JP3952095B2 - Automatic registration adjustment method in multi-color printing press - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
According to the present invention, in a multi-color form printing machine, each registration mark printed by each printing unit is imaged by a camera, and the control device automatically performs registration based on the imaging signal. The present invention relates to an automatic register adjustment method.
[0002]
[Prior art]
In the conventional automatic registration adjustment method using this type of camera, one area camera is used, a registration mark is captured within a limited field of view by this one area camera, for example, 15 mm square, The amount of color misregistration and the direction for correcting misregistration are detected for each color, and based on the detection results, the registration of all colors is matched by moving the plate cylinder of each color to eliminate misregistration from the reference color. ing.
[0003]
In this case, for example, in the case of four-color printing, as shown in FIG. 1, the two opposite circles on the intersection of eight equal angles on the circumference are made into one color mark, and this is the above-mentioned mark. It is placed in a 15 mm square camera field of view, and circles of each color are equally arranged on the circumference to recognize that they are in register. This registration mark is so small that it does not stand out even if it enters the pattern. For example, a mark having a diameter of 0.3 mm on a circumference of 2 mm is used.
[0004]
[Problems to be solved by the invention]
In a multi-color form printing machine, when the plate cylinder is changed by resizing, etc., it is necessary to make coarse adjustments so that the registration marks for each color are focused in the inspection area within the camera field of view. However, this rough adjustment has to be performed manually by an operator, so that there is a problem that the printing preparation time becomes long, the amount of waste paper increases, and the production efficiency does not increase.
[0005]
The present invention has been considered in view of the above, and automatic registration adjustment in a form printing machine in which registration in a multi-color form printing machine can be completely automated from coarse adjustment to fine adjustment. It is intended to provide a method.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, an automatic registration adjustment method in a multi-color printing press according to the present invention images a registration mark of each picture to be multi-colored printed on continuous paper with a camera, and based on this imaging signal, In an automatic registration adjustment method in a multi-color printing press in which each printing section is registered via the printing registration adjustment means of each color printing section in the control device, the registration mark of each picture is imaged by a line camera. seeking centroid position of each register mark in the signal, performs coarse adjustment by moving the register mark to a predetermined position relative to the print reference point as the centroid coincides in each register mark, then register mark this coarse adjustment Are imaged by an area camera, and fine adjustment is performed so that the centroid positions of the register marks completely coincide with each other using the image signal.
[0007]
Also, in the above-described automatic registration adjustment method in a multicolor printing press, the registration marks of each pattern are made of dumbbells with circles on both ends of a straight line, and each color is horizontal, vertical, right slope, left slope It was printed with different postures.
[0008]
Further, in the automatic register adjustment method in the multi-color printing press, among the register marks of each pattern, each register mark of the pattern from the first color to the fourth color is formed in a dumbbell shape with circles at both ends of the straight line. The printing was performed with different colors such as horizontal, vertical, right-tilt, left-tilt, etc. for each color, and the register mark of the fifth color pattern was rectangular.
[0009]
[Operation]
The line camera scans the entire width of the continuous paper and images registration marks of each pattern printed at an arbitrary position. Then, in the image signal picked up by this line camera, the print cylinder is adjusted by the printing register adjusting means so that the centroid positions of the register marks coincide with each other, and rough adjustment of the register is performed. .
[0010]
Next, the area camera captures each of the coarsely adjusted registration marks in the camera area, and finely adjusts the centroid positions of the respective registration marks by using the image pickup signal.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to FIG. In the figure, reference numerals 1a, 1b, 1c, 1d, and 1e denote first to fifth printing sections of a form printing machine for printing five colors on the continuous paper 2, each of which includes a plate cylinder 3 and an impression cylinder 4. ing. The cylinders 3 and 4 of the printing units are connected to a drive source (not shown) and rotate in synchronization with the running speed of the continuous paper 2 so that the images of the printing plates mounted on the plate cylinders 3 correspond to the respective colors. Printed. The plate cylinders 3 of the printing units 1a to 1e can be moved in the rotation direction and the axial direction by the respective printing register adjusters 5a, 5b, 5c, 5d, and 5e using a servo motor or the like. Yes.
