JPS60110454A - Registering controller for rotary press printer - Google Patents

Abstract

PURPOSE:To minimize the occurrence of damaged papers by correcting bad register on the basis of optimal corrected amount calculated from easily graspable exact parameters among elements which can participate in the registering control. CONSTITUTION:Bad register E calculated in a register shift detection circuit 31 is given to a PD control circuit 32, and the axial position of a compensator roller 20 is controlled. Registering is made by moving the axial position of the compensator roller on the basis of the optimizing value of gains KP and KD in PD control by any one of pass length 12 between the plate cylinder and the register mark detection position, the plate cylinder radius (r), the moveing speed (v) of the compensator roller, and printing speed V. By using exact graspable parameters in this way for PD control, registering control excellent in speediness and stability can be made.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a multicolor rotary printing press such as a rotogravure printing press, and particularly to a registration control method for correcting misregistration thereof.

[Technical background of the invention and its problems]

An apparatus for performing this type of register control has a configuration as shown in FIG. 1, for example. Here, only the unit of plate cylinder // and the unit of plate cylinder l- in a multicolor rotary printing press are shown.
, 22 are combined, and the printing material is conveyed from the plate cylinder unit to the plate cylinder unit.

A compensator roller I is provided along with a guide roller N on this inter-unit conveyance path, and by moving the axial position of this compensator roller J, it is possible to correct the misregistration, that is, the registration mark printed on the printing material by the front plate cylinder. The positional deviation of the register mark printed on the rear plate cylinder can be reduced to zero.

In order to control the axial position movement of this compensator roller, the output pulses of the pulse generator PG installed on the front plate cylinder /l and the output of the scanning head 8H installed near the rear plate cylinder 12 are misaligned. Detection circuit 3/
The detection output of this circuit 3/ is applied to the register motor drive circuit 33 via the FD control circuit 3 to operate the register monitor M that moves the axial position of the compensator roller.

In this case, the axis position movement control of the compensator roller is performed by so-called FD control, and is based on the following equation (1) using the misregistration E detected by the misregistration detection circuit 31 and its differential value /dt. The drive time Δt and rotational direction of the register motor M are determined, and the compensator roller is moved by the time Δt in accordance with the determined values.

Here, KP: Proportional gain (constant) KD: Differential gain (constant) Here, in the normal case, the values of the proportional gain Kp and the differential gain KD are fixed, and the values may vary depending on the configuration of the printing machine, printing conditions, etc. Hunting may occur depending on the path length, scanning head mounting position, condensator/roll speed, printing speed, cylinder circumference length, etc., or even if this is not the case, the responsiveness may deteriorate considerably.

Therefore, in the past, instead of making frequent corrections such as 7 times per rotation of the plate cylinder, corrections were made once every 10 rotations of the plate cylinder, or by changing the kick gain (K
Hunting is avoided by adjusting P and KD at the same time.

However, this method requires complicated operations because the operator has to adjust the number of corrections and the gain according to the printing conditions, and the adjustment does not cause any problems under any conditions. Since the gain is set quite low, it is not possible to achieve excellent control performance such as coordination and stability. In other words, performing seven corrections for more than one rotation of the plate cylinder means that an inferior result can be obtained compared to a case in which correction is performed every rotation.

This means that a larger amount of wasted paper is generated for a printing machine.

To avoid such problems, it is necessary to improve the coordination of control, but in register control, improving coordination results in a lack of stability. This is because many of the elements that may be involved in registration control have not yet been sufficiently analyzed, making it difficult to find an optimal point that satisfies both connectivity and stability. Here, factors that may be involved include, for example, in addition to those that are easy to accurately grasp, such as the rotational speed and dimensions of the various rollers of the printing press,
By placing the register mark detection position behind the plate cylinder position, there are problems that are difficult to accurately grasp, such as a timing lag between the device operation and its detection, and elongation of the paper used for printing.

For this reason, in conventional registration control, improvements have only been made through trial and error, and therefore no significant effects have been achieved.

[Purpose of the invention]

The present invention has been made in consideration of the above points, and when misregistration is detected, the optimum correction amount is automatically calculated according to the configuration of the printing machine and printing conditions at that time, and based on this calculated value, the optimum correction amount is automatically calculated. It is an object of the present invention to provide a registration control method that quickly corrects misregistration and minimizes the occurrence of paper waste.

