JP6676427B2 - Inkjet printing equipment - Google Patents

Description

  The present invention relates to an inkjet printing apparatus that performs printing by discharging ink from an inkjet head.

  In an ink jet printing apparatus, an ink mist in which the ink is in the form of mist is generated by ink discharge from an ink jet head. The ink mist may adhere to a print medium and stain printed matter. In addition, the ink mist causes contamination inside the apparatus. For this reason, in an inkjet printing apparatus, it is required to collect ink mist.

  On the other hand, for example, Patent Literature 1 discloses an ink jet printing apparatus in which suction fans are arranged upstream and downstream of an ink jet head in a print medium transport direction. In this inkjet printing apparatus, the ink mist is sucked and collected by a suction fan.

JP-A-2015-51524

  However, even if the ink mist is sucked by the suction fan as in Patent Literature 1, the ink mist may not be sufficiently collected depending on the amount of the generated ink mist. Therefore, there has been a demand for a technique capable of collecting ink mist more efficiently.

  The present invention has been made in view of the above, and an object of the present invention is to provide an ink jet printing apparatus that can efficiently collect ink mist.

  In order to achieve the above object, a first feature of an ink jet printing apparatus according to the present invention is that an ink jet head that is disposed above a print medium to be conveyed and discharges ink to the print medium, A blowing unit that is disposed above the printing medium in a predetermined range on the downstream side of the inkjet head and blows downward, and is disposed between the printing medium and the blowing unit, and the airflow from the blowing unit and the conveyance of the printing medium. Rectifying member that guides the airflow of the print medium to the outside of the print medium in the main scanning direction orthogonal to the transport direction of the print medium, and suctions ink mist contained in the airflow guided by the rectification member to the outside of the print medium in the main scanning direction. And a suction unit.

  A second feature of the ink jet printing apparatus according to the present invention is that an ink mist detecting unit that detects an amount of ink mist between the ink jet head and the rectifying member in a print medium transport direction, and a detection of the ink mist detecting unit. A control unit that adjusts at least one of the blowing air amount of the blowing unit and the suction air amount of the suction unit based on the ink mist amount.

  A third feature of the ink jet printing apparatus according to the present invention is that a first ink mist detecting unit that detects an amount of ink mist between the ink jet head and the rectifying member in a print medium conveying direction, and a print medium conveying direction. A second ink mist detection unit that detects the amount of ink mist on the downstream side of the rectifying member, and a control unit that adjusts the amount of air blown by the blowing unit and the amount of suction air by the suction unit. When the detected ink mist amount of the first ink mist detection unit is less than a first threshold value and the detected ink mist amount of the second ink mist detection unit is less than a second threshold value, the blowing air volume of the blowing unit and the suction unit Are set as the respective set airflow rates, and the detected ink mist amount of the first ink mist detection unit is equal to or more than the first threshold value, And when at least one of the detected ink mist amount of the second ink mist detection unit and the second threshold value or more is satisfied, at least one of the blowout air amount of the blowout unit and the suction airflow amount of the suction unit. To increase from the set air volume.

  A fourth feature of the ink jet printing apparatus according to the present invention is that at least one of the blowing air volume of the blowing unit and the suction air volume of the suction unit is adjusted according to the transport speed of the printing medium. is there.

  According to the first feature of the ink jet printing apparatus according to the present invention, the blowing unit blows air from above the print medium to below. The rectifying member guides the airflow from the blow-out portion and the airflow due to the transport of the print medium to the outside of the print medium in the main scanning direction orthogonal to the transport direction of the print medium. Then, the suction unit suctions and collects the ink mist contained in the airflow guided to the outside of the print medium in the main scanning direction by the rectifying member. Accordingly, the ink mist is guided to the suction unit and collected by the airflow in which the flow direction of the airflow from the blowing unit and the transport airflow is changed by the rectifying member, so that the ink mist can be efficiently collected.

  According to the second feature of the inkjet printing apparatus according to the present invention, the control unit adjusts at least one of the blowing air amount of the blowing unit and the suction air amount of the suction unit based on the amount of ink mist detected by the ink mist detecting unit. I do. Thereby, even if the amount of the ink mist changes, the ink mist can be efficiently collected. In addition, since the blowing air volume and the suction air volume are suppressed from being increased more than necessary, waste of power consumption and noise can be suppressed.

  According to the third feature of the inkjet printing apparatus according to the present invention, the control unit is configured such that the detected ink mist amount of the first ink mist detecting unit is less than the first threshold, and the detected ink mist amount of the second ink mist detecting unit is If it is less than the second threshold value, the blowout air volume of the blowout unit and the suction airflow of the suction unit are set as the respective set airflow volumes. When the detected ink mist amount of the first ink mist detection unit is at least one of a first threshold or more and the detected ink mist amount of the second ink mist detection unit is at least one of a second threshold or more, the control unit outputs At least one of the blowing air volume of the section and the suction air volume of the suction section is increased from the respective set air volumes. As described above, the amount of the ink mist is changed by adjusting the blowing air amount of the blowing unit and the suction air amount of the suction unit according to the detected ink mist amount of the first ink mist detecting unit and the second ink mist detecting unit. In addition, the ink mist can be efficiently collected. In addition, since the blowing air volume and the suction air volume are suppressed from becoming larger than necessary, waste of power consumption and noise can be reduced.

