Patent ID: 7151568

Claim:
A displacement sensor, comprising: an imaging unit for imaging a surface of a measurement object having a sectional light image from such an angle as to make a position of the light image look different in dependence on a displacement of the measurement object; and an image processing unit for computing the displacement of the measurement object by processing an image obtained from the imaging unit, wherein the imaging unit comprises: a two dimensional imaging device including a group of light receiving pixels arranged in a matrix having rows and columns 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 shift register for receiving the outputs of the vertical shift registers from top stages thereof, the light receiving pixels including 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, a front optically black pixel region comprising a first plurality of the rows extending in a direction parallel to the horizontal shift register, and a back optically black pixel region comprising a second plurality of the rows extending in a direction parallel to the horizontal shift register, wherein the photosensitive pixel region is interposed between the front optically black pixel region and the back optically black pixel region, and a drive control unit for controlling, according to a commanded electric charge transfer protocol, a feeding of signal electric charges from each 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 comprising 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.