GB1604109A

GB1604109A - Means for controlling and for presetting the register and for removing the paper waste on rotary multi-colour printing presses

Info

Publication number: GB1604109A
Application number: GB23146/78A
Authority: GB
Original assignee: Villamos Automatika Intezet
Current assignee: Villamos Automatika Intezet
Priority date: 1977-07-15
Filing date: 1978-05-26
Publication date: 1981-12-02
Also published as: DE2812453A1; DD135055A1; HU175688B; CH631109A5; IT1109074B; FI780919A; IT7868206A0; DE2812453C2

Abstract

The apparatus is suitable for controlling the displacement of colours, for preadjusting the register and for eliminating waste paper. To preadjust the register, the impression cylinders are set as a function of a quotient K which is calculated from the length of the web of paper between two printing units and from the circumference of the impression cylinders. Said quotient K is taken into consideration both in the automatic control of the image displacement and in the elimination of faulty printed products.

Description

(54) MEANS FOR CONTROLLING AND FOR PRESETTING THE REGISTER AND FOR REMOVING THE PAPER WASTE ON ROTARY MULTI-COLOUR PRINTING PRESSES (71) We, VILLAMOS AUTOMATIKA INTEZET, a Hungarian Company organised under the laws of Hungary, of 55, Krisztine Korut, Budapest 1, Hungary, do hereby declare the invention for which we pray that a patent may be granted to us and the method by which it is to be performed, to be particularly described in and by the following statement: The invention relates to an electronic arrangement for controlling the colour shift (image shift) for pre-setting the printing units or cutting registers and for removing the paper waste during multicolour printing.

Most multicolour printed products (eg. newpapers, journals and books) are produced on rotary printing presses. Each colour is printed by a separate printing unit (register) on to the paper running between the printing units. The printing presses are generally equipped with from 2 to 16 printing units and 1 to 2 cutting registers.

The paper may be fed as desired in the printing press, i.e. separate printing units may be disregarded or the direction of rotation of the cylinder may be changed (selection of the web direction). It is also possible to provide separating means in the printing press as for example with two different types of product are produced at the same time (selection of the printing direction).

The circumference of the printing cylinders may be changed according to the size of the printed product.

The prerequisite for printing products of good quality is that the different colours of the design being printed which are printed on the separate printing units must coincide exactly with one another. Since the relative length of the paper running between printing cylinders depends on the quality of the paper, the stretching of the web, the adhesion and other technological factors, individual colours may be displaced or shifted which results in a large amount of defective product of paper waste.

To maintain a permissible value for the colour shift, the length of the paper between adjacent printing cylinders should be controlled. Since it is impossible with the modern high-speed printing presses to achieve and guarantee adequate quality by manual control, automatic systems for controlling the printing cylinders and suitable for this purpose have been suggested. An example of such a system is that developed by the British firm Crossfield, and produced in the German Democratic Republic under the name "REG ISTOMAT".

The fundamental concept of such register-controlling systems is that a measuring figure, or register mark, is printed on each printing units - generally at a position externally of the design - in such a way that the relative position of the different register marks determines the shift of the image or colours in the design. The colour or image shift, i.e. the position of the register marks printed on the separate printing units is scanned by a two-channel optoelectronic web or path scanner and the colour or image shift is thereby measured. The difference between two such register marks, with respect to a predetermined reference mark, is referred to herein as a "fault" or "error" mark.

By the summation of the fault or error mark obtained from the evaluation of the register marks and the reference mark, a corrected control or fault mark value is obtained. The control fault mark value is supplied to the control system, so that the motor of the mechanism adjusting the length of the paper can be controlled to the correct direction of rotation. The basic mark adjusted in advance by an expert can achieve an artificially produced image or colour shift, which can be established by the asymmetry of the printing cylinders or by other technological factors.

As the control value is obtained from a fault or error mark (which is always determined by measurement of two register marks), the process is referred to as a "web-web" process.

However, if the relative position of two pages, or point of cutting on the cutting register has to be controlled, the measuring procedure is referred to as a "web-cylinder" process. In this latter case, only a single register mark can be scanned, and consequently, for comparison purposes, an artificially generated pulse has to be brought into operation. This pulse is generated by a pulse generator mounted on the printing cylinders at a suitable moment in time. This is in addition suitable for the gating of the register marks, and as a consequence this mark is referred to as a gate signal or gate mark.

In known register-control units, an independent, analog control unit is arranged which is dependent upon the printing press. The programming operation corresponding to the feeding of the paper is effected by different cables being plugged into corresponding connection.

Because of the analog character of these arrangements, these latter present numerous disadvantages, as a result of which the effectiveness thereof, is strongly influenced. One of these disadvantages is that the time constant of the regulators is large, so that the observation of the fault and the correction thereof takes such a long time that, in the meanwhile, many defective copies will have been printed. Within limits which are determined by expense and size, it is not possible to provide for accuracy of control when variable parameters such as web stretching, length of track and velocity are taken into account.

An additional disadvantage is that with the changing of printing programme, register presetting cannot be carried out, and accordingly the adjustment of the machine has to be effected with a considerable loss of time and material. Furthermore, known systems cannot eject the paper waste. Accordingly, separate systems for removing paper waste have to be associated with the printing press. The defective copies are removed by the measurement of the change in width of the register marks on the separating printing units (the register marks being printed in superposed relation). As a consequence, the value of the image or colour shift cannot be adJusted according to printing umts and the correction of the defects or errors cannot be taken into account.

An additional disadvantage of known systems is that technological data (such as track length, cylinder circumference, error correction) cannot be accurately adjusted. Everything is dependent on the skill of the typographer.

We have sought to obviate the disadvantages which have been referred to above. To this end, the present invention provides a system for controlling and for presetting registers in a rotary multicolour printing press which comprises an indicating device having a unit for determining a fault mark value (as defined above) and a web scanner circuit; a unit for forming a gate signal; a unit for measuring web speed; arithmetic units; a motor-control unit; and an operation-control unit, the output of the web scanner circuit being connected to the input of a circuit which measures the fault mark, while the unit forming the gate signal is so electronically connected to the unit measuring the fault mark that one output of a gate signal-forming circuit disposed in the unit forming the gate signal is connected to the input of the web-scanner circuit, while another output is connected to one input of the circuit measuring the error signal; impulse generators arranged on two sides in the unit forming the gate signal, which are at the same time each connected to an input of the gate signal-forming circuit, programming switches being connected to the additional input of the gate signal-forming circuit by way of multiplexers; one output of the circuit is connected to one input of an indicating circuit; another output of the gate signal-forming circuit is connected to one input of a circuit measuring the web speed, and to each of which inputs are connected the programming switches which, branching off from this point, are connected firstly to one input of the gate signal-forming circuit, and secondly through an electronic switch to an input of an arithmetic circuit; the other inputs of the arithmetic circuit are connected via additional multiplexers to a programming switch, the output of the arithmetic circuit being firstly connected to an input of another arithmetic circuit and by way of an electronic switch to one input of a stepwise counting-back circuit which is incorporated into the motor-control unit by way of the multiplexer, the circuits measuring the error signal being connected to one input of the second arithmetic circuit by way of additional multiplexers, while additional programming switches are connected to the other input of the arithmetic circuit by way of multiplexers; one output of the second arithmetic circuit is connected through an electronic switch to the input of the indicating unit, while the other output thereof is connected to one input of a stepwise counting-back circuit by way of multiplexers; the other input of the stepwise counting-back circuit having connected thereto, via an electronic switch, one output of the circuits measuring the speed of the web path and the same outputs, branching off from this point, are each connected to one input of other stepwise counting-back circuits; the outputs of the counting-back circuits are connected to the input of a stepping motor, while the other inputs of the same circuits are connected to terminal switches and to press-button switches.

The essence of the invention is that an electronic, digital system in which error marks or symbols derived as a sample in a time-multiplexer operating procedure and other parameters are processed by a plurality of independent control circuits by a common arithmetic system - corresponding to an algorithm developed for this purpose - of which the final result is the value of the control means (intervention signal), and the partial results indicate the values of the register presetting and the elimination of paper waste.

In the preferred embodiment of the invention, the system includes a paper waste discharge unit wherein the output of the arithmetic circuit branches off at the point where it is connected to the input of another arithmetic circuit, to an output of a paper waste-following circuit, the second arithmetic circuit is firstly connected to one input of the paper waste-following circuit, and then through the electronic switch to the input of the indicating unit, one input of the paper waste-following circuit having connected thereto a programming switch, while the other input has additional programming switches connected thereto by way of multiplexers, and its outputs are connected to an arrangement which ejects the paper waste.

The invention also provides a process for register presetting using the system as described above which comprises advancing the stepping motor into a relative zero position so as to adjust the cylinders governing the paper length calculating the integral quotient of the length of the paper path, between two adjacent printing units, according to the paper supply and circumference of the printing cylinder being used; when half the value "K", as herein defined, of the remainder is smaller than the adjustment permitted by the mechanical dimensions of the arrangement, conducting a number of advancing pulses to the stepping motor, this number being equal to half of the calculated remainder: as a result, adjusting the cylinders governing the paper length from the relative zero position to the required position and thereby mounting the printing cylinders corresponding to the design to be printed in an analogous angular position in the printing units; when half of the remainder is larger than the permitted adjustment, then deducting half the value of the roller circumference from the remainder and conducting a number of advancing pulses to the stepping motor, this number corresponding to half value of the remainder; thereby rotating the printing cylinder through 1800, relatively to the adjacent cylinders, and mounting it into the printing unit.

The invention is further illustrated by way of example in the accompanying Drawing.

Provided in the system is a unit 1 which generates fault or error marks as defined above.

The number of these units 1 corresponds to the number of the printing units and number of the cutting registers. Included in the unit 1 is a web-scanning circuit 1.1, which is connected to a circuit 1.2 for measuring the error marks which is connected to a programme-setting switch 1.3. The unit 1 is electronically connected to another unit 2 which forms the gate signals. Included in the unit 2 are the following components: arranged on each of the two sides is a pulse generator 2.1, each pulse generator 2.1 is connected to an input of a circuit 2.2 for forming a gate signal (said circuit having several inputs). Connected to the other inputs of this circuit 2.2, by way of a multiplexer 9.5, are programming switches 2.3 (not shown in detail) which shift the gate signal of the printing units. Each printing cylinder has associated therewith a programming switch. For convenience, we have only shown a single programming switch 2.3.

The unit 1 for generating the error marks is so connected to the unit 2 which forms the gate signals that one output of the latter unit is connect to the input of the web-scanner circuit 1.1, while another output is connected to an input of the circuit 1.2. One output of the gate signal-forming circuit 2.2 is connected to one input of an indicating circuit 8.1.

Another component of the circuit arrangement is formed by a web speed measuring unit 3.

Arranged in this unit 3 are two circuits 3.1 for measuring the web speed (one on the left and one on the right); connected to each input of the latter is a programming switch 3.2 for setting the value of the cylinder circumference and in addition one programming switch 3.3 for adjusting the control speed.

Connected to one input of each of the circuits 3.1 for measuring the web speed is an output of each of the circuits 2.2 which form the gate signals. The programming switches 3.2 which, as already mentioned, are connected to the circuits 3.1 for measuring the web seed, are also connected to inputs to the circuits 2.2, and also by way of an electronic switch 4.3, which is in arithmetic unit 4, to one input of arithmetic circuit 4.1. Included in the arithmetic unit is a programming switch 4.2 for adjusting the length of the track or running distances (a programming switch 4.2 is associated with each one of the printing units), the programming switches being connected by way of a multiplexer 4.4 to one input of the arithmetic circuit 4.1. The output of the arithmetic circuit 4.1 is connected, on the one hand, to one input of another arithmetic circuit 5.1 (which is provided in another arithmetic unit 5), and on the other hand (branching off from this point) to an input of a paper waste-following circuit 7.1 (which is incorporated into the unit for discharging the paper waste).

Connected to one input of the arithmetic circuit 5.1 (by which of another multilexer 9.5 similar to that previously referred to) are the circuits 1.2 which measure the error marks or symbols, another input of the same arithmetic circuit 5.1 being connected by way of other analog multiplexers 9.5 to programming switches 5.2 (which switch into circuit the basic mark or symbol). The number of the programming switches 5.2 corresponds to the number of the printing units.

One output of the arithmetic circuit 5.1 is on the one hand connected to one input of the paper waste-following circuit 7.1, and on the other hand, through an electronic switch 9.6, to the input of an indicating circuit 8.1 of the indicating unit 8.

By way of electronic switch 9.6 and a multiplexer 9.5 which is similar to that previously referred to, the other output of the arithmetic circuit 5.1 is connected to one input of a counting-back circuit 6.1 (which is incorporated into the motor-control unit and the number of which corresponds to that of the printing units).

Connected to the other input of the counting-back circuit 6.1 and by way of an electronic switch 9.6 is an output of each circuit 3.1 which measures the web speed and, from a branch, the same outputs are connected to the similar input of the couting-back circuits 6.1 (which are arranged in the other motor-control units). The outputs of the counting-back circuits are connected to the inputs of stepping motors 6.2 while the other inputs of the same circuits are connected to a limit switch 6.3 and to press-button switches 6.4 which ensure the control operation. Connected to one input of the paper waste-following circuit 7.1 is a programming switch 7.2 which determines the sequence of the distance which is travelled, while the other input has connected thereto, by way of another multiplexer 9.5, programming switch 7.3 for the paper waste control circuit. The outputs of the circuit for eliminating the paper waste and forming part of the waste paper-following circuit 7.1 are connected to the means known per se for removing the paper waste. Included in opertion-control unit 9 is a circuit 9.1 which controls the operation and which has at least one output. The outputs thereof are connected to the control inputs of the functional units (under the references 1 to 8), (the units are not shown in the drawing). Connected to the inputs of the operation-control unit 9 are switches 9.2 which effect the presetting of the registers, switches 9.3 which determine the control operation and by way of multiplexers 9.5, switches 9.4. The automatic operation and the printing direction are set by the switches 9.4. As regards the switches 9.2 and 9.3, two are provided, namely, one on the right-hand side and one on the left-hand side. The number of the switches 9.4 corresponds to the number of the printing units.

The arrangement is operated as follows: The relative image or colour shifts of the figures which are printed by the adjacent printing units is determined by the unit 1 for measuring the error marks in such a way that the register marks are scanned by the two-channel, optoelectronic path-scanner circuit 1.1 and the distance between register pulses Ra, Rb, which are produced from the scanned symbols by comparison, is measured by the web-scanner measuring circuit 1.2 by means of measuring frequency fAj FAb, from the unit measuring the web speed, by counting of the pulses. A programme corresponding to the paper feed, the determination of the web direction or the selection of the measurement methods (web-web, or web-cylinder) and also the correction of the sign of the measured errors or defects are adjusted by the switches 1.3.

The register marks are generally printed on a void or empty position and are selected by the gate signal G (from the interference signals originating from the printed designs of figures) generated by the unit 2 which forms the gate signal. The gate signal G is produced as follows: The circuit 2.2 which forms the gate signal continuously measures the angular position of the printing cylinders in relation to a zero position. This measurement is effected by counting the pulses, which arrive either from the pulse generators 2.1 which are driven by the press from the right-hand side or left-hand side. As the register mark or symbol on the printing unit reaches the web-scanner circuit 1.1 - under the action of the press-button incorporated into the scanner unit a signal, which is the numerical value of the angular position of the printing cylinder at that time, is transferred into the indicating circuit 8.1.

The indicated value is adjusted by means of the programming switch 2.3 (which shifts the indicated value). The gate signal G is generated by the circuit 2.2 producing the gate signal according to the angular position at the time of the printing cylinder and an auxiliary pulse is produced in the middle of the gate signal, which pulse is necessary for measuring the "web-cylinder" type of operation. The pulse width of the gate signal is constant, independent of the cylinder circumference.

Frequencies fA, fv (defined below) which are proportional to the web speed and which are for measuring the image or colour shift, and also for advancing the stepping motor adjusting the length of the paper path are generated by the unit 3 which measures the web speed. Since the rotary press can be divided, this function is carried out by way of circuits 3.1 of similar construction for measuring the web velocity. The web velocity or speed is calculated from the unit which measures the speed from the frequencies of the pulses of the pulse generator 2.1 and from the value of the circumferences of the printing cylinder, this latter value being set by the programming switch 3.2 The algorithm which is necessary for this purpose is as follows: Vp = 113 T X in which = = web velocity (ms-1) 1 = cylinder circumference (m) = = pulse member of the pulse generator T = time of the removal of a specimen.

The algorithm of the circuit, which generates the measurement frequency fA is: V fA = 10 4 . fo, in which f0 = frequency of the time signal (corresponding to the necessary accuracy of measurement, which amounts to 0.01mm, and expediently f0 = 1 Mc/s).

The stepping or advancing frequency fv is likewise proportional to the web speed, but may be adjusted by the programming switches 3.3.

V fv = H . fA, in which V = the value which is adjusted by the programming switch 3.3.

The parameters K and Ck, which are necessary for control purposes, and respectively the values RE of the register presetting, are calculated by the arithmetic unit 4. Parameter K indicates (corresponding to the paper feed) the value of the cylinder circumference between two adjacent cylinders, but related to the path length K = 1 in which L = path length in mm, 1 = cylinder circumference in mm.

The value of the path length is established by the programming switch 4.2 and the value of the cylinder circumference is adjusted by the programming switch 3.2.

Parameter Ck represents the modified value of the value K.

Ck = cK + 1, in which 16 c = adjustable constant.

The value of the register presetting: RE1 = L - K.l (in mm) When the value RE, is greater than that of the modified path length, which is dependent on the press, then the register pre-adjustment is effected automatically in accordance with the value RE2: RE2 = L-K.L - 1 2 with register presetting effected by means of the modified value, the printing cylinder is to be adjusted by 1800.

The calculations are carried out continuously by the arithmetic unit 4. The calculated values are separately stored, each in accordance with printing units. The programming switches 4.2 belonging to the individual printing units are associated by way of multiplexers with the arithmetic circuit 4.1.

That value X of the path modification which is necessary for aprinting operation taking place without picture shift is calculated by an arithmetic unit 5 in accordance with the following algorithm.

X = K(An - An-l) + Ck s An-ls in which n = H + H ~, and 2 Hn = Hm + Kk Hm = measured error in a period of n, Hk = basic signal, adjusted by the programming switches.

The algorithm gives a PD-character control of good quality. Since a web operator is used according to the invention, instead of a time operator, which is usual with other control means, the effect of the variable parameter (web speed, path length) no longer occurs. The necessary path increments are assured by the frequencies fA,fV which are generated in the unit 3 measuring the web speed.

The algorithm also contains correlation calculations.

Within an appropriate range, the control procedure as described above can be established simply by digital circuits.

The value X of the control system is calculated separately, according to printing units, and according to cylinder revolution, by the arithmetic circuit 5 and is fed forward to the step-by-step recounting circuit 6.1. The component results are stored in a store installed in the calculating unit.

The value X which is calculated in the arithmetic unit 5, or the value RE which is calculated with the register presetting in the arithmetic unit 5, are fed forward into the stepwise recounting circuit 6.1 of the motor-control unit 6.

In the control operation, the recorded value X, dependent on the use of the machine, is counted back by the stepwise switching frequencies f or fvb, i.e. the stepping motor connects as many steps as correspond to the value X. The direction is determined by the sign of the value X. The register presetting is preferably carried out in two cycles: 1. The stepping motors are set in the bottom end position. This position is scanned by the limit switches 6.3 and indicated.

