SURFACE DEFECT INSPECTION APPARATUS FOR CYLINDRICAL INSPECTION TARGET

PROBLEM TO BE SOLVED: To provide a surface defect inspection apparatus for a cylindrical inspection target, which can inspect a defect generated on the surface of the cylindrical inspection target by a simple configuration.SOLUTION: Inspection units each of which including illumination means 2 for emitting light 3 having a dot-like cross section, light conversion means 4 for converting the dot-like light 3 into light 9 having a linear cross section which is arrayed on a straight line vertical to the center of a cylindrical inspection target 1 and separated from the surface of the inspection target 1 by a predetermined distance and applying the linear light 9 in a length direction of the inspection target 1, reflection means 5 for receiving the linear light 9 and reflecting the linear light 9 to the center 11 of the inspection target 1, and detection means 6a for receiving regular reflected light 8a reflected from a surface having no defect without receiving irregularly reflected light 8b reflected from a defect 7 of the inspection target 1 and detecting an amount of received light on each position of the regular reflected light 8a are arranged on the whole periphery of the inspection target 1, and determination means 10 which determines the defect 7 on the surface of the inspection target 1 and the position of the defect 7 from amounts of received light of regular reflected light 8a on respective positions detected from the whole periphery of the inspection target 1 is provided.