EP1156387A2 - Method and apparatus for adjusting registration - Google Patents

Abstract

Method detects the entry of a print medium (2) into a printer (1) and calculates the beginning of digital generation of partial color images (3,3',3,3') to achieve a register supported positioning of color prints on the substrate. The leading edge (5) of the print medium is precisely determined when it enters the printer after which the relative positions of partial color images are determined. The invention also relates to a device for adjusting the register position.

Description

The invention relates to a method for register setting with a detection of Entry of a printing substrate into a printing press and calculation of the start the digital generation of partial color images for achieving a register-based Position of the partial color prints on a printing substrate.

The invention further relates to a device for register adjustment after aforementioned method on a printing press with several color printing units Generation of several partial color prints, with a sensor the entry of a printing substrate captured in the printing press and a computer the start of the generation of partial color images by means of digital generation of the same on one Carrier element calculated and initiated.

The printing of colored representations, in particular colored images, takes place in that several partial color images are printed on top of each other. These are usually the ones Colors yellow, magenta and cyan as well as black. Special colors are also available if required added. By printing these colors on top of each other you can create all color compositions achieve, the quality of the prints significantly from the register Overprinting the partial color images depends. In digital, for example electrostatic printing is the registration of the overprint achieved by controlling the imaging devices such that the Partial color images meet in register when transferred to a printing substrate. This must be set and adjusted if necessary during printing become. Since the partial color images are newly generated for each individual print image adjustment or correction possible after each printing process.

From US 5, 678, 128 is a method and an apparatus of the aforementioned Kind known in which a sensor for detecting the entry of a printing substrate arranged and a controller for the printing starts of the printing units to achieve the Registration is provided. As the sensor for the detection of the printing substrates lies within the machine, there is only a very short time to complete the calculation to be able to make before the first partial color image for transfer to the printing substrate must be generated. On the one hand, this requires a high computing capacity and on the other hand, it limits the speed of the printing process. Should the register match not only be achieved with regard to the beginning of the picture, but also with respect to several or many defined areas of the partial color images, so increases the computational effort required is considerable. However, this is available in short standing time not possible. So there are possibilities in the state of the art limited to achieve a high register accuracy of the partial color images.

The invention is therefore based on the object of a method and a device of the type mentioned in such a way that more time to calculate the Setting values for register setting are available.

The object is achieved with respect to the method according to the invention in that the Printing substrate is detected before and after it enters the printing press Acquisition, the calculation of the relative positions of the partial color images takes place and that with the entry into the press an accurate detection of the leading edge of the Printing substrate is made and the basis for the determination of the starts the generation of the partial color images precalculated with regard to their relative positions is made.

With regard to the device, the object is achieved in that one of the printing press upstream sensor detects the printing substrate before it enters the printing press and sends a signal to the computer, whereupon the computer determines the relative positions of the partial color images calculated, and that the sensor arranged in the printing machine outputs a signal Means for determining the release of start signals for those related to their Relative positions precalculated generation of the partial color images there.

With the invention, the higher computational complexity is thus achieved even before a Print substrates processed in the printing press and the determined values are held in such a way that only one assignment of the front edge of the in the printing press entering printing substrate to the pre-calculated relative positions required is. The assignment is made by releasing start signals for the generation of the Part color images based on pre-calculated data. This is with little computing effort connected, which can be mastered in a short time. That way, despite that seen overall high computing effort a precise and fast assignment of Print substrate possible based on the calculated values. The invention thereby enables to achieve an exact relative position of the partial color images. The invention allows thus achieve a higher print quality and the calculation of the register setting is no longer a bottleneck for increasing the printing speed.

The advantages of the invention mentioned already have an effect if only one calculation the relative position of the beginning of the partial color images takes place. Particularly advantageous is the increase in computing time according to the invention, however, if the Calculation of the relative positions of the partial color images, both the beginning of the image and the Location of defined areas, in which the partial color images are divided, includes. there these areas can be pixel lines of the partial color images or a specified one Number of pixel lines.

