JP2009029046A - Method of calculating controlled variable by registration adjusting mechanism and arithmetic unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method, of calculating a controlled variable by a registration adjusting mechanism, which enables rapid correcting of a registration error, even in case there is a backlash in the registration adjusting mechanism arranged at an offset printer. <P>SOLUTION: This method comprises the following procedural steps: (Step 1) A registration error is entered in an arithmetic unit. (Step 2) A correction pattern is generated per a register mark to be printed by the offset printer by changing the reference register mark and calculating the controlled variable of the registration adjusting mechanism for matching the reference register mark with the other register mark. (Step 3) The controlled variable of each registration adjusting device is decided by selecting, from among the generated correction patterns, the correction pattern, based on which the number of the registration adjusting devices is minimum and consequently, the shift direction of a plate cylinder is reversed to the previous shift direction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technique for controlling a registration error generated in an offset printing machine, and more particularly to a technique for controlling a registration error in consideration of backlash of a registration adjusting mechanism provided in the offset printing machine.

  When multi-color printing is performed on an offset printing press, a register mark called a register mark, generally a cross-shaped mark, is printed on the paper together with a pattern in each printing unit. A registration error of each color is detected with reference to.

  When registering printed materials manually, the operator uses a magnifying glass with a memory to detect registration errors from the registration marks printed on the paper and adjusts the registration of the sidelay etc. provided in the offset printing press. The generated registration error is corrected by operating the mechanism in accordance with the detected registration error.

  In addition, when registering an offset printing machine automatically, a registration device is installed in the offset printing machine, and the registration device captures a registration mark printed online, and each of the images of the registered registration mark images. The control amount for correcting the registration error is automatically calculated by determining the center of gravity position of the registration mark, and the calculated control amount is input to the registration adjustment mechanism (for example, Patent Document 1).

  As described above, when the registration error is corrected regardless of whether it is manual or automatic, the registration error generated in the offset printing press is corrected by the operation of the registration adjusting mechanism such as the side layout.

JP-A-7-304162

  However, a gear is used for the registration adjustment mechanism provided in each printing unit of the offset printing press, so if there is a backlash in the registration adjustment mechanism, the registration adjustment mechanism is activated to correct the detected registration error. Even if it is done, the plate cylinder does not shift as instructed due to the effect of backlash, and it is necessary to perform registration work several times before registering, and a lot of adjustment time and waste paper occur. There was a case.

  Accordingly, an object of the present invention is to provide a method and a calculation apparatus for calculating a control amount that can quickly correct a registration error even when a backlash occurs in a registration adjusting mechanism provided in an offset printing press. .

  The first invention for solving the above-described problem is to calculate a control amount of a register adjusting mechanism used for correcting a register error occurring in an offset printing machine by shifting the phase and position of the plate cylinder. Step a): a step of inputting the registration error obtained from a registration mark printed by an offset printing machine to an arithmetic unit that calculates a control amount of the registration adjustment mechanism; step b): reference A correction pattern for correcting the registration error is calculated by changing the registration mark serving as a reference to calculate the control amount of the registration adjustment mechanism for aligning the registration mark with the other registration mark. Step for generating each registration mark printed in Step c): Shifting the plate cylinder from the correction pattern generated in Step b) The step of determining the control amount of each of the registration adjusting devices is executed by selecting the correction pattern that minimizes the number of the registration adjusting devices whose direction is opposite to the previous one. It is the method characterized by this.

  According to the first aspect described above, the direction in which the plate cylinder is shifted is selected by selecting the correction pattern that minimizes the number of the register adjusting devices in which the direction in which the plate cylinder is shifted is opposite to the previous one. Since the number of the same register adjusting devices becomes the maximum, the influence of backlash that the register adjusting mechanism has can be reduced.

  Further, the second invention is the method according to the first invention, wherein in the step c), the arithmetic unit determines that the direction in which the plate cylinder is shifted in the selected correction pattern is the previous one. If there is the register adjusting device which is reversed, the backlash generated by the register adjusting mechanism is added to the control amount.

