JP2019155671A - Inkjet recording device and maintenance method - Google Patents

Abstract

To provide an inkjet recording device that can suppress clogging of a vacuum path while avoiding staining of a structure of the device and a recording medium, and a maintenance method.SOLUTION: An inkjet recording device comprises a head unit having an ink flow path, an ink discharge head and a deaeration part, a vacuum suctioning part that performs suction operation for suctioning air in the deaeration part, and a control part. The deaeration part has: a deaeration membrane provided at a midway of the ink flow path; a vacuum path through which the deaeration membrane is connected to a vacuum suctioning part; a storing part, provided at the midway of the vacuum path, which stores liquid components of ink leaked out from the deaeration membrane; a trap having a discharge path for discharging the liquid components of the ink stored in the storing part to the outside; and a discharge path opening/closing part that opens or closes the discharge path. The control part perform suction control by which the suction operation by the vacuum suctioning part is started when the discharge path is opened so that the liquid components of ink in the discharge path are suctioned.SELECTED DRAWING: Figure 8

Description

  The present invention relates to an ink jet recording apparatus and a maintenance method.

  2. Description of the Related Art Conventionally, there is an inkjet recording apparatus that forms an image or the like by ejecting ink from a nozzle provided in an ink ejection head onto a recording medium. In the ink jet recording apparatus, if gas is contained in the ink supplied from the ink flow path to the ink discharge head, the pressure applied when the ink is discharged is not normally transmitted to the ink from the nozzle. Ink ejection failure may occur. On the other hand, there is a technique for providing a deaeration part for desorbing gas in the ink in the ink flow path to suppress the occurrence of ink ejection failure (for example, Patent Document 1).

  As this deaeration part, one side of the gas-permeable deaeration film is brought into contact with the ink in the ink flow path, and the side opposite to the one side is brought into contact with the vacuum path, thereby A gas having a configuration in which the gas is desorbed by being sucked into the vacuum path is often used. In this deaeration unit, the liquid component of the ink that has oozed out of the degassing membrane (for example, monomer) is stored so that the liquid does not directly enter the vacuum pump for making the vacuum path into a vacuum state. A trap is provided in the middle of the vacuum path. The trap can discharge the liquid component of the stored ink to the outside from the discharge port.

  A deaeration film in the deaeration part is provided inside a head unit having an ink discharge head and an ink flow path. On the other hand, the trap is often provided outside the head unit in order to facilitate the operation of discharging the stored liquid component.

JP 2010-58413 A

However, when the path from the degassing membrane to the trap becomes long, the solvent of the liquid component of the ink vaporizes in the path and the solute is fixed, or the liquid component itself is solidified (phase change) and fixed. As a result, the vacuum path may become clogged.
On the other hand, if a trap is provided in the vicinity of the deaeration film inside the head unit so that the liquid component of the leaked ink is guided to the trap, the ink liquid component is discharged from the trap and then discharged. The liquid component of the ink remaining in the discharge path connected to the outlet is dropped on an apparatus configuration directly related to image recording (for example, a conveyance surface on which a recording medium is placed) to contaminate the apparatus configuration or perform recording. There is a risk that the recording medium may be soiled by dripping onto the medium.
As described above, the conventional technique has a problem that it is not easy to suppress clogging of the vacuum path while avoiding contamination of the apparatus configuration and the recording medium.

  An object of the present invention is to provide an ink jet recording apparatus and a maintenance method capable of suppressing clogging of a vacuum path while avoiding contamination of the apparatus configuration and recording medium.

In order to achieve the above object, the invention of the ink jet recording apparatus according to claim 1 comprises:
An ink flow path, an ink discharge head that has nozzles and discharges ink supplied from the ink flow paths from the nozzles, and a deaeration unit that desorbs gas in the ink flowing through the ink flow paths. Having a head unit;
A vacuum suction unit that performs a suction operation of sucking air in the deaeration unit;
A control unit;
With
The degassing part is
A gas permeable degassing membrane that is provided in the middle of the ink flow path and has one surface in contact with the ink in the ink flow path;
A surface of the degassing membrane opposite to the one surface is connected to the vacuum suction portion, and the desorption membrane is detached from the ink in accordance with the suction operation of the vacuum suction portion and passes through the degassing membrane. A vacuum path through which the separated gas flows;
A storage part that is provided in the middle of the vacuum path and stores the liquid component of the ink leaked from the degassing membrane; and a discharge path for discharging the liquid component of the ink stored in the storage part to the outside. Trap and
A discharge path opening / closing portion for opening or closing the discharge path;
Have
The control unit performs suction control to start the suction operation by the vacuum suction unit when the discharge path is open to suck the liquid component of the ink in the discharge path.

According to a second aspect of the present invention, in the ink jet recording apparatus according to the first aspect,
The discharge port of the discharge path is exposed to the outside of the head unit.

The invention according to claim 3 is the ink jet recording apparatus according to claim 2,
The head unit includes a housing that accommodates the ink discharge head in a state where the opening of the nozzle is exposed to the outside of the head unit.
The trap is housed in the housing;
The discharge port is exposed outside the housing.

The invention according to claim 4 is the ink jet recording apparatus according to claim 2 or 3,
A transport unit that transports the recording medium placed on the transport surface;
The discharge path is provided at a position where the discharge port faces the transport surface.

The invention according to claim 5 is the ink jet recording apparatus according to claim 2 or 3,
A transport unit for transporting a recording medium placed on the transport surface;
Movement for moving the head unit between a first position where the nozzle opening of the ink ejection head faces the transport surface and a second position where the nozzle opening does not face the transport surface And
With
The discharge path is provided at a position where the discharge port faces the transport surface during a part of the period during which the head unit moves between the first position and the second position.

The invention according to claim 6 is the ink jet recording apparatus according to any one of claims 1 to 5,
The control unit controls an opening / closing operation of the discharge path by the discharge path opening / closing unit.

The invention according to claim 7 is the inkjet recording apparatus according to claim 6,
The deaeration unit has a communication path opening / closing part that opens or closes a communication path that allows communication between the inside of the vacuum path and the outside of the atmospheric pressure.
The control unit controls the opening / closing operation of the communication path by the communication path opening / closing unit,
Perform discharge control to open the discharge path in a state where the communication path is open and discharge the liquid component of the ink stored in the storage unit to the outside,
The suction control is performed after the discharge control,
A discharge path closing control for closing the discharge path is performed following the suction control.

The invention according to claim 8 is the ink jet recording apparatus according to claim 7,
The communication path opening / closing part is a solenoid valve.

The invention according to claim 9 is the ink jet recording apparatus according to any one of claims 1 to 8,
A plurality of the head units are provided,
The vacuum suction unit sucks air in the vacuum path in the plurality of head units.

