US 4,384,337 AGranted

Zonal ink distribution measuring method and system

AssigneeMAN Roland Druckmaschinen AG

InventorsHans E. Mamberer, Dieter Hirt

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Abstract

To avoid edge effects and local variations of differences in transducers across zones of material to be printed from which print control signals are to be derived, for example to control the localized or zone adjustment positions of a flexible doctor blade with respect to an ink ductor roller in an offset printing machine, a first standard sample providing, for example, white signals, is first scanned, then a standard sample, providing for example totally inked zones, is scanned, and then the actual printing sample. From each of the scannings, signals are derived with respect to print zones, for example columns in a newpaper layout, the signals being compared to form a difference or comparison signal from the first two standards (light and dark) in the respective zones, which difference signal is stored, with respect to the respective zones, in a file memory (11); this difference signal then is compared with processed transduced signals derived from the actual text to be printed, for conversion into output signals for display, storage or control of the printing machines in accordance with the respective ink coverage of the zones which were scanned.

Claims14

Dependent claims

Apparatus for electro-optical measurement of information coverage on zones of a surface of an areal carrier (C) and deriving corresponding representative utilization signals, particularly for control of ink zone adjustment means (26, S) in a printing apparatus (B, D),

in which the distribution of the degree of inking of zones of the surface area is determined, having
electro-optical transducing means (1, 2, 3, 4, 19) providing en electrical signal representative of the relative distribution of ink in the respective zones of the surface area,
and comprising, in accordance with the invention,
a memory (11, a comparator (10, 12) and control means (6, 13, 14) including a selector controlling the sequencing of comparison, and storage of signals,
said memory and comparator being connected to and receiving signals from said transducing means covering respective zones, and processing said signals, upon introduction of the carrier with the surface into the transducing apparatus to derive therefrom and provide said utilization signals applicable to respective zones,
said memory and comparator being connected and arranged for
(a) upon selection of a first calibrating mode and upon introduction of a first standard surface (A) having a first extreme value of ink covering into the transducer means, receiving first transduced signals transmitted by the transducer means, and storing said first received signals;
(b) upon selection of a second calibrating mode and upon introduction of a second standard surface (B) having an opposite and second extreme value of ink covering into the transducer means, receiving second transduced signals transmitted by the transducing means, and comparing with said stored first transduced signals to form a difference of the second transduced signals with respect to said stored first transduced signals to derive difference signals, and storing said difference signals in the memory (11);
and
(c) upon selection of a third or controlled operating mode and introduction of a carrier having a surface (C) carrying indicia intended for printing into the transducing means, receiving third transduced signals transmitted by the transducing means to derive operating transduced signals, and comparing the signals for the respective zones covered by the zones of the surface in the transducing means in said comparator (12) with said stored difference signals of the respective zones in the memory (11) to derive utilization signals;
output means (7, 8, 26) for receiving said utilization signals;
and sequencing control means (13, 14) controlling said memory (11) and comparator (10, 12) for selectively receiving and storing the respective signals applied thereto.

9 more elements

Method of deriving utilization signals representative of the information coverage on zones of a surface of an areal carrier (C), particularly for control of ink zone adjustment means (26, S) in a printing apparatus (B, D), for determination of the distribution of the degree of inking of zones of the surface area, using

electro-optical transducing means providing electrical signals representative of the relative distribution of ink in the respective zones of the surface of the carrier, and memory, difference forming, and comparison apparatus including a selector controlling the sequencing of the steps, the memory (11) providing storage of signals, and, comprising the steps of
introducing a first standard surface (A) having a first extreme value of ink covering into the transducer means and deriving first transduced signals;
applying said first transduced signals to the memory;
storing said first transduced signals;
introducing a second standard surface (B) having an opposite and second extreme value of ink covering into the transducer means and deriving second transduced signals;
forming a difference signal of said second transduced signals with respect to said stored first transduced signals, and storing said difference signals in the memory (11);
introducing a carrier having a surface carrying indicia intended for printing into the transducing means and deriving third transduced signals;
comparing said third transduced signals with said stored difference signals in the memory, with respect to the respective zones covered by the zones of the surface in the transducing means by comparing, in a comparator, the third transduced signals for the respective zones with said stored difference signals of the respective zones;
and deriving an output signal representative of the result of said comparison.

6 more elements

Dependencies are inferred from the claim text.