JP2016198991A - Screen printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a screen printer which corrects an inclination of a printing medium, such as a web, relative to a screen frame to prevent displacement of a print position even when the inclination occurs.SOLUTION: A screen printer includes: a printing cylinder 18 configured to apply travel force to a web 101 serving as a printing medium and supporting the web 101 which is subject to screen printing; and a plate frame support device 31 supporting the screen frame. The screen printer is provided with: a camera 21 for detecting an inclined angle of the web 101 relative to the screen frame; and a control device for rotating the screen frame on the basis of a detection result of the camera 21 to correct a position relationship between the screen frame and a print position on the web 101.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a screen printer that performs printing using a screen frame.

  For example, in a screen printing machine in which a belt-like web as a printing medium is run in the extending direction and screen printing is performed on the web at the position of the printing cylinder, the running web has a screen frame on the printing cylinder. The printing position with respect to the web may deviate from the predetermined position with respect to the web. In order to cope with such a case, in Patent Document 1, the position of the screen frame on which the screen is stretched can be adjusted in one direction and the other direction perpendicular to the one direction. That is, in the screen printing machine described in Patent Document 1, the screen frame is abutted on the two adjacent sides by the screen abutting means, and the other two adjacent sides are pressed against the adjuster to adjust the position. The

JP 2009-241464 A

  In the configuration of Patent Document 1, as described above, the screen frame is abutted on the two adjacent sides by the screen abutting means, and the other two adjacent sides are pressed against the adjuster to adjust the position. The screen frame is adjusted in two orthogonal directions. However, the position of the web is not only shifted in the running direction and the direction perpendicular thereto, but may be skewed by meandering or the like. In the case of such skew, the web is inclined with respect to the running direction and also with respect to the screen frame. Therefore, it is difficult to cope with the displacement of the printing position by adjusting the positions in two orthogonal directions.

  The present invention has been made paying attention to such problems existing in the prior art. An object of the present invention is to provide a screen printing apparatus capable of correcting the inclination even when the printing position of a printing medium such as a web is inclined with respect to the screen frame and preventing the deviation of the printing position.

  In order to achieve the above object, in the present invention, the printing cylinder is provided with a printing cylinder that supports the printing medium and a plate frame support device that supports the screen frame, while applying a running force to the printing medium. In a screen printing machine that performs screen printing on the screen, a detecting means for detecting an inclination angle of the printing medium with respect to the screen frame, and the screen frame and the printing medium by rotating the screen frame based on a detection result by the detecting means Correction means for correcting the positional relationship with the upper printing position is provided.

  In the above configuration, when the print medium is inclined with respect to the screen frame by, for example, skewing, the detection unit detects the inclination of the print medium. Then, based on the detection result, the correcting means rotates the screen frame and corrects the angle. For this reason, the angular deviation between the print position of the print medium and the screen frame is eliminated, and the screen frame and the print position of the print medium are matched.

  In the present invention, the inclination angle of the printing medium with respect to the screen frame means that the printing position on the printing medium is inclined with respect to a predetermined position in a plane parallel to the plane in which the screen is arranged in the screen frame. Refers to the angle of the case. The rotation of the screen frame means that the screen frame is rotated in a plane parallel to the plane where the screen is arranged.

  According to the present invention, since the position of the screen frame can be corrected in accordance with the inclination angle of the printing position on a print medium such as a web, there is an effect that printing with high accuracy is possible.

FIG. 3 is a simplified diagram showing a web travel route having a screen printing machine. (A), (b) is a top view which shows the pattern printed on the web, respectively. The perspective view which shows a plate frame support apparatus. The perspective view which shows the plate frame support apparatus of the state which removed the cover. The top view which shows the plate frame support apparatus of the state which removed the cover. The partial top view of a plate frame support apparatus. The block diagram which shows the electrical constitution of a screen printer. The flowchart which shows the program operation | movement of a screen printer. (A) shows an inner frame and a screen frame, a schematic diagram showing a state in which the screen frame is corrected in the X-axis direction, (b) a schematic diagram showing a state in which the screen frame is corrected in the Y-axis direction, (c) FIG. 4 is a schematic diagram showing a state in which the screen frame is rotated and corrected. (A) is a schematic diagram showing the relationship between the center of rotation correction and the center of the screen frame, (b) is a diagram showing the amount of movement of the screen frame after correction rotation of the screen frame.

