Patent ID: 8115753

Claim:
A method of discerning between user interaction states in a touch screen system, comprising: receiving a first signal from a first detector of said touch screen system, said first signal representing a first image of an object interacting with a touch screen; receiving a second signal from a second detector, said second signal representing a second image of the object interacting with the touch screen; processing the first signal to determine approximated coordinates of a first pair of outer edges of the object; processing the second signal to determine approximated coordinates of a second pair of outer edges of the object; calculating an approximated touch area based on the approximated coordinates of the first pair of outer edges and the approximated coordinates of the second pair of outer edges of the object; if the approximated touch area is less than or equal to a threshold touch area, determining that the object interacting with the touch screen indicates a tracking state; if the approximated touch area is greater than the threshold touch area, determining that the object interacting with the touch screen indicates a selection state; if the object interacting with the touch screen indicates the selection state, determining whether the object moves relative to the touch screen; if the object moves relative to the touch screen, re-calculating the approximated touch area and determining whether the re-calculated touch area remains greater than or equal to the threshold touch area; and if the re-calculated touch area remains greater than the threshold touch area, determining that the object interacting with the touch screen indicates a dragging state.