JP2018047649A - Inkjet printing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet printing device that can efficiently collect ink mist while suppressing a mechanism for collecting ink mist from being enlarged.SOLUTION: An inkjet printing device 3 comprises: an inkjet head arranged above a web W to be conveyed; a blowoff fan 61A, arranged adjacent to the web W at one side in a width direction of the web W in a prescribed range at a downstream side of the inkjet head in a conveyance direction of the web W, which blows air toward the other side in the width direction of the web W; a blowoff fan 61B, arranged, opposing to the blowoff fan 61A, adjacent to the web W at the other side in the width direction of the web W, which blows air toward the one side in the width direction of the web W; and a suction fan 62, arranged above the web W in the prescribed range at the downstream side of the inkjet head in the conveyance direction of the web W, which suctions ink mist.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an inkjet printing apparatus that prints by ejecting ink from an inkjet head.

  In an ink jet printing apparatus, ink mist in which ink is atomized is generated by ink ejection from an ink jet head. Ink mist may adhere to the print medium and stain the printed matter. Ink mist may also cause dirt inside the apparatus. For this reason, the ink jet printing apparatus is required to collect ink mist.

  On the other hand, for example, Patent Document 1 has a suction port that sucks ink mist and two blowout ports that are arranged on the upstream side and the downstream side of the suction port in the conveyance direction of the print medium and blow out air. A mist recovery mechanism is disclosed. The suction port and the two outlets are disposed on the downstream side of the inkjet head and are formed over the entire width of the inkjet head.

  In this mist collecting mechanism, the upstream outlet blows out air to guide the air containing the ink mist to the suction opening. The downstream outlet blows out air for adjusting the position of the air blown out from the upstream outlet so that the air blown out from the upstream outlet is appropriately sucked into the suction outlet. . Thereby, the ink mist can be efficiently sucked and collected by the suction port.

JP-A-2015-83372

  However, since the mist collection mechanism of Patent Document 1 described above has a suction port and two blowout ports formed over the entire width of the inkjet head, the mechanism has been enlarged.

  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 capable of efficiently collecting ink mist while suppressing an increase in size of a mechanism for collecting ink mist.

  In order to achieve the above object, a first feature of an ink jet printing apparatus according to the present invention is an ink jet head which is arranged above a print medium to be transported and ejects ink onto the print medium for printing and transport of the print medium. A first blowing section that is arranged adjacent to the print medium on one side in the width direction of the print medium and blows toward the other side in the width direction of the print medium within a predetermined range on the downstream side of the inkjet head in the direction And a second blowing part that is disposed adjacent to the print medium on the other side in the width direction and opposed to the first blowing part, and blows toward the one side in the width direction of the printing medium; Located above the print medium within a predetermined range on the downstream side of the inkjet head in the transport direction, sucks ink mist. It lies in and a that suction portion.

  A second feature of the ink jet printing apparatus according to the present invention is that the suction portion is disposed above a central portion of the print medium in the width direction.

  A third feature of the inkjet printing apparatus according to the present invention is based on at least one of a printing rate by the inkjet head, a conveyance speed of the printing medium, and an environmental temperature, and the first blowing unit, the second blowing unit, and It is further provided with an air volume control unit for adjusting an air volume of at least one of the suction units.

  A fourth feature of the ink jet printing apparatus according to the present invention is that at least one of a movement drive unit that moves the suction unit along the transport direction, a print rate by the ink jet head, a transport speed of the print medium, and an environmental temperature. And a suction position control unit that controls the movement driving unit to adjust the position of the suction unit in the transport direction.

  The fifth feature of the ink jet printing apparatus according to the present invention is further provided with an air volume balance adjusting section that adjusts the air volume of the first blowing section and the second blowing section according to the distribution of the printing rate in the width direction. It is in.

  According to the first feature of the ink jet printing apparatus according to the present invention, the first blowing section blows air from one side to the other side in the width direction of the print medium, and is disposed opposite to the first blowing section. 2 The blowing section blows air from the other side in the width direction of the print medium toward one side. The suction unit sucks and collects the ink mist above the print medium. Thereby, the diffusion of the ink mist to the outside of the print medium is suppressed, and the ink mist is collected and collected inside the print medium, so that the ink mist can be collected efficiently. Further, since the ink mist is collected by the first blowing portion, the second blowing portion, and the suction portion arranged above the print medium, which are arranged adjacent to one side and the other side in the width direction of the print medium, An increase in the size of the mechanism for collecting the ink mist can be suppressed. Therefore, according to the first feature of the ink jet printing apparatus according to the present invention, it is possible to efficiently collect the ink mist while suppressing an increase in the size of the mechanism for collecting the ink mist.

