Printing apparatus and ink mist collection method

Abstract

To suppress adhesion of ink to a recovery nozzle for sucking and recovering ink mist.SOLUTION: A space Su and a space Sd are provided on both sides of the recovery nozzle 4 in the transport direction Dm. The pressure for generating the clean air flow Fcu from the upper side to the lower side in the space Su is applied to the space Su from only the lower side of the upper side and the lower side, so that the clean air flow Fcu is generated. Further, the pressure for generating the clean air flow Fcd directed from the upper side to the lower side in the space Sd is applied to the space Sd only from the lower side out of the upper side and the lower side, so that the clean air flow Fcd is generated. At this time, the pressure for generating the clean air flow Fcu and the pressure for generating the clean air flow Fcd are generated by the recovery nozzle 4 sucking air from the intake opening Ani. The clean air flow Fcu flowing out downward from the space Su flows into the recovery nozzle 4 from the intake opening Ani, and the clean air flow Fcd flowing out downward from the space Sd flows into the recovery nozzle 4 from the intake opening Ani.SELECTED DRAWING: Figure 14

Description

[Technical Field]

[0001] The present invention relates to a technique for collecting ink mist that is generated when ink is ejected onto a printing medium to print an image. [Background technology]

[0002] Ink mist is generated in printing devices that print images on print media by ejecting ink from an ejection head. This ink mist can contaminate the print media and the printing device. Patent Document 1 therefore provides a mechanism for collecting the ink mist. This mist collection mechanism has a suction port that sucks in air containing the mist. Furthermore, a first blowout port and a second blowout port are provided on either side of the suction port, and each of the first blowout port and the second blowout port blows out air. This allows for efficient collection of the mist from the suction port. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-083372 Summary of the Invention [Problem to be solved by the invention]

[0004] According to the technology of Cited Document 1, pressure is applied from both sides to generate an airflow for blowing air from the first outlet. That is, an airflow from above to below is generated at the first outlet, and air is blown out from the first outlet. At this time, pressure (positive pressure) generated by a blowing mechanism such as a fan or pump is applied to the first outlet from above. Furthermore, pressure (negative pressure) generated by suctioning air through the suction port is applied to the first outlet from below. In this configuration, depending on the balance between the pressure applied from above by the blowing mechanism and the pressure applied from below by suction through the suction port, the airflow sucked from the suction port can become complexly turbulent. As a result, mist can adhere to the inner wall of the recovery nozzle, contaminating the recovery nozzle. This can lead to problems such as increased maintenance costs for cleaning the recovery nozzle and ink accumulated in the recovery nozzle falling onto the printing medium. This problem is also true for the second outlet.

[0005] The present invention has been made in consideration of the above-mentioned problems, and has an object to make it possible to suppress adhesion of ink to a recovery nozzle that sucks and recovers ink mist. [Means for solving the problem]

[0006] A printing device according to the present invention includes a print medium transport unit that transports a print medium in a transport direction, an ejection head that faces the print medium and ejects ink onto the print medium, and a recovery nozzle that is arranged downstream of the ejection head in the transport direction and has an intake opening that faces the print medium from one side in a direction perpendicular to the print medium, and that sucks ink mist generated by the ejection of ink from the ejection head through the intake opening, and a first space is provided between the recovery nozzle and the ejection head in the transport direction, and a second space is provided downstream of the recovery nozzle, and the first air flows from one side of the first space to the other side opposite to the one side. A first airflow is generated by applying pressure to the first space from only the other of the one side and the other side, and a second airflow is generated by applying pressure to the second space from only the other of the one side and the other side to generate a second airflow moving from one side to the other in the second space, the pressure to generate the first airflow and the pressure to generate the second airflow are generated by the recovery nozzle sucking air from the intake opening, and the first airflow flowing out from the first space to the other side flows into the recovery nozzle from the intake opening, and the second airflow flowing out from the second space to the other side flows into the recovery nozzle from the intake opening.

[0007] The ink mist recovery method according to the present invention comprises the steps of: transporting a print medium in a transport direction; ejecting ink onto the print medium from an ejection head facing the print medium; and sucking ink mist generated by the ejection of ink from the ejection head through an intake opening by a recovery nozzle disposed downstream of the ejection head in the transport direction and having an intake opening facing the print medium from one side in a direction perpendicular to the print medium. In the transport direction, a first space is provided between the recovery nozzle and the ejection head, and a second space is provided downstream of the recovery nozzle, and an air intake opening is provided in the first space from one side to the other side opposite the one side. The first airflow is generated by applying pressure to the first space from only the other of the one side and the other side to generate a first airflow directed toward the first side, and the second airflow is generated by applying pressure to the second space from only the other of the one side and the other side to generate a second airflow in the second space from one side to the other, the pressure to generate the first airflow and the pressure to generate the second airflow being generated by the recovery nozzle sucking air from the intake opening, the first airflow flowing out from the first space to the other side flows into the recovery nozzle from the intake opening, and the second airflow flowing out from the second space to the other side flows into the recovery nozzle from the intake opening.

[0008] In the present invention (printing device and ink mist recovery method) configured in this manner, a first space and a second space are provided on both sides of the recovery nozzle. A first airflow is generated in the first space by applying pressure from only the other of the one and the other sides to the first space, thereby generating a first airflow moving from one side to the other side opposite the first side. A second airflow is generated in the second space by applying pressure from only the other of the one and the other sides to the second space, thereby generating a second airflow. The pressure for generating the first airflow and the pressure for generating the second airflow are generated by the recovery nozzle sucking air from the intake opening. The first airflow flowing out from the first space to the other side flows into the recovery nozzle from the intake opening, and the second airflow flowing out from the second space to the other side flows into the recovery nozzle from the intake opening.

[0009] In this way, without applying pressure to the first space from one side, the recovery nozzle suctions air through the intake opening, generating pressure from the airflow. This applies the pressure to the first space only from the other side, generating a first airflow in the first space. This generates a relatively gentle first airflow. When this first airflow flows into the recovery nozzle from the intake opening, it generates a first airflow layer, in other words, a clean airflow layer, along the inner wall of the recovery nozzle on the first space side. Similarly, without applying pressure to the second space from one side, the recovery nozzle suctions air through the intake opening, generating pressure from the airflow to the second space only from the other side, generating a second airflow in the second space. This generates a relatively gentle second airflow. When this second airflow flows into the recovery nozzle from the intake opening, it generates a second airflow layer, in other words, a clean airflow layer, along the inner wall of the recovery nozzle on the second space side. Air containing ink mist sucked through the intake opening passes between the layers on both sides. As a result, the ink mist is prevented from adhering to the inner wall of the recovery nozzle, which in turn prevents ink from adhering to the recovery nozzle that sucks and recovers the ink mist.

[0010] The printing device may also be configured so that the size of the intake opening in the transport direction is greater than 2 mm and smaller than 7 mm, which effectively prevents ink mist from adhering to the inner wall of the recovery nozzle.

[0011] The printing device may also be configured so that the ejection head has a nozzle opening surface facing the print medium and an ejection nozzle that opens at the nozzle opening surface, and ejects ink from the ejection nozzle onto the print medium, and the first space is provided from the print medium transported by the print medium transport unit to one side of the nozzle opening surface. With this configuration, a layer of relatively clean airflow is generated along the inner wall of the recovery nozzle, effectively preventing ink mist from adhering to the inner wall of the recovery nozzle.

[0012] The printing device may also be configured so that the second space is provided from the print medium transported by the print medium transport unit to one side of the nozzle opening surface. In this configuration, a layer of relatively clean airflow is generated along the inner wall of the recovery nozzle, effectively preventing ink mist from adhering to the inner wall of the recovery nozzle.

[0013] The printing device may also be configured such that the recovery nozzle includes a first standing plate erected on one side of the air intake opening on the upstream side of the air intake opening in the transport direction, and a second standing plate erected on one side of the air intake opening on the downstream side of the air intake opening in the transport direction, with the thickness of the first standing plate being less than 2 mm in the transport direction, and the thickness of the second standing plate being less than 2 mm. This configuration minimizes the influence of the thicknesses of the first and second standing plates, ensuring the generation of a relatively clean airflow layer along the inner wall of the recovery nozzle. As a result, adhesion of ink mist to the inner wall of the recovery nozzle can be effectively prevented.

[0014] The printing device may also be configured such that the recovery nozzle includes a first standing plate erected on one side of the intake opening upstream of the intake opening in the transport direction, and a second standing plate erected on one side of the intake opening downstream of the intake opening in the transport direction, with the thickness of the first standing plate being smaller than the size of the intake opening, and the thickness of the second standing plate being smaller than the size of the intake opening in the transport direction. This configuration reduces the influence of the thicknesses of the first and second standing plates, ensuring the generation of a relatively clean airflow layer along the inner wall of the recovery nozzle. As a result, adhesion of ink mist to the inner wall of the recovery nozzle can be effectively prevented.

[0015] The printing device may also be configured so that the first space extends from the print medium transported by the print medium transport unit to one side of one end of the recovery nozzle. In this configuration, a layer of relatively clean airflow is generated along the inner wall of the recovery nozzle, effectively preventing ink mist from adhering to the inner wall of the recovery nozzle.

[0016] The printing device may also be configured so that the second space extends from the print medium transported by the print medium transport unit to one side of one end of the recovery nozzle. In this configuration, a layer of relatively clean airflow is generated along the inner wall of the recovery nozzle, effectively preventing ink mist from adhering to the inner wall of the recovery nozzle.

[0017] The printing device may also be configured so that the first space and the second space are connected via a space provided on one side of one end of the recovery nozzle. With this configuration, a layer of relatively clean airflow is generated along the inner wall of the recovery nozzle, effectively preventing ink mist from adhering to the inner wall of the recovery nozzle.

[0018] The printing device may also be configured to further include a head support member that supports the ejection head and a nozzle support member that supports the recovery nozzle relative to the head support member, the head support member having a sidewall plate positioned between the ejection head and the recovery nozzle in the transport direction, and the nozzle support member supporting the recovery nozzle with a first space between the sidewall plate and the recovery nozzle. With this configuration, ink mist is prevented from adhering to the inner wall of the recovery nozzle. This makes it possible to prevent ink from adhering to the recovery nozzle, which sucks and recovers the ink mist.

[0019] The printing device may also be configured so that the inclination between the recovery nozzle and an imaginary line perpendicular to the printing medium facing the recovery nozzle is within 5 degrees. This configuration effectively prevents ink mist from adhering to the inner wall of the recovery nozzle.

