Printer, correction program for printer, and method for deriving image correction value for printer

Abstract

Provided are a printer capable of accurately performing an inspection, a correction program for the printer, and a method for deriving an image correction value for the printer.　The printer comprises: a printer main body 2 for printing on a sheet of paper while feeding the sheet of paper in the feed direction; a line camera 3 for generating a plurality of pitch images by imaging, at regular time intervals, the sheet of paper being fed in the feed direction by the printer main body 2; a captured image generating means 4 for generating, on the basis of the plurality of pitch images generated by the line camera 3, a captured image in which at least a portion of the sheet of paper appears; and a corrected image output means 5 for correcting, on the basis of a correction value, the length of the captured image or the plurality of pitch images in the top-bottom direction, which is a direction corresponding to the feed direction, and outputting the image as a corrected image.

Description

Printing machine, correction program for printing machine, and method for deriving correction values ​​for images for printing machine

[0001] The present invention relates to a printing press, a correction program for a printing press, and a method for deriving correction values ​​for an image for a printing press.

[0002] Conventionally, there has been known an image input device used in conjunction with a printing press, such as that disclosed in Patent Document 1, which is configured to capture image data of a print pattern from a printed matter printed by the printing press and running.

[0003] The image input device is equipped with a line sensor that repeatedly scans to capture line image data at a constant cycle, and is configured to be able to generate two-dimensional image data by arranging multiple line image data obtained by this line sensor.

[0004] Patent No. 3811565

[0005] However, in the above-mentioned conventional image input device, the length of the two-dimensional image data in the direction corresponding to the running direction of the printed matter contains errors due to various factors, so when the measurement results of this two-dimensional image data are used for inspection, there is a problem in that the accuracy of the inspection is reduced.

[0006] In view of the above, an object of the present invention is to provide a printing machine capable of performing inspection with high accuracy, a correction program for the printing machine, and a method for deriving correction values ​​for an image for the printing machine.

[0007] The printing press of the present invention comprises a printing press main body that prints on a paper sheet while feeding the paper sheet along a feed direction; a line camera that generates a plurality of pitch images by capturing images of the paper sheet being fed along the feed direction by the printing press main body at regular time intervals; an image generation means that generates an image that captures at least a portion of the paper sheet based on the plurality of pitch images generated by the line camera; and a correction image output means that corrects the length of the captured image or the plurality of pitch images in the vertical direction, which is the direction corresponding to the feed direction, based on a correction value and outputs the corrected image.

[0008] According to the printing press having the above configuration, it is possible to obtain a corrected image that matches the actual length of the sheet by correcting the captured image, thereby enabling inspection to be performed with high precision.

[0009] The printing press of the present invention may be configured such that the correction value is set in accordance with the sheet feed speed of the printing press body.

[0010] According to the printing press having the above configuration, the captured image can be corrected with a correction value corresponding to the set sheet feed speed, thereby improving the accuracy of the inspection.

[0011] The image correction program for a printing press of the present invention is applied to a printing press that includes a computer comprising: a printing press main body that prints on a paper sheet while feeding the paper sheet along a feed direction; a line camera that generates a plurality of pitch images by capturing images of the paper sheet being fed along the feed direction by the printing press main body at regular time intervals; and an image generation means that generates an image in which at least a portion of the paper sheet is visible based on the plurality of pitch images generated by the line camera, and causes the computer to function as a correction image output means that corrects the length of the captured image or the plurality of pitch images in the vertical direction, which is the direction corresponding to the feed direction, based on a correction value and outputs the corrected image.

[0012] According to the correction program for a printing press having the above configuration, a corrected image that matches the actual size of the sheet can be obtained by correcting the captured image, thereby enabling inspection to be performed with high accuracy.

[0013] The method for deriving a correction value for an image for a printing press of the present invention includes a printing press main body that prints on a sheet while feeding the sheet in a feed direction, a reference-marked sheet composed of a sheet including a first reference and a second reference that are spaced apart in a top-to-bottom direction, which is a direction corresponding to the feed direction, a line camera that generates a plurality of pitch images by capturing images of the reference-marked sheet at regular time intervals while the reference-marked sheet is being fed along the feed direction within the printing press main body, and an image generation means that generates an image that shows an area of ​​the reference-marked sheet that includes at least the first reference and the second reference based on the plurality of pitch images generated by the line camera, and derives a correction value for the top-to-bottom length of the captured image based on the normal length between the first reference and the second reference that are spaced apart in the top-to-bottom direction of the reference-marked sheet and the number of pixels between the first reference and the second reference in the captured image generated by the image generation means.

