Heidelberger Druckmaschinen Ag

Heidelberger Druckmaschinen

Rudolf Karl Uhrig

Gerhard Loffler

Offset printing method wherein ink in the form of screened half-tone dots or pixels and unscreened printing-image elements is applied to a printing surface of a recording medium by means of a printing device; a printing form being generated from signals reproducing a printed image; the printing form being inked with an inking device; and the ink being transferred to the printing surface, upon transport of the recording medium relative to the printing device; the signals being processed in a control device for the printing device; includes, near the printing device and before the printing form is generated on a screen or monitor, forming a copy of the printed image from the signals reproducing the printed image and from signals containing parameters of the printing device; whenever the copy deviates from a desired printed image, manually inputting correction values for local inking into the control device, until the copy corresponds to the desired printed image; and generating the printing form and adjusting the elements affecting the inking with the signals reproducing the desired printed image and from signals containing fixed printing-press characteristics.

Offset printing method

A process for filmless production of a ready-to-print printing form and for using it in an offset printing press includes exposing a printing form sensitive in an emission range of light-emitting diodes to an image in an exposure unit by means of a computer-controlled LED bar, passing the exposed printing form through a developing stage wherein the printing form is developed, and then feeding-in the printing form via a high-speed feeding-in device for printing forms, and positioning the fed-in printing form on a plate cylinder; and apparatus for performing the process.

Process for filmless production of a printing form

A method of automatically controlling deviations in the liquid ink and dampening liquid feed in an offset printing press includes irradiating a layer formed of liquid ink and ingredients of a dampening liquid deposited on a plate cylinder of the press with at least one source of radiation, selectively interposing, in the radiation path between the radiation source and the irradiated liquid layer, wave length absorption filters, selecting certain wavelengths most heavily absorbed by at least one of the liquids, comparing measured values for the ink layer and the individual ingredients of the dampening liquid with a given nominal value and, in accordance with a quantitative deviation between the measured and the nominal values, automatically actuating a control circuit for regulating the feed of the liquid ink and the dampening liquid; and a device for carrying out the foregoing method.

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Schriesheim, Germany

Rudolf Karl Uhrig