JP2006159638A - Method/device for controlling printing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a print quality from deteriorating and also enhance the reliability of the print quality. <P>SOLUTION: This method for controlling a printing machine of one mode includes the following procedures: color management data are continuously measured from printed matter 19 continuously printed using a printing machine 4, then it is diagnosed, based on the continuously measured color management data, whether or not an unstable condition of a halftone dot shape to such an extent that a print color tone is not adversely affected in a printing process by the printing machine 4, has occurred. In case it is diagnosed that the unstable condition of a halftone dot shape to such an extent that the print color tone is not adversely affected, has not occurred, control parameters of a normal state are set. On the other hand, in case it is diagnosed that the unstable condition of a halftone dot shape to such an extent that the print color tone is not adversely affected, has occurred, control parameters for stability control which are different from the control parameters of the normal state and do not adversely affect the dispersion width of the color control data, are set, and the printing machine 4 is controlled using the set control parameters. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a printing press control method and apparatus for improving print quality.

  Normally, in offset printing, it is necessary to appropriately adjust the amount of ink in order to obtain a high-quality printed matter.

  If the amount of ink is insufficient, the printing density becomes low and the volume or glossiness is insufficient. On the other hand, if the ink amount is excessive, the printing density becomes high and halftone dots are lost, making it difficult to reproduce the desired gradation.

  In offset printing, it is necessary to adjust the amount of water as well as the amount of ink.

  When the amount of water is large relative to the amount of ink, the ink is excessively emulsified and it becomes difficult to obtain a stable print quality. Conversely, if the amount of water is small relative to the amount of ink, scumming may occur.

  Therefore, the operator adjusts the balance between the ink amount and the water amount (hereinafter referred to as “ink / water balance”) so that a desired gradation can be reproduced. The operator visually checks the printed matter and makes adjustments so that the ink amount and the water amount are appropriate, thereby obtaining an expressive printed matter.

  However, printers frequently change state due to various variables associated with materials such as ink or paper or the printing site environment. The state of the printer changes slightly even during printing. For this reason, the ink density or ink / water balance of a printed matter (for example, a printing sheet) changes, and as a result, the printing color tone may change.

  In order to stably obtain expressive prints in such a situation, it is required that the operator has advanced skill to accurately grasp slight color changes and adjust the ink amount and water amount. The

  However, there is a problem that the number of operators having such skill is decreasing.

  A skilled operator can frequently observe the state of the printing press and finely adjust the amount of ink and the amount of water so that a desired printed matter can be obtained. However, even an operator having such a skilled technique does not check all the printed materials, and it is not easy to always grasp the state of the printing press.

  Even if the operator feels that there has been a change in the printed matter, it is difficult to accurately determine how much this change is and what is the cause of this change. .

  Inventions for solving such problems are disclosed in, for example, Japanese Patent No. 3265902 (Patent Document 1), Japanese Patent No. 3218910 (Patent Document 2), and Japanese Patent No. 3149723 (Patent Document 3). Yes. The apparatus relating to Patent Documents 1 to 3 detects colorimetric data of a printed material appropriately extracted during printing, compares the colorimetric data obtained from the reference printed material with the detected colorimetric data, and Detect slight color changes.

  Some commercially available devices measure the color of the color bars laid out in the printed material, and detect changes in color tone by comparing the measured colorimetric data with the colorimetric data of the standard printed material. There is a device to do. An in-line color tone control device, which is an example of a commercially available device, automatically adjusts to a desired ink amount by converting a change in color tone into an ink amount and feeding it back to the ink key opening.

  Japanese Patent Laid-Open No. 2001-325092 (Patent Document 4) discloses a printing press remote diagnosis system that effectively detects an abnormality at each printing base or diagnoses print quality using the Internet.

  In this Patent Document 4, a WWW server connects a service base that groups a number of local printing bases for each region and a general management base that manages service information for error recovery together with technical information of each printing machine. It is connected. The service base is equipped with a print quality detection device for detecting the print quality from the sample printed matter and quantifying the print quality. The print quality data representing the quantified print quality is transferred from the service base to the general base via the network. Then, a predetermined diagnosis is performed at the supervision base, and the diagnosis result is transmitted to the service base or the service person. Thereby, when an abnormality occurs in the printing press, the printing press can be repaired efficiently.

Japanese Patent Application Laid-Open No. 2004-195740 (Patent Document 5) compares the amount of change in color management data after a predetermined period of time with a diagnostic condition for diagnosing the state of a printed material, and prints based on the comparison result. A printing press diagnostic apparatus for diagnosing the state of a printing machine is disclosed.
Japanese Patent No. 3265902 Japanese Patent No. 3218910 Japanese Patent No. 3149723 JP 2001-325092 A JP 2004-195740 A

  Since the apparatus relating to Patent Documents 1 to 3 and the inline color tone control device have been developed for the purpose of adjusting the ink amount for color tone adjustment using the density value or colorimetric value of the printed material being printed, It is difficult to appropriately adjust the printing finish in consideration of the state of the printing press that changes from moment to moment.

  For example, when the target density and the like are determined using the above-described inline color tone control device and printing is performed, if the printing machine is in a good state, it can be quickly adjusted to the same color tone. However, if the printing machine is not in good condition, even if printing is performed so that the measured colorimetric data has the target density, the tone reproduction changes due to the influence of the printing state, and the same level. It becomes difficult to obtain a printed matter.

