Printing apparatus

Abstract

To provide a printing device that can enhance a quality of a printed medium, while drying the printed medium.SOLUTION: A drying part has a first contact heating part provided inside an enclosure, and a second contact heating part provided at a downstream side in a conveying direction of the first contact heating part, inside the enclosure. The first contact heating part has a first contact heating surface configured to contact a back side of a printed medium. The second contact heating part has a second contact heating surface configured to contact the back side of the printed medium. The first contact heating surface is curved into a shape protruding in the opposite direction of the direction of the second contact heating surface, and the second contact heating surface is curved into a shape protruding in the opposite direction of the direction of the first contact heating surface. The first contact heating surface is larger in curvature radius than the second contact heating surface.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a printing apparatus that performs printing on a medium by discharging a liquid onto the medium and dries the printed medium.

Background Art

[0002] For example, Patent Document 1 discloses a printing apparatus that performs printing on a medium by discharging a liquid onto the medium conveyed in a conveyance direction. The printing apparatus includes a drying unit that dries the printed medium. As such a drying unit, there is one that includes a housing and a contact heating unit provided inside the housing. The contact heating unit dries the printed medium by contacting the printed medium.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in such a printing apparatus, there is a risk that the quality of the printed medium may deteriorate as the printed medium is dried by contact with the contact heating unit.

Means for Solving the Problems

[0005] A printing apparatus for solving the above problems comprises a transport unit configured to transport a medium in the transport direction, a printing unit configured to print on the medium by discharging a liquid onto the medium transported by the transport unit, and a drying unit configured to dry the printed medium after it has been printed by the printing unit, wherein the drying unit comprises a housing, a first contact heating unit provided inside the housing, and a second contact heating unit provided inside the housing downstream of the first contact heating unit in the transport direction, the first contact heating unit having a first contact heating surface configured to face and contact the back surface of the printed medium opposite to the printed surface of the printed medium, and the second contact heating unit facing the back surface of the printed medium The transport unit has a second contact heating surface that faces the surface and is configured to contact the back surface of the printed medium, and the transport unit has a folding section provided downstream of the first contact heating unit in the transport direction and upstream of the second contact heating unit in the transport direction, the folding section is configured to fold the printed medium that has come into contact with the first contact heating surface back onto the second contact heating surface, the first contact heating surface and the second contact heating surface are surfaces facing opposite directions from each other, the first contact heating surface is curved to protrude in the opposite direction to the second contact heating surface, the second contact heating surface is curved to protrude in the opposite direction to the first contact heating surface, and the radius of curvature of the first contact heating surface is larger than that of the second contact heating surface. [Brief explanation of the drawing]

[0006] [Figure 1] This is a schematic front view of a printing apparatus. [Figure 2] This is a front view showing the drying and conveying sections. [Figure 3] This is a schematic cross-sectional view of a label sheet. [Modes for carrying out the invention]

[0007] [First Embodiment] An embodiment of the printing apparatus will be described below with reference to the drawings. In the following description, the shorter side of the medium M will be defined as the width direction X, and the direction that intersects (for example, perpendicular to) the width direction X and the vertical direction Z will be defined as the longitudinal direction Y. One side of the width direction X will be defined as the first width direction X1, and the other side of the width direction X will be defined as the second width direction X2. One side of the longitudinal direction Y will be defined as the first longitudinal direction Y1, and the other side of the longitudinal direction Y will be defined as the second longitudinal direction Y2. The upper side of the vertical direction Z will be defined as the upper Z1, and the lower side of the vertical direction Z will be defined as the lower Z2. The direction in which the medium M is transported will be defined as the transport direction D.

[0008] <Configuration of the printing device 10> As shown in Figure 1, the printing device 10 may be, for example, a roll-to-roll printing device. A roll-to-roll printing device prints on a medium M as continuous paper. The printing device 10 may also be a printer that prints on label sheets as the medium M. The printing device 10 may also be a serial inkjet printer.

[0009] The printing apparatus 10 comprises a support section 11, a transport section 12, and a printing section 13. The support section 11 is configured to support the medium M. In particular, the support section 11 supports the medium M transported by the transport section 12 in the printing area PA where printing is performed by the printing section 13.

[0010] The printing apparatus 10 may include a feeding unit 15. The feeding unit 15 feeds the medium M. The feeding unit 15 includes a support shaft 15A and a feeding motor 15B. The support shaft 15A rotatably supports a roll body R on which the medium M is wound in a roll shape. The feeding motor 15B is a power source that rotates the support shaft 15A. In the feeding unit 15, the long medium M is fed out from the roll body R as the support shaft 15A rotates due to the drive of the feeding motor 15B.

[0011] The transport unit 12 is configured to transport the medium M in the transport direction D. The transport unit 12 transports the medium M supplied by the feeding unit 15 in the transport direction D. The transport unit 12 comprises a transport roller pair 20 and a transport motor 21. The transport roller pair 20 is located upstream of the printing unit 13 in the transport direction D. The transport roller pair 20 comprises a transport drive roller 20A and a transport driven roller 20B. The transport drive roller 20A is rotatable by the drive of the transport motor 21. The transport driven roller 20B rotates in conjunction with the rotation of the transport drive roller 20A. The transport motor 21 is the power source for the transport drive roller 20A. The transport unit 12 transports the medium M supplied from the feeding unit 15 in the transport direction D while holding (nipping) it, as the transport drive roller 20A rotates due to the drive of the transport motor 21. Thus, the transport unit 12 is configured to transport the medium M along the transport path 22 in the transport direction D. In other words, the printing apparatus 10 is equipped with a transport path 22 for transporting the medium M.

[0012] The printing apparatus 10 may include a winding unit 16. The winding unit 16 winds the printed medium M into a roll. The winding unit 16 includes a winding shaft 16A and a winding motor 16B. The winding shaft 16A supports the printed medium M. The winding motor 16B is the drive source for the winding shaft 16A. The winding unit 16 winds the medium M by rotating the winding shaft 16A driven by the winding motor 16B. The winding unit 16 may also include a tensioning unit that applies tension to the printed medium M.

[0013] The printing unit 13 is configured to print on a medium M supported by the support unit 11. The printing unit 13 comprises a guide shaft 30, a carriage 31, a liquid discharge head 32, and a carriage motor 33. The guide shaft 30 is provided so as to be aligned with the width direction X. The carriage 31 is supported by the guide shaft 30. The carriage 31 supports the liquid discharge head 32. The carriage 31 is scanned along the axial direction of the guide shaft 30 by the drive of the carriage motor 33. In other words, the carriage 31 is scanned along the width direction X.

[0014] The liquid discharge head 32 is located on the lower Z2 side of the carriage 31 in the vertical Z direction. The liquid discharge head 32 has a plurality of nozzles 34 from which liquid is discharged. The plurality of nozzles 34 open toward the medium M supported by the support unit 11. The liquid discharge head 32 discharges liquid from the plurality of nozzles 34 toward the medium M supported by the support unit 11. In this way, the printing unit 13 is configured to print on the medium M by discharging liquid toward the medium M which is conveyed by the transport unit 12.