  According to the second feature of the ink jet printing apparatus according to the present invention, since the suction portion is disposed above the central portion of the print medium in the width direction, the ink is blown by the air blown from the first blowing portion and the second blowing portion. Ink mist can be collected at the center of the print medium in the width direction, where a large amount of mist gathers. Thereby, ink mist can be collected more efficiently.

  According to the third feature of the inkjet printing apparatus according to the present invention, the first blowing section, the second blowing section, and the suction are based on at least one of the printing rate by the inkjet head, the conveyance speed of the printing medium, and the environmental temperature. Adjust the air volume of at least one of the parts. As a result, the air volume of at least one of the first blowing section, the second blowing section, and the suction section is adjusted to an air volume corresponding to the amount of ink mist that is generated, thereby reducing waste of power consumption and noise. it can.

  According to the fourth aspect of the inkjet printing apparatus of the present invention, the position of the suction portion in the print medium conveyance direction is adjusted based on at least one of the printing rate by the inkjet head, the conveyance speed of the print medium, and the environmental temperature. To do. As a result, the position of the suction unit is adjusted according to the amount of ink mist generated and the strength of the air flow, so that it is possible to reduce ink mist that flows downstream without being collected by the suction unit.

  According to the fifth feature of the ink jet printing apparatus according to the present invention, the air volume of the first blowing section and the second blowing section is adjusted according to the distribution of the printing rate in the width direction of the print medium. As a result, the air volume of each of the first blowing section and the second blowing section is set according to the distribution of ink mist in the width direction of the print medium, so that waste of power consumption and noise can be further suppressed.

1 is a schematic configuration diagram of a printing system including an inkjet printing apparatus according to an embodiment. FIG. 2 is a plan view of an ink jet head and an ink mist collection unit of the ink jet printing apparatus in the printing system shown in FIG. 1. FIG. 2 is a perspective view of an ink jet head and an ink mist collection unit of the ink jet printing apparatus in the printing system shown in FIG. 1. FIG. 2 is a control block diagram of the printing system shown in FIG. 1. 3 is a flowchart for explaining the operation of the printing system shown in FIG. 1. It is a figure for demonstrating the distribution of the printing rate in a printed image. It is a perspective view for demonstrating the airflow in an ink mist collection | recovery part. It is a top view for demonstrating an example of the airflow in an ink mist collection | recovery part. It is a top view for demonstrating the other example of the airflow in an ink mist collection | recovery part. It is a top view for demonstrating the further another example of the airflow in an ink mist collection | recovery part.

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

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

  FIG. 1 is a schematic configuration diagram of a printing system including an inkjet printing apparatus according to an embodiment of the present invention. FIG. 2 is a plan view of an ink jet head and an ink mist collection unit of the ink jet printing apparatus in the printing system shown in FIG. FIG. 3 is a perspective view of an ink jet head and an ink mist collection unit of the ink jet printing apparatus in the printing system shown in FIG. FIG. 4 is a control block diagram of the printing system shown in FIG. In the following description, the direction orthogonal to the paper surface of FIG. Also, the top, bottom, left, and right of the paper surface in FIG.

  As shown in FIGS. 1 and 4, the printing system 1 according to the present embodiment includes an unwinding device 2, an inkjet printing device 3, and a winding device 4.

  The unwinding device 2 unwinds the web W, which is a long print medium made of film, paper, or the like, to the inkjet printing device 3. The unwinding device 2 includes a web roll support shaft 11, a brake 12, and an unwinding device control unit 13.

  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 a roll of the web W.

  The brake 12 brakes the web roll support shaft 11. Thereby, tension | tensile_strength is provided to the web W between the web roll 16 and the conveyance roller 43 of the inkjet printing apparatus 3 mentioned later.

  The unwinding device control unit 13 controls the braking force of the brake 12 in order to adjust the tension of the web W. The unwinding device control unit 13 includes a CPU, a RAM, a ROM, a hard disk, and the like.

