JPH1067091A - Correction of misregister and device for correcting misregister - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve rapid detection of a misregister whenever it occurs by detecting a register mark which is printed on both ends of a web and is already past a dryer and a cooling device, and thereby measuring the width of the web. SOLUTION: The width of a web is measured by detecting register marks 107, 108 which are printed on both ends of the web and are already past a dryer 112a and a cooling device 120a, with the assistance of detectors 109, 110. Consequently, some change in the width of the web caused by the thermal effects of the dryer 112a and the cooling device 120a is reflected in the measured width of the web as a width change. Besides, the rapid detection of a misregister attributed to the change of the web width is made. In addition, the cooling conditions of the cooling device 120a for making the measured width of the web coincide with a target web width are determined by calculation. Based on these cooling conditions, the cooling device 120a is controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention belongs to the technical field of printing on a web. In particular, the present invention relates to a method and an apparatus for correcting a register shift that corrects a register shift caused by a change in a web width in each printing unit when performing overprinting in a gravure printing machine or the like.

[0002]

2. Description of the Related Art In a gravure printing machine or the like for performing multicolor printing, a registration mark for printing on a side portion of a web in a printing unit of each color is detected by an optical detector, and a registration error when performing overprinting is reduced. In some cases, the compensator device is activated when the direction of misregistration is parallel to the web transport direction (phase), and when the misregistration direction is orthogonal to the web transport direction (meandering). The misregistration is corrected by operating the side lay device of the plate cylinder.
In the case of such a misregistration due to the simple movement of the top and bottom (phase, meandering) of the web, the misregistration can be corrected by this method. However, if the web width (the dimension in the direction perpendicular to the web transport direction) changes under the influence of the heat of the drying unit or cooling roller of the printing unit, the side of the web on which the register mark is printed may be used. The register on the side of the part is out of register on the opposite side.

Conventionally, the operator of the printing press has dealt with the misregistration caused by the change in the web width by visually inspecting the printed matter after passing the final unit. In other words, when there is a misregistration, the cooling water flow rate of the cooling roller of the printing unit one upstream of the printing unit of the printing color is adjusted. The adjustment is performed by manually operating an opening / closing valve of the cooling water so as to be registered in the entire width direction of the web.

[0004]

The operation of correcting the misregistration by the operator has the following problems. In order to eliminate oversight, the operator must constantly monitor misregistration, and the work load is large. Since the misregistration is inspected after printing all colors, for example, when there is misregistration of a color printed by a printing unit near the uppermost stream, the detection is delayed and many defective prints are generated. When the web is changed due to splicing or the like, a sudden change in the web width may occur. However, all of the measures must be performed by the operator, and the work load is large, it takes a long time, and many defective prints are generated. Even if the web width changes due to a change in the flow rate of the cooling water of the cooling roller, it takes time to inspect the correction state of the misregistration, and trial and error is required, and many defective prints are generated. Since the temperature of the cooling roller is controlled by changing the flow rate of the cooling water flowing into the cooling roller, the response when the set temperature is changed is slow, which also makes adjustment difficult.

Accordingly, an object of the present invention relates to misregistration caused by a change in the web width, which enables quick detection of misregistration, automatic calculation of appropriate cooling conditions for correcting misregistration, and a cooling roller. An object of the present invention is to provide a register correcting method and a register correcting device which can perform automatic control for setting the cooling condition.

[0006]

SUMMARY OF THE INVENTION To achieve the above objects, the present invention provides a method and apparatus for correcting misregistration by detecting a registration mark printed on both sides of a web after passing through a dryer and a cooling device. It has a configuration in which a web width is measured, a cooling condition of the cooling device for making the measured web width coincide with a target web width is calculated, and the cooling device is controlled based on the calculated cooling condition. According to the present invention,
Web width is measured by detecting register marks printed on both sides of the web after passing through a dryer and cooling device. Therefore, if the web width changes under the influence of the heat from the dryer and the cooling device, the measured web width includes the change, and furthermore, the misregistration due to the change in the web width occurs. In this case, the detection is performed promptly. Further, since the cooling condition of the cooling device that matches the measured web width with the target web width is calculated,
Appropriate cooling conditions for correcting misregistration are automatically obtained. Further, since the cooling device is controlled based on the calculated cooling condition, the correction of the misregistration is completely automated.