[0015] The liquid ejection head 32 is a serial head type that ejects liquid as the carriage 31 moves in the width direction X, but it may also be a line head type. The liquid may be, for example, ink. The liquid may be, for example, one color or multiple colors.

[0016] In this manner, the printing device 10 prints on the entire medium M by alternately performing transport operations and printing operations. The transport operation is the operation of transporting the medium M to the transport unit 12. The printing operation is the operation of spraying liquid from the liquid discharge head 32 onto the medium M supported by the support unit 11 while moving the carriage 31 back and forth.

[0017] The printing apparatus 10 includes a drying unit 14. The drying unit 14 is located downstream of the printing unit 13 in the transport direction D. The drying unit 14 is configured to dry the medium M after printing by the printing unit 13. The drying unit 14 includes a housing 40. The transport path 22 passes through the inside of the housing 40.

[0018] The housing 40 may be equipped with an opening / closing door 40A. The opening / closing door 40A is provided on the first width direction X1 side of the housing 40. The drying unit 14 can dry the medium M being transported along the transport path 22 when the opening / closing door 40A is closed. The drying unit 14 allows the user to place the medium M inside the housing 40 when the opening / closing door 40A is open. The drying unit 14 allows the user to perform maintenance on the inside of the housing 40 when the opening / closing door 40A is open.

[0019] The printing apparatus 10 includes a control unit 17. The control unit 17 may comprehensively control the printing apparatus 10 and control various operations executed by the printing apparatus 10. In particular, the control unit 17 can control the conveyance unit 12, the printing unit 13, the drying unit 14, the feeding unit 15, and the winding unit 16. That is, the control unit 17 is configured to perform control related to printing on the medium M. The control unit 17 may include one or more processors that execute various processes according to a program, one or more dedicated hardware circuits such as application-specific integrated circuits that execute at least a part of the various processes, or a combination thereof. The processor includes a CPU and memories such as a RAM and a ROM, and the memories store program codes or instructions configured to cause the CPU to execute processes. The memory, that is, the computer-readable medium, includes any readable medium accessible by a general-purpose or dedicated computer.

[0020] <Configuration of the drying unit 14> As shown in FIG. 2, in the drying unit 14, the housing 40 includes a first side wall 40B and a second side wall 40C. The first side wall 40B is a wall portion on the first longitudinal direction Y1 side of the housing 40. The second side wall 40C is a wall portion on the second longitudinal direction Y2 of the housing 40. In FIG. 2, illustration of the conveyance path 22 inside the housing 40 is omitted.

[0021] The housing 40 includes a supply port 40D. The supply port 40D is provided on the first side wall 40B. The supply port 40D is an opening for conveying the printed medium M from the outside of the housing 40 to the inside of the housing 40. In other words, the supply port 40D is an opening for conveying the printed medium M from the outside of the first drying unit 41 described later to the inside of the first drying unit 41.

[0022] The housing 40 includes a discharge port 40E. The discharge port 40E is provided on the first side wall 40B. The discharge port 40E is an opening for conveying the printed medium M from the inside of the housing 40 to the outside of the housing 40. In other words, the discharge port 40E is an opening for conveying the printed medium M from the inside of the second drying unit 42 described later to the outside of the second drying unit 42.

[0023] The housing 40 includes a first communication port 40F. The first communication port 40F is provided on the second side wall 40C. The first communication port 40F is an opening for conveying the printed medium M from the inside of the first drying unit 41 described later to the outside of the first drying unit 41.

[0024] The housing 40 includes a second communication port 40G. The second communication port 40G is provided on the second side wall 40C. The second communication port 40G is an opening for conveying the printed medium M from the outside of the second drying unit 42 described later to the inside of the second drying unit 42.

[0025] The drying unit 14 may include a first drying unit 41. The first drying unit 41 is provided inside the housing 40. The first drying unit 41 dries the printed medium M conveyed from the supply port 40D.

[0026] The drying unit 14 may include a second drying unit 42. The second drying unit 42 is provided inside the housing 40. The second drying unit 42 dries the printed medium M conveyed from the second communication port 40G.

[0027] The first drying unit 41 is located upstream of the second drying unit 42 in the conveying direction D. In the first drying unit 41, the direction toward the second longitudinal direction Y2 is the conveying direction D. In the second drying unit 42, the direction toward the first longitudinal direction Y1 is the conveying direction D.

[0028] The first drying unit 41 includes a first contact heating unit 43. That is, the drying unit 14 includes the first contact heating unit 43. The first contact heating unit 43 is provided inside the housing 40. The first contact heating unit 43 is provided at a position facing the back surface of the printed medium M. The back surface of the printed medium M is the surface on the opposite side of the printing surface of the printed medium M. The first contact heating unit 43 dries the printed medium M by contacting the back surface of the printed medium M.

[0029] The first contact heating section 43 includes a first contact heating surface 51. The first contact heating surface 51 is the surface in the first contact heating section 43 that faces the back surface of the printed medium M. The first contact heating surface 51 is configured to contact the back surface of the printed medium M. The first contact heating surface 51 is positioned to face in the opposite direction to the second contact heating surface 55, which will be described later. The first contact heating surface 51 may be a surface with a larger area than the support surface on which the medium M is supported in the support section 11.

[0030] The first contact heating surface 51 is curved so as to protrude downward Z2 in the vertical direction Z. In other words, the first contact heating surface 51 is curved so as to protrude toward the first non-contact heating section 44, which will be described later. To put it another way, the first contact heating surface 51 is curved so as to protrude toward the opposite direction from the second contact heating surface 55, which will be described later.

[0031] The first contact heating surface 51 may be a surface formed from a metal plate, for example, an aluminum plate. In particular, the first contact heating surface 51 may be configured to curve along a support member (not shown). Furthermore, the first contact heating surface 51 may employ a radius of curvature that increases the degree of adhesion with the printed medium M while suppressing an increase in the size of the drying section 14 in the vertical direction Z.

[0032] Furthermore, the first contact heating surface 51 may be plated with electroless nickel on the surface that contacts the back surface of the printed medium M. For example, the thickness of the first contact heating surface 51 may be approximately 3 mm, and the thickness of the electroless nickel plating may be approximately 10 μm. In this way, the first contact heating surface 51 is configured to reduce the frictional force between it and the back surface of the printed medium M when it comes into contact with it.

[0033] The first contact heating unit 43 includes a first heater 52. The first heater 52 may be a rubber heater provided on the back surface of the first contact heating surface 51. The first heater 52 heats the first contact heating surface 51. As a result, the first contact heating unit 43 dries the printed medium M that comes into contact with the first contact heating surface 51.

[0034] The first contact heating section 43 comprises a first engaging section 53 and a second engaging section 54. The first engaging section 53 is provided on the first longitudinal direction Y1 side of the first contact heating section 43. The first engaging section 53 can engage with a first support section 47, which will be described later. The second engaging section 54 is provided on the second longitudinal direction Y2 side of the first contact heating section 43. The second engaging section 54 can engage with a second support section 48, which will be described later. In this way, the first contact heating section 43 is supported by the first support section 47 and the second support section 48, which will be described later.

