DE4413735A1 - Control of regulation of dot size produced by rotary printing press - Google Patents

Control of regulation of dot size produced by rotary printing press

Info

Publication number
DE4413735A1
DE4413735A1 DE19944413735 DE4413735A DE4413735A1 DE 4413735 A1 DE4413735 A1 DE 4413735A1 DE 19944413735 DE19944413735 DE 19944413735 DE 4413735 A DE4413735 A DE 4413735A DE 4413735 A1 DE4413735 A1 DE 4413735A1
Authority
DE
Germany
Prior art keywords
control
printing
dot size
pressure
setting
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
DE19944413735
Other languages
German (de)
Other versions
DE4413735C2 (en
Inventor
Gerhard Loeffler
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Heidelberger Druckmaschinen AG
Original Assignee
Heidelberger Druckmaschinen AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Heidelberger Druckmaschinen AG filed Critical Heidelberger Druckmaschinen AG
Priority to DE19944413735 priority Critical patent/DE4413735C2/en
Publication of DE4413735A1 publication Critical patent/DE4413735A1/en
Application granted granted Critical
Publication of DE4413735C2 publication Critical patent/DE4413735C2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B41PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41FPRINTING MACHINES OR PRESSES
    • B41F33/00Indicating, counting, warning, control or safety devices
    • B41F33/0036Devices for scanning or checking the printed matter for quality control

Abstract

Before printing is commenced, a desired value (Rsoll) of dot size is stored in the controller (25). Continuous measurements of the actual size (Rist) are made by an image sensor (26).The results of the comparison are used to vary the spacing of the axes (3,8,9) of the cylinders (2,4,5) and hence the contact pressures. The dot size can also be influenced by the quantity, compsn. and temp. of moisture supplied (15) from a container (17), and by the temp. of the ink (18).

Description

The invention relates to a method for control or Control the dot size when printing on one Substrate. The invention is in rotary printing presses applicable where there is contact between the substrate and the pressure generating cylinders takes place and where that Print image is composed of halftone dots.

To achieve high print quality, it is necessary monitor the dot sizes. Ideally they are optically effective screen dot sizes in the printed image and the die Raster dot sizes representing the template are identical. For Approaching this ideal case is used in the Reproduction process printing characteristics that dependency of the Screen tones in the printed image from those in the screen film describe. To determine a current pressure characteristic are measuring fields with raster levels of certain tonal value and a solid field printed. The measuring fields are marked with a Densitometer with regard to the color densities in full tone and in evaluated the grid levels, from which the screen tone values result in the printed image. The current pressure characteristic is only valid for a certain combination of printing ink, Printing material, pressure between those producing the print Cylinders, from the properties of a Pressure transmission material z. B. the rubber blanket and the mode of operation of the printing plate carrying the printing form, e.g. B. reacting positively or negatively. In practice occurs a deviation from the ideal pressure characteristic, which as Dot gain is called.  

The printing presses are used to control and regulate the Coloring connected to a control or regulating device, in which material and copy process dependent Desired pressure characteristic curves can be stored, which after the method described above were determined.

Certain are determined in accordance with these pressure characteristics Operating variables set to defined values and constructive precautions taken so that in the print image an optimal print contrast results. Examples are the Setting the composition and the amount of a Fountain solution and the size of the pressure supply between a plate cylinder and a rubber impression cylinder Called offset printing machine.

A disadvantage of the known methods is that one a specific machine type specifies a pressure characteristic at the mechanical peculiarities of the machine in question are not taken into account, and that during printing the pressure characteristic, e.g. B. by wear of the pressure plate and by external influences, such as temperature fluctuations, Fluctuations in humidity and deflection of the cylinders and Thickness fluctuations in the substrate, can change constantly, so that corrective actions by the printer are necessary, as far as this can visually detect changes can; in addition, measurements on individual measuring fields are not representative of the dot size in the entire printed image.

The object of the invention is to provide a method that a largely precise presetting of the pressing between a printing form cylinder and a Transfer cylinder, as well as an ongoing control or Control of the dot size during printing enables.

