Electrode plate inspection method, method for fabricating power storage device, and electrode plate inspection apparatus

An electrode plate inspection apparatus comprising:

• a conveyor that conveys an electrode plate in which a coating material containing an active material is applied onto a current collector plate and rolled, in a longitudinal direction of the electrode plate;
• an illuminator that obliquely applies linear light extending in a width direction of the electrode plate onto a surface of the coating material of the electrode plate that is being conveyed by the conveyor;
• an acquirer that is disposed on a path of specular reflection of light applied by the illuminator by the coating material, and sequentially acquires specular reflection at multiple positions in the longitudinal direction of the coating material;
• and
• a determiner that determines whether a depression is present on the coating material, wherein
• the determiner includes
• a first processor that divides the specular reflection acquired by the acquirer in the width direction, and obtains a representative value of lightnesses at the multiple positions in the longitudinal direction for each of a plurality of regions in the width direction,
• a second processor that obtains a correction value with which the representative values of lightnesses are uniform among the regions in the width direction, for each of the regions in the width direction,
• a third processor that adds the correction value to the lightnesses of the specular reflection in each of the regions in the width direction, and
• a fourth processor that detects a dark portion with a lightness lower than a predetermined threshold and determines the detected dark portion as a depression, in a lightness distribution of the specular reflection after addition of the correction values.