[0035] The first drying section 41 may include a first non-contact heating section 44. In other words, the drying section 14 may include a first non-contact heating section 44. The first non-contact heating section 44 is provided inside the housing 40. The first non-contact heating section 44 is positioned to face the first contact heating section 43. In particular, the first non-contact heating section 44 is positioned to face the first contact heating surface 51. The first non-contact heating section 44 is positioned so as to sandwich the first contact heating section 43 from the transport path 22.

[0036] The first non-contact heating unit 44 is configured to blow air onto the printed surface of the printed medium M without contacting it. Specifically, the first non-contact heating unit 44 may include a heater (not shown), a blower (not shown), and a plurality of air outlets (not shown). The plurality of air outlets (not shown) are provided at positions facing the transport path 22. The first non-contact heating unit 44 heats the air inside with the heater. The first non-contact heating unit 44 blows the heated air from a plurality of air nozzles by driving the blower. In this way, the first non-contact heating unit 44 dries the printed medium M by blowing air onto the printed surface of the printed medium M without contacting it.

[0037] In the first drying section 41, the first contact heating section 43 and the first non-contact heating section 44 are arranged to be separated by a predetermined distance. In the first drying section 41, the first contact heating section 43 and the first non-contact heating section 44 are arranged to straddle the transport path 22. The predetermined distance is the minimum distance necessary to improve the drying efficiency of the medium M and to miniaturize the drying section 14. The predetermined distance may be, for example, about 15 mm.

[0038] The second drying section 42 includes a second contact heating section 45. In other words, the drying section 14 may also include a second contact heating section 45. The second contact heating section 45 is provided inside the housing 40. The second contact heating section 45 is positioned opposite the back surface of the printed medium M. The second contact heating section 45 dries the printed medium M by contacting the back surface of the printed medium M.

[0039] The second contact heating section 45 includes a second contact heating surface 55. The second contact heating surface 55 is the surface in the second contact heating section 45 that faces the back surface of the printed medium M. The second contact heating surface 55 is configured to contact the back surface of the printed medium M. The second contact heating surface 55 is positioned to face in the opposite direction to the first contact heating surface 51. The second contact heating surface 55 may be a surface with a larger area than the support surface on which the medium M is supported in the support section 11.

[0040] The second contact heating surface 55 is curved so as to protrude upward Z1 in the vertical direction Z. In other words, the second contact heating surface 55 is curved so as to protrude toward the second non-contact heating section 46, which will be described later. To put it another way, the second contact heating surface 55 is curved so as to protrude toward the opposite direction from the first contact heating surface 51.

[0041] The second contact heating surface 55 may be a surface formed from a metal plate, similar to the first contact heating surface 51, and may be a surface formed from, for example, an aluminum plate. In particular, the second contact heating surface 55 may be configured to curve along a support member (not shown). Furthermore, the second contact heating surface 55 may employ a radius of curvature that increases the degree of adhesion with the printed medium M while suppressing an increase in the vertical Z direction of the drying section 14.

[0042] Furthermore, the second contact heating surface 55 may be plated with electroless nickel on the surface that contacts the back surface of the printed medium M. For example, the thickness of the second contact heating surface 55 may be approximately 3 mm, and the thickness of the electroless nickel plating may be approximately 10 μm. In this way, the second contact heating surface 55 is configured to reduce the frictional force between it and the back surface of the printed medium M when it comes into contact with the back surface of the printed medium M.

[0043] The second contact heating section 45 includes a second heater 56. The second heater 56 may be a rubber heater provided on the back surface of the second contact heating surface 55. The second heater 56 heats the second contact heating surface 55. As a result, the second contact heating section 45 dries the printed medium M that comes into contact with the second contact heating surface 55.

[0044] The second contact heating section 45 includes a third engaging section 57 and a fourth engaging section 58. The third engaging section 57 is provided on the first longitudinal direction Y1 side of the second contact heating section 45. The third engaging section 57 can engage with the first support section 47, which will be described later. The fourth engaging section 58 is provided on the second longitudinal direction Y2 side of the second contact heating section 45. The fourth engaging section 58 can engage with the second support section 48, which will be described later. In this way, the second contact heating section 45 is supported by the first support section 47 and the second support section 48, which will be described later.

[0045] The second drying section 42 includes a second non-contact heating section 46. In other words, the drying section 14 may include a second non-contact heating section 46. The second non-contact heating section 46 is provided inside the housing 40. The second non-contact heating section 46 is positioned to face the second contact heating section 45. In particular, the second non-contact heating section 46 is positioned to face the second contact heating surface 55. The second non-contact heating section 46 is positioned so as to sandwich the second contact heating section 45 from the transport path 22.

[0046] The second non-contact heating unit 46 is configured to blow air onto the printed surface of the printed medium M without contacting it, similar to the first non-contact heating unit 44. Specifically, the second non-contact heating unit 46 may include a heater (not shown), a blower (not shown), and a plurality of air outlets (not shown). The plurality of air outlets (not shown) are provided at positions facing the transport path 22. The second non-contact heating unit 46 heats the air inside with the heater. The second non-contact heating unit 46 blows the heated air from a plurality of air nozzles by driving the blower. In this way, the second non-contact heating unit 46 dries the printed medium M by blowing air onto the printed surface of the printed medium M without contacting it.

[0047] In the second drying section 42, the second contact heating section 45 and the second non-contact heating section 46 are arranged to be separated by a predetermined distance. In the second drying section 42, the second contact heating section 45 and the second non-contact heating section 46 are arranged to straddle the transport path 22. The predetermined distance is the minimum distance necessary to improve the drying efficiency of the medium M and to miniaturize the drying section 14. The predetermined distance may be, for example, about 15 mm.

[0048] Thus, the drying section 14 is arranged in the following order from above Z1 in the vertical direction Z: second non-contact heating section 46, second contact heating section 45, first contact heating section 43, and first non-contact heating section 44. In other words, the second non-contact heating section 46, second contact heating section 45, first contact heating section 43, and first non-contact heating section 44 are located in overlapping positions in the vertical direction Z. To put it another way, the first contact heating section 43 is located below Z2 in the vertical direction Z compared to the second contact heating section 45.

[0049] Furthermore, the first contact heating section 43 is located upstream of the second contact heating section 45 and the second non-contact heating section 46 in the transport direction D. The first non-contact heating section 44 is located upstream of the second contact heating section 45 and the second non-contact heating section 46 in the transport direction D. In other words, the second contact heating section 45 is located downstream of the first contact heating section 43 in the transport direction D.

[0050] The drying section 14 includes a first support section 47. The first support section 47 is provided inside the housing 40. The first support section 47 is positioned on the first longitudinal direction Y1 side of the first contact heating section 43 and the second contact heating section 45. The first support section 47 may be attached to the first side wall 40B. The first support section 47 is configured to support the first contact heating section 43 and the second contact heating section 45 from the first longitudinal direction Y1 side.

[0051] The drying section 14 includes a second support section 48. The second support section 48 is provided inside the housing 40. The second support section 48 is positioned on the second longitudinal direction Y2 side of the first contact heating section 43 and the second contact heating section 45. The second support section 48 may be attached to the second side wall 40C. The second support section 48 is configured to support the first contact heating section 43 and the second contact heating section 45 from the second longitudinal direction Y2 side.