The invention consists in that by means of at least one Image recording device, which is directed onto the printing material  actual value signals for the grid point size be determined and a control or regulating device be fed. The actual value signals are with Setpoint signals for the grid point size are compared, the have previously been entered into the control or regulating device. The resulting comparison value is converted into a specified law a control signal for a Actuator derived that a change in Halftone dot size causes.

The setpoint signals can be a device for generating the Printing form can be removed.

If the control device contains a computer, then said laws in the form of programs specified that generate said control signals.

The halftone dot size can be particularly strong by a Adjust the cylinder pressure adjustment device that the Pressure between two cylinders involved in the pressure automatically adjusted until the comparison value reaches a minimum has reached.

Another way to influence the dot size, results from the fact that on the basis of said comparison values the thickness of the documentation material for the lifts Printing form cylinders and transfer cylinders as long as is varied until using the image recording device optimal pressure contrast is determined. The determined optimal print contrast can be used for comparison purposes in the Control or regulating device can be stored. For The so-called proven kissprint method.

The method makes it possible to determine the screen dot size to adapt the optimum to any position in the print image.  

The image recording device is suitable for the whole Detect print image so that actual value signals for Dot size not only from special measuring fields attack.

In a variant of the invention it is provided that To change the dot size locally in the print image in which the Control signals on a device for Cylinder pressure setting that is able to act Locally change the pressure between said cylinders. In this way, for example, inhomogeneities in the Rubber blanket of a pressure transfer cylinder Compensate offset press.

The control signals can further operations influence that determine the grid point size. In addition to the Cylinder pressure adjustment can change the ink supply Quantity of dampening solution in offset printing, the temperature of the ink and the dampening solution and the proportions of Fountain solution additives in the fountain solution are constantly changing become.

It is also possible that the setpoint signals for the Screen dot size in the form of a print characteristic in advance in the Control or regulating device can be stored, and that a current one from the signals of the image recording device Pressure characteristic is derived. As a comparison value between This then creates a dot gain from which said Control signals for actuators to influence the Grid point size can be derived.

The invention is still based on an embodiment are explained in more detail:

In the figure, a printing unit 1 of an offset printing machine is shown. It consists of a printing cylinder 2 with a fixed axis 3 , a transfer cylinder 4 and a printing form cylinder 5 , each with axes 8 and 9 displaceable in the directions 6 and 7 .

The transfer cylinder 4 and the printing form cylinder 5 are displaceable in linear bearings 10 and 11 , the axes 8 and 9 being coupled to hydraulic working cylinders 12 and 13, respectively, which effect the displacement in the directions 6 and 7 . A web 14 runs in the printing nip between the transfer cylinder 4 and the printing cylinder 2 and is printed on the upper side. Furthermore, a device 15 for supplying fountain solution and an ink application device 16 are assigned to the printing form cylinder 5 . Controllable metering valves 19 , 20 are provided for setting the supply of dampening solution from a dampening solution storage container 17 and of ink from an ink storage container 18 . The device 15 for supplying dampening solution and the ink application device 16 act in ink zones distributed uniformly over the width of the printing form cylinder 5 . The temperature of the dampening solution in the dampening solution reservoir 17 and the color in the ink reservoir 18 can be controlled by means of heating coils 21 , 22 . The dampening solution reservoir 17 is connected to a container 23 for a dampening solution additive, a valve 24 being provided for controlling the metering of the dampening solution additive. For controlling the printing machine is a control or regulating device 25 is provided which has inputs to which target and actual signals R target, R are supplied to the halftone dot size of the printed image. The actual value signals R IST for the screen dot size are obtained with the aid of an image recording device 26 which scans the full area of the printed image. The control or regulating device 25 has a series of control outputs which are connected to the actuating elements for the working cylinders 12 , 13 , to the control inputs of the metering valves 19 , 20 and 24 and to the heating windings 21 , 22 .

