Abstract: Printing forms or metallized images can be prepared electrophotographically by a process comprising the electrostatic chargeup, imagewise exposure and tonering of a photoconductor layer applied to an electroconductive base material, followed by fixing of the tonered image areas, removal of the photoconductive layer in the non-image areas by decoating and, where appropriate, etching of the bared base material surface. A recording material is used that comprises a photoconductive layer containing at least one organic n-conducting pigment in a concentration between 10 and 50 percent by weight and an organic p-conducting photoconductor in a concentration of 0 to 20 percent by weight, based on the layer weight, together with a binder which is soluble or dispersible in aqueous-alkaline solution. The decoating is carried out with an aqueous-alkaline decoater solution, which preferably contains alkali metal hydroxides and/or phosphates.

Abstract: Disclosed is a device for the electrophotographic manufacture of printing forms, comprising a loading table, an exposure table and a developing table arranged in the device one after the other in the transport direction A of printing plates. The loading table is pivotable and is equipped with spring suction devices, by means of which the uppermost printing plate can be removed from a plate magazine. After the printing plate has been removed, the loading table is swung into its horizontal position, a corona is moved over the loading table and the photoconductive layer of the printing plate is loaded to the required voltage. The printing plate is transported from the loading table to the exposure table and from the latter to the developing table by means of compressed air which forms a cushion underneath the printing plate. The printing plate is guided on the cushion in suspension from processing station to procesing station.

Abstract: Disclosed is a liquid developer device for a recording material which comprises at least one conveying device for applying a liquid developer to the recording material and a developer electrode attached to the conveying device in a manner such that the electrode floats on the developer layer at a constant distance from the recording material. In a further embodiment, the recording material, which has a latent electrostatic image on both its surfaces, is passed vertically between conveying devices. Also disclosed is a process for using both devices.

Abstract: The present invention relates to a suction device for securely holding printing plates in a processing position by sub-atmospheric pressure. The suction device comprises a turnstile arrangement with four suction tables in two mutually perpendicular planes and is connected to a motor which rotates the turnstile arrangement in 90.degree. steps. Four suction chambers are located in a hub part of the turnstile arrangement, these chambers being connected, via pressure lines, to a vacuum source for generating sub-atmospheric pressure. The supporting surface of each suction table comprises suction slots, which communicate in pairs, each of these communicating pairs of suction slots being connected to the associated suction chamber via a common suction passage. Each suction chamber comprises a piston with its piston rod being guided outwardly through an end face of the hub part and carrying a circular plate.

Abstract: An original holder for a printing plate processing apparatus for rapid exchange of an original in a vacuum frame covered by a glass plate and exposed in the exposure device of a printing plate processing apparatus. The glass plate is held in its open position by a gas pressure element to facilitate insertion of the original. Two U-shaped metal sheets serve as supports for two vacuum frames which are each evacuated following insertion of an original and closing of the glass cover plate. Swivel joints are attached at the sides of the supports which enable the original holder to be pivoted through an angle of 360.degree. and which are additionally horizontally slidable in the guides of supporting and guiding arms. The vacuum frames are individually pivotably mounted in their supports by ball guides in guide tracks.

Abstract: An electrophotographic apparatus for producing printing masters utilizing modulated laser light as the exposure source and a continuous process for producing such printing masters involving the steps of plate conveyance, synchronous charging and exposure, and electrostatic development and fusing of electrophotographic printing masters suitable for use in offset or lithographic printing processes. The apparatus comprises a transport system for sequentially conveying printing masters to the exposure platen which retains the masters in a fixed plane for synchronous charging and exposure, utilizing as a light source, a modulated laser beam. The optical and deflecting components of the exposure system are mounted in a moveable carriage member adapted to traverse a plane substantially parallel to the plane of the exposure platen such that the exposure laser will raster scan the platen area.