[0052] Thus, the first support portion 47 is provided at one of the positions that sandwich the first contact heating portion 43 and the second contact heating portion 45 in the transport direction D. The second support portion 48 is provided at the other of the positions that sandwich the first contact heating portion 43 and the second contact heating portion 45 in the transport direction D. In other words, the first support portion 47 and the second support portion 48 are a pair of support portions provided at positions that sandwich the first contact heating portion 43 and the second contact heating portion 45 in the transport direction D.

[0053] <Configuration of the transport unit 12> The transport unit 12 includes a first roller 23 and a second roller 24. The first roller 23 is a roller for transporting the printed medium M from outside the first drying unit 41 to inside the first drying unit 41. The second roller 24 is a roller for transporting the printed medium M from inside the second drying unit 42 to outside the second drying unit 42.

[0054] The first roller 23 and the second roller 24 may be driven rollers that rotate together with the friction of the printed medium M. The first roller 23 and the second roller 24 may also be driven rollers that rotate by the drive of a drive source, or they may be a roller pair consisting of a driven roller and a driven roller.

[0055] The transport unit 12 includes a folding unit 25. The folding unit 25 is located downstream of the first contact heating unit 43 in the transport direction D, and upstream of the second contact heating unit 45 in the transport direction D. The folding unit 25 is configured to transport the printed medium M, which has been transported to the outside of the first drying unit 41, into the inside of the second drying unit 42. In other words, the folding unit 25 is configured to fold the printed medium M, which has come into contact with the first contact heating surface 51, back toward the second contact heating surface 55. To put it another way, the folding unit 25 transports the printed medium M, which has been transported toward the second longitudinal direction Y2, by folding it toward the first longitudinal direction Y1.

[0056] The folding section 25 may include a first folding roller 26 and a second folding roller 27. The first folding roller 26 is a roller for transporting the printed medium M, which has been transported to the outside of the first drying section 41, to the second folding roller 27. The second folding roller 27 is a roller for transporting the printed medium M, which has been transported by the first folding roller 26, into the inside of the second drying section 42.

[0057] The first folding roller 26 and the second folding roller 27 may be driven rollers that rotate together with the friction of the printed medium M. The first folding roller 26 and the second folding roller 27 may also be driven rollers that rotate by the drive of a drive source, or they may be a roller pair consisting of a driven roller and a driven roller.

[0058] The first roller 23 is positioned to transport the printed medium M above Z1 in the vertical Z direction from the supply port 40D. The first folding roller 26 is positioned to transport the printed medium M above Z1 in the vertical Z direction from the first communication port 40F. In other words, the first roller 23 and the first folding roller 26 are positioned so that the back surface of the printed medium M in the first drying section 41 is in contact with the first contact heating surface 51. As a result, in the first drying section 41, the printed medium M is pressed against the first contact heating surface 51 on its back surface and tension is applied in the transport direction D. In this way, the first roller 23 and the first folding roller 26 are positioned so that the printed medium M in the first drying section 41 is in contact with the first contact heating section 43, but not with the first non-contact heating section 44.

[0059] The second roller 24 is positioned so that the lowest end of the roller is below Z2 in the vertical direction Z from the discharge port 40E when transporting the printed medium M. The second folding roller 27 is positioned so that the printed medium M is below Z2 in the vertical direction Z from the second communication port 40G when transporting the printed medium M. In other words, the second roller 24 and the second folding roller 27 are positioned so that the printed medium M in the second drying section 42 is in contact with the second contact heating surface 55. As a result, in the second drying section 42, the back surface of the printed medium M is pressed against the second contact heating surface 55 and tension is applied in the transport direction D. In this way, the second roller 24 and the second folding roller 27 are positioned so that the printed medium M in the second drying section 42 is in contact with the second contact heating section 45, but not with the second non-contact heating section 46.

[0060] In this embodiment, the folded portion 25 and the second side wall 40C are provided inside the housing 40, but this is not limited to this. For example, the second side wall 40C may be the outermost part of the housing 40, and the folded portion 25 may be provided outside the housing 40. The first roller 23 and the second roller 24 are provided outside the housing 40, but this is not limited to this. For example, the first side wall 40B may not be the outermost part of the housing 40, and at least one of the first roller 23 and the second roller 24 may be provided inside the housing 40. The housing 40 may also include an intake port (not shown) for taking in outside air and an exhaust port (not shown) for discharging internal air to the outside.

[0061] <Radius of curvature of each contact heating surface> In this configuration, the first contact heating surface 51 has a larger radius of curvature and a gentler arc shape than the second contact heating surface 55. In other words, the first contact heating surface 51 has less curvature than the second contact heating surface 55. To give a specific example, the first contact heating surface 51 may have a radius of curvature of 3700 mm, and the second contact heating surface 55 may have a radius of curvature of 3000 mm, but is not limited to these.

[0062] The second contact heating unit 45 is located downstream of the first contact heating unit 43 in the transport direction D. Therefore, the second contact heating unit 45 dries the printed medium M that has been dried by the first contact heating unit 43. In other words, the second contact heating unit 45 dries the medium M with a lower water content than the first contact heating unit 43. Therefore, the second contact heating unit 45 dries the medium M with a higher temperature than the first contact heating unit 43.

[0063] Thus, when paper is used as an example of the medium M, it was found that the medium M tends to shrink more easily along the transport direction D on the second contact heating surface 55 than on the first contact heating surface 51. Therefore, by making the radius of curvature of the second contact heating surface 55 smaller than that of the first contact heating surface 51, the tension of the medium M in the transport direction D can be increased. Consequently, the shrinkage of the medium M along the transport direction D can be suppressed.

[0064] In particular, as shown in Figure 3, when a label sheet LS is used as an example of the medium M, a significant effect is achieved by making the radius of curvature of the second contact heating surface 55 smaller than the radius of curvature of the first contact heating surface 51.

[0065] The label sheet LS comprises a liner layer 91, an adhesive layer 92, and a face layer 93. The label sheet LS is formed by laminating the liner layer 91, the adhesive layer 92, and the face layer 93.

[0066] The liner layer 91 is, for example, the backing paper of the label sheet LS. The liner layer 91 becomes the back surface BS of the printed medium M. The liner layer 91 may be made of paper, for example. The face layer 93 is, for example, the layer on which printing is performed by the printing unit 13. The face layer 93 becomes the printed surface PS of the printed medium M. The face layer 93 may be made of film, for example.

[0067] The adhesive layer 92 is provided between the liner layer 91 and the face layer 93. The adhesive layer 92 may be a layer made of, for example, an adhesive. The adhesive layer 92 is a layer for attaching the face layer 93 to the liner layer 91.

[0068] In the first region R1, the label sheet LS is heated by the drying section 14. In the second region R2, which is other than the first region R1, the label sheet LS is not heated by the drying section 14. Therefore, the adhesive layer 92 is not fluid in the second region R2, but becomes fluid in the first region R1 due to heating by the drying section 14. The face layer 93 is made of film, for example, and in the first region R1, a force is applied to it to expand along the transport direction D due to heating by the drying section 14. On the other hand, the liner layer 91 is made of paper, and in the first region R1, a force is applied to it to contract along the transport direction D due to heating by the drying section 14.

