JPS62201751A - Defective signature checking device - Google Patents

Abstract

PURPOSE:To detect shifting of folding position of a signature and bending thereof automatically and correctly by measuring the area of the signature within a field of view of image pickup means to be compared with a reference area. CONSTITUTION:Area measuring circuits 106, 107 measure the area of the corner portions of a signature within fields S1, S2 of view of sensor heads 101a, 101b and signals A1, A2 are supplied to comparison circuits 110, 111. Simultaneously, signals G1, G2 concerning the corner portion of the side end front portion of the signature and the corner portion of the side end rear portion thereof output from reference area setting portions 108, 109 are supplied. The comparison circuits respectively compare the signals A1, A2 with the signals G1, G2 and calculate a difference therebetween. Difference signals D1, D2 showing the comparison results are respectively supplied to decision circuits 112, 113. The decision circuits judge whether the difference signals are within the specified permissible range or not, and decide if the signature is regular or not, and in case of any defective signature, signals J1, J2 are supplied to a display portion 114.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a folding defect inspection device for detecting folding defects and folding accuracy of signatures folded to a predetermined size by a folding machine connected to a rotary printing press.

[Conventional technology]

In general, a rotary printing press is connected in-line with a triangular plate, a rotary folding machine, and a chopper folding machine for folding the web after printing into predetermined specifications (size, number of pages, fold strength). Ordinary folding machines can be roughly divided into A-size series and B-size series, depending on the size of the printing press, and each can produce several types of folds. Although the machine is adjusted so that each sheet is folded at a predetermined position, some signatures may not be folded at the correct position due to poor paper tension, changes in printing press speed, etc. The causes of this include fluctuations in the running state of the paper due to fluctuations in paper tension, and the fact that the signatures are not held parallel to each other due to the relationship between the mouth and the insert blade.

For this reason, the printing operator must inspect the signatures each time they are discharged from the folding machine. However, folding defects do not necessarily occur continuously and may not be detected immediately, making it difficult to prevent paper loss. Furthermore, if a folding defect is discovered, it becomes necessary to go back and inspect the signatures from a long time ago, resulting in a loss of time.

[Problem that the invention seeks to solve]

This invention was made to deal with the above-mentioned circumstances,
It is an object of the present invention to provide a folding defect inspection device having a simple configuration capable of automatically and accurately detecting deviations and bends in folding positions of signatures.

[Means for solving problems]

The folding defect inspection device according to the present invention includes an imaging means for imaging two corners, a front corner and a rear corner of one side edge of a printed matter discharged from a rotary folding machine and conveyed to a chopper folding machine; The apparatus includes a means for measuring the area of the signature within the field of view of the imaging means from the output of the image pickup means, and a determining means for comparing the measured area with a reference area and detecting folding defects according to the comparison result.

[Effect]

According to the folding defect inspection device according to the present invention, images are taken of two corners, a front end corner and a rear end corner of one side edge of a printed matter discharged from a rotary folding machine and conveyed to a chopper folding machine, and the imaging means By measuring the area of the signature within the field of view and comparing the measured area with a reference area, defects such as chopper folding and jaw folding can be detected.

〔Example〕

An embodiment of the folding defect inspection apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing the configuration of a folding machine of a rotary printing press equipped with a folding defect inspection device according to a first embodiment. The folding machine consists of a rotary folding machine and a chopper folding machine. The printing paper (rolled paper) discharged from the fourth color printing unit is squeezed by a triangular plate 15, a nip roller 16, etc., and folded into two with the center line in the paper flow direction as a crease.

The paper folded into two is supplied to a rotary folding machine. The rotary folding machine has a folding body section consisting of an insertion section 17, a plug section 8, and a delivery section 19. The insert 17 is provided with a needle 23 that moves up and down at a predetermined timing in synchronization with the rotation of the insert 17, and that protrudes from the insert 17 or sinks into the body. When the needle 23 protrudes from the barrel, it pierces the tip of the two-fold paper, and the two-fold paper is wound around the insert 17 by rotation of the insert 17 (in the direction of the half-hour hand as shown by the arrow).

When the two-fold paper is wrapped around the insert 17 at a predetermined angle, it will flow due to the folding action of the insert blade 20 disposed on the insert 17 and the jaw 21 disposed on the stopper 18. It is folded into four around a predetermined fold orthogonal to the direction. After that, the needle 23 is buried in the insertion side 17, and the mouth 2
The four-folded sheet including the portion folded by step 1 is conveyed to the stopper 18 side. At that time, when the stopper 18 rotates by a predetermined angle, the cutting blade 24 arranged on the stopper 1B and the holder 25 of the insert 17 cut the four-fold paper into a predetermined length to make signatures. . Furthermore, after that, when the stopper 18 rotates by a predetermined rotation angle, the stopper 18 and the delivery member 19 transfer the signature p held in the stopper member 18 to the claw 22 arranged in the delivery member 19. do.

