JP6074945B2 - Rotary printing press - Google Patents

Description

  The present invention relates to a rotary printing press that performs desired printing on a sheet, and more particularly, to a rotary printing press that has a function of suppressing generation of damaged paper due to a cutting position shift that occurs during paster.

  FIG. 1 is a diagram showing an outline of an offset rotary printing press generally used as an example of a rotary printing press. The offset rotary printing press shown in FIG. 1 shows a case of a four-color press provided with four printing units. In FIG. 1, 1a, 1b, 1c and 1d are printing units, 2 is a tension pickup roller, 3 is a drying unit, 4 is a compensator roller, 5 is a paper supply unit, 5a is a first paper roll, and 5b is a second paper. It is a roll, and a substrate (hereinafter, paper) 100 is conveyed in the direction of arrow 10.

  The paper printed by the printing units 1a, 1b, 1c, and 1d is dried by the drying unit 3, and after passing through the compensator roller 5, a cutting register mark (hereinafter referred to as a mark) printed by the mark sensor 6 is read. Based on the read mark position, the cut-off control unit 8 calculates the operation amount of the compensator roller 4 in the direction indicated by the arrow 7 and drives the motor 9.

  The path length of the paper is adjusted by the position of the compensator roller 4 moved in the direction of the arrow 7 by driving the motor 9, and the paper 100 is sent to the next folding process and cutting process, and is cut at a desired position.

  FIG. 2 is a diagram showing a method of cutting at the desired position. As shown in FIG. 2, for example, a mark 12 is printed on a printed pattern (printed pattern in which four colors are overlaid) 11. The desired cutting position 13 is adjusted by the operator when printing is normally performed. In this case, after confirming that printing is normally performed, the operator adjusts the position of the compensator roller 5 by operating the cut-off control unit 8, and as a result, the sheet 100 is moved to a desired position (within an allowable value). The position is cut at 13).

  Using the detected coordinates detected by the mark sensor 6 when adjusting the position of the compensator roller 5 as reference coordinates, the mark 12 is read at the same rotational phase of the printing unit, and the read mark coordinates and the reference coordinates are determined. In comparison, the reference coordinates are set as the reference mark position, the coordinates of the read mark are set as the mark position, and the amount of deviation between the two positions is set as the magnitude of the positional deviation between the reference mark position and the detected mark position. FIG. 3 is a diagram showing the reference mark position and the detected mark position. FIG. 3A shows the position of the mark 14 read when adjusted by the operator at the time of normal printing. The position is the reference mark position. FIG. 3B shows a case where the read mark position 14a is shifted in the minus direction (the direction opposite to the transport direction) with respect to the sheet transport direction 15, and the magnitude of the shift is indicated by reference numeral 16a. FIG. 3C shows a case where the read mark position 16a is shifted in the plus direction (the same direction as the transport direction) with respect to the sheet transport direction 15, and the magnitude of the shift is indicated by reference numeral 16b. The cut-off controller 8 calculates the amount of operation of the compensator roller 5 according to the magnitude and direction of the deviation shown in FIGS. 3A and 3B, and the compensator roller 5 is driven by the arrow 7 by driving the motor 9. Move in the direction. In this way, the paper 100 is cut at a desired cutting position 13.

FIG. 4 is a diagram showing, for example, the magnitude of deviation between the normal reference mark position and the detected mark position. In this case, the amount of operation of the compensator roller 5 is small, and the cutting is performed at the desired position. In this case, as a result, the sheet is cut within the cutting allowable range.

  There is a case where the interval between the marks 12 is largely deviated. This phenomenon occurs particularly in the following cases. In the paper supply unit 5 shown in FIG. 1, for example, when the remaining amount of the first paper roll 5a decreases during printing, paper splicing (hereinafter referred to as “paster”) is performed on the second paper roll 5b by a paster device (not shown). Immediately after the paster, the paper of the first paper roll 5a is cut and separated, and the paster is completed.

  When switching from a small winding roll (first paper roll 5a) to a large winding roll (second paper roll 5b) at the time of this paster, the pulling state of the paper changes greatly, so The position of the pattern to be printed varies greatly.

  FIG. 5 is a diagram for explaining variations in the position of the printed pattern. In normal times (when not in the paster), the interval between the marks 12 is d1 (or in the vicinity of d1). The interval (d2 to d4) greatly fluctuates and differs from d1, and the printed matter in this case becomes a defective product. The change in the position of the printed pattern is settled after the paster is finished, and the mark interval of the mark 12 returns to d1 again.