[0069] Thus, in the first region R1, heating of the drying section 14 causes the adhesive layer 92 of the label sheet LS to become fluid, and a force is applied to cause the face layer 93 to expand along the transport direction D, while a force is applied to cause the liner layer 91 to contract. As a result, in the first region R1, a portion of the face layer 93 of the label sheet LS tends to lift away from the liner layer 91, causing wrinkles to form on the label sheet LS. In particular, it was found that the label sheet LS tended to wrinkle more on the second contact heating surface 55 than on the first contact heating surface 51.

[0070] Therefore, by making the radius of curvature of the second contact heating surface 55 smaller than that of the first contact heating surface 51, the tension of the label sheet LS in the transport direction D can be increased. Consequently, shrinkage of the label sheet LS along the transport direction D can be suppressed.

[0071] <Operation of the First Embodiment> The operation of the first embodiment will now be described. In the printing device 10, when a print command is input, the transport unit 12 transports the medium M along the transport path 22. The medium M transported along the transport path 22 is supported by the support unit 11 in the printing area PA. Printing is performed on the medium M supported by the support unit 11 by the printing unit 13. After printing, the medium M is transported to the drying unit 14. The printed medium M transported to the drying unit 14 is dried by the drying unit 14.

[0072] More specifically, in the first drying section 41, the printed medium M is transported such that its back surface contacts the first contact heating surface 51, and its printed surface does not contact the first non-contact heating section 44. In particular, the printed medium M is positioned so that its back surface is pressed against the curved first contact heating surface 51. As a result, the printed medium M is dried by the first contact heating section 43 and the first non-contact heating section 44. The printed medium M dried in the first drying section 41 is then transported from the first drying section 41 to the second drying section 42 by the folding section 25.

[0073] In the second drying section 42, the printed medium M is transported such that its back surface contacts the second contact heating surface 55, and its printed surface does not contact the second non-contact heating section 46. Specifically, the printed medium M is positioned so that its back surface is pressed against the curved second contact heating surface 55. As a result, the printed medium M is dried by the second contact heating section 45 and the second non-contact heating section 46.

[0074] In particular, the second contact heating surface 55 is configured to have a smaller radius of curvature than the first contact heating surface 51. The second contact heating surface 55 is located downstream of the first contact heating surface 51 in the transport direction D. Therefore, a medium M with a lower water content is placed on the second contact heating surface 55 than on the first contact heating surface 51. In other words, a medium M with a higher temperature is placed on the second contact heating surface 55 than on the first contact heating surface 51. By configuring the second contact heating surface 55 to have a smaller radius of curvature than the first contact heating surface 51, the force applied to the second contact heating surface 55 in the direction perpendicular to the curved surface can be greater than that applied to the first contact heating surface 51. This makes it possible to suppress the contraction of the medium M with respect to the transport direction D.

[0075] <Effects of the First Embodiment> The effects of the first embodiment will be described. (1) The drying unit 14 includes a housing 40, a first contact heating unit 43 provided inside the housing 40, and a second contact heating unit 45 provided inside the housing 40 downstream of the first contact heating unit 43 in the transport direction D. The first contact heating unit 43 has a first contact heating surface 51 configured to contact the back surface of the printed medium M. The second contact heating unit 45 has a second contact heating surface 55 configured to contact the back surface of the printed medium M. The first contact heating surface 51 is curved to protrude in the opposite direction to the second contact heating surface 55, and the second contact heating surface 55 is curved to protrude in the opposite direction to the first contact heating surface 51. Therefore, the printed medium M can be brought into contact with the first contact heating surface 51 and the second contact heating surface 55 while pressed against them. As a result, by using both the first contact heating section 43 and the second contact heating section 45, and by increasing the degree of adhesion between the first contact heating surface 51 and the second contact heating surface 55 and the printed medium M, the drying efficiency of the printed medium M can be improved. Therefore, the quality of the printed medium M can be improved as it dries.

[0076] (2) In particular, the first contact heating surface 51 has a larger radius of curvature than the second contact heating surface 55. Therefore, the second contact heating surface 55, which is located downstream of the first contact heating surface 51, can be pressed against the printed medium M with a greater force than the first contact heating surface 51. As a result, shrinkage of the printed medium M along the transport direction D can be suppressed at the second contact heating surface 55, where the temperature of the printed medium M tends to rise. Consequently, the quality of the printed medium can be improved as the printed medium M dries.

[0077] (3) The folding section 25 is located downstream of the first contact heating section 43 in the transport direction D, and upstream of the second contact heating section 45 in the transport direction D. The folding section 25 is configured to fold the printed medium M that has come into contact with the first contact heating surface 51 back onto the second contact heating surface 55. The first contact heating surface 51 and the second contact heating surface 55 are surfaces facing opposite directions. Therefore, by using the folding section 25, the first contact heating surface 51 and the second contact heating surface 55 can be arranged so that they are not adjacent to each other along the transport direction D. This makes it possible to suppress the enlargement of the drying section 14 in the transport direction D.

[0078] (4) The first contact heating surface 51 and the second contact heating surface 55 are surfaces formed from a metal plate. Therefore, by using the first contact heating surface 51 and the second contact heating surface 55 which are formed from a metal plate with high thermal conductivity, the drying efficiency of the medium M can be improved. Consequently, the quality of the printed medium M can be improved as the printed medium M dries.

[0079] (5) The first contact heating surface 51 and the second contact heating surface 55 are surfaces that have been electroless plated. Therefore, even when the degree of adhesion between the first contact heating surface 51 and the second contact heating surface 55 and the printed medium M is increased, the frictional force between the first contact heating surface 51 and the second contact heating surface 55 and the printed medium M can be reduced. In this way, damage to the printed medium M that comes into contact with the first contact heating surface 51 and the second contact heating surface 55 can be suppressed. In addition, for example, the printed medium M that comes into contact with the first contact heating surface 51 and the second contact heating surface 55 can be smoothly transported without the need for a mechanism to separate the printed medium M from the first contact heating surface 51 and the second contact heating surface 55. Therefore, the quality of the printed medium M can be improved as the printed medium M dries.

[0080] (6) The drying unit 14 has a first non-contact heating unit 44 and a second non-contact heating unit 46 that blow air onto the printed surface of the printed medium M without contacting it. The first non-contact heating unit 44 is positioned opposite the first contact heating surface 51. The second non-contact heating unit 46 is positioned opposite the second contact heating surface 55. Therefore, by using the first contact heating unit 43, the second contact heating unit 45, the first non-contact heating unit 44, and the second non-contact heating unit 46, the drying efficiency of the printed medium M can be improved. Consequently, the quality of the printed medium M can be improved as it dries.

[0081] [Example of changes] This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0082] In the above embodiment, for example, the first contact heating surface 51 and the second contact heating surface 55 may each have an electroless plating different from electroless nickel plating applied to the surface that contacts the back surface of the printed medium M. In other words, the first contact heating surface 51 and the second contact heating surface 55 may each have an electroless plating applied to the surface that contacts the back surface of the printed medium M. This makes it possible to improve the quality of the printed medium M as it dries after printing.