  In the above-mentioned Patent Document 4, an abnormality occurs to stop printing, and the user can receive an efficient service when requesting a repair from a printer manufacturer. However, the control of the printing press in this case has not been studied.

  In the above-mentioned Patent Document 5, the state of the printing press is diagnosed, but the control up to the printing press is not considered.

  In conventional control of a general printing press, colorimetric data measured from a printed material is used for ink key control and not for water control.

  The state of the printing press and the state of consumables such as blankets or rollers provided in the printing press change from moment to moment. The printing color tone is affected by such changes in the state of the printing press and the state of the consumables. Even if the state of the printing press or the state of consumables has changed, there has not been an abnormality enough to repair the printing press. In general, adjustment of the printing press, adjustment of consumables, consumables It can be dealt with by exchanging.

  When color management data is continuously measured for printed matter that has been printed continuously, the variation width of the value of the color management data varies depending on the state of the printing press or the state of consumables, even if the print color tone is not affected. .

  However, the control of the conventional printing press does not take into account the change in the variation width of the color management data caused by the status of the printing press or the consumables.

  For this reason, when the variation width of the continuously measured color management data becomes larger than the steady state, it may be difficult to appropriately control the printing press.

  The present invention has been made in view of the above circumstances, and provides a printing press control method and apparatus for preventing deterioration in printing quality by a printing press, improving the reliability of printing quality, and executing stable control. The purpose is to do.

  Specific means taken for realizing the present invention will be described below.

  In the printing press control method according to the first example of the present invention, the color management data is continuously measured from the printed matter continuously printed by the printing press, and the printing press is based on the continuously measured color management data. Diagnose whether halftone dot instability that does not affect printing color tone has occurred in printing by, and halftone dot instability that does not affect printing color tone has not occurred When the control parameters in the standard state are set, and when it is diagnosed that an unstable state of the halftone dot shape that does not affect the print color tone has occurred, it differs from the control parameters in the standard state. Control parameters for stable control that do not affect the variation width of the color management data are set, and the printing press is controlled using the set control parameters.

  In this printing press control method, the halftone dot unstable state that does not affect the printing color tone is a state in which the variation width of the color management data is larger than a predetermined range, and the standard state control is performed. The parameter may include a dead zone in the standard state, and the control parameter for stable control may include an extended dead zone whose range is expanded as compared with the dead zone in the standard state.

  In addition to the standard state dead zone, the standard state control parameters include the standard state time constant, delay time, and gain adjustment, and an unstable state of halftone dots that does not affect the print color tone has occurred. As a control parameter for stable control, extended dead band, time constant larger than the standard state time constant, delay time larger than the standard state delay time, gain adjustment smaller than the standard state gain adjustment At least one of them may be set.

  Also, in this printing press control method, a value representing the ink / water balance in the printing press is measured, whether or not the ink / water balance is in a poor state, and the ink / water balance is diagnosed as being in a bad state. In this case, control is performed to make the ink / water balance stable, and then it is diagnosed whether or not an unstable state of the halftone dot shape that does not affect the print color tone by printing by the printing press has occurred. Also good.

  Also, in this printing press control method, a management gauge for detecting an unstable state of a halftone dot shape that does not affect the printing color tone is printed on the printed matter continuously printed by the printing press. Then, the state of the management gauge may be measured, and it may be diagnosed based on the measurement result whether or not an unstable state having a halftone dot shape that does not affect the print color tone has occurred.

  A printing press control apparatus according to a second example of the present invention includes an acquisition unit that acquires color management data continuously measured from a printed matter continuously printed by the printing press, and a printing press based on the color management data. When it is diagnosed that there is no halftone dot instability that does not affect the print color tone when printing with, the control parameters in the standard state are set so that the print color tone is not affected. Parameter changing means for setting a control parameter for stable control that is different from the control parameter in the standard state and does not affect the variation width of the color management data when it is diagnosed that an unstable state of the point shape has occurred; And color management control means for controlling the printing press based on the set control parameters.

  If the halftone dot shape is unstable due to doubly or slur, the printer must be maintained. As for doubles and slurs, there are transient / chronic ones, small ones / large ones, etc. In the first and second inventions described above, the ones that are temporary, small ones are controlled, and others. It is desirable to inform the operator that the halftone dot shape is unstable due to double or slur. To determine whether or not halftone dot instability has occurred due to transient, minor microscopic doubles or slurs, set a threshold for the duration of doublet or slur generation and the variation width of color management data. It can be judged by whether or not the value is exceeded.

  If the duration of occurrence of doubles and slurs, and the variation width of the color management data exceed a threshold value, the control according to the first and second aspects of the invention may be defective. It is assumed that the control according to the first and second inventions is not executed.

  According to the first and second aspects of the present invention, for example, it is continuously measured by a change in the halftone dot shape caused by a slight double, slur, quality or material of the printing paper that does not affect the printing color tone. Even when the variation width of the color management data becomes larger than that in the steady state, it is possible to perform stable control that keeps the color management data constant while keeping the variation width constant, instead of executing the abnormal control.

  Further, even when a poor ink / water balance state occurs and the continuously measured color management data changes periodically, stable control can be performed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same portions are denoted by the same reference numerals and description thereof is omitted.

