JP2508829B2 - Registration method in web printing - Google Patents

Description

The present invention relates to a registration method for web printing in printing such as a gravure printing method, a lithographic printing method and a relief printing method.

[Conventional technology]

Conventionally, in web printing such as a gravure printing machine, a plurality of printing units are arranged during a printing process from a paper feeding unit to a winding unit, and a web paper is sequentially printed with a plurality of colors through the printing unit. The register mark is printed together with each printing unit when printing, and printing is performed while detecting the position of any register mark printed on the upstream side.

A conventional registration method for performing web printing based on the register mark will be described for gravure printing.

FIG. 4 shows a gravure printing machine. The gravure printing machine 1 arranges a printing unit according to the number of printing colors between a paper feeding unit 2 for feeding out a web paper a and a winding unit 3 for winding the printed web paper a, and this printing unit is The web paper a is used to sequentially print from the first color. In the illustrated gravure printing machine, printing units 4, 5 and 6 are installed so as to perform three-color printing.

On the side of the paper feed unit 2, a tension detector 8 is connected to the roller 7 located near the unwinding, and a signal from the tension detector 8 is output to the paper feed tension control unit 9 to enable the paper feed tension control unit. The control signal is output to the motor 10 side, which is the driving device of the paper feeding unit 2, while measuring the correspondence with the web paper tension set and input at 9, and the rotation speed of the motor 10 is changed at any time to feed the paper. The rotation speed of the section 2 is controlled (that is, it corresponds to the change in the web paper diameter).

Also on the winding section 3 side, the rotation speed is controlled in the same manner as the paper feeding section. To this end, a tension detector 12 is connected to a roller 11 located in the vicinity of the winding unit 3, a signal from this tension detector 12 is output to a winding tension control unit 13, and this winding tension control unit
The control signal is output to the motor 14 side of the winding unit 3 while measuring the correspondence with the web paper tension set and input at 13, and the rotation speed of the motor 14 is changed at any time to rotate the winding unit 3. Control the speed.

The gravure printing machine 1 is provided so as to rotate the gravure cylinders of the respective printing units at the same speed, detect printing misalignment, and adjust the paper path between the printing units to register. In order to achieve this, first, nip rollers 15 and 16 are arranged on the upstream side of the first color printing unit 4 in the sheet feeding direction and on the downstream side of the third color printing unit 6 in the sheet feeding direction to control the rotation thereof.

A tension detector 18 is connected to the roller 17 located near the downstream of the nip roller 15, and a signal from the tension detector 18 is input to the in-field tension controller 19. And the first
The set tension on the upstream side of the printing unit is received by the in-field tension control unit 19 from the speed control unit described later as a signal,
The in-field tension controller 19 is provided so as to change the number of rotations of the motor 20 that rotates the nip roller 15 and feed the paper so that the web paper tension matches the set tension.

A tension detector 22 is connected to the roller 21 located near the upstream side of the nip roller 16, and a signal from the tension detector 22 is input to the outfield tension controller 23. Then, the outfield tension control unit 23 receives the tension on the downstream side of the final printing unit from the speed control unit (described later) as a signal,
The outfield tension control unit 23 is provided so as to change the rotation speed of the motor 24 for rotating the nip roller 16 at any time so as to feed the web paper to the winding unit 3 so that the web paper tension matches the set tension.

In addition to the control on the upstream side of the printing unit 4 and the downstream side of the printing unit 6 described above, the following control is performed.

Gravure cylinder 25,26,27 of each printing unit 4,5,6
Are driven by the motors 28 having the same diameter and using the same drive source so that the peripheral speeds thereof are the same. The motor 28
The rotation is controlled by the speed controller 29, and the gravure cylinders 25, 26, 27 are controlled to rotate at a constant speed. Then, print conditions such as the cylinder diameter, the tension on the upstream side of the first printing unit and the tension on the downstream side of the final printing unit are set and input to the speed control unit 29, and the operation corresponding to this printing condition is applied to the nip rollers 15 and 16. As described above, a signal for controlling the tension is sent to the in-field tension control section 19 and the out-field tension control section 23.

Since the state of the web paper a differs from the initial state due to expansion and contraction of the web paper and external conditions, the first color is printed by the printing unit 4, and then the second color and the third color are registered. Try to make a match.

This registration is performed on the basis of a register mark that is printed simultaneously with the printing of the first color or a register mark that is printed with the printing unit on the upstream side. On the downstream side of the cylinder 26 of the printing unit 5 and on the downstream side of the printing unit 6, mark sensors 30 and 31 for detecting register marks of a predetermined color are provided opposite the web paper a, and detection signals from the mark sensors 30 and 31 are provided. A second color registration unit 34 and a third color registration unit 35 are provided for controlling the compensator rollers 32, 33 in response to this.

