JP2020152009A - Printer and dry method - Google Patents

Abstract

To provide a printer which effectively utilizes a non-contact area of a heat roller to improve energy efficiency of a dry part, and to provide a dry method.SOLUTION: A dry part 30 of a printer 1 has a heat roller 31, a first guide plate 33, and fans 37 to 39. A print sheet 9 contacts with an outer peripheral surface of the heat roller 31 at a contact area A1 that is a part of a periphery of the heat roller 31. The first guide plate 33 spreads along the outer peripheral surface of the heat roller 31 at a contact area A2 that is another part of the periphery of the heat roller 31. When the fans 37 to 39 are operated, airflow occurs in a first arc space 330 between the non-contact area A2 of the heat roller 31 and the first guide plate 33 to generate hot air. The hot air is utilized at another part of the dry part 30 to improve energy efficiency of dry processing.SELECTED DRAWING: Figure 4

Description

The present invention relates to a technique for drying ink adhering to a printing medium in a printing apparatus that prints an image on a long strip-shaped printing medium by an inkjet method.

Conventionally, there is known a printing apparatus that prints an image by ejecting ink toward the printing paper while transporting the long strip-shaped printing paper in the longitudinal direction. Some printing devices of this type are provided with a heat roller type drying section. The heat roller type drying unit heats and dries the ink by bringing the printing paper into contact with the surface of the heated heat roller. A conventional printing apparatus provided with a heat roller type drying unit is described in, for example, Patent Document 1.

Japanese Unexamined Patent Publication No. 2012-76227

However, in the heat roller type heating unit, the printing paper is brought into contact with the surface of the heat roller while conveying a series of printing paper. Therefore, the printing paper cannot be brought into contact with the entire circumference of the heat roller. That is, around the heat roller, there is a contact area where the printing paper contacts and a non-contact area where the printing paper does not pass. In the non-contact region, there is a problem that the heat of the heat roller is not effectively used for drying the ink.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a printing apparatus and a drying method capable of effectively utilizing a non-contact region of a heat roller to improve the energy efficiency of a drying portion. And.

In order to solve the above problems, the first invention of the present application is a printing apparatus that prints an image on a long strip-shaped printing medium by an ink jet method, and uses a transport mechanism for transporting the print medium in the longitudinal direction and the transport mechanism. A head that ejects ink toward the surface of the printed medium to be conveyed and a drying portion that dries the ink adhering to the printing medium on the downstream side of the conveying path from the head are provided, and the drying portion prints. A heat roller that rotates about a rotation axis extending parallel to the width direction of the medium, a heat source provided inside the heat roller, and an arc-shaped first guide arranged to face the outer peripheral surface of the heat roller. It has a plate and an airflow generating portion that generates an airflow in a first arcuate space between the heat roller and the first guide plate, and the print medium is a contact region that is a part around the heat roller. In contact with the outer peripheral surface of the heat roller, the first guide plate spreads along the outer peripheral surface of the heat roller in a non-contact region which is another portion around the heat roller.

The second invention of the present application is the printing apparatus of the first invention, and the drying portion further includes a relay duct for sending a gas passing through the first arc-shaped space to a printing medium.

The third invention of the present application is the printing apparatus of the second invention, in which the relay duct sends a gas that has passed through the first arc-shaped space to the contact region.

The fourth invention of the present application is the printing apparatus of the third invention, in which the drying portion is an arc-shaped second guide arranged to face the outer peripheral surface of the heat roller in the contact region of the heat roller. The relay duct further comprises a plate, and the relay duct sends gas to the second arc-shaped space between the printing medium supported by the heat roller and the second guide plate.

The fifth invention of the present application is the printing apparatus of the second invention, in which the relay duct sends a gas that has passed through the first arc-shaped space to a printing medium on the downstream side of a transport path from the heat roller. ..

The sixth invention of the present application is the printing apparatus of any one of the second to fifth inventions, and the drying portion further includes a suction portion for sucking gas from the first arc-shaped space. The suction portion has a plurality of suction ports arranged in the width direction, and the upstream end portions of the relay duct are connected to both ends in the width direction of the suction portion, and the size of the plurality of suction ports is large. Gradually decreases from the center in the width direction to both ends in the width direction.