(First embodiment)
In the present embodiment, when it is diagnosed that the halftone dot shape is not in a steady state based on color management data continuously measured from a printed matter continuously (continuously) printed by a printing press, A printing press control device that performs control of the printing press by extending the dead zone in the control and controls the ink / water balance to be appropriate when it is diagnosed that a poor ink / water balance has occurred. Will be described.

  In this embodiment, the color management data (measurement data) measured from the printed material is described as representing a density value, but may be represented as a colorimetric value or the like.

  FIG. 1 is a block diagram illustrating a configuration example of a printing press control apparatus according to the present embodiment.

  In the present embodiment, the printing diagnosis apparatus 1, the printing press control apparatus 2, and the control apparatus 3 are attached to a printing press (offset rotary press) 4.

  The printing machine 4 continuously prints a printed material including printing control patches of black, indigo, red, and yellow. The measuring heads 5a and 5b measure the color management data of the web 19 after passing through the black, indigo, red, and yellow printing units 4a to 4d provided in the printing machine 4.

  Each printing unit 4 a to 4 d is provided with a blanket cylinder 6, a plate cylinder 7, and an ink roller 8. In FIG. 1, reference numerals of the blanket cylinder 6, the plate cylinder 7, and the ink roller 8 are attached only to the printing unit 4a, and reference numerals are omitted for the other printing units 4b to 4d.

  The print diagnosis apparatus 1 includes a rule reception unit 9, a recording unit 10, an acquisition unit 11, a diagnosis unit 12, and a display unit 13.

  The rule receiving unit 9 receives an unstable state (halftone dot failure occurrence state) that does not affect the print color tone caused by the quality / material of the double, slur, and printing paper, for example, from an operator, The rule data 10a used for detecting the ink / water balance failure state is received, and the rule data 10a is recorded in the recording unit 10.

  The acquisition unit 11 acquires each color management data continuously measured by the measurement heads 5 a and 5 b and provides each color management data to the diagnosis unit 12 and the display unit 13.

  The acquisition unit 11 acquires the measurement value of the ink / water balance of each of the printing units 4 a to 4 d of the printing machine 4 and provides the measurement value of the ink / water balance to the diagnosis unit 12 and the display unit 13.

  Based on the color management data received from the acquisition unit 11, the measured value of the ink / water balance, and the rule data 10a recorded in the recording unit 10, the diagnosis unit 12 does not affect the print color tone. An unstable state of the halftone dot shape and a poor ink / water balance state are detected, and diagnostic data indicating the diagnosis result is provided to the display unit 13, the color management control unit 15 and the parameter change unit 16 of the printing press control device 2. .

  For example, when the change state of the color management data corresponds to the state indicated by the rule data 10a, it is diagnosed that the halftone dot is in an unstable state that does not affect the print color tone caused by double or slur. . Further, when the measured value of the ink / water balance is outside the predetermined allowable range, it is diagnosed that the ink / water balance is in a poor state.

  The display unit 13 displays a continuous change in the color management data received from the acquisition unit 11. The display unit 13 displays the contents of the diagnostic data received from the diagnostic unit 12.

  The printing press control apparatus 2 includes an acquisition unit 14, a color management control unit 15, and a parameter change unit 16.

  The acquisition unit 14 acquires each color management data measured by the measurement heads 5a and 5b. The acquisition unit 14 acquires the measurement value of the ink / water balance of each of the printing units 4 a to 4 d of the printing machine 4 and provides the measurement value of the ink / water balance to the color management control unit 15.

  The color management control unit 15 obtains a control execution value such as an ink key operation amount, an ink key opening, and a water amount so that the color management data received from the acquisition unit 14 belongs to a dead zone (allowable range) determined by a reference value. The control execution value is provided to the control device 3.

  Note that the dead zone is a range in which the current state of the control of the printing press is maintained. The dead zone refers to a range set as an area where predetermined control is not performed on the target value. Generally, the stability of the control system is increased by providing such an operation gap. The tendency of the control system to be stabilized due to the presence of the dead zone appears prominently when there are many disturbances to be controlled.

  The control parameters used in the color management control unit 15 include, for example, a dead zone provided for a time constant, a delay time, a gain constant, and a target value. The color management control unit 15 performs gain adjustment, PID control, and the like based on this control parameter.

  The control parameters used in the color management control unit 15 are the case where the print diagnostic apparatus 1 diagnoses the halftone dot shape as a standard state (stable state) and the case where it is diagnosed as an unstable state that does not affect the print color tone. And changed.

  In addition, when the diagnosis data received from the diagnosis unit 12 indicates a poor ink / water balance state, the color management control unit 15 determines the ink / water balance based on the measurement value of the ink / water balance received from the acquisition unit 14. For example, a control execution value such as an ink key operation amount, an ink key opening degree, and a water amount used for printing is obtained, and this control execution value is provided to the control device 3.

  The parameter changing unit 16 displays the color management control unit 15 when the content of the diagnostic data received from the diagnostic unit 12 represents a halftone dot unstable state that does not affect the print color tone such as double or slur. Change the control parameters used in.

  For example, when the parameter changing unit 16 is diagnosed as having a printing dot failure occurrence state, the color change control is performed with a time constant, a large delay time, and a small gain adjustment value that are larger than those in the standard state (steady state). In addition to setting in the unit 15, an extended dead zone obtained by extending the range of the dead zone in the standard state is set in the color management control unit 15.