  According to the second invention described above, if there is the register adjusting device in which the direction in which the plate cylinder is shifted is opposite to the previous one, the arithmetic unit adds backlash generated by the register adjusting mechanism to the control amount. Thus, even when the direction in which the plate cylinder is shifted is opposite to the previous direction, it is possible to eliminate the influence of backlash that the registration adjusting mechanism has.

  Furthermore, the third invention is an arithmetic device for calculating a control amount of a registration adjusting mechanism used for correcting a registration error occurring in an offset printing machine by shifting the phase and position of the plate cylinder. In addition, a control amount of the registration adjustment mechanism for aligning the other registration mark with the registration mark that is used as the input means for inputting the registration error is calculated by changing the registration mark as the reference. Thus, a correction pattern for correcting the registration error is generated for each registration mark printed by an offset printing machine, and the number of the registration adjusting devices in which the direction in which the plate cylinder is shifted is opposite to the previous one is minimized. By selecting the correction pattern, the control means for determining the control amount of each of the registration adjusting devices and the selected correction pattern are referred to, and the direction in which the plate cylinder is shifted is referred to as the correction pattern. Characterized in that it comprises a storage means for storing for each adjusting device.

  Furthermore, the fourth invention is the arithmetic device according to the third invention, wherein the control amount arithmetic means provided in the arithmetic device is a direction in which the plate cylinder is shifted in the selected correction pattern. If there is the register adjusting device that is opposite to the previous one, the backlash generated by the register adjusting mechanism is added to the control amount.

  According to the third invention and the fourth invention, the same effects as those of the first invention and the second invention described above can be obtained.

  According to the above-described present invention, it is possible to provide a method and a calculation device for calculating a control amount that can quickly correct a registration error even if there is a backlash in the registration adjusting mechanism provided in the offset printing press.

  From here, the method according to the present invention will be described in detail with reference to the drawings. First, an offset printer will be briefly described. FIG. 1 is a diagram illustrating an offset sheet-fed printing press 1.

  In the offset sheet-fed printing press 1, a Y (yellow) pattern and a register mark are printed on the paper supplied from the paper supply unit 11 a by the first printing unit 10 and an M (magenta) pattern by the second printing unit 10. And the registration mark are printed in the third printing unit 10 with the C (cyan) pattern and the registration mark, and the last printing unit 10 is printed with the K (black) pattern and the registration mark. Discharged.

  Each printing unit 10 is provided with a registration adjusting mechanism 12 for adjusting a registration error occurring in the offset printing machine 1 by shifting the phase and position of the plate cylinder 13. In the offset printing machine 1, as the registration adjusting mechanism 12, there are a mechanism for shifting the phase of the plate cylinder 13, a mechanism for shifting the lateral position of the plate cylinder 13, and a mechanism for shifting the angle of the axis of the plate cylinder 13. It is common to be provided.

  FIG. 2 is a view for explaining the register adjusting mechanism 12, FIG. 2 (a) is a view for explaining a side layout mechanism 12a for shifting the lateral position of the plate cylinder 13, and FIG. It is a figure explaining plate cylinder twist mechanism 12b which shifts the angle of 13 axes.

  In the sidelay mechanism 12a shown in FIG. 2A, the rotation transmission shaft 124a is rotated by the rotation of the sidelay motor 120a, and the tooth gear 121a (worm wheel) is rotated by the rotation of the rotation transmission shaft 123a. When the screw gear 122a (worm) meshing with the tooth gear 121a (worm wheel) rotates, the plate cylinder 13 moves to the right / left depending on the rotation direction of the screw gear 122a (worm).

  In the plate cylinder twisting mechanism 12b illustrated in FIG. 2B, the screw gear 122b (worm) is rotated by the rotation of the twist motor 120b, and the tooth gear 121b (worm wheel) meshed with the screw gear 122b (worm). ) Rotates, the axis of the plate cylinder 13 is twisted in the forward / reverse direction according to the rotational direction of the screw gear 122b (worm).

  As described above, since a gear is used for the register adjusting mechanism provided in the offset printing press 1, backlash between the gears becomes a problem when the register adjusting mechanism 12 is operated.

