Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F7/00—Rotary lithographic machines
  • B41F7/02—Rotary lithographic machines for offset printing
  • B41F7/025—Multicolour printing or perfecting on sheets or on one or more webs, in one printing unit
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41C—PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES
  • B41C1/00—Forme preparation
  • B41C1/18—Curved printing formes or printing cylinders
  • B41C1/182—Sleeves; Endless belts
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F13/00—Common details of rotary presses or machines
  • B41F13/02—Conveying or guiding webs through presses or machines
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F13/00—Common details of rotary presses or machines
  • B41F13/08—Cylinders
  • B41F13/10—Forme cylinders
  • B41F13/12—Registering devices
  • B41F13/14—Registering devices with means for displacing the cylinders
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F7/00—Rotary lithographic machines
  • B41F7/02—Rotary lithographic machines for offset printing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M1/00—Inking and printing with a printer's forme
  • B41M1/06—Lithographic printing

Definitions

• the invention relates to a method for producing printing forms, which serve the printing of a printing material web with a seamless transition or seamless variable format image in offset printing, according to the preamble of claim 1. Furthermore, the invention relates to a method for printing a printing substrate with a seamless or transitionless endless or format-variable printed image, which is gesgesammennot from at least two printing forms, in offset printing using such printing forms.
• the printing of a substrate web with a seam-free or seamless continuous or formatvariablem print image is so far only to an insufficient extent possible because the offset printing printing forms are used, the defined length and / or beyond a pressure-free area for the device for fastening the printing form on the printing form cylinder, commonly referred to as a clamping channel, and thus leave a pressure-free area on the substrate during printing.
• an overall separation of the respective printing ink must be divided into at least two printing forms for each printing ink of the printed image to be printed, so that With a first printing form, a first partial separation of the total separation of the respective printing ink and with a second printing form a second partial separation of the total separation of the respective printing ink onto the printing material can be printed.
• the second subseparation of the second printing form prints in those regions or sections of the printing material web to be printed, which can not be printed with the first subseparation of the first printing form due to the limited length thereof.
• the second subseparation of the second printing form accordingly fills in the first subseparation of the first printing form in the regions in which the first subseparation of the first printing form can not print on the printing material.
• DE 31 17 663 A1 discloses a seamless or seamless, endless printing of a substrate web by means of two printing plates, which print partially overlapping the substrate.
• the present invention has the object, a novel method for producing printing forms, which are used to print a substrate web with a seamless endless or format variable image in offset printing, and a corresponding method for printing a substrate web with a seamless endless or formatvariablen To create print image in offset printing.
• the Bacseparation of each ink is divided into the subseparations, that the substrate web can be printed in the first sections exclusively from the first subseparation of the first printing form and in second sections exclusively from the second subseparation of the second printing form, however, in third sections of Substrate printing with the first subseparation of the first printing form and the second subseparation of the second printing form overlapping or superimposed can be printed.
• the total separation of the respective printing ink is subdivided into the subseparations of the respective printing ink in such a way that expected tone value fluctuations are compensated by means of a tone value correction in the superimposition of the two subseparations in the printing, wherein the tone value correction is effected depending on the degree of superposition of the two subseparations.
• an area ratio is introduced. This is the division of the print image on the involved in the printing process at least two printing plates.
• the area fraction usually moves between 0% and 100%, since a division of one printing or pixel onto at least two printing forms involved in the printing otherwise represent a change in the visual impression compared to the non-divided print image and thus not to a identical optical reproduction of the original print image would result.
• the total separation of the respective printing ink is divided among the subseparations in such a way that the first subseparation in the first sections of the printing material web provides 100% surface area of the respective area coverage for the respective printing ink that the second subseparation in the second sections of the printing material web provides for the respective ink 100% area fraction of the respective area coverage, and that for the third sections of the printing substrate, the first subseparation provides a position-dependent first area portion of the respective area coverage and the second subseparation a position-dependent second area portion of the respective area coverage.
• the total separation of the respective printing ink is preferably subdivided into the subseparations of the respective printing ink such that in the third sections of the printing material web with the first area fraction of the first subseparation and the second area fraction of the second subseparation at least at some positions of the third sections of the printing material web in total overfilling as 100% area fraction of the respective area coverage of the respective printing ink can be printed on the substrate.
• the total separation of the respective printing ink is divided into the subseparations of the respective printing ink in such a way that in the third sections of the printing material web with the first area fraction of the first subseparation and the second area fraction of the second subseparation at each position of the third sections of the printing substrate web 100% in total Area fraction of the respective area coverage of the respective printing ink can be printed on the substrate.
• the two subseparations are designed such that they can be printed overfilling with the same in the third sections, a high quality seamless endless or variable format printing can be realized in offset printing.
