JP2004314583A - Method for carving of plate cylinder for intaglio printing by electronic rotogravure printing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for the carving of a plate cylinder for the intaglio printing by an electronic rotogravure printing machine in which a support screen is carved on the plate cylinder on top of carving a text and/or an image on the basis of text and/or image data, that is to say, it is to form the support screen by the proper carving of the plate cylinder, advantages, which are provided by the support screen in a printing process by the plate cylinder for the intaglio printing are further improved and utilized in an optimum manner, as a result, the text and/or the image can be excellently reproduced compared with the conventional one. <P>SOLUTION: The support screen is solved by variably setting it depending on the text and/or the image data at least regarding its size. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to engraving a plate cylinder for intaglio printing with an electronic gravure printing machine, wherein a support screen (Stuetzraster) is engraved on the plate cylinder in addition to engraving the text and / or image based on the text and / or image data. For the method for.
[0002]
[Prior art]
In addition to engraving text and / or images on the intaglio printing cylinder, so-called support screens are also engraved. This support screen has the task of staking the printing ink locally during the printing process. If this support screen is not provided, the printing ink will bleed over the engraved area, especially in the case of deep engravings. This printing ink bleeding occurs more strongly as the text and / or image engraving becomes deeper and larger.
[0003]
This support screen is implemented in principle in two basic gravure printing methods, namely for both vibration engraving and line engraving, on the aforementioned intaglio printing cylinders. You. In the case of vibratory engraving, the support screen is generated in effect by a screen pattern inherent in the vibratory engraving, and the "cells" generated in the vibratory engraving determine the geometric dimensions of the support screen there. The lines that occur between the cells correspond to a density of 0%. Due to the screen pattern generated in the vibratory engraving by the cells, for example, the characters or texts generated by vibratory engraving often give the impression that they are torn. That is, the edges of the characters often give an unstable impression. While reducing the screen size will result in better reproduction of the character's edge area, the reduction in screen width will also result in a reduction in cell size. Therefore, when this method is employed, the central region of the character line also has a relatively small cell size, which is disadvantageous. This is because the maximum achievable print density is reduced in this case.
[0004]
In the case of the method of line engraving of text and / or images on a plate cylinder, multiple individual support screens are formed, which support screens, as in the case of vibratory engraving with a screen-patterned arrangement of cells therein. Are not formed, but rather in the use of line engraving the support screens described above must be provided separately.
[0005]
Of course, the support screen has the same function in principle in both vibration engraving and line engraving, that is, has the effect of preventing the printing ink from oozing beyond the engraving area.
[0006]
The support screen exists on the plate cylinder with a predetermined mesh width, and the mesh width is constant. This means that: That is, for example, the engraved character or text is also traversed by the support screen, i.e., in this example, the engraved character has a support screen pattern, and this therefore also applies to the image. Even so. This means that the support points (die Stetzstellen) of the support screen are also present at regular intervals from each other. In this case, if the spacing is selected to be small, the possibility of printing errors is improved as much as possible, and the volume advantage is of course diminished, especially when slightly extending fine character lines have to be engraved or printed. On the other hand, if the spacing is chosen to be large, the possibility of printing errors is exacerbated, especially in the area of large-area character lines.
[0007]
Depending on the conventional support screen, the advantage of the improved reproduction of the characters or text inherently obtained, especially when using the line engraving method, over the vibratory engraving method is nevertheless not optimally utilized. You can see that.
[0008]
[Problems to be solved by the invention]
The object of the invention is therefore to provide a method for engraving a plate cylinder of the type mentioned at the outset, that is to form a support screen by corresponding engraving of a plate cylinder, by which method The advantages that the support screen provides in the printing process with a plate cylinder for intaglio printing are further improved and more optimally utilized, resulting in better text and / or image reproduction than before, and It should be possible in principle to maintain the engraving methods conventionally used for the formation of texts and / or images and support screens.
[0009]
[Means for Solving the Problems]
The object is achieved in that the support screen is variably set, at least with respect to its size, depending on the text and / or image data.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
The advantage of the present invention is that, basically, the support screen is flexibly adapted to the engraving data, i.e. the spacing of the support points of the support screen is selectable, can be performed in engraving on the plate cylinder, and the support screen is always The actual engraving data or images and texts can be covered in the best possible way. According to the invention, the support screen can be changed at least with respect to the text and / or the size of the image, depending on the edge conditions in which the character and the image are present.
[0011]
Advantageously, for example, the lines forming the support screen are variably set as a function of the text and / or image data, at least with respect to their distance from one another. By this means, it is much better achieved that, for example, thin text is not torn by the support screen.
