Method and apparatus for inspecting the outer appearance of a spherical article

An apparatus for inspecting the outer appearance of a spherical article, comprising

• rotating means for supporting and rotating the spherical article in a predetermined direction at a predetermined speed,
• means for illuminating light to a selected position on the spherical surface of the spherical article in a tangential direction and in line with the rotational direction of the spherical article,
• a line sensor camera for taking a line image of the spherical surface in the vicinity of the selected position and along a line perpendicular to the light illuminating direction, and
• image converter means for receiving image data from the line sensor camera and constructing a two-dimensional image from the image data,
• wherein an abnormal brightness change which appears in the two-dimensional image as a result of an undesirable protrusion on the spherical surface shutting out the light is detected, thereby detecting the presence of the undesirable protrusion.

A method for inspecting the outer appearance of a spherical article, comprising the steps of:

• illuminating light to a selected position on the spherical surface of the spherical article in a tangential direction,
• rotating the spherical article in line with the light illuminating direction,
• operating a line sensor camera to take a line image of the spherical surface in the vicinity of the selected position and along a shooting direction in an angular range of 45 to 90 degrees to the light illuminating direction, the line sensor camera delivering image data,
• constructing a two-dimensional image from the image data, and
• detecting an abnormal brightness change which appears in the two-dimensional image as a result of an undesirable protrusion on the spherical surface shutting out the light, thereby detecting the presence of the undesirable protrusion.

An apparatus for inspecting the outer appearance of a spherical article, comprising

• rotating means for supporting and rotating the spherical article in a predetermined direction at a predetermined speed,
• means for illuminating light to a selected position on the spherical surface of the spherical article in a tangential direction and in line with the rotational direction of the spherical article,
• a line sensor camera for taking a line image of the spherical surface in the vicinity of the selected position and along a line forming an angle of 45 to 90 degrees to the light illuminating direction and,
• image converter means for receiving image data from the line sensor camera and constructing a two-dimensional image from the image data,
• wherein an abnormal brightness change which appears in the two-dimensional image as a result of an undesirable protrusion on the spherical surface shutting out the light is detected, thereby detecting the presence of the undesirable protrusion.