JP2023130959A - liquid discharge device - Google Patents

Abstract

To provide a liquid discharge device which can inhibit occurrence of air bubbles effectively.SOLUTION: According to an embodiment, a liquid discharge device includes: a supply tank; a first temperature adjustment device; a deaeration module; a liquid discharge head; and a second temperature adjustment device. The supply tank supplies a liquid. The first temperature adjustment device heats the liquid to a first temperature. The deaeration module deaerates the liquid heated to the first temperature. The liquid discharge head discharges the deaerated liquid. The second temperature adjustment device heats the liquid to a second temperature lower than the first temperature in the liquid discharge head.SELECTED DRAWING: Figure 2

Description

Embodiments of the present invention relate to a liquid ejection device.

2. Description of the Related Art Liquid ejecting devices are provided that circulate liquid such as ink to a head and eject droplets from the head. Such a liquid ejection device performs degassing to remove gases such as oxygen while circulating the liquid in order to suppress ejection failure due to air bubbles.

However, conventional liquid ejection devices having non-circulating heads that do not circulate liquid may not be able to sufficiently suppress the generation of bubbles in the liquid.

International Publication No. 2017/094515

In order to solve the above problems, a liquid ejection device that can effectively suppress the generation of bubbles is provided.

According to an embodiment, a liquid ejection device includes a supply tank, a first temperature adjustment device, a degassing module, a liquid ejection head, and a second temperature adjustment device. The supply tank supplies liquid. A first temperature adjustment device heats the liquid to a first temperature. The degassing module degasses the liquid heated to the first temperature. The liquid ejection head ejects the degassed liquid. A second temperature adjustment device heats the liquid in the liquid ejection head to a second temperature lower than the first temperature.

FIG. 1 is a diagram schematically showing a configuration example of a liquid ejection device according to a first embodiment. FIG. 2 is a block diagram showing a configuration example of the head unit according to the first embodiment. FIG. 3 is a block diagram showing a configuration example of a head unit according to the second embodiment. FIG. 4 is a block diagram showing a configuration example of a head unit according to the third embodiment. FIG. 5 is a block diagram showing a configuration example of a head unit according to the fourth embodiment.

Hereinafter, a liquid ejection device according to an embodiment will be described using the drawings.
(First embodiment)
First, a first embodiment will be described.
The liquid ejection device according to the embodiment forms an image on a medium such as paper using a liquid ejection head that ejects ink. The liquid ejection device ejects ink droplets within a pressure chamber of a liquid ejection head onto a medium to print an image on the medium. Examples of the liquid ejecting device include an office liquid ejecting device, a barcode liquid ejecting device, a POS liquid ejecting device, an industrial liquid ejecting device, a 3D liquid ejecting device, and the like. Note that the medium on which the liquid ejecting device forms an image is not limited to a specific configuration. Further, ink is an example of a liquid.

FIG. 1 schematically shows a configuration example of a liquid ejection device 2. As shown in FIG.
As shown in FIG. 1, the liquid ejection device 2 includes a housing 2111, a medium supply section 2112, an image forming section 2113, a medium discharge section 2114, a transport device 2115 as a support device, and a maintenance device 2117. A control unit 2118 is provided.

The liquid ejection device 2 conveys ink, etc. as a recording medium, which is an object to be ejected, along a predetermined transport path 2001 from a medium supply section 2112 to a medium discharge section 2114 through an image forming section 2113. This is an inkjet printer that performs image forming processing on paper P by ejecting liquid.

The medium supply unit 2112 includes a plurality of paper feed cassettes 21121. The image forming section 2113 includes a support section 2120 that supports the paper P, and a plurality of head units 2130 that are arranged above the support section 2120 to face each other.

The support unit 2120 includes a conveyor belt 21201 provided in a loop shape in a predetermined area where image formation is performed, a support plate 21202 that supports the conveyor belt 21201 from the back side, and a plurality of belt rollers 21203 provided on the back side of the conveyor belt 21201. , is provided.

As will be described later, the head unit 2130 includes a liquid ejection head 1 as an inkjet head, a supply tank 2132 as a liquid tank mounted on the liquid ejection head 1, and pumps 2134 and 2136 that supply ink. Be prepared. The head unit 2130 will be detailed later.

