Dr. Ing. Rudolf Hell Gmbh

Ing. Rudolf Hell Gmbh

Dieter Grieger

Siegfried Beisswenger

Wolfgang Boppel

Heinz Taudt

Jurgen Dolves

A method and device for measuring the density of color layers of printing inks that are still wet is provided in which a polarized light source is directed toward the color layer along an axis of illumination which is inclined at the Brewster angle relative to the surface normal line of the color layer.

Method and device for measuring the density of color layers of printing

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.

Apparatus and method for engraving with an electron beam

An orifice for coupling a highly-evacuated electron beam gun to a rotating print form cylinder for engraving is provided such that the gun has a rigid cover with an opening for the electron beam at its end facing the print form cylinder and a flexible band is arranged at the cover which partially surrounds the print form cylinder. The band is pivoted at the cover and at least one of the pivot points is elastically designed and pivoting occurs with the aid of springs which are adjustable with respect to the spring force.

Orifice for coupling an electron beam gun to print form cylinders

The invention relates to a method for the production of a printing form by the scanning point-by-point and line-by-line of an image pattern along successive cylindrical peripheral image lines and engraving cavities along corresponding cylindrical peripheral engraving lines by an engraving member having an engraving needle as a cutting tool, and includes the steps of generating image signals from the image pattern from along one of the cylindrical peripheral image lines, and engraving a number of cavities at the beginning of an engraving line to depths substantially less than the depths defined by the corresponding image signals. Then the other cavities of said engraving line are engraved to depths which are defined by the nominal values. Subsequently the incomplete cavities of said engraving line are re-engraved in accordance with the corresponding image signals. Another object of the invention is to control the movement of said engraving needle into an engraving position for engraving cavities and into a rest position after an engraving line has been completed.

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Kiel, Germany

Dieter Grieger