PURPOSE: To detect automatically, sensitively and exactly a defect such as a coat pick, etc. by placing a light source for illuminating a paper surface, and an image pickup device for facing the paper surface, in the direction of 25W60° of one side of a perpendicular of a glossy paper surface, and in the direction of 0W20° of the opposite side, respectively.
CONSTITUTION: As for a base paper 1' which is rewound from a base paper roll 4, a paint is applied to it by a coater 5, and it is dried through a doctor knife 6 and a dryer 7, and subsequently, an applied layer is rewetted by a rewetting liquid, and the paper is wound to a drum 8 and its polishing is executed, and wound to a winder 9 through a guide roller. Also, a defect detecting device consists of a drum 2, a projector 10, an image pickup device 3 and a signal processor 11. As for the radius of this drum 2, it is suitable to be ≥200mm, and the projector 10 and the image pickup device 3 are placed at a position which has been separated upward by 25W60° from its tangent line, and at a position which has been separated upward by a range of 0W20° from the tangent line, in its opposite side, respectively. also, a pulse signal which has been detected by a level selector of the processor 11 is a detecting signal of a defect of a glossy paper, and a warning device is driven by operating a relay by this pulse signal.
YUKI KAZUHIKO
TOMITA KURA
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