JP2011098551A - Printing device - Google Patents

Abstract

A printing apparatus capable of shortening the time required to heat ink is provided.
A double-sided printing apparatus includes an inkjet head that ejects ink, a supply pipe in which a flow path for the ink supplied to the inkjet head is formed, and an outer side of the supply pipe. The heat generating member 31 that generates heat due to the eddy current, the coil 35 that generates the lines of magnetic force for causing the eddy current to flow through the heat generating member 31, and the electromagnetic wave shielding member 33 that surrounds the outside of the coil 35 are provided.
[Selection] Figure 3

Description

  The present invention relates to a printing apparatus that heats ink.

  Patent Document 1 includes a print head for printing an image, an ink tank in which ink is stored, a tube and a pump for circulating ink between the ink tank and the print head, and a heater provided in the ink tank. An inkjet printer comprising the same is disclosed.

  In the ink jet printer of Patent Document 1, the ink in the ink tank is heated by a heater in order to give the ink an appropriate viscosity. Then, the heated ink is supplied to the print head via a pump and a tube. In this state, the print head discharges the supplied ink droplets onto the print medium. As a result, the image is printed on the print medium.

JP-A-10-175307

  However, the technique of Patent Document 1 has a problem that it takes time to heat ink.

  SUMMARY An advantage of some aspects of the invention is that it provides a printing apparatus that can shorten the time required to heat ink.

  In order to achieve the above object, an invention according to claim 1 is directed to an ink jet head for discharging ink, a supply pipe in which a flow path for the ink supplied to the ink jet head is formed, and a flow path for the ink. A heat generating member that generates heat due to an eddy current, a coil that generates a line of magnetic force for causing the eddy current to flow through the heat generating member, and an electromagnetic wave shielding member that includes a metal and surrounds the outside of the coil. It is characterized by that.

  According to a second aspect of the present invention, the coil is disposed on the opposite side of the ink flow path with the heat generating member interposed therebetween.

  The invention according to claim 3 further includes a heat conductive member having higher heat conductivity than the heat generating member, and provided between the heat generating member and the ink flow path. To do.

The invention according to claim 4 is characterized in that the heat generating member or the electromagnetic wave shielding member has a thickness equal to or larger than δ represented by the following formula (1).

  According to the first aspect of the present invention, an eddy current is generated in the heat generating member by the magnetic force lines generated from the coil. Thereby, the heat generating member generates heat by induction heating, and the ink flowing through the supply pipe is heated. By using induction heating in this way, the invention of claim 1 can reduce the time required for heating the ink.

  According to the invention of claim 2, by arranging the heat generating member between the coil and the ink flow path, the electromagnetic wave extending from the coil is shielded by the heat generating member. Thus, the invention of claim 2 can suppress the ink from being deteriorated by electromagnetic waves.

  According to the invention of claim 3, by providing the heat conducting member between the heat generating member and the ink flow path, the heat generated by the heat generating member can be efficiently conducted to the ink by the heat conducting member. .

  According to the invention of claim 4, by configuring the heat generating member to have a thickness equal to or larger than δ represented by the formula (1), most of the electromagnetic waves generated by the coil of the heat generating member can be absorbed by the skin effect. As a result, it is possible to further reduce the deterioration of the ink by electromagnetic waves.

1 is an overall configuration diagram of a duplex printing apparatus according to a first embodiment. It is a front view of the heater vicinity. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. It is a cross-sectional view of the heater according to the second embodiment. It is a whole perspective view of the heater by a 3rd embodiment. It is a whole perspective view of the heater by a 4th embodiment. It is a cross-sectional view of the heater along the VII-VII line in FIG. It is a cross-sectional view of the heater according to the fifth embodiment.