[0012]
Downstream of the printing units 1a to 1e, a speed detector 6 that detects the running speed of the continuous paper 2, a line camera 7 that uses the entire width of the continuous paper 2 as an imaging area, and a part of the continuous paper 2 in the width direction. For example, an area camera 8 having an image pickup area on one side and outside the vertical perforation is disposed to face the continuous paper 2. Reference numeral 9 denotes illumination for brightening the imaging surfaces of the cameras 7 and 8. Reference numeral 10 denotes a register adjustment control device, which includes a signal input circuit 10a, a comparison operation processing circuit 10b, a cpu 10c, and the like.
[0013]
FIG. 3 shows first, second, third, fourth, and fifth registration marks 11a, 11b, 11c, 11d, and 11e printed by the first to fifth printing units 1a to 1e. Among them, the first to fourth registration marks 11a to 11d are dumbbells having circles at both ends of the straight line, and the fifth registration mark 11e is rectangular. The first register mark 11a is, for example, horizontal (the width direction of the continuous paper 2), the second register mark 11b is vertical (the running direction of the continuous paper 2), the third register mark 11c is inclined to one side, The register mark 11d is inclined to the other side.
[0014]
In each of the registration marks 11a to 11e, the first to fourth registration marks 11a to 11d are longer than the third registration mark 11c in the length of the first registration mark 11a and the second registration mark 11b. The register mark 11c is longer than the fourth mark 11d. The size of the fifth register mark 11e is larger than the circles provided at both ends of each straight line of the first to fourth register marks 11a to 11d.
[0015]
The registration marks 11a to 11e are printed at predetermined positions with respect to the patterns printed by the printing units 1a to 1e, and the centroids coincide with each other as shown in FIG. When the printing is performed in a state, the images of the printing units 11a to 11e are in register. Each of the registration marks 11a to 11e is printed on one side in the width direction of the continuous paper 2 outside the vertical perforation 2a as shown in FIG. 5, for example, and the area camera 8 is opposed to this portion. ing. In addition, the line camera 7 scans the entire width of the continuous paper 2 on the upstream side to detect the registration marks 11a to 11e.
[0016]
Next, an automatic register adjusting method using the automatic register adjusting apparatus having the above configuration will be described.
[0017]
When five-color printing is performed on the continuous paper 2 by the printing units 1a to 1e, the registration marks 11a to 11e are printed for each pattern of each color. At this time, if the patterns do not match, for example, if the patterns are shifted little by little in the running direction (and slightly shifted in the width direction of the continuous paper 2), the registration marks 11a to 11e at this time are shown in FIG. As shown in FIG. It is assumed that the print areas of the registration marks 11a to 11e at this time are wider than the imaging area of the area camera 8.
[0018]
In this state, the registration marks 11 a to 11 e are imaged by the line camera 7. Each registration mark imaged by the line camera 7 is input to the registration adjustment control device 10 and recognized as position information in the running direction (and width direction) of the continuous paper 2 for each registration mark. Note that the traveling speed of the continuous paper 2 at this time is detected by the speed detector 6.
[0019]
The registration adjustment control device 10 recognizes the shape and position information of each of the registration marks 11a to 11e by an input signal from the line camera, and then corrects coordinates for matching the centroids of the registration marks 11a to 11e with respect to the printing reference position. Is calculated. At this time, for example, the first registration mark 11a may be used as a reference.
[0020]
The calculated numerical values of the corrected coordinates of the registration marks 11a to 11e are output as movement signals (data communication or the like) to the printing registration adjusters 5a to 5e of the printing units 1a to 1e. As a result, the phase in the rotational direction and width direction of each plate cylinder 3 in each printing unit is moved and adjusted in a direction that converges toward a predetermined position with respect to the printing reference position. At this time, the registration accuracy becomes rough due to the resolution of the line camera 7.
