JP5936416B2 - Method for correcting misalignment in inkjet printing apparatus and inkjet printing apparatus - Google Patents

Description

The present invention relates to a positional deviation correction method and inkjet printing equipment in an ink jet printing apparatus, in particular, the paper to be printed, a technique for correcting deviation of the ejection positions of ink droplets occurring in the conveying direction of the print medium such as film About.

2. Description of the Related Art Conventionally, an ink jet printing apparatus rolls a print medium and prints the print medium with an ink jet printing unit provided on the transport path. The printing unit
In the case of color printing, print heads for each color are arranged in the order of, for example, black (K), cyan (C), magenta (M), and yellow (Y) along the conveyance path. The print heads for the respective colors are arranged side by side in the main scanning direction so as to cover the entire print area in the width direction (main scanning) of the print medium. Therefore, in this type of inkjet printing apparatus, printing can be performed on a print medium while feeding the print medium in the transport path direction (sub-scanning direction) without moving the print head in the main scanning direction (see Patent Document 1). ). This method is called a one-pass method.

  Since the print heads of the respective colors are provided along the conveyance path, for example, if droplets of the respective color inks are ejected to the same portion of the print medium, the ink droplets are ejected from the black (K) print head. Thereafter, after a predetermined delay time, it is necessary to eject ink droplets from the cyan (C) print head. This delay time t is L if the distance between the black (K) print head and the cyan (C) print head is L, and the print medium transport speed (hereinafter also referred to as “print speed”) is V. / V. If the distance between the print heads is the same, the magenta (M) print head has a 2 × t delay time 2t from the black (K) print head, and the yellow (Y) print head has black (K). Ink droplets are ejected from the print head with a delay time of 3 × t.

  If the delay time is not set properly or the printing speed fluctuates undesirably, the print head of each color will not be able to correctly eject ink droplets to the position in the sub-scanning direction, which is called misregistration (color misregistration). A printing position shift (also simply referred to as “position shift” in the present specification) occurs. Conventionally, an inkjet printing apparatus is provided with an image sensor downstream of the printing unit in the conveyance direction of the printing medium, reads a pattern printed on the printing medium, calculates the amount of positional deviation of printing, and adjusts the delay time. The position deviation is corrected.

JP 2012-16894 A

However, the conventional example having such a configuration has the following problems.
Whenever printing conditions such as printing speed or tension value change, the amount of printing misalignment is measured and the delay time is adjusted.However, the amount of misalignment at the beginning of printing is quite large. It is difficult to adjust an appropriate delay time. For this reason, the delay time is adjusted by measuring the amount of displacement several times. As described above, according to the conventional method, every time the printing condition is changed, it takes time to correct the misregistration.

  The present invention has been made in view of such circumstances, and an ink jet that can prevent a decrease in printing efficiency by shortening the time required to correct a printing misalignment as much as possible when the printing conditions change. It is an object of the present invention to provide a misregistration correction method in a printing apparatus, an inkjet printing apparatus, and a misregistration amount storage table creation method in an inkjet printing apparatus.

  As a result of intensive studies to achieve the above object, the present inventors have obtained the following knowledge. That is, the delay time is obtained by dividing the separation distance in the transport direction from the upstream ink nozzle to the downstream ink nozzle by the transport speed of the print medium. However, even when the downstream ink nozzles were driven using the calculated delay time, a printing misalignment occurred. As a result of various investigations, it has been found that the amount of misregistration of printing changes depending on the printing conditions, particularly the magnitude of the tension value acting on the printing medium and the slowness of the conveyance speed of the printing medium. As a result, if the amount of misregistration of printing is measured and stored in advance according to multiple types of printing conditions consisting of a combination of tension to be set on the printing medium and the conveyance speed of the printing medium, it is actually used. It is possible to grasp in advance the amount of misregistration under the printing conditions. Therefore, by correcting the calculated delay time using the misregistration amount measured in advance, it is possible to set the delay time suitable for the printing condition in which the misregistration is minimized.

The present invention conceived based on the above knowledge has the following configuration.
That is, the present invention includes a plurality of ink nozzles along the transport path of the print medium, and after ejecting ink from the ink nozzles on the upstream side of the transport path, the ink on the downstream side from the upstream ink nozzles In an ink jet printing apparatus configured to eject ink from the downstream ink nozzle when a predetermined delay time corresponding to a separation distance in the transport direction to the nozzle and a transport speed of the print medium has elapsed. A misregistration correction method, comprising: a printing misregistration amount corresponding to a printing condition obtained by adding a material and a thickness of the print medium to a combination of at least a tension value acting on the print medium and a conveyance speed of the print medium; The delay time is corrected before printing based on the conveyance speed of the print medium, and printing is performed by driving the downstream ink nozzle with the corrected delay time. And wherein the door.

According to the present invention, the predetermined delay time is set after the ink is ejected from the ink nozzle on the upstream side of the transport path of the print medium and before the ink is ejected from the ink nozzle on the downstream side. This delay time is a value obtained by dividing the separation distance in the transport direction from the upstream ink nozzle to the downstream ink nozzle by the transport speed of the print medium. However, the set delay time is not necessarily an appropriate value, and printing misalignment occurs when printing is actually executed. This misalignment depends on the tension value of the print medium and the conveyance speed of the print medium. In view of this, the amount of misregistration of printing corresponding to the printing conditions is determined in advance by adding at least the combination of the tension value of the printing medium and the conveyance speed of the printing medium to the material and thickness of the printing medium . By dividing this misregistration amount by the conveyance speed of the printing medium, a correction amount for the delay time can be obtained. As described above, according to the present invention, the amount of misregistration of printing and the conveyance of the printing medium according to the printing condition in which the material and thickness of the printing medium are added to the combination of at least the tension value acting on the printing medium and the conveyance speed of the printing medium. Since the delay time is corrected before printing based on the speed, it is possible to suppress the positional deviation of printing as much as possible from the beginning of printing, thereby improving the printing quality and the printing efficiency. In addition, since the printing misalignment also changes depending on the material and thickness of the print medium, in addition to the combination of the tension value acting on the print medium and the conveyance speed of the print medium, the delay time depends on the material and thickness of the print medium. Correct. Thereby, it is possible to further reduce the positional deviation of printing.