The implementation of the method for controlling or regulating the grid point size is described below:
Before the start of printing, the setpoint signals R Soll are stored in the control or regulating device 25 . With the aid of the image recording device 26 , actual value signals R IST for the grid point size are continuously generated and fed to the control or regulating device 25 . In the control or regulating device 25 , the actual value signals R IST are compared with the setpoint signals R Soll depending on the coordinate. The working cylinders 12 , 13 are actuated as a function of comparison signals, so that there is a change in the distance between the axes 3 , 8 , 9 . As a result, the pressure between the printing cylinder 2 and the transfer cylinder 4 on the web 14 and between the transfer cylinder 4 and the printing form cylinder 5 is changed. A change in the pressure causes a change in the screen dot size in the printed image. In this way, a deviation of the screen dot size from the target value is constantly compensated. In addition to the change in the pressure, the screen dot size can be influenced by the amount of dampening solution supplied via the device 15 for supplying the dampening solution, the proportion of the dampening solution addition supplied to the dampening solution and the temperature of the dampening solution and the color. For this purpose, corresponding control signals to the valves 19 , 20 , 24 and the heating windings 21 , 22 are output at the outputs of the control or regulating device 25 .

When a described in German Utility Model DE 91 15 526 U1 transfer cylinder 15 is used, then there is the possibility of the pressure between the cylinders 2, 4, 5 in the direction of the generating lines and in the circumferential direction of the cylinders 2, 4, details of a function set. 5 This makes it possible to compensate for changes in the screen dot size which, for. B. caused by the deflection of the axes 3 , 8 , 9 and by inhomogeneities in the elastic material on the surface of the transfer cylinder 5 .

The setpoint signals R Soll can also be input into the control or regulating device 25 in the form of a pressure characteristic. The current pressure characteristic curve, which is compared with the stored pressure characteristic curve, is then determined in the control or regulating device 25 from the signals of the image recording device 26 . The difference between the two characteristic curves gives the dot gain from which the control signals for the working cylinders 12 , 13 , the valves 19 , 20 , 24 and the heating windings 21 , 22 can be derived.

Reference list

1 printing unit
2 printing cylinders
3 axis
4 transfer cylinders
5 printing form cylinders
6 , 7 directions
8 , 9 axes
10 , 11 linear bearings
12 , 13 working cylinders
14 lane
15 Device for supplying dampening solution
16 paint application device
17 fountain solution reservoir
18 ink reservoirs
19 , 20 metering valves
21 , 22 heating coils
23 containers
24 valve
25 control or regulating device
26 Image acquisition device.

Claims (5)

1. A method for controlling or regulating the screen dot size when printing on a printing material,
  • - In which a raster dot size in the print image on the printing material ( 14 ) contained actual value signal R IST within a control or regulating device ( 25 ) is compared with a signal that represents the target value R target for the raster dot size, and from the comparison value obtained according to a a control signal for an actuator ( 12 , 13 , 19 , 20 , 21 , 22 , 24 ) is derived from the prescribed law,
  • - And in which the actual value signal R IST is generated by means of at least one image recording device ( 26 ) directed at the printing material ( 14 ) and is fed to the control or regulating device ( 25 ).
2. The method according to claim 1, characterized in that a device ( 12 , 13 ) for adjusting the cylinder pressure of the cylinders involved in the pressure ( 2 , 4 , 5 ) is automatically adjusted with the control signal until the comparison value has reached a minimum.
3. The method according to claim 2, characterized in that a device ( 12 , 13 ) for adjusting the cylinder pressure is used which locally allows a partial change in the pressure between the cylinders ( 2 , 4 , 5 ) and the printing material ( 14 ).
4. The method according to claim 2, characterized in that at least one of the following settings are additionally changed by the control signal:
  • - the setting of the ink supply,
  • - the setting of the amount of dampening solution in offset printing,
  • - setting the temperature of the paint,
  • - the setting of the temperature of the dampening solution and
  • - The setting of the proportions of fountain solution additives in the fountain solution.
5. The method according to claim 1, characterized in
  • - That a predetermined printing characteristic curve is stored in the control or regulating device ( 25 ), which contains the dependency of the screen tone value in the print image on the screen tone value of a printing form generating the print image,
  • - And that the predetermined pressure characteristic is compared with a current pressure characteristic, which is derived from the signals of the image recording device.
DE19944413735 1994-04-20 1994-04-20 Method for controlling or regulating the printing process of an autotypically working printing machine when printing under pressure on a printing material Expired - Fee Related DE4413735C2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DE19944413735 DE4413735C2 (en) 1994-04-20 1994-04-20 Method for controlling or regulating the printing process of an autotypically working printing machine when printing under pressure on a printing material