[0012]
Advantageously, the support screen has an arbitrarily selectable direction relative to the text and / or the image. In this case, it is possible in principle to arbitrarily orient the direction of the support screen relative to the text and / or image to be engraved, and in this case a crucial parameter for the orientation of the support screen May be any type of text or image to be engraved or printed. Different orientations of the support screen may be selected for a given text and / or image type.
[0013]
According to a particularly advantageous embodiment of the method of the invention, the spacing of the lines of the support screen from one another is kept essentially constant when large areas of text and / or image areas are present. Therefore, in such a case, the static support screen is prioritized. Of course, the line spacing should be adjusted constant, for example to achieve the desired print density, depending on the subsequent desired printing process.
[0014]
Support screens having regularly square, rectangular or diamond shaped cells, although other shapes are possible, are selected in a further advantageous embodiment of the method of the invention as follows. That is, the course of the main axis of the support screen is arbitrarily selectable relative to the text and / or the image, and is advantageously selected such that the main axis runs perpendicular to the text and / or the image. Such a course is very useful for certain support screens provided on the plate cylinder, if very high print densities are to be achieved in the subsequent printing process.
[0015]
In another advantageous embodiment of the method of the invention, the main axis runs at an acute angle to the text and / or the image, ie the main axis of the support screen wraps around the plate cylinder in a so-called spiral.
[0016]
It is particularly advantageous if the support screen is formed up to the edge area of the negative text and / or the image, that is to say, for example, that the actual contour area of the text or text and the image is not covered by the support screen. As a result, so-called outlining of an edge area of a character or an image is realized, and furthermore, in the case of a positive character, a negative character, a positive image, or a negative image.
[0017]
For example, the support screen is advantageously set different from the size of the text and / or other areas of the image, at least in terms of its size, at least in the edge area of the text and / or the image, thereby advantageously providing text and images It is achieved that the support screen does not have the same effect as the large area in the narrow area. This means that in these areas the support screen has a relatively small effect on the subsequent printing process. This is achieved, for example, by a change in the density of the support screen.
[0018]
It is also possible that the support screen completely avoids at least text and / or outline areas of the image, which can be positive characters or texts, negative characters or texts and even images, and thus characters or images. Outlining is performed in the edge region.
[0019]
The engraving depth of the support screen has a predetermined value, which corresponds to a density between the density of the surface and the density of the data to be engraved. For this reason, it is very advantageous to set the engraving depth of the support screen variably depending on the text and / or data prepared for engraving the image. This means that the density can be freely parameterized by this measure and can be adapted to the subsequent printing process by means of the plate cylinder provided with the support screen of the invention.
[0020]
Similarly, it is very advantageous to select or set the density of the support screen depending on the text characters and their density. That is, both the line geometry and density of the support screen can be adapted to the character geometry and its density.
[0021]
Therefore, ultimately, the density of the support screen in the edge regions of the characters of the text is advantageously chosen to be different from the central region of the characters. That is, a dynamic adaptation of the formation of the support screen is performed. That is, the density of the support points changes due to the density change in the edge region of the character, and may also change compared to the density in the central region of the character. This assists in character outlining.
[0022]
【Example】
The invention will be described in more detail with reference to the accompanying schematic drawings in terms of its printing technology.
[0023]
First, please refer to FIG. FIG. 1 shows in part the use of a static support screen 10 in a plate cylinder. This static support screen 10 corresponds to a support screen as heretofore used in the prior art. Two drawbacks can be seen from this. The support screen 10 first falls into the negative characters, and the support screen 10 is not optimally provided for positive characters. See the image on the right and the image on the left.
[0024]
In contrast, FIG. 2, which shows the use of a dynamic support screen 10 according to the invention, does not have these disadvantages. It can clearly be seen that in the method according to the invention, much better reproduction of the negative characters is achieved by contouring and much better reproduction of the positive characters is achieved by the separation associated with the objects in the positive layer. See the image on the right and the image on the left.
[0025]
The actual support screen 10 here e.g. spirals around the plate cylinder and in both directions. Reference numeral 11 denotes a periodically repeating line of the support screen 10. The support screen here forms a square, approximately square field or mesh in both examples. It can be clearly seen from FIG. 2 that, with reference to the image on the right, the support screen 10 is not drawn in the immediate vicinity of the negative character, whereby the outlining of the negative character is achieved. In addition, a much better reproduction of the negative character of FIG. 2 by contouring can be seen as compared to the corresponding character of FIG. 1, and the positive character of the left image of FIG. 2 compared to the positive character of the left image of FIG. The separation associated with the better objects of the characters can be seen.
