Photoelectrophoretic imaging apparatus having a device for increasing

Abstract

A photoelectrophoretic imaging machine for producing, in a preferred embodiment, full color copies from opaque originals or, alternatively, copies from transparencies. In a preferred embodiment, the formation of photoelectrophoretic images occur between two thin injecting and blocking webs at least one of which is partially transparent and the image formed is transferred to a paper web. The injecting and blocking webs may be disposable, thus, cleaning systems are not required. The injecting web is provided with a conductive surface and is driven in a path to the inking station where a layer of photoelectrophoretic ink is applied to the conductive web surface. The inked injecting web is driven in a path passing the deposition scorotron at the precharge station and into contact with the blocking web to form the inkweb sandwich at the imaging roller in the imaging zone. The conductive surface of the injecting web is grounded and a high voltage is applied to the imaging roller subjecting the sandwich to a high electric field at the same time as the scanning optical image is focusssed on the nip or interface between the injecting and blocking webs, and development takes place. The photoelectrophoretic image is carried by the injecting web to the transfer zone, into contact with the paper web at the transfer roller where the image is transferred to the paper web giving the final copy. In one preferred embodiment, a pressure mechanism is provided to ride against two webs and the imaging or transfer roller on either or both sides of the imaging or transfer zone during imaging or transfer in order to increase the friction force between the webs and thereby prevent slip at the imaging or transfer zone.