The seventh invention of the present application is the printing apparatus of any one invention from the first invention to the sixth invention, and the first guide plate includes a main plate covering the outside of the first arc-shaped space and the first guide plate. It has a pair of side plates that cover both ends of an arcuate space in the width direction.

The eighth invention of the present application is the printing apparatus of any one invention from the first invention to the seventh invention, in which the direction of rotation of the heat roller and the direction of airflow in the first arc-shaped space are mutually exclusive. The opposite direction.

The ninth invention of the present application is the printing apparatus of any one of the first to eighth inventions, and the temperature of the gas introduced into the first arcuate space is the temperature of the outer peripheral surface of the heat roller. Lower than and higher than the ambient temperature.

The tenth invention of the present application is the printing apparatus of the ninth invention, and the drying portion further includes an introduction duct for introducing a gas heated by the heat source into the first arc-shaped space.

The eleventh invention of the present application is a drying method for drying an ink adhering to a printing medium while transporting the printing medium in the longitudinal direction in a printing apparatus for printing an image on a long strip-shaped printing medium by an inkjet method. The steps include a) a step of bringing the print medium into contact with the outer peripheral surface of the heat roller while rotating a heat roller having a built-in heat source, and b) a step of supplying a heated gas to the print medium. In a), the print medium is brought into contact with the outer peripheral surface of the heat roller in the contact area which is a part around the heat roller, and in the step b), the non-contact area which is another part around the heat roller. In, the gas heated by the heat roller is supplied to the printing medium.

According to the first to tenth inventions of the present application, warm air is generated by flowing a gas through the first arcuate space between the non-contact region of the heat roller and the first guide plate to generate warm air in the dry portion. It can be used elsewhere. As a result, the non-contact region of the heat roller can be effectively utilized to improve the energy efficiency of the drying process.

In particular, according to the second to fifth inventions of the present application, the warm air generated by the non-contact region of the heat roller is sent to the printing medium. As a result, the ink adhering to the print medium can be efficiently dried.

In particular, according to the sixth invention of the present application, the suction amount of gas from the first arc-shaped space to the suction portion can be made uniform in the width direction. As a result, for example, the suction amount of the gas near both ends in the width direction becomes extremely large, and it is possible to suppress the suction of the gas while the heating is insufficient. Therefore, sufficiently heated warm air can be sent from the first arc-shaped space to the relay duct.

In particular, according to the seventh invention of the present application, the diffusion of gas flowing through the first arc-shaped space is suppressed. As a result, the gas flowing through the first arc-shaped space can be efficiently heated.

In particular, according to the eighth invention of the present application, the gas comes into contact with more surfaces of the outer peripheral surface of the heat roller while the gas passes through the first arcuate space. As a result, warm air can be generated more efficiently in the first arc-shaped space.

In particular, according to the ninth invention of the present application, the temperature drop of the heat roller can be suppressed by introducing a gas having a temperature higher than the environmental temperature into the first arc-shaped space.

In particular, according to the tenth invention of the present application, the heat from the heat source can be effectively used.

Further, according to the eleventh invention of the present application, the gas heated in the non-contact region of the heat roller is supplied to the printing medium. As a result, the non-contact region of the heat roller can be effectively utilized to improve the energy efficiency of the drying process.

It is a figure which showed the structure of the printing apparatus. It is a bottom view of the head unit. It is a block diagram which showed the electrical connection between a control part and each part in a printing apparatus. It is a figure which looked at the vicinity of the dry part of a printing apparatus from one side in the width direction. It is sectional drawing of the heat roller and the 1st guide plate seen from the VV position of FIG. It is a perspective view of the 1st suction part. It is a figure which looked at the vicinity of the dry part of the printing apparatus which concerns on 2nd Embodiment from one side in the width direction. It is a figure which looked at the vicinity of the dry part of the printing apparatus which concerns on 3rd Embodiment from one side in the width direction.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<1. First Embodiment>
<1-1. Printing device configuration>
FIG. 1 is a diagram showing a configuration of a printing apparatus 1 according to a first embodiment of the present invention. The printing device 1 is a device that prints an image on the surface of the printing paper 9 by an inkjet method while transporting the printing paper 9 which is a long strip-shaped printing medium. As shown in FIG. 1, the printing apparatus 1 includes a transport mechanism 10, four head units 20, a drying unit 30, and a control unit 40. The transport mechanism 10, the four head units 20, and the drying unit 30 are housed inside the exterior housing 100 of the printing apparatus 1.

