| 摘要 |
The present invention is intended to correct print pitches P at which a pattern A is printed on a plastic film 1 repeatedly. A first optical sensor detects positions at which the pattern A is printed on the plastic film 1 repeatedly, to measure the print pitches P individually. A first stretching device 4 stretches the plastic film 1 after measuring the print pitch P to correct the print pitches P individually. A second optical sensor detects the positions after correcting the print pitch P to measure a sum of print pitches P(1)+P(2)+ - - - - +P(N) of a number of patterns A. A second stretching device 10 stretches the plastic film 1 after measuring the sum of print pitches to correct the sum of print pitches. |
