OPTICAL MEASUREMENT CIRCUIT AND LIQUID CRYSTAL DISPLAY INCLUDING OPTICAL MEASUREMENT CIRCUIT, AND METHOD OF DRIVING THE SAME

PROBLEM TO BE SOLVED: To provide an optical measurement circuit for accurately measuring an intensity of an external light in real time, and to provide a liquid crystal display including it, and method of driving the same. SOLUTION: The optical measurement circuit includes: a first photosensor 1 for outputting a first reference current corresponding to a first reference light; a second photosensor 2 for outputting a second reference current corresponding to a second reference light; a third photosensor 3 for outputting an external light current corresponding to the external light; a first current memory for sensing and reproducing the first reference current; a second current memory for sensing and reproducing a differential current between the first and second reference currents; a readout circuit having a storage capacitor charged by the differential current between the first and second reference currents flowing in the storage capacitor during a first time, and discharged by the differential current between the external light current and the first reference current flowing from the storage capacitor during a second time; and a determination section for calculating the intensity of the external light by utilizing the intensities of the first and second reference lights, and the first and second times. COPYRIGHT: (C)2009,JPO&INPIT