STEEL SHEET INSPECTION APPARATUS STEEL SHEET INSPECTION METHOD AND STEEL SHEET MANUFACTURING METHOD

摘要

This steel sheet inspection apparatus (1) is characterized by being provided with: a magneto optic element (5) that converts magnetic domain structures of a steel sheet (S) which is being inspected to optical characteristics that can be detected as optical characteristics; a light source (7) that projects linearly polarized light onto the magneto optic element (5); a detector (12) that detects linearly polarized light in which the plane of polarization has been rotated in response to the magnetic domain structures of the steel sheet (S) which has been transferred to the magneto optic element (5); and a drive mechanism that drives at least the magneto optic element in such a manner that the steel sheet (S) and the magneto optic element (5) are brought into contact and separated. Yields can thus be improved due to the fact that magnetic domains of steel sheets are visually inspected immediately after magnetic domain refinement processing.