JPS5811158A - Twisted register detection device for rotary printing presses - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a twist register detection device for detecting whether or not a printing plate mounted on a plate cylinder of a rotary printing press is correctly mounted on the plate cylinder without one twist. It is related to.

When the printing plate is attached to the plate cylinder by one screw, the printing condition becomes oblique with respect to the paper, so various proposals have been made regarding means for detecting installation errors in the twisting direction of the printing plate. However, it has not yet been put to practical use. Conventionally, the mounting state of the printing plate was adjusted by visually judging the printing situation while repeating trial printing and stopping the printing press. This has the drawbacks that it takes a long time and requires a great deal of skill for adjustment.

The present invention has the purpose of fundamentally eliminating such drawbacks of the conventional technology, and aims to provide a pair of register marks at symmetrically opposite positions in the vertical direction on the printing plate surface, and to use a mark sensor provided opposite to the register marks. We have developed an extremely effective torsional register detection device for rotary printing presses that detects torsional register errors in printing plates by detecting them as electrical signals and electrically processing this detection output. It is something.

Hereinafter, the present invention will be explained in detail with reference to figures showing examples.

FIG. A pair of register marks 3m and 3b are provided, and in this example, each register mark is formed as a plane line along the vertical direction.

FIG. 2 is a diagram showing the relationship between a printing plate and a mark sensor, etc., in which a printing plate 5 is mounted on a printing cylinder 4 rotating in the direction of the arrow, and is opposed to register marks 3m and 3b on its surface. Only one reflective light-receiving type mark sensor 6 is provided, and this f'L generates a detection output corresponding to the rotating register marks 3a, 3bVc.
On the side surface of the plate cylinder 4, there are adjacent objects 7a, such as bolts, corresponding to the V raster marks 3a, 3b.

7b is fixed, this is detected by a proximity switch 8vc as a pulse word generator, and the next pulse signal is generated in synchronization with the detection output of the mark sensor 6 in accordance with the rotation of the plate cylinder 4. It has become.

In addition, printing plate 5 is a "plate vise device for sheet-fed printing presses" (utility model registration order, June 1, 1981) filed separately by the applicant.
It is wound around the plate cylinder 4 and mounted on the plate cylinder 4 by a method such as 3).

3 and 4 are configuration diagrams of the mark sensor 6, in which light lfM from a light source 21 such as a lamp is transmitted to a mirror 2
The light is condensed and projected by two or divided mirrors 22a and 22b, and the reflected light from both points in the left and right direction of the register mark 3 is received by a pair of light receiving elements 24a and 24b through lenses 23a and 23b, and the light is reflected from the left and right sides of the register mark 3. 3 is detected as an electrical signal. Note that 25a to 25e are light shielding plates.

Figure 5 is a block diagram of the electric circuit, and the light receiving element 24m
, 24b are amplified by a total amplifier AI+A2, and then both outputs are given to a differential amplifier DA. After determining the detection level difference between the light receiving elements 24m and 24b, a holding circuit I (Dl) such as a capacitor memory is applied. .

It is given to HD2.

10,000, the pulse signal from the proximity switch 8 is sent to the pulse separation circuit 1i, which is configured by a flip-flop circuit, a Gerd circuit, etc. Here, the nl given to 3PSE is separated into those corresponding to the proximal body γa and those corresponding to the proximal body 1b, and the one corresponding to the proximal body 7a corresponding to the register mark 3a is sent to the holding circuit HDI, and the one corresponding to the proximal body 7a is sent to the register mark 3b. The signal generated by the corresponding near-i body 7b is sent to the holding circuit HD2 as a strobe signal.

Therefore, the holding circuit HD1 has a detection level difference corresponding to the register mark 3a, and the holding circuit HD2 has a detection level difference corresponding to the register mark 3b.
The respective held outputs of n, n, etc., which are repeatedly held, are compared by a comparator CP and sent out as a twisting register detection output OUT.

Therefore, with respect to the straight line 10 in the vertical direction perpendicular to the rotation axis 9, the register marks 3m, 3b are displaced in the left-right direction, so to speak, the amount of light incident on the light receiving elements 24m, 24b becomes non-uniform, and this difference The output is determined by the dynamic amplifier DA, and is held in the holding circuits MDI and HD2 in correspondence with the register marks 3m and 3b, respectively, and the difference between the two holding outputs is further determined by J-1; the yield CP is calculated. This output indicates the position of the register marks 3a, 3b (i') with respect to the straight line 10, and this represents the torsional register error of the printing plate 5.

Note that the torsional register detection output OUT is displayed on a predetermined display device''!
By adjusting the mounting status of the printing plate 5 on the plate cylinder 4 according to the displayed values given to the height indicator, etc., the torsional registration error can be easily and quickly adjusted.

In addition, the above-mentioned "plate vise device" comes with a scale for adjusting the PL, and by adopting this, the PL adjustment can be adjusted according to the correlation between this scale and the detected torsion registration error. If you do it,
Adjustment becomes easier.

However, instead of the proximity switch 8, a rotary encoder connected to the rotating shaft 9 may be used, and the output of the differential amplifier DA may be converted into a digital signal, and the holding circuits HDl, H
The same effect can be achieved even if a general memory or the like is used for D2, and various modifications are possible.

In addition, since the detection output obtained from the pair of light receiving elements 24m and 24b is taken out via the differential amplifier DA (i7), in-phase noise components are suppressed and detection accuracy is improved. It is possible to obtain the torsional appearance error detection accuracy fc of Cheng Fart.

As is clear from the above description, according to the present invention, the twist and misregistration errors in printing plate installation can be detected stably and with high accuracy using a single mark sensor, and the configuration is simplified and the rotary printing machine Adjustment of the mounting status of the printing plate on the plate cylinder becomes easy and quick, and this has a remarkable effect in rotary printing presses for various uses.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention, in which Fig. 1 is a plan view of a printing plate, Fig. 2 is a diagram showing the relationship between the printing plate and mark sensors, etc., and Figs. 3 and 4 show the configuration of the mark sensor. The figure shown in FIG. 5 is a block diagram of the electric circuit. 3g, 3ba * a-register mark, 4e...
Plate cylinder, 5φ...Printing plate, 6...Mark sensor, 74
, 7b... Proximity body, 8... Proximity switch (pulse generator), 24a, 24b... Light receiving purple sweet potato, DA
...differential amplifier, river) 1, HD2...holding circuit, cp...comparator. Patent applicant: Komori Printing Machinery Co., Ltd. Agent: Masaki Yamakawa (1 person) 317

Claims (1)

[Claims] A single plate having a pair of 7 register marks provided at symmetrically opposite positions in the vertical direction on the printing plate surface attached to the plate cylinder of a rotary printing press, and a pair of light-receiving purple potatoes provided opposite to the register marks. a mark sensor, a differential amplifier receiving each detection output from each of the light-receiving purple sweet potatoes as input, and a pulse generator that generates a pulse signal synchronized with the detection output corresponding to each register mark according to the rotation of the plate cylinder. and each individual holding circuit that individually holds the output of the differential amplifier in response to the pulse signal in correspondence with the detection output corresponding to each register mark, and each holding output of each holding circuit is compared. A torsional register detection device for a rotary printing press, characterized by comprising a comparator that