  According to the fourth feature of the ink jet printing apparatus according to the present invention, the set air volume of at least one of the blowing air volume of the blowing unit and the suction air volume of the suction unit is adjusted according to the transport speed of the print medium. Thus, even if the degree of ink mist generation changes depending on the transport speed of the print medium, the ink mist can be efficiently collected. In addition, since the blown air volume is suppressed from increasing more than necessary, waste of power consumption and noise can be reduced.

1 is a schematic configuration diagram of an inkjet printing apparatus according to an embodiment. FIG. 2 is a plan view of a head unit and an ink mist collection unit of the inkjet printing apparatus shown in FIG. FIG. 2 is a perspective view of a head unit and an ink mist collecting unit of the inkjet printing apparatus shown in FIG. FIG. 2 is a control block diagram of the inkjet printing apparatus shown in FIG. 1. FIG. 4 is an explanatory diagram of an airflow in an ink mist collection unit. It is a flowchart for demonstrating the control of a blowing fan. It is a flowchart for demonstrating the control of a blowing fan.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same or equivalent parts and components are denoted by the same or similar reference numerals throughout the drawings.

  The embodiments described below exemplify an apparatus or the like for embodying the technical idea of the present invention. The technical idea of the present invention is based on the material, shape, structure, arrangement, etc. of each component. Is not specified as: Various changes can be made to the technical idea of the present invention within the scope of the claims.

  FIG. 1 is a schematic configuration diagram of an inkjet printing apparatus according to an embodiment of the present invention. FIG. 2 is a plan view of a head unit and an ink mist collecting unit of the inkjet printing apparatus shown in FIG. FIG. 3 is a perspective view of a head unit and an ink mist collecting unit of the inkjet printing apparatus shown in FIG. FIG. 4 is a control block diagram of the inkjet printing apparatus shown in FIG. In the following description, the direction perpendicular to the paper surface of FIG. The upper, lower, left, and right sides of the paper surface in FIG.

  As shown in FIG. 1 and FIG. 4, the inkjet printing apparatus 1 according to the present embodiment includes a sending unit 2, a transport unit 3, a head unit 4, an ink mist collecting unit 5, a winding unit 6, And a control unit 7.

  The sending unit 2 sends a web W, which is a long print medium made of paper, film, or the like, to the transport unit 3. The delivery unit 2 includes a web roll support shaft 11, a delivery motor 12, guide rollers 13 and 14, and an upstream buffer unit 15.

  The web roll support shaft 11 rotatably supports the web roll 16. The web roll support shaft 11 is formed in a long shape extending in the front-rear direction. The web roll 16 is obtained by rolling the web W.

  The feed motor 12 rotates the web roll support shaft 11 clockwise in FIG. The rotation of the web roll support shaft 11 causes the web roll 16 to rotate in the same direction, and the web W is sent to the downstream side (right side) in the transport direction.

  The guide rollers 13 and 14 guide the web W between the web roll 16 and the upstream buffer unit 15.

  The upstream buffer section 15 absorbs the slack of the web W between the guide roller 14 and a guide roller 26 of the transport section 3 described later. The upstream buffer section 15 includes support rollers 17 to 20 and dancer rollers 21 and 22.

  The support rollers 17 to 20 support the web W between the guide rollers 14 and 26. The support rollers 17 to 20 are arranged at the same height with an interval in the left-right direction.

  The dancer rollers 21 and 22 push down the web W by their own weight between the support rollers 17 and 18 and between the support rollers 18 and 19 to absorb the slack of the web W. The dancer rollers 21 and 22 move up and down according to the slack amount of the web W.

  The transport unit 3 transports the web W sent by the sending unit 2. The transport section 3 includes guide rollers 26 to 30, a pair of tension applying rollers 31, a brake 32, a plurality of lower head support members 33, a pair of transport rollers 34, and a transport motor 35.

  The guide roller 26 guides the web W between the upstream buffer section 15 of the feeding section 2 and the tension applying roller 31. The guide rollers 27 to 29 guide the web W between the tension applying roller 31 and the most downstream (leftmost) lower head support member 33. The guide roller 30 guides the web W between the most downstream (rightmost) lower head support member 33 and the transport roller 34.

  The pair of tension applying rollers 31 applies tension to the web W. The pair of tension applying rollers 31 are driven to rotate by the web W conveyed by the pair of conveying rollers 34 while nipping the web W. When a brake is applied to one tension applying roller 31 by the brake 32, tension is applied to the web W between the transport roller 34 and the tension applying roller 31.

  The brake 32 applies a brake to one tension applying roller 31. The brake 32 is, for example, a powder brake.

