JPH0298447A - Faulty follow-up print detection device - Google Patents

Abstract

PURPOSE:To make possible the detection of generation of faulty printed paper even when it is not monitored constantly, prevent faulty printed paper from being involved and thereby increase the quality by allowing a fault detection signal to be output automatically, if a preprint section and a follow-up print section are misregistered during follow-up printing. CONSTITUTION:For faulty follow-up print detection, a misalignment deviation U obtained by an arithmetic and logic operation device 26 is sent to a comparator 28. The comparator 28 has already a tolerable misalignment deviation V set by a tolerable value entry device 29. The tolerable misalignment deviation V is a maximum allowable value accepted as a deviation value between a preprint section and a follow-up print section. If a larger misalignment than the tolerable misalignment deviation V occurs, the print is faulty, and the printed section where such fault has occurred is discarded as a waste paper. The comparator 28 compares a misalignment deviation U with the tolerable misalignment deviation V, and if the misalignment deviation U is larger, outputs a fault detection signal G. The detection of any follow-up defect by the comparator 28 is continuously performed even after the control is switched to a follow-up printing control device 14.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an additional printing defect detection device that outputs a defect detection signal when an additional printing defect occurs.

<Conventional technology> After printing on a roll paper using an offset rotary printing machine or a gravure rotary printing machine, the four-roll paper is rolled into a -H roll shape, and the offset rotary printing is performed on the pre-printed roll paper in this way. When printing again with a printing machine or the like, so-called reprinting, it is necessary to match the register between the previously printed pattern (preprint section) and the pattern to be printed (reprint section).

Once printed, the paper expands and contracts due to printing pressure, drying, and cooling, and the pitch of adjacent register marks becomes shorter than the preset reference pitch. Therefore, when performing additional printing, it is necessary to control the tension of the roll paper so that the pitch of register marks and specific patterns (these are referred to as "reference marks") is equal to the reference pitch.

Here, a conventional technique for reprinting will be explained with reference to FIG. In the figure, roll paper 1 has been printed in advance by an offset rotary printing machine, and this pre-printed roll [1 passes between a dancer roller 2 and a roller 3 pressed against it, and is guided roller 4
．． It is guided along the surface of the tensiman roller 5 and guide roller 6 and sent to the plate cylinder 7 for additional printing. When the tension of the roll paper 1 increases, the tensian roller 5 moves clockwise in the drawing centering on the roller 4, and when the tension decreases, it moves counterclockwise around the roller 4.

The plate cylinder 7 rotates by receiving rotational force from a main motor (not shown), and the rotational force of the main motor is further transmitted to the dancer roller 2 through a harmonic drive 8. By adjusting the harmonic drive 8 using the collection motor 9, the rotational speed of the dancer roller 2 can be controlled and the tension of the roll paper 1 can be adjusted.

On the other hand, the encoder 11 detects the rotation of the plate cylinder 7, the photoelectric sensor 12 detects the register mark which is a reference mark, and the tensile sensor 13 is connected to the tensian roller 5 and detects the tension of the roll paper 1.

The additional printing 9 control device 14 includes a register control section 14
a and a tension control section 14b.

The register control unit 14a determines the pitch of adjacent register marks from the printing speed obtained from the count signal of the encoder 11 and the detection timing of the register marks by the photoelectric sensor 12, and calculates the deviation between this pitch and the reference pitch. . The tension control unit 14b adjusts the correction fan motor 9 and changes the tension of the roll paper l by the dancer roller 2 so that the deviation calculated by the register control unit 14a becomes zero. At this time, the detection signal from the tension sensor 13 is fed back,
This allows for accurate tension control. By adjusting the tension v4 in this way, the pitch of the register mark becomes equal to the reference pitch.

The roll paper 1 is fed out from an automatic splicing device 15, and the next roll paper 1 is automatically spliced just before the preceding roll paper 1 ends, making it possible to splice the roll papers one after another without stopping printing. .

<Problems to be Solved by the Invention> At the start of printing, registration is not achieved just by setting the pitch of the register symbol equal to the reference pitch, so the plate cylinder 7 is moved and printing is performed using the initially printed pattern and additional printing. Initial settings must be made to align the position with the pattern to be used.

Also, when paper splicing is performed using the automatic paper splicing device 15,
When the paper seam passes through the printing unit, when the ink tack (viscosity) fluctuates, or when the dampening solution becomes unbalanced, the tension of the roll paper 1 fluctuates and the print section I lose track of the difference between this and the reprint department.

As described above, misregistration occurs during initial settings or when the tension changes, so conventionally, a person constantly monitors the paper to find and remove the misregistered waste paper.

During automatic paper splicing, the automatic paper splicing device 15 issues an alarm, so it is known that paper waste will occur. However, from the time paper waste occurs until the paper returns to normal condition, there must be constant human supervision. It won't happen.

