JP2018130898A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printer capable of reducing waste of a web.SOLUTION: When stopping printing in a halfway of a web roll R, a control part 5 causes a printing part 3A to print a second mark indicating a start position of a next page, then stops transport of the web W by a transport part 2. Then, when restarting printing from a halfway of the web roll R, the control part 5 causes the transport part 2 to rewind the web W so that the second mark is moved to a regulated return position or an upstream side thereof, then, restarts transport of the web W. Then when a mark sensor 4A detects the second mark after restart of transport of the web W, based on the timing, the control part 5 causes a printing part 3A to restart printing on a front surface of the web W, then, causes a printing part 3B to restart printing control of an image of each page on a back surface of the web W based on a timing when the mark sensor 4B detects a first mark or a second mark indicating a start position of each page.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a printing apparatus for printing on a web.

  2. Description of the Related Art There is known a printing apparatus that prints on a web by discharging ink from an inkjet head while the web is unwound and conveyed from a web roll in which a long web is wound into a roll.

  In such a printing apparatus, printing may be stopped in the middle of the web roll by ending the print job in the middle of the web roll or by interrupting printing due to a trouble or the like in the middle of the print job. In this case, the subsequent printing is resumed from the middle of the web roll (see, for example, Patent Document 1).

Japanese Patent Laying-Open No. 2015-63073

  In the printing apparatus described above, when printing is performed, web conveyance is started, and when the web conveyance speed reaches a predetermined print conveyance speed, printing by the inkjet head is started. At this time, a portion of the web that has passed through the ink jet head before reaching the printing conveyance speed is not used for printing and is wasted. For this reason, when the situation which restarts printing from the middle of the above-mentioned web roll generate | occur | produces, waste of a web will increase.

  The present invention has been made in view of the above, and an object of the present invention is to provide a printing apparatus that can reduce web waste.

  In order to achieve the above object, a first feature of a printing apparatus according to the present invention includes a conveyance unit that unwinds and conveys a web from a web roll, and an inkjet head that prints an image by discharging ink onto the web. And printing the first mark indicating the image of each page and the start position for each page on the first surface of the web conveyed by the conveying unit, and at the time of printing stop in the middle of the web roll A first printing unit for printing a second mark having a shape different from the first mark, which indicates a start position of the next page and substitutes for the first mark corresponding to the page, and the first printing unit in the web conveyance direction. A first detection unit disposed on the upstream side of one printing unit for detecting the second mark; and the first mark and the second marker disposed on the downstream side of the first printing unit. A second detection unit for detecting ink and an inkjet head that is disposed downstream of the second detection unit and that ejects ink onto a web to print an image, wherein the second detection unit is the first detection unit. Based on the timing at which the mark or the second mark is detected, the second printing unit that prints the image of each page on the second surface of the web, the transport unit, the first printing unit, and the second printing unit are controlled. A control unit that stops printing of the web by the transport unit after the second mark is printed by the first printing unit when printing is stopped in the middle of the web roll, After the web conveyance is resumed, the conveyance unit moves the second mark to a position where the web conveyance speed can reach the predetermined printing conveyance speed before the second mark reaches the first printing unit. After the web is rewound, the conveyance of the web is resumed, and the printing of the first surface by the first printing unit is resumed based on the timing at which the first detection unit detects the second mark after the conveyance of the web is resumed. And resuming printing control of the image of each page of the second surface by the second printing unit based on the timing at which the second detection unit detects the first mark or the second mark.

  A second feature of the printing apparatus according to the present invention is that when the control unit restarts printing of the first surface by the first printing unit after stopping printing in the middle of the web roll, the second feature is provided. It is to control the first printing unit to perform printing to overwrite the second mark so that the mark has the same shape as the first mark.

  A third feature of the printing apparatus according to the present invention is that the printing apparatus includes a conveyance unit that unwinds and conveys the web from the web roll, and an inkjet head that discharges ink onto the web to print an image, and is conveyed by the conveyance unit. Printing an image of each page on the web and printing a mark indicating a start position of the next page when printing is stopped in the middle of the web roll; upstream of the printing unit in the web conveyance direction A detection unit for detecting the mark, and a control unit for controlling the transport unit and the printing unit, wherein the control unit is configured to perform the printing when stopping printing in the middle of the web roll. After the mark is printed by the printing section, the conveyance of the web by the conveyance section is stopped, and the web reaches the printing section after the web conveyance is resumed. After the web is rewound by the transport unit so that the mark moves to a position at which the transport speed can reach a predetermined print transport speed, the web transport is resumed. Printing by the printing unit is resumed based on the timing at which the mark is detected.

