JP2022122105A - Printer - Google Patents

Abstract

To provide a printer capable of printing a printing pattern at the normal position of a print sheet.SOLUTION: A printer comprises: imaging means for imaging an object 31 printed by a printing unit so as to include a plurality of register marks 7-10 in association with a conveyance reference of the object 31; prescribed area acquisition means for acquiring a prescribed area 25 including the register marks 7-10 from an image captured by the imaging means; and indexing means for indexing the conveying-direction position of at least the register mark 7 of a reference color among the register marks 7-10 on the basis of the conveying-direction setting position of the area 25 acquired by the prescribed area acquisition means. The conveying-direction position of the area 25 is set on the basis of the conveyance reference when the object 31 is conveyed for printing.SELECTED DRAWING: Figure 4

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing press having a printing unit that prints a printed pattern and registration marks for register measurement having the same color as the printed pattern on a printing object.

In such a printing press, the same number of register marks for register measurement as the number of printing units used are printed on the margins at both ends in the width direction of the printing paper, which is the object to be printed. For example, in Japanese Unexamined Patent Application Publication No. 2002-200001, each register mark is composed of a first group of register marks and a second group of register marks. The first register mark group consists of register marks (four in FIG. 3A) of each color including the reference color (black). The second register mark group consists of the same number of register marks (four in FIG. 3A) as the first register mark group, all of which are of the reference color (black). Further, the second register mark group is shifted in parallel by a predetermined distance in a direction (horizontal direction) orthogonal to the arrangement direction (vertical direction) of the first register mark group. The spacing is set to be the same as the spacing of the first register marks in the same direction (vertical direction) as the arrangement direction (vertical direction) of the mark group.

An image of the printing paper being conveyed is captured by an in-line camera, and the positions of the four color registration marks of the first registration mark group and the four same color (black) registration marks of the second registration mark group from the obtained captured image. respectively. Based on the acquired positions, the distance between the marks of the reference color of the first register mark group and the other three-color registration marks, and the reference color of the reference color of the second register mark group and the other reference colors. Then, the distances between the marks and the register marks are calculated. Further, the inter-mark distances in the horizontal direction between the four register marks of the first register mark group and the four register marks of the second register mark group that are adjacent in the horizontal direction are calculated. Then, by controlling the register adjusting device of the printing unit so that each of the calculated distances between marks in the vertical direction and the horizontal direction becomes a predetermined value, the register of each color image is automatically adjusted. A matching method is proposed.

Japanese Patent No. 6030732

By the way, when the plate of the reference color (black) is attached to the printing cylinder, the attachment position of the plate to the printing cylinder may become inappropriate (shift from the normal position). In this case, the printed pattern of the reference color and the registration mark of the reference color printed on the printing paper deviate from their normal positions with respect to the printing paper. In this state, if the distance between the marks of the other colors is calculated based on the registration mark of the reference color and the registration is adjusted as in Patent Document 1, the position of the printed pattern is deviated from the normal position with respect to the printing paper. printed on Then, for example, when the position of the print pattern with respect to the print paper is set so that the four sides of the print paper are cut to the same size from the edge of the paper, the print pattern is cut from the normal position with respect to the print paper as described above. If there is a misalignment, the cutting dimensions will be different on each side. As a result, the setting of the cutting machine has to be changed for each side, resulting in a problem of reduced workability. Further, in double-sided printing, if the position of the printed pattern on one side of the printing paper is shifted from the normal position, there is also the inconvenience that the front and back sides are out of register.

SUMMARY OF THE INVENTION An object of the present invention is to provide a printing press capable of printing a print pattern at a regular position on an object to be printed.

In order to achieve the above object, a printing machine according to the present invention is a printing machine comprising a printing unit for printing a printed pattern and a register mark for register measurement on a printing object in a color including a reference color, wherein the register mark an imaging means for capturing an image of a print target printed by the printing unit so as to include a reference mark for transporting the print target in association with a transport reference of the print target, and acquiring a predetermined area including the register mark from the image captured by the imaging means. a predetermined area acquiring means, and an indexing means for determining the position in the transport direction of at least one of the register marks of the reference color based on the set position in the transport direction of the predetermined area acquired by the predetermined area acquiring means; , wherein the predetermined area has a position in the transport direction based on the transport reference when the print object is transported in printing.