Thereafter, the pawl 22 releases the signature p from its grip at the timing when the signature p is to be introduced into the conveyor belt 5 of the chopper folding machine. As a result, the signatures folded into four by the rotary folding machine are supplied to the chopper folding machine.

The signature p is conveyed while being sandwiched between the conveyor belts 5 of the chopper folding machine until it hits the front stopper 4 of the chopper folding machine. The signature p is pushed between two opposing nip rollers 3, and is folded by the chopper blade 2 parallel to the paper flow.
Eight-fold signature p is obtained. This signature p is placed one portion at a time on a lower conveyor belt 13 by an impeller 12 provided below the nip roller 3. Due to this movement, signatures p are continuously produced by the folding machine.

In this embodiment, the good/bad quality of rotary folding (mouth folding) and chopper folding is detected by inspecting four-folded signatures supplied from the rotary folding machine to the chopper folding machine. For this reason, sensor heads 101a, 101b and a timing sensor 102 are provided above the chopper table 1 of the chopper folding machine, as shown in FIG. Sensor head I
The output from the timing sensor 102 is supplied to the inspection device main body 100. sensor head LO
1a and 101b are provided on the left side in the flow direction of the signature p. The sensor heads 101a and 101b are composed of optical area sensors having a speed that can correspond to the signatures being conveyed, and their imaging fields of view s, s2 are respectively located at the left end of the signature p in the conveyance direction, as shown in FIG. It includes two corners, one at the front end and the other at the rear end. Sensor head 1ota, L
Olb may be a small television camera. Note that to increase accuracy, a shutter synchronized with the speed of the sensor head and strobe lighting may be used together. timing sensor 1
02 is an optical sensor (e.g. , transmissive or reflective beam switch, etc.).

Here, the sensor heads 101a and 101b are configured to image the corner of the side edge of the signature p on the left side in the flow direction, even if the width of the printing paper changes. This is because the position does not change.

The position of the fold in two by the triangular plate 15 in the rotary folding machine does not change even if the width of the printing paper changes.

If the sensor heads 1OLa and 1o1b are configured to image the side edge of the signature p on the right side in the flow direction, the sensor head LQLa is activated every time the width of the printing paper changes.

The position of 101b must also be changed. Contrary to FIG. 1, if the triangular plate 15 is on top of the printing paper, the fold will be on the right side in the flow direction of the chopper folder.

The principle of detecting defective signatures according to the present invention will be explained with reference to the example of defective signatures shown in FIG. Figure 4(a) shows the normal case, Figure 4(b) shows the same case when the fold k of the mouth fold is shifted parallel to the other, and Figure 4(C) shows the same case when the fold k of the mouth fold is bent. Figure (d) shows a case where the chopper fold line C is shifted in parallel, and Figure (θ) shows a case where the chopper fold line C is bent. In both of these cases, the positions of the front and rear corners of the side edges of the signature p are shifted, so the sensor heads 101a and 101b
The area of signature p within the field of view changes. Therefore, a defective fold can be detected by measuring the area of the signature p within the field of view of the sensor head 101aS101b and comparing it with a normal area.

This situation is shown in FIG. The normal signature p is shown by the solid line.
1, and the dashed line indicates signature p2 with a bent end fold.
The broken line indicates the signature p3 in which the chopper fold is shifted.

In this case, in the case of folding errors, the position of the front end of the signature p hardly changes, but the position of the corner of the rear end of the signature p changes significantly. Therefore, if the field of view S1 of the sensor head 10La is widened in the direction along the side edge of the signature p, the area change will be large even with a small folding defect, and accurate detection will be realized. Also, the field of view S2 of the sensor head 101b is the signature p.
If it is made large in the direction along the rear end, the change in area becomes large even in the case of a small degree of folding failure, and accurate detection can be realized.

Additionally, if the paper size of the printing machine changes, the position of the trailing edge of the signature p changes in the conveyance direction of the signature p, as described above, so it may be necessary to move the position of the sensor head totb in some cases. . Of course, if the field of view S2 of the sensor head 101b is widened in the conveyance direction of the signature p, the need to move the sensor head 101b is reduced, but this tends to reduce the resolution, so the sensor It is necessary to set the field of view S2 of the head LO1b.

Inspection device main body 1 that performs detection based on such a principle
A circuit diagram of 00 is shown in FIG. sensor head 101a,
Imaging signals 11 and I2 outputted from 101b are supplied to binarization circuits 104 and 105, respectively.