The invention according to claim 10 is the ink jet recording apparatus according to claim 7 or 8,
A plurality of the head units are provided,
The vacuum suction unit sucks air in the vacuum path in the plurality of head units,
When performing the suction control for one head unit among the plurality of head units, the control unit closes the communication path and the discharge path of the head unit excluding the one head unit.

The invention according to claim 11 is the ink jet recording apparatus according to any one of claims 1 to 10,
The discharge path opening / closing part is a solenoid valve.

The invention according to claim 12 is the inkjet recording apparatus according to any one of claims 1 to 11,
The ink ejection head is supplied with ink having a characteristic that changes between a gel state and a sol state,
The head unit has an ink heating section for heating the ink,
The ink discharge head discharges the ink heated by the ink heating unit from the nozzle.

In order to achieve the above object, the invention of the maintenance method according to claim 13
An ink flow path, an ink discharge head that has nozzles and discharges ink supplied from the ink flow paths from the nozzles, and a deaeration unit that desorbs gas in the ink flowing through the ink flow paths. Having a head unit;
A vacuum suction unit that performs a suction operation of sucking air in the deaeration unit;
With
The degassing part is
A gas permeable degassing membrane that is provided in the middle of the ink flow path and has one surface in contact with the ink in the ink flow path;
A surface of the degassing membrane opposite to the one surface is connected to the vacuum suction portion, and the desorption membrane is detached from the ink in accordance with the suction operation of the vacuum suction portion and passes through the degassing membrane. A vacuum path through which the separated gas flows;
A storage part that is provided in the middle of the vacuum path and stores the liquid component of the ink leaked from the degassing membrane; and a discharge path for discharging the liquid component of the ink stored in the storage part to the outside. Trap and
A discharge path opening / closing portion for opening or closing the discharge path;
A maintenance method for an ink jet recording apparatus comprising:
A suction step of sucking the liquid component of the ink in the discharge path by starting the suction operation by the vacuum suction section when the discharge path is open.

  According to the present invention, there is an effect that clogging of the vacuum path can be suppressed while avoiding contamination of the apparatus configuration and the recording medium.

It is a figure which shows schematic structure of an inkjet recording device. It is a figure which shows the internal structure of a head unit. It is a figure explaining the mode of movement of a head unit. It is a schematic diagram which shows the structure of an ink supply mechanism. It is sectional drawing which shows the internal structure of a deaeration module. It is sectional drawing which shows the structure of a 1st trap. It is a block diagram which shows the main function structures of an inkjet recording device. It is a flowchart which shows the control procedure of a deaeration part maintenance process. It is a time chart which shows the operation state of the vacuum pump in a deaeration part maintenance process, an air | atmosphere communication valve, and a discharge path on-off valve.

  Hereinafter, embodiments of the image forming apparatus and the image forming method of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing a schematic configuration of an ink jet recording apparatus 1 according to an embodiment of the present invention.
The ink jet recording apparatus 1 includes a paper feeding unit 10, an image recording unit 20, a paper discharge unit 30, a control unit 60 (FIG. 7), and the like. Under the control of the control unit 60, the inkjet recording apparatus 1 conveys the recording medium P stored in the paper feeding unit 10 to the image recording unit 20, and the image recording unit 20 records an image on the recording medium P. The recorded recording medium P is conveyed to the paper discharge unit 30.
As the recording medium P, in addition to paper such as plain paper or coated paper, various media capable of solidifying the ink ejected on the surface, such as a cloth or a sheet-like resin, can be used.

  The paper supply unit 10 includes a paper supply tray 11 that stores the recording medium P, and a medium supply unit 12 that conveys and supplies the recording medium P from the paper supply tray 11 to the image recording unit 20. The medium supply unit 12 includes a ring-shaped belt whose inner side is supported by two rollers, and conveys the recording medium P by rotating the roller while the recording medium P is placed on the belt.

  The image recording unit 20 includes a conveyance drum 21 (conveyance unit), a delivery unit 22, a paper heating unit 23, a head unit 24, a fixing unit 25, a delivery unit 26, and the like.

The transport drum 21 has a rotating shaft extending in a direction perpendicular to the drawing of FIG. 1 (hereinafter referred to as the width direction) in a state where the recording medium P is held on a transport surface 21a which is a cylindrical outer peripheral surface. By rotating, the recording medium P is transported in the transport direction along the transport surface 21a. The transport drum 21 includes a claw portion 211 (FIG. 3) and an intake portion 212 (FIG. 3) (not shown) for holding the recording medium P on the transport surface 21a. The recording medium P is held on the conveyance surface 21a by being pressed by the claw portion 211 and sucked to the conveyance surface 21a by the intake portion 212.
The transport drum 21 is connected to a transport drum motor (not shown) for rotating the transport drum 21 and rotates by an angle proportional to the rotation amount of the transport drum motor.

  The delivery unit 22 delivers the recording medium P conveyed by the medium supply unit 12 of the paper supply unit 10 to the conveyance drum 21. The delivery unit 22 is provided at a position between the medium supply unit 12 and the conveyance drum 21 of the paper supply unit 10, and holds one end of the recording medium P conveyed from the medium supply unit 12 by the swing arm unit 221. Then, it is delivered to the transport drum 21 through the delivery drum 222.

  The paper heating unit 23 is provided between the arrangement position of the transfer drum 222 and the arrangement position of the head unit 24, and the recording medium P conveyed by the conveyance drum 21 performs the recording so that the temperature is within a predetermined temperature range. The medium P is heated. The sheet heating unit 23 includes, for example, an infrared heater, and energizes the infrared heater based on a control signal supplied from the control unit 60 to cause the heater to generate heat.

  The head unit 24 records an image by ejecting ink onto the recording medium P at an appropriate timing according to the rotation of the transport drum 21 on which the recording medium P is held based on the image data. The head unit 24 is disposed with a predetermined distance between the ink discharge surface and the transport drum 21. In the ink jet recording apparatus 1 of the present embodiment, four head units 24 respectively corresponding to four color inks of yellow (Y), magenta (M), cyan (C), and black (K) are transported in the recording medium P. They are arranged so as to be arranged at predetermined intervals in the order of Y, M, C, and K colors from the upstream side.

