Apparatus and method for monitoring the surface character of circular objects

Apparatus for monitoring the surface character of an elongated generally circular test object, such as a coated cable, the test object being longitudinally movable along a path relative to said apparatus, said apparatus comprising:

• an optical system having an apparent axis substantially coincident with the centerline of said test object path, said optical system comprising means for providing a source beam of electromagnetic radiation, means for rotating said beam about the apparent optical axis, means for dividing the rotating source beam into a plurality of beams, each beam of the plurality traversing an arc of predetermined angular extent about its own respective optical axis, at least one of said divided-beam axes differing from said apparent optical axis, the cumulative angle traversed by said plurality of divided beams being at least about 360.degree., means for directing each of said plurality of divided beams toward said apparent optical axis such that it is incident with and scans a respective arcuate segment of the 360.degree. circumference of any said test object thereat, thereby avoiding interruption of said rotating beam by a test object on said object path and affording a scan of the entire 360.degree. circumference of any said test object such that the beam is reflected by the scanned portion of the circumference of the surface of any said test object thereat, and means for detecting the beam reflected from said scanned portion of the circumference of the test object and providing electrical signals indicative of the intensity thereof;
• and
• utilization means responsive to said electrical signals for providing an indication of the surface character of the test object.