Defect inspection system and defect inspection method

A defect inspection method, characterized by comprising:

• a step of capturing images of a face surface and a back surface of a plywood, which is sequentially conveyed by conveyors disposed spaced apart from each other in a conveying direction, in a gap between the conveyors, using imaging devices disposed at positions vertically above and vertically below the gap between the conveyors, and generating depth information in a board thickness direction based on the captured images of the face surface and the back surface of the plywood;
• a step of generating, by a shape measurement device, shape information by measuring a shape in the board thickness direction at a location different from a location of the gap between the conveyors;
• and
• a step of detecting, by an analysis device, a defect of deformation in the plywood due to warpage or bending by analyzing the depth information acquired by the imaging devices and the shape information acquired by the shape measurement device,
• wherein the step of detecting, by the analysis device, a defect in the plywood includes a first step of correcting, by a correction processing unit of the analysis device, the depth information based on the shape information, and a second step of detecting, by a defect detection unit of the analysis device, a defect in the plywood due to deformation based on the depth information corrected by the correction processing unit.