JP2002014510A - Method and device for correction of register error in multicolor printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To utilize a correction value to a correct a register error that can be allotted to a position of an angle of a machine member in fine partitions in a way that can be repeated. SOLUTION: In the device, any error in roundness of the machine member that affects the register is derived, this is allotted to the position of the angle of the machine member and the correction value to control formation of a color separation image in at least one image cylinder is determined.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for correcting a register error in a multicolor printing press having a plurality of devices for digitally forming a color separation image, wherein a correction value is obtained. The invention also relates to a method for correcting registration errors in a multi-color printing press, which is assigned to the angular position of at least one image cylinder and is taken into account for the control of the formation of color separation images in the image cylinder. Apparatus for correcting registration errors in a color printing press, wherein the multicolor printing press includes a plurality of devices for digitally forming a color separation image and at least one control unit for controlling the plurality of devices. And at least one memory, at least one memory for forming a color separation image assigned to the angular position of at least one image cylinder. The data for determining the correction value is stored, to a device for correcting the register error in the multi-color printing press.

[0002]

2. Description of the Related Art Color display, especially printing of a color image, is performed by printing a plurality of color separation images on top of each other. These are usually yellow, magenta, cyan and black inks. Other inks are added if needed. Overprinting of these inks results in a full ink composition, where the quality of the print is essentially the registered in-register of the color separation image.
overprinting). In the case of digital, e.g. electrostatic, printing, the registration of overprinting is obtained by: That is, the image forming apparatus is controlled so that the color separation images are registered when they are transferred to the print substrate and overlap each other.

US Pat. No. 5,287,162 discloses a method and apparatus of the above type, in which a calibration table is created which contains correction values for the image formation of the image cylinder. Register marks are printed by various ink mechanisms to create these calibration tables, and the time required by these register marks from their formation to their detection is detected. Such time is then used to calculate a correction value. These correction values are assigned to the angular position of the image cylinder in the form of a calibration table.

However, error detection using such a register mark has the following disadvantages. This has the disadvantage that the sum of all errors is detected, so that individual error sources can no longer be assigned to a periodic repetition of these errors. The registration error is mainly due to the non-roundness of the machine member that transfers the image or the substrate.
ess). If the non-circularity of the image cylinder is added to the non-circularity of the image transfer cylinder or other machines, such as the drive rollers of the carrier of the printed circuit board, these can no longer be assigned directly to the angular position of the image cylinder by the prior art. Absent. This is because these mechanical members never rotate simultaneously with the image cylinder. There is no such simultaneous rotation even when the diameters are adjusted to each other.
This is because phenomena such as slip and overdrive occur. Overdrive is the faster rotation of a cylinder where one cylinder is driving another cylinder than the rotation of a rigid cylinder. This is due to the compression of the elastic jacket in the contact area of the cylinder. Slip occurs especially when one mechanical member is driven by another mechanical member. For example, this is the case when the image transfer cylinder is driven by a carrier for the printed circuit board, and this carrier is also driven by a drive roller. The image cylinder is also driven by the carrier or the image transfer cylinder. Despite the fact that there is no assignment of aperiodic changes to periodic angular positions, in addition to the errors repeated by the rotation of the mechanical member periodically,
Aperiodic changes such as drift due to temperature changes are also detected by register mark detection. This makes it difficult to analyze the errors detected as a sum.

[0005] In addition, the printing of register marks is cumbersome.
This is all the more so, especially for the assignment to angular positions, which requires continuous registration mark printing. These angular positions include all angular positions and angular position combinations of all mechanical components that affect registration. further,
The accuracy of the calibration table assigned to the angular position is limited by the resolution accuracy of the printed register marks, so that accurate correction to finely partitioned areas of the color separation image is not possible.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to make it possible to use correction values for register errors which can be assigned in a repeatable manner to the angular position of a machine member in a small section. It is.

[0007]

The object of the present invention is to provide a method, wherein the roundness error of a machine member which affects the register is determined and assigned to the angular position of the machine member, from which the color in at least one image cylinder is determined. The problem is solved by determining a correction value for controlling the formation of a decomposed image, and the above-mentioned problem is solved in an apparatus in which the correction value is determined based on a roundness error of a mechanical member that affects registration. This is done by: at least one control unit, by assigning a circularity error to the angular position of the mechanical member, via at least a correction value for the angular position of the at least one image cylinder, Is configured to determine for control of the formation of a color separation image in one image cylinder.

[0008]

DETAILED DESCRIPTION OF THE INVENTION An advantage of the present invention is that major error sources based on non-circularity are accurately assigned to these non-circular machine parts. In this way, it is possible to control the image formation of the image cylinder in such a way that errors with periodic repetition are detected by the angular position of the member and these errors are compensated. Thus, when an image start or a region of a color-separated image is formed in the image cylinder, the image forming control unit "knows" the error by the periodicity of these errors tied to the mechanical member,
It is possible to control this image formation to compensate for these errors already in the early stages of the image formation by compensation, for example by expansion or compression of the image components.
A so-called “error” canceled by a transfer error during image formation is incorporated. As a result, registered color separation images are printed in all partial areas of the image, and these different color separation images are registered and accurately reach the printed circuit board. The present invention allows for a pre-computation of the error, where different periodicity error sources are detected separately,
This allows the above-described image formation calculations with error compensation.

In this case, the present invention does not require the printing of a register mark. This is because out-of-roundness can be detected in other ways, and more specifically, so as not to be confused with an error having a different periodicity or an error having no periodicity. Of course, the printing of the registration marks, the detection of the image start or the image components can additionally be performed to make other corrections. Nevertheless, in this case the advantages of the classified detection of errors of different periodicity remain. This is because these errors are compensated before the detection of the already printed register marks.

In the present invention, it does not matter which transfer path is provided for the color separation image. The apparatus for forming the color separation images is only one of these color separation images.
In one or in each case one image cylinder. The transfer of the color separation image from one or more image cylinders directly to the substrate is then performed, or a further transfer member is provided and these further transfer members already overlap one another. The images or individual color separation images are separately transferred. Also, the color separation images already overlap one another in the image cylinder, or only when transferred to the printed circuit board, or overlap each other on the transfer member halfway to the printed circuit board.

Embodiments of the present invention relating to roundness errors to be considered follow these transfer paths and members. Therefore, it is configured such that the roundness error of the image cylinder is determined for determining the correction value. In multi-color printing presses having image transfer cylinders, the roundness errors of these image transfer cylinders are determined to determine correction values and are taken into account for controlling the formation of color-separated images in the image cylinders. In addition, the roundness error of the drive roller of the carrier for the printed circuit board is also detected and taken into account in determining correction values for controlling the formation of the color separation image in the image cylinder. With regard to the device for performing these method steps, a sensor for detecting these roundness errors and at least one control for calculating the correction value are also provided. A more detailed embodiment will be further described.

There are various methods for determining the roundness error. It can be arranged that the roundness error is determined by direct measurement on the machine component. However, it is also possible that the angular position of the mechanical member affecting the register is detected and the roundness error is determined from the mutual positional relationship (gegenseitige Zordnung) of these angular positions. With respect to the device, a device is provided for detecting roundness errors and assigning these roundness errors to angular positions. In this case, these devices may be sensors for detecting roundness errors, or may be rotation angle transmitters. These rotation angle transmitters are connected to a computer, and the computer is configured to determine the roundness error and the correction value from the mutual positional relationship between the angular positions of the mechanical members. Since the roundness errors are detected by the associated angular position, they are valid roundness errors including slip, overdrive or similar phenomena.

The correction value is provided only for the image start part. However, in order to achieve high printing accuracy, it is proposed that correction values be assigned to predetermined areas of the color separation image and taken into account for their formation. in this case,
A color separation image is an individual image line or a group of image lines. Advantageously, the predetermined area of the color separation image is determined by assigning the image area to a predetermined angular sequence of image cylinders. With respect to the device, at least one control unit is configured to take into account correction values for predetermined areas of these color separation images in their formation.

With respect to the correction value, the correction value is detected once and is configured to be considered as a machine-specific parameter. For this purpose, at least one
One memory is configured to store the roundness error together with its angular position assignment as a machine-specific nominal value.

The correction values are also detected before printing is performed and are taken into account for this printing. As a result, the correction value can be determined again, or the parameter unique to the machine can be corrected. Of course, the correction value can be continuously detected and considered. In particular, due to the continuous redetermination of the correction values, drifts of the correction values, which may be caused, for example, by temperature and stress changes in the machine, can also be taken into account by the continuous updating of the correction values.

In order to also carry out corrections over the image width, it is arranged that a plurality of correction values are detected and taken into account over the area of the image width. However, it is also possible to detect a plurality of correction values over an area of the image width and determine and consider an average correction value therefrom. For this, a corresponding arrangement of the sensors and a corresponding configuration of the at least one control unit are required for the device.

The above detection of the control data and the determination of the correction values lead to good results without the need to print register marks or to check by similar control fields,
Produces high register retention. This is therefore particularly advantageous. This is because such register correction can be performed very quickly. But, of course,
The present invention does not preclude checking and possibly correcting correction values by printing and detecting the color separation image. In this case, the test printing of the image start portion and the test printing of another predetermined area of the color separation image are performed on these color separation images. Of course, a register mark can be printed as a test print of the color separation image and evaluated accordingly. As regards the device, in this case at least one sensor for the detection of the test print and a test print for checking and correcting the correction values, for example a test mark for evaluating the register mark, are provided.

Of course, the arrangements described for the above methods are assigned corresponding embodiments of the device and vice versa.

[0019]

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described with reference to an embodiment shown in the drawings. Shown is a multicolor printing press, typically two out of four or more printing units.
Only one printing unit 25, 25 'is shown.
This is for simplicity and must be considered to include more printing units. Each printing unit 2
Use devices 2, 2 ',... For digital formation of color-separated images 3, 3',. These devices 2, 2 ', ... are arranged in the image cylinders 5, 5', .... The color separation images 3, 3 ',... Are first transferred from the image cylinders 5, 5',. , 7 ′,... Are transferred to the printed circuit board 12. The printed circuit board 12 is on a carrier 11 and the carrier 1
1 is driven by a driving roller 10, in which case the printed circuit board 12 moves in the transport direction 27. The image transfer cylinder 7,
Are driven, and the image transfer cylinders 7, 7 ',... Drive the image cylinders 5, 5',. The image transfer cylinder 7 of the carrier 11,
On the side opposite to 7 ',... There is a further counter pressure roller. These counter pressure rollers have been omitted for simplicity.
When the printed board 12 is detected by the sensor 26 for detecting the printed board 12, a signal is supplied to the control units 17, 17 ',. The image formation of 5 ′,... Is controlled, and the color separation images 3, 3 ′,.

Color separation image 3 on printed circuit board 12
For the registered transfer of 3 ',..., The data including the assignment of the printing units 25, 25',. Must be supplied to the control units 17, 17 ', .... In order to realize clean printing, in addition to these data, non-printing of mechanical members such as image cylinders 5, 5 ',..., Image transfer cylinders 7, 7',. There must be correction data that takes into account the roundness. Still other data includes other sources of error that affect register retention. The data and the correction data are stored in the memory 18, as nominal values 19, 19 ',.
18 ',... Machine-specific nominal value 19,1
This storage of 9 ', ... is done by the machine manufacturer.
Alternatively, these machine-specific nominal values 19, 19 ', ... can be updated from time to time or continuously.

One example of such an update or collection of the data required by the controllers 17, 17 ', ... to control the devices 2, 2', ... is the roundness error. This is an arrangement of sensors 20 for measurement. Such a sensor 20 can be used to control the image cylinder 5,
, 5 ',..., Image transfer cylinders 7, 7',..., Drive rollers 10 or other mechanical members. These sensors 20 for measuring the roundness errors comprise the roundness errors 6, 6 ', ... of the image cylinders 5, 5', ..., the image transfer cylinders 7, 7 ', .... , And the roundness error 9 of the drive roller 10 are determined. These data are supplied to the control units 17, 17 ',... The control units 17, 17 ',... Transmit these roundness errors 6, 6',.
7, 7 ', ...; 10 angular positions 4,
13, 13 ', ...; 14, and the angular positions 4, 4 of the image cylinders 5, 5', ...
The correction values for 4 ′,.
The calculation is performed for controlling the formation of the color separation images 3, 3 ',... In 5',... And these corrections are incorporated in the control of the image formation.

The stored machine-specific nominal value 19,1
In addition to the correction by 9 ′,... And the correction based on the measurement of the roundness error, there are still other methods of correcting the register error. The rotational angle transmitter 21 affects the register. All the mechanical members 5, 5 ', ...; 7, 7', ...; 10 angular positions 4, 4 ', ...; 13, 13', ...; measure 14;
Further, the computers 22, 22 ',.
The roundness errors 6, 6 ', ...; 8, 8', ...; 9 are obtained from the mutual positional relationship of 4 ', ...; 13, 13', ...;
Therefore, it is configured to calculate the correction value. For this purpose, the rotation angle transmitter 21 is connected to the image cylinder 5,
, 5 ',..., Image transfer cylinders 7, 7',. Each printing unit 25, 2
Are equipped with computers 22, 22 ′,..., And these computers 22, 22 ′,. 1
7, 17 ', .... .. Control the image formation of the image cylinders 5, 5 ',..., And in some cases, machine-specific nominal values 19, 19 for the next printing. ', ... can be updated.

In this embodiment, various methods for correction are adopted, that is, machine-specific nominal values 19,1.
A memory 20 having a 9 ',..., A sensor 20 for measuring roundness errors and computers 22, 2
A rotation angle transmitter 21 having 2 ′,... Is employed. Of course, one of these three methods may be provided, or these memories 18, 18 ',...
. And the detection of the roundness error by the computers 22, 22 ',...

This drawing further shows that the printed circuit board 12 in front of the printing unit 25 does not yet include a color separation image, and that the color separation images 3, 3 ',.
The state brought to the printed circuit board 12 by 5 'is shown. Therefore, the intermediate printed circuit board 12 includes one color separation image 3 and the left printed circuit board 12 includes two color separation images 3.
And 3 '. Thus, usually four color separation images 3, 3 ',...
5 ′,...

An image width 16 is written on the right printed circuit board 12. It is possible to detect the above data over the entire image width 16 and calculate an average value, for example, and use this average value as a basis for controlling the formation of the color separation images 3, 3 ',. It is to show that there is. The connections of the individual components are indicated by data flow connections and arrows.

In addition to the correction of register errors according to the invention, it is of course also possible to provide a sensor 23 for test printing, for example for the detection of register marks. The sensor 23 is connected to an evaluation device 24, which calculates the correction and supplies it to the control units 17, 17 ',... For updating the correction value.

The embodiments shown are, of course, merely examples, and any machine embodiment as described above is conceivable.

[Brief description of the drawings]

FIG. 1 is a schematic view of a multicolor printing press of the present invention.

[Explanation of symbols]

1 Multi-color printing press 2,2 ', ... Device for digital formation of color separation image 3,3', ... Color separation image 4,4 ', ... Angle position of image cylinder 5, 5 ', ... Image cylinder 6,6', ... Roundness error of image cylinder 7,7 ', ... Image transfer cylinder 8,8', ... Roundness error of image transfer cylinder 9 Roundness error of drive roller of carrier for printed circuit board 10 Drive roller 11 Carrier for printed circuit board 12 Printed circuit board 13, 13 ',... Angular position of image transfer cylinder 14 Angular position of drive roller 15 Image Start part 15 ', 15 ", ..., 15 Other predetermined area of ^n- color separation image 16 Image width 17, 17', ... Control part 18, 18 ', ... Memory 19, 19', ... machine-specific nominal values 20 Sensors for measuring roundness errors 22, 22 ', ... Computer 23 Sensors for detecting test prints Sensor 24 Evaluation device 25, 25 ', ... Printing unit 26 Sensor for detecting printed circuit board 26 Transport direction

