EP2523809B1 - Method and apparatus for optimizing the relative position of at least two printing-unit cylinders - Google Patents

Description

The invention relates to a method according to the preamble of claim 1 and a device according to the preamble of claim 6.
Such methods and devices are used in printing machines and especially in flexographic printing presses for adjusting the distance of the cylinders involved in the printing process. Only when this distance is optimized, it comes to the order of a printed image, in which the ink transfer is in the desired range.
The EP 1249346 A1 proposes for this purpose, to examine the printed image, which comes after the hiring of the cylinder involved in the printing process against each other, with an optical sensor. Based on the results, the employment is optimized. This procedure leads to good starting results. However, at the beginning of the printing process, images of inferior quality are often printed until the job is optimized.
For waste prevention proposes the EP 1 916 102 A1 To measure the topography of the printing plate or the printing cylinder with a laser or by mechanical scanning and in this way to obtain values that can be used in the printing press before starting the printing operation for adjusting the printing cylinder. In this measurement of the surface of the printing plate cylinder, however, a number of factors that affect the transfer of color in the printing operation, not taken into account. These factors include the behavior of the printing plate under the conditions prevailing in the printing gap and the Change almost all physical characteristics of the pressure in the current printing operation.
In particular, in order to maintain a proper employment, it has been known for some time to monitor the pressure in the nip during the printing process. The EP 0 867 281 A1 suggests this for a flexographic printing machine. However, it has been shown that due to dynamic changes of the printing plates even at a constant pressure in the nip to undesirable changes in the printed image can occur.
The DE 10 2008 025 287 A1 discloses a method for adjusting the pressure in a nip at which the width of the print zone is measured. For this purpose, a flat sensor carrier is inserted into the nip. On this sensor carrier two pressure sensors are mounted at a certain distance from each other. With these pressure sensors, the pressure in the pressure gap can be measured and determine how wide the zone is, in which a certain minimum pressure is not exceeded.

The WO 2008/028516 A1 discloses a method and apparatus for determining the properties of a nip. With an optical measuring device, the rotational speeds of both rolls can be determined. From these measured values, the specific properties of the pressure gap can be determined.

Among the disadvantages of the method described above is that it can not be used in the current printing operation and that with it only the width of the Zugdruckzone and not their full-scale expression is measurable. Therefore, the object of the present invention is to remedy these disadvantages.
For this purpose, the invention of the DE 10 2008 025 287 A1 According to their teachings, the optimization of the relative position - before the printing operation - is performed on the basis of measured values.

The object is solved by the claims 1 and 6.

The present invention accordingly achieves the object by recording measured values which comprise first values relative to the size of the surface with which at least one of the cylinders involved in the printing process touches another body. This may once be the absolute size of this area meant. Of this size, however, a share of a possible contact surface can be derived. As already mentioned, the method according to the invention can also be used during printing operation under certain conditions.
In this case, the present invention makes use of the fact that, in particular in the gravure or high-pressure processes, it depends on which components of the printing form touch the printing material in the printing nip. When high pressure printing the raised areas of the printing form during gravure printing in the engraved areas color transported and also transferred to the substrate.
As a result, it is important for the quality of the print image that all areas of the printing form to be printed also come into contact with the printing material. The same naturally also applies to a color transfer between cylinders upstream of the printing gap. In flexographic printing machines, this can be the transfer of ink from an anilox roll to the forme cylinder. Also In offset printing presses, ink and / or fountain solution is transferred between a number of rollers.
Therefore, in the present invention, the size of the areas in contact with another body is measured. This further body can be another printing cylinder, the color to be transferred. When the two printing couple cylinders are printing plate cylinders and impression cylinders, the printing material imparts contact. However, it is also possible to introduce as an additional body an additional measuring body, which is otherwise not involved in the printing process.
If such a further body has the same distance from a printing cylinder as the respective other of the at least two printing group cylinders, the optimization of the relative position of the two cylinders relative to one another can easily be carried out with the aid of the measured values of the further body. However, the further body can also be one of the at least two printing cylinder. If the at least two printing cylinders of the printing plate and the impression cylinder, so often touch these under the intermediary of the printing material. In particular, when the measurements are carried out on the printing plate cylinder, the so-called area coverage, that is, the proportion of the print image is actually transferred to the substrate when the plate cylinder is in turn fully colored, by a measurement on the printing plate cylinder and not on the substrate such as for the doctrine of EP 1249346 A1 be determined. This possibility is very advantageous, since the completeness of the image transfer is of course exactly the size that one intends to optimize by setting the relative position.
In the context of the invention, it is provided that, in addition to the first values for at least one first physical quantity, second values are also measured for a second size. Thus, it is possible to measure the values of the size of the contact surface with a printing film having a plurality of pressure sensors, which can measure the contact pressure, which results in each case in a partial area of the area. The second measurement values may be pressure values that are expressed, for example, in eleven exposed areas of the nip. It is also possible with a flexible printing plate print marks on the substrate aufzudrucken and to use the increase in area of the pressure point as a result of an increase of Anstelldruckes as a second value. Alternatively, the positions of the roller bearings could also be assigned as second values to the respectively determined first measured values. Also, a measurement of the position of the respective roll shell - which could be done for example with optical measuring means - appears advantageous. Importantly, in all of these methods, certain first values relating to the interface can be assigned to the relative position of the rollers or to pressure in the nip. Often the determination of the second values will be limited to the front end areas of the roller.
The determination of the second values in addition to the first values is particularly advantageous if the determination of the first values takes place in a device which is external to the actual printing unit and is often referred to as external stretching. In this case, it can be determined in the external horizontal bar at which relative position and / or at which adjusting pressure (second values) to another body a satisfactory positioning situation (first values) is achieved. The printing unit cylinder thus measured can then be positioned in the printing unit accordingly (that is to say corresponding to the second values with good first values) to the at least one other printing unit cylinder.
On this catfish you can save the certainly more expensive measuring devices to determine the first values in the printing unit. Measured values for carrying out the method according to the invention can also be obtained by recording electromagnetic radiation. Often you will record this radiation, which is reflected by the surface of one of the inking cylinder.
One way is to take advantage of the effect of frustrated total reflection. For this purpose, a light-conducting body can be brought to the printing cylinder. In a contact between a total reflecting surface of the light guide or radiation conductor and the surface of the printing cylinder, the effect of total reflection is usually weakened (especially if the surface is optically denser (higher refractive index) than the light guide and a diffuse reflection on the surface of the cylinder leads.
aufzudrucken and to use the increase in area of the pressure point as a result of an increase of Anstelldruckes as a second value. Alternatively, the positions of the roller bearings could also be assigned as second values to the respectively determined first measured values. Also, a measurement of the position of the respective roll shell - which could be done for example with optical measuring means - appears advantageous. Importantly, in all of these methods, certain first values relating to the interface can be assigned to the relative position of the rollers or to pressure in the nip. Often the determination of the second values will be limited to the front end areas of the roller.
The determination of the second values in addition to the first values is particularly advantageous if the determination of the first values takes place in a device which is external to the actual printing unit and is often referred to as external stretching. In this case, it can be determined in the external horizontal bar at which relative position and / or at which adjusting pressure (second values) to another body a satisfactory positioning situation (first values) is achieved. The printing unit cylinder thus measured can then be positioned in the printing unit accordingly (that is to say corresponding to the second values with good first values) to the at least one other printing unit cylinder.
In this way one can save the certainly more expensive measuring devices for determining the first values in the printing unit. Measured values for carrying out the method according to the invention can also be obtained by recording electromagnetic radiation. Often you will record this radiation, which is reflected by the surface of one of the inking cylinder.
One way is to take advantage of the effect of frustrated total reflection. For this purpose, a light-conducting body can be brought to the printing cylinder. In a contact between a total reflecting surface of the light guide or radiation conductor and the surface of the printing cylinder, the effect of total reflection is usually weakened (especially if the surface is optically denser (higher refractive index) than the light guide and a diffuse reflection on the surface of the cylinder leads.

