JPH0315553A - Plate registration detector of printing machine - Google Patents

Abstract

PURPOSE:To enable deviation in plate register to be automatically detected by a method wherein a plurality of control register marks are printed at an optional stage of a printing machine and besides, one control register mark is printed conforming to those register marks at another stage. CONSTITUTION:For a first stage printing unit, a printing color is 'black', and reference marks mb1 to 4 and beltlike control register marks MB11 to 16, MB21 to 26 are printed together with a pattern. For a second stage printing unit, the printing color is 'indigo', and reference marks MC1 to 4 and beltlike control register marks MC12, MC22 are printed together with the pattern. Hereinafter in the same way at a third stage to a sixth stage, cross reference marks and control register marks are also printed. In the case where deviation in plate register is detected, those control register marks M are read by scanning with 302a. Positional information in relation to marks which was actually, in a superimposed manner, printed is calculated with a central processor 223, and deviated amounts in registration among respective printing units are calculated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a plate register detection device for a printing press, and is intended to be able to automatically detect plate register misalignment between printing units. The misregistration of the plate detected in this way is
The plate register is adjusted to eliminate misalignment by being input into the control unit of the register device or judged by a human being.

Conventional technology FIG. 8 shows a six-color offset sheet-fed printing press.

This printing machine 10 includes a paper feeding device 20, six stages of printing units 31, 32, 33, 34, 35, and 36, and a paper discharging device 40.
It is equipped with Each of the printing units 31 to 36 includes a plate cylinder R8 on which a printing plate for printing is mounted, and a rubber cylinder R on which an image on the printing plate is transferred in opposition to the plate cylinder RH.

And this rubber body R. It has an impression cylinder RA that applies printing pressure against it. The paper 50 sent out from the paper feeder 20 is transferred to a rubber cylinder R. The printing is carried out by passing between the transfer cylinder R
u to move to the adjacent printing unit. Paper 50 that has passed through the final stage printing unit 36 and has been printed in six colors
are sent to the paper discharge device 40 and stacked thereon.

Each of the printing units 31 to 36 prints a cross-shaped reference mark (register mark) on the paper 50 along with the picture. Then, on the paper 50 that has been printed in six colors, the positions of the overprinted reference marks match perfectly)+f
, the registration between each printing unit will be matched. Furthermore, when the reference mark is misaligned, the register of each printing unit is adjusted until the misalignment of the reference mark disappears. Adjustment of misregistration is performed by directly operating the register device of the printing unit manually by an operator or remotely using a remote control.

<Problems to be Solved by the Invention> Conventionally, the misalignment of the reference mark has been inspected by an operator visually observing it with a magnifying glass or the like.

In the past, visual inspection was used, which made it impossible to accurately read the amount of misalignment, and the reality was that correction work was performed several times through trial and error until the register was perfectly aligned.

Therefore, the registration work takes a lot of time and generates a lot of wasted paper. Furthermore, it required a troublesome and mentally tiring task to visually observe minute misregistrations.

In view of the above-mentioned prior art, the present invention provides a plate register detection device for a printing press that can automatically detect plate register misalignment between printing units.

Means for Solving the Problems> The present invention to solve the above problems prints a plurality of control register marks at any stage of offset printing m, and at the same time prints one control register mark at each of the other stages according to the plurality of control register marks. The present invention is characterized in that two control register marks are printed, and the misregistration between printing units is calculated and detected from the amount of misalignment of the overprinted control register marks.

<Example> Embodiments of the present invention will be described in detail below based on the drawings.

FIG. 1 shows an embodiment of the invention. In the figure, an offset printing machine 110 prints a sheet 150 sent out from a sheet feeding device 120 using six stages of printing units 131 to 136, and stacks the printed sheet 150 on a sheet discharging device 140.

Each of the printing units 131 to 136 prints a cross-shaped reference mark m and a control register mark M at the corner of the paper 150, as shown in FIG. 2, along with a pattern of each color.

In other words, the first printing unit 131 prints in color 4? It is "black" and includes reference marks mb1 to mb4 as shown in FIG. ．． Print 26.

The printing color of the two-stage printing unit 132 is "indigo", and the reference mark mC as shown in FIG.
, ~4, and a band-shaped control register mark MC12.
, MC2■ is printed.

