Hoechst Aktiengesellschaft

Agfa-gevaert

Agfa Gevaert Nv

Eastman-kodak Company

Agfa Graphics Nv

Helmuth Haberhauer

Rudolf Zertani

Norbert Kraemer

Joan T Vermeersch

Marc Irene Van Damme

Eric Verschueren

Guido I Hauquier

Mathias Eichhorn

Erwin Lind

J&ouml;rg Jung

Jorg Jung

Rudolf Holz

Gerhard Spingath

Jörg Jung

According to the present invention there is provided a heat mode imaging element for making a lithographic printing plate having on a lithographic base with a hydrophilic surface a first layer including a polymer, soluble in an aqueous alkaline solution but not in water and less than 5% by weight versus the polymer, soluble in the aqueous alkaline solution of a hydrophilic polymer and a top layer on the same side of the lithographic base as the first layer which top layer is IR-sensitive and unpenetrable for or insoluble in an alkaline developer wherein said first layer and said top layer may be one and the same layer; characterized in that said top layer contains a compound selected from the group consisting of a polymer in an amount from 30 mg to 500 mg/m , a triaryl methane dye and a phthalocyanine dye.

Heat mode sensitive imaging element for making positive working printing plates

According to the present invention there is provided a heat mode imaging element for making a lithographic printing plate having on a lithographic base with a hydrophilic surface a first layer including a polymer, soluble in an aqueous alkaline solution and a top layer on the same side of the lithographic base as the first layer which top layer is unpenetrable for or insoluble in an alkaline developer containing SiO.sub.2 in the form of silicates; characterized in that said first layer and said top layer comprise a compound capable of converting IR-light into heat.

Method for making positive working printing plates from a heat mode

Thermally imageable material, consisting of a substrate and two layers (a) and (b) built up thereon in the stated sequence:

Thermally imageable material

A laser exposure apparatus utilizing a laser, beam divider, modulator, beam expander, beam combiner, polygonal mirror and also a scanner lens, path-folding mirror and a reference mask. The laser beam is divided in the beam divider into a writing beam and a reference beam, both of which are brought together by means of two path-folding mirrors and a beam combiner. The writing beam is then guided through an exposure slit onto a printing form by a path-folding mirror. One additional exposure device is disposed upstream and/or downstream of the exposure slot, and in the direction of conveyance of the printing form. Only one of the additional exposure devices is switched on during operation, so that either a preexposure or an afterexposure is accomplished in addition to the laser main exposure of the printing form.

Laser exposure apparatus for printing forms to be imagewise exposed

A preexposure device having a linear LED arrangement for preexposing printing forms over their full area. The linear LED arrangement comprises at least two rows of LED modules which are offset with respect to one another. Each module is made up of a plurality of light-emitting diodes. The linear LED arrangement is disposed within a housing which is closed off at the bottom by means of a light scattering plate.

Preexposure device for printing forms to be imagewise exposed

An aftertreatment apparatus and method for printing plates which have been imagewise exposed having an exposure station and a heating station which are arranged one behind the other in the direction of conveyance of the printing plates along a conveyance track. The exposure station contains a linear LED arrangement which in turn has at least two rows of LED modules which are offset with respect to one another. The LED modules are made up of a plurality of light-emitting diodes. The housing of the heating station is thermally insulated on three sides and is open at the bottom in the direction of a reflector table over which the printing plates are passed.

Aftertreatment apparatus for imagewise exposed printing plates

Disclosed is a developing apparatus and process for the liquid development of electrostatic charge images on an image carrier material. The developing apparatus includes a device for spraying a liquid developer onto the image carrier material to be developed, and a developing electrode connected to a direct-current voltage source. The developing electrode comprises an electrically conductive web positioned in operative relationship to the image carrier layer, the web is unwound from a supply roll and wound up on a take-up roll, the distance of the web-shaped developing electrode from the surface of the image carrier material being adjustable by means of at least one guide roll.

Developing apparatus for the liquid development of electrostatic charge

The invention relates to a developing apparatus which, in a preferred embodiment, includes a first charging device comprising a rotating device, preferably designed as a brush having a core which is connected to a first voltage source. A single component developer is fed, from a developer feed unit, to the first charging device, by means of a metering roller. The charging device is enclosed by a trough, which is connected to a voltage source. A scraper in glancing contact with the bristles of the first charging device imparts an additional charge to the developer by tribo-electricity and sprays particles of developer on the bristles onto a developing roller. A second charging device, in the form of a second brush having a core connected to said voltage source may also be used. The grid is then positioned between the charging devices. A second scraper functions, in a similar manner, in conjunction with the second charging device. The developing roller is connected to a second voltage source and particles of developer, which form a uniform layer on the peripheral surface of the developing roller, are attracted by a latent charge image on a recording medium, to thereby obtain a developed charge image.

Apparatus for developing an electrostatic latent image on a recording

An apparatus for developing latent electrostatic images in an electrophotographic copier are disclosed, the developer including an image carrier having a conductive backing layer and a photoconductive layer, a magnetic brush developer, a voltage source connected with the magnetic brush developer, and a high-ohmic resistance connecting the backing layer with ground, the voltage source and high-ohmic resistance establishing a potential difference between the magnetic brush developer and the backing layer to prevent a voltage breakdown at the image carrier which may result in undesirable streaking and fogging of an electrostatic copy. The high-ohmic resistance may be adjusted in accordance with the amount of current generated in the developer mixture whereby the flow of current from the developer through the photoconductive layer to the backing layer is impeded to prevent a voltage breakdown. In a first embodiment, the image carrier is a planar printing plate. In a second embodiment, the image carrier is a cylindrical drum having the photoconductive layer arranged on its outer peripheral surface, with charge and transfer coronas arranged adjacent the photoconductive surface, and the embodiment includes a semiconductor unit connected in parallel with the high-ohmic resistance.

Electrophotographic apparatus for developing latent electrostatic charge

A process and apparatus for controlling development of electrostatic latent charge images. A development electrode is utilized both to measure a background voltage of an image-free initial portion on the surface of the recording medium and to control the development voltage in accordance with the measured background voltage.

Process and apparatus for developing an electrostatic latent image

A device for fusing toner on a carrier of electrostatic images, the carrier having a predetermined width and moving through a fusion zone heated by infrared radiation, the device comprising a plurality of shortwave infrared radiating means arranged above and transverse to the moving direction of the carrier, each of the radiating means having a length less than the width of the carrier, each of the radiating means being mutually unaligned with the remaining plurality of the radiating means, and wherein the ends of the infrared radiating means are interleaved in a comb-like manner in the center of the fusion zone.

Growing community of inventors

Taunusstein, Germany

Helmuth Haberhauer