| 摘要 |
PURPOSE:To simplify the device and to improve its operativity, by detecting the variance in thickness of a sheet by detecting the size of standing roll resin formed on back surfaces of three rolls. CONSTITUTION:On back surfaces of rolls 4, 4' and 4'', photoelectric tubes 6 are arrayed at prescribed intervals in the width direction of the rolls. Photoelectric tubes 6 pair with light emission parts and then receive the reflected light of light emitted from respective light emission parts toward the lead-in part of sheet 3 in the gap between rolls 4 and 4''. Since roll resin stand at the lead-in part of sheet 3, the reflected light varies with its size. For this purpose, the size of the standing roll resin at each part in the width direction of the roll can be detected by permitting a level meter to indicate the output level of each photoelectric tube 6, so that the variance in thickness of sheet 3 can be detected. |