In this case, the light is diffusely reflected back into the light guide, traverses it substantially transversely to its original propagation direction, therefore hits at an acute angle to the printing cylinder remote from the surface of the light guide and therefore occurs - for lack of total reflection because of the acute angle - from the light guide out.
If the light reflected in this way is recorded by a sensor which measures the intensity of the reflected light or of the electromagnetic radiation, for example, a measured variable is obtained that depends on the size of the contact surface.
To improve the effect and to avoid contamination of the light guide, a further foil-like body will be provided between the cylinder surface and the total reflecting surface of the light guide, which, inter alia, has an optical density which weakens the total reflection to a suitable extent. The film may be attached to the cylinder or preferably the total reflecting surface in a manner that allows for more intimate contact of the film with the total reflecting surface due to the pitch of the cylinder.

• Es hat sich gezeigt, dass die Fläche, mit der eine Flexodruckplatte Farbe überträgt, als Funktion der Anstellung nach Erreichen eines ersten Berührungspunktes (oft Kiss-Print-Punkt genannt) stark ansteigt, um dann in eine Sättigung zu gehen. Daher ist es möglich, eine Optimierung der Relativposition der beteiligten Zylinder anhand des Verlaufs der Flächenzunahme herbeizuführen:
  • Zu diesem Zweck kann eine Überquetschung des zu messenden Zylinders vorgenommen werden, um in den Sättigungsbereich zu kommen. Es ist jedoch auch möglich, aufgrund einer analytischen und/oder empirischen Kenntnis des Sättigungsverhaltens den Anstellprozess bei einem bestimmten Kurvenverlauf zu stoppen.

Auf diese Weise kann eine optimierte Relativposition der zumindest zwei am Druckprozess beteiligten Zylinder angenommen werden, wenn die ersten Werte bei der Anstellung des zumindest einen Zylinders an den einen weiteren Zylinder einen Sollwert von einem Sättigungspunkt entfernt liegen.When evaluating the first values (regardless of whether with pressure sensors, optically or otherwise as measured), a comparison can be made with absolute nominal values. However, a target image, in which the pressure-active components of the printing plate are distinguished from inactive, appears to be more advantageous especially with regard to a printing plate cylinder in high or low pressure. By comparing the measured contact image ("where does contact") with the target image is also clearer, where employment is still catching up. Another possibility, which shows good results especially in the high-pressure process flexographic printing, is the evaluation of the area increase:

• It has been found that the area with which a flexographic printing plate transmits color increases sharply as a function of placement after reaching a first point of contact (often called a kiss-print point), and then saturates. Therefore, it is possible to optimize the To bring about the relative position of the cylinders involved based on the course of the area increase:
  • For this purpose, an over-squeezing of the cylinder to be measured can be made to come in the saturation region. However, it is also possible to stop the setting process for a specific curve due to an analytical and / or empirical knowledge of the saturation behavior.

In this way, an optimized relative position of the at least two cylinders involved in the printing process can be assumed if the first values are at the setting of the at least one cylinder to the one further cylinder a desired value of a saturation point.

Which measured values are generated with the various devices and which measurements are thus based on the curves or graphs mentioned, will be further elaborated in the present description.

An apparatus for carrying out the method according to the invention has a measuring device with which the size of the surface, with which at least one printing cylinder cylinder touches a further body, can be measured.
As already mentioned, such a measuring device may comprise a foil which has pressure sensors each measuring the pressure in a surface section. If the resolution of this printing film is therefore sufficiently large-and thus the individual area sections are sufficiently small-even the contact of individual pressure points with the measuring device can be measured. If the number of pressure points coming into contact with the measuring device when the printing cylinder is set stagnates after a strong growth phase, the above-mentioned saturation approaches.
In a device utilizing frustrated total reflection and measuring the light intensity of the diffuse reflected radiation, the measured light intensity saturates when the interface between the cylinder and the measuring device no longer grows as in the growth phase of further employment.

Fig. 1

Eine beispielhafte Lichtintensitätsverteilung, wie sie sich für die Kamera 8 in Figur 2 ergibt

Fig. 2

Ein Schema einer erfindungsgemäßen Vorrichtung mit einem Lichtleiter 5

Fig. 3

Ein Schema einer zweiten erfindungsgemäßen Vorrichtung

Fig. 4

Ein Schema einer dritten erfindungsgemäßen Vorrichtung

Fig. 5

Ein Schema einer vierten erfindungsgemäßen Vorrichtung

Fig. 6

Den Schnitt A-A aus Figur 5

Fig. 7

Eine Ansicht aus Figur 6

Fig. 8

Ein Schema einer fünften erfindungsgemäßen Vorrichtung

Fig. 9

Ein Schema einer sechsten erfindungsgemäßen Vorrichtung

Fig. 10

Ein Schema einer der dritten erfindungsgemäßen Vorrichtung analogen Vorrichtung

Fig. 11

Ein Schema eines Farbwerkes einer Zentralzylinderflexodruckmaschine

Fig. 12

Ein Druckplattenzylinder mit Drucksensoren zur Ermittlung zweiter Werte

Fig. 13

Eine Skizze einer Messwalze 49

Fig. 14

Eine zeitliche Aneinanderreichung von Messwerten der Messwalze 49

Further embodiments of the invention will become apparent from the description and the claims.
The individual figures show:

Fig. 1

An exemplary light intensity distribution, as for the camera 8 in FIG. 2 results

Fig. 2

A diagram of a device according to the invention with a light guide 5

Fig. 3

A diagram of a second device according to the invention

Fig. 4

A schematic of a third device according to the invention

Fig. 5

A diagram of a fourth device according to the invention

Fig. 6

The cut AA FIG. 5

Fig. 7

A view from FIG. 6

Fig. 8

A schematic of a fifth device according to the invention

Fig. 9

A diagram of a sixth device according to the invention

Fig. 10

A schematic of an apparatus analogous to the third apparatus according to the invention

Fig. 11

A schematic of an inking unit of a central cylinder flexographic printing machine

Fig. 12

A plate cylinder with pressure sensors to determine second values

Fig. 13

A sketch of a measuring roller 49

Fig. 14

A chronological juxtaposition of measured values of the measuring roller 49

• Sie weist gegenüber mechanischem Druck eine gewisse Flexibilität auf. Sie kann die Strahlung 6 diffus reflektieren und sie besitzt einen höheren Brechungsindex n2 als der Körper 5.

