Abstract: A transfer mechanism and method are provided for utilization in a high speed electrophotographic printing process of the type wherein the electrophotoconductive cylinder on which the image is formed travels at a peripheral speed of at least 100 ft./min. Transfer of the image is made to a continuous web of paper or the like travelling synchronously with the cylinder surface speed. A transfer corona focuses a narrow band of ions proximate the cylinder-web interface to attract at least 95% of the solids, toner particles from the cylinder to the travelling web. The charge on the transfer corona exceeds the charge on the image portions of the rotating cylinder by at least about 5,000 volts.

Abstract: An apparatus in which an elevator movably supports a drawer having a tray associated therewith. The tray receives successive sheets at a loading station. The elevator moves continuously downwardly to maintain the uppermost sheet of the stack of sheets on the tray at a preselected location in the loading station until the drawer and tray are positioned at a discharge station located interiorly of a housing. The sheets are transferred from the tray to the drawer which advances the sheets from the discharge station to an unloading station located externally of the housing. A door opens, in synchronism with the movement of the drawer, to enable the sheets to pass from the discharge station to the unloading station located exteriorly of the housing.

Abstract: In a high speed electrophotographic printing apparatus and method wherein a charge of desired polarity and potential is applied uniformly to a photoconductive surface of a rapidly rotating drum, an improvement is provided which comprises an electrometer located adjacent the drum surface for sensing and measuring the charge imparted to the surface. The electrometer is operatively connected through a programmable logic controller to a variable power output that drives the corona array to impart the charge to the drum surface. Irregularities in charge potential imparted to the surface are thereby measured by the electrometer with appropriate adjustment being made in the charge applied to the drum by the corona array.

Abstract: An automated system and method are provided to supply a liquid toner dispersion to the printing station of a high speed electrophotographic printing press. A highly concentrated form of the liquid toner dispersion is supplied in a first container. Density measurement of the liquid toner in a process tank controls the feed of concentrate to the process tank. Liquid level switches in the process tank control toner carrier liquid flow to the process tank. Conductivity sensor monitoring of the toner in the process tank controls the flow of liquid charge control agent into the process tank. Flow rate of the liquid toner from the process tank to the printing station of the printing unit is controlled by a sensor, logic circuitry, and motorized adjustable flow valve and flow meter.