(Embodiment)
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings.
As shown in FIG. 1, a travel path 12 of a web 101 as a print medium is provided in an apparatus frame 11 of a screen printing machine. The web 101 travels in the direction of the arrow. In order to define the travel path 12, a plurality of (5 in the embodiment) guide rollers 13 to 17 and a printing cylinder 18 are supported on the apparatus frame 11 in order from the upstream side of the travel path 12. The guide rollers 13 to 17 are freely rotated, and the printing cylinder 18 is positively rotated by a motor 19 shown in FIG. 7 to give a running force to the web 101.

  A plate frame support device 31 is disposed above the printing cylinder 18 so as to be moved up and down by an actuator (not shown) and movable along the traveling direction of the web 101 by another actuator (not shown). A screen frame 34 described later is supported by the plate frame support device 31. When the web 101 is wound on the printing cylinder 18 and is driven by the rotation of the printing cylinder 18, a printing pattern is formed on the web 101 by the screen 35 stretched on the screen frame 34. .

  As shown in FIGS. 2A and 2B, in the screen printing machine of the present embodiment, the print pattern 102 is continuously printed on the web 101 at a predetermined interval, and on the print pattern 102. Another print pattern 102 is overprinted. Further, when printing the first print pattern 102, corresponding to each print pattern 102, a small first mark 103 positioned at both width ends of the web 101 and a first mark 103 positioned at one width end of the web 101. A larger second mark 104 is printed.

  On the upstream side of the printing cylinder 18, a pair of left and right cameras 21 are installed as detection means at a position between the printing cylinder 18 and the guide roller 17 on the most downstream side. One mark 103 is detected. An optical sensor 22 is disposed between the guide rollers 15 and 16 on the upstream side of the camera 21, and this optical sensor 22 detects the second mark 104 of the web 101.

  Then, during the second and subsequent printing on the web 101, the first mark 103 is captured by the camera 21, and the position of the first mark 103 is detected. When the position of the first mark 103 is deviated from the reference position, the web 101 is controlled by controlling the amount of rotation of the printing cylinder 18 and the plate frame support device 31 according to the amount of deviation. Correction control of at least one of position adjustment of a screen frame 34 to be described later is executed. By this correction control, the position adjustment of the print pattern 102 to be overlaid in the second and subsequent printing is executed.

  Here, on the upstream side of the camera 21, the second mark 104 is detected by the sensor 22, so that defective overprinting is prevented in advance and the work before the start of printing is simplified. That is, the first mark 103 is formed small in order to detect the position of the web 101 with high accuracy. On the other hand, as shown in FIGS. 2A and 2B, the position of the first print pattern 102 may deviate from the predetermined position, and the interval between the print patterns 102 may differ from the predetermined value. In such a case, since the first mark 103 is small, even if the printing pattern 102 reaches the printing position, the first mark 103 may not be captured by the camera 21 if it is out of the fixed position. However, even in such a case, the large second mark 104 is detected by the optical sensor 22 prior to the detection of the first mark 103 on the upstream side of the camera 21. For this reason, the feed amount of the web 101 can be adjusted by adjusting the rotation amount of the printing cylinder 18 so that the first mark 103 paired with the second mark 104 faces the camera 21.

  Therefore, it is possible to prevent misalignment of overlap printing in normal continuous printing. Further, at the time of starting the second and subsequent printings, or at the time of resuming after the interruption of printing, it is possible to save the operator from aligning the web 101 by inching feed while visually checking the web 101.