  For example, in the sidelay mechanism 12a, when the plate cylinder 13 is moved to the MS and when the plate cylinder 13 is moved to the GS, the rotation direction of the sideley motor 120a is reversed and the rotation direction of the screw gear 122a is also reversed. Therefore, when the shift amount is equal to or less than the backlash of the tooth gear 121a and the screw gear 122a, the plate cylinder 13 is moved to the GS immediately after the plate cylinder 13 is moved to the MS immediately after the plate cylinder 13 is moved to the MS. The registration error may not be corrected.

  The method according to the present invention has been devised in view of such a problem, and is input by a method of calculating a control amount of the register adjusting mechanism 12 in consideration of a gear backlash of the register adjusting mechanism 12. This is a method executed by the arithmetic unit 2 that calculates the control amount of the registration adjusting mechanism 12 from the registration error.

  FIG. 7 is a block diagram of the arithmetic device 2. The calculation device 2 refers to the input means 21 to which the registration error is input, the control means 20 to calculate / determine the control amount of the registration adjustment device 12, and the determined control amount of the registration adjustment device 12, and the plate cylinder 13 Storage means 22 for storing the direction in which the shift is made for each register adjustment device 12.

  The arithmetic device 2 may be a computer that is incorporated in the automatic registration device and calculates the control amount of the registration adjustment mechanism 12 from the registration error. In addition, the calculation device 2 controls the registration adjustment mechanism 12 based on the registration error input by the operator. It may be a single computer that calculates the quantity.

  The control means 20 provided in the arithmetic unit 2 is realized by a CPU, an electric circuit necessary for operating the CPU, and a computer program for the CPU to execute the method according to the present invention. The input means 21 is a keyboard. The storage means 22 is realized by a memory such as a RAM.

  The method according to the present invention is characterized by an algorithm for calculating the control amount of the register adjusting device 12 for correcting the register error obtained from the register mark, and is printed by the offset printing machine 1. It does not depend on the shape of the register mark.

  FIG. 3 is a flowchart showing the procedure of the method according to the present invention. The procedure shown in FIG. 3 is a calculation device 2 that is a computer that calculates the control amount of the registration adjustment mechanism 12 from the input registration error, except for the first correction, in order to correct the registration error. This is a procedure executed every time the control amount is calculated.

  At the beginning of this procedure, the registration error occurring in the offset printing press 1 is input to the input means 21 of the arithmetic unit 2 (step S1). The registration error input to the computing device 2 is a registration error when a predetermined registration mark (for example, M registration mark) is used as a reference from among YMCK registration marks printed on paper.

  When the arithmetic device 2 is incorporated in the automatic registration device, the registration error input to the arithmetic device 2 is a value obtained from an image obtained by photographing the registration mark by the automatic registration device, and the arithmetic device 2 is a single unit. In the case of an apparatus, the value is measured by an operator using a magnifying glass or the like from a printed register mark.

  FIG. 4 is a diagram illustrating an example of the registration error input to the arithmetic device 2. The registration error shown in FIG. 4 is a registration error when the M registration mark is used as a reference. The registration mark of K and C has a registration deviation of +0.08 mm with respect to the registration mark of M, and the registration of Y. The mark has a misregistration of −0.08 mm with respect to the M register mark.

  “+” Or “−” given to the registration error indicates the direction in which the registration error occurs, and the direction of “−” means the direction opposite to “+”.

  For example, when the registration error is a lateral misregistration, a registration error given “+” means that the register is misaligned in the MS direction, and a registration error given “−” is a GS error. This means that the direction is misaligned.

  When the registration error is input, the control means 20 of the arithmetic unit 2 calculates the control amount of the registration adjustment mechanism for aligning the other registration mark with the reference registration mark by changing the reference registration mark. Then, a correction pattern for correcting the registration error is generated for each registration mark (here, each YMCK registration mark) printed by the offset printing press (step S2).

  In the present embodiment, since the number of colors of the offset printing machine 1 is four colors of YMCK, four correction patterns for register error are generated. Further, if the number of colors of the offset printing machine 1 is five, five registration error correction patterns are generated.

  FIG. 5 is a diagram showing a correction pattern generated by the arithmetic device 2. FIG. 5 is a correction pattern generated by the arithmetic unit 2 in order to correct the registration error shown in FIG. 4, and four correction patterns are shown with reference to each of the YMCK registration marks.