[0083] In the above embodiment, for example, the first contact heating surface 51 and the second contact heating surface 55 may be coated with fluorine on the surfaces that come into contact with the back surface of the printed medium M. This improves the quality of the printed medium M as it dries after printing.

[0084] In the above embodiment, for example, the first contact heating surface 51 and the second contact heating surface 55 may be embossed on their surfaces. This improves the quality of the printed medium M as it dries after printing.

[0085] In the above embodiment, for example, the first contact heating surface 51 and the second contact heating surface 55 may be further subjected to electroless plating on the embossed surface, or further subjected to a fluorine coating treatment on the embossed surface. This makes it possible to improve the quality of the printed medium M as it dries after printing.

[0086] In the above embodiment, for example, the first drying section 41 and the second drying section 42 may be arranged to overlap horizontally. That is, the first drying section 41 and the second drying section 42 may be arranged to overlap in the longitudinal direction Y. In such a case, for example, the vertical direction Z in Figure 2 becomes the longitudinal direction Y, and the longitudinal direction Y in Figure 2 becomes the vertical direction Z. More specifically, for example, the area Z1 above the vertical direction Z in Figure 2 becomes the second longitudinal direction Y2, the area Z2 below the vertical direction Z in Figure 2 becomes the first longitudinal direction Y1, the first longitudinal direction Y1 in Figure 2 becomes the area Z1 above the vertical direction Z, and the second longitudinal direction Y2 in Figure 2 becomes the area Z2 below the vertical direction Z.

[0087] In the above embodiment, for example, at least one of the first non-contact heating section 44 and the second non-contact heating section 46 may be omitted. In other words, the non-contact heating section may be provided at least one of the positions facing the first contact heating surface 51 and the position facing the second contact heating surface 55, or it may not be provided at all. Also, at least one of the first non-contact heating section 44 and the second non-contact heating section 46 corresponds to an example of a non-contact heating section.

[0088] In the above embodiment, for example, the first support portion 47 may be composed of multiple members. For example, the first support portion 47 may be divided into a member that supports the first contact heating portion 43 and a member that supports the second contact heating portion 45. For example, the second support portion 48 may be composed of multiple members. For example, the second support portion 48 may be divided into a member that supports the first contact heating portion 43 and a member that supports the second contact heating portion 45.

[0089] In the above embodiment, for example, the control unit 17 may adjust the control content of the drying unit 14. As a specific example, the control unit 17 may be able to switch whether or not to drive the first contact heating unit 43, the first non-contact heating unit 44, the second contact heating unit 45, and the second non-contact heating unit 46 based on instructions input by the user. For example, the control unit 17 may be able to adjust the drying time for drying the printed medium M based on instructions input by the user. For example, the control unit 17 may be able to set a standard drying temperature based on instructions input by the user. For example, any drying temperature between 50 and 100 degrees may be set.

[0090] In the above embodiment, a serial printer was used as the printing device 10, but it is not limited to this. For example, a lateral printer or a line printer may be used as the printing device 10. A lateral printer is a printer in which the carriage can move in two directions, the main scanning direction and the sub-scanning direction. A line printer is a printer equipped with multiple nozzles arranged at a constant pitch in the width direction X, and capable of simultaneously dispensing liquid over the width of the medium M.

[0091] The medium M is not limited to what is dispensed from a roll R. The medium M may be paper, resin films or sheets, resin-metal composite films, laminate films, textiles, nonwoven fabrics, metal foils, metal films, ceramic sheets, etc. The medium M may also be towels or clothing such as shirts.

[0092] The printing device 10 is not limited to a printer, but may also be a multifunction device that has a scanner mechanism and a copy function in addition to the printing function. As used herein, the expression "at least one of" means one or more of the desired options. For example, as used herein, if there are two options, the expression "at least one of" means either one option or both of the two options. As another example, as used herein, if there are three or more options, the expression "at least one of" means either one option or any combination of two or more options.

[0093] [Note] The technical concepts and their effects that can be understood from the embodiments and modifications described above are described below.

[0094] (A) The printing apparatus comprises a transport unit configured to transport a medium in a transport direction, a printing unit configured to print on the medium by discharging a liquid onto the medium transported by the transport unit, and a drying unit configured to dry the printed medium printed by the printing unit, wherein the drying unit comprises a housing, a first contact heating unit provided inside the housing, and a second contact heating unit provided inside the housing downstream of the first contact heating unit in the transport direction, wherein the first contact heating unit has a first contact heating surface configured to face and contact the back surface of the printed medium, which is opposite to the printed surface of the printed medium, and the second contact heating unit faces the back surface of the printed medium The conveying unit has a second contact heating surface that faces the back surface of the printed medium and is configured to contact the back surface of the printed medium, and the conveying unit has a folding section provided downstream of the first contact heating unit in the conveying direction and upstream of the second contact heating unit in the conveying direction, the folding section is configured to fold the printed medium that has come into contact with the first contact heating surface back onto the second contact heating surface, the first contact heating surface and the second contact heating surface are surfaces facing opposite directions to each other, the first contact heating surface is curved to protrude in the opposite direction to the second contact heating surface, the second contact heating surface is curved to protrude in the opposite direction to the first contact heating surface, and the radius of curvature of the first contact heating surface is larger than that of the second contact heating surface.

[0095] This configuration allows the printed medium to be pressed against the first and second contact heating surfaces. This increases the degree of adhesion between the first and second contact heating surfaces and the printed medium, thereby improving the drying efficiency of the printed medium. Consequently, the quality of the printed medium can be improved as it dries.

[0096] In addition, the second contact heating surface, located downstream of the first contact heating surface, can be pressed against the printed media with greater force than the first contact heating surface. This suppresses shrinkage of the printed media along the transport direction at the second contact heating surface, where the temperature of the printed media tends to rise. Therefore, the quality of the printed media can be improved as it dries.

[0097] Furthermore, by using a folded portion, the first contact heating surface and the second contact heating surface can be arranged so that they are not adjacent to each other along the conveying direction. This makes it possible to suppress the enlargement of the drying section in the conveying direction.

[0098] (B) In a printing apparatus, the first contact heating surface and the second contact heating surface may be surfaces formed from a metal plate. This configuration allows for improved drying efficiency of the medium by using a first and second contact heating surface made of a metal plate with high thermal conductivity. Consequently, the quality of the printed medium can be improved as it dries after printing.

[0099] (C) In the printing apparatus, the first contact heating surface and the second contact heating surface may be surfaces that have been electroless plated. This configuration reduces the frictional force between the first and second contact heating surfaces and the printed medium. Thus, damage to the printed medium in contact with the first and second contact heating surfaces can be suppressed, and the printed medium in contact with the first and second contact heating surfaces can be smoothly transported. Therefore, the quality of the printed medium can be improved as it dries.