In this embodiment, the liquid ejection head 1 includes four color liquid ejection heads 1 of cyan, magenta, yellow, and black, and four color supply tanks 2132 that respectively accommodate inks of these colors. Supply tank 2132 is connected to liquid ejection head 1 .

The liquid ejection head 1 is connected to a maintenance device 2117 that collects ink.
For example, the maintenance device 2117 sucks and collects ink remaining on the outer surface of the nozzle plate during maintenance. The maintenance device 2117 collects ink within the liquid ejection head 1 during maintenance. The maintenance device 2117 has a tray, a tank, and the like that store the collected ink.

The conveyance device 2115 conveys the paper P along the conveyance path 2001 from the paper feed cassette 21121 of the medium supply section 2112 to the medium discharge section 2114 through the image forming section 2113. The conveyance device 2115 includes a plurality of guide plate pairs 21211 to 21218 arranged along the conveyance path 2001 and a plurality of conveyance rollers 21221 to 21228. The transport device 2115 supports the paper P so as to be movable relative to the liquid ejection head 1 .

The control unit 2118 includes a CPU 21181 as an example of a processor, and memories such as a ROM (Read Only Memory) that stores various programs, and a RAM (Random Access Memory) that temporarily stores various variable data, image data, etc. and an interface section for inputting data from the outside and outputting data to the outside.

Note that the liquid ejection device 2 may include other configurations as needed in addition to the configuration shown in FIG. 1, or a specific configuration may be excluded from the liquid ejection device 2.

Next, the head unit 2130 will be explained.
FIG. 2 is a block diagram showing a configuration example of the head unit 2130. As shown in FIG. 2, the head unit 2130 includes a liquid ejection head 1, an ink flow path 10, a temperature adjustment device 11, a degassing module 12, a vacuum regulator 13, a vacuum pump 14, a sub tank 15, a temperature adjustment device 16, and a temperature adjustment device 16. It includes a flow path 111, an ink flow path 121, vacuum paths 131 and 141, an ink flow path 151, a supply tank 2132, pumps 2134 and 2136, and the like.

The liquid ejection head 1 is connected to a supply tank 2132 serving as a liquid storage section. The liquid ejection head 1 is a non-circulating head that is supplied with ink from a supply tank 2132 and discharges the ink to a maintenance device 2117 during maintenance. The liquid ejection head 1 includes a nozzle plate in which nozzles for ejecting liquid are formed. The liquid ejection head 1 is arranged with nozzles facing downward. However, the orientation of the liquid ejection head 1 is not limited to a posture in which the nozzles face downward. For example, the liquid ejection head 1 may be arranged with the nozzle facing upward or perpendicular to the direction of gravity.

The temperature adjustment device 11 (first temperature adjustment device) heats the ink stored in the supply tank 2132 to a first temperature. The temperature adjustment device 11 includes a temperature control water tank that stores temperature controlled water such as water, a pump that supplies the temperature controlled water, a temperature controller that adjusts the temperature of the temperature controlled water, and the like. The temperature control water tank is connected to the temperature control channel 111. Further, the temperature controller is, for example, a heater or a cooler.

The temperature adjustment device 11 uses a temperature controller to adjust the temperature of the temperature-controlled water tank to a predetermined temperature. The temperature adjustment device 11 supplies temperature-controlled water from a temperature-controlled water tank to a temperature-controlled channel 111 using a pump. Further, the temperature adjustment device 11 collects temperature-controlled water from the temperature-controlled flow path 111 to the temperature-controlled water tank.

The temperature control channel 111 functions as a heat exchanger that exchanges heat between the ink stored in the supply tank 2132 and the temperature control water. For example, the temperature control channel 111 is a channel that passes through the outer layer or inside of the supply tank 2132.

The temperature of the ink stored in the supply tank 2132 is adjusted to the first temperature by temperature adjustment water from the temperature adjustment device 11.

Further, the supply tank 2132 is connected to the ink flow path 121. The ink flow path 121 is connected to the degassing module 12. That is, the supply tank 2132 is connected to the degassing module 12 via the ink flow path 121.

A pump 2136 is installed in the ink flow path 121.
Pump 2136 supplies ink from supply tank 2132 to degassing module 12 . The pump 2136 is, for example, a liquid pump configured with a piezoelectric pump. The pump 2136 is connected to the control section 2118 and is driven and controlled by the control section 2118.

The deaeration module 12 is installed downstream of the temperature adjustment device 11. Here, downstream refers to a position closer to the liquid ejection head 1.

