JUDGEMENT DEVICE FOR POSITION OF COLORED BAND ON SUBSTRATE

PURPOSE:To prevent the occurrence of an error due to the faulty judgement of an operator, by a method wherein optical detecting ends are located to opposite ends of an allowable deflection width of a boundary line of each of both sides of a colored band, and a substrate is moved along the longitudinal direction of the colored band. CONSTITUTION:In case a deflection width is permissible by + or -DELTAB as against each of distances C and D from a long side 4, serving as a reference, to boundary lines 5 and 6 at both sides of a magnetic band 3 with a width B, measuring points C1, C2, D1, and D2 having, a fine area, are selected, as shown in a drawing, in positions at the opposite ends of the allowable deflection range, a card 1 is moved in a longitudinal direction, and a change in brightness at the measuring points is optically selected. This decides whether or not the boundary lines 5 and 6 at the opposite ends of the magnetic band 3 are respectively positioned within the allowable deflection width range over an approximately whole length of a card 1, and decides whether the position of the magnetic band 3 is right or wrong. In order to increase a detecting precision, the smaller as much as possible the measuring point is, the more favorable it is, and thereby a device is, as shown in the drawing, provided with an optical detecting end 9 employing an optical fiber.