JP2022085532A - Printer, printing method, and printing program - Google Patents

Abstract

To provide a printer capable of effectively detecting a register error.SOLUTION: A printer 10 includes: printing units 11A to 11D; a register mark printing part 15 for printing a register mark on a predetermined position of a web 50; a mark sensor 23 for detecting a register mark; a detection control part for making the mark sensor 23 detectable in such a first detection time zone that the first register mark passes through a detection region of the mark sensor 23 and such a second detection time zone different from the first detection time zone that the second register mark passes through the detection region of the mark sensor 23; and a register error computing part for computing a register error of a first printing unit and a second printing unit on the basis of a relative position between the first register mark and the second register mark detected by the mark sensor 23.SELECTED DRAWING: Figure 1

Description

The present invention relates to a printing technique.

The rotary press, which is a printing device that prints on moving roll paper, is equipped with a plurality of printing units and sequentially prints each color such as cyan (C), magenta (M), yellow (Y), and black (K). Aligning the printing plates of each color is called "matching the register". For this purpose, as a technique, the registration error, which is the misalignment of the printing plate of each color, is detected, and the feed rate of each part of the roll paper and the rotation speed of the plate cylinder around which the printing plate of each color is wound are adjusted so as to reduce it. It is known.

Japanese Unexamined Patent Publication No. 2014-1770119

In Patent Document 1, each printing unit prints a register mark at a predetermined position in order to detect a registration error. Register marks of each color are printed on the roll paper at regular intervals, and adjacent register marks are simultaneously detected by a mark sensor having two photodetecting elements arranged at the same intervals. The relative distance of these simultaneously detected register marks and the deviation from the desired value are detected as registration errors, and registration control is performed to reduce them.

In Patent Document 1, since adjacent register marks are simultaneously detected by a mark sensor, a color material that is difficult to detect by any of the register marks (for example, a light color material or a transparent or translucent color material such as varnish). ), The registration error cannot be detected.

The present invention has been made in view of these circumstances, and an object of the present invention is to provide a printing apparatus capable of effectively detecting a registration error.

In order to solve the above problems, the printing apparatus of one aspect of the present invention is provided in the first printing unit and the second printing unit for printing on the moving object to be printed, and the first printing unit, and is provided on the object to be printed. The first mark printing unit that prints the first register mark at a predetermined first position and the second print unit are provided to print the second register mark at a predetermined second position of the object to be printed. The second mark printing unit, the mark sensor for detecting the first register mark and the second register mark, and the mark sensor in the first detection time zone when the first register mark passes through the detection area of the mark sensor. The detection control unit and the mark sensor are in a detectable state, and the mark sensor is in a detectable state in a second detection time zone different from the first detection time zone in which the second register mark passes through the detection area of the mark sensor. A registration error calculation unit for calculating a registration error between the first print unit and the second print unit based on the detected relative positions of the first register mark and the second register mark is provided.

In this embodiment, since the registration error can be calculated based on the relative positions of the register marks detected in different detection time zones, the degree of freedom is higher than that of Patent Document 1 in which the simultaneous detection of adjacent register marks is restricted. For example, when a certain register mark is printed with a color material that is difficult to detect, the register mark is not used for calculating the registration error, and another register mark printed with a color material that is easy to detect is selected effectively. Register error can be calculated.

Another aspect of the present invention is a printing method. In this method, when the first printing unit prints on a moving object, the step of printing the first register mark at a predetermined first position and when the second printing unit prints on the object to be printed. In addition, the step of printing the second register mark at a predetermined second position, and the mark sensor, the first register mark in the first detection time zone in which the first register mark passes through the detection area of the mark sensor. And the step of detecting the second register mark in the second detection time zone different from the first detection time zone in which the second register mark passes through the detection area of the mark sensor, and the second one detected by the mark sensor. A step of calculating a registration error between the first print unit and the second print unit based on the relative positions of the register mark 1 and the register mark 2 is provided.

It should be noted that any combination of the above components and the conversion of the expression of the present invention between methods, devices, systems, recording media, computer programs and the like are also effective as aspects of the present invention.

According to the present invention, it is possible to provide a printing apparatus capable of effectively detecting a registration error.

It is a figure which shows the structure of the printing apparatus which concerns on embodiment of this invention. It is a figure which shows the positional relationship of a register mark. It is a figure which shows the structure of a printing unit. It is a block diagram which shows the structure of a register control device. It is a figure which shows typically the method of giving an address. It is a figure which shows the specific example of the gate selection of the gate selection part. It is a figure which shows the register error which occurs at the time of low-speed operation. It is a figure which shows the register error which occurs at the time of high-speed operation.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In the description and drawings, the same or equivalent components, members, and processes are designated by the same reference numerals, and duplicate description will be omitted as appropriate. The scales and shapes of the illustrated parts are set for convenience of explanation and are not limitedly interpreted unless otherwise specified. The embodiments are exemplary and do not limit the scope of the invention in any way. Not all features and combinations thereof described in the embodiments are essential to the invention.