The degassing module 12 degasses the ink heated to the first temperature. That is, the degassing module 12 removes gases such as oxygen from the ink. Here, the degassing module 12 reduces the amount of dissolved oxygen in the ink.

The degassing module 12 includes a degassing chamber into which ink flows, and a decompression chamber that is in contact with the degassing chamber through a separation membrane that does not allow liquid such as ink to pass through.

The reduced pressure chamber is connected to the vacuum regulator 13 via a vacuum path 131. Vacuum regulator 13 is connected to vacuum pump 14 via vacuum path 141. That is, the decompression chamber is connected to the vacuum pump 14 via the vacuum regulator 13.

The vacuum pump 14 reduces the pressure in the decompression chamber of the degassing module 12 via the vacuum regulator 13 under the control of the control unit 2118.
The vacuum regulator 13 adjusts the degree of vacuum in the decompression chamber of the degassing module 12 . That is, the vacuum regulator 13 adjusts the air pressure from the vacuum pump 14. The vacuum regulator 13 adjusts the degree of vacuum (degree of reduced pressure) generated by the vacuum pump 14 and supplies air pressure to the reduced pressure chamber of the degassing module 12 . The vacuum regulator 13 may adjust the degree of vacuum under the control of the control unit 2118.

The degassing chamber of the degassing module 12 is connected to the ink flow path 121. That is, ink flows into the degassing chamber of the degassing module 12 from the supply tank 2132 via the ink flow path 121.

The degassing chamber of the degassing module 12 degasses the ink inside by reducing the pressure in the decompression chamber.
Further, the degassing chamber of the degassing module 12 is connected to the ink flow path 151. The ink flow path 151 is connected to the sub tank 15. That is, the degassing chamber of the degassing module 12 supplies degassed ink to the sub-tank 15 via the ink flow path 151.

Sub tank 15 is formed downstream of supply tank 2132. Ink that has been degassed from the ink flow path 151 flows into the sub-tank 15 . The sub-tank 15 stores degassed ink.

The sub tank 15 is a tank that temporarily stores ink. For example, the storage capacity of the sub-tank 15 is smaller than the storage capacity of the supply tank 2132.

The sub tank 15 is connected to the ink flow path 10. The ink flow path 10 is connected to the liquid ejection head 1. That is, the sub-tank 15 is connected to the liquid ejection head 1 via the ink flow path 10.

A pump 2134 is installed in the ink flow path 10.
The pump 2134 supplies ink from the sub-tank 15 to the liquid ejection head 1 . The pump 2134 is, for example, a liquid pump configured with a piezoelectric pump. The pump 2134 is connected to the control section 2118 and is driven and controlled by the control section 2118.

Degassed ink flows into the liquid ejection head 1 from the ink flow path 10 . The liquid ejection head 1 ejects ink onto the paper P supported by the support section 2120 under the control of the control section 2118.

For example, the liquid ejection head 1 includes a pressure chamber communicating with a nozzle, an actuator that expands or contracts the volume of the pressure chamber, and the like. Ink flows into the pressure chamber of the liquid ejection head 1 . The liquid ejection head 1 drives the actuator to expand or contract the pressure chamber under the control of the control unit 2118. By changing the volume of the pressure chamber, ink within the pressure chamber is ejected from the nozzle.

Further, the liquid ejection head 1 includes a temperature-controlled water flow path. The temperature-controlled water flow path functions as a heat exchanger that exchanges heat between the ink in the liquid ejection head 1 and the temperature-controlled water from the temperature control device 16 . For example, the temperature-controlled water flow path is formed so as to pass near the pressure chamber.

The temperature control water flow path of the liquid ejection head 1 is connected to temperature control flow paths 161a and 161b.

The temperature control channels 161a and 161b are connected to the temperature control device 16.
The temperature adjustment device 16 (second temperature adjustment device) heats the ink within the liquid ejection head 1 to a second temperature lower than the first temperature. The temperature adjustment device 16 includes a temperature control water tank that stores temperature control water, a pump that supplies the temperature control water, a temperature controller that adjusts the temperature of the temperature control water, and the like. The temperature-controlled water tank is connected to the temperature-controlled channels 161a and 161b. Further, the temperature controller is, for example, a heater or a cooler.

The temperature adjustment device 16 is a temperature controller that adjusts the temperature-controlled water tank to a predetermined temperature. The temperature adjustment device 16 supplies temperature-controlled water from a temperature-controlled water tank to the temperature-controlled channel 161a using a pump. The temperature adjustment device 16 also collects temperature-controlled water from the temperature-controlled flow path 161b to the temperature-controlled water tank.
The temperature of the ink within the liquid ejection head 1 is adjusted to a second temperature by temperature adjustment water from the temperature adjustment device 16.

Next, an example of the operation of the head unit 2130 will be described.
Here, it is assumed that the supply tank 2132 stores ink.

The control unit 2118 drives the temperature adjustment device 11. The temperature adjustment device 11 heats the ink stored in the supply tank 2132 to a first temperature.

When the ink stored in the supply tank 2132 is heated to the first temperature, the control unit 2118 drives the vacuum pump 14. As a result, the pressure in the decompression chamber of the degassing module 12 is reduced to a predetermined pressure.

When the pressure in the vacuum chamber is reduced, the control unit 2118 controls the pump 2136 to supply ink from the supply tank 2132 to the degassing module 12. The degassing module 12 degasses the supplied ink. Here, since the ink is heated to the first temperature, the saturated dissolved oxygen amount of the ink decreases. Since oxygen up to the amount of dissolved oxygen at that temperature is released, the degassing module 12 can effectively degas the ink.

When the ink is degassed, the control unit 2118 controls the pump 2134 to supply the degassed ink to the sub tank 15. When the ink is supplied to the sub-tank 15, the control unit 2118 controls the pump 2134 to supply the ink from the sub-tank 15 to the liquid ejection head 1.

When ink is supplied to the liquid ejection head 1, the control unit 2118 drives the temperature adjustment device 16. The temperature adjustment device 16 heats the ink within the liquid ejection head 1 to a second temperature.

By heating the ink within the liquid ejection head 1 to the second temperature, characteristics such as viscosity of the ink are appropriately adjusted.
Furthermore, since the second temperature is lower than the first temperature, the saturated dissolved oxygen amount of the ink in the liquid ejection head 1 is greater than the saturated dissolved oxygen amount of the ink in the supply tank 2132. Therefore, bubbles are less likely to be generated in the ink within the liquid ejection head 1.

When the ink in the liquid ejection head 1 is heated to the second temperature, the control unit 2118 causes the liquid ejection head 1 to eject the ink.

Note that the temperature adjustment device 11 may be shared by a plurality of head units 2130. Further, the temperature adjustment device 16 may be shared by a plurality of head units 2130.

Further, the head unit 2130 may include a temperature sensor in the supply tank 2132 that measures the temperature of the ink. The control unit 2118 may control the temperature adjustment device 11 based on the temperature of the ink stored in the supply tank 2132. Further, the control unit 2118 may control the timing of ink supply from the supply tank 2132 to the degassing module 12 based on the temperature of the ink stored in the supply tank 2132.

Moreover, the vacuum pump 14 and the vacuum regulator 13 may be formed integrally.
Further, the temperature adjustment device 11 may include a heater that directly heats the ink stored in the supply tank 2132.
Further, the control unit 2118 may drive the temperature adjustment device 11, the vacuum pump 14, or the temperature adjustment device 16 in advance.

The liquid ejecting device configured as described above heats the ink to the first temperature and then degasses the ink. As a result, the liquid ejecting device can effectively degas the ink. Further, the liquid ejection device heats the ink in the liquid ejection head to a second temperature lower than the first temperature. As a result, the liquid ejection apparatus can prevent bubbles from forming in the ink in the liquid ejection head.
(Second embodiment)
Next, a second embodiment will be described.
The liquid ejection device according to the second embodiment differs from that according to the first embodiment in that the ink is heated to the first temperature in the sub-tank. Therefore, the other points will be designated by the same reference numerals and detailed explanation will be omitted.

FIG. 1 schematically shows a configuration example of a liquid ejection device 2' according to a second embodiment. As shown in FIG. 1, the liquid ejecting device 2' includes a head unit 2130' instead of the head unit 2130.

FIG. 3 is a block diagram showing an example of the configuration of the head unit 2130'. As shown in FIG. 3, the head unit 2130' includes the liquid ejection head 1, the temperature adjustment device 11, the degassing module 12, the vacuum regulator 13, the vacuum pump 14, the sub-tank 15, the temperature adjustment device 16, the ink channel 20, the vacuum It includes paths 131 and 141, a temperature control channel 211, an ink channel 221, an ink channel 251, a supply tank 2132, pumps 2134 and 2136, and the like.

Supply tank 2132 is connected to ink flow path 221. The ink flow path 221 is connected to the sub tank 15. That is, the supply tank 2132 is connected to the sub-tank 15 via the ink flow path 221.

A pump 2136 is installed in the ink flow path 221.
Pump 2136 supplies ink from supply tank 2132 to sub tank 15 .

The temperature adjustment device 11 heats the ink stored in the sub-tank 15 to a first temperature. Similar to the first embodiment, the temperature adjustment device 11 includes a temperature adjustment water tank, a pump, a temperature controller, and the like. The temperature control water tank is connected to the temperature control channel 211.

The temperature adjustment device 11 uses a temperature controller to adjust the temperature of the temperature-controlled water tank to a predetermined temperature. The temperature adjustment device 11 supplies temperature control water from a temperature control water tank to the temperature control channel 211 using a pump. Further, the temperature adjustment device 11 collects temperature-controlled water from the temperature-controlled flow path 211 to the temperature-controlled water tank.

The temperature control channel 211 functions as a heat exchanger that exchanges heat between the ink stored in the sub tank 15 and the temperature control water. For example, the temperature control channel 211 is a channel that passes through the outer layer or inside of the sub-tank 15.

The temperature of the ink stored in the sub-tank 15 is adjusted to the first temperature by temperature adjustment water from the temperature adjustment device 11.

Further, the sub tank 15 is connected to the ink flow path 251. The ink flow path 251 is connected to the degassing module 12. That is, the sub-tank 15 is connected to the degassing module 12 via the ink flow path 251.

A pump 2134 is installed in the ink flow path 251.
Pump 2134 supplies ink from subtank 15 to degassing module 12 .

The deaeration module 12 is installed downstream of the temperature adjustment device 11.

The degassing module 12 degasses the ink heated to the first temperature. Similar to the first embodiment, the degassing module 12 includes a degassing chamber into which ink flows, and a decompression chamber in contact with the degassing chamber via a separation membrane that does not allow liquid such as ink to pass through.

The degassing chamber of the degassing module 12 is connected to the ink flow path 221. That is, ink flows into the degassing chamber of the degassing module 12 from the sub-tank 15 via the ink flow path 221.

Further, the degassing chamber of the degassing module 12 is connected to the ink flow path 20 . The ink flow path 20 is connected to the liquid ejection head 1 . That is, the degassing chamber of the degassing module 12 supplies degassed ink to the liquid ejection head 1 via the ink flow path 20.

Next, an example of the operation of the head unit 2130' will be described.
Here, it is assumed that the supply tank 2132 stores ink.

The control unit 2118 controls the pump 2136 to supply ink from the supply tank 2132 to the sub tank 15. When ink is supplied to the sub-tank 15, the control unit 2118 drives the temperature adjustment device 11. The temperature adjustment device 11 heats the ink stored in the sub-tank 15 to a first temperature.

When the ink stored in the sub-tank 15 is heated to the first temperature, the control unit 2118 drives the vacuum pump 14. As a result, the pressure in the decompression chamber of the degassing module 12 is reduced to a predetermined pressure.

When the pressure in the decompression chamber is reduced, the control unit 2118 controls the pump 2134 to supply ink from the sub-tank 15 to the degassing module 12. The degassing module 12 degasses the supplied ink. Here, since the ink is heated to the first temperature, the saturated dissolved oxygen amount of the ink decreases. Therefore, the degassing module 12 can effectively degas the ink.

When the ink is degassed, the degassed ink is supplied to the liquid ejection head 1.

When ink is supplied to the liquid ejection head 1, the control unit 2118 drives the temperature adjustment device 16. The temperature adjustment device 16 heats the ink within the liquid ejection head 1 to a second temperature.

By heating the ink within the liquid ejection head 1 to the second temperature, characteristics such as viscosity of the ink are appropriately adjusted.
Furthermore, since the second temperature is lower than the first temperature, the saturated dissolved oxygen amount of the ink in the liquid ejection head 1 is greater than the saturated dissolved oxygen amount of the ink in the supply tank 2132. Therefore, bubbles are less likely to be generated in the ink within the liquid ejection head 1.

