JP5870794B2 - Image recording apparatus and image recording method - Google Patents

Description

  The present invention relates to a technique for recording an image by ejecting liquid onto a stopped recording medium while intermittently conveying the recording medium, and in particular, surface modification treatment is performed on the recording medium prior to liquid ejection onto the recording medium. It relates to the technology to be executed.

  Patent Document 1 describes an image recording apparatus in which a recording head ejects ink onto a recording medium supported on a platen to print an image on the recording medium. In particular, in this image recording apparatus, the recording medium is intermittently conveyed on the platen, and the recording head records an image on the recording medium stopped on the platen. Thus, the recording head ejects ink onto the recording medium that is sequentially conveyed onto the platen to record an image.

JP 2011-194797 A

  By the way, in the above apparatus for recording an image by ejecting a liquid such as ink onto a recording medium, it is important to firmly fix the liquid on the recording medium. Therefore, it is conceivable to perform the surface modification treatment on the recording medium using a surface modification machine such as a corona treatment machine. Specifically, a surface reformer is disposed on the upstream side of the recording head in the recording medium conveyance path, and the surface modification is performed on the recording medium that passes in front of the surface reformer as the recording medium is conveyed. What is necessary is just to perform a process. Thereby, the recording medium subjected to the surface modification treatment can be supplied to the recording head, and the fixability of the liquid ejected by the recording head to the recording medium can be improved.

  However, the recording medium for which the surface reformer performs the surface modification process is intermittently conveyed as described above. Therefore, the surface reformer needs to perform the surface modification process on the recording medium that passes intermittently in front of the surface reformer. At this time, it is ideal that the surface modification process can be started as soon as the passage of the recording medium is started. However, in practice, the surface modification process is started after the passage of the recording medium is started. Causes a time difference.

  If such a time difference is large, the recording medium may pass through the front of the surface reformer without being subjected to the surface modification process, and a region where the surface modification process is insufficient may occur in the recording medium. . In such a case, if an image is recorded by removing the insufficient area of the surface modification process, the recording medium is wasted correspondingly to the insufficient area, and if the image is recorded in the insufficient area of the surface modification process, this shortage Image unevenness may occur between the area and the other areas. Therefore, in any case, it is preferable to suppress the shortage area of the surface modification treatment.

  The present invention has been made in view of the above problems, and in the technology for recording an image by ejecting liquid onto a recording medium that is stopped while intermittently conveying the recording medium, the surface of the recording medium is subjected to surface modification treatment. An object of the present invention is to provide a technique capable of suppressing the shortage area of the surface modification treatment.

  In order to achieve the above object, an image recording apparatus according to the present invention ejects liquid onto a recording medium that is stopped on the supporting member and a supporting member that supports the recording medium conveyed along the conveying path. A recording head for recording an image, a surface reformer for executing a surface modification process for modifying the surface of the recording medium at a processing position upstream of the support member in the transport path in response to a processing execution signal, and a transport path A conveyance unit that intermittently conveys the recording medium from the upstream side to the support member and intermittently conveys the recording medium from the upstream side of the conveyance path to the processing position, and a processing unit that passes the recording medium to the processing position intermittently. In contrast, a relative movement mechanism that performs a relative movement process for moving the recording medium to the upstream side of the conveyance path, and a surface reformer during a passage period in which the recording medium passes through the processing position with intermittent conveyance to the processing position. Processing real And a control section that gives a signal, the control unit in advance before the start of the passing time, is characterized in that to perform the relative movement process of the relative movement mechanism.

  In order to achieve the above object, an image recording method according to the present invention records an image by ejecting liquid onto a recording medium that is stopped on a support member while conveying the recording medium along a conveyance path. In the method, a surface modification process for performing a surface modification process on a recording medium at a processing position upstream of a support member in a conveyance path using a surface modification machine that receives a process execution signal and performs a surface modification process And a conveying step of intermittently conveying the recording medium from the upstream side of the conveying path to the support member and intermittently conveying the recording medium from the upstream side of the conveying path to the processing position to pass the recording medium to the processing position; A relative movement step of performing a relative movement process of moving the recording medium relative to the processing position to the upstream side of the conveyance path, and a transit period in which the recording medium passes the processing position along with the intermittent conveyance to the processing position. To, while performing the surface modification step giving processing execution signal to the surface reformer is characterized by executing a previously relative movement step before the start of the pass period.

  In the invention configured as above (image recording apparatus and image recording method), the recording medium is intermittently conveyed toward the downstream side of the conveyance path, and the liquid is ejected onto the recording medium that is stopped on the support member. To record an image. In addition, a surface reformer that performs a surface modification process in response to a process execution signal is provided, and the surface modification process can be performed on the recording medium at a processing position upstream of the support member in the transport path. Yes. Therefore, according to the present invention, the surface reforming process is performed on the recording medium by appropriately giving a processing execution signal to the surface reformer while passing the recording medium to the processing position.

  Specifically, according to the intermittent conveyance of the recording medium to the support member, the recording medium is intermittently conveyed from the upstream side of the conveyance path to the processing position, so that the recording medium passes through the processing position intermittently. Then, during the passage period in which the recording medium passes through the processing position along with the intermittent conveyance to the processing position, a processing execution signal is given to the surface reformer, and the surface modification processing is performed on the recording medium passing through the processing position. Is done. At this time, if the surface modification machine cannot start the surface modification process immediately after the passage period starts (that is, the recording medium starts to pass through the processing position), the surface modification process as described above is insufficient. There was a possibility that a large amount of the area was generated.

  On the other hand, in the present invention, a relative movement process for moving the recording medium relative to the processing position to the upstream side of the transport path is executed in advance before the start of the passage period. Therefore, when the passage period starts, the area that has already undergone the surface modification process is moved relative to the processing position on the upstream side of the transport path. Therefore, for a while from the start of the passage period, since the region that has already undergone the surface modification treatment passes through the treatment position, even if the start of the surface modification treatment is delayed from the start of the passage period, It is possible to reduce the shortage area of quality processing.

  By the way, the transport unit has a feed shaft that supports a roll formed by winding a recording medium in a roll shape on the upstream side of the processing position in the transport path, and records fed from the roll by rotating the feed shaft in the forward direction. The image recording apparatus can be configured to intermittently pass the medium to the processing position. At this time, the image recording apparatus may be configured such that the relative movement mechanism performs the relative movement process by rewinding the recording medium to the roll by rotating the feeding shaft in the reverse direction.

  However, the amount of the recording medium to be rewound on the roll depends on the roll diameter in addition to the rotation amount of the feeding shaft. Therefore, when it is desired to manage the movement amount of the recording medium in the relative movement process, it is necessary to control the rotation amount of the feeding shaft while referring to the roll diameter.

  Therefore, the relative movement mechanism includes a first adjustment member that adjusts the first buffer amount, which is the length of the recording medium from the roll to the surface reformer, and the length of the recording medium from the surface reformer to the support member. A second adjusting member that adjusts a certain second buffer amount, and performing the relative movement process by increasing the first buffer amount by the moving amount while decreasing the second buffer amount by the moving amount. A recording apparatus may be configured.

  In such a configuration, instead of reducing the recording medium on the downstream side of the transport path from the surface reformer by the amount of movement, the relative movement is achieved by increasing the recording medium on the upstream side of the transport path from the surface reformer by the amount of movement. Processing is executed. Accordingly, the recording medium can be relatively moved to the upstream side of the transport path by the moving amount without rewinding the recording medium on the roll. As a result, even when the amount of movement of the recording medium in the relative movement process is managed, it is not particularly necessary to refer to the roll diameter, and the management can be easily performed.