  In the present invention, it is preferable that the ink nozzle on the upstream side of the transport path is any one of black (K), cyan (C), magenta (M), and yellow (Y) in the transport direction. Nozzles provided in an ink discharge line head arranged in a direction perpendicular to the ink discharge line, and the ink nozzles on the downstream side of the transport path are arranged along the transport path on the downstream side of the ink discharge line head installed on the upstream side. Ink nozzles respectively provided in the remaining three ink discharge line heads installed. According to this configuration, a delay time from when ink is ejected from the ink nozzles provided in the upstream ink ejection line head to when ink is ejected from the ink nozzles provided in the downstream ink ejection line head is appropriate before printing. Therefore, color misregistration can be suppressed as much as possible from the beginning of printing.

  In the present invention, preferably, the ink nozzles on the upstream side of the transport path are arranged upstream of the plurality of inkjet heads arranged in a staggered manner in the direction perpendicular to the transport direction in the ink discharge line head. Ink nozzles provided in the inkjet head, and the ink nozzles on the downstream side of the transport path are ink nozzles provided in the inkjet head arranged on the downstream side of the ink discharge line head. According to this configuration, the delay time from when ink is ejected from the ink nozzle provided in the inkjet head arranged upstream in the same ink ejection line head to when ink is ejected from the ink nozzle provided in the downstream inkjet head Is appropriately corrected before printing, so that a positional shift occurring in the same color can be suppressed as much as possible from the beginning of printing.

  In the present invention, preferably, the ink nozzles on the upstream side of the transport path are arranged upstream of the transport path in each of a plurality of inkjet heads arranged in a staggered manner in a direction perpendicular to the transport direction in the ink discharge line head. Of the plurality of head modules arranged on the downstream side and the downstream side of the head module. The ink nozzle is provided (claim 4). According to this configuration, the delay time from when ink is ejected from the ink nozzles provided in the upstream head module in the inkjet head to when ink is ejected from the ink nozzles provided in the downstream head module is appropriate before printing. Therefore, the positional deviation between the nozzle rows in the head module can be suppressed as much as possible from the beginning of printing.

(Delete)

The present invention also relates to an inkjet printing apparatus, and includes a print medium supply unit that feeds a print medium wound in a roll shape, a plurality of drive rollers provided along a print medium conveyance path, and a conveyance path. A plurality of types of ink jet printing units, a print medium collection unit that winds and collects printed print media in a roll shape, and a combination of at least a tension value that acts on the print medium and a conveyance speed of the print medium A misregistration amount detection pattern is printed according to the printing conditions, the misregistration amount detection pattern is used to detect the misregistration amount of printing, and the detected misregistration amount is written. The positional deviation amount storage table storing the amount, the separation distance between the upstream side ink nozzle and the downstream side ink nozzle of the transport path of the printing unit, and the printing medium A delay time calculating means for calculating a delay time based on the transport speed of the printer, and a misregistration amount corresponding to one printing condition is read from the misregistration amount storage table, and the delay is based on the misalignment amount and the transport speed of the print medium. Delay time correction means for correcting the time before printing, and ink discharge control means for discharging ink from the downstream ink nozzle when the corrected delay time has elapsed after discharging ink from the upstream ink nozzle (Claim 5 ).

The actions and effects of the ink jet printing apparatus according to the present invention are as follows. First, the delay time is calculated based on the separation distance between the upstream ink nozzle and the downstream ink nozzle in the transport path of the printing unit and the transport speed of the print medium. Further, the positional deviation amount corresponding to one printing condition (the tension value of the printing medium and the conveyance speed of the printing medium) is read from the positional deviation amount storage table. The delay time is corrected before printing based on the amount of misalignment and the conveyance speed of the print medium. During printing, after the ink is ejected from the upstream ink nozzle, the ink is ejected from the downstream ink nozzle when the corrected delay time has elapsed. According to the present invention, since the misregistration amount storage table storing the misregistration amount of printing corresponding to a plurality of types of printing conditions is provided, the misregistration amount when printing is performed under one printing condition to be set. You can know in advance. Using this misregistration amount, it is possible to properly correct the delay time before printing, so printing misregistration can be minimized from the beginning of printing, improving print quality and printing efficiency. You can plan. The misregistration amount storage table prints misregistration amount detection patterns according to a plurality of types of printing conditions, detects misregistration amounts of printing using the misregistration amount detection patterns, and detects misregistration. Since it is created by writing the quantity, it can be created easily.

Further, in the present invention , the misregistration amount detection pattern is individually printed, and the misregistration amount of printing under a plurality of types of printing conditions is detected using the individually printed misregistration amount detection pattern. Preferred (Claim 6 ). According to this configuration, the misregistration amount storage table can be easily created.

Further, in the present invention , an image sensor is provided on the downstream side of the printing unit, the misregistration amount detection pattern is continuously printed, and the misregistration amount detection pattern that is continuously printed is printed by the image sensor. scanning to it is preferable to continuously detect the amount of positional deviation printed in a plurality of types of printing conditions (claim 7). According to this configuration, the misregistration amount storage table can be created easily and quickly.

Furthermore, in the present invention , an image sensor is provided on the downstream side of the printing unit, and the position shift amount of the position shift amount detection marker printed beside the actual print area during normal printing is scanned by the image sensor. detecting a positional deviation amount in the printing conditions during printing execution, but updating the positional displacement amount storage table using the positional displacement amount obtained by the detected preferred (claim 8). The amount of printing misregistration is not constant, and changes due to the influence of ambient temperature and humidity. According to this configuration, the content of the misregistration amount storage table is updated with the misregistration amount detected during normal printing, so that the delay time can be appropriately corrected in consideration of the influence of ambient temperature and humidity. .

Further, in the present invention, the positional deviation amount of the positional deviation amount detection marker printed beside the actual printing area during normal printing is scanned by the image sensor, and the positional deviation amount under the printing condition during printing is detected. Preferably, the misregistration amount storage table is updated using the detected misregistration amount. The amount of printing misregistration is not constant, and changes due to the influence of ambient temperature and humidity. According to this configuration, the content of the misregistration amount storage table is updated with the misregistration amount detected during normal printing, so that the delay time can be appropriately corrected in consideration of the influence of ambient temperature and humidity. .

Further, in the present invention, it is preferable that the plurality of printing conditions include a material and a thickness of the printing medium in addition to a combination of a tension value acting on the printing medium and a conveyance speed of the printing medium. . Since the delay time is corrected according to the material and thickness of the print medium in addition to the combination of the tension value acting on the print medium and the conveyance speed of the print medium, it is possible to further reduce the positional deviation of printing.