• the method according to the invention for printing a printing material web with a seamless or endless printing image uses the printing forms produced by the printing plate production method according to the invention.
• the invention relates to a method for producing printing forms which serve for printing a printing material web with a seamless, endless or format-variable printed image in offset printing. Furthermore, the invention relates to a device for producing such printing plates and a method for printing a printing material web with a seamless transitionless or format variable printed image in offset printing using such printing forms.
• the total separation of the respective printing ink is subdivided into at least two printing forms for each printing ink to be applied in offset printing during seamless or format-variable printing on the printing substrate, so that a first partial printing of the total separation of the respective printing ink and of a second printing separation takes place with a first printing form Printing form a second
• Partial separation of the total separation of the respective printing ink can be printed on the substrate.
• the total separation of the respective printing ink is subdivided into the subseparations such that the printing material web can be printed in first sections exclusively by the first subseparation of the first printing form, that the printing substrate web can be printed in second sections exclusively by the second subseparation of the second printing form, and that the printing material web in third sections of the first sub-separation of the first printing form and the second sub-separation of the second printing form overlapping can be printed, so that between the subseparations of each ink no hard, edge-like transition, but rather a soft, running transition in Printed image exists.
• the total separation of the respective printing ink is divided among the subsections in such a way that the first subseparation in the first sections of the printing material web for the respective printing ink 100% area fraction of the respective area coverage of the respective printing ink can be printed on the substrate web , which can also be printed on the printing substrate with the help of the second subseparations in the second sections of the printing substrate for the respective ink 100% area fraction of the respective area coverage of the respective ink, and that in the third sections of the printing material with the first part separation, a position-dependent first surface portion the respective area coverage and the second subseparation a position-dependent second area ratio of the respective area coverage of the respective ink can be printed on the substrate web.
• an embodiment in which the Bacseparation is distributed to the subseparations that in the third sections of the printing substrate with the first area portion of the first subseparation and the second area portion of the second subseparation in at least some positions, preferably at each position, the third Sections of the substrate web in total overfilling more than 100% area fraction of the respective area coverage of the respective printing ink can be printed on the substrate, because in this way a particularly advantageous, high-quality seamless or seamless endless or variable format printing of the substrate in offset printing is possible.
• the printing material web in the first sections is printed exclusively by the first partial separation of the first printing form.
• the second subsections of the printing material web it is printed exclusively by the second subseparation of the second printing form.
• the third sections of the printing material web is printed the same overlapping or superimposed by two subseparations of the two printing plates, preferably overfilling.
• the total separation of the respective printing ink is preferably divided in such a way on the subseparations of the respective printing ink, that in the third sections of the printing substrate, in which overlapping or superimposed printed with two subseparations, the position-dependent first area portion of the first subseparation at the respective area coverage and the Position-dependent second area portion of the second subseparation at the respective area coverage is represented by a gradient, so that then depending on the gradient, the area proportions change continuously.
• the total separation of the respective printing ink is divided in such a way on the subseparations of the respective printing ink, that in the third sections of the printing material starting from the first sections of the printing material in the direction of the second sections of the printing substrate, the area fraction of the first subseparation of a first portion decreases to a second portion and the surface portion of the second subseparation increases from the second portion to the first portion, whereas in the third portions of the printing material starting from the second portions thereof towards the first portions thereof the area fraction of the second subseparation of the first share decreases to the second share and the area proportion of the first partial separation increases from the second share to the first share.
• the first portion is usually 100%, but can be designed depending on the subject, substrate, etc. also less than 100%, for example 80%.
• the second fraction is usually 0%, but depending on the subject and / or printing material, it may also be greater than 0%, for example up to about 20%, without making the transition visually recognizable. These transitions are preferably configured continuously, for example in the form of a linear or parabolic or other gradient.
• a first alternative to the tonal value correction of tone value fluctuations can be provided that for the first sections and the second sections of the printing material in which the subseparations do not overlap, no tonal correction is performed, however, that for the third sections of the printing material in which the Superimpose partial separations in the printing, position-dependent tonal correction is carried out in such a way that the tonal value correction in the form of a Tonwerterhöhung is greatest at those positions of the third sections to which the surface portions of the subseparations are most similar.
• the tonal increase is greatest at those positions at which both partial separations provide in each case approximately 50% area fraction at the respective area coverage of the respective printing ink.
• the tonal value correction can take place such that a tonal value reduction takes place for the first and second sections in which the partial separations do not overlap.