[0014] According to the method for deriving correction values ​​for images for a printing press having the above configuration, it is possible to obtain correction values ​​for correcting the captured image to match the actual size of the sheet of paper (reference sheet), thereby enabling inspection to be performed with high accuracy.

[0015] As described above, the printing press, the correction program for the printing press, and the method for deriving correction values ​​for an image for the printing press of the present invention can achieve the excellent effect of enabling inspection to be performed with high precision.

[0016] FIG. 1 is a block diagram showing the configuration of a printing press according to one embodiment of the present invention. FIGS. 2A, 2B, and 2C are explanatory diagrams illustrating the operation of a line camera in the printing press according to the same embodiment. FIGS. 3A and 3B are explanatory diagrams illustrating the operation of a captured image generating means in the printing press according to the same embodiment, illustrating a case where a pitch image can be acquired. FIGS. 4A and 4B are explanatory diagrams illustrating the operation of a captured image generating means in the printing press according to the same embodiment, illustrating a case where a pitch image cannot be acquired. FIG. 5 is a schematic diagram of a printing press according to this embodiment. FIG. 6 is an explanatory diagram of the process flow for creating a corrected image in a printing press according to the same embodiment. FIG. 7 is an explanatory diagram of a printing press according to another embodiment of the present invention, illustrating the process flow for creating a corrected image. FIG. 8 is an explanatory diagram of a printing press according to yet another embodiment of the present invention, illustrating the process flow for creating a corrected image.

[0017] Hereinafter, a printing press according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0018] As shown in Figure 1, the printing press 1 of this embodiment comprises a printing press main body 2, a line camera 3 that generates multiple pitch images by capturing images of sheets (reference sheets described later) being fed in the feed direction by the printing press main body 2 at regular time intervals, an image capture generation means 4 that generates an image of the sheets (reference sheets described later) being fed by the printing press main body 2 based on the multiple pitch images generated by the line camera 3, a correction image output means 5 that corrects the length of the captured image in the direction corresponding to the feed direction based on a correction value and outputs the corrected image, and a memory means 6 that stores information.

[0019] As shown in Figure 5, the printing press main body 2 has a paper feed section 20 that picks up and feeds out sheets one by one from the pile, a printing section 21 that prints on the printing surface of the sheet while transporting the sheet from the paper feed section 20 in the feed direction, and a paper discharge section 22 that discharges the printed sheet.

[0020] The printing surface of the paper sheet may be single-sided or double-sided.

[0021] The printing section 21 of this embodiment has a plurality of printing units 210 .

[0022] The printing unit 210 includes a group of ink rollers 2100 that delivers ink supplied from an ink fountain key, a plate cylinder 2101 to which ink is supplied by the group of ink rollers, a rubber cylinder 2102 to which ink is transferred from the plate cylinder, an impression cylinder 2103 for transferring the ink from the rubber cylinder 2102 to sheets of paper, and a transfer cylinder 2104 for handing over sheets of paper to the impression cylinder 2103.

[0023] 5, a gripper for gripping a sheet is attached to the impression cylinder 2103, and the impression cylinder 2103 is configured to feed the sheet by rotating while the sheet is gripped by the gripper. Therefore, the feed direction in this embodiment refers to the direction in which the impression cylinder 2103 feeds the sheet gripped by the gripper.

[0024] As shown in Figure 6, the reference-marked sheet P1 is composed of a first reference Ma1 and a second reference Ma2 that are aligned in a direction that matches the feed direction (hereinafter referred to as the top-bottom direction) when the sheet is being fed within the printing unit 21.

[0025] The reference-marked sheet P1 has a leading end P10 (grip end) that is arranged toward the front side in the feeding direction, and a trailing end P11 (tail end) that is arranged toward the rear side in the feeding direction.

[0026] The references shown in Figure 6 are such that the first reference Ma1 is constituted by the leading end P10 of the sheet P, and the second reference Ma2 is constituted by a mark printed at a position shifted from the leading end P10 of the reference-marked sheet P1 toward the trailing end P11.

[0027] The first reference Ma1 and the second reference Ma2 may be set on the sheet P before the image is captured by the line camera 3 (i.e., the sheet P may be a reference-attached sheet P1 before the image is captured by the line camera 3).

