JPH0449044A - Registrating method of split plate cylinder - Google Patents

Abstract

PURPOSE:To make shear in registration always zero in operation by actuating a registrating device by a method wherein a photoelectric sensor capable of detecting mutual phase shear of register marks of a plate cylinder body of and a plate mounted on a cell of each color on travelling paper, is respectively provided to the plate cylinder body and the cell. CONSTITUTION:A photoelectric sensor 11 is so established as to be capable of detecting a position of a register mark of each plate cylinder body 4 and each cell 5 which is printed on travelling paper with each blanket cylinder 2 for each one rotation of a split plate cylinder 3. For instance, when a register mark 7 (red) and a register mark 7 (yellow) are shifted by ec and ew circumferentially in a width direction, those shears are detected with a photoelectric sensor 11 (yellow). Further, shears in both circumferential and width directions are detected simultaneously with one set of photoelectric sensors 11. Furthermore, this detection can be performed always at an optional printing speed. When the shear is detected, a registering device respectively provided circumferentially in the width direction for each plate cylinder 4 and each cell 5 is actuated and the shear is so corrected as to be made zero.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a plate registration method applied to a rotary printing press equipped with a divided plate cylinder.

[Conventional technology]

FIG. 1 shows a common pressure multicolor printing unit of a newspaper offset rotary printing press having a divided plate cylinder. The divided plate cylinders 3 are arranged around the common impression cylinder 1 via four sets of blankets 81i12, which are electrically distributed in a planetary manner and print black, indigo, red, and yellow, respectively. The divided plate cylinder 3 consists of a plate cylinder main body 4 and a cell 5 as shown in FIG. 3, and a plate 6 shown in FIG. 2 is attached to each of these members.
Score lines (hereinafter referred to as register marks) 7 necessary for alignment in the circumferential and width directions are placed in the shape of a ten.

Therefore, these register marks 7 are printed on a running paper, and the deviations between these pattern register marks are visually measured. A registration device (none of which is shown) is activated to perform registration.

[Problem to be solved by the invention]

The above-mentioned conventional technology has the following problems.

Since the correction is made by visually observing the misalignment between the registration marks for each color printed at low speed, it is necessary to perform the correction operation several times. hair
Registration that ensures there is no misalignment of books (hairline register)
It requires considerable skill to perform this, and it is difficult to obtain an accurate hairline register. Furthermore, since register adjustment is performed at low speed, the accuracy of register adjustment is not always maintained during high-speed printing operation. (This often changes.

) [Means for solving the problem] A photoelectric sensor capable of detecting the mutual phase shift of the register marks of the plate mounted on the plate cylinder body and cell for each color on the running paper every rotation of dividing plate #41 is installed in the plate cylinder body. and each cell.

[Effect]

The photoelectric sensor can detect misregistration in the circumferential and width directions between the plates of the plate cylinder body and between the plates of the cell, respectively, during printing at any speed. It is therefore possible to operate the circumferential and widthwise registration devices to eliminate these misregistrations.

〔Example〕

A registration photoelectric sensor 11 according to the present invention is installed in the multicolor printing unit shown in FIG. In Figures 1 to 3,
The photoelectric sensor 11 is provided so as to be able to detect each rotation of the divided plate Ni 43 at each registration mark 7 for each plate cylinder body 4 and cell 5 printed on the running paper in each blanket 1ii12. Therefore, for example, as shown in Figure 2, the dragonfly 7
(red) and register mark 7 (key) are circumferential and width direction eQ
and h are shifted, the photoelectric sensor (key) 11 detects these shifts. Incidentally, a set of photoelectric sensors 11 can simultaneously detect deviations in the circumferential and width directions. Also, this detection can be performed at any printing speed.

In the above embodiment, the photoelectric sensor 11 is provided for each color, but the photoelectric sensor 11 after printing the final color is
It is also possible to provide a set of photoelectric sensors at the (key) position to perform color separation and detect the shift of the register mark 7 between tiles of each hue.

When a misalignment is detected, circumferential and widthwise registration devices (not shown) provided for each plate cylinder body 4 and each cell 5 are operated to correct the misalignment to zero.

〔Effect of the invention〕

The method for registering a divided plate cylinder according to the present invention includes registration lines (register marks) of plates attached to each of the plate cylinder main body and cells that constitute the divided plate cylinder of a rotary printing press, and the divided plate of these register marks. and a photoelectric sensor that detects the position tilt for each rotation of the cylinder, and by adjusting the position # of the plate cylinder body and the cell based on the signal regarding the shift in register mark position for each color detected by the photoelectric sensor, the following effects can be achieved. has.

Printing can be performed at any printing speed using a photoelectric sensor that detects the register marks on the plate attached to the plate cylinder main body and cells of the divided plate cylinder, and the position 1' of these register marks printed on the running paper every 11 rotations of the divided plate 1i. It is possible to detect misregistration and operate the registration device to always reduce misregistration to zero during operation.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view of a multicolor printing unit implementing the present invention, FIG. 2 (k) is a side view and a front view of the plate,
FIG. 3 is a front view showing a main part of the divided plate cylinder in cross section. 3. Divided plate cylinder 7. Registration ruled line (register mark) 1
1... Photoelectric sensor 81 diagram

Claims (1)

[Claims] Registration lines (register marks) for plates attached to each of the plate cylinder bodies and cells that make up the divided plate cylinder of a rotary printing press.
and a photoelectric sensor that detects the positions of these register marks every rotation of the divided plate cylinder, and adjusts the positions of the plate cylinder main body and the cells based on the signal regarding the deviation of the register mark position for each color detected by the photoelectric sensor. A method for registering a divided plate cylinder.