JP2018176532A - Printing method and printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printing method by which adjustment of a printing position can be easily and adequately performed, and a printer.SOLUTION: After plural printing patterns together with alignment marks are over-printed on a continuous paper sheet 100, a positional relationship between a front stage alignment mark and a rear stage alignment mark is determined. In the case that the rear stage alignment mark is displaced with respect to the front stage alignment mark, a printing position of a rear stage printing pattern to the continuous paper sheet 100 is adjusted. Positions of virtual alignment marks for every printing patterns are set based on positional data on plural front stage alignment marks and positional data on plural rear stage alignment marks, the printing position of the rear stage printing pattern is adjusted based on the positional relationship between both virtual alignment marks.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a printing method and a printing machine adapted to overprint a printing pattern.

  When overprinting a print pattern on a medium to be printed such as continuous paper, it is required to establish a predetermined positional relationship without shifting the positional relationship between the print pattern of the former stage and the print pattern of the latter stage. Be done. For this purpose, the position of the printed print pattern needs to be detected for confirmation.

  In Patent Document 1, there is a technology in which a plurality of alignment marks printed on a print target are photographed by an alignment camera, and when the positions of the alignment marks are shifted, the positions of the printing plate and the print target are corrected. It is disclosed.

  In Patent Document 2, when the support mechanism for supporting the printing substrate is made of a transparent material, the alignment camera photographs the alignment mark of the printing substrate through the transparent material, and the position of the alignment mark is shifted, A technique is disclosed that corrects the position of the support mechanism.

JP, 2011-161810, A JP 2012-71506 A

  In the techniques of Patent Document 1 and Patent Document 2, a plurality of alignment marks are photographed by a camera, the position of each alignment mark is determined, and the position of the printing plate or printing object or support mechanism is adjusted according to the position. I am trying to adjust. Therefore, in order to adjust the position of the plate or the like according to the position data detected at a plurality of locations, the sequence for the adjustment may be complicated, and in some cases, the adjustment may not be accurately performed, and the overprinting may be performed. Misalignment may occur between the upper and lower print patterns.

  An object of the present invention is to provide a printing method and a printing machine which can adjust the printing position easily and appropriately based on the alignment mark.

  In order to achieve the above object, in the present invention relating to the printing method, after overprinting a plurality of print patterns together with the alignment marks on the medium to be printed, the positional relationship between the front alignment marks and the rear alignment marks is determined. In the printing method for adjusting the printing position of the printing pattern of the latter stage on the print medium, when the alignment mark of the latter stage is displaced with respect to the alignment mark of the former stage, position data of a plurality of alignment marks of the former stage The position of the virtual alignment mark for each of the printing patterns is set based on the position data of the plurality of alignment marks in the rear and the rear, and the print position of the printing pattern in the rear is determined based on the positional relationship between the virtual alignment marks. It is characterized by adjusting.

  In the present invention relating to a printing machine, in the printing apparatus in which a plurality of printing patterns are overlapped and printed on a medium to be printed, and a plurality of alignment marks are printed simultaneously with the printing of each printing pattern Mark recognition means for recognizing the position of the virtual alignment mark; virtual alignment mark setting means for setting a virtual alignment mark between a plurality of alignment marks for each of the printing patterns recognized by the mark recognition means; Means for determining the displacement between the front and rear virtual alignment marks set by the means, and when the rear alignment mark is displaced relative to the front alignment mark, the position of the rear printing pattern changes To adjust the print position to And a means.

  In the present invention, the position of the alignment mark on the rear stage can be detected, and the positional relationship between the alignment mark on the front stage and the alignment mark on the rear stage can be detected to adjust the printing position, and overprinting can be performed accurately. Then, virtual alignment marks can be set for each print pattern, and the displacement of the print pattern can be determined by the displacement of the positional relationship of the alignment marks, so the process for determination can be simplified.

  In the present invention, it is possible to easily and appropriately adjust the printing position based on the alignment mark.

BRIEF DESCRIPTION OF THE DRAWINGS The simplification figure of the printing machine of embodiment. The top view which shows a screen frame and its related mechanism. BRIEF DESCRIPTION OF THE DRAWINGS The block diagram which shows the electric constitution of the printing machine of embodiment. (A)-(e) is a schematic diagram which simplifies and shows the relationship between a 1st, 2nd alignment mark and a camera. The top view which shows the processing condition of a 1st alignment mark. The top view which shows the processing condition of a 2nd alignment mark. The flowchart which shows the operation program of an embodiment.

(Embodiment)
Hereinafter, an embodiment of the present invention will be described based on the drawings.
As shown in FIG. 1, in the printing machine of the present embodiment, screen printing is performed on a belt-like continuous sheet 100 as a medium to be printed. The continuous sheet 100 is conveyed from the right side to the left side in FIG. 1 in the X-axis direction. Between the left and right frames 11 of the printing machine, a plurality of guide rollers 12 for guiding the continuous sheet 100, a printing cylinder 13 for circumferentially supporting the continuous sheet 100, and an upstream tension application, sequentially from the upstream side in the transport direction. The device 14 and the floating device 31 are arranged. A downstream tensioning device 16 is disposed downstream of the floating device 31 outside the frame 11.

  The guide roller 12 can freely rotate. The printing cylinder 13 is intermittently positively rotated in the X-axis direction which is the conveyance direction of the continuous sheet 100 by the servomotor 21. The printing cylinder 13 has suction holes (not shown) for suctioning the back surface of the continuous sheet 100 by driving a blower (not shown). Above the printing cylinder 13, a screen frame 17 is provided to stretch the screen 19. The screen frame 17 constitutes a printing unit together with the printing cylinder 13. Reference numeral 18 denotes an ink processing unit consisting of a squeegee and a doctor.

  The upstream tension applying device 14 and the downstream tension applying device 16 apply tension to the continuous sheet 100. As shown in FIG. 1 and FIG. 2, the floating device 31 sprays air on the continuous sheet 100 between the upstream side feed roller 32 which can freely rotate and the downstream side feed roller 33 which is positively rotated, and continuously. Raise the sheet 100.

  As shown in FIG. 2, in the screen frame 17, one of the plates 23 and 25 having pattern printing units 22 and 27 for printing a pattern is installed. Then, as shown in FIG. 5 and FIG. 6, on the printing cylinder 13, a first printing pattern (hereinafter referred to as a first pattern) 101 described later by the pattern printing unit 22 of one plate 23 for the continuous sheet 100. Is screen-printed, and a second printing pattern (hereinafter referred to as a second pattern) 111 is screen-printed by the pattern printing unit 27 of the other plate 25.

  Mark printing parts 24 and 26 are provided on both sides of the pattern printing parts 22 and 27 in both printing forms 23 and 25, respectively, and the first alignment marks 102 and the second alignment marks 102 are provided on the left and right of the first pattern 101 and the second pattern 111, respectively. The alignment mark 106 is screen printed simultaneously with the patterns 101 and 111. In FIG. 4, the first alignment mark 102 and the second alignment mark 106 are drawn in an overlapping state, but in reality there is almost no overlapping, and printing is performed separately.

  A support frame 51 is supported by the frame 11, and the screen frame 17 is supported by the support frame 51. The driving of the servomotor 52 moves the support frame 51 in the X-axis direction, which is the transport direction, to adjust the position, and the servomotor 53 moves the screen frame 17 in the Y-axis direction orthogonal to the transport direction. Is adjusted.

Above the floating device 31, a pair of left and right cameras 44 for photographing the printed patterns 101 and 111 and checking whether the printing result is good or bad is provided.
A pair of left and right cameras 45 are disposed in the vicinity of the printing cylinder 13 on the upstream side of the printing cylinder 13 in the rotational direction with respect to the upper end of the printing cylinder 13. The two cameras 45 constitute mark recognition means, and photograph the two alignment marks 102 and 106, respectively.

  The cameras 44 and 45 are connected to the control device 56 shown in FIG. 3 and the motors 21, 52 and 53 are connected. The control device 56 controls the operation of each of the servomotors 21, 52, 53 as a driving means according to a routine described later based on an image pickup signal from the camera 45. In the present embodiment, the control device 56 constitutes mark recognition means, virtual alignment mark setting means, judgment means and control means.

Next, the operation of the printing machine configured as described above will be described.
The continuous sheet 100 is conveyed in the direction of the arrow in FIG. 1, and the first pattern 101 and the first alignment mark 102 shown in FIG. 5 are screen printed on the printing cylinder 13 (see FIG. 4A). The portion of the continuous paper 100 on which the printing of the first pattern 101 and the first alignment mark 102 is finished is sent to the floating device 31. Then, on the floating device 31, the quality of each of the printed first patterns 101 on the continuous sheet 100 is sequentially determined by the camera 44 and conveyed to a dryer (not shown) or the like downstream of the printing press. The drawings of FIGS. 1 to 6 including FIGS. 4 (a) to 4 (e) are simply shown for the sake of explanation, and many of the constitutions such as the positional relationship of each member are actual It is drawn differently from things.

