JP3454823B2 - Apparatus for measuring misregistration between individual colors in multi-color printing on a web-rotary printing press - Google Patents

Description

The invention relates to a device for measuring the misregistration between individual colors during multicolor printing in a web-fed rotary printing press as claimed in the preamble of claim 1. .

Web with one dryer for each printing mechanism-
In a rotary printing press, one register mark is printed on a strip arranged next to the actual image in order to detect misregistration after passing through each printing mechanism. Therefore, after passing through the second printing mechanism, there are two registration marks, which represent the colors to be printed, respectively, or their relative position to each other, whereby in the case of four-color printing. After passing through the four printing mechanisms, a total of four registration marks are present on the side strips.

After passing through the second printing mechanism, a first check is made of possible misregistration. For this reason, according to a device of the aforementioned type, which is known, for example, from DE 4037728, a web inspection can also be configured in each inspection head, for example in the form of a fiber optic measuring receiver. The member exists. In a fiber optic measurement receiver, the web inspection members can only be spaced with a minimum mutual spacing of 18 mm due to their constructional dimensions. As a result, the registration marks must be placed with a minimum mutual spacing of 20 mm. With such a device, misregistration is detected by the measurement reception of one and two color, two and three color and three and four color register marks. A time signal is specified as a measurement value for generating the register shift by multiplying the respective web speed.

In this case, first of all, the fact that the space in the lateral strips on which the register marks are printed is limited results in the disadvantage that the register marks themselves require large dimensions. Because the registration mark is 20mm in the running direction of all printed paper.
Because they are printed at mutually spaced intervals, which results in space problems for printing additional marks that are also required on the lateral strips in some printing methods.

In addition, there is a light spot adjustment error that causes a 20 mm gap in the pre-applied registration marks. because,
This is because the optical axes of the web inspection members cannot be precisely aligned with each other so that the 20 mm spacing can be accurately maintained. However, the evaluation device and the control device for correcting the misregistration receive an actual value of 20 mm, so that the adjustment error must be compensated for by a fine adjustment by hand. This is only done by experts and is even more time consuming.

The object of the invention is therefore to provide a web according to the preceding concept of claim 1 which is simple in construction and allows space saving in the lateral strips present for the arrangement of the register marks. It is an object of the present invention to provide an apparatus for measuring misregistration between individual colors when printing multiple colors in a rotary printing press.

This problem is solved by the features of claim 1.

With the device according to the invention, the spacing between individual register marks or printed marks can be reduced to a scheduled spacing of 3-5 mm. This results in significant space savings as well as anti-waste paper savings.

Furthermore, in the device according to the invention, only one web inspection member needs to be mechanically adjusted, in which case:
In principle, detection can be carried out on the rollers.
More advantageously, fluttering of the web can be eliminated and dead time is saved in the device according to the invention.

Furthermore, an absolute distance measurement of the distance between the two registration marks can be carried out, which has the further advantage that nulling is no longer necessary. This allows
Saves dead time and waste of waste paper. The scheduled mark interval indicates that the print registration is zero.

Another advantage of the device according to the invention is that the switching from level control to sequence control is also possible, preferably automatically, for example during machine operation or during web change. In this case, level measurement means a measurement in which the misregistration is always related to the first color. In this case, however, the known device has the disadvantage that printing is no longer performed in the state of the printing press, which results in
The measurement has to wait until the first color reaches the final printing mechanism.

Such a drawback can be eliminated in the device according to the invention by first performing a sequence measurement, in which the measurement is performed by the respective preceding color. If all the colors have been printed and arrive at the last printing mechanism, the device according to the invention can be advantageously and automatically switched over to the level measurement described above, which results in anti-waste paper savings. Can be achieved.

In the device according to the invention, in which the detection of two marks is carried out by only one web inspection element, the register marks or print marks are arranged one behind the other in the direction of travel of the whole printing paper. The printed marks can be detected optically as in the case of conventional double web inspection members,
It is converted to an electrical analog signal and sent to an automatic registration device. However, unlike traditional types of devices,
Advantageously, only electrical signals need be sent to the automatic registration device.

The dependent claims describe advantageous refinements of the invention.

The web inspection element is preferably designed as a fiber optic web inspection element.

In the device according to the invention, the advantage is that the mark spacing can be clearly shortened, even if the register marks are arranged in front of and behind one another and at a distance from each other, also aligned in the running direction of the printing paper. As a result, the space problems mentioned at the beginning no longer occur when using the device according to the invention.

An electrical window is attached to select the register marks detected and evaluated by the evaluation device. The window selects the detected mark and thus, at each measuring point, despite the aligned placement of the register marks, and despite the fact that only one web inspection member is present, always The dragonfly that must be used to measure the misregistration at each time is detected and evaluated.

With the device according to the invention, measurement reception is preferably carried out in dependence on each printing mechanism.

The details, features and advantages of the invention will become apparent from the following description of an embodiment with the aid of the drawings.

