JPH04244850A - Registering apparatus of printing press - Google Patents

Abstract

PURPOSE:To automatically perform registering without looking printed matter by detecting the position of the register mark on the surface of a plate and the rotary position of a printing cylinder. CONSTITUTION:A means 8 detecting the rotary position of a plate cylinder 1 of each color or the rotary positions of both of the plate cylinder 1 and an impression cylinder 3, a means operating the shift quantity of the rotary position of the plate cylinder 1 of each color from the detected position or the shift quantities of the rotary positions of both cylinders 1,3 from the detected positions, a means 7 detecting the register mark on the surface of the plate of each color plate cylinder and a means operating the shift quantity of the position of each color Plate surface from the detected position of the mark are provided. Next, from the rotary position shift quantity, the register mark shift quantity and a preliminarily inputted shift quantity judging standard, it is judged whether shift quantity is corrected by a judging means. The shift quantity is corrected on the basis of the signal of the judging means.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a register adjustment device for printing machines.

0002

2. Description of the Related Art Conventional register adjustment involves visually inspecting the register marks or patterns on printed matter, manually adjusting the amount of deviation, and repeating this process several times. Recently, devices have also appeared that extract the printed matter, measure the amount of misalignment of the register mark with a sensor, and make offline adjustments.

0003

The register adjustment work, which is mainly performed when changing printing plates, is a very time-consuming work that accounts for 20 to 30% of the printing preparation process. The main reason for this is to visually check the overlap of each color of the registration marks on the printed matter, recognize the amount of adjustment, and make adjustments. This is what is called manual adjustment. Moreover, it is rare for adjustments to be completed in one go, and the method is to repeat the adjustment little by little over and over again. As a result, the time required for adjustment work and the amount of paper waste increase, which becomes a bottleneck in the printing process.

[0004] Furthermore, the method of measuring the register marks on printed matter with a sensor and adjusting it off-line also has a drawback in terms of the accuracy of the sensor that separates colors, and although it is possible to shorten the time slightly, it is not sufficient in terms of automation. Not. SUMMARY OF THE INVENTION An object of the present invention is to provide a register adjustment device capable of shortening the time required for register adjustment work performed when exchanging printing plates in a printing machine, and further automating the register adjustment work.

[0005]

[Means for solving the problem] The printing cylinders of printing machines, that is, the plate cylinder, blanket cylinder, and impression cylinder, are basically connected by gears. There will be no madness. In other words, it is sufficient that the rotational position of the plate cylinder and the position of the printing plate match. Based on this idea, we measured the rotational position of each color plate cylinder using a high-frequency encoder, etc., and on the other hand, in order to understand the plate surface position, we measured the register mark on the plate surface in each place with a camera or photo sensor, and calculated the difference between the two. The amount of misregistration is automatically adjusted vertically and horizontally while driving.

[0006]

[Operation] By measuring the rotational position of the printing cylinder for each color and the rotational position of the register mark on the printing plate (the deviation between the two for each color is the registration adjustment amount), automatic adjustment is possible. As a result, register adjustment is automatically completed in a few turns after the printing plate is installed. Further, even if a rotational misalignment occurs between the printing cylinders for some reason, adjustment can be made by detecting the rotational position of each printing cylinder, and the registration adjustment time in the printing process can be greatly reduced. Moreover, it can be adjusted every rotation, and almost no paper waste occurs.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. 1 to 8. This example is an example in which no rotational deviation occurs in each printing cylinder. Although this register adjustment device can be applied to multicolor printing of two or more colors, two-color printing will be explained here. A printing unit generally includes a plate cylinder 1, a blanket cylinder 2, an impression cylinder 3, and an intermediate cylinder 4 that connects the units. The register adjustment device according to the present invention includes a camera or photosensor 7 for detecting the position of the register mark on the plate surface of the first color printing unit 5 and the second color printing unit 6, and a rotational position detection of the plate cylinder 1 in the printing unit. Attach the high frequency encoder 8. In the pictorial processing of the detection results, as shown in FIG. 2, the amount of misregistration is determined from the respective positions of the register mark and the rotation of the plate cylinder, and the allowable value is determined. An example of the amount of misregistration in FIG. 2 is shown in FIG. If the amount of misregistration is greater than the allowable value, perform register adjustment. Moreover, if it is within the allowable value, each position is detected again in order to detect the deviation of the next rotation.

This situation is shown in FIGS. 3 and 4. This diagram is 1
This is a case where the positions of the plate cylinders 1 for each color and the second color are synchronized. When the photo sensor 7 scans the register mark in the vertical direction, the register mark pulses A, A, and C in the figure are detected. This is the same for the second color, and if this is synchronized with the rotation pulses of the first and second colors, there will be no misregistration. When a misregister occurs, the pulse of the register mark deviates from the rotation pulse. Therefore, it is possible to verify this amount of deviation from the rotation pulse interval and use it as the amount and direction of register correction.