In the method and apparatus for correcting misregistration of the present invention, the target web width is measured by detecting a register mark printed on both sides of the web before passing through a dryer and a cooling device. Thus, according to the present invention, the measured web width is a target web width that does not change under the influence of heat from the dryer and the cooling device. Moreover, the process or means can be common to the process or means for detecting a change in web width,
The measurement accuracy of the change in the web width can be extremely improved. In the method and the device for correcting misregistration of the present invention, a cooling roller is used as a cooling device. The cooling roller can efficiently cool by contacting the web,
The misregistration correction can be performed promptly and accurately.

[0008]

Next, the present invention will be described by way of embodiments. FIG. 1 is a schematic diagram showing the configuration of the present invention together with two adjacent printing unit portions of a gravure printing machine. In FIG. 1, 101a, 101b are printing units, 102a, 102b are plate cylinders, 103a, 103
b is a plate cylinder side motor, 104 is a web, 105a,
105b, 106a, 106b, 107 and 108 are register marks, 109 and 110 are register mark detectors, 111 is a processing device, 112a and 112b are dryers, 113 is a transfer signal of the web 104, 114 is a compensator motor,
120 is a cooling roller, 121 is a cooling water inlet, 122 is a cooling water outlet, and 123 is a flow control valve.

[0009] The web 104 is transferred from the printing unit 101a to the printing unit 101b by a transfer device (not shown). In the printing unit 101a, printing is performed on the web 104 when the web 104 passes through the plate cylinder 102a. The register mark 105a and the register mark 106a on both sides of the web 104 are register marks printed by the plate cylinder 102a together with main print items (picture characters and the like).
After printing is performed by the plate cylinder 102a, the web 104 enters the dryer 112a. The dryer 112a blows hot air onto the web 104 to dry the transferred ink by printing. The heated web 104 passing through the dryer 112a contacts the cooling roller 120a and is cooled. Thereafter, the web 104 is guided by a guide roller and the printing unit 101 is moved.
b.

In the printing unit 101b, the web 1
In 04, printing is performed when the sheet passes through the plate cylinder 102b.
The register mark 107 and the register mark 108 on both sides of the web 104 are register marks that are printed by the plate cylinder 102b together with main print items (picture characters and the like). The register mark 105b and the register mark 106b are obtained by printing the register mark printed by the printing unit 101a on the printing unit 101b as the web 104 is transferred. The register mark 105b, the register mark 106b, the register mark 107, and the register mark 108 are printed at a predetermined interval on a predetermined portion of the web 104 when the print registration is correct. The register mark 105b and the register mark 107 on one side of the web 104 are
Register mark detector 1 provided above one side of
09 is detected. The register mark 106b and the register mark 108 on the other side of the web 104 are detected by a register mark detector 110 provided above the other side of the web 104. Then, the register mark detector 109 and the register mark detector 110 output a detection signal of the register mark to the processing device 111.

As shown in FIG. 1, the registration mark is detected by the register mark detector 109 and the register mark detector 110 after the web 104 is printed by the plate cylinder 102b and enters the dryer 112b. Before it is done. Therefore, the relative positions of the register mark 105b and the register mark 106b shown on the printing unit 101b are
It is a registration mark that may be displaced from a predetermined relative position defined by the plate cylinder 102a due to the dimensional change of the web 104 under the influence of heat by the dryer 112a and the cooling roller 120a after printing. . Further, the relative position between the register mark 107 and the register mark 108 is not affected by heat after printing, so that the web 104 does not change its dimensions, and is displaced from a predetermined relative position defined by the plate cylinder 102b. Being a mark is impossible.

The register mark detection signals input to the processing unit 111 are a register mark 105b detection signal, a register mark 107 detection signal, a register mark 106b detection signal, and a register mark 108 detection signal. Processing device 1
Reference numeral 11 denotes a transfer signal 11 indicating the transfer speed and transfer distance of the web 104 output by a rotary encoder or the like provided on a line shaft or the like of the printing press together with these four signals.
Enter 3. Based on them, signal and data processing is performed, and a misregistration (phase) in a direction parallel to the web transport direction, a misregistration (meandering) in a direction perpendicular to the web transport direction, and a misalignment in a direction perpendicular to the web transport direction are performed. Deriving the distance (web width). Furthermore, based on the derived data, the amount of operation for optimizing them is derived,
The output is output to the flow control valve 123 of the printing unit 101a, the plate cylinder side motor 103b of the printing unit 101b, and the compensator motor 114 between the printing units.

FIG. 1 shows the relationship between the upstream printing unit 101a and the immediately downstream printing unit 101b, but this relationship can be extended to all printing units adjacent upstream and downstream. it can. For example, for a printing unit immediately downstream of the printing unit 101b, the printing unit 101b is
The position is the same as 1a. The printing unit 10
With respect to the upstream printing unit adjacent to 1a, the printing unit 101a has the same position as the printing unit 101b.

