Patent ID: 7499813
Filing Date: 2009-03-03
Classification: G01B,G01N

Abstract:
1. A flaw inspection device, which inspects for presence of a flaw on a surface of a workpiece, comprising: a surface position measurement device that, while rotating said workpiece around a predetermined rotational axis, measures a surface position of an inspection region of said workpiece in a direction perpendicular to said rotational axis, with respect to angular position of the workpiece about the rotational axis; a surface waveform acquisition means which receives an output signal of said surface position measurement means and acquires surface waveform data, which specifies said surface position with respect to the angular position of the workpiece; a high frequency waveform extraction means, which extracts, from said surface waveform data, high frequency waveform data that has a frequency higher than a predetermined frequency or high frequency waveform data that specifies a change of a position within an angular range smaller than a predetermined angle; and a flaw decision means that determines whether a flaw exists at said inspection region, based upon said extracted high frequency waveform data.