JP 2006-76036 A JP 2011-201113 A

  FIG. 5 is a diagram showing the reference mark position and the detected mark position deviation at the time of the paster. At the time of the paster, it is necessary to make a large paper conveyance path for the paster. Are greatly different intervals (d2 to d4). In that case, in the conventional rotary printing press shown in FIG. 1, the cutoff controller 8 largely operates the compensator roller 4 in the downward direction indicated by the arrow 7 based on the mark position read by the mark sensor 6. In addition, as shown in FIG. 6, the reference mark position and the detected mark position deviation overflow as shown by the portion surrounded by the broken line 17 and result in cutting at a greatly deviated position, and the printed matter becomes defective. End up. However, the portion indicated by the broken line 18 that is a part of the overflow is a portion on which the printed pattern is not displaced, and the cutting position is not performed at a predetermined position because the compensator roller 4 has been operated largely. This is where the printed matter becomes defective. For this reason, the non-defective part 18 is judged as defective by the cutting position control.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a rotary printing machine that can eliminate the overflow of mark position deviation that occurs when printing paper at the time of paster passes the mark sensor 6 and can suppress the occurrence of paper loss. .

Therefore, the invention according to claim 1 of the present invention is
A rotary printing press that has one or more printing units and performs pattern printing on paper supplied from any one of at least two paper rolls, and then cuts the printed paper at a desired position. There,
A mark detection unit, a cutting position control unit, and a paster notification unit. The mark detection unit includes a cutting registration mark printed on the paper by the printing unit or a feature point of a printed pattern (hereinafter, cutting). A register mark or a feature point of a printed picture is called a mark),
The cutting position control means, based on the position of the mark detected by the mark detecting means, and means for controlling the cutting position of the sheet by adjusting the path length of the sheet,
The paster notification means is means for notifying the cutting position control means of paster generation information when switching the supply of paper from any one of the paper rolls to another paper roll (hereinafter referred to as a paster). ,
When the mark position detected by the sensor at the time when the cutting position is adjusted so that cutting is performed at a normal position is set as a reference mark position, the mark detection means Calculate the difference from the reference mark position as the size of the mark position deviation,
The cutting position control means includes a first cutting position control means for performing cutting position control in a case other than the paster time (a case other than the paster time is referred to as normal time), and a second cutting position control for performing the cutting position control in the paster time. And position control means,
The time immediately after the size of the mark position deviation becomes maximum after switching to the second cutting position control means after a preset sheet conveyance length has elapsed from the time when the paster generation information is received from the paster notification means. a rotary printing press and returning again the first cutting position control means when the size is accommodated within the allowable range of the mark position displacement later.

The invention according to claim 2 of the present invention is
Method for determining the time point immediately after the size of the mark position displacement becomes maximum, the magnitude of the mark positional deviation is measured each time the plate cylinder of the printing unit is at least one revolution, the mark position at a certain time claim the magnitude of the deviation is smaller than the size of the mark position displacement at the previous time, the size of the mark positional deviation of time when the there is and obtains a time point immediately became maximum The rotary printing press according to 1.

The invention according to claim 3 of the present invention is
The second cutting position control means does not perform the cutting position control until the time immediately after the magnitude of the mark position deviation is maximized, and immediately after the mark position deviation is maximized. The paper path length adjustment value is calculated on the basis of the mark position deviation magnitude immediately after the mark position deviation magnitude is maximized when the time point is determined. Item 3. A rotary printing machine according to item 1 or 2.

  According to the rotary printing press of the present invention, it is possible to perform cutting without causing an overflow of mark position deviation in the conventional cutting registration at the time of paster. Further, since only the program for the second cutting position control means is added to the conventional rotary printing press, it is not necessary to modify the machine and can be achieved at a low cost.

