JP2008273208A - Method for operating printing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for operating a printing machine, especially an off-set printing machine, for printing a sheetlike or rolled printing medium in a plurality of printing units of the printing machine using a plurality of printing plates manufactured by taking into consideration the image data of a prepress base and the data of the printing medium. <P>SOLUTION: At least an un-printed portion and/or at least a printed portion of the printing medium is measured. At least an actually measured value is compared with at least a reference value depending on the printing medium. From the compared result, it is judged whether or not the printing medium to be actually used coincides with the printing medium used as the reference in manufacturing the respective printing plates to be used in printing concerning its characteristics or the data of the printing medium. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for operating a printing press, particularly an offset printing press, according to the first part of claim 1.

  In a sheet-fed printing press, a sheet-like printing medium in the form of a so-called sheet is moved through a plurality of printing units, so that a print image is transferred to these sheet-shaped printing bodies. The For printing, a plate mold, typically a printing plate, is used in each printing unit, and these are produced in consideration of prepress-based image data as well as printing object data. Is done. That is, since the printed image produced in the printing process is affected by the printing medium to be used, data relating to the printing medium is already taken into consideration at the time of plate making or in the prepress process. In offset printing, the type of printing medium is determined based on the specified characteristics. This is based on an increase in value or print characteristics, a color range reproducible in the printed material, and a show-through of the printed image transferred to the substrate during printing. A color gamut that can be reproduced in a printed material is also called a color gamut, and show-through is also called opacity.

  When a printing medium that has different characteristics or data from the printing medium that was the basis for plate making is used when the printing medium is actually printed on a printing press, the position of the colored portion of the printed material is greatly shifted. , Printing failure may occur. In some cases, the entire printed copy is not used and must be discarded. This causes high costs. Until now, there is no known method of operating a printing press that takes this problem into account.

  From the background as described above, the present invention has been made with an object of obtaining a new operation method for a printing press, particularly an offset printing press.

  This problem is solved by the method described in claim 1.

  According to the invention, at least one non-printed part and / or at least one printed part of the printing medium is measured, and at least one actual value detected in this case is at least one which depends on the printing medium Based on the comparison result, the printed material actually used is based on the printed material used as the basis for producing the printing plate used for printing with respect to the characteristics or the printed material data. It is determined whether or not they match.

  By means of the method according to the invention, measuring at least one non-printed part and / or at least one printed part of a substrate, and in that case detecting an actual value and depending on this to a reference value dependent on the substrate For the first time is proposed. Based on this comparison result, it is possible to determine whether or not the printing medium actually used for printing matches the printing medium that is the basis for plate making in the prepress process. In some cases, based on this comparison result, the printing process may be stopped to avoid printing failure.

  Preferred variants of the invention emerge from the dependent claims and the following description.

    An exemplary embodiment of the present invention will be described in detail with reference to the drawings, but the present invention is not limited to the illustrated exemplary embodiment.

  In FIG. 1, a sheet-fed printing press 10 is shown in a greatly simplified view. The sheet-fed printing press 10 includes one sheet feeding device 11, one sheet ejection device 12, and a sheet feeding device 11. And a plurality of printing units 13 disposed between the paper discharge devices 12. These printing units 13 are preferably configured as offset printing units, and are used to transfer a partial print image to a printing material to be printed.

  The figure shows one plate cylinder 14, one transfer cylinder 15 and one impression cylinder 16 for each printing unit 13. Each plate cylinder 14 has a plate, and each transfer cylinder 15 has a plate cylinder. A transfer mold is arranged. The plate mold is generally a printing plate, and the transfer plate is a rubber blanket. Therefore, the plate cylinder 14 is also called a plate cylinder, and the transfer cylinder 15 is also called a rubber cylinder.

A printing plate placed on the printing plate cylinder 14 and used for printing is produced based on print image data and based on data or characteristics of a printing medium to be printed in a so-called prepress process. The data or characteristics of the printing medium to be considered at the time of plate making are particularly as follows.
-Color of non-printing part of the substrate,
-Gloss of non-printing parts of the substrate
-Increasing tone value or printing characteristics of printing ink during printing,
-Color range reproducible when printing, so-called color gamut,
-The so-called opacity of the printed image seen through the back of the substrate.

  According to the intent of the present invention, at least one non-printed part and / or at least one printed part of the substrate is measured, and at least one actual value detected in this case is at least one depending on the substrate. Compared to one reference value. Based on this comparison result, the substrate to be actually used for printing matches the substrate to be used as the basis for producing the printing plate used for printing in the prepress process with respect to its characteristics or substrate data. It is determined whether or not to do so.

  If it is determined that the substrate to be actually used is different from the substrate on which the printing plate used for printing is based, an error message or warning is automatically generated and reported. . When the characteristic difference between the printing medium actually used and the printing medium assumed in the prepress process is large, the printing machine is stopped or printing of the number of copies is interrupted depending on circumstances. On the other hand, when the characteristic difference is relatively small, feedback control is preferably performed by influencing the printing parameters in order to minimize the color shift caused by the characteristic difference.

  When measuring at least one non-printed part of the substrate, at least one non-printed part or all non-printed parts are measured by one colorimeter and / or one gloss meter and / or one This is done using two opacity meters. FIG. 1 shows, as a specific example, one colorimeter 17 for measuring a plurality of non-printing portions of a printing medium, which is arranged on the upstream side of the printing unit 13 and is therefore printed. The body is grasped by measurement before printing. This meter 17 that measures at least one or all non-printed parts of the substrate, measures the substrate in-line or online in the press during the printing process or during print production. .