  Thereafter, the continuous sheet 100 on which the first pattern 101 is printed is set again in the printing machine, and the second pattern 111 is superimposed and printed on the first pattern 101, and the predetermined distance from the first alignment mark 102 The second alignment mark 106 is printed at the position where Then, as described above, the second pattern 111 is photographed by the camera 44 in order to determine whether the printing state or the positional relationship with the first pattern 101 is good or bad.

  When printing the second pattern 111, the process shown in the flowchart of FIG. 7 is executed. In this process, program data stored in a storage unit (not shown) in control device 56 is read out, and the program proceeds under the control of a central processing unit (not shown) in control device 56 as well. .

  That is, the continuous sheet 100 which has finished the printing of the first pattern 101 and the first alignment mark 102 is set again in the printing machine and conveyed in the X-axis direction (S1). In addition, the plate 25 in the screen frame 17 is changed to one for printing the second pattern 111 and the second alignment mark 106. Next, as shown in FIG. 4B, when the pair of first alignment marks 102 on both sides of the first pattern 101 in the leading portion of the continuous sheet 100 respectively face the pair of cameras 45, the continuous sheet 100 is conveyed. It is stopped (S2). Then, both first alignment marks 102 are imaged by the camera 45 (S3).

  Here, as shown in FIG. 5, the control device 56 recognizes the positional relationship between the imaging origin 103 set at the center in the imaging area by both cameras 45 and the position data of the first alignment mark 102. That is, the controller 56 recognizes the coordinates of the imaging origin 103 and the coordinates of the first alignment mark 102. Then, when displacement occurs in the X axis direction or the Y axis direction between the imaging origin 103 on the left and right and the first alignment mark 102, the control device 56 determines the displacement amount in the X axis direction and the Y axis direction, That is, the difference between the coordinates of the imaging origin 103 and the coordinates of the first alignment mark 102 is determined (S4).

  Then, the control device 56 averages and calculates each displacement amount in the X-axis direction and Y-axis direction of the first alignment marks 102 on the left and right with respect to the imaging origin 103 on the left and right, that is, the value of the difference in position. Next, the control device 56 sets a virtual alignment mark 104 at an intermediate position between the left and right first alignment marks 102 based on the value of the averaged displacement amount (S5). Then, the control device 56 compares the coordinates of the position of the virtual origin 105 set between the left and right imaging origins 103 with the coordinates of the position in the X axis direction and the Y axis direction between the virtual alignment mark 104. Then, the difference in position between the virtual origin 105 and the virtual alignment mark 104 is calculated (S6).

  Next, the control device 56 determines whether the difference has occurred in at least one of the X-axis direction and the Y-axis direction (S7). When there is a difference in at least one of the X axis direction and the Y axis direction, at least one of the motor 21 and the motor 53 is operated to operate at least one of the printing cylinder 13 and the screen frame 17 (S8). That is, when the difference is generated in the X-axis direction, the rotation amount is adjusted by changing the amount of forward rotation of the printing cylinder 13 by the difference. When the difference occurs in the Y-axis direction, the screen frame 17 is moved in one direction or the other direction in the Y-axis direction. In this manner, when the position of the first alignment mark 102 is displaced from the predetermined position, the printing position on the continuous sheet 100 is adjusted and corrected in the two axial directions of the X axis direction and the Y axis direction.

  Next, while the continuous sheet 100 is conveyed, the second pattern 111 is redundantly printed on the first pattern 101 at the head position at the leading end of the continuous sheet 100, as shown in FIG. 4C. The second alignment marks 106 are simultaneously printed on the left and right ends outside the two patterns 111 (S10).

  Thereafter, the continuous sheet 100 is reversely run (S11), and the second alignment mark 106 outside the second pattern 111 is imaged by the camera 45 (S12) as shown in FIGS. 5 and 4D. Also in this case, processing similar to that at the time of photographing of the first alignment mark 102 is performed.

  That is, the control device 56 determines displacement amounts in the X-axis direction and the Y-axis direction between the position data of the left and right imaging origins 103 and the second alignment marks 106, that is, a difference (S13). Then, the control device 56 averages and calculates displacement amounts in the X axis direction and Y axis direction of the second alignment marks 106 on the left and right with respect to the imaging origin 103 on the left and right, that is, calculates. Next, the control device 56 sets a virtual alignment mark 112 at an intermediate position between the left and right second alignment marks 106 based on the averaged displacement amount (S14). Then, the control device 56 compares the virtual origin 105 set between the left and right imaging origins 103 with the position in the X-axis direction and the Y-axis direction between the virtual alignment mark 112 and the virtual origin 105. The difference in position between the virtual alignment mark 112 and the virtual alignment mark 112 is calculated (S15).

