BERNOULLI-EFFECT WEB STABILIZER

A system and method for generating indicia of registration error between respective, separately adjustable printing units of a printing press, the printing units cooperating to print an image on a moving web, the system being of the type comprising a photo-optical control, having a field of view and depth-of-field, for generating output signals indicative of a predetermined relative disposition of marks on a web passing through the field of view within the depth-of-field of the photo-optical control as the web moves in relation to the printing units, and processing circuits, responsive to the photo-optical output signals, for generating signals indicative of deviations of the registration marks printed by the printing units from the predetermined relative disposition; improved wherein: the photo-optical control is disposed proximate to the printing units, and, having associated therewith an air driven stabilizer structure for maintaining the web within the depth of field by creating a Bernoulli effect.