| 摘要 |
PROBLEM TO BE SOLVED: To restrain the reduction in the spark detecting accuracy due to the reduction with the lapse of time in the sensitivity of an image pickup device, and also reduce the dispersion in the spark detecting accuracy due to the indivisual difference in the image pickup device. SOLUTION: The surface layer inclusion detecting device is provided with a hot scarfer 5, a camera 6 for photographing a basin, and an image pickup device 10 by which a treatment for actualizing a spark to the photographed data is performed for picking out the spark by comparing it with a threshold value. In this case, an elapsed-time correcting means 44 by which at least either of the photographed data or the threshold value is corrected so as to be corresponded to the elapsed-time reduction of the sensitivity of the camera 6 is provided. The device is also provided with an initial correction value memory CM1 in which the value for correcting the individual dispersion in the photoelectric conversion characteristic at the time when the camera 6 is a new article is stored, and an initial characteristic correcting means 38d for correcting the photographed data in accordance therewith. |