The transport mechanism 10 is a mechanism for transporting the printing paper 9 in the transport direction along the longitudinal direction thereof. The transport mechanism 10 of the present embodiment includes a winding roller 11, a plurality of transport rollers 12, and a take-up roller 13. A motor (not shown) as a power source is connected to some rollers of the transport mechanism 10. When the motor is operated, the printing paper 9 is unwound from the unwinding roller 11 and is conveyed along the conveying path composed of the plurality of conveying rollers 12. Each transfer roller 12 guides the printing paper 9 to the downstream side of the transfer path by rotating about the horizontal axis. Further, the printed paper 9 after being conveyed is collected by the take-up roller 13.

A part of the transport mechanism 10 may be a device independent of the other parts. For example, a part of the transport mechanism 10 including the unwinding roller 11 and a part including the take-up roller 13 may be a separate device from the other parts of the transport mechanism 10.

The four head units 20 are units for ejecting ink to the printing paper 9 conveyed by the conveying mechanism 10. The printing device 1 ejects ink droplets from each head unit 20 while the printing paper 9 passes under the four head units 20 only once, and prints an image on the printing paper 9. It is a one-pass printing device. As shown in FIG. 1, the printing paper 9 moves substantially horizontally along the arrangement direction of the head units 20 below the four head units 20. At this time, the printing surface of the printing paper 9 is directed upward (head unit 20 side). The four head units 20 are droplets of ink of each color of black (K), cyan (C), magenta (M), and yellow (Y), which are color components of a multicolor image (hereinafter, simply "ink droplets"). ) Is ejected onto the printing surface of the printing paper 9.

Although the colors of the inks ejected from the four head units 20 are different from each other, the structures of the four head units 20 are almost the same. FIG. 2 is a bottom view of one head unit 20. As shown in FIG. 2, the head unit 20 of the present embodiment has a housing 21 and two heads 22 fixed to the housing 21. Each of the two heads 22 has an exposed discharge surface on the lower surface of the housing 21. Further, as shown in FIG. 2, the two heads 22 are arranged so as to be displaced from each other in the transport direction, and the two heads 22 cover the entire width direction of the printing paper 9 (horizontal direction orthogonal to the transport direction). The positions in the width direction are also shifted so as to cover the above.

Further, as shown enlarged in FIG. 2, a plurality of nozzles 221 are regularly arranged on the lower surface of each head 22. The plurality of nozzles 221 are arranged so as to be displaced from each other in the width direction, and one nozzle 221 is assigned to a region having a width of 1 pixel on the printing paper 9. At the time of printing, ink droplets are ejected from the plurality of nozzles 221 of each head 22 toward the printing surface of the printing paper 9. As a result, each of the four head units 20 prints a monochrome image on the printing surface of the printing paper 9. Then, a multicolor image is formed on the printing surface of the printing paper 9 by superimposing the four monochromatic images.

The number of heads 22 included in one head unit 20 may be one or three or more. Further, the number of the head units 20 included in the printing apparatus 1 may be 1 to 3 or 5 or more. For example, the printing apparatus 1 may further include a head unit 20 that ejects a spot color ink, in addition to the four head units 20 that eject inks of each color of black, cyan, magenta, and yellow.

The drying unit 30 is a processing unit for drying the ink adhering to the printing paper 9. The drying unit 30 is arranged on the downstream side of the transport path with respect to the four head units 20. As shown in FIG. 1, the drying unit 30 has a heat roller 31 and a halogen lamp 32 provided inside the heat roller 31. The heat roller 31 is a cylindrical roller having an outer diameter larger than that of the transport roller 12. The heat roller 31 rotates about a rotation axis extending parallel to the width direction of the printing paper 9. The halogen lamp 32 is a heat source for heating the heat roller 31. When a drive current is supplied to the halogen lamp 32, the halogen lamp 32 generates heat, which heats the heat roller 31.