  According to the first feature of the printing apparatus according to the present invention, when the printing is stopped in the middle of the web roll, the control unit causes the first printing unit to print the second mark and then conveys the web by the conveying unit. Stop. Thereafter, the control unit moves the second mark so that the second mark moves to a position where the web conveyance speed can reach the predetermined printing conveyance speed before the second mark reaches the first printing unit after the web conveyance is resumed. After the web is rewound, the web conveyance is resumed. The control unit restarts printing of the first surface by the first printing unit based on the timing at which the first detection unit detects the second mark after the web conveyance is resumed, and the second detection unit detects the first mark or The printing control of the image of each page on the second surface by the second printing unit based on the timing at which the second mark is detected is resumed. Thus, when printing is resumed from the middle of the web roll, printing of the first page after resuming printing is started from the same position as when there was no printing stop in the middle of the web roll. For this reason, it is possible to suppress occurrence of a useless portion on the web between the last page before resuming printing and the next page. As a result, web waste can be reduced.

  According to the second feature of the printing apparatus according to the present invention, the control unit controls the first printing unit to perform printing to overwrite the second mark so that the second mark has the same shape as the first mark. . Thereby, since the shapes of the first mark and the second mark are unified, it is possible to reduce the occurrence of erroneous mark recognition when the first mark and the second mark are used for position detection of each page in the post-processing apparatus. .

  According to the third feature of the printing apparatus according to the present invention, when the printing is stopped in the middle of the web roll, the control unit causes the printing unit to print the mark and then stops the conveyance of the web by the conveyance unit. After that, the control unit causes the web to rewind the web so that the mark moves to a position where the web conveyance speed can reach the predetermined printing conveyance speed before the mark reaches the printing unit after the web conveyance is resumed. After that, the conveyance of the web is resumed. And a control part restarts printing by a printing part based on the timing which the detection part detected the mark after restarting conveyance of a web. Thus, when printing is resumed from the middle of the web roll, printing of the first page after resuming printing is started from the same position as when there was no printing stop in the middle of the web roll. For this reason, it is possible to suppress occurrence of a useless portion on the web between the last page before resuming printing and the next page. As a result, web waste can be reduced.

1 is a schematic configuration diagram of a printing apparatus according to an embodiment. FIG. 2 is a control block diagram of the printing apparatus shown in FIG. 1. 3 is a flowchart for explaining the operation of the printing apparatus shown in FIG. 1. It is a figure which shows an example of a 1st mark. It is a figure which shows an example of a 2nd mark. FIG. 2 is an image diagram for explaining the operation of the printing apparatus shown in FIG. 1. FIG. 2 is an image diagram for explaining the operation of the printing apparatus shown in FIG. 1. FIG. 2 is an image diagram for explaining the operation of the printing apparatus shown in FIG. 1. It is a figure which shows the other example of a 2nd mark.

  Embodiments of the present invention will be described below with reference to the drawings. Throughout the drawings, the same or equivalent parts and components are denoted by the same or equivalent reference numerals.

  The following embodiments exemplify devices for embodying the technical idea of the present invention, and the technical idea of the present invention is the material, shape, structure, arrangement, etc. of each component. Is not specified as follows. The technical idea of the present invention can be variously modified within the scope of the claims.

  FIG. 1 is a schematic configuration diagram of a printing apparatus according to an embodiment of the present invention. FIG. 2 is a control block diagram of the printing apparatus shown in FIG. In the following description, the top, bottom, left, and right of the paper surface in FIG. Further, the direction orthogonal to the paper surface of FIG.

  As shown in FIGS. 1 and 2, the printing apparatus 1 according to the present embodiment includes a transport unit 2, printing units 3 </ b> A and 3 </ b> B, mark sensors 4 </ b> A and 4 </ b> B, and a control unit 5.

  The conveyance unit 2 unwinds and conveys the web W from the web roll R in which the web W, which is a long print medium made of film, paper, or the like, is wound in a roll shape. The transport unit 2 includes an unwinding unit 11, a print transport unit 12, and a winding unit 13. In the following description, upstream and downstream mean upstream and downstream in the conveyance direction of the web W during printing, which is a direction from the unwinding unit 11 to the winding unit 13.

  The unwinding unit 11 unwinds the web W from the web roll R to the print conveying unit 12. The unwinding unit 11 includes a web roll support shaft 21 and an unwinding motor 22.

  The web roll support shaft 21 supports the web roll R in a rotatable manner. The web roll support shaft 21 is formed in a long shape extending in the front-rear direction.

  The unwinding motor 22 rotates the web roll support shaft 21. When the web W is unwound from the unwinding portion 11, the unwinding motor 22 rotates the web roll support shaft 21 in the clockwise direction in FIG. 1.

