CN107813606A - Liquid circulating apparatus, liquid liquid discharging device and liquid spitting method - Google Patents

Abstract

The present invention provides a liquid circulation device, a liquid discharge device, and a liquid discharge method capable of adaptively maintaining the liquid pressure of a nozzle. A liquid circulation device according to an embodiment includes a regulator tank, a first pump, a second pump, and a pressure regulator. The regulator tank is disposed in a circulation path passing through the liquid ejection head that ejects the liquid, and stores the liquid supplied to the liquid ejection head. The first pump is provided between the primary side of the liquid discharge head and the adjustment tank in the circulation path, and feeds the liquid to the liquid discharge head. The second pump is provided between the secondary side of the liquid discharge head and the adjustment tank in the circulation path, and sends the liquid to the adjustment tank. The pressure adjustment unit adjusts the liquid delivery capabilities of the first pump and the second pump based on the pressures on the primary side and the secondary side of the liquid discharge head in the circulation path.

Description

Liquid circulation device, liquid ejection device, and liquid ejection method

technical field

Embodiments of the present invention relate to a liquid circulation device, a liquid discharge device, and a liquid discharge method.

Background technique

There is known a liquid discharge device that includes a liquid discharge head that discharges a liquid, and a liquid circulation device that circulates the liquid through a circulation path including the liquid discharge head. Such a liquid discharge device adjusts the pressure of a plurality of tanks provided in the circulation path with a pump to adjust the liquid pressure of the nozzles of the liquid discharge head. However, when the capacity of the pump changes over time, it becomes difficult to adjust the liquid pressure.

Contents of the invention

The technical problem to be solved by the present invention is to provide a liquid circulation device, a liquid ejection device, and a liquid ejection method capable of adaptively maintaining the liquid pressure of a nozzle.

A liquid circulation device according to an embodiment includes a regulator tank, a first pump, a second pump, and a pressure regulator. The adjustment tank is disposed in a circulation path passing through the liquid ejection head that ejects the liquid, and stores the liquid supplied to the liquid ejection head. The first pump is provided between the primary side of the liquid discharge head and the adjustment tank in the circulation path, and feeds the liquid to the liquid discharge head. The second pump is provided between the secondary side of the liquid discharge head and the adjustment tank in the circulation path, and sends the liquid to the adjustment tank. The pressure adjustment unit adjusts the liquid delivery capabilities of the first pump and the second pump based on the pressures on the primary side and the secondary side of the liquid ejection head in the circulation path.

A liquid discharge device according to an embodiment includes: the above-mentioned liquid circulation device; the liquid discharge head that discharges liquid; and an upstream tank disposed between the first pump and the liquid discharge head in the circulation path for for storing liquid; a downstream tank disposed between the second pump and the liquid discharge head in the circulation path for storing liquid; a first pressure detection part for detecting the pressure in the upstream tank; and The second pressure detection unit detects the pressure in the downstream tank, the regulating tank is disposed between the downstream tank and the upstream tank in the circulation path, and the pressure regulating unit is based on the pressure in the upstream tank. The pressure of the pressure and the pressure in the downstream tank control the liquid delivery capacity of the first pump and the second pump.

The liquid discharge method according to the embodiment includes: detecting the primary side and the secondary side of the liquid discharge head respectively in a circulation path passing through the liquid discharge head which discharges the liquid and a regulating tank which stores the liquid supplied to the liquid discharge head and based on the pressure values of the primary side and the secondary side, the first pump provided on the primary side of the liquid discharge head in the circulation path and all the pumps provided in the circulation path The liquid delivery capacity of the second pump on the secondary side of the liquid ejection head is adjusted.

Description of drawings

FIG. 1 is a side view showing the configuration of an inkjet recording device according to an embodiment.

FIG. 2 is an explanatory diagram showing the configuration of the liquid ejection device according to the embodiment.

FIG. 3 is an explanatory view showing the configuration of a liquid ejection head of the liquid ejection device.

FIG. 4 is an explanatory diagram showing the configuration of a piezoelectric pump of the liquid ejection device.

FIG. 5 is a block diagram showing the configuration of a control unit of the liquid ejection device.

FIG. 6 is a flowchart showing a control method of the liquid ejection device.

FIG. 7 is an explanatory diagram showing the configuration of a liquid ejection device according to another embodiment.