FIG. 2 is a diagram illustrating an internal configuration of the head unit 24. FIG. 2A is a schematic diagram of the internal configuration when the head unit 24 is viewed from the front. FIG. 2B is a schematic diagram of the internal configuration when the head unit 24 is viewed from the conveyance drum 21 side. The head unit 24 is viewed from the front when the head unit 24 is viewed from a direction parallel to the transport direction of the recording medium P at a position facing the head unit 24 on the transport surface 21a of the transport drum 21. Say.
The head unit 24 includes a housing 24a and a plurality (six in this case) of ink discharge heads 240 (recording heads) housed in the housing 24a. In the ink ejection head 240, the nozzles N that eject ink are arranged in two rows along the width direction to form two nozzle rows, and these two nozzle rows have an arrangement interval of the nozzles N in the width direction. They are arranged in a state shifted from each other by a half. The ink ejection head 240 is provided with a recording element for ejecting ink from the nozzle N corresponding to each nozzle N. The recording element includes a pressure chamber (channel) that communicates with the nozzle N and stores ink, a piezoelectric element provided on a wall surface of the pressure chamber, and an electrode for generating an electric field by applying a voltage to the piezoelectric element. Have. When a voltage signal having a drive waveform that deforms the piezoelectric element is applied to the electrode of the recording element, the pressure chamber is deformed in accordance with the voltage signal and the pressure in the pressure chamber changes, and the pressure changes in accordance with the change in the pressure. Ink is ejected from the nozzle N communicating with the pressure chamber.

  The six ink discharge heads 240 included in the head unit 24 are arranged in a staggered pattern so that the arrangement range of the nozzles N in the width direction is continuous. Each head unit 24 is fixed in a state of being engaged with a through hole provided in a member constituting the lower surface of the casing 24a, and a nozzle opening surface provided with an opening of the nozzle N is a casing 24a. It is exposed outside.

The arrangement range in the width direction of the nozzles N included in the head unit 24 covers the width in the width direction of an area in which an image can be recorded in the recording medium P conveyed by the conveyance drum 21. The head unit 24 is used at a fixed position during image recording, and ejects ink from the nozzles N at predetermined intervals in the conveyance direction (interval in the conveyance direction) according to the conveyance of the recording medium P. Then, the image is recorded by the single pass method.
The number of nozzle rows that the ink discharge head 240 has may be one row or three or more rows. Further, the number of ink discharge heads 240 included in the head unit 24 may be five or less, or seven or more.

The ink ejected from the nozzles N of the ink ejection head 240 is ink that is polymerized and cured by irradiating with predetermined energy (in this embodiment, ultraviolet rays). Accordingly, an ink (phase change ink) having a property of changing phase between a gel state and a sol state is used. Here, the gel state is included in the solid and the sol state is included in the liquid. The ink is uniformly liquefied (solified) by being heated to a predetermined phase change temperature (for example, about 40 ° C. to 60 ° C.) or higher, while being kept at a normal room temperature (about 0 ° C. to 30 ° C.). Gelates in the temperature range below the phase change temperature.
In the present embodiment, the ink heating unit 240 c provided in the ink ejection head 240 is heated to a temperature at which the ink becomes a sol state, and the sol state ink is ejected from the nozzle N. The ink ejected from the nozzle N and landed on the recording medium P is cooled to room temperature and quickly becomes a gel state.

In addition, each ink discharge head 240 is supplied into the ink discharge head 240, an inlet 240 a into which ink supplied into the ink discharge head 240 flows, an outlet 240 b into which ink discharged from the ink discharge head 240 flows out, and the ink discharge head 240. And an ink heating unit 240c for heating the ink.
The head unit 24 is provided with an ink flow path 242 through which ink supplied to the inlet 240a and ink discharged from the outlet 240b flow. In FIG. 2A, the ink flow path 242 connected to the inlet 240a is shown, and the direction of ink flow is indicated by a solid arrow.

In addition, the head unit 24 is provided with a deaeration unit 40 (FIG. 7) that desorbs gas in the ink flowing through the ink flow path 242. In FIG. 2, the deaeration module 41, the 1st trap 42, and the vacuum path | route 44 are drawn among the components of the deaeration part 40. FIG. In addition, a second trap 43 connected to the vacuum path 44 and a vacuum pump 51 (vacuum suction unit) that performs a suction operation for sucking air inside the vacuum path 44 are provided outside the head unit 24. . Among the components connected to the vacuum path 44, the deaeration module 41 and the first trap 42 are provided inside the casing 24a, and the second trap 43 is provided outside the casing 24a. In FIG. 2A, the gas flow direction in the vacuum path 44 is indicated by a dashed arrow. The vacuum path 44 is not particularly limited. For example, a silicon tube or the like can be used.
The deaeration module 41 is provided in the middle of the ink flow path 242 and includes a deaeration film 416 (FIG. 5), which will be described later, that desorbs gas in the ink.
The first trap 42 and the second trap 43 are provided in the middle of the vacuum path 44 and store the liquid component (mainly monomer) of the ink leaked from the deaeration film 416. Among these, the first trap 42 is provided in the vicinity of the deaeration module 41. The first trap 42 is fixed in a state where it is engaged with a through hole provided in a member constituting the lower surface of the casing 24a, and a discharge port for discharging the stored liquid component of the ink is provided. It is exposed outside the housing 24a.

The head unit 24 having such a configuration is arranged in a state where the nozzle opening surface of the ink discharge head 240 exposed from the lower surface of the casing 24 a and the discharge port of the first trap 42 face the transport surface 21 a of the transport drum 21. Is done.
Further, as shown in FIG. 3, the head units 24 are provided so as to be individually movable along the width direction. Specifically, the head unit 24 includes a first position where the nozzle opening surface of the ink discharge head 240 faces the conveyance surface 21a of the conveyance drum 21, and the nozzle opening surface of the ink discharge head 240 does not face the conveyance surface 21a. It is provided to be movable between the second positions. Here, an ink receiving portion 28 is provided at a position facing the nozzle opening surface of the head unit 24 at the second position. The ink receiving unit 28 is a member that receives the monomer discharged from the discharge port of the first trap 42 and the ink discharged from the head unit 24 during maintenance of the head unit 24. Under the control of the control unit 60, the head unit 24 is moved to the first position by the head unit moving drive unit 72 (moving unit) during image formation, and the second unit during a maintenance operation described later. Move to position.

  The fixing unit 25 includes a light emitting unit arranged over the width of the conveyance drum 21 and irradiates the recording medium P placed on the conveyance drum 21 with energy rays such as ultraviolet rays from the light emission unit. Then, the ink discharged on the recording medium P is cured and fixed. The light emitting unit of the fixing unit 25 is arranged to face the conveyance drum 21 on the downstream side in the conveyance direction with respect to the arrangement position of the head unit 24 in the conveyance direction.

  The delivery unit 26 includes a belt loop 262 having an annular belt supported on the inside by two rollers, and a cylindrical transfer drum 261 that transfers the recording medium P from the transport drum 21 to the belt loop 262. The recording medium P transferred from the transfer drum 21 onto the belt loop 262 by the transfer drum 261 is transferred by the belt loop 262 and sent to the paper discharge unit 30.