The printing paper 9 is carried into the drying unit 30 after receiving the ink ejected from the four head units 20. In the drying unit 30, the heat roller 31 rotates while supporting the printing paper 9 to convey the printing paper 9. At this time, the outer peripheral surface of the heat roller 31 comes into contact with the back surface of the printing paper 9 (the surface opposite to the printing surface). Then, the heat accumulated in the heat roller 31 by the halogen lamp 32 is conducted to the printing paper 9 from the outer peripheral surface of the heat roller 31. As a result, the solvent evaporates from the ink adhering to the printing surface of the printing paper 9, and the ink dries.

A more detailed configuration of the drying portion 30 will be described later.

The control unit 40 is a processing unit for controlling the operation of each unit in the printing apparatus 1. As conceptually shown in FIG. 1, the control unit 40 is composed of a computer having a processor 41 such as a CPU, a memory 42 such as a RAM, and a storage unit 43 such as a hard disk drive. A computer program P for executing a printing process including a drying process described later is installed in the storage unit 43.

FIG. 3 is a block diagram showing an electrical connection between the control unit 40 and each unit in the printing device 1. As shown in FIG. 3, the control unit 40 includes the above-mentioned transport mechanism 10, four head units 20, and a drying unit 30 (heat roller 31, halogen lamp 32, first fan 37, second fan 38, which will be described later, and (Including the third fan 39) and each of them are communicably connected. The control unit 40 temporarily reads the computer program P stored in the storage unit 43 into the memory 42, and the processor 41 performs arithmetic processing based on the computer program P to control the operation of each of the above units. As a result, the printing process in the printing apparatus 1 proceeds.

<1-2. Composition of dry part>
Subsequently, a more detailed configuration of the drying unit 30 will be described. FIG. 4 is a view of the vicinity of the drying portion 30 of the printing apparatus 1 as viewed from one side in the width direction.

The heat roller 31 is rotatably supported by a pair of side walls provided inside the exterior housing 100 via bearings. The halogen lamp 32 is a columnar heat source arranged along the rotation axis O of the heat roller 31. When the printing process is executed, the driving current is supplied from the control unit 40 to the halogen lamp 32. As a result, the halogen lamp 32 emits light and generates heat, and the heat roller 31 is heated.

Hereinafter, the angle range through which the printing paper 9 passes in the periphery of the heat roller 31 is referred to as a “contact area A1”. Further, the angle range around the heat roller 31 through which the printing paper 9 does not pass is referred to as a “non-contact area A2”. In the example of FIG. 4, the contact region A1 is a range of about 180 ° about the rotation axis O in the periphery of the heat roller 31. The printing paper 9 that has passed below the four head units 20 comes into contact with the outer peripheral surface of the heat roller 31 in the contact area A1. Then, in the contact region A1, the ink droplets adhering to the printing paper 9 receive heat from the heat roller 31. As a result, the ink droplets are dried and the ink is fixed on the printing surface of the printing paper 9.

Further, as shown in FIG. 4, the drying portion 30 of the present embodiment includes a first guide plate 33, a second guide plate 34, a relay duct 35, an exhaust duct 36, a first fan 37, a second fan 38, and a second. It has 3 fans 39.

The first guide plate 33 is an arc-shaped plate arranged in the non-contact region A2 around the heat roller 31. FIG. 5 is a cross-sectional view of the heat roller 31 and the first guide plate 33 as viewed from the VV position of FIG. As shown in FIG. 5, the first guide plate 33 has a main plate 331 and a pair of side plates 332. The main plate 331 is arranged so as to face the outer peripheral surface of the heat roller 31, and spreads along the outer peripheral surface of the heat roller 31. The pair of side plates 332 extend inward in the radial direction from both ends in the width direction of the main plate 331.

