| 摘要 |
<p>Granular objects flowing in a continuous form are irradiated by light, image element signals from a solid-state image device are binarized by a threshold value of a predetermined luminance brightness determined for detecting a defective portion of a granular object of a first level, and the above image element signals are also binarized by a threshold value of a predetermined luminance brightness determined for detecting a defective portion of a second level. The second level is for a tone of color heavier than that of the first level. When a defective image element signal is detected from the binarized image elements, an image element of a defective granular object at the center location is specified based on the data of the image element signals from the solid-state image device binarized by the threshold value of a predetermined luminance brightness determined for detecting the outward form of the granular object and the specified defective granular object image element, and the sorting signal is outputted to act on the center location of the defective granular object corresponding to the image element at the specified center location. A granular object having a heavily colored portion which, even small in size, has influence to the product value can be effectively ejected. Sorting yield is improved by not sorting out the granular objects having a defective portion which is small and only lightly colored thus having no influence to the product value. <IMAGE></p> |