Explanation of reference signs

1...Inkjet recording device, 10...Liquid discharge device, 10A...Liquid discharge device, 11...Head supporting mechanism 11a...Carriage, 12...Medium supporting mechanism, 13...Main control device, 20...Liquid discharge head, 21...Nozzle Plate, 21a...nozzle hole, 22...substrate, 23...manifold, 24...actuator, 25...ink pressure chamber, 28...flow path, 30...circulation device, 31...circulation path, 31a...first flow path, 31b... Second flow path, 31c...third flow path, 31d...fourth flow path, 32...intermediate tank (adjusting tank), 33...first circulation pump (first pump), 34...upstream tank (first tank), 35...downstream tank (second tank), 36...second circulation pump (second pump), 37a, 37b...on-off valve, 38...module control section, 39a, 39b...pressure sensor, 51...cassette, 52...supply Road, 53...supply pump, 54...liquid level sensor, 60...piezoelectric pump, 70...control board, 71...CPU, 72...storage unit, 73...communication interface.

Detailed ways

Hereinafter, a liquid ejection device 10 and an inkjet recording device 1 including the liquid ejection device 10 according to one embodiment will be described with reference to FIGS. 1 to 6 . In each figure, for convenience of description, the components are appropriately enlarged, reduced, or omitted. FIG. 1 is a side view showing the configuration of an inkjet recording device 1 . FIG. 2 is an explanatory diagram showing the configuration of the liquid ejection device 10 . FIG. 3 is an explanatory diagram showing the configuration of the liquid ejection head 20 . FIG. 4 is an explanatory diagram showing the configurations of the first circulation pump 33 , the second circulation pump 36 , and the replenishment pump 53 . FIG. 5 is a block diagram showing the module control unit 38 of the liquid ejection device 10 . FIG. 6 is a flowchart showing a method of controlling the liquid ejection device 10 .

The inkjet recording device 1 shown in FIG. 1 includes a plurality of liquid ejection devices 10, a head support mechanism 11 for supporting the liquid ejection devices 10 in a movable manner, a medium support mechanism 12 for supporting the recording medium S in a movable manner, and a main controller. device 13.

As shown in FIG. 1 , a plurality of liquid discharge devices 10 are arranged in parallel in a predetermined direction and supported by a head support mechanism 11 . The liquid ejection device 10 integrally includes a liquid ejection head 20 and a circulation device 30 . The liquid ejection device 10 ejects, for example, ink I as a liquid from the liquid ejection head 20 , thereby forming a desired image on a recording medium S disposed opposite.

The plurality of liquid ejection devices 10 respectively eject multi-color inks such as cyan ink, magenta ink, yellow ink, black ink, and white ink, and the color or characteristics of the ink 1 used are not limited. For example, transparent glossy ink can be ejected instead of white ink, and special ink that develops color when irradiated with infrared rays or ultraviolet rays, etc. The plurality of liquid ejection devices 10 have the same configuration although the inks they use are different.

The liquid ejection head 20 shown in FIG. 3 is an inkjet head and includes a nozzle plate 21 having a plurality of nozzle holes 21 a , a substrate 22 , and a manifold 23 bonded to the substrate 22 . The substrate 22 is bonded to face the nozzle plate 21 , and has a predetermined shape forming a predetermined ink flow path 28 including a plurality of ink pressure chambers 25 between the nozzle plate 21 and the nozzle plate 21 . An actuator 24 is provided at a portion of the substrate 22 facing each ink pressure chamber 25 . The substrate 22 includes partition walls arranged between the plurality of ink pressure chambers 25 in the same row. The actuator 24 is arranged to face the nozzle hole 21a, and the ink pressure chamber 25 is formed between the actuator 24 and the nozzle hole 21a.

The liquid ejection head 20 internally constitutes a predetermined flow path 28 having an ink pressure chamber 25 through the nozzle plate 21 , the substrate 22 , and the manifold 23 . An actuator 24 including electrodes 24 a and 24 b is provided at a portion of the substrate 22 facing each ink pressure chamber 25 . The actuator 24 is connected to the driving circuit. The liquid ejection head 20 deforms the actuator 24 according to the voltage under the control of the module control unit 38 to eject the liquid from the nozzle holes 21a arranged oppositely.

