Patent ID: 6639587
Filing Date: 2003-10-28
Classification: G06F

Abstract:
An apparatus for determining a relative contact position on a touch panel sensor comprising an X-resistance and a Y-resistance, the X-resistance having a first X-connection and a second X-connection, and the Y-resistance having a first Y-connection and a second Y-connection, the apparatus comprising:means for connecting the first X-connection to an X capacitor; means for connecting the first Y-connection to a Y capacitor; means for connecting the first X-connection, the second X-connection, the first Y-connection, the second Y-connection, the X capacitor, and the Y capacitor so that each of two or more circuits are enabled to measure the relative resistance between each of the first X-connection, the second X-connection, the first Y-connection, and the second Y-connection, each of the two or more circuits having a sense point; means for configuring each of the two or more circuits to be charged to peak capacity; means for configuring each of the two or more circuits to discharge below a predetermined threshold as measured at the sense point; means for connecting each of the two or more circuits to measure an elapsed time for to each circuit to discharge below the predetermined threshold; and means for determining from the elapsed time that each of the two or more circuits the relative contact position.