Next, a processing system for correcting misregistration will be described. FIG. 2 is a block diagram showing an example of the configuration of a processing system for correcting misregistration in the present invention. 2, reference numeral 201 denotes a processing device for performing signal processing and data processing (the processing device 111 in FIG. 1); 202, a register scanning head (register mark detectors 109 and 110 in FIG. 1);
Reference numeral 03 denotes a web transfer detector for detecting a web transfer speed and a transfer distance (outputs the transfer signal 113 in FIG. 1), 204 denotes a plate cylinder side motor (103b in FIG. 1), and 205 denotes a compensator motor (compensator in FIG. 1). Motor 11
4) and 206 are cooling water flow valves (cooling water flow valve 123 in FIG. 1). Further, the processing device 201 has a further detailed configuration, 207 is a register control device, and 208 is an arithmetic device.

The register control device 207 of the processing device 201
A register mark detection signal output by the register scanning head 202 and a web transfer signal output by the web transfer detector are input. Then, the operation amount for correcting the misregistration (meandering) to the plate cylinder side lay motor 204 and the compensator also output the operation amount for correcting the misregistration (phase) to the data 205. Further, the register control device 206 outputs the amount of register shift (change in web width) to the arithmetic device 207 of the processing device 201. The arithmetic unit 207 outputs an operation amount for correcting a change in the web width to the cooling water flow valve 205.

Next, a process of correcting a misregistration will be described. FIG. 3 is a flowchart showing an example of the process of correcting a misregistration in the present invention. Misregistration (phase, meandering) can be detected only from the registration marks on one side of the web (details will be described later). First, in step S301, the register scanning head 202
The register control device 206 calculates the amount of misregistration (phase, meandering) based on the detection signal of the register mark on the man side (operating side) output by the controller. The amount of misregistration (phase, meandering) obtained here is used in steps S302, S305, and S309, and the processing after each step is performed simultaneously. Next, step S30
In 2, the register control device 206 determines the presence or absence of a register shift (phase). If there is a register shift (phase), the process proceeds to step S303. If there is no register shift (phase), the process returns to step S301 and returns to step S301. repeat.

In step S303, the register control unit 206 calculates a moving direction and a moving amount (time) of the compensating roller for correcting a register shift (phase). Next, in step S304, the register control device 206 outputs the operation amount to the compensator motor 205 and moves the compensator by the calculated movement amount. Then, step S3
Return to 01 and repeat the above. In step S305 simultaneously with the correction of the register shift (phase), in step S305, the register control device 206 determines whether there is a register shift (meandering).
If there is a misregistration (meander), the process proceeds to step S306. If there is no misregistration (meander), the process proceeds to step S301.
Return to and repeat the above.

In step S306, the register control unit 206 calculates the moving direction and the moving amount (time) of the plate cylinder for correcting the misregistration (meandering). Next, step S3
At 07, the register control unit 206 outputs the operation amount to the plate cylinder side lay motor 204 and moves the plate cylinder by the calculated movement amount. Then, the process returns to step S301 to repeat the above.

On the other hand, in step S308, the register control device 20 receives the detection signal of the register mark on the gear side (operation side) output from the register scanning head 202.
Numeral 6 calculates the amount of misregistration (meandering). This step S3
08 and the aforementioned step S301 are processed simultaneously. Next, in step S309, the register control device 2
06 outputs the manside (operation side) misregistration amount (S
The arithmetic unit 208 inputs the amount of misregistration (meandering) on the gear side (mechanical side) and the gear side (mechanical side), and computes the difference between the misregistration amounts (web register).

Next, in step S310, the arithmetic unit 208 determines whether there is any misregistration (web width). If there is misregistration (web width), the process proceeds to step S311 where there is no misregistration (web width). If so, step S3
Return to 01 and repeat the above. In step S311, the arithmetic unit 208 calculates a cooling water flow rate change amount (valve opening / closing amount). Next, in step S312, the arithmetic unit 208 outputs an operation amount to the cooling water flow valve 206, and opens and closes the valve by the calculated opening and closing amount. Next, in step S313, the arithmetic unit 208 calculates and recognizes the next control timing. When the next control timing is recognized, the process returns to step S308 to repeat the above.