[0021]
Next, the registration marks 11 a to 11 e moved to predetermined positions with respect to the print reference position by the rough adjustment are imaged by the area camera 8. Each registration mark imaged by the area camera 8 is input to the registration adjustment control device 10 and recognized as position information for matching the centroids of the respective registration marks.
[0022]
The registration adjustment control device 10 recognizes the shape and position information of the registration marks 11a to 11e, and then calculates the corrected coordinates of the registration marks 11a to 11e with respect to the print reference position. The calculated correction coordinates of the registration marks 11a to 11e are output as movement signals (data communication or the like) to the printing registration adjusters 5a to 5e of the printing units 1a to 1e, and the printing units 1a to 1e are output. The plate cylinder 3 is moved, and the registration marks 11a to 11e are finely adjusted so that their centroids coincide as shown in FIG. Since the resolution of the area camera 8 at this time is higher than that of the line camera 7, precise adjustment is performed.
[0023]
The registration marks used in the method of the present invention are the registration marks 11a to 11d with circles at both ends of a straight line and the square registration marks 11e. For example, as shown in FIG. Even when 11e overlaps, the registration adjustment can be performed by the resolution processing of imaging by the next area camera 8.
[0024]
【The invention's effect】
According to the present invention, since the rough adjustment of the registration adjustment in the multicolor printing is automatically performed, the registration in the multicolor printing can be completely automated. The number of steps can be omitted, the printing preparation time can be shortened, and the number of waste paper can be reduced, thereby improving the production efficiency.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing an example of a conventional register mark.
FIG. 2 is a schematic configuration explanatory diagram of an apparatus for carrying out the method of the present invention.
3 (a), (b), (c), (d), and (e) are registration marks used in the method of the present invention.
FIG. 4 is an explanatory diagram showing a state in which the centroids of the register marks coincide with each other.
FIG. 5 is an explanatory diagram showing a state in which each register mark is printed on a continuous sheet.
FIG. 6 is an explanatory diagram showing an example of a coarsely adjusted register mark.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1a, 1b, 1c, 1d, 1e ... Printing part, 2 ... Continuous paper, 3 ... Plate cylinder, 4 ... Impression cylinder, 5a, 5b, 5c, 5d, 5e ... Printing registration adjuster, 6 ... Speed detector, 7 ... Line camera, 8 ... Area camera, 9 ... Light, 10 ... Registration adjustment control device, 11a, 11b, 11c, 11d, 11e ... Registration mark.

Claims (3)

A register mark of each pattern printed on a continuous sheet of paper is imaged by a camera, and based on this imaging signal, each control unit performs registration of each printing unit via a printing register adjusting unit of each color printing unit. the automatic registration adjustment process in the multi-color printing machine, so as to image the register mark of each picture by the line camera, obtains the centroid position of each register mark at the imaging signal, centroid of each register mark matches The register mark is moved to a predetermined position with respect to the printing reference point, and coarse adjustment is performed.Then, the coarsely adjusted register mark is imaged by an area camera, and the centroid position of each register mark is completely detected by this imaging signal. An automatic register adjustment method in a multi-color printing press, wherein fine adjustment is performed so as to match. The registration marks of each pattern are printed in dumbbells with rounded ends on a straight line, and each color is printed with different postures such as horizontal, vertical, right slope, left slope, etc. Item 2. An automatic register adjustment method for a multicolor printing machine according to Item 1. Among the registration marks for each pattern, the registration marks for the 1st to 4th colors are made of dumbbells with circles at both ends of the straight line, and each color has a horizontal, vertical, and right slope. 2. The automatic register adjustment method for a multi-color printing press according to claim 1, wherein printing is performed while changing the posture such as left-inclination and the like, and the registration mark of the fifth color image is rectangular.

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