The present invention is made to realize a two dimensional optical sensor array having improved performance, for instance, at least one of improved response time, improved intermixing problem, improved dynamic range, improved ability to sense a lower illuminance optical image and improved signal to noise ratio. For these purposes, an optical sensor array with a novel sensing method is proposed. For sensing each of the optical sensor in the array, one of a selected group of plurality of interconnecting means is selected and is driven from a first electrical potential to a second electrical potential while rest of the selected group of plurality of interconnecting means are kept to the first electrical potential, then, photo-electrical current from optical sensors connected to the selected one of the selected group of plurality of interconnecting means is sequentially sensed at around the second electrical potential through the selected one of the selected group of plurality of interconnecting means, by sequentially driving each one of unselected group of plurality of interconnecting means from a third electrical potential to a fourth electrical potential and then from the fourth electrical potential to the third electrical potential.