Abstract: Apparatus for duplex printing comprising: a first impression roller (24) on which a first side of a sheet (22) having a leading edge and a trailing edge is printed referenced to the leading edge; a second impression roller (26) on which a second side of the sheet is printed; and a transport system (20) that removes a printed sheet from the first impression roller (24) and transports it to the second impression roller (26), the transport system comprising a perfector (32) that receives the sheet and grips it along both the leading and trailing edges of the sheet, which perfector turns the sheet over and transfers the sheet trailing edge first towards the second impression roller.

Abstract: A method for registration of print separations in a printer comprising: (a) printing a first pattern, for which at least one image characteristic varies relatively weakly with misregistration, using at least one of first and second separations; (b) printing a second pattern, for which said at least one image characteristic varies relatively strongly with misregistration, using said at least one first and second separations; (c) determining said at least one image characteristic for the first and second patterns; and (d) correcting the mutual registration of said at least one first and second separations responsive to a difference in the determined at least one image characteristic for the first and second patterns.

Abstract: An imaging device including a selectively charged imaging surface, having a width and moving in a direction perpendicular to the width and a toner applicator, the applicator including an applicator chamber having a top portion and containing a supply of liquid toner and a slit nozzle having a long dimension comparable to the imaging surface width and being fed from the top portion, the slit nozzle further including an outlet from which the toner is applied to an application region of the imaging surface. The supply of liquid toner preferably includes a supply of pressurized liquid toner. Preferably, the imaging device further includes a developer surface situated proximate to the imaging surface downstream of said application region.

Abstract: Imaging apparatus including a photoreceptor, a charging station operative to charge the photoreceptor including an active length of corona wire operatively juxtaposed with the photoreceptor and a corona wire dispenser containing an undispensed length of corona wire contiguous with the active length and at least as long as the active length. The apparatus also includes an exposure station operative to selectively discharge portions of the photoreceptor to form a latent image thereon and a developer operative to develop the latent image. The corona wire dispenser is operative to dispense an appropriate length of the undispensed corona wire to replace the active length of corona wire.