Patent ID: 8294688
Filing Date: 2012-10-23
Classification: G06F

Abstract:
1. An apparatus comprising: a first resistive screen extending in a first direction and a second direction; a second resistive screen extending in the first direction and the second direction and separated from the first resistive screen; a first reference resistor; a voltage source configured to apply a voltage across a series combination of the first reference resistor and the first resistive screen; a voltage detector configured to measure a first voltage across the reference resistor; and a controller configured to have at least a one touch mode of operation for determining a location at which the first resistive screen is being touched bringing it into contact with the second resistive screen at one location and to have at least a two touch mode of operation for determining two locations at which the first resistive screen is being simultaneously touched bringing it into contact with the second resistive screen at two locations, wherein the mode of the controller is dependent upon the first voltage measured by the voltage detector, and wherein the controller is configured when in the two touch mode of operation to calculate a displacement from a centre location using a linear relationship between a deviation and the first voltage.