According to the above configuration, the position of the register mark in the transport direction is calculated based on the position of the predetermined area in which the position in the transport direction is set with reference to the transport reference when transporting the print object in printing. A pattern can be printed at a regular position with respect to the printing object.

Further, in the printing press according to the present invention, the predetermined areas are located at both ends in the width direction of the print object, and the predetermined area at one end and the predetermined area at the other end are located in the conveying direction of the print object. may be at the same position in

As described above, the predetermined areas are located at both ends of the print object in the width direction, and the predetermined area at one end and the predetermined area at the other end are at the same position in the conveying direction of the print object. It can be seen that the print pattern is printed with an inclination with respect to the print target (so-called oblique image).

Further, the printing press according to the present invention includes detecting means for detecting the orientation of the conveyed printing object in the conveying direction and the width direction, and the orientation of the printing object detected by the detecting means is the set orientation. and determining means for determining whether or not the allowable range is exceeded, and the determining means does not perform indexing for the print target determined by the determining means as exceeding the allowable range. may be configured.

According to the above configuration, when the judging means judges that the orientation of the object to be printed exceeds the allowable range for the set orientation, the indexing means does not calculate the position of the register mark. As a result, it is possible to prevent the printed pattern from being printed out of the normal position with respect to the printing object.

Further, in the printing press according to the present invention, the printing unit includes a front side printing unit that prints the front side of the printing object and a back side printing unit that prints the back side of the printing object, and the imaging means includes the Front-side imaging means for imaging the front side of a print object and back-side imaging means for imaging the back side of the printing object, wherein the predetermined area acquisition means acquires the front-side image taken by the front-side imaging means and the back-side imaging means. It may be configured to obtain a predetermined area including the register mark from each of the images of the back surface captured by the means.

According to the above configuration, by acquiring the predetermined area on the front side and the predetermined area on the back side of the print object, the registration of the front side and the back side can be performed, and the relative positions of the front side and the back side can be registered.

According to the present invention, the position of the register mark in the conveying direction is determined based on the position of the predetermined area in which the position in the conveying direction is set with reference to the conveying reference. can be provided.

1 is a side view of a printing press; FIG. 3 is a block diagram showing a control configuration for registration in the printing press; FIG. It is a figure explaining a captured image. It is a figure explaining a predetermined area. 10 is a flow chart for registering; FIG. 6 is a sub-flowchart for performing the in-plane misregistration calculation of FIG. 5; FIG.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A printing press that performs registration according to an embodiment of the present invention will be described below with reference to the drawings.

The printing machine includes a paper stacking table 1, a paper feeding section 3 for feeding printing paper sheets, which are objects to be printed, one by one from the paper stacking table 1 by a feeder device 2, and the printing paper fed from the paper feeding section 3. a pre-printing printing unit (front-side printing unit) 4 for performing four-color printing on a sheet, a reversing device 5 capable of reversing the printing paper (printed matter) printed by the pre-printing printing unit 4, and a reversing device A printing unit for post-printing (back side printing unit) 6 for performing four-color printing on the reverse side of the printing paper reversed in 5 or on the front side of the printing paper without reversing it, and conveying the printing paper after printing. and a paper discharge unit 17 for discharging paper. The case where the printing paper is reversed by the reversing device 5 will be described below. The printing press further includes a first in-line camera (CCD image sensor, RGB camera, etc.) 11 for imaging the surface of the printing paper printed by the printing unit 4 for pre-printing, and a printing unit 6 for post-printing. and a second in-line camera (CCD image sensor, RGB camera, etc.) 16 that captures an image of the back surface of the printing paper. The first in-line camera 11 is front side imaging means, and the second in-line camera 16 is back side imaging means. The front-side imaging means and the back-side imaging means constitute an imaging means. In FIG. 1, the paper stacking table 1 side is the front side, the paper discharge section 17 side is the rear side, and the direction perpendicular to the conveying direction of the printing paper (the direction across the paper surface) is the left-right direction (or width direction). It is explained below.

