Patent ID: 6975307

Claim:
A method for detecting touch-point coordinates, applicable to a touch-point detecting apparatus for a resistive touch panel, wherein said resistive touch panel includes a first touch-panel resistor and a second touch-panel resistor, said touch-point detecting apparatus includes a plurality of switches and a plurality of resistors, and is coupled to the following five elements of a first power supply, a second power supply, said first touch-panel resistor, said second touch-panel resistor, and said resistive touch panel, and said first power supply and said second power supply are used for respectively applying constant voltages to said first touch-panel resistor and said second touch-panel resistor, said touch-point detecting apparatus comprising a first switch, a second switch, a third switch, a fourth switch, a first external resistor, a second external resistor, a third external resistor, and a fourth external resistor, wherein said third external resistor is coupled to a third power supply, said third external resistor and a first end of said fourth external resistor are coupled at a first node, said first switch and said first touch-panel resistor are coupled to a second end of said fourth external resistor at a second node, said first switch and said second switch are coupled to said first touch-panel resistor, said second switch is coupled to said first touch-panel resistor at a third node, said third switch and said fourth switch are coupled to said second touch-panel resistor at a fourth node and a fifth node respectively, and said first external resistor and said second external resistor are coupled to said first power supply and said second power supply respectively, and are coupled to said first switch and said third switch respectively, said method comprising the steps of: detecting pressure for determining whether there is an external force exerted on the resistive touch panel according to a pressure detection signal produced by performing the detecting pressure step; if so, proceeding to the next step; comparing pressure for determining whether said external force is effective according to a first signal and a second signal that are produced by the comparing pressure step; detecting a first coordinate by performing first-coordinate detecting of a touch point at which the external force is exerted on the resistive touch panel, to produce a first coordinate signal indicative of the first coordinate of said touch point; and detecting a second coordinate by performing second-coordinate detecting of said touch point at which the external force is exerted on the resistive touch panel, to produce a second coordinate signal indicative of the second coordinate of said touch point.