A first arc-shaped space 330 along the outer peripheral surface of the heat roller 31 is interposed between the heat roller 31 and the first guide plate 33. The main plate 331 covers the outside of the first arc-shaped space 330. The pair of side plates 332 cover both ends of the first arc-shaped space 330 in the width direction.

The second guide plate 34 is an arc-shaped plate arranged in the contact region A1 around the heat roller 31. The second guide plate 34, like the first guide plate 33, has a main plate and a pair of side plates. The main plate is arranged so as to face the printing surface of the printing paper 9 supported on the outer peripheral surface of the heat roller 31, and spreads along the outer peripheral surface of the heat roller 31. The pair of side plates extend inward in the radial direction from both ends in the width direction of the main plate.

A second arc-shaped space 340 along the outer peripheral surface of the heat roller 31 is interposed between the printing paper 9 supported by the outer peripheral surface of the heat roller 31 in the contact region A1 and the second guide plate 34. The main plate of the second guide plate 34 covers the outside of the second arc-shaped space 340. The pair of side plates of the second guide plate 34 cover both ends of the second arc-shaped space 340 in the width direction.

The relay duct 35 is a tubular member that connects the first arc-shaped space 330 and the second arc-shaped space 340. The upstream end of the relay duct 35 is connected to the first guide plate 33 via the first suction portion 351. The downstream end of the relay duct 35 is connected to the second guide plate 34. The internal space of the relay duct 35 serves as a flow path for sending the gas that has passed through the first arc-shaped space 330 to the second arc-shaped space 340. The relay duct 35 may be covered with a heat insulating material in order to suppress the temperature drop of the gas in the relay duct 35.

FIG. 6 is a perspective view of the first suction unit 351. The first suction unit 351 is a hollow member that connects the first arc-shaped space 330 and the relay duct 35. As shown in FIG. 6, a plurality of slit-shaped suction ports 352 are provided on the surface of the first suction portion 351 on the side of the first arc-shaped space 330. The plurality of suction ports 352 are arranged at intervals in the width direction. The upstream end of the relay duct 35 branches into two and is connected to openings 353 provided at both ends of the first suction portion 351 in the width direction.

The first suction unit 351 sucks the gas in the first arc-shaped space 330 by the suction force from the relay duct 35. Therefore, the suction force of the gas per unit area is larger in the vicinity of both ends in the width direction of the first suction portion 351 than in the vicinity of the center in the width direction of the first suction portion 351. However, as shown in FIG. 6, in the present embodiment, the size of the plurality of suction ports 352 gradually decreases from the central portion in the width direction to both ends in the width direction. Therefore, despite the difference in suction force described above, the suction amount of gas at the suction port 352 near the center in the width direction and the suction amount of gas at the suction ports 352 near both ends in the width direction are different. It is made almost uniform.

The exhaust duct 36 is a tubular member that connects the second arc-shaped space 340 and the external space of the exterior housing 100. The upstream end of the exhaust duct 36 is connected to the second guide plate 34 via a second suction portion 361 similar to the first suction portion 351 described above. The downstream end of the exhaust duct 36 is exposed to the outside of the exterior housing 100. The internal space of the exhaust duct 36 serves as a flow path for discharging the gas that has passed through the second arc-shaped space 340 to the outside of the exterior housing 100.

The first fan 37 is arranged near one end of the first guide plate 33 in the circumferential direction (rotational direction centered on the rotation axis O of the heat roller 31). The second fan 38 is arranged near the downstream end of the relay duct 35. The third fan 39 is arranged near the downstream end of the exhaust duct 36. When the printing process is executed, the current supplied from the control unit 40 causes the first fan 37, the second fan 38, and the third fan 39 to rotate. Then, the gas (for example, air) in the exterior housing 100 is introduced into the first arc-shaped space 330 via the first fan 37. Then, an air flow from the first arc-shaped space 330 passes through the first suction portion 351 and the relay duct 35, the second arc-shaped space 340, the second suction portion 361, and the exhaust duct 36, and flows toward the outside of the exterior housing 100. It is formed.