If the second mark 104 is not detected by the optical sensor 22, the operation of the screen printing machine is stopped because the printing has been completed or an abnormal situation has occurred.
Next, the configuration of the plate frame support device 31 will be described.

  As shown in FIGS. 3 to 5, an inner frame 33 is installed in an outer frame 32 of a rectangular frame shape of the plate frame support device 31 so as to be movable in all directions within a horizontal plane. The screen frame 34 is placed in a fixed state. A screen 35 is stretched within the screen frame 34 (see FIGS. 9A to 9C).

  4 and 6, a support base 38 is supported on one side 321 of the outer frame 32 through a rail 36 and a guided body 37 on the guide rail 36 so as to be movable in the X-axis direction. . A first X-axis motor 39 that can rotate forward and backward is supported on the one side 321, and a bracket 40 is fixed to the support base 38. A screw shaft 41 connected to the motor shaft of the first X-axis motor 39 is screwed into a female screw member 42 fixed to the bracket 40. Then, the support base 38 is reciprocated in the X-axis direction by the action of the screw by the rotation of the first X-axis motor 39.

  As shown in FIGS. 4 to 6, on both sides of the first X-axis motor 39, first and second Y-axis motors 43 and 44 that can be rotated forward and backward are mounted on the support base 38. The bracket 45 is fixed to the inner frame 33 at positions corresponding to 43 and 44. A female screw member 47 is rotatably supported on the lower surface of the bracket 45 via a shaft 46, and the female screw member 47 is provided on the guide surface 48 of the support base 38 so as to be movable in a horizontal plane. The female screw member 47 is screwed with a screw shaft 49 connected to the motor shafts of the two Y-axis motors 43 and 44 (see the simplified diagram on the left side of FIG. 5). Then, the bracket 45 is reciprocated in the Y-axis direction by the action of screws by the rotation of the Y-axis motors 43 and 44, and the inner frame 33 is moved in the same direction. The inner frame 33 is moved in the X-axis direction by the first X-axis motor 39 via the first and second Y-axis motors 43 and 44, the bracket 45, and the like. A pressing member 50 made of an air cylinder is attached to the tip of the bracket 45 to press the frame portion 341 of the screen frame 34 on the inner frame 33 and fix the screen frame 34 in the inner frame 33.

  Therefore, the moving force in the Y-axis direction by the Y-axis motors 43 and 44 is applied to the inner frame 33 and the screen frame 34 via the female screw member 47, the bracket 45, and the pressing member 50. Further, the moving force in the X-axis direction by the first X-axis motor 39 causes the inner frame 33 and the screen frame to pass through the female screw member 42, the bracket 40, the support base 38, the Y-axis motors 43 and 44, the bracket 45, the pressing member 50, and the like. 34.

  As shown in FIGS. 4 and 5, on the inner side of the side 322 facing the one side 321 of the outer frame 32, a support bar 61 is installed between both sides 323 of the outer frame 32. Is mounted with a second X-axis motor 62 that can rotate forward and backward. A screw shaft 63 extending in the X-axis direction and connected to the motor shaft of the second X-axis motor 62 is screwed into a female screw member 65 on the guide surface 64 on the support bar 61. A guide rail 66 extending in the Y-axis direction is fixed to the upper surface of the female screw member 65. A guided member 67 is engaged on the guide rail 66. A bracket 68 is fixed to the inner frame 33, and the guided member 67 is rotatably connected to the bracket 68 by a shaft 69 (see the simplified diagram at the lower right in FIG. 5). The female screw member 65 and the guided member 67 are moved in the X-axis direction by the action of the screw by the rotation of the second X-axis motor 62, and a moving force in the X-axis direction is applied to the inner frame 33.

