JPS60250956A - Method and apparatus for adjusting phase of plate cylinder - Google Patents

Abstract

PURPOSE:To eliminate such troublesomeness as adjusting phases of individual units once after printing is done by automatically regulating the position of a compensator roll depending on the circumference and phase of a plate cylinder of each unit prior to the printing. CONSTITUTION:For example, phase differences of registers for plate cylinders 211 and 212 of units #1, #2 are detected with phase adjusting registers 211A- 213A and sensors 221-223 and the phase difference alpha is converted into a pulse width with a flip flop 282. A pulse train PT is outputted at a specified interval with a rotary encoder 2 and enters a controller 4 via an AND gate 292 together with a phase difference signal to determine the phase difference depending on the circumference of the plate cylinders. Then, a CPU5 calculates the pass length between printing sections from the circumference of the plate cylinders and the position of a compensator roll 262 detected with a rotary encoder 252 and starts a motor 272 to drive a screw and move the compensator roll 262 if correction is needed. Likewise, adjustment is done between the units #2, #3.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and device for adjusting the phase of a printing plate cylinder in a printing system, and more particularly to a method and device for adjusting the phase of a printing plate cylinder using a compensator roll, which is optimal for printing with a rotogravure printing press. .

When printing with a rotogravure printing press, a plate cylinder is attached to the printing press to print uniform colors for each unit. The reference registration marks (remaining colors must overlap) may be different for each color. It is necessary to print so that the reference register marks of each color overlap with other colors. Conventionally, after printing once, an operator visually observed the state of misalignment of each color and determined the phase of the plate cylinder of each unit. I was trying to manually adjust it on a trial basis. For this reason,
The phase adjustment of the plate cylinders of each unit is extremely complicated, and in particular, the phase adjustment requires a great deal of effort and time. This invention was made under these circumstances, and the position of the compensator roll is automatically adjusted from one phase of the plate cylinder circumference of each unit before printing, and after the phase adjustment by the compensator roll, the position of the compensator roll is This allows printing to be performed accurately and quickly.

This invention will be explained below.

The present invention relates to a printing plate phase adjustment method and device for a printing system in which plate cylinders are attached to a printing press and each color is printed unit by unit. A sensor detects the phase adjustment register mark as a phase difference between each plate, and a compensator roll is moved in accordance with the amount of deviation to match the patterns of each unit.

FIG. 1 shows a schematic configuration of a printing system to which the method of the present invention is applied. Continuous printing paper 1 is fed from a paper feed stand 11 of a paper feed unit IO and is sent to a printing unit 20 via an inlet roller 12. , the paper l printed by the printing section 20 is sent to the paper discharge section 30.

Here, the printing section 20 is composed of three color units #1 to #3 in this example, and each unit I11 to Minoru3.
are plate cylinders 21 (211-213) and impression cylinders 23 (231-213).
233), and near each of the first plate cylinders 211 to 213 there are sensors 22 ( 221 to 223) are provided. Further, in order to vary the paper path length between each unit, a motor 27 (272-273) is used to move a compensator roll 26 (262-273) by a screw nut.
263) is provided. And each plate cylinder 211-2
13 are each rotationally driven by a main motor 24, and compensator rolls 262 and 263 are each driven by a motor 2.
72 and 273. A rotary encoder 2 that outputs a pulse train PT is connected to the rotating shaft of the main motor 24, and the pulse train PT is input to AND gates 1-292 and 283. In addition, compensator rolls 272 and 27
Rotary encoders 252 and 253 are also connected to the motors 272 and 273 that move the motors 3, and pulse trains PTI and PT2 for detecting the position are sent to the control device 4, which in turn sends the pulse trains PTI and PT2 to the CPU (for example, a microprocessor) 5. It is connected. Each detection signal from sensors 221 to 223 is sent to flip-flops 282 and 283, respectively.
are input to the respective AND gates 292 and their Q outputs are input to the AND gate 292.
and 293, and the AND with the output pulse train PT of the rotary encoder 2 is sent to the control device 4. Further, the operator can manually input a reset signal R9 to the CPU 5, and the CPU 5 drives the main motor 24 and the motors 272 and 273 via the control device 4.

In the following configuration, the operation thereof will be explained with reference to the flowchart in FIG. 2 and the waveform diagrams in FIGS. 3(A) to 3(H).

When printing, first attach the printing plate cylinders to each unit I11 to 113 according to the printing instructions, etc. (steps Sl, S2), and press the automatic phase correction selection button (not shown).
In step S3), the reset switch is turned on to input a reset signal R9 to the CPU 5. In step S4), the circumference of the mounted plate cylinder is input to the CPU 5 using a keyboard or the like. This allows the CPU
5 starts the main motor 24 through the control device 4,
Each unit sl of the printing section 20, *3 plate cylinder 2 (211~
213), then instructs the control device 4 to start the preset and enters the preset operation state (step S
? ). The phase adjustment operation between units #1 and 112 is performed in steps 0 to S15, and the phase adjustment operation between units #2 and 113 is performed in steps S20 to S25, but here, the operation between units #1 and 112 is performed. The explanation will be given according to the flowchart.