As shown in FIG. 2 , the circulation device 30 is integrally connected to the upper portion of the liquid ejection head 20 via a metal connection member. The circulation device 30 has: a predetermined circulation path 31 passing through the liquid ejection head 20 and configured to circulate the liquid; an intermediate tank 32 as a regulating tank, a first circulation pump 33, and a first circulation pump 33 that are sequentially provided on the circulation path 31. The upstream tank 34 as the first tank, the downstream tank 35 as the second tank, and the second circulation pump 36; a plurality of on-off valves 37a and 37b; and a module control unit 38 control the liquid ejection operation.

In addition, the circulation device 30 includes a cassette 51 as a supply tank, a supply path 52 , and a supply pump 53 provided outside the circulation path 31 . The cartridge 51 is configured to hold ink supplied to the intermediate tank 32 , and the air chamber inside is opened to the atmosphere. The supply path 52 is a flow path connecting the intermediate tank 32 and the cassette 51 . The replenishment pump 53 is provided in the supply path 52 , and sends the ink in the cartridge 51 to the intermediate tank 32 .

The first flow path 31a to the fourth flow path 31d and the supply path 52 constituting the circulation path 31 include pipes made of metal or resin materials, and pipes covering the outer surfaces of the pipes, for example, PTFE pipes. The circulation path 31 includes a first flow path 31a connecting the intermediate tank 32 to the upstream tank 34, a second flow path 31b connecting the upstream tank 34 to the supply port 20a of the liquid ejection head 20, and a second flow path 31b connecting the recovery port 20b of the liquid ejection head 20 to the supply port 20a of the liquid ejection head 20. The third flow path 31c connected to the downstream tank 35 and the fourth flow path 31d connecting the downstream tank 35 and the intermediate tank 32 .

The circulation path 31 reaches the supply port 20a of the liquid ejection head 20 through the first flow path 31a and the second flow path 31b from the intermediate tank 32, and passes through the third flow path 31c and the fourth flow path from the recovery port 20b of the liquid ejection head 20. 31d to reach the middle box 32.

The intermediate tank 32 is connected to the liquid discharge head 20 through the circulation path 31 and is configured to be able to store liquid. In order to prevent mixing of air bubbles, a diaphragm 32 a made of, for example, polyimide or PTFE is formed on the liquid surface in the intermediate tank 32 . The intermediate tank 32 is provided with an on-off valve 37 a configured to be able to open the air chamber in the intermediate tank 32 to the atmosphere. In addition, a liquid level sensor 54 is provided on the liquid surface of the intermediate tank 32 .

The upstream tank 34 is arranged on the upstream side of the liquid discharge head 20 and is configured to be able to store liquid. In order to prevent mixing of air bubbles, a diaphragm 34 a made of, for example, polyimide or PTFE is formed on the surface of the liquid in the upstream tank 34 . The upstream tank 34 is provided with a first pressure sensor 39 a as a first pressure detection unit.

The downstream tank 35 is arranged on the downstream side of the liquid discharge head 20 and is configured to store liquid. In order to prevent mixing of air bubbles, a diaphragm 35 a made of, for example, polyimide or PTFE is formed on the surface of the liquid in the downstream tank 35 . The downstream tank 35 is provided with a second pressure sensor 39b as a second pressure detection unit.

The first pressure sensor 39 a detects the pressure of the air chamber in the upstream tank 34 and sends the detection data to the module control unit 38 .

The second pressure sensor 39 b detects the pressure of the air chamber in the downstream tank 35 and sends the detection data to the module control unit 38 .

The first pressure sensor 39 a and the second pressure sensor 39 b are, for example, semiconductor piezoresistive pressure sensors, which output pressure as electrical signals. The semiconductor piezoresistive pressure sensor includes a diaphragm that receives pressure from the outside, and a semiconductor strain gauge formed on the surface of the diaphragm. The semiconductor piezoresistive pressure sensor converts the resistance change under the piezoresistive effect of the strain gauge along with the deformation of the diaphragm caused by the external pressure into an electrical signal to detect the pressure.

The liquid level sensor 54 includes a float 55 floating on the liquid surface and moving up and down, and Hall ICs 56a and 56b provided at two predetermined positions up and down. The liquid level sensor 54 uses the Hall ICs 56a and 56b to detect that the float 55 has reached the upper limit position and the lower limit position, thereby detecting the amount of ink in the intermediate tank 32 and sending the detected data to the module control unit 38 .