These operations will be described with reference to the printing unit 5.
When the mark sensor 30 detects the passage of the register mark printed by the printing of the first color and the register mark printed by the second color, and the detection signals of the respective colors are received by the second color register 34, the second color The registration unit 34 determines whether or not there is a difference in the detection signals, and if there is a difference, outputs a control signal to the motor 36 to operate the motor 36. The motor 36 moves and stops the position of the compensator roller 32 arranged on the upstream side of the printing unit 5. As described above, when there is a difference in the detection signals, the position of the compensator roller 32 is changed. Is changed to change the paper path to the gravure cylinder 26 so that the difference is eliminated, that is, the register marks are overlapped. The printing unit 6 is also controlled in the same manner. The mark sensor 31 detects the passage of the register mark of the first color or the register mark of the second color and the register mark printed by the third color. When the third color registration unit 35 receives the difference, the third color registration unit 35 determines whether there is a difference in the detection signals, and if there is a difference, outputs a control signal to the motor 37 for operation. . The motor 37 moves and stops the position of the compensator roller 33, which is arranged on the upstream side of the printing unit 6, and when there is a difference in the detection signals, the position of the compensator roller 33 changes to the cylinder 27. Is controlled so that the reference register mark and the register mark of the third color overlap.

The setting of the register mark detection timing and the paper path adjustment are performed as follows.

Description will be given based on the pattern shown in FIG. In addition,
1 schematically illustrates one printing unit.

In this pattern, 30a indicates the scanner of the mark sensor 3, and 34a indicates the arithmetic element of the second color register 34. The scanner 30a detects the reference register mark and the second color register mark, converts the detection signal into a detection signal having a certain height and width through a scanner amplifier having a built-in detection signal, and arithmetic element 34a. Send to. Further, the speed detector 38 detects the paper feed speed from the web paper a passing through the gravure cylinder 26 and sends it as a speed signal to the arithmetic element 34a. An encoder 39 is connected to the gravure cylinder 26, and the rotation state of the gravure cylinder 26 is sent to the arithmetic element 34a as a signal, which is formed as a pulse signal (2 ° / 360 °) in the arithmetic element 34a, and a gate (10 ° / Also forms 360 °).

Based on the pulse signal formed by the arithmetic element 34a and the speed signal from the speed detector 38, this gate is rotated on the cylinder circumferential surface by 0 to 360 °, and the register mark position and the gate position are set by the oscilloscope. It is provided for adjustment.

In the arithmetic element 34a, the direct current power source is managed so that the motor 36 can be rotated normally and reversely, and the deviation amount between the reference register mark and the second color register mark is calculated based on the input signal, The operation amount of the motor 36 for eliminating this deviation amount is calculated, and the motor 36 is controlled.

[Problems to be Solved by the Invention]

In the conventional gravure printing machine, as described above,
Subsequent printing was performed using one of the register marks printed on the upstream side as a reference.

However, in the above-mentioned registration printing, since the register mark printed on the upstream side during the printing process is used as a reference, a plurality of colors are printed on the web paper once while the correspondence with the printing surface is measured again. The colors could not be printed. That is, when registering is performed based on the register mark printed on the stretched web paper while changing the tension in the pre-printing process,
The variable amount of the web paper was accumulated, and the slack and the tension of the web paper more than the adjustment amount occurred in the paper path adjusting portion for registration during the reprinting process. Further, even when reprinting is performed on the back side of the web paper, the reference register mark in the preprinting cannot be used at all.

Therefore, it has been a problem to make it possible to perform printing on the same side or the back side of a printed web sheet while measuring the correspondence with the print side, that is, while performing the registration.

[Means for solving the problem]

The present invention has been made in consideration of the above problems,
In printing a plurality of colors in order through a plurality of printing units arranged in the printing process from the paper feeding unit to the winding unit on a web paper having a printed register mark printed in at least one color in advance, Based on the rotation of the gravure cylinder and the rotation of one of the nip rollers, the nip rollers positioned on the upstream side and the downstream side of the printing unit in the respective feeding directions are rotated at a constant speed to provide a constant feeding speed. While generating a cylinder pulse signal and a nip roller pulse signal, the mark sensor detects the printed register mark of the web paper or the register mark printed by the upstream printing unit, and in each printing unit, the cylinder pulse signal Control to control the peripheral velocity of gravure cylinder based on Accordingly, by in register to adjust the rotational phase of the gravure cylinder for Okugyo timing of the web sheet a to the line feeding at a predetermined speed, it is to solve the above problems.