Interessant sind auch die Flexibilität, Formbarkeit und Tiefe der Einheit Folie Separatoren: Je nach Rauhigkeit und Härte der zu vermessenden Walze können diese eingestellt werden. Ist zum Beispiel ein Druckplattenrylinder mit einer flexiblen Druckform und einem geringen Abstand zwischen erhabenen und tiefliegenden Bereichen der Druckform zu untersuchen, ist eine relativ harte "Auslegung" der Einheit Separatoren 11/Folie 3 und ein geringer Abstand der Folie 3 zu dem Körper 5 zu empfehlen. Ist die zu untersuchende Walze hingegen einer Rasterwalze 37 mit einer harten Oberfläche, die große Abstände zwischen erhabenen und tiefliegenden Bereichen aufweist, so ist eine relativ weiche "Auslegung" der Einheit Separatoren 11/Folie 3 und ein geringer Abstand der Folie 3 zu dem Körper 5 zu empfehlen.
Wenn - wie in Figur 2 gezeigt - der Rasterpunkt 2 in Richtung des Pfeiles 12 gegen die Folie 3 gedrückt wird, bekommt die Folie 3 Kontakt zum Körper 5. Die Totalreflexion wird im Bereich der Kontaktfläche zwischen Körper 5 und Folie 3 aufgehoben, die Folie 3 reflektiert die Strahlung diffus in den Körper 5 zurück. Diejenigen Anteile der diffusen Strahlung 13, die unter passendem spitzen Winkel ß auf die Wand 7 einfallen, durchdringen diese fast vollständig.
Als Folge registriert die Kamera 8 einen Zuwachs an Lichtintensität, der im Verhältnis zu der Kontaktfläche zwischen Rasterpunkt 2 und Körper 5 steht (auch wenn die Folie 3 vermittelt).
Der Kamera (eigentlich Sensor für elektromagnetische Strahlung) bietet sich ein Bild, wie es in Figur 1 skizziert ist. Mit 9 ist die Berührungsfläche eines Rasterpunktes auf dem Körper gekennzeichnet. Die Kamera bekommt einen klaren Eindruck von der Größe der Berührungsfläche. Die Berührungsfläche 9 befindet sich in dem Kontaktbereich 10, der sich beispielsweise zwischen zwei Zylindern als Walzenspalt ausprägt. Der Kontaktbereich 10 ist also der Flächenbereich, in dem überhaupt Kontakt zwischen den Zylindern stattfinden könnte. Die Berührungsfläche 9 ist ein Teilbereich des Kontaktbereichs 10, in dem 9 tatsächlich Kontakt stattfindet.
Wenn der transparente Körper 5 und der Druckformträger 1 als gegeneinander abrollende Zylinder ausgeprägt sind, dann bilden sich während des Abrollvorganges verschiedene Kontaktbereiche 10', 10" aus, die nacheinander das Sichtfeld der Kamera 8 durcheilen. Wenn der Druckformträger 1 ein ganzes Druckbild trägt, so kann die Kamera das Berührungsbild dieses Druckbildes auf dem Körper 5 beziehungsweise der Folie 3 aus sukzessive aufgenommenen Kontaktbereichen 10, 10', 10" zusammensetzen.
In den zukünftigen Kontaktbereichen 10', 10" sind in Figur 1 die zukünftigen Berührungsflächen 9'und 9" skizziert.
Zeichnet die Kamera 8 die Intensität des in der beschriebenen Weise von der Folie 3 aufgrund der Berührung durch die Druckform remittierten Lichtes auf, so ist die Lichtintensität - wie erwähnt - ein Maß für die Kontaktfläche. Sie kann für verschiedene Zonen des Kontaktbereiches gemessen werden. Vergleiche mit absoluten Sollwerten sind möglich. Es ist auch möglich, zu prüfen in wie weit sich die Lichtintensitätswerte im Ganzen Kontaktbereich oder vorteilhafterweise in einzelnen Zonen desselben einem Sättigungspunkt annähern. Aufgrund von Berechnungen und/oder Erfahrungswerten ist es möglich zu bestimmen, in welchem Abstand von diesem Sättigungspunkt eine optimierte Anstellung erreicht ist.
Figur 3 zeigt eine alternative Vorrichtung. Wieder wird elektromagnetische Strahlung 6 von der Strahlungsquelle 4 emittiert. Der Winkel γ unter dem die Strahlung 6 auf den Körper 5 trifft, führt dazu, dass die Strahlung weitgehend in den Körper eindringt und erst an der Grenzfläche 17 (Übergang in ein optisch dünneres Medium) eine Totalreflexion erfährt, wenn sich der Körper 5 nicht - wie gezeigt - in Kontakt mit dem Rasterpunkt 2 befindet. Als Folge der Totalreflexion an der Grenzfläche 17 kommt ein sehr großer Teil der von der Strahlungsquelle 4 eingestrahlten Strahlung 6 an der Kamera 8 an. Kommt der Rasterpunkt 2 - der hier anders als in Figur 2 einen direkten Kontakt mit dem Körper 5 hat - in Kontakt mit dem Körper 5 wird die Totalreflexion geschwächt, da der Rasterpunkt einen höheren Brechungsindex hat als der Körper 5.
Als Folge kommt es wieder zu einer diffusen Reflexion an dem Rasterpunkt 2 (diffus reflektierte Strahlung 13) sowie zu einer Transmission in den Rasterpunkt hinein (Strahlung 16).
Die Berührung durch den Rasterpunkt führt also zu einer Abnahme der von der Kamera zu messenden Lichtintensität. Diese Abnahme ist eine Funktion der Berührungsfläche 9 zwischen Rasterpunkt 2 und Körper 5. (Dies wäre auch so, wenn wieder eine Folie mit höherem Brechungsindex als der Körper 5 zwischen Körper 5 und Rasterpunkt 2 wäre)
Auch Figur 4 zeigt eine Vorrichtung bei der Lichtquelle 4, transparenter Körper 5, Rasterpunkt 2 und Kamera 8 derart angeordnet beziehungsweise geformt sind, dass als Folge eines Kontaktes zwischen Rasterpunkt 2 und Körper 5 und der damit einhergehenden Schwächung der Totalreflexion eine Abnahme der von der Kamera 8 zu messenden Lichtintensität zu vermelden ist. Diese ist wieder eine Funktion der Berührungsfläche 9 und kann zur Messung derselben eingesetzt werden.
Die Figuren 5 bis 7 zeigen eine Vorrichtung die nach dem in Bezug auf Figur 2 dargelegten Prinzip funktioniert. Allerdings ist hier der transparente Körper 5 bereits als transparente Walze 25 ausgeführt. Der in Figur 2 dargestellte Druckplattenträger 1 ist hier ein Druckplattenzylinder 21. Die Walzenanordnung von transparenter Walze 25 und Druckplattenzylinder 21 kann in der skizzierten Weise in einem externen Reck 22 vorgenommen werden. Wie bereits weiter oben angesprochen, kann eine solche Anordnung auch in einem Druckwerk vorgenommen werden. Dann wäre der transparenten Walze entweder die weitere Funktion einer normalerweise im Druckwerk angeordneten Walze zuzuweisen oder die Walze 25 wäre zusätzlich in dem betreffenden Druckwerk anzuordnen.
In beiden Fällen sind die beiden Walzen oder Zylinder 21, 25 gegeneinander anzustellen, was in Figur 5 durch den Pfeil 26, der die Bewegungsrichtung des Walzenbocks 18 andeutet, skizziert ist. Dieser bewegt sich mit der Walzenlagerung 19 und der transparenten Walze 25 in Richtung auf den Druckplattenzylinder 21. Diese Bewegung des Bocks 18 dürfte in der Regel mit Schienenführungen, Linearmotoren oder Spindeltrieben auf dem Grundgestell des Recks 23 bewerkstelligt werden. Die Darstellung all dieser Einzelkomponenten ist im vorliegenden Zusammenhang nicht nötig. In allen Fällen ist es dem Fachmann mittlerweile möglich, die Position des Bockes 18 mit Positionsgebem wie auch Drehgebern (v. a. beim Spindeltrieb) zu überwachen. In dieser Position beziehungsweise den Positionen der beiden Walzenlagern 19 und 20 an den Stirnseiten der transparenten Walze 25 können zweite Werte im Sinne der vorliegenden Druckschrift liegen. Zusätzlich oder alternativ ist es möglich, zumindest einen der beiden Zylinder 21, 25 mit Drucksensoren zu beaufschlagen. Auf diese Weise kann der im Walzenspalt entstehende Druck gemessen und als zweiter Wert herangezogen werden. Auch im Hinblick auf diese zweiten Druckwerte ist es von Vorteil, wenn zumindest zwei Werte aus jeweils dem Bereich eines stirnseitigen Endes des Walzenspaltes zur Verfügung stehen. Hierbei kann die Gewinnung der zweiten Messwerte auch auf kleinere Teilbereiche beziehungsweise Teilflächen beschränkt werden. Demgegenüber ist es von Vorteil, wenn die ersten Werte zumindest von den Bereichen gewonnen werden, in denen eine Berührung zwischen Zylindern stattfinden kann (beim Druckformzylinder z. B. Größe der Druckform).
Mit Hilfe der in der Regel leichter zu gewinnenden zweiten Werte kann dann die Relativposition wieder gefunden werden, bei der die ersten Werte zu der Größe der Berührungsfläche in einem gewünschten Bereich lagen.
Dies ist insbesondere dann von Vorteil, wenn die ersten Werte zu der Berührungsfläche in einem externen Reck 22 gewonnen werden und dann in dem Druckwerk lediglich dieselbe optimierte Anstellsituation wie in dem externen Reck 22 wieder aufgefunden werden soll.
Figur 6 zeigt die transparente Walze 25 aus Figur 5 aus dem Blickwinkel der Pfeile 29 entlang des Schnitts A-A noch einmal detaillierter:

• An den Stirnseiten der Walze 25 sind Strahlungsträgerhalter 24 angebracht, die Strahlungsquellen 4 tragen. Die Strahlungsquellen 4 sind derart zu der Walze 25 positioniert, dass die Strahlung analog wie in Figur 2 in dem transparenten Körper bleibt, da sie eine Totalreflexion an dessen Außenwänden erfährt. Die Totalreflexion wird jedoch unterbunden, wenn die Folie 3 von Elementen des Druckplattenzylinders an die Wände der transparenten Walze gedrückt wird. Als Folge werden für die Kamera 8 innerhalb der Walze 25 die Berührungsflächen 9 analog zu der in den Figuren 2 und 1 dargestellten Situation sichtbar. Rollen die Walzen 25 und 21 bei ihrer Berührung gegeneinander ab, ist es möglich, verschiedene Kontaktbereiche 10 zusammenzusetzen und so einen Eindruck von der Farbübertragung der gesamten Druckplatte des Druckplattenzylinders 21 zu gewinnen (also des gesamten Druckbildes des Druckwerkes). Diese Möglichkeit besteht nach der vorliegenden Erfindung wohlgemerkt, ohne dass Farbe auf den Bedruckstoff aufgebracht werden muss und ohne, dass Makulatur durch einen Andruck entstehen muss.

Natürlich kann jedoch die Lehre der Erfindung auch bei gleichzeitiger Übertragung von Farbe angewandt werden, wie später noch gezeigt wird.
Figur 7 zeigt die Walze 25 aus Sicht der Pfeile 20, wobei unter anderem die Walzenlagerung 19', der Träger der Strahlungsquellen 24 und die Folie 3 aus darstellerischen Gründen weggelassen wurden.
Figur 8 entspricht weitgehend Figur 5, wobei die Funktion der transparenten Walze 25 wieder von einem transparenten Körper 5 wahrgenommen wird. In diesen wird von der Strahlungsquelle 4 Strahlung eingestrahlt. Der für diese Strahlung transparente Köper 5 kann mit dem Bock gegen den Zylinder 21 angestellt werden. Der Körper hängt hierbei an dem Lagerarm des Bockes 34 und kann entlang der Schiene 33 in vertikaler Richtung hin und herbewegt werden, wie es von den Pfeilen 32 angedeutet wird. Körper 5 und Zylinder 21 können so aneinander abrollen (Drehbewegung des Zylinders durch Pfeile 31 skizziert). Auf diese Weise kann auch mit der in Figur 8 dargestellten Vorrichtung ein größerer Umfangsbereich des Zylinders 21 in einen rollenden Kontakt mit dem Körper gebracht werden. Auf die Darstellung irgendwelcher Aktoren zur Bewegung des Körpers 5 wurde verzichtet.
In Figur 9 ist eine Vorrichtung skizziert, die vom optischen Prinzip her wie die Vorrichtung nach Figur 3 funktioniert: berührt der Körper 5 den Zylinder 21 so kommt durch die Schwächung der Totalreflexion an den Berührungsflächen weniger Strahlung 6 bei der Kamera 8 an.
Der Körper 5 wird nach Figur 9 wie ein Stempel entlang der Schiene 33 gegen den Zylinder 21 angestellt. Durch eine Mehrzahl solcher Anstellprozesse kann die ganze Oberfläche des Zylinders 21, der zu diesem Zweck sukzessive um gewisse Winkel gedreht werden kann, abgetastet werden. Fig. 2 shows a device according to the invention, in which an optimized relative position between the at least two printing unit cylinders is found by the evaluation of electromagnetic radiation. This radiation is emitted by the radiation source 4. It enters the body 6 transparent to the radiation 6 at an angle which leads to a total reflection of the radiation 6 on the walls 7 of the body 5. The angle of incidence α of the radiation 6 on the walls 7 must move within a certain range in order to allow the total reflection. Another condition for total reflection is that the refractive index n1 of the body 5 is greater than the refractive index n0 of the surrounding air. Due to these circumstances, the body 5 serves as the conductor of the radiation 6. In the case of light as a light guide.
The separators 11 space the film 3 on the body 5 and may also attach it to the body 5. The film has three important properties in this context and would be interchangeable with any material that also has these properties:

• It has a certain flexibility compared to mechanical pressure. It can diffusely reflect the radiation 6 and has a higher refractive index n 2 than the body 5.