FIG. 1 shows the configuration of the printing apparatus 10 according to the embodiment of the present invention. The printing apparatus 10 includes a first printing unit 11A for printing black (K), a second printing unit 11B for printing cyan (C), a third printing unit 11C for printing magenta (M), and yellow (Y). ) Is printed, the fourth printing unit 11D, and the register control device 30 are provided. Hereinafter, the first printing unit 11A to the fourth printing unit 11D are collectively referred to as a printing unit 11 as appropriate. The print color of each print unit 11 is not limited to the above, and any print color can be assigned to each print unit 11 in any order. Further, in order to print more colors, five or more printing units may be provided.

The first printing unit 11A includes a first plate cylinder 13A, a first impression cylinder 17A, a first drive motor 19A, and a first encoder 21A. The second printing unit 11B includes a second plate cylinder 13B, a second impression cylinder 17B, a second drive motor 19B, a second encoder 21B, and a second mark sensor 23B. The third printing unit 11C includes a third plate cylinder 13C, a third impression cylinder 17C, a third drive motor 19C, a third encoder 21C, and a third mark sensor 23C. The fourth printing unit 11D includes a fourth plate cylinder 13D, a fourth impression cylinder 17D, a fourth drive motor 19D, a fourth encoder 21D, and a fourth mark sensor 23D. Hereinafter, the first plate cylinder 13A to the fourth edition cylinder 13D are appropriately collectively referred to as a plate cylinder 13, and the first impression cylinder 17A to the fourth impression cylinder 17D are appropriately collectively referred to as an impression cylinder 17, and the first drive motors 19A to 19A to The fourth drive motor 19D is appropriately collectively referred to as a drive motor 19, the first encoder 21A to the fourth encoder 21D are appropriately collectively referred to as an encoder 21, and the second mark sensor 23B to the fourth mark sensor 23D are appropriately referred to as a mark sensor 23. Collectively referred to as.

The printing device 10 prints the web 50, which is a roll paper, as a printed matter. Each printing unit 11 is installed along the moving direction of the web 50. The web 50 is guided by a guide roller 25 arranged along the movement path, and the plate cylinder 13 and the impression cylinder 17 of each printing unit 11 provide a pattern of each color corresponding to the printing plate wound around the plate cylinder 13. It is printed sequentially.

The plate cylinder 13 has a reference mark printing unit 14 and a register mark printing unit 15 as a mark printing unit. FIG. 2A shows the positional relationship of the first register mark 53A to the fourth register mark 53D when there is no registration error, and FIG. 2B shows the positional relationship when there is a registration error. In FIG. 2A, the registration mark 52 is also shown. The registration mark 52 as a reference mark is printed by the reference mark printing unit 14 of each plate cylinder 13. The first register mark 53A is printed at a predetermined first position by the register mark printing unit 15 of the first plate cylinder 13A, and the second register mark 53B is printed at a predetermined first position by the register mark printing unit 15 of the second plate cylinder 13B. The third register mark 53C is printed at two positions, the third register mark 53C is printed at a predetermined third position by the register mark printing unit 15 of the third plate cylinder 13C, and the fourth register mark 53D is printed with the register mark of the fourth plate cylinder 13D. It is printed at a predetermined fourth position by the unit 15. Hereinafter, the first register mark 53A to the fourth register mark 53D are collectively referred to as a register mark 53 as appropriate.

In FIG. 2A where there is no registration error, the register mark 52 and the first register mark 53A are printed at an interval L0, and each register mark 53 is printed at a regular position at an interval L1. That is, the relative distance between the first position where the first register mark 53A is printed and the second position where the second register mark 53B is printed, and the second position where the second register mark 53B is printed and the third register mark 53C are. The relative distance of the third position to be printed and the relative distance of the third position where the third register mark 53C is printed and the fourth position where the fourth register mark 53D is printed are both equal to the interval L1. In FIG. 2B where there is a register error, the register mark 53 is printed out of the normal position. In the illustrated example, the second register mark 53B is deviated from the normal position. At this time, the relative distance between the first register mark 53A and the second register mark 53B is smaller than the normal L1, and the difference is a registration error. Similarly, the relative distance between the second register mark 53B and the third register mark 53C is larger than the normal L1, and the difference is also a registration error.