  At this time, the relative movement mechanism has a winding roller that winds the recording medium from the back surface while facing the surface reformer with the recording medium interposed therebetween, and the first adjustment member is located upstream of the winding roller in the transport path. And the second adjustment member is a second adjustment roller for winding the recording medium from the surface on the downstream side of the winding roller in the transport path, and the relative movement mechanism is: It further has a rotation support shaft that rotates around the intermediate position between the first adjustment roller and the second adjustment roller while supporting the first adjustment roller and the second adjustment roller, and the relative movement processing is performed by rotating the rotation support shaft. The image recording apparatus may be configured to execute the above.

  In such a configuration, by rotating the rotation support shaft, the first adjustment roller and the second adjustment roller are moved like a seesaw, and recording is performed from the upstream side to the downstream side of the conveyance path with the surface reformer interposed therebetween. The medium can be moved. Therefore, it can be said that the relative movement process can be executed simply by rotating the rotation support shaft, which is preferable.

  In addition, the relative movement mechanism moves the surface reformer to the downstream side of the transport path, thereby moving the processing position where the surface reformer performs the surface reforming process to the downstream side of the transport path to perform the relative movement process. The image recording apparatus may be configured to execute the above. Even in such a configuration, it is possible to appropriately execute the relative movement process before the start of the passage period, and to suppress the insufficient region of the surface modification process.

  At this time, the relative movement mechanism has a winding roller that winds the recording medium from the back surface while facing the surface reformer across the recording medium, and when the passing period ends, the winding roller is moved downstream of the conveyance path. The image recording device is configured to execute the relative movement process by moving the surface reformer and the recording medium away from each other and then moving the surface reformer to a position facing the winding roller. May be.

  Thus, by separating the distance between the surface reformer and the recording medium at the end of the passage period, the surface reformer whose temperature has increased with the execution of the surface reforming process is separated from the recording medium to some extent. Can be cooled in place. Then, after cooling the surface reformer in this way, the surface reformer is moved to a position facing the winding roller, thereby mitigating the effect of heat generated by the surface reformer on the recording medium. can do.

  The conveyance unit may configure the image recording apparatus so that the operation of intermittently conveying the recording medium to the support member and the operation of intermittently passing the recording medium to the processing position are executed at different timings. In such a configuration, the operation of intermittently transporting the recording medium to the support member and the operation of intermittently passing the recording medium to the processing position can be executed at appropriate timings.

1 is a schematic diagram illustrating an example of a printing system to which the present invention can be applied. The top view which shows the structure of a recording unit partially. FIG. 2 is a block diagram schematically showing an electrical configuration included in the printing system of FIG. 1. The side view which showed typically the corona treatment unit in 1st Embodiment. 6 is a timing chart illustrating an example of a printing operation executed in the first embodiment. The side view which showed typically the corona treatment unit in 2nd Embodiment. 10 is a timing chart illustrating an example of a printing operation executed in the second embodiment.

First Embodiment FIG. 1 is a schematic diagram showing an example of a printing system to which the present invention is applicable. In FIG. 1 and the following drawings, XYZ orthogonal coordinates with the Z axis as the vertical axis are also shown as necessary in order to clarify the arrangement relationship of each part of the apparatus. In the following explanation, the direction in which each coordinate axis (the arrow) faces is a positive direction, the opposite direction is a negative direction, the positive side of the Z axis is the upper side, and the negative side of the Z axis is the lower side.

  The printing system 100 includes a host device 200 that generates print data based on image data received from an external device such as a personal computer, and a printer 300 that prints an image based on print data received from the host device 200. The printer 300 prints an image on the sheet S using an ink jet method while conveying a long sheet S (web) wound at both ends in a roll shape by a roll-to-roll method. (Form an image).

  As shown in FIG. 1, the printer 300 includes a main body case 1 having a substantially rectangular parallelepiped shape. In the main body case 1, a feeding unit 2 that feeds out the sheet S from a roll R 1 around which the sheet S is wound, a printing chamber 3 that performs printing by ejecting ink onto the fed sheet S, and a sheet S to which the ink has adhered are arranged. A drying unit 4 for drying and a winding unit 5 for winding the dried sheet S as a roll R2 are arranged.

  More specifically, the inside of the main body case 1 is partitioned vertically in the Z-axis direction by a flat base 6 arranged in parallel (that is, horizontally) to the XY plane, and the upper side of the base 6 is the printing chamber 3. It has become. A platen 30 is fixed to the upper surface of the base 6 at a substantially central portion in the printing chamber 3. The platen 30 has a rectangular shape, and supports the sheet S from below by its upper surface parallel to the XY plane. Then, the recording unit 31 performs printing on the sheet S supported on the platen 30.

  On the other hand, the feeding unit 2, the drying unit 4, and the winding unit 5 are disposed below the base 6. The feeding unit 2 is disposed below the platen 30 in the negative direction of the X axis (left obliquely lower in FIG. 1) and includes a rotatable feeding shaft 21. The sheet S is wound around the feeding shaft 21 in a roll shape, and the roll R1 is supported. On the other hand, the winding unit 5 is disposed below the platen 30 in the positive X-axis direction (downwardly to the right in FIG. 1), and includes a rotatable winding shaft 51. And the sheet | seat S is wound up by this winding shaft 51 in roll shape, and roll R2 is supported. Further, the drying unit 4 is disposed directly below the platen 30 between the feeding unit 2 and the winding unit 5 in the X-axis direction. The drying unit 4 is slightly above the feeding unit 2 and the winding unit 5.

  Then, the sheet S is transported along the transport path Pc from the feeding unit 2 to the winding unit 5 and sequentially passes through the printing chamber 3 and the drying unit 4. Specifically, the sheet S fed from the feeding shaft 21 provided in the feeding unit 2 is guided to the printing chamber 3 via a corona treatment unit 8 described later. Inside the printing chamber 3, two rollers 72 and 73 are arranged in this order in the positive X-axis direction of the sheet S. Then, the sheet S guided into the printing chamber 3 is wound around these two rollers 72 and 73. The rollers 72 and 73 are arranged in a straight line (that is, horizontally) in the X-axis direction so as to sandwich the platen 30, and the tops thereof are the same height as the upper surface of the platen 30 (surface that supports the sheet S). So that the position is adjusted. Accordingly, the sheet S wound around the roller 72 moves horizontally (in the X-axis direction) while being in sliding contact with the upper surface of the platen 30 until reaching the roller 73. Then, the sheet S wound around the roller 73 is guided downward.

  Below the roller 73 (below the base 6), two rollers 74 and 75 are arranged in this order in the negative X-axis direction. The sheet S wound around the rollers 74 and 75 is guided between the rollers 74 and 75 in parallel (that is, horizontally) in the X-axis direction. A drying unit 4 is disposed between the rollers 74 and 75. Accordingly, the sheet S wound around the roller 74 changes its direction in the negative X-axis direction and passes through the inside of the drying unit 4 until reaching the roller 75. Below the roller 75, the two rollers 76 and 77 are arranged in this order in the positive direction of the X axis. Then, the sheet S wound around the roller 76 changes its direction in the X axis positive direction and reaches the roller 77. Further, the sheet S wound around the roller 77 is wound around the winding shaft 51 of the winding unit 5 arranged in the positive X-axis direction of the roller 77.

  In this way, the sheet S fed out from the feeding unit 2 passes through the printing chamber 3 and the drying unit 4 and is taken up by the winding unit 5. The sheet S is subjected to various processes such as a printing process in the printing chamber 3 and a drying process in the drying unit 4.

  The printing process in the printing chamber 3 is executed by the recording unit 31 arranged on the upper side of the platen 30. The recording unit 31 uses an ink jet system to supply ink supplied by an ink supply mechanism (not shown) from an ink cartridge CR disposed at the end in the negative X-axis direction (the left end in FIG. 1) in the printing chamber 3 using a sheet S. To be printed. Specifically, the recording unit 31 includes a carriage 32, a flat support plate 33 attached to the lower surface of the carriage 32, and a plurality of recording heads 34 attached to the lower surface of the support plate 33.

  FIG. 2 is a plan view partially showing the configuration of the recording unit. As shown in FIG. 2, on the lower surface of the support plate 33, fifteen recording heads 34 are arranged in two rows in a staggered manner at an equal pitch in the Y-axis direction. These recording heads 34 eject ink from nozzles 35 and have the same configuration. Therefore, in the following, the details of the configuration will be described on behalf of one recording head 34.

  On the lower surface of the recording head 34, a plurality of (for example, 180) nozzles 35 are linearly arranged at equal pitches in the Y-axis direction to form one nozzle row 35L, and the plurality of nozzle rows 35L are arranged in the X-axis direction. They are lined up at equal pitches. The plurality of nozzle rows 35L arranged on the lower surface of the recording head 34 correspond to mutually different ink colors. For example, when eight colors of ink are used, eight nozzle rows 35L are arranged on the lower surface of the recording head 34. The nozzles 35 belonging to the same nozzle row 35L eject the same color ink, while the nozzles 35 belonging to different nozzle rows 35L eject different color inks. The nozzle 35 is of a piezo type that ejects ink out of the tube by applying a voltage to a piezo element attached to a fine tube filled with ink and deforming it.

  Returning to FIG. 1, the description will be continued. The carriage 32 of the recording unit 31 configured as described above is movable together with the support plate 33 and the recording head 34. Specifically, a first guide rail 36 extending in the X-axis direction is provided in the printing chamber 3, and the carriage 32 receives the driving force of the first CR motor Mx (FIG. 3) and receives the first guide. It moves along the rail 36 in the X-axis direction. Further, a second guide rail (not shown) extending in the Y-axis direction is provided in the printing chamber 3, and the carriage 32 receives the driving force of the second CR motor My (FIG. 3) and receives the second guide. Move along the rail in the Y-axis direction.

  Then, printing is executed by moving the carriage 32 of the recording unit 31 two-dimensionally within the XY plane with respect to the sheet S stopped on the upper surface of the platen 30. Specifically, the recording unit 31 performs an operation (main scanning) of ejecting ink from each nozzle 35 of the recording head 34 to the sheet S while moving the carriage 32 in the X-axis direction (main scanning direction). In this main scanning, a two-dimensional image is printed by arranging a plurality of one-line images (line images) extending in the X-axis direction and spaced apart in the Y-axis direction, formed by ink ejected from one nozzle. Is done. Then, the main scanning and the sub scanning for moving the carriage 32 in the Y-axis direction (sub scanning direction) are alternately performed, and a plurality of main scannings are performed (lateral scanning method).

  That is, when the recording unit 31 completes one main scan, the recording unit 31 performs sub-scanning to move the carriage 32 in the Y-axis direction. Subsequently, the recording unit 31 moves the carriage 32 in the X-axis direction (opposite to the previous main scanning) from the position moved by the sub-scanning. As a result, a new main scan line image is formed between each of the plurality of line images already formed by the previous main scan. Then, these main scanning and sub-scanning are executed alternately. That is, in the printer 300, the operation (main scanning) in which an intermediate generation image including a plurality of line images is formed by ejecting ink from the nozzles 35 while moving the carriage 32 in the X-axis direction is performed in the Y-axis direction. By changing the position (sub-scanning) and executing a plurality of times, an image in which the intermediate generation images are superimposed is formed.

  In this way, one printing is executed by executing a plurality of main scans. Here, one main scan is referred to as “pass”, and one printing executed by a plurality of passes is referred to as “frame”. Further, an intermediate generated image formed on the sheet S in one pass is referred to as “one pass image”.

  The reason why the main scanning and the sub scanning are alternately repeated is to improve the resolution. That is, by executing M passes and superimposing M one-pass images, it is possible to obtain an image for one frame having a resolution M times that of the one-pass image. Therefore, the recording unit 31 executes printing of one frame by executing the number of passes corresponding to the resolution of the image to be printed. Incidentally, the carriage 32 can reciprocate in the X-axis direction. Therefore, the recording unit 31 efficiently executes a plurality of passes by executing passes on each of the forward path and the return path of the carriage 32.

  The printing of one frame as described above is repeatedly executed while the sheet S is moved intermittently in the X-axis direction. Specifically, a predetermined range over almost the entire upper surface of the platen 30 is a printing area. Then, the sheet S is intermittently conveyed in the X-axis direction in units of a distance (intermittent conveyance distance) corresponding to the length in the X-axis direction of the printing area, and stopped on the upper surface of the platen 30 during the intermittent conveyance. One frame is printed on the sheet S to be printed. Specifically, when printing of one frame is completed on the sheet S stopped on the platen 30, the sheet S is transported in the X-axis direction by the intermittent transport distance, and the unprinted surface of the sheet S stops on the platen 30. . Subsequently, printing of one frame is newly performed on this unprinted surface, and when this is completed, the sheet S is conveyed again in the X-axis direction by the intermittent conveyance distance. These series of operations are repeatedly executed.

  In order to keep the sheet S stopped on the upper surface of the platen 30 flat during intermittent conveyance, the platen 30 includes a mechanism for sucking the stopped sheet S on the upper surface thereof. Specifically, a large number of suction holes (not shown) are opened on the upper surface of the platen 30, and a suction portion 37 is attached to the lower surface of the platen 30. When the suction unit 37 operates, a negative pressure is generated in the suction hole on the upper surface of the platen 30, and the sheet S is sucked on the upper surface of the platen 30. The suction unit 37 sucks the sheet S while the sheet S is stopped on the platen 30 for printing, thereby keeping the sheet S flat. And the sheet S can be smoothly conveyed.

  Further, a heater 38 is attached to the lower surface of the platen 30. The heater 38 heats the platen 30 to a predetermined temperature (for example, 45 degrees). Accordingly, the sheet S is primarily dried by the heat of the platen 30 in parallel with receiving the printing process from the recording head 34. And the drying of the ink which landed on the sheet | seat S is accelerated | stimulated by this primary drying.

  In this way, on the upper surface of the platen 30, the sheet S that has received one frame of printing and is primarily dried moves along with the intermittent conveyance of the sheet S and reaches the drying unit 4. The drying unit 4 executes a drying process in which the ink landed on the sheet S is completely dried by air heated for drying. Then, the sheet S that has been subjected to the drying process reaches the winding unit 5 as the sheet S is intermittently conveyed, and is wound as a roll R2.

  As described above, the printing / drying process is performed on the sheet S by the recording unit 31 and the drying unit 4. In addition to the recording unit 31 and the drying unit 4 described above, the printer 300 includes functional units such as a corona treatment unit 8 and a maintenance unit 9. Next, details of these configurations and operations will be described.

  The corona treatment unit 8 is disposed between the roll R1 of the feeding shaft 21 and the roller 72 (platen 30) in the conveyance path Pc, and includes a corona treatment machine 80 and a sheet reverse feed mechanism 82. The corona treatment machine 80 includes a corona discharge electrode 801 that faces the surface of the sheet S, and an electrode cover 802 that covers the corona discharge electrode 801. On the other hand, the sheet reverse feed mechanism 82 winds the sheet S from the front surface and winds the sheet S from the front surface on the upstream and downstream sides of the conveyance path Pc with respect to the ground roller 821 and the ground roller 821 facing the corona treatment device 80. There are swing rollers 822 and 823 to be hung. Then, the sheet S is subjected to corona treatment at a processing position Ap (in other words, a position wound around the earth roller 821) facing the corona treatment machine 80.

  The sheet reverse feeding mechanism 82 has a rotation support shaft 824. The rotation support shaft 824 is rotatable about an intermediate position between the swing rollers 822 and 823 as a rotation axis C824 while rotatably supporting the swing rollers 822 and 823 at both ends thereof. Therefore, as will be described in detail later, the sheet S can be moved relative to the processing position Ap of the corona processor 80 by appropriately rotating the rotation support shaft 824.

  The corona discharge electrode 801 is connected to the discharge bias generator 84 (FIG. 3), while the earth roller 821 is grounded. Therefore, when a discharge bias is applied to the corona discharge electrode 801 from the discharge bias generator 84, a corona discharge is generated between the corona discharge electrode 801 and the earth roller 821, and the surface of the sheet S at the processing position Ap is generated. Corona treatment (surface modification treatment) is performed. Thus, energy by corona discharge is applied to the surface of the sheet S, the surface of the sheet S is modified, and the wettability of the sheet S with respect to ink is improved. Then, the sheet S that has been subjected to the corona treatment is supplied to the platen 30 and is subjected to a printing process by the recording unit 31. Incidentally, the corona treatment machine 80 having such a configuration has a property of generating heat as the corona treatment is performed.

  The maintenance unit 9 is provided at a position deviating from the platen 30 in the negative X-axis direction, and performs maintenance on the recording head 34 that retreats to the home position (position directly above the maintenance unit) during non-printing. The maintenance unit 9 includes 15 caps 91 provided in a one-to-one correspondence with the 15 recording heads 34, and an elevating unit 93 that moves the cap 91 up and down.

  Maintenance performed by the maintenance unit 9 includes capping, cleaning, and wiping. Capping is a process in which the cap 91 is raised by the elevating part 93 and the recording head 34 in the home position is covered with the cap 91. By this capping, it is possible to suppress an increase in the viscosity of the ink in the nozzles 35 of the recording head 34. The cleaning is a process for forcibly discharging ink from the nozzles 35 by generating a negative pressure in the cap 91 with the recording head 34 capped. By this cleaning, ink with increased viscosity, bubbles in the ink, and the like can be removed from the nozzle 35. Wiping is a process of wiping a surface (nozzle opening forming surface) in which the openings of the nozzles 35 are arranged in the recording head 34 with a wiper (not shown). By this wiping, the ink can be wiped off from the nozzle opening forming surface of the recording head 34.

  The above is the outline of the apparatus configuration included in the printing system 100. Subsequently, FIG. 3 is added to FIG. 1 described above, and the electrical configuration of the printing system of FIG. 1 will be described in detail. Here, FIG. 3 is a block diagram schematically showing the electrical configuration of the printing system of FIG.

  As described above, the printing system 100 includes the printer 300 and the host device 200 that controls the printer 300. The host device 200 is configured by, for example, a personal computer, and includes a printer driver 210 that controls the operation of the printer 300 and a transfer control unit 220 that manages a communication function with the printer 300. The printer driver 210 is constructed by a CPU (Central Processing Unit) included in the host device 200 executing a program for the printer driver 210.

  In addition, the host device 200 includes a media drive unit 240 that accesses a medium 230 that stores a printer driver program and reads the program. As this medium 230, various media such as a CD (Compact Disc), a DVD (Digital Versatile Disc), a USB (Universal Serial Bus) memory, and the like can be used.

  Furthermore, the host device 200 includes a monitor 250 configured with a liquid crystal display or the like and an operation unit 260 configured with a keyboard, a mouse, or the like as an interface with the worker. Note that a touch panel display may be used as the monitor 250, and the operation unit 260 may be configured by the touch panel of the monitor 250. In addition to the image to be printed, a menu screen is displayed on the monitor 250. Therefore, the operator operates the operation unit 260 while confirming the monitor 250 to open the print setting screen from the menu screen, and various types such as the type of the print medium, the size of the print medium, the print quality, and the plate number are displayed. Printing conditions can be set.

  The type of print medium (that is, sheet S) is broadly classified into paper and film. Specific examples include high-quality paper, cast paper, art paper, coated paper, and the like for paper, and synthetic paper, PET (Polyethylene terephthalate), PP (polypropylene), and the like for film. As the size of the print medium, the width of the sheet S (width in the Y-axis direction) is set. The print quality can be set by selecting one print mode from a plurality of print modes prepared according to the printing resolution. An example is as follows. That is, in the printer 300, the resolution can be changed by changing the number of passes executed in one frame. Therefore, a plurality of print modes having different numbers of passes executed in one frame may be prepared, and a print mode having the number of passes corresponding to the printing resolution may be selected. Thus, printing can be executed with a resolution corresponding to the number of passes of the selected print mode. Note that the print quality may be set by directly inputting the resolution instead of the print mode. The number of plates is set when a plurality of plates (images) are printed in the same area of the print medium. Specifically, the number of plates to be printed is set. Incidentally, when a plurality of versions are set, an image for each version can be displayed on the monitor 250.

  The printer driver 210 includes a host control unit 211 that controls display on the monitor 250 and input processing from the operation unit 260 as described above. That is, the host control unit 211 displays various screens such as a menu screen and a print setting screen on the monitor 250 and performs processing according to the contents input from the operation unit 260 on the various screens. Accordingly, the host control unit 211 generates a control signal necessary for controlling the printer 300 in accordance with an input from the worker.

  Further, the printer driver 210 includes an image processing unit 213 that performs image processing on image data received from an external device and generates print data. Specifically, image processing such as resolution conversion processing, color conversion processing, and halftone processing is executed.

  The control signal generated by the host control unit 211 and the print data generated by the image processing unit 213 are transferred to the printer control unit 400 provided in the main body case 1 of the printer 300 via the transfer control unit 220. Is done. The transfer control unit 220 can perform bi-directional serial communication with the printer control unit 400. The transfer control unit 220 transfers control signals and print data to the printer control unit 400, and sends response signals to the printer control unit 400. Are transmitted to the host control unit 211.

  The printer control unit 400 includes a head controller 410 and a mechanical controller 420. The head controller 410 controls the recording head 34 based on the print data transmitted from the printer driver 210. Specifically, the head controller 410 controls ink ejection from the nozzles 35 of the recording head 34 based on print data. At this time, the timing of ejecting ink from the nozzles 35 is controlled based on the movement of the carriage 32 in the X-axis direction. That is, a linear encoder E32 that detects the position of the carriage 32 in the X-axis direction is provided in the printing chamber 3. Then, the head controller 410 refers to the output of the linear encoder E32 to eject ink from the nozzles 35 at a timing according to the movement of the carriage 32 in the X-axis direction.

  On the other hand, the mechanical controller 420 mainly controls a function of controlling the intermittent conveyance of the sheet S and the driving of the carriage 32. Specifically, the mechanical controller 420 outputs the conveyance motor Ms that drives the sheet conveyance system including the feeding unit 2, the rollers 71 to 77, and the winding unit 5 to the output of the encoder Emc that detects the rotation of the conveyance motor Ms. Based on the control, the sheet S is intermittently conveyed. The mechanical controller 420 controls the first CR motor Mx to cause the carriage 32 to move in the X-axis direction for main scanning, and controls the second CR motor Mx to perform sub-scanning. Is moved in the Y-axis direction by the carriage 32.

  Then, the head controller 410 and the mechanical controller 420 perform these controls as appropriate while synchronizing them, so that the number of passes corresponding to the resolution is executed for the sheet S that is intermittently conveyed, and 1 frame Minutes of printing. As a result, an image for one frame having a desired resolution is printed on the sheet S.

  The mechanical controller 420 can execute various controls in addition to the above-described control for the printing process. Specifically, the mechanical controller 420 detects the on / off state of the power switch SW, and executes the activation process of each unit of the printer 300 when the power switch SW is turned on. Further, the mechanical controller 420 feedback-controls the heater 38 based on the output of the temperature sensor S30 that detects the temperature of the upper surface of the platen 30, and based on the output of the temperature sensor S4 that detects the temperature inside the drying unit 4. Then, temperature control such as feedback control of the drying unit 4 is executed. Further, the mechanical controller 420 can perform various operations such as adjusting the negative pressure generated in the suction hole of the platen 30 by controlling the suction unit 37 and performing predetermined maintenance by controlling the maintenance unit 9. is there. In particular, as will be described later, the mechanical controller 420 of this embodiment controls the sheet reverse feeding mechanism 82 and the discharge bias generating unit 84 to execute the surface modification process on the sheet S.