The figure which shows the outline of the offset rotary printing machine generally used. The figure which shows the method of cutting at a desired position in an offset rotary printing press. The figure which shows the reference | standard mark position and the detected mark position. The figure which shows the reference mark position at the time of normal, and the detected mark position shift. The figure which shows the reference | standard mark position and the mark position shift detected at the time of paster. The figure which shows that the reference mark position and the detected mark position deviation overflow. The figure which shows the outline of an offset rotary printing press as an example of the rotary printing press of this invention. The figure which shows the magnitude | size of the mark position shift in the case of the conventional offset rotary printing press. The figure which shows the magnitude | size of the mark position shift by the 1st cutting position control means in the case of the offset rotary printing press by this invention, and the 2nd cutting position control means. The schematic diagram for demonstrating the method to detect the time (T5) immediately after the magnitude | size of mark position shift becomes the maximum. The flowchart which calculates | requires the time (T5) immediately after the magnitude | size of mark position shift becomes the maximum. The figure which shows the outline of the offset rotary printing machine generally used. The figure for showing the whole driving | operation operation | movement of the web offset printing press of an example of this invention, and demonstrating in detail the flow after the paster especially. The figure for showing the whole driving | operation operation | movement of the web offset printing press of an example of this invention, and demonstrating in detail the flow after the paster especially.

  Hereinafter, an embodiment of the present invention will be described in detail with respect to an offset printing machine as an example of a rotary printing machine with reference to the drawings.

  FIG. 7 is a diagram showing an outline of an offset rotary printing press as an example of the rotary printing press of the present invention. The rotary offset printing press shown in FIG. 7 shows a case of a four-color press provided with four printing units. In FIG. 7, 21a, 21b, 21c, and 21d are printing units, 22 is a tension pickup, 23 is a drying unit, 24 is a compensator roller, 25 is a paper supply unit, 25a is a first paper roll, and 25b is a second paper roll. The paper 100 is conveyed in the direction of the arrow 10.

  The papers printed by the printing units 21a, 21b, 21c, and 21d are dried by the drying unit 23, passed through the compensator roller 24, and then printed marks or printed feature points (hereinafter referred to as marks or marks). The feature point of the printed pattern is referred to as a mark) is read by the mark sensor 26 as the mark detection means, and the cut-off control unit 28 operates in the direction indicated by the arrow 27 of the compensator roller 24 based on the read mark position. The amount is calculated and the motor 29 is driven.

  The cutting position is controlled by adjusting the path length of the sheet from the compensator roller 24 to the folding process and the cutting process according to the position of the compensator roller 24 moved in the direction of the arrow 27 by the drive of the motor 29. It is sent to the folding process and the cutting process, and is cut at a desired position (within an allowable range).

  Reference numeral 30 denotes a paster notification unit which is a paster notification means. For example, when the paper supply is switched from the first paper roll 25a to the second paper roll 25b (hereinafter referred to as a paster), the paster generation information is cut. This is notified to the cut-off control unit 28 which is a position control means.

  The mark detection means, the first cutting position control means, and the second cutting position control means according to the present invention will be described.

  The mark detection means will be described. A mark sensor 26 serving as a mark detection means detects a mark and is provided at a position immediately before the folding process and the cutting process. The mark detection means uses the mark position when the operator adjusts the compensator roller 24 and confirms the cutting position at the time of normal printing after the start of printing as the reference mark position. The amount of position shift is defined as the amount of mark position shift. The mark detection means outputs the magnitude of the mark position deviation to the cut-off control unit 28. As the mark sensor 26 used here, an optical sensor or a two-dimensional camera can be used, but it is desirable to use an optical sensor from the viewpoint of cost.

The first cutting position control means and the second cutting position control means will be described. Both the first cutting position control means and the second cutting position control means perform cutting position control according to the procedure described below. The cut-off control unit 28, which is the first cutting position control means and the second cutting position control means, corresponds to a target value (the target value is a value corresponding to the magnitude Δd of the mark position deviation of the input detection signal. The mark position deviation allowable range is indicated, and the amount of operation is calculated so that the mark position deviation falls within the same range as the cutting position deviation allowable range since cutting is performed in accordance with the mark position deviation. Further, the cutoff control unit 28 calculates a target position in the vertical direction of the compensator roller 24 from the operation amount.

  The compensator roller to which the operation amount is input matches the vertical position indicated by the arrow 27 with the target position of the cutoff control unit 28. By changing the position of the compensator roller 24, the path length of the paper 100 between the compensator roller 24 and the folding process and the cutting process is operated, and the cutting is thereby performed.

  8 and 9 are diagrams for explaining the first cutting position control means and the second cutting position control means, and FIG. 8 shows the magnitude of the mark position deviation in the case of a conventional offset rotary printing press. FIG. 9 shows the magnitude of the mark position deviation by the first cutting position control means and the second cutting position control means in the case of the offset rotary printing press according to the present invention.