  The control device 3 receives a control execution value from the color management control unit 15 and controls the printing press 4 according to the control execution value. For example, the control device 3 operates the ink key according to the ink key operation amount and the ink key opening received from the color management control unit 15, and operates the mechanism for supplying moisture according to the amount of water used for printing.

  The printing machine 4 continuously prints a printed material including printing control patches of black, indigo, red, and yellow.

  In the present embodiment, the measurement heads 5a and 5b continuously measure the color management data of the printing control patches of black, indigo, red, and yellow for a plurality of printed materials continuously printed by the printing machine 4. .

  FIG. 2 is a diagram illustrating an example of a measurement position on a printed material (print sheet).

  In the margin portion of the print layout 17 on the web 19, a color bar 18 including, for example, a single color solid patch and a single color flat mesh patch is arranged as a print control patch.

  In the present embodiment, the measuring heads 5a and 5b measure the entire color bar 18 printed on the web 19 during printing.

  The in-line type printer control device 2 compares the measured color management data with the reference value, obtains the ink key operation amount and ink key opening so as to obtain an appropriate ink amount, and achieves an appropriate ink / water balance. An appropriate amount of water is obtained, and the obtained ink key operation amount, ink key opening degree, and amount of water are provided to the control device 3.

  As a measuring method for continuously measuring the monochromatic solid patch and the monochromatic flat mesh patch, a method of measuring each of the upper printing surface side and the lower printing surface side of the printing machine 4 with a plurality of measuring heads may be applied.

  Further, since it is expensive to add the measurement heads 5a and 5b, the entire color bar 18 is not measured, but any patch including a single color flat patch and a single color solid patch among the patches included in the color bar 18 is used. Only the position may be measured to realize continuous measurement.

  In the present embodiment, four positions on the web 19 including the monochrome flat mesh patch and the monochrome solid patch are measured by one measuring head 5a and 5b on the upper printing surface side and the lower printing surface side of the printing machine 4, respectively. Suppose that

  The relationship between the web 19, the print layout 17, and the measurement positions P1 to P4 in the present embodiment is shown in FIG.

  The printing layout by the offset rotary press usually includes the contents of 8 pages or 16 pages on each of the upper printing surface and the lower printing surface. In FIG. 2 above, the contents of 8 pages are printed on one side of the print layout 17.

  In FIG. 2, the contents of four pages are arranged in a direction (width direction) perpendicular to the printing direction. That is, in this embodiment, four surfaces A1 to A4 are arranged in the width direction.

  Since the arrangement of the pattern or the arrangement of the characters is determined according to the arrangement of the surfaces A1 to A4, it is possible to grasp the unstable state of the halftone dot shape so as not to affect the print color tone for each of the surfaces A1 to A4. Do.

  In the present embodiment, in the measurement of the color bar 18, single-color solid patches of black, indigo, red, and yellow, and single-color flat net patches of black, indigo, red, and yellow that exist at the center positions of the four surfaces A1 to A4. Are measured continuously.

  In the present embodiment, based on quality and materials such as ink or paper, or various fluctuation factors associated with the printing site environment, the state of the printing press, and the state of consumables such as blankets or rollers provided in the printing press. The variation width of the value of the color management data generated in this way is detected. In order to detect this variation width, it is necessary to increase the measurement frequency more than usual.

  The expansion of the dead zone range in the present embodiment will be described below.

  First, a description will be given of changing the dead zone when a halftone dot unstable state that does not affect the print color tone occurs.

  FIG. 3 shows an example of the change state of the density value of the patch continuously measured with increasing the measurement frequency in the case where the unstable state of the halftone dot shape that does not affect the print color tone has not occurred. It is a graph.

  When the unstable state of the halftone dot shape that does not affect the print color tone does not occur, the variation width of the density value is sufficiently small with respect to the range of the dead zone. For this reason, even when the density value is outside the dead zone and the control by the printing press control device 2 is performed, the density value is appropriately controlled without being affected by the variation width.

  On the other hand, FIG. 4 shows the change state of the density value of the patch continuously measured with increasing the measurement frequency when the halftone dot instability that does not affect the printing color tone occurs. It is a graph which shows an example.

  When an unstable state having a halftone dot shape that does not affect the print color tone occurs, the amplitude of vibration of the density value with respect to the dead zone range increases. For this reason, when the density value is out of the dead zone and the control by the printing press control device 2 is performed, the density value control affected by the amplitude of the vibration is executed.

  For example, although the density value exceeds the upper limit of the dead zone due to the variation width, control for decreasing the density value is executed, and as a result, the entire density value may exceed the lower limit of the dead zone. Furthermore, when the entire density value exceeds the lower limit of the dead zone, control for increasing the density value is executed. As a result, the density value may greatly exceed the upper limit of the dead zone, and overshoot may occur.

  FIG. 5 is a graph showing a first example of the change state of the density value of the patch when the dead zone is changed according to the present embodiment.

  In this embodiment, when a halftone dot unstable state that does not affect the print color tone has not occurred, density value control is executed in the dead zone in the standard state.

  When a halftone dot unstable state that does not affect the print color tone occurs, control is executed based on the extended dead zone that is expanded from the dead zone in the standard state.

  As a result, even if an unstable state of a halftone dot shape that does not affect the print color tone occurs and the variation width of the density value increases, the variation width for the expanded dead zone may not be abnormally controlled. The density value is appropriately controlled.

  Next, the change of the control parameter when a poor ink / water balance state occurs will be described.