  The paper discharge unit 30 includes a plate-shaped paper discharge tray 31 on which the recording medium P sent out from the image recording unit 20 by the delivery unit 26 is placed.

Next, an ink supply mechanism that supplies ink to the ink discharge head 240 in the inkjet recording apparatus 1 will be described.
FIG. 4 is a schematic diagram showing the configuration of the ink supply mechanism.
In FIG. 4, the ink supply mechanism related to one head unit 24 of the inkjet recording apparatus 1 is extracted and shown, but in the other head units 24 as well, ink is applied to the ink discharge head 240 by the same ink supply mechanism. Supplied.

In the ink supply mechanism of FIG. 4, the ink in the main tank 271 included in the ink supply unit 27 provided outside the head unit 24 is supplied to the first sub tank 241 provided in the head unit 24 by the supply pump 272. . In the head unit 24, the ink flow indicated by a thick line is formed so as to form an ink circulation path from the first sub tank 241 to the first sub tank 241 through the deaeration module 41, the second sub tank 245, and the ink discharge head 240. A path 242 is provided, and the ink can be circulated through the ink circulation path by the liquid feeding operation of the circulation pump 243.
As described above, the ink in the ink ejection head 240 is heated by the ink heating unit 240c to form a sol. Further, the ink in each part other than the ink ejection head 240 in the head unit 24 is also heated by an ink heating unit (not shown) provided in the head unit 24 and maintained in a sol form.

  The main tank 271 is provided outside the head unit 24 and stores ink of a color corresponding to the head unit 24. The capacity of the main tank 271 is not particularly limited, but a large capacity of about several liters to several tens of liters is used, for example.

  The supply pump 272 sends the ink stored in the main tank 271 to the first sub tank 241 in the head unit 24. The supply pump 272 is not particularly limited, and for example, a volume transfer type pump such as a diaphragm pump, a tube pump that feeds liquid by squeezing a tube with a roller, or the like can be used.

  The first sub tank 241 is a small ink chamber that stores ink supplied from the main tank 271 and supplied to the ink discharge head 240. The first sub-tank 241 is a container opened to the outside, and is maintained at substantially atmospheric pressure regardless of increase or decrease in the amount of ink.

  The degassing module 41 desorbs (degass) the gas in the ink that has flowed from the first sub tank 241. The deaerated ink is sent to the second sub tank 245 through the check valve 244 by the circulation pump 243.

  The circulation pump 243 sends the ink deaerated by the deaeration module 41 to the second sub tank 245. The configuration of the circulation pump 243 is not particularly limited, but for example, a configuration similar to the supply pump 272 can be used. A check valve 244 provided between the circulation pump 243 and the second sub tank 245 prevents the ink sent to the second sub tank 245 from flowing back.

  The second sub tank 245 is a small ink chamber in which the ink deaerated by the deaeration module 41 is temporarily stored, and is sealed except for a connection portion with the ink flow path 242. The second sub tank 245 is not particularly limited, but has the same capacity as the first sub tank 241. The second sub tank 245 is connected to the inlet 240 a of each ink discharge head 240 via the ink flow path 242, and supplies the ink discharged from the nozzle N of each ink discharge head 240 to the ink discharge head 240.

  The outlet 240b of the ink discharge head 240 is connected to the first sub tank 241 via the valve 246, and a part of the ink that is not discharged from the nozzle N of the ink discharge head 240 can be returned to the first sub tank 241. It has become.

On the other hand, the deaeration module 41 is connected to the first trap 42, the atmosphere communication valve 451 (communication path opening / closing part), the communication switching valve 452, the second trap 43, and the vacuum pump 51 via the vacuum path 44. . When the vacuum pump 51 performs a suction operation of sucking air in the vacuum path 44, gas is desorbed from the ink in the deaeration module 41, and the desorbed gas flows through the vacuum path 44. The vacuum pump 51 does not necessarily need to bring the inside of the vacuum path 44 to an ultra-high vacuum state, and performs pressure reduction necessary for deaeration.
Among these, the deaeration module 41, the first trap 42, the atmosphere communication valve 451, the communication switching valve 452, and the vacuum path 44 constitute the deaeration unit 40.
The deaeration unit 40 is provided in each head unit 24, and only one second trap 43 and one vacuum pump 51 are common to the four head units 24 of Y, M, C, and K. Is provided.

FIG. 5 is a cross-sectional view showing the internal structure of the deaeration module 41.
The deaeration module 41 has a shape in which a gas permeable deaeration membrane 416 made of a number of hollow fiber membranes covers the periphery of the central tube 414 inside the outer shell 411. One end of the central tube 414 is connected to the ink inlet 412 and the other is sealed with a plug 414a. An infinite number of fine holes 414b (sewing holes) are provided on the outer wall of the central tube 414, and ink flowing into the central tube 414 from the ink inlet 412 flows out of the fine holes 414b to the surroundings and is deaerated. It passes through the film 416 and flows out from the ink outlet 413.

  The deaeration membrane 416 has a large number of hollow fine thread structures with one end closed, and the membrane surface has gas permeability. The other end of the fine fiber structure of the degassing membrane 416 is connected to the gas outlet 415, and the vacuum pump 51 sucks the gas in the vacuum path 44, thereby reducing the pressure inside the fine fiber structure of the degassing membrane 416. The In this state, when the ink contacts the membrane surface of the degassing membrane 416 (the outer surface of the fine hollow fiber structure, one surface of the degassing membrane), only the gas in the ink selectively permeates the membrane surface. Ink is degassed. That is, by providing a large number of fine degassing films 416, the contact area between the ink and the film surface is widened, so that degassing is performed efficiently.

  The deaeration film 416 sometimes leaks out the monomer, which is a liquid component of the ink, to the vacuum path 44 side where the pressure is reduced by the vacuum pump 51 together with the gas component.

  In the first trap 42 and the second trap 43, not only the gas but also the leaked monomer from the degassing module 41 is sucked and flows into the vacuum path 44. It plays the role which prevents producing malfunctions, such as destroying the pump 51. FIG. The first trap 42 and the second trap 43 are, for example, in a small tank shape, and a monomer is stored therein. Moreover, the 1st trap 42 and the 2nd trap 43 can discharge | emit the stored monomer outside by opening a discharge port.

  As described above, the first trap 42 is provided in the vicinity of the deaeration module 41 in the housing 24 a of the head unit 24. The monomer immediately after leaking from the degassing membrane 416 of the degassing module 41 is stored in the first trap 42. If the degassing membrane 416 is not deteriorated or damaged, the amount of monomer leaking from the degassing membrane 416 is very small (for example, about several cc per day). The capacity is used.