That is, in the present embodiment, the three fans, the first fan 37, the second fan 38, and the third fan 39, generate an air flow in the flow path from the first arc-shaped space 330 to the exhaust duct 36. It becomes. However, the number of fans constituting the airflow generating unit is not limited to three, and may be one to two, or four or more. Further, the position of each fan may be different from the position of the example of FIG.

The gas flowing through the first arc-shaped space 330 is heated by the heat of the heat roller 31. As a result, the temperature of the gas flowing through the first arcuate space 330 rises. Further, as the temperature of the gas rises, the humidity of the gas decreases. The heated gas becomes warm air having a temperature higher than the temperature of the gas in other parts of the outer housing 100 and lower than the temperature of the outer peripheral surface of the heat roller 31. That is, warm air is generated by using the portion of the non-contact region A2 that does not come into contact with the printing paper 9 on the outer peripheral surface of the heat roller 31.

In particular, in the present embodiment, both ends of the first arc-shaped space 330 in the width direction are covered with the side plates 332. Therefore, the diffusion of the gas flowing through the first arcuate space 330 to the outside in the width direction is suppressed. As a result, the gas flowing through the first arcuate space 330 is efficiently heated.

Further, in the present embodiment, the direction of rotation of the heat roller 31 and the direction of the air flow formed in the first arc-shaped space 330 are opposite to each other. In this way, while the gas passes through the first arcuate space 330, it comes into contact with more surfaces of the outer peripheral surface of the heat roller 31. As a result, warm air can be generated more efficiently in the first arcuate space 330.

Further, as described above, in the present embodiment, the size of the plurality of suction ports 352 of the first suction portion 351 that sucks gas from the first arc-shaped space 330 is changed from the central portion in the width direction to both ends in the width direction. It is getting smaller and smaller as you go. As a result, the amount of gas sucked from the first arcuate space 330 to the first suction portion 351 is made uniform in the width direction. By doing so, for example, the suction amount of the gas in the vicinity of both ends in the width direction becomes extremely large, and it is possible to suppress the suction of the gas while the heating is insufficient. Therefore, sufficiently heated warm air can be sent from the first arc-shaped space 330 to the relay duct 35.

The warm air generated in the first arc-shaped space 330 is sent from the first arc-shaped space 330 to the second arc-shaped space 340 through the inside of the first suction portion 351 and the relay duct 35. Then, the warm air is supplied to the printing surface of the printing paper 9 supported on the outer peripheral surface of the heat roller 31 in the contact region A1. Therefore, the ink droplets adhering to the printing surface of the printing paper 9 receive not only the heat from the heat roller 31 but also the heat from the warm air. This promotes evaporation of the solvent from the ink droplets. Further, as described above, since the humidity of the warm air is low, the solvent in the ink evaporates more positively into the warm air. As a result, the ink droplets adhering to the printing surface of the printing paper 9 can be efficiently dried.

The humidity of the warm air that has passed through the second arc-shaped space 340 is increased by the vapor of the solvent evaporated from the ink droplets. This high-humidity warm air is discharged to the outside of the exterior housing 100 through the second suction portion 361 and the exhaust duct 36. By discharging the warm air used for drying to the outside of the exterior housing 100 in this way, it is possible to suppress an increase in the humidity of the gas in the internal space of the exterior housing 100. Therefore, the gas introduced into the first arc-shaped space 330 can be maintained in a low humidity state. As a result, the drying efficiency of the ink droplets in the drying portion 30 can be further improved.

As described above, in the printing apparatus 1 of the present embodiment, in the non-contact region A2 through which the printing paper 9 does not pass, gas is flowed through the first arc-shaped space 330 between the heat roller 31 and the first guide plate 33. Generates warm air. Then, the generated warm air is used to accelerate the drying of the ink droplets adhering to the printing surface of the printing paper 9. As a result, the non-contact region A2 of the heat roller 31 can be effectively utilized to increase the energy efficiency of the drying process in the drying unit 30.

<2. Second Embodiment>
Subsequently, the second embodiment of the present invention will be described focusing on the differences from the first embodiment. FIG. 7 is a view of the vicinity of the drying portion 30 of the printing apparatus 1 according to the second embodiment as viewed from one side in the width direction.