  The above is the outline of the electrical configuration of the printing system of FIG. Next, details of the printing operation executed in the first embodiment will be described. As described above, the printer 300 is provided with the corona treatment unit 8 that performs the surface modification process (corona treatment) on the sheet S. In the printing operation executed by the printer 300, the surface modification process for the sheet S is appropriately executed. Therefore, in the following, the operation of the corona processing unit (FIG. 4) will be described, and then the printing operation (FIG. 5) executed by the printer 300 will be described.

  FIG. 4 is a side view schematically showing the corona treatment unit in the first embodiment. As described above, the corona treatment unit 8 includes the corona treatment machine 80 and the sheet reverse feed mechanism 82. Then, the sheet S can be moved relative to the processing position Ap of the corona processor 80 by appropriately rotating the rotation support shaft 824 of the sheet reverse feeding mechanism 82. Specifically, as shown in FIG. 4, the rotation support shaft 824 can take a state where the rotation angle is an angle θ (+) and a state where the rotation angle is an angle θ (−). When the rotation angle of the rotation support shaft 824 is switched from the angle θ (+) to the angle θ (−), a part of the sheet S on the downstream side of the transport path Pc from the processing position Ap is transported from the processing position Ap. Move upstream of Pc.

  That is, when the rotation angle is switched from the angle θ (+) to the angle θ (−), the swing roller 822 at the processing position Ap from the roll R1 is lowered while winding the sheet S from above. On the other hand, the swing roller 823 between the processing position Ap and the roller 72 (platen 30) moves up while winding the sheet S from above. As a result, the sheet S that is on the downstream side of the transport path Pc from the processing position Ap moves from the roll R1 to the processing position Ap. This will be described in more detail as follows.

The length of the sheet S on the upstream side of the conveyance path from the processing position Ap and the length of the sheet S on the downstream side are defined as follows.
Upstream buffer amount Lu: Length of the sheet S from the roll R1 to the processing position Ap.
Downstream buffer amount Ld: the length of the sheet S from the processing position Ap to the platen 30.

Further, the upstream and downstream buffer amounts Lu and Ld in each rotation state of the rotation support shaft 824 are defined as follows.
Buffer amount Lu (+): upstream buffer amount Lu when the rotation angle is angle θ (+).
Buffer amount Lu (−): Upstream buffer amount Lu when the rotation angle is angle θ (−).
Buffer amount Ld (+): upstream buffer amount Ld when the rotation angle is angle θ (+).
Buffer amount Ld (−): upstream buffer amount Ld when the rotation angle is angle θ (−).

When the movement amount of the sheet S between the upstream side and the downstream side of the transport path Pc at the processing position Ap is ΔS, the following relational expression Lu (+) − Lu (−) = − {Ld (+) − Ld (-)} = ΔS
Is established. That is, when the rotation angle of the rotation support shaft 824 is switched from the angle θ (+) to the angle θ (−), the upstream buffer amount Lu is increased by the movement amount ΔS, while the downstream buffer amount Ld is increased by the movement amount ΔS. Only decrease. That is, the sheet S having a length corresponding to the movement amount ΔS located on the downstream side of the transport path Pc at the processing position Ap moves between the roll R1 and the processing position Ap.

  Thus, by switching the rotation angle of the rotation support shaft 824 from the angle θ (+) to the angle θ (−), the sheet S is moved relative to the processing position Ap by the movement amount ΔS to the upstream side of the conveyance path Pc. (Sheet reverse feed processing). Further, as can be understood from the above description, when the rotation angle of the rotation support shaft 824 is switched from the angle θ (−) to the angle θ (+), the sheet S is moved downstream of the conveyance path Pc with respect to the processing position Ap. Can be moved relative to each other by a movement amount ΔS. The above is the details of the operation of the corona treatment unit. Subsequently, a printing operation executed by the printer 300 will be described.

  FIG. 5 is a timing chart showing an example of the printing operation executed in the first embodiment. In the following description, the expression “forward direction” or “reverse direction” is used to indicate the rotation direction of the roller 72 and the feeding shaft 21. In this case, the “positive direction” indicates a rotation direction in which the sheet S is conveyed from the upstream side to the downstream side of the conveyance path Pc, and the “negative direction” indicates that the sheet S is upstream from the downstream side of the conveyance path Pc. The direction of rotation for conveying toward the side shall be indicated.

  As described above, in the printer 300, printing is performed on the surface of the sheet S that is stopped on the upper surface of the platen 30 while the sheet S is intermittently conveyed to the upper surface of the platen 30. Therefore, in the printing operation, a conveyance command for controlling the intermittent conveyance of the sheet S is output from the mechanical controller 420. Specifically, in the example shown in FIG. 5, the conveyance command is output between time t1 and t2 and between time t3 and t4, while the conveyance command is not output between time t2 and t3 (FIG. 5). (5) “Conveyance command” graph).

  While the conveyance command is output, the roller 72 (drive roller) rotates in the forward direction (clockwise direction in FIG. 1), and conveys the sheet S from the upstream side of the conveyance path Pc to the platen 30. Further, in accordance with the rotation of the roller 72, the feeding shaft 21 also rotates in the forward direction (clockwise in FIG. 1), and the sheet S is fed to the roller 72 from the upstream side of the conveyance path Pc via the corona treatment unit 8. Transport. Thus, the sheet S conveyed by the roller 72 to the platen 30 is fed from the roll R1 of the feeding shaft 21 and supplied to the roller 72. On the other hand, while the conveyance command is not output, the roller 72 and the feeding shaft 21 stop rotating and stop the conveyance of the sheet S to the platen 30.

  Further, the sheet S intermittently conveyed in this way intermittently passes the processing position Ap of the corona processing unit 8 (graph of “sheet passing state” in FIG. 5). Specifically, in the example shown in FIG. 5, the sheet S passes through the processing position Ap between time t1 and t2 and between time t3 and t4, while the sheet S is processed between time t2 and t3. It stops at the position Ap. That is, during the passage period Tp (between times t1 and t2 and between times t3 and t4), the sheet S passes through the processing position Ap toward the downstream side of the transport path Pc, while the stop period Ts (times t2 to t3). In the meantime, the sheet S stops at the processing position Ap (conveying step).

  Then, the mechanical controller 420 gives a discharge command for controlling on / off of the corona processor 80 to the discharge bias generator 84 in accordance with the timing at which the sheet S passes the processing position Ap. Specifically, the mechanical controller 420 outputs a discharge command to the discharge bias generator 84 during the passage period Tp of the sheet S, but does not output a discharge command during the stop period Ts of the sheet S. The discharge bias generator 84 receives the discharge bias output in response to the discharge command, and the corona treatment machine 80 executes corona discharge.

  As shown in the “discharge status” graph of FIG. 5, the corona discharge of the corona treatment machine 80 starts discharging after a certain delay time d from the start of the passage period Tp of the sheet S, and the sheet S It ends with the end of the passage period Tp. Thus, a time difference d occurs from the start of the passage period Tp of the sheet S to the rise of the corona discharge. Therefore, the surface modification process is not performed on the sheet S that has passed the processing position Ap during the delay time d from the start of the passage period Tp of the sheet S. Then, the surface modification process (corona process) is performed only on the sheet S that has passed the processing position Ap between the rise of the corona discharge and the end of the sheet S passage period Tp (surface modification process). ).

  Therefore, in this embodiment, the mechanical controller 420 causes the sheet reverse feed mechanism 82 to appropriately execute the sheet reverse feed process in order to suppress the region where the surface modification process is insufficient, regardless of the delay of the rise of the corona discharge. That is, during the predetermined time Tb (the predetermined time Tb from the start of the stop period Ts in the example of FIG. 5) in the stop period Ts of the sheet S, the rotation support shaft 824 is moved from the angle θ (+) to the angle θ (−). The sheet reverse feed processing is executed (relative movement process).