  FIG. 6 is a graph showing an example of a change in the density value of a patch continuously measured by increasing the measurement frequency when a poor ink / water balance state occurs.

  When a poor ink / water balance occurs, the patch density values measured continuously with increasing frequency appear to change periodically, or the density values of both solid and flat patches The variation width becomes large.

  FIG. 7 is a graph showing an example of a control result of the density value of the patch measured continuously when a poor ink / water balance state occurs.

  When the amplitude of the cycle becomes large and the density value is out of the dead zone and is controlled by the printing press control device 2, the density value is affected by the influence of the amplitude of the periodic change.

  For example, when the density value exceeds the upper limit of the dead zone due to a periodic change, control for decreasing the density value is executed, and as a result, the entire density value may exceed the lower limit of the dead zone. Furthermore, when the entire density value exceeds the lower limit of the dead zone, control for increasing the density value is executed many times, the density value greatly exceeds the upper limit of the dead zone, and hunting may occur.

  On the other hand, when an ink / water balance failure occurs, control to make the ink / water balance appropriate is first performed, and the process returns to the diagnosis.

  In the present embodiment, when there is no poor ink / water balance, the density value is controlled using a standard dead zone.

  When a poor ink / water balance occurs, the ink / water balance is made appropriate.

  In the following, the operation in the case where a halftone dot unstable state that does not affect the print color tone occurs in the printing press control apparatus 2 and the print diagnostic apparatus 1 according to the present embodiment will be described.

  When the print diagnostic apparatus 1 diagnoses that a halftone dot instability that does not affect the print color tone due to the quality, material, etc. of the double, slur, and printing paper has occurred in the printed matter, the print diagnostic apparatus 1 Outputs an alarm to notify the operator and also notifies the printing press control device 2.

  When an unstable state having a halftone dot shape that does not affect the printing color tone occurs, the variation in halftone dots is larger than that in the standard state. For this reason, if control with a narrow dead zone is performed, excessive control may be performed as a result.

  Therefore, the printing press control device 2 sets an extended dead zone wider than the dead zone used in the standard state when the halftone dot unstable state occurs to a slight extent that does not affect the print color tone. I do.

  In the present embodiment, the printing press control device 2 sets an extended dead zone when a halftone dot unstable state that does not affect the print color tone occurs, and sets the time constant and delay time as standard. The gain adjustment value may be made smaller than that in the standard state, and may be made smaller than that in the standard state.

  In this embodiment, the dead zone, extended dead zone, time constant before and after the change, delay time before and after the change, and gain adjustment value before and after the change are obtained in advance using an actual machine, and appropriate values are obtained. .

  That is, the printing press control device 2 sets a control parameter that emphasizes stability rather than the control parameter in the standard state when a halftone dot unstable state that does not affect the printing color tone occurs, and controls the ink amount. Execute.

  In the following, the operation of the printing press control apparatus 2 and the print diagnosis apparatus 1 according to the present embodiment when an ink / water balance failure occurs will be described.

  When the print diagnostic apparatus 1 diagnoses that a poor ink / water balance has occurred in the printed matter, the print diagnostic apparatus 1 outputs an alarm to notify the operator and also notifies the printing press control apparatus 2.

  When a poor ink / water balance occurs, the ink transfer / transfer is unstable compared to the standard condition, so correlate the ink key opening with the density on the printed matter. Becomes difficult. In this state, if the ink key is moved unnecessarily, hunting may occur.

  Therefore, when a poor ink / water balance state occurs, the printing press controller 2 first adjusts the amount of water to bring the ink / water balance into an appropriate state, and then controls the amount of ink.

  As a specific water amount adjustment, the original roller rotation speed may be adjusted little by little until it is confirmed that the continuous density change between the single-color solid patch and the single-color flat mesh patch is stable. In addition, as the adjustment of the water amount, the ink amount is estimated based on the ink original roller rotation speed and the ink key opening, and a correlation table between the estimated ink amount and the water roller rotation speed is provided. The rotational speed of the water source roller may be adjusted so that the ink / water balance is achieved.

  If it is recognized that a defective ink / water balance always occurs in the same printing unit, the printing diagnosis apparatus 1 notifies the operator that maintenance is to be performed because the printing machine 4 is in a poor state.

  FIG. 8 is a flowchart illustrating an example of a control process executed by the print diagnosis apparatus 1 and the printing press control apparatus 2 according to the present embodiment.

  In step S1, the measurement heads 5a and 5b continuously measure color management data indicating the density value of the patch of the color bar 18.

  In step S2, the print diagnosis apparatus 1 generates a halftone dot unstable state that does not affect the print color tone based on the continuous change of the density value obtained from the color management data and the rule data 10a. And whether a poor ink / water balance has occurred.

  In the case where neither the halftone dot instability state that does not affect the printing color tone nor the ink / water balance failure state has occurred, in step S3, the printing press controller 2 controls the control parameters in the standard state. Is set, and the process proceeds to step S6.

  When an unstable state having a halftone dot shape that does not affect the printing color tone occurs, in step S4, the printing press control device 2 changes the standard dead zone to an extended dead zone. Control parameters are set, and the process proceeds to step S6.

  If a defective state of ink / water balance occurs, in step S5, the printing press controller 2 appropriately controls the ink / water balance by adjusting the amount of water, and the process proceeds to step S6.

