Abstract: A double sheet detector includes a pair of rollers forming a nip through which a fed sheet passes, causing the rollers to separate. The amount of separation is transmitted to a transducer which generates a signal proportional to the sheet thickness. Signals from the transducer are frequently sensed and averaged over one or more full revolutions of the rollers, so that signal variations resulting from irregularities in the shape of the rollers are canceled out.

Abstract: A double sheet detector includes a pair of rollers forming a nip through which a fed sheet passes, causing the rollers to separate. The amount of separation is transmitted to a transducer which generates a signal proportional to the sheet thickness. Signals from the transducer are frequently sensed and averaged over one or more full revolutions of the rollers, so that signal variations resulting from irregularities in the shape of the rollers are canceled out.

Abstract: A feeder head includes suction belts to sequentially feed top sheets from a stack of sheets (e.g., paper). Before the belts receive suction and drive power, a suction cup raises the top sheet at a location between the belts to produce a corrugated shape in the top sheet which induce separation of a second sheet that might be adhered to the top sheet. A double sheet detector includes a pair of rollers forming a nip through which a fed sheet passes, causing the rollers to separate. The amount of separation is transmitted to a transducer which generates a signal proportional to the sheet thickness. Signals from the transducer are frequently sensed and averaged, so that signal variations resulting from irregularities in the shape of the rollers are canceled out.

Abstract: Printed sheets are delivered from a printer to a coating machine which feeds the sheets successively to a coating nip formed between a coating cylinder and an impression cylinder. A transport mechanism advances the sheets through the coating nip. The arrival of each sheet is sensed, and a control unit determines a speed necessary for each sheet to be initially fed in order to reach the coating nip simultaneously with an image area of the coating cylinder and with grippers of the transport mechanism, as well as at a speed equal to a surface speed of the coating cylinder. Independently driven rollers advance each sheet at that sheet's determined speed (e.g., acceleration or deceleration).

Abstract: The identical printing of a stack of sheets (e.g., paper) is performed by vertically stacked inkjet printing units, each of which prints sheets at a printing speed. All sheets are fed from a stack along an infeed path at a feeding speed which is faster than the printing speed. The sheets are sequentially introduced into the respective printing heads, e.g., by the actuation of a gate mechanism disposed in the infeed path. After the sheets have been printed in the printing units at the slower printing speed, and after the print medium has been fixed, the sheets are discharged from the printing units and fed along a common outfeed path at the higher feeding speed. For variable-data printing, raster image processing is performed by assigned separate RIP computer units to process respective batches of the pages of the printing job.

Abstract: A feeder head includes suction belts to sequentially feed top sheets from a stack of sheets (e.g., paper). Before the belts receive suction and drive power, a suction cup raises the top sheet at a location between the belts to produce a corrugated shape in the top sheet which induce separation of a second sheet that might be adhered to the top sheet. A double sheet detector includes a pair of rollers forming a nip through which a fed sheet passes, causing the rollers to separate. The amount of separation is transmitted to a transducer which generates a signal proportional to the sheet thickness. Signals from the transducer are frequently sensed and averaged, so that signal variations resulting from irregularities in the shape of the rollers are canceled out.

Abstract: Keyless inking and dampening systems and methods are disclosed which employ application, subtractive and dampening roller systems to control the ink/dampening fluid film on the form roller. A clean-up roller removes residual ink from non-image areas on the printing plate.

Abstract: Keyless inking systems and methods are disclosed which employs a main form roller and a smaller clean-up roller, both in contact with a rotating printing plate. Separate application and subtractive roller systems control the ink film on the form roller. The clean-up roller removes residual ink from non-image areas on the printing plate. The clean-up roller is in ink communication with the main form roller through a vibrating roller. Mechanisms are provided to selectively engage and disengage the various rollers.