Returning to FIG. 1, in the plate cylinder 13 in the nth stage from the front, the reference mark printing unit 14 and the register mark printing unit 15 are provided at intervals of L0 + (n-1) × L1. The circumferences of all the plate cylinders 13 are the same, and by rotating each plate cylinder 13 once, a pattern of each color is printed once, and the pattern is printed continuously by repeating the process. As shown in FIG. 2A, in each printing, the registration mark 52 is printed at the same position by the reference mark printing unit 14 of each plate cylinder 13, and the register mark printing unit 15 of each plate cylinder 13 is L1. Each register mark 53 is printed at intervals of.

Each plate cylinder 13 is rotationally driven by an individual drive motor 19. During the printing operation of the printing apparatus 10, each drive motor 19 is electrically synchronized in rotation, and each plate cylinder 13 rotates at the same rotation speed. That is, the printing apparatus 10 is configured by a sectional drive method. Each drive motor 19 is provided with an encoder 21 on its mechanical shaft.

The encoder 21 is an incremental encoder. The encoder 21 outputs a predetermined number of A-phase and B-phase pulse signals and one Z-phase pulse signal for each rotation of the plate cylinder 13. The A-phase and B-phase pulse signals are counted by the counter, and the count value is reset by the Z-phase pulse signal. The phase (rotational position) of the plate cylinder 13 is detected by the count value of the pulse signal. The encoder 21 may be an absolute type serial encoder regardless of the method as long as it can detect the phase of the plate cylinder 13.

FIG. 3 shows the configuration of the printing unit 11. The mark sensor 23 is provided on the downstream side of the plate cylinder 13 of the same printing unit 11. The mark sensor 23 has a plurality of photodetecting elements T1 and T2. The first photodetector element T1 on the upstream side and the second photodetector element T2 on the downstream side are arranged at an interval L1. Therefore, the adjacent register marks 53A to 53D printed at the same interval L1 can be detected by the photodetecting elements T1 and T2 at substantially the same timing.

FIG. 4 is a block diagram showing the configuration of the register control device 30. This configuration is realized by the CPU, memory, or other LSI of an arbitrary computer in terms of hardware, and is realized by a program stored in the memory in terms of software. Here, the functional blocks realized by their cooperation are shown.

The register control device 30 includes a control unit 31 and a storage unit 41. The control unit 31 includes a detection control unit 33, a non-adjacent mark registration error calculation unit 35 as a second registration error calculation unit, an adjacent mark registration error calculation unit 37 as a first registration error calculation unit, and a registration error. A calculation switching unit 38 and a registration error correction unit 39 are provided. The storage unit 41 is a general-purpose memory that stores information related to the control of the control unit 31.

The detection control unit 33 individually sets the detection time zone in which each mark sensor 23B to 23D is in a detectable state. As shown in FIG. 2A, in one printing corresponding to one rotation of each plate cylinder 13, the registration mark 52 and four registration marks 52 are formed in the vertical band-shaped region of FIG. 2, which is the moving direction of the web 50. The register marks 53A to 53D are printed, but other patterns and information (not shown) are also printed in this band-shaped area. In order to prevent erroneous detection due to these other patterns and information, the detection time zone of each mark sensor 23B to 23D is limited so that only the registration mark 52 and the register mark 53 can be detected. The detection time zone of each mark sensor 23B to 23D is set based on the address associated with the rotation angle of each plate cylinder 13B to 13D of the printing units 11B to 11D provided therein.

FIG. 5 schematically shows an address assignment method using the print unit 11D as an example. When the plate cylinder 13D of the printing unit 11D rotates clockwise to print on the web 50, the register mark printing unit 15 shown in the figure prints the register mark 53D. This figure shows a state in which the register mark 53D comes to the position of the photodetector element T1 of the mark sensor 23D. At this time, the register mark 53D moves the distance from the print point P to Ld. Assuming that the rotation angle of the plate cylinder 13D during that period is θd, the radius of the plate cylinder 13D is r and Ld = rθd.

As described with reference to FIG. 2, the web 50 has other register marks 53A to 53C printed by the register mark printing unit 15 of the other printing units 11A to C provided in front of the printing unit 11D. The distance Lc of the register mark 53C from the print point P is Ld + L1, the distance Lb of the register mark 53B from the print point P is Ld + 2L1, and the distance La of the register mark 53A from the print point P is Ld + 3L1. Further, the web 50 has a register mark 52 printed by the reference mark printing unit 14 of each printing unit 11A to D. The distance Ls of the registration mark 52 from the printing point P is Ld + 3L1 + L0.

The distance from the print point P of each of these marks is associated with the phase (rotation angle) of the plate cylinder 13D by dividing by the radius r of the plate cylinder 13D. That is, in the illustrated state, the phase of the register mark 53D is θd, the phase θc of the register mark 53C is Lc / r = θd + L1 / r, and the phase θb of the register mark 53B is Lb / r = θd + 2L1 / r. The phase θa of the register mark 53A is La / r = θd + 3L1 / r, and the phase θs of the register mark 52 is Ls / r = θd + (3L1 + L0) / r.

Further, these phases are translated into addresses represented by consecutive integers from zero to the maximum value Amax. This address monotonically increases from zero to the maximum value Amax (eg, 2047) during one rotation of the plate cylinder 13D in the clockwise direction, and becomes zero again at the start of the next rotation. The reference rotation position of the plate cylinder 13D at which the address becomes zero can be arbitrarily set. Assuming that the address of the register mark 53D in the state where the illustrated register mark printing unit 15 is rotated by θd from the printing point P is Ad, the address Ac of the register mark 53C is Ad + Amax × (θc−θd) / 2π, and the register mark 53B. The address Ab of is Ad + Amax × (θb−θd) / 2π, the address Aa of the register mark 53A is Ad + Amax × (θa−θd) / 2π, and the address As of the register mark 52 is Ad + Amax × (θs−θd) / It is 2π.

Here, paying attention to the photodetector element T1 of the mark sensor 23D, the timing at which each mark passes through the detection region of the photodetector element T1 is expressed by an address as follows. The address Ad1 when the register mark 53D passes through T1 is Ad (as shown), the address Ac1 when the register mark 53C passes through T1 is Ad-Amax × (θc-θd) / 2π, and the register mark 53B is T1. The address Ab1 when passing through is Ad-Amax × (θb-θd) / 2π, the address Aa1 when the register mark 53A passes through T1 is Ad-Amax × (θa-θd) / 2π, and the register mark 52 is T1. The address As1 when passing through is Ad-Amax × (θs-θd) / 2π. Since the register mark 53C, the register mark 53B, the register mark 53A, and the register mark 52 pass through T1 at a time before the state shown in the figure, the address of the phase difference is subtracted from Ad.

As described above, the timing at which each mark passes through the detection region of the photodetector element T1 of the mark sensor 23D can be expressed by an address associated with the rotation angle of the plate cylinder 13D. Similarly, the timing at which each mark passes through the detection area of the photodetector element T2 of the mark sensor 23D can also be expressed by an address. For example, the address Ac2 in the illustrated state where the register mark 53C comes to the position of the photodetector element T2 is Ad. Further, with respect to the mark sensors 23B and 23C provided in the other printing units 11B and 11C, the passing timing of each mark can be expressed by an address associated with the rotation angle of the plate cylinders 13B and 13C. Here, since the rotation angles of the plate cylinders 13B to 13D can be detected by the encoders 21B to 21D, the register control device 30 can grasp the addresses of the plate cylinders 13B to 13D in real time and use them for the control.

Returning to FIG. 4, the detection control unit 33 sets the detection time zone of each mark sensor 23B to 23D based on the address. For example, in the example of FIG. 5, a predetermined address range including the address Ad1 is set as the detection time zone in which the photodetector element T1 detects the register mark 53D. Similarly, a predetermined address range including the address Ac1 is set as the detection time zone in which the optical detection element T1 detects the register mark 53C, and the address Ab1 is set as the detection time zone in which the optical detection element T1 detects the register mark 53B. A predetermined address range including the address range is set, a predetermined address range including the address Aa1 is set as a detection time zone in which the optical detection element T1 detects the register mark 53A, and a detection time in which the optical detection element T1 detects the dragonfly mark 52. A predetermined address range including the address As1 is set as a band. Hereinafter, the address range set for each mark is referred to as a gate, and the address width is referred to as a gate width.

The gate width set for each mark can be arbitrarily set, but it is preferable that the gate width is the same for all marks and the length of each detection time zone is the same. Also, considering the moving speed of the web 50, a predetermined range centered on the regular position of each mark in the detection time zone (for example, when the distance between each mark is about 20 mm, it is less than ± 10 mm from the center of each mark). The gate width may be dynamically adjusted so as to pass through the detection area of the mark sensor 23. Further, it is preferable that the above gates are set so as not to overlap each other so that the detection time zones do not overlap with a plurality of marks.

As described above, the detection control unit 33 sets the gate (or detection time zone) of each mark sensor 23B to 23D based on the address, so that each mark sensor 23B to 23D has only the register mark 52 and the register marks 53A to D. Can be detected, and false detection due to other patterns or information printed in the same band-shaped area can be prevented.

In the printing unit 11D shown in FIG. 5, five marks 52 and 53A to 53D gates are set for each of the photodetector elements T1 and T2. Therefore, a total of 10 gates are set in the print unit 11D. Similarly, in the printing unit 11C, four gates of marks 52 and 53A to 53C are set for each of the photodetecting elements T1 and T2. Therefore, a total of eight gates are set in the print unit 11C. Further, in the printing unit 11B, three gates of the marks 52 and 53A to 53B are set for each of the photodetecting elements T1 and T2. Therefore, a total of 6 gates are set in the print unit 11B. In this way, a total of 24 gates are set in the entire printing apparatus 10. Hereinafter, it is referred to as Glmn to distinguish these gates. l is an integer of 2 to 4, l = 2 represents the print unit 11B, l = 3 represents the print unit 11C, and l = 4 represents the print unit 11D. m is 1 or 2, m = 1 represents the photodetector element T1, and m = 2 represents the photodetector element T2. n is an integer of 0 to 4, n = 0 represents the register mark 52, and n = 1 to 4 represent the register marks 53A to 53D, respectively. Therefore, a total of 24 gates are represented as follows. G210, G211, G212, G220, G221, G222, G310, G311, G312, G313, G320, G321, G322, G323, G410, G411, G412, G413, G414, G420, G421, G422, G423, G424.

The non-adjacent mark registration error calculation unit 35 includes a gate selection unit 351 and a registration error calculation unit 352. The gate selection unit 351 selects any two gates at different addresses from a total of 24 gates Glmn for the calculation by the registration error calculation unit 352. Here, in order to improve the calculation accuracy in the registration error calculation unit 352, it is preferable to select a gate included in the same print unit 11 (a gate having the same l), but a gate included in a different print unit 11 is selected. You may.

A specific example of gate selection of the gate selection unit 351 will be described with reference to FIG. This figure shows the gates of the register marks 53A to 53D of the photodetector elements T1 and T2 of the printing unit 11D. The horizontal axis indicates the address of the plate cylinder 13D. As described above, when the plate cylinder 13D rotates during printing, the address increases monotonically, so the horizontal axis represents the passage of time.

The illustrated addresses Aa1, Ab1, Ac1, and Ad1 have been described above. The address Aa1 is provided with a gate G411 in which the photodetector element T1 detects the register mark 53A. The address Ab1 is provided with a gate G412 in which the photodetection element T1 detects the register mark 53B and a gate G421 in which the photodetection element T2 detects the register mark 53A. The address Ac1 is provided with a gate G413 in which the photodetector element T1 detects the register mark 53C and a gate G422 in which the photodetector element T2 detects the register mark 53B. The address Ad1 is provided with a gate G414 in which the photodetector T1 detects the register mark 53D and a gate G423 in which the photodetector T2 detects the register mark 53C. The distance between the addresses Aa1, Ab1, Ac1, and Ad1 is ΔA, and the address Ad1 + ΔA is provided with a gate G424 in which the photodetector T2 detects the register mark 53D.

As described above, at each of the addresses Ab1 to Ad1, there are two gates, the gates G412 to G414 of the photodetector element T1 and the gates G421 to G423 of the photodetector element T2. Since the adjacent mark registration error calculation unit 37, which will be described later, calculates the registration error, the combination of these gates having the same address does not have to be selected by the gate selection unit 351 of the non-adjacent mark registration error calculation unit 35. That is, the gate selection unit 351 mainly selects any two gates provided at different addresses. The selection of this gate may be performed by the same photodetector element or may be performed by different photodetector elements. In the former case, for example, gate G411 and gate G414 are selected. In the latter case, for example, gate G413 and gate G421 are selected. Although FIG. 6 shows only the gate of the print unit 11D, the gate selection unit 351 may select the gates of other print units 11B and 11C. As a result, the registration error can be calculated by the registration error calculation unit 352 based on any combination of gates of any printing unit.

The registration error calculation unit 352 calculates the registration error based on the signals detected by the photodetector at the two gates selected by the gate selection unit 351. As shown in FIG. 6, at each gate, pulses due to the register marks 53A to 53D are detected. If there is no register error, each pulse is in the same position within each gate. Conversely, if there is a register error, each pulse is in a different position within each gate. Therefore, the registration error can be calculated by comparing the relative positions of each pulse in each gate. For example, when the position in each gate is represented by the address in the gate where the left end address of the gate is zero, the difference between the addresses of the rising positions of each pulse in each gate becomes a registration error.

For example, the registration error calculated for the gate G411 and the gate G414 is a registration error between the print unit 11A printed with the register mark 53A of the gate G411 and the print unit 11D printed with the register mark 53D of the gate G414. The registration error calculated for the gate G413 and the gate G421 is a registration error between the print unit 11C printed with the register mark 53C of the gate G413 and the print unit 11A printed with the register mark 53A of the gate G421. In this way, the registration error of any print unit can be calculated.