[0020] The printing device may also be configured such that the ejection head has a nozzle opening surface facing the print medium and ejection nozzles that open on the nozzle opening surface, ejecting ink onto the print medium from the ejection nozzles, and the width of the first space in the transport direction is wider than the distance between the print medium being transported by the print medium transport unit and the nozzle opening surface. With this configuration, the ejection nozzles can be positioned close to the print medium while ensuring a wide first space. Therefore, the first airflow from the first space toward the intake opening is more likely to occur than the airflow from between the nozzle opening surface and the print medium toward the intake opening. In other words, the generation of airflow from between the ejection nozzles and the print medium toward the intake opening of the recovery nozzle can be suppressed. As a result, ink can be stably ejected from the ejection head onto the print medium. [Effects of the Invention]

[0021] As described above, according to the present invention, it is possible to prevent ink mist from adhering to the inner wall of the recovery nozzle. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a front view schematically showing a printing apparatus according to the present invention. [Figure 2] FIG. 2 is a diagram schematically illustrating an example of a mist collection unit included in the printing apparatus of FIG. 1. [Figure 3A] FIG. 2 is a perspective view schematically showing the external configuration of a recovery nozzle. [Figure 3B] FIG. 2 is a front view schematically showing the external configuration of the recovery nozzle. [Figure 4] FIG. 3 is a perspective view schematically showing the internal configuration of the recovery nozzle. [Figure 5A] FIG. 3 is a cross-sectional view schematically showing the internal configuration of the recovery nozzle. [Figure 5B] FIG. 3 is a cross-sectional view schematically showing the internal configuration of the recovery nozzle. [Figure 6] FIG. 4 is a diagram illustrating the operation of the recovery nozzle. [Figure 7] FIG. 4 is a perspective view schematically showing an exhaust connector of the exhaust duct. [Figure 8] FIG. 4 is a side view schematically showing the mist removal unit and the suction unit. [Figure 9] FIG. 4 is a partial cross-sectional view that schematically illustrates, with emphasis, the operation performed by raising and lowering the ejection head and the recovery nozzle. [Figure 10] FIG. 2 is a perspective view schematically illustrating the external configuration of the cushioning material. [Figure 11] FIG. 10 is a partial cross-sectional view that schematically illustrates, with emphasis, the operation performed by raising and lowering the ejection head and the recovery nozzle in a configuration that includes a buffer material. [Figure 12] FIG. 4 is a partial cross-sectional view schematically showing the positional relationship between a base frame that supports the ejection head and a recovery nozzle. [Figure 13A] FIG. 4 is a diagram schematically showing a mechanism for attaching the recovery nozzle to a base frame that supports the ejection head. [Figure 13B] FIG. 4 is a diagram schematically showing a mechanism for attaching the recovery nozzle to a base frame that supports the ejection head. [Figure 13C] FIG. 4 is a diagram schematically showing a mechanism for attaching the recovery nozzle to a base frame that supports the ejection head. [Figure 14] FIG. 4 is a partial cross-sectional view schematically showing the functions of spaces provided on both sides of the recovery nozzle. [Figure 15A] FIG. 10 is a perspective view schematically showing a modified example of the recovery nozzle. [Figure 15B] FIG. 15B is a diagram schematically showing a modified example of the mechanism for supporting the recovery nozzle of FIG. 15A relative to the ejection head. [Figure 15C] FIG. 15B is a partial cross-sectional view schematically showing a modified example of the mechanism for supporting the recovery nozzle of FIG. 15A relative to the ejection head. [Figure 16A] 10A and 10B are diagrams showing the results of a simulation of the diffusion state of ink mist sucked into a recovery nozzle. [Figure 16B] 10A and 10B are diagrams showing the results of a simulation of the diffusion state of ink mist sucked into a recovery nozzle. [Figure 16C] 10A and 10B are diagrams showing the results of a simulation of the diffusion state of ink mist sucked into a recovery nozzle. [Figure 16D] 10A and 10B are diagrams showing the results of a simulation of the diffusion state of ink mist sucked into a recovery nozzle. [Figure 16E] FIG. 10 is a table showing the suitability of the width of the intake opening. [Figure 17A] FIG. 10 is a diagram showing a schematic diagram of an experiment conducted to confirm the influence of the tilt of the suction nozzle. [Figure 17B] FIG. 17B is a table showing the results of the experiment of FIG. 17A. [Figure 18A] 10A and 10B are diagrams showing the results of a simulation of the diffusion state of ink mist sucked into a recovery nozzle. [Figure 18B] FIG. 10 is a table showing the suitability of the width of the intake opening. [Figure 19] 10A and 10B are partial cross-sectional views schematically showing modified examples of the positional relationship of the recovery nozzle with respect to the ejection head. [Figure 20A] FIG. 10 is a partial cross-sectional view schematically showing a modified example of the printing device. [Figure 20B] FIG. 20B is a diagram schematically illustrating a clean air supply unit provided in the printing apparatus of FIG. 20A. DETAILED DESCRIPTION OF THE INVENTION

[0023] FIG. 1 is a front view showing a schematic diagram of a printing device according to the present invention. In FIG. 1 and the following figures, the horizontal X direction, the horizontal Y direction perpendicular to the X direction, and the vertical Z direction are indicated as appropriate. Furthermore, one side X1 and the other side X2 of the X direction are indicated as appropriate. Here, the one side X1 and the other side X2 face in opposite directions.

[0024] The printing device 1 includes a housing 11, a color printing unit 12 arranged within the housing 11, a white printing unit 13 arranged above the color printing unit 12 within the housing 11, and a transport unit 2 that transports the printing medium M using a plurality of rollers arranged within the housing 11. In other words, the housing 11 accommodates the color printing unit 12, the white printing unit 13, and the transport unit 2.

[0025] The color printing unit 12 has a plurality of (four) ejection heads 121 arranged above the printing medium M transported by the transport unit 2 in the direction of travel of the printing medium M (the direction from the other side X2 to the one side X1). Each of the ejection heads 121 has a nozzle facing from above toward the surface M1 of the printing medium M passing below it, and ejects different color inks from the nozzles using an inkjet method. Here, color ink refers to ink other than white, and includes inks such as cyan, magenta, yellow, and black. In this way, each of the ejection heads 121 of the color printing unit 12 prints a color image on the surface M1 of the printing medium M by ejecting color inks from above onto the surface M1 of the printing medium M passing below it.

[0026] The white printing unit 13 also has a single ejection head 131 arranged above the printing medium M transported by the transport unit 2. The ejection head 131 has nozzles facing from above toward the surface M1 of the printing medium M passing below it, and ejects white ink from the nozzles using an inkjet method. In this way, the ejection head 131 of the white printing unit 13 prints a white image on the surface M1 of the printing medium M by ejecting white ink from above onto the surface M1 of the printing medium M passing below it.

[0027] An inlet 111 opens in the side wall of the housing 11 on the other side X2, and the printing medium M is carried into the housing 11 through the inlet 111. In contrast, the transport unit 2 has an inlet section 21. The inlet section 21 has a plurality of rollers 211 arranged in the X direction below the color printing unit 12, and transports the printing medium M carried in through the inlet 111 from the other side X2 to the one side X1 while supporting the printing medium M with the plurality of rollers 211.

[0028] The transport unit 2 also has an upward transport unit 22 provided on one side X1 of the carry-in unit 21. The upward transport unit 22 has a plurality of rollers 221 arranged in the Z direction on one side X1 of the color printing unit 12. The upward transport unit 22 changes the traveling direction of the printing medium M from one side X1 to the upward side by bending the printing medium M transported by the carry-in unit 21 upward using the roller 221 located at the bottom of the plurality of rollers 221, and then transports the printing medium M upward while being supported by the plurality of rollers 221. In this way, the printing medium M is transported from the lower side of the color printing unit 12 to the upper side by the upward transport unit 22.

[0029] Furthermore, the conveying unit 2 has an upper conveying unit 23 provided above the color printing unit 12. The upper conveying unit 23 has a plurality of rollers 231 arranged in the X direction above the color printing unit 12. The upper conveying unit 23 changes the traveling direction of the printing medium M from the upper side to the other side X2 by using a roller 231 located at the end of one side X1 of the plurality of rollers 231 to bend the printing medium M conveyed from the upward conveying unit 22 to the other side X2, and then conveys the printing medium M to the other side X2 while being supported by the plurality of rollers 231.

[0030] The conveying unit 2 also has a downward conveying unit 24 provided on the other side X2 of the upper conveying unit 23. The downward conveying unit 24 has a plurality of rollers 241 arranged in the Z direction on the other side X2 of the color printing unit 12. The downward conveying unit 24 changes the traveling direction of the print medium M from the other side X2 to the downward side by bending the print medium M conveyed from the upper conveying unit 23 downward using the roller 241 located at the upper end of the plurality of rollers 241, and then conveys the print medium M downward while being supported by the rollers 241. Of the plurality of rollers 241 included in the downward conveying unit 24, the uppermost roller 241 is located above the respective ejection heads 121 of the color printing unit 12, and the lowermost roller 241 is located below the respective ejection heads 121 of the color printing unit 12. In other words, the downward conveying unit 24 conveys the print medium M from the upper side to the lower side of the color printing unit 12.

[0031] The transport unit 2 further includes a color transport unit 25 located below the upper transport unit 23 and on one side X1 of the downward transport unit 24. The color transport unit 25 includes a plurality of rollers 251 arranged in the X direction and in contact with the back surface M2 of the printing medium M, and the printing medium M transported from the downward transport unit 24 is supported below the color printing unit 12 by the plurality of rollers 251. In this manner, the plurality of rollers 251 of the color transport unit 25 contact the back surface M2 of the printing medium M transported from the downward transport unit 24 from below, thereby supporting the printing medium M from below, and transporting the printing medium M from the other side X2 to the one side X1. Each ejection head 121 of the color printing unit 12 ejects color ink from above onto the front surface M1 of the printing medium M transported along the front surface M1 by the color transport unit 25.

