Patent ID: 6933975

Claim:
An imaging apparatus comprising: a two-dimensional array of image sensor elements being configured to sense a first set of image elements of a target moving in a first direction with respect to the two-dimensional array of image sensor elements, to integrate light from the set of image elements into corresponding pixel values, and to shift the pixel values along the image sensor elements in the first direction according to a clock rate; a plurality of rows of image sensor elements spaced from each other, extending in the first direction, and being configured to sense a second set of image elements of the target moving in the first direction, to integrate light from the rows of image sensor elements into corresponding pixel values, and to shift the pixel values along the rows of image sensor elements in the first direction according to the clock rate, the plurality of rows having the same number of image sensor elements, each row having image sensor elements that are different in length from the image sensor elements of the other rows; and a measurement module coupled with the plurality of rows of image sensor elements to measure the sharpness of detected image elements sensed by the image sensor elements in each row and to identify the row of image sensor elements having the sharpest detected image elements sensed by the image sensor elements.