An embodiment of the invention provides that the times for generating the electrostatic latent partial color images to achieve register correspondence calculated and made the basis for control or regulation. Another, particularly advantageous embodiment provides that the positions of the generation of Partial color images relative to their transfer points on the printing substrate Achieving register correspondence and with the paths of the print substrate up to be coordinated with the transfer agencies. The second embodiment has the Advantage that errors result from the time-position assignment, for example from a time-path or a time-angle assignment result, not included in the calculation become. As a result, a more precise control or regulation and thus one achieved higher register accuracy and better print quality.

The device can be developed in such a way that it is capable of all of the above Realize process features. The following configurations are advantageous for this the device:

It is expediently provided that the computer is designed in such a way and with Data for the relative position of the carrier elements for the partial color images and one Substrate carrier is loaded that he carries out a calculation with respect to the relative positions the partial color images, the beginning of the image and the position of the defined areas, in which the sub-color images are subdivided includes and on this basis the facilities controls for the generation of the partial color images. The data for the relative position of the Carrier elements and a substrate carrier can be obtained in different ways become. It can be path-time data of the image or substrate bearing Act elements, or it is possible to provide location data representing these elements concern and which are assigned to each other. It is also possible to use calibration tables enter the corresponding empirical values, the different positions of bildoder can be assigned to substrate-bearing elements. Most convenient is a calibration table that the support element with a surface for the generation of Partial color images, this is usually an image cylinder, is assigned. For one The angular positions of these elements can be assigned. The mentioned data can also be printed and recorded register marks determine. For the latter purpose it is proposed that the device at least has a sensor for detecting a component of a partial color image and the Computer is designed such that it detects the relative positions of the individual partial color images among themselves to achieve register correspondence and the relative position of the substrate carrier for positioning the pressure on the latter. Such defined components of a partial color image can be the register marks, however, it is also possible to define other defined components, such as limits Picture.

An advantageous development of the device provides sensors for detecting Angular positions of the elements transferring the color image and the angular positions the drive roller of the substrate carrier in front, wherein the computer is designed such that he the angular positions of the sub-color image-transmitting elements to each other Achievement of register coincidence and the angular positions of the drive roller of the substrate carrier with the aforementioned angular positions. With the above Sensors can also be sensors for detecting routes, for example of register marks, or it can be sensors, the travel times of image- or substrate-bearing elements. So sensors for detection the paths of the surfaces of the carrier elements, for example the image cylinders, be provided, and sensors for detecting paths of the surfaces can also be provided of image transmission elements, for example transmission cylinders, be provided. A sensor for detecting the path of the substrate carrier is also for the assignment of the printing substrates to the partial color images possible. Preferably However, angular position sensors are provided as sensors and one is found Verification for the corresponding angular positions instead.

Fig. 1

eine Druckmaschine mit einer Vorrichtung der erfindungsgemäßen Art und

Fig. 2

ein Farbdruckwerk der Druckmaschine in perspektivischer Sicht.

The invention is explained below with reference to an embodiment shown in the drawing. Show it

Fig. 1

a printing press with a device of the type according to the invention and

Fig. 2

a color printing unit of the printing press in perspective.