[0032] At this time, the front surface M1 of the printing medium M transported by the color transport unit 25 faces upward, and the back surface M2 of the printing medium M faces downward. More specifically, the printing medium M is transported through the transport entrance 111 with its front surface M1 facing upward, and is transported by the transport unit 21 from the other side X2 to the one side X1. After passing through the transport unit 21, the printing medium M is turned upside down by the upward transport unit 22 and the upper transport unit 23, and then transported by the upper transport unit 23 from the one side X1 to the other side X2. Therefore, the front surface M1 of the printing medium M transported by the upper transport unit 23 faces downward. After passing through the upper transport unit 23, the printing medium M is turned upside down by the downward transport unit 24 and the color transport unit 25, and then transported by the color transport unit 25 from the other side X2 to the one side X1. Therefore, the front surface M1 of the printing medium M transported by the color transport unit 25 faces upward.

[0033] The transport unit 2 also has rollers 261 and 262 that come into contact with the printing medium M upstream of the color transport unit 25 in the traveling direction of the printing medium M. The roller 261 is a drive roller that drives the printing medium M.

[0034] Furthermore, the transport unit 2 has a reversing transport unit 27 that turns upside down twice the printing medium M transported from the color transport unit 25 to one side X1. This reversing transport unit 27 has multiple rollers 271, 272 that are arranged in the Z direction on one side X1 of the color transport unit 25 and come into contact with the back surface M2 of the printing medium M. Of the multiple rollers 271, 272, the uppermost roller 271 is a drive roller that drives the printing medium M. This roller 271 bends the printing medium M transported from the color transport unit 25 downward, thereby changing the traveling direction of the printing medium M from one side X1 to the bottom. In addition, the lowermost roller 272 bends the printing medium M transported from the roller 271 to the other side X2, thereby changing the traveling direction of the printing medium M from the bottom to the other side X2. In this way, the rollers 271, 272 contacting the back surface M2 of the printing medium M turn the printing medium M upside down, so that the back surface M2 of the printing medium M faces upward and the front surface M1 of the printing medium M faces downward.

[0035] The reverse conveying section 27 also has a plurality of rollers 273 that are arranged in the X direction below the color conveying section 25 and on the other side X2 of the rollers 272 and that come into contact with the back surface M2 of the printing medium M. These rollers 273 convey the printing medium M conveyed from the rollers 272 from one side X1 to the other side X2. In this way, the printing medium M with the back surface M2 facing upward is conveyed from one side X1 to the other side X2 by the plurality of rollers 273 that come into contact with the back surface M2 of the printing medium M.

[0036] Furthermore, the reverse conveying section 27 has a plurality of rollers 273 and a plurality of rollers 274, 276, and 277 that are arranged in the Z direction on the other side X2 of the downward conveying section 24 and that come into contact with the back surface M2 of the printing medium M. Of the plurality of rollers 274 to 277, the bottom roller 274 bends the printing medium M conveyed from the plurality of rollers 273 upward, thereby changing the traveling direction of the printing medium M from the other side X2 to the top, and the top roller 277 bends the printing medium M conveyed from roller 274 via roller 276 toward one side X1, thereby changing the traveling direction of the printing medium M from the top to one side X1. In this way, the rollers 274 to 277 that come into contact with the back surface M2 of the printing medium M turn the printing medium M upside down, so that the front surface M1 of the printing medium M faces upward and the back surface M2 of the printing medium M faces downward.

[0037] The reverse conveying section 27 also has a roller 278 that is disposed above the upper conveying section 23 and on one side X1 of the roller 277 and that comes into contact with the back surface M2 of the printing medium M. The roller 278 conveys the printing medium M conveyed from the roller 277 from the other side X2 toward the one side X1. In this way, the roller 278 that comes into contact with the back surface M2 of the printing medium M conveys the printing medium M with the front surface M1 facing upward from the other side X2 toward the one side X1.

[0038] In this way, the reverse conveying unit 27 conveys the printing medium M conveyed from the color conveying unit 25 downward by the rollers 271 and 272, and then changes the traveling direction of the printing medium M to the other side X2 by the roller 272 and conveys the printing medium M upside down, thereby inverting the front surface M1 and back surface M2 of the printing medium M. Next, the reverse conveying unit 27 conveys the printing medium M from the one side X1 to the other side X2 by the multiple rollers 273, and then conveys the printing medium M upward by the rollers 274 to 277. Furthermore, the reverse conveying unit 27 changes the traveling direction of the printing medium M to the one side X1 by the roller 277, thereby again inverting the front surface M1 and back surface M2 of the printing medium M upside down, and conveys the printing medium M from the other side X2 to the one side X1 by the roller 278.

[0039] In this way, the reverse conveying unit 27 turns the front surface M1 and back surface M2 of the printing medium M upside down twice using only the rollers 271-278, which come into contact with the back surface M2 of the printing medium M and rotate while wrapping the back surface M2 around it. In other words, the reverse conveying unit 27 can turn the front surface M1 and back surface M2 of the printing medium M upside down twice without providing any support members such as rollers or air turn bars on the front surface M1 side of the printing medium M.

[0040] The conveying unit 2 also has a white conveying unit 28 that is provided above the upper conveying unit 23 and on one side X1 of the rollers 278 of the reverse conveying unit 27. This white conveying unit 28 has rollers 281, and the printing medium M conveyed from the rollers 278 of the reverse conveying unit 27 is supported below the white printing unit 13 by the rollers 281. In this way, the rollers 281 of the white conveying unit 28 contact from below the back surface M2 of the printing medium M conveyed from the rollers 278 of the reverse conveying unit 27, thereby supporting the printing medium M from below and conveying the printing medium M from the other side X2 to the one side X1. The ejection head 131 of the white printing unit 13 then ejects white ink from above onto the front surface M1 of the printing medium M that is conveyed along the front surface M1 by the white conveying unit 28.

[0041] Furthermore, the transport unit 2 has an output unit 29 that is provided above the upper transport unit 23 and on one side X1 of the white transport unit 28. The output unit 29 has a plurality of rollers 291, 292, 293 that are arranged in the X direction and that come into contact with the back surface M2 of the printing medium M. The roller 291 is a drive roller that drives the printing medium M, and the rollers 292 and 293 rotate as the printing medium M is transported. Meanwhile, an output opening 112 opens in the side wall on the one side X1 of the housing 11, and the plurality of rollers 291 to 293 of the output unit 29 transport the printing medium M from the other side X2 toward the one side X1 while contacting the back surface M2 of the printing medium M from below, thereby transporting the printing medium M from the other side X2 toward the one side X1.

[0042] In the printing device 1 described above, the transport unit 2 transports the printing medium M along the path shown in FIG. 1 using multiple rollers. The color printing unit 12 ejects color inks onto the printing medium M transported by the transport unit 2 to print a color image (color image printing), and the white printing unit 13 ejects white ink onto the printing medium M to print a white image (white image printing). In this printing device 1, some of the color inks ejected from each ejection head 121 of the color printing unit 12 scatter as ink mist. Also, some of the white ink ejected from the ejection head 131 of the white printing unit 13 scatters as ink mist. Therefore, the printing device 1 is provided with a mist collection unit 3 (FIG. 2) for collecting the ink mist. Note that the following description will focus on the mist collection unit 3 for the color printing unit 12, but a similar mist collection unit 3 can also be provided for the white printing unit 13.

[0043] FIG. 2 is a diagram schematically illustrating an example of a mist collection unit included in the printing apparatus of FIG. 1. In FIG. 2, the rollers included in the transport unit 2 are collectively referred to as rollers 201. FIG. 2 also illustrates one of a pair of support plates 202 included in the transport unit 2. That is, the transport unit 2 has a pair of support plates 202 arranged with a gap in the Y direction. The roller 201 is arranged parallel to the Y direction between the pair of support plates 202 and is rotatably supported by the pair of support plates 202. The print medium M is transported in the transport direction Dm by the transport unit 2.

[0044] The mist collection unit 3 has a collection nozzle 4 that is arranged above the print medium M supported by the transport unit 2. In particular, the mist collection unit 3 is provided with a plurality of collection nozzles 4 corresponding to the plurality of ejection heads 121, respectively, and each of the plurality of collection nozzles 4 is arranged downstream in the transport direction Dm of the corresponding ejection head 121. A base frame 14 is arranged between the collection nozzle 4 and the ejection head 121 that corresponds to the collection nozzle 4, and the collection nozzle 4 is fixed to the corresponding ejection head 121 by the base frame 14.

[0045] FIG. 3A is a perspective view schematically illustrating the external configuration of the recovery nozzle, and FIG. 3B is a front view schematically illustrating the external configuration of the recovery nozzle. FIG. 3A shows one side Y1 and the other side Y2 in the Y direction, and the downstream side Dmd and the upstream side Dmu in the transport direction Dm. Here, the one side Y1 and the other side Y2 face opposite each other, and the downstream side Dmd and the upstream side Dmu face opposite each other. As shown in FIG. 2, the mist collection unit 3 has multiple collection nozzles 4 with different inclinations, but these nozzles share a common configuration except for their inclinations. Therefore, FIGS. 3A and 3B illustrate a mist collection unit 3 arranged parallel to the Z direction. In this description, the Z direction corresponds to the "direction perpendicular to the printing medium" in this specification, the upper side in the Z direction corresponds to the "one side" in this specification, and the lower side in the Z direction corresponds to the "other side" in this specification.

[0046] The recovery nozzle 4 has a nozzle housing 41 that is long in the Y direction, and a flow path space S (FIGS. 5A and 5B) that serves as an air flow path is provided inside the nozzle housing 41. The nozzle housing 41 has side covers 411 and 412 that are spaced apart in the transfer direction Dm. The side cover 411 stands upright parallel to the Z direction on the upstream side Dmu of the side cover 412 (i.e., on the side of the corresponding ejection head 121). The side cover 412 stands upright parallel to the Z direction on the downstream side Dmd of the side cover 411 (i.e., on the opposite side of the corresponding ejection head 121).

[0047] The nozzle housing 41 also has side covers 413 and 414 spaced apart in the Y direction. The side cover 413 extends in the Z direction while inclining in the Z direction on one side Y1 of the side cover 414. The side cover 414 stands parallel to the Z direction on the other side Y2 of the side cover 413. The side covers 411, 412, 413, and 414 surround the flow path space S inside the nozzle housing 41 from the sides (horizontally). The side cover 411 also has a top cover 415 that is provided to connect the upper ends of the side covers 411, 412, 413, and 414. The top cover 415 covers the flow path space S surrounded by the side covers 411, 412, 413, and 414 from above.