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Heiko Honord Germany Kiel Zukoring 3 (72) Inventor Michael Kowartsik United States New York Rochester West Forest Drive 46 (72) Inventor Christopher Liston United States New York Rochester Tar Westland Avenue 72 (72) Inventor Patrick Metzler Germany, Göttdorf Linden Hof 65 (72) Inventor Robert Peffer, United States of America New York Penfield Jackson Road Extension 89 (72) Inventor Karl Heinz-Peter Germany Morphsee Captain-Thiessen- Jake 2 (72) Inventor John Thompson United States New York Rochester (No address) F-term (reference) 2H027 DA50 DE07 ED30 EE02 EE06 ZA07 2H030 AA01 AB02 AD17 BB16 BB42 5C077 LL02 LL12 MP08 PP05 PP33 PP74 PQ22 TT08 5C0 MA03 PA07

Claims (24)

[Claims] 1. A register in a multicolor printing press (1) having a plurality of devices (2, 2 ',...) For digitally forming color-separated images (3, 3',...). A method for correcting an error, wherein a correction value is determined and at least one
The angular position (4,5) of the two image cylinders (5,5 ', ...)
4 ′,...) And the image cylinder (5,
5 ′,...) In the color separation image (3, 3 ′,...)
A method for correcting register errors in a multi-color printing press (1), which is taken into account for the control of the formation of the machine parts (5, 5 ', ...;
7, 7 ', ...; 10) roundness error (6, 6', ...;
8, 8 ', ...; 9), and the angular position (4, 4', ..., 10) of the mechanical member (5, 5 ', ...; 7, 7', ...; 10). ., 13, 13 ′,... 14), and from there the color separation image (3, 5) in the at least one image cylinder (5, 5 ′,.
3 ′,...), A correction value for controlling the formation of a 3 ′,... 2. The method according to claim 1, wherein a roundness error (6, 6 ′,...) Of the image cylinder (5, 5 ′,...) Is determined for determining the correction value. Item 7. The method according to Item 1. 3. For a multicolor printing press (1) having image transfer cylinders (7, 7 ′,...), The image transfer cylinders (7, 7 ′,. ..) is obtained, and the color separation image (3, 5) in the image cylinder (5, 5 ′,...) Is obtained.
3. Method according to claim 1, characterized in that it is taken into account for controlling the formation of 3 ′,. 4. A carrier (11) for a printed substrate (12).
The roundness error (9) of the drive roller (10) is detected,
The correction values are taken into account for controlling the formation of color-separated images (3, 3 ′,...) In the image cylinders (5, 5 ′,...). Item 4. The method according to one of Items 1 to 3. 5. The roundness error (6, 6 ′,...; 8,
8 ', ...; 9) are the mechanical members (5,5', ...; 7,
Method according to one of claims 1 to 4, characterized in that it is determined by direct measurement in 7 ', ...; 10). 6. The mechanical member (5,
7, 7 ', ...; 10) angular position (4,
13, 13 ', ...; 14) are detected, and the roundness error (6, 6', ...; 8, 8 ', ...; 9) Position (4, 4 ', ...; 13, 13', ...; 14)
Characterized by the mutual positional relationship of
The method according to claim 1. 7. The correction value is a color separation image (3, 3 ′,...)
, A predetermined area (15, 15 ′, 15 ″,..., 1)
7. Method according to claim 1, wherein the method is assigned to 5 ⁿ ) and is taken into account for their formation. 8. A predetermined area (15, 15 ′, 15 ″,..., 15 ⁿ ) of the color separation image (3, 3 ′,...) Includes image cylinders (5, 5 ′,. 8. The method according to claim 7, characterized in that it is determined by the assignment of image areas to a predetermined angular sequence of ..). 9. The method according to claim 1, wherein the correction value is detected once and considered as a machine-specific parameter.
9. The method according to one of 8 above. 10. The correction value is detected before printing is performed,
The method according to claim 1, wherein the method is considered for printing. 11. The method as claimed in claim 1, wherein the correction values are continuously detected and taken into account. 12. The method according to claim 1, wherein a plurality of correction values are detected and taken into account over an area of the image width. 13. The method according to claim 1, wherein a plurality of correction values are detected over an area of the image width, and an average correction value is taken into account. 14. The correction value of a color-separated image (3,
