| 摘要 |
PURPOSE:To enable detecting of a shear in a printing pattern by means of a simple constitution at an inexpensive cost and even by means of an on-line, by a method wherein given window parts are formed in a printing pattern, and are opticaly detected. CONSTITUTION:Printing patterns 2a and 2b are printed on the surface and the back of a clear film 1, and a reference window part 31, and detecting window parts 32, 33 for displacement in directions of flow and width are formed in the patterns. The reference window part 31 is formed such that a permeation is always conducted by a given length, and an oblong window part 32b and a triangle window part 33b, whose lengthes are equal to that of the reference window part 31 in the case of no shear in printing, are formed in the window parts 32 and 33, respectively. In the construction, a photo source 4 and a detector 5 generate an output signal only for a time corresponding to a lentgth of a permeating part, an AND is taken by a circuit 7, the number of pulses corresponding to an output signal width is counted (8), and differences in detecting time of the window parts 32 and 33 to the reference window part 31 are computed by a computing part 9 to detect a shear in printing. This permits the simple detection of the shear in a pattern by an on-line. |
