US3084621A - Process and apparatus for controlling register on rotogravure printing machines - Google Patents

Description

April 9, 1963 A. GUASTAVINO 3,084,621

PROCESS AND APPARATUS FOR CONTROLLING REGISTER ON ROTOGRAVURE PRINTING MACHINES Filed May 15, 1961 4 Sheets- Sheet 1 I k PHOTOELEETRIC DETECTOR T52 MAGNETIC 2 2i! CORRECTION W F. 1 MOTOR J IMP I MAIN DRIVE MOTOR MAIN DRIVE PHOT ELECTRIC DETE CONTROLLER f, INVENTOR. 'U'ANTONIO GUASTAVINO BY 62 I /7 ATTORNEY.

A nl 9, 1963 A. GUASTAVINO ,0

PROCESS AND APPARATUS FOR CONTROLLING REGISTER ON ROTOGRAVURE PRINTING MACHINES Filed May 15, 1961 4 Sheets-Sheet 2 INVENTOR ANTONIO GUASTAVINO ATTORNEY.

A ril 9, 1963 A. GUASTAVINO 3,084,621

PROCESS AND APPARATUS FOR CONTROLLING REGISTER ON ROTOGRAVURE PRINTING MACHINES Filed May 15, 1961 4 Sheets-Sheet 5 6. Fig: 9.

/9 20 2/ o q fmlg L24 4 INVENTOR 13. ANTONIO GUASTAWNO If I N J]! 11' BY 2 ATTORNEY.

Aprll 9, 1963 A. GUASTAVINO 3,084,621

PROCESS AND APPARATUS FOR CONTROLLING REGISTER ON ROTOGRAVURE PRINTING MACHINES Filed May 15, 1961 4 Sheets-Sheet 4 /4i LT ADV;

/4m JV nvz i Mn Fig. '14.

INVENTOR ANTONIO GUASTAVINO AT TORNE Y.

3,984,621 PROCESS AND APPARATUS FOR CONTROLLING REGISTER ON ROTGGRAVURE PRINTING MA- CHTNES Antonio Guastavino, Eng. Pietro Guazzo, Via XX Setternbre 74, Turin, Italy Filed May 15, 1961, Ser. No. 110,208 Claims priority, application Italy May 14, 1960 12 Claims. (Cl. 101-181) The present invention relates to a method and apparatus for controlling the register on rotograv-ure printing machines.

It is known that the polychrome printing process consists in successively printing monochromatic images, thus obtaining a good polychrome image, provided that the various monochromatic images are applied in exactly superposed relationship.

In the particular case of r-otogravure machines, the sheet is continuously unwound from a roll of paper, goes through a first section where the first monochromatic image is printed and subsequently passes through the following sections, where the other monochromatic images are printed in turn, and finally is wound up on a roll.

Various systems are known for effecting the automatic control of the printing register, that is .the perfect superposing of the monochromatic images.

These existing systems usually work as follows:

The first section of the machine prints a register mark in addition to the corresponding monochromatic image, and the register mark is detected, in each of the following sections, by a photoelectric cell system that generates a signal indicating the position of the paper in that section; furthermore a device rigidly connected to the printing roll of each section generates a signal indicating the angular position of said roll; and finally a control device receives both signals and compares them, that is compares the relative position of the paper and of the printing roll of the related section, and, if necessary, corrects the position of the printing roll relative to the paper by means of a correcting motor and a mechanical differential.

Since the above arrangement is provided at each section of the printing press, this equipment is very complicated and consequently very expensive.

One of the purposes of the present invention is to provide an automatic control system which is much more simple and ensures satisfactory and safe operation.

In accordance with an important aspect of the invention, a single control group is provided that acts in cycle for checking and correcting in turn the working conditions in each section of the press.