[0028] Therefore, the first reference Ma1 and the second reference Ma2 may be set for the sheet P before it is used in the printing press 1, or may be set for the sheet P by printing by the printing unit 21.

[0029] When using a reference-marked sheet P1 to check the position of the print in the vertical direction relative to the sheet P, the worker measures the length from the first reference Ma1 to the second reference Ma2 and checks whether this measured length (hereinafter referred to as the measured length D1) matches the length considered to be correct (hereinafter referred to as the normal length).

[0030] If the measured length D1 matches the normal length, the printing unit 21 can be used to determine that the position of the printing in the vertical direction relative to the sheet P is correct, and if the measured length D1 does not match the normal length, the printing unit 21 can be used to determine that the position of the printing in the vertical direction relative to the sheet P is shifted from the correct position.

[0031] The line camera 3 is attached to the printing press main body 2. The line camera 3 is also disposed at a position where it can capture an image of the reference-marked sheet P1.

[0032] The line camera 3 of this embodiment is arranged facing the impression cylinder 2103. The line camera 3 of this embodiment is also arranged facing the impression cylinder 2103 (the so-called final impression cylinder) of the printing unit 210 that is most downstream in the feed direction (see FIG. 5).

[0033] The image of the reference-marked sheet P1 can be captured by the line camera 3 even when the printing unit 21 is not printing. Specifically, the image of the reference-marked sheet P1 can be captured by the line camera 3 by directly attaching the reference-marked sheet P1 to the impression cylinder 2103 at which the line camera 3 is pointed and capturing an image while the printing unit 21 is driven.

[0034] The pitch image Ip generated by the line camera 3 is an image with one pixel in the vertical direction and multiple pixels in the width direction perpendicular to the vertical direction. The length of each pixel in the pitch image Ip in the vertical direction is set to 0.26 mm.

[0035] The line camera 3 is configured to be able to image only a portion of the reference-attached sheet P1 in the top-bottom direction, but to be able to image the entire area of ​​the reference-attached sheet P1 in the width direction.

[0036] The line camera 3 is configured so that after capturing an image, it can capture the next image before the reference-marked sheet P1 moves a distance corresponding to the length of the pitch image Ip in the vertical direction. In other words, the line camera 3 is configured so that it can repeatedly capture images while shifting the imaging range for the reference-marked sheet P1 at intervals that are smaller than the length of the pitch image Ip in the vertical direction.

[0037] Therefore, among the plurality of pitch images Ip, pitch images Ip adjacent in chronological order partially overlap in the area of ​​the reference-marked sheet P1 shown.

[0038] For example, as shown in Figures 2(a) and 2(b), the area of ​​the reference-marked sheet P1 captured in the imaging area R1 where the line camera 3 first captured the reference-marked sheet P1 and the area of ​​the reference-marked sheet P1 captured in the imaging area R2 where the line camera 3 captured the reference-marked sheet P1 the second time partially overlap in the vertical direction, and as shown in Figures 2(b) and 2(c), the area of ​​the reference-marked sheet P1 captured in the imaging area R2 where the line camera 3 captured the reference-marked sheet P1 the second time and the area of ​​the reference-marked sheet P1 captured in the imaging area R3 where the line camera 3 captured the reference-marked sheet P1 the third time partially overlap in the vertical direction.

[0039] The line camera 3 is configured to repeatedly capture images of a region of one reference-marked sheet P1 that includes at least the first reference Ma1 and the second reference Ma2. In this embodiment, the following description will be given by taking an example of repeatedly capturing images of the entire length of the reference-marked sheet P1 in the vertical direction.

[0040] As shown in Figure 6, the image generation means 4 is configured to generate an image In showing the reference sheet P1 by arranging and combining multiple pitch images Ip generated by the line camera 3 in a vertical direction.

[0041] More specifically, the captured image generating means 4 is configured to perform a selection process for selecting a plurality of pitch images Ip generated by the line camera 3 to be used to generate the captured image In, and a combination process for generating the captured image In by arranging the plurality of pitch images Ip selected in the selection process in a vertical direction and combining them.

[0042] In the selection process, the image generation means 4 selects a pitch image Ip whose center in the vertical direction overlaps with the position indicated by the selection criterion for each of a plurality of selection criteria indicating the vertical position of the reference-marked sheet P1, the selection criterion being set at predetermined intervals in the vertical direction.

