Hoechst Aktiengesellschaft

Detlef Winkelmann

Heinz Herrmann

Bernd Lohr

Peter Padberg

Helmut Stieger

A process for producing color images electrophotographically by means of toner image transfer, wherein toner images of different colors are successively transferred to an adhesive layer with application of pressure, is disclosed. The process produces colored copy true to the original, and is particularly useful for producing images for film proofing methods.

Process for producing color images

Disclosed is a process for preparing a planographic printing plate by electrophotographic or electrographic means by producing a charge image on a photoconductive or highly insulating layer, developing the image onto the free surface of a dielectric intermediate carrier in contact with the photoconductor or highly insulating layer by means of a developer, which comprises dispersed thermoplastic particles having a melting range from about 90.degree. to 130.degree. C., and transferring and fixing the toner image to the planographic printing plate at a temperature within the melting range of the thermoplastic particles after the intermediate carrier has been separated from the charge image.

Process for preparing a planographic printing plate

The present invention relates to an electrophotographic copier for the repetitive copying of originals. The copier comprises a transport apparatus having two film webs for transporting the original through an exposing station with the original being inserted between these film webs. The film webs of the transport apparatus are securely bonded together along a strip and form in the entry zone in advance of the exposing station a single-sided, Y-shaped pocket for the positioning of the leading edge of the original against the joint seam of the two film webs.

Electrophotographic copier

This invention relates to an electrophotographic material comprising an electrically conductive support, a photoconductive layer based on at least one organic photoconductive substance on the support, and a protective layer composed of at least one polymeric substance covering the photoconductive layer, said protective layer containing at least one photoconductive organic compound in a quantity of about 0.1 to 30 percent by weight, based on the weight of polymeric substance.

Alcohol soluble, organic photoconductor containing polymeric protective

Apparatus for producing positive enlarged copies from positive or negative microfilm, in which the photoconductive element can be charged either negatively or positively so that one developing liquid containing particles of only one polarity can be used to create positive copies regardless of whether the original microfilm is positive or negative. The apparatus includes a reusable photoconductive web having an aluminum backing, a perforated development electrode, and a transfer station for transferring the developed image to paper.

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Wiesbaden, Germany

Detlef Winkelmann