SUMMARY OF THE INVENTION In view of the above-mentioned prior art, it is an object of the present invention to provide an additional printing defect detection device that automatically outputs a defect detection signal when a misregistration occurs during additional printing.

Means for Solving the Problems> The configuration of the present invention for solving the above problems is as follows: When printing with a rotary printing machine on a roll paper that has been printed and has reference marks attached at intervals, This is a reprinting defect detection device that detects misregistration between a previously printed pattern and a pattern to be printed, which detects a reference mark on roll paper and outputs a mark detection signal every time the reference mark is detected. a rotational phase detector which is attached so as to rotate once when the plate cylinder rotates once and outputs a count signal and a zero signal, and a reference position on the circumferential surface of the plate cylinder based on the count signal and zero signal. a circuit that determines the position of the reference mark on the roll paper based on the mark detection signal and outputs an integrated count value indicating the positional relationship between the reference mark position and the reference position; A calculation device that calculates and outputs a deviation that indicates how much the positional relationship between the reference mark position and the reference position deviates from a predetermined positional relationship to ensure registration, and a preset allowable deviation deviation. and a defect detection device including a comparator that outputs a defect detection signal when the deviation deviation is larger than the deviation deviation.

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

Note that the same parts as in the prior art are given the same reference numerals.

FIG. 1 shows an embodiment of the invention. In the figure, a roll paper 1 fed out from an automatic splicing device 15 has been printed in advance by an offset rotary printing machine, and registration marks are attached at intervals along the feeding direction. This roll paper 1 has a length of 630 (m) and is sent to the lithographic side 7, where it is aligned with the pre-printed pattern and the pattern to be printed is reprinted thereon.

The rotary encoder 11 is mounted so that it rotates once when the plate cylinder 7 rotates once, and outputs two count signals A, B and a zero signal Z whose phases are shifted according to the rotation.

The number of pulses of count signals A and B is 2500 per encoder 1101 rotation, and zero signal 2 is 2500 per encoder 11 rotation.
This is a pulse signal that outputs one pulse every time the motor rotates once.

The photoelectric sensor 12 is connected to the plate cylinder 7 in the feeding direction of the roll paper 1.
It is arranged at a position upstream from the roll paper 1, detects a register mark which is a reference mark attached to the roll paper 1, and outputs a mark detection signal 12a every time it is detected. Note that, as a matter of course, one registration symbol is attached to one pre-printed pattern in correspondence to one pattern.

Further, the photoelectric sensor 12 may detect a characteristic part of the printed patterns as a reference mark.

The tension sensor 13 is connected to the tension roller 5 and detects the tension of the roll paper 1. Tensile roller 5
A roll paper 1 guided by a guide roller 4 is wound around the roll paper 1, and the roll paper 1 is guided to a guide roller 6.

The eight-monic drive 8 transmits the rotational force of the main motor to the dancer roller 2. The dancer roller 2 clamps the roll paper 1 between the roller 3 and the correct run motor 9.
Since the rotation transmission characteristics of the harmonic drive 8 can be changed, the tension of the roll paper 1 can be adjusted.

The reprint control device 14 includes a register control section 14a that determines the pitch of the register mark and calculates the deviation between this pitch and the reference pitch, and a tensian that outputs a command E to the correction motor 9 so that the calculated deviation becomes zero. It has a control section 14b.

The defect detection/phase control device 20 has the function of a defect detection device that outputs a defect detection signal G when a misregister occurs during reprinting, and a correction motor that changes the phase of the roll paper 1 to coarsely adjust the register. This device also has the function of a phase control device that outputs a command F to the input terminal 9.

The forward/reverse discrimination circuit 21 of this device 20 uses a count signal A
By comparing the phase of the count signal B and the phase of the count signal B, it is determined whether the encoder 11 and, in turn, the plate cylinder 7 are in the normal or reverse direction. During printing, the encoder 11 and the plate cylinder 7 rotate normally. The pulse number correction circuit 22 corrects the number of pulses of the input count signals A and B so that the plate surface of the plate cylinder 7 (Chief 630 Peng) is 0.1+a.
A pulse signal P in which one pulse corresponds to m is output. The specific method of pulse number correction is based on the count signal A.
, B is multiplied by 4 to make 1000G pulses, and then the number of pulses is thinned out at a ratio of 165150/262144 using a pulse number compensator (commercially available as a custom IC).

The first counter 23 counts the number of pulses of the pulse signal qP and outputs a count integrated value Q. This counter 23 is cleared every time the zero signal Z is output, and the count integrated value Q returns to zero.

In the first comparison M24, a reference pulse value R corresponding to the reference position on the circumferential surface of the #ji cylinder 7 is set, and the number of pulses of this reference pulse value R is such that when the registration is correct, a zero signal is generated. This is the number of pulses of the pulse signal P that occurs during the period after mark detection signal 12m is output. Then, the comparator 24 determines that the count integrated value Q is the reference pulse value R.
A count start signal S is output when the count becomes equal to .