Also interesting are the flexibility, formability and depth of the unit Film Separators: Depending on the roughness and hardness of the roll to be measured, these can be adjusted. For example, if examining a printing plate cylinder with a flexible printing plate and a small distance between raised and lowered areas of the printing form, a relatively hard "design" of the unit separators 11 / slide 3 and a small distance of the film 3 to the body 5 is recommended , If, on the other hand, the roller to be examined is an anilox roller 37 with a hard surface which has large distances between raised and lowered regions, a relatively soft "design" of the unit is separators 11 / foil 3 and a small distance between the foil 3 and the body 5 to recommend.
If - as in FIG. 2 shown - the grid point 2 is pressed in the direction of arrow 12 against the film 3, the film gets 3 contact with the body 5. The total reflection is canceled in the area of the contact surface between the body 5 and 3, the film 3 reflects the radiation diffused in the Body 5 back. Those portions of the diffuse radiation 13, which incident on the wall 7 at a suitable acute angle ß, penetrate almost completely.
As a result, the camera 8 registers an increase in light intensity, which is in proportion to the contact area between grid point 2 and body 5 (even if the film 3 mediates).
The camera (actually sensor for electromagnetic radiation) offers itself a picture, like it in FIG. 1 outlined. 9 marks the contact surface of a grid point on the body. The camera gets a clear idea of the size of the touchpad. The contact surface 9 is located in the contact region 10, which is for example between two cylinders as a nip. The contact area 10 is thus the surface area in which contact between the cylinders could take place at all. The contact surface 9 is a partial region of the contact region 10 in which 9 actually takes contact.
When the transparent body 5 and the printing form support 1 are in the form of cylinders rolling against each other, different contact areas 10 ', 10 "are formed during the rolling operation, which successively rush through the field of view of the camera 8 For example, the camera can assemble the contact image of this print image on the body 5 or the film 3 from successively received contact areas 10, 10 ', 10 ".
In the future contact areas 10 ', 10 "are in FIG. 1 the future contact surfaces 9'and 9 "outlined.
If the camera 8 records the intensity of the light remitted in the described manner from the film 3 due to the contact with the printing form, then the light intensity, as mentioned, is a measure for the contact surface. It can be measured for different zones of the contact area. Comparisons with absolute nominal values are possible. It is also possible to check how far the light intensity values in the whole contact area or, advantageously, in individual zones thereof are approaching a saturation point. Based on calculations and / or empirical values, it is possible to determine at which distance from this saturation point an optimized employment is achieved.
FIG. 3 shows an alternative device. Again, electromagnetic radiation 6 is emitted from the radiation source 4. The angle γ under which the radiation 6 strikes the body 5 causes the radiation to penetrate largely into the body and only at the interface 17 (transition into an optically thinner medium) undergoes a total reflection when the body 5 is not -. as shown - in contact with the grid point 2. As a consequence of the total reflection at the interface 17, a very large part of the radiation 6 irradiated by the radiation source 4 arrives at the camera 8. If the grid point 2 - the here different than in FIG. 2 a direct contact with the Body 5 has - in contact with the body 5, the total reflection is weakened because the grid point has a higher refractive index than the body. 5
As a result, diffuse reflection at the halftone dot 2 (diffusely reflected radiation 13) and transmission into the halftone dot (radiation 16) again occurs.
The contact through the grid point thus leads to a decrease in the light intensity to be measured by the camera. This decrease is a function of the contact surface 9 between grid point 2 and body 5. (This would also be the case if again a film with higher refractive index than the body 5 between body 5 and grid point 2)
Also FIG. 4 shows a device at the light source 4, transparent body 5, halftone dot 2 and camera 8 are arranged or shaped such that as a result of contact between grid 2 and body 5 and the concomitant weakening of the total reflection, a decrease in the camera 8 to be measured Light intensity is reported. This is again a function of the contact surface 9 and can be used to measure the same.
The FIGS. 5 to 7 show a device according to the FIG. 2 principle is working. However, here the transparent body 5 is already designed as a transparent roller 25. The in FIG. 2 shown here is a printing plate cylinder 21. The roller assembly of transparent roller 25 and pressure plate cylinder 21 can be made in the manner outlined in an external 22 bar. As already mentioned above, such an arrangement can also be made in a printing unit. Then the transparent roller would either assign the further function of a roller normally arranged in the printing unit or the roller 25 would additionally be arranged in the relevant printing unit.
In both cases, the two rollers or cylinders 21, 25 against each other, which is in FIG. 5 is sketched by the arrow 26, which indicates the direction of movement of the roller block 18. This moves with the roller bearing 19 and the transparent roller 25 in the direction of the printing plate cylinder 21. This movement of the trestle 18 is usually likely with rail guides, linear motors or spindle drives on the base frame of the deck 23 are accomplished. The representation of all these individual components is not necessary in the present context. In all cases, it is now possible for the skilled person to monitor the position of the Bockes 18 with Positiongebem as well as encoders (especially in the spindle drive). In this position or the positions of the two roller bearings 19 and 20 on the end faces of the transparent roller 25 may be second values within the meaning of the present document. Additionally or alternatively, it is possible to pressurize at least one of the two cylinders 21, 25 with pressure sensors. In this way, the resulting pressure in the nip can be measured and used as a second value. With regard to these second pressure values, it is also advantageous if at least two values are available from the region of an end face of the nip in each case. In this case, the extraction of the second measured values can also be limited to smaller partial areas or partial areas. In contrast, it is advantageous if the first values are obtained at least from the areas in which a contact between cylinders can take place (for example, in the case of a printing form cylinder size of the printing plate).
With the help of the usually easier to obtain second values, the relative position can then be found again, in which the first values to the size of the contact surface were in a desired range.
This is advantageous in particular when the first values for the contact surface in an external bar 22 are obtained and then only the same optimized setting situation as in the external bar 22 is to be found again in the printing unit.
FIG. 6 shows the transparent roller 25 from FIG. 5 from the perspective of the arrows 29 along the section AA again in more detail:

• Radiation carrier holders 24, which carry radiation sources 4, are attached to the end faces of the roller 25. The radiation sources 4 are positioned relative to the roller 25 such that the radiation is analogous to that in FIG FIG. 2 remains in the transparent body, as it experiences a total reflection on its outer walls. However, the total reflection is inhibited when the film 3 is pressed by elements of the printing plate cylinder to the walls of the transparent roller. As a result, for the camera 8 within the roller 25, the contact surfaces 9 analogous to that in the FIGS. 2 and 1 shown situation visible. Rolling the rollers 25 and 21 against each other in their contact, it is possible to assemble different contact areas 10 and so to gain an impression of the color transfer of the entire printing plate of the printing plate cylinder 21 (ie the entire printed image of the printing unit). This possibility exists according to the present invention mind you, without having to apply color to the substrate and without that waste must be created by a pressure.