In FIG. 6 showing the gate of the printing unit 11D, the gates G414 and G424 detect the register mark 53D printed by the printing unit 11D itself. As shown in FIG. 5, the register mark 53D has only moved by a distance Ld from the print point P, and it is usually unthinkable that a large register error will occur during that time. Therefore, there is no problem even if the photodetecting elements T1 and T2 cannot detect the register mark 53D at the gates G414 and G424. For example, when printing with a color material that is difficult for the printing unit 11D to detect (for example, a light color material or a transparent or translucent color material such as varnish), the register mark 53D may not be detected, but the gate. It can be treated as if the pulse of the register mark 53D rises at the desired position in G414 and G424, and the registration error with the pulse rising position of another gate can be calculated. The above contents also apply to the gates G313 and G323 of the printing unit 11C and the gates G212 and G222 of the printing unit 11B.

The adjacent mark registration error calculation unit 37 calculates the registration error based on the signals detected by the photodetecting elements T1 and T2 at the gates having the same address. In FIG. 6 showing the gate of the print unit 11D, the combination of the gates G412 and G421 at the address Ab1, the gates G413 and G422 at the address Ac1 and the gates G414 and G423 at the address Ad1 is the calculation target. Further, in the print unit 11C, the gates G312, G321, the gates G313, and G322 are the calculation targets, and in the print unit 11B, the gates G212 and G221 are the calculation targets. In the combination of these gates having the same address, the photodetecting elements T1 and T2 spaced apart from each other at the same interval L1 as the register mark 53 can simultaneously detect the adjacent register mark 53, so that the gate such as the gate selection unit 351 can be detected. No selection required. The registration error calculation method is as described above for the registration error calculation unit 352. According to such an adjacent mark registration error calculation unit 37, it is possible to calculate the registration error of the adjacent printing unit 11 that has printed the adjacent register mark 53.

The registration error calculation by the non-adjacent mark registration error calculation unit 35 and the registration error calculation by the adjacent mark registration error calculation unit 37 described above may be used at the same time, or may be switched by the registration error calculation switching unit 38. good. For example, the registration error calculation switching unit 38 uses the adjacent mark registration error calculation unit 37 when the movement speed of the web 50 is less than a predetermined threshold value, such as during printing, and is not when the movement speed of the web 50 is equal to or higher than the threshold value. The adjacent mark registration error calculation unit 35 is used.

At this time, the gate selection unit 351 of the non-adjacent mark registration error calculation unit 35 is printed with the reference color of the color printed by the printing unit 11A that is first printed on the web 50 by all the printing units 11. The gate for detecting the register mark 53A is selected as one gate, and the gate for detecting the register marks 53B to 53D printed by the other printing units 11B to D is selected as the other gate. In FIG. 6 showing the gate of the print unit 11D, any gate G411 or G421 that detects the register mark 53A of the reference color is selected as one gate, and any of the gates 53B to 53D other than the reference color is detected as the other gate. Select a gate. By doing so, the non-adjacent mark registration error calculation unit 35 can calculate the registration error of the print unit 11A for printing the reference color and the print units 11B to 11D for printing other than the reference color, respectively. The color printed by the print unit 11 other than the print unit 11A may be used as the reference color. On the other hand, the adjacent mark registration error calculation unit 37 calculates the registration error of the printing units 11A to 11D for printing the adjacent colors.

That is, the registration error calculation switching unit 38 calculates the registration error based on the adjacent color by the adjacent mark registration error calculation unit 37 at low speed, and calculates the registration error based on the reference color by the non-adjacent mark registration error calculation unit 35 at high speed. Calculate.

As schematically shown in FIG. 7, the operation of each printing unit is stable while the moving speed of the web 50 is small and acceleration is generated until the web 50 reaches the normal operating speed, such as during printing. However, since there is also the influence of tension fluctuations between the printing units, a large registration error may occur between the printing units. The example of FIG. 7 shows how a registration error represented by e occurs between the printing units with respect to the example of FIG. 6 having no registration error. First, in the gate G413 that detects the register mark 53C, the pulse (dotted line) deviates from the normal position (solid line) by e due to the registration error e between the print unit 11D and the print unit 11C. Next, in the gate G412 that detects the register mark 53B, the registration error e between the print unit 11C and the print unit 11B is further added, so that the pulse is deviated by 2e from the normal position. Similarly, in the gate G411 that detects the register mark 53A, the registration error e between the print unit 11B and the print unit 11A is further added, so that the pulse deviates from the normal position by 3e. At this time, since the pulse (dotted line) of the register mark 53A printed in the reference color goes out of the gate, the non-adjacent mark registration error calculation unit 35 using the reference color cannot calculate the registration error. On the other hand, according to the adjacent mark registration error calculation unit 37 using the adjacent color, the registration error can be corrected in order from the pair of the gates G414 and G423 having the smaller registration error. As described above, at low speeds, it is preferable to use the adjacent mark registration error calculation unit 37 that utilizes adjacent colors.