When the ink in the liquid ejection head 1 is heated to the second temperature, the control unit 2118 causes the liquid ejection head 1 to eject the ink.

Note that the temperature adjustment device 11 may include a heater that directly heats the ink stored in the sub-tank 15.
Further, the control unit 2118 may drive the temperature adjustment device 11, the vacuum pump 14, or the temperature adjustment device 16 in advance.

The liquid ejecting device configured as described above heats the ink to the first temperature in the sub tank. Further, the sub-tank is installed downstream of the supply tank. Therefore, the liquid ejection apparatus can suppress heat radiation from the ink until the ink heated to the first temperature is supplied to the liquid ejection head.
(Third embodiment)
Next, a third embodiment will be described.
The liquid ejection device according to the third embodiment differs from that according to the first embodiment in that the degassed ink is returned to the supply tank. Therefore, the other points will be designated by the same reference numerals and detailed explanation will be omitted.

FIG. 1 schematically shows a configuration example of a liquid ejection device 2'' according to a third embodiment. As shown in FIG. 1, the liquid ejecting device 2'' includes a head unit 2130'' instead of the head unit 2130.

FIG. 4 is a block diagram showing a configuration example of the head unit 2130''. As shown in FIG. 4, the head unit 2130'' includes a liquid ejection head 1, an ink flow path 10, a temperature adjustment device 11, a degassing module 12, a vacuum regulator 13, a vacuum pump 14, a sub tank 15, a temperature adjustment device 16, It includes a temperature control channel 111, vacuum channels 131 and 141, temperature control channels 161a and 161b, an ink channel 221, ink channels 321a and 321b, a supply tank 2132, pumps 2134 and 2136, and the like.

Supply tank 2132 is connected to ink channels 321a and 321b. The ink channels 321a and 321b are connected to the degassing chamber of the degassing module 12.

Here, the ink flow path 321a supplies ink from the supply tank 2132 to the degassing chamber of the degassing module 12. Further, the ink flow path 321b supplies ink from the degassing chamber of the degassing module 12 to the supply tank 2132.

Ink flows into the degassing chamber of the degassing module 12 from the supply tank 2132 via the ink flow path 321a. Furthermore, ink degassed from the deaeration chamber of the deaeration module 12 flows into the supply tank 2132 via the ink flow path 321b.

That is, the deaeration module 12 deaerates the ink flowing from the supply tank 2132 and supplies the deaerated ink to the supply tank 2132.

Next, an example of the operation of the head unit 2130'' will be described.
Here, it is assumed that the supply tank 2132 stores ink.

The control unit 2118 drives the temperature adjustment device 11. The temperature adjustment device 11 heats the ink stored in the supply tank 2132 to a first temperature.

When the ink stored in the supply tank 2132 is heated to the first temperature, the control unit 2118 drives the vacuum pump 14. As a result, the pressure in the decompression chamber of the degassing module 12 is reduced to a predetermined pressure.

When the pressure in the decompression chamber is reduced, the control unit 2118 controls a pump (not shown) to supply ink from the supply tank 2132 to the degassing module 12 via the ink flow path 321a. The degassing module 12 degasses the supplied ink. Here, since the ink is heated to the first temperature, the saturated dissolved oxygen amount of the ink decreases. Therefore, the degassing module 12 can effectively degas the ink.

When the ink is degassed, the degassed ink returns to the supply tank 2132 via the ink flow path 321b. The degassed ink is supplied again to the degassing module 12, and the ink stored in the supply tank continues to be degassed.

When the ink stored in the supply tank 2132 is degassed, the control unit 2118 controls the pump 2136 to supply the degassed ink to the sub tank 15. When the ink is supplied to the sub-tank 15, the control unit 2118 controls the pump 2134 to supply the ink from the sub-tank 15 to the liquid ejection head 1.

When ink is supplied to the liquid ejection head 1, the control unit 2118 drives the temperature adjustment device 16. The temperature adjustment device 16 heats the ink within the liquid ejection head 1 to a second temperature.

By heating the ink within the liquid ejection head 1 to the second temperature, characteristics such as viscosity of the ink are appropriately adjusted.
Furthermore, since the second temperature is lower than the first temperature, the saturated dissolved oxygen amount of the ink in the liquid ejection head 1 is greater than the saturated dissolved oxygen amount of the ink in the supply tank 2132. Therefore, bubbles are less likely to be generated in the ink within the liquid ejection head 1.