2. The stepping motors are moved "upwardly", corresponding to the value recorded in the stepwise recounting circuit 6.1.

With the register presetting, the stepwise advancing frequency is independent of the web speed.

Advancing of the stepping motors carried out manually, is effected by means of the switches 6.4. The discharge of the defective printed matter is carried out by the paper waste separation device 7 under the control of a paper waste ejection arrangement which is connected to it.

The circuit 7.1 which follows the paper waste contains stepping registers, the number of which corresponds to that of the printing units. The length of the registers corresponds to a largest possible K-value, which is equal to the number of printed items which can be printed on one path distance between the adjacent printing units.

Both the value of the picture shift adjusted by the programming switch 7.3 and the permitted value of the shift, and also the value Hn (which is the algebraic sum of the measured error and of the basic symbol or sign) are compared with one another; thereafter the circuit determines whether the impression on the indicated printing unit is defective or is suitable. If the impression is defective, a detect sign or symbol is recorded in the K-section of the stepping register belonging to the printing unit, which mark or symbol is advanced with each revolution of a cylinder.

The connection of the separate stepping registers (corresponding to the respective paper position) can be carried out by the programming switch 7.2 which determines the sequence of the path.

The discharge arrangement for the paper waste provides for the fact that each defective printed article produced on any one of the printing units can be separated out, independently of the cylinder circumference and the paper supply, at the end of the machine.

The operating state of the system, and also the calculated values, are digitally indicated by the indicating means 8, according to printing units. The indicating means 8 also contains an oscilloscope, on which are recorded the relative positions of the gate signal and of the register marks. The external control signals of the means are produced by the operational control unit 9. By means of the switches 9.2 and 9.3, it is possible to establish the register presetting or controls on the right and left sides, the switches 9.4 establishing the automatic operation of the individual printing units and the direction of the impression.

By means of the multiplexers 9.5, which are of similar construction and consequently are represented by similar reference numbers the connections of the unit 1 measuring the fault symbols or marks, of the motor-control units 6 and of the other operations and programming units are carried out in accordance with the programme of the operationcontrol unit.

Although the presetting of the register of the printing press is effected automatically by means of the system, the system is only able to function without any defects if the storage of the data is accurately carried out by an expert. As a consequence, the presetting of the register, the control of the colour shift and the discharge of the faulty printed articles may be effected in accordance with the technological operations as hereinafter described. The cylinders of the system for adjusting the paper length, are adjusted into a relative zero position, i.e. into an end position, as a result of advancing the stepping motor which is provided. Thereafter, by means of the same arrangement, there is established the quotient of the length of the paper path between the adjacent printing unit - according to the position of the papers - and the circumference of the printing cylinder which is used; if the half value K of the remainder is smaller than the possibility of adjustment which can be allowed by the mechanical dimensi opposite to the advance. The register series connected in this manner are each advanced according to the number of revolutions of the cylinders. Thereafter, the value of the image or colour shift measured after each cylinder revolution is compared with the permissible value of the detect or error, which is adjusted by a programming switch which is associated with each printing unit. When the measured value of the picture shift is larger than the adjusted value, then the register "k", which belongs to a register series associated with the given printing unit, is triggered from its basic position. This triggered state is evaluated for a defective impression. The output of the last register is then reached as the last printed item leaves the printing unit. It is by this signal that the ejection device is actuated.

