JP2000168053A - Register correcting device for sheet-fed printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a register correcting device for a sheet-fed printer capable of automatically correcting a register deviation caused by an operating speed difference. SOLUTION: This register correcting device for a sheet-fed printer comprises an operating speed monitoring means 9 for always monitoring an operating speed, a storage means 10 for storing data for correcting a register by previously measuring register deviation characteristics corresponding to the speed at each printing unit 3, and a control means 11 receiving speed information from the means 9 to read correction data from the means 10 and to send a correction command signal to a register correcting means 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-color printing sheet-fed printing press, and more particularly to an apparatus for correcting a register caused by a difference in operation speed.

[0002]

2. Description of the Related Art In a multicolor printing sheet-fed printing press, a printing plate is wound around a number of plate cylinders corresponding to the number of colors, and printing is performed in the order of each color. At this time, good printing quality cannot be obtained unless each color is sequentially printed on the correct position on one sheet.

In order to obtain the correct registration for each color to be printed in a number of successive printing units, a cross-shaped mark, commonly called a register mark, is printed in the margin of the sheet. Then, the amount of misregistration of the register mark for each color is measured, and registration adjustment is performed by finely moving the plate cylinder itself or the printing plate for each printing unit.

[0004] Incidentally, when the register shift is classified, there are a parallel shift that is shifted in parallel to the top and bottom / left and right directions of the sheet, and a distortion obtained by combining the shift in the top and bottom / left and right directions. Regarding misregistration.

[0005] By the way, in register adjustment for preparation before printing, 4,000 to 6,000 sheets per hour (hereinafter, referred to as "sheets") are used.
Abbreviated as s / h. ), The register adjustment operation is performed in a relatively low-speed operation state. Such a speed is adopted, of course, because the registering operation is easily performed, and the occurrence of waste paper during the adjusting operation is minimized.

On the other hand, the actual printing operation speed as the so-called final printing is given the highest priority on the operation efficiency.
High speeds such as ~ 14,000 s / h are employed.

[0007] Accordingly, even if the register is once matched in the register adjustment operation at a low speed, a register shift in the vertical direction occurs in a high-speed final printing operation. This is because the load increases due to the increase in the operation speed in the sheet conveyance system gear group such as the transfer cylinder and the impression cylinder, and the gears are slightly deformed according to this, resulting in a rotational phase shift. , The load also increases in proportion thereto, so that the shift amount also increases. In addition, as the printing unit moves to the downstream printing unit, the shift amount of the rotational phase is accumulated, and the register shift increases.

[0008]

2. Description of the Related Art Conventionally, every time the operating speed is changed, an operator takes out a print sample, measures the amount of deviation with a loupe or the like, and corrects the register for each printing unit. By the way, the device and work contents for register correction are
Both plate cylinder adjustment by adjusting the plate cylinder itself and plate adjustment by adjusting the plate are well known.

However, such manual adjustment by the operator is inevitable every time printing is stopped / restarted, which is not only burdensome but also inefficient, and causes a large amount of waste paper during correction work. There was a problem.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has as its object to provide an advanced register correcting apparatus. The object of the present invention is to automatically correct a register shift caused by a difference in driving speed. It is to make.

[0011]

According to the present invention, there is provided a register correcting device according to the present invention, comprising: an operating speed monitoring means (9) for constantly monitoring an operating speed; Storage means (1) for measuring the registered misregistration characteristics and storing data for register correction.
0) and control means (11) for receiving speed information from the operating speed monitoring means (9), reading correction data from the storage means (10), and sending a correction command signal to the register correction means (8). Have

[0012]

After the register adjustment, even if the operation speed increases for the final printing operation, the register correcting means (8) of each printing unit is operated based on the correction data stored in advance, whereby the register shift is performed. Is prevented.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic side view of a multicolor sheet-fed printing press provided with a register correction device according to the present invention.
It is a graph which shows an example of register correction data.

In FIG. 1, reference numeral (1) denotes a paper feed unit where sheets to be printed are prepared, and (2) denotes a paper discharge unit where piles of printed sheets are piled. In the illustrated printing press, four printing units (3) corresponding to four colors are provided, and each printing unit (3) includes a plate cylinder (4), a blanket cylinder (5), and an impression cylinder (6). And a transfer cylinder (7) constituting a sheet transport system is linked between the impression cylinders (6) of the printing unit (3). The plate cylinder (4) of these printing units (3) is provided with a well-known register correcting means for finely adjusting the plate cylinder itself or the printing plate in the vertical direction. It is shown.

As described above, the register adjustment work is performed in the low-speed operation state, and even if the register of all the printing units (3) once agrees perfectly, it is avoided that the register is shifted in the high-speed final printing operation. I can't. The fact is that the printing unit (3) on the downstream side (that is, on the side of the discharge unit (2))
And is also a characteristic inherent to the printing press.

Therefore, in the present invention, an operation speed monitoring means (9) using a rotary encoder or the like is provided near the impression cylinder (6) of the most upstream printing unit (3), for example, and the operation speed s / H is constantly monitored.

As shown in FIG. 2, trial printing is performed in advance under various speed conditions, and data of the amount of misregistration generated at that time is stored in the storage means (10). The storage means (10) is specifically a part of a computer in a control console (not shown) of the printing press.

In FIG. 2, a register adjustment operation is performed at an operating speed of 4,000 s / h, and the amount of register shift of the other printing units (3) with respect to the first printing unit (3) at the most upstream position is zero, ie, Make sure that the register matches perfectly. After that, the amount of misregistration is measured by changing the operation speed, and the amount of misregistration with respect to the first printing unit (3) serving as a reference (of course, the amount of misregistration in the downstream fourth printing unit (3) is the largest). Convert to data. By the way, 12,000s /
In h, the displacement amount of the fourth printing unit (3) is 0.16 m
When the register correcting means (8) of the printing unit (3) is finely moved in the vertical direction by this amount, the registration with the reference first printing unit (3) matches. is there. For an intermediate speed not shown, an interpolation value can be used as appropriate.

Specifically, the control means (11) as a computer in the control console receives speed information from the operating speed monitoring means (9), and outputs correction data corresponding to the speed from the storage means (10). It reads and sends a required amount of correction command signal to the register correcting means (8) of each printing unit (3) to operate it.

[0020]

According to the register correcting apparatus according to the present invention, the register shift caused by the difference in driving speed can be automatically corrected, so that the work load on the operator is greatly reduced and the occurrence of waste paper is extremely reduced. There is a significant effect that it can be suppressed.

[Brief description of the drawings]

FIG. 1 is a schematic side view of a multicolor printing sheet-fed printing press provided with a register correcting device according to the present invention.

FIG. 2 is a graph showing an example of register correction data.

[Explanation of symbols]

 Reference Signs List 3 printing unit 4 plate cylinder 8 register correction means 9 operating speed monitoring means 10 storage means 11 control means

Claims (1)

[Claims] An operation speed monitoring means for continuously monitoring an operation speed in a multicolor printing sheet-fed printing machine in which a number of printing units are linked by a sheet conveying system and each of the printing units is provided with a register correcting means. 9), a storage unit (10) for measuring the register shift characteristic corresponding to each printing unit and corresponding to the operating speed in advance, and storing data for register correction, and the operating speed monitoring unit (9). Control means (11) for receiving speed information, reading correction data from said storage means (10), and sending a correction command signal to said register correction means (8).