  In this case, when printing the second alignment mark 106, the second alignment mark 106 is a first alignment mark in order to avoid that the second alignment mark 106 overlaps the first alignment mark 102 and the image discrimination becomes difficult. It is printed with a predetermined distance from 102. Therefore, the calculation of the difference in position based on the comparison in S15 is executed, excluding the value of the amount of deviation, in anticipation of the amount of deviation. Further, in order to clarify the difference between the first alignment mark 102 and the second alignment mark 106, their shapes or colors may be distinguished. For example, the first alignment mark 102 may be ring-shaped, the second alignment mark 106 may be blackened, or the first alignment mark 102 may be black and the second alignment mark 106 may be red to avoid confusion and misidentification. Let's do it.

  Then, the control device 56 determines whether the difference is generated in at least one of the X-axis direction and the Y-axis direction (S16). When a difference occurs in at least one of the X axis direction and the Y axis direction, at least one of the motor 52 and the motor 53 is operated to set the screen frame 17 in the X axis direction and the Y axis direction. At least one is moved by an amount corresponding to the difference (S17). That is, in this case, the position of the screen frame 17 is moved to adjust the printing position without adjusting the rotational phase of the printing cylinder 13. In this manner, when the position of the first alignment mark 102 is displaced from the predetermined position, the printing position for the continuous sheet 100 is at least one of the two axial directions of the X-axis direction and the Y-axis direction. It is corrected.

  Thereafter, as shown in FIG. 4E, the continuous sheet 100 is conveyed (S18), and the first pattern 101 and the second pattern 111 are overprinted so as to have a predetermined positional relationship (S19). .

Therefore, the following effects can be obtained in the present embodiment.
(1) The position of the first alignment mark 102 can be detected, and the rotational phase of the printing cylinder 13 and the position of the screen frame 17 can be adjusted based on the detection. Therefore, the first pattern 101 can be continuously printed at an appropriate position without being misaligned with respect to the continuous sheet 100.

  (2) The position of the second alignment mark 106 is detected, and the positional relationship between the first alignment mark 102 and the second alignment mark 106 is detected to change the rotational phase of the printing cylinder 13 without changing the phase. The position of the frame 17 can be adjusted in the X axis direction and the Y axis direction. That is, the second pattern 111 is printed on the first pattern 101 on the continuous sheet 100 without moving the printing cylinder 13 on which the first pattern 101 has already been printed, in other words, without moving the continuous sheet 100. Since the position can be adjusted, overprinting by the second pattern 111 with respect to the first pattern 101 can be accurately performed.

  (3) A pattern to be overprinted by determining the positional relationship between the first alignment mark 102 and the second alignment mark 106 printed at the beginning of the continuous sheet 100 using the camera 45 at a position on the printing cylinder 13 The displacement between 101 and 111 is corrected. Therefore, the useless printing of the patterns 101 and 111 can be prevented. On the other hand, a long transport path is formed between the printing cylinder 13 and the camera 44 on the floating device 31. Therefore, for example, when the camera 44 on the floating device 31 captures the first alignment mark 102 and the second alignment mark 106 so that the print positions of the patterns 101 and 111 can be adjusted, The number of patterns 101 and 111 corresponding to the length is printed. Then, after the patterns 101 and 111 are printed, the positions of the first alignment mark 102 and the second alignment mark 106 are determined. Therefore, when displacement occurs between the patterns 101 and 111, wasted printing of some of the patterns 101 and 111 in a portion corresponding to the length of the transport path occurs.

  (4) One virtual alignment mark 104, 112 is set corresponding to each of the patterns 101, 111, and the displacement of the pattern 111 with respect to the pattern 101 can be judged by the displacement of the positional relationship of the virtual alignment marks 104, 112. The process for can be simplified. On the other hand, when correcting the printing position by judging the displacement of the pattern 111 with respect to the pattern 101 based on the displacement between the alignment marks 102 and 106 on both sides of the patterns 101 and 111, the alignment marks 102, There are multiple correction criteria for 106. Therefore, it can not be avoided that the sequence for the correction becomes complicated.

(Modification example)
The present invention is not limited to the embodiment described above, and can be embodied in the following manner.

