Patent ID: 7633300

Claim:
A method for evaluating touch signals applied to an analog resistive touch unit with first and second, spaced-apart resistance foils which have contacts (A, B and C, D respectively) at their respective opposing end zones arranged in perpendicular directions (X-direction, Y-direction) comprising the steps of: (a) applying a test voltage (UX, UY) to one resistance foil at a time, (b) measuring a current (IX, IY) through one resistance foil at a time, said current caused by said test voltage (UX, UY) being applied to the resistance foil, said measuring occurring if no touch has occurred, (c) storing the measured current per each foil as a desired current value (IXS, IYS), (d) after a determination that at least one touch occurred and after updating the desired current value (IXS, IYS), applying the test voltage to one resistance foil at a time, (e) measuring the actual current (IX, IY) in the resistance foil having the test voltage applied to it, (f) comparing said actual current (IX, IY) with the desired current value (IXS, IYS) for this resistance foil, and (g) in the event that the actual current (IX, IY) measured in at least one of the resistance foils is greater than the corresponding desired current value (IXS, IYS) for that foil, judging that a double touch occurred.