Patent ID: 8441459

Claim:
An in-cell capacitive touch panel comprising: a first gate line; a second gate line; and a sensing unit comprising: at least one sensing liquid crystal capacitor; a first transistor, being controlled by said first gate line to charge said sensing liquid crystal capacitor and to generate a reference voltage at a first electrode of said sensing liquid crystal capacitor, and comprising a drain being connected to said first gate line; a source being connected to said sensing liquid crystal capacitor; and a gate being connected to said first gate line and said sensing liquid crystal capacitor, wherein said reference voltage is adjusted based on a voltage of said first gate line and a voltage variation ΔV p of said reference voltage is expressed by an equation: Δ ⁢ ⁢ V p = C gs C gs + C slc · Δ ⁢ ⁢ V g , wherein ΔV g is a voltage drop of said voltage of said first gate line, ΔV p is said voltage variation of said reference voltage, C gs is a gate-source capacitance of said first transistor and C slc is a capacitance of said sensing liquid crystal capacitor; a second transistor being driven by said reference voltage and generating an output current based on the received said reference voltage, wherein a gate of said second transistor is connected to said first electrode of said sensing liquid crystal capacitor and receives said reference voltage; and a third transistor being coupled to said second transistor and connected to said second gate line and a readout line, being controlled by said second gate line, and transferring said output current to said readout line.