1 shows a printing press 1 with a device of the type according to the invention. Printing substrates 1 are fed to printing substrates 2 by means of a belt 29 and then passed through the machine by means of a substrate carrier 28, printing substrates 2 having four color printing units 10, 10 ', 10 ", 10 "'happen. The color printing units 10, 10 ', 10 ", 10"' have devices 13, 13 ', 13 ", 13"' for generating partial digital color images 3, 3 ', 3 ", 3"' which are placed on surfaces of carrier elements 14, 14 ', 14 ", 14"' are generated. These carrier elements 14, 14 ', 14 ", 14"' are designed as image cylinders. Such partial color images 3, 3 ', 3 ", 3"' can of course also be produced on tapes or in succession on a single image cylinder. In the illustrated embodiment, the partial color images 3, 3 ', 3 ", 3"' are transmitted to image transfer cylinders 26, 26 ', 26 ", 26''' and from there to transfer points 9, 9 ', 9", 9 "' Transfer printing substrates 2. The partial color images 3, 3 ', 3 ". 3 "'cover the paths 8, 8', 8", 8 '''from their generation to their transmission, these paths being shown as thick lines in FIG. 1. These paths 8, 8 ', 8 ", 8""are expediently detected as angular positions 8, 8', 8", 8 "'by the sensors 24, 24', 24", 24 "'being designed as angular position transmitters. The positions of the substrate carrier 28 are expediently recorded as the angular positions of the drive roller 33, in that the sensor 30 is designed as an angular position transmitter. This is generated before the next printing substrate 2 arrives at the respective color printing unit 10, 10 ', 10 ", 10"'.

In order to achieve high quality register-based prints, the partial color prints 4, 4 ', 4 ", 4"' can be printed exactly on top of each other. For this purpose it is already in the stand known in the art to arrange a sensor 23 that the entry of the printing substrates 2nd detected in the printing press 1. This sensor 23 registers the arrival of the leading edge 5 of a printing substrate 2 and gives a signal 17 to the computer 12. According to the state of the It is known in the art that such a computer 12 determines the times of the partial color images 3, 3 ', 3 ", 3"' from their generation to their transfer 9, 9 ', 9 ", 9"' to the Print substrates 2 and the times that the print substrates 2 from their detection by the Sensor 23 to the transfer points 9, 9 ', 9 ", 9"' need, calculated and the Generation of the partial color images 3, 3 ', 3 ", 3"' controls such that the image beginnings 6th to match.

The illustrated embodiment corresponds to a development of the invention provides that the computer 12 positions 8, 8 ', 8 ", 8"' - so angles or paths of Partial color images 3, 3 ', 3 ", 3"' - in their relative position assigns to each other and then this Positions 8, 8 ', 8 ", 8"' with positions 11, 11 ', 11 ", 11"' of the printing substrate 2 in such a way that the image starts 6 on the correct position of the printing substrates 2 come to lie.

The problem with prior art machines has been that these computations must be completed before the printing substrate 2 the first transfer point 9 "'. With today's fast running of printing presses it is the Available time too short, which means that this is a bottleneck for the increase in speed is involved or that the calculation processes are greatly simplified Need to become. Both are undesirable, especially since the requirement for higher print quality also requires much more extensive calculations. This is based on the Representation of Fig. 2 explained.

2 shows a color printing unit 10 of the printing press 1 in a perspective view. This color printing unit 10 shows how the partial color image 3 is subdivided into defined areas 7, 7 ', 7 ", ..., 7 ⁿ , in order for each of these defined areas 7, 7', 7", ..., 7 ⁿ to calculate positions 8 and 11. Correspondingly, these positions 8, 8 ', 8 ", 8''' and positions 11, 11 ', 11", 11 "' - when they are reached by the printing substrate 2, the generation of the partial color images 3, 3 ', 3", 3 "'must begin - calculated for all color printing units 10, 10', 10", 10 "'in order to bring them in line for all defined areas 7, 7', 7", ..., 7 ⁿ . However, such a computation effort can generally no longer be carried out after the entry of a printing substrate 2 into the printing press at the sensor 23.