On the other hand, FIG. 8 schematically shows a state in which the web 50 reaches the normal operating speed and the acceleration is almost zero at high speed. After reaching the normal operating speed, unlike the low speed in FIG. 7, the operation of each printing unit is stable, so that even if a registration error occurs, it stays between some of the printing units 11. The example of FIG. 8 shows a state in which a registration error represented by e occurs between the printing units 11D and 11C with respect to the example of FIG. 6 having no registration error. Since no registration error occurs between the print units 11A to 11C, the same registration error e occurs at the gate that detects the register marks 53A to 53C. These registration errors e can be corrected by both the non-adjacent mark registration error calculation unit 35 using the reference color and the adjacent mark registration error calculation unit 37 using the adjacent color, but when the adjacent mark registration error calculation unit 37 is used, the registration error e can be corrected. , The registration error may remain. For example, the two gates G412 and G421 at address Ab1 and the two gates G413 and G422 at address Ac1 compare register marks of adjacent colors, but the pulse positions in these gate pairs are the same (both pulses are e only). It is out of alignment). Therefore, there is a possibility that these pulses will continue to be deviated from the normal position by e. On the other hand, according to the non-adjacent mark registration error calculation unit 35 that uses the reference color, the registration error e of the gate G411 is first corrected based on the registration error calculation of the gate G411 (reference color) and G414, and then the gate G411 and the gate G411. , The registration error e of each of G412 and G413 is corrected based on the registration error calculation of each of the gates G412 and G413. Therefore, residual registration error is prevented. As described above, at high speed, it is preferable to use the non-adjacent mark registration error calculation unit 35 that uses the reference color.

Since the moving speed of the web 50 can be calculated based on the output of the encoder 21 of each printing unit 11, the low speed time and the high speed time of the web 50 can be distinguished by comparing the calculation result with a predetermined threshold value. Further, the switching in the registration error calculation switching unit 38 may be performed based on the acceleration of the web 50. That is, the registration error calculation switching unit 38 uses the adjacent mark registration error calculation unit 37 when the acceleration of the web 50 is equal to or higher than a predetermined threshold value (such as when printing), and when the acceleration of the web 50 is less than the threshold value (normal operation). After reaching the speed, etc.), the non-adjacent mark registration error calculation unit 35 is used. The acceleration of the web 50 can also be calculated based on the output of the encoder 21 of each printing unit 11. Further, the switching in the registration error calculation switching unit 38 may be performed based on the manual operation of the operator of the printing device 10.

The registration error correction unit 39 corrects the registration error calculated by the non-adjacent mark registration error calculation unit 35 and the adjacent mark registration error calculation unit 37. The registration error correction unit 39 outputs a correction signal to the drive motor 19 of the printing unit 11 or the side tray (not shown) in which the registration error occurs. The drive motor 19 or the sidelay drives the plate cylinder 13 so that the registration error is corrected based on the correction signal. The drive motor 19 corrects the registration error in the moving direction of the web 50, and the sidelay corrects the registration error in the width direction perpendicular to the moving direction of the web 50.

According to the above embodiment, the non-adjacent mark registration error calculation unit 35 can effectively calculate the registration error based on any combination of gates of any printing unit 11. Since the register marks 53 that are not adjacent to each other can be selected from different addresses or gates in the detection time zone, the degree of freedom in calculating the examination error is dramatically increased. For example, when a certain register mark 53 is printed with a color material that is difficult to detect, the register mark 53 is not used for calculating the registration error, and another register mark 53 printed with a color material that is easy to detect is selected. Register error can be calculated.

Further, a non-adjacent mark registration error calculation unit 35 using a reference color and an adjacent mark registration error calculation unit 37 using an adjacent color are provided and switched by the registration error calculation switching unit 38 to change the moving state of the printed matter. Appropriate registration error calculation can be performed according to the above.

The present invention has been described above based on the embodiments. It is understood by those skilled in the art that the embodiments are exemplary and that various modifications are possible in the combination of each of these components and each processing process, and that such modifications are also within the scope of the present invention.

In the embodiment, the web 50, which is a roll-up paper, is exemplified as the printed matter, but the printing device 10 can print on any printed matter. For example, it may be a sheet made of any material, or it may be the surface of an individual having an arbitrary shape such as a container or a product.

