JPS60176763A - Register monitoring in multicolor rotary press - Google Patents

Abstract

PURPOSE:To prevent overlooking of register failures by printing marks on a web with each color printing unit and by displaying a warning at such time when the extent of the maximum register failure which is obtained by subtracting the minimum value from the maximum value of the register failure exceeded a specified value. CONSTITUTION:Register marks m1-m6 are arranged regularly along one side of a web P and are spaced as specified and as many as the colors to be used. Register failures between some of the above marks and others are searched for and the maximum register failure is obtained by subtracting the minimum value from the maximum value of the above register failures, and in the event when the maximum value of the register failure exceeds the specified value, a warning is displayed, detecting even such a register failure as the one that could be overlooked during a register monitoring between the two colors.

Description

[Detailed description of the invention]

(Technical Field) The present invention relates to a method for monitoring misregistration on a finished pattern in a multicolor rotary printing press such as a rotogravure printing press. (Prior Art) In order to obtain a natural color pattern or a pattern made of multiple colors by printing, a multicolor printing technique is generally used in which patterns of each required color are overprinted. Printing machines that use this type of multicolor printing technique need to ensure that the images of each color are accurately superimposed on the printed book, and this inspection, so-called misregistration monitoring, is carried out to remove defective printed books. It also controls the register of printing presses. Conventionally, to monitor this misregistration, reference marks for positioning, so-called register marks, are printed in the margins of each color pattern on a printed book, and a monitor visually checks and intuitively understands the register marks as the amount of misregistration. method is adopted. For this reason, it is necessary for the monitor to be sufficiently skilled, and even then, it is difficult to obtain misplaced monitoring results with sufficient accuracy. Devices that monitor misregistration and perform misregistration control based on this monitoring have become widely used. This is done by attaching marks called register marks to the margins of each color picture on a printed book, in addition to the reference marks mentioned above, for detecting misregistration, and detecting these register marks with a scanning head to generate a detection signal (register mark). signal) is judged by a judgment circuit to detect the presence or absence of misregistration. (Problems with the Prior Art) However, since this registration control device generally detects the misregistration between each two colors and corrects the misregistration,
It is not possible to monitor the maximum misregistration between colors at the same point on the paper. That is, even if the misregistration between each of the two colors is within the allowable range, the total misregistration as an addition or value may exceed the allowable range. Furthermore, even if the misregistrations between the two colors detected for each unit are simply added together, the value does not represent the total misregistration because of the existence of a time lag in printing. (Object of the Invention) The present invention has been made in consideration of the above points, and is designed to correct the misregistration between one color and all the colors being printed in a multicolor rotary printing machine. The present invention aims to provide a method that calculates the maximum misregistration from the maximum and minimum values of the misregistrations and displays a warning when the maximum misregistration exceeds a predetermined value. (Summary of the Invention) To achieve this object, the present invention prints register marks on the web using printing units of each color, and prevents misregistration between some of these register marks and other register marks. , a method is provided in which the minimum value is subtracted from the maximum value among the misregistrations to obtain the maximum misregistration, and a warning is displayed when the maximum misregistration exceeds a predetermined value. Furthermore, in the present invention, among various marks printed on the web,
The present invention provides a method for quickly and accurately detecting the presence or absence of misregistration by setting a gate so that only register marks can be detected reliably. (Example) The present invention will be described below with reference to the accompanying drawings. Figure 1 shows the configuration of a rotogravure printing press.
, 2.3 are plate cylinders, and an impression cylinder 4°5.6 is arranged facing each other, thereby forming three printing units.

[There is. Although gravure rotary printing presses usually have a configuration of six or seven units, only three units are shown here for convenience of explanation. In this printing press, the web P is sent from a pre-stage unit (not shown), enters the first-stage unit shown, and then sequentially reaches the next-stage unit via a guide roller 7 and a convenser roll 8. The convencator roll 8 is moved in axial position by a motor 9 to change the bus length of the web. This bus length control is performed between each unit. The web that has left the final stage unit is taken up by the take-up unit ]0, but in the middle of the process, the scanning head moves from IIK to L.