  The inkjet printing apparatus 3 prints an image on the web W while conveying the web W unwound from the unwinding apparatus 2. The inkjet printing apparatus 3 includes a transport unit 21, printing units 22 </ b> A and 22 </ b> B, ink mist collection units 23 </ b> A and 23 </ b> B, a temperature sensor 24, and a printing device control unit 25.

  The transport unit 21 transports the web W unwound from the unwinding device 2. The transport unit 21 includes guide rollers 31 to 40, 20 head lower support members 41, a meandering control unit 42, a pair of transport rollers 43, and a transport motor 44.

  The guide rollers 31 to 40 guide the web W conveyed in the inkjet printing apparatus 3. The guide rollers 31 to 40 are driven to rotate by the web W being conveyed. The guide rollers 31 to 40 are formed in a long shape extending in the front-rear direction.

  The guide rollers 31 and 32 guide the web W between the unwinding device 2 and the meandering control unit 42. The guide roller 31 is disposed at the lower left end of the inkjet printing apparatus 3. The guide roller 32 is disposed between the guide roller 31 and a meandering control roller 46A of a meandering control unit 42 described later.

  The guide rollers 33 to 39 guide the web W between the meandering control unit 42 and the conveying roller 43. The guide roller 33 is disposed on the left side of a meandering control roller 46B of a meandering control unit 42 described later. The guide roller 34 is disposed above the guide roller 33. The guide roller 35 is substantially the same height as the guide roller 34 and is disposed on the right side of the guide roller 34. The guide roller 36 is disposed below the guide roller 35 and at a position higher than the guide roller 33. The guide roller 37 is disposed on the left side of the guide roller 36, in the vicinity of the right side of the web W between the guide rollers 33 and 34, and at the same height as the guide roller 36. The guide roller 38 is disposed on the lower right side of the guide roller 37. The guide roller 39 is disposed slightly below the right side of the guide roller 38.

  The guide roller 40 guides the web W between the conveyance roller 43 and the winding device 4. The guide roller 40 is disposed at the lower right end of the inkjet printing apparatus 3.

  The head lower support member 41 supports the web W directly below the printing unit 22A and directly below the printing unit 22B. The head lower support member 41 is formed in a long shape extending in the front-rear direction. Ten head support members 41 are arranged between the guide rollers 34 and 35 that are directly below the printing unit 22A and between the guide rollers 36 and 37 that are directly below the printing unit 22B. Two head lower support members 41 are provided immediately below each head unit 51 between the guide rollers 34 and 35 that are directly under the printing unit 22A and between the guide rollers 36 and 37 that are directly under the printing unit 22B. Has been placed.

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

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

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

  The pair of transport rollers 43 transport the web W toward the winding device 4 while nipping the web W. The conveyance roller 43 is formed in a long shape extending in the front-rear direction. The pair of transport rollers 43 are disposed between the guide rollers 39 and 40.

  The transport motor 44 drives the transport roller 43 to rotate.

  The printing unit 22A prints an image on the front surface of the web W. The printing unit 22A is disposed above the web W between the guide rollers 34 and 35. The printing unit 22A includes five head units 51.

  The printing unit 22B prints an image on the back side of the web W. The printing unit 22B is disposed above the web W between the guide rollers 36 and 37. The printing unit 22B includes five head units 51 as in the printing unit 22A.

  The head unit 51 has an inkjet head 56 as shown in FIGS. The inkjet head 56 prints an image by ejecting ink onto the web W. In each of the printing units 22A and 22B, the inkjet heads 56 of the five head units 51 eject inks of different colors. The ink jet head 56 has ten head modules 57.

  The head module 57 has a plurality of nozzles (not shown) that are open in the ink ejection surface facing the web W and are arranged along the main scanning direction (front-rear direction), and ejects ink from the nozzles. The head modules 57 are arranged in a staggered manner in the inkjet head 56.

  The ink mist collection unit 23A collects ink mist generated by ink ejection in the printing unit 22A. The ink mist collection unit 23A is arranged in the vicinity of the downstream side of the printing unit 22A in the web W conveyance direction (sub-scanning direction). As shown in FIGS. 2 (a), 3 (a), and 4, the ink mist collecting unit 23A includes blowing fans 61A and 61B (corresponding to the first blowing unit and the second blowing unit in the claims) and suction. A fan (corresponding to a suction part in claims) 62 and a suction fan moving motor 63 (corresponding to a movement drive part in claims) are provided.