The drying portion 30 of the printing apparatus 1 of FIG. 7 has a pair of third guide plates 51 in place of the second guide plate 34. The pair of third guide plates 51 are arranged so as to face each other on the printing surface and the back surface of the printing paper 9 at positions downstream of the heat roller 31 in the transport path of the printing paper 9. Further, side plates (not shown) connecting a pair of third guide plates 51 are arranged on both sides of the printing paper 9 in the width direction. The space surrounded by the pair of the third guide plates 51 and the pair of side plates is a layered space 510 through which the printing paper 9 can pass.

As shown in FIG. 7, the upstream end of the third guide plate 51 is connected to the downstream end of the relay duct 35. Further, the downstream end of the third guide plate 51 is connected to the upstream end of the exhaust duct 36.

When the printing process is executed, the first fan 37, the second fan 38, and the third fan 39 are rotated by the current supplied from the control unit 40. Then, the gas (for example, air) in the exterior housing 100 is introduced into the first arc-shaped space 330 via the first fan 37. Then, an air flow from the first arc-shaped space 330 to the outside of the exterior housing 100 is formed through the first suction portion 351, the relay duct 35, the layered space 510, the second suction portion 361, and the exhaust duct 36. ..

The warm air generated in the first arc-shaped space 330 is sent from the first arc-shaped space 330 to the layered space 510 through the inside of the first suction portion 351 and the relay duct 35. Then, the warm air is supplied to the printing surface and the back surface of the printing paper 9 passing through the layered space 510. Therefore, even if the ink droplets adhering to the printing paper 9 that have passed through the heat roller 31 are not sufficiently dried, the ink droplets are further dried by warm air in the layered space 510. Therefore, the ink droplets adhering to the printing paper 9 can be dried more reliably.

<3. Third Embodiment>
Subsequently, the third embodiment of the present invention will be described focusing on the differences from the first embodiment. FIG. 8 is a view of the vicinity of the drying portion 30 of the printing apparatus 1 according to the third embodiment as viewed from one side in the width direction.

The drying unit 30 of the printing apparatus 1 of FIG. 8 has an introduction duct 52 in addition to the configuration of the first embodiment. The upstream end of the introduction duct 52 is open toward the vicinity of the halogen lamp 32 inside the heat roller 31. The downstream end of the introduction duct 52 is connected to the upstream end of the first guide plate 33 via the first fan 37.

In this embodiment, when the first fan 37 is rotated, the gas heated by the halogen lamp 32 is introduced into the first arc-shaped space 330 through the introduction duct 52. That is, the gas preheated to a temperature lower than the temperature of the outer peripheral surface of the heat roller 31 and higher than the environmental temperature is introduced into the first arc-shaped space 330. In this way, warm air can be generated more efficiently than when an unheated gas is introduced into the first arcuate space 330. Further, the residual heat of the halogen lamp 32 can be effectively utilized. Further, by introducing a gas having a temperature higher than the environmental temperature into the first arc-shaped space 330, it is possible to suppress a temperature drop of the heat roller 31.

<4. Modification example>
Although the first to third embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments.

In the above embodiment, a halogen lamp is used as a heat source for the heat roller. However, instead of the halogen lamp, another heating element may be used as the heat source.

Further, in the above embodiment, the number of heat rollers included in the printing apparatus is one. However, the number of heat rollers included in the printing apparatus may be two or more. When two or more heat rollers are continuously arranged on the transfer path of the printing paper, it becomes more difficult to widen the contact area in each heat roller. Therefore, as in the above embodiment, it is more important to effectively utilize the non-contact region to improve the energy efficiency of the drying process.

Further, the printing apparatus of the above embodiment prints an image on printing paper as a printing medium. However, the printing medium in the present invention may be a sheet-shaped printing medium (for example, a resin film or the like) other than general paper.

In addition, each element appearing in the above-described embodiment or modification may be appropriately combined as long as there is no contradiction.

