectively turned on, so that a ghost key phenomenon is avoided.