Coulter Systems Corporation

Michael J Szymanski

Manfred R Kuehnle

Harold J Weber

Kenneth D Fraser

Kenneth A Lindblom

James C Compton

John N Poulakis

Donald S Cleveland

Electrophotographic imaging apparatus, particularly for color proofing, is provided for normal daylight operation including a light-tight housing having a framework mounting plural spaced functional processing stations for charging, imaging, toning, transfer and, optionally, cleaning, all interior of the housing. A platen assembly mounting an electrophotographic member is translated along a linear path, the assembly being guided by a rail and a track secured along the entire length of the framework. A copyboard is disposed below the carriage within the imaging station and carries a transparency. The electrophotographic member is translated past the charging station for charging same and brought to the imaging station where the copyboard is raised, to establish an intimate engagement with the member established and exposed to an interior disposed radiant energy source. After exposure, the copyboard is lowered and the member translated to the toning station where one of plural available toning modules has been raised to intercept the platen whereby to establish a toning gap for toning with liquid toner carried by said one module during passage past said module. The member next is translated to the transfer station for transfer to a pre-wet sheet of transfer medium. A registration system is provided at both imaging and transfer stations to assure registration between the member and the transparency on the one hand and the member and the transfer medium on the other hand at the respective station whereby all functional tolerance relationships being maintained independent of the framework.

Electrophotographic imaging apparatus and method particularly for color

A method and apparatus is provided for toning a latent electrostatic image on an exposed photoconductive surface of an electrophotographic member, using liquid toner comprising toner particles suspended in an electrically insulating liquid dispersant. Plural, generally identical, toner modules are arranged side by side at a first level, each module comprising a toner tray having a development electrode mounted on the upper surface thereof. The development electrode has a planar upper surface. A motor operates an articulated linkage which causes the tray to be elevated to a second level for toning, one of the modules being selected from the others. Antifriction bearing surfaces are mounted on the upper surface of the tray at opposite ends of the development electrode. The antifriction surfaces extend upwardly of the development electrode a short distance slightly above the upper surface thereof to define a gap between the development electrode and the surface to be toned. A toggle actuated control valve can be provided to direct the toner flow over the electrode in the direction of the movement of said surface, changing the direction of flow during the reciprocal movement of said surface. Alternatively, the flow of toner may be continuous over the planar electrode. During toning, a bias voltage is applied between the development electrode and the photoconductive surface to establish an electrical field within the gap for assisting toning. The charge level to which the toner responds is above the residual level thereby leaving the nonimaged or background area of the photoconductive surface free of toner particles.

Toning system for electrostatic imaging apparatus

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Medford, MA, United States of America

Michael J Szymanski