[0048] A bottom cover 417 extending in the Y direction is provided on the bottom 416 of the nozzle housing 41. The bottom cover 417 is provided horizontally so as to connect the side covers 412, 414. In other words, the side cover 412 stands upward from the end of the bottom cover 417 on the downstream side Dmd, and the side cover 414 stands upward from the end of the bottom cover 417 on the other side Y2. The bottom cover 417 extends from the lower end of the side cover 412 to the upstream side Dmu, and faces the end of the upstream side Dmu of the flow path space S inside the nozzle housing 41 from below.

[0049] Furthermore, the nozzle housing 41 has a nozzle intake section 42 that protrudes downward from a bottom cover 417 at the bottom 416 of the nozzle housing 41. The nozzle intake section 42 extends in the Y direction so as to be adjacent to the bottom cover 417 from the upstream side Dmu. An intake opening Ani that extends in the Y direction opens downward at the bottom 421 (lower end) of the nozzle intake section 42. The intake opening Ani of the nozzle intake section 42 faces the flow path space S from below on the upstream side Dmu of the bottom cover 417 and communicates with the flow path space S. This intake opening Ani faces the surface M1 of the printing medium M supported by the rollers 201 of the transport section 2 from above.

[0050] The nozzle housing 41 also has a nozzle exhaust section 43 that protrudes downward from the bottom 416. The nozzle exhaust section 43 is located downstream Dmd from the nozzle intake section 42 and on one side Y1 of the bottom cover 417. This nozzle exhaust section 43 is offset to one side Y1 in the Y direction from the printing medium M supported by the rollers 201 of the conveyance section 2, and does not face the printing medium M. At the lower end of this nozzle exhaust section 43, an exhaust opening Ano opens downward. This exhaust opening Ano communicates with the flow path space S inside the nozzle housing 41. At the lower end of the nozzle exhaust section 43, a flange 431 is provided to surround the exhaust opening Ano.

[0051] As described above, the recovery nozzle 4 has an intake opening Ani that faces the printing medium M from above, and an exhaust opening Ano that is offset in the Y direction from the printing medium M. The intake opening Ani and the exhaust opening Ano are connected to each other via a flow path space S inside the nozzle housing 41. Therefore, as will be described later, when the exhaust opening Ano is sucked, an airflow Fn (FIGS. 5A and 5B) is formed that flows from the intake opening Ani through the flow path space S to the exhaust opening Ano.

[0052] Fig. 4 is a perspective view showing a typical internal configuration of the recovery nozzle, Figs. 5A and 5B are cross-sectional views showing a typical internal configuration of the recovery nozzle, and Fig. 6 is a diagram showing a typical operation of the recovery nozzle. The recovery nozzle 4 has a partition wall 441 arranged in the flow path space S. The partition wall 441 is provided between the side covers 411 and 412 in the transport direction Dm and extends in the Z direction. The partition wall 441 faces the side cover 411 from the downstream side Dmd and faces the side cover 412 from the upstream side Dmu.

[0053] The partition wall 441 and the side cover 411 are erected in the Z direction from both ends of the bottom 421 of the nozzle intake section 42 in the transport direction Dm, with the lower end of the partition wall 441 forming a side wall on the downstream side Dmd of the nozzle intake section 42, and the lower end of the side cover 411 forming a side wall on the upstream side Dmu of the nozzle intake section 42. An intake opening Ani is provided between the lower end of the side cover 411 and the lower end of the partition wall 441. A gap Ci is formed between the side cover 411 and the partition wall 441 in the transport direction Dm, and the intake opening Ani faces and communicates with the gap Ci from below. Furthermore, a gap Co is formed between the side cover 411 and the partition wall 441 in the transport direction Dm. The gaps Ci and Co communicate with each other above the partition wall 441. Furthermore, the nozzle exhaust section 43 is connected to the end of one side Y1 of the gap Co, so that the gap Co and the exhaust opening Ano are in communication with each other. Therefore, the airflow Fn flows from the intake opening Ani through the gap Ci and the gap Co in this order to reach the exhaust opening Ano.

[0054] The recovery nozzle 4 also has an eave 443 (FIGS. 4 and 5B) provided at the upper end 442 of the partition wall 441. The eave 443 curves upward from the upper end 442 of the partition wall 441 and protrudes toward the downstream side Dmd. That is, the eave 443 protrudes from the partition wall 441 into the gap Co. The eave 443 is provided biased toward the exhaust opening Ano (one side Y1) with respect to the upper end of the partition wall 441. That is, the eave 443 is provided in a range between positions Pa and Pb in the Y direction at the upper end 442 of the partition wall 441. Here, position Pa is the end position of the one side Y1 of the upper end 442 of the partition wall 441, and position Pb is a position between the end position of the one side Y1 and the end position of the other side Y2 of the upper end 442 of the partition wall 441 (an intermediate position in this example). Therefore, in the range where the eave 443 is not provided (FIG. 5A), the airflow Fn flowing from the gap Ci to the gap Co is not particularly restricted. On the other hand, in the range where the eaves 443 is provided (FIG. 5B), the airflow Fn flowing from the gap Ci to the gap Co is restricted by the eaves 443. As a result, as shown in FIG. 6, in the range close to the exhaust opening Ano in the Y direction, the airflow Fn is restricted by the eaves 443, but in the range far from the exhaust opening Ano in the Y direction, the airflow Fn is not restricted by the eaves 443. By providing such eaves 443, it is possible to suppress variation in the Y direction of the suction force supplied to the intake opening Ani.

[0055] 2, the mist collection unit 3 has a plurality of exhaust ducts 5 corresponding to the plurality of collection nozzles 4, and each of the plurality of exhaust ducts 5 is connected to a corresponding collection nozzle 4. The exhaust duct 5 has an exhaust connector 51 (FIG. 7) connected to a flange 431 of the corresponding collection nozzle 4.

[0056] FIG. 7 is a perspective view schematically illustrating the exhaust connector of the exhaust duct. The exhaust connector 51 has a flange 511 that faces the flange 431 of the recovery nozzle 4 from below. The exhaust connector 51 also has a duct opening Adi that opens upward in the flange 511. That is, the flange 511 is provided so as to protrude laterally from the duct opening Adi. The exhaust connector 51 also has a connector pipe 512 that extends downward from the flange 511 and communicates with the duct opening Adi. The connector pipe 512 extends at an angle downward toward one side X1 in the X direction. The exhaust connector 51 also has a flange 513 provided at the lower end of the connector pipe 512. Of the flange 511 at the upper end and the flange 513 at the lower end of the exhaust duct 5, at least the flange 513 is positioned below the print medium M supported by the rollers 201 of the transport unit 2.

[0057] The exhaust duct 5 also has a stay 52 that attaches the exhaust connector 51 to the support plate 202 of the conveying unit 2. The stay 52 is attached to the support plate 202 directly or via a beam or the like. The stay 52 has a mounting plate 521 that is supported horizontally. The flange 513 of the exhaust connector 51 contacts the mounting plate 521 of the stay 52 from above and is fastened to the mounting plate 521 with screws or the like. In this way, the exhaust connector 51 of the exhaust duct 5 is attached to the support plate 202 of the conveying unit 2 via the stay 52.

[0058] The exhaust duct 5 also has an exhaust pipe 53 (FIG. 2) attached to the lower end of the connector pipe 512. The exhaust pipe 53 is positioned below the print medium M supported by the rollers 201 of the conveyance unit 2. A through hole that opens to the connector pipe 512 is provided in the mounting plate 521, and the upper end of the exhaust pipe 53 is attached to the lower end of the connector pipe 512 from below through the through hole. In this way, the exhaust pipe 53 extends downward from the lower end of the connector pipe 512. The exhaust pipe 53 communicates with the duct opening Adi via the connector pipe 512.

[0059] Furthermore, as shown in Fig. 8, the mist collection unit 3 has a mist removal unit 6 and a suction unit 7. Fig. 8 is a side view showing the mist removal unit and the suction unit. The mist removal unit 6 and the suction unit 7 are disposed below the printing medium M supported by the rollers 201 of the transport unit 2, and face the printing medium M from below.

[0060] Each of the multiple exhaust ducts 5 is connected to the suction unit 7 via the mist removal unit 6. That is, the lower end of the exhaust pipe 53 of each of the multiple exhaust ducts 5 is connected to the mist removal unit 6. The mist removal unit 6 has a mist removal pipe 61 that connects the lower end of the exhaust duct 5 to the suction unit 7 and a filter attachment unit 62 provided for the mist removal pipe 61. A filter 31 can be attached to and detached from the filter attachment unit 62 from one side Y1 in the Y direction. The filter attachment unit 62 is, for example, a protrusion that protrudes inward inside the mist removal pipe 61. The filter 31 can be attached to the filter attachment unit 62 by placing the filter 31 on this protrusion. Note that, here, one mist removal pipe 61 and one filter 31 are provided in common for the multiple exhaust ducts 5, but one mist removal pipe 61 and one filter 31 may be provided individually for each of the multiple exhaust ducts 5.

[0061] The suction section 7 has a plurality of fan units 71 corresponding to the plurality of exhaust ducts 5, respectively, and each of the plurality of exhaust ducts 5 is connected to the corresponding fan unit 71 by a mist removal pipe 61. Each fan unit 71 has two suction fans 72, and the two suction fans 72 generate suction force to suck air from the mist removal pipe 61.

[0062] When the fan unit 71 starts and the suction fan 72 rotates, an airflow Fd is generated from the duct opening Adi through the connector pipe 512, the exhaust pipe 53, and the mist removal pipe 61 to the suction unit 7, and this airflow Fd sucks the duct opening Adi. In this way, the suction force generated by the fan unit 71 is supplied to the duct opening Adi through the mist removal pipe 61, the exhaust pipe 53, and the connector pipe 512. As described above, the exhaust opening Ano faces the duct opening Adi from above. Therefore, the suction force supplied to the duct opening Adi sucks the exhaust opening Ano, and an airflow Fn ( FIGS. 5A and 5B ) is formed that runs from the intake opening Ani to the exhaust opening Ano through the flow path space S. As a result, the ink mist sucked through the intake opening Ani rides on the airflow Fn and reaches the duct opening Adi. Furthermore, the ink mist that reaches the duct opening Adi rides on the airflow Fd and travels from the duct opening Adi toward the fan unit 71. Furthermore, the filter 31 is present in the middle of the airflow Fd that flows from the duct opening Adi toward the fan unit 71. Therefore, the filter 31 removes ink mist that is carried on the airflow Fd from the airflow Fd.