[Summary of the invention]

To achieve this objective, in the present invention, the plate cylinder unit is based on the prospect that it will be possible to perform control using elements that can be easily grasped accurately among the elements that can be involved in the above-mentioned registration control. path length (11), path length between the plate cylinder and the register mark detection position (1,), plate cylinder radius (r), moving speed of the convencator roller (v), and printing speed (V)
Gain KP in FD sub-control by either one of
Registration is achieved by moving the axial position of the convencator roller based on the optimized value of KD.

[Embodiments of the invention]

An embodiment of the present invention will be described with reference to the accompanying drawings.

Referring again to FIG. 1, the configuration of the multicolor rotary printing press will be explained in more detail.

In FIG. 7, the printing material passes through the guide roller 23 between the front unit, that is, the plate cylinder // and the impression cylinder λ/, where printing of the first color is performed, and then the guide roller 3 and the convencator roller J1 Further, it passes through the guide roller 3 and reaches the rear unit, that is, between the plate cylinder/co and the impression cylinder 2, where printing of the second color is performed, and then passes through the guide roller and reaches the next stage unit 6 or the take-out section ◇ Here, the front stage In the unit, the first register mark is printed on the printing material when the first color is printed, and in the subsequent unit, the No. 1 register mark is printed on the printing material when the second color is printed. These register marks are detected by the scanning head SR at a detection position located behind the printing position of the subsequent unit, that is, the contact position between the plate cylinder/co and the impression cylinder 2 in the conveying direction of the printing material, and the detection signal is It is applied to the misregistration detection circuit 3/.

This detection signal contains the deviation ΔTe in the detection timing of the two register marks.

On the other hand, the misregistration detection circuit 3 is supplied with a pulse signal representing the rotational speed of the plate cylinder l/, that is, the conveying speed V of the printing material, from a pulse generator PG attached to the plate cylinder I/C. (This pulse generator PG forms a gate signal for detecting the register mark.) Therefore, using this pulse signal and the detection signal of the scanning head SH, the register error E is detected in the register detection circuit 3/. Calculated.

That is, P=-VXΔT.

ri n X 2πr×ΔTe ・・・・・・・・・ (,2
) where n: number of rotations of the plate cylinder // r: radius of the plate cylinder.

This misregistration E is given to the FD control circuit 3, and a register motor drive signal is formed by PD calculation, and the register motor drive circuit 33 drives the register motor M, which rotates at a constant speed, to adjust the axial position of the convencator roller. controlled. This performs registration.

When the register motor M that moves the axial position of the convencator roller is of a constant speed operating type, the amount of movement of the axial position of the convencator roller is proportional to the drive time of the register motor M.

Therefore, the FD control circuit 3 calculates this drive time according to a general formula for pin control. In other words, the drive time Δt
Then, Δt=KpKx+Kn(Ex-Ex,)...
(3) Here, KP: proportional gain KD; differential gain EK: currently detected misregistration PK;: previously detected misregistration. However, this driving time Δt is made not to exceed the rotation period of the plate cylinder so that it can be corrected for each rotation of the plate cylinder.

As a result of repeated studies by the inventor of the present invention, it has been experimentally confirmed that KP and KD in the above equation (J) can be calculated using the following equations (S) and (s).

That is, fr (12)・1゜Kp-□ ・・・・・・・・・ (su) ■ ■ Here 11: Path length between plate cylinder units 12: Path between plate cylinder and registration mark detection position Length V: Moving speed of the convencator roller r: Radius of the plate cylinder, f, , f is a function of 1□, f8
indicates that it is a function of r, and f and ~f3 are also monotonically decreasing functions and take positive values. In other words, it is.

Next, the validity of the above equations @) and <s) is shown in Figures 2 to 7.
This can be confirmed from the experimental results shown in Figures (a) and (1)).

First, Figure 2 shows a state in which all the elements for register control in a multicolor rotary printing press have been optimized;
By comparing Figures 7(a) and 7(b) with this Figure 2, it becomes clear whether or not they are appropriate. The state shown in FIG. 2 was obtained as follows.

Parameters First, the parameters of the multicolor rotary printing press are as follows unless otherwise noted.

(1) Tension T The tension T for supplying the printing material to the front unit is constant (15~), and that to the rear unit is 15±ΔT2G). (2) Conveying speed of the printing material V 100 (m/min) constant It is.

(3) Plate cylinder radius r θ, lg(m).