After that, 3rd tier (red), 4th tier (yellow), 5th tier (special color 1),
The six-stage (special color 2) printing units 133 to 136 print cross-shaped reference marks and control register marks as shown in FIG. 3 tc+ to (f).

When the plate registers between the printing units 131 to 136 are completely matched, the marks of the combinations 1 to 2 shown below are printed completely overlapping each other without shifting.

■ mb1, me,, mm1, my1, mx 1,
, mx 2, ■ m b2, m c2, mm2'
, m y2, mx 12, mx 22■ m b
3, m c,, mm3, m y3, mx 13
, mx 23■ mb4, mC4, mm4, my4,
mx14, mx24 ■ MB, MC ■ MB13, MM, 3 ■ MB, 4, MY, 4 ■ MB, 5, MXI, 5 ■ MB, 6, MX2, 6 [Phase] MB, MC O 2 MB, MM23 @ MB24 , MY24 ■ MB , MX125 ■ MB26, MX226 Therefore, when the plate registers between the printing units 131 to 136 completely match, the overprinted paper 150
A reference mark m 1 and control register marks M 1 and M 2 as shown in FIG. 4 are imprinted on the wafer. The mark position and shape in Figure 4 are exactly the same as the first mark.
The printing unit 131 of the column is exactly the same as that of FIG. 3 (Al).

On the other hand, when the plate registration between the printing units 131 to 136 is out of alignment, the finished printing data reference mark and control register mark will be out of alignment and will be different from those shown in Figures 4 and 3 (al). That is, for example, as shown in FIG.

The print quality control device 200 shown in FIG.
10, and as shown in FIG. 6, it also incorporates a misregistration amount calculation/detection section 220 and a print quality control section 230, on which the printed paper 150 is placed.

A mark reading device 300 is attached to this print quality control device 200.

As shown in FIG. 7, the mark reading device 300 includes a circuit board 301, a line sensor unit 302, a lamp house 303, and a reading window 304 and a finder 305.
is dawning. When detecting plate misregistration in the vertical direction, this mark reading device 300 detects M,
,, M12, M,, M,4, M,5,7 8 Ml6 is installed so that it can be read through the reading window 304, and when detecting plate misregistration in the left and right direction, control register marks M21M22, M23, M24,
It is attached so that M2, , M26 can be taken in through the reading window 304.

When detecting plate misregistration, as shown in FIG. are scanned and read by each sensor cell 302a, each sensor signal is binarized by a comparator 306, and the I
/O interface 307. The output binary signal a becomes high level where the control register mark M is present, and becomes low level elsewhere. Note that the operation of scanning and reading by the sensor cell 302a is started by pressing the "start" key on the operation panel 210.

The register thread amount calculation/detection unit 220 (see FIG. 6) includes a sensor controller 221, a memory 222, and a central processing unit@
(CPU) 2 2 3, communication interface 224,
It has an I/O interface 225 and a bus 226. The memory 222 stores in advance the position information of the control register mark M overprinted when there is no misregistration of the printing plate, that is, the position information representing the mark shown in FIG. 4 as a reference position. Also, the binary signal α sent from the mark reading device 300
is temporarily stored in the memory 222, and based on this binary signal data, the central processing unit 223 calculates the position information of the marks actually overprinted. The amount of misregistration between each printing unit is then calculated by comparing the calculated position information with the preset reference position information.

Here, the method of calculating the amount of registration will be explained using the case of vertical registration as an example.As mentioned above, the reference position is
Con1-low shown in the figure, JL register mark M1, ~1
6, and the marks actually printed and read by the mark reading device 300 are, for example, control register marks M1 to 16 shown in FIG. In this case, the CPU 223 of the misregistration amount calculation/detection section 300 calculates the relative misregistration amount d1'' between the units based on the black color (mark M1,).
d6' is calculated using the following formula using the number of sensor cells as a unit.

dl' 1(dl-dl)Xψ d2' = (d2-di)Xψ, d3' 1(d3-di)Xψ3 d4' = (d4-di)Xψ4 ds' 1(d5-di) d6-dl'l Using the conversion coefficient X from the number of cells to the actual length, calculate the relative offset actual length (unit: mmlD1 to D6) by the following calculation.