[0063] The printing device 1 also includes a lifting drive mechanism 17 that raises and lowers the base frame 14 that fixes the recovery nozzle 4 to the ejection head 121. The lifting drive mechanism 17 has a lifting plate 171 to which the base frame 14 is attached, and an actuator 172 that raises and lowers the lifting plate 171. When the actuator 172 raises the lifting plate 171, the lifting plate 171 rises, taking the ejection head 121 and the recovery nozzle 4 with it. When the actuator 172 lowers the lifting plate 171, the lifting plate 171 lowers, taking the ejection head 121 and the recovery nozzle 4 with it. As a result, the operation shown in FIG. 9 is performed.

[0064] 9 is a partial cross-sectional view that highlights and schematically illustrates the operations performed by raising and lowering the discharge head and recovery nozzle. As shown in FIG. 9, the discharge head 121 is driven in the Z direction by the actuator 172 between a print height Hhl and a non-print height Hhh that is higher than the print height Hhl (in other words, farther from the print medium M). The flange 431 is also driven in the Z direction by the actuator 172 between a proximity height Hnl and a separation height Hnh that is higher than the proximity height Hnl (in other words, farther from the flange 511).

[0065] During image printing, in which the ejection head 121 ejects color inks onto the print medium M to print a color image, the actuator 172 lowers the ejection head 121 and the recovery nozzle 4. As a result, as shown in the "During Image Printing" section of FIG. 9 , the ejection head 121 is positioned at the printing height Hhl and ejects ink onto the print medium M while facing the print medium M supported by the roller 201 from above. During this image printing, the flange 431 of the recovery nozzle 4 is positioned at the proximity height Hnl and faces the flange 511 from above. As a result, the exhaust opening Ano faces the duct opening Adi at the proximity height Hnl. The suction unit 7 also operates the suction fan 72 of the fan unit 71 to generate suction force. At this time, the flange 431 and the flange 511 are spaced apart from each other at the proximity height Hnl, leaving a gap between them in the Z direction. Therefore, a gap also exists in the Z direction between the exhaust opening Ano and the duct opening Adi at the proximity height Hnl. However, because this gap is very small, the suction force supplied to the duct opening Adi by the suction unit 7 is sufficiently transmitted to the exhaust opening Ano, generating the airflow Fn described above. As a result, the ink mist generated during image printing is collected by the airflow Fn and the airflow Fd from the intake opening Ani of the collection nozzle 4 into the filter 31.

[0066] During non-image printing, when the ejection head 121 is not printing a color image, the actuator 172 raises the ejection head 121 and the recovery nozzle 4. As a result, as shown in the "Non-Image Printing" column in Fig. 9, the ejection head 121 is positioned at a non-printing height Hhh and separated upward from the print medium M supported by the roller 201. During this non-image printing, the flange 431 of the recovery nozzle 4 is positioned at a separation height Hnh and separated upward from the flange 511.

[0067] In the above example, no particular member is provided between the flange 431 of the nozzle exhaust portion 43 and the flange 511 of the exhaust connector 51. Alternatively, a buffer material 32 (FIGS. 10 and 11) may be provided between them.

[0068] Fig. 10 is a perspective view showing the external appearance of the buffer material, and Fig. 11 is a partial cross-sectional view showing the operation performed by raising and lowering the discharge head and recovery nozzle in a configuration equipped with the buffer material. The only difference between the operation example in Fig. 9 and the operation example in Fig. 11 is the presence or absence of the buffer material 32, so this difference will be mainly explained, and the same parts will be assigned the same reference numerals and explanations thereof will be omitted as appropriate.

[0069] The cushioning material 32 is made of sponge or rubber and is configured with a frame 321 that surrounds a communication opening A32 that penetrates in the Z direction. In other words, the communication opening A32 is provided in the center of the cushioning material 32. The cushioning material 32 is provided between the flange 431 and the flange 511 and is adhered to the bottom surface of the flange 431. When the flange 431 is positioned at the separation height Hnh during non-image printing, the cushioning material 32 is separated upward from the flange 511.

[0070] On the other hand, when the flange 431 is positioned at the proximity height Hnl during image printing, the cushioning material 32 comes into contact with the upper surface of the flange 511. In particular, the cushioning material 32 comes into contact with both the bottom surface of the flange 431 and the upper surface of the flange 511, and is crushed and deformed by the flanges 431 and 511 in the Z direction. In other words, the cushioning material 32 fills the gap between the flanges 431 and 511. During this image printing, the communication opening A32 faces the exhaust opening Ano from below and faces the duct opening Adi from above, and the exhaust opening Ano and the duct opening Adi communicate with each other via the communication opening A32.

[0071] As described above, during image printing, the suction unit 7 operates the suction fan 72 of the fan unit 71 to generate suction force. The suction force supplied to the duct opening Adi by the suction unit 7 is transmitted to the exhaust opening Ano via the communication opening A32, generating the airflow Fn described above. As a result, the ink mist generated during image printing is collected by the airflow Fn and the airflow Fd from the intake opening Ani of the recovery nozzle 4 into the filter 31.

[0072] 12 is a partial cross-sectional view showing the positional relationship between the base frame that supports the ejection head and the recovery nozzle. The base frame 14 has a base plate 141 that stands in the Z direction, a support plate 142 that stands in the Z direction at Dmu upstream of the base plate 141, and a bottom plate 143 that supports the support plate 142 relative to the base plate 141. These plates 141, 142, and 143 may be configured as a single unit, or may be configured as separate pieces.

[0073] The ejection head 121 is disposed on the upstream side Dmu of the support plate 142 and attached to the side surface of the upstream side Dmu of the support plate 142. The recovery nozzle 4 is disposed on the downstream side Dmd of the base plate 141 and attached with a gap (space Su) from the side surface of the downstream side Dmd of the base plate 141. The base frame 14 faces the printing medium M from above with a gap, and the ejection head 121 and recovery nozzle 4 supported by the base frame 14 also face the printing medium M from above with a gap.

[0074] As described above, the base frame 14 is attached to the lift plate 171 of the lift drive mechanism 17, and the base frame 14, ejection head 121, and recovery nozzle 4 are raised and lowered by the lift drive mechanism 17. FIG. 12 shows a state during image printing in which the ejection head 121 is positioned at a printing height Hhl. As shown in FIG. 12, the ejection head 121 has a nozzle opening surface 122 that faces the printing medium M from above. In the nozzle opening surface 122, the ejection nozzles 123 open toward the surface M1 of the printing medium M and eject ink toward the surface M1.

[0075] In the transfer direction Dm, a space Su is provided on the upstream side Dmu of the recovery nozzle 4, and a space Sd is provided on the downstream side Dmd of the recovery nozzle 4. That is, the space Su is open on the upstream side Dmu of the recovery nozzle 4 (nozzle housing 41) in the transfer direction Dm, i.e., between the recovery nozzle 4 (nozzle housing 41) and the base plate 141, and air can flow through the space Su. This space Su is provided in the Z direction from below the lower end of the recovery nozzle 4 (the lower end of the nozzle intake unit 42) to above the upper end of the recovery nozzle 4 (the upper end of the top cover 415). Furthermore, a space Sd is open on the downstream side Dmd of the recovery nozzle 4 (nozzle housing 41) in the transfer direction Dm, and air can flow through the space Sd. This space Sd is provided in the Z direction from below the lower end of the recovery nozzle 4 (the lower end of the nozzle intake unit 42) to above the upper end of the recovery nozzle 4 (the upper end of the top cover 415). The spaces Su and Sd are connected to each other via a space St above the upper end of the recovery nozzle 4 (top cover 415).

[0076] 13A to 13C are diagrams that schematically show the attachment mechanism for the recovery nozzle to the base frame that supports the ejection head. As shown in these figures, the printing device 1 is provided with an attachment mechanism 15 that attaches the recovery nozzle 4 to the base frame 14. This attachment mechanism 15 has two spacer plates 151 and 152 that are attached to a base plate 141 of the base frame 14. In other words, a side surface 141d on the downstream side Dmd of the base plate 141 is a plane that is perpendicular to the transport direction Dm, and the pair of spacer plates 151 and 152 are fixed to the side surface 141d of the base plate 141 with a gap in the Y direction.

[0077] Of the two spacer plates 151, 152, the spacer plate 151 on one side Y1 is fastened to the side surface 141d by two screws 153 arranged in the Z direction. This spacer plate 151 has two screw holes 154 arranged in the Y direction, and each screw hole 154 penetrates the spacer plate 151 in the conveying direction Dm. Furthermore, the spacer plate 152 on the other side Y2 is fastened to the side surface 141d by two screws 155 arranged in the Z direction. This spacer plate 152 has two screw holes 156 arranged in the Z direction, and each screw hole 156 penetrates the spacer plate 152 in the conveying direction Dm. In this way, the two spacer plates 151, 152 protrude downstream Dmd from the side surface 141d of the base plate 141.

[0078] Furthermore, the mounting mechanism 15 has two support plates 157, 158 provided corresponding to the two spacer plates 151, 152, respectively. The support plate 157 is fastened to the side surface of the spacer plate 151 on the downstream side Dmd by two screws 159 aligned in the Y direction. Thus, the support plate 157 protrudes toward the downstream side Dmd from the side surface of the spacer plate 151. The support plate 158 is fastened to the side surface of the spacer plate 152 on the downstream side Dmd by two screws 159 aligned in the Y direction. Thus, the support plate 158 protrudes toward the downstream side Dmd from the side surface of the spacer plate 152.

[0079] In contrast, the recovery nozzle 4 has two mounting plates 451, 452 that protrude from both ends of the nozzle housing 41 in the Y direction. The two mounting plates 451, 452 are provided to correspond to the two spacer plates 151, 152. In the conveying direction Dm, each of the mounting plates 451, 452 is provided at the end of the upstream side Dmu of the nozzle housing 41, and the side surfaces of the mounting plates 451, 452 on the downstream side Dmd are flush with the side surface of the nozzle housing 41 on the downstream side Dmd. However, it is not essential that these be flush, and the mounting plates 451, 452 may protrude toward the upstream side Dmu relative to the nozzle housing 41.

[0080] The mounting plate 451 protrudes toward the one side Y1 from the end of the one side Y1 of the nozzle housing 41. This mounting plate 451 is fastened to the spacer plate 151 by two screws 453 arranged in the Y direction. That is, the mounting plate 451 is attached to the spacer plate 151 by screwing the two screws 453 into two screw holes 154 opened in the spacer plate 151, respectively. In addition, the support plate 157 abuts against the mounting plate 451 attached to the spacer plate 151 from below.