FIG. 6 is a cross-sectional view showing the configuration of the first trap 42.
As shown in FIG. 6, the first trap 42 has a main body 421 in which a reservoir 422 communicating with the vacuum path 44 is provided. The storage unit 422 stores the monomer leaked into the vacuum path 44. The main body part 421 is provided with a discharge path 423 that communicates with the storage part 422 and extends downward from the bottom of the storage part 422. Further, a discharge path opening / closing valve 424 (discharge path opening / closing section) that opens or closes the discharge path 423 is provided in the middle of the discharge path 423. By opening the discharge path opening / closing valve 424, the monomer stored in the storage unit 422 can be discharged to the outside from the discharge port 425 at the lower end of the discharge path 423.

  The second trap 43 stores monomer that could not be captured by the first trap 42, and also stores the monomer in the first trap 42 when the deaeration film 416 of the deaeration module 41 is damaged and a large amount of ink leaks. Accepts and stores ink that cannot be removed. In addition, the second trap 43 is provided with an ink storage amount detection unit 431 that detects the storage amount of the stored monomer (or ink) and outputs the result to the control unit 60. When the detection result of the ink storage amount by the ink storage amount detection unit 431 exceeds a predetermined upper limit value, the communication switching valves 452 corresponding to all the head units 24 are closed and the first trap 42 of each head unit 24 is closed. By stopping the flow of ink and monomer from the second trap 43 to the second trap 43, the ink and monomer can be prevented from overflowing from the second trap 43 and reaching the vacuum pump 51. Since the second trap 43 functions as an ink buffer when the deaeration module 41 fails in this way, a larger capacity than the first trap 42, for example, about 150 cc is used.

  The vacuum pump 51 sucks gas so that the inside of the vacuum path 44 from the deaeration module 41 to the vacuum pump 51 is maintained within a predetermined negative pressure range lower than atmospheric pressure in the deaeration unit 40. 40 to the outside. The operation of the vacuum pump 51 is controlled by the control unit 60.

The atmosphere communication valve 451 switches the communication state of the communication path 44a that connects the inside of the vacuum path 44 and the outside of the atmospheric pressure by an opening / closing operation. The atmosphere communication valve 451 is in an open state, thereby communicating the inside of the deaeration unit 40 sucked by the vacuum pump 51 with the outside (atmosphere).
The communication switching valve 452 switches the communication state between the first trap 42 and the second trap 43 by an opening / closing operation. The communication switching valve 452 is closed to stop the flow of gas or liquid (monomer or ink) from the first trap 42 to the second trap 43, and the monomer or ink overflows from the second trap 43. Suppresses the occurrence of Further, since all the communication switching valves 452 corresponding to the four head units 24 are closed, the flow of gas or liquid from the second trap 43 to the vacuum pump 51 is stopped, and the monomer or ink is supplied to the vacuum pump 51. It is possible to suppress the occurrence of a problem that the vacuum pump 51 fails due to the inflow.
A protective valve for protecting the vacuum pump 51 may be further provided between the second trap 43 and the vacuum pump 51.
For example, an electromagnetic valve is used as the atmospheric communication valve 451 and the communication switching valve 452 and the discharge path opening / closing valve 424 of the first trap 42 described above, and the control unit 60 can automatically control the opening / closing operation. It has become.

FIG. 7 is a block diagram showing the main functional configuration of the inkjet recording apparatus 1.
The ink jet recording apparatus 1 includes the supply pump 272, the circulation pump 243, the vacuum pump 51, the ink heating unit 240c, the discharge path opening / closing valve 424, the atmosphere communication valve 451, the communication switching valve 452, and the ink storage amount detection unit. In addition to the deaeration unit 40 having the 431, the paper heating unit 23, and the fixing unit 25, a CPU 61 (Central Processing Unit) (recording control means), a RAM 62 (Random Access Memory), a ROM 63 (Read Only Memory), and A control unit 60 having a storage unit 64, an ink discharge head control unit 71, a head unit movement drive unit 72, a transport drive unit 73, an input / output interface 74, a bus 75, and the like are provided.

  The CPU 61 reads various control programs and setting data stored in the ROM 63, stores them in the RAM 62, and executes the programs to perform various arithmetic processes. Thereby, the CPU 61 controls the overall operation of the ink jet recording apparatus 1.

  The RAM 62 provides a working memory space to the CPU 61 and stores temporary data. The RAM 62 may include a nonvolatile memory.

  The ROM 63 stores various control programs executed by the CPU 61, setting data, and the like. Instead of the ROM 63, a rewritable nonvolatile memory such as an EEPROM (Electrically Erasable Programmable Read Only Memory) or a flash memory may be used.

  The storage unit 64 stores a print job (image recording command) input from the external apparatus 2 via the input / output interface 74, image data related to the print job, and the like. As the storage unit 64, for example, an HDD (Hard Disk Drive) is used, and a DRAM (Dynamic Random Access Memory) or the like may be used in combination.

  The ink ejection head control unit 71 outputs various control signals and image data to the head driving unit provided in the ink ejection head 240 at an appropriate timing according to the control signal from the control unit 60. Here, the control signal includes a signal designating a drive waveform related to the drive signal supplied from the head drive unit to the recording element. The head drive unit supplies a drive signal having a drive waveform to the electrodes in the recording element of the ink discharge head 240 in accordance with the control signal and image data input from the ink discharge head control unit 71, so that the nozzles of the recording element Ink is ejected from N.

  The head unit movement drive unit 72 moves the head unit 24 in the width direction between the first position and the second position in accordance with a control signal from the control unit 60.

  The transport driving unit 73 supplies a drive signal to the transport drum motor of the transport drum 21 based on the control signal supplied from the control unit 60 to rotate the transport drum 21 at a predetermined speed and timing. Further, the transport drive unit 73 supplies a drive signal to the motor for operating the medium supply unit 12, the delivery unit 22, and the delivery unit 26 based on the control signal supplied from the control unit 60, and the recording medium P Is supplied to the transport drum 21 and discharged from the transport drum 21.

  The input / output interface 74 is means for transmitting / receiving data to / from the external device 2 and is configured by any one of various serial interfaces, various parallel interfaces, or a combination thereof.

  The bus 75 is a path for transmitting and receiving signals between the control unit 60 and other components.

  The external device 2 is a personal computer, for example, and supplies a print job, image data, and the like to the control unit 60 via the input / output interface 74.