  The print conveyance unit 12 conveys the web W that has been unwound from the unwinding unit 11. The print conveyance unit 12 includes guide rollers 31 to 40, ten head lower support members 41, a meandering control unit 42, an encoder 43, a pair of conveyance rollers 44, and a conveyance motor 45.

  The guide rollers 31 to 40 guide the web W transported in the print transport unit 12. The guide rollers 31 to 40 are driven to rotate by the web W being conveyed. The guide rollers 31 to 40 are formed in a long shape extending in the front-rear direction.

  The guide rollers 31 and 32 guide the web W between the unwinding unit 11 and the meandering control unit 42. The guide roller 31 is disposed in the vicinity of the right side of the unwinding portion 11. The guide roller 32 is disposed between the guide roller 31 and a meandering control roller 46A of a meandering control unit 42 described later.

  The guide rollers 33 to 39 guide the web W between the meandering control unit 42 and the conveyance roller 44. The guide roller 33 is disposed on the left side of a meandering control roller 46B of a meandering control unit 42 described later. The guide roller 34 is disposed above the guide roller 33. The guide roller 35 is substantially the same height as the guide roller 34 and is disposed on the right side of the guide roller 34. The guide roller 36 is disposed below the guide roller 35 and at a position higher than the guide roller 33. The guide roller 37 is disposed on the left side of the guide roller 36, in the vicinity of the right side of the web W between the guide rollers 33 and 34, and at the same height as the guide roller 36. The guide roller 38 is disposed on the lower right side of the guide roller 37. The guide roller 39 is disposed slightly below the right side of the guide roller 38.

  The guide roller 40 guides the web W between the conveyance roller 44 and the winding unit 13. The guide roller 40 is disposed in the vicinity of the left side of the winding unit 13.

  The head lower support member 41 supports the web W between the guide rollers 34 and 35 and between the guide rollers 36 and 37. The head lower support member 41 is formed in a long shape extending in the front-rear direction. Ten head support members 41 are arranged between the guide rollers 34 and 35 and between the guide rollers 36 and 37, respectively. Between the guide rollers 34 and 35 and between the guide rollers 36 and 37, the 10 head lower support members 41 are arranged so that the web W draws a convex arch upward.

  The meandering control unit 42 corrects the meandering of the web W. The meandering control unit 42 includes meandering control rollers 46 </ b> A and 46 </ b> B and a meandering control motor 47.

  The meander control rollers 46A and 46B are rollers for guiding the web W and correcting the meandering of the web W. The meandering control rollers 46A and 46B are formed in a long shape extending in the front-rear direction. The meandering control rollers 46A and 46B are configured such that the angle in the axial direction with respect to the front-rear direction on the vertical plane can be adjusted. The meandering control roller 46 </ b> A is disposed on the right side of the guide roller 32. The meandering control roller 46B is disposed above the meandering control roller 46A.

  The meandering control motor 47 rotates the meandering control rollers 46A and 46B around an axis orthogonal to the vertical plane in order to adjust the angle of the meandering control rollers 46A and 46B with respect to the front-rear direction on the vertical plane. .

  The encoder 43 is connected to the guide roller 34 and outputs a pulse signal for each predetermined rotation angle of the guide roller 34.

  The pair of transport rollers 44 transport the web W toward the winding unit 13 while nipping the web W. The conveyance roller 44 is formed in a long shape extending in the front-rear direction. The pair of transport rollers 44 is disposed between the guide rollers 39 and 40.

  The transport motor 45 rotates the transport roller 44.

  The winding unit 13 winds the web W printed by the printing units 3 </ b> A and 3 </ b> B while being transported by the printing transport unit 12. The winding unit 13 includes a winding shaft 48 and a winding motor 49.

  The winding shaft 48 winds and holds the web W. The winding shaft 48 is formed in a long shape extending in the front-rear direction.

  The winding motor 49 rotates the winding shaft 48. The web W is wound around the winding shaft 48 by the winding shaft 48 rotating in the clockwise direction in FIG.

  3 A of printing parts print the image of each page of a front surface on the front surface (equivalent to the 1st surface of a claim) of the web W. The printing unit 3A prints a first mark 61 and a second mark 62, which will be described later. The printing unit 3 </ b> A is disposed near the upper portion of the web W between the guide rollers 34 and 35. The printing unit 3A includes five head units 51. The printing unit 3A corresponds to the first printing unit in the claims.

  The printing unit 3B prints an image of each page on the back side of the web W (corresponding to the second side of the claims). The printing unit 3 </ b> B is disposed in the vicinity of the upper portion of the web W between the guide rollers 36 and 37. The printing unit 3B includes five head units 51 as in the printing unit 3A. The printing unit 3B corresponds to the second printing unit in the claims.

  The head unit 51 includes an inkjet head 52 that prints an image by ejecting ink onto the web W. The inkjet head 52 has a plurality of nozzles (not shown) arranged along the front-rear direction, and ejects ink from the nozzles. In each of the printing units 3A and 3B, the five inkjet heads 52 eject inks of different colors.

  The mark sensor 4 </ b> A is a sensor for detecting the second mark 62. The mark sensor 4A is disposed on the upstream side of the printing unit 3A. More specifically, the mark sensor 4A is disposed on the front surface side (upper side) of the web W between the guide roller 34 and the printing unit 3A. The mark sensor 4A is composed of, for example, an optical sensor having a light emitting unit and a light receiving unit. The mark sensor 4A corresponds to a first detection unit in claims.

  The mark sensor 4 </ b> B is a sensor for detecting the first mark 61 and the second mark 62. The mark sensor 4B is disposed downstream of the printing unit 3A and upstream of the printing unit 3B. More specifically, the mark sensor 4B is disposed on the front surface side (lower side) of the web W between the guide roller 36 and the printing unit 3B. The mark sensor 4B is composed of, for example, an optical sensor similar to the mark sensor 4A. The mark sensor 4B corresponds to a second detection unit in claims.

  The control unit 5 controls the operation of the entire printing apparatus 1. The control unit 5 includes a CPU, a RAM, a ROM, a hard disk, and the like.

  When printing, the control unit 5 controls the printing unit 3A and 3B to eject an ink from the inkjet head 52 and print an image while the web W is being conveyed by the conveyance unit 2.

  Further, when the printing is stopped in the middle of the web roll R, the control unit 5 causes the printing unit 3 </ b> A to print the second mark 62 and then stops the conveyance of the web W by the conveyance unit 2. After that, when resuming printing from the middle of the web roll R, the control unit 5 rewinds the web W by the conveyance unit 2 so that the second mark 62 moves to a specified return position described later or upstream thereof, The conveyance of the web W is resumed. When the mark sensor 4A detects the second mark 62 after resuming the conveyance of the web W, the control unit 5 resumes printing of the front surface of the web W by the printing unit 3A based on the timing. At the same time, the control unit 5 controls the printing of the image of each page on the back surface of the web W by the printing unit 3B based on the timing at which the mark sensor 4B detects the first mark 61 or the second mark 62A after overwriting described later. Let it resume.

  Here, as to the case of stopping printing in the middle of the web roll R, as will be described later, when printing is interrupted due to a user instruction or trouble in the middle of the print job, or due to the print job in the middle of the web roll R, Printing may have been terminated.

  Next, the operation of the printing apparatus 1 will be described.

  FIG. 3 is a flowchart for explaining the operation of the printing apparatus 1. 3 is started when a print job is input to the printing apparatus 1 from an external apparatus such as a personal computer.

  In step S <b> 1 of FIG. 3, the control unit 5 determines whether or not the printing operation by the current print job is the first printing operation with the web roll R currently set in the unwinding unit 11.

  When it is determined that the printing operation by the current print job is the first printing operation with the current web roll R (step S1: YES), in step S2, the control unit 5 causes the conveyance unit 2 to convey the web W. Let it begin. Specifically, the control unit 5 controls the unwinding motor 22, the transport motor 45, and the winding motor 49 to move in the transport direction during printing, which is a direction from the unwinding unit 11 to the winding unit 13. The web W is started to be conveyed. Here, when the conveyance speed of the web W is accelerated to a predetermined print conveyance speed Vg after the conveyance of the web W is started, the control unit 5 controls the conveyance unit 2 so as to maintain the print conveyance speed Vg.

  Next, in step S3, the control unit 5 controls each inkjet head 52 of the printing unit 3A to start printing on the web W based on the print job. Here, the control unit 5 starts printing by the printing unit 3A after the conveyance speed of the web W reaches the printing conveyance speed Vg.

  Thereby, printing of the image of each page of the front surface of the web W is started. Here, the control unit 5 controls the printing unit 3 </ b> A to print the first mark 61 indicating the start position of each page in the conveyance direction of the web W at the time of printing as shown in FIG. 4 for each page.

  The first mark 61 is used for alignment between the front page and the back page. The first mark 61 is printed outside the area where the page image is printed. The first mark 61 has a rectangular shape, and two sides are orthogonal to the conveyance direction of the web W, and the other two sides are parallel to the conveyance direction of the web W. Of the two sides orthogonal to the web W conveyance direction, the side 61a, which is the downstream side, coincides with the start position of the page.

  The first mark 61 is detected by the mark sensor 4B after being printed by the printing unit 3A. When the mark sensor 4B detects the first mark 61, the control unit 5 controls the printing unit 3B to print the image of the back side page based on the timing. Specifically, the control unit 5 applies the number of output pulses from the encoder 43 after the mark sensor 4B detects the first mark 61 to the front surface page where the first mark 61 indicates the start position. The printing unit 3B is caused to start printing from the start position of the corresponding back side page. In this way, the image of each page on the back side of the web W is printed in alignment with each page on the front side.

  After the printing by the printing unit 3A is started, in step S4 in FIG. 3, the control unit 5 determines whether to interrupt printing. Here, for example, the control unit 5 determines that the printing is to be interrupted when a print interruption is instructed by a user operation on an operation input unit (not shown) or when a trouble that needs to be interrupted occurs.

  If it is determined that printing is to be interrupted (step S4: YES), in step S5, the control unit 5 determines whether the printing unit 3A is in the middle of printing a page when it is determined that printing is to be interrupted.

  When the printing unit 3A determines that the page is being printed (step S5: YES), the control unit 5 repeats step S5 until the printing unit 3A finishes printing the page.

  When the printing unit 3A determines that the page is not being printed (step S5: NO), in step S6, the control unit 5 prints the second mark 62 as shown in FIG. 5 at the start position of the next page. The printing unit 3A is controlled. Here, the control unit 5 controls the printing unit 3A not to print the image of the next page.

  The second mark 62 is a mark indicating the start position of the next page when printing is stopped in the middle of the web roll R. Further, the second mark 62 is an alternative to the first mark 61 for the page. The second mark 62 is printed outside the area where the page image is printed.

  The second mark 62 has a shape different from that of the first mark 61. Specifically, the second mark 62 has a shape in which a blank portion 62 a is formed with respect to the first mark 61. That is, the second mark 62 is formed by two rectangular portions 62b and 62c separated by the blank portion 62a. A downstream end side 62d of the rectangular portion 62b arranged on the downstream side coincides with the start position of the page.

  When the printing of the second mark 62 is completed, the control unit 5 controls the conveyance unit 2 to stop the conveyance of the web W in step S7 of FIG.

  As a result, as shown in FIG. 6, if the page P1 is the last printed page before printing is interrupted, the second mark 62 is printed at the start position of the next page of the page P1, and the next page of the page P1. The printing operation is stopped in a state where printing of the image is not started.

  Here, when the printing unit 3B is in the middle of printing the page when it is determined that the printing is interrupted, the control unit 5 continues the printing by the printing unit 3B until the end of the page, and when the printing of the page ends. Stop. When the printing of the second mark 62 on the front surface of the web W is completed and the printing unit 3B is in the middle of printing the page on the back surface, the control unit 5 determines when the printing of the page is completed. Then, the conveyance of the web W by the conveyance unit 2 is stopped.

  Next, in step S8 of FIG. 3, the control unit 5 determines whether or not to resume the printing operation. Here, for example, the control unit 5 is in a state in which a printing operation is possible when an instruction to resume printing is given by a user operation on an operation input unit (not shown) or a trouble that causes printing interruption is solved. In this case, it is determined that the printing operation is resumed. If it is determined that the printing operation is not yet resumed (step S8: NO), the control unit 5 repeats step S8.

  When it is determined that the printing operation is to be resumed (step S8: YES), in step S9, the control unit 5 conveys the second mark 62 so that the second mark 62 moves to the upstream side of the mark sensor 4A or upstream. The part 2 is controlled to rewind the web W. Specifically, the control unit 5 controls the unwinding motor 22, the transport motor 45, and the winding motor 49 to print the web W until the second mark 62 moves to the specified return position or upstream thereof. Transport in the opposite direction to the current transport direction.

  Here, the specified return position of the second mark 62 is the amount of the web W conveyance distance during the acceleration period from the start of conveyance of the web W until the conveyance speed of the web W reaches the printing conveyance speed Vg. This is a position upstream from the most upstream inkjet head 52. For this reason, when the second mark 62 moves to the specified return position or upstream thereof, the conveyance speed of the web W becomes the printing conveyance speed Vg until the second mark 62 reaches the printing unit 3A after the conveyance of the web W is resumed. Thus, the second mark 62 moves to a position where it can be reached.

  Note that the control unit 5 determines whether the second mark 62 has moved to the specified return position or upstream thereof by a sensor (not shown) installed at the specified return position, for example, when the web W is rewound. Judging. In addition, a predetermined rewinding amount sufficient to move the second mark 62 to the predetermined return position or upstream thereof is set in advance, and when the web W is rewound, the control unit 5 sets only the specified rewinding amount. You may control the conveyance part 2 so that the web W may be rewound.

  By rewinding the web W from the state of FIG. 6, as shown in FIG. 7, the second mark 62 is moved upstream of the specified return position upstream of the mark sensor 4A or upstream thereof.

  Next, in step S10 of FIG. 3, the control unit 5 controls the transport unit 2 to resume transport of the web W in the transport direction during printing.

  Next, in step S11, the control unit 5 determines whether or not the second mark 62 is detected by the mark sensor 4A. When determining that the second mark 62 has not been detected (step S11: NO), the control unit 5 repeats step S11.

  Here, when the web W is rewound in step S9, there may be a first mark 61 that moves to the upstream side from the mark sensor 4A depending on the page size and the like. In this case, after resuming the conveyance of the web W, the mark sensor 4 </ b> A detects the first mark 61 before detecting the second mark 62. However, since the first mark 61 and the second mark 62 have different shapes, it is possible to distinguish both.

  When it is determined that the second mark 62 is detected by the mark sensor 4A (step S11: YES), the control unit 5 determines the weight of the web W by the printing unit 3A based on the detection timing of the second mark 62 in step S12. Control to resume surface printing.

  Specifically, the control unit 5 resumes printing from the start position of the page indicated by the second mark 62 based on the number of output pulses of the encoder 43 after the mark sensor 4A detects the second mark 62. Controls the printing unit 3A. At this time, the control unit 5 omits printing the first mark 61 on the first page after resuming printing, and instead, the second mark 62 has the same shape as the first mark 61. The printing unit 3A is controlled so as to perform overwriting. Specifically, the control unit 5 controls the printing unit 3 </ b> A to perform printing that fills the blank portion 62 a of the second mark 62.

  As a result, as shown in FIG. 8, the page P2, which is the first page after resuming printing, is printed at the same position as when printing was not interrupted. The overwritten second mark 62 </ b> A has the same shape as the first mark 61.

  Here, before the conveyance of the web W is resumed, the web W is rewound until the second mark 62 moves to the specified return position or upstream thereof. Therefore, when the second mark 62 reaches the printing unit 3A. The web W has reached the printing conveyance speed Vg and is ready for printing.

  From the page following the first page after resuming printing, the control unit 5 prints the image of each page and the first mark 61 on the front surface of the web W by the printing unit 3A, as before the interruption of printing. Let

  When the mark sensor 4A detects the second mark 62 after resuming the conveyance of the web W, the control unit 5 causes the web W by the printing unit 3B based on the timing at which the mark sensor 4B detects the first mark 61 or the second mark 62A. The print control of the image of each page on the back side is resumed.

  Specifically, the control unit 5 sets the number of output pulses of the encoder 43 after the mark sensor 4B detects the first mark 61 that reaches the printing unit 3B first after the detection of the second mark 62 by the mark sensor 4A. Based on this, the printing unit 3B is caused to start printing from the start position of the back surface page corresponding to the front page where the first mark 61 indicates the start position.

  As a result, if printing of the first page has not yet started on the back side of the web W when printing is interrupted, printing starts from the first page of the back side. For example, in the case of the examples of FIGS. 6 to 8, the printing unit 3B starts printing the back side page corresponding to the page P1 based on the timing when the mark sensor 4B detects the first mark 61 corresponding to the page P1. The

  On the other hand, when the printing is interrupted after the printing on the back surface of the web W is started, the printing on the back surface is resumed from the next page after the last printed page before the printing is interrupted.

  Similarly, after that, the control unit 5 determines the image of each page from the start position of each page on the back surface of the web W based on the number of output pulses of the encoder 43 after the mark sensor 4B detects each first mark 61. Is printed on the printing unit 3B.

  Here, even when the second mark 62A overwritten in the same shape as the first mark 61 is detected by the mark sensor 4B, the web W is transferred to the printing unit 3B by the same control as when the first mark 61 is detected. The image of the back page is printed. That is, the second mark 62 A overwritten in the same shape as the first mark 61 functions as an alternative to the first mark 61.

  When printing is resumed as described above in step S12 of FIG. 3, the control unit 5 returns to step S4.

  If it is determined in step S1 that the printing operation by the current print job is not the first printing operation in the current web roll R (step S1: NO), the control unit 5 proceeds to step S9.

  Here, when the print operation by the current print job is not the first print operation by the current web roll R, that is, when the print operation by the current print job starts from the middle of the web roll R, the previous print job The printing operation by is terminated in the middle of the web roll R. In this case, as will be described later, the conveyance of the web W is stopped after the second mark 62 is printed at the start position of the next page of the last page on the front surface at the end of the previous print job. That is, in this case, the conveyance of the web W is stopped in the same state as when printing is interrupted in the middle of the above-described print job.