On-off valves 37 a and 37 b are provided in the intermediate tank 32 and the downstream tank 35 , respectively. The on-off valves 37a and 37b are, for example, normally closed solenoid on-off valves that open when the power is turned on and close when the power is off. The on-off valves 37 a and 37 b are configured to open and close under the control of the module control unit 38 , so that the air chambers of the intermediate tank 32 and the downstream tank 35 can be opened and closed to the atmosphere, respectively.

The first circulation pump 33 is provided on the first flow path 31 a of the circulation path 31 . The first circulation pump 33 is disposed between the primary side of the liquid discharge head 20 and the intermediate tank 32 and upstream of the upstream tank 34 , and sends liquid to the liquid discharge head 20 disposed downstream.

The second circulation pump 36 is provided in the fourth flow path 31d of the circulation path 31 . The second circulation pump 36 is disposed between the secondary side of the liquid ejection head 20 and the intermediate tank 32 , and is disposed downstream of the downstream tank 35 , and sends the liquid to the intermediate tank 32 disposed downstream.

The replenishment pump 53 is provided on the supply path 52 . The replenishment pump 53 sends the ink I held in the cartridge 51 to the intermediate tank 32 .

The first circulation pump 33 , the second circulation pump 36 , and the replenishment pump 53 are constituted by, for example, a piezoelectric pump 60 as shown in FIG. 4 . The piezoelectric pump 60 includes a pump chamber 58 , a piezoelectric actuator 59 provided in the pump chamber 58 and vibrated by a voltage, and check valves 61 and 62 arranged at the inlet and outlet of the pump chamber 58 . The piezoelectric actuator 59 is configured to vibrate at a frequency of about 50 Hz to 200 Hz, for example. The first circulation pump 33 , the second circulation pump 36 , and the replenishment pump 53 are connected to a drive circuit by wiring, and are configured to be controllable under the control of the module control unit 38 . In the piezoelectric pump 60 , when an AC voltage is applied and the piezoelectric actuator 59 operates, the volume of the pump chamber 58 changes. In the piezoelectric pump 60, when the applied voltage changes, the maximum change amount of the piezoelectric actuator 59 changes, and the volume change amount of the pump chamber 58 changes. Then, when the volume of the pump chamber 58 is deformed to increase, the check valve 61 at the inlet of the pump chamber 58 is opened, and ink flows into the pump chamber 58 . On the other hand, when the volume of the pump chamber 58 decreases, the check valve 62 at the outlet of the pump chamber 58 opens, and the ink flows out from the pump chamber 58 . The piezoelectric pump 60 repeatedly expands and contracts the pump chamber 58 to transport the ink I downstream. Therefore, when the voltage applied to the piezoelectric actuator 59 is high, the liquid feeding ability is strong, and when the voltage is small, the liquid feeding ability is weak. For example, in this embodiment, the voltage applied to the piezoelectric actuator 59 is varied between 50V and 150V.

As shown in FIG. 5 , the module control unit 38 includes a CPU 71 , a drive circuit for driving each component, a storage unit 72 for storing various data, and a communication with an external device 70 on a control board 70 integrally mounted on the circulation device 30 . The main control device 13 communicates with the communication interface 73. The storage unit 72 includes, for example, a program memory and a RAM.

The module control unit 38 communicates with the main control device 13 while being connected to the main control device 13 via the communication interface 73 , and receives various information such as operating conditions.

Input operations by the user and instructions from the main control unit 13 of the inkjet recording apparatus 1 are sent to the CPU 71 of the module control unit 38 through the communication interface 73 . In addition, various information acquired by the module control unit 38 is sent to the PC application or the main control unit 13 of the inkjet recording apparatus 1 via the communication interface 73 .

The CPU 71 corresponds to a central part of the module control unit 38 . The CPU 71 controls each part according to the operating system and application programs to realize various functions of the liquid ejection device.

Drive circuits 75 a , 75 b , and 75 c of various pumps 33 , 36 , and 53 of the circulation device 30 and various sensors 39 a , 39 b , and 54 are connected to the CPU 71 .