Next, the maintenance operation of the deaeration unit 40 in the inkjet recording apparatus 1 of the present embodiment will be described.
The monomer leaking from the deaeration film 416 is gradually stored in the storage unit 422 of the first trap 42 in the deaeration unit 40 while the deaeration unit 40 performs the deaeration. For this reason, before a monomer overflows from the storage part 422, the operation | movement (deaeration part maintenance operation | movement) which discharges | emits a monomer from the discharge port 425 needs to be performed. The frequency of the deaeration unit maintenance operation is a frequency at which the first trap 42 does not become full depending on the amount of monomer leaking from the deaeration module 41 to the first trap 42, for example, once a day, the inkjet recording apparatus 1. At startup.

The discharge path 423 of the first trap 42 is provided at a position where the discharge port 425 faces the transport surface 21a of the transport drum 21 when the head unit 24 is at the first position for image recording (FIG. 2). reference). Further, when the head unit 24 moves between the first position and the second position, the discharge port 425 moves on the transport unit while facing the transport unit. That is, the discharge path 423 is provided at a position where the discharge port 425 faces the transport surface 21a during a part of the period during which the head unit 24 moves between the first position and the second position.
For this reason, if the monomer is discharged from the discharge port 425 by a normal method in which the discharge path on / off valve 424 is opened and then closed, the monomer remains in the vicinity of the discharge port 425 in the discharge path 423 after the discharge path on / off valve 424 is closed. While the image recording by the head unit 24 is being performed or while the head unit 24 is moving in the width direction, the dropped monomer is dropped onto the transport surface 21a of the transport drum 21 and the recording medium P on the transport surface 21a. May end up. When the monomer is dropped from the discharge port 425 in this way, the recording medium P is fouled directly or indirectly, so that wasteful consumption of the recording medium P increases or image recording efficiency for cleaning the inkjet recording apparatus 1 is increased. Or drop.

  Therefore, in the deaeration unit maintenance operation of the present embodiment, when the discharge path opening / closing valve 424 is opened for monomer discharge, the suction operation by the vacuum pump 51 is started to suck the monomer in the discharge path 423. Suction control is performed. By performing such suction control, the monomer remaining in the discharge path 423 after the monomer in the storage section 422 is discharged can be drawn to the storage section 422 side, so the discharge path opening / closing valve 424 is closed. Generation | occurrence | production of the malfunction that a monomer will dripping unintentionally from the discharge port 425 after making it let it be made to be suppressed. Further, even if the monomer in the discharge path 423 cannot be completely sucked (removed) by the suction operation of the vacuum pump 51 and the monomer remains between the discharge path opening / closing valve 424 and the discharge port 425, the monomer is discharged during the suction operation. By closing the path opening / closing valve 424, the space between the discharge path opening / closing valve 424 and the residual monomer becomes negative pressure, and the residual monomer is drawn to the discharge path opening / closing valve 424 side. Dripping from the outlet 425 is suppressed.

Next, a control procedure by the control unit 60 of a process (deaeration part maintenance process) for performing the deaeration part maintenance operation will be described.
FIG. 8 is a flowchart showing a control procedure of the deaeration unit maintenance process.
FIG. 9 is a time chart showing operating states of the vacuum pump 51, the atmosphere communication valve 451, and the discharge path opening / closing valve 424 in the deaeration unit maintenance process.
Prior to the start of the deaeration unit maintenance process, the control unit 60 stops the operation of the vacuum pump 51 and closes all the air communication valves 451 and the discharge path opening / closing valves 424 in all the head units 24.

  When the deaeration unit maintenance process is started, the control unit 60 outputs a control signal to the head unit movement driving unit 72 to move the maintenance-target head unit 24 from the first position to the second position ( Step S101).

  The controller 60 opens the atmosphere communication valve 451 to open the communication path 44a, and allows the inside of the vacuum path 44 and the storage section 422 of the first trap 42 to communicate with the outside of the atmospheric pressure (step S102, FIG. 9). Timing T1).

  In this state, the control unit 60 opens the discharge path opening / closing valve 424 to open the discharge path 423, and the monomer stored in the storage section 422 of the first trap 42 is discharged from the discharge port 425 through the discharge path 423. The discharge control for discharging is performed (step S103, timing T2 in FIG. 9).

  After the start of the discharge control, when a predetermined time for the monomer in the storage unit 422 to be discharged elapses, the control unit 60 closes the communication path 44a by closing the atmospheric communication valve 451 and performs the suction operation of the vacuum pump 51. The suction control is started to suck the monomer in the discharge path 423 (step S104, timing T3 in FIG. 9) (suction step).

  When a predetermined time has elapsed after the start of the suction control, the control unit 60 performs the discharge path closing control for closing the discharge path 423 by closing the discharge path opening / closing valve 424 (step S105, timing T4 in FIG. 9). Thereby, the communication between the inside of the vacuum path 44 and the outside of the storage part 422 of the first trap 42 is cut off, and the vacuum suction in the vacuum path 44 by the vacuum pump 51 is started. Transition to a possible state.

After the discharge path closing control is started, the control unit 60 outputs a control signal to the head unit movement driving unit 72 to move the head unit 24 from the second position to the first position (step S106).
When the process of step S106 ends, the control unit 60 ends the deaeration unit maintenance process.

As described above, the inkjet recording apparatus 1 according to this embodiment includes the ink flow path 242 and the nozzle N, the ink discharge head 240 that discharges the ink supplied from the ink flow path 242 from the nozzle N, and the ink. A head unit 24 having a deaeration unit 40 that desorbs gas in the ink flowing through the flow path 242; a vacuum pump 51 that performs a suction operation of sucking air in the deaeration unit 40; and a control unit 60. The deaeration unit 40 is provided in the middle of the ink flow path 242, and one surface of the gas permeable deaeration film 416 whose one surface is in contact with the ink in the ink flow path 242 and the deaeration film 416. A vacuum path 44 that connects the surface opposite to the surface and the vacuum pump 51, and a desorption gas that has been desorbed from the ink and permeated through the degassing film 416 according to the suction operation of the vacuum pump 51 flows; In the middle of A first trap 42 having a reservoir 422 for storing the monomer (ink liquid component) leaked from the degassing membrane 416 and a discharge path 423 for discharging the monomer stored in the reservoir 422 to the outside. The discharge path opening / closing valve 424 that opens or closes the discharge path 423, and the control unit 60 opens the vacuum path 51 when the discharge path 423 is opened by opening the discharge path opening / closing valve 424. The suction operation is started to suck the monomer in the discharge path 423 by starting the suction operation.
According to such a configuration, the monomer remaining in the discharge path 423 after the monomer in the storage unit 422 is discharged can be drawn into the storage unit 422 side. For this reason, after the discharge path 423 is closed by the discharge path opening / closing valve 424, the monomer is unintentionally dripped from the discharge port 425 to the outside of the head unit 24 and is directly related to image recording (for example, the transport surface 21a ) And the problem of fouling the recording medium P can be suppressed.
Further, by providing the first trap 42 in the head unit 24, the monomer leaked from the degassing film 416 can be guided to the first trap 42 and stored before the monomer leaks to the vacuum path 44. Generation | occurrence | production of the malfunction which a monomer adheres to the vacuum path | route 44 and is blocked can be suppressed.