  The blow-out fan 61A is disposed adjacent to the web W on the front side, which is one side in the width direction (front-rear direction) of the web W, within a predetermined range on the downstream side of the inkjet head 56 on the most downstream side of the printing unit 22A. . The blowing fan 61A blows air toward the rear side, which is the other side in the width direction of the web W. A blowout port (not shown) of the blowout fan 61 </ b> A is disposed above the upper surface of the web W.

  Here, the predetermined range on the downstream side of the most downstream inkjet head 56 in the printing unit 22A is a range set in advance as a range in which a large amount of ink mist exists on the downstream side of the inkjet head 56 on the most downstream side in the printing unit 22A. is there. This range is set based on experiments, for example.

  The blower fan 61B is disposed on the rear side of the web W, adjacent to the web W and facing the blower fan 61A. The blowing fan 61B blows air toward the front side. A blowout port (not shown) of the blowout fan 61B is disposed above the upper surface of the web W.

  The suction fan 62 is disposed above the central portion of the web W in the front-rear direction within a predetermined range on the downstream side of the inkjet head 56 on the most downstream side of the printing unit 22A. The suction fan 62 sucks air including ink mist from below.

  The suction fan moving motor 63 moves the suction fan 62 along the conveyance direction of the web W.

  The ink mist collection unit 23B collects ink mist generated by ink ejection in the printing unit 22B. The ink mist collection unit 23B is disposed near the downstream side of the printing unit 22B. As shown in FIG. 2B, FIG. 3B, and FIG. 4, the ink mist collection unit 23B is similar to the ink mist collection unit 23A described above, and includes blowing fans 61A and 61B, a suction fan 62, and a suction fan. A fan moving motor 63.

  The temperature sensor 24 detects the environmental temperature at the place where the inkjet printing apparatus 3 is installed.

  The printing device control unit 25 controls the operation of the entire inkjet printing device 3. The printing apparatus control unit 25 includes a CPU, a RAM, a ROM, a hard disk, and the like. As the CPU operates according to a program stored in a hard disk or the like, a transport control unit 71, a discharge control unit 72, a fan control unit 73, and a suction position control unit 74 are constructed.

  The conveyance control unit 71 controls the conveyance roller 43 to convey the web W.

  The ejection control unit 72 controls the ejection of ink by the inkjet head 56 of the printing units 22A and 22B.

  The fan control unit 73 controls driving of the blowing fans 61A and 61B and the suction fan 62. Further, the fan control unit 73 adjusts the air volume of the blower fans 61A and 61B and the suction fan 62 based on the printing rate by the inkjet head 56 of the printing units 22A and 22B, the conveyance speed of the web W, and the environmental temperature. The fan control unit 73 individually adjusts the air volume of the blower fans 61A and 61B according to the distribution of the printing rate in the width direction of the web W. The fan control unit 73 adjusts the air volume of the blowing fans 61A and 61B and the suction fan 62 by PWM (Pulse Width Modulation) control. The fan control unit 73 corresponds to an air volume control unit and an air volume balance adjustment unit in claims.

  The suction position control unit 74 controls the suction fan moving motor 63 on the basis of the printing rate by the inkjet head 56 of the printing units 22A and 22B, the conveyance speed of the web W, and the environmental temperature, and the suction fan in the conveyance direction of the web W. 62 is adjusted. The position of the suction fan 62 in the conveyance direction of the web W is the same position as the blower fans 61A and 61B or on the downstream side thereof.

  The winding device 4 winds the web W printed by the inkjet printing device 3. The winding device 4 includes a winding shaft 81, a winding motor 82, and a winding device control unit 83.

  The winding shaft 81 winds and holds the web W. The winding shaft 81 is formed in a long shape extending in the front-rear direction.

  The winding motor 82 rotates the winding shaft 81 in the clockwise direction in FIG. The web W is wound around the winding shaft 81 by the rotation of the winding shaft 81.

  The winding device control unit 83 controls driving of the winding motor 82. The winding device control unit 83 includes a CPU, a RAM, a ROM, a hard disk, and the like.

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

  FIG. 5 is a flowchart for explaining the operation of the printing system 1. The process of the flowchart in FIG. 5 starts when the inkjet printing apparatus 3 receives a print job from an external apparatus such as a personal computer.