[Action]

In the present invention, the register controller receives the nip roller pulse signal and the cylinder pulse signal at the initial stage of the sheet feeding under the condition that the feeding speed of each printing unit is set to a constant speed by the nip roller. The peripheral surface speed of the gravure cylinder is determined by the cylinder diameter signal and the cylinder pulse signal set and input to, and the peripheral surface speed of the nip roller and the peripheral surface speed of the gravure cylinder become the same speed based on the nip roller pulse signal. To control. After that, the pre-printed register mark detected on the upstream side of the printing unit is used as the reference register mark, and this printed register mark and the plate surface reference position set on the gravure cylinder of each printing unit (for example, register mark engraving) Part)), that is, adjusting the rotation of the gravure cylinder to shift the phase and align the printed register mark with the plate reference position for initial registration.
After this matching operation, the setting is input as the normal printing stage, and the printing is continued.

Then, in consideration of the case where the pre-printed web paper is expanded or contracted due to environmental conditions, printing is performed while registering during the normal printing step. This is done in each printing unit, and the register control unit always receives the mark detection signal of the printed register mark detected on the upstream side of each printing unit, and the initial detection of the mark detection signal on the nip roller pulse signal. The pulse difference number between the plate reference position obtained at registration and the plate reference position detection signal is constantly grasped and compared with the pulse difference number obtained at the time of inputting the above-mentioned normal printing stage, and the pulse difference between the two is detected. If there is a difference in the number, the register control unit that constantly receives the cylinder pulse signal changes the peripheral speed of the gravure cylinder based on this cylinder pulse signal, that is, in the direction to eliminate the difference in the number of pulse differences between the two. It will change the phase of the cylinder.

〔Example〕

Next, the present invention will be described in detail based on the embodiments shown in FIGS. 1 to 3.

FIG. 1 shows a printing unit that implements the method of the present invention and devices arranged around the printing unit. The devices are similarly arranged in each printing unit, and one printing unit is illustrated. Explain.

Reference numeral 40 in the drawing denotes a motor, and the motor 40 is a single drive source for rotating the nip roller 41 located on the upstream side of the printing unit at a constant speed. A speed control unit 42 is connected to the motor 40, and the speed control unit 42 is provided so that the paper feed speed of each printing unit is constant under the printing conditions set and input in the speed control unit 42.

A pulse generator 43 is attached to the nip roller 41, and a nip roller pulse signal is sent from the pulse generator 43 to the register controller 44.

A mark sensor 45 is provided on the upstream side of the printing unit so as to face the web paper a passing through the nip roller 41, and the mark sensor 45 detects the register mark of the pre-printing. The register mark for pre-printing serves as a reference for subsequent printing, and the mark detection signal of the register mark serving as the reference is sent from the mark sensor 45 to the register control unit 44.

A pulse generator 46 is attached to the gravure cylinder 25, and the pulse generator 46 is provided so that a cylinder pulse signal is sent to the register control unit 44.

When the mark engraving part is detected on the circular orbit of the mark engraving part of the gravure cylinder 25, the mark sensor 47 is installed oppositely, and when the mark engraving part is detected as the plate reference position during initial registration, the mark sensor 47 outputs the engraving part detection signal. That is, the plate reference position detection signal is provided to the register control unit 44. The rotation of the gravure cylinder 25 is controlled by the register control unit 44.
Drive 48.

At the beginning of sheet feeding, the rotation phase of the gravure cylinder is changed through the register control unit 44 based on the mark detection signal A and the marking portion detection signal B input to the register control unit 44, and the reference register mark and the plate surface are changed. The initial registration is performed by adjusting the corresponding positional relationship with the reference position, and at the time of shifting to the normal printing process, the register control unit 44 sends the mark detection signal A and the plate reference position detection signal B at that time to the nip roller. Corresponding to the pulse signal C, the pulse difference number I between the mark detection signal A and the plate surface reference position detection signal B on the nip roller pulse signal is stored (see FIG. 2).

During the normal printing process, the register control unit 44 constantly inputs the mark detection signal A and the plate surface reference position detection signal B.
The difference between the pulse difference number obtained from and the above pulse difference number I is processed to determine the presence or absence of the difference, and if there is no difference, it is calculated based on the cylinder pulse signal that is always input. The gravure cylinder is controlled to maintain constant rotation. When the above difference occurs, the register control unit
Reference numeral 44 indicates the operation amount of the motor 48 based on the constantly input cylinder pulse signal so that the pulse difference number obtained from the mark detection signal A and the plate surface reference position detection signal B coincides with the pulse difference number I. Calculation processing is performed and the result is output to the motor 48 side, whereby the number of rotations of the motor 48 is changed and registration is performed.