  In step S <b> 6, the printing press control device 2 obtains a control execution value based on the color management data and the set control parameter, and provides the control execution value to the control device 3 of the printing press 4.

  In step S7, when the process of the printing diagnosis apparatus 1 and the printing press control apparatus 2 is continued, the process returns to step S1, and when the process is not continued, the process ends.

  For example, in the present embodiment, the printing press controller 2 controls the control parameters (time constants) set in the standard state in advance when a dot-shaped unstable state that does not affect the printing color tone occurs. , At least one of the dead time, the gain adjustment value, and the dead zone provided for the target value) is set to be a control parameter that emphasizes more stability, thereby controlling the ink amount.

  Further, for example, in the present embodiment, when the ink / water balance is poor, the printing press controller 2 first adjusts the amount of water and supplies the amount of ink and the amount of water supplied to the group of ink rollers 8. The balance is set appropriately, and thereafter, control parameters are set again based on the diagnosis result of the print diagnostic apparatus 1.

  In the present embodiment described above, a halftone dot unstable state and a poor ink / water balance state that do not affect the print color tone are diagnosed.

  When the halftone dot instability that does not affect the print color tone occurs, the dead zone set for the continuously measured color management data is expanded. Changed to be possible. When a poor state of ink / water balance occurs, the ink / water balance is optimized.

  As a result, the state of the printing machine 4, the state of consumables such as blankets or rollers provided in the printing machine 4, the variation in the value of color management data due to the quality and material of the printing paper, and the periodic change Etc. can be suppressed, overshoot and hunting can be prevented, and stable printing can be performed.

  In the present embodiment, by performing control according to the result of diagnosing an unstable state of a halftone dot shape that does not affect the print color tone and a poor state of ink / water balance, a control parameter suitable for the control is set. It can be used, can perform control suitable for the contents of diagnosis, can prevent deterioration of print quality by the printing machine 4, and can ensure the reliability of print quality.

  In the present embodiment, the type of control executed by the printing press control apparatus 2 includes, for example, PID control.

The PID control is a control obtained by adding and synthesizing three actions: a proportional action, an integral action, and a derivative action, and can be expressed by the following equation (1).

  Here, y represents the manipulated variable, e represents the deviation (target value / actual value), Kp represents the proportional gain, TI represents the integration time, and TD represents the differentiation time.

  In the above control, the time constant (T) is a constant characterizing the speed of response, and means the time until the final value reaches 63.2% in the step response of the first-order lag system.

  The first order delay means a delay of the system in which the step response changes exponentially and settles to a constant value.

  The step response means a response when the input signal suddenly changes from a certain value to another certain value.

  The delay time means the time required for the step response to reach 50% of the final value, and is a measure of quick response.

  Gain adjustment means adjustment of a gain constant for changing the stability and responsiveness of the automatic control system.

  In the present embodiment, the range of the dead band is changed when a halftone dot instability that does not affect the print color tone occurs.For example, the control parameter is set for matters that are not the change of the dead band range. It may be changed to execute stable control. For example, when a halftone dot unstable state that does not affect the print color tone occurs, the control parameter may be changed so as to make it difficult to satisfy the control start condition.

(Second Embodiment)
In the present embodiment, a modification of the first embodiment will be described.

  In the first embodiment, when it is diagnosed by the printing diagnostic apparatus 1 that the halftone dot shape is in an unstable state that does not affect the printing color tone, the printing press control apparatus 2 automatically performs the standard state. The time constant and the delay time are increased, the gain adjustment value is decreased, and the range of the dead zone is increased.

  However, the change of the control parameter may be performed at the operator's discretion. For example, when the print diagnostic apparatus 1 diagnoses an unstable state of a halftone dot shape that does not affect the print color tone, the print diagnostic apparatus 1 notifies the operator of an alarm.

  If the operator determines that there is a halftone dot instability that does not affect the print color tone based on the quality / materials of doubles, slurs, and printing papers, is this failure ongoing? Determine whether it is temporary.

  When the operator determines that stable control is difficult at present, the operator controls the printing press control device 2 to increase the time constant and delay time, to decrease the gain adjustment value, and to increase the dead zone range compared to the standard state. Change the parameters.

  Similarly, for example, when the printing diagnostic apparatus 1 diagnoses a poor ink / water balance, the printing diagnostic apparatus 1 notifies the operator of an alarm.

  The operator determines whether or not the ink / water balance is in a poor state, and if it is determined that the ink / water balance is in a bad state, the operator determines whether the failure is continuous or temporary.

  When the operator determines that stable control is difficult at present, the operator instructs the printing press control device 2 to adjust the water amount. Thereafter, the printing press control apparatus 2 adjusts the amount of water, changes the control parameters, and executes the ink amount control.

(Third embodiment)
In the present embodiment, a specific example of the print diagnostic apparatus according to the first and second embodiments will be described.

  FIG. 9 is a diagram showing a specific example of the measurement position P1 of the color bar 18 used in the present embodiment. The other measurement positions P2 to P4 are the same as the measurement position P1.

  In the present embodiment, the measurement position P1 of the color bar 18 printed on the printed material includes a single-color solid patch 20 for black, indigo, red, and yellow, and a single-color flat in the range of 60% to 85%. A halftone patch 21 having a halftone dot area ratio of 40% to 50% is disposed.

