Film transport apparatus and film transport control method

摘要

A film transport apparatus includes: an edge sensor that detects a lateral position deviation of a film; a lateral position correction device that corrects a lateral position of the film with a guide roll; a tension sensor that detects tensions applied respectively near left and right ends of the film; and a control unit that executes feedback control such that the lateral position correction device is controlled on the basis of the lateral position deviation detected by the edge sensor so that the film is located at a target position. The control unit changes the feedback control based on a left and right tension difference, which is a difference between the tension applied near the left end of the film and the tension applied near the right end of the film, the tensions being detected by the tension sensor.

主权项

1. A film transport apparatus that transports a film, comprising:
a lateral position deviation detecting portion that detects a lateral position deviation of the film; a lateral position correcting portion that corrects a lateral position of the film with a guide roll; a tension detecting portion that detects tensions applied respectively near left and right ends of the film; and a control portion that executes feedback control such that the lateral position correcting portion is controlled based on the lateral position deviation detected by the lateral position deviation detecting portion so that the film is located at a target position, wherein the control portion changes the feedback control based on a left and right tension difference, which is the difference between the tension applied near the left end of the film and the tension applied near the right end of the film, the tensions being detected by the tension detecting portion; the control portion calculates a transient left and right tension difference based on the left and right tension difference; the control portion calculates a gain value based on the transient left and right tension difference, the transient left and right tension difference being related to the gain value such that the gain value decreases as the transient left and right tension difference increases; and the control portion calculates a target speed for actuating the guide by multiplying the lateral position deviation by the gain value.