METHOD AND APPARATUS FOR DETECTION OF PINHOLE OF FILM

摘要

PROBLEM TO BE SOLVED: To provide an apparatus by which by which a very small pinhole incapable of having been detected by an optical pinhole detector in conventional cases can be detected including positional information in both the width direction and the length direction of a film. SOLUTION: A potential is applied across a first electrode 2b having a width in the size or higher in the film width direction of a second electrode 3 on which a film 1 is run so as to come into contact with its surface and the second electrode 3 which is set opposedly it the second electrode 2b so as to be brought close to, or brought into contact with, the other face of the film 1. A signal which is generated at a time when a pinhole part in the film is electrified is detected by a receiving part which is installed along any of the electrodes. The position in both the length direction and the width direction on the film 1 of the pinhole part is specified.