However, in the drawings: FIG. 1 is a highly simplified schematic view of an automatic registration device for monitoring a web-fed rotary printing press, including a measuring device according to the invention, and FIG. FIG. 4 is a schematic view showing a section of the whole paper and a web inspection member schematically shown, and FIG. 3 corresponds to FIG. 2 of a register mark configuration corresponding to a web inspection member which is schematically simplified. Fig. 4 shows a signal generated through the device according to the invention
FIG. 6 is a diagram showing an example, FIG. 5 is a diagram for explaining a first example of signal generation, and FIG. 6 corresponds to FIG. 5 of a second example for signal generation. It is a figure.

In the schematic simplified view of FIG. 1, an automatic registration with a control device 1 for monitoring a web-rotary printing press 2 as is known in principle from DE 40 37 728 A1. A device is provided and in this case the device according to the invention is incorporated in an automatic registration device. The invention is embodied both in a separate device for measuring misregistration as well as in an automatic registering device, which comprises the device according to the invention as claimed in the claims of the present application. In order to supplement the content, the complete published content of German Patent DE 4037728 is cited in the content of the present application.

The web-fed rotary printing machine 2 shown in FIG. 1 has four printing mechanisms 3 to 6 in the embodiment, in which yellow, red, blue and black inks are printed. The running printing all-paper-shaped printing material 7 is successively introduced.

For this purpose, each of the printing mechanisms 3 to 6 has a respective impression cylinder 8, 9, 10 and 11 which rotates in the ink fountain. As shown in FIG. 1, the material web 7 is sequentially guided through the printing mechanisms 3 to 6, in which case the material web 7 is guided via the impression cylinders 8 to 11, respectively.

Each printing mechanism of the web-fed rotary printing machine 2 further comprises drying devices 12, 13, 14 and 15, which drying devices 12 to 15 are located under the pressure of their own when viewed in the direction of travel of the material web 7. It is located behind the torso 8, 9, 10 and 11. Dryer 12 ~
15 can also be configured, for example, in the form of a drying drum.

Furthermore, the printing mechanism 3,4, which has a registration roller device,
5 has adjusting members 16, 17 and 18, which have an adjusting motor 19, 20 and 21, respectively.

The automatic registration device, which shows a control device arranged in a casing (not shown), has a center unit 22 for detecting and storing all control parameters and control characteristics.

Furthermore, the automatic registration device has a plurality of control units, which are designed, for example, as pluggable modules, of which the control unit 23 is shown. These control units are used for control of top-and-bottom registration and / or for combined control of top-and-bottom registration and left-to-right registration. Also, for this purpose, the adjusting motors 19 to 21 mentioned above act on the adjusting members 16, 17 and 18, respectively.

As explained at the outset, in multicolor printing carried out on the web-fed rotary printing machine 2, the device according to the invention for measuring the misregistration between the individual inks is incorporated in the overall device described in FIG. Has been. The device according to the invention comprises an inspection device 24. The inspection device 24 includes a printing mechanism 4,
The inspection heads 25, 26 and 27 are provided at the respective measurement points in 5 and 6. These inspection heads 25 to 27 detect register marks or register marks P1 to P4 (see FIGS. 2 and 3). For this reason, the inspection heads 25, 26 and 27 are
It is arranged at a suitable point in 4, 5 and 6 behind the impression cylinder in the running direction L of the web material 7.

The inspection heads 25, 26 and 27 are connected to the signal receiving unit of the inspection device 24. This inspection device 24 further provides the detected signal to an evaluation device 33 which is connected to the center unit 22. This evaluation device 33 displays the individual register marks P1 to P4.
The relative position of each other is measured.

In contrast to previously known devices for measuring misregistration, the device according to the invention has each inspection head 25-27 having only one web inspection element. This web inspection member is designated by T ₁ , T ₂ and T ₃ in FIG.

The web inspection elements T _{1 to} T ₃ are preferably embodied as fiber optic web inspection elements. These web inspection members T _{1 to} T ₃ optically detect the register marks P _{1 to} P ₄ and generate electric analog signals, which are sent to the evaluation device 33. The evaluation device 33 measures the regulation of the relative positions of the register marks P1 to P4 using the sent signal, and the generated result is controlled by the control unit via the center unit 22.
It is supposed to be sent to 23. The control unit 23 is further connected via conductors 40, 41 and 42 to adjusting motors 19, 20 and 21 for carrying out registration correction.

In the schematic and highly simplified view of FIG. 2, a portion of the material web or printed whole paper 7 having four images 43, 44, 45 and 46 is shown in this example. Image 43
To 46 correspond to the register marks P1 to P4, and these register marks P1 to P4 are printed together on the side strip 47 of the printing paper 7 when the images 43 to 46 are printed. Image 44,45 from FIG.
And the correspondence of the web inspection members T ₁ , T ₂ and T ₃ to 46 is clear. Here, only one web inspection element T ₁ , T ₂ or T ₃ is provided for each measuring point and inspection head, which web inspection element detects the respective register marks and produces a corresponding signal.

FIG. 3 shows the arrangement of the register marks P1 and P2 and the distance A between them. From this figure, the register marks are arranged in front of and behind each other when viewed in the running direction L of the printing paper 7,
And correspondingly the respective web inspection component T ₁ , T ₂ or T
Clearly detected by ₃ . Interval A is
It can be suppressed to 3-5 mm.

