EP0802054A2 - Method and apparatus for printing individual self-supporting objects - Google Patents

Abstract

Objects (14) such as compact discs.credit cards etc are fed onto a rotary table (12) and are indexed across a number of screen printing stations (20-23)The print screen is mounted in a fixture mounted on a coordinate table that can be moved in X and Y directions and can be rotated. The screen position is monitored relative to an object by a camera and can be adjusted under computer control (62). A second camera (70) can be used to provide a reference image.

Description

The invention relates to a method and a device for printing self-supporting individual objects, in particular those objects whose extent perpendicular to the at least one surface to be printed is generally relatively small. It can be z. B. to act CDs, phone cards, credit cards or the like. Especially with these objects, very small lot sizes are often to be printed. Lot sizes of just several hundred CDs or phone cards are not uncommon. The consequence of this is that a disproportionate amount of time is required to convert the printing press from one lot to the next. In addition, the changeover, that is, the adjustment of the printing units to the print image of the following lot, requires very well-trained operating personnel in the machines customary today if a print image of good quality is to be produced. The demands on the quality of the printed image are becoming ever greater.

From EP 0488092 B1 a screen printing machine for printing web material is known, in which registration marks attached to the web material are monitored by a camera. The screen printing stencils are arranged in an adjustable manner and are provided with servomotors that can be controlled by a computer depending on the positions of the registration marks determined by the camera. The setting However, the screen printing stencils, depending on the position of registration marks on the printed matter, do not result in any significant relief when converting printing machines. In addition, the quality that can be achieved in this way does not meet the requirements that are common in many cases today.

Accordingly, the invention has for its object to modify a method according to the preamble of claim 1 and a device according to the preamble of claim 11 or 14 so that a quick changeover, which should be done largely automatically, is possible and also good quality of the generally multicolored printed image can be achieved.

To achieve this object, the invention provides a method for printing self-supporting individual objects with at least two individual print images to be applied successively to the object by means of a printing unit each, which complement one another on the object to form an overall print image, with this being printed on the object with at least one individual print image captured by a camera system and the representation of the actual position of the individual print image relative to the object carrying it is compared in a computer with a stored representation of the desired position and depending on the result of the comparison if the actual position of the individual print image deviates from its desired Position the position of the printing unit and / or the position of a subsequent object for the printing process is changed according to the result of the comparison.

A major advantage of the invention is that it detects the printed image and thus the immediate result of the printing process and uses this result as a yardstick for assessing the quality, the latter being essentially determined by the fact that the individual printed images are correctly positioned on the object and thus all individual print images optimally complement one another to form the overall print image. When converting the machine for printing a new lot for a screen printing machine, for example, it is sufficient to roughly align the screen printing stencils required for the new lot in the previously usual manner, that is to say essentially manually. The time required for this is relatively small. The fine adjustment, i.e. the exact matching of the individual screen printing stencils to the object and thus the individual print images to each other, takes place automatically, namely by capturing the print image by the camera system and comparing the determined actual print image or the position thereof with the stored target print image .

The production of the target print image or the storage of the same presents no difficulty. It is thus possible to enter the individual print images one after the other in the computer, which can also be combined into the resulting overall print image. The individual print images can, for example, be in the form of the usual slides which are to be transferred to the screen printing stencil. These slides can be recorded individually by the camera, it only being necessary to ensure that any slides have a defined position when recording slides or the like. However, it is also easily possible to enter the individual print images in the form of digital data using a floppy disk or the like in the memory of the computer.

When applying the individual print image to the object using a printing cylinder, for example in the offset printing process, it can be advantageous if the actual position of the individual print image does not deviate from the target position, but not the position of the printing unit, but that of the following object for the Change the execution of the printing process accordingly. This means that the object is appropriately aligned before it is printed. Of course, it would also be possible to do this using screen printing. However, in the case of a screen printing unit, because of its simple construction, it is generally easier to So to adjust the template relative to the object, which is in a holder during printing and occupies a certain position.

After adapting the actual position of each individual print image to its target position, the printing of the following objects can be carried out without any further ongoing comparison between the actual position and the target position. This will generally be readily possible when printing small batch sizes, since the risk that the actual position of one or the other individual print image will subsequently change is relatively small.