  As shown in FIG. 8, in the cutting position control in the case of a conventional offset rotary printing press, a cutting position defect occurs in the section M during paster, and the paper in the meantime becomes waste paper. As described above, this is caused by a change in the pulling state of the paper at the time of the paster, and a phenomenon that the interval between the printed patterns is increased due to the large fluctuation of the paper in the front and rear direction (front and rear in the transport direction) in the paper transport direction. Because. In this case, when a printed matter having a large printed pattern interval at the time of the paster reaches the position of the mark sensor 26, a positive direction is used to correct a misalignment of the mark that is greatly shifted in the negative direction in order to correct the cutting position. The correction is suddenly controlled in the (paper transport direction), overflowed as surrounded by the broken line 17, and further corrected again in the negative direction to finally control the size of the mark position deviation within the allowable range. Yes. For this reason, the correction takes time, and the portion surrounded by the broken line 18 is actually a non-defective print, but the cutting position is defective. In other words, the portion surrounded by reference numeral 18 is a portion where the interval between the printed pictures has returned to normal, but the cutting position becomes poor because the mark reading position is greatly displaced in the plus direction due to overflow. .

  Therefore, the first cutting position control means and the second cutting position control means according to the present invention perform cutting position control as shown in FIG. The cutting position control of the section A and the section D is performed by the first cutting position control means. Section A and section D are normal cases, and printing is performed in a normal state. The first cutting position control means can use a cutting position control that is conventionally performed.

  Sections other than the above sections, that is, section B and section C, are subjected to cutting control by the second cutting position control means. In section B, the conveyance length of the sheet from the printing unit 21a to the mark sensor 26 after the start of the paster is counted (in this case, the conveyance length of the sheet is counted, but in the case of an offset rotary printing press, Since the size of the cylinder is constant, the number of printed sheets may be counted instead of counting the transport length of the paper.) From the point when the transport length is counted up, the size of the mark position deviation is maximized. This is a section up to a point in time immediately after the first cutting position control means is switched to the second cutting position control means, and the cutting position control is performed by the second cutting position control means. In the section B, only the measurement of the mark position deviation is performed, and the cutting position control is not performed. The section C is a section from the time immediately after the mark position size reaches the maximum to the allowable range (in other words, the mark position size within the allowable range means that the cutting position is shifted. Is a section in which the mark position greatly deviating in the minus direction is gradually corrected in the plus direction, and is cut by the first cutting position control means. As in the case of position control, there is no significant overflow in the positive direction.

  FIG. 10 is a schematic diagram for explaining a method of detecting a time point (T5) immediately after the magnitude of the mark position deviation, which is the beginning of the section C, is maximized. Reference numeral 31 indicates the magnitude of the mark position deviation. In the graph, reference numeral 32 indicates the time when the conveyance length of the sheet from the printing unit 21a to the mark sensor 26 after the start of the paster is counted, and the conveyance length is counted up. It is a waveform which shows the magnitude | size of the mark position shift to the time 33 when becomes in the allowable range. P1 to P5 indicate the magnitude of the mark position deviation at each time point (P1 to P5 are all mark position deviations in the minus direction and the mark position deviation is large in the direction of the arrow 34). The mark position deviation magnitudes P <b> 1 to P <b> 5 are acquired from the mark sensor 26.

  FIG. 11 shows a flow for obtaining a time point (T5) immediately after the mark position deviation becomes maximum. A method for obtaining the time point (T5) immediately after the maximum mark position deviation is maximized will be described with reference to FIGS.

  After the start of the paster (S1) (in this case, the timing signal for starting the paster is obtained from the paster device), the paster generation information is notified from the paster notifying unit 30 to the cut-off control unit 28 serving as a cutting position control means, and the cut-off control is performed. The unit 28 counts the conveyance length of the sheet from the printing unit 21a to the mark sensor 26, and when the conveyance length is counted up, the cutting position control by the second cutting position control means from the first cutting position control means. (S2). First, the size of P1 is acquired (S3). Next, P2 is obtained after one rotation of the plate cylinder (S4), and P1 and P2 are compared. If P1 ≧ P2 (YES in S5), the time immediately after (T2) the maximum mark position deviation becomes the maximum value As required. In the case of FIG. 11, P1 <P2 (NO in S5), and the size of the mark position deviation is not yet maximized at this point, so P3 is acquired after one more rotation of the plate cylinder (S6). ). When P2 and P3 are compared and P2 ≧ P3 (YES in S7), (T3) is obtained as a time immediately after the maximum mark position deviation is maximized. If P2 <P3 (NO in S7), P4 is acquired after one more rotation of the plate cylinder (S8). When P3 and P4 are compared and P3 ≧ P4 (YES in S9), (T4) is obtained as the time immediately after the maximum mark position deviation is reached. If P3 <P4 (NO in S9), then P5 is acquired after one more rotation of the plate cylinder (S10). When P4 and P5 are compared and P4 ≧ P5 (YES in S11), (T5) is obtained as the time immediately after the maximum mark position deviation is maximized (S12). In the case of FIG. 11, (T5) is obtained as the time immediately after the maximum mark position deviation is maximized.

