Patent ID: 7839392

Claim:
A sensing circuit for sensing an externally provided pressure on a panel including a first substrate, a second substrate corresponding to the first substrate to have an opposite electrode, and an insulating layer interposed between the first and second substrates, the sensing circuit comprising: a sensing capacitor including a sensing electrode on the first substrate, the insulating layer and the opposite electrode, the sensing electrode being connected to a first node; a first switching element comprising: a first source electrode receiving a first voltage; a first gate electrode receiving a first switching signal; and a first drain electrode electrically connected to the first node; a second switching element outputting a second current, the second switching element comprising: a second source electrode receiving a second voltage; a second gate electrode receiving a second switching signal; and a second drain electrode electrically connected to a second node; and a third switching element outputting a third current, the third switching element comprising: a third source electrode receiving a third voltage; a third gate electrode electrically connected to the sensing electrode at the first node; and a third drain electrode electrically connected to the second switching element at the second node, wherein a capacitance of the sensing capacitor is increased by the externally provided pressure, and a voltage level of the first node is decreased by the increased capacitance of the sensing capacitor, and wherein an amount of the third current is decreased by the decreased voltage level of the first node.