On the other hand, the invention also offers the possibility of capturing the actual print images during production and comparing them with the respective target print image, so that deviations are detected and corrected immediately. Regardless of whether only the initial setting of the position of the printing units and / or the position of an object to be printed is checked or whether the ongoing production is also monitored, it is possible to capture the overall print image formed by at least two individual print images by a camera system and to display them compare at least one actual position of at least one individual print image relative to the object carrying it in the computer with the representation of a stored target position and make a correction as a function of the result of the comparison. The camera systems available today for monitoring print images are able to differentiate colors and thus when recording the overall print image, which is composed of several individual print images, to select a particular individual print image, which can then be compared with the target print image assigned to it in the computer . Such camera systems "resolving" the overall print image are particularly suitable for monitoring ongoing production, since they make it possible to manage with only one camera, which then only records the overall print image.

The devices used to carry out the above-described method are expediently provided with servomotors which, depending on the result of the comparison of the actual position and the desired position, adjust the position of the printing unit and / or that of the object accordingly.

Fig. 1

die Draufsicht einer Vorrichtung zum Bedrucken von flachen Einzelobjekten unter Anwendung des Siebdruckverfahrens,

Fig. 2

der vereinfachte Schaltplan einer Einrichtung zum Einstellen der Druckwerke der Vorrichtung gemäß Fig. 1,

Fig. 3A - 3C

jeweils ein Objekt mit einem Druckbild in stark vereinfachter Darstellung,

Fig. 4

die Draufsicht einer Siebdruckschablone zur Herstellung des Einzeldruckbildes gemäß Fig. 3A und Fig. 3B,

Fig. 5

die Seitenansicht eines Siebdruckwerkes mit zugehöriger Verstelleinrichtung in größerem Maßstab,

Fig. 6

eine Ansicht etwa in Richtung der Pfeile VI-VI der Fig. 5,

Fig. 7

eine Ansicht in Richtung der Pfeile VII-VII der Fig. 5,

Fig. 8

eine Ansicht in Richtung der Pfeile VIII-VIII der Fig. 5,

Fig. 9

eine Ansicht in Richtung der Pfeile IX-IX der Fig. 5,

Fig. 10

eine Ansicht in Richtung der Pfeile X-X der Fig. 5,

Fig. 11

die Seitenansicht einer Druckmaschine zum Bedrucken von Karten,

Fig. 12

den Ausschnitt XII aus Fig. 11 in wesentlich größerem Maßstab,

Fig. 13

eine Ansicht etwa in Richtung der Pfeile XIII - XIII der Fig. 12,

Fig. 14

einen Schnitt nach der Linie XIV - XIV der Fig. 13.

In the drawing, some embodiments of the invention are shown in the diagram. Show it:

Fig. 1

the top view of a device for printing flat individual objects using the screen printing method,

Fig. 2

the simplified circuit diagram of a device for setting the printing units of the device according to FIG. 1,

3A-3C

one object each with a printed image in a highly simplified representation,

Fig. 4

the top view of a screen printing stencil for producing the individual print image according to FIGS. 3A and 3B,

Fig. 5

the side view of a screen printing unit with associated adjustment device on a larger scale,

Fig. 6

a view approximately in the direction of arrows VI-VI of FIG. 5,

Fig. 7

a view in the direction of arrows VII-VII of Fig. 5,

Fig. 8

a view in the direction of arrows VIII-VIII of Fig. 5,

Fig. 9

a view in the direction of arrows IX-IX of Fig. 5,

Fig. 10

a view in the direction of arrows XX of FIG. 5,

Fig. 11

the side view of a printing machine for printing cards,

Fig. 12

the section XII of Fig. 11 on a much larger scale,

Fig. 13

a view approximately in the direction of arrows XIII - XIII of FIG. 12,

Fig. 14

a section along the line XIV - XIV of FIG. 13th

The base frame of the device shown in Fig. 1 carries a round circular table 12 which can be rotated step by step around a vertical axis and serves to hold and transport the individual objects 14 to be printed, which in this case are CDs. For this purpose, the transport table 12 is provided with brackets 16 which are arranged coaxially to the drive shaft of the table 12 close to the circumference thereof. The individual objects to be printed are accordingly transported along a circular transport path in the direction of arrow 18 from a receiving station I to a removal station VI, between which the treatment stations are located. The objects to be printed are inserted into the holder 16 located in the receiving station I by known devices which are assigned to the table 12 and have no connection with the invention. In the removal station VI, the printed object located there is removed from the holders using a removal device, also not shown. The device is provided with four screen printing units 20, 21, 22, 23, of which only the stencil frame 26 and the screen printing stencil 27 carried by it are shown in FIG. 1.