Of course, however, the teachings of the invention can also be applied to the simultaneous transfer of color, as will be shown later.
FIG. 7 shows the roller 25 from the perspective of the arrows 20, among other things, the roller bearing 19 ', the carrier of the radiation sources 24 and the film 3 have been omitted for illustrative reasons.
FIG. 8 corresponds largely FIG. 5 , wherein the function of the transparent roller 25 is again perceived by a transparent body 5. In this radiation is irradiated by the radiation source 4. The transparent to this radiation body 5 can be made with the buck against the cylinder 21. The body in this case hangs on the bearing arm of the bracket 34 and can be moved along the rail 33 in the vertical direction, as indicated by the arrows 32. Body 5 and cylinder 21 can thus roll against each other (rotational movement of the cylinder is indicated by arrows 31). This way can also with the in FIG. 8 a larger peripheral portion of the cylinder 21 are brought into rolling contact with the body. On the representation of any actuators to the movement of the body 5 has been omitted.
In FIG. 9 is a device outlined by the optical principle as the device according to FIG. 3 works: the body 5 touches the cylinder 21 so comes through the weakening of the total reflection at the contact surfaces less radiation 6 at the camera 8 at.
The body 5 is after FIG. 9 as a stamp along the rail 33 against the cylinder 21 employed. By a plurality of such Anstellprozesse the entire surface of the cylinder 21, which can be successively rotated for this purpose by certain angles, scanned.

FIG. 10 a device shows a structure, the from the beam path forth FIG. 4 remind. Again, the light intensity decreases due to contact between body 5 and cylinder 21. If the body is moved by means of a rail 33 along the cylinder surface (shown by double arrow 35), again different contact areas 10 between body 5 and cylinder 21 can be covered at different times.
In the figures, a variety of devices have been shown, in which a determination of the contact surface 9 was made by means of optical methods. If this undertaking is carried out with the aid of duck foil (pressure sensor in foil form), the printing foil takes the place of the surface of the body 5 or the roller 25, which touches the cylinder 21. One advantageous in part for the optical methods film 3 is not required to do so usually. Also, in this context, no description of a ray path or the like is required. Therefore, no additional figures need to be described at this point, which show a printing film instead of the described surface of the body 5 or the roller 25.
In FIG. 11 For example, two inking units 36 and 38 of a central cylinder flexographic printing machine with a central cylinder 40 are roughly sketched. In these color or printing works it is shown how methods according to the invention can also be used. In a Zentralzylinderflexodruckmaschine of the type shown, a printing material 39 is fed to a central cylinder 40 and pressed there by means of a feed roller 41. The printing substrate 39 is transported by the rotation of the impression cylinder through nips 42, which the impression cylinder 40 with the Druckplattenzylindem 21 (called in flexographic printing forme cylinder) pronounced. In these nips he is 39 printed with the color of the respective printing unit, so that a multi-colored printing unit is created. There are now Zentralzylinderflexodruckmaschinen, which have a two-digit number of such inking units 36, 38. The direction of rotation of the cylinders 21, 40 and 37 is indicated by the arrows A, B and C.
The pressure in the flexographic printing process takes place here by the raised components of so-called clichés 45 - ie flexible printing forms - often as Raster points 2 are configured. The clichés are often colored by so-called anilox rollers 37 - ie also printing unit rollers in the sense of this document.
Other elements of the printing units such as doctoring chambers or roller blocks for adjusting the cylinder and roller 40, 21, 37 are in FIG. 11 not shown.
In FIG. 11 the impression cylinder 40 is equipped with a transparent body 5 and a camera 8. The transparent body 5 forms virtually a window in the lateral surface of the impression cylinder 40 (the impression cylinder is thus partially transparent). The camera 8 is rotated by the impression cylinder and in this way remains during the rotation of the impression cylinder 40 in a position in which it 8 diffuse radiation 13, which penetrates from the body 5 record. The operating principle of the measuring device 47 from camera 8 and body 5 in FIG. 11 corresponds to the functional principle, which is based on the Figures 3 and 5 to 7 has already been explained:
At at least one front end of the impression cylinder 40, radiation is emitted by radiation sources 4 into the transparent body 5 (eg in FIG FIG. 6 shown). This is subject to a total reflection on the surfaces of the body 5, which is weakened when touches between parts of the cliché 45 and the body 5 come about. These contacts can also be mediated by a film 3. The printing material 39 can take the role of the film 3. It is advantageous to provide separators 11 between film 3 or printing material web 39 and body 5.
When the printing plate cylinders 21 are re-set using the measuring device 47 of the impression cylinder 40 (initial setting of the relative position between these two printing cylinder cylinders 40, 21) and the impression cylinder 40 transports stock 39 during this process, the production of waste paper is unlikely to occur be avoided.
However, it is possible that the measuring device 47 during a rotation of the impression cylinder data to the touch of the impression cylinder 40 with multiple or even all printing plate cylinders 21 wins. Thus, the relative positions can be optimized much faster than with positioning, the optimization of the relative positions at the beginning of printing Make inking unit 36, 38 for inking unit. Another advantage of the just described method is that it can do without second values in the sense of this document. Furthermore, a continuous dynamic monitoring of the contact surface 9 during the printing operation in the manner described appears particularly advantageous.

• Mit der in Figur 11 gezeigten Messvorrichtung 48 werden erste Werte gewonnen, indem die transparente Walze 25 mit der Anstellvorrichtung 43 gegen den im Farbwerk 38 befindlichen Druckplattenzylinder 21 angestellt wird. Zu den optimierten ersten Werten zur Größe der Berührungsfläche 9 zwischen den Zylindern 21 und 25 werden mit den Drucksensoren 46 zweite (Anpressdruck-)Werte gemessen.