[0100] (D) In ​​the printing apparatus, the electroless plating may be electroless nickel plating. This configuration reduces the frictional force between the first and second contact heating surfaces and the printed medium. Thus, damage to the printed medium in contact with the first and second contact heating surfaces can be suppressed, and the printed medium in contact with the first and second contact heating surfaces can be smoothly transported. Therefore, the quality of the printed medium can be improved as it dries.

[0101] (E) In the printing apparatus, the first contact heating surface and the second contact heating surface may be embossed surfaces. This configuration reduces the frictional force between the first and second contact heating surfaces and the printed medium. Thus, damage to the printed medium in contact with the first and second contact heating surfaces can be suppressed, and the printed medium in contact with the first and second contact heating surfaces can be smoothly transported. Therefore, the quality of the printed medium can be improved as it dries.

[0102] (F) In the printing apparatus, the first contact heating surface and the second contact heating surface may be surfaces that have been subjected to electroless plating. This configuration reduces the frictional force between the first and second contact heating surfaces and the printed medium. Thus, damage to the printed medium in contact with the first and second contact heating surfaces can be suppressed, and the printed medium in contact with the first and second contact heating surfaces can be smoothly transported. Therefore, the quality of the printed medium can be improved as it dries.

[0103] (G) In the printing apparatus, the first contact heating surface and the second contact heating surface may be surfaces that have been treated with a fluorine coating. This configuration reduces the frictional force between the first and second contact heating surfaces and the printed medium. Thus, damage to the printed medium in contact with the first and second contact heating surfaces can be suppressed, and the printed medium in contact with the first and second contact heating surfaces can be smoothly transported. Therefore, the quality of the printed medium can be improved as it dries.

[0104] (H) In the printing apparatus, the first contact heating surface and the second contact heating surface may be surfaces formed of aluminum. This configuration reduces the frictional force between the first and second contact heating surfaces and the printed medium. Thus, damage to the printed medium in contact with the first and second contact heating surfaces can be suppressed, and the printed medium in contact with the first and second contact heating surfaces can be smoothly transported. Therefore, the quality of the printed medium can be improved as it dries.

[0105] (I) In a printing apparatus, the drying unit has a non-contact heating unit that blows air onto the printed surface of the printed medium without contacting it, and the non-contact heating unit may be provided at least one of the positions facing the first contact heating surface and the position facing the second contact heating surface.

[0106] This configuration allows for improved drying efficiency of the medium by using a first contact heating section, a second contact heating section, and a non-contact heating section. Therefore, the quality of the printed medium can be improved as it dries after printing.

[0107] (J) In the printing apparatus, the first contact heating unit and the second contact heating unit are located in positions that overlap in the vertical direction, and the first contact heating unit may be located vertically below the second contact heating unit. This configuration produces the same effect as (A). [Explanation of Symbols]

[0108] BS...back side, D...conveying direction, LS...label sheet, M...medium, PA...printing area, PS...printing surface, R...roll body, R1...first area, R2...second area, X...width direction, X1...first width direction, X2...second width direction, Y...longitudinal direction, Y1...first longitudinal direction, Y2...second longitudinal direction, Z...vertical direction, Z1...upward, Z2...downward, 10...printing device, 11...support unit, 12...conveying unit, 13...printing unit, 14...dry Drying section, 15... Feeding section, 15A... Support shaft, 15B... Feeding motor, 16... Winding section, 16A... Winding shaft, 16B... Winding motor, 17... Control unit, 20... Conveying roller pair, 20A... Conveying drive roller, 20B... Conveying driven roller, 21... Conveying motor, 22... Conveying path, 23... First roller, 24... Second roller, 25... Folding section, 26... First folding roller, 27... Second folding roller 30... Guide shaft, 31... Carriage, 32... Liquid discharge head, 33... Carriage motor, 34... Nozzle, 40... Housing, 40A... Opening / closing door, 40B... First side wall, 40C... Second side wall, 40D... Supply port, 40E... Discharge port, 40F... First communication port, 40G... Second communication port, 41... First drying section, 42... Second drying section, 43... First contact heating section, 44... First non-contact heating section, 45... Second contact heating section Part 46...Second non-contact heating part, 47...First support part, 48...Second support part, 51...First contact heating surface, 52...First heater, 53...First engagement part, 54...Second engagement part, 55...Second contact heating surface, 56...Second heater, 57...Third engagement part, 58...Fourth engagement part, 61...First guide part, 62...Second guide part, 63...Third guide part, 64...Fourth guide part, 91...Liner layer, 92...Adhesive layer, 93...Face layer

Claims

1. A transport unit configured to transport a medium in the transport direction, A printing unit configured to print on a medium by discharging a liquid onto the medium being transported by the transport unit, A drying unit configured to dry the printed medium printed by the printing unit, Equipped with, The drying section is The casing and A first contact heating unit is provided inside the housing, The housing has a second contact heating section located downstream of the first contact heating section in the transport direction, The first contact heating portion has a first contact heating surface configured to face the back surface of the printed medium, which is opposite to the printed surface of the printed medium, and to contact the back surface of the printed medium. The second contact heating portion has a second contact heating surface configured to face the back surface of the printed medium and to contact the back surface of the printed medium. The first contact heating surface and the second contact heating surface are surfaces formed from a plate material. The transport section has a folding section located downstream of the first contact heating section in the transport direction and upstream of the second contact heating section in the transport direction. The folded portion is configured to fold the printed medium that has come into contact with the first contact heating surface back onto the second contact heating surface. The first contact heating surface and the second contact heating surface are surfaces facing opposite directions. The first contact heating surface is curved to form a protruding shape in the direction opposite to the second contact heating surface. The second contact heating surface is curved so as to protrude in the direction opposite to the first contact heating surface. The first contact heating surface has a larger radius of curvature than the second contact heating surface. A printing apparatus characterized by the following features.

2. A conveying unit configured to convey a medium in the conveying direction, A printing unit configured to print on a medium by discharging a liquid onto the medium being transported by the transport unit, A drying unit configured to dry the printed medium printed by the printing unit, Equipped with, The drying section is The casing and A first contact heating unit is provided inside the housing, The housing has a second contact heating section located downstream of the first contact heating section in the transport direction, The first contact heating portion has a first contact heating surface configured to face the back surface of the printed medium, which is opposite to the printed surface of the printed medium, and to contact the back surface of the printed medium. The second contact heating portion has a second contact heating surface configured to face the back surface of the printed medium and to contact the back surface of the printed medium. The first contact heating surface and the second contact heating surface are surfaces facing opposite directions. The aforementioned transport unit is A first roller that transports the printed medium from the outside to the inside of the drying section, A second roller that transports the printed medium from the inside to the outside of the drying section, It has a folded portion located downstream of the first contact heating portion in the transport direction and upstream of the second contact heating portion in the transport direction, The aforementioned folded portion is, The printed medium that has come into contact with the first contact heating surface is configured to be folded back onto the second contact heating surface. A first folding roller is provided downstream in the conveying direction of the first contact heating surface, It has a second folding roller provided upstream of the second contact heating surface in the conveying direction and downstream of the first folding roller in the conveying direction, The curved portion formed by the first roller, the first contact heating surface, and the first folding roller is defined as the first curved portion. When the curved portion formed by the second roller, the second contact heating surface, and the second folding roller is defined as the second curved portion, The first curved portion is curved to form a protruding shape in the opposite direction to the second curved portion, The second curved portion is curved to form a protruding shape in the opposite direction to the first curved portion, The first curved portion has a larger radius of curvature than the second curved portion. A printing apparatus characterized by the following features.

