Patent ID: 8682949

Claim:
A proximity detection device for detecting an approach and/or a position of an object, the proximity detection device comprising: plural transmitting electrodes corresponding to one of two dimensions in a detection area on a supporting unit and receiving electrodes corresponding to the other of the two dimensions of the detection area; a multiline driving unit that simultaneously applies periodic alternating voltages to at least two electrodes of the transmitting electrodes to drive the at least two transmitting electrodes; a current measurement unit that measures current values or amounts of accumulated charge from the receiving electrodes in synchronization with driving of the at least two transmitting electrodes; a computing unit that calculates the approach and/or the position of the object toward the detection area by converting the current values or the amounts of accumulated charge measured by the current measurement unit into values in response to electrostatic capacitances of respective intersections between the transmitting electrodes and the receiving electrodes; and a control unit that manages statuses and sequences of the multiline driving unit, the current measurement unit, and the computing unit, wherein the computing unit includes: a linear computing unit that performs linear computation to convert the current values or the amounts of accumulated charge measured by the current measurement unit into values in response to the electrostatic capacitances of the respective intersections between the transmitting electrodes and the receiving electrodes, and a proximity computing unit that computes the approach and/or the position of the object toward the detection area from an output of the linear computing unit, and wherein the linear computing unit includes a memory unit that stores an interim result of the linear computation performed by the linear computing unit so as to allow the interim result to be read out at plural times.