Other purposes and characteristics of the invention will be apparent in the following description of an illustrative embodiment with reference to the attached drawings wherein on which FIG. 1 is a diagrammatic view of an automatic control device of the above described existing type;

FIG. 2 is a diagrammatic view of a register control device according to the present invention;

FIG. 3 is a diagram of the disposition of the register marks provided on a sheet of the paper in accordance with this invention;

FIG. 4 is a diagram of a photoelectric detection device included in the apparatus embodying this invention;

FIG. 5 is a diagram of a magnetic detection device for indicating the roll position in the apparatus embodying this invention;

FIG. 6 is a diagram of the control device included in a preferred form of the apparatus embodying this invention;

FIG. 7 is a diagram illustrating the control device;

the output voltage of identify the lines defining the 3,084,621 Patented Apr. 9, 1963 ice FIG. 8 is a diagram of a circuit which operates the correcting device;

FIG. 9 is a diagram of a circuit for operating the selector;

FIG. 10 is a diagram of the voltage at various points in the circuit of FIG. 9;

FIG. 11 is a diagram of the selector;

FIG. 12 is a diagram of the voltage at various points in the selector of FIG. 11;

FIG. 13 shows the disposition of the register marks according to another embodiment of the invention, and

FIG. 14 is a diagram of the voltage at a number of points in the circuit.

As clearly shown on FIG. 1 of the drawing, a device of the known type includes a roll B from which a continuous sheet of paper 1 is unwound and then undergoes the action of the printing rolls S S etc. in the subsequent sections before being rewound on a roll B The several rolls S S etc. are driven by the main drive MP of the printing machine with roll S of the first section being driven directly, while for each of the remaining sections, the drive is effected through a differential D adjusted by a correction motor M under the action of a control device C A photoelectric detector TE is located in front of the sheet coming out of roll S while a magnetic detector TM turns as a unit with the printing roll S the signals generated by the two detectors TE; and TM being transmitted to the C device that compares them and, if necessary, operates motor M and consequently corrects the rotational position of roll S through differential D According to the known procedure, the controlling group C TE TM M must be repeated for each of .the printing sections with the exception of the first section. According to the present invention, a more simple and efficient automatic control system is obtained, which represents a big saving in equipment as only one photoelectric head serves to detect all of the register marks, and only one magnetic head detects the position of one of the various printing rolls and finally only one device compares the relative phases of the signals obtained from the two detectors and operates the correction means associated with each of the printing rolls, excepting the one with which the magnetic detecting head is associated.

The diagram on FIG. 2 illustrates the above arrangement embodying the invention. In this diagram only four printing rolls have been shown for the purpose of simplification, but it is to be understood that a greater number of sections may be included.

There is only one controlling system TE, TM, C and it is equipped with an automatic selector S, operated electronically. The operation will be made clear with the following:

For example, in a machine for the printing of six colors, each roll of the first five sections, prints, in addition to the corresponding monochromatic image, a register mark near the edge of the sheet. At the start-up, the machine is checked manually, that is the various monochromatic images are checked to see whether they are printed in exactly superposed relationship. Then sheet 1 appears as shown on FIGURE 3, where numerals 2 and 3 size of the sheet, that is the lines along which the paper will be cut, after printing, and numeral 4 identifies polychrome printed area.

On the edge of the sheet five register marks, 1 H m 7 TV V are shown each of them being in the position 'where it is printed when the machine is in correct register and the polychrome image is perfect.

After the machine has been manually checked, magnetic recorder device TM and photoelectric detector TE are inter-connected in such a way that, when marks I H III 1V V pass in front of head TE, a corre- 3 spending signal is recorded in the magnetic memory of device TM.

At this point the preparatory stage ends and automatic operation may commence.

The machine, driven by main drive MP, acts on the sheet v1 to advance the latter past the rolls S S S which respectively print thereon images in the corresponding colors together with the respective register marks I II V Upon commening automatic operation, the selector S is in position 1. The first mark on each portion of sheet is detected by device TE and a resulting signal is compared by device C with a signal resulting from the first mark recorded in the magnetic memory. If the detected and recorded marks are simultaneous, it means that the first monochromatic image that has been printed is, in relation to the last one, in the same relative position it had at the beginning, when the machine was checked with the desired precision. The control device C compares the occurrence of the two marks, and, when both marks are simultaneous, does not transmit any driving action to motor M If, on the contrary, thetwo signals are not simultaneous, device C detects the need for a correction and, through selector S, whichas mentioned aboveis in its first position, acts on motor M rotating it in one direction or the other; this rotation of correction motor M acts, through differential D on printing roll S to restore the latter to its correct relative position. Immediately after the first signal has passed, to motor M the selector S advances automatically to position 2.