[0081] The mounting plate 452 protrudes toward the other side Y2 from the end of the other side Y2 of the nozzle housing 41. This mounting plate 452 is fastened to the spacer plate 152 by two screws 454 arranged in the Z direction. That is, the mounting plate 452 is attached to the spacer plate 152 by threading the two screws 454 into two screw holes 156 opened in the spacer plate 152, respectively. In addition, the support plate 158 abuts the mounting plate 452 attached to the spacer plate 152 from below.

[0082] In this way, the recovery nozzle 4 is attached to the base plate 141 via two spacer plates 151, 152 arranged at a distance in the Y direction. The spacer plates 151, 152 abut against the base plate 141 of each upstream side Dmu, and abut against the recovery nozzle 4 (mounting plates 451, 452) of each downstream side Dmd. These spacer plates 151, 152 ensure a space Su between the base plate 141 and the recovery nozzle 4. In other words, the spacer plates 151, 152 create a space Su between the recovery nozzle 4 and the base plate 141.

[0083] Fig. 14 is a partial cross-sectional view showing the functions of the spaces provided on both sides of the recovery nozzle. In the example shown in Fig. 14, similar to the above, the side cover 411 and the partition wall 441 extend parallel to each other in the Z direction, and the intake opening Ani is opened between the lower ends of the side cover 411 and the partition wall 441.

[0084] When the intake opening Ani is suctioned and the airflow Fn described above is generated in the flow path space S of the recovery nozzle 4 (FIGS. 5A and 5B), a clean airflow Fcu is generated that flows from the space Su into the intake opening Ani. That is, as the intake opening Ani is suctioned, negative pressure is applied to the space Su from below, generating the clean airflow Fcu. This clean airflow Fcu descends into the space Su along the outer wall of the side cover 411, reaches the underside of the nozzle intake section 42, and then flows into the intake opening Ani. In this way, the clean airflow Fcu that has flowed into the intake opening Ani rises along the inner wall of the side cover 411 (the wall on the downstream Dmd side). As a result, a layer of clean airflow Fcu is generated inside the nozzle housing 41 of the recovery nozzle 4, rising from the intake opening Ani along the side cover 411.

[0085] Similarly, when an airflow Fn is generated as a result of suction at the intake opening Ani, a clean airflow Fcd is generated that flows from the space Sd into the intake opening Ani. That is, as a result of suction at the intake opening Ani, negative pressure is applied to the space Sd from below, generating the clean airflow Fcd. This clean airflow Fcd descends through the space Sd along the side cover 412 and the outer wall of the partition 441, reaches the underside of the nozzle intake section 42, and then flows into the intake opening Ani. In this way, the clean airflow Fcd that has flowed into the intake opening Ani rises along the inner wall of the partition 441 (the wall on the upstream Dmu side). In this way, inside the nozzle housing 41 of the recovery nozzle 4, a layer of clean airflow Fcd is generated that rises from the intake opening Ani along the partition 441.

[0086] The space Sc above the recovery nozzle 4 in the space Sd is sufficiently separated from the gap between the ejection head 121, which is the source of ink mist, and the printing medium M. Therefore, the air in the space Sc is clean and contains almost no ink mist. In contrast, the clean air flow Fcu flows from the space Sc through the space St into the space Su, and then into the intake opening Ani. The clean air flow Fcd flows from the space Sc into the intake opening Ani via the part of the space Sd below the space Sc. Therefore, the clean air flows Fcu and Fcd supply clean air from the space Sc to the intake opening Ani.

[0087] Furthermore, when an airflow Fn is generated in conjunction with suction at the intake opening Ani, a mist collection airflow Fm is generated that collects the ink mist. This mist collection airflow Fm contains ink mist generated when the ejection head 121 on the upstream side Dmu of the recovery nozzle 4 ejects ink onto the surface M1 of the printing medium M. When the airflow Fn reaches the intake opening Ani from the upstream side Dmu of the recovery nozzle 4 along the printing medium M, it flows into the intake opening Ani. In this way, the mist collection airflow Fm that has flowed into the intake opening Ani rises between the clean airflows Fcu and Fcd.

[0088] In the embodiment described above, a space Su (first space) and a space Sd (second space) are provided on both sides of the recovery nozzle 4 in the transfer direction Dm. The clean airflow Fcu (first airflow) in the space Su is generated by applying pressure to the space Su from only the lower side of the upper and lower sides to generate a clean airflow Fcu (first airflow). The clean airflow Fcd in the space Sd is generated by applying pressure to the space Sd from only the lower side of the upper and lower sides to generate a clean airflow Fcd. In this case, the pressure for generating the clean airflow Fcu and the pressure for generating the clean airflow Fcd are generated by the recovery nozzle 4 sucking air from the intake openings Ani. The clean air flow Fcu flowing downward from the space Su flows into the recovery nozzle 4 from the intake opening Ani, and the clean air flow Fcd flowing downward from the space Sd flows into the recovery nozzle 4 from the intake opening Ani.

[0089] In this way, the pressure of the airflow generated by the collection nozzle 4 suctioning air from the intake opening Ani is applied to the space Su only from below, without applying pressure to the space Su from above, thereby generating a clean airflow Fcu in the space Su. This generates a relatively gentle clean airflow Fcu. When this clean airflow Fcu flows into the collection nozzle 4 from the intake opening Ani, it generates a layer of clean airflow Fcu along the inner wall of the collection nozzle 4 on the space Su side. Similarly, without applying pressure to the space Sd from above, the pressure of the airflow generated by the collection nozzle 4 suctioning air from the intake opening Ani is applied to the space Sd only from below, thereby generating a clean airflow Fcd in the space Sd. This generates a relatively gentle clean airflow Fcd. When this clean airflow Fcd flows into the collection nozzle 4 from the intake opening Ani, it generates a layer of clean airflow Fcd along the inner wall of the collection nozzle 4 on the space Sd side. The mist recovery airflow Fm containing the ink mist sucked in from the intake opening Ani passes between the layers on both sides, which prevents the ink mist from adhering to the inner wall of the recovery nozzle 4. This makes it possible to prevent ink from adhering to the recovery nozzle 4, which sucks in and recovers the ink mist.

[0090] Specifically, the width Wa (size) of the intake opening Ani in the transport direction Dm is preferably greater than 2 mm and less than 7 mm (FIG. 14). This effectively prevents ink mist from adhering to the inner wall of the recovery nozzle 4.

[0091] The ejection head 121 has a nozzle opening surface 122 facing the printing medium M and ejection nozzles 123 that open at the nozzle opening surface 122, and ejects ink from the ejection nozzles 123 onto the printing medium M. Meanwhile, the space Su is provided from the printing medium M transported by the transport unit 2 (printing medium transport unit) to above (one side of) the nozzle opening surface 122 (FIG. 12). With this configuration, a layer of relatively clean airflow (clean airflow Fcu) is generated along the inner wall of the recovery nozzle 4, effectively preventing ink mist from adhering to the inner wall of the recovery nozzle 4.

[0092] Furthermore, the space Sd is provided from the print medium M transported by the transport unit 2 to above (one side of) the nozzle opening surface 122. With this configuration, a layer of relatively clean airflow (clean airflow Fcd) is generated along the inner wall of the recovery nozzle 4, effectively preventing ink mist from adhering to the inner wall of the recovery nozzle 4.

[0093] The recovery nozzle 4 also includes a side cover 411 (first upright plate) erected upward (on one side) from the intake opening Ani on the upstream side Dmu of the intake opening Ani in the transport direction Dm, and a partition wall 441 (second upright plate) erected upward (on one side) from the intake opening Ani on the downstream side Dmd of the intake opening Ani in the transport direction Dm. In relation to this, it is preferable that the thickness Tu of the side cover 411 is smaller than 2 mm, and the thickness Td of the partition wall 441 is smaller than 2 mm in the transport direction Dm ( FIG. 14 ). By making the side cover 411 and the partition wall 441 thin in this way, the effects of the thicknesses Tu and Td of the side cover 411 and the partition wall 441 are suppressed, and layers of the clean airflows Fcu and Fcd can be reliably generated along the inner wall of the recovery nozzle 4. As a result, adhesion of ink mist to the inner wall of the recovery nozzle 4 can be effectively suppressed.

[0094] Furthermore, in the transport direction Dm, the thickness Tu of the side cover 411 is smaller than the width Wa of the intake opening Ani, and the thickness Td of the partition wall 441 is smaller than the width Wa of the intake opening Ani. By configuring the side cover 411 and the partition wall 441 to be thin in this way, the effects of the thicknesses Tu and Td of the side cover 411 and the partition wall 441 are suppressed, and layers of the clean airflows Fcu and Fcd can be reliably generated along the inner wall of the recovery nozzle 4. As a result, adhesion of ink mist to the inner wall of the recovery nozzle 4 can be effectively suppressed.

[0095] Furthermore, the space Su is provided from the print medium M transported by the transport unit 2 to above (one side of) the upper end of the recovery nozzle 4. With this configuration, a layer of relatively clean airflow (clean airflow Fcu) is generated along the inner wall of the recovery nozzle 4, effectively preventing ink mist from adhering to the inner wall of the recovery nozzle 4.

[0096] Furthermore, the space Sd is provided from the print medium M transported by the transport unit 2 to above (one side of) the upper end of the recovery nozzle 4. With this configuration, a layer of relatively clean airflow (clean airflow Fcd) is generated along the inner wall of the recovery nozzle 4, effectively preventing ink mist from adhering to the inner wall of the recovery nozzle 4.

[0097] Furthermore, the spaces Su and Sd are connected via a space St provided above (on one side of) the upper end of the recovery nozzle 4. With this configuration, a layer of relatively clean airflow (clean airflow Fcu) is generated along the inner wall of the recovery nozzle 4, effectively preventing ink mist from adhering to the inner wall of the recovery nozzle 4.

[0098] The system also includes a base frame 14 (head support member) that supports the ejection head 121, and an attachment mechanism 15 (nozzle support member) that supports the recovery nozzle 4 relative to the base frame 14. The base frame 14 has a base plate 141 (side wall plate) that is positioned between the ejection head 121 and the recovery nozzle 4 in the transport direction Dm. In contrast, the attachment mechanism 15 supports the recovery nozzle 4 with a space Su between the base plate 141 and the recovery nozzle 4 (FIGS. 13A to 13C). This configuration prevents ink mist from adhering to the inner wall of the recovery nozzle 4. This makes it possible to prevent ink from adhering to the recovery nozzle 4, which sucks and recovers the ink mist.