  In addition, FIG. 1 shows one measuring instrument 18 that is used to measure at least one printed portion of a substrate, where at least one printed portion or all printed portions are It is designed to be measured by one colorimeter.

  The meter 18 is incorporated into the sheet-fed press downstream of the printing unit 13, as shown in FIG. 1, so that at least one or all of the printed portions are measured after printing the substrate. Again, this has come to be done inline or online during print production.

  The actual values detected by one meter or all the meters 17, 18 are transmitted to one control device 19, where the actual values detected are compared with reference values that depend on the substrate. Each detected actual value is compared with a plurality of reference values stored for each type of substrate having different characteristics or substrate data in the control device 19, and based on the comparison result, the actual values are compared. It is determined whether or not the printing medium used for printing matches the printing medium used as the basis for producing the plate used for printing with respect to the characteristics or printing medium data.

  This comparison can be performed using software installed in the control device 19. Alternatively, the comparison software may be incorporated directly into one meter or all meters 17,18.

  The measurement of at least one or all non-printed parts as well as the measurement of at least one or all printed parts is a single colorimeter, specifically one that detects the actual value of the so-called L * a * b color space It is preferable to use a spectrocolorimeter. The actual values of these L * a * b color spaces are compared with the reference values of multiple L * a * b color spaces. Specifically, all actual values are stored for each type of substrate. It is compared with multiple reference values. Subsequently, based on the result of the comparison, whether or not the printing material actually used matches with the printing material on which the printing plate was based when the printing plate was baked in the prepress process with respect to the characteristics or printing data. Is determined.

  The measurement of at least one or all non-printed parts as well as at least one or all printed parts using a colorimeter, in particular a spectrocolorimeter, is preferably carried out according to the standard. For this purpose, one black backing for measurement is arranged on the back side of the printing medium along the conveyance path of the printing medium passing through the printing machine at a position facing the colorimeter.

  According to the method of the present invention, whether or not the printing medium actually used matches the printing medium that is the basis of the plate making in the prepress process in terms of its characteristics or printing medium data, for print production. In-line or on-line inspection is possible.

  When the difference in the type of the printing medium confirmed by the inspection is relatively small, it is possible to compensate for the generated color misregistration by feedback control of the process parameter. When the difference is relatively large, it is preferable to stop the printing process in order to avoid printing failure.

  The present invention can be used in a sheet-fed printing machine and a winding printing machine. The present invention can be used for double-sided printing as well as single-sided printing of non-printed materials. Double-sided printing is also called front / backside printing in the case of a sheet-fed printing machine, but this includes cases where the properties of the printing medium differ on both sides. In this case, different reference values are stored correspondingly for each surface.

It is the schematic of the printing machine comprised as a sheet-fed printing machine for demonstrating the printing press operating method by this invention.

Explanation of symbols

10 sheet-fed printing press
11 Paper feeder
12 Output device
13 Printing unit
14 plate cylinder
15 Transfer cylinder
16 impression cylinder
17 Meter
18 Measuring instrument
19 Control unit

Claims (12)

A method of operating a printing machine, particularly an offset printing machine, in which a sheet-shaped or roll-shaped printing material is produced in consideration of prepress-based image data and printing material data in a plurality of printing units of the printing machine. In a method of printing using a plurality of plate dies,
Measuring at least one non-printed part and / or at least one printed part of the substrate, and comparing at least one actual value detected at this time with at least one reference value depending on the substrate; Based on the comparison result, whether or not the printing medium actually used matches with the printing medium on which the printing plate used for printing is based on the characteristics or printing data. How to determine.   The method according to claim 1, wherein the at least one or all non-printed parts are measured using a single colorimeter.   The method according to claim 1, characterized in that the at least one or all non-printed parts are measured using a single gloss meter.   The method of claim 1, wherein the at least one or all non-printed portions are measured using a single opacity meter.   5. A method according to any one of the preceding claims, characterized in that the at least one or all printed parts are measured using a single colorimeter.   Compare all detected actual values with multiple reference values stored for each type of substrate with different characteristics or substrate data, and based on the comparison result, the substrate to be actually used Is determined whether or not it matches with the substrate to be printed on which the printing plate used for printing is based on its characteristics or substrate data. The method as described in any one of.   The at least one or all non-printing parts are measured before printing the printing body and / or after printing the printing body, according to any one of claims 1 to 6, Method.   The method according to any one of claims 1 to 7, characterized in that the at least one or all printed portions are measured after printing the substrate.   As a colorimeter, one spectral colorimeter that detects the actual value of the L * a * b color space is used, and each actual value of the L * a * b color space is used as the L * a * b color space. The method according to claim 1, wherein the method is compared with a plurality of reference values.   An error message is automatically generated and displayed when it is determined that the substrate to be actually used is different from the substrate on which the printing plate used for printing is based. 10. The method according to any one of claims 1 to 9, characterized in that   When it is determined that the substrate to be actually used is different from the substrate on which the printing plate used for printing is based, the parameters of the printing process are automatically adapted. 11. The method according to any one of claims 1 to 10, characterized in that   Measuring the at least one or all non-printed portions of the substrate and / or the at least one or all printed portions of the substrate in an in-line or online manner with respect to a printing process. 12. The method according to any one of claims 1 to 11, wherein

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