  In step S1 of FIG. 5, the fan control unit 73 of the ink jet printing apparatus 3 sets the air volume of the blowing fans 61A and 61B and the suction fan 62 of the ink mist collection units 23A and 23B.

  Specifically, the fan control unit 73 calculates the printing rate in the print image for each of the front surface and the back surface of the web W based on the print job. Further, the fan control unit 73 acquires the set web W conveyance speed from the setting information included in the print job. In addition, the fan control unit 73 acquires the current environmental temperature from the temperature sensor 24. Here, the conveyance speed of the web W is set according to the maximum number of drops per pixel corresponding to the type of the web W and the printing resolution.

  Then, the fan control unit 73 sets the air volumes of the blower fans 61A and 61B and the suction fan 62 of the ink mist collecting unit 23A according to the front surface printing rate, the web W conveyance speed, and the environmental temperature. Further, the fan control unit 73 sets the air volume of the blower fans 61A and 61B and the suction fan 62 of the ink mist collection unit 23B according to the printing rate of the back surface, the conveyance speed of the web W, and the environmental temperature.

  Here, the higher the printing rate, the greater the number of ink ejections from the nozzles of the inkjet head 56, and the more ink mist. For this reason, if the conveyance speed of the web W and the environmental temperature are the same, the air flow rate of the blower fans 61A and 61B and the suction fan 62 is set to increase as the printing rate increases.

  Further, the faster the web W is transported, the stronger the transport air current is, and the ink liquid columns ejected from the nozzles are more likely to be divided by the transport air stream before landing on the web W, so that the ink mist increases. For this reason, if the printing rate and the environmental temperature are the same, the air flow rate of the blower fans 61A and 61B and the suction fan 62 is set to increase as the web W conveyance speed increases.

  Further, the lower the environmental temperature, the lower the viscosity of the ink, and the liquid column of the ink ejected from the nozzles is more likely to be cut, so that the ink mist increases. For this reason, if the printing rate and the conveyance speed of the web W are the same, the air volume of the blower fans 61A and 61B and the suction fan 62 is set to be larger as the environmental temperature is lower.

  In addition, the fan control unit 73 adjusts the set air volume of the blower fans 61A and 61B according to the distribution of the printing rate in the width direction (front-rear direction) of the web W.

  Here, for example, it is assumed that the print area based on the print job is divided into a print page area Af, a print page area Ar, and a tag data print area At as shown in FIG. It is assumed that the printing rate is higher in the rear printing page area Ar than in the front printing page area Af. The tag data printing area At is an area where a mark image indicating the cut position of the web W and a code image indicating various information are printed.

  In this case, the print page area Ar has a higher printing rate than the print page area Af, and the tag data print area At exists, so the area on the rear side of the web W is the area on the front side. The printing rate is higher than that.

  Therefore, for example, if the print image of the front surface of the web W is an image as shown in FIG. 6, the fan control unit 73 is configured so that the blowing fan 61B is more effective than the blowing fan 61A in the ink mist collection unit 23A. Adjust so that the set air volume becomes large. Then, the fan control unit 73 sets the ratio of the set air volume of the blower fan 61A and the set air volume of the blower fan 61B in accordance with the ratio of the printing rate for the front area of the web W and the printing rate for the rear area. And

  Returning to FIG. 5, in step S <b> 2, the suction position control unit 74 adjusts the position of the suction fan 62 of the ink mist collection unit 23 </ b> A based on the front surface printing rate, the web W conveyance speed, and the environmental temperature. . Further, the suction position control unit 74 adjusts the position of the suction fan 62 of the ink mist collection unit 23B based on the printing rate of the back surface, the conveyance speed of the web W, and the environmental temperature.

  Here, assuming that the position of the suction fan 62 in the web W conveyance direction is constant, the more ink mist that is generated, the more ink mist that flows downstream without being collected by the suction fan 62. Also, the faster the web W is transported, the stronger the transport airflow and the easier the ink mist is flown, so there is a high possibility that the ink mist that flows downstream without being collected by the suction fan 62 will increase.

  Therefore, in the inkjet printing apparatus 3, in order to reduce ink mist that cannot be collected by the suction fan 62 and flows downstream from the suction fan 62, the suction fan 62 is based on the printing rate, the web W conveyance speed, and the environmental temperature. Adjust the position.