The processing for correcting the misregistration has been described above. Next, the calculation performed by the arithmetic unit 208 will be described. First, an example of a method of calculating the cooling water flow rate change amount (valve opening / closing amount) will be described. The calculation of the cooling water flow rate change amount (valve opening / closing amount) can be performed, for example, by the following mathematical expression 1.

A = K1 × H × L × ΔEn × ΔT × R × S × Wt where A: Cooling roller valve opening / closing amount K1; Coefficient H; Constant relating to web width (paper width) L; Constant for the contact path length ΔEn; lateral register shift amount due to web width change ΔT; cooling roller temperature change amount R; constant for current value of cooling roller temperature S; constant for web transfer speed Wt; constant for cooling water temperature

Next, an example of a method of calculating a control cycle performed by the arithmetic unit 208 will be described. The calculation of the control cycle can be performed, for example, by the following mathematical formula 4.

T = K2 × (h × ΔA + P × S) where: t; control period K2; coefficient h; response speed of changing the opening / closing amount of the cooling roller valve ΔA; Constant for inter-path length S; Constant for web transfer speed

Here, an example of a method for detecting the above-mentioned misregistration (width, transfer, meandering) will be specifically described. FIG. 4 is a diagram showing a triangular register mark as an example of the register mark. FIG. 4A shows the principle of detecting a register shift due to a change in web width together with a triangular register mark. FIG. 4B shows the principle of detecting a register shift due to a phase change and a register shift due to meandering, together with a triangular register mark. This register mark can be detected by an optical register mark detector having a light projecting part and a light receiving part. The register mark detector detects reflected light in a small detection area, and outputs a detection signal for distinguishing whether the detection area is outside or inside the register mark based on a change in the intensity of the reflected light.

In FIG. 4A, the register mark and the register mark are the register marks on the left side of the web, and are detected by the register mark detector 109. The register mark and a straight line crossing the register mark are the register mark detector 109.
Is shown. The register mark and the register mark are register marks on the right side of the web, and are detected by the register mark detector 110. The register mark and a straight line crossing the register mark indicate the detection trajectory of the register mark detector 110. All of the register marks to register marks are register marks printed by the plate cylinder 102a of the printing unit 101a. As shown, the register mark is a right-angled triangle having an angle θ.

It is assumed that the positional relationship between the register mark on the left side of the web and the register mark on the right side of the web is proper. The interval between the register marks at that time is a predetermined distance W1 in the web width direction. At this time, the crossing distance a of the register mark is calculated by the processing device 111 from the detection signal of the register mark detector 109 and the transfer signal 113, and the detection signal of the register mark detector 110 and the transfer signal 1 are calculated.
From 13, the crossing distance b of the register mark is calculated by the processing device 111. Then, the time elapses, the interval between the register mark and the register mark becomes W2, and the crossing distance c of the register mark is calculated by the processing device 111 from the detection signal of the register mark detector 109 and the transfer signal 113,
The crossing distance d of the register mark is calculated by the processing device 111 from the detection signal of the register mark detector 110 and the transfer signal 113.

In this case, change in web width (W2-W1)
Has the mathematical relationship shown in the following Expression 3, and can be calculated by the processing device 111.

(W2−W1) = (abc + d) / tan θ

In FIG. 4B, the register marks to register marks are all register marks on the left side of the web (or all right sides of the web) and the register mark detector 109.
(Or register mark detector 110). A straight line that crosses the register mark to the register mark is a register mark detector 109 (or a register mark detector 11).
0) shows a detection trajectory. Note that it is clear that the description before the parentheses () and the description inside the parentheses () are equivalent by always taking one, so in the following description, the description inside the parentheses () is omitted for convenience. I do. The register mark and the register mark are the plate cylinder 10 of the printing unit 101a.
2a is a register mark printed by the printing unit 101a.
It is a register mark printed by 2a. As shown, the register mark is a right-angled triangle having an angle θ.

It is assumed that the positional relationship between the register mark and the register mark is proper. The interval between the register marks and the direction (phase) parallel to the web transport direction of the register marks is a predetermined distance H1, and the interval in the direction (meandering) orthogonal to the web transport direction is the predetermined distance D1. At that time, the detection signal of the register mark detector 109 and the transfer signal 11
From 3, the crossing distance e of the register mark, the crossing distance f of the register mark, and the distance H1 are calculated by the processing device 111. Then, as time elapses, the interval between the register mark and the register mark in the direction (phase) parallel to the web transport direction becomes H2, and the direction perpendicular to the web transport direction (meandering).
Is a predetermined distance D2. Further, the crossing distance g of the register mark, the crossing distance h of the register mark, and the distance H2 are calculated from the detection signal of the register mark detector 109 and the transfer signal 113 by the processing device 111.

