| 摘要 |
PURPOSE:To prevent hunting by adding a control of the tension of a film to a control by a differential mechanism. CONSTITUTION:The titled apparatus comprises an infeed roll 5 for giving a tension to a film 2, a printing unit 6, a detector 22 for detecting a printing by said unit, and differential mechanisms DF1 and DF2 provided in a drive mechanism for driving printing members 6a and 6b of the printing unit 6. A signal 23 of the detector 22 is inputted to these differential mechanisms DF1 and DF2 to control the printing. The apparatus is so designed that the signal 23 of the detector 22 is inputted also to a speed change gear 27 provided in the drive mechanism for the infeed roll 5 so as to control the tension of the film 2. Such a control by the tension of the film as described above is a slow control (integral control). Therefore it tends to delay the control by the differential mechanisms, and thus hunting of the control is prevented. |