• a position dependent tone reduction is performed, such that the tone reduction is lowest at those positions to which the surface portions of the subseparations are most similar.
• the offset printing plates for the seamless or seamless endless or variable format printing of a printing substrate are prepared such that for each ink to be printed Retroabsparation the respective ink is provided, which is greater than the circumferential extent of the forme cylinder is, on which the printing forms are to be placed for printing.
• the circumferential extent of the total separation of the respective printing ink is 50% longer than the cylinder circumference of the forme cylinder.
• the total separation then has a length corresponding to 150% of the cylinder circumference of the forme cylinder used for printing.
• the division of the surface portions of thePolseparation takes place on the subseparations after the screening of thePolseparation. If the partial separations are printed in register, it is ensured that the grid system used, including the local position of the halftone dots, is retained without restriction in the printed image of the finished printed product, despite the division of the overall separation into partial separations.
• each ink is rasterized to a so-called primary grid for this purpose, in which case a non-periodic screening or a periodic screening can be used.
• the rasterized total separation of each ink is stored.
• the rastered total separation forms a primary grid.
• Tonwertkorrektur namely, as described above, to compensate for in the superimposition of
• This tonal correction preferably takes place weighted in a location-dependent manner, wherein the tonal value correction preferably has its maximum effect in those areas of the partial separations in which the partial separations develop the maximum superimposition in the pressure.
• a so-called alpha channel is used for this tonal value correction in order to mask the still unscreened total separation of the respective printing ink for tonal value correction.
• the corresponding tonwertkorrigêttechnischseparation is then rastered below again to form the primary grid.
• the rastered total separation of each ink with the help of a secondary grid whose raster frequency is lower than the raster frequency of the primary grid or its point size greater than the dot size of the primary grid is divided into screened subseparations for the respective ink.
• a so-called overlay mask is provided, which defines the overlapping or overlapping of the subseparations in the third sections, wherein this overlay mask is screened to form the secondary grid, namely via a non-periodic or a periodic screening.
• Primary grid and secondary grid can each be both periodic or both non-periodic.
• the raster frequency of the primary raster is higher than the raster frequency of the secondary raster.
• the primary grid may be periodic and the secondary grid non-periodic or conversely the primary grid non-periodic and the secondary grid periodic.
• the secondary grid is coarser than the primary grid.
• the primary grid is superimposed with the secondary grid, preferably erased.
• the primary grid is superimposed with the inverted secondary grid, in particular erased. Subsequently, the two screened subseparations are present for the respective printing ink, which have the length of the total separation.
• the length of the subseparations is subsequently limited to the length of the peripheral extent of the printing plates, preferably such that when the length of the overall separation is 50% greater than the circumferential extent of the forme cylinder used for printing, both subsections are one by one compared to the overall separation Third, namely the first subseparation relative to a first end of the total separation and the second subseparation relative to an opposite second end of the total separation.
• each ink is subsequently used to expose the printing plates so as ultimately to provide the printing plates for the seamless offset printing.
• the order of the individual steps can also be varied.
• the tonal correction can be done before the screening of the total separation of the respective printing ink or after the screening of the total separation of the respective printing ink.
• the printing plates produced with the aid of the method according to the invention are typically printing plates which are positioned for free printing on a printing material web with a seamless continuous or format-variable printed image on corresponding form cylinders of a web-fed printing press.
• the printing plates, the printing material superimposed overlap or printing on each printing ink, are preferably arranged on form cylinders that print rotated by 180 ° to each other, in which therefore the clamping channels for receiving the printing plates are offset by 180 ° to each other.
• a printing material web with high quality can be printed seamlessly or in a format-variable manner without seams or transition.
• the apparatus for producing the offset printing plates using the method according to the invention is a prepress apparatus having means for automatically or automatically carrying out the method, namely software modules implemented by software, with the aid of which the total separation of each print ferns to the above-described Art can be divided automatically or automatically to the subseparations.
• the total separation per ink divided into subseparations then replenishes to form the total separation, resulting in a seamless or endless print product during printing.
• the transition between the subseparations is overlapping, that is not hard in the sense of a smooth or stepped, but at the latest in the case of register deviations emerging optically perceptible edge but rather soft merging into each other.
• the offset printing it is possible to print in high quality seamless or seamlessly continuous or format-variable printing.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Printing Methods (AREA)
• Ink Jet (AREA)
• Manufacture Or Reproduction Of Printing Formes (AREA)

Applications Claiming Priority (1)

Publications (3)

Family

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Family Applications (1)

Country Status (6)

Family Cites Families (11)

• 2013
  • 2013-07-26 DE DE102013107996.2A patent/DE102013107996A1/de not_active Withdrawn
• 2014
  • 2014-07-17 EP EP14177387.9A patent/EP2829400B1/de active Active
  • 2014-07-17 ES ES14177387.9T patent/ES2597243T3/es active Active
  • 2014-07-25 US US14/340,878 patent/US20150027331A1/en not_active Abandoned
  • 2014-07-25 JP JP2014151637A patent/JP2015042489A/ja active Pending
  • 2014-07-25 CN CN201410357832.9A patent/CN104339822A/zh active Pending

Non-Patent Citations (1)

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