In the present embodiment, the first motor is constituted by the first and second Y-axis motors 43 and 44, and the second motor is constituted by the first and second X-axis motors 39 and 62.
On both sides of the second X-axis motor 62, guide rails 71 extending in the X-axis direction are fixed to the upper surface of the support bar 61. A guided member 72 is movably provided on the guide rail 71, and a guide rail 73 extending in the Y-axis direction is fixed on the guided member 72. A pair of brackets 74 are fixed to the inner frame 33, and a guided member 76 is rotatably supported by the brackets 74 via a shaft 75. The guided member 76 is engaged with the guide rail 73 (see the simplified diagram in FIG. 5). Then, the moving force in the X-axis direction by the second X-axis motor 62 is applied to the inner frame 33 via the female screw member 65, the bracket 68, and the like. The guide rail 71, the guided member 72, the bracket 74 and the like constitute a load receiving means. The load receiving means allows the inner frame 33 to move and rotate in the X and Y axis directions by the action of the guide rail 71 extending in the X axis direction, the guide rail 73 extending in the Y axis direction, and the shaft 75. The load of the inner frame 33 is supported.

  Another bracket 77 is fixed to the inner frame 33 in the vicinity of the bracket 74, and the frame portion 341 of the screen frame 34 in the inner frame 33 is pressed to the tip of the bracket 77, so that the screen frame 34 is attached to the inner frame 33. A pressing member 78 for fixing to 33 is provided.

  Then, when both X-axis motors 39 and 62 are simultaneously rotated in the same direction, the inner frame 33 is moved in the X-axis direction as shown in FIG. As both Y-axis motors 43 and 44 are simultaneously rotated in the same direction, the inner frame 33 is moved in the Y-axis direction as shown in FIG. 9B. Further, as both Y-axis motors 43 and 44 are moved in opposite directions and the second X-axis motor 62 is rotated in either the forward or reverse direction, as shown in FIG. Is rotated in a horizontal plane. When the inner frame 33 is rotated in the horizontal plane, the members connected to the shafts 46, 69, and 75 in the brackets 45, 68, and 74 are rotated, and the guide surface 48 and the guide rails 66 and 71 are rotated. , 73 are slid and the inner frame 33 is allowed to rotate.

As shown in FIG. 3, covers 90 and 91 are attached to the sides 321 and 322 of the outer frame 32 in a detachable manner to prevent dust from adhering to the guide rails and shaft portions.
As shown in FIG. 7, the screen printing machine of this embodiment includes a control device 81 as detection means and correction means. Video data from the camera 21 is input to the control device 81 via an image processing device 82. In addition, a detection signal from the optical sensor 22 is input. The motors 19, 39, 43, 44, 62 are servo motors, and the controller 81 controls the operations of the motors 19, 39, 43, 44, 62 via the servo amplifiers 83-87.

Next, the operation of the screen printing machine of the embodiment configured as described above will be described. FIG. 8 shows a routine of a program executed under the control of the control device 81.
In the routine of FIG. 8, when the screen printing machine is operated, in step S (hereinafter simply referred to as S) 1, the plate frame support device 31 is moved from the print end position to the print start position. In S <b> 2, the camera 21 reads the first mark 103 on the web 101 arranged at a predetermined print start position, and determines the position of the first mark 103, that is, the position and orientation of the print pattern 102. In S3, a difference between the reference position of the first mark 103 determined in advance and stored in the control device 81 and the actual position of the first mark 103 detected in S2 are confirmed. In this case, the difference between the reference position and the position of the print pattern 102 is confirmed not only in the traveling direction and the width direction of the web 101 but also in the inclination direction that is the combined direction thereof.

  In the confirmation of the deviation amount in S3, if there is a deviation in the position of the print pattern 102, a correction value is set in S4 so that the deviation is eliminated according to the difference between the reference position of the first mark 103 and the actual position. Is done. That is, when the deviation occurs in the feeding direction of the web 101, the correction value of the feeding amount of the printing cylinder 18 is set by calculation in S4. When the deviation occurs in the width direction of the web 101, a correction value in the X-axis direction of the screen frame 34 is set by calculation in S5 described later. When the deviation occurs in the inclination direction of the web 101, a correction value in the rotation direction of the screen frame 34 is set in S7 and S8 described later.

  As described above, in the shift amount confirmation in S3, if there is a shift in the width direction of the web 101 between the print pattern 102 and the screen frame 34, in S5, as shown in FIG. In the width direction (X-axis direction) of the web 101, a correction movement amount of the screen frame 34, that is, a correction rotation amount of both X-axis motors 39 and 62 is set. Then, in S6, both X-axis motors 39 and 62 are simultaneously rotated in the same direction by the correction rotation amount, and correction for eliminating the difference between the screen frame 34 and the position of the print pattern 102 in the width direction of the web 101 is executed. Is done.

  S7 to S11 are routines for rotating the screen frame 34 in a horizontal plane with respect to the inclination of the print pattern 102. That is, when the web 101 is skewed and the print pattern 102 is inclined, the corrected rotation amounts of the first and second Y-axis motors 43 and 44 are set by calculation in S7. In S8, the correction rotation amount of the second X-axis motor is set by calculation. Here, since the rotation correction of the screen frame 34 is executed by the simultaneous reverse rotation of the first and second Y-axis motors 43 and 44 and the rotation of the second X-axis motor 62, the rotation amount of the first X-axis motor 39 is corrected. Is not set. In S9, the Y-axis motors 43 and 44 are simultaneously rotated in either the forward or reverse direction simultaneously, and the second X-axis motor 62 is rotated in either the forward or reverse direction, whereby FIG. As shown, the screen frame 34 is rotated to the left or right in the horizontal plane, and correction is performed.

  As described above, the correction operation of the screen frame 34 is executed by the rotation of both the Y-axis motors 43 and 44 and the second X-axis motor 62, and as shown in FIGS. 10 (a) and 10 (b). The screen frame 34 is rotated around the center α1 existing between the Y-axis motors 43 and 44 on the X-axis motor 39 side. Therefore, since the center α2 of the screen frame 34 and the rotation center α1 are separated from each other, in the next S10, the screen frame 34 is in a corrected rotation state centered on the center α2. Correction movement amounts β and γ in the X-axis direction and the Y-axis direction are set. In S11, both X-axis motors 39 and 62 are rotated in the same direction by the corrected movement amounts β and γ, and both Y-axis motors 43 and 44 are rotated in the same direction. In this way, the position of the screen frame 34 is corrected so that the screen frame 34 is not inclined with respect to the print pattern 102.

  In S12, the printing cylinder 18 is rotated so that the rotation amount reflects the correction amount in S4, so that the deviation between the print pattern 102 and the screen frame 34 in the Y-axis direction is eliminated. As described above, the shift in the tilt direction, which is a combination of the X-axis direction, the Y-axis direction, and the two axis directions, between the print pattern 102 and the screen frame 34 is eliminated. In this state, the web 101 travels, and the plate frame support device 31 is reciprocated to perform screen printing. Therefore, a required pattern is printed on the web 101 without any deviation. .

If there is no deviation between the screen frame 34 and the print pattern 102, the operation process is skipped in order to eliminate the deviation.
This embodiment can obtain the following effects.

  (1) The camera 21 for detecting the inclination angle of the web 101 with respect to the screen frame 34, and the screen frame 34 relative to the position of the print pattern 102 of the web 101 by rotating the screen frame 34 based on the detection result by the camera 21. And a control device 81 for correcting the angle. For this reason, when the print pattern 102 is tilted with respect to the screen frame 34, the tilt is captured by the camera 21, and the tilt angle and the tilt amount are determined by the control device 81. Then, the control device 81 adjusts the angle of the screen frame 34 by the first, second Y-axis motors 43 and 44 and the second X-axis motor 62 to correct the inclination with respect to the web 101. For this reason, overprinting can be performed with high accuracy without shifting.

  (2) In the correction in the inclination direction of the screen frame 34, the correction is performed so that the screen frame 34 is rotated around the center thereof, so that the correction in the inclination direction can be appropriately performed.