  As described above, when (T5) is obtained as the time immediately after the maximum mark position deviation, the cutting position control by the second cutting position control means is performed at the time (T5). When the mark position deviation falls within the allowable range (reference numeral 33), the cutting position is again controlled by the first cutting position control means. As described above, from the time point 32 to the time point (T5), only the mark position deviation is monitored, the cutting position control by the second cutting position control means is not performed, and the mark position deviation is large. When the time immediately after the maximum is determined, the paper path length adjustment value is calculated based on the mark position deviation immediately after the maximum mark position deviation. Perform cutting position control.

FIG. 12 is a flowchart showing the overall operation of an offset rotary printing press as an example of the rotary printing press of the present invention. After the start of operation (C1), the rotational speed of the printing press is confirmed (C2). If the rotational speed is equal to or higher than the setting (YES in C3), first, the cutting position is controlled by the first cutting position control means (C4). . When the rotational speed is equal to or less than the setting (C3 NO), the process proceeds to step (C2). The presence / absence of the paster is confirmed (C5). If there is a paster (YES in C6), the paper conveyance length is counted, and when it is counted up (C7), the first cutting position control means Switching to cutting position control by the second cutting position control means (C8). Next, a time immediately after the maximum mark position deviation is obtained (C9), and after that time is obtained, it is confirmed that the mark position deviation is within an allowable range (C10). ), And returns to the cutting position control by the first cutting position control means (C11).

  FIGS. 13 and 14 show the overall operation of an offset rotary printing press as an example of the rotary printing press according to the present invention, and are diagrams for specifically explaining the flow after the paster. In the operation flow shown in FIG. 13, after the start (F1), the rotation speed of the printing press is confirmed (F2). As a result, if the rotation speed is equal to or higher than the set rotation speed (YES in F3), the first cutting is performed. Cutting position control is performed by the position control means (F4). When the rotation speed is equal to or less than the set rotation (NO in F3), the process proceeds to step (F2). Next, the presence / absence of a paster is confirmed (F5). When the paster is present (YES in F6), the cut-off control unit 28 counts the conveyance length of the sheet from the printing unit 21a to the mark sensor 26 (F7). When it is up (F8), the cutting position control by the first cutting position control means is stopped, and the cutting position control by the second cutting position control means is activated (F9). When there is no paster (NO in F6), the process proceeds to step (F2).

  Next, the waveform 31 (FIG. 10) indicating the magnitude of the mark position deviation is monitored (F10), and then the process proceeds to step (F11) shown in FIG.

  Next, while monitoring the change in the waveform in which the mark position deviation increases in the minus direction, the time point when the mark position deviation reaches the maximum value is confirmed (F11), and after passing the maximum value, the compensator roller is operated to make a minus value. The mark position deviation in the direction is reduced (the waveform is corrected in the plus direction) (F12). Next, when the waveform moves in the plus direction, the operation of the compensator roller is interrupted when the return rate returns from a maximum value to a preset return rate, for example, 60% (F13). This is because the second cutting position control means gives an instruction of the operation amount to the compensator roller, and there is a time lag until the compensator roller is operated by the instruction, so that the return rate reaches 60% as described above. At this point, the operation of the compensator roller is interrupted.

  Next, when returning to the return rate, the compensator roller is operated in the reverse direction to converge the mark position deviation to near the zero value (F14), and when the mark position deviation falls within an allowable range (for example, ± 0.3 mm). Then, the cutting position control by the second cutting position control means is finished (F15), and the cutting position control by the first cutting position control means is resumed (F16). Thereafter, the process proceeds to step (F2) in FIG.

