| 摘要 |
PURPOSE:To enable accurate measurement even under superior measurement conditions by arranging one-sided terminals of optical fibers annularly at a light emission part and by installing a rotatable laser light emitting device in te center of them. CONSTITUTION:When laser light emitting device 17 is rotated by motor 18 as shown by arrow A to generate laser light, the light focuses on the terminal part of optical fibers 10 through lens 20 and it is led to a projection part at prescribed intervals of time via respective optical fibers 10 in the order of codes 1, 2-(n). Then, they are projected upon photodetector 13 in said order. The scanning of thus projected laser light is started by sensor 19 for scanning starting point detection and it is excluded by material 1 to be rolled and not photodetected by photodetector 13. The time from the scanning starting point to the photodetection of photodetector 13 is counted as clock pulses by control panel 16 and from the relation between the scanning time and scanning speed, the distance from the scanning starting point is calculated, so that the widthwise shape of material 1 to be rolled can be found. |