For example, the CPU 71 functions as a circulation unit that circulates ink by controlling the operations of the circulation pumps 33 and 36 .

Also, the CPU 71 functions as a replenishment unit that controls the operation of the replenishment pump 53 based on information detected by the liquid level sensor 54 and the pressure sensors 39 a and 39 b to replenish ink from the cartridge 51 to the circulation path 31 .

Furthermore, the CPU 71 controls the liquid delivery capabilities of the first circulation pump 33 and the second circulation pump 36 based on the information detected by the first pressure sensor 39 a, the second pressure sensor 39 b, and the liquid level sensor 54 to adjust the ink flow rate of the nozzle hole 21 a. Pressure function of the pressure regulator unit.

The storage unit 72 includes, for example, a program memory and a RAM. Application programs and various setting values are stored in the storage unit 72 . The storage unit 72 stores, for example, various set values such as a calculation formula for calculating the ink pressure of the nozzle holes 21 a, a target pressure range, and an adjustment maximum value of each pump as control data for pressure control.

Hereinafter, the liquid ejection method in the liquid ejection device 10 and the control method of the liquid ejection device 10 according to the present embodiment will be described with reference to the flowchart of FIG. 6 .

The CPU waits in Act1 for an indication that the loop has started. For example, when an instruction to start a cycle is detected by an instruction from the main controller 13, the process proceeds to Act2. It should be noted that, as the printing operation, the main controller 13 forms an image on the recording medium S by performing an ink ejection operation while reciprocating the liquid ejection device 10 in a direction perpendicular to the conveyance direction of the recording medium S. Specifically, the CPU 71 conveys the carriage 11 a provided in the head supporting mechanism 11 in the direction of the recording medium S, and reciprocates in the arrow A direction. Also, the CPU 71 sends an image signal corresponding to the image data to the drive circuit 75e of the liquid ejection head 20, and selectively drives the actuator 24 of the liquid ejection head 20 to eject ink droplets onto the recording medium S from the nozzle holes 21a.

In Act2, the CPU 71 drives the first circulation pump 33 and the second circulation pump 36 to start the ink circulation operation. The ink I circulates from the intermediate tank 32 to the upstream tank 34 , the liquid ejection head 20 , and flows into the intermediate tank 32 again via the downstream tank 35 . Through this circulation operation, impurities contained in the ink I are removed by the filter provided in the circulation path 31 .

In Act3, the CPU 71 opens the on-off valve 37a of the intermediate tank 32 to open to the atmosphere. Since the intermediate tank 32 is open to the atmosphere and has a constant pressure at all times, the pressure drop in the circulation path due to ink consumption of the liquid ejection head 20 is prevented. Here, when there is concern about the temperature rise of the on-off valve 37a due to opening the on-off valve 37a for a long time, the on-off valve 37a may be opened only periodically for a short time. If the pressure of the circulation path does not drop excessively, the ink pressure of the nozzles can be kept constant even if the on-off valve 37 a is closed. It should be noted that the solenoid-type on-off valve 37a is normally closed (normal close). Therefore, even when the power supply to the device is suddenly stopped due to a power failure or the like, the on-off valve 37a can be closed instantly to shield the intermediate tank 32 from the atmospheric pressure and seal the circulation path 31 . Therefore, it is possible to suppress the ink I from dripping from the nozzle holes 21 a of the liquid ejection head 20 .

In Act4, the CPU 71 detects pressure data on the upstream side and downstream side sent from the first pressure sensor 39a and the second pressure sensor 39b. Further, the CPU 71 detects the liquid level of the intermediate tank 32 based on the data sent from the liquid level sensor 54 .

In Act5, the CPU 71 starts liquid level adjustment. Specifically, the CPU 71 drives the replenishment pump 53 based on the detection result of the liquid level sensor 54 to replenish ink from the cartridge 51 and adjust the liquid level position to an appropriate range. For example, when the ink droplet ID is ejected from the nozzle hole 21 a during printing, and the ink amount in the intermediate tank 32 decreases momentarily and the liquid level drops, ink replenishment is performed. When the amount of ink increases again and the output of the liquid level sensor 54 is reversed, the CPU 71 stops the replenishment pump 53 .