  As described above, since the ink mist increases as the printing rate increases, the position of the suction fan 62 is set to the downstream side as the printing rate increases as long as the web W conveyance speed and the environmental temperature are the same. .

  In addition, as the web W conveyance speed increases, the ink mist increases and the ink mist tends to flow downstream. Therefore, if the printing rate and the environmental temperature are the same, the faster the web W conveyance speed, The position of the suction fan 62 is set on the downstream side.

  Further, since the ink mist increases as the environmental temperature is lower, the position of the suction fan 62 is set to the downstream side as the environmental temperature is lower if the printing rate and the web W conveyance speed are the same.

  The air volume of the blower fans 61A and 61B and the suction fan 62 and the position of the suction fan 62 according to the printing rate, the conveyance speed of the web W, and the environmental temperature, and the position of the suction fan 62 are determined based on experiments in advance.

  Next, in step S <b> 3, the unwinding device control unit 13, the transport control unit 71 of the printing device control unit 25, and the winding device control unit 83 start transporting the web W.

  Specifically, the unwinding device control unit 13 starts driving the brake 12, the transport control unit 71 starts driving the transport motor 44, and the winding device control unit 83 starts driving the winding motor 82. . Thereby, the web W is conveyed from the unwinding device 2 toward the winding device 4. When the web roll support shaft 11 is braked by the brake 12 of the unwinding device 2, the web W is conveyed while tension is applied between the web roll 16 and the conveyance roller 43.

  Next, in step S4, the fan control unit 73 starts driving the blowing fans 61A and 61B and the suction fan 62 of the ink mist collection units 23A and 23B. The fan control unit 73 drives the blowing fans 61A and 61B and the suction fan 62 of the ink mist collection units 23A and 23B with the set air volume set in step S1.

  Next, in step S <b> 5, the ejection control unit 72 controls the inkjet heads 56 of the printing units 22 </ b> A and 22 </ b> B to print an image on the web W based on the print job.

  During printing, when ink is ejected from the inkjet head 56, ink mist is generated. Most of the generated ink mist flows from the inkjet head 56 to the downstream side due to the conveyance airflow generated by the conveyance of the web W. The ink mist is collected by the ink mist collecting units 23A and 23B.

  For example, in the ink mist collecting unit 23A, as shown in FIG. 7, airflows Fa and Fb generated by the blowing fans 61A and 61B flow from the front side and the rear side to the center side of the web W, respectively. Thereby, the ink mist is caused to flow toward the center in the width direction of the web W. Then, in the central portion in the width direction of the web W, the ink mist rises and is collected by the suction fan 62 by the upward air flow Fc by the suction operation of the suction fan 62.

  Similarly to the ink mist collecting unit 23A, the ink mist is collected in the center in the width direction of the web W by the blowing fans 61A and 61B and is collected by being sucked by the suction fan 62 in the ink mist collecting unit 23B. .

  Here, when the generated ink mist is small and the conveyance speed of the web W is low, the suction fan 62 is disposed at a position close to the most downstream inkjet head 56. In this case, for example, as shown in FIG. 8, the suction fan 62 is disposed at the same position as the blowing fans 61 </ b> A and 61 </ b> B in the web W conveyance direction.

  In this case, as shown in FIG. 8, the airflow Fm including the ink mist flows toward the suction fan 62 by the airflows Fa and Fb generated by the blowing fans 61 </ b> A and 61 </ b> B, and the ink mist is collected by the suction fan 62. Since the generated ink mist is small and the conveyance air flow due to the conveyance of the web W is weak, even if the suction fan 62 is close to the inkjet head 56, the ink mist that cannot be collected by the suction fan 62 and flows downstream is suppressed. It is done. Further, by collecting the ink mist at a position close to the inkjet head 56, the diffusion of the ink mist can be suppressed.

  When a large amount of ink mist is generated and the web W is conveyed at a high speed, as shown in FIG. 9, the suction fan 62 is disposed downstream of the blowing fans 61A and 61B. In this case, the air flow Fm including the ink mist flows downstream from the blowing fans 61A and 61B while being drawn toward the center in the width direction of the web W by the air flows Fa and Fb generated by the blowing fans 61A and 61B. Then, the ink mist is collected by the suction fan 62.