3. A conveying unit configured to convey a medium in the conveying direction, A printing unit configured to print on a medium by discharging a liquid onto the medium being transported by the transport unit, A drying unit configured to dry the printed medium printed by the printing unit, Equipped with, The drying section is The casing and A first contact heating unit is provided inside the housing, The housing has a second contact heating section located downstream of the first contact heating section in the transport direction, The first contact heating portion has a first contact heating surface configured to face the back surface of the printed medium, which is opposite to the printed surface of the printed medium, and to contact the back surface of the printed medium. The second contact heating portion has a second contact heating surface configured to face the back surface of the printed medium and to contact the back surface of the printed medium. The first contact heating surface and the second contact heating surface are surfaces facing opposite directions. The aforementioned transport unit is A first roller that transports the printed medium from the outside to the inside of the drying section, A second roller that transports the printed medium from the inside to the outside of the drying section, It has a folded portion located downstream of the first contact heating portion in the transport direction and upstream of the second contact heating portion in the transport direction, The aforementioned folded portion is, The printed medium that has come into contact with the first contact heating surface is configured to be folded back onto the second contact heating surface. A first folding roller is provided downstream in the conveying direction of the first contact heating surface, It has a second folding roller provided upstream of the second contact heating surface in the conveying direction and downstream of the first folding roller in the conveying direction, The curved portion formed by the first roller, the first contact heating surface, and the first folding roller is defined as the first curved portion. When the curved portion formed by the second roller, the second contact heating surface, and the second folding roller is defined as the second curved portion, The first curved portion is curved to form a protruding shape in the opposite direction to the second curved portion, The second curved portion is curved to form a protruding shape in the opposite direction to the first curved portion, The first curved portion has a gentler curve than the second curved portion. A printing apparatus characterized by the following features.

4. In a printing apparatus according to any one of claims 1 to 3, The first contact heating surface and the second contact heating surface are surfaces formed from a metal plate. A printing apparatus characterized by the following features.

5. In the printing apparatus according to claim 4, The first contact heating surface and the second contact heating surface are surfaces that have been electroless plated. A printing apparatus characterized by the following features.

6. In the printing apparatus according to claim 5, The aforementioned electroless plating is electroless Ni plating. A printing apparatus characterized by the following features.

7. In the printing apparatus according to claim 4, The first contact heating surface and the second contact heating surface are surfaces that have been embossed. A printing apparatus characterized by the following features.

8. In the printing apparatus according to claim 7, The first contact heating surface and the second contact heating surface are surfaces that have been subjected to electroless plating. A printing apparatus characterized by the following features.

9. In the printing apparatus according to claim 4, The first contact heating surface and the second contact heating surface are surfaces that have been treated with a fluorine coating. A printing apparatus characterized by the following features.

10. In the printing apparatus according to any one of claims 4 to 9, The first contact heating surface and the second contact heating surface are surfaces formed of aluminum. A printing apparatus characterized by the following features.

11. In the printing apparatus according to any one of Claims 1 to 3, The aforementioned enclosure is A supply port, which is an opening for transporting the printed medium from the outside of the housing to the inside of the housing, It has an outlet which is an opening for transporting the printed medium from the inside of the housing to the outside of the housing, The supply port and the discharge port are provided on the same side wall. A printing apparatus characterized by the following features.

12. In a printing apparatus according to any one of claims 1 to 11, The drying unit has a non-contact heating unit that blows air onto the printed surface of the printed medium without contacting it. The non-contact heating portion is provided at least one of the following positions: a position facing the first contact heating surface and a position facing the second contact heating surface. A printing apparatus characterized by the following features.

13. In the printing apparatus according to claim 12, The printing apparatus has a control unit that individually controls the first contact heating unit, the second contact heating unit, and the non-contact heating unit. A printing apparatus characterized by the following features.

14. A conveying unit configured to convey a medium in the conveying direction, A printing unit configured to print on a medium by discharging a liquid onto the medium being transported by the transport unit, A drying unit configured to dry the printed medium printed by the printing unit, Equipped with, The drying section is The casing and A first contact heating unit is provided inside the housing, The housing has a second contact heating section located downstream of the first contact heating section in the transport direction, The first contact heating portion has a first contact heating surface configured to face the back surface of the printed medium, which is opposite to the printed surface of the printed medium, and to contact the back surface of the printed medium. The second contact heating portion has a second contact heating surface configured to face the back surface of the printed medium and to contact the back surface of the printed medium. The transport section has a folding section located downstream of the first contact heating section in the transport direction and upstream of the second contact heating section in the transport direction. The folded portion is configured to fold the printed medium that has come into contact with the first contact heating surface back onto the second contact heating surface. The first contact heating surface and the second contact heating surface are surfaces facing opposite directions. The first contact heating surface is curved to form a protruding shape in the direction opposite to the second contact heating surface. The second contact heating surface is curved so as to protrude in the direction opposite to the first contact heating surface. The first contact heating surface has a larger radius of curvature than the second contact heating surface. The drying unit has a non-contact heating unit that blows air onto the printed surface of the printed medium without contacting it. The non-contact heating portion is provided at least one of the following positions: a position facing the first contact heating surface and a position facing the second contact heating surface. A printing apparatus characterized by the following features.

15. In a printing apparatus according to any one of claims 1 to 14, The first contact heating section and the second contact heating section are provided in positions that overlap in the vertical direction. The first contact heating section is located vertically below the second contact heating section. A printing apparatus characterized by the following features.

16. A conveying unit configured to convey a medium in the conveying direction, A printing unit configured to print on a medium by discharging a liquid onto the medium being transported by the transport unit, A drying unit configured to dry the printed medium printed by the printing unit, Equipped with, The drying section is The casing and A first contact heating unit is provided inside the housing, The housing has a second contact heating section located downstream of the first contact heating section in the transport direction, The first contact heating portion has a first contact heating surface configured to face the back surface of the printed medium, which is opposite to the printed surface of the printed medium, and to contact the back surface of the printed medium. The second contact heating portion has a second contact heating surface configured to face the back surface of the printed medium and to contact the back surface of the printed medium. The transport section has a folding section located downstream of the first contact heating section in the transport direction and upstream of the second contact heating section in the transport direction. The folded portion is configured to fold the printed medium that has come into contact with the first contact heating surface back onto the second contact heating surface. The first contact heating surface and the second contact heating surface are surfaces facing opposite directions. The first contact heating surface is curved to form a protruding shape in the direction opposite to the second contact heating surface. The second contact heating surface is curved so as to protrude in the direction opposite to the first contact heating surface. The first contact heating surface has a larger radius of curvature than the second contact heating surface. The first contact heating section and the second contact heating section are provided in positions that overlap in the vertical direction. The first contact heating section is located vertically below the second contact heating section. A printing apparatus characterized by the following features.

Images