In Act6, the CPU 71 detects the ink pressure of the nozzles based on the pressure data. Specifically, the ink pressure in the nozzle hole 21 a is calculated using a predetermined calculation formula based on the pressure data on the upstream side and the downstream side sent from the pressure sensor.

For example, by the average value of the pressure value Ph of the air chamber of the upstream case 34 and the pressure value P1 of the air chamber of the downstream case 35 and the water head difference between the liquid level height and the nozzle surface height in the upstream case 34 and the downstream case 35 The generated pressure ρgh is added to obtain the ink pressure Pn of the nozzle. Here, ρ: the density of ink, g: the acceleration of gravity, and h: the distance in the height direction between the liquid surface in the upstream tank 34 and the downstream tank 35 and the nozzle surface. The liquid surface heights in the upstream tank 34 and the downstream tank 35 coincide with the diaphragm 34a and the diaphragm 35a, and the diaphragm 34a and the diaphragm 35a are set to have the same height.

In addition, as the pressure adjustment process, the CPU 71 calculates the drive voltage based on the ink pressure Pn of the nozzle calculated from the pressure data. Then, the CPU 71 drives the first circulation pump 33 and the second circulation pump 36 so that the ink pressure Pn of the nozzles becomes an appropriate value so that the ink I does not leak from the nozzle holes 21a of the liquid ejection head 20 and does not flow from the nozzles. The negative pressure to the extent that the pores attract air bubbles maintains the meniscus Me. Here, as an example, the upper limit of the target value is set to P1H, and the lower limit is set to P1L.

In Act7, the CPU 71 judges whether or not the ink pressure Pn of the nozzle is within an appropriate range, that is, whether or not P1L≦Pn≦P1H. If it is out of the appropriate range (No in Act7), the CPU 71 determines whether or not the ink pressure Pn of the nozzle exceeds the target value upper limit P1H as Act8.

The ink pressure of the nozzles of the liquid ejection head 20 is increased when the first circulation pump 33 is driven relatively strongly, and is depressurized when the second circulation pump 36 is driven relatively strongly.

The CPU 71 further judges whether the driving voltage is within the adjustment range of each pump 33, 36 (Act9, Act12). pressure.

Specifically, when the ink pressure Pn of the nozzle is out of the appropriate range (No in Act7), and the ink pressure Pn of the nozzle does not exceed the upper limit P1H of the target value (No in Act8), that is, the ink pressure Pn of the nozzle is lower than the target value. In the case of the lower limit P1L, as Act9, the CPU 71 determines whether the driving voltage V+ of the first circulating pump 33 on the pressurizing side is equal to or greater than the adjustment maximum value Vmax, that is, whether it exceeds the adjustable range of the first circulating pump 33 . When the drive voltage V+ of the first circulating pump 33 on the pressurizing side is equal to or greater than the adjusted maximum value Vmax (Yes in Act9), the CPU 71 lowers the voltage of the second circulating pump to pressurize as Act10. On the other hand, if the driving voltage V+ of the first circulating pump on the pressurizing side is less than the maximum adjustment value Vmax and is within the adjustable range (No in Act9), then as Act11, the CPU 71 increases the driving voltage of the first circulating pump 33 to perform Pressurize.

In Act 8, when the ink pressure Pn of the nozzle exceeds the upper limit P1H of the target value (Yes in Act 8), as Act 12, the CPU 71 judges whether the driving voltage V− of the second circulation pump 36 on the decompression side is equal to or greater than the adjusted maximum value Vmax, That is, whether the adjustment range of the second circulation pump 36 is exceeded. When the drive voltage V− of the second circulation pump 36 on the decompression side is equal to or greater than the adjusted maximum value Vmax (YES in Act 12 ), the CPU 71 reduces the voltage of the first circulation pump 33 to perform decompression in Act 13 . On the other hand, if the driving voltage V− of the second circulation pump 36 on the decompression side is less than the maximum adjustment value Vmax and is within the adjustable range (No in Act12), then as Act14, the CPU 71 increases the driving voltage of the second circulation pump 36 to decompress.

Thereafter, the CPU 71 performs feedback control of Act4 to Act14 until a loop end command is detected in Act15. Then, when the CPU 71 detects a cycle end instruction based on, for example, a command from the main controller 13 (Yes in Act 15 ), the on-off valve 37a of the intermediate tank 32 is closed to seal the intermediate tank 32 (Act 16 ). Furthermore, CPU71 stops the 1st circulation pump 33 and the 2nd circulation pump 36, and ends circulation process (Act17).