  As a result, prior to the surface reforming process for the sheet S executed in the passage period Tp (t3 to t4) following the stop period Ts (t2 to t3), the upstream side of the transport path Pc with respect to the processing position Ap. The sheet S is moved by the movement amount ΔS. As a result, a part of the sheet S subjected to the surface modification process in the passage period Tp (t1 to t2) before the stop period Ts (t2 to t3) (the part corresponding to the movement amount ΔS) is the processing position Ap. Move to the upstream side of the transport path Pc. Therefore, in the subsequent passing period Tp (t3 to t4), the sheet S that has already undergone the surface modification process passes through the processing position Ap for a predetermined time ΔT from the start of the passing period Tp. Therefore, even if the rise of the corona discharge is delayed by the delay time d from the passage period Tp, the amount of the sheet S for which the surface modification process is insufficient can be suppressed.

  In particular, if the movement amount ΔS in the sheet reverse feeding process is set so that the time ΔT is equal to or longer than the delay time d, the occurrence of the sheet S in which the surface modification process is insufficient can be suppressed almost completely. Can do. Incidentally, the delay time d of the rise of the corona discharge can be experimentally obtained in advance. Specifically, a period from when the discharge command is generated to when discharge of energy necessary for the surface modification of the sheet S starts may be obtained as the delay time d. The amount of the sheet S that passes through the processing position Ap during the delay time d can be obtained by multiplying the delay time d by the passage speed of the sheet S. Therefore, if the movement amount ΔS is set to be equal to or larger than the passage amount of the sheet S thus obtained, the corona discharge is completed until the predetermined time ΔT when the sheet S that has already undergone the surface modification treatment passes the processing position Ap is completed. Can be completed, and the generation of the sheet S in which the surface modification treatment becomes insufficient can be suppressed almost completely.

  Note that such a sheet reverse feeding process is executed every stop period Ts in which the sheet S stops at the processing position Ap. Therefore, when the rotation support shaft 824 is rotated to the angle θ (−) for the sheet reverse feed processing, the rotation support shaft 824 is returned to the angle θ (+) in preparation for the next sheet reverse feed processing. It is necessary to keep. Therefore, in this embodiment, the rotation support shaft 824 is moved during the predetermined time Tf (the predetermined time Tf from the start of the passage period Tp in the example of FIG. 5) of the passage period Tp in which the sheet S passes the processing position Ap. The sheet is rotated from the angle θ (−) to the angle θ (+) to prepare for the next reverse sheet feeding process.

  As described above, according to the first embodiment, ink is ejected onto the stopped sheet S on the platen 30 while the sheet S is intermittently conveyed toward the downstream side of the conveyance path Pc. Record an image. In addition, a corona treatment machine 80 that performs surface modification processing in response to the discharge command is provided, and surface modification processing can be performed on the sheet S at the processing position Ap upstream of the platen 30 in the transport path Pc. ing. Therefore, in this embodiment, the sheet S is passed through the processing position Ap, and a surface modification process is performed on the sheet S by appropriately giving a discharge command to the corona processor 80 (the discharge bias generator 84 connected thereto). Is running.

  Specifically, according to the intermittent conveyance of the sheet S to the platen 30, the sheet S is intermittently conveyed from the upstream side of the conveyance path Pc to the processing position Ap, so that the sheet S intermittently passes the processing position Ap. To do. Then, a discharge command is given to the discharge bias generator 84 during the passage period Tp in which the sheet S passes the processing position Ap along with the intermittent conveyance to the processing position Ap, and the surface is changed to the sheet S that passes the processing position Ap. Quality processing is performed. At this time, when the passage period Ap starts (that is, when the sheet S starts to pass the processing position Ap) and the corona treatment machine 80 cannot start the surface modification process immediately, the area where the surface modification process is insufficient. There was a possibility that a large amount of was generated in the sheet S.

  On the other hand, in this embodiment, the sheet reverse feeding process in which the sheet S is relatively moved to the upstream side of the transport path Pc with respect to the processing position Ap is executed in advance before the passage period Tp starts. Therefore, when the passage period Tp starts, the area that has already undergone the surface modification process is moved relative to the processing position Ap to the upstream side of the transport path Pc. Therefore, for a while after the start of the passage period Tp, since the region already subjected to the surface modification process passes through the processing position Ap, even if the start of the surface modification process is delayed from the start of the passage period Tp. Thus, it is possible to suppress the shortage area of the surface modification treatment.

  In particular, in this embodiment, the movement amount ΔS is set to be larger than the passage amount of the sheet S that passes the processing position Ap during the delay time d from the start of the passage period Tp to the rise of the corona discharge. As a result, the start-up of corona discharge can be completed before the predetermined time ΔT when the sheet S that has already undergone the surface modification processing passes the processing position Ap, and the surface modification processing becomes insufficient. The generation of the sheet S can be suppressed almost completely.

  Incidentally, the sheet reverse feeding process as described above may be executed by rotating the feeding shaft 21 in the reverse direction and rewinding the sheet S to the roll R1. However, the amount of the sheet S to be rewound on the roll depends on the diameter of the roll R1 in addition to the rotation amount of the feeding shaft 21. Therefore, when it is desired to manage the movement amount ΔS of the sheet S in the reverse sheet feeding process (for example, when it is desired to set the movement amount ΔS to be greater than or equal to the passage amount of the sheet S passing the processing position Ap at the delay time d as described above). Therefore, it is necessary to control the rotation amount of the feeding shaft 21 while referring to the roll diameter.

  In contrast, in this embodiment, the sheet reverse feeding mechanism 82 adjusts the upstream buffer amount Lu that is the length of the sheet S from the roll R1 to the corona processor 80 (processing position Ap). In addition, a downstream buffer amount Ld that is the length of the sheet S from the corona processor 80 (processing position Ap) to the platen 30 is provided. Then, the sheet reverse feed mechanism is executed by increasing the upstream buffer amount Lu by the movement amount ΔS while decreasing the downstream buffer amount Ld by the movement amount ΔS.

  In such a configuration, instead of reducing the sheet S on the downstream side of the transport path Pc from the corona processing machine 80 (processing position Ap) by the movement amount ΔS, the upstream side of the transport path Pc from the corona processing machine 80 (processing position Ap). The sheet reverse feeding process is executed by increasing the sheet S by the movement amount ΔS. Thus, the sheet S can be moved relative to the corona processor 80 by the movement amount ΔS upstream of the conveyance path Pc without rewinding the sheet S on the roll R1. As a result, even when the movement amount ΔS of the sheet S in the sheet reverse feeding process is managed, it is not particularly necessary to refer to the diameter of the roll R1, and the management can be easily performed.

  In particular, in the sheet reverse feed mechanism 82 of this embodiment, an earth roller 821 is provided to wind the sheet S from the back surface while facing the corona treatment device 80 with the sheet S interposed therebetween, and the swing rollers 822 and 823 are Then, the sheet S is wound from the surface with the earth roller 821 interposed therebetween. These swing rollers 822 are supported at both ends of a rotation support shaft 824 that rotates with the respective intermediate positions as a rotation axis C824.

  In such a configuration, by rotating the rotation support shaft 824, the rocking rollers 822 and 823 are moved like a seesaw, and the sheet S is moved from the upstream side to the downstream side of the conveyance path Pc with the corona processor 80 interposed therebetween. Can be moved. Therefore, it can be said that the sheet reverse feeding process can be executed simply by rotating the rotation support shaft 824, which is preferable.