Diese werden in der Regel gespeichert. Sie geben wieder, bei welchen Druckverhältnissen (zweite Werte) an beiden Enden des Walzenspaltes eine optimale Flächendeckung bestand, die mit Hilfe der transparenten Walze festgestellt wurde. Vor Druckbeginn wird dann der Druckplattenzylinder 21 gegen den Gegendruckzylinder 40 angestellt. In erster Näherung ist davon auszugehen, dass bei den gleichen Anspressdruckwerten im Walzenspalt 42 (zweite Werte) auch dieselbe optimierte Flächendeckung zustande kommt, so dass ein Andruck bei denselben Anspressdruckwerten vorgenommen werden kann. Vorteilhafterweise wird man jedoch im Laufe der Zeit Korrekturfaktoren für den Anspressdruck einführen, die berücksichtigen, dass die Zylinder 25 und 40 unterschiedliche Durchmesser haben und dass der Bedruckstoff 39 eine gewisse Elastizität aufweist.
Im Prinzip ist mit dem soeben geschilderten Verfahren ein makulaturfreier Erstandruck möglich. Des Weiteren ist es möglich, die Änderung der Flächendeckung mit dem Zylinder 25 von Zeit zu Zeit zu überprüfen, wobei die Verschmutzung desselben 25 mit Farbe natürlich zu berücksichtigen ist.
Statt die Drucksensoren 46 bei der Ausführung des geschilderten Verfahrens an dem Druckplattenzylinder 21 anzubringen, können diese 46 auch sowohl am Gegendruckzylinder 40 als auch am transparenten Zylinder 25 angebracht werden. Dies gilt auch für andere Mittel, mit denen zweite Werte im Sinne dieser Anmeldung gewonnen werden können.
Wie bereits geschildert, können zweite Werte im Sinne der vorliegenden Druckschrift auch durch Positionsgeber, die die Position des jeweiligen Zylinders in seiner Anstellvorrichtung 43 wiedergeben, gewonnen werden. Insbesondere beim Einsatz von Linearmotoren kann auch die Anstellkraft gemessen werden. Da die Zylinder von stirnseitigen Lagern gehalten werden und diese in der Regel jeweils über eine Anstellvorrichtung verfügen, ist es vorteilhaft, zumindest zwei zweite Werte zu der Anstellsituation an jeweils einem stirnseitigen Ende des Zylinders zu erheben.
Das anhand der Messvorrichtung 48 zuletzt geschilderte Verfahren, das auch zweite Werte verwendet, ist auch dann vorteilhaft, wenn die ersten Werte mit einem externen Reck 22 gewonnen werden.
Die Figuren 13 und 14 verdeutlichen noch einmal die Gewinnung erster und zweiter Messwerte. In Figur 13 ist eine Messwalze 49 gezeigt, die ebenfalls über Drucksensoren 46 zur Gewinnung zweiter Werte verfügt. Die hier gezeigten Drucksensoren überstreichen einen rechteckigen Messbereich. Es ist zweckmässig, wenn dieser Drucksensoren einen gewissen Druckanstieg kontinuierlich messen können, so dass genau zuzuordnen ist, bei welchen Drücken an beiden stirnseitigen Enden der Walze 49 sich welche erste Werte ergeben haben.Another measuring device 48, which in FIG. 11 is shown, consists of a cylinder 25, which is analogous to the cylinder 25 in the FIGS. 5 to 7 is constructed. He 25 has a positioning device 43 which is articulated at the articulation point 44 fixed, for example, on the machine frame. The cylinder 25 can be made to the printing cylinder 21 and 37 of the inking units 36 and 38 and so measure the contact surface 9 (first values).
In FIG. 12 a printing plate cylinder 21 is shown as it is often used in the execution of the flexographic printing process. He 21 wears a flexible cliche 45. In addition, the in FIG. 12 shown cylinder 21 equipped with two pressure sensors 46, which are located in the vicinity of the front ends of the cylinder 21. These pressure sensors 46 can determine the contact pressure in the nip 42 and thus determine second values in the sense of this publication.
These can be used as follows:

• With the in FIG. 11 shown first values are obtained by the transparent roller 25 is made with the adjusting device 43 against the pressure plate cylinder 21 located in the inking unit 38. For the optimized first values for the size of the contact area 9 between the cylinders 21 and 25, second (contact pressure) values are measured with the pressure sensors 46.

These are usually saved. They indicate at which pressure conditions (second values) at both ends of the nip there was an optimal area coverage, which was determined by means of the transparent roller. Before printing begins, the printing plate cylinder 21 is then turned against the impression cylinder 40. As a first approximation, it can be assumed that the same optimized area coverage is achieved at the same nip pressure values in the nip 42 (second values), so that a pressure is applied at the same nip pressure values can. Advantageously, however, one will introduce over the course of time correction factors for the print pressure, which take into account that the cylinders 25 and 40 have different diameters and that the printing material 39 has a certain elasticity.
In principle, a waste-free recovery pressure is possible with the method just described. Furthermore, it is possible to check the change in area coverage with the cylinder 25 from time to time, taking into account the contamination of the same 25 of course with color.
Instead of attaching the pressure sensors 46 in the execution of the described method to the printing plate cylinder 21, these 46 can also be attached to both the impression cylinder 40 and the transparent cylinder 25. This also applies to other means with which second values in the sense of this application can be obtained.
As already described, second values in the sense of the present document can also be obtained by position sensors which reproduce the position of the respective cylinder in its setting device 43. In particular, when using linear motors and the contact force can be measured. Since the cylinders are held by end-side bearings and these usually each have a setting device, it is advantageous to raise at least two second values for the positioning situation at a respective end face of the cylinder.
The method last described using the measuring device 48, which also uses second values, is also advantageous if the first values are obtained with an external bar 22.
The FIGS. 13 and 14 clarify again the extraction of first and second readings. In FIG. 13 a measuring roller 49 is shown, which also has pressure sensors 46 for obtaining second values. The pressure sensors shown here cover a rectangular measuring range. It is expedient if these pressure sensors can continuously measure a certain increase in pressure so that it can be precisely assigned at which pressures at both end faces of the roller 49 which first values have resulted.

In the middle region in the axial direction of the roller is the measuring range 50 for the first measured values. It is useful to subdivide it 50 into sections 51.
If this measuring area 50 is represented by a printing foil, the size of the subareas 51 often results from the resolution of the printing foil (resolution = in which area units pressure can be measured). For many of these slides, it is only possible to provide binary information about the prevailing pressure (if a certain pressure threshold is exceeded or not). However, the use of such a film may be sufficient.
It is also possible to make the measuring area 50 of the measuring roller 49 essentially as the aforementioned light-conducting body 5 or as the transparent roller 25. Also in this case, portions 51 of the measuring range 50 can be formed. This can be done, inter alia, by assigning the camera 8, the light emerging from the light guide 5 or the transparent roller 25 radiation to the subregions. For this purpose, the camera 8 may inter alia consist of a diode array which is mounted very close to the light guide.
FIG. 14 shows a collection of measured values of the measuring roller 49, which results in a period T, while the measuring roller 49 is turned against a cliché roller 21.
In the illustrated period T, the cliché 45 is just starting to unroll on the measuring roller. The contact area, that is, the total area in which contact between the measuring roller and the cliché is possible, is - for illustrative reasons - outlined by the rectangles 45 ', 45 "and 45"'.
At the beginning of the period T (top), no contact (rectangle 45 ') is present at all and no first measured values in the partial regions 51 of the measuring region 50 are determined. Only the pressure sensors 46, which have sensors which are raised above the surface of the roller 49, are already in contact with the plate roller 21 and each deliver a measured value 46 '(the measured values of the two sensors 46 recorded at one time are often different To set an optimized roll position, it may even be necessary to set different measured values at the two ends. After another rotation of the roller has due to further employment of the rollers 21, 49 A contact surface 9 is formed in a partial region 51 of the measuring region 50 which lies within the possible contact surface 49 ", which is illustrated as a black square in a partial region 51. In this way it is made clear that in this partial region a contact of the cylinders 21, 49 has taken place with a certain intensity If, for example, simple printing foils are used to determine the second values, then the associated statement that a contact with a certain minimum pressure has occurred in a certain subarea.
At the time of the recording of the contact surface 9, the pressure sensors 46 also report changed second pressure values 46 "which are characteristic of the relative position of the rollers 21, 49 relative to each other at this time the area coverage of a pressure at a certain relative position of the rollers can characterize each other.
After another roll revolution - and the associated further employment of the rollers 21, 49 against each other - four contact surfaces 9 have already formed within the possible contact surface 45 '".

• bis eine Sollfläche (z. B. Teilbereiche 51 der Messfläche 50, die Kontakt melden) erreicht ist und / oder
• bis die Kontaktflächen 9 einen gewissen Anteil an dem möglichen Kontaktbereich ausmacht und / oder
• bis die Kontaktfläche 9 in ihrer Ausdehnung und Gestalt einem Sollbild entspricht und / oder
• bis der Zuwachs an Kontaktfläche 9, der sich bei weiterer Anstellung der Walzen gegeneinander ergibt, ein Sättigungsverhalten zeigt oder ein bestimmtes (oft empirisch oder analytisch ermitteltes) Verhalten zeigt, das eine baldige Sättigung erwarten lässt ("Kurvenverlauf").