  Further, the discharge port 425 of the discharge path 423 is exposed to the outside of the head unit 24. More specifically, the head unit 24 includes a housing 24a that houses the ink ejection head 240 with the opening of the nozzle N exposed to the outside of the head unit 24, and the first trap 42 includes the housing 24a. The outlet 425 is exposed to the outside of the housing 24a. In such a configuration, when the monomer is dropped from the discharge port 425, there may be a problem that the apparatus structure such as the conveyance surface 21a or the like or the recording medium P is landed and contaminated, but the above-described configuration suppresses the occurrence of the problem. can do.

  Further, a transport drum 21 for transporting the recording medium P placed on the transport surface 21a is provided, and the discharge path 423 is provided at a position where the discharge port 425 faces the transport surface 21a. In such a configuration, when the monomer is dropped from the discharge port 425, there is a problem that the toner is landed on the transport surface 21a or the recording medium P on the transport surface 21a and is contaminated. Can be suppressed.

  Further, the conveyance drum 21 that conveys the recording medium P placed on the conveyance surface 21a, the first position where the opening of the nozzle N of the ink discharge head 240 faces the conveyance surface 21a, and the opening of the nozzle N Includes a head unit movement driving unit 72 that moves the head unit 24 between a second position that does not oppose the transport surface 21a, and the discharge path 423 includes the head unit 24 at the first position and the second position. The discharge port 425 is provided at a position facing the transport surface 21a in a part of the period during the movement between the two. In such a configuration, when the monomer drops from the discharge port 425 when the head unit 24 moves between the first position and the second position, the transport surface 21a or the recording medium P on the transport surface 21a is dropped. Although the malfunction which landes and makes it pollute generate | occur | produces, generation | occurrence | production of the said malfunction can be suppressed with the above-mentioned structure.

  Further, the control unit 60 controls the opening / closing operation of the discharge path 423 by the discharge path opening / closing valve 424. Thereby, switching of opening and closing of the discharge path 423 can be performed easily and at high speed.

  The deaeration unit 40 includes an atmosphere communication valve 451 that opens or closes the communication path 44 a that allows the inside of the vacuum path 44 to communicate with the outside of the atmospheric pressure. The control unit 60 communicates with the atmosphere communication valve 451. The opening / closing of the path 44a is controlled, the discharge path 423 is opened in a state where the communication path 44a is opened, the discharge control for discharging the monomer stored in the storage unit 422 to the outside is performed, and the suction control is continued after the discharge control. The discharge path closing control for closing the discharge path 423 is performed after the suction control. According to this, the operation of discharging the monomer from the storage unit 422 and the operation of depressurizing the vacuum path after the discharge of the monomer are automatically performed under the control of the control unit 60, and the device configuration and the recording medium P are contaminated. Can be avoided.

  In addition, by using the air communication valve 451 as an electromagnetic valve, the communication path 44 a can be easily and rapidly switched under the control of the control unit 60.

  The inkjet recording apparatus 1 includes a plurality of head units 24, and the vacuum pump 51 sucks air in the vacuum paths 44 in the plurality of head units 24. According to such a configuration, since the gas in the ink in the plurality of head units 24 can be deaerated using the single vacuum pump 51, the configuration of the inkjet recording apparatus 1 is simplified and the manufacturing cost is increased. Can be suppressed.

  In addition, when performing the suction control for one head unit 24 among the plurality of head units 24, the control unit 60 closes the communication path 44a and the discharge path 423 of the head unit excluding the one head unit. Thereby, it is possible to sufficiently secure the suction force for drawing the monomer in the discharge path 423 in the suction control.

  Further, by using the discharge path opening / closing valve 424 as an electromagnetic valve, the discharge path 423 can be switched between opening and closing easily and at high speed under the control of the control unit 60.

  The ink discharge head 240 is supplied with ink having a characteristic that changes between a gel state and a sol state, and the head unit 24 includes an ink heating unit 240c that heats the ink. 240 ejects ink heated by the ink heating section 240c from the nozzle N. In such a configuration, when the monomer leaked from the degassing film 416 to the vacuum path 44 is cooled and phase-changed to a sol state, the vacuum path 44 may be clogged. However, the first trap 42 is provided in the head unit 24. As a result, the ink can be guided to the first trap 42 and stored before the phase of the monomer changes to the sol state, so that the occurrence of the problem can be suppressed.

  Further, the maintenance method of the ink jet recording apparatus 1 of the above embodiment includes a suction step of starting the suction operation by the vacuum pump 51 when the discharge path 423 is opened to suck the monomer in the discharge path 423. According to such a method, the clogging of the vacuum path can be suppressed while avoiding the contamination of the apparatus configuration and the recording medium P.

Note that the present invention is not limited to the above-described embodiments and modifications, and various modifications can be made.
For example, in the above-described embodiment, an example in which electromagnetic valves are used as the atmosphere communication valve 451, the communication switching valve 452, and the discharge path opening / closing valve 424 has been described. Other various valves can be used.

  In the above-described embodiment, the air communication valve 451, the communication switching valve 452, and the discharge path opening / closing valve 424 have been described using an example of opening and closing under the control of the control unit 60. It can be opened and closed by hand, and can be opened and closed by a human hand.

Moreover, although the said embodiment demonstrated using the example which performs a deaeration part maintenance operation | movement at the time of starting of the inkjet recording device 1, it is not restricted to this. For example, the deaeration unit maintenance operation may be started at an arbitrary timing according to the operator's instruction.
Further, the storage unit 422 of the first trap 42 is provided with a storage amount detection unit for detecting the storage amount of the monomer, and the deaeration unit maintenance operation is performed when the storage amount of the monomer in the storage unit 422 exceeds a predetermined reference value. May be started. In addition, when the storage part 422 is provided in the 1st trap 42 in this way and the capacity | capacitance of the storage part 422 is fully ensured, when the storage amount of the monomer of the 1st trap 42 exceeds a reference value, the vacuum pump 51 Since the monomer can be prevented from overflowing from the first trap 42 by taking measures such as stopping the second trap 43, the second trap 43 may not be provided.

  Further, the present invention may be applied to the inkjet recording apparatus 1 in which the discharge port 425 is not exposed to the outside of the head unit 24. Also in the ink jet recording apparatus 1 having such a configuration, the monomer dropped from the discharge port 425 to the inside of the head unit 24 can reach the outside through the internal structure of the head unit 24. However, the problem of fouling may occur, but the occurrence of the problem can be suppressed by applying the present invention.

