| 摘要 |
<p>PURPOSE:To automatically detect a part of a defective shape by projecting a laser light in parallel to the surface of a roll, converting the amount of the detected light into an electric signal, comparing the electric signal with a preset threshold value, and fixing the distance between the laser light and a plate-like member optionally. CONSTITUTION:A laser projecting device 1 projects a laser light in parallel to the surface of a roll or a plate-like member which is sent on the roll. The light is detected by a photodetecting device 2 and converted to an electric signal. The electric signal is amplified at an amplifier 4 to remove influences of noises. The amplified electric signal is compared with a preset threshold value at a comparator circuit 5. Accordingly, whether the laser light is received correctly is detected. A to-be-detected part is fixed by lift devices 3a, 3b which adjust the setting height of the devices 1, 2 in accordance with the lowest limit of the to-be-detected part of a defective shape from the surface of the roll. The light projecting and detecting devices 1, 2 are set by the lift devices 3a, 3b so that the setting height 9 of the laser beams 8 is the lowest limit of the height 7 of the to-be-detected part. The failure of the shape is detected when an optical path of the laser beams 8 is shut by the part 6 of the defective shape.</p> |