According to the present invention, at least the combination of the tension value acting on the printing medium and the printing medium conveyance speed plus the printing medium material and thickness, the printing displacement amount and the printing medium conveyance speed according to the printing conditions are obtained. Since the delay time is corrected before printing on the basis of this, it is possible to suppress the printing misalignment as much as possible from the beginning of printing, thereby improving the printing quality and the printing efficiency. In addition, since the printing misalignment also changes depending on the material and thickness of the print medium, in addition to the combination of the tension value acting on the print medium and the conveyance speed of the print medium, the delay time depends on the material and thickness of the print medium. Correct. Accordingly, it is possible to further reduce the printing positional deviation.

1 is a schematic configuration diagram illustrating an entire inkjet printing apparatus according to a first embodiment. It is a figure which shows schematic structure of a printing unit. It is a figure which shows schematic structure of an ink discharge line head. It is a figure which shows schematic structure of an inkjet head. 1 is a block diagram illustrating a schematic configuration of a control system of an ink jet printing apparatus according to Embodiment 1. FIG. It is explanatory drawing of a color gap, (a) is a state without a color gap, (b) is a figure which shows the state in which the color gap generate | occur | produced. It is a figure which shows the relationship between the color shift amount and a tension value. It is a figure which shows the relationship between the color shift amount and tension value at the time of correcting the color shift with a predetermined tension value. It is a figure which shows the relationship between the color shift amount and the conveyance speed of continuous paper WP. It is a schematic diagram of a positional deviation amount storage table. It is explanatory drawing of the same color position shift, (a) is a state in which there is no same color position shift, (b) is a figure which shows the state in which the same color position shift has occurred. It is explanatory drawing of the position shift between columns, (a) is a state without the position shift between columns, (b) is a figure which shows the state which the position shift between columns generate | occur | produced. 6 is a block diagram illustrating a schematic configuration of a control system of an ink jet printing apparatus according to Embodiment 2. FIG. It is explanatory drawing of the marker for position shift amount detection.

Hereinafter, an ink jet printing apparatus according to a first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram illustrating the entire inkjet printing apparatus according to the first embodiment.

  The ink jet printing apparatus according to the present embodiment includes a paper feeding unit 1, an ink jet printing apparatus main body 3, and a paper discharge unit 5. For example, the paper supply unit 1 feeds and supplies a continuous paper WP wound in a roll shape as a printing medium. The printing apparatus main body 3 performs printing on the supplied continuous paper WP. The paper discharge unit 5 winds and collects the printed continuous paper WP in a roll shape. The paper feed unit 1 corresponds to the print medium supply unit in the present invention, and the paper discharge unit 5 corresponds to the print medium collection unit in the present invention.

  The paper supply unit 1 holds the roll-shaped continuous paper WP so as to be rotatable about a horizontal axis, and unwinds and supplies the continuous paper WP to the printing apparatus main body 3. The paper discharge unit 5 winds the continuous paper WP printed by the printing apparatus main body 3 around the horizontal axis. When the supply side of the continuous paper WP is the upstream side and the discharge side of the continuous paper WP is the downstream side, the paper feeding unit 1 is disposed on the upstream side of the printing apparatus main body 3, and the paper discharge unit 5 is on the downstream side of the printing apparatus main body 3. Is arranged.

  The printing apparatus main body 3 rolls the continuous paper WP fed out from the paper supply unit 1 toward the paper discharge unit 5, and sequentially drives a plurality of drive rollers 7, 9, from the upstream side along the conveyance path. 11 and 13 are provided. The driving rollers 7, 9 and 13 cooperate with the pressing roller 15 to sandwich and convey the continuous paper WP. The drive roller 11 is a heat roller for drying the ink printed on the continuous paper WP. Hereinafter, “drive roller 11” is also referred to as “heat roller 11”. The heat roller 11 does not use a press roller in order to avoid ink adhesion to the press roller. In addition to the drive rollers 7, 9, 11, and 13, a plurality of guide rollers 17 that guide the continuous paper WP are provided on the conveyance path.

  An inkjet printing unit 19 is provided on the downstream side of the second drive roller 9 from the upstream side. The printing unit 19 includes an ink discharge line head 21 that discharges ink droplets. Specifically, as shown in FIGS. 1 and 2, the transport direction is indicated in order from the upstream side along the transport path (the transport direction is indicated by TD in FIG. 2), for example, black (K), cyan (C), Four ink discharge line heads 21K, 21C, 21M, and 21Y are individually provided for magenta (M) and yellow (Y). The ink discharge line heads 21K, 21C, 21M, and 21Y extend in the horizontal direction (the width direction of the continuous paper WP and the direction perpendicular to the paper surface in FIG. 2) orthogonal to the conveyance direction of the continuous paper WP. Thereby, it is possible to print the print area in the width direction of the continuous paper WP without moving the head.

  If attention is paid to the printing unit 19, the ink nozzle provided in the ink discharge line head 21K provided on the most upstream side corresponds to the ink nozzle on the upstream side in the present invention. The ink nozzles provided in the ink discharge line heads 21C, 21M, and 21Y provided on the downstream side with respect to the ink discharge line head 21K correspond to the ink nozzles on the downstream side in the present invention.

Further, as shown in FIG. 3, the ink discharge line heads 21K, 21C, 21M, and 21Y have a plurality of inkjet heads 23 (23 ₁ to 23 ₈ ) arranged in a staggered manner in the width direction of the continuous paper WP. It extends to. Paying attention to one of the ink discharge heads 21, the ink nozzles provided in the inkjet head 23 _1, 23 3, _{23 5,} 23 ₇ provided on the upstream side of the transport path, it corresponds to the ink nozzles on the upstream side in the present invention To do. On the other hand, the ink nozzles provided in the downstream inkjet head ₂₃ 2 provided on the _side, 23 _4, 23 6, 23 ₈ corresponds to the ink nozzles on the downstream side in the present invention. In addition, the code | symbol TD in FIG. 3 shows the conveyance direction of the continuous paper WP.

