A displacement sensor comprising an imaging unit and an image processing unit. The imaging unit comprises a two dimensional imaging device and a drive control unit. The two dimensional imaging device includes a group of light receiving pixels arranged in a matrix so as to correspond to a field of view of a standard imaging unit, a plurality of vertical shift registers corresponding to different columns of the pixels, and a horizontal register for receiving the outputs of the vertical shift registers from top stages thereof, a photosensitive pixel region being defined in a prescribed horizontal band having a sufficiently narrower width than that would be provided by the total number of horizontal lines and interposed between a front optically black pixel region and a back optically black pixel region. The drive control unit controls, according to a commanded electric charge transfer protocol, a feeding of signal electric charges from each light receiving pixel to the vertical shift register of a corresponding column, a vertical transfer of signal electric charges in the vertical shift register of each column, and a horizontal transfer of signal electric charges in the horizontal shift register. The image processing unit comprises electric charge transfer protocol command means for giving an electric charge transfer protocol to the drive control unit of the imaging unit in dependence of a content of the image process.