[0043] For example, as shown in Figures 3(a) and 3(b), if the position indicated by the selection criterion CP overlaps with the center of the pitch image Ip, the pitch image Ip is acquired as data to be used to generate the captured image.

[0044] On the other hand, if the position indicated by the selection criterion CP does not overlap with the pitch image Ip, as shown in Figure 4(a), or if the position indicated by the selection criterion CP overlaps with an area outside the center of the pitch image Ip, as shown in Figure 4(b), the pitch image Ip is not acquired.

[0045] As shown in FIG. 6, in the combining process, the captured image generating means 4 generates a captured image In by arranging and combining the plurality of pitch images Ip selected in the selection process in the vertical direction.

[0046] The size of the captured image In in the vertical direction (captured image size) is derived from the sum of the numbers of pixels in the vertical direction of the plurality of pitch images Ip.

[0047] The captured image size expressed in number of pixels can be converted to a length expressed in meters (captured image length) using the following formula (1) based on the number of pixels in the vertical direction of the captured image In (the number of pixels indicated by the captured image size) and the length in the vertical direction of each pixel that makes up the captured image In (captured pixel length).

[0048] In the following formula (1), Ln is the captured image length, Np is the number of pixels in the vertical direction of the captured image In, and Sn is the captured pixel length.

[0049]

[0050] The captured image length derived by the above formula (1) represents the vertical length (captured range length) of the range of the reference-marked sheet P1 that is to be captured, but as shown in table (1) below, if the number of pitch images Ip used to generate the captured image In changes, the number of pixels in the vertical direction of the captured image In (i.e., the captured image size) also changes.

[0051]

[0052] For example, if the imaging range length is 26 mm and the number of pixels in the corrected image Ic is 100 when the line camera 3 successfully captures the imaging range, but if the number of pixels in the corrected image Ic is 99, the imaging length will be a value different from the imaging range length.

[0053] Furthermore, if the value of the captured image length is different from the value of the captured range length, the length from the first reference Mb1 to the second reference Mb2 (captured measurement length D2) derived (converted) based on the captured image In may not match the actual measured length D1.

[0054] In this case, the length from the first reference Ma1 to the second reference Ma2 of the reference-marked sheet P1 cannot be accurately derived based on the captured image In, and it becomes impossible to correctly perform an inspection to confirm the correctness of the printing position in the vertical direction relative to the sheet P.

[0055] The corrected image Ic generated by the corrected image output means 5 is an image corrected so that the captured image length of the captured image In matches the imaging range length in accordance with the number of pixels in the vertical direction of the captured image In.

[0056] As shown in FIG. 1, the corrected image output means 5 includes a correction value derivation means 50 that performs processing to derive a correction value, a corrected pixel length derivation means 51 that performs processing to derive a corrected pixel length obtained by correcting the captured pixel length with the correction value, and a generation processing means 52 that generates a corrected image by performing processing to expand or shrink each pixel in the captured image to match the corrected pixel length.

[0057] The correction value derivation means 50 is configured to derive a correction value using the following formula (2) based on the imaging range length, the imaging pixel length, and the number of pixels in the vertical direction of the captured image (captured image size).

[0058] In the following equation (2), C is a correction value, Ls is the imaging range length, Sn is the imaging pixel length, and Np is the number of pixels in the vertical direction of the captured image.

[0059]

[0060] The correction pixel length deriving means 51 is configured to derive the correction pixel length based on the imaging pixel length and the correction value using the following formula (3): In the following formula (3), Sc is the correction pixel length, Sn is the imaging pixel length, and C is the correction value.

[0061]

[0062] The vertical size of the corrected image generated by the generation processing means 52 (corrected image size) can be converted into a length expressed in metric units (corrected image length) using the following formula (4) based on the number of pixels in the vertical direction of the corrected image and the normal pixel length: In formula (4), Lc is the corrected image length, Np is the number of pixels in the vertical direction of the corrected image, and Sc is the corrected pixel length.

[0063]

[0064] The corrected image generated by the generation processing means 52 is corrected so that the size of the corrected image matches the length of the imaging range, even if the number of pixels in the vertical direction (the sum of the number of pixels in the vertical direction of the pitch images used to generate the captured image before correction) is different, as shown in Table (2) below.

