Abstract: An electrophotographic printing machine of the type having a latent image recorded on an imaging member wherein said latent image is developed and transferred to a media substrate during successive printing cycles of successive print jobs, including a charging device for producing a voltage potential on the media substrate to transfer the developed latent image to the media substrate, said charging device including a coronode member and shield; a first voltage supply for apply a shield voltage to said shield; a second voltage supply for applying a wire voltage to said coronode member; a voltage monitor for measuring the voltage on the shield, said voltage monitor periodically polling the voltage during a cycle of a print job and generating a voltage measured signal as a function thereof; controller, responsive to a media type of each media substrate and said voltage monitor, for adjusting said wire voltage to said coronode member in respect to said shield voltage to said shield to compensate for process imped

Abstract: A feed apparatus which combines a slider crank feed head drive system and cam actuated stack height sensing system to form a new combined shuttle feeder. The new feed head drive includes the replacement of a solenoid driven feed head with a more reliable stepper driven twin slider crank drive. Included in the slider crank drive for the feed head is an integral cam as part of the crank arm mounted to the motor shaft. This cam is designed drives a stack height sensor to drop and lift the stack height sensing arm to sense stack height after the sheet trail edge has passed the point of arm contact with the stack. The cam also provides a “service mode” position for the stack height arm which lifts it out of the way of the paper supply when it is opening. The cam dwells in a neutral home position during the rest of the drive out and return motion of the feed head.

Abstract: A feed apparatus which combines a slider crank feed head drive system and cam actuated stack height sensing system to form a new combined shuttle feeder. The new feed head drive includes the replacement of a solenoid driven feed head with a more reliable stepper driven twin slider crank drive. Included in the slider crank drive for the feed head is an integral cam as part of the crank arm mounted to the motor shaft. This cam is designed drives a stack height sensor to drop and lift the stack height sensing arm to sense stack height after the sheet trail edge has passed the point of arm contact with the stack. The cam also provides a “service mode” position for the stack height arm which lifts it out of the way of the paper supply when it is opening.

Abstract: A sheet stacking tray system for stacking different sizes of copy sheets on a stack supporting tray to be fed upstream to a reproduction apparatus for printing, on which tray the stack is registered against a side registration edge. An upstanding stack rear edge guide is track mounted for movement at an angle to that side registration edge to provide a large repositioning movement in the upstream direction together with automatic lateral movement toward or away from that side registration edge, so as to engage the rear edge of a stack of larger sheets further from the registration edge, more centrally of the downstream edge of those sheets, and to engage smaller sheets closer to the registration edge and thus more towards their centers. Two independent upstanding stack side edge guides may be repositionable towards the registration edge independently of, and not overlapping, any position of the angulary moving rear edge guide.

Abstract: A sheet feeder feeds sheets separated from a stack to a feed head which is translatable toward take away nip rolls. The sheets are separated from the stack by fluffers and acquired by an acquisition surface of the feed head which is in communication with a vacuum pressure. An air knife is used, in conjunction with a corrugation surface, to separate any secondarily acquired sheets from the acquisition surface. The time for acquiring the sheet is determined from the opening of a vacuum valve in communication with the feed head to the acquiring of the sheet by the acquisition surface. A controller adjusts the position of a supporting tray that supports the stack to maintain the sheet acquisition time as short as possible.

Abstract: A sheet feeder feeds sheets separated from a stack to a feed head which is translatable toward take away nip rolls. The sheets are separated from the stack by fluffers and acquired by an acquisition surface of the feed head which is in communication with a vacuum pressure. An air knife is used, in conjunction with a corrugation surface, to separate any secondarily acquired sheets from the acquisition surface. The time for acquiring the sheet is determined from the opening of a vacuum valve in communication with the feed head to the acquiring of the sheet by the acquisition surface. The time for acquiring the sheets is dependent on the sheet characteristics.

Abstract: A stack height assembly consisting of two transmissive sensors and two flags, the stack height of a feeder module can be set to three different levels depending on the weight of the media. This “optimization” of the stack height to address the media's failure mode results in increased latitude. When feeding lightweight media, the stack height is set larger in order to increase the gap to the feedhead. This allows more room for separation of the media using fluffer jets. This increased gap also reduces the chances that the un-acquired media will be fluffed into contact with the acquisition surface and subsequently be shingle fed into the take away roll due to the friction between sheets. When feeding heavyweight media the stack height will be set smaller. This reduces the gap to the feedhead and reduces the time required to acquire.

Abstract: The present invention is directed to device for feeding sheets seriatim from a stack. The sheet feed device includes a variable vacuum source being selectively actuable to acquire and release a top sheet from a stack; a feedhead, attached to the vacuum source to acquire the top sheet of the stack; a device to determine a plurality of predetermined properties of the sheets and to generate signals indicative thereof; and a controller to receive the generated signals and generate a signal to selectively control the vacuum source.