| 摘要 |
<p>PROBLEM TO BE SOLVED: To measure the outer diameter of a rolled film having the outer diameter of every kind on-line inexpensively and accurately and to always hold a focus matching state to detect the presence of the difference in level of the rolled film inexpensively and accurately even if the outer diameter of the rolled film increases. SOLUTION: The outer diameter of the rolled film 15 during taking-up is measured by an outer diameter sensor 30 and, if the outer diameter of the rolled film 15 is ready to increase to exceed the measurable range of the outer diameter sensor 30, the outer diameter sensor 30 is moved in the outer diameter increase direction of the rolled film 15 by required moving quantity L within the measurable range to continue measurement and, on and after, this operation is repeated until measurement is completed.</p> |