The unit is then ready to effect ina similar way the comparision of the second register mark II and the corresponding second magnetic signal: as described above, with the only difference that any possible correction required acts on roll S because of the position of selector S.

It is superfluous to repeat the same description for all the remaining printing sections.

In short, the device according to the invention, during the operation of the machine checks, for each sheet into which the web will be cut, whether the first five monochromatic images printed by the first five machine sections have the same positions relative to the printing roll of the last section as they had at the beginning of operations, that is, after the manual checking of the machine and, if necessary, suitably corrects the position of each of the rolls.

The electrical circuits capable of functioning as described above can have different forms, of which illustrative examples are described below:

(a) Detector TE As shown on FIG. 4, the detector TE includes a light system, formed by a lamp L and a lens that concentrates the light of the lamp, generating a luminous spot on the sheet 1, in the position of marks I II IV and a photoelectric cell E, which receives from another lens 0 the light coming from said sheet I, that is which senses the above mentioned marks, as the latter pass the detector.

The signal generated by the photoelectric cell is sent to an electronic amplifier, which includes tubes 5, 6, 7.

Voltage variations occur at the points 8, 9, 10 of the amplifier circuit, as diagrammatically illustrated.

(b) Detector TM As shown on FIG. 5, the detector TM includes a magnetic drum, 11, that is a pulley with a band of magnetic material thereon capable of receiving a magnetic recording, a magnetic head 12 and an amplifier with three tubes 13, 14, 15 and with an output In.

The magnetic head 12 has three functions, namely:

(I) It cancels the previous recording on the magnetic drum, and for this purpose the coil of the magnetic head is connected to a source or continuous voltage.

(II) It records on the magnetic drum, and for this purpose the coil of the head 12 is connected between points 17 and 10 of the circuit for the detector TE (FIG. 4); and

(III) It detects the signals recorded on the drum, and for this purpose the coil of the head is connected to the amplifier of FIG. 5 and, more precisely, to the grid circuit of valve 13.

The amplitude of the signal generated by the head TM in response to a recorded magnetic impulse on the magnetic drum is a function of the drums speed, and this fact constitutes a source of error.

To avoid that cause of error, a signal is introduced at the entrance of valve 1'4, from a tachometric dynamo, not shown, the speed of which is proportional to the speed of the main drive MP (FIG. 2).

(c) Detector Device C As shown in FIG. 6, the circuit of the control device C is formed by a channel that elaborates the signal from detector TE and a channel that elaborates the information from recorder TM. Each channel includes a squaring circuit (part 43) a bistable circuit (part 44) and an integrator circuit (part 45). The signals from the apparatus TM consist of negative voltage impulses (FIG. 14a) which surge whenever the areas of the band on which magnetic impulses have been recorded pass under the magnetic head.

Such voltage impulses indicate the position of the printing roller S In a similar way the information from the apparatus TE consists of negative voltage impulses (FIG. 1412) which are produced every time the signals I II III etc. are sensed by the photoelectric cell (FIG. 3). Such voltage impulses indicate the position on the paper of the monochromatic images printed by rollers S S S etc.

FIG. 14b shows 3 signals corresponding to the sensing of the signals I II III by the cell E of detector TE, while FIG. 14a shows three corresponding signals generated by TM. If the corresponding signals from TE and TM occur simultaneously the monochromatic images printed by rollers S S S etc. are in the correct position with respect to the roller S and the image printed by the latter, and therefore the apparatus is in register; otherwise there is an error of register.

In FIG. 14, it has been assumed that there was no error of register in the case of the first signals, an error of register in a certain sense in the case of the second signals, and an error of register in the opposite sense in the case of the third signals.

In FIG. 14, the abscissae represent time, and therefore the difference of phase between the second signal is the error of register measured in terms or" time. On? course, it is important to know the error of register measured in terms of position and for this purpose the speed of. displacement of the paper must be considered.

FIGS. 14c and 14d represent the output voltages from the squaring circuits 43 (points 109 and 118)); when their input terminals (points 46 and 4-7) receive the impulse shown on FIGS. 14a and 14b.

FIGS. Me and 14 show the voltages at the points 102 and 101 of one of the bistable circuits and FIGS. 14g and 14h show the voltages at the points 1% and 103 of theother bistable circuit.

FIGS. 141 and 14! show the grid voltages at points 111 and 112 of the integrator circuits. It is clearly seen that one of the integrators has a negative grid voltage when the error of register is in one sense, and that such negative grid voltage persists for a length of time equal to the error of register in time, while the second integrator has a negative grid voltage, when the error of register is in the opposite sense, and which persists a time which is equal to the error of register measured as time.

The points 113 of the integrator circuits are supplied with a voltage proportional to the speed of the paper.

The integrators produce voltages at their output termispa goat nals 48, 49, as represented by FIGS. 14m and 1411, only when their grid voltages are negative.

The value of the voltage DVi (FIG. 14m or 14m) is proportional to the product of the time during which the grid of each integrator is negative (error of register in time) multiplied by the voltage at point 113 (proportional to the paper speed); therefore the voltage DVi is proportional to the error of register in printing.

Besides, one or the other integrator presents the voltage, thereby indicating the sense of the error.

(d) Driving Device of the Correcting Circuit In accordance the present invention the outlet terminal 48 or 49 of the integrator of each channel of the control device C, is connected to the inlet 18 of the circuit represented on FIG. 8, which is formed substantially by thyratrons 19, 20, 21 etc., the number of which is equal to the number of the printing sections S S S etc., excepting the last one, indicated at S The action of each of the thyratrons causes the excitation of a corresponding relay Ra Ra Ra etc., that feeds energizing current to the corresponding correction motor M M M etc. (FIG. 3) to eifect rotation of the latter in one direction.

A similar circuit is provided for the integrator of the other channel and drives the same correction motors, but in the opposite direction.

The correction signals coming from circuit C are directed to the various machine section under the control of the screen grids of tubes 19, 20, 21 etc.

When the voltage at the outlet of the integrator of a channel exceeds the value of the negative control grid bias of the various tubes 19, 20, 21 etc. (and this happens when the error in the register exceeds a certain fixed value), the screen grid of the related tube is given a zero potential and starts to conduct, while the other tubes, the screen grids of which are at negative po ten tial, are blocked.

When a tube begins to conduct and the corresponding relay is energized, for instance relay Ra a delay circuit (not shown) is activated, and keeps the relay excited and consequently maintains the correction current for a fixed time.

(c) Selector Device S The selector device is formed by a squaring circuit, FIG. 9 and by the selector circuit itself (FIG. 11).

The inlet 22 of the circuit (FIG. 9) receives the sig nal coming from point of the circuit of FIG. 4.

The operation of the circuit of FIG. 9 will be apparent from the curves of FIG. 10 giving the variations of the voltage at several points of the circuit in relation to time. Specifically, curve 28 gives the voltage at the inlet 22, curve 29 represents the voltage at point 25, curve 30 represents the voltage at point 26, and curve 31 represents the voltage at the outlet 27. The various curves have a periodical pattern and the portions of the curves indicated at A and B correspond to the passage of a register mark I II etc. printed on the sheet.

The function of the circuit of FIG. 9 is to give a posi tive impulse at the outlet 27 for each mark printed on the paper.

The selector illustrated by FIG. 11 consists of a number of bistable circuits connected together by the known ring connection. In the drawing, three sections are shown and are schematically divided by lines -F-F, GG.

The inlet 32 is connected to point 27 of FIG. 9.

The shape of the voltage curves are shown on FIG. 12.

Curve 33 shows the voltage of the arriving signal, the line 34 on the left is the inlet front, the line 35 on the right, is the outlet front.

Curve 36 shows the shape of voltages entering the selector, curves 37, 38, 39 show the polarization voltages of the screen grids of tubes 19, 20, 21, (FIG. 8). Point 40, that is the first section (FIG. 11) feeds the screen grids of tubes 19 (in both channels), point 41, that is located in the corresponding position, but in the sec end section of FIG. 11, feeds the screen grids of tubes 20 and so on.

The result is that the possible integration of the integrator that can be caused by the inlet front of the first marks I (in the case when there is an error in the register) causes the interference operation only of tube 19' of FIG. 8, which is the only one that, in that interval of time, has its screen grid grounded.

If, on the contrary, the integration is caused by the inlet front of the second signal II tube 20 (FIG. 8) will enter into operation, as that tube has its screen grid grounded during that interval of time.

It is to be understood that the above described arrangements are illustrative and that numerous variations and modifications can be eifected therein without departing from the scope or spirit of this invention.

Particularly, the selector, schematically shown on FIG. 2, can be of electronic construction-as described-or of a mechanical or electro-mechanical type.

Furthermore the method can be practiced with the following variation described with reference to FIG. 13.

The first section of the machine prints on the edge of the sheet as many marks IA, IB, IC, ID, IE as there are subsequent sections. Each following section prints a register mark, shown as II, III, IV, V, VI.

The printing rolls are built in such a way as to have, when the monochromatic images are perfectly registered, the corresponding marks aligned with each other, that is, mark II facing mark IA, mark III corresponding to mark IB, etc. as on FIG. 13. After passing through the last printing section, the paired marks are sensed by a photoelectric cell device generating signals which act on inlets 46 and 47 (FIG. 6) to produce control signals at outlets 48 and 49 as previously described herein.

I claim:

1. A method for controlling register of the successive monochromatic images applied to each part of a web of paper by a series of printing couples in a rotogravure printing press, comprising the steps of A. applying to each part of the web, at each of the series of printing couples other than one of the latter, a characteristically located register mark in addition to the corresponding monochromatic image,

B. successively detecting, only at the last printing couple of said series, the several register marks applied previously to each part of the web,

C. comparing the timing of the successively detected register marks with the timing of reference signals generated so as to correspond to the positional relationship between each part of the Web and the point at which the register marks are detected,

D. generating successive correction signals in response to any deviations between said detected register marks and reference signals,

E. supplying .the successive correction signals to the several printing couples, in order, with the exception of said one printing couple, and

F. positionally adjusting each printing couple to which a correction signal is supplied in the sense to eliminate the deviation between the related register mark and reference signal, thereby to maintain correct register between the monochromatic image applied at said one printing couple and the monochromatic images applied at the other printing couples.

2. The method as in claim 1;

wherein said one printing couple is the last of said series of printing couples, and said reference signals are generated in response to the rotation of said last printing couple.

3. The method as in claim 1;

wherein said one printing couple is the first of said series printing couples, and

wherein characteristically located reference marks cor- 8,084,621 7 8 responding in number to said other printing couples wherein said means generating reference signals inare applied to each part of the web at said first printcludes ing Couple, and said reference marks are detected at a. a magnetic drum rotatable with said one print- Said last printing couple to establish the timing of ing cylinder and having magnetic impulses Said reference signals. spaced apart circumferentially thereon,

4. In a multicolor printing press having a series of b. a pick-up head located adjacent said drum to printing cylinders acting successively on a web of paper provide electrical impulses at the frequency at to apply related superposed monochromatic images to which said magnetic impulses pass said head, each section of the web, apparatus for controlling register c. amplifier means receiving said electrical imf the monochromatic images applied to each section of 10 pulses from said head and amplifying the same the Web, comprising: to provide said reference signals, and

A. means on each of the printing cylinders, with the exception of one of said cylinders, for applying to each section of the web a characteristically located register mark in addition to the corresponding monochromatic image;

B. drive means for simultaneously rotating said printing cylinders and including correction means for rotationally adjusting each of the printing cylinders exd. means controlling the amplification by said amplifier in accordance With the speed of said drive means so that the amplitude of said reference signals is independent of the speed of rotation of said one cylinder.

8. In a multicolor printing press, apparatus for controlling register of the monochromatic images applied to each section of the web as in claim 4;

cept said one cylinder; wherein said device comparing the register signals with C. photoelectric detecting means at the last of said the reference signals includes electronic circuit means printing cylinders successively sensing the register having two channels receiving said re ister and refmarks applied to each section of the web and generence signals and each being made up of a squaring crating successive, correspondingly timed electrical circuit, a bis-stable circuit and an integrator circuit, register signals; said circuits of each channel being interconnected to D. means generating reference signals timed so as to provide a voltage impulse at the output of the intecorrespond to the timing of said register signals upon grator circuit of one of said channels when a register correct register of the corresponding images with signal precedes the corresponding reference signal the image applied by said one cylinder; and to provide a voltage impulse at the output of the E. a device comparing said registervsignals with said integrator circuit of the other channel when a register reference signals and generating a correction signal in response to any deviation of a register signal from the corresponding reference signal; and

F selector means connecting said device successively with each of said correction means associated with the printing cylinders except said one cylinder so that each correction signal is thereby fed to the related correction means for rotationally adjusting the corresponding printing cylinder in the sense eliminating the register error leading to the generation of said correction signal.