In the embodiment, the mark sensor 23 is provided with two detection elements T1 and T2, but the mark sensor 23 may have one detection element. At this time, in the example of FIG. 6, only the waveform of T1 (or T2) is obtained, but the gate selection unit 351 selects any two gates from the gates G411 to G414 having different addresses or detection time zones. Since the registration error calculation unit 352 can calculate the registration error, the registration error between the printing units 11A to 11D can be corrected. Further, if the gate selection unit 351 selects the gate G411 as one gate and the gates G412 to G414 as the other gate with the reference color as the print color of the print unit 11A, the registration error calculation based on the reference color can be performed. can. Further, if the gate selection unit 351 selects two adjacent gates from the gates G411 to G414, the registration error calculation based on the adjacent colors can be performed.

The functional configuration of each device described in the embodiment can be realized by hardware resources or software resources, or by cooperation between hardware resources and software resources. Processors, ROMs, RAMs, and other LSIs can be used as hardware resources. Programs such as operating systems and applications can be used as software resources.

10 printing device, 11 printing unit, 13 plate cylinder, 14 reference mark printing unit, 15 register mark printing unit, 21 encoder, 23 mark sensor, 30 register control device, 33 detection control unit, 35 non-adjacent mark registration error calculation unit, 37 Adjacent mark registration error calculation unit, 38 registration error calculation switching unit, 39 registration error correction unit, 53 register mark, 351 gate selection unit, 352 registration error calculation unit, T1 first light detection element, T2 second light detection element.

Claims (7)

A first printing unit and a second printing unit that print on a moving object to be printed,
A first mark printing unit provided in the first printing unit and printing a first register mark at a predetermined first position of the printed matter, and a first mark printing unit.
A second mark printing unit provided in the second printing unit and printing a second register mark at a predetermined second position of the printed matter, and a second mark printing unit.
A mark sensor that detects the first register mark and the second register mark, and
The mark sensor is in a detectable state during the first detection time zone in which the first register mark passes through the detection area of the mark sensor, and the second register mark passes through the detection area of the mark sensor. A detection control unit that enables the mark sensor to be detected in a second detection time zone different from the detection time zone of 1.
A register error calculation unit that calculates a register error between the first print unit and the second print unit based on the relative positions of the first register mark and the second register mark detected by the mark sensor. A printing device to be equipped. The mark sensor is provided in the subsequent printing unit of the first printing unit and the second printing unit.
The printing device according to claim 1, wherein the detection control unit sets the first detection time zone and the second detection time zone according to the rotation angle of the plate cylinder of the printing unit provided with the mark sensor. .. The first printing unit and the second printing unit can be selected from a plurality of printing units.
The detection control unit sets the first detection time zone according to the selection of the first printing unit, and sets the second detection time zone according to the selection of the second printing unit. Item 2. The printing apparatus according to Item 1 or 2. A third printing unit provided immediately before or after the first printing unit to print on the printed matter, and a third printing unit.
The third printing unit is provided with a third mark printing unit for printing a third register mark at a predetermined third position of the printed matter.
The mark sensor includes two detection units that are spaced apart from each other at a relative distance between the first position and the third position, and the first register mark and the third register mark are provided during the first detection time zone. Detects register marks at the same time and
The registration error calculation unit calculates a registration error between the first print unit and the third print unit based on the relative positions of the first register mark and the third register mark detected by the mark sensor. The printing apparatus according to any one of claims 1 to 3. The mark sensor is provided in the last printing unit of the first printing unit, the second printing unit, and the third printing unit.
The printing apparatus according to claim 4, wherein the detection control unit sets the first detection time zone and the second detection time zone according to the rotation angle of the plate cylinder of the printing unit provided with the mark sensor. .. A step of printing a first register mark at a predetermined first position when printing on a moving object to be printed by the first printing unit.
A step of printing a second register mark at a predetermined second position when the second printing unit prints on the printed matter, and a step of printing the second register mark.
The mark sensor detects the first register mark in the first detection time zone when the first register mark passes through the detection area of the mark sensor, and the second register mark is the detection area of the mark sensor. The step of detecting the second register mark in the second detection time zone different from the first detection time zone passing through the
A printing method including a step of calculating a registration error between the first printing unit and the second printing unit based on the relative positions of the first register mark and the second register mark detected by the mark sensor. .. A step of printing a first register mark at a predetermined first position when printing on a moving object to be printed by the first printing unit.
A step of printing a second register mark at a predetermined second position when the second printing unit prints on the printed matter, and a step of printing the second register mark.
The mark sensor detects the first register mark in the first detection time zone when the first register mark passes through the detection area of the mark sensor, and the second register mark is the detection area of the mark sensor. The step of detecting the second register mark in the second detection time zone different from the first detection time zone passing through the
A computer executes a step of calculating a registration error between the first print unit and the second print unit based on the relative positions of the first register mark and the second register mark detected by the mark sensor. A printing program to let you.

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