/ register mark is detected, detection output (shows the shape and arrangement of the register mark on the register pin surface, P is the web and ml-~6 is the register mark. As shown in the figure, the register mark m1~ ~6 The number of printed colors should be regularly arranged, but if the registration is poor, the spacing between adjacent marks may become inappropriate.
Even if the distance between adjacent marks is an appropriate value, the distance between adjacent marks may be an inappropriate value. On the side extensions of the web P to which the register marks ml to m6 are attached, various marks including the aforementioned register marks are attached. In order to monitor misregistration, it is necessary to detect only the register mark, so a gate setting circuit is provided in the main body 12 of the apparatus so as to extract only the register signal from among the signals from the scanning radar 11. Therefore, the gate setting circuit will be explained with reference to FIGS. 3 to 6, and then misregistration monitoring will be explained with reference to FIGS. 7 and 8. Figure 3 shows the most primitive method of gate setting. In this figure, a register signal from a scanning radar 11 and a reference pulse signal from a rotary encoder 13 connected to a plate cylinder 3 are applied to an apparatus main body 12 indicated by a dashed line. That is, the device main body 12 takes in the reference pulse from the rotary encoder 13 to the signal processing circuit 104 via the gate generation circuit 101, and also takes in the reference pulse from the scanning head 11 via the waveform shaping circuit 102 or 103.
The register signals from the two sensors are taken into the signal processing circuit 104. The signal processing circuit 104 further includes a console 1.
Gate open and gate open inputs from 05 are also provided. Input from the console 105 is given by an operator's operation, and the operator inputs the input from the onroscope 10.
While looking at the screen of 7, the gate signal Sg is register mark 8.
The input to the console 105 is determined depending on whether or not there is a relationship that exactly includes m. That is, if some input is given to the console 105, the signal processing circuit 104 gives the input data from the console 105 to the gate creation circuit 101, and receives the gate signal formed by the gate creation circuit 101 at this time. Then, this gate signal and the register signal from the waveform shaping circuit 102 or 103 are superimposed and displayed on the oscilloscope 107. In the displayed signal waveform, if there is a problem in the temporal relationship between the gate signal Sg and the register signal Sm, the input is adjusted by the console 105 until an appropriate relationship is achieved. After the gate setting is performed in this manner, the register monitoring device WX106 monitors the mutual relationship of the register signals given from the signal processing circuit 1.04, and displays any abnormality. FIG. 4 shows the configuration of an automatic gate setting device according to the present invention, which uses a microconbeater. This device uses a register signal RASRB from a scanning head 11 and a rotary encoder 13.
The plate circumference setting circuit 11 receives the spider reference pulse as input.
Circumference signal from 0, gate setting start button 202
A gate signal is formed based on the start command signal from , and the setting input by operating the color number setting signal from the color number setting digital switch 203, and is output to the register monitoring device 1utt. That is, the scanning register signal R
A and RB are given to the register signal processing circuit 111 via waveform shaping circuits 102 and 103, and HA and RB are
. Three signals of RA (XRE) are formed, these three signals are fed to the interface 117, and the reference pulse of the rotary encoder 13 is fed to the two counters IIJ8.
, 109, and in the counter 108, 1 of the plate cylinder 3
The number of reference pulses corresponding to the rotation is counted, the counter 109 counts the number of reference pulses corresponding to the interval between register signals, and the count result is provided to the interface 117. Here, the counter 108 is supplied with a plate circumference signal from the interface 117 every one revolution of the plate cylinder, and the counter 109 is supplied with a register signal RA ORE from the interface 117, and the count is cleared each time. Next, various setting inputs are as follows. First, in the case of manual setting, the plate circumference setting circuit 110 is given a set value by the digital switch 2υ1, and this is sent to the interface 117 as is. On the other hand, in the case of automatic setting, as shown in the drawing diagram, a yard meter 204 is provided, and a signal corresponding to the number of web travel meters is received from the yard meter 2 (14), and a counter JO8 is sent via an interface 117 for each rotation of the plate. By receiving the plate rotation signal, a plate circumference signal is formed and given to the interface 117. The detected misregistration speed is corrected based on this plate circumference value and the plate rotation speed that can be calculated from the rotary encoder 13. As a setting input, Gate setting start button 2 outside this
A signal for starting the setting operation by 02 and a color number setting digital switch 2, which is provided as necessary and is indicated by a broken line and is used to set the number of printing colors used in gravure printing.