The liquid ejection device 10 configured as above detects the pressure on both the upstream side and the downstream side of the liquid ejection head 20, and performs feedback control of the pressure by the pressurized first circulation pump 33 and the second circulation pump 36, thereby enabling adaptive To maintain the ink pressure of the nozzle. To this end, for example, an adaptive pressure control can be achieved even in the case of changes in pump performance over time.

In addition, since the piezoelectric pump 60 is used as the circulation pumps 33 and 36 in the liquid discharge device 10, the configuration is simple, and material selection is easy. That is, the piezoelectric pump 60 does not require a large drive source such as a motor or a solenoid, and can be smaller than a general diaphragm pump, piston pump, or tube pump. In addition, for example, if a tube pump is used, there is a possibility that the tube may come into contact with the ink, so it is necessary to select a material so as not to cause deterioration of the tube or the ink. On the other hand, by using the piezoelectric pump 60, material selection becomes easy. For example, in the present embodiment, the liquid-contacting (immersion) member of the piezoelectric pump 60 can be made of SUS316L, PPS, PPA, or polyimide, which are excellent in chemical resistance.

In addition, in the above-mentioned embodiment, by using the first circulation pump 33 on the upstream side that can pressurize when the voltage is raised and can depressurize when the voltage is lowered, and can depressurize when the voltage is raised and can increase the pressure when the voltage is lowered, The second circulation pump 36 on the downstream side of the pressure can be used, so that other pumps can be used when the driving voltage exceeds the adjustable range, so high-precision control can be realized. In addition, the first circulation pump 33, the second circulation pump 36, the replenishment pump 53, the pressure sensors 39a, 39b, the liquid level sensor 54, the control board 70, and other ink supply, circulation, and pressure adjustment functions can be integrated in the circulation device 30. Control the desired functionality. For this reason, the connection and electrical connection of the flow path between the main body of the inkjet recording apparatus 1 and the carriage 11 a can be simplified compared to a large stationary circulation apparatus. As a result, it is possible to reduce the size, weight and cost of the inkjet recording device 1 .

In addition, in the liquid ejection device 10, since the components required for feedback control are integrally mounted on the control board 70, only information data such as operation instructions and status notifications that do not require high-speed response flow through the communication interface 73. An effect can be obtained in which the data transmission speed requirement of the communication interface 73 can be reduced.

[Second Embodiment]

Hereinafter, a liquid ejection device 10A according to a second embodiment of the present invention will be described with reference to FIG. 7 . FIG. 7 is an explanatory diagram showing the configuration of the liquid ejection device 10A. It should be noted that the liquid ejection device 10A according to the second embodiment is the same as the liquid ejection device 10 according to the above-mentioned first embodiment except that the cartridge 51 is used as the intermediate tank 32 , and therefore common descriptions are omitted.

As shown in FIG. 7 , in the liquid discharge device 10A according to the second embodiment, an intermediate tank 32 that can be opened to the atmosphere is arranged as the intermediate tank 32 on the circulation path 31 between the upstream tank 34 and the downstream tank 35 . . That is, the cartridge 51 in the liquid ejection device 10 is used as the intermediate tank 32 . In addition, the intermediate tank 32 may be open to the atmosphere at ordinary times. Also in this embodiment, the same effect as that of the first embodiment described above can be obtained. In addition, by using the cassette 51 as the intermediate case 32, the structure can be omitted.

It should be noted that the configuration of the liquid circulation device in the embodiment described above is not limited. For example, the liquid ejection devices 10 and 10A can also eject liquids other than ink. The liquid ejection device that ejects liquid other than ink may be, for example, an apparatus that ejects a liquid containing conductive particles for forming a wiring pattern on a printed circuit board.

In addition to the above, the liquid ejection head 20 may have, for example, a configuration in which ink droplets are ejected by deforming a vibrating plate by static electricity, or a configuration in which ink droplets are ejected from nozzles using thermal energy such as a heater.

In addition, in the above-mentioned embodiment, an example in which the liquid ejection device is used for the inkjet recording device 1 is shown, but it is not limited to this, and it can also be applied to 3D printers, industrial manufacturing machines, and medical applications, and can Realize compactness, weight reduction and cost reduction.