[0065]

[0066] Here, as described above, the correction image output means 5 is configured so that the correction pixel length derivation means 51 directly acquires the correction value derived by the correction value derivation means 50 and then performs a process to derive the correction pixel length, and the generation processing means 52 can generate a correction image; the correction pixel length derivation means 51 is also configured so that it acquires the correction value (correction value information), which is the correction value derived by the correction value derivation means 50 and is stored in the memory means 6, and then performs a process to derive the correction pixel length, and the generation processing means 52 can generate a correction image.

[0067] The storage means 6 stores correction values ​​to be used for each conveyance speed of the sheet P set in the printing unit 21 (the feed speed of the sheet P by the impression cylinder 2103 shown in FIG. 5).

[0068] More specifically, the memory means 6 stores a plurality of feed speed information indicating the feed speed of sheets of paper by the printing unit 21, and a plurality of correction value information indicating correction values, each of which is associated with a different feed speed information.

[0069] The correction value information indicates a correction value derived under conditions in which the printing unit 21 is printing while transporting sheets at the feed speed indicated by the associated feed speed information.

[0070] Therefore, by selecting feed speed information indicating the same speed as the feed speed set in the printing unit 21 and correction value information associated with this feed speed information, the correction pixel length derivation means 51 can derive the corrected image length using a correction value appropriate to the sheet feed speed by the printing unit 21, without requiring the correction value derivation means 50 to perform a process to derive a correction value.

[0071] Furthermore, if the feed speed set in the printing unit 21 changes, by selecting feed speed information indicating the same speed as the changed feed speed and the correction value information associated with this feed speed information, the corrected pixel length derivation means 51 becomes able to derive the corrected image length using a correction value appropriate to the sheet feed speed by the printing unit 21 without requiring the correction value derivation means 50 to perform a process to derive a correction value.

[0072] In the printing machine 1 of this embodiment, the captured image generating means 4, the corrected image output means 5, and the storage means 6 are configured by a computer.

[0073] A program that causes the computer to function as the captured image generating means 4 and a program that causes the computer to function as the corrected image output means 5 are stored in the storage means 6 .

[0074] In addition, the program that causes a computer to function as a correction image output means 5 is applied to a printing press 1 that has a printing unit 21 that prints on the sheets as they are fed in the feed direction, a line camera 3 that generates multiple pitch images by taking images of the sheets being fed in the feed direction by the printing unit 21 at regular time intervals, and an image generation means 4 that generates an image of the sheet based on the multiple pitch images generated by the line camera 3, and includes a correction program for the printing press 1 that causes the computer to function as a correction image output means 5 that corrects the length of the captured image or the pitch image in the vertical direction, which is the direction corresponding to the feed direction, based on a correction value and outputs the corrected image.

[0075] The configuration of the printing press 1 according to this embodiment is as described above. Next, the operation of the printing press 1 and the method for deriving the correction values ​​will be described.

[0076] As shown in Figure 6, the printing press 1 performs the following operations: feeding a reference-marked sheet P1 by the printing unit 21; generating a pitch image Ip by the line camera 3; generating an image In by the image generation means 4; and generating and outputting a corrected image Ic by the corrected image output means 5.

[0077] The printing unit 21 operates to feed the reference-marked sheet P1 along the feed direction while the printing unit 21 is not printing. Specifically, by driving the printing unit 21 with the reference-marked sheet P1 directly attached to the impression cylinder to which the line camera 3 is pointed, a state is created in which the reference-marked sheet P1 is fed along the feed direction within the printing unit 21.

[0078] The line camera 3 captures an image of the reference-marked sheet P1 while it is being fed in the feed direction within the printing unit 21, thereby generating a plurality of pitch images Ip.

[0079] The captured image generating means 4 selects from the plurality of pitch images Ip those to be used for generating the captured image In, and generates the captured image In based on the selected plurality of pitch images Ip.

[0080] The correction image output means 5 derives a correction value using a correction value derivation means 50, derives a correction pixel length by correcting the correction pixel length with the correction value using a correction pixel length derivation means 51, and generates a correction image Ic that matches the correction pixel length by expanding or reducing the pixel length of the captured image In using a generation processing means 52.

[0081] The correction value derivation method is performed by the correction value derivation means 50. The correction value derivation method derives a correction value for the length in the vertical direction of the captured image In based on the imaging range length and the captured image size (the number of pixels in the vertical direction of the captured image In).