  Here, when a large amount of ink mist is generated, the web W is transported at a high speed and the transport air current is strong, if the suction fan 62 is disposed near the inkjet head 56 as shown in FIG. Even if the air volume of 61B and the suction fan 62 is increased, the ink mist cannot be sufficiently collected, and the ink mist may flow downstream from the suction fan 62.

  On the other hand, when the suction fan 62 is disposed as shown in FIG. 9, the suction fan 62 sucks the ink mist when it gathers at the center in the width direction of the web W on the downstream side of the blowing fans 61 </ b> A and 61 </ b> B. Thereby, ink mist can be collected efficiently.

  Here, the more the ink mist that is generated, the higher the transport speed of the web W and the stronger the transport airflow, the more the suction fan 62 is disposed on the downstream side. It is possible to reduce the flow of ink mist.

  Further, for example, when printing an image with a printing rate distribution as shown in FIG. 6, as shown in FIG. 10, the airflow Fb of the blower fan 61B is larger than the airflow Fa of the blower fan 61A. It is adjusted as follows. As described above, the air blow amount by the front blowing fan 61A on the side where the printing rate in the width direction of the web W is low (the ink mist is small) is used as the rear blowing fan on the side where the printing rate is high (the ink mist is high). By suppressing the air volume to be smaller than the air volume by 61B, waste of power consumption and noise can be suppressed.

  If there is a change in the printing rate during the print job, at least one of the air volume of the blower fans 61A and 61B and the air volume of the suction fan 62 may be changed accordingly. Further, the position of the suction fan 62 may be changed according to the change in the printing rate. Further, if there is a change in the distribution of the printing rate in the width direction of the web W during the print job, the airflows of the blower fans 61A and 61B may be adjusted individually accordingly.

  Returning to FIG. 6, in step S <b> 6, the fan control unit 73 determines whether printing based on the print job is finished. If it is determined that printing has not been completed (step S6: NO), the fan control unit 73 repeats step S6.

  When it is determined that the printing is finished (step S6: YES), in step S7, the fan control unit 73 stops the blower fans 61A and 61B and the suction fan 62.

  Next, in step S8, the unwinding device control unit 13, the conveyance control unit 71, and the winding device control unit 83 end the conveyance of the web W. Specifically, the unwinding device control unit 13 stops the brake 12, the transfer control unit 71 stops the transfer motor 44, and the winding device control unit 83 stops the winding motor 82. Thereby, a series of operation | movement is complete | finished.

  As described above, in the inkjet printing apparatus 3, the blowing fan 61A blows air from the front side of the web W toward the rear side, and the blowing fan 61B blows air from the rear side of the web W toward the front side. Then, the suction fan 62 sucks and collects the ink mist above the web W. Thereby, the diffusion of the ink mist to the outside of the web W is suppressed, and the ink mist is collected and collected inside the web W, so that the ink mist can be collected efficiently. Further, since the ink mist is collected by the blowing fans 61A and 61B arranged adjacent to the front and rear sides of the web W and the suction fan 62 arranged above the web W, the ink mist is collected. The increase in size of the mechanism can be suppressed. Therefore, according to the inkjet printing apparatus 3, it is possible to efficiently collect the ink mist while suppressing an increase in the size of the mechanism for collecting the ink mist.

  Further, since the suction fan 62 is disposed above the central portion of the web W in the width direction, a large amount of ink mist is collected by the blowing fans 61A and 61B, and the ink mist is collected at the central portion of the web W in the width direction. Can be recovered. Thereby, ink mist can be collected more efficiently.

  Further, in the inkjet printing apparatus 3, the air volume of the blower fans 61 </ b> A and 61 </ b> B and the suction fan 62 is adjusted based on the printing rate, the web W conveyance speed, and the environmental temperature. Thereby, since the air volume of the blower fans 61A and 61B and the suction fan 62 is adjusted to the air volume corresponding to the amount of ink mist generated, waste of power consumption and noise can be suppressed.

  Further, in the inkjet printing apparatus 3, the position of the suction fan 62 in the web W conveyance direction is adjusted based on the printing rate, the web W conveyance speed, and the environmental temperature. As a result, the position of the suction fan 62 is adjusted according to the amount of ink mist generated and the strength of the conveying airflow, so that the ink mist flowing downstream without being collected by the suction fan 62 can be reduced.