[0099] The specific configurations of the recovery nozzle 4 and attachment mechanism 15 can be changed as appropriate. Therefore, they may be configured as shown in Figures 15A to 15C. Figure 15A is a perspective view schematically showing a modified example of the recovery nozzle, Figure 15B is a view schematically showing a modified example of the mechanism that supports the recovery nozzle of Figure 15A relative to the discharge head, and Figure 15C is a partial cross-sectional view schematically showing a modified example of the mechanism that supports the recovery nozzle of Figure 15A relative to the discharge head.

[0100] 15A is disposed on the downstream side Dmd of the ejection head 121 in the transport direction Dm, similar to the recovery nozzle 4 described above, and sucks in ink mist. This recovery nozzle 8 has a nozzle housing 81. The nozzle housing 81 has a nozzle intake section 82 having an intake opening Ani at its lower end, and a nozzle exhaust section 83 connected to an exhaust duct that exhausts air from the nozzle intake section 82. The nozzle exhaust section 83 is disposed at the upper end of the nozzle housing 81, and the nozzle intake section 82 extends downward from the nozzle exhaust section 83. The nozzle exhaust section 83 also protrudes from the nozzle intake section 82 to the downstream side Dmd in the transport direction Dm. When suction force is applied to the nozzle exhaust section 83 via the exhaust duct, this recovery nozzle 8 sucks in ink mist through the intake opening Ani that opens at the lower end of the nozzle intake section 82.

[0101] The nozzle intake section 82 has two side plates 821 and 822. Each of the side plates 821 and 822 is a flat plate that is perpendicular to the conveying direction Dm. The side plates 821 and 822 face each other with a gap in between in the conveying direction Dm, and the side plate 821 is located upstream Dmu of the side plate 822. The intake opening Ani is provided between the lower ends of the side plates 821 and 822. Therefore, the airflow that flows into the recovery nozzle 4 from the intake opening Ani travels upward between the side plates 821 and 822 to reach the nozzle exhaust section 83.

[0102] The base frame 14 supporting the discharge head 121 has two side plates 144, 145 spaced apart in the conveyance direction Dm, and a bottom plate 146 connecting the lower ends of the side plates 144, 145. The discharge head 121 is placed on the bottom plate 146 from above, between the side plates 144 and 145. In this way, the discharge head 121 is supported by the bottom plate 146 of the base frame 14.

[0103] The base frame 14 is provided with an attachment mechanism 16 that attaches the recovery nozzle 8. The attachment mechanism 16 attaches the recovery nozzle 8 to the downstream side plate 145 of the two side plates 144, 145, the side plate 145 on the downstream side Dmd. The attachment mechanism 16 has a spacer 161, which has a screw hole 162 that penetrates in the conveying direction Dm. The spacer 161 has a large diameter portion 163 that is positioned between the side plates 821 and 822 in the conveying direction Dm, and a small diameter portion 164 that protrudes from the large diameter portion 163 to the upstream side Dmu. The diameter of the outer circumferential surface of the large diameter portion 163 is larger than the diameter of the outer circumferential surface of the small diameter portion 164, and the large diameter portion 163 protrudes from the small diameter portion 164 in a flange-like shape.

[0104] The large diameter portion 163 is sandwiched between the side plates 821 and 822, and abuts against the side plate 821 on the upstream side Dmu and abuts against the side plate 822 on the downstream side Dmd. In other words, a space is secured between the side plates 821 and 822 by the large diameter portion 163.

[0105] The side plate 821 has an insertion hole 823 formed in the conveying direction Dm corresponding to the small diameter portion 164 of the spacer 161. Meanwhile, the small diameter portion 164 is inserted into the insertion hole 823 and protrudes from the side plate 821 to the upstream side Dmu. The end of this upstream side Dmu of the side plate 821 abuts against the side plate 145 of the base frame 14 from the downstream side Dmd. In other words, a space Su is secured between the side plate 821 and the side plate 145 by the small diameter portion 164.

[0106] Furthermore, an insertion hole 824 is formed in the side plate 822 of the recovery nozzle 8, facing the screw hole 162 of the spacer 161. Furthermore, a screw hole 147 is formed in the side plate 145 of the base frame 14, facing the screw hole 162 of the spacer 161. Then, a screw inserted into the insertion hole 824, the screw hole 162, and the screw hole 147 from the downstream side Dmd is screwed into the screw hole 147. In this way, the recovery nozzle 8 is attached to the base frame 14 by the attachment mechanism 16.

[0107] Furthermore, the recovery nozzle 8 has two mounting plates 841 that protrude from both ends of the nozzle housing 81 in the Y direction. Each mounting plate 841 is provided with an insertion hole 842. Then, screws are inserted into the insertion holes 842 from the downstream side Dmd and screwed into the side plates 145, thereby attaching the recovery nozzle 8 to the base frame 14.

[0108] 16A to 16D are diagrams showing the results of a simulation of the diffusion of ink mist sucked into the recovery nozzle. Dots in each diagram represent ink mist. Each diagram shows results when the transport speed of the print medium M in the transport direction Dm is 100 mpm (meters per minute), the width of the space Su in the transport direction Dm is 2 mm, and the suction pressures of the air intake opening Ani are 10 Pa, 15 Pa, and 20 Pa. Furthermore, FIG. 16A shows the simulation results when the width (slit width) of the air intake opening Ani in the transport direction Dm is 7 mm, FIG. 16B shows the simulation results when the width (slit width) of the air intake opening Ani in the transport direction Dm is 6 mm, FIG. 16C shows the simulation results when the width (slit width) of the air intake opening Ani in the transport direction Dm is 5 mm, and FIG. 16D shows the simulation results when the width (slit width) of the air intake opening Ani in the transport direction Dm is 4 mm.

[0109] These results show that when the suction pressure is in the range of 10 Pa to 20 Pa and the width Wa (slit width) of the intake opening Ani is in the range of 4 to 6 mm, a layer of clean air is clearly formed inside the side cover 411 and inside the partition wall 441. On the other hand, when the width Wa of the intake opening Ani is 7 mm, it is clear that turbulence occurs in this layer of clean air. Therefore, it can be said that the width Wa of the intake opening Ani should preferably be less than 7 mm.

[0110] FIG. 16E is a table showing the suitability of the width of the intake opening. This table shows the width (slit width) of the intake opening Ani and whether or not the inner wall of the recovery nozzle 4 (in other words, the wall surfaces of the side cover 411 and the partition wall 441) is soiled by ink mist. In this table, "◯" indicates no soiling, and "×" indicates the presence of soiling. In the figure, the results when the intake opening Ani is 2.5 mm were confirmed by experiment, not by the above simulation.

[0111] FIG. 17A is a diagram showing the details of an experiment to confirm the effect of suction nozzle tilt. In the experiment shown in FIG. 17A, a teardrop-shaped suction nozzle was created, and components equivalent to side cover 411 and partition wall 441 were attached to the opening at the tip of the suction nozzle. Furthermore, glossy photographic paper was attached inside both components. Then, while changing the tilt θ of the suction nozzle relative to an imaginary line perpendicular to print medium M, the ink mist adhering to the glossy photographic paper was confirmed when ink mist was sucked by the suction nozzle. The tilt θ of the suction nozzle relative to the imaginary line is expressed, for example, as the angle between the imaginary line and side cover 411 (or partition wall 441).

[0112] FIG. 17B is a table showing the results of the experiment shown in FIG. 17A. This table shows the angle between the suction nozzle and the printing medium M and whether or not the inner wall of the recovery nozzle 4 (in other words, the wall surfaces of the side cover 411 and the partition wall 441) was stained by ink mist. In this table, "◯" indicates no stain, "×" indicates stain, and "Δ" indicates that staining was observed but acceptable. In this example, staining by ink mist is acceptable when the angle is between 95 degrees and 60 degrees. Therefore, for example, the angle of the suction nozzle relative to the printing medium M may be set to between 85 degrees and 95 degrees. In other words, the inclination θ (absolute value) of the suction nozzle relative to an imaginary line perpendicular to the printing medium M should be set to 5 degrees or less. This configuration effectively prevents ink mist from adhering to the inner wall of the recovery nozzle.

[0113] 18A shows the results of a simulation of the diffusion of ink mist sucked into the recovery nozzle. The dots in the figure represent ink mist. The figure shows the results when the transport speed of the print medium M in the transport direction Dm is 100 mpm (meters per minute), the suction pressure of the intake opening Ani is 20 Pa, and the width Wa (slit width) of the intake opening Ani is 5 mm, and the width of the space Su in the transport direction Dm is 2 mm and 3 mm.

[0114] 18B is a table showing the suitability of the width of the intake opening. This table shows the width (gap) of the space Su, the presence or absence of ink mist contamination on the inner wall of the recovery nozzle 4 (in other words, the wall surfaces of the side cover 411 and the partition wall 441), and the presence or absence of ink mist contamination around the ejection head 121. In this table, "◯" indicates no contamination, and "×" indicates contamination. From this result, it can be seen that if the width of the space Su in the transport direction Dm is made greater than 2 mm, it is possible to prevent ink mist contamination in both the recovery nozzle 4 and the ejection head 121.

[0115] In the embodiment described above, the printing medium M corresponds to an example of the "printing medium" of the present invention, the transport direction Dm corresponds to an example of the "transport direction" of the present invention, the transport unit 2 corresponds to an example of the "printing medium transport unit" of the present invention, the ejection head 121 corresponds to an example of the "ejection head" of the present invention, the intake opening Ani corresponds to an example of the "intake opening" of the present invention, the recovery nozzle 4 or the recovery nozzle 8 corresponds to an example of the "recovery nozzle" of the present invention, the space Su corresponds to an example of the "first space" of the present invention, the space Sd corresponds to an example of the "second space" of the present invention, the clean air flow Fcu corresponds to an example of the "first air flow" of the present invention, and the clean air flow Fcd corresponds to an example of the "second air flow" of the present invention, the printing device 1 corresponds to an example of the "printing device" of the present invention, the nozzle opening surface 122 corresponds to an example of the "nozzle opening surface" of the present invention, the discharge nozzle 123 corresponds to an example of the "discharge nozzle" of the present invention, the side cover 411 corresponds to an example of the "first standing plate" of the present invention, the partition wall 441 corresponds to an example of the "second standing plate" of the present invention, the base frame 14 corresponds to an example of the "head support member" of the present invention, the mounting mechanism 15 or the mounting mechanism 16 corresponds to an example of the "nozzle support member" of the present invention, and the base plate 141 corresponds to an example of the "side wall plate" of the present invention.