1 Printing equipment 9 Printing paper 10 Conveying mechanism 11 Unwinding roller 12 Conveying roller 13 Rewinding roller 20 Head unit 21 Housing 22 Head 30 Drying part 31 Heat roller 32 Halogen lamp 33 1st guide plate 34 2nd guide plate 35 Relay duct 36 Exhaust duct 37 1st fan 38 2nd fan 39 3rd fan 40 Control unit 51 3rd guide plate 52 Introduction duct 100 Exterior housing 330 1st arc-shaped space 331 Main plate 332 Side plate 340 2nd arc-shaped space 351 1st Suction part 352 Suction port 353 Opening 361 Second suction part 510 Layered space A1 Contact area A2 Non-contact area

Claims (11)

A printing device that prints images on a long strip-shaped printing medium by an inkjet method.
A transport mechanism that transports the print medium in the longitudinal direction,
A head that ejects ink toward the surface of the print medium conveyed by the transfer mechanism, and
A drying portion for drying the ink adhering to the printing medium on the downstream side of the transport path from the head,
With
The dry part
A heat roller that rotates around a rotation axis that extends parallel to the width direction of the print medium,
A heat source provided inside the heat roller and
An arcuate first guide plate arranged to face the outer peripheral surface of the heat roller, and
An airflow generating portion that generates an airflow in the first arcuate space between the heat roller and the first guide plate,
Have,
The print medium comes into contact with the outer peripheral surface of the heat roller in a contact area that is a part of the periphery of the heat roller.
The first guide plate is a printing apparatus that spreads along an outer peripheral surface of the heat roller in a non-contact region that is another portion around the heat roller. The printing apparatus according to claim 1.
The dry part
A printing apparatus further comprising a relay duct for sending a gas that has passed through the first arc-shaped space to a printing medium. The printing apparatus according to claim 2.
The relay duct is a printing device that sends a gas that has passed through the first arc-shaped space to the contact area. The printing apparatus according to claim 3.
The dry part
Further having an arc-shaped second guide plate arranged to face the outer peripheral surface of the heat roller in the contact region of the heat roller.
The relay duct is a printing device that sends gas to a second arc-shaped space between a printing medium supported by the heat roller and the second guide plate. The printing apparatus according to claim 2.
The relay duct is a printing device that sends a gas that has passed through the first arc-shaped space to a printing medium on the downstream side of a transport path from the heat roller. The printing apparatus according to any one of claims 2 to 5.
The dry part
Further having a suction portion for sucking gas from the first arc-shaped space,
The suction portion has a plurality of suction ports arranged in the width direction, and has a plurality of suction ports.
The upstream ends of the relay duct are connected to both ends in the width direction of the suction portion.
A printing device in which the sizes of the plurality of suction ports gradually decrease from the central portion in the width direction to both ends in the width direction. The printing apparatus according to any one of claims 1 to 6.
The first guide plate is
A main plate that covers the outside of the first arc-shaped space and
A pair of side plates covering both ends of the first arc-shaped space in the width direction,
Has a printing device. The printing apparatus according to any one of claims 1 to 7.
A printing apparatus in which the direction of rotation of the heat roller and the direction of airflow in the first arc-shaped space are opposite to each other. The printing apparatus according to any one of claims 1 to 8.
A printing apparatus in which the temperature of the gas introduced into the first arc-shaped space is lower than the temperature of the outer peripheral surface of the heat roller and higher than the environmental temperature. The printing apparatus according to claim 9.
The dry part
A printing apparatus further comprising an introduction duct for introducing a gas heated by the heat source into the first arc-shaped space. In a printing device that prints an image on a long strip-shaped printing medium by an inkjet method, it is a drying method that dries the ink adhering to the printing medium while transporting the printing medium in the longitudinal direction.
a) A process of bringing the print medium into contact with the outer peripheral surface of the heat roller while rotating the heat roller having a built-in heat source.
b) The process of supplying the heated gas to the print medium and
Have,
In step a),
In the contact area which is a part around the heat roller, the print medium is brought into contact with the outer peripheral surface of the heat roller.
In step b),
A drying method in which a gas heated by the heat roller is supplied to a printing medium in a non-contact region which is another part around the heat roller.

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