Further, each ink jet head 23 is composed of two head modules 25 (25 ₁ , 25 ₂ ) as shown in FIG. The ink nozzles 27 provided in the head module 25 are arranged with a half-pitch shift in the width direction of the continuous paper WP. Paying attention to one of the inkjet head 23, the ink nozzles 27 provided in the head module 25 ₁ provided on the upstream side of the conveying path (27 ₁₎ corresponds to the ink nozzles on the upstream side in the present invention. On the other hand, the ink nozzle 27 (27 ₂₎ provided in the head module 25 ₂ provided on the downstream side corresponds to the ink nozzles on the downstream side in the present invention.

  All the ink nozzles 27 provided in the printing unit 19 are controlled by the head drive circuit 29 at the timing of each ink discharge. The head drive circuit 29 corresponds to the ink ejection control means in the present invention.

  Returning to FIG. 1, a drying unit 31 is provided on the downstream side of the printing unit 19. The drying unit 31 includes the heat roller 11 described above. The heat roller 11 incorporates an infrared lamp (not shown). A warm air blowing portion 33 is provided along the circumferential surface of the heat roller 11 to blow warm air toward the circumferential surface of the heat roller 11.

  An inspection unit 35 is provided on the downstream side of the drying unit 31. The inspection unit 35 includes an image sensor 37. The inspection unit 35 scans the printing area of the continuous paper WP with the image sensor 37 to inspect whether there is any positional deviation of printing, dirt or omission in the printed portion. The inspected continuous paper WP is fed downstream by the drive roller 13 and taken up and collected by the paper discharge unit 5.

  A plurality of tension sensors 39, 41, and 43 are provided along the conveyance path of the printing apparatus main body 3 to measure the tension acting on the continuous paper WP. The tension sensor 39 detects the tension acting on the continuous paper WP between the drive rollers 7 and 9. The tension sensor 41 detects the tension acting on the continuous paper WP between the driving roller 9 and the heat roller 11. The tension sensor 43 detects the tension acting on the continuous paper WP between the heat roller 11 and the driving roller 13.

  Furthermore, the ink jet printing apparatus according to the first embodiment includes a main control unit 45 and an operation unit 47. The main control unit 45 comprehensively controls each component of the inkjet printing apparatus, and includes a central processing unit (CPU) and the like. The operation unit 47 operates the ink jet printing apparatus, and includes, for example, a touch panel and various switches. As will become clear from the description to be described later, the main control unit 45 has functions as a positional deviation amount storage table, a delay time calculation means, and a delay time correction means in the present invention.

  Next, the configuration of the control system of the inkjet printing apparatus according to the first embodiment will be described with reference to FIG. FIG. 5 is a block diagram illustrating a schematic configuration of a control system of the ink jet printing apparatus according to the first embodiment.

  In FIG. 5, the components shown by the same reference numerals as those shown in FIG. 1 are the same as the components described in FIG. The drive rollers 7, 9, 11, and 13 are driven by motors M1, M2, M3, and M4, respectively. A drive circuit 49 is connected to each of the motors M1 to M4, and rotation detection sensors R1 to R4 for detecting each rotation speed are attached. In FIG. 5, the configurations of the drive system and the control system of the drive rollers 7 and 13 are not shown. The motor M2 is a reference motor for transporting the continuous paper WP at a predetermined reference speed. The main control unit 45 is a control system for driving the motor M2 at a reference speed, a reference speed setting unit 51 for setting a reference speed, and a subtractor for calculating a deviation between the reference speed and the detected speed value of the motor M2. 53 and a speed controller 55 that adjusts the rotational speed of the motor M2 so that the deviation is eliminated. The speed control unit 55 employs PID control, for example. The reason why the second motor M2 is used as a reference instead of using the first motor M1 of the drive system as the reference is that the feeding speed of the continuous paper WP fed out from the paper feeding unit 1 varies greatly, and the influence thereof. Is to avoid.

  The main control unit 45 drives the motor M3 with a predetermined rotation speed ratio (draw ratio) with respect to the motor M2 to generate a speed difference between the drive rollers 9 and 11, thereby generating tension on the continuous paper WP. As a means (tension generating means) for this purpose, the following control system is provided. The control system includes a draw ratio setting unit 57 for setting a rotation speed ratio (draw ratio) of the motor M3 with respect to the motor M2, and a multiplier 59 that multiplies the reference speed and the draw ratio to output a rotation speed command. A subtractor 61 for calculating a deviation between the rotation speed command, the detected speed value of the motor M3, and a speed correction value described later, and a speed control unit 63 for adjusting the rotation speed of the motor M3 so that the deviation is eliminated. Yes.

  Further, the main control unit 45 includes the following control system as means (tension control means) for maintaining the tension acting on the continuous paper WP between the drive rollers 9 and 11 at a predetermined value. The control system includes a tension setting unit 65 for setting a tension target value to be applied to the continuous paper WP, a subtractor 67 for calculating a deviation between the tension target value and the tension detection value from the tension sensor 41, and the deviation. And a tension control unit 69 that calculates a speed correction value of the motor M3 and applies it to the subtractor 61 so as to eliminate this. The tension control unit 69 employs PI (proportional / integral) control, for example.

  Similarly, the main control unit 45 includes the same speed control system and tension control system as the motor M3 described above for the motors M1 and M4.

  Further, the main control unit 45 discharges ink from the ink nozzles on the upstream side of the transport path, and then separates the separation distance in the transport direction from the upstream ink nozzles to the downstream ink nozzles and the transport speed of the continuous paper WP. In order to eject ink from the downstream ink nozzle when a predetermined delay time corresponding to the time elapses, the following configuration is provided.

  First, the main control unit 45 includes an inter-nozzle distance storage unit 71. The inter-nozzle distance storage unit 71 stores in advance a separation distance (hereinafter also referred to as “inter-nozzle distance”) between the upstream ink nozzle and the downstream ink nozzle as a fixed value. The following values are stored as the inter-nozzle distance.

(1) Distance between Ink Ejection Line Heads First, distances L _KC , L _KM , L _KY to the respective ink ejection line heads 21C, 21M, 21Y with reference to the ink ejection line head 21K on the most upstream side of the transport path ( 2) is stored.

(2) upstream of the inkjet head ₂₃ 1 in the inkjet head distance each ink discharge line head _21, 23 _3, 23 5, 23 ₇ downstream of the inkjet head ₂₃ 2 relative to the _{23 4,} 23 6, 23 ₈ A distance L _{H to} (see FIG. 3) is stored.

(3) Distance head module 25 ₁ on the upstream side of the head module distance between the inkjet head 23 to the head module 25 and _second reference the downstream L _{M (see} FIG. 4) is stored.