For this reason, the invention provides for a sensor 15 to be arranged in front of the printing press 1 and for this sensor 15 to be arranged, for example, on the belt 29 for feeding printing substrates 2 to the printing press 1. This sensor 15 detects the front edge 5 of a printing substrate 2 and sends a signal 16 to the computer 12 so that it starts calculating the positions 8, 8 ′, 8 ″, 8 ″ ″ and assigns them to one another according to the register possible that the computer 12 already calculates the positions 11, 11 ', 11 ", 11"' of the printing substrate 2 on the substrate carrier 28 and these positions 11, 11 ', 11 ", 11"' in a corresponding manner to the positions 8, 8 ', 8 ", 8"' so that all image starts 6 of the partial color prints 4, 4 ', 4 ", 4"' come to the correct places on the printing substrates 2. Furthermore, the computer 12 also takes these calculations for the defined areas 7, 7 ', 7 ", ..., 7 ^{n of} the partial color images 3, 3', 3", 3 "'before. Instead of the named positions 8, 8 ', 8 ", 8"', 11, 11 ', 11 ", 11"', the corresponding positions 8, 8 ', 8 ", 8"', 11, 11 ', 11 ", 11 '''of the surfaces of the partial color image-transmitting elements 14, 14', 14 '', 14"', 26, 26', 26 ", 26"'matched to one another and these with the paths 11, 11', 11 '' , 11 '''of the surface of the substrate carrier 28 can be coordinated.

If the printing substrate 2 guided on the belt 29 now arrives at the printing press 1, that is on the substrate carrier 28 and is detected by the sensor 23, the computer 12th after receiving signal 17, these calculations are only those that are now precisely recorded Assign front edge 5 of print substrate 2.

The control data 27, 27 ', 27 ", 27"' are thus provided by the computer 12 for the register-related assignment of the partial color images 3, 3 ', 3 ", 3"' and the assignment of the same to the printing substrate 2. Devices 18, 18 ', 18 ", 18"' are provided for releasing these data 27, 27 ', 27 ", 27"', which determine their release according to the time or preferably according to the position of the printing substrate 2 on the substrate carrier 28. The data 27, 27 ', 27 ", 27""are then based on start signals 19, 19', 19", 19 "" for the image beginnings 6 and for the defined areas 7, 7 ', 7 ",. .., 7 ⁿ released and the partial color images 3, 3 ', 3 ", 3"' are created.

Around the positions 11, 11 ', 11 ", 11"' 'of the substrate carrier 28 or one lying on it Print substrate 2 the positions 8, 8 ', 8 ", 8"' of the partial color images 3, 3 ', 3 ", 3"' to be able to assign and also to be able to assign the latter to each other, it is required that positions of the substrate carrier 28 and the image cylinders 14, 14 ', 14 ", 14 "'. The positions of the image transfer cylinders are also expedient 26, 26 ', 26 ", 26"' detected. The detection of positions 11, 11 ', 11 ", 11 "'of the substrate carrier 28 is the already mentioned sensor 30, which the data 21 the Computer 12 transmitted. Furthermore, the sensors 24, 24 ', 24 ", 24' '' are for detection the positions of the image cylinders 14, 14 ', 14 ", 14"' provided the corresponding ones Data 20, 20 ', 20 ", 20'" also be sent to the computer 12. Also for the image transfer cylinders 26, 26 ', 26 ", 26'" sensors 25, 25 ', 25' ', 25' '' are provided, their Data is also transmitted to the computer 12, these data lines for clarity were not drawn for the sake of With sensors 30, 24, 24 ', 24 ", 24 "', 25, 25', 25", 25 '"can also be an angular position transmitter Act sensors that detect path markings on the surfaces.

Positions can also be recorded using register marks, for this purpose is a Sensor 22 is provided which determines the positions of printed register marks. It can be a sensor 22 'which directly determines the position assignments of the Register marks are recorded and this data is sent to the computer 12. Such a capture register marks can also be designed as a route or time recording. she can also to check the aforementioned calculations or to serve them by a Correct regulation. The correction can be made for each creation of a part color image 3, 3 ', 3 ", 3"'.

The arrow 31 shows the direction of transport of the printing substrates 2, the impression cylinder 32 and the arrows without reference numerals in the cylinders, which indicate the direction of rotation of the same.