03. These various inputs and setting inputs are performed on interface 1.
17 to the CPU and RAM via the bus 118, the CPU is manipulated according to the program in the ROM to form a gate signal, and the gate signal is output to the register monitoring equipment 106 via the path 118 and interface 117. . FIG. 5 is a timing chart showing various signals 6 in the device of FIG. 4, including the register signal RA. The relationship between RB and reference pulses and gate signals is shown. In this figure, A-m6J is a signal detected by one of the two optical sensors in the scanning head, and JB-m6B is a signal detected by the other. In this case, since there are six printing colors, the web There are 6 register marks printed on the , so there are also 6 register signals. Since the two optical sensors are arranged a predetermined distance apart along the running direction of the web, the register signal mIA% m
6m and mI B-m6 B are temporally shifted. Here, two optical sensors are arranged so that register signals RA and RB overlap with each other with a temporal shift of one mark. Therefore, if we take RAθRB, mIA-m6A and ml
Since it overlaps with B-m6B five times, it is 5Fc5 as shown in the figure.
You will get two outputs. Using these five outputs, it is determined that the signal is a register signal. That is, the register mark is, for example, 20 mm.
It should be printed at intervals, and if the register mark is printed correctly, RA @ RB is equal to 2o
Five items appear consecutively at timings corresponding to mm intervals. And RA (lI RB appears like this only in register marks. Therefore, when the interval of Rh (') RB is measured using the reference pulse, the number of reference pulses n1 to n6 is obtained. This measurement is The color/reader 109 performs this using the reference pulse and the register signal.Then, the CPU monitors the count contents of the counter 109, and when a correct RA ('HRB' is obtained), it recognizes it as a register mark and sets the gate. The gate is set from the rising edge of the register signal mIA to the rising edge of m6B, and the counter 113 corresponding to the rising edge of mIA
8 and the count value M2 of the counter 108 corresponding to the rising edge of m6]3 are written into the RAM. Gate settings are subsequently performed using this plum, M2, and register marks detected within this gate are monitored to detect misregistration. However, in this gate setting method using Ml and M2, M is determined by the program. The gate timing can be set to any position before M2 and after M2. Here, the gate period is from the rising edge of m1m to the rising edge of m6B, but variations such as using the falling edge or the middle between the rising edge and the falling edge can be freely made. FIG. 6 is a flowchart showing the operation of the apparatus shown in FIG. 4, which will be explained. First, input the register signal (8). This input timing is the rising edge of the signal, and it is assumed that the register signal RA is detected at the moment when RAθR13 is established. Therefore, even if a so-called register mark is detected, the count value Ml of color/re108 at that time is stored in RAMK'.
! (S2). Then, set 1=1 indicating that it is the first color register signal in row 5 (Sa). When i-1 is set, the counter 109 starts counting reference pulses (S4). Next, the success or failure of RA convex RB is checked between register signals RA and RB (day 5). Ra ('RB is established for register signal RA at m25 to m6A (for RB, mIB - m
5B), and is not valid in other cases, for example, in the detection of registration marks. When this Rh7RB does not hold,
The counter will continue to count up until it reaches 88
) Return to step 81 again and repeat the above operation. Counter 1090 count over means, for example, if the reference pulse is one per 1 mm of the web, and if the register marks are normally spaced at 21 mm intervals, then the space is 25 mm.