The paper feeding unit 3 includes a front contact mechanism ( (not shown), and a needle (horizontal needle) mechanism (not shown) that moves the printing paper to one end in the horizontal direction and aligns the positions of the left and right (width direction) edges of the printing paper. The paper feeding unit 3 also includes front contact detection means (detection sensor, not shown) for detecting the position of the leading end (front end) of the printing paper aligned by the front contact mechanism, and a needle (horizontal needle) mechanism. A stylus detection means (detection sensor, not shown) is provided for detecting the positions of the left and right ends of the printing paper aligned by the . Based on the detection results of both detection means, it can be determined whether the postures of the aligned printing paper in the transport direction and the width direction are normal (whether they are within the allowable range). The printing paper aligned in the normal position in the paper feeder 3 is held in the normal position by the transport cylinder, which will be described later, and transported to the printing unit 4 . Further, the printing paper which is detected to be out of the normal position by both of the detecting means is held at a position deviated from the normal position on the conveying cylinder and conveyed to the printing section 4 by the conveying cylinder, which will be described later.

The printing unit 4 for pre-printing prints special colors other than colors (including gold, silver, fluorescent colors, etc.), which are four process colors K (also called black and black), C (cyan), M ( It is equipped with four printing units 4A, 4B, 4C and 4D for printing printed patterns and register marks 7, 8, 9 and 10 for register measurement in magenta (magenta) and Y (yellow). The printing unit 6 for post-printing, like the printing unit 4 for pre-printing, prints in the four process colors K (black, also called black), C (cyan), M (magenta), and Y (yellow). It has four printing units 6A, 6B, 6C, 6D for printing register marks 12, 13, 14, 15 for design and register measurement. In the case of not reversing, in post-printing, a special color other than the four process colors (including gold, silver, fluorescent color, etc.) may be printed in a color different from that of the printing unit 4 for pre-printing. .

Each of the printing units 4A includes a plate cylinder (not shown) around which a plate is wound, a rubber cylinder (not shown, also called a blanket cylinder) to which ink is transferred from the plate cylinder, and a blanket cylinder to support printing paper. An impression cylinder (not shown) for transferring the ink on the blanket cylinder to the printing paper by pressure contact, and a paper feed cylinder (not shown) arranged at the forward end side in the transport direction for transferring the printing paper to the impression cylinder of the printing unit 4A. and a transfer cylinder (not shown) positioned between the impression cylinders for transferring the printed paper from the impression cylinder of the previous printing unit to the impression cylinder of the next printing unit. Feed cylinders, impression cylinders and transfer cylinders are collectively referred to as transport cylinders. The transport cylinder has a pawl and a pawl rest for gripping the front end of the printing paper to hold the printing paper.

Each of the printing units 4A, . . . is provided with a registration device, and as shown in FIG. By doing so, the registration can be adjusted correctly. A possible cause of misregistration is that the plate is not mounted on the plate cylinder in the proper position.

As shown in FIG. 3, a captured image 32 captured by the first inline camera 11 and the second inline camera 16 includes a rectangular printing paper 31 having a front end 31A, a rear end 31B, a left end 31C, and a right end 31D. Obtained in range. As shown in FIG. 4, the register marks 7, 8, 9, and 10 printed on the surface (pre-printed surface) of the printing paper 31 are square, and are spaced apart from each other in the vertical direction. From the direction front), K (black, also called black), C (cyan), M (magenta), and Y (yellow) are printed in order. Of the four color register marks 7, 8, 9, and 10, three register marks 8, 9, and 10 from the second register mark 8 to the fourth register mark 10 from the top side in the vertical direction Three square marks 20, 21 and 22 having the same shape and size and having K (also called black or black) are printed on the left side in the horizontal direction. These three marks 20, 21, and 22 are printed to confirm the vertical orientation of the printed printing paper, and may be omitted.

As shown in FIG. 1, the first in-line camera 11 is used for post-printing in order to capture an image of the printing paper immediately after being printed on the impression cylinder of the fourth printing unit 4D of the printing unit 4 for pre-printing from diagonally above. is attached to a box 23 arranged on the front upper portion of the first printing unit 6A of the printing section 6 of FIG. The second in-line camera 16 is positioned above the front end side of the paper discharge section 17 to capture an image of the printing paper immediately after being printed on the impression cylinder of the fourth printing unit 6D of the printing section 6 for post-printing from obliquely above. It is attached to the upper front side of the arranged box 24 .