  Therefore, when it is determined that the print operation by the current print job is not the first print operation in the current web roll R (step S1: NO), the control unit 5 is the same as when the print operation is resumed after the print interruption. In step S9, the subsequent processing is performed. Thereby, the web W is rewound (step S9), and then the conveyance of the web W is resumed (step S10). When the second mark 62 is detected by the mark sensor 4A (step S11), the second mark 62 is overwritten, and printing control of the image of each page on the front surface and the back surface is resumed. (Step S12).

  When it is determined in step S4 that printing is not interrupted (step S4: NO), in step S13, the control unit 5 determines whether printing based on the print job is finished. If it is determined that printing has not ended (step S13: NO), the control unit 5 returns to step S4.

  When it is determined that printing based on the print job has been completed (step S13: YES), in step S14, the control unit 5 determines whether or not the printing operation by the current print job is ended in the middle of the web roll R. . Here, when the web W of a length that can continue printing remains on the upstream side of the last page printed by the current print job, the control unit 5 performs the print operation by the current print job as the web It is determined to end in the middle of the roll R.

  When it is determined that the printing operation is finished in the middle of the web roll R (step S14: YES), in step S15, the control unit 5 starts the next page following the page printed last on the front surface of the web W. The printing unit 3A is controlled to print the second mark 62.

  Next, in step S <b> 16, the control unit 5 controls the transport unit 2 to stop the transport of the web W.

  When it is determined that the printing operation is completed using the web W of the web roll R (step S14: NO), the control unit 5 omits step S15, and stops the conveyance of the web W in step S16. To control.

  When the conveyance of the web W is stopped in step S16, a series of operations are ended.

  As described above, in the printing apparatus 1, when printing is stopped in the middle of the web roll R, the control unit 5 causes the printing unit 3A to print the second mark 62 and then conveys the web W by the conveyance unit 2. Stop. Thereafter, when resuming printing from the middle of the web roll R, the control unit 5 causes the web W to be rewound by the transport unit 2 so that the second mark 62 moves to the specified return position or upstream thereof, and then the web W Resume transport. Then, when the mark sensor 4A detects the second mark 62 after resuming conveyance of the web W, the control unit 5 resumes printing of the front surface of the web W by the printing unit 3A based on the timing. At the same time, the control unit 5 restarts the printing control of the image of each page on the back surface of the web W by the printing unit 3B based on the timing when the mark sensor 4B detects the first mark 61 or the second mark 62A.

  Thereby, when printing is resumed from the middle of the web roll R, printing of the first page after resuming printing is started from the same position as when there was no printing stop in the middle of the web roll R. For this reason, on the web W, it is possible to suppress occurrence of a waste (damaged paper) portion between the last page before resuming printing and the next page. As a result, the waste of the web W can be reduced.

  In the printing apparatus 1, the control unit 5 overwrites the second mark 62 so that the second mark 62 has the same shape as the first mark 61 when resuming printing after stopping printing in the middle of the web roll R. The printing unit 3A is controlled to perform printing.

  Thereby, the shape of the 1st mark 61 and the 2nd mark 62 is unified. As a result, when the first mark 61 and the second mark 62A are used for position detection of each page in a post-processing apparatus such as a cutter apparatus that cuts the web W for each page, it is possible to reduce the occurrence of erroneous mark recognition. Here, in the post-processing device, when there are a plurality of types of marks on the web W, the marks may not be recognized properly.

  In the embodiment described above, the first mark 61 having the shape shown in FIG. 4 is used. However, the shape of the first mark is not limited to this, and the mark sensors 4A and 4B can detect the start position of the page. If it is.

  In the above-described embodiment, the second mark 62 having the shape shown in FIG. 5 is used. However, the shape of the second mark is not limited to this. The shape of the second mark may be any shape as long as a part of the first mark is blank and can be made the same shape as the first mark by printing over the second mark. For example, instead of the second mark 62 in FIG. 5, the second mark 63 having the shape shown in FIG. 9 may be used. The second mark 63 has a shape in which blank portions 63a and 63b are formed with respect to the first mark 61 of FIG. That is, the second mark 63 is formed by three rectangular portions 63c to 63e divided by the blank portions 63a and 63b. Of the rectangular portions 63c to 63e, the downstream end side 63f of the most downstream rectangular portion 62c coincides with the start position of the page.

  In the above-described embodiment, when printing is resumed from the middle of the web roll R, the second mark 62 is overwritten on the second mark 62 so that the second mark 62 has the same shape as the first mark 61. Printing that overwrites the second mark 62 may be omitted. Even in this case, for the first page of the front surface after resuming printing, the second mark 62 is used as an alternative to the first mark 61 and the front page and the rear page are aligned. Can do.