  As described above, the offset rotary printing press is described as an example of the rotary printing press. However, according to the rotary printing press of the present invention, when the paper conveyance length is counted from the start of the paster until the set value is reached ( Or, when the number of printed sheets reaches a set value), switching from the first cutting position control means to the second cutting position control means to perform the cutting position control, which has occurred in a conventional offset rotary printing press. The overflow of the mark position deviation is eliminated, and as a result, the generation of damaged paper can be suppressed.

  Further, the rotary printing press of the present invention can be realized at low cost without being subjected to mechanical restrictions by adding a program for the second cutting position control means to the conventionally used rotary printing press.

1a, 1b, 1c, 1d ... printing unit 2 ... tension pickup roller 3 ... drying unit 4 ... compensator roller 5 ... paper supply unit 5a ... first paper roll 5b ... Second paper roll 6 ... mark sensor 7 ... arrow 8 indicating the direction in which the compensator roller is operated ... cut-off control unit 9 ... motor 10 ... direction in which the paper is conveyed Shown arrow 11 ... Printed pattern (printed pattern with 4 colors superimposed)
12 ... Mark 13 ... Desired cutting position 14 ... Reference mark position 14a, 14b ... Read mark position 15 ... Arrows 16a, 16b indicating paper transport direction ... Reference mark The amount of deviation 17 of the read mark ... The portion 18 where the mark position deviation has overflowed 18 ... The non-defective parts 21a, 21b, 21c, 21d, where there is no deviation of the printed pattern in part of the overflow 22 ... tension pickup roller 23 ... drying unit 24 ... compensator roller 25 ... paper supply unit 25a ... first paper roll 25b ... second paper roll 26 ... mark sensor 27 ... Arrow indicating the direction in which the compensator roller is operated 28 ... Cut-off control unit 29 ... Motor 30 ... Suta notification section 100 ... the printing material (paper)
d1 to d4... interval P1, P2, P3, P4, P5... mark size deviation at the time of paster M. mark position deviation from the start of the paster is within an allowable range. Sections A and D: Section B in which cutting position control is performed by the first cutting position control means Section B: Section C in which the size of the mark position deviation is monitored: By the second cutting position control means Section where cutting position control is performed

Claims (3)

A rotary printing press that has one or more printing units and performs pattern printing on paper supplied from any one of at least two paper rolls, and then cuts the printed paper at a desired position. There,
A mark detection unit, a cutting position control unit, and a paster notification unit. The mark detection unit includes a cutting registration mark printed on the paper by the printing unit or a feature point of a printed pattern (hereinafter, cutting). A register mark or a feature point of a printed picture is called a mark),
The cutting position control means, based on the position of the mark detected by the mark detecting means, and means for controlling the cutting position of the sheet by adjusting the path length of the sheet,
The paster notification means is means for notifying the cutting position control means of paster generation information when switching the supply of paper from any one of the paper rolls to another paper roll (hereinafter referred to as a paster). ,
The mark detection means uses, as a reference mark position, the position of the mark detected by the sensor when the cutting position is adjusted so that cutting is performed at a normal position, and the position of the mark detected by the sensor and the reference Calculate the difference from the mark position as the size of the mark position deviation,
The cutting position control means includes a first cutting position control means for performing cutting position control in a case other than the paster time (a case other than the paster time is referred to as normal time), and a second cutting position control for performing the cutting position control in the paster time. And position control means,
The time immediately after the size of the mark position deviation becomes maximum after switching to the second cutting position control means after a preset sheet conveyance length has elapsed from the time when the paster generation information is received from the paster notification means. rotary printing press, wherein a back again to the first cutting position control means when the size of the mark positional deviation falls within the allowable range or higher. Method for determining the time point immediately after the size of the mark position displacement becomes maximum, the magnitude of the mark positional deviation is measured each time the plate cylinder of the printing unit is at least one revolution, the mark position at a certain time claim the magnitude of the deviation is smaller than the size of the mark position displacement at the previous time, the size of the mark positional deviation of time when the there is and obtains a time point immediately became maximum A rotary printing press according to 1. The second cutting position control means does not perform the cutting position control until the time immediately after the magnitude of the mark position deviation is maximized, and immediately after the mark position deviation is maximized. The paper path length adjustment value is calculated on the basis of the mark position deviation magnitude immediately after the mark position deviation magnitude is maximized when the time point is determined. Item 3. A rotary printing machine according to item 1 or 2.

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