  The lower head support member 33 supports the web W directly below the head unit 4. The plurality of lower head support members 33 are arranged between the guide rollers 29 and 30 at intervals in the left-right direction.

  The pair of transport rollers 34 transport the web W to the winding unit 6 while nipping the web W.

  The transport motor 35 drives the transport roller 34 to rotate.

  The head unit 4 prints an image on the web W transported by the transport unit 3. The head unit 4 includes inkjet heads 41A to 41D. In addition, the suffixes (A to D) of the alphabets in the reference numerals of the ink jet heads 41A to 41D may be omitted and may be collectively described.

  The ink jet heads 41A to 41D discharge ink onto the web W being conveyed. The ink jet heads 41A to 41D discharge inks of different colors (for example, black, cyan, magenta, and yellow). The inkjet heads 41 </ b> A to 41 </ b> D are arranged in parallel in the sub-scanning direction (left-right direction), which is the transport direction of the web W, above the web W between the guide rollers 29 and 30. Each of the inkjet heads 41A to 41D has six head modules 42.

  The head module 42 has a plurality of nozzles (not shown) that are opened on the ink ejection surface facing the web W and are arranged along a main scanning direction (front-rear direction) orthogonal to the transport direction of the web W, The ink is ejected from the nozzle. The head modules 42 are arranged in a staggered manner in the inkjet head 41. That is, in the inkjet head 41, two head rows each including three head modules 42 arranged at equal pitches in the front-rear direction are arranged so as to be shifted by a half pitch in the front-rear direction.

  The ink mist collection unit 5 collects ink mist generated by ink ejection from the inkjet head 41. The ink mist collection unit 5 is arranged near the downstream side of the head unit 4. The ink mist collection unit 5 includes a blow-out fan (corresponding to a blow-out unit in the claims) 51, a flow regulating member 52, suction fans (corresponding to a suction unit in the claims) 53A and 53B, and an upstream ink mist detection unit (claims). And a downstream ink mist detector (corresponding to a second ink mist detector in the claims) 55.

  The blower fan 51 blows air from above the web W to below. The blower fan 51 is disposed above a central portion of the web W in the front-back direction within a predetermined range on the downstream side of the inkjet head 41D in the web W transport direction (left-right direction). Here, the predetermined range on the downstream side of the inkjet head 41D is a range set in advance as a range where a large amount of ink mist exists on the downstream side of the inkjet head 41D. This range is set based on experiments, for example.

  The rectifying member 52 guides the blowout airflow, which is an airflow from the blowout fan 51, and the transport airflow, which is an airflow generated by transporting the web W, to the outside (front side and rear side) of the web W in the front-rear direction (main scanning direction). It is a member. The rectifying member 52 is disposed between the web W and the blowing fan 51. More specifically, the rectifying member 52 is disposed at a position within a predetermined range on the downstream side of the inkjet head 41D, similar to the blower fan 51, in the left-right direction. In the up-down direction, the rectifying member 52 is arranged at a position where the interval with the web W is a predetermined interval and is close to the web W but not in contact therewith.

  The rectifying member 52 includes a blowout airflow rectifying unit 56, a transport airflow rectifying unit 57, and a wall 58.

  The blowout air flow rectifying unit 56 changes the traveling direction of the blowout airflow from the blowout fan 51 from downward to forward and backward. The blowout airflow rectification section 56 is formed in a rectangular shape in plan view that extends over the entire width of the web W.

  The blowout air flow rectification unit 56 has a front first surface 56a and a rear second surface 56b. The first surface 56a is formed in a shape that shifts from a plane parallel to the web W to a curved surface that curves upward as the front surface 56a advances from the front side to the rear side. The second surface 56b is formed in a shape in which the first surface 56a is reversed. The first surface 56a and the second surface 56b intersect at the center of the web W in the front-rear direction, and form a ridge portion 56c parallel to the left-right direction.

  The transport airflow rectification section 57 changes the traveling direction of the transport airflow due to the transport of the web W from right to forward and backward. As shown in FIG. 2, the transport airflow rectification unit 57 projects leftward (upstream) from the left side of the blowout airflow rectification unit 56 at the center in the front-rear direction of the blowout airflow rectification unit 56 in plan view. Is formed.

  The transport airflow rectification unit 57 has a first surface 57a on the front side and a second surface 57b on the rear side. The first surface 57a is a curved surface that curves upward toward the right side (downstream side) and the rear side. The second surface 57b is formed in a shape obtained by inverting the first surface 57a back and forth. The first surface 57a and the second surface 57b intersect at the center of the web W in the front-rear direction and form a ridge 57c parallel to the left-right direction. The right end (downstream end) of the ridge portion 57c is connected to the left end (upstream end) of the ridge portion 56c of the blowout airflow rectification unit 56.

  The wall 58 blocks airflow downstream of the flow regulating member 52. The wall portion 58 is provided upright at the right end (downstream end) of the blowout airflow rectification portion 56.

  The suction fans 53A and 53B suction ink mist contained in the airflow guided to the outside of the web W in the front-rear direction by the rectifying member 52. The suction fans 53 </ b> A and 53 </ b> B are adjacent to the front side and the rear side of the flow regulating member 52, respectively, and are disposed below the web W. The suction fans 53A and 53B have suction ports 53a for sucking air, and are installed with the suction ports 53a facing upward.

  The upstream ink mist detector 54 detects the amount of ink mist between the inkjet head 41D and the rectifying member 52. The upstream ink mist detection unit 54 has ink mist sensors 59A and 59B. The ink mist sensors 59A and 59B are arranged adjacent to the front side and the rear side of the web W between the inkjet head 41D and the rectifying member 52 in the left-right direction. As the ink mist sensors 59A and 59B, for example, a particle sensor having a light emitting element and a light receiving element and measuring the concentration of particles in the air from the amount of light received by the light receiving element can be used.

  The downstream ink mist detector 55 detects the amount of ink mist on the downstream side of the flow regulating member 52. The downstream ink mist detection unit 55 has ink mist sensors 60A and 60B. The ink mist sensors 60 </ b> A and 60 </ b> B are arranged downstream of the flow regulating member 52 and adjacent to the front side and the rear side of the web W, respectively. As the ink mist sensors 60A and 60B, for example, the above-described particle sensors can be used, similarly to the ink mist sensors 59A and 59B of the upstream ink mist detection unit 54.

  The winding unit 6 winds the web W printed by the head unit 4. The winding unit 6 includes guide rollers 61 to 63, a downstream buffer unit 64, a winding shaft 65, and a winding motor 66.

  The guide rollers 61 and 62 guide the web W between the transport roller 34 of the transport section 3 and the downstream buffer section 64. The guide roller 63 guides the web W between the downstream buffer section 64 and the winding shaft 65.

  The downstream buffer section 64 absorbs the slack of the web W between the guide rollers 62 and 63. The downstream buffer section 64 includes support rollers 71 to 73 and dancer rollers 74 and 75.

  The support rollers 71 to 73 support the web W between the guide rollers 62 and 63. The support rollers 71 to 73 are arranged at the same height with an interval in the left-right direction.

  The dancer rollers 74 and 75 push down the web W by their own weight between the support rollers 71 and 72 and between the support rollers 72 and 73, and absorb the slack of the web W. The dancer rollers 74 and 75 move up and down according to the slack amount of the web W.

  The winding shaft 65 winds and holds the web W. The winding shaft 65 is formed in a long shape extending in the front-rear direction.

  The winding motor 66 rotates the winding shaft 65 clockwise in FIG. The web W is wound around the winding shaft 65 by the rotation of the winding shaft 65.

  The control unit 7 controls the operation of each unit of the inkjet printing apparatus 1. The control unit 7 includes a CPU, a RAM, a ROM, a hard disk, and the like.

  When performing printing, the control unit 7 drives the delivery unit 2, the transport unit 3, and the winding unit 6 to transport the web W, and discharges ink from the inkjet head 41 to print on the web W. In addition, the control unit 7 drives the blowing fan 51 and the suction fans 53A and 53B of the ink mist collecting unit 5 to collect the ink mist.

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

  When a print job is input, the control unit 7 starts transporting the web W. Specifically, the control unit 7 starts driving the delivery motor 12, the brake 32, the transport motor 35, and the winding motor 66. As a result, the web W is transported from the feeding section 2 to the winding section 6. In the transport unit 3, the web W is transported while tension is applied to the web W by applying a brake to the tension applying roller 31 by the brake 32.

  Here, in the inkjet printing apparatus 1, the control unit 7 can select any of the standard mode, the high-speed print mode, and the low-speed print mode as the print mode. The standard mode is a mode in which printing is performed while the web W is transported at the standard transport speed. The high-speed printing mode is a mode in which printing is performed while the web W is transported at a high transport speed higher than the standard transport speed. The low-speed printing mode is a mode in which printing is performed while the web W is transported at a low transport speed lower than the standard transport speed.

  The control unit 7 selects a print mode according to the maximum number of drops per pixel according to the type of the web W and the print resolution. Then, the control unit 7 controls the feed motor 12, the transport motor 35, and the take-up motor 66 to transport the web W at a transport speed according to the selected print mode.

  Further, the control section 7 starts driving of the blowing fan 51 and the suction fans 53A and 53B of the ink mist collecting section 5.

  After starting conveyance of the web W and starting driving of the blowing fan 51 and the suction fans 53A and 53B, the control unit 7 controls the inkjet heads 41A to 41D based on the print job to eject ink, thereby controlling the image. To print.

  When ink is ejected from the inkjet heads 41A to 41D, ink mist is generated. Most of the generated ink mist flows downstream from the inkjet heads 41A to 41D due to the transport airflow. The ink mist is collected by the ink mist collecting unit 5.