  (3) The screen frame 34 is rotated by rotating the first and second Y-axis motors 43 and 44 in opposite directions and rotating the second X-axis motor 62 forward or backward. Therefore, the angle of the screen frame 34 can be adjusted stably with high accuracy.

  (4) The motor is composed of a pair of X-axis motors 39 and 62 that move the screen frame in the X-axis direction and a pair of Y-axis motors 43 and 44 that move the screen frame in the other direction. The position can be adjusted with high accuracy and stability in the X-axis direction and the Y-axis direction.

(5) Since the load receiving means including the guide rails 71 and the like are provided on both sides of the second X-axis motor 62, the angle of the screen frame 34 can be adjusted stably.
(Example of change)
The present invention is not limited to the embodiment described above, and may be embodied in the following manner.

In the above-described embodiment, the belt-like web 101 is used as the print medium, but a single-sheet print medium is used.
The position correction of the screen frame 34 in the traveling direction (Y-axis direction) of the web 101 is performed by moving the screen frame 34 to the screen frame 34.

  The rotation of the screen frame 34 for correcting the positional relationship between the screen frame 34 and the printing position on the web 101 is performed by rotating one of the first or second Y-axis motors 43 and 44 forward or backward. about.

(Other technical ideas)
The technical idea grasped from the embodiment is as follows.
(A) During printing on a print medium, a first mark and a second mark larger than the first mark are printed on the print medium outside the print pattern in correspondence with the print pattern, and the print pattern is overlaid. In printing, the first mark is detected to recognize the position of the print pattern, and the second mark is detected upstream of the detection position of the first mark in the feeding direction of the print medium to align the print medium. Screen printing method to do.

  (B) First detection means for detecting the first mark on the print medium, and second detection means for detecting the second mark on the print medium upstream of the first detection means in the feeding direction of the print medium. And a recognition means for recognizing the position of the print pattern on the print medium according to the detection result of the first mark detection means, and a correction for correcting the print position on the print medium according to the recognition result of the recognition means. And a screen printing machine.

  DESCRIPTION OF SYMBOLS 18 ... Printing cylinder, 21 ... Camera, 31 ... Plate frame support apparatus, 34 ... Screen frame, 35 ... Screen, 39 ... 1st X-axis motor, 43 ... 1st Y-axis motor, 44 ... 2nd Y-axis motor, 62 ... 2X Axis motor, 80 ... control device, 321 ... side, 322 ... side.

Claims (6)

In a screen printing machine that applies a running force to a print medium, includes a printing cylinder that supports the print medium, and a plate frame support device that supports a screen frame, and performs screen printing on the printing cylinder.
Detecting means for detecting an inclination angle of the print medium with respect to the screen frame;
A screen printing machine provided with correction means for correcting the positional relationship between the screen frame and the printing position on the print medium by rotating the screen frame based on the detection result by the detection means.   2. The screen printing machine according to claim 1, wherein the correction unit includes two types of motors capable of rotating in the forward and reverse directions with different shaft directions, and rotates the screen frame for correction by a combination of rotation directions of the motors.   The motor comprises a pair of first motors capable of rotating in the forward and reverse directions that move the screen frame in one direction, and a pair of second motors capable of rotating in the forward and reverse directions that move in other directions that intersect the one direction. Item 3. A screen printing machine according to Item 2.   4. The pair of first motors is provided on one side of the screen frame, one second motor is provided on the one side, and another second motor is provided on the other side facing the one side. The screen printing machine described in 1.   The correction means rotates the screen frame by rotating the pair of first motors in opposite directions and rotating the second motor on the other side in either forward or reverse direction, The screen printing machine according to claim 4, wherein both the first motor and the second motor are rotated in the same direction so that the screen frame rotates about its own center.   6. The screen printing machine according to claim 4, wherein load receiving means for receiving the load of the screen frame and allowing the rotation of the screen frame is provided at both side positions of the other second motor.