Patent ID: 6919882

Claim:
A position detection device for use on a plane surface to determine the position of a capacitive coupling device, comprising: two arrays of row and column conductive wires are isolated by an insulated layer, said row wires have a pitch of c, between each row wire there is a common row wire separated from the row wire with a distance of c/2; said column wires have a pitch of d, between each column wire, there is a common column wire separated from the column wire with a distance of d/2; said common row wires are connected to a common row terminal; said common column wires are connected to a common column terminal; a wire selecting decoder and a driver supplying AC signal to said row wires and said column wires, as well as common row and common column wires sequentially; and supplying a specific voltage level to said common wires, which are not being supplied the AC signal; also supplying specific DC voltage to rows or columns, which are not being supplied the AC signal an oscillator generates the required frequency and amplitude of the AC signal voltage and supplies said signal voltage to a microprocessor; said microprocessor supplies said sequential signal via a bus to said wire selected decoder and driver; a capacitive coupling device senses the detected signal at a point of said plane surface and transmits said detected signal to an amplifier via a shielding wire; an amplitude detector receives and detects the amplitude of said detected signal from said capacitive coupling device and transmits to an A/D converter; said A/D converter converts said detected signal amplitude to a digital signal and communicates with said microprocessor.