METHOD AND DEVICE FOR DETECTING DEFECT

摘要

PROBLEM TO BE SOLVED: To surely detect a defect of an inspected object such as a sheet member by simple constitution using pressurized gas. SOLUTION: A tip of a nozzle 54 provided with a back pressure chamber 55 is approached to an outer face of the inspected object 1, the pressurized gas of fixed pressure is supplied to the back pressure chamber 55 to blow out the pressurized gas from the tip of the nozzle 54 toward the inspected object 1, pressure of the back pressure chamber 55 is detected while moving the inspected object 1 relatively with respect to the nozzle 54, and a recessed part 5, a protruded part 5' and a through hole 6 are detected thereby based on a change of the pressure of the back pressure chamber 55.