FIG. 2 shows a control block diagram for registering in a printing press. The control unit 18 acquires predetermined areas 25, 25 including the register marks 7, 8, 9, 10 from the captured image 32 captured by the first inline camera 11 and the second inline camera 16. indexing means 28 for respectively calculating the positions of a plurality of registration marks 7, 8, 9, 10 from each predetermined area 25 obtained by the predetermined area obtaining means 27; and a judgment means 30 for judging whether or not the orientation of the printing paper detected by the detection means 29 for detecting the orientation of the printing paper exceeds the allowable range for the set orientation. As shown in FIG. 3, the range of the imaged image 32 includes a pair of left and right sides 32A and 32B set on the impression cylinder 35 beyond the printing paper 31, and a pair of front and rear sides set at the start end and the rear end in the conveying direction. It is defined by sides 32C and 32D.

The captured image 32 is obtained in association with the number of pulses of an encoder that detects the rotation of the impression cylinder (or another transport cylinder). Specifically, the conveying direction position of the captured image 32 is stored in the control unit 18 in association with the number of pulses detected by the encoder using the conveying direction center position of the nail plate of the impression cylinder as a conveying reference (origin). . In FIG. 3, H indicates the position corresponding to the transportation reference in the captured image 32 .

The predetermined area obtaining means 27 obtains the predetermined areas 25 and 25 as rectangular areas including the registration mark group and one of the left and right edges (the left edge 31C and the right edge 31D) of the printing paper 31 in the captured image 32 . The positions of the leading side (front side 25C) and the trailing side (rear side 25D) in the feeding direction that define the range of the predetermined areas 25, 25 in the feeding direction are determined by the register mark group as the number of pulses from the feeding reference H. preset to include. In FIG. 3, L indicates the transport direction distance corresponding to the number of pulses from the transport reference H to the front edge 25C. In addition, the positions of the sides (left side 25A, right side 25B) defining the lateral range of the predetermined areas 25, 25 are related to the size information of the printing paper 31, and the register marks and the left and right edges (left edges 31C, 31C, 31C) of the printing paper 31 are It is set in advance so as to include one of the right ends 31D). 4 shows the predetermined area 25 on the right side in FIG. 4 shows a photographed image of the outer peripheral surface of the impression cylinder 35 protruding rightward from the right end (end 31D) of the printing paper 31. As shown in FIG.

The indexing means 28 identifies the reference-color register mark 7 from the acquired images of the predetermined areas 25, 25, specifies the center of gravity 7G of the reference-color register mark 7, and further determines the center of gravity 7G from the front side 25C. A distance L1 in the conveying direction and a distance W1 in the horizontal direction from the left and right edges (left edge 31C or right edge 31D) of the printing paper 31 at the center of gravity 7G are determined (measured). Further, the indexing means 28 specifies the centers of gravity 8G, 9G, 10G of the register marks 8, 9, 10 of other colors, respectively, and the centers of gravity 8G, 9G, 10G of the reference colors relative to the center of gravity 7G of the register marks 7 of the reference colors. Determine (measure) the relative distance. The control unit 18 determines whether the calculated distances (distance L1, distance W1) and each relative distance are within the allowable range. to control the device 19; As a result, the print pattern can be printed at a regular position on the printing paper. Note that the distance L1 may be calculated as a distance from the rear side 25D.

As shown in FIG. 3, the predetermined areas 25 are located at both ends of the printing paper 31 in the width direction. They are arranged at the same position in the paper transport direction. The control unit 18 compares the distance L1 calculated in each of the predetermined areas 25 by the indexing means 28 with the relative distances of the centers of gravity 8G, 9G, and 10G in the conveying direction with respect to the center of gravity 7G, and determines the printed pattern relative to the printing paper 31. The presence or absence of tilt (so-called oblique image) is grasped. If there is an oblique image, the registration device 19 is controlled to eliminate the oblique image. By arranging the predetermined areas 25, 25 at both ends of the printing paper 31 in the width direction in this way, even if there is an oblique image, the printing pattern can be printed at the correct position on the printing paper.