When the ink in the liquid ejection head 1 is heated to the second temperature, the control unit 2118 causes the liquid ejection head 1 to eject the ink.

Note that the control unit 2118 may simultaneously heat and degas the ink stored in the supply tank 2132.

The liquid ejecting device configured as described above supplies ink from the supply tank to the degassing module and returns the degassed ink to the supply tank. As a result, the liquid ejection device can continue to degas the ink stored in the supply tank. Therefore, the liquid ejecting device can effectively degas the ink.
(Fourth embodiment)
Next, a fourth embodiment will be described.
The liquid ejection device according to the fourth embodiment differs from that according to the second embodiment in that the degassed ink is returned to the sub-tank. Therefore, the other points will be designated by the same reference numerals and detailed explanation will be omitted.

FIG. 1 schematically shows a configuration example of a liquid ejection device 2''' according to a fourth embodiment. As shown in FIG. 1, the liquid ejecting device 2''' includes a head unit 2130''' instead of the head unit 2130.

FIG. 5 is a block diagram showing a configuration example of the head unit 2130'''. As shown in FIG. 5, the head unit 2130''' includes a liquid ejection head 1, an ink flow path 10, a temperature adjustment device 11, a degassing module 12, a vacuum regulator 13, a vacuum pump 14, a sub tank 15, and a temperature adjustment device 16. , vacuum paths 131 and 141, temperature control channels 161a and 161b, temperature control channel 211, ink channel 221, ink channels 421a and 421b, supply tank 2132, pumps 2134 and 2136, and the like.

The sub-tank 15 is connected to ink channels 421a and 421b. The ink channels 421a and 421b are connected to the degassing chamber of the degassing module 12.

Here, the ink flow path 421a supplies ink from the sub-tank 15 to the degassing chamber of the degassing module 12. Further, the ink flow path 421b supplies ink from the degassing chamber of the degassing module 12 to the sub tank 15.

Ink flows into the degassing chamber of the degassing module 12 from the sub-tank 15 via the ink flow path 421a. Furthermore, ink degassed from the degassing chamber of the degassing module 12 flows into the sub-tank 15 via the ink flow path 421b.

That is, the deaeration module 12 deaerates the ink flowing from the sub-tank 15 and supplies the deaerated ink to the sub-tank 15.

Next, an example of the operation of the head unit 2130''' will be described.
Here, it is assumed that the supply tank 2132 stores ink.

The control unit 2118 controls the pump 2136 to supply ink from the supply tank 2132 to the sub tank 15. When ink is supplied to the sub-tank 15, the control unit 2118 drives the temperature adjustment device 11. The temperature adjustment device 11 heats the ink stored in the sub-tank 15 to a first temperature.

When the ink stored in the sub-tank 15 is heated to the first temperature, the control unit 2118 drives the vacuum pump 14. As a result, the pressure in the decompression chamber of the degassing module 12 is reduced to a predetermined pressure.

When the pressure in the decompression chamber is reduced, the control unit 2118 controls a pump (not shown) to supply ink from the sub-tank 15 to the degassing module 12 via the ink flow path 421a. The degassing module 12 degasses the supplied ink. Here, since the ink is heated to the first temperature, the saturated dissolved oxygen amount of the ink decreases. Therefore, the degassing module 12 can effectively degas the ink.

When the ink is degassed, the degassed ink returns to the sub tank 15 via the ink flow path 421b. The degassed ink is supplied again to the degassing module 12, and the ink stored in the supply tank continues to be degassed.

When the ink stored in the sub-tank 15 is degassed, the control unit 2118 controls the pump 2134 to supply ink from the sub-tank 15 to the liquid ejection head 1 .

When ink is supplied to the liquid ejection head 1, the control unit 2118 drives the temperature adjustment device 16. The temperature adjustment device 16 heats the ink within the liquid ejection head 1 to a second temperature.

By heating the ink within the liquid ejection head 1 to the second temperature, characteristics such as viscosity of the ink are appropriately adjusted.
Furthermore, since the second temperature is lower than the first temperature, the saturated dissolved oxygen amount of the ink in the liquid ejection head 1 is greater than the saturated dissolved oxygen amount of the ink in the supply tank 2132. Therefore, bubbles are less likely to be generated in the ink within the liquid ejection head 1.