  In the correction pattern, the control amount of the register adjusting device 12 provided other than the printing unit 10 that prints the reference color is described. The control amount of the register adjusting device 12 includes the shift amount and the shift direction of the plate cylinder 13. Is described.

  According to FIG. 5, when the M registration mark is used as a reference, the control amount of the registration adjusting mechanism 12 provided in the K and C printing units 10 is “−0.08 mm”, and the Y printing unit 10 is provided. The control amount of the registered register adjusting mechanism 12 is “+0.08 mm”.

  Since the registration error values of K and C are the same, when the registration marks of K and C are used as a reference, the control amount of the registration adjustment mechanism 12 provided in the M printing unit 10 is “+0.08 mm”. The control amount of the register adjusting mechanism 12 provided in the Y printing unit 10 is “+0.16 mm”.

  When the Y register mark is used as a reference, the control amount of the register adjusting mechanism 12 provided in the K, C, and M printing units 10 is “−0.08 mm”.

  When the control unit 20 of the arithmetic unit 2 generates the control amount of the register adjusting mechanism 12 based on each register mark to be printed, the control unit 20 selects one of the generated correction patterns of the register adjusting mechanism 12 according to a predetermined rule. Two correction patterns are selected (step S3). Details of the control unit 20 of the arithmetic unit 2 selecting one correction pattern according to a predetermined rule will be described later.

  When the control unit 20 of the arithmetic device 2 selects one correction pattern from the calculated correction patterns of the register adjustment mechanism 12 according to a predetermined rule, the control unit 20 controls the register adjustment device 12 described in the selected correction pattern. The amount is notified to each registration adjusting device 12, and the registration error is corrected by shifting the phase and position of the plate cylinder 13 according to the control amount (step S4), and the procedure illustrated in FIG.

  From here, the contents of step S3 executed in the procedure shown in FIG. 3, that is, the control unit 20 of the arithmetic unit 2 from among the correction patterns generated in accordance with the register marks printed by the offset printer 1, The content of selecting one correction pattern according to the defined rule will be described in detail.

  FIG. 6 is a flowchart showing a procedure in which the control means 20 of the arithmetic device 2 selects a correction pattern. In order for the control means 20 of the arithmetic device 2 to determine the correction pattern, the control means 20 of the arithmetic device 2 uses the register adjusting device as the direction in which the register adjusting device 12 has shifted the plate cylinder 13 to the previous shift direction. A correction pattern in which the number of registration adjusting devices 12 in which the shift direction of the plate cylinder 13 is opposite to the previous one is minimized is selected from the correction patterns generated this time (step S30).

  For example, taking the correction pattern shown in FIG. 5 as an example, when all the previous shift directions are “−”, the number of the shift direction of the plate cylinder 13 opposite to the previous is the reference mark of M. Is "1", "2" when the K and C register marks are the reference, and "0" when the Y register mark is the reference, the shift direction of the plate cylinder 13 is opposite to the previous one. As the correction pattern that minimizes the number of occurrences, the control means 20 of the arithmetic unit 2 selects the correction pattern when the Y register mark is used as a reference.

  When a plurality of correction patterns are selected as the correction patterns that minimize the number of registration adjusting devices 12 in which the shift direction of the plate cylinder 13 is opposite to the previous one, the correction with the smaller number of registration adjusting devices 12 to be operated is performed. Select a pattern.

  After selecting a correction pattern that minimizes the number of shifts of the plate cylinder 13 opposite to the previous shift direction, the arithmetic unit 2 controls the shift direction of the plate cylinder 13 to be reverse to the previous correction pattern in the selected correction pattern. Check whether there is an amount (step S31), and with respect to the control amount in which the shift direction of the plate cylinder 13 is reversed from the previous time, the backlash of the register adjustment mechanism 12 is reduced to eliminate the influence of the backlash of the register adjustment mechanism 12. Add (step S32).

  For example, if the control amount in which the shift direction of the plate cylinder 13 is opposite to the previous time is “0.05 mm” and the backlash of the register adjusting mechanism 12 is “0.05 mm”, the control amount is “0.05 mm”. Backlash “0.05 mm” is added, and the control amount becomes “0.10 mm”.

