| 摘要 |
PROBLEM TO BE SOLVED: To solve the following problem: when a long-length film is wound, the film is wrinkled in a winding roll, and biting foreign matter occurs, and for this reason, it is not easy to detect irregularity generated in the film by the wrinkle and the foreign matter during winding.SOLUTION: A film inspection method is performed during winding a long-length film by a winding roll, and can confirm irregularity even during winding by a film inspection method having: a step of winding the long-length film by the winding roll; and a step of confirming the presence or absence of irregularity of the film surface by applying strobe light having a light emission cycle Ts to which a ratio of a rotation period Tr of the winding roll is not m:1 nor 1:m (m is a natural number) on the film surface of the winding roll.SELECTED DRAWING: Figure 1 |