When the ink in the liquid ejection head 1 is heated to the second temperature, the control unit 2118 causes the liquid ejection head 1 to eject the ink.

Note that the control unit 2118 may simultaneously perform heating and degassing of the ink stored in the sub-tank 15.

The liquid ejecting device configured as described above supplies ink from the sub-tank to the degassing module and returns the degassed ink to the sub-tank. As a result, the liquid ejecting device can continue to degas the ink stored in the sub-tank. Therefore, the liquid ejecting device can effectively degas the ink stored in the sub-tank.

Further, the liquid ejecting device heats the ink to a first temperature in the sub tank. Further, the sub-tank is installed downstream of the supply tank. Therefore, the liquid ejection apparatus can suppress heat radiation from the ink until the ink heated to the first temperature is supplied to the liquid ejection head.

Although several embodiments of the invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included within the scope and gist of the invention, as well as within the scope of the invention described in the claims and its equivalents.

DESCRIPTION OF SYMBOLS 1...Liquid ejection head, 2...Liquid ejection device, 2'...Liquid ejection device, 2''...Liquid ejection device, 2'''...Liquid ejection device, 10...Ink channel, 11...Temperature adjustment device, 12... Degassing module, 13... Vacuum regulator, 14... Vacuum pump, 15... Sub tank, 16... Temperature adjustment device, 20... Ink channel, 111... Temperature regulation channel, 121... Ink channel, 131... Vacuum path, 141... Vacuum path, 151... Ink channel, 161a... Temperature regulation channel, 161b... Temperature regulation channel, 211... Temperature regulation channel, 221... Ink channel, 251... Ink channel, 321a... Ink channel, 321b... Ink channel, 421a... Ink channel, 421b... Ink channel, 2001... Conveyance path, 2111... Housing, 2112... Medium supply section, 2113... Image forming section, 2114... Medium discharge section, 2115... Conveyance device, 2117 ...Maintenance device, 2118...Control unit, 2120...Support unit, 2130...Head unit, 2130'...Head unit, 2130''...Head unit, 2130'''...Head unit, 2132...Supply tank, 2134...Pump, 21121 ...Paper feed cassette, 21181...CPU, 21201...Transport belt, 21202...Support plate, 21203...Belt roller, 21211...Guide plate pair, 21212...Guide plate pair, 21213...Guide plate pair, 21214...Guide plate pair, 21215... Guide plate pair, 21216... Guide plate pair, 21217... Guide plate pair, 21218... Guide plate pair, 21221... Conveying roller, 21222... Conveying roller, 21223... Conveying roller, 21224... Conveying roller, 21225... For conveying Roller, 21226...Conveyance roller, 21227...Conveyance roller, 21228...Conveyance roller, P...Paper.

Claims (5)

a supply tank for supplying liquid;
a first temperature adjustment device that heats the liquid to a first temperature;
a degassing module that degasses the liquid heated to the first temperature;
a liquid ejection head that ejects the degassed liquid;
a second temperature adjustment device that heats the liquid in the liquid ejection head to a second temperature lower than the first temperature;
A liquid ejection device comprising: The first temperature adjustment device heats the liquid stored in the supply tank to the first temperature,
The deaeration module is formed downstream of the supply tank, deaerates the liquid flowing from the supply tank, and supplies the deaerated liquid to the liquid ejection head.
The liquid ejection device according to claim 1. A sub-tank formed downstream of the supply tank and storing the liquid from the supply tank,
The first temperature adjustment device heats the liquid stored in the sub-tank to the first temperature,
The degassing module is formed downstream of the sub-tank, deaerates the liquid flowing from the sub-tank, and supplies the degassed liquid to the liquid ejection head.
The liquid ejection device according to claim 1. The first temperature adjustment device heats the liquid stored in the supply tank to the first temperature,
The deaeration module deaerates the liquid flowing from the supply tank and supplies the deaerated liquid to the supply tank.
The liquid ejection device according to claim 1. A sub-tank formed downstream of the supply tank and storing the liquid from the supply tank,
The first temperature adjustment device heats the liquid stored in the sub-tank to the first temperature,
The deaeration module is formed downstream of the subtank, deaerates the liquid flowing from the subtank, and supplies the degassed liquid to the subtank.
The liquid ejection device according to claim 1.