In addition, as the first circulation pump 33 , the second circulation pump 36 , and the replenishment pump 53 , instead of the piezoelectric pump 60 , for example, a tube pump, a diaphragm pump, or a piston pump may be used.

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

Claims (10)

1. a kind of liquid circulating apparatus, possesses：

Regulating box, it is configured in the circulating path that head is shootd out by shooing out the liquid of liquid, storage supply to the liquid is shootd out The liquid of head；

First pump, shootd out in the circulating path located at the liquid between the primary side of head and the regulating box, to described Liquid shoots out head conveying liquid；

Second pump, shootd out in the circulating path located at the liquid between the secondary side of head and the regulating box, to described Regulating box conveys liquid；And

Pressure regulating unit, the primary side of head and the pressure of secondary side are shootd out based on the liquid in the circulating path, adjusted Save the liquor charging ability of first pump and second pump.

2. liquid circulating apparatus according to claim 1, wherein,

First pump and second pump are piezoelectric pumps.

3. liquid circulating apparatus according to claim 1, wherein,

The air chamber that the regulating box is configured to be formed inside can be to atmosphere opening.

4. liquid circulating apparatus according to claim 3, wherein,

By making the air chamber to atmosphere opening located at the open and close valve of the regulating box.

5. a kind of liquid liquid discharging device, possesses：

Liquid circulating apparatus described in claim 1；

The liquid for shooing out liquid shoots out head；

Upstream case, first pump is configured in the circulating path and between the liquid shoots out head, for storing liquid；

Downstream tank, second pump is configured in the circulating path and between the liquid shoots out head, for storing liquid；

First pressure test section, detect the pressure in the upstream case；And

Second pressure test section, the pressure in the downstream tank is detected,

The regulating box is configured in the circulating path between the downstream tank and the upstream case,

The pressure regulating unit controls first pump based on the pressure in the pressure and the downstream tank in the upstream case With the liquor charging ability of second pump.

6. liquid liquid discharging device according to claim 5, wherein,

The circulating path includes：First flow path, the primary side that the liquid is shootd out to head are connected with the upstream case；Second Road, the secondary side that the liquid is shootd out to head are connected with the downstream tank；3rd stream, by the regulating box and the upstream case Connection；And the 4th stream, the downstream tank is connected with the regulating box,

The regulating box be configured to be formed inside air chamber can to atmosphere opening,

First pump and second pump are piezoelectric pumps,

The pressure regulating unit makes the regulating box to atmosphere opening when carrying out pressure regulation, and is carrying out the pressure tune During section, make the voltage change for putting on the piezoelectrics of the piezoelectric pump, so as to control the liquor charging ability,

In the case of in the adjustable range that driving voltage is first pump, the pressure regulating unit makes to first pump Piezoelectrics apply voltage rise and pressurizeed,

In the case where driving voltage exceedes the adjustable range of first pump, the pressure regulating unit makes to second pump Piezoelectrics apply voltage decline and pressurizeed,

In the case of in the adjustable range that driving voltage is second pump, the pressure regulating unit makes to second pump Piezoelectrics apply voltage rise and depressurized,

In the case where driving voltage exceedes the adjustable range of second pump, the pressure regulating unit makes to first pump Piezoelectrics apply voltage decline and depressurized.

7. the liquid liquid discharging device according to claim 5 or 6, wherein,

The liquid liquid discharging device is also equipped with supply case, and the supply case is connected to the regulating box, and can store liquid,

The pressure regulating unit control supplies the supply action of liquid from the supply case to the regulating box.

8. a kind of liquid spitting method, including：

Shoot out head by shooing out the liquid of liquid and storage supply shoot out to the liquid head liquid regulating box circulation The liquid is detected in path respectively and shoots out the primary side of head and the pressure of secondary side；And

Pressure value based on the primary side and the secondary side, head is shootd out to the liquid in the circulating path First pump of primary side and the liquid in the circulating path shoot out the liquor charging ability of the second pump of the secondary side of head It is adjusted.

9. liquid spitting method according to claim 8, wherein,

First pump and second pump are piezoelectric pumps.

10. liquid spitting method according to claim 8, wherein,

The air chamber that the regulating box is configured to be formed inside can be to atmosphere opening.