←) Inter-unit path length 1° q, g(m).

<s> Path length between plate cylinder and register mark detection position 120
It is Guza (m).

(6) Axis movement speed of convencator roller vo, s
(m7 seconds).

(7) Other characteristic diagrams, such as tension change ΔT2, convencator roller position change ΔC1, register mark deviation E, etc., show only the above-mentioned parameters or changes from the initial values.

Description of Characteristic Diagram In Fig. 2, the register mark deviation is 0. s(wn
) is detected, the convencator roller is 0. The time Δt calculated by s (1B/?i))
move only. As a result, the convencator roller position moves from the initial position to a maximum of 10, b7 (- side position), and finally stops at the position of ±0..is (wrv).

Due to this position change Δ0 of the convencator roller, the maximum tension applied between the units to the printing material is ts +
o, bb (UP), minimum ls −o, 02
(K9), finally becomes 00G.

Due to this operation, the register mark deviation E gradually decreases over time and finally reaches 0.00 (1+1L).

This is how registration was achieved.

FIG. 3 shows the case where the printing speed V was changed, and in this case, the registration control was performed slightly more quickly and smoothly than in the standard state of FIG. 2. In other words, the above equations 0) and (S) do not include the printing speed V, and it has been confirmed that the registration control is not affected even if the printing speed changes.

FIGS. 7(a), (b) to 7(a), (b) are experimental results regarding the elements included in the above formulas @) and (S).

Figure (a) shows the gain K11. Leave KD as is and set inter-unit path length 1. from q, g (m) to /11 (m
). In this case, the calculated time Δt
However, since the gains are different from Kp and KD according to the above equations (G) and (S), a difference occurs.

On the other hand, in FIG. 7 (1,), the gains xP and KD were optimized using the above equations 0) and <s), so that the noching was almost completely suppressed.

Figure S (a) shows the bus length 12 between the plate cylinder and the register mark detection position with the gains KP and KD kept at their standard states.
, txt(m) to o,tg(m). In this case, −・enteng occurs.

On the other hand, in Fig. 5(b), the above (4=), (S)
Since the gains KP and KD were optimized using the formula, the noise was suppressed.

Figure 6 (a), (b) When the H convencator roller moving speed V is changed from o, s (g/sec) to l (-working) and the gain is kept at the standard state (the figure (a
)), the value calculated by the above (tI) and formula 9) is shown ((b) in the same figure), and the gain is
On the other hand, as shown in Fig. 7(a), when only KD of the gain KP and KD needs to be adjusted, that is, the plate cylinder radius r is set to 0. ．．
/su(m) is changed to O, O, r(m). As is clear from the above equations (I) and <s>, the plate cylinder radius r is included only in equation (5) and not in equation (0). Therefore, when the plate cylinder radius r is changed, only the gain KD is changed, and Kp is not changed.

In this respect, Fig. q (1), (b) to Fig. 6 (a), (b)
), the inter-unit path length 10, the bus length 12 between the plate cylinder and the register mark detection position, the moving speed V of the convencator roller, and the plate cylinder radius r are fundamentally different.

From the above explanation using the characteristic diagrams of FIGS. 2 to 7(a) and (b), the validity of the above equations (R) and (S) has been confirmed. Moreover, these equations (G) and (5) are composed only of elements that can be accurately grasped among the elements that can be involved in registration control. Then, Kp and KD calculated by these equations (da) and <S) can be used to respond well to the (fleeting) situations that are expected to occur in register control, so the control method for register control It can be said that this has been significantly organized.

The above explanation with reference to FIGS. 2 to 7 has shown how to deal with elements that are easy to accurately grasp among the elements involved in registration control.

Figures 3 and 3 show the results of an investigation into the influence of other factors, changes in the tension of the printing substrate and changes in the elongation coefficient (determined by the paper quality, for example), on registration control. First, Figure 3 shows the tension T of the printing material
This figure shows the effect of changing from [spp] to [30CK], which is no different from Figure 2. Next, Figure 2 shows the effect when the elongation coefficient of the substrate is changed from o, ooo Koko ['N] to o, oooos C'Ap], and in this case, it is similar to Fig. 2. The same characteristics were obtained.

In other words, it was confirmed that changes in the tension of the printing material or changes in paper quality do not require gain adjustment in registration control.