3 ',...), Which are checked by printing and detection, and possibly corrected.
The method of claim 1. 15. The method according to claim 14, wherein the test print of the image starter is printed as a color separation image. 16. As another color separation image (3, 3 ′,...), Another predetermined area (1) of the color separation image (3, 3 ′,.
Method according to claim 14 or 15, characterized in that a test print according to 5 ', 15 ", ..., ¹⁵ⁿ ) is printed. 17. A registration mark is printed as a color separation image (3, 3 ′,...).
17. The method according to one of claims 16 to 16. 18. An apparatus for correcting a register error in a multi-color printing press (1), wherein said multi-color printing press (1) digitally converts color separation images (3, 3 ′,...). (2, 2 ',...) And at least one control unit (17, 17',...) For controlling the plurality of devices (2, 2 ',...). ..) and at least one
Have at least one image cylinder (5, 5 ', ...) with at least one image cylinder (5, 5', ...) A multi-color printing press storing data for determining correction values for forming the color separation images (3, 3 ',...) Assigned to positions (4, 4',...). In the apparatus for correcting a register error in (1), the correction value may be a mechanical member (5, 5) that affects the register.
5 ′,...; 7, 7 ′,.
6 ', ...; 8,8', ...; 9)
This is done by the following: the at least one control (17, 17 ′,...) Comprises the mechanical members (5, 5 ′,. ; 10) at the angular positions (4,4 ', ...; 13,13', ...; 14) at the circularity errors (6,6 ', ...; 8,8', ..). .; 9) via assigning an angular position (4, 4 ',...) Of said at least one image cylinder (5, 5',...)
Correction values for the color separation image (3,5) in the at least one image cylinder (5,5 ', ...).
3 ′,...), The apparatus for correcting registration errors in a multi-color printing press (1), characterized in that it is arranged to determine for the control of the formation of 3 ′,. 19. At least one memory (18, 1)
8 ', ...) is the roundness error (6,6', ...; 8,
8 ′,..., 9) to the roundness error (6, 6 ′,.
8 ', ...; 9) angular position (4,4', ...; 13,1)
Device according to claim 18, characterized in that it is stored as a machine-specific nominal value (19, 19 ', ...) together with an assignment to 3', ...; 14). 20. Roundness errors (6, 6 ',...; 8,
8 ', ...; 9) and the roundness error (6,
8, 8 ', ...; 9) at the angular position (4,
Device according to claim 18 or 19, characterized in that a device is provided for the assignment to 4 ', ...; 13, 13', ...; 14). 21. The apparatus according to claim 1, wherein the roundness error (6,
Device according to claim 20, characterized in that it is a sensor (20) for detecting 6 ', ...; 8, 8', ...; 9). 22. The device according to claim 1, wherein the device is a rotary angle transmitter (21), the rotary angle transmitter (21) being connected to at least one computer (22, 22 ′,...);
The computer (22, 22 ',...) Is provided with angular positions (4, 4', ...; 13) of mechanical members (5, 5 ', ...; 7, 7', ...; 10). , 13 ', ...; 14), the roundness error (6, 6', ...; 8,
Device according to claim 20, characterized in that it is arranged to determine 8 ', ...; 9) and thus a correction value. 23. At least one control unit controls a predetermined area (15, 15 ′,...) Of the color separation image (3, 3 ′,...).
Device according to one of claims 18 to 22, characterized in that correction values for 15 ", ..., ¹⁵ⁿ ) are configured to be taken into account in their formation. 24. At least one for the detection of test prints
24. Sensor according to one of claims 18 to 23, characterized in that one sensor (23) is provided and the evaluation device (24) evaluates the test print for checking and correcting correction values. Equipment.