  With respect to the control amount in which the shift direction of the plate cylinder 13 is reversed from the previous time, after the backlash of the register adjusting mechanism 12 is added to eliminate the influence of the backlash of the register adjusting mechanism 12, the control means 20 of the arithmetic unit 2 is used. Updates the shift direction of the plate cylinder 13 stored in the storage means 20 (step S33).

  When the shift direction of the plate cylinder 13 stored in the storage unit 20 is updated, the control unit 20 of the arithmetic unit 2 updates only the shift direction of the plate cylinder 13 of the registration adjusting mechanism 12 that has shifted the plate cylinder 13. The shift direction of the plate cylinder 13 of the registration adjusting mechanism 12 that does not shift the plate cylinder 13 is not updated.

  For example, in the above-described example, since a correction pattern based on the Y register mark is selected, the register mark other than Y, that is, the C, M, and K register marks are printed on the printing unit 10. The shift direction of the plate cylinder 13 of the provided register adjusting mechanism 12 is updated, and the shift direction of the plate cylinder 13 of the register adjusting mechanism 12 provided in the printing unit 10 that prints the Y register mark is not updated.

The figure explaining an offset sheet-fed printing press. The figure explaining a register adjustment mechanism. The flowchart which showed the procedure of the method concerning this invention. The figure which showed an example of the registration error input into a calculating device. The figure which showed the correction pattern which an arithmetic unit produces | generates. The flowchart which showed the procedure in which an arithmetic unit selects a correction pattern. The block diagram of an arithmetic unit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Offset sheet-fed printing machine 10 Printing unit 11a Paper feed part, 11b Paper discharge part 12 Registration adjustment apparatus 13 Plate cylinder 2 Computing apparatus 20 Control means 21 Input means 22 Storage means

Claims (4)

  A method of calculating a control amount of a register adjusting mechanism used for correcting a register error occurring in an offset printing machine by shifting a phase and a position of a plate cylinder. A step of inputting the registration error obtained from a registration mark printed by an offset printing machine to an arithmetic unit that calculates a control amount of the adjustment mechanism; step b): adding another registration mark to the reference registration mark A step of generating a correction pattern for correcting the registration error for each of the registration marks printed by an offset printing machine by calculating a control amount of the registration adjustment mechanism for alignment by changing the registration mark as a reference. Step c): The registration adjusting device in which the direction in which the plate cylinder is shifted is reversed from the previous one out of the correction patterns generated in Step b). The control unit calculates a control amount of the register adjustment mechanism, wherein a step of determining a control amount of each of the register adjustment devices is executed by selecting the correction pattern that minimizes the number. how to.   The method for calculating the control amount of the register adjusting mechanism according to claim 1, wherein in the step c), the calculation device determines that the direction in which the plate cylinder is shifted in the selected correction pattern is the previous time. A method for calculating a control amount of a register adjusting mechanism, wherein if there is the register adjusting device that is reversed, backlash generated by the register adjusting mechanism is added to the control amount.   An arithmetic unit that calculates a control amount of a registration adjusting mechanism used to correct a registration error occurring in an offset printing machine by shifting a phase and a position of a plate cylinder, and the registration error is input. The registration error is corrected by calculating the control amount of the registration adjustment mechanism for aligning the other registration marks with the reference registration mark by changing the reference registration mark. Generating a correction pattern for each of the registration marks to be printed by an offset printing machine, and selecting the correction pattern that minimizes the number of the registration adjusting devices in which the direction in which the plate cylinder is shifted is opposite to the previous one. Referring to the control means for determining the control amount of each of the registration adjusting devices and the selected correction pattern, the direction in which the plate cylinder is shifted is stored for each of the registration adjusting devices. Arithmetic apparatus characterized by comprising a storage means. The arithmetic unit according to claim 3, wherein the control amount calculation means provided in the arithmetic device includes, in the selected correction pattern, the registration adjustment in which a direction in which the plate cylinder is shifted is opposite to the previous one. If there is a device, an arithmetic device characterized in that backlash generated by the register adjusting mechanism is added to a control amount.

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