DETECTING DEVICE OF PIN HOLE FOR COLD-ROLLED STEEL PLATE

摘要

PURPOSE: An apparatus for examining pin-hole of cold rolled steel sheet is provided to increase the detection rate for pin-hole corresponding to the direction of thickness of a steel sheet and pin-hole corresponding to the inclined direction of thickness of a steel sheet by equipping an optical device using an LED pulse light. CONSTITUTION: The apparatus for examining pin-hole of cold rolled steel sheet comprises an infrared pulse LED (21) generating rays required for detecting pin-hole; a ray-irradiator (22) irradiating rays generated from the infrared pulse LED in various angles; an electric controller (23) transferring the infrared rays in the form of pulse; a condensing lens (24) condensing infrared rays when the infrared rays appear on the back side of cold rolled steel sheet after passing through pin-hole; an infra red linear CCD sensor (25) transferring condensed infrared rays to electrical signal; a computer (26) estimating/deciding whether or not pin-hole is on the cold rolled steel sheet by using transferred electrical signal in the infra red linear CCD sensor.