  In the ink mist collecting section 5, as shown in FIG. 5, the blown airflow Fd from the blower fan 51 flows downward. The blowout airflow Fd is divided into a front airflow Fdf and a rear airflow Fdr by a ridgeline portion 56c of the blowout airflow rectification unit 56. The forward side airflow Fdf is bent from the downward direction to the forward direction by the first surface 56a of the blowout airflow rectification unit 56. The rear airflow Fdr is bent from the lower side to the rearward direction by the second surface 56b of the blowout airflow rectifier 56. That is, the traveling direction of the blown airflow Fd is changed from downward to forward and rearward by the blown airflow straightening unit 56.

  Further, at the center in the front-rear direction, the transport airflow Ft is divided into a front airflow Ftf and a rear airflow Ftr by the ridgeline portion 57c of the transport airflow rectification section 57. The forward airflow Ftf is bent from the right to the front by the first surface 57a of the transport airflow rectification unit 57. The rear airflow Ftr is bent from the right to the rear by the second surface 57b of the transport airflow rectification unit 57. That is, the traveling direction of the transport airflow Ft is changed from right to forward and rearward by the transport airflow rectification unit 57.

  The front airflows Fdf and Ftf flow forward while the wall 58 suppresses the outflow from the rectifying member 52 to the downstream side. Thus, the air flows Fdf and Ftf guide the ink mist to the front side of the web W. Then, the airflows Fdf and Ftf flow into the suction port 53a together with the suctioned airflow Fbf by the suction fan 53A. Thus, the ink mist guided to the front side of the web W by the airflows Fdf and Ftf is sucked and collected by the suction fan 53A.

  The rear airflows Fdr and Ftr flow in the rearward direction while the flow of the airflow Fdr and Ftr on the rear side from the rectifying member 52 to the downstream side is suppressed by the wall portion 58. Thus, the air flows Fdr and Ftr guide the ink mist to the rear side of the web W. Then, the airflows Fdr and Ftr flow into the suction port 53a together with the suctioned airflow Fbr by the suction fan 53B. Thus, the ink mist guided to the rear side of the web W by the airflows Fdf and Ftr is sucked and collected by the suction fan 53B.

  When the printing based on the print job is completed, the control unit 7 stops the blowing fan 51 and the suction fans 53A and 53B of the ink mist collecting unit 5. Further, the control unit 7 terminates the conveyance of the web W. Specifically, the control unit 7 stops the feed motor 12, the brake 32, the transport motor 35, and the winding motor 66. Thus, a series of operations is completed.

  During the operation of the ink jet printing apparatus 1 described above, the control unit 7 drives the suction fans 53A and 53B of the ink mist collection unit 5 so that the suction air volume becomes a preset air volume.

  Further, the control unit 7 controls the blowing air volume of the blowing fan 51 based on the printing mode, the detected ink mist amount of the upstream ink mist detecting unit 54, and the detected ink mist amount of the downstream ink mist detecting unit 55.

  The control of the blowing fan 51 including the adjustment of the blowing air amount will be described with reference to the flowcharts of FIGS. 6 and 7 starts when a print job is input to the inkjet printing apparatus 1.

  In step S1 of FIG. 6, the control unit 7 determines whether the print mode corresponding to the current print job is the standard mode.

  When it is determined that the printing mode is the standard mode (step S1: YES), in step S2, the control unit 7 sets the blowing air volume to the standard air volume. Thereafter, the control section 7 proceeds to step S6.

  When determining that the print mode is not the standard mode (step S1: NO), in step S3, the control unit 7 determines whether the print mode is the high-speed print mode.

  If it is determined that the printing mode is the high-speed printing mode (step S3: YES), in step S4, the control unit 7 sets the blowing air volume to a high-speed printing air volume larger than the standard air volume. Thereafter, the control section 7 proceeds to step S6.

  Here, as the transport speed of the web W is higher, the transport airflow is stronger, and ink mist is more likely to be generated. This is because the stronger the transport airflow, the easier it is to cut off the tail of the ink ejected from the nozzles of the head module 42 and flying, and the more easily the ink becomes mist. Therefore, in the high-speed printing mode, in order to increase the ability of the ink mist collection unit 5 to collect ink mist, the blowing air volume is set to a high-speed printing air volume larger than the standard air volume.

  When it is determined that the printing mode is not the high-speed printing mode, that is, the printing mode is the low-speed printing mode (step S3: NO), in step S5, the control unit 7 sets the blowing air volume to the low-speed printing air volume smaller than the standard air volume. . Thereafter, the control section 7 proceeds to step S6.

  In step S6, the control section 7 starts driving of the blowing fan 51. Then, the control unit 7 drives the blowing fan 51 at the set air volume set in any of steps S2, S4, and S6.

  Next, in step S7, the control unit 7 determines whether or not the detected ink mist amount of the upstream ink mist detection unit 54 is equal to or larger than the first threshold value. The first threshold is a threshold for determining whether or not the amount of ink mist generated by the head unit 4 is increasing, and is determined in advance based on an experiment. Here, the higher the printing rate of the printed image, the larger the amount of ink mist generated.