  In the above-described embodiment, the case where the printing apparatus 1 performs double-sided printing on the web W has been described. However, printing may be performed only on one side of the web W. In the case of this single-sided printing, printing on the web W is performed by the printing unit 3A. In the case of single-sided printing, printing of the first mark 61 is omitted.

  In the printing operation of single-sided printing, when printing is stopped in the middle of the web roll R, the control unit 5 causes the printing unit 3A to print the second mark 62 after the printing unit 3A prints, similarly to the above-described double-sided printing. The conveyance of the web W by is stopped. Thereafter, when resuming printing from the middle of the web roll R, the control unit 5 causes the web W to be rewound by the transport unit 2 so that the second mark 62 moves to the specified return position or upstream thereof, and then the web W Resume transport. Then, when the mark sensor 4A detects the second mark 62 after resuming conveyance of the web W, the control unit 5 resumes printing of the web W by the printing unit 3A based on the timing.

  Thereby, even in the case of single-sided printing, when printing is resumed from the middle of the web roll R, the first page after printing resumes from the same position as when there was no printing stop in the middle of the web roll R. Be started. For this reason, on the web W, it is possible to suppress occurrence of a waste (damaged paper) portion between the last page before resuming printing and the next page. As a result, the waste of the web W can be reduced.

  Here, the second mark 62 in the case of the above-mentioned single-sided printing corresponds to a claim mark, and the mark sensor 4A corresponds to a detection unit of the claim.

  In addition, when the printing job of single-sided printing is stopped in the middle of the web roll R and printing is stopped, the next printing job executed after resuming conveyance of the web W may perform double-sided printing.

  The present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the components without departing from the scope of the invention in the implementation stage. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiments. For example, some components may be deleted from all the components shown in the embodiment.

DESCRIPTION OF SYMBOLS 1 Printing apparatus 2 Conveyance part 3A, 3B Printing part 4A, 4B Mark sensor 5 Control part 52 Inkjet head 61 1st mark 62, 62A, 63 2nd mark R Web roll W web

Claims (3)

A transport unit for unwinding and transporting the web from the web roll;
An inkjet head that prints an image by ejecting ink onto a web, and prints a first mark indicating an image of each page and a start position for each page on the first surface of the web conveyed by the conveyance unit; A second mark having a shape different from the first mark, which indicates the start position of the next page of the first surface when printing is stopped in the middle of the web roll and substitutes for the first mark corresponding to the page. A first printing section for printing
A first detector for detecting the second mark, disposed upstream of the first printing unit in the web conveyance direction;
A second detector for detecting the first mark and the second mark, arranged on the downstream side of the first printing unit;
Based on the timing at which the second detection unit detects the first mark or the second mark, the inkjet head is disposed on the downstream side of the second detection unit and prints an image by ejecting ink onto a web. A second printing section for printing an image of each page on the second surface of the web;
A controller that controls the transport unit, the first printing unit, and the second printing unit;
The controller is
At the time of printing stop in the middle of the web roll, the conveyance of the web by the conveyance unit is stopped after the second mark is printed by the first printing unit,
The web is moved by the transport unit so that the second mark moves to a position at which the web transport speed can reach a predetermined print transport speed before the second mark reaches the first printing unit after the web transport is resumed. After rewinding, resume web transport,
Based on the timing at which the first detection unit detects the second mark after resuming conveyance of the web, the first printing unit resumes printing of the first surface, and the second detection unit detects the first mark or A printing apparatus that resumes printing control of an image of each page of the second surface by the second printing unit based on the timing at which the second mark is detected.   When the control unit resumes printing of the first surface by the first printing unit after stopping printing in the middle of the web roll, the second mark has the same shape as the first mark. The printing apparatus according to claim 1, wherein the first printing unit is controlled to perform printing to overwrite the second mark. A transport unit for unwinding and transporting the web from the web roll;
It has an inkjet head that prints an image by ejecting ink onto a web, prints an image of each page on the web conveyed by the conveyance unit, and starts the next page when printing stops in the middle of the web roll A printing section for printing a mark indicating the position;
A detection unit for detecting the mark disposed on the upstream side of the printing unit in the web conveyance direction;
A controller that controls the transport unit and the printing unit;
The controller is
At the time of printing stop in the middle of the web roll, the conveyance of the web by the conveyance unit is stopped after the mark is printed by the printing unit,
After the web is rewound by the transport unit so that the mark moves to a position where the web transport speed can reach a predetermined print transport speed before the mark reaches the printing unit after the web transport is resumed. , Resume web transport,
A printing apparatus that resumes printing by the printing unit based on the timing at which the detection unit detects the mark after resuming web conveyance.