| 摘要 |
<p>The present invention determines whether there is an intermediate layer in the whole or within a predetermined range of a multilayer preform, is capable of acquiring the results of the determination in a short time, and is also capable of determining whether an upper end portion and a lower end portion of the intermediate layer are positioned in an allowable range. This multilayer preform inspecting method inspects whether there is an intermediate layer in a multilayer preform having a multilayer structure. In the method, the multilayer preform is irradiated with stripe-like light from the rear surface thereof, an image of the multilayer preform is picked up, and on the basis of a color shade detected from the image thus picked up, whether there is the intermediate layer is determined.</p> |