  When the detected ink mist amount of at least one of the ink mist sensors 59A and 59B is equal to or greater than the first threshold value, the control unit 7 determines that the detected ink mist amount of the upstream ink mist detection unit 54 is equal to or greater than the first threshold value. Judge that there is. When both the detected ink mist amounts of the ink mist sensors 59A and 59B are smaller than the first threshold value, the control unit 7 determines that the detected ink mist amount of the upstream ink mist detection unit 54 is smaller than the first threshold value.

  When it is determined that the amount of ink mist detected by the upstream ink mist detection unit 54 is equal to or larger than the first threshold value (step S7: YES), the control unit 7 proceeds to step S9 in FIG.

  When it is determined that the amount of ink mist detected by the upstream ink mist detection unit 54 is less than the first threshold value (step S7: NO), the control unit 7 controls the detection of ink mist by the downstream ink mist detection unit 55 in step S8. It is determined whether the amount is greater than or equal to a second threshold. The second threshold is a threshold for determining whether or not the ink mist collection unit 5 has sufficiently collected the ink mist, and is determined in advance based on an experiment.

  When the detected ink mist amount of at least one of the ink mist sensors 60A and 60B is equal to or greater than the second threshold, the control unit 7 determines that the detected ink mist amount of the downstream ink mist detector 55 is equal to or greater than the second threshold. Judge that there is. When both the detected ink mist amounts of the ink mist sensors 60A and 60B are less than the first threshold value, the control unit 7 determines that the detected ink mist amount of the downstream ink mist detection unit 55 is less than the second threshold value.

  When it is determined that the amount of ink mist detected by the downstream ink mist detection unit 55 is equal to or larger than the second threshold (step S8: YES), the control unit 7 proceeds to step S9 in FIG. If it is determined that the amount of ink mist detected by the downstream ink mist detection unit 55 is less than the second threshold (step S8: NO), the control unit 7 proceeds to step S13 in FIG.

  In step S9 of FIG. 7, the control unit 7 increases the blowing air volume of the blowing fan 51 by a predetermined amount from the setting air volume set in any of steps S2, S4, and S6. Thus, the ability of the ink mist collection unit 5 to collect ink mist is improved.

  Next, in step S10, it is determined whether the amount of ink mist detected by the upstream ink mist detection unit 54 is less than the first threshold. When it is determined that the amount of ink mist detected by the upstream ink mist detection unit 54 is equal to or larger than the first threshold value (step S10: NO), the control unit 7 repeats step S10.

  When it is determined that the amount of ink mist detected by the upstream ink mist detection unit 54 is less than the first threshold value (step S10: YES), the control unit 7 detects the ink mist of the downstream ink mist detection unit 55 in step S11. It is determined whether the amount is less than a second threshold. When it is determined that the amount of ink mist detected by the downstream ink mist detection unit 55 is equal to or larger than the second threshold (step S11: NO), the control unit 7 returns to step S10.

  When it is determined that the amount of ink mist detected by the downstream ink mist detection unit 55 is less than the second threshold (step S11: YES), the control unit 7 returns the blow air volume of the blow fan 51 to the set air volume. Thereafter, the control section 7 proceeds to step S13.

  In step S13, the control unit 7 determines whether printing based on the print job has been completed. If it is determined that printing has not been completed (step S13: NO), the control unit 7 returns to step S7 in FIG.

  When it is determined that the printing is completed (step S13: YES), the control unit 7 stops the blowing fan 51 in step S14. Thereby, the control of the blowing fan 51 ends.

  When the amount of ink mist detected by the upstream ink mist detection unit 54 is less than the first threshold value and the amount of ink mist detected by the downstream ink mist detection unit 55 is less than the second threshold value, The air volume is the set air volume. When at least one of the detected ink mist amount of the upstream ink mist detecting unit 54 is equal to or more than the first threshold value and the detected ink mist amount of the downstream ink mist detecting unit 55 is equal to or more than the second threshold value, the blowing air volume is The air volume is increased from the set air volume.

  As described above, in the inkjet printing apparatus 1, the blowing fan 51 blows air from above the web W to below. The rectifying member 52 guides the blowing airflow from the blowing fan 51 and the conveying airflow due to the conveyance of the web W to the outside of the web W in the front-rear direction. Then, the suction fans 53 </ b> A and 53 </ b> B suction and collect the ink mist contained in the airflow guided to the outside of the web W in the front-rear direction by the rectifying member 52. Thus, the ink mist is guided to the suction fans 53A and 53B and collected by the airflow in which the flow direction of the blown airflow and the transport airflow is changed by the rectifying member 52, so that the ink mist can be efficiently collected.