The invention can of course not only on a printing press according to the Realize the example shown, it is also possible, in accordance with differently designed To move printing presses. Printing presses are conceivable in which the Partial color images 3, 3 ', 3 ", 3"' 'are fed to an intermediate carrier, which transfers together to a printing substrate 2. It is also possible for the carrier elements 14, 14 ', 14 ", 14"' for the partial color images 3, 3 ', 3 ", 3"' as a band or in are designed differently. All variations of training of printing machines are conceivable, the advantage according to the invention also being achievable with these is.

Reference list

1

Printing press

2nd

Printing substrates

3, 3 ', 3 ", 3' ''

Part color images

4, 4 ', 4 ", 4' ''

Partial color prints

5

Front edge of the print substrate

6

Beginning of picture

7, 7 ', 7 ", ..., 7 ⁿ

defined areas of the partial color images

8, 8 ', 8 ", 8"'

Positions of the generation of the partial color images related to the Transfer points on the print substrate

9, 9 ', 9 ", 9"'

Transfer points of the partial color images on the printing substrate

10, 10 ', 10 ", 10" '

Color printing units

11, 11 ', 11 ", 11" '

Paths - also detectable as angular positions of the drive roller - des Printing substrates from the detection of entry into the printing press or the substrate carrier up to the transfer points

12th

Calculator for calculating the relative positions of the partial color images

13, 13 ', 13 ", 13" '

Devices for generating the partial color images

14, 14 ', 14 ", 14" '

Carrier element for the part color images

15

Sensor (upstream of the press)

16

Sensor 15 signal

17th

Signal from sensor 23

18, 18 ' 18 ", 18" '

Means for calculating the release of the start of production the partial color images

19, 19 ', 19 '', 19 '' '

Start signals for the generation of the partial color images

20, 20 ', 20 ", 20" '

Data for the relative position of the carrier elements for the partial color images

21

Data for the relative position of the substrate carrier

22

Sensor for recording travel times (e.g. register marks)

22 '

Sensor for detecting position assignments (e.g. from Register marks)

23

Sensor (located in the printing press) for detecting entry a printing substrate in the printing press

24.24 ', 24 ", 24 '"

Sensors for detecting positions of support elements for the Partial color images, e.g. B. of image cylinders

25.25 ', 25 ", 25 '"

Sensors for detecting positions of image transmission elements, e.g. B. of transfer cylinders

26.26 ', 26 ", 26 '"

Image transfer cylinder

27, 27 ', 27 ", 27 '"

Control data for the generation of the part-color images

28

Substrate carrier

29

Belt for feeding printing substrates to the printing machine

30th

Sensor for detecting the positions of the substrate carrier

31

Arrow: transport direction of the printing substrates

32

Impression cylinder

33

Drive roller of the substrate carrier

Claims (10)