A currently preferred embodiment of a screen printing unit is shown schematically on a larger scale in FIGS. 5-10. The screen printing stencil 27 and squeegee head 32 printing unit is guided up and down on two columns 25 of the machine frame 10. In particular, Fig. 5 shows that the printing unit has an upwardly extending vertical plate 29 which is connected to the machine frame and carries at its upper end a bracket 30 on which a support rod 31 for the doctor head 32 is horizontally displaceably mounted. The support rod 31 is held and guided by four rollers 33 which are provided with an approximately V-shaped profiled outer surface and cooperate with corresponding lateral boundaries of the support rod. The back and forth movements of the support rod 31 and thus the doctor head 32 are effected by a gear 34 which is driven in a suitable manner and which meshes with a toothed rack 35 which is firmly connected to the top of the holding rod 31.

On the underside of the console 30, two guide rails 36 are attached, which are provided on their mutually facing sides with V-shaped cutouts. Correspondingly profiled strips 37 are guided in these guide rails 36 and are carried by a first carriage 38. The latter can be adjusted in the direction of the X axis, that is to say perpendicular to the image plane of FIG. 5, by a first first servomotor 39, the spindle 40 of which is firmly connected to the first slide 38. The first servomotor 39 is carried by a plate 41 which is fixedly connected to the frame 10 of the device.

The first carriage 38 carries on its underside two guide rails 42, which are profiled in accordance with the guide rails 36 and serve to guide two strips 43, which are profiled in accordance with the strips 37. The strips 43 are carried by a second slide 44 which can be pushed back and forth radially within the guide rails 42 in the direction of the Y axis, that is to say in relation to the circular transport path of the machine according to FIG. 1, and is therefore adjustable. For this purpose, there is a second servomotor 45 carried by the second carriage 44, the spindle 46 of which is attached to the first carriage 38. The displacement of the first carriage 38 caused by the first servomotor 39 takes place essentially transversely to the longitudinal course of the spindle 46 of the second servomotor 45. This spindle 46 is attached to the first carriage 38.

The second carriage 44 carries on the underside two guide rails 47, which are profiled corresponding to the guide rails 36 and 42 for the first and second carriages 38 and 44, but which run in a circular arc. A third slide 48 is guided in these guide rails, the lateral limits of which correspond to the profile of the guide rails 47 are V-shaped in cross section.

On the underside of the third carriage 48, a substantially horizontally projecting support element 49 is fixedly attached, which carries the sieve frame 26. The arrangement is such that the radius of the circular third guide formed by the two guide rails 47 passes through the center of the screen. For this purpose, the connection between the cantilevered support element 49 for the screen frame 26 and the third slide 48 is designed to be positive, so that a movement of the screen frame 26 relative to the third slide 48 is not possible.

The setting of the third slide 48 relative to the second slide 44 carrying it is carried out by a third servomotor 51 which is fastened to the second slide 44 and whose spindle 52 is connected at its free end to a pin 53. The latter is mounted rotatably about a vertical axis in a rear extension 54 of the projecting holder 49 for the screen frame 26. The rotatable mounting is necessary because the third carriage is moved along a circular arc section. A pivotable attachment of the third servomotor 51 to the second carriage 44 is not necessary, however, since the extent of the adjustment is very small in each case, a maximum of a few mm, and thus the extent of the displacement which the pin 53 undergoes when the third carriage 48 is adjusted is correspondingly small and is in the range of the elastic deformability of the spindle 52.

By means of the servomotors 39, 45 and 51, the frame 26 with the screen printing stencil 27 located therein can be adjusted in accordance with the respective requirements in the directions of the arrows 77, 78; 92, 93; 52, 55, i.e. linear in two mutually perpendicular directions and additionally by means of a pivoting movement.

Since the doctor head 32 is carried by the console 30, the with is connected to the base frame 10 of the machine, the doctor head 32 does not take part in the adjustment movements of the screen printing stencil which take place essentially in the horizontal plane.