Furthermore, even if the first and second color printing cylinders 1 are not synchronized, the amount and direction of misregistration can be similarly determined by verifying the amount of offset between the printing cylinders. This situation is shown in FIG. Next, the adjustment of left and right register will be explained with reference to FIGS. 6 and 7. By using the register marks as shown in FIG. 6, the left and right registers can be easily adjusted. If there is a left-right misregistration, each print color scans positions such as A, B, and C in FIG. 7. If the registration standard is B, the misregistration at position A is (l2 −
l1 ), and the misregistration at position C is (l2 - l3
) amount, and this amount can be used as the correction amount.

The register mark used in the present invention does not need to be a particularly complicated mark, and may be a commonly used mark. However, in order to adjust the left and right register, a diagonal line is required. An example of the register mark is shown in FIG. 8, but various other marks are possible. In the first embodiment described above,
Although the case has been described in which the plate cylinder 1, blanket cylinder 2, and impression cylinder 3 of the printing unit are in a synchronized state, so-called rotational deviation does not occur, there may be a case where, for some reason, for example, the impression cylinder 3 causes rotational deviation. In this case, register adjustment is difficult with only the rotational position of the plate cylinder 1.

FIG. 9 shows a second embodiment. In this embodiment, a high frequency encoder 9 similar to that of the plate cylinder 1 is attached to the impression cylinder 3 in order to detect the amount of rotational deviation, thereby correcting the amount of deviation. The arithmetic processing in this case is as shown in FIG. An example of the misregistration in FIG. 8 is shown in FIG. 12. Note that according to the present invention, it is also possible to detect the rotational positions of all printing cylinders, including the plate cylinder, blanket cylinder, and impression cylinder.

0012

[Effects of the Invention] The register adjustment device for a printing press according to the present invention has the following features:
means for detecting the rotational position of the plate cylinder of each color or the plate cylinder and the impression cylinder; means for calculating the amount of rotational position deviation between the plate cylinder of each color or the plate cylinder and the impression cylinder from the detected position; A plate registration mark detection means, a means for calculating the positional deviation amount of each color plate from the same mark detection position, and a deviation amount from the rotational position deviation amount, the registration mark deviation amount, and a deviation amount judgment criterion input in advance. By providing means for determining whether or not correction is possible, and means for correcting the amount of deviation based on a signal from the determining means, the following effects are achieved.

[0013] By detecting the position of the register mark on the printing plate and the rotational position of the printing cylinder, the amount of misalignment is determined and the register is adjusted, so it is possible to automatically adjust the register without looking at the printed material. It is possible to register from the print of the eyes. Furthermore, in order to detect the register marks on the printing plate, existing inexpensive measuring instruments can be used instead of special measuring instruments such as photosensors or monochrome cameras required for color separation of the register marks on printed matter.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a first embodiment of the present invention.

FIG. 2 is an arithmetic processing diagram of the device shown in FIG. 1;

FIG. 3 is an explanatory diagram of registration marks and misregistration in the vertical direction.

FIG. 4 is a diagram showing the relationship between the rotation pulse of the plate cylinder and the pulse of the register mark, in the case where the plate cylinder positions of the first color and the second color are synchronized.

FIG. 5 shows a case where the plate cylinder positions of the first color and the second color are not synchronized in FIG. 4.

FIG. 6 is a diagram showing register marks in the left and right direction.

FIG. 7 is a state diagram for performing register adjustment in the left and right direction.

FIG. 8 is a schematic diagram of a register mark used in the present invention.

FIG. 9 is a configuration diagram of a second embodiment of the present invention.

FIG. 10 is a calculation processing diagram of the device shown in FIG. 9;

FIG. 11 is an illustration of misregistration in FIG. 2;

FIG. 12 is an illustration of misregistration in FIG. 10;

[Explanation of symbols]

1 Plate cylinder 5 1st color printing unit 6 2nd color printing unit 7. Camera or photo sensor 8 High frequency encoder

Claims (1)

[Claims] 1. Means for detecting the rotational position of the plate cylinder of each color or the plate cylinder and the impression cylinder, and means for calculating the amount of rotational position deviation between the plate cylinder of each color or the plate cylinder and the impression cylinder from the detected position. , means for detecting a plate cylinder register mark on each color plate cylinder, means for calculating the amount of positional deviation of each color plate from the same mark detection position, and a means for determining the amount of rotational positional deviation and the amount of registration mark deviation, and the amount of deviation inputted in advance. 1. A register adjustment device for a printing press, comprising: means for determining whether or not the amount of deviation can be corrected based on a reference; and means for correcting the amount of deviation based on a signal from the determining means.