(First embodiment)
Hereinafter, a double-sided printing apparatus according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an overall configuration diagram of a duplex printing apparatus according to a first embodiment. FIG. 2 is a front view of the vicinity of the heater. 3 is a cross-sectional view taken along line III-III in FIG. In the following description, the front side in FIG. Further, when viewed from the user, the upper, lower, left, and right directions are the upper, lower, left, and right directions.

  Note that a path indicated by a thick line in FIG. 1 is a transport path through which the printing paper is transported. A route indicated by a solid line among the transport routes is a normal route RC. The route indicated by the alternate long and short dash line in the transport route is the reverse route RR. A path indicated by a two-dot chain line in the transport path is a paper feed path RS. In the following description, upstream or downstream is assumed to be upstream or downstream in the transport direction.

  As shown in FIG. 1, the duplex printing apparatus 1 according to the first embodiment stores a paper feeding unit 2, a conveyance printing unit 3, a conveyance unit 4, a paper discharge unit 5, and a reversing unit 6. A housing 7 and a control unit 8 that performs overall control are provided.

  The paper feeding unit 2 is a unit that feeds the printing paper PA. The paper feed unit 2 is arranged on the most upstream side of the transport path. The paper feed unit 2 includes a paper feed table 11 and a plurality of pairs of paper feed rollers 12. The paper feed table 11 is arranged at the uppermost stream of the paper feed route RS. A printing paper PA for feeding paper is stacked on the paper feed tray 11. The paper feed roller 12 is disposed between the paper feed tray 11 and the transport printing unit 3. The paper feed roller 12 feeds the printing paper PA stacked on the paper feed tray 11 to the transport printing unit 3.

  The conveyance printing unit 3 is a unit that prints an image on the printing paper PA while conveying the printing paper PA. The transport printing unit 3 is disposed on the downstream side of the paper feeding unit 2. The conveyance printing unit 3 includes a registration roller 15, four sets of an ink supply unit 16 and an inkjet head 17, and a belt conveyance unit 18.

  The registration roller 15 is disposed between the paper feeding unit 2 and the belt conveyance unit 18. The registration roller 15 conveys the printing paper PA fed by the paper feeding unit 2 to the belt conveyance unit 18.

  As shown in FIG. 1, the ink supply unit 16 includes an ink tank 21, a supply pipe 22, an electromagnetic valve 23, and a heater 24.

  The ink tank 21 stores supply ink 90. The ink tank 21 is disposed on the upper portion of the housing 7. In each of the four ink tanks 21, inks 90 of different colors (for example, black, cyan, magenta, and yellow) are stored.

  The supply pipe 22 supplies the ink 90 stored in the ink tank 21 to the inkjet head 17. One end of the supply pipe 22 is connected to the ink tank 21. The other end of the supply pipe 22 is connected to the inkjet head 17. Inside the supply pipe 22, a flow path is formed through which the ink 90 supplied to the inkjet head 17 flows.

  The electromagnetic valve 23 switches the supply state and non-supply state of the ink 90. The electromagnetic valve 23 is provided in the middle of the supply pipe 22. The opening and closing of the electromagnetic valve 23 is controlled by the control unit 8 based on the amount of ink 90 inside the inkjet head 17.

  The heater 24 heats the ink 90 so as to have an appropriate temperature. The appropriate temperature of the ink 90 is a temperature at which the ink 90 can maintain an appropriate viscosity. The heater 24 is provided in the middle of the flow path of the ink 90 formed in the supply pipe 22. The heater 24 is preferably disposed in the vicinity of the inkjet head 17 so that the heated ink 90 is not cooled. As shown in FIGS. 2 and 3, the heater 24 includes a heat generating member 31, a heating unit 32, and an electromagnetic wave shielding member 33.