From these results, in registration control, the path length between plate cylinder units (11), the path length between the plate cylinder and the registration mark detection position t (lt), and the compensator roller movement speed (
FD sub-control gain x based on V) and plate cylinder radius (r)
It is only necessary to adjust B and xn.

In the above embodiment, it is assumed that the moving speed V of the convencator roller is constant, but depending on the model, the moving time is constant (plate cylinder rotation period T) and the moving speed is variable. In that case, the above equations (3) to (5) will be different. These are shown as the equation (J)'-(j)'.

v-Kp'Kx+Kn'(Ex-BK-1)...
・・・(J)'f+'(It)・V・1゜x P/ ax□ ・・・・・・・・・(→'f＊'(
:h)・fs'(rlV-11KD'=□...
... (j)' where K P': Proportional gain.

KD': Differential gain BK: Current register EK, : Register before one rotation of the plate cylinder 1, : Inter-unit path length 12: Path length between the plate cylinder and register mark detection position V: Compensator roller's Traveling speed ■ - Printing speed r: Plate cylinder radius; φ = fI, , f/, , f': Monotonically decreasing function [Effects of the invention] As described above, the present invention is applicable to registration in a multicolor rotary printing press. When performing FD sub-control for
Excellent speed and stability are achieved by optimizing the gain KP and KD in the FD sub-control based on the compensator roller movement speed (V), plate cylinder radius (r), and printing speed (V). Registration control can be performed. However, compared to the conventional method, the amount of waste paper generated is significantly reduced.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram showing the configuration of a multicolor rotary printing press to which the method of the present invention is applied, and Figures 2 to 7 (a) and (1)) are obtained through experiments to demonstrate the feasibility of the method of the present invention. Fig. 2 shows the standard state, Fig. 3 shows the case where only the printing speed is changed from the standard state, and Fig. q (a), (b)
Figure S (a) is a characteristic diagram before and after adjustment according to the present invention when the inter-unit bus length is changed. (b) is a similar characteristic diagram when the path length between the plate cylinder and the register mark detection position is changed, and Figures 6 (a) and (b) are similar characteristics when the moving speed of the convencator roller is changed. Figure 7 (a) and (1)) are similar characteristic diagrams when the plate cylinder radius is changed, Figure 8 is a characteristic diagram when the tension of the substrate is changed, and Figure 7 is the same characteristic diagram. It is a characteristic diagram when the elongation coefficient is changed. // , /, 2... plate cylinder, 2/ , 2:l...
Impression cylinder, 3... guide roller. PG...Pulse generator, 8 H...×Canning head. 1, ... path length between units, 1□ ... path length between the plate blade - and the register mark detection position, r ... plate cylinder radius.

Claims (1)

[Claims] 1. Misregistration is detected by reading the register marks printed by the front unit and the rear unit in a multicolor rotary printing press, and based on this detection signal, a compensator provided in the path between the units・In a registration control method for a rotary printing press in which the path length between units is changed by moving the rollers to correct misregistration between each color on the printing material, the detected misregistration is expressed by the following formula: The register of the rotary printing press is characterized in that the travel time -t of the compensator roller is calculated by calculation, and the compensator roller is moved at a constant speed V based on this calculated value to perform the path length control. Matching control method. Δt-KPIliK+KD(FiK-El/) ■ Δt≦T where KP: Proportional gain KD: Differential gain EK: Current misregistration PK,: Misregistration before one rotation of the plate cylinder 11: Inter-unit path length 1! : Path length between the plate cylinder and register mark detection position ■ = Compensator roller moving speed r : Plate cylinder radius fl, ft, f, : Monotonically decreasing function f+ , ft , fs
>OT: Plate cylinder rotation period λ, misregistration is detected by reading the register marks printed on the front unit and the rear unit in the multicolor rotary printing press, and based on this detection signal, the In a registration control method for a rotary printing press in which the path length between units is changed by moving the compensator roller to correct misregistration between each color on the printing material, the detected misregistration is shown in the following formula. Calculating the moving speed V of the compensator roller by performing FD calculation,
A registration control method for a rotary printing press, characterized in that the path length control is performed by moving a compensator roller by a time T corresponding to the plate cylinder rotation period based on this calculated value. V −K'p B K + K', D(K K 7 K
1-1. ) f', (1, door V-1° 11: Inter-unit path length 12: Path length between the plate cylinder and register mark detection position V: Printing speed r: Plate cylinder radius fl', f2'+f3: Monotonically decreasing function fH'*
, r21, fB”>.