Second Embodiment In the first embodiment, the sheet S is moved relative to the processing position Ap by moving the sheet S. However, the sheet S may be moved relative to the processing position Ap by moving the processing position Ap. Therefore, the corona treatment unit 8 of the second embodiment moves the corona treatment machine 80 to the downstream side of the transport path Pc, thereby moving the processing position Ap to the downstream side of the transport path, and with respect to the processing position Ap. The sheet S is relatively moved.

  Subsequently, the second embodiment will be described in detail. However, the second embodiment differs from the first embodiment mainly in the configuration and operation of the corona treatment unit 8. The description will be given, and the other parts will be denoted by the same reference numerals and the description will be omitted as appropriate. In addition, it cannot be overemphasized that the effect similar to 1st Embodiment is show | played also in 2nd Embodiment by comprising the structure which is common in 1st Embodiment.

  FIG. 6 is a side view schematically showing the corona treatment unit in the second embodiment. In addition to the corona treatment machine 80, the corona treatment unit 8 wraps the sheet S from the back surface and wraps the surface of the sheet S on the upstream and downstream sides of the ground roller 841 facing the corona treatment machine 80 and the ground roller 841. And rollers 842 and 843. When a discharge bias is applied from the discharge bias generator 84 to the corona discharge electrode 801, a corona discharge is generated between the corona discharge electrode 801 and the earth roller 821, and the surface of the sheet S at the processing position Ap is formed. Corona treatment (surface modification treatment) is performed.

  In this embodiment, each of the corona treatment machine 80 and the earth roller 841 is configured to be movable with respect to the X-axis direction. Specifically, the positive side position X (+) and the negative position in the X-axis direction are configured. It is movable between the side X (-). The corona treatment unit 8 can take the states 1 to 3 shown in FIG. 6 as necessary. In the state 1, both the corona treatment machine 80 and the earth roller 841 exist at the position X (−), and face each other to form the treatment position Ap at the position X (−). In state 2, the corona treatment machine 80 exists at the position X (−), and the earth roller 841 exists at the position X (+). In this state, the sheet S is separated from the corona processor 80 in the positive direction of the X axis, and the processing position Ap is not formed. In state 3, both the corona treatment machine 80 and the earth roller 841 are present at the position X (+), and face each other to form the treatment position Ap at the position X (+). As described above, in this embodiment, the state of the corona processor 80 can be changed from the state 1 to the state 3 and the processing position Ap can be moved in the positive direction of the X axis. It is possible to move to the downstream side of the transport path Pc with respect to S (processing position movement processing).

  FIG. 7 is a timing chart illustrating an example of a printing operation executed in the second embodiment. In the figure, the operations shown in the graphs of the conveyance command, the sheet passing state, the discharge command, and the discharge state are the same as those in FIG. 5 shown in the first embodiment. However, in the stop period Ts of the sheet S, the sheet reverse process is executed in the first embodiment, whereas the process position movement process is executed in the second embodiment. Specifically, it is as follows.

  At the start time of the stop period Ts (that is, the end time of the passage period Tp), the corona treatment machine 80 and the earth roller 841 are both in the position X (−), and the corona treatment unit 8 is in the state 1. Then, during the stop period Ts of the sheet S, the corona treatment unit 8 transitions from the state 1 to the state 3 via the state 2. That is, the ground roller 841 is moved from the position X (−) to the position X (+) over a predetermined time Tb1 (in the example of FIG. 7, the predetermined time Tb1 from the start of the stop period Ts) in the stop period Ts of the sheet S. Move to. Thus, the corona treatment unit 8 transitions to the state 2 where the distance between the sheet S and the corona treatment machine 80 is farther than the state 1. Further, in the stop period Ts of the sheet S, when the transition to the state 2 is completed and the time Tc has elapsed, a predetermined time Tb2 (predetermined time Tb2 before the end of the stop period Ts in the example of FIG. 7) is taken. Then, the corona treatment machine 80 moves from the position X (−) to the position (+) (state 3). Thus, during the stop period Ts, the processing position Ap moves relative to the sheet S by the movement amount ΔS toward the downstream side of the conveyance path (relative movement process).

  As a result, prior to the surface reforming process for the sheet S executed in the passage period Tp (t3 to t4) following the stop period Ts (t2 to t3), the upstream side of the transport path Pc with respect to the processing position Ap. The sheet S is relatively moved by the movement amount ΔS. As a result, a part of the sheet S subjected to the surface modification process in the passage period Tp (t1 to t2) before the stop period Ts (t2 to t3) (the part corresponding to the movement amount ΔS) is the processing position Ap. Move to the upstream side of the transport path Pc. Therefore, in the subsequent passing period Tp (t3 to t4), the sheet S that has already undergone the surface modification process passes through the processing position Ap for a predetermined time ΔT from the start of the passing period Tp. Therefore, even if the rise of the corona discharge is delayed by the delay time d from the passage period Tp, the amount of the sheet S for which the surface modification process is insufficient can be suppressed. Also in this embodiment, if the movement amount ΔS in the processing position movement process is set so that the time ΔT is longer than the delay time d, the generation of the sheet S in which the surface modification process becomes insufficient. Can be suppressed almost completely.

  Note that such processing position movement processing is executed every stop period Ts during which the sheet S stops at the processing position Ap. Therefore, when the processing position Ap is moved to the position X (+) for the processing position movement processing, the processing position Ap is returned to the position X (−) in preparation for the next processing position movement processing. There is a need. Therefore, in this embodiment, the corona processor 80 takes a predetermined time Tf (the predetermined time Tf from the start of the passage period Tp in the example of FIG. 7) of the passage period Tp in which the sheet S passes the processing position Ap. And moving the ground roller 841 from the position X (+) to the position X (−) while facing each other, the processing position Ap is returned from the X (+) to the position X (−). In preparation for the processing position movement process to be executed.

  As described above, in the second embodiment, the processing position moving process for moving the processing position Ap of the corona processing machine 80 relative to the sheet S to the downstream side of the transport path Pc is performed before the start of the passage period Tp. It is executed in advance. Therefore, when the passage period Tp starts, the region that has already undergone the surface modification process is moved relative to the processing position Ap to the upstream side of the transport path Pc. Therefore, for a while after the start of the passage period Tp, since the region already subjected to the surface modification process passes through the processing position Ap, even if the start of the surface modification process is delayed from the start of the passage period Tp. Thus, it is possible to suppress the shortage area of the surface modification treatment.

  Further, in this embodiment, when the passage period Tp ends, the earth roller 841 is moved to the downstream side of the transport path Pc, and the distance between the corona processor 80 and the sheet S is separated (state 2). And after time Tc passes from this state 2, a processing position movement process is performed by moving the corona processing machine 80 to the position facing the earth roller 841.

  Thus, by separating the distance between the corona treatment device 80 and the sheet S with the end of the passage period Tp, the corona treatment device 80 whose temperature has increased with the execution of the surface modification treatment is separated from the sheet S to some extent. Can be cooled in different places. And after cooling the corona treatment machine 80 in this way, the influence which the heat | fever emitted from a corona treatment machine has on the sheet | seat S is eased by moving the corona treatment machine 80 to the position which opposes the earth roller 841. be able to.

Others As described above, the printer 300 corresponds to the “image recording apparatus” of the present invention, the sheet S corresponds to the “recording medium” of the present invention, the transport path Pc corresponds to the “transport path” of the present invention, The ink corresponds to the “liquid” of the present invention, the platen 30 corresponds to the “supporting member” of the present invention, the recording head 34 corresponds to the “recording head” of the present invention, the feeding unit 2, the rollers 71 to 77, and The sheet conveyance system constituted by the winding unit 5 corresponds to the “conveyance unit” of the present invention, and the corona treatment device 80 and the discharge bias generation unit 84 function as a “surface reformer” in cooperation with each other. Ap corresponds to the “processing position” of the present invention, the mechanical controller 420 corresponds to the “control unit” of the present invention, and the discharge command corresponds to the “processing execution signal” of the present invention. In the first embodiment, the sheet reverse feed mechanism 82 corresponds to the “relative movement mechanism” of the present invention, the sheet reverse feed process corresponds to the “relative movement process” of the present invention, and the passage period Tp is the same as that of the present invention. Corresponds to “passing period”. In the second embodiment, the corona processor 80 and the earth roller 821 correspond to the “relative movement mechanism” of the present invention, the processing position movement processing corresponds to the “relative movement processing” of the present invention, and the upstream buffer amount. Lu corresponds to the “first buffer amount” of the present invention, the swing roller 822 corresponds to the “first adjusting member (roller)” of the present invention, and the downstream buffer amount Ld corresponds to the “second buffer amount” of the present invention. The swing roller 823 corresponds to the “second preparation member (roller)” of the present invention.

