Abstract: A workpiece inspecting apparatus for rotating a workpiece having a shape portion containing a convex portion and a concave portion which are periodically and repetitively formed on the workpiece and picking up images of the shape portion of the workpiece to inspect the workpiece, including a workpiece rotating mechanism that outputs reference pulses at a fixed interval while rotating the workpiece at a fixed rotational speed, an image pickup mechanism that picks up images of the shape portions of the workpiece every image pickup timing based on the reference pulses, an image pickup controller that synchronizes each of the shape portions of the workpiece with the image pickup timing, and an inspection controller that executes image processing of taking a difference between a pickup k-th (k represents an integer) image and a pickup (k+1)-th image and detects a defect on the basis of differential data representing the difference.

Abstract: A plurality of image sensors are arranged so that each of odd rows is constituted by image sensors lined up in the X direction, and each of even rows is constituted by image sensors, more than that of the odd row by 1, lined up in the X direction at the same pitch as the odd row with a 1/2 phase shift with respect to the odd row. Light receiving areas of image sensors on both ends of the even row include both ends in the X direction of an imaging target area image respectively, and a length in the Y direction of an area covering the light receiving areas of the image sensors on the first row to the light receiving areas of the image sensors on the last row is longer than a length in the Y direction of the imaging target area image.