Abstract: An image sensor and a method for processing image data, can reduce a large proportion of data signals corresponding to high illumination and a small proportion of data signals corresponding to low illumination in order to generate an image just like the original, by adjusting the reset sampling period pertaining to the data signals outputted from a unit pixel. The image sensor includes a first switch which is operated by a reset sampling signal for sampling reset voltage when a voltage drop in an image data signal occurs, in which the image data signal is applied from a picture element part, a first capacitor for storing the reset voltage applied from the first switch, a second switch which is operated by a data sampling signal for sampling data voltage after completion of the voltage drop in the image data signal, a second capacitor for storing the data voltage from the second switch, and an image data processing circuit equipped with a comparator for comparing the reset voltage with the data voltage.

Abstract: A unit pixel of a CMOS image sensor includes one PMOS for receiving light and generating electric signals and one NMOS that outputs the signals applied from the PMOS. Therefore, the pitch size of the pixel itself can be reduced, and the whole area by the image sensor can be also reduced. The present unit pixel improves image embodying characteristics even at low illumination, and does not require integration time, thereby enabling production of a moving picture at high speed. Further, the present unit pixel of the image sensor is formed using only a simple MOS process, which dramatically simplifies the fabrication steps. Therefore, process yield can be improved, while production cost savings can be realized. According to the present discussion, the unit pixel of a CMOS image sensor formed on a P type semiconductor substrate, includes an N type doped well, a PMOS for receiving light and generating electric signals, and an NMOS for outputting the signals from the PMOS.