  The present invention is not limited to the above-described embodiment, and various modifications can be made to the above-described one without departing from the spirit of the present invention. For example, in the above-described embodiment, the relative movement process for moving the sheet S to the upstream side of the conveyance path Pc with respect to the processing position Ap is performed by the sheet reverse feeding process or the processing position movement process. However, for example, the relative movement process may be executed by rotating the feeding shaft 21 in the reverse direction and rewinding the sheet S onto the roll R1.

  Further, the execution timing of the sheet reverse feeding process and the processing position movement process can be appropriately changed from the above-described contents. As an example, in the first embodiment, the sheet reverse feeding process is started at the same timing as the start of the stop period Ts. However, the sheet reverse feeding process may be started after a time from the stop period Ts.

  Also, various modifications can be made to the configuration of the conveyance system for conveying the sheet S. Therefore, for example, an elevating roller as disclosed in JP 2009-292129 A is provided between the corona treatment unit 8 and the roller 72, and the amount of sheets S that the roller 72 supplies to the platen 30 in one transport is provided. The corona treatment unit 8 and the roller 72 may be previously drawn out and stored (buffered). In this case, as shown in FIGS. 5 and 7, it is not always necessary to match the output timing of the conveyance command with the timing at which the sheet S passes the processing position Ap. Therefore, the supply of the sheet S to the platen 30 in accordance with the conveyance command and the passage of the sheet S to the processing position Ap can be executed at different timings and speeds. Accordingly, the operation of intermittently conveying the sheet S to the platen 30 and the operation of intermittently passing the sheet S to the processing position Ap can be executed at appropriate timings.

  Further, in the above-described embodiment, the time ΔT for passing the sheet S that has already undergone the surface modification processing through the processing position Ap is set to be equal to or longer than the delay time d. However, the time ΔT may be less than the delay time d. Even in this case, the processing position moving process for moving the processing position Ap of the corona processing machine 80 relative to the sheet S to the downstream side of the transport path Pc is executed in advance before the start of the passage period Tp. The effect of suppressing the shortage area of the surface modification treatment to a certain extent is exhibited to some extent.

  Moreover, in the said embodiment, the surface modification process was performed by the corona treatment. However, you may comprise so that surface modification processing may be performed by methods other than corona processing, for example, plasma processing.

  Further, in the above-described embodiment, the case where the present invention is applied to an inkjet printer using a piezo method has been described. However, it goes without saying that the present invention can also be applied to an ink jet printer using a thermal method.

  DESCRIPTION OF SYMBOLS 300 ... Printer, S ... Sheet, Pc ... Conveyance path, 8 ... Corona treatment unit, 80 ... Corona treatment machine, 801 ... Corona discharge electrode, 802 ... Electrode cover, 82 ... Sheet reverse feed mechanism, 821 ... Earth roller, 822 ... Swing roller, 823 ... Swing roller, 824 ... Rotation support shaft, Rotation support shaft 824, C824 ... Rotation shaft, 84 ... Discharge bias generator, 841 ... Earth roller, 842 ... Roller, 843 ... Roller, 21 ... Feeding shaft , 30 ... Platen, 34 ... Recording head, 72 ... Roller, 400 ... Printer control unit, 410 ... Head controller, 420 ... Mechanical controller

Claims (9)

A support member for supporting the recording medium conveyed along the conveyance path;
A recording head for recording an image by ejecting liquid onto the recording medium that is stopped on the support member;
A surface reformer for performing a surface modification process for modifying the surface of the recording medium at a processing position upstream of the support member in the transport path in response to a process execution signal;
The recording medium is intermittently transported from the upstream side of the transport path to the support member, and the recording medium is intermittently transported to the processing position from the upstream side of the transport path to the processing position. A transport section to pass through,
A relative movement mechanism that performs a relative movement process of moving the recording medium relative to the processing position to the upstream side of the conveyance path;
A control unit that gives the processing execution signal to the surface reformer during a passage period in which the recording medium passes through the processing position along with intermittent conveyance to the processing position;
The control unit causes the relative movement mechanism to execute the relative movement process in advance before the start of the passage period.   The transport unit has a feed shaft that supports a roll formed by winding the recording medium in a roll shape on the upstream side of the processing position in the transport path, and rotates the feed shaft in the forward direction to rotate the roll. The image recording apparatus according to claim 1, wherein the recording medium fed out from the recording medium is intermittently passed through the processing position.   The image recording apparatus according to claim 2, wherein the relative movement mechanism performs the relative movement process by rewinding the recording medium to the roll by rotating the feeding shaft in a reverse direction.   A first adjusting member that adjusts a first buffer amount that is a length of the recording medium from the roll to the surface modifier, and a length of the recording medium from the surface modifier to the support member. A second adjusting member for adjusting the second buffer amount, and performing the relative movement process by increasing the first buffer amount by the moving amount while decreasing the second buffer amount by the moving amount. The image recording apparatus according to claim 2. The relative movement mechanism has a winding roller for winding the recording medium from the back surface while facing the surface reformer across the recording medium,
The first adjustment member is a first adjustment roller that winds the recording medium from the surface on the upstream side of the winding roller in the transport path,
The second adjustment member is a second adjustment roller that winds the recording medium from the surface on the downstream side of the winding roller in the conveyance path,
The relative movement mechanism further includes a rotation support shaft that rotates around an intermediate position between the first adjustment roller and the second adjustment roller while supporting the first adjustment roller and the second adjustment roller, The image recording apparatus according to claim 4, wherein the relative movement process is executed by rotating a rotation support shaft.   The relative movement mechanism moves the surface reformer to the downstream side of the transport path, thereby moving the processing position where the surface reformer performs the surface reforming process to the downstream side of the transport path. The image recording apparatus according to claim 1, wherein the relative movement process is executed.   The relative movement mechanism has a winding roller that winds the recording medium from the back while facing the surface reformer across the recording medium, and when the passing period is over, the winding roller is moved to the transport path. And move the surface reformer to a position facing the winding roller to execute the relative movement process after separating the distance between the surface reformer and the recording medium. The image recording apparatus according to claim 6.   The said conveyance part performs the operation | movement which intermittently conveys the said recording medium to the said support member, and the operation | movement which passes the said recording medium intermittently to the said processing position at different timings. The image recording apparatus described in 1. In an image recording method for recording an image by ejecting liquid onto the recording medium that is stopped on the support member while conveying the recording medium along a conveyance path,
Using a surface reformer that performs a surface modification process in response to a process execution signal, the surface modification process is performed on the recording medium at a processing position upstream of the support member in the transport path. Process,
The recording medium is intermittently transported from the upstream side of the transport path to the support member, and the recording medium is intermittently transported to the processing position from the upstream side of the transport path to the processing position. A transport process to pass through,
A relative movement step of performing a relative movement process of moving the recording medium relative to the processing position to the upstream side of the conveyance path,
While the recording medium passes through the processing position with the intermittent conveyance to the processing position, the processing execution signal is given to the surface reformer to execute the surface modification step, while the passage period An image recording method characterized in that the relative movement step is executed in advance before starting.

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