SECURED TOUCH SCREEN

摘要

A secure touch screen device comprises a resistive touch screen having a plurality of touch positions, having a first pair of first and second terminals at opposite ends of a first axis of the touch screen, and a second pair of first and second terminals at opposite ends of a second axis of the touch screen, the second axis being orthogonal to the first axis. Upon pressing on a certain position on the touch screen there exist an electrical resistance between the first pair of terminals and an electrical resistance between the second pair of terminals, indicative of the position pressed. The first terminal of each pair of terminals is earthed, and the second terminal of each pair of terminals is connected to a variable resistance component connectable to a voltage source. The resistance of the variable resistance component is variable in a predetermined manner, the second terminal of each pairs of terminals being used to measure the resistance indicative of the position pressed.