Printing – Intaglio – Processes
Reexamination Certificate
1999-11-18
2001-10-16
Funk, Stephen R. (Department: 2854)
Printing
Intaglio
Processes
C358S296000
Reexamination Certificate
active
06302020
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention is in the field of electronic reproduction technology and is directed to a method for engraving rastered printing cylinders, particularly for rotor gravure, with an engraving element in an electronic engraving machine.
When engraving rastered printing cylinders in an electronic engraving machine, an engraving element that, for example, comprises an engraving stylus as a cutting tool moves along a rotating printing cylinder in the axial direction continuously or step-by-step. The engraving stylus controlled by an engraving signal cuts a sequence of depressions arranged in a raster, referred to below as cups, into the generated surface of the printing cylinder. The engraving signal is formed from the superimposition of an image signal representing the hues between “black” and “white” with a periodic raster signal. Together with the circumferential speed of the printing cylinder and the axial feed speed of the engraving element, the raster signal defines the geometry of the engraved raster. Whereas the periodic raster signal effects a vibrating lifting motion of the engraving stylus, the image signal—corresponding to the hues to be reproduced—controls the depths of the cups engraved into the generated surface of the printing cylinder.
Such an engraving machine for engraving printing cylinders is disclosed, for example, by WO-A-94/19900. This is a matter of a method for calibrating an engraving signal, whereby cups are engraved, the geometric actual dimensions of the engraved cups are measured, and whereby setting values are determined from the comparison of the measured actual value dimensions to predetermined rated dimensions, the engraving signal values for selected gradations being corrected with the setting values such that the actual gradations in fact engraved in the form of cups correspond to the rated gradations defined by the image signal values.
GB-A-1407487 discloses another engraving machine for engraving printing cylinders. This is a matter of a method for engraving a printing page composed of a plurality of image and text parts compiled according to a layout plan, whereby the engraving data required for engraving the printing page are compiled from the engraving data of the individual image and text parts according to the layout plan to form overall engraving lines before the engraving and are stored, and whereby the compiled engraving data of the overall engraving lines are read out in the engraving and supplied to the engraving element.
In manufacturing printing forms, particularly for packaging printing, sequential, i.e. successively sequencing engravings' must often be produced with the same or with different engraving parameters such as, for example, the raster parameters of screen angle and raster width. Examples of sequential engraving are the re-engraving of areas within an initial engraving or multiple engravings (copies) of half-tone images and line information or, respectively, bar codes in the axial direction. The sequential engravings can occur on a printing cylinder or on a plurality of printing cylinders having the same or different diameters.
Due to the function modes of traditional engraving machines, such sequential engravings with different engraving parameters on one printing cylinder or on a plurality of printing cylinders with, potentially, different diameters' cannot he automatically implemented in one pass, for example without intervention of an operator in a night shift, which is disadvantageous.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to improve a method for engraving rastered printing cylinders, particularly for rotor gravure, with an engraving element in an electronic engraving machine such that engravings with identical or different engraving parameters can be automatically implemented in one pass on at least one printing cylinder.
According to the method of the present invention for engraving a rastered printing cylinder for rotogravure with an engraving element in an electronic engraving machine, an engraving signal is acquired for driving an engraving element dependent on predetermined engraving parameters. With the engraving element, cups are engraved into a rotating printing cylinder arranged in a raster defined by predetermined engraving parameters, engraving depths of the cups representing engraved gradations. With the engraving element, for planar engraving of the cups, implementing the feed motion along the printing cylinder preceding axially relative to the printing cylinder, a geometry of the raster being determined, among other things, by a circumferential speed of the rotating printing cylinder and by a feed motion of the engraving element. At least one of circumferential speed and feed rate are set dependent on the predetermined engraving parameters. Engravings of individual engraving jobs sequencing in chronological succession or engraving areas of the printing cylinder with at least one engraving element are automatically implemented in one pass by an automatic executive sequencer programmable according to the individual engraving jobs. Dependent on respectively prescribed engraving parameters of the individual engraving jobs, control signals are generated in the executive sequencer, the control signals according to a position of the individual engraving areas on the printing cylinder automatically changing at least axial position and feed rate of the engraving element as well as the circumferential speed of the printing cylinder for following engraving job after the end of an engraving job.
REFERENCES:
patent: 3975761 (1976-08-01), Taudt et al.
patent: 4546232 (1985-10-01), Beisswenger et al.
patent: 4605957 (1986-08-01), Yamada
patent: 5186102 (1993-02-01), Kanno et al.
patent: 5416597 (1995-05-01), Mubaslat
patent: 5503876 (1996-04-01), Fields et al.
patent: 5822078 (1998-10-01), Hirai et al.
patent: 5847837 (1998-12-01), Ogawa
patent: 5892589 (1999-04-01), Beckett et al.
patent: 5947020 (1999-09-01), Bornhorst, Jr. et al.
patent: 6025921 (2000-02-01), Beckett et al.
patent: 25 13 042 (1980-03-01), None
patent: 40 17 164 (1991-12-01), None
patent: 0 108 376 (1984-05-01), None
patent: 0 207 246 (1987-01-01), None
patent: 1 407 487 (1975-09-01), None
patent: 2 100 092 (1982-12-01), None
patent: WO 94/19900 (1994-09-01), None
Becker Karsten
Bleihöfer-Sterzinger Reinhold Bruno
Lübcke Bernd
Funk Stephen R.
Heidelberger Druckmaschinen AG
Schiff & Hardin & Waite
LandOfFree
Method and device for engraving impression cyclinders does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and device for engraving impression cyclinders, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and device for engraving impression cyclinders will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2584493