A single print image is applied to the objects located in the holders 16 of the step-wise rotating table 12 in the individual printing stations II, III, IV, V, with all the individual printing images on each object, after passing through the printing station V, adding up to an overall printing image which is at the embodiment shown in Figures 1 and 2 composed of four partial print images. A dryer 57 for drying the printing ink applied in the respective previous station is arranged behind the printing stations II and V. Such dryers can also be connected downstream of the other printing stations III and IV.

A camera system is assigned to the removal station VI in such a way that the object provided with the overall printed image is captured by the camera 58 before it is removed from the holder. It is of course also possible to provide a special station for the camera system, which is arranged in the direction of rotation 18 of the plate 12 in front of the removal station VI, should this be necessary, for example, for reasons of space. FIG. 2 shows that the output of the camera system is connected via a line 60 to a computer 62, to which a screen 64 is assigned, on which the respectively recorded print image can be visually displayed. The actual position of the print image recorded by the camera 58 is compared in the computer 62 with the desired position of this print image stored in the computer. The result of the comparison is fed via a line 65 to a programmable control device 66, from which lines 20a, 21a, 22a, 23a lead to the servomotors 39, 45, 51 of the individual printing units in the printing stations 20, 21, 22, 23.

The desired positions of the individual print images to be applied in the stations 20, 21, 22, 23 stored in the computer 62 can be entered into the memory of the computer in this way that the slides 68 corresponding to the individual printed images are placed on a light table or the like 69 and are recorded successively by a camera 70, the positive located on the light table 69 in each case being oriented in a defined manner towards the camera so that all of the desired values recorded by the latter -Positions are also set in relation to each other. The successively recorded individual print images are fed to the computer 62 via lines 71, 72 and stored therein. The interposed screen 74 serves only to make the individual print image recorded in each case visible.

After being captured by the camera 70, the respective slide 68 can then be used in the usual way to produce the respective printed image of the screen printing stencil 27.

In deviation from the detection of the respective target position by the camera 70, there is also the possibility of introducing data corresponding to the target position directly into the computer 62 on a data carrier, as indicated by the arrow 76 in FIG. 2.

To set the screen printing stencils of the printing units 20, 21, 22, 23 in the stations II-V after changing the stencils, the procedure can be such that initially only one object in the station II is provided with a single print image in order to set the screen printing stencil 27 of the printing unit 20 and then after passing through the following stations in the removal station VI by the camera system 58. Then the computer 62 compares the detected actual position with the target position of this individual print image produced in the printing station II. If the actual position deviates from the target position, the position of the screen printing stencil 27 of the printing unit 20 is corrected by correspondingly actuating at least one of the servomotors. 3A shows the target position and FIG. 3B shows the actual position of the individual print image applied in station II, a comparison of this actual position with the target position would result, that via the control device 66 and the line 20a assigned to the printing station II, the servomotor 39 is switched on in such a way that the screen printing stencil 27 carried by the frame 26 undergoes a displacement in the direction of arrow 78 which corresponds to the distance 80 by which the actual position of deviates from the target position.

After correct setting of the screen printing template of the screen printing unit 20 located in the station II, the screen printing template of the printing unit 21 would be set in a corresponding manner in the printing station III, the target position of the printing unit 21 then having to be set effectively in the computer 62 in order to carry out the comparison. The screen printing stencils of the other stations would be set accordingly. After setting the screen printing stencils of all printing units, printing can then begin as part of normal production.

However, it is also possible, for the final adjustment of the screen printing stencils of all printing stations, to first apply all the individual printing images to an object and to have the resulting overall printing image recorded by the camera system 58, the actual positions of the individual printing images then being successively in the computer 62 with the respectively assigned target position is compared. It would only be necessary for the camera system 58 and / or computer 62 to be able to record and evaluate the individual print images separately. Technically, this is easily possible since the individual print images normally have different colors and the color differences can be recognized by the camera system 58 and / or by the computer 62.

With this variant, it is also possible, after the final adjustment of the screen printing stencils to adapt to the respective target position, before the start of production, to check the quality of the overall printed image even during the subsequent production by comparing the respective actual positions of the individual printed images with the respectively associated ones Monitor the target position on a random or continuous basis in order to record and correct deviations that could occur during normal production.

For the initial setting of the screen printing stencils of the printing units, any replacement objects of corresponding shape can be used instead of objects, if this is advantageous for cost reasons, so that the "real" objects are only introduced into the device when all printing units have been set correctly are. It may also be advantageous to carry out two or more printing processes for the initial setting of the screen printing stencils, the stencil being brought from the actual position into the target position step by step, that is to say after each printing process to a certain extent. Whether several setting steps are required for this initial setting can also depend on the size of the difference between the actual position and the target position.