  Returning to FIG. The main control unit 45 is based on the inter-nozzle distance read from the inter-head distance storage unit 71 and the transport speed of the continuous paper WP (in this embodiment, the reference speed VR set in the reference speed setting unit 51). A delay time calculation unit 73 for calculating the delay time is provided. The delay time calculation unit 73 corresponds to the delay time calculation means in the present invention. Specifically, the delay time from the ink discharge from the upstream ink nozzle to the ink discharge from the downstream ink nozzle is calculated as follows.

(1) Delay time between the ink discharge line heads The delay time T _KC of the ink discharge line head 21C with respect to the ink discharge line head 21K is obtained by dividing the separation distance L _KC between the ink discharge line heads 21K and 21C by the reference speed VR. Value L _KC / VR. Similarly, the delay time _{T KM} ink discharge line head 21M relative to the ink discharge line head 21K _is given by _L KM / VR. Further, the delay time _{T KY} ink discharge line head 21Y relative to the ink discharge line head 21K _is given by _L KY / VR.

(2) Delay time between ink jet heads The downstream ink jet heads 23 (23 ₂ , 23 ₄ ,...) Based on the upstream ink jet heads 23 (23 ₁ , 23 ₃ ,...) Of each ink discharge line head 21. delay time _{T H} of ...) is given by the value _L H / VR of the distance _{L H} of both the inkjet head is divided by the reference speed VR.

(3) the delay time TM of the head module 25 ₂ downstream with the head module 25 ₁ on the upstream side as a reference in delay time the ink jet head 23 between the head modules, the distance L _M of both modules at the reference speed VR The divided value is given by L _M / VR.

  Further, the main control unit 45 prints misregistration amounts corresponding to a plurality of types of printing conditions including combinations of tension values acting on the continuous paper WP and the conveyance speed of the continuous paper WP (reference speed VR in this embodiment). Is stored. Hereinafter, the positional deviation amount storage table 75 will be described in detail.

  Even when the ink discharge delay time of the downstream ink nozzle with reference to the upstream ink nozzle is set to the delay time calculated by the delay time calculation unit 73 described above, a printing misalignment may occur. . As described above, as a result of intensive studies by the present inventors, this positional deviation amount is a printing composed of a combination of a tension value acting on the continuous paper WP and the transport speed of the continuous paper WP (the reference speed VR in this embodiment). It became clear that it changed according to conditions. Hereinafter, the misregistration of printing will be described with reference to FIG.

If the delay time between the ink discharge line heads 21 is not appropriate, a color shift as shown in FIG. 6 occurs. When the delay time is appropriate, if the line segments are printed at the same position on the continuous paper WP with the four ink discharge line heads 21 (21K, 21C, 21M, and 21Y), as shown in FIG. , M and Y line segments accurately overlap. On the other hand, if the delay time is inappropriate, positional deviation occurs in each of the K, C, M, and Y line segments as shown in FIG. This is so-called “color shift”. The symbol ΔL _KC in FIG. 6B is an inter-color shift between KCs, ΔL _KM is an inter-color shift between KMs, and ΔL _KY is an inter-color shift between KYs. Since the ink discharge line head 21Y has the longest separation distance with respect to the upstream ink discharge line head 21K, the positional deviation amount ΔL _KY of printing by the ink discharge line head 21Y is the largest.

As shown in FIG. 7, the color shift amounts ΔL _KY , ΔL _KM , ΔL _KC change according to the tension value acting on the continuous paper WP (particularly, the tension value between the drive rollers 9, 11). The degree of change in the color misregistration amount according to the tension value differs depending on the color misregistration amounts ΔL _KY , ΔL _KM , ΔL _KC . Farthest distance long ink discharge line head 21K, the largest degree of change in color between the shift amount [Delta] L _KY between 21Y. Hereinafter, the color of the ink discharge line heads 21K and 21C having the shortest separation distance is large, with the degree of change in the color shift amount ΔL _KM of the ink discharge line heads 21K and 21M having the next longest separation distance from the ink discharge line head 21K. The degree of change in the amount of deviation ΔL _KC is the smallest.

As described above, since the degrees of change in the color misregistration amounts ΔL _KY , ΔL _KM , ΔL _KC corresponding to the tension values are different, as shown in FIG. 8, each color misregistration amount ΔL when the tension value is 10 kg. _Even if the delay time is set so that _KY , ΔL _KM , and ΔL _KC become zero, when the tension value changes, the respective color misregistration amounts ΔL _KY , ΔL _KM , ΔL _KC are generated. Therefore, it is necessary to adjust the delay time according to the new tension value.

Similar color misregistration also occurs when the transport speed of the continuous paper WP changes. FIG. 9 is a schematic diagram illustrating how the color shift amounts ΔL _KY , ΔL _KM , and ΔL _KC change according to the conveyance speed of the continuous paper WP.

As described above, the color shift amounts (position shift amounts) ΔL _KY , ΔL _KM , ΔL _KC are the tension values acting on the continuous paper WP and the transport speed of the continuous paper WP (the reference speed VR in this embodiment). Since it changes according to the printing condition consisting of the combination, the positional deviation amount of printing corresponding to a plurality of types of printing conditions is measured in advance and stored in the positional deviation amount storage table 75 as the positional deviation amount according to the printing conditions. Yes.

In this embodiment, three types of tension values to be applied to the continuous paper WP are prepared. For example, 5 kg (T5), 15 kg (T15), and 25 kg (T25) can be set. On the other hand, three types of speeds of 25 rpm (V25), 50 rpm (V50), and 120 rpm (V120) can be set as the conveyance speed of the continuous paper WP. In addition, rpm is the number of rotations of the drive roller 9 for 1 minute. In the present embodiment, the other printing conditions are (T5, V50), (T25, V50), (T15, V25), (T15, V120) on the basis of the printing condition composed of the combination of the tension value T15 and the conveyance speed V50. Can be set. A total of five types of printing conditions including the reference printing conditions can be set, and the misregistration amounts (position deviation amounts) ΔL _KY , ΔL _KM , ΔL _KC measured according to each printing condition are stored in the misregistration amount storage table. 75. FIG. 10 is a schematic diagram of misregistration amounts corresponding to the printing conditions stored in the misregistration amount storage table 75.