  The heat generating member 31 is inductively heated by eddy current, and shields electromagnetic waves (alternating current electric field) while transferring the heat to the ink 90. The heat generating member 31 is made of a single metal made of a ferromagnetic material such as iron or nickel, or an alloy such as nichrome or stainless steel containing the ferromagnetic material. The heat generating member 31 is preferably made of a material having a large resistance and including a ferromagnetic material. The heat generating member 31 is provided in the middle of the supply pipe 22 in which the flow path of the ink 90 is formed. An insertion hole 31 a through which the supply pipe 22 is inserted is formed at the center of the heat generating member 31. The inner diameter of the insertion hole 31 a is substantially equal to the outer diameter of the supply pipe 22. Thereby, the heat generating member 31 is provided in a substantially tight contact state on the outer periphery of the supply pipe 22.

  The heating unit 32 heats the ink 90 by induction heating (IH: Induction Heating) of the heat generating member 31. The heating unit 32 is provided so as to surround the heat generating member 31. The heating unit 32 includes a plurality of coils 35 and a covering material 36.

  The coil 35 is made of a metal winding. A plurality of coils 35 are arranged at predetermined intervals in the circumferential direction. The coil 35 is disposed on the opposite side of the heat generating member 31 from the flow path of the ink 90 in the supply pipe 22. The coil 35 is connected to a power supply unit (not shown) that supplies an alternating current. When an alternating current is supplied, the coil 35 generates magnetic lines of force for generating an eddy current in the heat generating member 31. Thereby, the heat generating member 31 is induction-heated.

  The covering material 36 insulates the coil 35. The covering material 36 is made of an insulating resin. The covering material 36 is formed so as to cover the outer periphery of the coil 35 and the outer periphery of the heat generating member 31.

  The electromagnetic wave shielding member 33 blocks electromagnetic waves radiated from the heating unit 32 to the outside. The electromagnetic wave shielding member 33 is made of a ferromagnetic material such as iron, nickel, or cobalt that has high electromagnetic wave shielding properties. The electromagnetic wave shielding member 33 may be made of a metal other than a ferromagnetic material. The electromagnetic wave shielding member 33 is formed so as to cover the side surface of the heating unit 32 and the outer periphery of the upper and lower surfaces.

Here, the radial thickness of the heat generating member 31 and the electromagnetic wave shielding member 33 is preferably δ or more represented by the following formula. This is because most electromagnetic waves are absorbed by the heat generating member 31 and the electromagnetic wave shielding member 33 by the skin effect, and the shielding properties of the electromagnetic waves are improved.

  The ink-jet head 17 ejects droplets of the ink 90 from the lower surface (ejection surface) to the printing paper PA. The inkjet head 17 has a piezoelectric member (not shown) for applying pressure to the ink. The inkjet head 17 ejects inks of different colors (for example, black, cyan, magenta, yellow). The inkjet head 17 includes a temperature sensor (not shown) that measures the temperature of the ink 90 and outputs the ink temperature to the control unit 8.

  The belt conveyance unit 18 conveys the printing paper PA while sucking it. The belt conveyance unit 18 is disposed on the opposite side of the inkjet head 17 across the normal route RC of the conveyance route.

  The transport unit 4 transports the printing paper PA printed by the transport printing unit 3 to the paper discharge unit 5 or the reversing unit 6. The transport unit 4 is disposed on the downstream side of the transport printing unit 3. The transport unit 4 includes a plurality of pairs of transport rollers 41 and a switching mechanism 42. The transport roller 41 is disposed along the normal route RC. The switching mechanism 42 switches the transport path of the printing paper PA between the paper discharge unit 5 and the reversing unit 6.

  The paper discharge unit 5 discharges and stacks the printed printing paper PA. The paper discharge unit 5 is disposed on the downstream side of the transport unit 4. The paper discharge unit 5 is disposed on the most downstream side of the normal route RC. The paper discharge unit 5 includes a plurality of pairs of paper discharge rollers 45 and a paper discharge stand 46. The paper discharge roller 45 is disposed between the switching mechanism 42 and the paper discharge stand 46. The paper discharge roller 45 discharges the printing paper PA conveyed from the conveyance unit 4 to the paper discharge tray 46.

  The reversing unit 6 reverses the single-side printed printing paper PA and re-feeds it to the transport printing unit 3. The reversing unit 6 is disposed between the switching mechanism 42 and the registration roller 15. The reversing unit 6 includes a plurality of pairs of reversing rollers 51, a switchback unit 52, and a flipper 53. The reverse roller 51 is arranged on the reverse path RR. The switchback unit 52 includes a space formed on the paper discharge tray 46. The flipper 53 guides the printing paper PA conveyed from the conveyance unit 4 to the switchback unit 52. The flipper 53 guides the printing paper PA conveyed from the switchback unit 52 to the conveyance printing unit 3.

(Printing operation)
Next, the printing operation of the duplex printing apparatus 1 according to the first embodiment described above will be described.

  First, when image data is input to the duplex printing apparatus 1, the control unit 8 executes a printing initial process. The printing initial process includes an ink temperature adjustment process. In the ink temperature adjustment process, the control unit 8 controls the heater 24 based on the ink temperature input from the temperature sensor of the inkjet head 17. Specifically, when the ink temperature is lower than the appropriate temperature of the ink 90, the control unit 8 supplies an alternating current to the coil 35 of the heating unit 32. Thereby, the coil 35 produces the magnetic force line from which direction and intensity | strength change. When the lines of magnetic force reach the heat generating member 31, eddy currents flow on the outer surface of the heat generating member 31. Due to this eddy current, Joule heat is generated in the heat generating member 31, and the heat generating member 31 is induction heated. This heat is transmitted to the ink 90 via the heat generating member 31, and the ink 90 is heated to an appropriate temperature.

  Here, when an alternating current flows through the coil 35, electromagnetic waves are radiated from the coil 35 to the inside. However, since the heater 24 includes the heat generating member 31 having electromagnetic wave shielding properties inside the heating unit 32, most of the electromagnetic waves are shielded by the heat generating member 31. As a result, the electromagnetic wave hardly reaches the ink 90. Further, the electromagnetic wave is radiated from the coil 35 to the outside. However, since the heater 24 includes the electromagnetic wave shielding member 33 outside the heating unit 32, most electromagnetic waves are shielded by the electromagnetic wave shielding member 33. Thereby, the electromagnetic wave hardly reaches the adjacent ink 90.

  Next, when the ink 90 reaches an appropriate temperature, the control unit 8 executes an image printing process. Hereinafter, an image printing operation by the image printing process will be described.

  First, in the image printing operation, unprinted printing paper PA is transported from any one of the paper feed trays 11 to the registration rollers 15 of the transport printing unit 3 along the paper feed path RS by the paper feed rollers 12.

  In the transport printing unit 3, the printing paper PA is transported to the belt transport unit 18 by the registration rollers 15. Thereafter, an image is printed on the printing paper PA by the droplets of the ink 90 ejected by the inkjet head 17 while being conveyed by the belt conveyance unit 18. The printing paper PA on which the image is printed is transported to the transport unit 4 by the belt transport unit 18. Next, in the transport unit 4, the printing paper PA is transported to the switching mechanism 42 by the transport roller 41.

  Here, in the case of single-sided printing, the printing paper PA is conveyed to the paper discharge unit 5 by the switching mechanism 42. In the paper discharge unit 5, the print paper PA is discharged to a paper discharge tray 46 by a paper discharge roller 45. Thereby, the single-sided printing operation is completed.

  On the other hand, in the case of duplex printing, the printing paper PA is guided to the reversing path RR of the reversing unit 6 by the switching mechanism 42. In the reversing unit 6, the printing paper PA is temporarily carried into the switchback unit 52 by the reversing roller 51 while being guided by the flipper 53. Thereafter, the printing paper PA is fed again to the registration roller 15 of the transport printing unit 3 by the reverse roller 51 while being guided by the flipper 53.

  In the transport printing unit 3, the printing paper PA is transported by the registration rollers 15 and the belt transport unit 18. Here, the unprinted surface of the printing paper PA is transported toward the inkjet head 17 side. As a result, the image is printed on the unprinted surface of the printing paper PA by the inkjet head 17. Thereafter, the double-side printed printing paper PA is transported by the transport unit 4. Next, the printing paper PA is guided by the switching mechanism 42, conveyed to the paper discharge unit 5, and then discharged to the paper discharge tray 46. As a result, images are printed on both sides, and the double-sided printing operation ends.

(Effect of 1st Embodiment)
Next, effects of the double-sided printing apparatus 1 according to the first embodiment described above will be described.

  In the heater 24 of the double-sided printing apparatus 1 according to the first embodiment, lines of magnetic force are generated from the coil 35 by passing an alternating current through the coil 35. Thereby, an eddy current flows into the heat generating member 31, and the heat generating member 31 is induction-heated. The heat generated in the heat generating member 31 is conducted through the heat generating member 31 to heat the ink 90. Thus, since the duplex printing apparatus 1 heats the ink 90 by induction heating, the time required for heating the ink 90 can be shortened.

  Further, in the heater 24 of the duplex printing apparatus 1, the heat generating member 31 having electromagnetic shielding properties is provided between the heating unit 32 having the coil 35 and the supply pipe 22 in which the flow path of the ink 90 is formed. Yes. Thereby, the electromagnetic wave radiated inward from the coil 35 is shielded by the heat generating member 31. As a result, the heater 24 can reduce the electromagnetic wave reaching the ink 90, so that the physical properties of the ink 90 can be prevented from deteriorating due to dielectric relaxation or electrophoresis of the coloring material.

  In the heater 24 of the double-sided printing apparatus 1, an electromagnetic wave shielding member 33 having an electromagnetic wave shielding property is provided so as to surround the heating unit 32 having the coil 35. Thereby, the electromagnetic wave radiated outward from the coil 35 is shielded by the electromagnetic wave shielding member 33. Since the heater 24 can reduce electromagnetic waves reaching the ink 90 of the adjacent ink supply unit 16, it can suppress deterioration of physical properties of the ink 90 due to dielectric relaxation or electrophoresis of the coloring material. Moreover, the influence with respect to apparatuses, such as the control part 8, by electromagnetic waves can also be suppressed.

  Furthermore, in the heater 24 of the double-sided printing apparatus 1, the thickness of the heat generating member 31 and the electromagnetic wave shielding member 33 is not less than δ represented by the above formula (1), so that the heater 24 includes the heat generating member 31 and the electromagnetic wave shielding member 33. The shielding effect of electromagnetic waves can be improved by the surface effect.

(Second Embodiment)
Next, a second embodiment in which the heater of the above-described embodiment is changed will be described. FIG. 4 is a cross-sectional view of the heater according to the second embodiment. In addition, the same code | symbol is attached | subjected to the structure similar to embodiment mentioned above, and description is abbreviate | omitted.

  As shown in FIG. 4, in the second embodiment, the heater 24 </ b> A includes a heat conducting member 37 </ b> A, a heat generating member 31 </ b> A, a heating unit 32, and an electromagnetic wave shielding member 33.

  The heat conducting member 37A is provided inside the heat generating member 31A so as to cover the outside of the supply pipe 22. In other words, the heat conducting member 37A is provided between the flow path of the ink 90 formed in the supply pipe 22 and the heat generating member 31A. The heat conducting member 37A is made of aluminum (Al) or copper (Cu) having higher heat conductivity than the heat generating member 31A. An insertion hole 37Aa through which the supply pipe 22 is inserted is formed at the center of the heat conducting member 37A.

  The heat generating member 31A is provided so as to cover the outside of the heat conducting member 37A. The heat generating member 31A has a radial thickness equal to or greater than δ shown in the above-described formula (1). The heat generating member 31A is made of a single metal or an alloy containing a ferromagnetic material.

  In the second embodiment, when an alternating current is supplied to the coil 35, lines of magnetic force are generated from the coil 35. Thereby, an eddy current flows through the heat generating member 31, and the heat generating member 31A is induction-heated. This heat is conducted to the ink 90 through the heat conducting member 37A having high thermal conductivity. As a result, the heater 24A of the second embodiment can heat the ink 90 quickly and efficiently.

  Further, the heat generating member 31A has a thickness equal to or larger than δ represented by the formula (1). Thereby, electromagnetic waves are not transmitted to the ink 90. As a result, the heater 24 </ b> A of the second embodiment can suppress the deterioration of the ink 90.

(Third embodiment)
Next, a third embodiment in which the heater of the above-described embodiment is changed will be described. FIG. 5 is an overall perspective view of the heater according to the third embodiment. In addition, the same code | symbol is attached | subjected to the structure similar to embodiment mentioned above, and description is abbreviate | omitted.

  As shown in FIG. 5, the heater 24B according to the third embodiment includes a heat generating member 31B and a heating unit 32B.

  The heat generating member 31B includes an encircling portion 31Ba surrounding the supply pipe 22 and a heat generating portion 31Bb. The heat generating part 31Bb is configured integrally with the surrounding part 31Ba. The heat generating portion 31Bb extends in a direction away from the supply pipe 22. Further, the heat generating portion 31Bb also functions as an electromagnetic wave shielding member that shields electromagnetic waves.

  The heating part 32B is embedded in the heat generating part 31Bb. The heating unit 32B includes a coil 35B and an insulating coating material 36B that covers the coil 35B.

  In the heater 24B of the third embodiment, when an alternating current is supplied to the coil 35B, the heat generating portion 31Bb of the heat generating member 31B generates heat by induction heating. This heat is transmitted through the heat generating portion 31Bb and the surrounding portion 31Ba, and the ink 90 is heated. Here, since the heat generating portion 31Bb of the heat generating member 31B extends in a direction away from the supply pipe 22, the second embodiment can increase the distance between the coil 35B that generates an electromagnetic wave and the supply pipe 22. As a result, the electromagnetic wave can be prevented from reaching the ink 90.

(Fourth embodiment)
Next, a fourth embodiment in which the heater of the above-described embodiment is changed will be described. FIG. 6 is an overall perspective view of the heater according to the fourth embodiment. FIG. 7 is a cross-sectional view of the heater taken along line VII-VII in FIG. In addition, the same code | symbol is attached | subjected to the structure similar to embodiment mentioned above, and description is abbreviate | omitted.

  As shown in FIGS. 6 and 7, the heater 24 </ b> C according to the fourth embodiment is configured to be able to heat four colors of ink 90.

  The heater 24C includes a heat generating member 31C, a heating unit 32C, and an electromagnetic wave shielding member 33C.

  The heat generating member 31 </ b> C includes iron and nickel, which are ferromagnetic materials, and is made of stainless steel that has low reactivity with the ink 90. The heat generating member 31C is configured in a substantially rectangular parallelepiped shape. In the heat generating member 31C, four flow paths 31Ca that are part of the flow paths of the four-color ink 90 are formed. Connecting portions 31Cb and 31Cc are formed at the upper end and the lower end of the heat generating member 31C. The connecting portion 31 </ b> Cb is connected to the end portion of the supply pipe 22 a of the ink 90 connected to the ink tank 21. The connecting portion 31 </ b> Cb is connected to the end portion of the supply pipe 22 a of the ink 90 connected to the inkjet head 17. Thereby, the ink 90 flows from one supply pipe 22a to the other supply pipe 22b through the flow path 31Ca.

  The heating unit 32C includes a plurality of coils 35C and an insulating coating material 36C that covers the coils 35C.