  The printing diagnostic apparatus 1 includes, for each of black, indigo, red, and yellow, a single-color solid patch 20, a single-color flat screen patch 21 having a dot area ratio of 60% to 85%, and a dot area ratio of 40% to 50%. Values (for example, density values) V1 to V3 of the color management data of the single color flat mesh patch 22 are acquired.

  FIG. 10 is a graph showing an example of a gradation reproduction curve for any one of black, indigo, red, and yellow.

  The print diagnostic apparatus 1 sets the color management data value V1 of the single color solid patch 20 and the color management data value of the single color flat halftone patch 21 in the range of 60% to 85% of the dot area ratio for each of black, indigo, red, and yellow. A difference D1 of V2 is obtained, and the value V2 of the single color flat halftone patch 21 in the range of 60% to 85% of the halftone dot area ratio and the color management data of the single color flat halftone patch 22 in the range of the dot area ratio of 40% to 50%. The difference D2 of the value V3 is obtained.

  The printing diagnosis apparatus 1 diagnoses the standard state when the balance state (ratio) between the difference D1 and the difference D2 is within a predetermined first allowable range for each of black, indigo, red, and yellow. If it is not within the allowable range, it is diagnosed that an unstable state of halftone dot shape that does not affect the print color tone has occurred.

  The print diagnostic apparatus 1 measures the ink amount and the water amount on the ink roller for each of black, indigo, red, and yellow with a sensor, and measures the ink / water balance based on the measurement result.

  Then, the printing diagnosis apparatus 1 diagnoses each ink, indigo, red, and yellow as normal if the measured value is within the predetermined second allowable range, and if not within the second allowable range, the ink / water balance is determined. Diagnose a bad condition.

  FIG. 11 is a flowchart illustrating an example of a diagnosis process performed by the print diagnosis apparatus 1 according to the present embodiment. The process of FIG. 11 is performed for each of the measurement positions P1 to P4.

  In step T1, the print diagnostic apparatus 1 determines the color management data value V1 of the single-color solid patch 20 and the color of the single-color flat mesh patch 21 in the range from 60% to 85% for each black, indigo, red, and yellow. The difference D1 between the management data value V2 is obtained, and the color management data value V2 of the monochrome flat halftone patch in the range of 60% to 85% of the halftone dot area ratio and the monochrome flat halftone of the range of the dot area ratio of 40% to 50%. The difference D2 of the value V3 of the patch color management data is obtained.

  In step T2, the printing diagnosis apparatus 1 obtains a value (for example, D1 / D2) representing the balance between the differences D1 and D2 for each of black, indigo, red, and yellow.

  In step T3, the printing diagnosis apparatus 1 determines whether the value representing the balance between the differences D1 and D2 is within the first allowable range for each of black, indigo, red, and yellow.

  In step T4, the print diagnosis apparatus 1 determines that the value representing the balance between the differences D1 and D2 is in the standard state for the color within the first allowable range, and returns to step T1.

  In step T5, the print diagnostic apparatus 1 determines whether the value representing the ink / water balance is within the second tolerance range for each color whose value representing the balance between the differences D1 and D2 is not within the first tolerance range.

  In step T6, the print diagnostic apparatus 1 affects the print color tone for colors in which the value representing the balance between the differences D1 and D2 is not within the first tolerance range and the value representing the ink / water balance is within the second tolerance range. It is diagnosed that a halftone dot instability that is not given is generated, and the process returns to step T1.

  In step T7, the print diagnostic apparatus 1 determines the ink / water balance for a color in which the value representing the balance between the differences D1 and D2 is not within the first tolerance range and the value representing the ink / water balance is not within the second tolerance range. Diagnose that a defect has occurred, and return to step T1.

(Fourth embodiment)
In the present embodiment, a modification of the third embodiment will be described.

  In the third embodiment, the occurrence of an unstable state of a halftone dot shape that does not affect the print color tone is diagnosed based on whether or not the value representing the balance between the differences D1 and D2 is within the first allowable range. Yes.

  However, in the present embodiment, it is assumed that a management gauge for detecting the instability of the halftone dot shape is arranged for black, indigo, red, and yellow at the measurement positions P1 to P4 of the color bar 18.

  FIG. 12 is a diagram illustrating an example of the measurement position P1 of the color bar 18 including the management gauge. The management gauge 23 is assigned to the measurement position P1 of the color bar 18 for each of black, indigo, red, and yellow. The measurement positions P2 to P4 are the same as the measurement position P1.

  FIG. 13 is a diagram illustrating a first example of the management gauge 23, and FIG. 14 is a diagram illustrating a second example of the management gauge 23. A change in density can be detected from the management gauge 23 shown in FIGS. The management gauge of FIG. 14 has a halftone dot area ratio of 50% and includes vertical lines and horizontal lines of image line: non-image line = 1: 1.

  The print diagnostic apparatus 1 observes the management gauge 23 for each color, and diagnoses that a halftone dot instability that does not affect the print color tone has occurred when a change in density appears.

  In each of the above embodiments, each component can be freely deformed as long as the same operation can be realized, the arrangement may be changed, and the components can be freely combined and divided. Is also possible. For example, the print diagnosis apparatus 1, the printing press control apparatus 2, and the control apparatus 3 may be combined. In addition, although the embodiment is a four-color machine of black, indigo, red, and yellow, it can be similarly applied to a one-color machine, a two-color machine, or a printing machine including a special color.

  The functions as the print diagnosis apparatus 1 and the printing press control apparatus 2 in the present embodiment may be realized by a computer that has read a program.

