| 摘要 |
PROBLEM TO BE SOLVED: To provide a surface inspection method for certainly detecting even minute surface defects. SOLUTION: A radiation light flux 5 from a projector 9 is reflected on a surface of a magnetic sheet 1, the reflected light is received by a light receiving sensor 7, thereby inspecting the surface of the magnetic sheet 1 based on a light receiving amount of the light receiving sensor 7. A light receiving optical axis 13 of the light receiving sensor 7 passes part of an incident region where the radiation light flux 5 comes into the surface of the magnetic sheet 1, and the incident point P1 where the center axis 12 of the radiation light flux 5 and the magnetic sheet 1 intersect is different from the incident point P2 where the light receiving optical axis 12 of the light receiving sensor 7 and the magnetic sheet 1 intersect. In the center axis 12 of the radiation light flux 5, the incident angleθ1 to the surface of the magnetic sheet 1 is set in the range of 20-40°, and the angular difference dθ(=¾θ1-θ2¾) between the incident angleθ1 of the center axis 12 of the radiation light flux 5 and the light receiving angleθ2 of the light receiving optical axis 13 of the light receiving sensor 7 is set in the range of 4-20°. COPYRIGHT: (C)2006,JPO&NCIPI
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