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19944413735 DE4413735C2 (en) 1994-04-20 1994-04-20 Method for controlling or regulating the printing process of an autotypically working printing machine when printing under pressure on a printing material

Publications (2)

Publication Number Publication Date
DE4413735A1 true DE4413735A1 (en) 1995-10-26
DE4413735C2 DE4413735C2 (en) 2003-09-25

Family

ID=6515971

Family Applications (1)

Application Number Title Priority Date Filing Date
DE19944413735 Expired - Fee Related DE4413735C2 (en) 1994-04-20 1994-04-20 Method for controlling or regulating the printing process of an autotypically working printing machine when printing under pressure on a printing material

Country Status (1)

Country Link
DE (1) DE4413735C2 (en)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1279501A2 (en) * 2001-07-26 2003-01-29 Dainippon Screen Mfg. Co., Ltd. Ink and water supply controller in printing machine, printing system with such controller, and program therefor
WO2004065127A2 (en) * 2003-01-24 2004-08-05 Windmöller & Hölscher Kg Method for the correction of variations in the amount of ink applied to the printed image occurring in the printing process
EP1525982A1 (en) * 2003-10-23 2005-04-27 G.D. Societa' Per Azioni Strip printing unit for an automatic machine
WO2005092613A2 (en) 2004-03-23 2005-10-06 Koenig & Bauer Aktiengesellschaft Printing machines having at least one machine element that can be adjusted by a setting element
WO2006131579A1 (en) * 2005-06-10 2006-12-14 Comexi, Sa Method of automatically adjusting the printing pressure in flexographic printers
EP1839854A1 (en) * 2006-03-31 2007-10-03 ELTROMAT GmbH Method and device for the optimal position adjustment in a rotary flexographic printing machine comprising several printing groups
EP1961569A1 (en) 2007-02-21 2008-08-27 Bobst Sa Device and method of adjustment for a rotary printing machine
EP1666252A3 (en) * 2001-03-27 2009-10-21 Windmöller & Hölscher KG Device and method for adjusting the printing image in a flexographic printing machine
EP2127876A1 (en) * 2008-05-26 2009-12-02 BST International GmbH Method and device for configuring a printed picture created by a rotary printer
DE102013005911A1 (en) 2012-04-30 2013-10-31 Heidelberger Druckmaschinen Ag Offset printing process
EP3526046A4 (en) * 2016-09-13 2020-06-24 Advanced Vision Technology (AVT) Ltd. System and method for controlling color characteristics of a printed image

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3209483A1 (en) * 1982-03-16 1983-09-29 Windmoeller & Hoelscher Method for automatically setting the inks printed by flexo printing machines for four-color printing
DE3925011A1 (en) * 1988-08-11 1990-05-17 Polygraph Leipzig Method and arrangement for monitoring the print quality of multicolor printed documents of an offset printing machine
EP0136542B1 (en) * 1983-09-20 1990-08-08 Kollmorgen Corporation Color printing control using halftone control areas
US5187376A (en) * 1990-12-20 1993-02-16 Toshiba Kikai Kabushiki Kaisha Print monitoring apparatus with data processing

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0505323B2 (en) * 1991-03-21 2001-11-07 Maschinenfabrik Wifag Method of adjusting the screendot sizes of a rotary offset printing machine
DE4229267A1 (en) * 1992-09-02 1994-03-03 Roland Man Druckmasch Method for controlling the printing process on an autotypically operating printing machine, in particular sheet-fed offset printing machine

