Linotype-Hell Ag

Ing. Rudolf Hell Gmbh

Dr. Ing. Rudolf Hell Gmbh

Dr. Ing. Rudolf Hill Gmbh

Wolfgang Boppel

Siegfried Beisswenger

Gerald Johannes Sermund

Michael Wilharm

Dieter Grieger

Method and apparatus for manufacturing a texture drum

Method and apparatus for manufacturing texture drums

In the implementation of the method for manufacturing a texture drum, a surface structure is produced in the region of a surface with an electron beam, preceding a charging occurring within a working interval with an electrons beam having an energy density generating a recess, the texture drum is charged during a pre-treatment interval by an electron beam having an energy density that leaves the surface structure essentially as it was formed.

An electron beam generator designed for engraving surfaces of printing form cylinders is switched to microscope operation during engraving pauses in order to make engraved cups visible immediately and without additional auxiliary equipment. During microscope operation, deflection parameters and an intensity of an electron beam produced by the electron beam generator are changed for appropriate scanning. An image signal is acquired by detecting secondary electrons generated by the beam interacting with the cups in the printing form surface.

Method for checking printing form surfaces engraved by means of an

A method for the topically precise subsequent-engraving of printing cylinders wherein special marks are engraved in the cylinder and evaluated. The marks are engraved in the form of cups forming a cup track. The cups serve as reference marks for an axial feed and start of the subsequent-engraving in a circumferential direction. After the printing cylinder has been mounted in an engraving machine for subsequent-engraving, the cylinder is placed in rotation and the scanner is moved over the previously engraved cup track axially. A maximum of the signals received from the scanner is identified and a location of the maximum in the cup track is retained as a reference value for the axial feed during the following engraving. A cup track is provided with at least one defined gap that is free of cups. A first cup following the gap is identified by means of the scanner and evaluated as a reference location for a start of engraving in the circumferential direction for the following subsequent-engraving.

Method for the topically precise subsequent engraving of printing

An electron beam generating system provides a high degree of steadiness of the beam current and comprises a heated cathode, an auxiliary electrode lying at a more negative potential than the cathode, and a transpierced anode. A diaphragm surrounding the beam and connected to a precision resistor is further provided at that side of the auxiliary electrode facing away from the cathode. A portion of the beam current influenced by the control electrode is blanked out by the diaphragm. The precision resistor is connected as an actual value generator to a regulator which is connected to a reference voltage, the output of the regulator influencing the potential of the control electrode over a final control element for the purpose of maintaining the beam current measured by the diaphragm constant.

Highly-steady beam generating for charged particles

Apparatus and method for engraving with an electron beam such that depressions of different sizes can be generated in the surface of a workpiece and the different sizes of depressions are produced by an electron beam and wherein during periods when depressions are not to be formed the electron beam remains on but is defocused so that it does not form depressions. A modification of the invention provides that at times when the beam is not being used to cut depressions that it is pulsed wherein the short pulses of the beam which engage the work surface do not do any cutting.

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Preetz, Germany

Wolfgang Boppel