As already mentioned, it is possible, inter alia, to determine the optimized roll position by setting the rolls 21, 49 against each other,

• until a desired surface (for example subregions 51 of the measuring surface 50 which report contact) is reached and / or
• until the contact surfaces 9 makes up a certain proportion of the possible contact area and / or
• until the contact surface 9 in its extension and shape corresponds to a desired image and / or
• until the increase in contact surface 9, which results in a further employment of the rollers against each other, shows a saturation behavior or shows a certain (often empirically or analytically determined) behavior that promises a rapid saturation ("curve").

In particular, the alternative listed in the last preceding indent can be implemented particularly well with the disclosed in this document optical methods. Here is the course of the camera 8 recorded light intensity as a function of the second values such as roll adjustment or pressure in the nip (at which the sensors 46 provide meaningful values) are recorded. In this case, the light intensity profile in the entire measuring range for the first measured values and / or the light intensity profile in a possible contact region 19 and / or the light intensity profile in partial regions 51 can be used to find the optimized relative position. LIST OF REFERENCE NUMBERS 1 Printing plate carrier 2 dot 3 foil 4 Source of electromagnetic radiation (eg of light) 5 Transparent body / optical fiber 6 Wave field (usually electromagnetic waves) 7 Total reflecting surface of the body 5 8th camera 9 Touchpad 10 contact area 11 separators 12 Arrow in "pressing direction" of grid point 2 in Fig. 2 13 Diffuse radiation (backscatter) 14 Measuring range of the camera 8 15 Serrations of the body 5 16 radiation 17 Total reflecting surface of the body 5 ( FIG. 3 ) 18 roller block 19, 19 ' Roller bearing transparent roller 25 20 Roller bearing pressure plate cylinder 21 21 Plate cylinder 22 horizontal bar 23 Basic frame of the deck 24 Carrier of the radiation sources 25 Transparent roller 26 Arrow in the direction of movement of the roller block 18 27 Arrow in the direction of rotation of the roller 21 28 Arrow in the direction of rotation of the roller 25 29 Arrow in the direction of the FIG. 6 30 Arrow in the direction of the FIG. 7 31 Arrow in the direction of rotation of the roller 32 Arrow in the direction of movement of the body 5 33 rail 34 bearing arm 35 double arrow FIG. 10 36 Printing / inking 37 anilox roller 38 Printing / inking 39 printing material 40 nip 41 contacting roller 42 nip 43 adjusting equipment 44 Articulation point of the adjusting device 45 cliche 46 Pressure sensor for determining second values 47 measuring device 48 measuring device 49 measuring roll 50 Measuring range for first values 51 Subareas of the measuring range 50 for first values 52 ABC Arrow in the direction of movement of a cylinder α Sharp angle, suitable for total reflection β Dull angle, radiation penetrates surface 7 γ Entry angle of the radiation into the body 5 t Time T Period 45 ', 45 ", 45"' Possible contact area measuring roller / cliché 46 ', 46 ", 46'" Measured values of the pressure sensors 46 50 ' Timing of the measured values 51 ' 51 ' Measured values in the subareas

Claims (10)

1. Method for optimizing the relative position of at least two printing-unit cylinders (21, 37, 40), in which the relative position of the at least two printing-unit cylinders is set on the basis of measured values,
   the measured values comprising first values relating to the size of the surface area (9) with which at least one of the printing-unit cylinders makes contact with a further body (5, 25, 40),
   and the measured values comprising second values relating to at least one second physical variable,
   characterized in that
   the first values for their part comprise measured values which are obtained on the basis of the recording of electromagnetic radiation (6, 13), wherein the electromagnetic radiation (6, 13) is reflected from a printing forme (1, 45), an ink transfer surface of a printing-unit cylinder (21, 37, 40) or a body which makes contact (3, 39) with the printing forme or the ink transfer surface of a cylinder (21, 37, 40) involved in the printing process, before the recording of the radiation is carried out.
2. Method according to Claim 1,
   characterized in that
   the second values comprise the setting pressure between the printing-unit cylinders (21, 37, 40) and/or the relative position of the printing-unit cylinder bearings.
3. Method according to one of the preceding claims,
   characterized in that
   the first values for their part comprise printing values which describe the pressure which builds up during the contact between at least one printing-unit cylinder (21, 37, 40) and the at least one further body (5, 25, 40) in unit areas of the possible contact region (10) between the at least one printing-unit cylinder (21, 37, 40) and the at least one further body (5, 25, 40).
4. Method according to one of the preceding claims,
   characterized in that
   electromagnetic radiation (6, 13) which (6, 13) was previously coupled out from a radiation conductor (5, 25) on account of frustrated total reflection is recorded.
5. Method according to one of the preceding claims,
   characterized in that
   an optimized relative position of the at least two printing-unit cylinders (21, 37, 40) is assumed when the first values during the setting of the at least one printing plate cylinder (21, 37, 40) on the one further body (5, 25, 40) lie at a distance from a setpoint of a saturation point.
6. Apparatus for optimizing the relative position of at least two printing-unit cylinders (21, 37, 40), with which an optimized relative position of the at least two printing-unit cylinders (21, 37, 40) can be determined on the basis of measured values, having a measuring apparatus (47, 48) with which measured values can be measured,
   which comprise first values relating to the size of the surface area with which at least one printing-unit cylinder (21, 37, 40) makes contact with a further body (5, 25, 40),
   and second values relating to at least one second physical variable,
   characterized in that
   the measuring apparatus comprises sensors (8) for recording electromagnetic radiation (6, 13), wherein the measuring apparatus has sources (4) of electromagnetic radiation (6, 13), and
   in that the electromagnetic radiation (6, 13) that can be emitted by the sources (4) of electromagnetic radiation can be reflected from a printing forme (1, 45), from an ink transfer surface of a printing-unit cylinder (21, 37, 40) or from a body which makes contact (3, 39) with the printing forme or the ink transfer surface of a cylinder (21, 37, 40) involved in the printing process, and can be recorded by sensors (8).
7. Apparatus according to the preceding claim,
   characterized in that
   the measuring apparatus is fitted in or on the at least one printing-unit cylinder (21, 37, 40) and/or in or on the one further body (5, 25).
8. Apparatus according to one of the two preceding claims,
   characterized in that
   the measuring apparatus comprises a pressure measuring unit, with which the pressure distribution which is produced in at least one part of the contact area between the printing-unit cylinder and the further body can be measured.
9. Apparatus according to one of the three preceding claims,
   characterized in that
   the measuring apparatus comprises the further body, and the further body (5, 25, 40) has areas which are transparent to the electromagnetic radiation (6, 13).
10. Apparatus according to one of the four preceding claims,
    characterized in that
    the sources (4) of electromagnetic radiation are arranged in relation to the areas (5, 25) that are transparent to the electromagnetic radiation (6, 13) in such a way that the areas serve as radiation conductors (5, 25).

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