Method and apparatus for detecting surface unevenness of object under inspection

An apparatus for detecting surface unevenness of an object under inspection, comprising:

• a first illuminator, among a plurality of illuminators, for casting slit light at a target surface of the object under inspection;
• a second illuminator, among the plurality of illuminators, for casting slit light at the target surface of the object under inspection from a different direction than the first illuminator;
• an image pickup for shooting a portion illuminated by the slit lights;
• a mover for moving the first and second illuminators and the image pickup and the object under inspection relative to each other;
• and
• a surface unevenness detector for detecting surface unevenness of the object under inspection based on luminance of a slit image shot by the image pickup,
• wherein a wavelength of the slit light cast from the first illuminator differs from a wavelength of the slit light cast from the second illuminator,
• wherein the image pickup shoots a reflected image of the portion where the slit lights reflect from the plurality of illuminators, and
• wherein the surface unevenness detector obtains luminance distribution waveforms for the mutually different wavelengths by image processing of the reflected image to separate it into reflected images for the mutually different wavelengths and detects surface unevenness of the object under inspection based on the luminance distribution waveforms obtained for the obtained mutually different wavelengths.