The exemplary embodiment illustrated in FIGS. 11 to 14 is a device for printing flat individual objects such as credit cards, telephone cards or the like. Such cards have a thickness of z. B. 0.6 mm. They are printed using the offset printing process, although it is not excluded that other printing processes, e.g. Screen printing. However, the offset printing process allows the application of detailed print images in many colors and shades of color by using a high-resolution raster print.

FIG. 11 shows that the device has an essentially linear structure such that the objects to be printed are fed from a magazine device 100 at one end of the machine and, after having passed through several printing stations and other treatment stations, are picked up at the other end by a collecting device 102 and there for further treatment or use. Because with this In the exemplary embodiment, two objects are transported and treated in pairs by the device (FIG. 13), the distance between the two devices 100 and 102 is bridged by two parallel transport tracks 104, 106, each of which can have several successive different transport devices. For this and with regard to other features, reference is made to DE 19534827, the disclosure content of which is included in this application.

The device is provided with several offset printing stations, of which stations I, II, III and IV are shown in FIG. 11 of the drawing. In this case, a primer can be applied to the cards in the printing station I, whereas at least some of the following printing stations apply individual printing images with specific colors and a specific pattern and all individual printing images add up to form an overall printing image. Arranged below the printing cylinder 108 is an impression cylinder 110, which supports the two cards printed in one operation during printing, which are passed between the two cylinders 108 and 110 in the usual manner during the printing process. The printing cylinder 108 is provided in the usual way with a printing blanket 112, which receives an ink application from a plate cylinder 114 (FIG. 12).

In the cases where the cards to be printed are provided with a cavity for a chip or the like, it is necessary to support the latter on the side opposite this surface separately during printing on the flat surface of the card which is not provided with the cavity. For this purpose, the impression cylinder is provided with at least one substantially radially arranged stamp which protrudes somewhat from the outer surface of the impression cylinder and engages in this cavity during the printing of the side of the card which does not have the cavity.

The fact that individual print images are applied in several successive printing stations, which become one Completing the overall print image requires careful alignment of the cards to the respective printing unit. In addition, the presence of the aforementioned stamp also requires precise alignment with the impression cylinder.

12 and 13 show that each card 116 of the card pair to be printed simultaneously is transported in the transport direction 118 by a pair of belts 120, 122 into an alignment station for the subsequent printing process. A suction bar 124 is arranged between the two belts 120a, 120b and 122a, 122b of each pair of belts, the upper boundary surface 128 provided with suction openings 126 of which is located a short distance below the level of the conveying belts 120a, 120b; 122a, 122b. Due to the vacuum created by the suction effect below the cards, they are pressed against the straps carrying them, so that even at high transport speeds, the cards can be carried along and securely positioned on the straps of the respective pair of straps. The alignment station of each of the two transport tracks 104, 106 is assigned an alignment rail 130, 132, which carries a guide surface 134, 136 on its side facing the respective pair of belts. This surface is V-shaped in cross section, as can be seen in particular in FIG. 14. The suction strips 124 end in the transport direction 118 shortly before the plane running transversely to the transport direction 118, in which the guide rails 130, 132 begin. For reasons of space, in the exemplary embodiment shown in the drawing, the guide rails are each arranged on the outside, that is to say on the side of a pair of belts 120 or 122, which faces away from the other pair of belts. The pairs of belts 120, 122 end approximately at half the length of the associated guide rails 130 and 132, respectively.

Each of the two guide rails 130, 132 is attached to a support rail 138 which runs parallel to the respectively associated guide rail and is attached to the machine frame 140 so as to be pivotable about a vertical axis 142. The pivot axis 142 thus runs essentially perpendicular to the main plane of the cards 116 located in the transport path 104 or 106. Each mounting rail 138 is assigned two servomotors 144, 146 such that the axis of rotation 142 is located between the two servomotors or the spindles 148, 150 thereof , which are connected to the respective mounting rail 138.