D1=-x-d1ゝD2=-x-d2'D3=-x-d3'D4=-x-d4'D5=-x-d5'D6=-x-d6' Misregistration amount calculation/detection section 220 For example, the obtained actual relative deviation lengths D1 to D6 are displayed on a display on the operation panel 210. Further, when the "transfer" key on the operation panel 210 is pressed, data indicating the actual relative deviation lengths D1 to D6 is transmitted to the print quality control section 230 through the communication interface 224.

The print quality control section 230 controls each printing unit 131 to 13.
Since we have data on where the adjustment position of each registration device in 6 is, we calculate the adjustment amount that will make the registration zero by referring to the actual relative deviation lengths D1 to D6, and calculate the calculated adjustment amount. Issue commands 11 12- to each register device to adjust by 11 12-. In this way, each printing unit 131-1
Thirty-six registration devices are controlled to automatically perform registration.

Here, calculations performed by the print quality control device 230 will be explained. The relative deviation actual lengths of each printing unit 131 to 136 are D1 to D
It is 6. On the other hand, the plate register remote control device, which is a function of the print quality control section 230, determines the current register operating positions of each printing unit 131 to 136 obtained from the position detector of the printing machine as PI, P2, ... P6. be. Therefore, both data are added to obtain the next data 81 to S6.

S1=D1+PI S2=D20P2 S3=D38P3 S4=D40P4 S5=D58P5 S6=D6+P6 Next, from 81 to S6, the maximum value SmsX and the minimum value S,
,,,. is extracted and the central value S=,d is calculated.

Next 81 ~S 6 Add S,,J, SXI, SX
2,...Calculate SX6.

SX1 = 31 + S SX2 = 3 2 + S SX3 = 53 + S SX4 = 34 + S SX5 = 35 + S SX6 = 36 + S The positioning operation of the registration device is performed automatically.

As described above, in this embodiment, a series of registration operations are automatically performed, so that the printing preparation process can be shortened and the amount of paper waste can be reduced.

In the above embodiment, the registration device was automatically adjusted according to the commands from the print quality control section 230, but the operator manually adjusts the registration when the operator sees the registration misregistration detected by the misregistration amount calculation/detection section 220. The registration may be performed by operating the device. Furthermore, the present invention is applicable not only to offset printing presses but also to other types of multicolor printing presses.

<Effects of the Invention> As specifically explained above in conjunction with the embodiments, according to the present invention, the misregistration of the control register mark printed by each printing unit is read by the mark reading device, and the amount of misregistration is determined based on the read data. Since the calculation/detection section calculates the misregistration between each printing unit, the amount of misregistration can be detected accurately and quickly. Therefore, the operator is freed from the tiring task of visual inspection, which has conventionally been performed.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram showing an embodiment of the present invention, Fig. 2 is a plan view showing paper, Fig. 3 is an explanatory diagram showing marks printed on paper, and Figs. 4 and 5 are overprinted marks. 6 is a configuration diagram showing each element of this embodiment along the signal transmission system, and FIG. 7 is an explanatory diagram showing 1. FIG. 8 is a perspective view showing a t-mark reading device, and FIG. 8 is a configuration diagram showing an offset printing press. In the figure, 0 is a printing machine, 0 is a print quality control device, 0 is an operation panel, 0 is a misregistration amount calculation/detection section, 0 is a print quality control section, and 0 is a mark reading device. Surface 11 20 21 22 23 30

Claims (1)

[Claims] It has a plurality of stages of printing units, and any one printing unit prints strip-shaped control register marks spaced apart from each other by the same number as the number of installed stages of the printing unit together with the pattern, and the remaining Each printing unit is a printing machine that prints a control register mark that has the same shape and area as one of the control register marks and is in phase with the one control register mark in one-to-one correspondence with the picture. and a mark reading device that reads control register marks printed over and over on paper by the printing machine and outputs a binary signal whose level changes depending on the presence or absence of the control register mark. A misregistration amount calculation/detection unit that calculates and detects the amount of misregistration between each printing unit by determining the position of the printed control register mark and comparing the determined position with a preset reference position. A printing press plate register detection device characterized by: