Arrangement for determining register deviations of a multicolor rotary printing machine

Information

  • Patent Grant
  • 6199480
  • Patent Number
    6,199,480
  • Date Filed
    Thursday, August 3, 1995
    29 years ago
  • Date Issued
    Tuesday, March 13, 2001
    23 years ago
Abstract
An apparatus in a multicolor rotary printing machine for determining register deviations, including a scanning device disposed behind a print gap of a last printing unit of the printing machine; at least one register mark line disposed on printing material movably disposed relative to the scanning device, wherein the scanning device is directed to the register mark line; a control circuit connected with the scanning device for processing signals from the scanning device, and a measuring, steering and regulating device receiving inputs from the control circuit in operative engagement with registers of the printing machine, and a plurality of section reference marks on the printing material, in alignment with the register mark line within scanning range of the scanning device for correcting the register deviations.
Description




BACKGROUND OF THE INVENTION




Field of the Invention




The invention relates to a multicolor rotary printing machine for printing sheets or webs, having on-line register adjustment, or register measuring devices. The invention serves for determining register deviations between different ink colors, especially deviations in regard to circumferential, side and diagonal register, which are to be minimized with register adjusting devices connected with a steering and control device.




The known art includes a stationary installed photo-electric scanning device for register marks, which is connected with a switching device for measuring register mark positions (DE 32 26 078 A1, DE 26 43 481 A1, DE 27 31 914 A1, DE 26 58 659 A1, DE 40 14 706 A1, and DE 40 14 708 A1).




The times between the register signals are evaluated between each other or in response to a reference signal, wherein the time/path relations of position deviations of the register marks can be evaluated. In the known devices, the scanning arrangement is connected with start/stop inputs of a counter circuit, whose counting state is proportional with the timed appearance of reference signals and register mark signals (DE 32 26 078 A1). As reference signal, it is possible to use, for example, a fixed edge on a cylinder transporting the printed material, which is detected by means of a scanning device. The known art has the drawbacks that the velocity of the printing material must be constant, which in practice cannot be assured. The peripheral velocity of a printing cylinder swings back and forth even at a constant printing speed as much as several tenths of a percent, which leads to an impermissibly high error in the measurement of the register marks when the register marks are sensed by the scanning device on the surface of the printing cylinder. The uneven velocity is a result of variations in the load on the printing machine drive since the load during printing is subject to strong variations both in regard to time and in regard location in the machine.




Furthermore, there are known devices by means of which the angular position and velocity of a cylinder transporting printing material can be measured with incremental or absolute angle transmitter (DE 26 58 659 A1, DE 27 31 914 A1).




In that manner, the appearance of the register marks are evaluated in relation to the angular position of the cylinder, and from which the actual deviation of a register mark can be determined on the basis of the sheet length in the form of a nominal value. In that case incremental angle transmitters are used, for generating a specially generated reference or zero pulse, which is used as a reference for the angular position at which the register mark signal appears.




Such angle transmitters for determining register deviation require additional investment, especially since the angle transmitter requires a certain mounting space and must, for the purpose of measurement, be mounted very precisely. Furthermore, the transmission of the measuring signals from the angle transmitter require additional electronic investments in order to assure high validity of the signals in the presence of noise. The measurement of the position of the register mark with angle transmitter is subject to error, since during the printing, especially due to forces caused by the gripper and forces appearing during and after the print slot in the printed material (i.e. the point of contact between superimposed rollers or cylinders or printing cylinders and forms), and at least in subregions a relative movement relating to the surface of the transporting cylinders, which can cause errors in the register signals relating to the angle transmitter signals.




In the European Patent application EP 04 44 583 A2, there is described marks printed on a printing material for determining registration, which include crossing lines visually printed for each print color, and which include a linear and a curved section which are machine-readable. The visual sensing of the register deviations is performed in economical off-line manner by means of an optical register cross reader. The machine sensing is performed by means of a video camera, by means of which scanning signals serve to control register adjusting devices.




The aforesaid method has the drawback that for on-line precise register adjustment the data for machine evaluation must be present in predetermined mutually separate positions on the printed material, which requires a relatively wide section of the printed material for the register marks, and require a photo-electric sensor matched to the register marks, and has a scanning width adjusted to the width of the register marks. Furthermore, this approach does not provide information as to which reference the measurements of the register deviations are related.




SUMMARY OF THE INVENTION




It is accordingly an object of the invention to provide an arrangement for determining register deviations in a multicolor rotary printing machine, which provides a high degree of accuracy, combined with low investment for determining positions of register marks printed on printing material.




The invention includes an arrangement for determining register deviations in a multicolor rotary printing machine, wherein at least one scanning device, positioned behind the last printing unit, and behind the printing slot, which scans at least one register mark line on the moving printing material in direction of additional section reference marks on the printing material. The section reference marks are designated in this manner, since the reference marks are formed as short line sections.




The section reference marks can be attained with exactly one printing unit, advantageously in the color which is especially or most suitable for the photo-electric receiver in the scanning device. The signals which are generated by the scanning of the register marks, and their section reference marks, are processed together in a circuit arrangement, and wherein the resulting signals derived from the register marks, and the section reference marks are available for determining the register deviations. The invention requires no additional transmitter for transmitting the machine rotary angle, or sensors for scanning of fixed edges on a transport cylinder in order to obtain a reference signal.




It is especially advantageous, for determining the diagonal register deviations, to provide register mark lines on the edge regions of the printing material, which each cooperate with a respective photo-electric scanning device, and to provide respective section reference marks for each register mark line.




A variation of the invention provides that a line of section reference marks is placed next to the respective register mark lines, wherein the line of section reference marks is composed of periodical line section screens, i.e. like steps in a ladder, wherein the line sections are placed at right angles (perpendicular) to the direction of movement of the printing material, and wherein the section reference marks are scanned with an additional photo-electric receiver in the scanning device.




An improvement in image resolution can be attained if a line of section reference marks is placed next to the respective register mark lines, and wherein the section reference marks are arranged as an uninterrupted row of right angle triangles, each having a respective short side of the triangle positioned on an uninterrupted straight line next to each other, and wherein the other short side of the triangle is perpendicular to the moving direction of the printing material, and wherein further the long sides of the triangles are parallel, and the section reference marks are scanned by an additional receiver of the scanning device.




In regard to the investment, it is advantageous if the section reference marks are located within the range of the register mark lines of a group of register marks, either ahead of or behind the register marks. Register mark signals and section reference mark signals can then be scanned by the same receiver of the scanning device. For signal processing, it is then advantageous if the section reference marks and the register mark groups are arranged so that the register mark group of one register mark line are aligned in time with the respective section reference marks on the other side of the printing material, and can be scanned with a respective scanning device for the other side of the printing material.




A further variation of the invention, which is advantageous for the signal processing, provides that the section reference marks are positioned within the respective register mark line, and the section reference marks are provided as equidistant line sections having their sides perpendicular to the moving direction of the printing material, and wherein the register marks from respective printing units are printed between adjacent line sections.




A version of the invention with especially low investment and high speed of signal processing can be attained if the section reference marks are positioned within the respective register mark lines, wherein each individual register mark is precisely located in the other register mark line, wherein the individual register marks and the individual section reference marks are sensed at substantially the same times by the respective scanning device, and the section register mark is formed as a single line section which has two parallel sides (i.e. edges) which are perpendicular to the moving direction of the printing material, and wherein the distance between the edges is exactly equal to the scanning with of the individual register marks, and which can be determined by scanning the individual respective register marks in their nominal positions.




In accordance with the invention, there is provided an apparatus in a multicolor rotary printing machine for determining register deviations, which includes a scanning device disposed behind a print gap of a last printing unit of the printing machine; at least one register mark line disposed on printing material movable relative to the scanning device, wherein the scanning device is directed to the register mark line; a control circuit connected with the scanning device for processing signals from the scanning device, and a measuring, steering and regulating arrangement receiving inputs from the control circuit in operative engagement with registers of the printing machine, and a plurality of section reference marks on the printing material, in alignment with the register mark line within scanning range of the scanning device for correcting the register deviations.




In accordance with another feature the apparatus includes a plurality of register mark lines, each connected with a respective scanning device, and wherein the scanning device is a photo-electric scanning device.




According to still another feature the apparatus includes a plurality of section reference marks arranged equi-distantly along the register mark line, wherein the section reference marks are each formed as a line section disposed perpendicular to the direction of movement of the printing material, and including a photo-electric receiver in the photo-electric scanning device for sensing the section reference marks.




According to an additional feature the apparatus further includes a plurality of section reference marks disposed next to the register mark line, wherein the section reference marks are arranged in the form of an uninterrupted row of right angle triangles, each triangle having a first short side, disposed uninterrupted on a straight line behind each other, a second short side, disposed at right angles to the direction of movement of the printing material, the triangles having respective long sides, disposed in parallel with each other, and including a further photo-electric receiver in the scanning device for scanning the long sides.




The apparatus according to the invention may further include a register mark group of register marks wherein the section reference marks are disposed at the side of the register mark line facing the center of the sheet, ahead of or following a respective group of register marks.




The apparatus can additionally include a first register mark line, and a first register mark group in the first register mark line, a second register mark line, and a second register mark group in the second register mark line, wherein the first register mark group in the first register mark line is sensed by a first scanning device, and wherein the second register mark groups are sensed simultaneously with the first register mark groups by a second scanning device.




According to still another feature the apparatus according to the invention includes section reference marks which are disposed at the inside of the respective register mark lines facing the center of the sheet, the section reference marks including a plurality of individual identical line sections having section edges disposed perpendicular to the direction of movement of the printing material, and wherein the register marks are disposed between mutually facing section reference marks.




According to a concomitant feature the apparatus according to the invention includes that the section reference marks are disposed, respectively, within the register mark lines, wherein the individual register marks of respective register mark lines are disposed exactly within an individual section reference mark of the other register mark line, and wherein the individual register marks and the individual section reference marks are scanned substantially simultaneously by their respective scanning device, wherein each of the section references marks are formed as individual line sections having parallel edges disposed perpendicularly to the direction of movement of the printing material, and wherein the scanning width (B) of each reference mark is exactly equal to the distance (B) between the parallel edges of adjacent register marks, when the respective individual register marks are scanned in their nominal position.




Although the invention is illustrated and described herein as embodied in an arrangement for determining register deviations of a multicolor rotary printing machine, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.




The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:











BRIEF DESCRIPTION OF THE DRAWING





FIG. 1

shows a diagrammatic representation of the invention as applied to printed material moving through a printing machine, and signal processing components connected with register adjusting devices;





FIG. 2

shows a register mark line with trapezoidal register marks and section reference marks in a periodical line pattern;





FIG. 3

shows a register mark line with triangular register marks and section reference marks in a periodical line pattern;





FIG. 4

shows a section reference mark line as a row of right angle triangles;





FIG. 5

shows arrangements of register marks and section reference marks disposed in respective lines, each line in alignment with a respective mark sensor and light source;





FIG. 6

shows a single line arrangement of register marks and section reference marks formed as line sections;





FIG. 7

shows an alternating assignment of register marks each exactly aligned with a respective section reference mark;





FIG. 8

shows a mark arrangement with respective measuring edges, that are relevant to the measurements;





FIG. 9

shows two lines of integrated section reference marks and register marks, with exemplary ink colors from respective printing units designated next the register marks;





FIG. 10

is a block diagram showing the major blocks of the electronic apparatus of the invention;





FIG. 11

shows details of the electronic control apparatus according to

FIG. 10

; and





FIGS. 12



a


,


12




b


and


12




c


together show a flowchart of the steps of a method for practicing the invention.











DESCRIPTION OF THE PREFERRED EMBODIMENTS





FIG. 1

shows in diagrammatic form elements of the apparatus according to the invention. The apparatus accordingly includes, for determining register deviations, two scanning devices


1


,


2


, which can slide perpendicularly to the sheet move direction indicated by arrow


3


along a cross bar


4


. A sheet


5


is driven by a drive


6


, via a diagrammatically illustrated gear-wheel transmission


7


, and by transport cylinders


8


,


9


, under scanning devices


1


,


2


.




The scanning devices


1


,


2


contain each a respective common light source


10


,


11


, a register mark sensor


12


,


13


, and a section reference mark sensor


14


,


15


. The register mark sensors


12


,


13


and the section reference mark sensors


14


,


15


are connected to a machine control arrangement


16


which includes a signal processing device


22


, which has printing machine controls


23


,


25


, which, among other tasks, operate to control register adjusting devices


24


for respective printing machine units (not shown).




In addition to the above-described on-line version of the invention, it is also possible to provide a version of the invention arranged externally to the printing machine. to that end, the sheet


5


is positioned fixedly on a measuring table, and the scanning devices


1


,


2


are arranged so that they can move in direction


3


of the sheet


5


in order to determine the register deviations.




In accordance with the invention, the sheet


5


has thereon two lines of section reference marks


18


,


19


, arranged along respective register mark lines


20


,


21


, in parallel therewith. The signals generated by the section reference mark sensors


14


,


15


and the register mark sensors


12


,


13


by scanning of the section reference marks


18


,


19


and the register marks


17


, are connected to a signal processing device


22


for processing of the register mark signals, which can be part of the aforesaid machine control arrangement


16


. Furthermore, the machine control arrangement


16


can include machine controls


23


,


25


, to each of which is connected a respective register adjusting device


24




a


and


24




b


of the individual printing units of a multicolor rotary printing machine, and a display device


22




a


for displaying the register mark deviations. An incremental angle transmitter


26


connected to a respective printing cylinder


9


of the printing machine is not necessary for obtaining the register deviations according to the present invention. The section reference marks


18


,


19


are advantageously printed by a respective printing unit with an ink color that is detected by the respective section register mark sensors


14


,


15


.




In

FIG. 2

, a register mark line


20


is placed in rows of pair-wise arranged trapezoid-shaped register marks


17


, respectively positioned before or behind every two respective pairs of start and end marks


27


,


28


, printed in the color of the respective printing unit on the sheet


5


. Adjacent to this register mark line


20


, there is a row of section reference marks


29


, which is advantageously printed in the color black, readily detectable by the respective section reference mark sensors


14


and


15


. The distance A between the respective mark lines


20


and


21


and the section reference mark lines


18


and


19


corresponds to the distance between the scanning points of the respective register mark sensors


12


and


13


and the respective section reference mark sensors


14


and


15


. The reference marks


18


,


19


are forming a screen or raster of periodically appearing short line sections, wherein the width of the line sections of the reference marks


18


is equal to the space between the sections of the reference marks


18


.





FIG. 3

shows the register marks as pairs of triangles


17


, wherein each pair of triangles


17


are printed by a respective printing unit. The corresponding section reference mark line


29


is, as in

FIG. 2

, formed as a line section screen. A high degree of accuracy can be attained by increasing the number of section reference marks


18


per unit of length, and wherein the signal processing device can additionally perform position or speed interpolation of the section reference signals.





FIG. 4

shows a version of the section reference marks


18


, wherein the section register mark line


20


is an uninterrupted periodic screen formed as a row of right-angle triangles


17


. one of the short sides


30


of the triangles is perpendicular to the move direction


3


of the sheet


5


. The other short side is positioned in the move direction, and the long sides


32


are all parallel to each other. By arranging the layout of the scanning geometry of the section reference mark sensors


14


to cover the entire width of the section reference mark line


29


, the rise time of the scanning signal obtained by scanning the long sides


32


of the triangles, the resolution of the definition of the register marks


17


can be improved.




In the arrangement shown in

FIG. 5

, the required investment in the scanning devices


1


,


2


is reduced due to placement of the section reference marks


18


,


19


within the range of the register mark lines


20


,


21


. Each scanning device


1


,


2


requires then only one photo-electric sensor for each line


20


,


21


, since the register marks


17


and the section reference marks


18


,


19


can accordingly be scanned one after the other in time sequence. In

FIG. 5

, the register marks


17


and the section reference marks


18


,


19


can be printed in both edge regions of the sheet


5


, so that the register marks


17


of the register mark line


20


can be scanned simultaneously with the section reference marks


19


of the register mark line


21


by the respective register mark sensors


12


,


13


, and with the section reference sensors


14


,


15


.





FIG. 6

shows the section reference marks


18


and the register marks


17


and also the start and end marks


27


,


28


, similarly arranged along a register mark line


20


. The significance of this is that the start mark


27


follows a first individual section reference mark


33


in one color, and that next each pair of triangle-shaped register marks


34


in a certain ink color, each followed by an individual section reference mark


35


printed in the standard ink color. This line


20


ends with the end mark


28


. The signals from the individual section reference marks


33


,


35


make it possible to perform an interpolation of the velocity of the sheet


5


in respective time intervals between the start mark


28


and the section reference mark


33


respectively between the individual section reference marks


33


,


35


. Assuming that the velocity variations of the sheet


5


in the range between two individual section reference marks


33


,


35


is negligible, it is possible to determine the position of the sheet by measuring its speed from the positions of the register marks


34


, and thereby make the necessary register corrections.





FIG. 7

shows a mark configuration wherein the section reference marks


18


,


19


are placed along respective register mark lines


20


,


21


. Each individual register mark


36


,


37


of a pair of register marks of a certain ink color of one register mark line


20


performs exactly as a section reference mark


38


,


39


in the other register mark line


20


,


21


. For each ink color there is provided in each register mark line


20


,


21


a pair of triangle-shaped register marks


17


, and a pair of section reference marks


18


,


19


respectively. The individual register marks


36


,


37


are scanned at substantially the same time by each respective register mark sensor


12


,


13


. The section reference mark sensors


14


,


15


are scanning the sheet edges in direction perpendicular to the move direction


3


of the sheet


5


at the same sheet latitude except for register deviations. In the exemplary embodiment described, the measures for measurements of the section reference marks


18


,


19


and


38


,


39


respectively, and their distances from each other are in millimeters. The section reference marks


19


are, as are start marks


40


, printed in the particular color printed by the respective printing unit, and are comprised of a single line section having a width of B, whose parallel edges are perpendicular to the move direction


3


of sheet


5


. Assuming that a single register mark


36


(or


37


) is positioned in its proper position, then it has a scanning width in the direction of move which is also equal to value of B. This version of the invention requires the least investment in regard to scanning devices


1


,


2


and in the circuit arrangement


22


, and offers a high processing speed.





FIG. 8

is a fractional view of the mark arrangement according to FIG.


7


. The register marks


7


are shown located away from their proper positions. In the following the arrangement of the signal processing as performed by the circuit arrangement


22


will be described by reference to the scanning points designated with a “P—”.




In regard to

FIG. 6

, if the section reference and register marks


33


,


34


are printed in their precise registration, then the scanning devices


1


,


2


(

FIG. 1

) will generate identical signal time sequences. Beginning with a leading signal edge P of a start mark


27


, high frequency timing pulses generated by a precise quartz crystal generator


51


(

FIG. 10

) are counted in reference counter


52


. The states of counter


52


for the occurrence of each of the edges designated with a “P—” of the register marks


17


in FIG.


8


and the reference register marks


18


or


19


are recorded in a memory, i.e. storage units


56




a


,


56




b


. Next these counter states are processed in a computer (CPU)


53


,

FIG. 10

, which is a part of the signal processing device


22


, and register errors, if required, are corrected by the register adjusting devices


24




a


,


24




b


(FIG.


1


). The circumferential register deviations UR


1 and UR




2


for register mark lines


20


,


21


(

FIG. 8

) are determined for example as follows:











UR
1

=



(


P
11

-

P
21


)

+

(


P
14

-

P
24


)


2







and




(
a
)







UR
2

=



(


P
25

-

P
15


)

+

(


P
28

-

P
18


)


2





(
b
)













wherein Pn is equal to the count of timing pulses received in the reference counter


52


(FIG.


10


), as described in more detail below, and wherein the subscript n relates to the respective edge of a register mark or reference mark. For example, in equation (a) P


11


represents the count in counter


52


at the moment the leading edge of register mark


36


is recorded in storage unit


1


. An edge detector detects the moment the edge of the mark passes under the respective register mark sensor


1


,


2


(FIG.


1


).




It follows that in equation (a), the difference P


11


-P


21


represents the time difference between the passing of the respective leading edge of register mark


36


, and the leading edge of reference mark


38


, and the difference P


14


-P


24


represents the time difference between the respective trailing edges of register mark


37


and reference mark


39


. As seen in equation (a) the sum of the differences is divided by


2


to give a mean value UR, of the time difference between the respective leading edges and the trailing edges for mark line


20


. Equation (b) performs the same operation on mark line


21


to give a means value UR


2


.




The diagonal register deviation can now be determined as:






SchRR=U


R2


-U


R1


  (c)






To that end it is necessary that the register mark lines


20


,


21


are located on the respective edge of the sheet


5


.




The side register deviations can be determined by equation (d) as:












SR
=








(


(


P
12

-

P
11


)

-

(


P
22

-

P
21


)


)

+

(


(


P
24

-

P
23


)

-

(


P
14

-

P
13


)


)


4

+














(


(


P
26

-

P
25


)

-

(


P
16

-

P
15


)


)

+

(


(


P
18

-

P
17


)

-

(


P
28

-

P
27


)


)


4








(
d
)













The above values indicated by P(I,K) represent the Ith line as determined at the sides of the edges. The advantage of the mark arrangement according to

FIGS. 6

,


7


and


8


is the complete independence of the determination of the register deviations from changes in the velocity of the sheet


5


. While, in the arrangement according to

FIGS. 2-5

, it must be assumed that the velocity of the sheet


5


is consistent, and determined by the geometry of the respective arrangement of the section reference marks


18


,


19


, the section length is shortened in the arrangement according to

FIGS. 7 and 8

, due to their closer approximation to the proper register adjustment. Determination of the register deviations is always more correct, if obtained as the value close to the correct position. Since only the counter states P(I,K) of the respective absolutely necessary edges are stored, the amount of information to be processed is minimal.




It follows that the values from equations (c) and (d) represent counts of pulses from the frequency generator


51


, as recorded in storage units


1


and


2


(


56




a


,


56




b


). In order to obtain the actual register errors in units of length, the respective counts must be multiplied in the central processing unit


56


by the distance the printing material moves during two counts of the frequency generator


51


.




In

FIG. 10

, the reference frequency generator is a very stable and precise pulse generator which generates a precise reference of e.g. one megahertz or any other suitable frequency high enough to define the movement of the printing material in sufficiently small increments as required for determining a high degree of definition of the register deviations. The program memory


57


contains in storage the control program for the CPU


53


, which are structured according to the flow charts shown in

FIGS. 12



a, b


and


c


, as described in more detail below. The data memory


58


serves to contain fixed and variable data as required for the operation of the CPU


53


in conventional manner.




The data bus


59


operates to transmit data between the various blocks


56




a


,


56




b


,


57


,


58


and CPU


53


as required according to the control program. The CPU


53


is connected via an output bus


61


to a motor actuation unit


62


, which represents each register motor for each register, i.e. the circumferential, side, and diagonal register motor (M)


63


for each printing unit. Such motors are quite conventional and are well known in the printing art. The motor


63


can, for example, be realized as stepping motors that are set back or forward by step pulses generated by the CPU


53


and transmitted via motor actuation circuit


62


by a bus


65


to each register motor


63


so that any register deviation determined by the CPU


53


is corrected.





FIG. 11

shows further circuit details of the block diagram shown in FIG.


10


.




The pre-processing circuit


54


includes two differentiating circuits


71


,


72


of conventional construction, with a common input


66


connected via signal line


66


to optical scanning device


1


(FIG.


1


), while pre-processing unit


54


′ is connected to scanning unit


2


via line


67


. When the scanning signal on signal line


66


goes active as a leading edge P


11


, P


13


, P


15


or P


17


(

FIG. 8

) of a register or reference mark is detected, a positive start pulse is generated on the differentiating circuit's output lead


73


, and when subsequently the trailing edge of the mark is detected, a positive end pulse is generated on the output lead


74


. The reference frequency circuit


51


, described above, drives a continuously running reference counter


52


formed of a counting chain of series-connected counters


76


of conventional construction. In other words, the reference counter


52


is a continuously running clock. A time difference circuit


60


is composed of storage units


1


and


2


. The reference counter


52


is coupled to storage units


1


and


2


by means of respective blocks of AND-gates


77


,


78


. At the moment the leading edge of a register or reference mark is detected the contents of the reference counter of that moment is transferred via AND-gates


77


, all being activated simultaneously by the leading edge pulse on line


73


, to corresponding registers


79


in storage unit


1


. The contents of storage unit


1


is next transmitted via CPU bus


59


to the CPU


53


. Similarly, when the trailing edge of the register or reference mark is detected, a trailing edge pulse is transmitted from differentiating circuit


72


via lead


74


, which activates AND-gates


78


, causing the contents of reference counter


52


, at that moment to be transferred into storage registers


81


of storage unit


2


. The contents of storage unit


2


is subsequently transferred via CPU bus


59


to CPU


53


. The CPU can next compute the time difference between the respective leading and trailing edges of each register and reference mark. It should be noted that counters


76


, the AND-gates


77


,


78


and storage registers


79


,


81


are shown only diagrammatically, and that several conventional details, such as reset functions, couplings


76


and data transfer gates etc. have not been shown in complete detail for the sake of clarity, since such details would be readily provided by a person having ordinary skills in design of electronic circuits.




The corresponding circuits for the other optical scanning device


2


(

FIG. 1

) are shown in the bottom part of

FIG. 11

with the same parts marked with the same reference numerals with a prime, e.g. the pre-processing circuit is shown as box


54


′, which constructed and operates in the same manner as pre-processing circuit


54


. The same remarks apply to storage units


56


′ and


56




b


′, that are part of time difference circuit


60


′.





FIGS. 12



a


,


12




b


and


12




c


show a flowchart describing the operation of the CPU in determining the register deviations, i.e. register errors, which are to be connected for the printing units.




The flowchart is described only briefly since the labels in each block are shown in sufficient detail to enable a person having ordinary skills in designing computer programs to provide a complete working program for the operation of the invention. The small numbered circles identify connections to parts of the flowchart shown on other sheets of the flow chart.




After start


100


, the register and reference marks are scanned and the leading and trailing edges P(I,K) are timed in steps


101


and


102


, until the marked edges for a respective unit are detected. Once a first leading edge is formed, a step counter is set for a first selected color n=O in step


103


. In step


104


, after the first color is selected, the edges P


11


-P


18


(

FIG. 8

) for storage unit


1


are searched. If no edges are found, an error or continue message is received in step


107


. Next the same color marks are searched in storage unit


2


in step


106


, and if not found an error message is again issued in step


107


.




When the edges are detected and their times are determined in the side register deviation equations SR


1


and SR


2


, if any, are computed by the CPU in step


108


, and the mean side register deviation SR is determined in step


109


. In step


111


the register deviations are normalized or standardized, i.e. converted from pulse count deviations to standard register deviations measured in e.g. millimeters in step


111


.




In step


112


, the circumferential deviation UR


1


is computed for storage unit


1


, and in step


113


for storage unit


2


, and standardized into millimeters in step


114


.




In step


116


, the diagonal register deviations DR are determined in normalized form as the difference between the respective circumferential register values UR


1


and UR


2


, and next, in step


117


, all register deviations in the first selected color are stored in memory of the CPU for subsequent execution, if necessary.




In step


118


, a test is made to determine if all colors have been scanned. If the answer is “no”, n is incremented by one in step


119


, returning the process to step


104


, and if the answer is “yes”, all register motors are activated to perform the required register corrections in step


121


.



Claims
  • 1. Device for obtaining register deviations in a multi-color rotary printing machine having a plurality of printing units, including a last printing unit having a printing slot, comprising:an opto-electronic scanning device disposed behind the printing slot of the last printing unit, said opto-electronic scanning device disposed in alignment with a register mark line printed on a printing material, and formed of a plurality of reference marks, and a plurality of register marks, printed in respective colors of the printing units, and wherein said scanning device is operative for generating signals representing edges of the reference marks and the register marks caused by relative movement of the printing material relative to the scanning device; a signal processing device for processing the edges of the reference marks and register marks connected with said scanning device, for determining as an actual value, for each register mark the time distance of at least one signal edge from a respective signal edge of a reference mark; wherein the reference marks each have two parallel edges perpendicular to the relative movement of the printing material; wherein the reference marks are each printed in exactly one color and have a defined distance between adjoining reference marks; and wherein at least one reference mark is disposed between two register marks in close proximity thereto.
  • 2. A device according to claim 1, wherein the reference marks and register marks are printed as identical arrangements at both sides of the printing material for determining diagonal register deviations.
  • 3. Apparatus in a multicolor rotary printing machine having registers, the apparatus operative for determining register deviations, the apparatus comprising a scanning device disposed behind a print gap of a last printing unit of the printing machine; at least one register mark line disposed on printing material movably disposed relative to the scanning device, wherein said scanning device is directed to said register mark line; a control circuit connected with said scanning device for processing signals from said scanning device, steering and regulating apparatus, receiving inputs from said control circuit in operative engagement with registers of said printing machine, and a plurality of reference section marks on said printing material, in alignment with said register mark line within scanning range of said scanning device for correcting said register deviations.
  • 4. Apparatus according to claim 3, including a further register mark line connected with a further respective scanning device, and wherein said scanning device is a photo-electric scanning device.
  • 5. Apparatus according to claim 4, wherein said plurality of section reference marks are arranged equi-distantly along said register mark line, wherein said reference marks are each formed as a line section disposed perpendicular to the direction of movement of said printing material, and including a photo-electric receiver in said photo-electric scanning device for sensing said section reference marks.
  • 6. Apparatus according to claim 4, wherein said plurality of section reference marks are disposed next to said register mark line, wherein said section reference marks are arranged in the form of an uninterrupted row of right angle triangles, each triangle having a first short side, disposed uninterrupted on a straight line behind each other, a second short side, disposed at right angles to the direction of movement of said printing material, said triangles having respective long sides, disposed in parallel with each other, and including a further photo-electric receiver in said scanning device for scanning said long sides.
  • 7. Apparatus according to claim 4, including a register mark group of register marks wherein said section reference marks are disposed at the side of said register mark line facing the center of said sheet, ahead of or following a respective group of register marks.
  • 8. Apparatus according to claim 7, including a first register mark line, and a first register mark group in said first register mark line, a second register mark line, and a second register mark group in said second register mark line, wherein said first register mark group in said first register mark line is sensed by a first scanning device, and wherein said second register mark groups are sensed simultaneously with said first register mark groups by a second scanning device.
  • 9. Apparatus according to claims 4, wherein said section reference marks are disposed at the inside of said respective register mark lines facing the center of said sheet, said section reference marks including a plurality of individual identical line sections each having section edges disposed perpendicular to the direction of movement of said printing material, and wherein said register marks are disposed between mutually facing section reference marks.
  • 10. Apparatus according to claim 4, wherein said section reference marks are disposed on the sides of said respective register mark lines facing the center of said sheet, wherein said individual register marks of the respective register mark lines are disposed exactly within the section reference groups of the other register mark line, and wherein the individual register marks and the individual section reference marks are scanned substantially simultaneously by their respective scanning device, wherein said section reference mark groups include at least a single line section having parallel edges disposed perpendicularly to the direction of movement of said printing material, and wherein the scanning width (B) is exactly equal to the distance (B) between the parallel edges of said line section, wherein said respective individual register marks are being scanned in their proper position.
Priority Claims (1)
Number Date Country Kind
42 18 760 Jun 1992 DE
CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of application Ser. No. 08/389,980, filed Feb. 14, 1995, now abandoned which was a file-wrapper continuation of Ser. No. 08/073,122, filed Jun. 7, 1993, now abandoned.

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Number Name Date Kind
3701464 Crum Oct 1972
4450766 Inomata et al. May 1984
4546700 Kishner et al. Oct 1985
4569584 St. John et al. Feb 1986
4698514 Hilmersson et al. Oct 1987
4731542 Doggett Mar 1988
Foreign Referenced Citations (10)
Number Date Country
381713 Oct 1964 CH
26 43 481 Mar 1978 DE
26 58 659 Jun 1978 DE
27 31 914 Jan 1979 DE
32 26 078 Feb 1983 DE
40 14 706 Nov 1991 DE
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0 131 241 Jan 1985 EP
1 442 678 Jul 1976 GB
62-68759 Mar 1987 JP
Continuations (1)
Number Date Country
Parent 08/073122 Jun 1993 US
Child 08/389980 US
Continuation in Parts (1)
Number Date Country
Parent 08/389980 Feb 1995 US
Child 08/510971 US