  When the detected ink mist amount of the upstream ink mist detection unit 54 is less than the first threshold value and the detected ink mist amount of the downstream ink mist detection unit 55 is less than the second threshold value, the control unit 7 sets Set the air volume. When at least one of the detected ink mist amount of the upstream ink mist detection unit 54 is equal to or more than the first threshold value and the detected ink mist amount of the downstream ink mist detection unit 55 is equal to or more than the second threshold value, the control unit 7 Increases the blowing air volume from the set air volume. As described above, by adjusting the blowing air amount of the blowing fan 51 according to the detected ink mist amount of the upstream ink mist detecting unit 54 and the downstream ink mist detecting unit 55, even if the amount of ink mist changes, Mist can be collected efficiently. In addition, since the blown air volume is suppressed from increasing more than necessary, waste of power consumption and noise can be reduced.

  Further, the control unit 7 adjusts the set air volume of the blowing fan 51 according to the web W transport speed. Thereby, even if the generation degree of the ink mist changes depending on the transport speed of the web W, the ink mist can be efficiently collected. In addition, since the blown air volume is suppressed from increasing more than necessary, waste of power consumption and noise can be reduced.

  In the above-described embodiment, at least one of the amount of ink mist detected by the upstream ink mist detection unit 54 is equal to or greater than the first threshold and the amount of ink mist detected by the downstream ink mist detection unit 55 is equal to or greater than the second threshold. When one of them is satisfied, the blowing air volume is increased by a predetermined amount from the set air volume. However, in this case, the amount of blown air is gradually increased from the set airflow, and the amount of ink mist detected by the upstream ink mist detector 54 is less than the first threshold, and the amount of ink mist detected by the downstream ink mist detector 55 When the value is less than two thresholds, the air volume may be returned to the set air volume.

  In the above-described embodiment, the blowing air volume of the blowing fan 51 is adjusted according to the detected ink mist amount of the upstream ink mist detecting unit 54 and the downstream ink mist detecting unit 55. It may be adjusted. Further, both the blowing air volume of the blowing fan 51 and the suction air volumes of the suction fans 53A and 53B may be adjusted. Specifically, at least one of the detection amount of the ink mist of the upstream ink mist detection unit 54 is equal to or more than the first threshold value and the detection mist amount of the downstream ink mist detection unit 55 is equal to or more than the second threshold value. In this case, the suction air volume of the suction fans 53A and 53B may be increased from the set air volume. Further, in this case, both the blow air volume of the blow fan 51 and the suction air volumes of the suction fans 53A and 53B may be increased from the respective set air volumes.

  In the above-described embodiment, the blowing air amount of the blowing fan 51 is adjusted according to the detected ink mist amount of the upstream ink mist detecting unit 54 and the downstream ink mist detecting unit 55, but the downstream ink mist detecting unit 55 is omitted. Alternatively, the blowing air volume may be adjusted according to the amount of ink mist detected by the upstream ink mist detection unit 54. In this case, when the amount of ink mist detected by the upstream ink mist detection unit 54 (corresponding to an ink mist detection unit in the claims) is equal to or greater than a threshold, the amount of blown air may be increased from the set air flow.

  Further, in a configuration in which the downstream ink mist detection unit 55 is omitted, the suction air amount of the suction fans 53A and 53B may be adjusted according to the amount of ink mist detected by the upstream ink mist detection unit 54. Further, both the blowing air volume of the blowing fan 51 and the suction air volumes of the suction fans 53A and 53B may be adjusted. Specifically, when the amount of ink mist detected by the upstream ink mist detection unit 54 is equal to or larger than the threshold value, the suction air volume of the suction fans 53A and 53B may be increased from the set air volume. Further, in this case, both the blow air volume of the blow fan 51 and the suction air volumes of the suction fans 53A and 53B may be increased from the respective set air volumes.

  In the above-described embodiment, the set air volume of the blowing fan 51 is adjusted according to the transport speed of the web W. However, the set air volume of the suction fans 53A and 53B may be adjusted according to the transport speed of the web W. Further, the set air volume of both the blowing fan 51 and the suction fans 53A and 53B may be adjusted according to the transport speed of the web W.

  In the above-described embodiment, the upstream ink mist detection unit 54 has the ink mist sensors 59A and 59B disposed adjacent to the front side and the rear side of the web W, respectively. However, the number of ink mist sensors constituting the upstream ink mist detection unit 54 and the arrangement in the main scanning direction are not limited to this. For example, as the upstream ink mist detection unit 54, one ink mist sensor disposed at the center of the web W in the main scanning direction between the inkjet head 41D and the rectification member 52 in the left-right direction may be used. The same applies to the downstream ink mist detector 55.

  In the above-described embodiment, the configuration in which the feeding unit 2 and the winding unit 6 are incorporated in the inkjet printing apparatus 1 has been described, but a configuration in which the feeding device and the winding device are connected to the inkjet printing apparatus as separate devices may be used. . Further, a cutting device for cutting the web or the like may be connected to the inkjet printing device as an external device.

  In the above-described embodiment, an ink jet printing apparatus using a web as a print medium has been described. However, the present invention is also applicable to an ink jet printing apparatus using cut paper or the like as a print medium.