Normally, the signature p has a lower reflectance than the chopper table, so the image signal 1. ．． In No. 12, the signature part is at a low level, and the chopper table part as a background is at a high level. Therefore, the binarization circuits 104 and 105 binarize the image signals 11 and I2 at a threshold level intermediate between the signal levels of the signature part and the chopper table part, so that the signature part has no level signal and the chopper table part has no level signal. Binarized signals B1 and B2 whose portions correspond to level signals are output.

Binarized signals B1 and B2 are each sent to the area measuring circuit 10B.
, 107. The timing signal t from the timing sensor 102 is also sent to the area measurement circuit toe.

107. The area measuring circuits 108 and 107 receive the input binary signal B1 when the timing signal t is supplied.
, B2, and count the number of sample data with no level. As a result, the area measuring circuits 10B, 1
07 is the field of view S1 of the sensor heads 101a and 101b,
The area of the corner of the signature in S2 is measured, and the area signals A1 and A are
2 is supplied to the first input terminal of the comparator circuit 110.111. The second input terminals of the comparison circuits 110, , ill receive reference area signals G1, G2 for the front corner of the side edge and the rear corner of the side edge of the signature, which are output from the reference area setting units 108 and 109, respectively. is supplied. Reference area signal G1, G
2 may be the area signals A and A2 obtained when the sensor head images the front corner of the side edge and the rear corner of the side edge of a normal signature, or may be used as is for multiple signatures. The area signals A1 and A2 may be averaged. Comparison circuit 110
．． 111 are area signals A1, A2 and reference signal G1, respectively.
, G2 and calculate the difference.

a difference signal D1 indicating the comparison result of the comparison circuits 110 and 111;
D2 are supplied to determination circuits 112 and 111, respectively.

The determination circuits 112 and 113 determine whether the fold is normal or defective depending on whether the difference signals D1 and D2 are within a predetermined tolerance range, and if the fold is defective, the defective folding signals J1 and J2 are displayed on the display section 114.
supply to. This allowable range is variable and can be freely set depending on the requirements for folding quality of signatures, inspection accuracy, etc.

Here, since two area signals from the sensor heads LO1a and LOLb are used, reliable inspection is possible.

If inspection is performed using only one of these methods, deviations in chopper folds may be detected, but chopper folds or mouth folds may not be detected.

A timing signal t from the timing sensor 102 is also supplied to the display section 114. The display unit 114 issues a warning as a fold failure if any one of the fold failure signals J1 and J2 is supplied when inspection of the signature is instructed by the generation of the timing signal t. The display mode may be a buzzer sound or lighting of a lamp, or an information signal corresponding to the number of occurrences may be generated and fed back to the adjustment control section of the folding machine to automatically adjust the folding machine.

In this way, according to this embodiment, images are taken of two corners, the front corner and the rear corner of one side of the printed matter discharged from the rotary folding machine and conveyed to the chopper folding machine, and the imaging means By measuring the area of the signature within the field of view and comparing the measured area with a reference area, defects such as chopper folding and jaw folding can be reliably detected.

Note that the present invention is not limited to the embodiments described above, and the detailed configuration of each part can be variously changed.

〔Effect of the invention〕

As explained above, according to the present invention, various folding defects can be detected with high precision with a simple configuration, and the quality of printed matter can be stabilized.
It is possible to provide a folding defect inspection device that can contribute to reducing paper waste.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the configuration of a folding machine of a rotary printing press equipped with a first embodiment of a folding defect inspection device according to the present invention;
The figure is a plan view showing the arrangement of the sensor in the first embodiment, Figure 3 is a diagram showing the field of view of the sensor head in the first embodiment, and Figures 4 (a) to (e) are diagrams showing examples of folding defects. , 5th
The figure is a diagram showing changes in the area of the corners of the signature within the field of view of the sensor head in the case of defective folding, and FIG. 6 is a block diagram showing the circuit configuration of the first embodiment. ■... Chopper table 2... Chopper blade 5... Conveyor belt 15... Triangular plate 17... Insertion cylinder 18... Plug 19... Delivery cylinder 100... Inspection device main body 10La, 101b...Sensor head 102...
Timing sensor 104.105... Binarization circuit toe, 107... Area position measurement circuit 112.1
13... Judgment circuit 114... Display circuit Applicant's agent Takehiko Suzue, patent attorney Figure 2 $1 ≦2 Figure 3 (d) (e) Figure 4 Figure 5

Claims (2)

[Claims] (1) An imaging means for imaging two corners, a front corner and a rear corner of one side edge of a printed matter discharged from a rotary folding machine and conveyed to a chopper folding machine, and imaging from the output of the imaging means. A folding defect inspection device comprising means for measuring the area of a signature within the field of view of the means, and determining means for comparing the measured area with a reference area and detecting folding defects according to the comparison result. (2) The folding defect inspection device according to claim 1, wherein the one side end is a side end where there is a two-fold crease formed by a triangular plate.