The inter-color shift amounts ΔL _KY , ΔL _KM , and ΔL _KC are substantially proportional to the separation distance between the ink discharge line heads. Therefore, if allowing some errors, by measuring the positional deviation amount [Delta] L _KY positional deviation amount is the largest ink discharge line head 21Y (ΔL _KY1 ~ΔL _KY5 in FIG. 10), the other of the displacement amount [Delta] L _KM (ΔL _{KM1 to} ΔL _KM5 ) and ΔL _KC (ΔL _{KC1 to} ΔL _KC5 ) are the ratio of the separation distance L _KM between the ink discharge line heads 21K and 21M to the separation distance L _KY between the ink discharge line heads 21K and 21Y, Similarly it is possible to know the ink discharge line head 21K, the ratio of the distance L _KC between 21C to simple.

  Returning to FIG. The main control unit 45 reads out a positional deviation amount corresponding to one printing condition from the positional deviation amount storage table 75, and based on the positional deviation amount and the transport speed (reference speed) of the continuous paper WP, the delay time calculation unit 73. Is provided with a delay time correction unit 77 for correcting the delay time calculated in (1). The delay time correction unit 77 corresponds to the delay time correction means in the present invention.

  The delay time correction process performed by the delay time correction unit 77 will be specifically described below.

(1) explaining a correction process of the delay time T _KY ink discharge line head 21Y relative to the corrected ink discharge line head 21K of the delay time between the ink discharge line head. For example, when the printing condition is (T15, V50), the positional deviation amount ΔLKY1 at that time is read from the positional deviation amount storage table 75. If the read positional deviation amount ΔL _KY1 is divided by the conveyance speed (V50) of the continuous paper WP at that time, a correction amount for the delay time can be obtained. For example, as shown in FIG. 6B, if the line segment Y is printed on the upstream side of the transport path with respect to the line segment K, the delay time of the ink discharge line head 21 </ b> Y. T _KY is determined to be longer than the appropriate value is subtracted from the correction amount a delay time T _KY. Conversely, in the case where the line segment Y are printed deviated to the downstream side of the conveying path with respect to the line segment K, the delay time T _KY ink discharge line head 21Y is determined that is shorter than the proper value Then, the correction amount is added to the delay time _TKY . Similarly, the correction amount of the delay time of the other ink discharge line heads 21M and 21C can be obtained by reading out the positional deviation amounts ΔL _KM1 and ΔL _KC1 of the line heads 21M and 21C from the positional deviation amount storage table 75.

(2) Correction of delay time between inkjet heads Refer to FIG. FIG. 11A is a schematic diagram showing a printing mode when the delay time between the inkjet heads is appropriate, and FIG. 11B is a schematic diagram showing a state of misalignment when the delay time is inappropriate. When the delay time between the ink jet heads is appropriate, for example, the upstream ink jet head and the downstream ink jet head of the ink discharge line head 21Y can cooperate to print a linear line segment. On the other hand, if the delay time is inappropriate, the line segment is deformed in a zigzag shape as shown in FIG. This is the so-called “same color position shift”.

For example ink jet head ₂₃ in the discharge line head 21Y (23 1, ₂₃ 3,...) Downstream of the inkjet head ₂₃ relative to the (23 2, ₂₃ 4, ...) correction processing delay time _{T H} of Is performed as follows. The positional deviation amount ΔL _KY1 of the ink ejection line head 21Y read from the positional deviation amount storage table 75 is set to the separation distance L _H of the inkjet head relative to the separation distance L _KY of the ink ejection line heads 21K and 21Y (see FIG. 3). By multiplying the ratio, it is possible to estimate the amount of displacement between the upstream and downstream inkjet heads 23. By dividing this misregistration amount by the conveyance speed of the continuous paper WP at that time, a correction amount for the delay time TH between the two inkjet heads 23 can be obtained.
Similarly, the delay time between the inkjet heads can be corrected for the other ink discharge line heads 21M and 21C.

(3) Correction of delay time between head modules Referring to FIG. FIG. 12A is a schematic diagram showing a printing mode when the delay time between the head modules is appropriate, and FIG. 12B is a schematic diagram showing a position shift when the delay time is inappropriate. When the delay time between the head modules is appropriate, the ink droplets ejected from the ink nozzles of both modules are arranged linearly in the width direction of the continuous paper WP. On the other hand, if the delay time is inappropriate, the ink droplets are arranged in a zigzag pattern as shown in FIG. This is the so-called “column misalignment”.

For example the correction process of the head module 25 _second delay time T _M of downstream relative to the head module 25 ₁ on the upstream side of the inkjet head 23 of the ink discharge line head 21Y is performed as follows. A position shift amount [Delta] L _KY1 ink discharge line head 21Y which is read from the positional deviation amount storing table 75, by multiplying the ratio of the distance L _M between the two head modules, both head module on the upstream side and the downstream side The amount of positional deviation between 25 ₁ and 25 ₂ can be estimated. By dividing this misregistration amount by the conveyance speed of the continuous paper WP at that time, the correction amount of the delay time TM between the head modules 25 ₁ and 25 ₂ can be obtained. Similarly, the delay time between the head modules can be corrected for the other ink discharge line heads 21M and 21C.

  Returning to FIG. The delay time corrected by the delay time correction unit 77 is given to the head drive circuit 29 as the ink discharge control means of the present invention. The head drive circuit 29 drives the ink nozzles of the respective ink discharge line heads 21 in accordance with the given delay time, so that the downstream ink nozzles are driven with an appropriate delay time with respect to the upstream ink nozzles. Is done.

  Next, a method for creating the misregistration amount storage table 75 in the inkjet printing apparatus according to the first embodiment will be described.

(1) First example of creation method (1-1) Printing process of misregistration amount detection pattern Predetermined misregistration amount detection pattern (for example, K, C, M, etc. as shown in FIG. 6) Y) is printed under the same printing condition.
(1-2) Detection process of misregistration amount The misregistration amount of printing between K-C, KM, and KY in the printing condition is detected using the printed misregistration amount detection pattern ( taking measurement.
The above steps (1-1) and (1-2) are repeated, and the misregistration amount detection patterns are individually printed under all printing conditions (in this embodiment, the five types of printing conditions shown in FIG. 10). For each printing condition, the amount of positional deviation of printing between K-C, KM, and KY is detected.
(1-3) Misregistration amount writing process The misregistration amount for each detected ink discharge line head 21 is written in the misregistration amount storage table 75 in association with five types of printing conditions.
By the above procedure, the misregistration amount storage table 75 can be easily created.