[0082] In the corrected image Ic generated by the generation processing means 52, as shown in Figure 6, the corrected image length matches the imaging range length (in this embodiment, the total length in the feed direction of the printed matter P2), and the length from the first reference Mc1 to the second reference Mc2 shown in the corrected image Ic matches the length from the first reference Ma1 to the second reference Ma2 on the printed matter P2.

[0083] Therefore, by comparing the length from the first reference Mc1 to the second reference Mc2 derived based on the corrected image Ic with the normal length, it is possible to accurately confirm whether the vertical position of the print on the sheet is correct or not.

[0084] As described above, according to the printing machine 1 of this embodiment, by correcting the captured image In, a corrected image Ic that matches the length of the reference sheet P1 can be obtained, thereby achieving the excellent effect of enabling inspection to be performed with high accuracy.

[0085] Furthermore, in the image correction program of this embodiment, by correcting the captured image In, a corrected image Ic that matches the actual length of the reference sheet P1 can be obtained, thereby enabling inspection to be performed with high accuracy.

[0086] Furthermore, in the correction value derivation method, a correction value for correcting the captured image In to match the actual length of the reference sheet P1 can be obtained, thereby enabling inspection to be performed with high accuracy.

[0087] Furthermore, in the printing press 1, the correction value is set according to the feed speed of the sheet P by the printing press main body 2 (printing unit 21), so the captured image In can be corrected with a correction value corresponding to the feed speed of the sheet P set in the printing press main body 2 (printing unit 21), thereby improving the accuracy of the inspection.

[0088] It should be noted that the printing press, the correction program for the printing press, and the method for deriving correction values ​​for images for the printing press according to the present invention are not limited to the above-described embodiments, and it goes without saying that various modifications can be made within the scope that does not deviate from the gist of the present invention.

[0089] In the above embodiment, the first reference Ma1, which constitutes the reference used to check the position of the print on the sheet in the top-bottom direction, is configured as a part of the reference-marked sheet P1, but is not limited to this configuration. For example, the first reference Ma1 may also be configured as a mark printed on the reference-marked sheet P1.

[0090] In the above embodiment, the pitch image has one pixel in the vertical direction, but the pitch image may have two or three pixels in the vertical direction, for example.

[0091] Although the pixel length of the pitch image in the above embodiment is 0.26 mm, the pixel length of the pitch image may be, for example, 0.13 mm to 0.39 mm.

[0092] Although the corrected image output means 5 in the above embodiment is configured to generate a corrected image by correcting the pre-correction pixel length of the captured image based on the correction value, the configuration is not limited to this. For example, as shown in Fig. 7, the corrected image output means 5 may be configured to generate a corrected image Ic by correcting the captured image length itself based on the correction value.

[0093] In this case, the corrected image output means 5 is configured to have, for example, a correction value derivation means that performs processing to derive a correction value, a corrected pixel image length derivation means that performs processing to derive a corrected image length by correcting the image length of the captured image In with the correction value, and a generation processing means that generates the corrected image Ic by extending or reducing the image length of the captured image In to match it to the corrected image length.

[0094] The correction value derivation means is configured to derive the correction value using the following formula (5): In the following formula (5), C is the correction value, Ls is the imaging range length, Sn is the imaging pixel length, and Np is the number of pixels in the vertical direction of the captured image In.

[0095]

[0096] The corrected image length deriving means is configured to derive the corrected image length using the following formula (6): In formula (6), Lc is the corrected image length, Np is the number of pixels in the vertical direction of the captured image In (captured image size), Sn is the captured pixel length, and C is the correction value.

[0097]

[0098] As described above, the corrected image output means 5 may be configured to generate a corrected image by correcting the pixel length of each of the pixels that make up the captured image In, as in the above embodiment, or may be configured to generate a corrected image Ic by correcting the entire length of the captured image (image length).

[0099] Although the corrected image output means 5 in the above embodiment generates the corrected image Ic by correcting the length in the vertical direction of the captured image In, the present invention is not limited to this configuration. For example, as shown in Fig. 8, the corrected image output means 5 may be configured to generate a corrected pitch image Ip2 by correcting the pixel length (pitch pixel length) in the vertical direction of the pitch image Ip, and to generate a captured image In showing the reference-marked sheet P1 by arranging and combining multiple corrected pitch images Ip2 in the vertical direction.

