Heidelberger Druckmaschinen Ag

Josef Haase

Helmut Kipphan

Werner Joss

Method of regulating an amount of dampening medium on a printing plate of an offset printing machine, includes determining the amount of dampening medium on the printing plate, adjusting the rotational speed of a dampening ductor and/or the like to a given set value so as to regulate the amount of dampening medium on the printing plate and, for regulation deviations wherein the set value is greater than an actual value, driving a controller with a greater amplification factor than for regulation deviations wherein the set value is smaller than the actual value.

Method of regulating dampening medium

A method of establishing a measuring location lying in an ink-free area for determining the thickness of a layer of dampening medium on the surface of an offset printing plate, which includes scanning the surface of the plate in a search run with a measuring head, and evaluating the thus obtained measurement data in a manner that a measuring location lies in a vertical zone of the offset printing plate with the smallest possible average area coverage, and a device for performing the method.

Method of establishing a measuring point for determining the thickness

Sensor device for analyzing a surface structure includes a lighting device for emitting a focussed beam of light rays directed onto a surface, a radiation detector element for sensing light rays reflected from the surface, and an evaluating device for determining the surface structure from signals emitted by the light-ray detector element, a parameter T.sub.N for the surface structure being determinable by the evaluating device in accordance with a third moment of distribution of intensity of the reflected light rays in accordance with an equation: ##EQU1## wherein n represents a number of measuring points along a scattering indicatrix corresponding to the light rays reflected from the surface; P.sub.i is an initialized measuring signal according to an equation: ##EQU2## wherein I.sub.i is in the intensity of the light rays on a measuring point i; K represents a scaling factor; and M has a value determinable from values for i and P.sub.i in accordance with the equation: ##EQU3##

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Neckargemund, Germany

Josef Haase