APPARATUS FOR DETECTING WIDTH AND SURFACE DEFECTS OF STEEL SHEET BY LINEAR LASER PART AND CAMERA PARTS INSTALLED ABOVE STEEL SHEET

摘要

PURPOSE: To provide an apparatus for scanning a linear laser in a width direction of the steel sheet from a linear laser part installed above the steel sheet, thereby detecting width and surface defects of the steel sheet at the same time to detect width and surface defects of steel sheet discharged from the exit side of a final stand of tandem cold mill at cold rolling plant irrespective of small space and rolling mill lubricant. CONSTITUTION: The apparatus for detecting width and surface defects of steel sheet by using linear laser comprises a linear laser part(20) for scanning a linear laser(L) of straight line along a width direction of steel sheet(1) from an upper part of the steel sheet; a first camera part(30) and a second camera part(35) installed an upper part of the left and right sides of the steel sheet to take a picture of laser reflected from the steel sheet; a third camera part(40) installed in an upper part of the center of the steel sheet to take a picture of laser reflected from the steel sheet; a steel sheet width detection part(51) for detecting width of the steel sheet by computing the laser detected in the first and second camera parts; and a steel sheet surface defect detection part(52) for detecting position and size of surface defects of the steel sheet by converting the laser signal of the third camera part into a pulse waveform if magnitude of laser signal detected in the third camera part is that of a standard signal.