[0026]
According to the invention, the support screen 10 is variably set, at least with respect to its size, depending on the text and / or image data. This variability relates to the lines 11 forming the support screen 10 as well as to the support points, and also to the density of the support screen at any selected position of the plate cylinder, where the text is corresponding to the desired preset. And / or may be variably formed depending on the image data. The field or mesh width of the support screen 10 may be different and wider throughout the plate cylinder, and may not be formed as can be seen in the image on the right side of FIG. 2, i.e., may be completely absent. There is also.
[0027]
The main axis directions of the support screen 10 of FIG. 2 run there at right angles, for example, and are inclined at an angle of approximately 45 ° with respect to the X or Y axis of the plate cylinder.
However, this embodiment illustrated in FIG. 2 merely shows the possibility of a principal axis orientation.
In principle, any suitable angle of the support screen depends on the text and / or the current text and image data for engraving the image, and also on other parameters such as printing density and printing ink. And can be selected for later printing.
[0028]
The routine for engraving the support screen on the plate cylinder proceeds as follows:
-Identification of characters-Character distinction by positive and negative characters-Finding the central area in the case of positive characters-Setting points of the support screen in the central and edge areas at constant or variable spacing of the support screen ,
Similarly:
-Finding the edge area in the case of a negative character-Setting the background area of the negative character and the points of the support screen in the edge area.
[0029]
The points of the support screen are freely chosen with regard to:
The density of the support points for the center and edge areas of the positive character; or the density of the support points for the background and the edge area of the negative character; the width of the support points;
[0030]
The location of the points on the support screen is selected as follows:
They are set at an arbitrary angle, but preferably perpendicular to the edge region; the density of these points is selected depending on the density of the central or edge region.
[0031]
The positions of the support screens are dynamic, and these positions can differ from one another on a character-by-character basis in their placement with respect to the text or image dataset and in their density.
[0032]
If the support screen does not reach the negative character, an outlining of this character type is realized, which is advantageous for the reproduction of this character type.
[0033]
The routine for overlaying the support screen should be automated as follows. That is:
-The dataset is assigned to a hot folder, which superimposes on the support screen,
The local location of the support screen is individually selected according to the actual data.
[0034]
The superimposition of the support screen is performed on the source data set or the engraving data set.
[Brief description of the drawings]
FIG. 1 illustrates forming a text by using static support registers in positive and negative characters by forming a support screen according to the prior art.
FIG. 2 illustrates a view similar to FIG. 1 in which the dynamic support screen of the present invention is used.
[Explanation of symbols]
10 Support screen 11 Line 12 Edge area 13 Central area

Claims (13)

A method for engraving a plate cylinder for intaglio printing by an electronic gravure printing machine,
Method for engraving a plate cylinder for intaglio printing with an electronic gravure printing press, in which a support screen (10) is engraved on the plate cylinder in addition to engraving the text and / or image based on the text and / or image data At
For engraving a plate cylinder for intaglio printing with an electronic gravure printing press, characterized in that said support screen (10) is variably set at least in terms of its size depending on text and / or image data. Method. Method according to claim 1, characterized in that the lines (11) forming the support screen (10) are variably set as a function of text and / or image data, at least with respect to their distance from one another. Method according to claim 1 or 2, characterized in that the support screen (10) has a direction which is arbitrarily selectable relative to the text and / or the image. 4. Method according to at least one of the preceding claims, characterized in that in the case of large areas of text and / or image areas the line spacing is kept essentially constant with respect to each other. 5. The method as claimed in claim 1, wherein the course of the main axis of the support screen is arbitrarily selectable relative to the text and / or the image. Method according to claim 5, characterized in that the main axis runs perpendicular to the text and / or the image. Method according to claim 5, characterized in that the main axis runs at an acute angle to the text and / or the image. Method according to at least one of the preceding claims, characterized in that the support screen (10) is formed up to the edge area (12) of the negative text and / or image. 8. The support screen (10) according to claim 7, characterized in that the support screen (10) is set differently from the size of the text and / or other areas of the image in at least its size in the edge area of the text and / or image. Method. Method according to at least one of the preceding claims, characterized in that the support screen (10) avoids at least text and / or contour areas of the image. At least one of the claims 1 to 10, characterized in that the engraving depth of the support screen (10) is variably set depending on the text and / or data supplied for engraving the image. The method of claim 1. 12. Method according to at least one of the preceding claims, characterized in that the density of the support screen (10) is selectable depending on the text characters and their density. 13. The method according to claim 12, characterized in that the density of the support screen (10) is selected to be different in a text character edge region (12) than in the character center region (13).

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