LIGHT SENSING CIRCUIT, A CONTROLLING METHOD OF THE SAME, AND A TOUCH PANEL COMPRISING THE LIGHT SENSING CIRCUIT, PARTICULARLY FOR JUDGING THE BRIGHTNESS OF LIGHT INCIDENT LIGHT BY SENSING THE CURRENT FLOWING IN A PHOTO DIODE

摘要

PURPOSE: A light sensing circuit, a controlling method of the same, and a touch panel comprising the light sensing circuit are provided to judge the brightness of the light incident to a photo diode by initializing the cathode electrode of the photo diode as regular voltage.;CONSTITUTION: A photo diode(D) generates current depending on the brightness of the light incident from the outside, and a driving transistor(Tr2) comprises a first electrode to which first power voltage is applied, a second electrode, and a gate electrode electrically connected to a cathode electrode. A first initializing transistor(Tr1) comprises a first electrode to which initializing voltage is applied, a second electrode connected to the gate electrode of the driving transistor, and a gate electrode to which previous scanning signal is applied.;COPYRIGHT KIPO 2010