(2) Second example of creation method (2-1) Printing process of misregistration amount detection pattern The misregistration amount detection pattern similar to the first example is continuously printed under all printing conditions.
(2-2) Detection process of misregistration amount Using the image sensor 37 of the inspection apparatus 35 shown in FIG. 1, a continuously printed misregistration amount detection pattern is scanned between K and C under all printing conditions. , KM, KY, and KY are detected (measured).
(2-3) Writing process of misregistration amount The misregistration amount for each detected ink ejection line head 21 is written in the misregistration amount storage table 75 in association with five types of printing conditions.
By the above procedure, the misregistration amount storage table 75 can be created easily and quickly.

  The operation of the ink jet printing apparatus according to the first embodiment after creating the misregistration amount storage table 75 as described above will be described.

  Please refer to FIG. 1 and FIG. The operator operates the operation unit 47 to set one printing condition from among five types of printing conditions. The tension value in the set printing conditions is set in the tension setting unit 65, and the conveyance speed (reference speed) of the continuous paper WP is set in the reference speed setting unit 51. Further, the operator operates the operation unit 47 to set the draw ratio of the motors M1, M3, and M4. For example, the draw ratio of the motor M3 is set in the draw ratio setting unit 57. Since the separation distance between the upstream nozzle and the downstream nozzle stored in the inter-nozzle distance storage unit 71 shown in FIG. 5 is a fixed value, these are stored in advance in the inter-nozzle distance storage unit 71 as default values. ing.

  When the printing conditions are set as described above, the delay time calculation unit 73 stores the continuous paper WP conveyance speed (reference speed) set in the reference speed setting unit 51 and the inter-nozzle distance storage unit 71. Based on the separation distance between the upstream nozzle and the downstream nozzle, the delay time of the downstream nozzle with respect to the upstream nozzle is calculated. Specifically, the delay time calculation unit 73 calculates (1) the delay time between the ink discharge line heads, (2) the delay time between the ink jet heads, and (3) the delay time between the head modules. . Each calculated delay time is given to the delay time correction unit 77.

  On the other hand, based on the tension value set in the tension setting unit 65 and the conveyance speed of the continuous paper WP set in the reference speed setting unit 51, the positional deviation corresponding to the printing condition set from the positional deviation amount storage table 75 is obtained. The quantity is read out. In the present embodiment, the respective displacement amounts of the ink discharge line heads 21Y, 21M, and 21C are read out. The read positional deviation amount is given to the delay time correction unit 77.

  The delay time correction unit 77 first calculates the correction amount of the delay time of each ink discharge line head 21 by dividing the given positional deviation amount of each ink discharge line head 21 by the transport speed of the continuous paper WP ( (See “(1) Correction of delay time between inkjet heads” above). Then, the delay time of each ink discharge line head 21 given from the delay time calculation unit 73 is corrected by the correction amount. Further, the delay time correction unit 77 performs the above-described (2) correction of the delay time between the ink jet heads and (3) correction of the delay time between the head modules. The corrected delay time is given to the head drive circuit 29.

  The delay time correction process as described above is performed before printing. Thereafter, printing is performed as follows. Briefly described below.

  First, the speed control unit 55 controls the motor M2 serving as a reference so as to have a set conveyance speed (reference speed). The speeds of the other motors M1, M3, M4 are controlled so as to have speed target values corresponding to the draw ratios set for them.

  The motors M1, M3, and M4 are tension controlled as follows along with the speed control. For example, the tension of the continuous paper WP between the drive rollers 9 and 11 is measured by the tension sensor 41 between the drive rollers 9 and 11. The measured tension value is fed back to the tension control system. The tension control unit 69 adjusts the speed command value by giving the speed correction value to the subtractor 61 of the speed control system so that the deviation of the subtractor 67 is eliminated. As a result, the tension between the drive rollers 9 and 11 is maintained at the set tension value. The tension is similarly controlled between the other driving rollers 7 and 9 and between the driving rollers 11 and 13.

  In the state where the speed control and tension control of the continuous paper WP are performed as described above, printing is started when the continuous paper WP reaches a predetermined transport speed. Since the head drive circuit 29 drives the downstream ink nozzles with a delay time appropriately corrected according to the printing conditions, printing misalignment occurs between the upstream ink nozzles and the downstream ink nozzles. Is suppressed.

(Example 2)
The inkjet printing apparatus according to the second embodiment will be described with reference to FIG.
FIG. 13 is a block diagram illustrating a schematic configuration of a control system of the ink jet printing apparatus according to the second embodiment. In FIG. 13, the components shown by the same reference numerals as those shown in FIG. 5 are the same as the components described in the first embodiment, and thus the description thereof is omitted here.

  This inkjet printing apparatus has a function for updating the contents of the misregistration amount storage table 75 during execution of printing. The amount of misregistration of printing changes due to the influence of the ambient temperature and humidity as well as the printing conditions such as the tension value and transport speed of the continuous paper WP. Since the ambient temperature and humidity are not constant and change during printing, the contents of the misregistration amount storage table 75 are preferably updated during printing.

Therefore, in this embodiment, in order to detect misregistration during execution of printing, as shown in FIG. 14, misregistration amount detection markers DM (DM1, DM2) are located beside the actual print area PA of the continuous paper WP. I try to print. The positional deviation amount detection marker DM1 is a marker printed on the side edge in the longitudinal direction of the continuous paper WP. The misregistration amount detection marker DM2 is a marker printed between adjacent actual print areas PA. Any one marker DM may be printed.

  The misregistration amount detection marker DM printed beside the actual printing area PA of the continuous paper WP as described above is scanned and read by the image sensor 37 of the inspection unit 35 provided on the downstream side of the printing unit 19. The main control unit 45 includes a misregistration amount detection unit 79 that detects the misregistration amount of printing between KY, KM, and KC from the image supplied from the image sensor 37. The table updating unit 81 associates the printing displacement amount (update data) between K-C, KM, and KY detected by the displacement amount detection unit 79 with the printing conditions at that time. The contents of the misregistration amount storage table 75 are written and the contents of the misregistration amount storage table 75 are updated.

  In the next printing, the delay time is corrected by using the updated misregistration amount in the misregistration amount storage table 75, so that the delay time is more appropriately corrected according to the ambient temperature change and humidity change. . Therefore, according to the present embodiment, it is possible to further reduce the printing positional deviation.

  The present invention is not limited to the above embodiment, and can be modified as follows.

