Abstract: A sphere size measuring unit (15) measures respective diameters of an object sphere in the course of processing and a standard sphere made of the same material as that of the object sphere and furthermore having a target diameter of the object sphere. A size difference calculation unit (161) calculates a size difference between the diameter of the object sphere and the diameter of the standard sphere. A determination unit (162) compares the obtained size difference with a threshold value so as to determine whether or not the diameter of the object sphere reaches the target value.

Abstract: A visual inspection system for ceramic balls inspects flaws in the surface of ceramic balls, and includes an oil tank holding oil, a rotation device for rotating a ceramic ball targeted for inspection that is immersed in the oil in the oil tank, so that detection of the ceramic ball is possible along a meridian, an imaging means for imaging the entire surface of the ceramic ball rotated by the rotation device, an image processing means for image processing an image imaged by the imaging means, and an assessing means for assessing the presence of flaws in the ceramic ball based on image data resulting from the image processing.

Abstract: An apparatus for inspecting surfaces of spheres such steel balls, on which sequentiality of cleaning and screening steps is attained without danger of rusting, and inspection accuracy and efficiency are enhanced, comprises a cleaning device for cleaning the spheres on a rotary disc with rotating brushes, a mechanism for inspecting and screening the cleaned spheres in oil in terms of non-defective and defective, and a removal device for removing both spheres separately. The mechanism includes a driving roller revolving and carrying thereon each sphere, a set of control rollers making tangential contact with the sphere thrusted along the outer circumference of the driving roller, a sensor for inspecting the surface of sphere while imparting a twist toward the sensor to the sphere by rotations of the driving roller and control rollers, and an oil tank holding therein the elements above.