The control unit 18 also controls the orientation of the printing paper 31 detected by the detection means 29 for detecting the orientation of the printing paper conveyed in the paper feeding unit 3 in the conveying direction and the horizontal direction (width direction) to the set orientation. A judgment means 30 is provided for judging whether or not the allowable range is exceeded. The detection means 29 includes the front contact detection means and needle detection means described above. Then, for the printing paper 31 judged by the judging means 30 to exceed the allowable range, the control unit 18 obtains the predetermined area 25 for registering and determines the positions of the register marks (the distances L1, W1 and each relative distance). That is, it is possible to avoid registering using the imaged image 32 of the printing paper 31 printed in a state where it is not held in a proper position on the impression cylinder. Therefore, it is possible to prevent the printed pattern from being printed at a position deviated from the normal position on the printing paper due to registration.

Next, registration in the printing press having the above configuration will be described with reference to the flow chart of FIG.

First, a touch panel GUI (Graphical User Interface, not shown) that enables various operations and settings of the printing press is used to set the position of the print pattern with respect to the printing paper (step S1). That is, the normal position of the print pattern on the printing paper is set. Specifically, for example, the center of the print pattern is aligned with the center of the printing paper 31 in the left-right direction and the transport direction (vertical direction).

Next, using the GUI, the positions of the predetermined areas (predetermined areas 25, 25) acquired by the predetermined area acquisition means 27 are set (step S2).

When the setting is completed, printing is started (step S3), and the printing paper is detected by the detecting means 29 (step S4). Next, in-plane misregistration calculation is performed on the preprinted surface (step S5). Further, if there is back side printing for post-printing, in-plane misregistration is calculated for the back side (step S6).

The in-plane misregistration calculation (steps S5 and S6) will be described with reference to the flowchart shown in FIG. First, the predetermined area 25 is acquired from the captured image 32 of the printing paper 31 by the predetermined area setting means 27 (step S20). Next, the positions of the register marks 7, 8, 9, 10 (the distances L1, W1 and the respective relative distances) are measured from the image of the predetermined area 25 by the indexing means 28 (step S21). The number of sheets of printing paper 31 at this time is counted (step S22). Next, the judgment means 30 judges whether or not the attitude of the printing paper 31 detected by the detection means 29 exceeds the allowable range for the set attitude (step S23). Then, the measurement results of the printing paper 31 that do not exceed the allowable range are used for misregistration calculation (step S24), and the measurement results of the printing paper 31 that exceed the allowable range are used for misregister calculation. It is removed from the object to be done (step S25).

When the number of measurement results included in the calculation target reaches a preset number (step S26), the measurement results are acquired and the measurement data are averaged (step S27). Subsequently, the deviation of the reference color register mark 7 from the printing paper is calculated (step S28). (step S29). In these deviation calculations, the average value calculated in step S27 is used to determine the deviation of the position of the reference color register mark 7 from the center value of the allowable range and the deviation of the reference color of the other color register marks 8, 9 and 10. The deviation from the center value of the allowable range of each relative position with respect to the register mark 7 is calculated.

Next, based on the misregistration calculated in steps 5 and 6, the registration device 19 is driven to achieve registration (step 7). Then, it is confirmed whether the in-plane registration between the front side and the back side (when there is printing on the back side) is within a predetermined allowable range (step S8). If it falls within the predetermined allowable range, the registration is terminated. If it does not fall within the predetermined allowable range, the process returns to before step S4 and registration is performed again. Here, the total number of sheets of printing paper 31 used for registration reaches the preset number of sheets. It is confirmed whether or not (step S9). If not, registration is performed again as described above. On the other hand, if it has arrived, it is possible that registration has not been performed normally, so error processing is performed (step S10), and registration is terminated. Error processing includes notifying the operator with a buzzer or warning light, or stopping the paper supply or printing machine.

It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.

In the above-described embodiment, a printing press having eight printing units was shown, but the printing press may have any number of units of one or more. Also, although a printing machine capable of double-sided printing has been shown, a printing machine capable of only single-sided printing may also be used. In the case of a single-sided printer, after printing one side of the printing paper, the printed side may be turned down and the unprinted top side may be printed again by the single-sided printer.