The second counter 25 counts the pulse signal P from the time when the count start signal S is input to the time when the mark detection signal 12m is input, and outputs the count integrated value T thus counted. This count integrated value T is a value that corresponds to the amount of deviation between the pattern printed in advance on the roll paper 1 (preprint section) and the pattern that will be reprinted from now on (reprint section), and when the registration is correct, the count integrated value T becomes zero. Then, when the zero signal Z is input, the count integrated value T is cleared.

The calculation device 26 calculates the deviation U between the previously printed pattern and the pattern to be reprinted based on the h-runt integrated value T.

The arithmetic unit 26 outputs a command F to operate the correction motor 9 so that the misregistration deviation υ becomes zero and the register is correct in order to perform phase control. When the phase of the image pre-printed on the roll paper 1 is ahead of the phase of the plate on the tab 9 and the plate cylinder 7, the collector motor 9 is activated to increase the tension of the roll paper 1, and vice versa. When the phase of the pattern printed in advance lags behind the phase of the image, the correction motor 9 is operated to lower the tension of the roll paper 1. By doing so, the deviation becomes smaller. The deviation is also displayed in the display word 27.

And the deviation is the plate register f/IJI attached to the printing press!
l Once it is within the correction range of the device (±1.5+m), the reprint control value! The control is switched to the command E of 1114. Thereafter, tension control is performed so that the pitch of the register mark becomes equal to the reference pitch.

On the other hand, in order to detect defective reprinting, the deviation deviation U obtained by the arithmetic unit 26 is sent to the second comparator 28. A permissible deviation deviation V is set in the comparator 28 by a permissible value input device 29. This allowable deviation deviation V is the maximum value allowed as the amount of deviation between the pre-print part and the reprint part. If a deviation larger than this allowable deviation deviation ■ occurs, it will result in a printing defect, and the printed part with the deviation will be damaged. Discard as paper. Then, the comparator 28 compares the deviation deviation U and the allowable deviation deviation (2), and outputs a defect detection signal G when the deviation deviation U is larger. As a matter of course, the additional printing failure detection based on the comparison N28 continues even after switching to the control by the additional printing control device 14.

By outputting the defect detection signal G, it is possible to notify that a printing defect has occurred. For example, an alarm bell can be installed, and the alarm bell can be activated by the defect detection No. G to notify of a defect in reprinting. In addition, if the drag device section is equipped with a spray marking device and the defect detection signal activates the spray marking device to spray ink on the edges of the signatures, marked defective paper can be easily removed. Be able to do it. Furthermore, in the case of a device equipped with a double delivery type paper ejecting device, the paper is delivered to one of the paper ejecting devices under normal conditions, and when a defect detection signal G is output, the paper ejecting section is switched and the defective paper is delivered to the other paper ejecting device. The system can also be configured to eject to the side.

<Effects of the Invention> As specifically explained above in conjunction with the embodiments, according to the present invention, a defect detection signal is automatically output when the registration between the preprint section and the additional printing section is misaligned when performing additional printing. As a result, the occurrence of defective paper can be detected without constant human monitoring, preventing the contamination of defective paper and improving quality.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an embodiment of the present invention, and FIG. 2 is a schematic diagram showing a conventional technique. In the drawing, 1 is a roll paper, 2 is a dancer roller, 3 is a roller, 4.6 is a guide roller, 5 is a tension roller 1, 7 is a plate cylinder, 8 is a harmonic drive, 9 is a corrective motor, 11 is an encoder , 12 is a photoelectric sensor) 12a is a mark detection signal, 13 is a tension sensor 1, 14 is a reprint control device, 14a is a register control section, 14b is a tension control section, 20 is a defect detection/phase control device, 21 is a positive 22 is a pulse number correction circuit, 23.25 is a counter, 24 is a comparison type, 26 is an arithmetic unit, 27 is a display type, and 28 is a comparison type.

Claims (1)

[Claims] When printing with a rotary printing machine on a roll paper that has been printed and has reference marks attached at intervals, the difference between the previously printed pattern and the pattern to be printed is detected. This is an additional printing defect detection device that detects misregistration, and includes a detector that detects a reference mark on roll paper and outputs a mark detection signal every time the reference mark is detected, and a detector that rotates once when the plate cylinder rotates once. A rotary phase detector is attached and outputs a count signal and a zero signal, and a reference position on the plate cylinder circumferential surface is determined based on the count signal and zero signal, and a reference position is determined on the roll paper based on the mark detection signal. A circuit that identifies the position of the reference mark and outputs an integrated count value that indicates the positional relationship between the reference mark position and the reference position, and a circuit that outputs a count integrated value that indicates the positional relationship between the reference mark position and the reference position. A calculation device that calculates and outputs a deviation indicating the degree of deviation from a predetermined positional relationship, and a device that outputs a defect detection signal when the deviation is larger than a preset allowable deviation. 1. A defect detection device for reprinting, comprising: a defect detection device equipped with a comparator that outputs an output.