A double-armed guide finger 152, 154 is provided on the side of each transport track 104, 106 opposite the guide rail 130, 132, which can be pivoted about an axis 156 parallel to the axis 142, that is to say vertical. Each guide finger 152, 154 is provided on its one arm with an extension 158 directed towards the respectively associated card 116, which, as can be seen in particular in FIG. 14, is also provided with a guide surface 160 with a V-shaped cross section. The other arm of each guide finger 152, 154 is acted upon by a spring 162 in such a way that the arm with the guide surface 160 is pressed against a longitudinal edge of the respectively associated card 116, as can be seen in particular in FIG. 13.

For the transport of the cards 116 into the printing unit, an additional transport device 164 is provided, which has two drivers 166, 168, one of which is assigned to one of the two transport tracks 104, 106 or the respectively associated pair of belts 120, 122. The transport device 164 is provided with two levers 172, 174 controlled by a cam plate 170 and a parallelogram 176 carrying the carriers 166, 168. When driven by the cam plate 170, the drivers perform reciprocating movements essentially in the transport direction 118 and in opposite directions and downward and upward movements, the drivers moving below the transport direction 118 being below the level of the pairs of belts 120 , 122 lying cards 116. In the upper position of the drivers 166, 168, they are located between the two toothed belts 120a, 120b and 122a, 122b, respectively. Grab it the drivers behind the card lying on the respective pair of belts, which is then advanced by the driver in the direction of transport 118 until the card with its front edge in the direction of transport is grasped by the two cylinders 108, 110 of the printing unit and in the course of printing by them in the direction is moved to two downstream pairs of belts 190, 192.

It is important that the drivers 166, 168 are carried by the transport device 164 with the interposition of servomotors 180, 182 such that the position of the respective driver in the transport direction 118 and opposite thereto can be adjusted relative to the transport device 164.

Fig. 11 shows that the printed objects pass through a control station V before leaving the device, which is provided with a camera system, not shown in detail, and the other devices described in connection with FIG. 2, which compare the actual print image or the Enable the actual position of the same with the target print image or the target position of the same. The computer of this station V is connected via lines 184 to the servomotors which are located in the alignment stations assigned to the individual printing stations and which can be designed as conventional stepping motors.

The two cards 116 transported in the direction of the printing station are moved so far in the transport direction 118 by the respective pair of belts 120, 122 that their rear limiting edge 186 is located behind the respective suction bar 124 in the transport direction and thus the driver 166 or. 168, at the end of its movement against the transport direction 118, can move upward behind the respective card 116 in order to advance it in its subsequent movement in the upper position, shown in FIGS. 12 and 13, in the transport direction 118 in the direction of the printing unit. Normally, the card is transported by the associated pair of belts 120 and 122 so far that the front edge 178 is located approximately in the area of the associated guide finger 152, 154. Due to the fact that the spring 162 acts on it, there is a certain frictional resistance which prevents the card from being carried along by the pair of belts 120 or 122. However, as already mentioned, the card assumes a position which enables the respective driver 166, 168 to engage behind the card at its rear edge 186, so that the further movement of the card in the direction of transport 118 takes place by the driver who also overcomes the frictional resistance between the guide rail 130 or 132 and the associated guide finger 152 or 154. During this movement along the guide rail, the card experiences an orientation transversely to the transport direction due to the pressure exerted by the guide finger against the guide rail, which is determined by the position of the guide rail 130 or 132. The card is aligned in the transport direction 118 by the position of the respective driver 166, 168. Since the transport device 164 carrying the drivers 166, 168 always executes the same movements that are defined by the curves 170, the driver 166 or 168, the position of the card 116, which it occupies relative to the circumference of the printing cylinder 108 or the printing blanket 112 located thereon, is also determined by the respectively associated servomotor.

The essential difference between the embodiment according to FIGS. 11-14 and the embodiment according to FIGS. 1-10 is that in the latter the printing units, namely the screen printing stencils, were aligned with the object to be printed, whereas in the embodiment according to FIGS. 11 - 13 the objects to be printed are aligned with the printing unit. Apart from this difference, however, there is agreement between the two embodiments with regard to the basic handling. Thus, a card or a pair of cards can first be provided in station II with a single print image, which is recorded in control station V and compared with the target position stored therein.

If the actual position deviates from the target position, at least one of the three servomotors of each alignment station is actuated accordingly. If, for the purpose of correcting the position and / or the angular position of the card, the respective guide rail 130 or 132 has to be adjusted, the actuation of one of the two servomotors 144, 146 is normally sufficient, since the extent of the adjustment required is generally so small that the pivoting of the guide rail caused by the actuation of a servomotor lies in the region of the elastic deformability of the elements of the other servomotor which are connected to the guide rail.