The above-described registering operation is performed in each printing unit, and printing is performed while making a correction when the register shift is confirmed.

As shown in another embodiment of FIG. 3, the nip rollers may be controlled by independent driving sources. In the embodiment shown in FIG. 3, the nip rollers 49 located on the upstream side of each printing unit are driven by motors 50 which are independent drive sources, and the motors 50 are controlled by the speed controller 42 and attached. The pulse generator 51 sends the nip roller pulse signal to the register control unit 44. As in the above-described embodiment, the mark sensor 45 is arranged on the upstream side of the printing unit so as to face the web paper a via the nip roller 49, the printed register mark is detected from the mark sensor 45, and this mark detection signal is sent. It is sent to the register control unit 44.

A reference detector 52 that detects the plate reference position set on the cylinder itself is attached to the gravure cylinder 25.When the plate reference position at the time of initial registration is detected from the rotating gravure cylinder, the reference detector 52 detects the plate surface. The reference position detection signal is sent to the register control unit 44.

Unlike the above-described embodiment, the pulse generator 54 is attached to the motor 53 that drives the gravure cylinder 25, and the register control unit is provided from the pulse generator 54.
A cylinder pulse signal is sent to 44. The register control unit 44 performs the same arithmetic processing as that of the above-described embodiment, and receives the nip roller pulse signal, the mark detection signal, the plate reference position detection signal, and the cylinder pulse signal to determine whether there is a difference in pulse difference number. Based on the result, the control of the operation amount of the motor 53 is sent to the variable speed motor control unit 55 as a signal, and the variable speed motor control unit 55 controls the motor 53 to perform registration.

A tension detector may be provided during the paper feeding process, and the degree of rotational shift of the printing plate cylinder such as a gravure printing plate may be adjusted based on a signal from the tension detector.

〔The invention's effect〕

As described above, according to the present invention, a plurality of printing units disposed in the printing process from the paper feeding unit to the winding unit are preliminarily printed on the web paper which has been printed in at least one color and has the printed register mark. When printing a plurality of colors sequentially through the unit, each of the nip rollers positioned on the upstream side and the downstream side in the paper feeding direction of each of the printing units is rotated at a constant speed to provide a constant paper feeding speed. The cylinder pulse signal and the nip roller pulse signal are generated based on the rotation and the rotation of any one nip roller, and the mark sensor detects the printed register mark of the web paper or the register mark printed by the upstream printing unit. Then, in each printing unit, the gravure series is based on the cylinder pulse signal. Since the register control unit that controls the peripheral speed of the printing plate cylinder of the rotary press such as a der adjusts the rotational phase of the printing plate cylinder with respect to the feed timing of the web paper a that is fed at a predetermined speed, it is necessary to register at least in advance. When printing multiple colors on a web printed with one color, it becomes possible to perform registration based on the register mark that is printed in advance in each printing unit, thus making it possible to efficiently print printed matter with pre-printing and post-printing. It is possible to produce the sheet, and the post-printing can be performed in correspondence with the back side of the pre-printing.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a gravure printing machine of an embodiment of a registration method in web printing according to the present invention, and FIG. 2 is an explanatory view showing a mark detection signal, a plate surface reference position detection signal and a nip roller pulse signal, FIG. 3 is an explanatory view showing another embodiment, FIG. 4 is an explanatory view showing a gravure printing machine for implementing the conventional example, and FIG. 5 is an explanatory view of the conventional example. 41,49 …… Nip roller 42 …… Speed control unit 44 …… Registration control unit 45,47 …… Mark sensor 52 …… Reference position detector

Claims (1)

(57) [Claims] 1. A plurality of colors are sequentially printed on a web paper which has been printed in at least one color in advance and has a printed register mark, through a plurality of printing units arranged during a printing process from a paper feeding section to a winding section. When printing, the nip rollers located on the upstream side and the downstream side of the printing unit in the paper feed direction are rotated at a constant speed to provide a constant paper feed speed, and the rotation of the printing plate cylinder and one of the nip rollers. Cylinder pulse signal and nip roller pulse signal are generated based on the rotation of the paper, and the above-mentioned printed register mark of the web paper or the register mark printed by the upstream printing unit is detected by the mark sensor, and each printing unit or In the printing unit after at least the first color printing unit, the cylinder A register control unit that controls the peripheral speed of the printing plate cylinder based on the pulse signal adjusts the rotational phase of the printing plate cylinder with respect to the transfer timing of the web paper a that is transferred at a predetermined speed, and makes registration. Registration method for web printing.