  The plurality of coils 35C are arranged in two rows parallel to the arrangement direction of the flow path 31Ca. One row of coils 35C is disposed on the opposite side of the other row of coils 35C with the heat generating member 31C interposed therebetween.

  The electromagnetic wave shielding member 33C is formed so as to surround the heat generating member 31C and the heating unit 32C. The electromagnetic wave shielding member 33C is configured such that the tip portions of the coupling portions 31Cb and 31Cc are exposed.

  In the heater 24C according to the fourth embodiment, when an alternating current is supplied to the coil 35C, an eddy current flows on the outer surface of the heat generating member 31C. Thereby, since the heat generating member 31C is induction-heated, the ink 90 flowing through the flow path 31Ca is heated. Here, in the fourth embodiment, since the ink 90 flows through the flow path 31Ca of the heat generating member 31C, the heat generating member 31C can directly heat the ink 90. Thereby, 4th Embodiment can improve thermal efficiency.

  Further, since the heat generating member 31C is made of stainless steel having low reactivity with the ink 90, it is possible to suppress deterioration of the ink 90 flowing through the flow path 31Ca.

(Fifth embodiment)
Next, a fifth embodiment in which the heater of the fourth embodiment described above is changed will be described. FIG. 8 is a cross-sectional view of the heater according to the fifth embodiment. In addition, the same code | symbol is attached | subjected to the structure similar to embodiment mentioned above, and description is abbreviate | omitted.

  The heater 24D according to the fifth embodiment includes a heat generating member 31D, a heating unit 32C, and an electromagnetic wave shielding member 33C.

  Four insertion holes 31Da are formed in the heat generating member 31D. The supply pipe 22 is inserted through the insertion hole 31Da. Thereby, the heater 24 according to the fifth embodiment can isolate the ink 90 from the heat generating member 31D. For this reason, it is possible to suppress the chemical reaction of the ink 90 by the heat generating member 31D. As a result, the fifth embodiment can expand the degree of freedom of materials applicable to the heat generating member 31D.

  As mentioned above, although this invention was demonstrated in detail using embodiment, this invention is not limited to embodiment described in this specification. The scope of the present invention is determined by the description of the claims and the scope equivalent to the description of the claims. Hereinafter, modified embodiments in which the above-described embodiment is partially modified will be described.

  The shape, arrangement, numerical value, material, and the like of the configuration of each embodiment described above can be changed as appropriate.

DESCRIPTION OF SYMBOLS 1 Duplex printing apparatus 3 Conveyance printing part 16 Ink supply part 17 Inkjet head 18 Belt conveyance part 21 Ink tank 22, 22a, 22b Supply pipe 23 Electromagnetic valve 24, 24A, 24B, 24C, 24D Heater 31, 31A, 31B, 31C, 31D Heat generation member 31Ba Surrounding part 31Bb Heat generation part 31Ca Flow path 31Cb, 31Cc Connection part 31a, 31Da Insertion hole 32, 32B, 32C Heating part 33, 33C Electromagnetic wave shielding member 35, 35B, 35C Coil 36, 36B, 36C Coating material 37A Thermal conductive member 90 ink

Claims (4)

An inkjet head that ejects ink;
A supply pipe formed with a flow path through which ink supplied to the inkjet head flows;
A heat generating member provided in the middle of the ink flow path and generating heat by eddy current;
A coil for generating lines of magnetic force for flowing eddy currents in the heat generating member;
An electromagnetic wave shielding member including a metal and surrounding the outside of the coil.   The printing apparatus according to claim 1, wherein the coil is disposed on a side opposite to the ink flow path with the heat generating member interposed therebetween.   3. The heat conduction member according to claim 1, further comprising a heat conduction member that is higher in heat conductivity than the heat generation member and provided between the heat generation member and the ink flow path. Printing device. The printing apparatus according to claim 1, wherein the heat generating member or the electromagnetic wave shielding member has a thickness equal to or larger than δ represented by the following formula (1).