In the above-described embodiment, relative distances to the reference color registration marks 7 are calculated for the color registration marks 8, 9, and 10 of colors other than the reference color registration marks 7. As with the mark 7, the distance in the transport direction from the front edge 25C (or the rear edge 25D) of the predetermined area 25 is determined, and the distance in the horizontal direction from the left and right edges (left edge 31C or right edge 31D) of the printing paper 31 is determined. It may be used for edge shift calculation.

Further, in the above embodiment, K (also called black or black) is used as the reference color, but a color other than K (also called black or black) can be used as the reference color.

Also, in the above-described embodiment, printing is performed in four colors, but the number of colors is not limited to four. For example, the number of colors may be five. Alternatively, the number of colors may be one. When the number of colors is one, the indexing means 28 calculates the distance L1 and the distance W1 of the register mark of the reference color using that color as the reference color, and the control unit 18 calculates both the calculated distances (distance L1, distance W1) is determined to be within the allowable range, and if it is determined to be out of the allowable range, the registration device 19 is controlled so as to be within the allowable range. As a result, a single-color print pattern can be printed at a regular position on the printing paper.

Further, in the above-described embodiment, when the judgment means 30 judges that the orientation of the printing paper exceeds the allowable range for the set orientation, the indexing means 28 does not perform the indexing. The acquisition of the predetermined area by the predetermined area acquisition unit 27 may not be performed in the first place.

Further, in the above embodiment, the center position of the gripper plate of the impression cylinder in the conveying direction is used as the conveying reference, but the conveying reference is not limited to this position. Any position of the transport cylinder can be set as a transport reference.

Further, in the above-described embodiment, the detection means 29 is the front contact detection means and the staple detection means of the paper feeding section 3, but is not limited to this. For example, the detection means may be configured to detect the posture of the printing paper on the transport cylinder by imaging.

1...Paper stacking table 2...Feeder device 3...Paper feed unit 4...Printing unit 4A, 4B, 4C, 4D... for printing special colors other than colors (including gold, silver, fluorescent colors, etc.) Printing unit 5 Reversing device 6 Printing unit 6A, 6B, 6C, 6D Printing unit 7, 8, 9, 10 Register mark 7G, 8G, 9G, 10G Center of gravity 11 First inline Camera (imaging means) 16 Second in-line camera 17 Paper discharge section 18 Control section 19 Registration device 20, 21, 22 Mark 25 Predetermined area 25A Left side 25B Right side , 25C front side 25D rear side 27 predetermined area acquisition means 28 indexing means 29 detection means 30 judgment means 31 printing paper 31A front end 31B rear end 32 Captured image 32A, 32B Side 32C, 32D Side 33 Mount Fuji 34 Cloud 34 Print pattern 35 Impression cylinder H Conveyance reference L, L1 Distance W1 Distance

Claims (4)

A printing machine having a printing unit that prints a printed pattern and a register mark for register measurement on a printing object in a color including a reference color,
imaging means for capturing an image of a print target printed by the printing unit so as to include the register mark in association with a conveyance reference of the print target;
a predetermined area acquiring means for acquiring a predetermined area including the register mark from the image captured by the imaging means;
indexing means for calculating the position in the transport direction of at least the reference color of the register marks out of the register marks based on the set position in the transport direction of the predetermined area acquired by the predetermined area acquiring means;
A printing machine according to claim 1, wherein the predetermined area is set at a position in a transport direction with reference to the transport reference used when transporting the print object in printing. The predetermined areas are located at both ends in the width direction of the print object, and the predetermined area at one end and the predetermined area at the other end are at the same position in the transport direction of the print object. A printing machine according to claim 1. detection means for detecting the orientation of the conveyed printing object in the conveying direction and the width direction; determining means for determining, wherein the determining means does not perform indexing for the print target determined by the determining means to exceed the allowable range. 3. The printing press according to item 1 or 2. The printing unit includes a front-side printing unit that prints the front surface of the printing object and a back-side printing unit that prints the back surface of the printing object, and the imaging means is a front-side imaging unit that images the front surface of the printing object. means and a rear side imaging means for imaging the rear side of the printing object, wherein the predetermined area acquisition means obtains an image of the front side captured by the front side imaging means and an image of the back side captured by the back side imaging means. 4. The printing press according to any one of claims 1 to 3, wherein the predetermined area including the register mark is obtained from the .

Images