A special orientation of the card 116 with respect to its height is not necessary, since the card is held in the deepest part of the V-shaped recess of both parts due to the V-shaped configuration of the guide surfaces on the guide rail and the cooperating guide finger. The positive connection between the card and the guide caused by the latter also prevents the card from being able to perform an uncontrolled movement under the action of the forces exerted by the driver 166 or 168 on the light card. The guide rail and the guide finger interacting therewith represent a positive guidance which is effective until the card is grasped by the printing unit, that is to say the two rollers 108, 110, and is pulled out of the guide formed by the guide rail and guide finger. The driver 166, 168 thus only needs to execute a stroke in the transport direction 118 which corresponds to approximately half the length of the card 116 in the transport direction.

It may be expedient to choose the basic setting of the printing unit such that the arrangement of the printed image on the printing blanket 112 of the printing cylinder 108 requires a slight inclination of the guide rail 130 or 132 such that the distance of the guide rail in a horizontal plane from the central axis of the transport path 104 or 106 increases somewhat in the direction of transport 118. 13 would this means that the distance between the two guide rails 130, 132 or the guide surfaces 134, 136 increases somewhat in the transport direction 118. In this way it is ensured that after transport by the respective driver 166 or 168 and the alignment that has taken place as a result, the card 116 in any case maintains its position when it is guided by the two rollers 108, 110 of the printing group from the guide formed by the guide rail and guide finger is pulled out.

11-14 also applies to the fact that monitoring is also possible during ongoing production operation, as has already been described in connection with the embodiment according to FIGS. 1-10. Of course, if two transport lanes 104, 106 are present and thus two cards are printed on at the same time, it is necessary to provide a camera in the monitoring station V for each transport lane and downstream devices for carrying out the comparison between the actual position and the target position, since the alignment the card in front of the printing unit of each transport lane, i.e. independently of the other transport lane.

Claims (17)

