INSPECTION APPARATUS FOR FILM PERFORATION

摘要

PROBLEM TO BE SOLVED: To easily and exactly inspect the perforation abnormality of a motion picture film. SOLUTION: The projection section of a projector projects a perforation image 12 on a screen. Photoelectric sensors 22 and 23 are disposed in positions where the transverse side and longitudinal side of the perforation image 12 cross. Auxiliary photoelectric sensors 24 and 25 are disposed in and out of the perforation image 12. A reference level value which is an evaluation reference for the offset of the perforation image 12 is obtained in accordance with the photoelectric signals from the auxiliary photoelectric sensors 24 and 25. The photoelectric signal levels from the photoelectric sensors 22 and 23 and the reference level value are compared and the offset quantity from the reference position of the perforation image 12 is measured. The inspection may be exactly carried out without complicating the structure of the inspection apparatus itself.