The adjustment of the printing positions of the first pattern 101 and the second pattern 111 is performed by adjusting the position of the screen frame 17 only.
In the embodiment, the adjustment of the printing position is performed based on the determination of the positions of the first alignment mark 102 and the second alignment mark 106 corresponding to the patterns 101 and 111 at the beginning of the continuous sheet 100. On the other hand, the print position is adjusted by determining the positions of the first alignment mark 102 and the second alignment mark 106 corresponding to the patterns 101 and 111 following the leading patterns 101 and 111.

The invention is embodied in a printing method and a printing machine for overprinting a pattern in three or more stages. Therefore, the detection of the alignment mark and the subsequent determination are also performed three or more times.
-Using a part of a pattern such as a pattern, a symbol or a character as an alignment mark without printing the alignment mark.

Implement the invention in a printing machine other than a screen printing machine, for example an offset printing machine.
The invention is embodied in a printing method and a printing machine in which a pattern is printed on a sheet as a printing medium.

  In the embodiment, the position data values of the left and right alignment marks 102 and 106 are averaged to set the positions of the virtual alignment marks 104 and 112. On the other hand, instead of averaging, values of position data of the left and right alignment marks 102, 106 are added or subtracted to form virtual alignment marks 104, 112 at the central position between the left and right alignment marks 102, 106. To set.

  Set the alignment marks 102 and 106 for each of the patterns 101 and 111 to 2 or more. For example, two alignment marks 102 and 106 may be provided at the left and right positions of the patterns 101 and 111, respectively.

(Other technical ideas)
The technical idea grasped from the above-mentioned embodiment is as follows.
The printing method according to claim 2, wherein (A) the front and rear alignment marks are printed on both sides of the printing pattern, and the virtual alignment mark is set at a central position between the two alignment marks.

Therefore, if the process regarding the position of the virtual alignment mark of the front | former stage and a back | latter stage is performed, overprinting can be performed appropriately by adjustment of a proper printing position.
The printing method according to claim 1 or 2, wherein (B) the front-stage alignment mark and the rear-stage alignment mark are printed at different positions.

Therefore, overlapping of the front and rear alignment marks can be avoided.
(C) A printing apparatus according to claim 3, wherein the mark recognition means comprises a camera for photographing the alignment mark, and a control means for processing image data photographed by the camera.

  Therefore, the virtual alignment mark can be easily set by photographing the alignment mark.

  DESCRIPTION OF SYMBOLS 13 printing cylinder 17 screen frame 21 motor 23 plate 25 plate 45 camera 52 motor 53 motor 56 control device 101 printing pattern 102 alignment mark 104 ... virtual alignment mark, 106 ... alignment mark, 111 ... printing pattern, 112 ... virtual alignment mark.

Claims (5)

After overprinting a plurality of printing patterns together with the alignment marks on the medium to be printed, the positional relationship between the front alignment mark and the rear alignment mark is determined, and the rear alignment mark is displaced with respect to the front alignment mark. In the printing method for adjusting the printing position of the printing pattern of the latter stage on the medium to be printed,
The position of the virtual alignment mark for each of the printing patterns is set based on the position data of the plurality of alignment marks in the previous stage and the position data of the plurality of alignment marks in the second stage, and the positional relationship between both virtual alignment marks is determined. A printing method to adjust the printing position of the printing pattern of the latter stage.   The virtual alignment marks are set at the positions between the front and rear alignment marks by averaging the values of the front position alignment data and the rear position alignment data respectively. Print method as described. In a printing apparatus in which a plurality of printing patterns are superimposed and printed on a printing medium, and a plurality of alignment marks are printed simultaneously with the printing of each printing pattern,
Mark recognition means for recognizing the position of each alignment mark;
Virtual alignment mark setting means for setting a virtual alignment mark between a plurality of alignment marks for each of the print patterns recognized by the mark recognition means;
A determination unit configured to determine a displacement between preceding and subsequent virtual alignment marks set by the virtual alignment mark setting unit;
A printing machine comprising: control means for adjusting the printing position so that the position of the printing pattern on the rear stage is changed when the alignment mark on the rear stage is displaced with respect to the alignment mark on the front stage. A printing cylinder which can be rotated while supporting the printing medium, and a screen frame for supporting a plate for printing a pattern on a continuous sheet on the printing cylinder;
The printing machine according to claim 3, wherein the control means controls the operation of at least one of the drive means for moving the printing cylinder and the screen frame in adjustment of the printing position in the previous stage. A printing cylinder which can be rotated while supporting the printing medium, and a screen frame for supporting a plate for printing a pattern on a continuous sheet on the printing cylinder;
The printing machine according to claim 3, wherein the control means controls the operation of the driving means for moving the screen frame in a state where the printing cylinder is stopped in the adjustment of the printing position in the latter stage.