  Further, in the inkjet printing apparatus 3, the air volume of the blower fans 61 </ b> A and 61 </ b> B is individually adjusted according to the distribution of the printing rate in the width direction of the web W. Thereby, since each air volume of blowing fan 61A, 61B is made into the air volume according to distribution of the ink mist in the width direction of the web W, waste of power consumption and noise can be suppressed more.

  In the above-described embodiment, the print rate, the web W conveyance speed, and the environmental temperature are used to control the air volume of the blower fans 61A and 61B and the suction fan 62. One or two of these are used. May be omitted.

  In the above-described embodiment, the air volumes of the blower fans 61A and 61B and the suction fan 62 are adjusted based on the printing rate, the web W conveyance speed, and the environmental temperature, but only one or two of these are adjusted. The air volume may be adjusted. Also in this case, one or two of the printing rate used for adjusting the air volume, the conveyance speed of the web W, and the environmental temperature may be omitted.

  In the above-described embodiment, the printing rate, the web W conveyance speed, and the environmental temperature are used to adjust the position of the suction fan 62 in the web W conveyance direction, but one or two of these are omitted. May be.

  In the above-described embodiment, the position of the suction fan 62 in the conveyance direction of the web W can be adjusted. However, the position of the suction fan 62 may be fixed. Further, in the above-described embodiment, the air volume of the blower fans 61A and 61B and the suction fan 62 is adjusted based on the printing rate, the web W conveyance speed, and the environmental temperature, and the suction fan 62 in the web W conveyance direction is adjusted. Although the position has been adjusted, the air volume of the blowing fans 61A and 61B and the suction fan 62 may be fixed.

  In the above-described embodiment, the configuration in which the ink mist collection units 23A and 23B are arranged on the downstream side of the inkjet head 56 at the most downstream side of the printing units 22A and 22B has been described. However, the ink mist collection units 23A and 23B may be arranged on the downstream side of the inkjet heads 56 of the printing units 22A and 22B.

  In the above-described embodiment, the configuration in which the unwinding device 2 and the winding device 4 are connected to the inkjet printing apparatus 3 as separate devices has been described. However, the unwinding unit and the winding unit are incorporated in the inkjet printing apparatus. But you can. Further, a cutting device or the like for cutting the web may be connected to the inkjet printing apparatus as an external device.

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

DESCRIPTION OF SYMBOLS 1 Printing system 2 Unwinding apparatus 3 Inkjet printing apparatus 4 Winding apparatus 21 Conveyance part 22A, 22B Printing part 23A, 23B Ink mist collection | recovery part 24 Temperature sensor 25 Printing apparatus control part 51 Head unit 56 Inkjet head 57 Head module 61A, 61B Blowing fan 62 Suction fan 63 Suction fan moving motor 71 Transport control unit 72 Discharge control unit 73 Fan control unit 74 Suction position control unit

Claims (5)

An ink jet head that is disposed above the transported print medium and that discharges and prints ink on the print medium;
Within a predetermined range on the downstream side of the inkjet head in the transport direction of the print medium, the print medium is arranged adjacent to the print medium on one side in the width direction of the print medium and blows toward the other side in the width direction of the print medium. A first blowing section;
A second blowing section that is disposed adjacent to the print medium on the other side in the width direction and facing the first blowing section, and blows air toward the one side in the width direction of the printing medium;
An inkjet printing apparatus, comprising: a suction unit that is disposed above the print medium and sucks ink mist within a predetermined range on the downstream side of the inkjet head in the transport direction.   The inkjet printing apparatus according to claim 1, wherein the suction portion is disposed above a central portion of the print medium in the width direction.   Air volume control that adjusts the air volume of at least one of the first blowing section, the second blowing section, and the suction section based on at least one of the printing rate by the inkjet head, the conveyance speed of the printing medium, and the environmental temperature. The inkjet printing apparatus according to claim 1, further comprising a unit. A movement drive unit for moving the suction unit along the conveyance direction;
A suction position control unit that controls the movement driving unit to adjust the position of the suction unit in the transport direction based on at least one of a printing rate by the inkjet head, a transport speed of the print medium, and an environmental temperature. The inkjet printing apparatus according to any one of claims 1 to 3, further comprising:   5. The air volume balance adjusting unit according to claim 1, further comprising an air volume balance adjusting unit that adjusts an air volume of the first blowing unit and the second blowing unit according to a distribution of a printing rate in the width direction. An ink jet printing apparatus as described in 1.