In this case, the phase change (H2-H1) is
Since H2 and H1 have already been obtained, the calculation can be immediately performed by the processing device 111. Further, the meandering interval (D2−D1) has a mathematical relationship represented by the following Expression 2, and can be calculated by the processing device 111. Note that D1
Is usually made to be zero in a state where there is no misregistration, but it is sufficient that the plate is almost zero, and it is not necessary to be exactly zero.

(D2−D1) = (ef−g + h) / tan θ

Although the present invention has been described with reference to the embodiment, the present invention is not limited to this embodiment, but can be carried out in various forms in the technical idea of the present invention. It is included in the invention. For example, although a cooling roller has been described as a cooling device, the present invention is not limited to this. A cooling device such as an air cooling fan that blows cooling air may be used, or a combination of a cooling roller and an air cooling fan or another cooling device may be used. A combination of a cooling device and a heating device may be used. By using them together, the responsiveness and stability of the control can be improved. Further, instead of controlling the flow rate of the cooling water of the cooling roll, the temperature of the cooling water may be controlled by a heater and a cooler. In the present invention, the web width is controlled by printing paper, synthetic paper, nonwoven fabric, plastic film such as polyvinyl chloride or polyethylene, metal foil such as aluminum foil, or a sheet or film of a composite material thereof, There is no particular limitation.

[0031]

As described above, according to the present invention, regarding the misregistration due to the change in the web width, the speed of detection when the misregistration occurs and the appropriate cooling conditions for correcting the misregistration are determined. A register correcting method and a register correcting device capable of performing automatic calculation and automatic control for setting a cooling roller to its cooling condition are provided. The present invention also provides a method for measuring a target web width by detecting a web width measuring means or a web width measuring process by detecting register marks printed on both sides of the web together with the web width before passing through a dryer and a cooling roller. Thus, the measured web width is a target web width that does not change under the influence of heat from the dryer and cooling rollers, and the process or means is a process or means for detecting a change in web width. Therefore, the measurement accuracy of the change in the web width can be extremely improved. Further, according to the present invention in which the cooling roller is used as the cooling device, the cooling roller can efficiently cool by contacting the web, and can correct the misregistration quickly and accurately.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a configuration of the present invention together with two adjacent printing unit portions of a gravure printing press.

FIG. 2 is a block diagram illustrating an example of a configuration of a processing system that corrects misregistration in the present invention.

FIG. 3 is a flowchart illustrating an example of a process of correcting a misregistration in the present invention.

FIG. 4 is a diagram showing a triangular register mark as an example of a register mark.

[Explanation of symbols]

101a, 101b Printing units 102a, 102b Plate cylinders 103a, 103b, 204 Plate cylinder side motor 104 Webs 105a, 105b, 106a, 106b, 107, 1
08 Register mark 109, 110 Register mark detector 111, 201 Processing unit 112a, 112b Drying unit 113 Transfer signal 114, 205 Compensator motor 120 Cooling roller 121 Cooling water inlet 122 Cooling water outlet 123 Flow control valve 202 Register scanning head 203 Web transfer Detector 206 Cooling water flow valve 207 Register control device 208 Computing device

Claims (6)

[Claims] 1. A web width measuring step of measuring a web width by detecting register marks printed on both sides of a web and passing through a dryer and a cooling device; and measuring the measured web width with a target web width. A register misregistration method comprising: a cooling condition calculating step of calculating a cooling condition of the cooling device to be matched; and a cooling device control step of controlling the cooling device based on the calculated cooling condition. 2. The web width measuring step includes measuring the target web width by detecting a register mark printed on both sides of the web together with the web width before passing through a dryer and a cooling device. The method for correcting misregistration according to claim 1, wherein: 3. A method according to claim 1, wherein said cooling device is a cooling roller. 4. A register correcting device comprising a web width measuring means, a cooling condition calculating means, and a cooling device control means, wherein the web width measuring means is printed on both sides of the web, and includes a dryer and a cooling device. Measuring the web width by detecting the register mark after passing through, the cooling condition calculating means calculates the cooling condition of the cooling device such that the measured web width is a target web width, The register correction device, wherein the cooling device control means controls the cooling device based on the calculated cooling condition. 5. The web width measuring means measures the target web width by detecting a register mark printed on both sides of the web together with the web width before passing through a dryer and a cooling device. The register correcting device according to claim 4, characterized in that: 6. A register correcting device according to claim 4, wherein said cooling device is a cooling roller.