WIDTH MEASURING APPARATUS

摘要

PROBLEM TO BE SOLVED: To enhance the accuracy of measuring the width of steel by setting the initial value of accumulation time in a CCD camera to an optimum. SOLUTION: When a CCD camera 10 picks up an image of steel, it transmits a video signal which assumes a value proportional to the accumulation time of electric charge based on the amount of light emitted spontaneously by the steel, and a full-width ATC control part 21 sets the initial value of the accumulation time in the CCD camera 10 in accordance with the video signal and correspondingly to the amount of light emitted spontaneously by the steel, and a differential edge ATC control part 22 controls the set value of the accumulation time in accordance with the video signal of the CCD camera 10. A computing part 30 calculates the width of the steel on the basis of the video signal from the CCD camera 10 during control of the accumulation time.