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

DESCRIPTION OF SYMBOLS 1 Ink-jet printing apparatus 2 Sending-out part 3 Conveying part 4 Head unit 5 Ink mist collection | recovery part 6 Winding-up part 7 Control part 41, 41A-41D Ink-jet head 42 Head module 51 Blowing fan 52 Straightening member 53A, 53B Suction fan 54 Upstream ink Mist detector 55 Downstream ink mist detector 56 Blow-out airflow rectification unit 57 Transport airflow rectification unit 58 Wall

Claims (8)

An inkjet head that is disposed above the transported print medium and that discharges ink onto the print medium;
Within a predetermined range on the downstream side of the inkjet head in the transport direction of the print medium, disposed above the central portion of the print medium in the main scanning direction orthogonal to the transport direction of the print medium, a blowing unit that blows downward,
A rectifying member that is disposed between a print medium and the blow-out unit and guides an air flow from the blow-out unit and an air flow due to conveyance of the print medium to the outside of the print medium in the main scanning direction,
A suction unit that suctions ink mist contained in the airflow guided to the outside of the print medium in the main scanning direction by the rectifying member ,
The rectifying member is formed so that the outer side is lower than the center in the main scanning direction, and the traveling direction of the air flow from the blowout portion is directed from the lower direction to one of the main scanning directions and to the other of the main scanning directions. inkjet printing apparatus according to claim Rukoto includes a blowout flow-guiding portion changing the direction. The rectifying member is connected to the upstream side of the blowout airflow rectifying unit in the print medium transport direction, and changes the traveling direction of the airflow due to the transport of the print medium from a direction parallel to the transport direction of the print medium to one of the main scanning directions. The ink jet printing apparatus according to claim 1, further comprising a transport airflow rectification unit that changes the direction toward the other of the heading direction and the main scanning direction. The inkjet printing apparatus according to claim 1, wherein the rectifying member has no gap through which the ink mist passes. 4. The ink jet printing apparatus according to claim 1, wherein the rectifying member further includes a wall erected at a downstream end of the blown air flow rectifying unit. 5. An ink mist detection unit that detects an amount of ink mist between the inkjet head and the rectifying member in a transport direction of a print medium,
5. The control device according to claim 1, further comprising: a controller configured to adjust at least one of a blowing air amount of the blowing unit and a suction air amount of the suction unit based on a detection ink mist amount of the ink mist detection unit. 6. The inkjet printing device according to any one of the above. A first ink mist detection unit that detects an amount of ink mist between the inkjet head and the rectifying member in a conveyance direction of a print medium;
A second ink mist detection unit that detects an amount of ink mist on the downstream side of the rectifying member in the transport direction of the print medium;
A control unit that adjusts a blowout air amount of the blowout unit and a suction airflow amount of the suction unit,
The control unit includes:
When the detected ink mist amount of the first ink mist detection unit is less than a first threshold value and the detected ink mist amount of the second ink mist detection unit is less than a second threshold value, the blowing air volume of the blowing unit and the suction unit Is the set air volume of each,
When the detected ink mist amount of the first ink mist detection unit is equal to or more than the first threshold, and the detected ink mist amount of the second ink mist detection unit is at least one of the second threshold value or more, The ink jet printing apparatus according to any one of claims 1 to 4, wherein at least one of a blowing air volume of a blowing unit and a suction air volume of the suction unit is increased from respective set air volumes. An inkjet head that is disposed above the transported print medium and that discharges ink onto the print medium;
A blowing unit that is disposed above the print medium within a predetermined range on the downstream side of the inkjet head in the conveyance direction of the print medium and blows downward,
A rectifying member that is disposed between the print medium and the blow-out unit, and guides the air flow from the blow-out unit and the air flow due to the conveyance of the print medium to the outside of the print medium in the main scanning direction orthogonal to the print medium conveyance direction,
A suction unit that suctions ink mist contained in the airflow guided to the outside of the print medium in the main scanning direction by the rectifying member,
A first ink mist detection unit that detects an amount of ink mist between the inkjet head and the rectifying member in a conveyance direction of a print medium;
A second ink mist detection unit that detects an amount of ink mist on the downstream side of the rectifying member in the transport direction of the print medium;
A control unit that adjusts a blowout air amount of the blowout unit and a suction airflow amount of the suction unit,
The control unit includes:
When the detected ink mist amount of the first ink mist detection unit is less than a first threshold value and the detected ink mist amount of the second ink mist detection unit is less than a second threshold value, the blowing air volume of the blowing unit and the suction unit Is the set air volume of each,
When the detected ink mist amount of the first ink mist detection unit is equal to or more than the first threshold, and the detected ink mist amount of the second ink mist detection unit is at least one of the second threshold value or more, An ink jet printing apparatus, characterized in that at least one of a blowing air volume of a blowing unit and a suction air volume of the suction unit is increased from respective set air volumes. Blowout air volume and one set air volume of at least one of the suction air amount of the suction portion of the balloon portion, to any one of claims 1 to 7, characterized in that it is adjusted in accordance with the conveyance speed of the printing medium An inkjet printing apparatus as described in the above.