JPS6391253A - Registering method of offset printer and its device - Google Patents

Abstract

PURPOSE:To enable correct registering operation by comparing a positional relationship between the centers of registering marks of each color printing plate and a trial print by using a computer to obtain a deflection value and actuating a registering adjustment device for the correction of the deflection value. CONSTITUTION:The related positions between the centers of registering marks written in each color printing plate are stored in a computer beforehand, and the related positions between the centers of the registering marks are entered into the computer by placing a trial print on a table 2. After this, the related position between the centers of both registering marks is compared to calculate a deflection value. Then a signal based on this deflection value is entered into a registering adjustment device 22 of a printer from the computer 21, and said device is actuated for registering operation. Consequently, no optical sensor for registering-mark reading which requires a high-precision installation position is necessary, and besides, accurate registering is ensured.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to a method and apparatus for registering an offset printing press.

Conventional technology In modern offset printing, it is desired to shorten the setup time as the number of printed sheets decreases. It will be done.

Various methods have been proposed in the past to shorten the registration time in these operations, but the typical one is shown in Figure 6, and an overview thereof will be explained below. do.

In this method, the printing plate 3 mounted on the first plate cylinder 30, 31
2. Burn registration marks 34°35 into 33 in advance,
The position of this mark 34, 35 is read by an optical sensor 36, 37 during low-speed rotation before printing, and the top, bottom, left and right of the plate cylinder are adjusted by pulse motors 39, 40 via the register adjustment device 38 of the first plate cylinder 32.

This is an attempt to make a twist adjustment. Furthermore, 41.4
2, 43 indicates a proximity switch.

Problems to be Solved by the Invention However, in such a method, Senna 36,
The accuracy of the mounting position of 37 must be made to be suitably high, and to date, no satisfactory one has been provided.

The present invention eliminates the disadvantages of the conventional registration method as described above, and eliminates the need for an optical sensor for reading registration marks that requires a highly accurate mounting position (and does not require accurate registration). The object of the present invention is to provide a registration method and device for the same.

Means for Solving the Problems In order to achieve the above-mentioned object, the present invention writes register marks for each color at positions that do not overlap each other by 1jL on each color printing plate, and writes positional marks between the centers of these register marks. The relationship is stored in the computer in advance, and then a test print printed by the printing plate is placed on this table, the center position of the register mark is determined, and the positional relationship between the centers and the previously memorized register are determined. This method is characterized in that a computer compares the positional relationship between the centers of the marks to determine a deviation value, and the computer operates a register adjustment device to correct this deviation value.

Furthermore, this invention achieves the above objects,
The registration device includes a table and a machine base having an image input camera installed horizontally movably above the table, a registration adjustment device for the printing press, and a computer, and the computer is located at the center of each color registration mark. The position information is stored, and the center position information of each color registration mark of the trial print inputted from the same camera is compared with this stored information, the deviation value is calculated, and the registration adjustment device is adjusted based on this deviation value information. The invention is characterized in that it operates to correct.

Embodiment FIG. 1 shows an outline of an embodiment of the present invention.
21 represents a machine stand, 21 represents a computer, and 22 represents a register adjustment device of the printing press.

In this embodiment, a pair of guide rails 8 are provided on both sides of the upright part 3 on one machine l in a direction perpendicular to the upright part 3.
A support member 9 having both ends movable in the Y-axis direction is provided above the table 2, and a pair of image input cameras 5 are installed on this support member 9 so as to be movable in the X-axis direction. There is.

The support member 9 has a pair of first/arm motors 6 for individually moving the camera 5 in the X-axis direction, and a second arm motor 6 for moving the support member 9 in the Y-axis direction. 7 are set up for each.

In the computer 21 shown in FIG. 1, 23 is an information processing section from the camera 5, which inputs information from the 24Fi processing section 23 and processes the information from the register adjustment device 22 based on the input information.
25 shows a control section consisting of a storage section, a comparison section, and an arithmetic section that operate the control operation.

The register adjustment device 22 may be completely similar to the conventional adjustment device 38, so detailed explanation thereof will be omitted.

A registration method performed by the above-mentioned registration device will be explained.

Fig. 5 shows an example of the register marks used in this registration method on a four-color machine, and 26.27°, 28.29 are those printed on the corner plate, the square plate, the flat plate, and the plate, respectively. This is the position where the paulownia is placed so that it does not overlap when it is inserted into a printed matter.

Regarding such register marks 26.27, 28.29,
The positional relationship between those centers is stored in the control unit 24 of the computer 21.

Next, the test prints printed by the printing plates for each color are placed on the chisel 2, and the registration marks 26' are placed on the prints.

The test print is moved by manual operation of a pulse motor so that 27', 28', and 29' (not shown) are within the field of view of the camera 5. In this way, with camera 5, register mark 2
The center positions of register marks 6', 27', 28', and 29' are determined, and the same processing as that for register marks 26, 27, 28, and 29 is performed, and the center of register mark 26' and other register marks are determined. The positional relationship between the centers of 27', 28', and 29' is input to the control unit 24, and the positional relationship between this and the center of the register mark 2
6, 27, 28, and 29 are compared with the previously stored positional relationships in the control unit 24, and the amount of deviation between the two is determined.

The deviation value signal obtained in this way is outputted from the control unit 24 to the register w4 adjustment device 22, and this register adjustment device 2
2 uses this signal to perform vertical, horizontal, and twist adjustments on the plate cylinder in the same manner as in the conventional system.

Effects of the Invention The present invention is as described above, in which the relative positions between the centers of the register marks written on each printing plate are recorded in advance on a computer, and then the trial printing is placed on the same table. The relative position between the centers of each register mark on this test print is input into a computer, and the deviation amount is calculated by comparing it with the relative position between the centers of the register marks on the proof print. Since the system inputs a signal based on the detected deviation value from the computer to the register adjustment device of the printing press and operates it to achieve registration, it eliminates the need for a register mark reading sensor that was previously required for registration. Compared to the past, where accurate registration was difficult because there was no need for it and it was difficult to accurately locate the sensor.
This has the effect of allowing extremely accurate registration.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of an embodiment of the invention, Fig. 2 is a slope view of the machine base of the same as above, Fig. 3 is a plan view of the same as above, Fig. 4 is a front view of the same as above, and Fig. 5 is a register mark. FIG. 6 is a perspective view of a conventional registration device. 1... Machine base 2... Table 5... Image input camera 21... Computer 22... Register adjustment device 26.27.28.29... Register mark on proof sheet Patent applicant Sumitomo Heavy Industries Ltd. Figure 5 Figure 6 & Experiments

Claims (1)

[Claims] 1. In multicolor printed matter, register marks are written on printing plates for each color so that the register marks for each color do not overlap each other, and the positions between the centers of these register marks are determined. The relationship between the two colors is stored in a computer in advance, and then a test print printed using the printing plate is placed on a table and the center position of each color register mark on this test print is determined.
The computer compares the positional relationship between the centers of the register marks with the positional relationship between the centers of corresponding register marks stored in the computer to determine the deviation value, and the computer instructs the printing machine to correct this deviation value. A registration method for an offset printing press, characterized by outputting a correction signal to a registration adjustment device. 2. A machine base having a table for placing printed matter on its surface and having an image input camera installed above the table so as to be movable in the horizontal direction, a registration adjustment device for the printing machine, and a computer; The computer has a storage unit that stores the center position information of each color register mark, and compares the center position information of each color register mark of the trial print inputted from the same camera with the stored information and outputs a deviation value signal. A registration device for an offset printing press, characterized in that the register adjustment device is configured to input the deviation value signal and adjust the position of the plate cylinder.