The distance A between the two register marks is detected via a signal generator, for example the rotation signal generators 30, 31 and 32 shown in FIG. Accordingly, as shown in FIG. 4, the counter is started by the leading edge V1 of the first signal S1 received by the respective web inspection member and stopped by the leading edge V2 of the second signal S2. The number of generated pulses directly corresponds to the distance A between the stroke distances or the register marks (for example, 5 pulses corresponds to a distance A of 5 mm), so that the device according to the invention Direct spacing measurements can be made. The deviation of the detected distances from the previously known actual distances between the register marks makes it possible to measure the misregistration of each.

To further illustrate and clarify the device of the present invention, FIG.
And FIG. 6 will be described below.

The presence of only one web inspection member T ₁ , T ₂ or T _{3 for} each inspection head causes a time lag between the registration marks P ₁ to P ₄ . This shift depends on the distance A between the register marks.

In order to digitize and reprocess the marks, each mark itself is digitized. Therefore, there are separate gates (gate 1, gate 2 in FIGS. 5 and 6) along each mark. In this case, the digitization principle for each mark corresponds to the principle in the double web inspection element. In the control device 1 shown in FIG. 1, an analog signal is applied to the same two digitizing stages, to which digitizing gates 1 and 2 respectively, one of the two gates, have corresponding marks. Sent for evaluation.

The spacing of the marks corresponds to the spacing in the image in a device according to the invention which uses only one web inspection member per measuring point. These intervals must be measured. For this reason a third gate (measurement gate) is used. This measuring gate has both digital marks K
It exists along 1, K2. These signals are sent to the counter stage previously mentioned for the measurement, which counter stage performs the described direct distance measurement.

The printing intervals of the marks corresponding to the distance A are then processed by suitable software.

According to FIG. 6, the distance between the register marks can be changed and input in principle. That is, a third or a plurality of other marks may be located between the detected marks. This advantageously makes it possible to switch the measuring method (level control or sequence control) or to arrange different register marks.

By means of the measuring device according to the invention, or an automatic registering device equipped with this measuring device, a web / web or web / cylinder control can advantageously be implemented.

For this reason, as explained at the beginning of the description with reference to the drawings, the invention provides, in addition to the measuring device defined in the claims, for automatic registration for multicolor printing in a web-rotary printing press 2. It is also embodied in the device. The web-fed rotary printing press has a control device 1 with a center unit 22 for detecting and storing all control parameters and control characteristics, and further controls upside-down registration and / or left-right registration. For this purpose, an inspection device 24 having a plurality of inspection heads and adjusting members 16, 17 and 18 is provided. In this case, measuring points and inspection heads 25-27
Only one web inspection element T ₁ , T ₂ and T ₃ is provided for each of the types and methods already mentioned.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-62-39242 (JP, A) West German Patent 4037728 (DE, B) (58) Fields investigated (Int.Cl. ⁷ , DB name) B41F 33 /14

Claims (3)

(57) [Claims] 1. A printing mechanism (3 to 3) for all printing paper (7).
In order to detect the register marks (P1 to P4) printed in different colors by 6) and having a predetermined length with respect to the traveling direction (L) of the printing all paper (7), the printing mechanism (3 to
6) An inspection device (24) having one inspection head (25 to 27) at each measurement position of the second and subsequent printing mechanisms (4 to 6), and detection of the inspection device (24). An evaluation device (33) for measuring the relative positions of the individual register marks (P1 to P4) based on the results, and an adjustment motor provided in each of the printing mechanisms (3 to 6) for performing registration correction. And a control unit (23) for controlling (19 to 21) based on the measurement result of the evaluation device (33). Of each of the inspection heads (25 to 27) has one fiber optic web inspection member (T ₁ , T ₂ , T ₃ ). The printing mechanism (3) prints the first register mark (P1) at a predetermined position on the printing all paper (7), The printing mechanisms (4 to 6) of the above are aligned in the running direction (L) of the printing paper (7) with respect to the register marks printed by the immediately preceding printing mechanism, and are arranged in front of the running direction and spaced from each other. first signal produced by printed register mark (P2 to P4) corresponding respectively to so that each web inspection member _{(T 1, T 2, T} 3) detects the first through dragonfly (S1) front edge (V1) by to start the counter, the leading edge of the second signal each web inspection member _{(T 1, T 2, T} 3) is produced by detecting the register mark to pass the second (S2) of The counter is stopped by (V2), and at the time (t) between the start and stop, the signal generator (30,31,3
2) Multicolor in a web-fed rotary printing press, characterized in that the distance (A) between the register marks (P1 to P4) is detected based on the total number of pulses counted by the counter. A device that measures the misregistration between individual colors when printing. 2. Device according to claim 1, characterized in that it is equipped with electrical windows for selecting the register marks (P1 to P4) detected and evaluated by the evaluation device (33). 3. Device according to claim 1, characterized in that it has a switching device for switching between sequence measurement and level measurement.