  In the above-described embodiment, the recording medium P is transported by the transport drum 21. However, the present invention is not limited to this. For example, the present invention may be applied to an ink jet recording apparatus that transports the recording medium P by a transport belt that is supported by a plurality of transport rollers and moves according to the rotation of the transport rollers.

  In the above embodiment, the single-pass inkjet recording apparatus 1 has been described as an example. However, the present invention may be applied to an inkjet recording apparatus that records an image while scanning a recording head.

  In the above-described embodiment, the inkjet recording apparatus 1 that discharges ink that is in a gel state at room temperature and becomes a sol state when heated is described as an example. You may apply this invention to the inkjet recording device 1 which discharges arbitrary inks.

  Although several embodiments of the present invention have been described, the scope of the present invention is not limited to the above-described embodiments, and includes the scope of the invention described in the claims and equivalents thereof. .

DESCRIPTION OF SYMBOLS 1 Inkjet recording device 10 Paper supply part 20 Image recording part 21 Conveying drum 21a Conveying surface 24 Head unit 24a Case 25 Fixing part 27 Ink supply part 271 Main tank 272 Supply pump 28 Ink receiving part 30 Paper discharge part 40 Deaeration part 41 Deaeration module 416 Deaeration membrane 42 First trap 421 Main body part 422 Storage part 423 Discharge path 424 Discharge path on / off valve 425 Discharge port 43 Second trap 431 Ink storage amount detection part 44 Vacuum path 44a Communication path 451 Atmospheric communication valve 452 Communication Switching valve 51 Vacuum pump 60 Control unit 71 Ink discharge head control unit 72 Head unit movement drive unit 73 Transport drive unit 240 Ink discharge head 240c Ink heating unit 241 First sub tank 242 Ink flow path 243 Circulation pump 244 Check valve 245 Second Sub tank N Nozzle Recording media

Claims (13)

An ink flow path, an ink discharge head that has nozzles and discharges ink supplied from the ink flow paths from the nozzles, and a deaeration unit that desorbs gas in the ink flowing through the ink flow paths. Having a head unit;
A vacuum suction unit that performs a suction operation of sucking air in the deaeration unit;
A control unit;
With
The degassing part is
A gas permeable degassing membrane that is provided in the middle of the ink flow path and has one surface in contact with the ink in the ink flow path;
A surface of the degassing membrane opposite to the one surface is connected to the vacuum suction portion, and the desorption membrane is detached from the ink in accordance with the suction operation of the vacuum suction portion and passes through the degassing membrane. A vacuum path through which the separated gas flows;
A storage part that is provided in the middle of the vacuum path and stores the liquid component of the ink leaked from the degassing membrane; and a discharge path for discharging the liquid component of the ink stored in the storage part to the outside. Trap and
A discharge path opening / closing portion for opening or closing the discharge path;
Have
The ink jet recording apparatus that performs suction control for sucking a liquid component of ink in the discharge path by starting the suction operation by the vacuum suction section when the discharge path is open.   The inkjet recording apparatus according to claim 1, wherein a discharge port of the discharge path is exposed to the outside of the head unit. The head unit includes a housing that accommodates the ink discharge head in a state where the opening of the nozzle is exposed to the outside of the head unit.
The trap is housed in the housing;
The inkjet recording apparatus according to claim 2, wherein the discharge port is exposed to the outside of the housing. A transport unit that transports the recording medium placed on the transport surface;
The inkjet recording apparatus according to claim 2, wherein the discharge path is provided at a position where the discharge port faces the transport surface. A transport unit for transporting a recording medium placed on the transport surface;
Movement for moving the head unit between a first position where the nozzle opening of the ink ejection head faces the transport surface and a second position where the nozzle opening does not face the transport surface And
With
The discharge path is provided at a position where a discharge port faces the transport surface during a part of a period during which the head unit moves between the first position and the second position. The inkjet recording apparatus according to 2 or 3.   The inkjet recording apparatus according to claim 1, wherein the control unit controls an opening / closing operation of the discharge path by the discharge path opening / closing unit. The deaeration unit has a communication path opening / closing part that opens or closes a communication path that allows communication between the inside of the vacuum path and the outside of the atmospheric pressure.
The control unit controls the opening / closing operation of the communication path by the communication path opening / closing unit,
Perform discharge control to open the discharge path in a state where the communication path is open and discharge the liquid component of the ink stored in the storage unit to the outside,
The suction control is performed after the discharge control,
The inkjet recording apparatus according to claim 6, wherein a discharge path closing control for closing the discharge path is performed subsequent to the suction control.   The inkjet recording apparatus according to claim 7, wherein the communication path opening / closing unit is an electromagnetic valve. A plurality of the head units are provided,
The ink jet recording apparatus according to claim 1, wherein the vacuum suction unit sucks air in the vacuum path in the plurality of head units. A plurality of the head units are provided,
The vacuum suction unit sucks air in the vacuum path in the plurality of head units,
The said control part closes the said communication path | route and said discharge path | route of a head unit except the said one head unit, when performing the said suction control about one head unit among these head units. Or an ink jet recording apparatus according to 8;   The inkjet recording apparatus according to claim 1, wherein the discharge path opening / closing unit is an electromagnetic valve. The ink ejection head is supplied with ink having a characteristic that changes between a gel state and a sol state,
The head unit has an ink heating section for heating the ink,
The ink jet recording apparatus according to claim 1, wherein the ink discharge head discharges the ink heated by the ink heating unit from the nozzle. An ink flow path, an ink discharge head that has nozzles and discharges ink supplied from the ink flow paths from the nozzles, and a deaeration unit that desorbs gas in the ink flowing through the ink flow paths. Having a head unit;
A vacuum suction unit that performs a suction operation of sucking air in the deaeration unit;
With
The degassing part is
A gas permeable degassing membrane that is provided in the middle of the ink flow path and has one surface in contact with the ink in the ink flow path;
A surface of the degassing membrane opposite to the one surface is connected to the vacuum suction portion, and the desorption membrane is detached from the ink in accordance with the suction operation of the vacuum suction portion and passes through the degassing membrane. A vacuum path through which the separated gas flows;
A storage part that is provided in the middle of the vacuum path and stores the liquid component of the ink leaked from the degassing membrane; and a discharge path for discharging the liquid component of the ink stored in the storage part to the outside. Trap and
A discharge path opening / closing portion for opening or closing the discharge path;
A maintenance method for an ink jet recording apparatus comprising:
A maintenance method comprising a suction step of starting the suction operation by the vacuum suction unit when the discharge path is open to suck the liquid component of the ink in the discharge path.

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