Method for printing self-supporting individual objects (14; 116) with at least two individual printed images to be applied to the object one after the other by means of a printing unit each, which complement one another on the object to form an overall printed image, characterized in that after the object has been printed on with at least one individual printed image a camera system (58) detects and compares the representation of the actual position of the individual print image relative to the object (14; 116) carrying it in a computer (62) with a stored representation of the target position and depending on the result of the comparison in the event of deviations the actual position of the individual print image from its target position, the position of the printing unit (2O, 21, 22, 23) and / or the position of a subsequent object (116) for the printing process is changed in accordance with the result of the comparison. Method according to Claim 1, characterized in that the target print image is taken from a template (68) via a camera (70) and is entered into the memory of a computer (62). Method according to Claim 1, characterized in that the target print image in the form of digital data (76) is entered into the memory of a computer (62). Method according to Claim 1, characterized in that when the individual print image is applied to the object (14) by means of screen printing, if the actual position of the individual print image deviates from the desired position, the position of the screen printing stencil (27) is changed accordingly. Method according to Claim 1, characterized in that when the individual print image is applied to the object (116) using a printing cylinder (108) if the actual position of the individual print image deviates from the desired position, the position of a subsequent object (116) for the implementation the printing process is changed accordingly. A method according to claim 1, characterized in that for checking the printing units (20, 21, 22, 23) in the individual printing stations (II, III, IV, V) an object (14) is only provided with a single print image and that The individual print image of each object is recorded by a camera system (58) and the representation of the actual position of the individual print image relative to the object (14) carrying it is compared in a computer (62) with the stored corresponding target position and if the actual position deviates of the individual print image from its target position, the position of the printing unit (20, 21, 22, 23) by which the respective individual print image was printed was changed in accordance with the result of the comparison and the printing of objects (14) with all for the production of the Total print image required individual print images takes place after all the printing units required for this have been checked and adjusted if necessary. A method according to claim 1, characterized in that After setting the printing unit (20, 21, 22, 23) and / or the position of the following object (116) to adapt the actual position of the individual print image to its target position, the printing of the following objects without further comparison between the actual position and target -Position is carried out. Method according to Claim 1, characterized in that the overall print image formed by at least two individual print images is captured by a camera system (58) and the representation of at least one actual position of at least one individual print image relative to the object (14; 116) carrying it in a computer (62 ) compared with the representation of a stored target position and depending on the result of this comparison if the actual position of the at least one individual print image deviates from its target position, the position of the printing unit (20, 21, 22, 23) and / or the position a following object (116) for the printing process is changed according to the result of the comparison. Method according to Claims 1 and 6, characterized in that, even after the initial setting of the position of the printing units (20, 21, 22, 23) and / or the position of a subsequent object (116) for the printing process when printing on further objects, at least random monitoring of the Actual position of the overall print image and a corresponding comparison with the target position of the individual print images. A method according to claim 1, characterized in that a change in the position of the printing unit (20, 21, 22, 23) and / or the position of a subsequent object (116) for the printing process is only carried out if the result of the comparison is determined Deviation exceeds a predetermined extent. Device for printing self-supporting individual objects (14) with at least two successively on the object individual print images to be applied, which add up to an overall print image on the object, the device having at least two print stations (II-V), transport means (12) for transporting the objects through the print stations and possibly further treatment stations and at least one camera system (58) and each printing unit is provided with an adjustable screen printing template (27) and servomotors (39, 45, 51) for setting the screen printing template, which can be controlled by a computer (62) which is connected to the camera system, characterized in that by the camera system (58) at least one of the individual print images is detected and the actual position of the individual print image thus determined is compared with a stored target position and the screen printing stencil (27) with which this individual print image was produced is adjusted depending on the result of the comparison. Apparatus according to claim 11, characterized in that the printing of the objects (14) with the overall print image takes place after setting the screen printing stencil (97) of all printing units (20, 21, 22, 23) required for the overall print image. Apparatus according to claim 11, characterized in that the device for adjusting the screen printing stencil (27) has three slides (38, 44, 48) which are mounted so as to be displaceable relative to one another, of which two slides (38, 44) are arranged such that they can be moved linearly at right angles to one another, and the third carriage (48) is displaceable along a curved guideway and one of the carriages (38) is displaceably mounted on the machine frame (10) and the other two carriages (44, 48) are each carried by a carriage (38, 44), and the servomotors (39, 45, 51) are each arranged between the frame (10) and one (38) of the slide and between one of the slide (38, 44) and another slide carried by the latter. Device for printing self-supporting individual objects (116) with at least two individual print images to be applied to the object one after the other, which complement one another on the object to form an overall print image, the device having at least two printing stations (I - IV), transport means (120, 122) for transporting the Objects by the printing stations and possibly further treatment stations and at least one camera system and the printing unit is provided with a printing cylinder (108), to which at least one plate cylinder (114) is assigned, and an impression cylinder (110) and in front of the in the transport direction (118) A printing station is arranged for aligning the object to be printed, characterized in that the alignment station is provided with a guide surface (160) which laterally delimits the movement path of the object for one side of the object and at a distance from this guide surface (160) which is in the essentially the extension of the obj ektes (116) transversely to the transport direction (118), there is a movable guide stop (152, 154) which is elastically loaded in the direction of the object located between it and the guide surface (160) and the guide surface by means of which the object in is aligned essentially transversely to its transport direction, at least one servomotor (144, 146) is assigned, by means of which the guide surface can be displaced and / or pivoted essentially parallel to the transport plane of the object and the transport of the object from the alignment device into the printing station by a driver (166, 168), which is carried for the purpose of positioning in the transport direction (118) with the interposition of a servomotor (180) and the servomotors (144, 146, 180) for adjusting the guide surface (160) and / or the driver (166, 168 ) can be controlled by a computer that is connected to the camera system and the servomotors depending on v The comparison of the actual position of the individual print image with its target position can be adjusted. Apparatus according to claim 14, characterized in that the actuator surface is assigned two servomotors (144, 146). Apparatus according to claim 14, characterized in that the guide surface (160) is carried by a guide rail (130, 132) which has a V-shaped cross section on its side facing the object (116) and which faces the guide surface (160) Side of the guide stop (152, 154) is also V-shaped in cross section such that the edges of the object, which are essentially parallel to the transport direction, are guided from the deepest area of the two V-shaped surfaces. Apparatus according to claim 14, characterized in that the individual print image to be transferred to the object (116) is aligned on the printing cylinder (108) in such a way that the guide surface (160) forms a small angle for the purpose of corresponding alignment of the object with the transport direction (118) such that the guide surface (160) increasingly moves away from a linear defining the transport direction in the transport direction of the object.

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