[0116] The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, the recovery nozzle 4 can be disposed relative to the ejection head 121 as shown in FIG. 19. FIG. 19 is a partial cross-sectional view schematically illustrating a modified positional relationship of the recovery nozzle relative to the ejection head. In the example of FIG. 19, the space Su between the base frame 14 and the recovery nozzle 4 has a width Ws in the transport direction Dm. Here, the width Ws is given, for example, as the narrowest distance between the base frame 14 and the recovery nozzle 4. Furthermore, the print gap Gp, which corresponds to the distance between the nozzle opening surface 122 of the ejection head 121 located at the printing height Hhl and the surface M1 of the printing medium M, is narrower than the width Ws of the space Su. In other words, the print gap Gp between the nozzle opening surface 122 and the surface M1 of the printing medium M when the ejection head 121 ejects ink onto the surface M1 of the printing medium M, is narrower than the width Ws of the space Su. For example, the width Ws of the space Su is 1 to 4 mm, and the print gap Gp is ​​0.8 to 1.5 mm. Furthermore, the suction gap Gs, which corresponds to the distance between the lower end of the recovery nozzle 4 and the surface M1 of the printing medium M, is, for example, equal to or wider than the print gap Gp.

[0117] In the example of FIG. 19 , the ejection head 121 has a nozzle opening surface 122 facing the printing medium M and ejection nozzles 123 that open at the nozzle opening surface 122. The ejection head 121 ejects ink from the ejection nozzles 123 onto the printing medium M. The width Ws of the space Su (first space) in the transport direction Dm is wider than the print gap Gp between the printing medium M transported by the transport unit 2 (printing medium transport unit) and the nozzle opening surface 122. This configuration allows the ejection head 121 to be positioned close to the printing medium M while ensuring a wide space Su. Therefore, the clean air flow Fcu (first airflow) from the space Su toward the intake opening Ani is more likely to occur than the airflow from between the nozzle opening surface 122 and the printing medium M toward the intake opening Ani. In other words, the generation of an airflow from between the ejection head 121 and the printing medium M toward the intake opening Ani of the recovery nozzle 4 can be suppressed. As a result, ink can be stably ejected from the ejection head 121 onto the printing medium.

[0118] FIG. 20A is a partial cross-sectional view schematically illustrating a modified example of a printing device, and FIG. 20B is a diagram schematically illustrating a clean air supply unit included in the printing device of FIG. 20A. The printing device 1 of FIG. 20A has a clean air supply unit 9. The clean air supply unit 9 has a clean air supply pipe 91 located downstream Dmd of the recovery nozzle 4 in the conveying direction Dm. This clean air supply pipe 91 is located parallel to the Y direction in the space Sc. The clean air supply pipe 91 also has an air outlet 911, which is a slit extending parallel to the Y direction. As indicated by the dashed arrow in FIG. 20A, air flows from the inside of the clean air supply pipe 91 to the outside (space Sc) through the air outlet 911. Note that the configuration of the air outlet 911 is not limited to a slit, and may be a plurality of holes arranged in the Y direction. An air inlet 912 opening to the outside of the housing 11 of the printing device 1 is provided at the Y end of the clean air supply pipe 91.

[0119] Furthermore, the clean air supply unit 9 has a filter 92 arranged in the clean air supply pipe 91. The filter 92 is arranged between the air outlet 911 and the air inlet 912 in the Y direction. Therefore, air that flows in from the air inlet 912 passes through the filter 92 and then flows out from the air outlet 911. Therefore, clean air from which foreign matter has been removed by the filter flows out from the air outlet 911. In this way, the air that flows out from the air outlet 911 becomes a clean air flow Fcd or a clean air flow Fcu and is sucked into the collection nozzle 4 through the intake opening Ani.

[0120] Furthermore, the width Wa (size) of the intake opening Ani is not limited to the above specific example.

[0121] Furthermore, the thickness Tu of the side cover 411 and the thickness Td of the partition wall 441 are not limited to the above specific examples.

[0122] Furthermore, the flange 431 of the nozzle exhaust portion 43 and the flange 511 of the exhaust duct 5 may be connected to each other. In this case, it is preferable that the exhaust duct 5 be able to be flexibly deformed.

[0123] Furthermore, the period during which the suction fan 72 operates is not limited to when images are being printed, and the suction fan 72 may be operated during both image printing and non-image printing.

[0124] Furthermore, the number and arrangement of the suction fans 72 can be changed as appropriate.

[0125] Furthermore, the cushioning material 32 may be bonded to the flange 511 instead of the flange 431 .

[0126] Furthermore, various materials are conceivable for the flanges 431 and 511. In other words, these materials may be resin or metal. [Industrial Applicability]

[0127] The present invention is applicable to all techniques for collecting ink mist that is generated when ink is ejected onto a print medium to print an image. [Explanation of symbols]

[0128] 1...Printing device 121...Discharge head 122...Nozzle opening surface 123...Discharge nozzle 14...Base frame 141...Base plate 15...Attachment mechanism 16...Attachment mechanism 2...Transport section 4...Recovery nozzle 411...Side cover 441...Bulkhead 8...Recovery nozzle Ani...Intake opening Dm: Conveying direction Fcd...clean airflow Fcu…clean airflow M…Print media Sd…Space Su…space

Claims

1. a print medium transport unit that transports the print medium in a transport direction; an ejection head that faces the print medium and ejects ink onto the print medium; a recovery nozzle that is disposed downstream of the ejection head in the transport direction, has an intake opening that faces the printing medium from one side in a direction perpendicular to the printing medium, and sucks ink mist generated by the ejection of ink from the ejection head through the intake opening; Equipped with a first space is provided between the recovery nozzle and the ejection head in the transport direction, and a second space is provided downstream of the recovery nozzle; applying a pressure to the first space from only the other side of the one side and the other side to generate a first airflow in the first space from the one side toward the other side opposite to the one side, thereby generating the first airflow; applying a pressure for generating a second airflow from the one side toward the other side in the second space to the second space only from the other side of the one side and the other side, thereby generating the second airflow; a pressure for generating the first airflow and a pressure for generating the second airflow are generated by the recovery nozzle suctioning air from the intake opening, the first airflow flowing out from the first space to the other side flows into the recovery nozzle through the intake opening, The second airflow that flows out from the second space to the other side flows into the recovery nozzle through the intake opening.

2. The printing device according to claim 1 , wherein the size of the intake opening in the transport direction is greater than 2 mm and smaller than 7 mm.

3. the ejection head has a nozzle opening surface facing the print medium and an ejection nozzle opening at the nozzle opening surface, and ejects ink from the ejection nozzle onto the print medium; The printing device according to claim 1 , wherein the first space is provided from the printing medium transported by the printing medium transport section to the one side of the nozzle opening surface.

4. The printing device according to claim 3 , wherein the second space is provided from the printing medium transported by the printing medium transport section to the one side of the nozzle opening surface.

5. the recovery nozzle has a first standing plate erected on the one side from the air intake opening on the upstream side of the air intake opening in the conveying direction, and a second standing plate erected on the one side from the air intake opening on the downstream side of the air intake opening in the conveying direction, 2. The printing device according to claim 1, wherein the thickness of the first standing plate is less than 2 mm and the thickness of the second standing plate is less than 2 mm in the transport direction.

6. the recovery nozzle has a first standing plate erected on the one side from the air intake opening on the upstream side of the air intake opening in the conveying direction, and a second standing plate erected on the one side from the air intake opening on the downstream side of the air intake opening in the conveying direction, 2. The printing device according to claim 1, wherein the thickness of the first standing plate in the transport direction is smaller than the size of the intake opening, and the thickness of the second standing plate is smaller than the size of the intake opening.

7. The printing device according to claim 1 , wherein the first space is provided from the printing medium transported by the printing medium transport section to the one side of the one end of the recovery nozzle.

8. The printing device according to claim 7 , wherein the second space is provided from the printing medium transported by the printing medium transport section to the one side of the one end of the recovery nozzle.

9. The printing apparatus according to claim 8 , wherein the first space and the second space are connected via a space provided on one side of one end of the recovery nozzle.

10. a head support member that supports the ejection head; a nozzle support member that supports the recovery nozzle relative to the head support member; Furthermore, the head support member has a sidewall plate located between the ejection head and the recovery nozzle in the transport direction, The printing apparatus according to claim 1 , wherein the nozzle support member supports the recovery nozzle with the first space between the side wall plate and the recovery nozzle.

11. 2. The printing device according to claim 1, wherein an inclination between the recovery nozzle and an imaginary line perpendicular to the printing medium that the recovery nozzle faces is within 5 degrees.

12. the ejection head has a nozzle opening surface facing the print medium and an ejection nozzle opening at the nozzle opening surface, and ejects ink from the ejection nozzle onto the print medium; The printing device according to claim 1 , wherein the width of the first space in the transport direction is greater than the distance between the printing medium transported by the printing medium transport section and the nozzle opening surface.

13. conveying the print medium in a conveyance direction; ejecting ink onto the printing medium from an ejection head facing the printing medium; a step of sucking ink mist generated by the ejection of ink from the ejection head through a recovery nozzle disposed downstream in the transport direction with respect to the ejection head and having an intake opening facing the printing medium from one side in a direction perpendicular to the printing medium; Equipped with a first space is provided between the recovery nozzle and the ejection head in the transport direction, and a second space is provided downstream of the recovery nozzle; applying a pressure to the first space from only the other side of the one side and the other side to generate a first airflow in the first space from the one side toward the other side opposite to the one side, thereby generating the first airflow; applying a pressure for generating a second airflow from the one side toward the other side in the second space to the second space only from the other side of the one side and the other side, thereby generating the second airflow; a pressure for generating the first airflow and a pressure for generating the second airflow are generated by the recovery nozzle suctioning air from the intake opening, the first airflow flowing out from the first space to the other side flows into the recovery nozzle through the intake opening, The second airflow flowing out from the second space to the other side flows into the recovery nozzle from the intake opening.

Images