Surface Defect Inspecting Method And Device

摘要

A method of inspecting an inspection target surface comprises: irradiating an irradiation light having a predetermined pattern on the inspection target surface; imaging the surface irradiated with the irradiation light; and inspecting the inspection target surface based on an obtained image of the inspection target surface. The irradiation light irradiated from an irradiation face has a mesh-like pattern including meshes of a same shape. Each mesh has an irradiation area smaller than a non-irradiation area in a plane normal to the optical axis. The inspection target surface is inspected based on lightness/darkness information of an image area in the obtained image corresponding to a non-irradiated area in the inspection target surface. A light point having intermediate brightness and formed in a dark face formed within the mesh is extracted as a defect candidate.