[0100] In this case, the correction values ​​stored in advance in the storage means 6 may be used.

[0101] In the above embodiment, the program that causes the computer to function as the captured image generating means 4 and the program that causes the computer to function as the corrected image output means 5 are stored in the storage means 6 of the printing machine 1, but this configuration is not limiting. For example, the program that causes the computer to function as the captured image generating means 4 and the program that causes the computer to function as the corrected image output means 5 may be stored in the storage means 6 external to the printing machine 1.

[0102] 5, the line camera 3 is arranged facing the final impression cylinder, but is not limited to this configuration. The line camera 3 may be arranged facing the impression cylinder 2103 of the printing unit 210 that is upstream of the printing unit 210 that is most downstream in the feed direction, as long as it can capture an image of the reference-marked sheet P1 in the conveying state.

[0103] In the printing press 1 of the above embodiment, an example has been given in which the line camera 3 captures an image of the reference-marked sheet P1 when the printing unit 21 is not printing, but the configuration is not limited to this. For example, the printing press 1 may be configured so that the line camera 3 captures an image of the reference-marked sheet P1 when the printing unit 21 is printing.

[0104] More specifically, the line camera 3 is configured to capture an image of the reference-marked sheet P1 being transported in the feed direction within the printing unit 21 where printing is being performed.

[0105] In this case, the first reference Ma1 and the second reference Ma2 may be set in advance for the sheet P before it is supplied to the paper feed unit 20, or may be set by the printing unit 21 printing.

[0106] 1...printing press, 2...printing press main body, 3...line camera, 4...captured image generating means, 5...corrected image output means, 6...storage means, 20...paper feed section, 21...printing section, 22...paper discharge section, 50...correction value deriving means, 51...corrected pixel length deriving means, 52...generation processing means, 210...printing unit, 2100...ink roller group, 2101...plate cylinder, 2102...blanket cylinder, 2103...impression cylinder, 2104...transfer cylinder, CP1, CP2, CP3...selection criterion, Ip...pitch image, Ip2...corrected pitch image, Ma1...first criterion, Ma2...second criterion, Mb1...first criterion, Mb2...second criterion, Mc1...first criterion, Mc2...second criterion, P1...sheet, P2...printed matter, R1, R2, R3...image capture area

Claims

1. A printing press comprising: a printing press main body that prints on a paper sheet while feeding the paper sheet in a feed direction; a line camera that generates a plurality of pitch images by capturing images of the paper sheet being fed in the feed direction by the printing press main body at regular time intervals; an image generation means that generates an image in which at least a portion of the paper sheet is visible based on the plurality of pitch images generated by the line camera; and a correction image output means that corrects the length of the captured image or the plurality of pitch images in the top-to-bottom direction, which is the direction corresponding to the feed direction, based on a correction value and outputs the image as a corrected image.

2. The printing press according to claim 1, wherein the correction value is set according to a feed speed of the sheet by the printing press body.

3. A correction program for a printing press, which is applied to a printing press comprising: a printing press main body that prints on a paper sheet while feeding the paper sheet in the feed direction; a line camera that generates a plurality of pitch images by capturing images of the paper sheet being fed in the feed direction by the printing press main body at regular time intervals; and an image generation means that generates an image in which at least a portion of the paper sheet is captured based on the plurality of pitch images generated by the line camera, and causes a computer to function as a correction image output means that corrects the length of the captured image or the plurality of pitch images in the vertical direction, which is the direction corresponding to the feed direction, based on a correction value and outputs the image as a corrected image.

4. A method for deriving a correction value for an image for a printing press in a printing press including a printing press main body that prints on a sheet while feeding the sheet in a feed direction, a reference-marked sheet consisting of a sheet including a first reference and a second reference spaced apart in a top-to-bottom direction which is a direction corresponding to the feed direction, a line camera that generates a plurality of pitch images by capturing an image of the reference-marked sheet at regular time intervals while the reference-marked sheet is being fed along the feed direction within the printing press main body, and an image generation means that generates an image that shows at least an area of ​​the reference-marked sheet that includes the first reference and the second reference based on the plurality of pitch images generated by the line camera, the method comprising: deriving a correction value for the top-to-bottom length in an image generated by the image generation means, based on a normal length between the first reference and the second reference spaced apart in the top-to-bottom direction of the reference-marked sheet and the number of pixels between the first reference and the second reference in the image generated by the image generation means.

Images