5. In a multicolor printing press, apparatus for controlling register of the monochromatic images applied to each section of the web as in claim 4;

wherein said one cylinder is the last printing cylinder of said series, and

said means generating reference signals includes electromagnetic means driven with said last cylinder so that the timing of said reference signals is proportional to said reference marks pass said additional photoelectric detecting means.

signal lags with respect to the corresponding reference signal. 9. In a multicolor printing press, apparatus for controlling register of the monochromatic images applied to each section of the web as in claim 8;

further comprising means supplying a voltage proportional to the speed of said drive means to said integrator circuit of each channel of said device comparing the register signals with the reference signals and causing said voltage impulses at the output of each integrator circuit to have a magnitude propor tional to both the deviation, in point of time, between the register and reference signals being compared, and the speed of movement of the web so that said magnitude of the voltage impulse is proportional to the extent of the register error.

10. In a multicolor printing press, apparatus for controlling register of the monochromatic images applied to each section of the web as in claim 8;

the rotational speedof said last cylinder. wherein said device further includes In multicolor pnntmg 'aPparatus a. two thyratron circuits connected to the respectrolling register of the monochromatic images applied to five Outputs of the integrator circuits of Said each secjuon P the as i damn 4; channels, each of said thyratron circuits having wherem said one cylinder is the first printing cylinder a Series of thyratmns corresponding to the p of sald genes i ing cylinders other than said one cylinder and said means generating reference signals includes being normally blocked and means on sald first cyhpderfpplymg to each [1. a relay connected with each thyratron to be Sectlon h Web a genes OI reference marks energized by a voltage impulse from the related charactensncany located so to .have predate? channel only when the thyratron is in conductive mined positional relationships with respect to Condition and the reglster f that 1321 2; wherein said selector means includes Web by 0 Owlng i mg b P a. electronic means for successively rendering concorreci niglstlir of Imagesapp 16 Sal due-tive the thyratrons of each thyratron circuit, following cylinders with the image applied by and L F l cyhnder b. circuit means controlled by each of said relays b. additional photoelectric detect ng means at said and extending to the related Correction means last Pnntmg cylmdel: successively si'nsmg the for operating the latter only when a voltage imreference marks applifid to each secuol-l of g pulse is received from one of said channels at a web by first cyhnder and genenltmg i time when the related thyratron is rendered conreference signals at the frequency with WhlCD ductive.

11. In a multicolor printing press, apparatus for controlling register of the monochromatic images applied to each section of the Web as in claim 10;

wherein each thyratron has a screen grid normally 7. in a multicolor printing press, apparatus for controlling register of the monochromatic images applied to each section of the web as in claim 4; g

maintained at a negative potential, and said electronic means of the selector means successively grounds the screen grids of the thyratrons.

12. In a multicolor printing press, apparatus for controlling register of the monochromatic images applied to each section of the Web as in claim 10;

further comprising time delay means for each relay operative to maintain the latter in energized condition for a predetermined time following cnergization thereof through the related thyratron.

References Cited in the file of this patent

Claims (2)

