Abstract: In a feeding device comprising turret arms having spindle shafts for supporting a web roll, an air brake for applying a braking force in a rotating direction to the spindle shafts, and an accelerating motor for applying a drive force in the rotating direction to the spindle shafts and a braking force in the rotating direction to the spindle shafts, a braking force control device has a tension control device which exercises control such that if a braking force required for the spindle shafts is lower than a constant value, only the braking force from the accelerating motor is supplied to the spindle shafts, and that if the braking force required for the spindle shafts is higher than the constant value, the braking force from the accelerating motor is supplied to the spindle shafts, and the braking force of the air brake is supplied to the spindle shafts.

Abstract: In a feeding device comprising turret arms having spindle shafts for supporting a web roll, an air brake for applying a braking force in a rotating direction to the spindle shafts, and an accelerating motor for applying a drive force in the rotating direction to the spindle shafts and a braking force in the rotating direction to the spindle shafts, a braking force control device has a tension control device which exercises control such that if a braking force required for the spindle shafts is lower than a constant value, only the braking force from the accelerating motor is supplied to the spindle shafts, and that if the braking force required for the spindle shafts is higher than the constant value, the braking force from the accelerating motor is supplied to the spindle shafts, and the braking force of the air brake is supplied to the spindle shafts.

Abstract: A defect print detecting device having photographing means for photographing as an image the surface of a printing plate having a pattern to print and mounted on a plate cylinder, which compares reference image data acquired at the beginning of printing using the photographing means with checking image data acquired during printing, thereby determining the quality of the printed matter.

Abstract: Light received by a light receiving element in a quality inspection device for printed matter, is controlled to a constant value by passing the received light through a graduated neutral density filter that is adjusted in position relative to the optical axis of the light receiving element in dependence on the feed speed of the printed matter.