WHAT WE CLAIM IS: 1. A system for controlling and presetting registers in a rotary multi-colour printing press which comprises an indicating device having a unit for determining a fault mark (as herein defined), and a wet scanner circuit; a unit for forming a gate signal; a unit for measuring the web speed; arithmetic units; a motor-control unit and; and an operationcontrol unit, the output of the web scanner circuit being connected to the input of a circuit which measures the fault mark, while the unit forming the gate signal is so electronically connected to the unit measuring the fault mark that one output of a gate signal-forming circuit disposed in the unit forming the gate signal is connected to the input of the web-scanner circuit, while another output is connected to one input of the circuit measuring the error signal; impulse generators arranged on two sides in the unit forming the gate signal, which are at the same time each connected to an input of the gate signal-forming circuit, programming switches being connected to the additional input of the gate signal-forming circuit by way of multiplexers; one output of the circuit is connected to one input of an indicating circuit; another output of the gate signal-forming circuit is connected to one input of a circuit measuring the web speed, and to each of which inputs are connected the programming switches which, branching off from this point, are connected firstly to one input of the gate signal-forming circuit, and secondly through an electronic switch to an input of an arithmetic circuit; the other inputs of the arithmetic circuit are connected via additional multiplexers to a programming switch, the output of the arithmetic circuit being firstly connected to an input of another arithmetic circuit and by way of an electronic switch to one input of a stepwise counting-back circuit which is incorporated into the motor-control unit, by way of the multiplexer, the circuits measuring the error signals being connected to one input of the second arithmetic circuit by way of additional multiplexers, while additional programming switches are connected to the other input of the arithmetic circuit, by way of multiplexers, one output of the second arithmetic circuit is connected through an electronic switch to the input of the indicating unit, while the other output thereof is connected to one input of a stepwise counting-back circuit by way of multiplexers; the other input of the stepwise counting-back circuit having connected thereto, via an electronic switch, one output of the circuits measuring the speed of the web path, and the same outputs, branching off from this point, are each connected to one input or other stepwise counting-back circuits, the outputs of the counting-back circuits are connected to the input of a stepping motor, while the other inputs of the same circuits are connected to terminal switches and to press-button switches.

2. A system as claimed in Claim 1, which includes a paper waste discharge unit wherein the output of the arithmetic circuit branches off at the point where it is connected to the input of another arithmetic circuit, to an output of a paper waste-following circuit, the second arithmetic circuit is firstly connected to one input of the paper waste-following circuit, and then through the electronic switch to the input of the indicating unit, one input of the paper waste-following circuit having connected thereto a programming switch, while the other input has additional programming switches connected thereto by way of multiplexers, and its outputs are connected to an arrangement which ejects the paper waste.

3. A system as claimed in Claim 1 or Claim 2, wherein an operation-control circuit is incorporated into the system, the outputs of said circuit being connected to the control inputs of the functional units of the system and the inputs of the operation-control circuit being connected, on the one hand, to the switches establishing the register pre-setting, and to the switches establishing the control, and on the other hand, by way of multiplexers to the switches which set the automatic operation.

4. A system for controlling and for presetting registers in a rotary multi-colour printing press substantially as described herein with reference to the accompanying drawing.

5. A process for register presetting in a rotary multi-colour printing press using a system according to any preceding Claim which comprise advancing the stepping motor into a relative zero position so as to adjust the cylinders governing the paper calculating the integral quotient of the length of the paper path, between two adjacent printing units, according to the paper supply and circumference of the printing cylinder being used; when half the value "K" (as herein defined) of the remainder is smaller than the adjustment

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. opposite to the advance. The register series connected in this manner are each advanced according to the number of revolutions of the cylinders. Thereafter, the value of the image or colour shift measured after each cylinder revolution is compared with the permissible value of the detect or error, which is adjusted by a programming switch which is associated with each printing unit. When the measured value of the picture shift is larger than the adjusted value, then the register "k", which belongs to a register series associated with the given printing unit, is triggered from its basic position. This triggered state is evaluated for a defective impression. The output of the last register is then reached as the last printed item leaves the printing unit. It is by this signal that the ejection device is actuated. WHAT WE CLAIM IS:

1. A system for controlling and presetting registers in a rotary multi-colour printing press which comprises an indicating device having a unit for determining a fault mark (as herein defined), and a wet scanner circuit; a unit for forming a gate signal; a unit for measuring the web speed; arithmetic units; a motor-control unit and; and an operationcontrol unit, the output of the web scanner circuit being connected to the input of a circuit which measures the fault mark, while the unit forming the gate signal is so electronically connected to the unit measuring the fault mark that one output of a gate signal-forming circuit disposed in the unit forming the gate signal is connected to the input of the web-scanner circuit, while another output is connected to one input of the circuit measuring the error signal; impulse generators arranged on two sides in the unit forming the gate signal, which are at the same time each connected to an input of the gate signal-forming circuit, programming switches being connected to the additional input of the gate signal-forming circuit by way of multiplexers; one output of the circuit is connected to one input of an indicating circuit; another output of the gate signal-forming circuit is connected to one input of a circuit measuring the web speed, and to each of which inputs are connected the programming switches which, branching off from this point, are connected firstly to one input of the gate signal-forming circuit, and secondly through an electronic switch to an input of an arithmetic circuit; the other inputs of the arithmetic circuit are connected via additional multiplexers to a programming switch, the output of the arithmetic circuit being firstly connected to an input of another arithmetic circuit and by way of an electronic switch to one input of a stepwise counting-back circuit which is incorporated into the motor-control unit, by way of the multiplexer, the circuits measuring the error signals being connected to one input of the second arithmetic circuit by way of additional multiplexers, while additional programming switches are connected to the other input of the arithmetic circuit, by way of multiplexers, one output of the second arithmetic circuit is connected through an electronic switch to the input of the indicating unit, while the other output thereof is connected to one input of a stepwise counting-back circuit by way of multiplexers; the other input of the stepwise counting-back circuit having connected thereto, via an electronic switch, one output of the circuits measuring the speed of the web path, and the same outputs, branching off from this point, are each connected to one input or other stepwise counting-back circuits, the outputs of the counting-back circuits are connected to the input of a stepping motor, while the other inputs of the same circuits are connected to terminal switches and to press-button switches.

permitted by the mechanical dimensions of the arrangement, conducting a number of advancing pulses to the stepping motor, this number being equal to half of the calculated remainder: as a result, adjusting the cylinders governing the paper length from the relative zero position to the required position and thereby mounting the printing cylinders, corresponding to the design to be printed in an analogous angular position in the printing units; when half of the remainder is larger than the permitted adjustment, then deducting half the value of the roller circumference from the remainder and conducting a number of advancing pulses to the stepping motor, this number corresponding to half value of the remainder; thereby rotating the printing cylinder through 1800, relatively to the adjacent cylinders, and mounting it into the printing unit.

6. A process for automatically controlling the image or colour shift in a rotary colour-printing press using a system according to any of Claims 1 to 4, wherein the value of the image or colour shift, calculated for the individual printing units according to the cylinder rotation, is fed into a common arithmetic circuit, then the value which modifies the paper length and which is necessary for controlling the image or colour shift is so calculated that, from the error value which is measured with one cylinder revolution "n", from which is subtracted the error value measured with the cylinder revolution "n-1", the difference being multiplied with the value "K" (as herein defined) and, to the result "D", is added the result of a multiplication, the factors of which are the value of the error measured with the cylinder revolution "n-1" and a constant "P", which is proportional to the length of the web path, whereafter the stepping motor adjusting the paper length is advanced by a number of advancing pulses which corresponds to half of the sum p+D and the frequency of the pulses is proportional to the speed of travel of the paper.

7. A process for ejecting defective printed articles using a system according to any of Claims 1 to 4, wherein each of the printing units has associated therewith a series of stepping registers, the number of the registers is the same as or larger than the maximum value "K" (as herein defined); thereafter, the series of registers are so connected to one another in accordance with a sequence determined by the position of the paper that the output of a leading register series is connected to the input of a register "K", calculated in the direction opposite to the advance, of the next stepping register series; the register series so connected to one another are then advanced according to one revolution of the cylinders and the value of the image or colour shift measured after the cylinder rotation is compared with the permissible error value which is set by each programming switch which is associated with the separate printing units; when the value of the image or colour shift is greater than the set value, then the register K of a register series belonging to the given printing unit is triggered from its basic position; the triggered position is evaluated for a defective printing and the output of the combined register series is then reached as the defective printed matter discharges from the last printing unit, as a result of which the ejection device is actuated.