When the count is reached, it is determined that the count is over. The 25 mm spacing here is set in the program. When a register mark is detected, RA ('1RB is established, so the count value n1 of the counter 109 at the moment when this is established is written to the RAM (86).Then, the written value is compared with a preset value no. (S7). This set value corresponds to the interval between register marks (20 non. in this case) from the plate circumference signal from the plate circumference setting circuit 110 and the reference pulse number per plate cylinder rotation from the counter 108. The register marks are 21 mm apart, but because there is a misalignment between the marks and the pattern and misregistration during printing, the no.
and nl are not necessarily equal and there is an error. Therefore, n
A certain amount of tolerance is required when comparing o and 01, and n
If the difference between o and nl is not within the allowable range, it is determined that the mark is not a register mark, and the process returns to step S1. On the other hand, n, and nl
If the difference between
o, an). That is, step 84 for the second color.
- Repeat S7. This is repeated until the fifth color, and the operations from steps 812 to St7 are performed for the sixth color. These steps correspond to steps 64 to S9, and only the logical formula 813 corresponding to step S5 is different from 85. This occurs at the rising edge of the register signal m6B in the timing chart of FIG.
This is to read the count value n6. Through this series of operations, the count value n1 of the counter 109
- n6 are read in sequence, and if any of these n1 to n6 is an incorrect value, the process returns to step S1. Also, if the value is correct, it means that the register mark has been detected, so the count value M2 of the counter 1139 at the rising edge of the register signal m6B is stored in the RAM K (J8
). This M2 indicates the gate closing timing, and the gate opened with the aforementioned Ml is closed with M2 (S, 1
9). Gate setting is based on a mechanical phase signal of plate cylinder rotation detected by a rotary encoder, so if there is a paper bus fluctuation, the mark's head arrival timing may be shifted, and the mark may not enter the gate. Therefore, the gate must be updated every time, and this can be done using one of the following methods. D) Gate timing detection (Sae) (Figs. 4 to 6) and misregistration detection alternately or periodically MI M2 written in the memory so as to maintain a constant interval from the falling edge of the MI I can do it. If only the register signal RA in Fig. 5 is detected, mIA ``-''2A + '' * m5A -mf
Measure the distance between the marks that touch each other like iA,
A method may be used in which the gate setting timing is determined by confirming that the interval is a predetermined interval (20 mm in this case). FIG. 7 shows the configuration of an apparatus that extracts only the register signal from among the detection signals of the scanning head based on this gate signal, and determines whether or not the registration is good based on the extracted register signal. In this figure, the part surrounded by a dashed line corresponds to the register monitoring device 106 in FIG. 5, which receives a gate signal from the gate setting circuit, judges whether the register signal from the input circuit is good or bad, and outputs the judgment results in various ways. feed into the circuit. That is, in the register monitoring device H1o6, the register processing circuit 1
21 forms and outputs a judgment signal based on the gate signal and register signal. The output circuit to which this judgment signal is given includes a misregistration indicator 122, an alarm 123, and a web mark 2124, which display the amount of misregistration and
affix defective marks to information and websites. In addition, in order to know the length of the defective part of the web, use a Jarl meter 1.
The meter signal from the meter 125 is given to a meter counter 127, and the meter signal from the yard meter 125 when a defect occurs is given to a defective meter counter 28. □ FIG. 8 shows operations such as calculation of misregistration to be determined by the registration monitoring device #106 shown in FIG. 7. First, the operator checks the web printing status and starts register monitoring when the registration is OK (E!21, 822)
. Upon starting the register monitoring, the gate setting operation is performed as described above (823). A register signal is taken in from K, and the register between each two colors is input (S24). The initially input misregistration is the positional misalignment between the picture and the mark, and is written into the RAM as a reference position, and is subsequently subtracted from the detected misregistration and used to correct the amount of misalignment. To detect misregistration, two optical sensors are used to detect only the arrival time difference corresponding to the misregistration of adjacent marks. The interval between the rising edge and the rising edge of the register signal from the scanning head 1.1 (Fig. M4) is measured as the mark arrival time difference, and the speed is corrected based on the plate circumference value and plate rotation speed that are already known, and the deviation from the reference position is Correct the amount and correct the misregistration. This method of using two optical sensors has the advantage of high accuracy because it detects only the time difference. In addition, a method can also be used in which one optical sensor is used to detect the intervals between all register marks as the arrival time, and the arrival time is calculated by subtracting the time corresponding to the interval between register marks during normal operation. Further, detection can be performed using not only the rising edge but also the falling edge or the intermediate point between the rising edge and the falling edge. If there are six printing colors, there are five intervals between register signals, and the misregistration between them is d! , ΔB2, ΔE
Let a, ΔE4, and ΔE5 be the deviations of each color with respect to the ``'' color, respectively. Rtt, 321, Bss, E41, Rs
Letting s and Eat, it can be expressed as follows. go ro 0 E21-ΔBon I Bst ROM1+ΔE2 B41田J1+△Bon2+△E3 Long51-J'l+△E2+ΔBon3+MuE4B61-LJ
Ll + Muchi + ΔB3 + ΔE4 + △E5 These B1t~E
The maximum value and minimum value among 61 are Kmax, respectively.
