Patent attributes
An optical cracked-grain selector that does not mistakenly identify normal grains of rice having no cracks as cracked grains due to the presence of the embryonic portion and/or surface scratches when optically identifying cracked grains of rice mixed in with material rice grains. An identification part in a cracked grain identification unit obtains a first rice grain image (having an embryonic portion and scratches) based on light passed through the rice grain that is received by a first CCD sensor built into a CCD camera of a photoreaction detection unit and a second rice grain image (having cracks, an embryo portion and scratches) based on light passed through the rice grain received by a second CCD sensor built into the CCD camera, acquires an image of the cracks by calculating a difference in the amount of light between the two rice grain images, and identifies a cracked grain.