  In this case, the program can be applied to a computer by writing it on a recording medium such as a magnetic disk (flexible disk, hard disk, etc.), optical disk (CD-ROM, DVD, etc.), semiconductor memory, or the like.

  It is also possible to transmit this program via a communication medium and apply it to a computer. The computer implements each function as a printing diagnosis apparatus and a printing press control apparatus by reading a program and controlling the operation by the program.

  The present invention is applied to a printing press control method and apparatus for obtaining a control execution value of a printing press.

1 is a block diagram showing a configuration example of a printing press control apparatus according to a first embodiment of the present invention. The figure which shows an example of the measurement position on printed matter. The graph which shows the example of the change state of the density value of the patch continuously measured by increasing the measurement frequency in case the unstable state of the halftone dot shape which does not affect the print color tone has occurred. The graph which shows the example of the change state of the density value of the patch continuously measured by increasing the measurement frequency when the halftone dot unstable state which does not affect the print color tone occurs. The graph which shows the 1st example of the change state of the density value of a patch in the case of changing a dead zone concerning the embodiment. The graph which shows the example of the change of the density value of the patch continuously measured by increasing the measurement frequency when the poor state of ink / water balance occurred. The graph which shows the example of the control result of the density value of the patch continuously measured by increasing the measurement frequency when the poor state of ink / water balance occurs. 6 is a flowchart showing an example of a control process executed by the printing diagnosis apparatus and the printing press control apparatus according to the embodiment. The figure which shows the specific example of the measurement position of the color bar used in the 3rd Embodiment of this invention. The graph which shows the example of the gradation reproduction curve about any color of black, indigo, red, and yellow. 6 is a flowchart illustrating an example of a diagnosis process performed by the print diagnosis apparatus according to the embodiment. The figure which shows the example of the measurement position of the color bar containing the management gauge which concerns on the 4th Embodiment of this invention. The figure which shows the 1st example of a management gauge. The figure which shows the 2nd example of a management gauge.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Printing diagnostic apparatus, 2 ... Printing machine control apparatus, 3 ... Control apparatus, 4 ... Printing machine, 4a-4db ... Printing unit, 5a, 5b ... Measuring head, 6 ... Blanket cylinder, 7 ... Plate cylinder, 8 ... Ink Roller, 9 ... rule receiving unit, 10 ... recording unit, 10a ... rule data, 11 ... acquisition unit, 12 ... diagnosis unit, 13 ... display unit, 14 ... acquisition unit, 15 ... color management control unit, 16 ... parameter change unit 17 ... Print layout, 18 ... Color bar, 19 ... Web

Claims (6)

In a printing press control method for controlling a printing press,
Continuously measuring color management data from printed matter continuously printed by the printing press,
Based on the continuously measured color management data, diagnosing whether an unstable state of halftone dot shape that does not affect the print color tone in printing by the printing press has occurred,
When it is diagnosed that an unstable state of the halftone dot shape that does not affect the printing color tone has not occurred, a control parameter in the standard state is set and the halftone dot shape does not affect the printing color tone. When it is diagnosed that an unstable state occurs, a control parameter for stable control that is different from the control parameter in the standard state and does not affect the variation width of the color management data is set.
A printing press control method, characterized by controlling the printing press using a set control parameter. The printing press control method according to claim 1, wherein:
The unstable state of the halftone dot shape that does not affect the print color tone is a state in which the variation width of the color management data is larger than a predetermined range,
The standard state control parameters include a standard state dead band;
The printing press control method, wherein the control parameter for stable control includes an extended dead zone whose range is expanded from the dead zone in the standard state. The printing press control method according to claim 2,
The standard state control parameters include a standard state time constant, delay time, and gain adjustment in addition to the standard state dead zone.
When it is diagnosed that a halftone dot instability that does not affect the print color tone has occurred, the control parameter for the stability control is greater than the extended dead zone, the time constant of the standard state At least one of a constant, a delay time larger than the delay time in the standard state, and a gain adjustment smaller than the gain adjustment in the standard state is set. The printing press control method according to any one of claims 1 to 3,
A value representing the ink / water balance in the printing press is measured to diagnose whether the ink / water balance is in a poor state;
When it is diagnosed that the ink / water balance is in a bad state, a control is performed so that the ink / water balance is stabilized, and then the printing color tone is not affected by printing by the printing machine. A printing press control method characterized by diagnosing whether or not an unstable state of a point shape has occurred. The printing press control method according to any one of claims 1 to 4,
The printed matter continuously printed by the printing machine is printed with a management gauge for detecting an unstable state of a halftone dot shape that does not affect the print color tone,
A printing press control method, comprising: measuring a state of the management gauge and diagnosing whether or not an unstable state having a halftone dot shape that does not affect the printing color tone has occurred based on the measurement result. In a printing press control device for controlling a printing press,
Obtaining means for obtaining color management data continuously measured from a printed matter continuously printed by the printing press;
Based on the color management data, when it is diagnosed that there is no halftone dot instability that does not affect the printing color tone in printing by the printing press, the control parameters in the standard state are set. When it is diagnosed that a halftone dot instability that does not affect the print color tone has occurred, it is different from the control parameter in the standard state and does not affect the variation width of the color management data. Parameter changing means for setting control parameters for stable control,
A printing press control apparatus comprising color management control means for controlling the printing press based on the set control parameter.

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