1m1n, the maximum misregistration ΔEmax between each color is given by ΔB+nax −Emax −111m1n. In step 825, necessary operations are performed using the above formulas, and the results are displayed on the display. Next, the above-mentioned ΔEmax is compared with the tolerance value, and the result is displayed on the display (826). The register tolerance value is given in advance by some means such as a numeric keypad, and for example, the RA
Memorize it in M etc. Related to the comparative judgment in step 826, a judgment is made as to whether the register is good or bad (827), and if it is defective, the defective meter counter is turned on (828), and if it is good, the defective meter counter is turned off (829). When there is a failure, alarms and webmarks operate as described above, and when there is a failure, these operations are stopped, but these are not shown in the flowchart. The operations of steps 824 to B29 are performed cyclically. (Fabric of the Invention) As described above, the present invention prints register marks on the web using printing units of each color, and corrects misregistration of openings between some register marks and other register marks. The maximum misregistration is obtained by subtracting the minimum value from the maximum value of this misregistration, and a warning is displayed when this maximum misregistration exceeds a predetermined value, so that it will not be overlooked when monitoring the registration between two colors. Even misregistration can be reliably detected. In addition, we have installed a gate circuit to reliably detect only the register marks among the various marks printed on the web.
Misregistration can be detected more quickly and accurately.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the configuration of a rotogravure printing press, Figure 2 is an explanatory diagram of register marks attached to a printed web,
FIG. 3 is an explanatory diagram of a gate setting method for register mark detection, FIG. 4 is a block diagram of a gate setting device according to the present invention, and FIG. 5 is a diagram showing signal waveforms of each part of the device of FIG. 4. 6 is a flowchart for explaining the operation of the P position in FIG. 4, FIG. 7 is a Pronk diagram showing the configuration of the register monitoring device 6 according to the present invention, and FIG. 8 is an operation of the device in FIG. 7. It is a flowchart for explaining. 1.2.3...Plate cylinder, 4,5.6...Basic fertilizer, 8...
・Convencator roll, 11...Sganning hend, 12...Device body. m...Register mark, R...Register (No. ii. Applicant's agent Kiyoshi Inomata Figure 7)

Claims (1)

[Claims] 1. Register marks are printed on the web using printing units of each color, and the misregistration between one register mark and another is determined, and the maximum value of this misregistration is determined. A register monitoring method for a multicolor rotary printing press in which a maximum register deviation is obtained by subtracting a minimum value from a predetermined value, and a warning signal is generated when this maximum register exceeds a predetermined value. 2. In a method in which register marks are printed on the web by each color printing unit and the misregistration between one register mark and another is known, the register signal and plate formed by register mark detection are used. The distance between the register marks is measured using a reference pulse formed in accordance with the rotation of the cylinder, and the distance between the register marks is a predetermined value, and the measurement is performed a number of times corresponding to the number of intervals between the register marks. When the register mark is detected, the gate signal generation timing is set using the first and last of the register signals, and this gate signal is used to detect the register mark from among the signals taken from the web. A register monitoring method for a multicolor rotary printing press, characterized in that only the register signal is extracted.