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3209483A1 (en) * 1982-03-16 1983-09-29 Windmoeller & Hoelscher Method for automatically setting the inks printed by flexo printing machines for four-color printing
EP0136542B1 (en) * 1983-09-20 1990-08-08 Kollmorgen Corporation Color printing control using halftone control areas
DE3925011A1 (en) * 1988-08-11 1990-05-17 Polygraph Leipzig Method and arrangement for monitoring the print quality of multicolor printed documents of an offset printing machine
US5187376A (en) * 1990-12-20 1993-02-16 Toshiba Kikai Kabushiki Kaisha Print monitoring apparatus with data processing

Non-Patent Citations (5)

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Title
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BRUNE: FOGRA-Forschungsbericht 6010, München 1975, S.40 ff. *
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Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1666252A3 (en) * 2001-03-27 2009-10-21 Windmöller & Hölscher KG Device and method for adjusting the printing image in a flexographic printing machine
EP1279501A3 (en) * 2001-07-26 2006-11-29 Dainippon Screen Mfg. Co., Ltd. Ink and water supply controller in printing machine, printing system with such controller, and program therefor
EP1279501A2 (en) * 2001-07-26 2003-01-29 Dainippon Screen Mfg. Co., Ltd. Ink and water supply controller in printing machine, printing system with such controller, and program therefor
US7444935B2 (en) 2003-01-24 2008-11-04 Windmoeller & Hoelscher Kg Method for correction of variations in the amount of ink applied in a printing process
DE10302747A1 (en) * 2003-01-24 2004-08-12 Windmöller & Hölscher Method for correcting variations in the amount of ink transferred to the printed image during the printing process
WO2004065127A2 (en) * 2003-01-24 2004-08-05 Windmöller & Hölscher Kg Method for the correction of variations in the amount of ink applied to the printed image occurring in the printing process
WO2004065127A3 (en) * 2003-01-24 2004-11-04 Windmoeller & Hoelscher Method for the correction of variations in the amount of ink applied to the printed image occurring in the printing process
EP1525982A1 (en) * 2003-10-23 2005-04-27 G.D. Societa' Per Azioni Strip printing unit for an automatic machine
WO2005092613A2 (en) 2004-03-23 2005-10-06 Koenig & Bauer Aktiengesellschaft Printing machines having at least one machine element that can be adjusted by a setting element
WO2005092613A3 (en) * 2004-03-23 2006-06-01 Andreas Ewald Heinrich Bernard Printing machines having at least one machine element that can be adjusted by a setting element
US7464645B2 (en) 2004-03-23 2008-12-16 Koenig & Bauer Aktiengesellschaft Printing machines having at least one machine element that can be adjusted by a setting element
WO2006131579A1 (en) * 2005-06-10 2006-12-14 Comexi, Sa Method of automatically adjusting the printing pressure in flexographic printers
ES2264390A1 (en) * 2005-06-10 2006-12-16 Comexi, S.A. Method of automatically adjusting the printing pressure in flexographic printers
EP1839854A1 (en) * 2006-03-31 2007-10-03 ELTROMAT GmbH Method and device for the optimal position adjustment in a rotary flexographic printing machine comprising several printing groups
EP1961569A1 (en) 2007-02-21 2008-08-27 Bobst Sa Device and method of adjustment for a rotary printing machine
EP2127876A1 (en) * 2008-05-26 2009-12-02 BST International GmbH Method and device for configuring a printed picture created by a rotary printer
DE102013005911A1 (en) 2012-04-30 2013-10-31 Heidelberger Druckmaschinen Ag Offset printing process
US9242449B2 (en) 2012-04-30 2016-01-26 Heidelberger Druckmaschinen Ag Offset printing method
EP3526046A4 (en) * 2016-09-13 2020-06-24 Advanced Vision Technology (AVT) Ltd. System and method for controlling color characteristics of a printed image

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