  (1) In Examples 1 and 2 described above, the tension value acting on the continuous paper WP and the transport speed of the continuous paper WP are used as printing conditions. However, the present invention further adds the following items as printing conditions. Also good. That is, the positional deviation of printing varies depending not only on the tension value and transport speed of the continuous paper WP, but also on the type of paper, for example, whether the paper has an elastic coefficient, whether it is easy to stretch or shrink, or the thickness of the paper. Therefore, in addition to the tension value of the print medium and the conveyance speed of the print medium as printing conditions, the material and thickness of the print medium are added, and the positional deviation amount of the printing is measured in advance according to the combination thereof, and the positional deviation amount storage table Is preferably created. As described above, by correcting the delay time based on many printing conditions, it is possible to further reduce the printing misalignment.

  (2) In the first and second embodiments, five types of print conditions can be set. However, the settable print conditions may be five types or less, or more.

  (3) In the first and second embodiments described above, a so-called one-pass ink jet printing apparatus is taken as an example, but the present invention is not limited to this method, and is also applicable to a so-called multi-pass ink jet printing apparatus. it can.

WP ... Continuous paper 1 ... Paper feed unit 3 ... Printing device body 5 ... Paper discharge unit 7, 9, 11, 13 ... Drive roller 19 ... Printing unit 31, 33, 35 ... Tension sensor 37 ... Main control unit 73 ... Delay time Calculation unit 75 ... Position deviation amount storage table 77 ... Delay time correction unit

Claims (10)

A plurality of ink nozzles are provided along the print medium transport path, and after ejecting ink from the ink nozzles on the upstream side of the transport path, in the transport direction from the upstream ink nozzles to the downstream ink nozzles. A misregistration correction method in an inkjet printing apparatus configured to eject ink from the downstream ink nozzle when a predetermined delay time corresponding to a separation distance and a conveyance speed of the printing medium has elapsed. And
Based on the amount of misalignment of printing and the conveyance speed of the printing medium according to the printing condition, which is a combination of at least the tension value acting on the printing medium and the conveyance speed of the printing medium plus the material and thickness of the printing medium A misregistration correction method in an ink jet printing apparatus, wherein a delay time is corrected before printing, and printing is performed by driving the downstream ink nozzles with the corrected delay time. In the ink jet printing apparatus according to claim 1,
The ink nozzle on the upstream side of the transport path is any one of black (K), cyan (C), magenta (M), and yellow (Y), and is arranged in a direction orthogonal to the transport direction. An ink nozzle provided in the ink discharge line head,
The ink nozzles on the downstream side of the transport path are ink nozzles respectively provided on the remaining three ink discharge line heads installed along the transport path on the downstream side of the ink discharge line heads installed on the upstream side. A misregistration correction method in an inkjet printing apparatus. In the ink jet printing apparatus according to claim 1,
The ink nozzles on the upstream side of the transport path are inks provided in an ink jet head disposed upstream of a plurality of ink jet heads disposed in a staggered manner in a direction orthogonal to the transport direction in the ink discharge line head. Nozzle,
A method of correcting misalignment in an ink jet printing apparatus, wherein the ink nozzles on the downstream side of the transport path are ink nozzles provided on an ink jet head disposed on the downstream side of the ink discharge line head. In the ink jet printing apparatus according to claim 1,
The ink nozzles on the upstream side of the transport path are disposed on the upstream side and the downstream side of the transport path in each of a plurality of inkjet heads arranged in a staggered manner in the direction perpendicular to the transport direction in the ink discharge line head. Among the plurality of head modules, an ink nozzle provided in the upstream head module,
A method of correcting misalignment in an ink jet printing apparatus, wherein the ink nozzles on the downstream side of the transport path are ink nozzles provided in a head module on the downstream side of the head modules. A print medium supply unit for feeding out a print medium wound in a roll;
A plurality of drive rollers provided along a conveyance path of the print medium;
An inkjet printing unit provided on the transport path;
A print medium recovery unit that winds and recovers the printed print medium in a roll;
A misregistration amount detection pattern is printed according to a plurality of types of printing conditions including a combination of at least a tension value acting on the print medium and a transport speed of the print medium, and printing is performed using the misregistration amount detection pattern. A misregistration amount storage table storing the misregistration amount of printing by detecting the misregistration amount and writing the detected misregistration amount;
A delay time calculation means for calculating a delay time based on a separation distance between an upstream side ink nozzle and a downstream side ink nozzle of a transport path provided in the printing unit and a transport speed of the print medium;
A delay time correction unit that reads a positional deviation amount corresponding to one printing condition from the positional deviation amount storage table, and corrects the delay time before printing based on the positional deviation amount and the conveyance speed of the print medium;
Ink jet printing comprising: ink discharge control means for discharging ink from the downstream ink nozzle when the corrected delay time has elapsed after discharging ink from the upstream ink nozzle apparatus. The inkjet printing apparatus according to claim 5,
Inkjet printing, wherein the misregistration amount detection pattern is individually printed, and the misregistration amount of printing under a plurality of types of printing conditions is detected using the individually printed misregistration amount detection pattern. apparatus. The inkjet printing apparatus according to claim 5,
An image sensor is provided on the downstream side of the printing unit,
The positional deviation amount detection pattern is continuously printed, and the continuously printed positional deviation amount detection pattern is scanned by the image sensor to continuously determine the positional deviation amount of printing under a plurality of types of printing conditions. An ink jet printing apparatus characterized by The inkjet printing apparatus according to claim 6,
An image sensor is provided on the downstream side of the printing unit,
The positional deviation amount of the positional deviation amount detection marker printed beside the actual printing area during normal printing is scanned by the image sensor, and the positional deviation amount in the printing condition during printing is detected and detected. An ink jet printing apparatus, wherein the misregistration amount storage table is updated using a misregistration amount. The inkjet printing apparatus according to claim 7,
The positional deviation amount of the positional deviation amount detection marker printed beside the actual printing area during normal printing is scanned by the image sensor, and the positional deviation amount in the printing condition during printing is detected and detected. An ink jet printing apparatus, wherein the misregistration amount storage table is updated using a misregistration amount. The inkjet printing apparatus according to claim 5, wherein
The inkjet printing apparatus, wherein the plurality of printing conditions include a material and a thickness of the printing medium in addition to a combination of a tension value acting on the printing medium and a conveyance speed of the printing medium.

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