Method for driving a photo-sensor by applying a pulse voltage to an auxiliary electrode during a non-read time

摘要

A method for driving a photo-sensor to produce an improved, stable output which exactly represents the incident light is disclosed. The photo-sensor has a pair of main electrodes found on a semiconductor layer with a photo-sensing area arranged therebetween. A semiconductor layer and an auxiliary electrode are formed on at least the photo-sensing area with an insulating area being interleaved therein. The auxiliary electrode is used for stabilizing the photosensing output and providing a signal proportional to the incident light. The method of driving such a photo-sensor includes applying a bias voltage to the auxiliary electrode in accordance with the carriers carrying a current of the semiconductor layer. A voltage of the same polarity as that of the bias voltage, but smaller in absolute value, is applied to the auxiliary electrode for a predetermine period of time in a non-read period of the photo-sensor to cause a next photo-sensor output to be read while a previous photo-sensor has been erased.