First, the phase difference between the register marks on the plate cylinders 211 and 212 of units IIl and #2 is detected as follows (step 5).
10). The sensors 221 to 223 detect the phase adjustment registration marks 211A to 213A of the rotating plate cylinders 211 to 213, and the detection signals are as shown in FIGS. 3(A) to 3(G), respectively. These detection signals are shifted by a time α proportional to the phase difference between the plate cylinders 211 and 212, and are input to a flip-flop (hereinafter referred to as FF) 282 to convert the phase difference α into a pulse width (D ) to obtain a signal as shown. The rotary encoder 2 outputs a pulse train PT at a predetermined interval, for example, 2000 pulses per rotation, as shown in FIG. 3 (F), and this pulse train PT and the phase difference signal shown in FIG. Since the pulse train signal shown in FIG. 3(G) is input to the gate 282, the pulse train signal shown in FIG. As a result, the phase angles of the plate cylinders 211 and 212 of units #1 and #2 become smaller, and the phase difference α becomes smaller than the plate cylinder circumference. next.

The plate cylinder circumference and rotary encoder 252 are input in advance.
't' From the detected position of the compensator roll 262, the path length from the printing section of the plate cylinder 211 of unit sl to the printing section of the plate cylinder 212 of unit 112 is calculated using CP and U5, and the path length is calculated from the above-mentioned phase difference α. The sum is calculated (step 512), and it is determined whether the position of the dragonfly 211A of unit sl matches the position of the dragonfly 212A of unit cloud 2 (step 513).

As a result, if there is no need for correction, the process is stopped (step 515), but if correction is necessary, the CPU 5 calculates the amount of correction, and the control device 4 and motor 272 drive the screw to rotate. Compensator roll 2
Move 62. Since the amount of movement can be detected by the rotary encoder 252 attached to the end of the screw, the compensator roll 262 can be moved by the required correction amount (step 514).

The above phase adjustment is similarly performed between units II2 and s3 in steps S20 to S25, and the phase α between units II and 112 is adjusted and
．． If the adjustment of the phase β between B and s3 is completed,
The preset operating state started in step S7 is canceled (step 530). When the presetting is completed, the operator turns on the print start button, thereby starting printing (step 531). In this case, the unit!
Since the phases of 11 to 113 are adjusted correctly, there will be no deviation in the pattern.

As described above, according to the present invention, it is possible to automatically adjust the phase of the plate cylinders of each unit in the printing section before the start of printing. This eliminates the hassle of printing, making it possible to perform printing tasks very efficiently. Additionally, although the present invention is particularly useful for continuous printing systems, it is equally applicable to general printing systems. Further, in the above embodiment, the number of printing units is three, but the number of units is arbitrary.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a printing system according to the present invention, FIG. 2 is a flowchart showing an example of the operation of the invention, and FIG. 3 is a waveform diagram showing the example of the operation of FIG. l...Printing paper, 2,252,253...Rotary encoder, 4...Control device, 5...CPU, 1
0... Paper feeding section, 20... Printing section, 30... Paper discharge section, 21 (211-213)... Plate cylinder, 22 (221-
223)...sensor, 23(231-233)...
Impression cylinder, 24... Main motor, 282, 283...
Compensator roll, 272, 273... motor,
282.283...Flip differential 0 knob, 11...Paper feed stand, 12...Entrance roller. Applicant's agent Yu Yasugata Figure 3

Claims (2)

[Claims] (1) In a printing system in which plate cylinders are attached to a printing press and each color is printed in units, phase adjustment register marks are printed on the margins of the plate cylinders of each unit, and the registration marks are printed near the plate cylinders of each unit. A sensor for detecting position adjustment register marks is provided, and the plate cylinder is rotated before printing, and the phase adjustment register mark printed on each plate cylinder is detected by the sensor as a phase difference between each plate cylinder. A method for adjusting the phase of a printing plate cylinder, characterized in that the amount of deviation is calculated from the circumference of the printing plate cylinder, and the compensator roll is moved by an amount corresponding to the amount of deviation, so that the patterns of each unit are matched. (2) With respect to a drive system consisting of a plate cylinder and an impression cylinder in each unit of the printing section and a compensator roll between each unit of the printing section, the drive system is configured such that the drive system rotates in phase synchronization with the main motor that drives the plate cylinder. a first rotary encoder attached to the drive system; a registration mark detection sensor for detecting registration marks for position adjustment of the plate cylinder for each unit of the printing section; a motor for moving the compensator roll; and a rotation shaft thereof. A second rotary encoder attached to the motor drives the drive system, compares pulse signals from each of the rotary encoders and a detection signal of the register mark detection sensor, and drives the motor to drive each of the printing units. 1. A printing plate phase adjustment device comprising: a control device for adjusting the phases of printing plates of a unit to the same level.