1. A METHOD FOR CONTROLLING REGISTER FOR THE SUCCESSIVE MONOCHROMATIC IMAGES APPLIED TO EACH PART OF A WEB OF PAPER BY A SERIES OF PRINTING COUPLES IN A ROTOGRAVURE PRINTING PRESS, COMPRISING THE STEPS OF A. APPLYING TO EACH PART OF THE WEB, AT EACH OF THE SERIES OF PRINTING COUPLES OTHER THAN ONE OF THE LATTER, A CHARACTERISTICALLY LOCATED REGISTER MARK IN ADDITION TO THE CORRESPONDING MONOCHROMATIC IMAGE, B. SUCCESSIVELY DETECTING, ONLY AT THE LAST PRINTING COUPLE OF SAID SERIES, THE SEVERAL REGISTER MARKS APPLIED PREVIOUSLY TO EACH PART OF THE WEB, C. COMPARING THE TIMING OF THE SUCCESSIVELY DETECTED REGISTER MARKS WITH THE TIMING OF REFERENCE SIGNALS GENERATED SO AS TO CORRESPOND TO THE POSITIONAL RELATIONSHIP BETWEEN EACH PART OF THE WEB AND THE POINT AT WHICH THE REGISTER MARKS ARE DETECTED, D. GENERATING SUCCESSIVE CORRECTION SIGNALS IN RESPONSE TO ANY DEVIATIONS BETWEEN SAID DETECTED REGISTER MARKS AND REFERENCE SIGNALS, E. SUPPLYING THE SUCCESSIVE CORRECTION SIGNALS TO THE SEVERAL PRINTING COUPLES, IN ORDER, WITH THE EXCEPTION OF SAID ONE PRINTING COUPLE, AND F. POSITIONALLY ADJUSTING EACH PRINTING COUPLE TO WHICH A CORRECTION SIGNAL IS SUPPLIED IN THE SENSE TO ELIMINATE THE DEVIATION BETWEEN THE RELATED REGISTER MARK AND REFERENCE SIGNAL, THEREBY TO MAINTAIN CORRECT REGISTER BETWEEN THE MONOCHROMATIC IMAGE APPLIED AT SAID ONE PRINTING COUPLE AND THE MONOCHROMATIC IMAGES APPLIED AT THE OTHER PRINTING COUPLES.

4. IN A MULTICOLOR PRINTING PRESS HAVING A SERIES OF PRINTING CYLINDERS ACTING SUCCESSIVELY ON A WEB OF PAPER TO APPLY RELATED SUPERPOSED MONOCHROMATIC IMAGES TO EACH SECTION OF THE WEB, APPARATUS FOR CONTROLLING REGISTER OF THE MONOCHROMATIC IMAGES APPLIED TO EACH SECTION OF THE WEB, COMPRISING: A. MEANS ON EACH OF THE PRINTING CYLINDERS, WITH THE EXCEPTION OF ONE OF SAID CYLINDERS, FOR APPLYING TO EACH SECTION OF THE WEB A CHARACTERISTICALLY LOCATED REGISTER MARK IN ADDITION TO THE CORRESPONDING MONOCHROMATIC IMAGE; B. DRIVE MEANS FOR SIMULTANEOUSLY ROTATING SAID PRINTING CYLINDERS AND INCLUDING CORRECTION MEANS FOR ROTATIONALLY ADJUSTING EACH OF THE PRINTING CYLINDERS EXCEPT SAID ONE CYLINDER; C. PHOTOELECTRIC DETECTING MEANS AT THE LAST OF SAID PRINTING CYLINDERS SUCCESSIVELY SENSING THE REGISTER MARKS APPLIED TO EACH SECTION OF THE WEB AND GENERATING SUCCESSIVE, CORRESPONDINGLY TIMED ELECTRICAL REGISTER SIGNALS; D. MEANS GENERATING REFERENCE SIGNALS TIMED SO AS TO CORRESPOND TO THE TIMING OF SAID REGISTER SIGNALS UPON CORRECT REGISTER OF THE CORRESPONDING IMAGES WITH THE IMAGE APPLIED BY SAID ONE CYLINDER; E. A DEVICE COMPARING SAID REGISTER SIGNALS WITH SAID REFERENCE SIGNALS AND GENERATING A CORRECTION SIGNAL IN RESPONSE TO ANY DEVIATION OF A REGISTER SIGNAL FROM THE CORRESPONDING REFERENCE SIGNAL; AND F. SELECTOR MEANS CONNECTING SAID DEVICE SUCCESSIVELY WITH EACH OF SAID CORRECTION MEANS ASSOCIATED WITH THE PRINTING CYLINDERS EXCEPT SAID ONE CYLINDER SO THAT EACH CORRECTION SIGNAL IS THEREBY FED TO THE RELATED CORRECTION MEANS FOR ROTATIONALLY ADJUSTING THE CORRESPONDING PRINTING CYLINDER IN THE SENSE ELIMINATING THE REGISTER ERROR LEADING TO THE GENERATION OF SAID CORRECTION SIGNAL.

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