Method for register setting with detection of the entry of a printing substrate (2) into a printing press (1) and calculation of the start of the digital generation of partial color images (3, 3 ', 3 ", 3'") in order to achieve a register-based position of the partial color prints (4, 4 ', 4 ", 4''') on a printing substrate (2),
characterized in that the printing substrate (2) is detected before it enters the printing press (1) and after this detection the calculation of the relative positions of the partial color images (3, 3 ', 3 ", 3'") is carried out and that with the entry into the printing machine (1) carries out a precise detection of the front edge (5) of the printing substrate (2) and serves as the basis for determining the starts of the generation of the partial color images (3, 3 ', 3 ", 3'''), which are precalculated with regard to their relative position is made. Method according to claim 1,
characterized in that the calculation of the relative positions of the partial color images (4, 4 ', 4 ", 4"') both the beginning of the image (6) and the position of defined areas (7, 7 ', 7 ", ..., 7 ⁿ ), into which the partial color images (3, 3 ', 3 ", 3'") are divided. Method according to claim 2,
characterized in that the areas (7, 7 ', 7 ", ..., 7 ⁿ ) are pixel lines of the partial color images (3, 3', 3", 3 '"). Method according to claim 2,
characterized in that the areas (7, 7 ', 7 ", ..., 7 ⁿ ) are each a fixed number of pixel lines. Method according to one of claims 1 to 4,
characterized in that the times for the generation of the electrostatic latent partial color images (3, 3 ', 3 ", 3'") are calculated in order to achieve register correspondence and are used as the basis for control or regulation. Method according to one of claims 1 to 4,
characterized in that the positions (8, 8 ', 8 ", 8"') of the generation of the partial color images (3, 3 ', 3 ", 3"') relative to their transfer points (9, 9 ', 9 ", 9 "') on the printing substrate (2) to achieve a register match and with the paths (11, 11', 11", 11 ''') of the printing substrate (2) to the transfer points (9, 9', 9 ", 9 '") can be coordinated. Device for register adjustment for carrying out a method according to one of claims 1 to 6 on a printing press (1) with a plurality of color printing units (10, 10 ', 10 ", 10"') for producing a plurality of partial color prints (4, 4 ', 4 ", 4 '"), whereby a sensor (13) detects the entry of a printing substrate (2) into the printing press (1) and a computer (12) detects the start of the generation of partial color images (3, 3', 3", 3 "') Devices (13, 13 ', 13 ", 13''') for digitally generating them on a carrier element (14, 14 ', 14", 14''') are calculated and initiated,
characterized in that a sensor (15) upstream of the printing press (1) detects the printing substrate (2) before it enters the printing press (1) and sends a signal (16) to the computer (12), whereupon the latter determines the relative positions of the partial color images (3,3 ', 3 ", 3'") and that the sensor (23) arranged in the printing press (1) transmits a signal (17) to devices (18, 18 ', 18 ", 18"') Determination of the release of start signals (19, 19 ', 19 ", 19"') for the generation of the partial color images (3, 3 ', 3'',3''') pre-calculated with regard to their relative positions. Device according to claim 7,
characterized in that the computer (12) is designed in such a way and with data (20, 20 ', 20 ", 20'", 21) for the relative position of the carrier elements (14, 14 ', 14 ", 14'") and a substrate carrier (28) is loaded so that it carries out a calculation which, with respect to the relative positions of the part-color images (4, 4 ', 4 ", 4"'), the beginning of the image (6) and the position of the defined areas (7, 7 ', 7 " , ..., 7 ⁿ ), into which the partial color images are divided, and on this basis controls the devices (13, 13 ', 13 ", 13''') for generating the partial color images. Device according to claim 8,
characterized in that it has at least one sensor (22) for detecting a defined component of a partial color image (3, 3 ', 3 ", 3"') and the computer (12) is designed such that it detects the relative positions of the individual so detected Partial color images (7, 7 ', 7'', ..., 7 ⁿ ) match each other to achieve register correspondence and the relative position of the substrate carrier (28) to position the print on the latter. Device according to claim 7 or 8,
characterized in that it has sensors (22 ', 24, 24', 24 ", 24"', 25, 25', 25 ", 25 '", 30) for detecting angular positions (8, 8', 8 ", 8 '") of the partial color image-transmitting elements (14, 14', 14", 14 "', 26, 26', 26", 26 ''') and the angular positions of the drive roller (33) of the substrate carrier (28) and the computer ( 12) is designed such that it has the angular positions (8, 8 ', 8 ", 8"') of the partial color image-transmitting elements (14, 14 ', 14 ", 14"', 26, 26 ', 26 ", 26'" ) with each other to achieve register correspondence and the angular positions (11, 11 ', 11 ", 11"') of the drive roller (33) of the substrate carrier (28) with the aforementioned angular positions (8, 8 ', 8 ", 8''') votes.

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